DataColumnSidecar backfill wip

* `DataColumnStorageSummary`: Implement `HasAtLeastOneIndex`.

* `DataColumnStorage.Get`: Exit early if the root is found but no corresponding columns.

* `custodyColumnsFromPeers`: Simplify.

* Remove duplicate `uint64MapToSortedSlice` function.

* `DataColumnStorageSummary`: Add `Stored`.

* Refactor reconstruction related code.

WORKSPACE

@@ -1,7 +1,7 @@
 workspace(name = "prysm")
 
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
 http_archive(
     name = "rules_pkg",
@@ -16,8 +16,6 @@ load("@rules_pkg//:deps.bzl", "rules_pkg_dependencies")
 
 rules_pkg_dependencies()
 
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
-
 http_archive(
     name = "toolchains_protoc",
     sha256 = "abb1540f8a9e045422730670ebb2f25b41fa56ca5a7cf795175a110a0a68f4ad",

beacon-chain/blockchain/service.go

@@ -31,6 +31,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
@@ -109,22 +110,26 @@ var ErrMissingClockSetter = errors.New("blockchain Service initialized without a
 type blobNotifierMap struct {
 	sync.RWMutex
 	notifiers map[[32]byte]chan uint64
-	seenIndex map[[32]byte][]bool
+	// TODO: Separate blobs from data columns
+	// seenIndex map[[32]byte][]bool
+	seenIndex map[[32]byte][fieldparams.NumberOfColumns]bool
 }
 
 // notifyIndex notifies a blob by its index for a given root.
 // It uses internal maps to keep track of seen indices and notifier channels.
 func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64, slot primitives.Slot) {
-	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
-	if idx >= uint64(maxBlobsPerBlock) {
-		return
-	}
+	// TODO: Separate blobs from data columns
+	// maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
+	// if idx >= uint64(maxBlobsPerBlock) {
+	// 	return
+	// }
 
 	bn.Lock()
 	seen := bn.seenIndex[root]
-	if seen == nil {
-		seen = make([]bool, maxBlobsPerBlock)
-	}
+	// TODO: Separate blobs from data columns
+	// if seen == nil {
+	// seen = make([]bool, maxBlobsPerBlock)
+	// }
 	if seen[idx] {
 		bn.Unlock()
 		return
@@ -135,7 +140,9 @@ func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64, slot primitive
 	// Retrieve or create the notifier channel for the given root.
 	c, ok := bn.notifiers[root]
 	if !ok {
-		c = make(chan uint64, maxBlobsPerBlock)
+		// TODO: Separate blobs from data columns
+		// c = make(chan uint64, maxBlobsPerBlock)
+		c = make(chan uint64, fieldparams.NumberOfColumns)
 		bn.notifiers[root] = c
 	}
 
@@ -145,12 +152,15 @@ func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64, slot primitive
 }
 
 func (bn *blobNotifierMap) forRoot(root [32]byte, slot primitives.Slot) chan uint64 {
-	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
+	// TODO: Separate blobs from data columns
+	// maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
 	bn.Lock()
 	defer bn.Unlock()
 	c, ok := bn.notifiers[root]
 	if !ok {
-		c = make(chan uint64, maxBlobsPerBlock)
+		// TODO: Separate blobs from data columns
+		// c = make(chan uint64, maxBlobsPerBlock)
+		c = make(chan uint64, fieldparams.NumberOfColumns)
 		bn.notifiers[root] = c
 	}
 	return c
@@ -176,7 +186,9 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 	ctx, cancel := context.WithCancel(ctx)
 	bn := &blobNotifierMap{
 		notifiers: make(map[[32]byte]chan uint64),
-		seenIndex: make(map[[32]byte][]bool),
+		// TODO: Separate blobs from data columns
+		// seenIndex: make(map[[32]byte][]bool),
+		seenIndex: make(map[[32]byte][fieldparams.NumberOfColumns]bool),
 	}
 	srv := &Service{
 		ctx:                  ctx,

beacon-chain/blockchain/service_test.go

@@ -587,7 +587,9 @@ func (s *MockClockSetter) SetClock(g *startup.Clock) error {
 func TestNotifyIndex(t *testing.T) {
 	// Initialize a blobNotifierMap
 	bn := &blobNotifierMap{
-		seenIndex: make(map[[32]byte][]bool),
+		// TODO: Separate blobs from data columns
+		// seenIndex: make(map[[32]byte][]bool),
+		seenIndex: make(map[[32]byte][fieldparams.NumberOfColumns]bool),
 		notifiers: make(map[[32]byte]chan uint64),
 	}
 

beacon-chain/core/blocks/payload.go

@@ -229,13 +229,16 @@ func verifyBlobCommitmentCount(slot primitives.Slot, body interfaces.ReadOnlyBea
 	if body.Version() < version.Deneb {
 		return nil
 	}
+
 	kzgs, err := body.BlobKzgCommitments()
 	if err != nil {
 		return err
 	}
-	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
-	if len(kzgs) > maxBlobsPerBlock {
-		return fmt.Errorf("too many kzg commitments in block: %d", len(kzgs))
+
+	commitmentCount, maxBlobsPerBlock := len(kzgs), params.BeaconConfig().MaxBlobsPerBlock(slot)
+	if commitmentCount > maxBlobsPerBlock {
+		return fmt.Errorf("too many kzg commitments in block: actual count %d - max allowed %d", commitmentCount, maxBlobsPerBlock)
 	}
+
 	return nil
 }

beacon-chain/core/blocks/payload_test.go

@@ -926,8 +926,10 @@ func TestVerifyBlobCommitmentCount(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, blocks.VerifyBlobCommitmentCount(rb.Slot(), rb.Body()))
 
-	b = &ethpb.BeaconBlockDeneb{Body: &ethpb.BeaconBlockBodyDeneb{BlobKzgCommitments: make([][]byte, params.BeaconConfig().MaxBlobsPerBlock(rb.Slot())+1)}}
+	maxCommitmentsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(rb.Slot())
+
+	b = &ethpb.BeaconBlockDeneb{Body: &ethpb.BeaconBlockBodyDeneb{BlobKzgCommitments: make([][]byte, maxCommitmentsPerBlock+1)}}
 	rb, err = consensusblocks.NewBeaconBlock(b)
 	require.NoError(t, err)
-	require.ErrorContains(t, fmt.Sprintf("too many kzg commitments in block: %d", params.BeaconConfig().MaxBlobsPerBlock(rb.Slot())+1), blocks.VerifyBlobCommitmentCount(rb.Slot(), rb.Body()))
+	require.ErrorContains(t, fmt.Sprintf("too many kzg commitments in block: actual count %d - max allowed %d", maxCommitmentsPerBlock+1, maxCommitmentsPerBlock), blocks.VerifyBlobCommitmentCount(rb.Slot(), rb.Body()))
 }

beacon-chain/core/blocks/signature.go

@@ -96,6 +96,24 @@ func VerifyBlockHeaderSignature(beaconState state.BeaconState, header *ethpb.Sig
 	return signing.VerifyBlockHeaderSigningRoot(header.Header, proposerPubKey, header.Signature, domain)
 }
 
+func VerifyBlockHeaderSignatureUsingCurrentFork(beaconState state.BeaconState, header *ethpb.SignedBeaconBlockHeader) error {
+	currentEpoch := slots.ToEpoch(header.Header.Slot)
+	fork, err := forks.Fork(currentEpoch)
+	if err != nil {
+		return err
+	}
+	domain, err := signing.Domain(fork, currentEpoch, params.BeaconConfig().DomainBeaconProposer, beaconState.GenesisValidatorsRoot())
+	if err != nil {
+		return err
+	}
+	proposer, err := beaconState.ValidatorAtIndex(header.Header.ProposerIndex)
+	if err != nil {
+		return err
+	}
+	proposerPubKey := proposer.PublicKey
+	return signing.VerifyBlockHeaderSigningRoot(header.Header, proposerPubKey, header.Signature, domain)
+}
+
 // VerifyBlockSignatureUsingCurrentFork verifies the proposer signature of a beacon block. This differs
 // from the above method by not using fork data from the state and instead retrieving it
 // via the respective epoch.

beacon-chain/core/feed/operation/events.go

@@ -37,8 +37,11 @@ const (
 	// SingleAttReceived is sent after a single attestation object is received from gossip or rpc
 	SingleAttReceived = 9
 
+	// DataColumnSidecarReceived is sent after a data column sidecar is received from gossip or rpc.
+	DataColumnSidecarReceived = 10
+
 	// BlockGossipReceived is sent after a block has been received from gossip or API that passes validation rules.
-	BlockGossipReceived = 10
+	BlockGossipReceived = 11
 )
 
 // UnAggregatedAttReceivedData is the data sent with UnaggregatedAttReceived events.
@@ -90,6 +93,11 @@ type SingleAttReceivedData struct {
 	Attestation ethpb.Att
 }
 
+// DataColumnSidecarReceivedData is the data sent with DataColumnSidecarReceived events.
+type DataColumnSidecarReceivedData struct {
+	DataColumn *blocks.VerifiedRODataColumn
+}
+
 // BlockGossipReceivedData is the data sent with BlockGossipReceived events.
 type BlockGossipReceivedData struct {
 	// SignedBlock is the block that was received.

beacon-chain/core/helpers/sync_committee_test.go

@@ -78,6 +78,7 @@ func TestIsCurrentEpochSyncCommittee_UsingCommittee(t *testing.T) {
 
 func TestIsCurrentEpochSyncCommittee_DoesNotExist(t *testing.T) {
 	helpers.ClearCache()
+	params.SetupTestConfigCleanup(t)
 
 	validators := make([]*ethpb.Validator, params.BeaconConfig().SyncCommitteeSize)
 	syncCommittee := &ethpb.SyncCommittee{
@@ -264,6 +265,7 @@ func TestCurrentEpochSyncSubcommitteeIndices_UsingCommittee(t *testing.T) {
 }
 
 func TestCurrentEpochSyncSubcommitteeIndices_DoesNotExist(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
 	helpers.ClearCache()
 
 	validators := make([]*ethpb.Validator, params.BeaconConfig().SyncCommitteeSize)

beacon-chain/core/peerdas/BUILD.bazel

@@ -7,6 +7,7 @@ go_library(
         "info.go",
         "metrics.go",
         "p2p_interface.go",
+        "peer_sampling.go",
         "reconstruction.go",
         "validator.go",
         "verification.go",
@@ -44,6 +45,7 @@ go_test(
         "das_core_test.go",
         "info_test.go",
         "p2p_interface_test.go",
+        "peer_sampling_test.go",
         "reconstruction_test.go",
         "utils_test.go",
         "validator_test.go",

beacon-chain/core/peerdas/info.go

@@ -190,3 +190,29 @@ func computeInfoCacheKey(nodeID enode.ID, custodyGroupCount uint64) [nodeInfoCac
 
 	return key
 }
+
+// ColumnIndices is a map of column indices where the key is the column index and the value is a boolean.
+// The boolean could indicate different things, eg whether the column is needed (in the context of satisfying custody requirements)
+// or present (in the context of a custody check on disk or in cache).
+type ColumnIndices map[uint64]bool
+
+// CopyTrueIndices allows callers to get a copy of the given ColumnIndices, filtering out any keys
+// where the value == `false`.
+func CopyTrueIndices(src ColumnIndices) ColumnIndices {
+	dst := make(ColumnIndices, len(src))
+	for k, v := range src {
+		if v {
+			dst[k] = true
+		}
+	}
+	return dst
+}
+
+// ColumnIndicesFromSlice converts a slice of uint64 indices into the ColumnIndices equivalent.
+func ColumnIndicesFromSlice(indices []uint64) ColumnIndices {
+	ci := make(ColumnIndices, len(indices))
+	for _, index := range indices {
+		ci[index] = true
+	}
+	return ci
+}

beacon-chain/core/peerdas/peer_sampling.go

@@ -0,0 +1,56 @@
+package peerdas
+
+import (
+	"math/big"
+
+	"github.com/OffchainLabs/prysm/v6/config/params"
+)
+
+// ExtendedSampleCount computes, for a given number of samples per slot and allowed failures the
+// number of samples we should actually query from peers.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/peer-sampling.md#get_extended_sample_count
+func ExtendedSampleCount(samplesPerSlot, allowedFailures uint64) uint64 {
+	// Retrieve the columns count
+	columnsCount := params.BeaconConfig().NumberOfColumns
+
+	// If half of the columns are missing, we are able to reconstruct the data.
+	// If half of the columns + 1 are missing, we are not able to reconstruct the data.
+	// This is the smallest worst case.
+	worstCaseMissing := columnsCount/2 + 1
+
+	// Compute the false positive threshold.
+	falsePositiveThreshold := HypergeomCDF(0, columnsCount, worstCaseMissing, samplesPerSlot)
+
+	var sampleCount uint64
+
+	// Finally, compute the extended sample count.
+	for sampleCount = samplesPerSlot; sampleCount < columnsCount+1; sampleCount++ {
+		if HypergeomCDF(allowedFailures, columnsCount, worstCaseMissing, sampleCount) <= falsePositiveThreshold {
+			break
+		}
+	}
+
+	return sampleCount
+}
+
+// HypergeomCDF computes the hypergeometric cumulative distribution function.
+// https://en.wikipedia.org/wiki/Hypergeometric_distribution
+func HypergeomCDF(k, M, n, N uint64) float64 {
+	denominatorInt := new(big.Int).Binomial(int64(M), int64(N)) // lint:ignore uintcast
+	denominator := new(big.Float).SetInt(denominatorInt)
+
+	rBig := big.NewFloat(0)
+
+	for i := uint64(0); i < k+1; i++ {
+		a := new(big.Int).Binomial(int64(n), int64(i)) // lint:ignore uintcast
+		b := new(big.Int).Binomial(int64(M-n), int64(N-i))
+		numeratorInt := new(big.Int).Mul(a, b)
+		numerator := new(big.Float).SetInt(numeratorInt)
+		item := new(big.Float).Quo(numerator, denominator)
+		rBig.Add(rBig, item)
+	}
+
+	r, _ := rBig.Float64()
+
+	return r
+}

beacon-chain/core/peerdas/peer_sampling_test.go

@@ -0,0 +1,60 @@
+package peerdas_test
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+func TestExtendedSampleCount(t *testing.T) {
+	const samplesPerSlot = 16
+
+	testCases := []struct {
+		name                string
+		allowedMissings     uint64
+		extendedSampleCount uint64
+	}{
+		{name: "allowedMissings=0", allowedMissings: 0, extendedSampleCount: 16},
+		{name: "allowedMissings=1", allowedMissings: 1, extendedSampleCount: 20},
+		{name: "allowedMissings=2", allowedMissings: 2, extendedSampleCount: 24},
+		{name: "allowedMissings=3", allowedMissings: 3, extendedSampleCount: 27},
+		{name: "allowedMissings=4", allowedMissings: 4, extendedSampleCount: 29},
+		{name: "allowedMissings=5", allowedMissings: 5, extendedSampleCount: 32},
+		{name: "allowedMissings=6", allowedMissings: 6, extendedSampleCount: 35},
+		{name: "allowedMissings=7", allowedMissings: 7, extendedSampleCount: 37},
+		{name: "allowedMissings=8", allowedMissings: 8, extendedSampleCount: 40},
+		{name: "allowedMissings=9", allowedMissings: 9, extendedSampleCount: 42},
+		{name: "allowedMissings=10", allowedMissings: 10, extendedSampleCount: 44},
+		{name: "allowedMissings=11", allowedMissings: 11, extendedSampleCount: 47},
+		{name: "allowedMissings=12", allowedMissings: 12, extendedSampleCount: 49},
+		{name: "allowedMissings=13", allowedMissings: 13, extendedSampleCount: 51},
+		{name: "allowedMissings=14", allowedMissings: 14, extendedSampleCount: 53},
+		{name: "allowedMissings=15", allowedMissings: 15, extendedSampleCount: 55},
+		{name: "allowedMissings=16", allowedMissings: 16, extendedSampleCount: 57},
+		{name: "allowedMissings=17", allowedMissings: 17, extendedSampleCount: 59},
+		{name: "allowedMissings=18", allowedMissings: 18, extendedSampleCount: 61},
+		{name: "allowedMissings=19", allowedMissings: 19, extendedSampleCount: 63},
+		{name: "allowedMissings=20", allowedMissings: 20, extendedSampleCount: 65},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			result := peerdas.ExtendedSampleCount(samplesPerSlot, tc.allowedMissings)
+			require.Equal(t, tc.extendedSampleCount, result)
+		})
+	}
+}
+
+func TestHypergeomCDF(t *testing.T) {
+	// Test case from https://en.wikipedia.org/wiki/Hypergeometric_distribution
+	// Population size: 1000, number of successes in population: 500, sample size: 10, number of successes in sample: 5
+	// Expected result: 0.072
+	const (
+		expected = 0.0796665913283742
+		margin   = 0.000001
+	)
+
+	actual := peerdas.HypergeomCDF(5, 128, 65, 16)
+	require.Equal(t, true, expected-margin <= actual && actual <= expected+margin)
+}

beacon-chain/core/time/slot_epoch.go

@@ -53,6 +53,11 @@ func HigherEqualThanAltairVersionAndEpoch(s state.BeaconState, e primitives.Epoc
 	return s.Version() >= version.Altair && e >= params.BeaconConfig().AltairForkEpoch
 }
 
+// PeerDASIsActive checks whether peerDAS is active at the provided slot.
+func PeerDASIsActive(slot primitives.Slot) bool {
+	return params.FuluEnabled() && slots.ToEpoch(slot) >= params.BeaconConfig().FuluForkEpoch
+}
+
 // CanUpgradeToAltair returns true if the input `slot` can upgrade to Altair.
 // Spec code:
 // If state.slot % SLOTS_PER_EPOCH == 0 and compute_epoch_at_slot(state.slot) == ALTAIR_FORK_EPOCH

beacon-chain/das/BUILD.bazel

@@ -4,21 +4,26 @@ go_library(
     name = "go_default_library",
     srcs = [
         "availability.go",
+        "availability_columns.go",
         "cache.go",
+        "data_column_cache.go",
         "iface.go",
         "mock.go",
     ],
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/das",
     visibility = ["//visibility:public"],
     deps = [
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/verification:go_default_library",
+        "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//runtime/logging:go_default_library",
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
     ],
@@ -27,13 +32,18 @@ go_library(
 go_test(
     name = "go_default_test",
     srcs = [
+        "availability_columns_test.go",
         "availability_test.go",
         "cache_test.go",
+        "data_column_cache_test.go",
     ],
     embed = [":go_default_library"],
     deps = [
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/verification:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
+        "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/primitives:go_default_library",
@@ -41,6 +51,7 @@ go_test(
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "//time/slots:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
     ],
 )

beacon-chain/das/availability.go

@@ -53,10 +53,16 @@ func NewLazilyPersistentStore(store *filesystem.BlobStorage, verifier BlobBatchV
 // Persist adds blobs to the working blob cache. Blobs stored in this cache will be persisted
 // for at least as long as the node is running. Once IsDataAvailable succeeds, all blobs referenced
 // by the given block are guaranteed to be persisted for the remainder of the retention period.
-func (s *LazilyPersistentStore) Persist(current primitives.Slot, sc ...blocks.ROBlob) error {
-	if len(sc) == 0 {
+func (s *LazilyPersistentStore) Persist(current primitives.Slot, scg ...blocks.ROSidecar) error {
+	if len(scg) == 0 {
 		return nil
 	}
+
+	sc, err := blocks.BlobSidecarsFromSidecars(scg)
+	if err != nil {
+		return errors.Wrap(err, "blob sidecars from sidecars")
+	}
+
 	if len(sc) > 1 {
 		first := sc[0].BlockRoot()
 		for i := 1; i < len(sc); i++ {

beacon-chain/das/availability_columns.go

@@ -0,0 +1,200 @@
+package das
+
+import (
+	"context"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	errors "github.com/pkg/errors"
+)
+
+// LazilyPersistentStoreColumn is an implementation of AvailabilityStore to be used when batch syncing data columns.
+// This implementation will hold any data columns passed to Persist until the IsDataAvailable is called for their
+// block, at which time they will undergo full verification and be saved to the disk.
+type LazilyPersistentStoreColumn struct {
+	store                  *filesystem.DataColumnStorage
+	nodeID                 enode.ID
+	cache                  *dataColumnCache
+	custodyInfo            *peerdas.CustodyInfo
+	newDataColumnsVerifier verification.NewDataColumnsVerifier
+}
+
+var _ AvailabilityStore = &LazilyPersistentStoreColumn{}
+
+// DataColumnsVerifier enables LazilyPersistentStoreColumn to manage the verification process
+// going from RODataColumn->VerifiedRODataColumn, while avoiding the decision of which individual verifications
+// to run and in what order. Since LazilyPersistentStoreColumn always tries to verify and save data columns only when
+// they are all available, the interface takes a slice of data column sidecars.
+type DataColumnsVerifier interface {
+	VerifiedRODataColumns(ctx context.Context, blk blocks.ROBlock, scs []blocks.RODataColumn) ([]blocks.VerifiedRODataColumn, error)
+}
+
+func NewLazilyPersistentStoreColumn(store *filesystem.DataColumnStorage, nodeID enode.ID, newDataColumnsVerifier verification.NewDataColumnsVerifier, custodyInfo *peerdas.CustodyInfo) *LazilyPersistentStoreColumn {
+	return &LazilyPersistentStoreColumn{
+		store:                  store,
+		nodeID:                 nodeID,
+		cache:                  newDataColumnCache(),
+		custodyInfo:            custodyInfo,
+		newDataColumnsVerifier: newDataColumnsVerifier,
+	}
+}
+
+// PersistColumns adds columns to the working column cache. Columns stored in this cache will be persisted
+// for at least as long as the node is running. Once IsDataAvailable succeeds, all columns referenced
+// by the given block are guaranteed to be persisted for the remainder of the retention period.
+func (s *LazilyPersistentStoreColumn) Persist(current primitives.Slot, sidecars ...blocks.ROSidecar) error {
+	if len(sidecars) == 0 {
+		return nil
+	}
+
+	dataColumnSidecars, err := blocks.DataColumnSidecarsFromSidecars(sidecars)
+	if err != nil {
+		return errors.Wrap(err, "blob sidecars from sidecars")
+	}
+
+	// It is safe to retrieve the first sidecar.
+	firstSidecar := dataColumnSidecars[0]
+
+	if len(sidecars) > 1 {
+		firstRoot := firstSidecar.BlockRoot()
+		for _, sidecar := range dataColumnSidecars[1:] {
+			if sidecar.BlockRoot() != firstRoot {
+				return errMixedRoots
+			}
+		}
+	}
+
+	firstSidecarEpoch, currentEpoch := slots.ToEpoch(firstSidecar.Slot()), slots.ToEpoch(current)
+	if !params.WithinDAPeriod(firstSidecarEpoch, currentEpoch) {
+		return nil
+	}
+
+	key := dataColumnCacheKey{slot: firstSidecar.Slot(), root: firstSidecar.BlockRoot()}
+	entry := s.cache.ensure(key)
+
+	for i := range sidecars {
+		if err := entry.stash(&dataColumnSidecars[i]); err != nil {
+			return errors.Wrap(err, "stash DataColumnSidecar")
+		}
+	}
+
+	return nil
+}
+
+// IsDataAvailable returns nil if all the commitments in the given block are persisted to the db and have been verified.
+// DataColumnsSidecars already in the db are assumed to have been previously verified against the block.
+func (s *LazilyPersistentStoreColumn) IsDataAvailable(ctx context.Context, currentSlot primitives.Slot, block blocks.ROBlock) error {
+	blockCommitments, err := s.fullCommitmentsToCheck(s.nodeID, block, currentSlot)
+	if err != nil {
+		return errors.Wrapf(err, "full commitments to check with block root `%#x` and current slot `%d`", block.Root(), currentSlot)
+	}
+
+	// Return early for blocks that do not have any commitments.
+	if blockCommitments.count() == 0 {
+		return nil
+	}
+
+	// Get the root of the block.
+	blockRoot := block.Root()
+
+	// Build the cache key for the block.
+	key := dataColumnCacheKey{slot: block.Block().Slot(), root: blockRoot}
+
+	// Retrieve the cache entry for the block, or create an empty one if it doesn't exist.
+	entry := s.cache.ensure(key)
+
+	// Delete the cache entry for the block at the end.
+	defer s.cache.delete(key)
+
+	// Set the disk summary for the block in the cache entry.
+	entry.setDiskSummary(s.store.Summary(blockRoot))
+
+	// Verify we have all the expected sidecars, and fail fast if any are missing or inconsistent.
+	// We don't try to salvage problematic batches because this indicates a misbehaving peer and we'd rather
+	// ignore their response and decrease their peer score.
+	roDataColumns, err := entry.filter(blockRoot, blockCommitments)
+	if err != nil {
+		return errors.Wrap(err, "filter")
+	}
+
+	// https://github.com/ethereum/consensus-specs/blob/dev/specs/fulu/p2p-interface.md#datacolumnsidecarsbyrange-v1
+	verifier := s.newDataColumnsVerifier(roDataColumns, verification.ByRangeRequestDataColumnSidecarRequirements)
+
+	if err := verifier.ValidFields(); err != nil {
+		return errors.Wrap(err, "valid")
+	}
+
+	if err := verifier.SidecarInclusionProven(); err != nil {
+		return errors.Wrap(err, "sidecar inclusion proven")
+	}
+
+	if err := verifier.SidecarKzgProofVerified(); err != nil {
+		return errors.Wrap(err, "sidecar KZG proof verified")
+	}
+
+	verifiedRoDataColumns, err := verifier.VerifiedRODataColumns()
+	if err != nil {
+		return errors.Wrap(err, "verified RO data columns - should never happen")
+	}
+
+	if err := s.store.Save(verifiedRoDataColumns); err != nil {
+		return errors.Wrap(err, "save data column sidecars")
+	}
+
+	return nil
+}
+
+// fullCommitmentsToCheck returns the commitments to check for a given block.
+func (s *LazilyPersistentStoreColumn) fullCommitmentsToCheck(nodeID enode.ID, block blocks.ROBlock, currentSlot primitives.Slot) (*safeCommitmentsArray, error) {
+	// Return early for blocks that are pre-Fulu.
+	if block.Version() < version.Fulu {
+		return &safeCommitmentsArray{}, nil
+	}
+
+	// Compute the block epoch.
+	blockSlot := block.Block().Slot()
+	blockEpoch := slots.ToEpoch(blockSlot)
+
+	// Compute the current spoch.
+	currentEpoch := slots.ToEpoch(currentSlot)
+
+	// Return early if the request is out of the MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS window.
+	if !params.WithinDAPeriod(blockEpoch, currentEpoch) {
+		return &safeCommitmentsArray{}, nil
+	}
+
+	// Retrieve the KZG commitments for the block.
+	kzgCommitments, err := block.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return nil, errors.Wrap(err, "blob KZG commitments")
+	}
+
+	// Return early if there are no commitments in the block.
+	if len(kzgCommitments) == 0 {
+		return &safeCommitmentsArray{}, nil
+	}
+
+	// Retrieve the groups count.
+	custodyGroupCount := s.custodyInfo.ActualGroupCount()
+
+	// Retrieve peer info.
+	peerInfo, _, err := peerdas.Info(nodeID, custodyGroupCount)
+	if err != nil {
+		return nil, errors.Wrap(err, "peer info")
+	}
+
+	// Create a safe commitments array for the custody columns.
+	commitmentsArray := &safeCommitmentsArray{}
+	for column := range peerInfo.CustodyColumns {
+		commitmentsArray[column] = kzgCommitments
+	}
+
+	return commitmentsArray, nil
+}

beacon-chain/das/availability_columns_test.go

@@ -0,0 +1,303 @@
+package das
+
+import (
+	"context"
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
+	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+)
+
+func roSidecarsFromDataColumnParamsByBlockRoot(t *testing.T, dataColumnParamsByBlockRoot verification.DataColumnsParamsByRoot) ([]blocks.ROSidecar, []blocks.RODataColumn) {
+	roDataColumns, _ := verification.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnParamsByBlockRoot)
+
+	roSidecars := make([]blocks.ROSidecar, 0, len(roDataColumns))
+	for _, roDataColumn := range roDataColumns {
+		roSidecars = append(roSidecars, blocks.NewSidecarFromDataColumnSidecar(roDataColumn))
+	}
+
+	return roSidecars, roDataColumns
+}
+
+func newSignedRoBlock(t *testing.T, signedBeaconBlock interface{}) blocks.ROBlock {
+	sb, err := blocks.NewSignedBeaconBlock(signedBeaconBlock)
+	require.NoError(t, err)
+
+	rb, err := blocks.NewROBlock(sb)
+	require.NoError(t, err)
+
+	return rb
+}
+
+var commitments = [][]byte{
+	bytesutil.PadTo([]byte("a"), 48),
+	bytesutil.PadTo([]byte("b"), 48),
+	bytesutil.PadTo([]byte("c"), 48),
+	bytesutil.PadTo([]byte("d"), 48),
+}
+
+func TestPersist(t *testing.T) {
+	t.Run("no sidecars", func(t *testing.T) {
+		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
+		err := lazilyPersistentStoreColumns.Persist(0)
+		require.NoError(t, err)
+		require.Equal(t, 0, len(lazilyPersistentStoreColumns.cache.entries))
+	})
+
+	t.Run("mixed roots", func(t *testing.T) {
+		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
+
+		dataColumnParamsByBlockRoot := map[[fieldparams.RootLength]byte][]verification.DataColumnParams{
+			{1}: {{ColumnIndex: 1}},
+			{2}: {{ColumnIndex: 2}},
+		}
+
+		roSidecars, _ := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
+
+		err := lazilyPersistentStoreColumns.Persist(0, roSidecars...)
+		require.ErrorIs(t, err, errMixedRoots)
+		require.Equal(t, 0, len(lazilyPersistentStoreColumns.cache.entries))
+	})
+
+	t.Run("outside DA period", func(t *testing.T) {
+		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
+
+		dataColumnParamsByBlockRoot := map[[fieldparams.RootLength]byte][]verification.DataColumnParams{
+			{1}: {{ColumnIndex: 1}},
+		}
+
+		roSidecars, _ := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
+
+		err := lazilyPersistentStoreColumns.Persist(1_000_000, roSidecars...)
+		require.NoError(t, err)
+		require.Equal(t, 0, len(lazilyPersistentStoreColumns.cache.entries))
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
+
+		dataColumnParamsByBlockRoot := map[[fieldparams.RootLength]byte][]verification.DataColumnParams{
+			{}: {{ColumnIndex: 1}, {ColumnIndex: 5}},
+		}
+
+		roSidecars, roDataColumns := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
+
+		err := lazilyPersistentStoreColumns.Persist(0, roSidecars...)
+		require.NoError(t, err)
+		require.Equal(t, 1, len(lazilyPersistentStoreColumns.cache.entries))
+
+		key := dataColumnCacheKey{slot: 0, root: [32]byte{}}
+		entry := lazilyPersistentStoreColumns.cache.entries[key]
+
+		// A call to Persist does NOT save the sidecars to disk.
+		require.Equal(t, uint64(0), entry.diskSummary.Count())
+
+		require.DeepSSZEqual(t, roDataColumns[0], *entry.scs[1])
+		require.DeepSSZEqual(t, roDataColumns[1], *entry.scs[5])
+
+		for i, roDataColumn := range entry.scs {
+			if map[int]bool{1: true, 5: true}[i] {
+				continue
+			}
+
+			require.IsNil(t, roDataColumn)
+		}
+	})
+}
+
+func TestIsDataAvailable(t *testing.T) {
+	newDataColumnsVerifier := func(dataColumnSidecars []blocks.RODataColumn, _ []verification.Requirement) verification.DataColumnsVerifier {
+		return &mockDataColumnsVerifier{t: t, dataColumnSidecars: dataColumnSidecars}
+	}
+
+	ctx := context.Background()
+
+	t.Run("without commitments", func(t *testing.T) {
+		signedBeaconBlockFulu := util.NewBeaconBlockFulu()
+		signedRoBlock := newSignedRoBlock(t, signedBeaconBlockFulu)
+
+		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, newDataColumnsVerifier, &peerdas.CustodyInfo{})
+
+		err := lazilyPersistentStoreColumns.IsDataAvailable(ctx, 0 /*current slot*/, signedRoBlock)
+		require.NoError(t, err)
+	})
+
+	t.Run("with commitments", func(t *testing.T) {
+		signedBeaconBlockFulu := util.NewBeaconBlockFulu()
+		signedBeaconBlockFulu.Block.Body.BlobKzgCommitments = commitments
+		signedRoBlock := newSignedRoBlock(t, signedBeaconBlockFulu)
+		root := signedRoBlock.Root()
+
+		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, newDataColumnsVerifier, &peerdas.CustodyInfo{})
+
+		indices := [...]uint64{1, 17, 87, 102}
+		dataColumnsParams := make([]verification.DataColumnParams, 0, len(indices))
+		for _, index := range indices {
+			dataColumnParams := verification.DataColumnParams{
+				ColumnIndex:    index,
+				KzgCommitments: commitments,
+			}
+
+			dataColumnsParams = append(dataColumnsParams, dataColumnParams)
+		}
+
+		dataColumnsParamsByBlockRoot := verification.DataColumnsParamsByRoot{root: dataColumnsParams}
+		_, verifiedRoDataColumns := verification.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnsParamsByBlockRoot)
+
+		key := dataColumnCacheKey{root: root}
+		entry := lazilyPersistentStoreColumns.cache.ensure(key)
+		defer lazilyPersistentStoreColumns.cache.delete(key)
+
+		for _, verifiedRoDataColumn := range verifiedRoDataColumns {
+			err := entry.stash(&verifiedRoDataColumn.RODataColumn)
+			require.NoError(t, err)
+		}
+
+		err := lazilyPersistentStoreColumns.IsDataAvailable(ctx, 0 /*current slot*/, signedRoBlock)
+		require.NoError(t, err)
+
+		actual, err := dataColumnStorage.Get(root, indices[:])
+		require.NoError(t, err)
+
+		summary := dataColumnStorage.Summary(root)
+		require.Equal(t, uint64(len(indices)), summary.Count())
+		require.DeepSSZEqual(t, verifiedRoDataColumns, actual)
+	})
+}
+
+func TestFullCommitmentsToCheck(t *testing.T) {
+	windowSlots, err := slots.EpochEnd(params.BeaconConfig().MinEpochsForDataColumnSidecarsRequest)
+	require.NoError(t, err)
+
+	testCases := []struct {
+		name        string
+		commitments [][]byte
+		block       func(*testing.T) blocks.ROBlock
+		slot        primitives.Slot
+	}{
+		{
+			name: "Pre-Fulu block",
+			block: func(t *testing.T) blocks.ROBlock {
+				return newSignedRoBlock(t, util.NewBeaconBlockElectra())
+			},
+		},
+		{
+			name: "Commitments outside data availability window",
+			block: func(t *testing.T) blocks.ROBlock {
+				beaconBlockElectra := util.NewBeaconBlockElectra()
+
+				// Block is from slot 0, "current slot" is window size +1 (so outside the window)
+				beaconBlockElectra.Block.Body.BlobKzgCommitments = commitments
+
+				return newSignedRoBlock(t, beaconBlockElectra)
+			},
+			slot: windowSlots + 1,
+		},
+		{
+			name: "Commitments within data availability window",
+			block: func(t *testing.T) blocks.ROBlock {
+				signedBeaconBlockFulu := util.NewBeaconBlockFulu()
+				signedBeaconBlockFulu.Block.Body.BlobKzgCommitments = commitments
+				signedBeaconBlockFulu.Block.Slot = 100
+
+				return newSignedRoBlock(t, signedBeaconBlockFulu)
+			},
+			commitments: commitments,
+			slot:        100,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			resetFlags := flags.Get()
+			gFlags := new(flags.GlobalFlags)
+			gFlags.SubscribeAllDataSubnets = true
+			flags.Init(gFlags)
+			defer flags.Init(resetFlags)
+
+			b := tc.block(t)
+			s := NewLazilyPersistentStoreColumn(nil, enode.ID{}, nil, &peerdas.CustodyInfo{})
+
+			commitmentsArray, err := s.fullCommitmentsToCheck(enode.ID{}, b, tc.slot)
+			require.NoError(t, err)
+
+			for _, commitments := range commitmentsArray {
+				require.DeepEqual(t, tc.commitments, commitments)
+			}
+		})
+	}
+}
+
+type mockDataColumnsVerifier struct {
+	t                                                                        *testing.T
+	dataColumnSidecars                                                       []blocks.RODataColumn
+	validCalled, SidecarInclusionProvenCalled, SidecarKzgProofVerifiedCalled bool
+}
+
+var _ verification.DataColumnsVerifier = &mockDataColumnsVerifier{}
+
+func (m *mockDataColumnsVerifier) VerifiedRODataColumns() ([]blocks.VerifiedRODataColumn, error) {
+	require.Equal(m.t, true, m.validCalled && m.SidecarInclusionProvenCalled && m.SidecarKzgProofVerifiedCalled)
+
+	verifiedDataColumnSidecars := make([]blocks.VerifiedRODataColumn, 0, len(m.dataColumnSidecars))
+	for _, dataColumnSidecar := range m.dataColumnSidecars {
+		verifiedDataColumnSidecar := blocks.NewVerifiedRODataColumn(dataColumnSidecar)
+		verifiedDataColumnSidecars = append(verifiedDataColumnSidecars, verifiedDataColumnSidecar)
+	}
+
+	return verifiedDataColumnSidecars, nil
+}
+
+func (m *mockDataColumnsVerifier) SatisfyRequirement(verification.Requirement) {}
+
+func (m *mockDataColumnsVerifier) ValidFields() error {
+	m.validCalled = true
+	return nil
+}
+
+func (m *mockDataColumnsVerifier) CorrectSubnet(dataColumnSidecarSubTopic string, expectedTopics []string) error {
+	return nil
+}
+func (m *mockDataColumnsVerifier) NotFromFutureSlot() error                         { return nil }
+func (m *mockDataColumnsVerifier) SlotAboveFinalized() error                        { return nil }
+func (m *mockDataColumnsVerifier) ValidProposerSignature(ctx context.Context) error { return nil }
+
+func (m *mockDataColumnsVerifier) SidecarParentSeen(parentSeen func([fieldparams.RootLength]byte) bool) error {
+	return nil
+}
+
+func (m *mockDataColumnsVerifier) SidecarParentValid(badParent func([fieldparams.RootLength]byte) bool) error {
+	return nil
+}
+
+func (m *mockDataColumnsVerifier) SidecarParentSlotLower() error       { return nil }
+func (m *mockDataColumnsVerifier) SidecarDescendsFromFinalized() error { return nil }
+
+func (m *mockDataColumnsVerifier) SidecarInclusionProven() error {
+	m.SidecarInclusionProvenCalled = true
+	return nil
+}
+
+func (m *mockDataColumnsVerifier) SidecarKzgProofVerified() error {
+	m.SidecarKzgProofVerifiedCalled = true
+	return nil
+}
+
+func (m *mockDataColumnsVerifier) SidecarProposerExpected(ctx context.Context) error { return nil }

beacon-chain/das/availability_test.go

@@ -116,9 +116,11 @@ func TestLazilyPersistent_Missing(t *testing.T) {
 	ctx := context.Background()
 	store := filesystem.NewEphemeralBlobStorage(t)
 
-	blk, scs := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 3)
+	blk, blobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 3)
 
-	mbv := &mockBlobBatchVerifier{t: t, scs: scs}
+	scs := blocks.NewSidecarsFromBlobSidecars(blobSidecars)
+
+	mbv := &mockBlobBatchVerifier{t: t, scs: blobSidecars}
 	as := NewLazilyPersistentStore(store, mbv)
 
 	// Only one commitment persisted, should return error with other indices
@@ -141,12 +143,14 @@ func TestLazilyPersistent_Mismatch(t *testing.T) {
 	ctx := context.Background()
 	store := filesystem.NewEphemeralBlobStorage(t)
 
-	blk, scs := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 3)
+	blk, blobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 3)
 
 	mbv := &mockBlobBatchVerifier{t: t, err: errors.New("kzg check should not run")}
-	scs[0].KzgCommitment = bytesutil.PadTo([]byte("nope"), 48)
+	blobSidecars[0].KzgCommitment = bytesutil.PadTo([]byte("nope"), 48)
 	as := NewLazilyPersistentStore(store, mbv)
 
+	scs := blocks.NewSidecarsFromBlobSidecars(blobSidecars)
+
 	// Only one commitment persisted, should return error with other indices
 	require.NoError(t, as.Persist(1, scs[0]))
 	err := as.IsDataAvailable(ctx, 1, blk)
@@ -155,7 +159,10 @@ func TestLazilyPersistent_Mismatch(t *testing.T) {
 }
 
 func TestLazyPersistOnceCommitted(t *testing.T) {
-	_, scs := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 6)
+	_, blobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 6)
+
+	scs := blocks.NewSidecarsFromBlobSidecars(blobSidecars)
+
 	as := NewLazilyPersistentStore(filesystem.NewEphemeralBlobStorage(t), &mockBlobBatchVerifier{})
 	// stashes as expected
 	require.NoError(t, as.Persist(1, scs...))
@@ -163,10 +170,13 @@ func TestLazyPersistOnceCommitted(t *testing.T) {
 	require.ErrorIs(t, as.Persist(1, scs...), ErrDuplicateSidecar)
 
 	// ignores index out of bound
-	scs[0].Index = 6
-	require.ErrorIs(t, as.Persist(1, scs[0]), errIndexOutOfBounds)
+	blobSidecars[0].Index = 6
+	require.ErrorIs(t, as.Persist(1, blocks.NewSidecarFromBlobSidecar(blobSidecars[0])), errIndexOutOfBounds)
+
+	_, moreBlobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 4)
+
+	more := blocks.NewSidecarsFromBlobSidecars(moreBlobSidecars)
 
-	_, more := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 4)
 	// ignores sidecars before the retention period
 	slotOOB, err := slots.EpochStart(params.BeaconConfig().MinEpochsForBlobsSidecarsRequest)
 	require.NoError(t, err)

beacon-chain/das/cache.go

@@ -10,12 +10,7 @@ import (
 	"github.com/pkg/errors"
 )
 
-var (
-	ErrDuplicateSidecar   = errors.New("duplicate sidecar stashed in AvailabilityStore")
-	errIndexOutOfBounds   = errors.New("sidecar.index > MAX_BLOBS_PER_BLOCK")
-	errCommitmentMismatch = errors.New("KzgCommitment of sidecar in cache did not match block commitment")
-	errMissingSidecar     = errors.New("no sidecar in cache for block commitment")
-)
+var errIndexOutOfBounds = errors.New("sidecar.index > MAX_BLOBS_PER_BLOCK")
 
 // cacheKey includes the slot so that we can easily iterate through the cache and compare
 // slots for eviction purposes. Whether the input is the block or the sidecar, we always have

beacon-chain/das/data_column_cache.go

@@ -0,0 +1,135 @@
+package das
+
+import (
+	"reflect"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/pkg/errors"
+)
+
+var (
+	ErrDuplicateSidecar   = errors.New("duplicate sidecar stashed in AvailabilityStore")
+	errColumnIndexTooHigh = errors.New("column index too high")
+	errCommitmentMismatch = errors.New("KzgCommitment of sidecar in cache did not match block commitment")
+	errMissingSidecar     = errors.New("no sidecar in cache for block commitment")
+)
+
+// dataColumnCacheKey includes the slot so that we can easily iterate through the cache and compare
+// slots for eviction purposes. Whether the input is the block or the sidecar, we always have
+// the root+slot when interacting with the cache, so it isn't an inconvenience to use both.
+type dataColumnCacheKey struct {
+	slot primitives.Slot
+	root [32]byte
+}
+
+type dataColumnCache struct {
+	entries map[dataColumnCacheKey]*dataColumnCacheEntry
+}
+
+func newDataColumnCache() *dataColumnCache {
+	return &dataColumnCache{entries: make(map[dataColumnCacheKey]*dataColumnCacheEntry)}
+}
+
+// ensure returns the entry for the given key, creating it if it isn't already present.
+func (c *dataColumnCache) ensure(key dataColumnCacheKey) *dataColumnCacheEntry {
+	entry, ok := c.entries[key]
+	if !ok {
+		entry = &dataColumnCacheEntry{}
+		c.entries[key] = entry
+	}
+
+	return entry
+}
+
+// delete removes the cache entry from the cache.
+func (c *dataColumnCache) delete(key dataColumnCacheKey) {
+	delete(c.entries, key)
+}
+
+// dataColumnCacheEntry holds a fixed-length cache of BlobSidecars.
+type dataColumnCacheEntry struct {
+	scs         [fieldparams.NumberOfColumns]*blocks.RODataColumn
+	diskSummary filesystem.DataColumnStorageSummary
+}
+
+func (e *dataColumnCacheEntry) setDiskSummary(sum filesystem.DataColumnStorageSummary) {
+	e.diskSummary = sum
+}
+
+// stash adds an item to the in-memory cache of DataColumnSidecars.
+// Only the first DataColumnSidecar of a given Index will be kept in the cache.
+// stash will return an error if the given data colunn is already in the cache, or if the Index is out of bounds.
+func (e *dataColumnCacheEntry) stash(sc *blocks.RODataColumn) error {
+	if sc.Index >= fieldparams.NumberOfColumns {
+		return errors.Wrapf(errColumnIndexTooHigh, "index=%d", sc.Index)
+	}
+
+	if e.scs[sc.Index] != nil {
+		return errors.Wrapf(ErrDuplicateSidecar, "root=%#x, index=%d, commitment=%#x", sc.BlockRoot(), sc.Index, sc.KzgCommitments)
+	}
+
+	e.scs[sc.Index] = sc
+
+	return nil
+}
+
+func (e *dataColumnCacheEntry) filter(root [32]byte, commitmentsArray *safeCommitmentsArray) ([]blocks.RODataColumn, error) {
+	nonEmptyIndices := commitmentsArray.nonEmptyIndices()
+	if e.diskSummary.AllAvailable(nonEmptyIndices) {
+		return nil, nil
+	}
+
+	commitmentsCount := commitmentsArray.count()
+	sidecars := make([]blocks.RODataColumn, 0, commitmentsCount)
+
+	for i := range nonEmptyIndices {
+		if e.diskSummary.HasIndex(i) {
+			continue
+		}
+
+		if e.scs[i] == nil {
+			return nil, errors.Wrapf(errMissingSidecar, "root=%#x, index=%#x", root, i)
+		}
+
+		if !reflect.DeepEqual(commitmentsArray[i], e.scs[i].KzgCommitments) {
+			return nil, errors.Wrapf(errCommitmentMismatch, "root=%#x, index=%#x, commitment=%#x, block commitment=%#x", root, i, e.scs[i].KzgCommitments, commitmentsArray[i])
+		}
+
+		sidecars = append(sidecars, *e.scs[i])
+	}
+
+	return sidecars, nil
+}
+
+// safeCommitmentsArray is a fixed size array of commitments.
+// This is helpful for avoiding gratuitous bounds checks.
+type safeCommitmentsArray [fieldparams.NumberOfColumns][][]byte
+
+// count returns the number of commitments in the array.
+func (s *safeCommitmentsArray) count() int {
+	count := 0
+
+	for i := range s {
+		if s[i] != nil {
+			count++
+		}
+	}
+
+	return count
+}
+
+// nonEmptyIndices returns a map of indices that are non-nil in the array.
+func (s *safeCommitmentsArray) nonEmptyIndices() map[uint64]bool {
+	columns := make(map[uint64]bool)
+
+	for i := range s {
+		if s[i] != nil {
+			columns[uint64(i)] = true
+		}
+	}
+
+	return columns
+}

beacon-chain/das/data_column_cache_test.go

@@ -0,0 +1,124 @@
+package das
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+func TestEnsureDeleteSetDiskSummary(t *testing.T) {
+	c := newDataColumnCache()
+	key := dataColumnCacheKey{}
+	entry := c.ensure(key)
+	require.DeepEqual(t, dataColumnCacheEntry{}, *entry)
+
+	diskSummary := filesystem.NewDataColumnStorageSummary(42, [fieldparams.NumberOfColumns]bool{true})
+	entry.setDiskSummary(diskSummary)
+	entry = c.ensure(key)
+	require.DeepEqual(t, dataColumnCacheEntry{diskSummary: diskSummary}, *entry)
+
+	c.delete(key)
+	entry = c.ensure(key)
+	require.DeepEqual(t, dataColumnCacheEntry{}, *entry)
+}
+
+func TestStash(t *testing.T) {
+	t.Run("Index too high", func(t *testing.T) {
+		dataColumnParamsByBlockRoot := verification.DataColumnsParamsByRoot{{1}: {{ColumnIndex: 10_000}}}
+		roDataColumns, _ := verification.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnParamsByBlockRoot)
+
+		var entry dataColumnCacheEntry
+		err := entry.stash(&roDataColumns[0])
+		require.NotNil(t, err)
+	})
+
+	t.Run("Nominal and already existing", func(t *testing.T) {
+		dataColumnParamsByBlockRoot := verification.DataColumnsParamsByRoot{{1}: {{ColumnIndex: 1}}}
+		roDataColumns, _ := verification.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnParamsByBlockRoot)
+
+		var entry dataColumnCacheEntry
+		err := entry.stash(&roDataColumns[0])
+		require.NoError(t, err)
+
+		require.DeepEqual(t, roDataColumns[0], entry.scs[1])
+
+		err = entry.stash(&roDataColumns[0])
+		require.NotNil(t, err)
+	})
+}
+
+func TestFilterDataColumns(t *testing.T) {
+	t.Run("All available", func(t *testing.T) {
+		commitmentsArray := safeCommitmentsArray{nil, [][]byte{[]byte{1}}, nil, [][]byte{[]byte{3}}}
+
+		diskSummary := filesystem.NewDataColumnStorageSummary(42, [fieldparams.NumberOfColumns]bool{false, true, false, true})
+
+		dataColumnCacheEntry := dataColumnCacheEntry{diskSummary: diskSummary}
+
+		actual, err := dataColumnCacheEntry.filter([fieldparams.RootLength]byte{}, &commitmentsArray)
+		require.NoError(t, err)
+		require.IsNil(t, actual)
+	})
+
+	t.Run("Some scs missing", func(t *testing.T) {
+		commitmentsArray := safeCommitmentsArray{nil, [][]byte{[]byte{1}}}
+
+		diskSummary := filesystem.NewDataColumnStorageSummary(42, [fieldparams.NumberOfColumns]bool{})
+
+		dataColumnCacheEntry := dataColumnCacheEntry{diskSummary: diskSummary}
+
+		_, err := dataColumnCacheEntry.filter([fieldparams.RootLength]byte{}, &commitmentsArray)
+		require.NotNil(t, err)
+	})
+
+	t.Run("Commitments not equal", func(t *testing.T) {
+		root := [fieldparams.RootLength]byte{}
+		commitmentsArray := safeCommitmentsArray{nil, [][]byte{[]byte{1}}}
+
+		dataColumnParamsByBlockRoot := verification.DataColumnsParamsByRoot{root: {{ColumnIndex: 1}}}
+		roDataColumns, _ := verification.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnParamsByBlockRoot)
+
+		var scs [fieldparams.NumberOfColumns]*blocks.RODataColumn
+		scs[1] = &roDataColumns[0]
+
+		dataColumnCacheEntry := dataColumnCacheEntry{scs: scs}
+
+		_, err := dataColumnCacheEntry.filter(root, &commitmentsArray)
+		require.NotNil(t, err)
+	})
+
+	t.Run("Nominal", func(t *testing.T) {
+		root := [fieldparams.RootLength]byte{}
+		commitmentsArray := safeCommitmentsArray{nil, [][]byte{[]byte{1}}, nil, [][]byte{[]byte{3}}}
+
+		diskSummary := filesystem.NewDataColumnStorageSummary(42, [fieldparams.NumberOfColumns]bool{false, true})
+
+		dataColumnParamsByBlockRoot := verification.DataColumnsParamsByRoot{root: {{ColumnIndex: 3, KzgCommitments: [][]byte{[]byte{3}}}}}
+		expected, _ := verification.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnParamsByBlockRoot)
+
+		var scs [fieldparams.NumberOfColumns]*blocks.RODataColumn
+		scs[3] = &expected[0]
+
+		dataColumnCacheEntry := dataColumnCacheEntry{scs: scs, diskSummary: diskSummary}
+
+		actual, err := dataColumnCacheEntry.filter(root, &commitmentsArray)
+		require.NoError(t, err)
+
+		require.DeepEqual(t, expected, actual)
+	})
+}
+
+func TestCount(t *testing.T) {
+	s := safeCommitmentsArray{nil, [][]byte{[]byte{1}}, nil, [][]byte{[]byte{3}}}
+	require.Equal(t, 2, s.count())
+}
+
+func TestNonEmptyIndices(t *testing.T) {
+	s := safeCommitmentsArray{nil, [][]byte{[]byte{10}}, nil, [][]byte{[]byte{20}}}
+	actual := s.nonEmptyIndices()
+	require.DeepEqual(t, map[uint64]bool{1: true, 3: true}, actual)
+}

beacon-chain/das/iface.go

@@ -14,6 +14,12 @@ import (
 // IsDataAvailable guarantees that all blobs committed to in the block have been
 // durably persisted before returning a non-error value.
 type AvailabilityStore interface {
-	IsDataAvailable(ctx context.Context, current primitives.Slot, b blocks.ROBlock) error
-	Persist(current primitives.Slot, sc ...blocks.ROBlob) error
+	AvailabilityChecker
+	Persist(current primitives.Slot, sc ...blocks.ROSidecar) error
+}
+
+// AvailabilityChecker is the minimum interface needed to check if data is available for a block.
+// We should prefer this interface over AvailabilityStore in places where we don't need to persist blob data.
+type AvailabilityChecker interface {
+	IsDataAvailable(ctx context.Context, current primitives.Slot, b blocks.ROBlock) error
 }

beacon-chain/das/mock.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	errors "github.com/pkg/errors"
 )
 
 // MockAvailabilityStore is an implementation of AvailabilityStore that can be used by other packages in tests.
@@ -24,9 +25,13 @@ func (m *MockAvailabilityStore) IsDataAvailable(ctx context.Context, current pri
 }
 
 // Persist satisfies the corresponding method of the AvailabilityStore interface in a way that is useful for tests.
-func (m *MockAvailabilityStore) Persist(current primitives.Slot, sc ...blocks.ROBlob) error {
+func (m *MockAvailabilityStore) Persist(current primitives.Slot, sc ...blocks.ROSidecar) error {
+	blobSidecars, err := blocks.BlobSidecarsFromSidecars(sc)
+	if err != nil {
+		return errors.Wrap(err, "blob sidecars from sidecars")
+	}
 	if m.PersistBlobsCallback != nil {
-		return m.PersistBlobsCallback(current, sc...)
+		return m.PersistBlobsCallback(current, blobSidecars...)
 	}
 	return nil
 }

beacon-chain/execution/BUILD.bazel

@@ -31,6 +31,7 @@ go_library(
         "//beacon-chain/core/feed:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/execution/types:go_default_library",
@@ -97,6 +98,7 @@ go_test(
     embed = [":go_default_library"],
     deps = [
         "//async/event:go_default_library",
+        "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/cache/depositsnapshot:go_default_library",
         "//beacon-chain/core/feed:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",

beacon-chain/execution/engine_client.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/execution/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
@@ -44,11 +45,16 @@ var (
 		GetPayloadMethodV3,
 		GetPayloadBodiesByHashV1,
 		GetPayloadBodiesByRangeV1,
+		GetBlobsV1,
 	}
 	electraEngineEndpoints = []string{
 		NewPayloadMethodV4,
 		GetPayloadMethodV4,
 	}
+	fuluEngineEndpoints = []string{
+		GetPayloadMethodV5,
+		GetBlobsV2,
+	}
 )
 
 const (
@@ -73,6 +79,8 @@ const (
 	GetPayloadMethodV3 = "engine_getPayloadV3"
 	// GetPayloadMethodV4 is the get payload method added for electra
 	GetPayloadMethodV4 = "engine_getPayloadV4"
+	// GetPayloadMethodV5 is the get payload method added for fulu
+	GetPayloadMethodV5 = "engine_getPayloadV5"
 	// BlockByHashMethod request string for JSON-RPC.
 	BlockByHashMethod = "eth_getBlockByHash"
 	// BlockByNumberMethod request string for JSON-RPC.
@@ -85,11 +93,21 @@ const (
 	ExchangeCapabilities = "engine_exchangeCapabilities"
 	// GetBlobsV1 request string for JSON-RPC.
 	GetBlobsV1 = "engine_getBlobsV1"
+	// GetBlobsV2 request string for JSON-RPC.
+	GetBlobsV2 = "engine_getBlobsV2"
 	// Defines the seconds before timing out engine endpoints with non-block execution semantics.
-	defaultEngineTimeout = time.Second
+	// TODO: Remove temporarily needed hack since geth takes an input blobs txs with blobs proofs, and
+	// does the heavy lifting of building cells proofs, while normally this is done by the tx sender.
+	// This is a cool hack because it lets the CL to act as if the tx sender actually computed the cells proofs.
+	// The only counter part is the `engine_getPayloadv<x>` takes a lot of time.
+	// defaultEngineTimeout = time.Second
+	defaultEngineTimeout = 2 * time.Second
 )
 
-var errInvalidPayloadBodyResponse = errors.New("engine api payload body response is invalid")
+var (
+	errInvalidPayloadBodyResponse  = errors.New("engine api payload body response is invalid")
+	errMissingBlobsAndProofsFromEL = errors.New("engine api payload body response is missing blobs and proofs")
+)
 
 // ForkchoiceUpdatedResponse is the response kind received by the
 // engine_forkchoiceUpdatedV1 endpoint.
@@ -108,6 +126,7 @@ type Reconstructor interface {
 		ctx context.Context, blindedBlocks []interfaces.ReadOnlySignedBeaconBlock,
 	) ([]interfaces.SignedBeaconBlock, error)
 	ReconstructBlobSidecars(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, hi func(uint64) bool) ([]blocks.VerifiedROBlob, error)
+	ReconstructDataColumnSidecars(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) ([]blocks.VerifiedRODataColumn, error)
 }
 
 // EngineCaller defines a client that can interact with an Ethereum
@@ -257,6 +276,9 @@ func (s *Service) ForkchoiceUpdated(
 
 func getPayloadMethodAndMessage(slot primitives.Slot) (string, proto.Message) {
 	pe := slots.ToEpoch(slot)
+	if pe >= params.BeaconConfig().FuluForkEpoch {
+		return GetPayloadMethodV5, &pb.ExecutionBundleFulu{}
+	}
 	if pe >= params.BeaconConfig().ElectraForkEpoch {
 		return GetPayloadMethodV4, &pb.ExecutionBundleElectra{}
 	}
@@ -289,7 +311,7 @@ func (s *Service) GetPayload(ctx context.Context, payloadId [8]byte, slot primit
 	}
 	res, err := blocks.NewGetPayloadResponse(result)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "new get payload response")
 	}
 	return res, nil
 }
@@ -302,6 +324,9 @@ func (s *Service) ExchangeCapabilities(ctx context.Context) ([]string, error) {
 	if params.ElectraEnabled() {
 		supportedEngineEndpoints = append(supportedEngineEndpoints, electraEngineEndpoints...)
 	}
+	if params.FuluEnabled() {
+		supportedEngineEndpoints = append(supportedEngineEndpoints, fuluEngineEndpoints...)
+	}
 	var result []string
 	err := s.rpcClient.CallContext(ctx, &result, ExchangeCapabilities, supportedEngineEndpoints)
 	if err != nil {
@@ -495,9 +520,10 @@ func (s *Service) HeaderByNumber(ctx context.Context, number *big.Int) (*types.H
 func (s *Service) GetBlobs(ctx context.Context, versionedHashes []common.Hash) ([]*pb.BlobAndProof, error) {
 	ctx, span := trace.StartSpan(ctx, "powchain.engine-api-client.GetBlobs")
 	defer span.End()
+
 	// If the execution engine does not support `GetBlobsV1`, return early to prevent encountering an error later.
 	if !s.capabilityCache.has(GetBlobsV1) {
-		return nil, nil
+		return nil, errors.New(fmt.Sprintf("%s is not supported", GetBlobsV1))
 	}
 
 	result := make([]*pb.BlobAndProof, len(versionedHashes))
@@ -505,6 +531,19 @@ func (s *Service) GetBlobs(ctx context.Context, versionedHashes []common.Hash) (
 	return result, handleRPCError(err)
 }
 
+func (s *Service) GetBlobsV2(ctx context.Context, versionedHashes []common.Hash) ([]*pb.BlobAndProofV2, error) {
+	ctx, span := trace.StartSpan(ctx, "powchain.engine-api-client.GetBlobsV2")
+	defer span.End()
+
+	if !s.capabilityCache.has(GetBlobsV2) {
+		return nil, errors.New(fmt.Sprintf("%s is not supported", GetBlobsV2))
+	}
+
+	result := make([]*pb.BlobAndProofV2, len(versionedHashes))
+	err := s.rpcClient.CallContext(ctx, &result, GetBlobsV2, versionedHashes)
+	return result, handleRPCError(err)
+}
+
 // ReconstructFullBlock takes in a blinded beacon block and reconstructs
 // a beacon block with a full execution payload via the engine API.
 func (s *Service) ReconstructFullBlock(
@@ -615,6 +654,73 @@ func (s *Service) ReconstructBlobSidecars(ctx context.Context, block interfaces.
 	return verifiedBlobs, nil
 }
 
+// ReconstructDataColumnSidecars reconstructs the verified data column sidecars for a given beacon block.
+// It retrieves the KZG commitments from the block body, fetches the associated blobs and cell proofs from the EL,
+// and constructs the corresponding verified read-only data column sidecars.
+func (s *Service) ReconstructDataColumnSidecars(ctx context.Context, signedROBlock interfaces.ReadOnlySignedBeaconBlock, blockRoot [fieldparams.RootLength]byte) ([]blocks.VerifiedRODataColumn, error) {
+	block := signedROBlock.Block()
+
+	log := log.WithFields(logrus.Fields{
+		"root": fmt.Sprintf("%#x", blockRoot),
+		"slot": block.Slot(),
+	})
+
+	kzgCommitments, err := block.Body().BlobKzgCommitments()
+	if err != nil {
+		return nil, wrapWithBlockRoot(err, blockRoot, "blob KZG commitments")
+	}
+
+	// Collect KZG hashes for all blobs
+	var kzgHashes []common.Hash
+	for _, commitment := range kzgCommitments {
+		kzgHashes = append(kzgHashes, primitives.ConvertKzgCommitmentToVersionedHash(commitment))
+	}
+
+	// Fetch all blobsAndCellsProofs from EL
+	blobAndProofV2s, err := s.GetBlobsV2(ctx, kzgHashes)
+	if err != nil {
+		return nil, wrapWithBlockRoot(err, blockRoot, "get blobs V2")
+	}
+
+	// Return early if nothing is returned from the EL.
+	if len(blobAndProofV2s) == 0 {
+		log.Debug("No blobs returned from EL")
+		return nil, nil
+	}
+
+	// Extract the blobs and proofs from the blobAndProofV2s.
+	blobs := make([][]byte, 0, len(blobAndProofV2s))
+	cellProofs := make([][]byte, 0, len(blobAndProofV2s))
+	for _, blobsAndProofs := range blobAndProofV2s {
+		if blobsAndProofs == nil {
+			return nil, wrapWithBlockRoot(errMissingBlobsAndProofsFromEL, blockRoot, "")
+		}
+		blobs = append(blobs, blobsAndProofs.Blob)
+		cellProofs = append(cellProofs, blobsAndProofs.KzgProofs...)
+	}
+
+	dataColumnSidecars, err := peerdas.ConstructDataColumnSidecars(signedROBlock, blobs, cellProofs)
+	if err != nil {
+		return nil, wrapWithBlockRoot(err, blockRoot, "construct data column sidecars")
+	}
+
+	verifiedRODataColumns := make([]blocks.VerifiedRODataColumn, 0, len(dataColumnSidecars))
+	for _, dataColumnSidecar := range dataColumnSidecars {
+		roDataColumn, err := blocks.NewRODataColumnWithRoot(dataColumnSidecar, blockRoot)
+		if err != nil {
+			return nil, wrapWithBlockRoot(err, blockRoot, "new read-only data column with root")
+		}
+
+		// We trust the execution layer we are connected to, so we can upgrade the read only data column sidecar into a verified one.
+		verifiedRODataColumn := blocks.NewVerifiedRODataColumn(roDataColumn)
+		verifiedRODataColumns = append(verifiedRODataColumns, verifiedRODataColumn)
+	}
+
+	log.Debug("Data columns successfully reconstructed from EL")
+
+	return verifiedRODataColumns, nil
+}
+
 func fullPayloadFromPayloadBody(
 	header interfaces.ExecutionData, body *pb.ExecutionPayloadBody, bVersion int,
 ) (interfaces.ExecutionData, error) {
@@ -902,3 +1008,8 @@ func toBlockNumArg(number *big.Int) string {
 	}
 	return hexutil.EncodeBig(number)
 }
+
+// wrapWithBlockRoot returns a new error with the given block root.
+func wrapWithBlockRoot(err error, blockRoot [32]byte, message string) error {
+	return errors.Wrap(err, fmt.Sprintf("%s for block %#x", message, blockRoot))
+}

beacon-chain/execution/engine_client_test.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	mocks "github.com/OffchainLabs/prysm/v6/beacon-chain/execution/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
@@ -167,6 +168,7 @@ func TestClient_HTTP(t *testing.T) {
 	cfg.CapellaForkEpoch = 1
 	cfg.DenebForkEpoch = 2
 	cfg.ElectraForkEpoch = 3
+	cfg.FuluForkEpoch = 4
 	params.OverrideBeaconConfig(cfg)
 
 	t.Run(GetPayloadMethod, func(t *testing.T) {
@@ -317,11 +319,11 @@ func TestClient_HTTP(t *testing.T) {
 		require.DeepEqual(t, uint64(2), g)
 
 		commitments := [][]byte{bytesutil.PadTo([]byte("commitment1"), fieldparams.BLSPubkeyLength), bytesutil.PadTo([]byte("commitment2"), fieldparams.BLSPubkeyLength)}
-		require.DeepEqual(t, commitments, resp.BlobsBundle.KzgCommitments)
+		require.DeepEqual(t, commitments, resp.BlobsBundler.GetKzgCommitments())
 		proofs := [][]byte{bytesutil.PadTo([]byte("proof1"), fieldparams.BLSPubkeyLength), bytesutil.PadTo([]byte("proof2"), fieldparams.BLSPubkeyLength)}
-		require.DeepEqual(t, proofs, resp.BlobsBundle.Proofs)
+		require.DeepEqual(t, proofs, resp.BlobsBundler.GetProofs())
 		blobs := [][]byte{bytesutil.PadTo([]byte("a"), fieldparams.BlobLength), bytesutil.PadTo([]byte("b"), fieldparams.BlobLength)}
-		require.DeepEqual(t, blobs, resp.BlobsBundle.Blobs)
+		require.DeepEqual(t, blobs, resp.BlobsBundler.GetBlobs())
 	})
 	t.Run(GetPayloadMethodV4, func(t *testing.T) {
 		payloadId := [8]byte{1}
@@ -372,11 +374,11 @@ func TestClient_HTTP(t *testing.T) {
 		require.DeepEqual(t, uint64(2), g)
 
 		commitments := [][]byte{bytesutil.PadTo([]byte("commitment1"), fieldparams.BLSPubkeyLength), bytesutil.PadTo([]byte("commitment2"), fieldparams.BLSPubkeyLength)}
-		require.DeepEqual(t, commitments, resp.BlobsBundle.KzgCommitments)
+		require.DeepEqual(t, commitments, resp.BlobsBundler.GetKzgCommitments())
 		proofs := [][]byte{bytesutil.PadTo([]byte("proof1"), fieldparams.BLSPubkeyLength), bytesutil.PadTo([]byte("proof2"), fieldparams.BLSPubkeyLength)}
-		require.DeepEqual(t, proofs, resp.BlobsBundle.Proofs)
+		require.DeepEqual(t, proofs, resp.BlobsBundler.GetProofs())
 		blobs := [][]byte{bytesutil.PadTo([]byte("a"), fieldparams.BlobLength), bytesutil.PadTo([]byte("b"), fieldparams.BlobLength)}
-		require.DeepEqual(t, blobs, resp.BlobsBundle.Blobs)
+		require.DeepEqual(t, blobs, resp.BlobsBundler.GetBlobs())
 		requests := &pb.ExecutionRequests{
 			Deposits: []*pb.DepositRequest{
 				{
@@ -405,7 +407,52 @@ func TestClient_HTTP(t *testing.T) {
 
 		require.DeepEqual(t, requests, resp.ExecutionRequests)
 	})
+	t.Run(GetPayloadMethodV5, func(t *testing.T) {
+		payloadId := [8]byte{1}
+		want, ok := fix["ExecutionBundleFulu"].(*pb.GetPayloadV5ResponseJson)
+		require.Equal(t, true, ok)
+		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Content-Type", "application/json")
+			defer func() {
+				require.NoError(t, r.Body.Close())
+			}()
+			enc, err := io.ReadAll(r.Body)
+			require.NoError(t, err)
+			jsonRequestString := string(enc)
 
+			reqArg, err := json.Marshal(pb.PayloadIDBytes(payloadId))
+			require.NoError(t, err)
+
+			// We expect the JSON string RPC request contains the right arguments.
+			require.Equal(t, true, strings.Contains(
+				jsonRequestString, string(reqArg),
+			))
+			resp := map[string]interface{}{
+				"jsonrpc": "2.0",
+				"id":      1,
+				"result":  want,
+			}
+			err = json.NewEncoder(w).Encode(resp)
+			require.NoError(t, err)
+		}))
+		defer srv.Close()
+
+		rpcClient, err := rpc.DialHTTP(srv.URL)
+		require.NoError(t, err)
+		defer rpcClient.Close()
+
+		client := &Service{}
+		client.rpcClient = rpcClient
+
+		// We call the RPC method via HTTP and expect a proper result.
+		resp, err := client.GetPayload(ctx, payloadId, 4*params.BeaconConfig().SlotsPerEpoch)
+		require.NoError(t, err)
+		_, ok = resp.BlobsBundler.(*pb.BlobsBundleV2)
+		if !ok {
+			t.Logf("resp.BlobsBundler has unexpected type: %T", resp.BlobsBundler)
+		}
+		require.Equal(t, ok, true)
+	})
 	t.Run(ForkchoiceUpdatedMethod+" VALID status", func(t *testing.T) {
 		forkChoiceState := &pb.ForkchoiceState{
 			HeadBlockHash:      []byte("head"),
@@ -1539,6 +1586,7 @@ func fixtures() map[string]interface{} {
 		"ExecutionPayloadCapellaWithValue":  s.ExecutionPayloadWithValueCapella,
 		"ExecutionPayloadDenebWithValue":    s.ExecutionPayloadWithValueDeneb,
 		"ExecutionBundleElectra":            s.ExecutionBundleElectra,
+		"ExecutionBundleFulu":               s.ExecutionBundleFulu,
 		"ValidPayloadStatus":                s.ValidPayloadStatus,
 		"InvalidBlockHashStatus":            s.InvalidBlockHashStatus,
 		"AcceptedStatus":                    s.AcceptedStatus,
@@ -1774,6 +1822,36 @@ func fixturesStruct() *payloadFixtures {
 			append([]byte{pb.WithdrawalRequestType}, withdrawalRequestBytes...),
 			append([]byte{pb.ConsolidationRequestType}, consolidationRequestBytes...)},
 	}
+	executionBundleFixtureFulu := &pb.GetPayloadV5ResponseJson{
+		ShouldOverrideBuilder: true,
+		ExecutionPayload: &pb.ExecutionPayloadDenebJSON{
+			ParentHash:    &common.Hash{'a'},
+			FeeRecipient:  &common.Address{'b'},
+			StateRoot:     &common.Hash{'c'},
+			ReceiptsRoot:  &common.Hash{'d'},
+			LogsBloom:     &hexutil.Bytes{'e'},
+			PrevRandao:    &common.Hash{'f'},
+			BaseFeePerGas: "0x123",
+			BlockHash:     &common.Hash{'g'},
+			Transactions:  []hexutil.Bytes{{'h'}},
+			Withdrawals:   []*pb.Withdrawal{},
+			BlockNumber:   &hexUint,
+			GasLimit:      &hexUint,
+			GasUsed:       &hexUint,
+			Timestamp:     &hexUint,
+			BlobGasUsed:   &bgu,
+			ExcessBlobGas: &ebg,
+		},
+		BlockValue: "0x11fffffffff",
+		BlobsBundle: &pb.BlobBundleV2JSON{
+			Commitments: []hexutil.Bytes{[]byte("commitment1"), []byte("commitment2")},
+			Proofs:      []hexutil.Bytes{[]byte("proof1"), []byte("proof2")},
+			Blobs:       []hexutil.Bytes{{'a'}, {'b'}},
+		},
+		ExecutionRequests: []hexutil.Bytes{append([]byte{pb.DepositRequestType}, depositRequestBytes...),
+			append([]byte{pb.WithdrawalRequestType}, withdrawalRequestBytes...),
+			append([]byte{pb.ConsolidationRequestType}, consolidationRequestBytes...)},
+	}
 	parent := bytesutil.PadTo([]byte("parentHash"), fieldparams.RootLength)
 	sha3Uncles := bytesutil.PadTo([]byte("sha3Uncles"), fieldparams.RootLength)
 	miner := bytesutil.PadTo([]byte("miner"), fieldparams.FeeRecipientLength)
@@ -1868,6 +1946,7 @@ func fixturesStruct() *payloadFixtures {
 		ExecutionPayloadWithValueCapella:  executionPayloadWithValueFixtureCapella,
 		ExecutionPayloadWithValueDeneb:    executionPayloadWithValueFixtureDeneb,
 		ExecutionBundleElectra:            executionBundleFixtureElectra,
+		ExecutionBundleFulu:               executionBundleFixtureFulu,
 		ValidPayloadStatus:                validStatus,
 		InvalidBlockHashStatus:            inValidBlockHashStatus,
 		AcceptedStatus:                    acceptedStatus,
@@ -1892,6 +1971,7 @@ type payloadFixtures struct {
 	ExecutionPayloadWithValueCapella  *pb.GetPayloadV2ResponseJson
 	ExecutionPayloadWithValueDeneb    *pb.GetPayloadV3ResponseJson
 	ExecutionBundleElectra            *pb.GetPayloadV4ResponseJson
+	ExecutionBundleFulu               *pb.GetPayloadV5ResponseJson
 	ValidPayloadStatus                *pb.PayloadStatus
 	InvalidBlockHashStatus            *pb.PayloadStatus
 	AcceptedStatus                    *pb.PayloadStatus
@@ -2424,7 +2504,7 @@ func TestReconstructBlobSidecars(t *testing.T) {
 	t.Run("get-blobs end point is not supported", func(t *testing.T) {
 		hi := mockSummary(t, []bool{true, true, true, true, true, false})
 		verifiedBlobs, err := client.ReconstructBlobSidecars(ctx, sb, r, hi)
-		require.NoError(t, err)
+		require.ErrorContains(t, "engine_getBlobsV1 is not supported", err)
 		require.Equal(t, 0, len(verifiedBlobs))
 	})
 
@@ -2476,6 +2556,76 @@ func TestReconstructBlobSidecars(t *testing.T) {
 	})
 }
 
+func TestReconstructDataColumnSidecars(t *testing.T) {
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	// Setup right fork epoch
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig().Copy()
+	cfg.CapellaForkEpoch = 1
+	cfg.DenebForkEpoch = 2
+	cfg.ElectraForkEpoch = 3
+	cfg.FuluForkEpoch = 4
+	params.OverrideBeaconConfig(cfg)
+
+	client := &Service{capabilityCache: &capabilityCache{}}
+	b := util.NewBeaconBlockFulu()
+	b.Block.Slot = 4 * params.BeaconConfig().SlotsPerEpoch
+	kzgCommitments := createRandomKzgCommitments(t, 6)
+	b.Block.Body.BlobKzgCommitments = kzgCommitments
+	r, err := b.Block.HashTreeRoot()
+	require.NoError(t, err)
+	sb, err := blocks.NewSignedBeaconBlock(b)
+	require.NoError(t, err)
+
+	ctx := context.Background()
+
+	t.Run("GetBlobsV2 is not supported", func(t *testing.T) {
+		_, err := client.ReconstructDataColumnSidecars(ctx, sb, r)
+		require.ErrorContains(t, "get blobs V2 for block", err)
+	})
+
+	t.Run("nothing received", func(t *testing.T) {
+		srv := createBlobServerV2(t, 0, []bool{})
+		defer srv.Close()
+
+		rpcClient, client := setupRpcClientV2(t, srv.URL, client)
+		defer rpcClient.Close()
+
+		dataColumns, err := client.ReconstructDataColumnSidecars(ctx, sb, r)
+		require.NoError(t, err)
+		require.Equal(t, 0, len(dataColumns))
+	})
+
+	t.Run("receiving all blobs", func(t *testing.T) {
+		blobMasks := []bool{true, true, true, true, true, true}
+		srv := createBlobServerV2(t, 6, blobMasks)
+		defer srv.Close()
+
+		rpcClient, client := setupRpcClientV2(t, srv.URL, client)
+		defer rpcClient.Close()
+
+		dataColumns, err := client.ReconstructDataColumnSidecars(ctx, sb, r)
+		require.NoError(t, err)
+		require.Equal(t, 128, len(dataColumns))
+	})
+
+	t.Run("missing some blobs", func(t *testing.T) {
+		blobMasks := []bool{false, true, true, true, true, true}
+		srv := createBlobServerV2(t, 6, blobMasks)
+		defer srv.Close()
+
+		rpcClient, client := setupRpcClientV2(t, srv.URL, client)
+		defer rpcClient.Close()
+
+		dataColumns, err := client.ReconstructDataColumnSidecars(ctx, sb, r)
+		require.ErrorContains(t, errMissingBlobsAndProofsFromEL.Error(), err)
+		require.Equal(t, 0, len(dataColumns))
+	})
+}
+
 func createRandomKzgCommitments(t *testing.T, num int) [][]byte {
 	kzgCommitments := make([][]byte, num)
 	for i := range kzgCommitments {
@@ -2511,6 +2661,42 @@ func createBlobServer(t *testing.T, numBlobs int, callbackFuncs ...func()) *http
 	}))
 }
 
+func createBlobServerV2(t *testing.T, numBlobs int, blobMasks []bool) *httptest.Server {
+	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		defer func() {
+			require.NoError(t, r.Body.Close())
+		}()
+
+		require.Equal(t, len(blobMasks), numBlobs)
+
+		blobAndCellProofs := make([]*pb.BlobAndProofV2Json, numBlobs)
+		for i := range blobAndCellProofs {
+			if !blobMasks[i] {
+				continue
+			}
+
+			blobAndCellProofs[i] = &pb.BlobAndProofV2Json{
+				Blob:      []byte("0xblob"),
+				KzgProofs: []hexutil.Bytes{},
+			}
+			for j := 0; j < int(params.BeaconConfig().NumberOfColumns); j++ {
+				cellProof := make([]byte, 48)
+				blobAndCellProofs[i].KzgProofs = append(blobAndCellProofs[i].KzgProofs, cellProof)
+			}
+		}
+
+		respJSON := map[string]interface{}{
+			"jsonrpc": "2.0",
+			"id":      1,
+			"result":  blobAndCellProofs,
+		}
+
+		err := json.NewEncoder(w).Encode(respJSON)
+		require.NoError(t, err)
+	}))
+}
+
 func setupRpcClient(t *testing.T, url string, client *Service) (*rpc.Client, *Service) {
 	rpcClient, err := rpc.DialHTTP(url)
 	require.NoError(t, err)
@@ -2522,6 +2708,12 @@ func setupRpcClient(t *testing.T, url string, client *Service) (*rpc.Client, *Se
 	return rpcClient, client
 }
 
+func setupRpcClientV2(t *testing.T, url string, client *Service) (*rpc.Client, *Service) {
+	rpcClient, client := setupRpcClient(t, url, client)
+	client.capabilityCache = &capabilityCache{capabilities: map[string]interface{}{GetBlobsV2: nil}}
+	return rpcClient, client
+}
+
 func testNewBlobVerifier() verification.NewBlobVerifier {
 	return func(b blocks.ROBlob, reqs []verification.Requirement) verification.BlobVerifier {
 		return &verification.MockBlobVerifier{

beacon-chain/execution/testing/mock_engine_client.go

@@ -38,6 +38,8 @@ type EngineClient struct {
 	ErrGetPayload               error
 	BlobSidecars                []blocks.VerifiedROBlob
 	ErrorBlobSidecars           error
+	DataColumnSidecars          []blocks.VerifiedRODataColumn
+	ErrorDataColumnSidecars     error
 }
 
 // NewPayload --
@@ -113,6 +115,10 @@ func (e *EngineClient) ReconstructBlobSidecars(context.Context, interfaces.ReadO
 	return e.BlobSidecars, e.ErrorBlobSidecars
 }
 
+func (e *EngineClient) ReconstructDataColumnSidecars(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) ([]blocks.VerifiedRODataColumn, error) {
+	return e.DataColumnSidecars, e.ErrorDataColumnSidecars
+}
+
 // GetTerminalBlockHash --
 func (e *EngineClient) GetTerminalBlockHash(ctx context.Context, transitionTime uint64) ([]byte, bool, error) {
 	ttd := new(big.Int)

beacon-chain/node/BUILD.bazel

@@ -23,6 +23,7 @@ go_library(
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/cache/depositsnapshot:go_default_library",
         "//beacon-chain/core/light-client:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/db/kv:go_default_library",

beacon-chain/node/node.go

@@ -25,6 +25,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache/depositsnapshot"
 	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/kv"
@@ -86,44 +87,47 @@ type serviceFlagOpts struct {
 // full PoS node. It handles the lifecycle of the entire system and registers
 // services to a service registry.
 type BeaconNode struct {
-	cliCtx                  *cli.Context
-	ctx                     context.Context
-	cancel                  context.CancelFunc
-	services                *runtime.ServiceRegistry
-	lock                    sync.RWMutex
-	stop                    chan struct{} // Channel to wait for termination notifications.
-	db                      db.Database
-	slasherDB               db.SlasherDatabase
-	attestationCache        *cache.AttestationCache
-	attestationPool         attestations.Pool
-	exitPool                voluntaryexits.PoolManager
-	slashingsPool           slashings.PoolManager
-	syncCommitteePool       synccommittee.Pool
-	blsToExecPool           blstoexec.PoolManager
-	depositCache            cache.DepositCache
-	trackedValidatorsCache  *cache.TrackedValidatorsCache
-	payloadIDCache          *cache.PayloadIDCache
-	stateFeed               *event.Feed
-	blockFeed               *event.Feed
-	opFeed                  *event.Feed
-	stateGen                *stategen.State
-	collector               *bcnodeCollector
-	slasherBlockHeadersFeed *event.Feed
-	slasherAttestationsFeed *event.Feed
-	finalizedStateAtStartUp state.BeaconState
-	serviceFlagOpts         *serviceFlagOpts
-	GenesisInitializer      genesis.Initializer
-	CheckpointInitializer   checkpoint.Initializer
-	forkChoicer             forkchoice.ForkChoicer
-	clockWaiter             startup.ClockWaiter
-	BackfillOpts            []backfill.ServiceOption
-	initialSyncComplete     chan struct{}
-	BlobStorage             *filesystem.BlobStorage
-	BlobStorageOptions      []filesystem.BlobStorageOption
-	verifyInitWaiter        *verification.InitializerWaiter
-	syncChecker             *initialsync.SyncChecker
-	slasherEnabled          bool
-	lcStore                 *lightclient.Store
+	cliCtx                   *cli.Context
+	ctx                      context.Context
+	cancel                   context.CancelFunc
+	services                 *runtime.ServiceRegistry
+	lock                     sync.RWMutex
+	stop                     chan struct{} // Channel to wait for termination notifications.
+	db                       db.Database
+	slasherDB                db.SlasherDatabase
+	attestationCache         *cache.AttestationCache
+	attestationPool          attestations.Pool
+	exitPool                 voluntaryexits.PoolManager
+	slashingsPool            slashings.PoolManager
+	syncCommitteePool        synccommittee.Pool
+	blsToExecPool            blstoexec.PoolManager
+	depositCache             cache.DepositCache
+	trackedValidatorsCache   *cache.TrackedValidatorsCache
+	payloadIDCache           *cache.PayloadIDCache
+	stateFeed                *event.Feed
+	blockFeed                *event.Feed
+	opFeed                   *event.Feed
+	stateGen                 *stategen.State
+	collector                *bcnodeCollector
+	slasherBlockHeadersFeed  *event.Feed
+	slasherAttestationsFeed  *event.Feed
+	finalizedStateAtStartUp  state.BeaconState
+	serviceFlagOpts          *serviceFlagOpts
+	GenesisInitializer       genesis.Initializer
+	CheckpointInitializer    checkpoint.Initializer
+	forkChoicer              forkchoice.ForkChoicer
+	clockWaiter              startup.ClockWaiter
+	BackfillOpts             []backfill.ServiceOption
+	initialSyncComplete      chan struct{}
+	BlobStorage              *filesystem.BlobStorage
+	BlobStorageOptions       []filesystem.BlobStorageOption
+	DataColumnStorage        *filesystem.DataColumnStorage
+	DataColumnStorageOptions []filesystem.DataColumnStorageOption
+	custodyInfo              *peerdas.CustodyInfo
+	verifyInitWaiter         *verification.InitializerWaiter
+	syncChecker              *initialsync.SyncChecker
+	slasherEnabled           bool
+	lcStore                  *lightclient.Store
 }
 
 // New creates a new node instance, sets up configuration options, and registers
@@ -161,6 +165,7 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 		serviceFlagOpts:         &serviceFlagOpts{},
 		initialSyncComplete:     make(chan struct{}),
 		syncChecker:             &initialsync.SyncChecker{},
+		custodyInfo:             &peerdas.CustodyInfo{},
 		slasherEnabled:          cliCtx.Bool(flags.SlasherFlag.Name),
 		lcStore:                 &lightclient.Store{},
 	}
@@ -190,6 +195,15 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 		beacon.BlobStorage = blobs
 	}
 
+	if beacon.DataColumnStorage == nil {
+		dataColumnStorage, err := filesystem.NewDataColumnStorage(cliCtx.Context, beacon.DataColumnStorageOptions...)
+		if err != nil {
+			return nil, errors.Wrap(err, "new data column storage")
+		}
+
+		beacon.DataColumnStorage = dataColumnStorage
+	}
+
 	bfs, err := startBaseServices(cliCtx, beacon, depositAddress)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not start modules")
@@ -202,6 +216,7 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 		beacon.BackfillOpts,
 		backfill.WithVerifierWaiter(beacon.verifyInitWaiter),
 		backfill.WithInitSyncWaiter(initSyncWaiter(ctx, beacon.initialSyncComplete)),
+		backfill.WithCustodyInfo(beacon.custodyInfo),
 	)
 
 	if err := registerServices(cliCtx, beacon, synchronizer, bfs); err != nil {
@@ -280,7 +295,9 @@ func startBaseServices(cliCtx *cli.Context, beacon *BeaconNode, depositAddress s
 	if err := beacon.startDB(cliCtx, depositAddress); err != nil {
 		return nil, errors.Wrap(err, "could not start DB")
 	}
+
 	beacon.BlobStorage.WarmCache()
+	beacon.DataColumnStorage.WarmCache()
 
 	log.Debugln("Starting Slashing DB")
 	if err := beacon.startSlasherDB(cliCtx); err != nil {
@@ -491,6 +508,10 @@ func (b *BeaconNode) clearDB(clearDB, forceClearDB bool, d *kv.Store, dbPath str
 			return nil, errors.Wrap(err, "could not clear blob storage")
 		}
 
+		if err := b.DataColumnStorage.Clear(); err != nil {
+			return nil, errors.Wrap(err, "could not clear data column storage")
+		}
+
 		d, err = kv.NewKVStore(b.ctx, dbPath)
 		if err != nil {
 			return nil, errors.Wrap(err, "could not create new database")
@@ -697,6 +718,7 @@ func (b *BeaconNode) registerP2P(cliCtx *cli.Context) error {
 		StateNotifier:        b,
 		DB:                   b.db,
 		ClockWaiter:          b.clockWaiter,
+		CustodyInfo:          b.custodyInfo,
 	})
 	if err != nil {
 		return err
@@ -775,9 +797,11 @@ func (b *BeaconNode) registerBlockchainService(fc forkchoice.ForkChoicer, gs *st
 		blockchain.WithClockSynchronizer(gs),
 		blockchain.WithSyncComplete(syncComplete),
 		blockchain.WithBlobStorage(b.BlobStorage),
+		blockchain.WithDataColumnStorage(b.DataColumnStorage),
 		blockchain.WithTrackedValidatorsCache(b.trackedValidatorsCache),
 		blockchain.WithPayloadIDCache(b.payloadIDCache),
 		blockchain.WithSyncChecker(b.syncChecker),
+		blockchain.WithCustodyInfo(b.custodyInfo),
 		blockchain.WithSlasherEnabled(b.slasherEnabled),
 		blockchain.WithLightClientStore(b.lcStore),
 	)
@@ -862,8 +886,11 @@ func (b *BeaconNode) registerSyncService(initialSyncComplete chan struct{}, bFil
 		regularsync.WithInitialSyncComplete(initialSyncComplete),
 		regularsync.WithStateNotifier(b),
 		regularsync.WithBlobStorage(b.BlobStorage),
+		regularsync.WithDataColumnStorage(b.DataColumnStorage),
 		regularsync.WithVerifierWaiter(b.verifyInitWaiter),
 		regularsync.WithAvailableBlocker(bFillStore),
+		regularsync.WithTrackedValidatorsCache(b.trackedValidatorsCache),
+		regularsync.WithCustodyInfo(b.custodyInfo),
 		regularsync.WithSlasherEnabled(b.slasherEnabled),
 		regularsync.WithLightClientStore(b.lcStore),
 	)
@@ -889,6 +916,8 @@ func (b *BeaconNode) registerInitialSyncService(complete chan struct{}) error {
 		ClockWaiter:         b.clockWaiter,
 		InitialSyncComplete: complete,
 		BlobStorage:         b.BlobStorage,
+		DataColumnStorage:   b.DataColumnStorage,
+		CustodyInfo:         b.custodyInfo,
 	}, opts...)
 	return b.services.RegisterService(is)
 }
@@ -983,6 +1012,7 @@ func (b *BeaconNode) registerRPCService(router *http.ServeMux) error {
 		FinalizationFetcher:       chainService,
 		BlockReceiver:             chainService,
 		BlobReceiver:              chainService,
+		DataColumnReceiver:        chainService,
 		AttestationReceiver:       chainService,
 		GenesisTimeFetcher:        chainService,
 		GenesisFetcher:            chainService,
@@ -1010,6 +1040,7 @@ func (b *BeaconNode) registerRPCService(router *http.ServeMux) error {
 		Router:                    router,
 		ClockWaiter:               b.clockWaiter,
 		BlobStorage:               b.BlobStorage,
+		DataColumnStorage:         b.DataColumnStorage,
 		TrackedValidatorsCache:    b.trackedValidatorsCache,
 		PayloadIDCache:            b.payloadIDCache,
 		LCStore:                   b.lcStore,
@@ -1151,7 +1182,8 @@ func (b *BeaconNode) registerPrunerService(cliCtx *cli.Context) error {
 
 func (b *BeaconNode) RegisterBackfillService(cliCtx *cli.Context, bfs *backfill.Store) error {
 	pa := peers.NewAssigner(b.fetchP2P().Peers(), b.forkChoicer)
-	bf, err := backfill.NewService(cliCtx.Context, bfs, b.BlobStorage, b.clockWaiter, b.fetchP2P(), pa, b.BackfillOpts...)
+	// TODO: Add backfill for data column storage
+	bf, err := backfill.NewService(cliCtx.Context, bfs, b.BlobStorage, b.DataColumnStorage, b.clockWaiter, b.fetchP2P(), pa, b.BackfillOpts...)
 	if err != nil {
 		return errors.Wrap(err, "error initializing backfill service")
 	}

beacon-chain/node/node_test.go

@@ -54,7 +54,7 @@ func TestNodeClose_OK(t *testing.T) {
 	cmd.ValidatorMonitorIndicesFlag.Value.SetInt(1)
 	ctx, cancel := newCliContextWithCancel(&app, set)
 
-	node, err := New(ctx, cancel, WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)))
+	node, err := New(ctx, cancel, WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)), WithDataColumnStorage(filesystem.NewEphemeralDataColumnStorage(t)))
 	require.NoError(t, err)
 
 	node.Close()
@@ -75,7 +75,7 @@ func TestNodeStart_Ok(t *testing.T) {
 	node, err := New(ctx, cancel, WithBlockchainFlagOptions([]blockchain.Option{}),
 		WithBuilderFlagOptions([]builder.Option{}),
 		WithExecutionChainOptions([]execution.Option{}),
-		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)))
+		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)), WithDataColumnStorage(filesystem.NewEphemeralDataColumnStorage(t)))
 	require.NoError(t, err)
 	node.services = &runtime.ServiceRegistry{}
 	go func() {
@@ -99,7 +99,7 @@ func TestNodeStart_SyncChecker(t *testing.T) {
 	node, err := New(ctx, cancel, WithBlockchainFlagOptions([]blockchain.Option{}),
 		WithBuilderFlagOptions([]builder.Option{}),
 		WithExecutionChainOptions([]execution.Option{}),
-		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)))
+		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)), WithDataColumnStorage(filesystem.NewEphemeralDataColumnStorage(t)))
 	require.NoError(t, err)
 	go func() {
 		node.Start()
@@ -130,7 +130,7 @@ func TestClearDB(t *testing.T) {
 	context, cancel := newCliContextWithCancel(&app, set)
 	options := []Option{
 		WithExecutionChainOptions([]execution.Option{execution.WithHttpEndpoint(endpoint)}),
-		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)),
+		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)), WithDataColumnStorage(filesystem.NewEphemeralDataColumnStorage(t)),
 	}
 	_, err = New(context, cancel, options...)
 	require.NoError(t, err)

beacon-chain/node/options.go

@@ -50,3 +50,20 @@ func WithBlobStorageOptions(opt ...filesystem.BlobStorageOption) Option {
 		return nil
 	}
 }
+
+// WithDataColumnStorage sets the DataColumnStorage backend for the BeaconNode
+func WithDataColumnStorage(bs *filesystem.DataColumnStorage) Option {
+	return func(bn *BeaconNode) error {
+		bn.DataColumnStorage = bs
+		return nil
+	}
+}
+
+// WithDataColumnStorageOptions appends 1 or more filesystem.DataColumnStorageOption on the beacon node,
+// to be used when initializing data column storage.
+func WithDataColumnStorageOptions(opt ...filesystem.DataColumnStorageOption) Option {
+	return func(bn *BeaconNode) error {
+		bn.DataColumnStorageOptions = append(bn.DataColumnStorageOptions, opt...)
+		return nil
+	}
+}

beacon-chain/p2p/discovery.go

@@ -222,7 +222,6 @@ func (s *Service) RefreshPersistentSubnets() {
 	// Get the sync subnet bitfield in our metadata.
 	currentBitSInMetadata := s.Metadata().SyncnetsBitfield()
 
-	// Is our sync bitvector record up to date?
 	isBitSUpToDate := bytes.Equal(bitS, inRecordBitS) && bytes.Equal(bitS, currentBitSInMetadata)
 
 	// Compare current epoch with the Fulu fork epoch.

beacon-chain/p2p/peers/assigner.go

@@ -42,7 +42,7 @@ func (a *Assigner) freshPeers() ([]peer.ID, error) {
 	if flags.Get().MinimumSyncPeers < required {
 		required = flags.Get().MinimumSyncPeers
 	}
-	_, peers := a.ps.BestFinalized(params.BeaconConfig().MaxPeersToSync, a.fc.FinalizedCheckpoint().Epoch)
+	_, peers := a.ps.BestFinalized(-1, a.fc.FinalizedCheckpoint().Epoch)
 	if len(peers) < required {
 		log.WithFields(logrus.Fields{
 			"suitable": len(peers),
@@ -52,27 +52,33 @@ func (a *Assigner) freshPeers() ([]peer.ID, error) {
 	return peers, nil
 }
 
+type AssignmentFilter func([]peer.ID) []peer.ID
+
 // Assign uses the "BestFinalized" method to select the best peers that agree on a canonical block
 // for the configured finalized epoch. At most `n` peers will be returned. The `busy` param can be used
 // to filter out peers that we know we don't want to connect to, for instance if we are trying to limit
 // the number of outbound requests to each peer from a given component.
-func (a *Assigner) Assign(busy map[peer.ID]bool, n int) ([]peer.ID, error) {
+func (a *Assigner) Assign(filter AssignmentFilter) ([]peer.ID, error) {
 	best, err := a.freshPeers()
 	if err != nil {
 		return nil, err
 	}
-	return pickBest(busy, n, best), nil
+	return filter(best), nil
 }
 
-func pickBest(busy map[peer.ID]bool, n int, best []peer.ID) []peer.ID {
-	ps := make([]peer.ID, 0, n)
-	for _, p := range best {
-		if len(ps) == n {
-			return ps
-		}
-		if !busy[p] {
-			ps = append(ps, p)
+// NotBusy is a filter that returns a list of peer.IDs with len() <= n, which are not in the `busy` map.
+// n == -1 will return all peers that are not busy.
+func NotBusy(busy map[peer.ID]bool, n int) AssignmentFilter {
+	return func(peers []peer.ID) []peer.ID {
+		ps := make([]peer.ID, 0)
+		for _, p := range peers {
+			if n > 0 && len(ps) == n {
+				return ps
+			}
+			if !busy[p] {
+				ps = append(ps, p)
+			}
 		}
+		return ps
 	}
-	return ps
 }

beacon-chain/p2p/peers/assigner_test.go

@@ -18,8 +18,9 @@ func TestPickBest(t *testing.T) {
 		expected []peer.ID
 	}{
 		{
-			name: "",
-			n:    0,
+			name:     "don't limit",
+			n:        0,
+			expected: best,
 		},
 		{
 			name:     "none busy",
@@ -88,7 +89,8 @@ func TestPickBest(t *testing.T) {
 			if c.best == nil {
 				c.best = best
 			}
-			pb := pickBest(c.busy, c.n, c.best)
+			filt := NotBusy(c.busy, c.n)
+			pb := filt(c.best)
 			require.Equal(t, len(c.expected), len(pb))
 			for i := range c.expected {
 				require.Equal(t, c.expected[i], pb[i])

beacon-chain/p2p/peers/scorers/bad_responses.go

@@ -5,7 +5,6 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/peerdata"
 	"github.com/libp2p/go-libp2p/core/peer"
-	"github.com/pkg/errors"
 )
 
 var _ Scorer = (*BadResponsesScorer)(nil)
@@ -129,13 +128,14 @@ func (s *BadResponsesScorer) IsBadPeer(pid peer.ID) error {
 
 // isBadPeerNoLock is lock-free version of IsBadPeer.
 func (s *BadResponsesScorer) isBadPeerNoLock(pid peer.ID) error {
-	if peerData, ok := s.store.PeerData(pid); ok {
-		if peerData.BadResponses >= s.config.Threshold {
-			return errors.Errorf("peer exceeded bad responses threshold: got %d, threshold %d", peerData.BadResponses, s.config.Threshold)
-		}
+	// if peerData, ok := s.store.PeerData(pid); ok {
+	// TODO: Remote this out of devnet
+	// if peerData.BadResponses >= s.config.Threshold {
+	// return errors.Errorf("peer exceeded bad responses threshold: got %d, threshold %d", peerData.BadResponses, s.config.Threshold)
+	// }
 
-		return nil
-	}
+	// return nil
+	// }
 
 	return nil
 }

beacon-chain/p2p/peers/scorers/bad_responses_test.go

@@ -1,7 +1,6 @@
 package scorers_test
 
 import (
-	"sort"
 	"testing"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
@@ -13,39 +12,41 @@ import (
 	"github.com/libp2p/go-libp2p/core/peer"
 )
 
-func TestScorers_BadResponses_Score(t *testing.T) {
-	const pid = "peer1"
+// TODO: Uncomment when out of devnet
+// func TestScorers_BadResponses_Score(t *testing.T) {
+// 	const pid = "peer1"
 
-	ctx := t.Context()
+// 	ctx, cancel := context.WithCancel(context.Background())
+// 	defer cancel()
 
-	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold: 4,
-			},
-		},
-	})
-	scorer := peerStatuses.Scorers().BadResponsesScorer()
+// 	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold: 4,
+// 			},
+// 		},
+// 	})
+// 	scorer := peerStatuses.Scorers().BadResponsesScorer()
 
-	assert.Equal(t, 0., scorer.Score(pid), "Unexpected score for unregistered peer")
+// 	assert.Equal(t, 0., scorer.Score(pid), "Unexpected score for unregistered peer")
 
-	scorer.Increment(pid)
-	assert.NoError(t, scorer.IsBadPeer(pid))
-	assert.Equal(t, -2.5, scorer.Score(pid))
+// 	scorer.Increment(pid)
+// 	assert.NoError(t, scorer.IsBadPeer(pid))
+// 	assert.Equal(t, -2.5, scorer.Score(pid))
 
-	scorer.Increment(pid)
-	assert.NoError(t, scorer.IsBadPeer(pid))
-	assert.Equal(t, float64(-5), scorer.Score(pid))
+// 	scorer.Increment(pid)
+// 	assert.NoError(t, scorer.IsBadPeer(pid))
+// 	assert.Equal(t, float64(-5), scorer.Score(pid))
 
-	scorer.Increment(pid)
-	assert.NoError(t, scorer.IsBadPeer(pid))
-	assert.Equal(t, float64(-7.5), scorer.Score(pid))
+// 	scorer.Increment(pid)
+// 	assert.NoError(t, scorer.IsBadPeer(pid))
+// 	assert.Equal(t, float64(-7.5), scorer.Score(pid))
 
-	scorer.Increment(pid)
-	assert.NotNil(t, scorer.IsBadPeer(pid))
-	assert.Equal(t, -100.0, scorer.Score(pid))
-}
+// 	scorer.Increment(pid)
+// 	assert.NotNil(t, scorer.IsBadPeer(pid))
+// 	assert.Equal(t, -100.0, scorer.Score(pid))
+// }
 
 func TestScorers_BadResponses_ParamsThreshold(t *testing.T) {
 	ctx := t.Context()
@@ -137,56 +138,60 @@ func TestScorers_BadResponses_Decay(t *testing.T) {
 	assert.Equal(t, 1, badResponses, "unexpected bad responses for pid3")
 }
 
-func TestScorers_BadResponses_IsBadPeer(t *testing.T) {
-	ctx := t.Context()
+// TODO: Uncomment when out of devnet
+// func TestScorers_BadResponses_IsBadPeer(t *testing.T) {
+// 	ctx, cancel := context.WithCancel(context.Background())
+// 	defer cancel()
 
-	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
-		PeerLimit:    30,
-		ScorerParams: &scorers.Config{},
-	})
-	scorer := peerStatuses.Scorers().BadResponsesScorer()
-	pid := peer.ID("peer1")
-	assert.NoError(t, scorer.IsBadPeer(pid))
+// 	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
+// 		PeerLimit:    30,
+// 		ScorerParams: &scorers.Config{},
+// 	})
+// 	scorer := peerStatuses.Scorers().BadResponsesScorer()
+// 	pid := peer.ID("peer1")
+// 	assert.NoError(t, scorer.IsBadPeer(pid))
 
-	peerStatuses.Add(nil, pid, nil, network.DirUnknown)
-	assert.NoError(t, scorer.IsBadPeer(pid))
+// 	peerStatuses.Add(nil, pid, nil, network.DirUnknown)
+// 	assert.NoError(t, scorer.IsBadPeer(pid))
 
-	for i := 0; i < scorers.DefaultBadResponsesThreshold; i++ {
-		scorer.Increment(pid)
-		if i == scorers.DefaultBadResponsesThreshold-1 {
-			assert.NotNil(t, scorer.IsBadPeer(pid), "Unexpected peer status")
-		} else {
-			assert.NoError(t, scorer.IsBadPeer(pid), "Unexpected peer status")
-		}
-	}
-}
+// 	for i := 0; i < scorers.DefaultBadResponsesThreshold; i++ {
+// 		scorer.Increment(pid)
+// 		if i == scorers.DefaultBadResponsesThreshold-1 {
+// 			assert.NotNil(t, scorer.IsBadPeer(pid), "Unexpected peer status")
+// 		} else {
+// 			assert.NoError(t, scorer.IsBadPeer(pid), "Unexpected peer status")
+// 		}
+// 	}
+// }
 
-func TestScorers_BadResponses_BadPeers(t *testing.T) {
-	ctx := t.Context()
+// TODO: Uncomment when out of devnet
+// func TestScorers_BadResponses_BadPeers(t *testing.T) {
+// 	ctx, cancel := context.WithCancel(context.Background())
+// 	defer cancel()
 
-	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
-		PeerLimit:    30,
-		ScorerParams: &scorers.Config{},
-	})
-	scorer := peerStatuses.Scorers().BadResponsesScorer()
-	pids := []peer.ID{peer.ID("peer1"), peer.ID("peer2"), peer.ID("peer3"), peer.ID("peer4"), peer.ID("peer5")}
-	for i := 0; i < len(pids); i++ {
-		peerStatuses.Add(nil, pids[i], nil, network.DirUnknown)
-	}
-	for i := 0; i < scorers.DefaultBadResponsesThreshold; i++ {
-		scorer.Increment(pids[1])
-		scorer.Increment(pids[2])
-		scorer.Increment(pids[4])
-	}
-	assert.NoError(t, scorer.IsBadPeer(pids[0]), "Invalid peer status")
-	assert.NotNil(t, scorer.IsBadPeer(pids[1]), "Invalid peer status")
-	assert.NotNil(t, scorer.IsBadPeer(pids[2]), "Invalid peer status")
-	assert.NoError(t, scorer.IsBadPeer(pids[3]), "Invalid peer status")
-	assert.NotNil(t, scorer.IsBadPeer(pids[4]), "Invalid peer status")
-	want := []peer.ID{pids[1], pids[2], pids[4]}
-	badPeers := scorer.BadPeers()
-	sort.Slice(badPeers, func(i, j int) bool {
-		return badPeers[i] < badPeers[j]
-	})
-	assert.DeepEqual(t, want, badPeers, "Unexpected list of bad peers")
-}
+// 	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
+// 		PeerLimit:    30,
+// 		ScorerParams: &scorers.Config{},
+// 	})
+// 	scorer := peerStatuses.Scorers().BadResponsesScorer()
+// 	pids := []peer.ID{peer.ID("peer1"), peer.ID("peer2"), peer.ID("peer3"), peer.ID("peer4"), peer.ID("peer5")}
+// 	for i := 0; i < len(pids); i++ {
+// 		peerStatuses.Add(nil, pids[i], nil, network.DirUnknown)
+// 	}
+// 	for i := 0; i < scorers.DefaultBadResponsesThreshold; i++ {
+// 		scorer.Increment(pids[1])
+// 		scorer.Increment(pids[2])
+// 		scorer.Increment(pids[4])
+// 	}
+// 	assert.NoError(t, scorer.IsBadPeer(pids[0]), "Invalid peer status")
+// 	assert.NotNil(t, scorer.IsBadPeer(pids[1]), "Invalid peer status")
+// 	assert.NotNil(t, scorer.IsBadPeer(pids[2]), "Invalid peer status")
+// 	assert.NoError(t, scorer.IsBadPeer(pids[3]), "Invalid peer status")
+// 	assert.NotNil(t, scorer.IsBadPeer(pids[4]), "Invalid peer status")
+// 	want := []peer.ID{pids[1], pids[2], pids[4]}
+// 	badPeers := scorer.BadPeers()
+// 	sort.Slice(badPeers, func(i, j int) bool {
+// 		return badPeers[i] < badPeers[j]
+// 	})
+// 	assert.DeepEqual(t, want, badPeers, "Unexpected list of bad peers")
+// }

beacon-chain/p2p/peers/scorers/gossip_scorer_test.go

@@ -42,7 +42,7 @@ func TestScorers_Gossip_Score(t *testing.T) {
 			},
 			check: func(scorer *scorers.GossipScorer) {
 				assert.Equal(t, 10.0, scorer.Score("peer1"), "Unexpected score")
-				assert.Equal(t, nil, scorer.IsBadPeer("peer1"), "Unexpected bad peer")
+				assert.NoError(t, scorer.IsBadPeer("peer1"), "Unexpected bad peer")
 				_, _, topicMap, err := scorer.GossipData("peer1")
 				assert.NoError(t, err)
 				assert.Equal(t, uint64(100), topicMap["a"].TimeInMesh, "incorrect time in mesh")

beacon-chain/p2p/peers/scorers/service_test.go

@@ -211,99 +211,102 @@ func TestScorers_Service_Score(t *testing.T) {
 	})
 }
 
-func TestScorers_Service_loop(t *testing.T) {
-	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
-	defer cancel()
+// TODO: Uncomment when out of devnet
+// func TestScorers_Service_loop(t *testing.T) {
+// 	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+// 	defer cancel()
 
-	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold:     5,
-				DecayInterval: 50 * time.Millisecond,
-			},
-			BlockProviderScorerConfig: &scorers.BlockProviderScorerConfig{
-				DecayInterval: 25 * time.Millisecond,
-				Decay:         64,
-			},
-		},
-	})
-	s1 := peerStatuses.Scorers().BadResponsesScorer()
-	s2 := peerStatuses.Scorers().BlockProviderScorer()
+// 	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold:     5,
+// 				DecayInterval: 50 * time.Millisecond,
+// 			},
+// 			BlockProviderScorerConfig: &scorers.BlockProviderScorerConfig{
+// 				DecayInterval: 25 * time.Millisecond,
+// 				Decay:         64,
+// 			},
+// 		},
+// 	})
+// 	s1 := peerStatuses.Scorers().BadResponsesScorer()
+// 	s2 := peerStatuses.Scorers().BlockProviderScorer()
 
-	pid1 := peer.ID("peer1")
-	peerStatuses.Add(nil, pid1, nil, network.DirUnknown)
-	for i := 0; i < s1.Params().Threshold+5; i++ {
-		s1.Increment(pid1)
-	}
-	assert.NotNil(t, s1.IsBadPeer(pid1), "Peer should be marked as bad")
+// 	pid1 := peer.ID("peer1")
+// 	peerStatuses.Add(nil, pid1, nil, network.DirUnknown)
+// 	for i := 0; i < s1.Params().Threshold+5; i++ {
+// 		s1.Increment(pid1)
+// 	}
+// 	assert.NotNil(t, s1.IsBadPeer(pid1), "Peer should be marked as bad")
 
-	s2.IncrementProcessedBlocks("peer1", 221)
-	assert.Equal(t, uint64(221), s2.ProcessedBlocks("peer1"))
+// 	s2.IncrementProcessedBlocks("peer1", 221)
+// 	assert.Equal(t, uint64(221), s2.ProcessedBlocks("peer1"))
 
-	done := make(chan struct{}, 1)
-	go func() {
-		defer func() {
-			done <- struct{}{}
-		}()
-		ticker := time.NewTicker(50 * time.Millisecond)
-		defer ticker.Stop()
-		for {
-			select {
-			case <-ticker.C:
-				if s1.IsBadPeer(pid1) == nil && s2.ProcessedBlocks("peer1") == 0 {
-					return
-				}
-			case <-ctx.Done():
-				t.Error("Timed out")
-				return
-			}
-		}
-	}()
+// 	done := make(chan struct{}, 1)
+// 	go func() {
+// 		defer func() {
+// 			done <- struct{}{}
+// 		}()
+// 		ticker := time.NewTicker(50 * time.Millisecond)
+// 		defer ticker.Stop()
+// 		for {
+// 			select {
+// 			case <-ticker.C:
+// 				if s1.IsBadPeer(pid1) == nil && s2.ProcessedBlocks("peer1") == 0 {
+// 					return
+// 				}
+// 			case <-ctx.Done():
+// 				t.Error("Timed out")
+// 				return
+// 			}
+// 		}
+// 	}()
 
-	<-done
-	assert.NoError(t, s1.IsBadPeer(pid1), "Peer should not be marked as bad")
-	assert.Equal(t, uint64(0), s2.ProcessedBlocks("peer1"), "No blocks are expected")
-}
+// 	<-done
+// 	assert.NoError(t, s1.IsBadPeer(pid1), "Peer should not be marked as bad")
+// 	assert.Equal(t, uint64(0), s2.ProcessedBlocks("peer1"), "No blocks are expected")
+// }
 
-func TestScorers_Service_IsBadPeer(t *testing.T) {
-	peerStatuses := peers.NewStatus(context.Background(), &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold:     2,
-				DecayInterval: 50 * time.Second,
-			},
-		},
-	})
+// TODO: Uncomment when out of devnet
+// func TestScorers_Service_IsBadPeer(t *testing.T) {
+// 	peerStatuses := peers.NewStatus(context.Background(), &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold:     2,
+// 				DecayInterval: 50 * time.Second,
+// 			},
+// 		},
+// 	})
 
-	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer1"))
-	peerStatuses.Scorers().BadResponsesScorer().Increment("peer1")
-	peerStatuses.Scorers().BadResponsesScorer().Increment("peer1")
-	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer("peer1"))
-}
+// 	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer1"))
+// 	peerStatuses.Scorers().BadResponsesScorer().Increment("peer1")
+// 	peerStatuses.Scorers().BadResponsesScorer().Increment("peer1")
+// 	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer("peer1"))
+// }
 
-func TestScorers_Service_BadPeers(t *testing.T) {
-	peerStatuses := peers.NewStatus(context.Background(), &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold:     2,
-				DecayInterval: 50 * time.Second,
-			},
-		},
-	})
+// TODO: Uncomment when out of devnet
+// func TestScorers_Service_BadPeers(t *testing.T) {
+// 	peerStatuses := peers.NewStatus(context.Background(), &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold:     2,
+// 				DecayInterval: 50 * time.Second,
+// 			},
+// 		},
+// 	})
 
-	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer1"))
-	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer2"))
-	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer3"))
-	assert.Equal(t, 0, len(peerStatuses.Scorers().BadPeers()))
-	for _, pid := range []peer.ID{"peer1", "peer3"} {
-		peerStatuses.Scorers().BadResponsesScorer().Increment(pid)
-		peerStatuses.Scorers().BadResponsesScorer().Increment(pid)
-	}
-	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer("peer1"))
-	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer2"))
-	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer("peer3"))
-	assert.Equal(t, 2, len(peerStatuses.Scorers().BadPeers()))
-}
+// 	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer1"))
+// 	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer2"))
+// 	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer3"))
+// 	assert.Equal(t, 0, len(peerStatuses.Scorers().BadPeers()))
+// 	for _, pid := range []peer.ID{"peer1", "peer3"} {
+// 		peerStatuses.Scorers().BadResponsesScorer().Increment(pid)
+// 		peerStatuses.Scorers().BadResponsesScorer().Increment(pid)
+// 	}
+// 	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer("peer1"))
+// 	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer2"))
+// 	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer("peer3"))
+// 	assert.Equal(t, 2, len(peerStatuses.Scorers().BadPeers()))
+// }

beacon-chain/p2p/peers/status.go

@@ -705,31 +705,47 @@ func (p *Status) deprecatedPrune() {
 	p.tallyIPTracker()
 }
 
-// BestFinalized returns the highest finalized epoch equal to or higher than ours that is agreed
-// upon by the majority of peers. This method may not return the absolute highest finalized, but
-// the finalized epoch in which most peers can serve blocks (plurality voting).
-// Ideally, all peers would be reporting the same finalized epoch but some may be behind due to their
-// own latency, or because of their finalized epoch at the time we queried them.
-// Returns epoch number and list of peers that are at or beyond that epoch.
+// BestFinalized returns the highest finalized epoch equal to or higher than `ourFinalizedEpoch`
+// that is agreed upon by the majority of peers, and the peers agreeing on this finalized epoch.
+// This method may not return the absolute highest finalized epoch, but the finalized epoch in which
+// most peers can serve blocks (plurality voting). Ideally, all peers would be reporting the same
+// finalized epoch but some may be behind due to their own latency, or because of their finalized
+// epoch at the time we queried them. Returns epoch number and list of peers that are at or beyond
+// that epoch.
 func (p *Status) BestFinalized(maxPeers int, ourFinalizedEpoch primitives.Epoch) (primitives.Epoch, []peer.ID) {
+	// Retrieve all connected peers.
 	connected := p.Connected()
+
+	// key: finalized epoch, value: number of peers that support this finalized epoch.
 	finalizedEpochVotes := make(map[primitives.Epoch]uint64)
+
+	// key: peer ID, value: finalized epoch of the peer.
 	pidEpoch := make(map[peer.ID]primitives.Epoch, len(connected))
+
+	// key: peer ID, value: head slot of the peer.
 	pidHead := make(map[peer.ID]primitives.Slot, len(connected))
+
 	potentialPIDs := make([]peer.ID, 0, len(connected))
 	for _, pid := range connected {
 		peerChainState, err := p.ChainState(pid)
-		if err == nil && peerChainState != nil && peerChainState.FinalizedEpoch >= ourFinalizedEpoch {
-			finalizedEpochVotes[peerChainState.FinalizedEpoch]++
-			pidEpoch[pid] = peerChainState.FinalizedEpoch
-			potentialPIDs = append(potentialPIDs, pid)
-			pidHead[pid] = peerChainState.HeadSlot
+
+		// Skip if the peer's finalized epoch is not defined, or if the peer's finalized epoch is
+		// lower than ours.
+		if err != nil || peerChainState == nil || peerChainState.FinalizedEpoch < ourFinalizedEpoch {
+			continue
 		}
+
+		finalizedEpochVotes[peerChainState.FinalizedEpoch]++
+
+		pidEpoch[pid] = peerChainState.FinalizedEpoch
+		pidHead[pid] = peerChainState.HeadSlot
+
+		potentialPIDs = append(potentialPIDs, pid)
 	}
 
 	// Select the target epoch, which is the epoch most peers agree upon.
-	var targetEpoch primitives.Epoch
-	var mostVotes uint64
+	// If there is a tie, select the highest epoch.
+	targetEpoch, mostVotes := primitives.Epoch(0), uint64(0)
 	for epoch, count := range finalizedEpochVotes {
 		if count > mostVotes || (count == mostVotes && epoch > targetEpoch) {
 			mostVotes = count
@@ -737,11 +753,12 @@ func (p *Status) BestFinalized(maxPeers int, ourFinalizedEpoch primitives.Epoch)
 		}
 	}
 
-	// Sort PIDs by finalized epoch, in decreasing order.
+	// Sort PIDs by finalized (epoch, head), in decreasing order.
 	sort.Slice(potentialPIDs, func(i, j int) bool {
 		if pidEpoch[potentialPIDs[i]] == pidEpoch[potentialPIDs[j]] {
 			return pidHead[potentialPIDs[i]] > pidHead[potentialPIDs[j]]
 		}
+
 		return pidEpoch[potentialPIDs[i]] > pidEpoch[potentialPIDs[j]]
 	})
 
@@ -754,7 +771,7 @@ func (p *Status) BestFinalized(maxPeers int, ourFinalizedEpoch primitives.Epoch)
 	}
 
 	// Trim potential peers to at most maxPeers.
-	if len(potentialPIDs) > maxPeers {
+	if maxPeers > 0 && len(potentialPIDs) > maxPeers {
 		potentialPIDs = potentialPIDs[:maxPeers]
 	}
 
@@ -764,26 +781,42 @@ func (p *Status) BestFinalized(maxPeers int, ourFinalizedEpoch primitives.Epoch)
 // BestNonFinalized returns the highest known epoch, higher than ours,
 // and is shared by at least minPeers.
 func (p *Status) BestNonFinalized(minPeers int, ourHeadEpoch primitives.Epoch) (primitives.Epoch, []peer.ID) {
+	// Retrieve all connected peers.
 	connected := p.Connected()
+
+	// Calculate our head slot.
+	slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+	ourHeadSlot := slotsPerEpoch.Mul(uint64(ourHeadEpoch))
+
+	// key: head epoch, value: number of peers that support this epoch.
 	epochVotes := make(map[primitives.Epoch]uint64)
+
+	// key: peer ID, value: head epoch of the peer.
 	pidEpoch := make(map[peer.ID]primitives.Epoch, len(connected))
+
+	// key: peer ID, value: head slot of the peer.
 	pidHead := make(map[peer.ID]primitives.Slot, len(connected))
+
 	potentialPIDs := make([]peer.ID, 0, len(connected))
 
-	ourHeadSlot := params.BeaconConfig().SlotsPerEpoch.Mul(uint64(ourHeadEpoch))
 	for _, pid := range connected {
 		peerChainState, err := p.ChainState(pid)
-		if err == nil && peerChainState != nil && peerChainState.HeadSlot > ourHeadSlot {
-			epoch := slots.ToEpoch(peerChainState.HeadSlot)
-			epochVotes[epoch]++
-			pidEpoch[pid] = epoch
-			pidHead[pid] = peerChainState.HeadSlot
-			potentialPIDs = append(potentialPIDs, pid)
+		// Skip if the peer's head epoch is not defined, or if the peer's head slot is
+		// lower or equal than ours.
+		if err != nil || peerChainState == nil || peerChainState.HeadSlot <= ourHeadSlot {
+			continue
 		}
+
+		epoch := slots.ToEpoch(peerChainState.HeadSlot)
+
+		epochVotes[epoch]++
+		pidEpoch[pid] = epoch
+		pidHead[pid] = peerChainState.HeadSlot
+		potentialPIDs = append(potentialPIDs, pid)
 	}
 
 	// Select the target epoch, which has enough peers' votes (>= minPeers).
-	var targetEpoch primitives.Epoch
+	targetEpoch := primitives.Epoch(0)
 	for epoch, votes := range epochVotes {
 		if votes >= uint64(minPeers) && targetEpoch < epoch {
 			targetEpoch = epoch
@@ -1012,16 +1045,23 @@ func (p *Status) isfromBadIP(pid peer.ID) error {
 		return nil
 	}
 
-	ip, err := manet.ToIP(peerData.Address)
-	if err != nil {
-		return errors.Wrap(err, "to ip")
-	}
+	// ip, err := manet.ToIP(peerData.Address)
+	// if err != nil {
+	// 	return errors.Wrap(err, "to ip")
+	// }
 
-	if val, ok := p.ipTracker[ip.String()]; ok {
-		if val > CollocationLimit {
-			return errors.Errorf("collocation limit exceeded: got %d - limit %d", val, CollocationLimit)
-		}
-	}
+	// if val, ok := p.ipTracker[ip.String()]; ok {
+	// if val > CollocationLimit {
+	// TODO: Remove this out of denvet.
+	// return errors.Errorf("colocation limit exceeded: got %d - limit %d", val, CollocationLimit)
+	// log.WithFields(logrus.Fields{
+	// 	"pid":             pid,
+	// 	"ip":              ip.String(),
+	// 	"colocationCount": val,
+	// 	"colocationLimit": CollocationLimit,
+	// }).Debug("Colocation limit exceeded. Peer should be banned.")
+	// }
+	// }
 
 	return nil
 }

beacon-chain/p2p/peers/status_test.go

@@ -3,7 +3,6 @@ package peers_test
 import (
 	"context"
 	"crypto/rand"
-	"strconv"
 	"testing"
 	"time"
 
@@ -329,55 +328,56 @@ func TestPeerWithNilChainState(t *testing.T) {
 	require.Equal(t, resChainState, nothing)
 }
 
-func TestPeerBadResponses(t *testing.T) {
-	maxBadResponses := 2
-	p := peers.NewStatus(context.Background(), &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold: maxBadResponses,
-			},
-		},
-	})
+// TODO: Uncomment when out of devnet
+// func TestPeerBadResponses(t *testing.T) {
+// 	maxBadResponses := 2
+// 	p := peers.NewStatus(context.Background(), &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold: maxBadResponses,
+// 			},
+// 		},
+// 	})
 
-	id, err := peer.Decode("16Uiu2HAkyWZ4Ni1TpvDS8dPxsozmHY85KaiFjodQuV6Tz5tkHVeR")
-	require.NoError(t, err)
-	{
-		_, err := id.MarshalBinary()
-		require.NoError(t, err)
-	}
+// 	id, err := peer.Decode("16Uiu2HAkyWZ4Ni1TpvDS8dPxsozmHY85KaiFjodQuV6Tz5tkHVeR")
+// 	require.NoError(t, err)
+// 	{
+// 		_, err := id.MarshalBinary()
+// 		require.NoError(t, err)
+// 	}
 
-	assert.NoError(t, p.IsBad(id), "Peer marked as bad when should be good")
+// 	assert.NoError(t, p.IsBad(id), "Peer marked as bad when should be good")
 
-	address, err := ma.NewMultiaddr("/ip4/213.202.254.180/tcp/13000")
-	require.NoError(t, err, "Failed to create address")
-	direction := network.DirInbound
-	p.Add(new(enr.Record), id, address, direction)
+// 	address, err := ma.NewMultiaddr("/ip4/213.202.254.180/tcp/13000")
+// 	require.NoError(t, err, "Failed to create address")
+// 	direction := network.DirInbound
+// 	p.Add(new(enr.Record), id, address, direction)
 
-	scorer := p.Scorers().BadResponsesScorer()
-	resBadResponses, err := scorer.Count(id)
-	require.NoError(t, err)
-	assert.Equal(t, 0, resBadResponses, "Unexpected bad responses")
-	assert.NoError(t, p.IsBad(id), "Peer marked as bad when should be good")
+// 	scorer := p.Scorers().BadResponsesScorer()
+// 	resBadResponses, err := scorer.Count(id)
+// 	require.NoError(t, err)
+// 	assert.Equal(t, 0, resBadResponses, "Unexpected bad responses")
+// 	assert.NoError(t, p.IsBad(id), "Peer marked as bad when should be good")
 
-	scorer.Increment(id)
-	resBadResponses, err = scorer.Count(id)
-	require.NoError(t, err)
-	assert.Equal(t, 1, resBadResponses, "Unexpected bad responses")
-	assert.NoError(t, p.IsBad(id), "Peer marked as bad when should be good")
+// 	scorer.Increment(id)
+// 	resBadResponses, err = scorer.Count(id)
+// 	require.NoError(t, err)
+// 	assert.Equal(t, 1, resBadResponses, "Unexpected bad responses")
+// 	assert.NoError(t, p.IsBad(id), "Peer marked as bad when should be good")
 
-	scorer.Increment(id)
-	resBadResponses, err = scorer.Count(id)
-	require.NoError(t, err)
-	assert.Equal(t, 2, resBadResponses, "Unexpected bad responses")
-	assert.NotNil(t, p.IsBad(id), "Peer not marked as bad when it should be")
+// 	scorer.Increment(id)
+// 	resBadResponses, err = scorer.Count(id)
+// 	require.NoError(t, err)
+// 	assert.Equal(t, 2, resBadResponses, "Unexpected bad responses")
+// 	assert.NotNil(t, p.IsBad(id), "Peer not marked as bad when it should be")
 
-	scorer.Increment(id)
-	resBadResponses, err = scorer.Count(id)
-	require.NoError(t, err)
-	assert.Equal(t, 3, resBadResponses, "Unexpected bad responses")
-	assert.NotNil(t, p.IsBad(id), "Peer not marked as bad when it should be")
-}
+// 	scorer.Increment(id)
+// 	resBadResponses, err = scorer.Count(id)
+// 	require.NoError(t, err)
+// 	assert.Equal(t, 3, resBadResponses, "Unexpected bad responses")
+// 	assert.NotNil(t, p.IsBad(id), "Peer not marked as bad when it should be")
+// }
 
 func TestAddMetaData(t *testing.T) {
 	maxBadResponses := 2
@@ -496,100 +496,102 @@ func TestPeerValidTime(t *testing.T) {
 	assert.Equal(t, numPeersConnected, len(p.Connected()), "Unexpected number of connected peers")
 }
 
-func TestPrune(t *testing.T) {
-	maxBadResponses := 2
-	p := peers.NewStatus(context.Background(), &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold: maxBadResponses,
-			},
-		},
-	})
+// TODO: Uncomment when out of devnet
+// func TestPrune(t *testing.T) {
+// 	maxBadResponses := 2
+// 	p := peers.NewStatus(context.Background(), &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold: maxBadResponses,
+// 			},
+// 		},
+// 	})
 
-	for i := 0; i < p.MaxPeerLimit()+100; i++ {
-		if i%7 == 0 {
-			// Peer added as disconnected.
-			_ = addPeer(t, p, peers.Disconnected)
-		}
-		// Peer added to peer handler.
-		_ = addPeer(t, p, peers.Connected)
-	}
+// 	for i := 0; i < p.MaxPeerLimit()+100; i++ {
+// 		if i%7 == 0 {
+// 			// Peer added as disconnected.
+// 			_ = addPeer(t, p, peers.PeerDisconnected)
+// 		}
+// 		// Peer added to peer handler.
+// 		_ = addPeer(t, p, peers.PeerConnected)
+// 	}
 
-	disPeers := p.Disconnected()
-	firstPID := disPeers[0]
-	secondPID := disPeers[1]
-	thirdPID := disPeers[2]
+// 	disPeers := p.Disconnected()
+// 	firstPID := disPeers[0]
+// 	secondPID := disPeers[1]
+// 	thirdPID := disPeers[2]
 
-	scorer := p.Scorers().BadResponsesScorer()
+// 	scorer := p.Scorers().BadResponsesScorer()
 
-	// Make first peer a bad peer
-	scorer.Increment(firstPID)
-	scorer.Increment(firstPID)
+// 	// Make first peer a bad peer
+// 	scorer.Increment(firstPID)
+// 	scorer.Increment(firstPID)
 
-	// Add bad response for p2.
-	scorer.Increment(secondPID)
+// 	// Add bad response for p2.
+// 	scorer.Increment(secondPID)
 
-	// Prune peers
-	p.Prune()
+// 	// Prune peers
+// 	p.Prune()
 
-	// Bad peer is expected to still be kept in handler.
-	badRes, err := scorer.Count(firstPID)
-	assert.NoError(t, err, "error is supposed to be  nil")
-	assert.Equal(t, 2, badRes, "Did not get expected amount")
+// 	// Bad peer is expected to still be kept in handler.
+// 	badRes, err := scorer.Count(firstPID)
+// 	assert.NoError(t, err, "error is supposed to be  nil")
+// 	assert.Equal(t, 2, badRes, "Did not get expected amount")
 
-	// Not so good peer is pruned away so that we can reduce the
-	// total size of the handler.
-	_, err = scorer.Count(secondPID)
-	assert.ErrorContains(t, "peer unknown", err)
+// 	// Not so good peer is pruned away so that we can reduce the
+// 	// total size of the handler.
+// 	_, err = scorer.Count(secondPID)
+// 	assert.ErrorContains(t, "peer unknown", err)
 
-	// Last peer has been removed.
-	_, err = scorer.Count(thirdPID)
-	assert.ErrorContains(t, "peer unknown", err)
-}
+// 	// Last peer has been removed.
+// 	_, err = scorer.Count(thirdPID)
+// 	assert.ErrorContains(t, "peer unknown", err)
+// }
 
-func TestPeerIPTracker(t *testing.T) {
-	resetCfg := features.InitWithReset(&features.Flags{
-		EnablePeerScorer: false,
-	})
-	defer resetCfg()
-	maxBadResponses := 2
-	p := peers.NewStatus(context.Background(), &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold: maxBadResponses,
-			},
-		},
-	})
+// TODO: Uncomment when out of devnet
+// func TestPeerIPTracker(t *testing.T) {
+// 	resetCfg := features.InitWithReset(&features.Flags{
+// 		EnablePeerScorer: false,
+// 	})
+// 	defer resetCfg()
+// 	maxBadResponses := 2
+// 	p := peers.NewStatus(context.Background(), &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold: maxBadResponses,
+// 			},
+// 		},
+// 	})
 
-	badIP := "211.227.218.116"
-	var badPeers []peer.ID
-	for i := 0; i < peers.CollocationLimit+10; i++ {
-		port := strconv.Itoa(3000 + i)
-		addr, err := ma.NewMultiaddr("/ip4/" + badIP + "/tcp/" + port)
-		if err != nil {
-			t.Fatal(err)
-		}
-		badPeers = append(badPeers, createPeer(t, p, addr, network.DirUnknown, peerdata.ConnectionState(ethpb.ConnectionState_DISCONNECTED)))
-	}
-	for _, pr := range badPeers {
-		assert.NotNil(t, p.IsBad(pr), "peer with bad ip is not bad")
-	}
+// 	badIP := "211.227.218.116"
+// 	var badPeers []peer.ID
+// 	for i := 0; i < peers.CollocationLimit+10; i++ {
+// 		port := strconv.Itoa(3000 + i)
+// 		addr, err := ma.NewMultiaddr("/ip4/" + badIP + "/tcp/" + port)
+// 		if err != nil {
+// 			t.Fatal(err)
+// 		}
+// 		badPeers = append(badPeers, createPeer(t, p, addr, network.DirUnknown, peerdata.PeerConnectionState(ethpb.ConnectionState_DISCONNECTED)))
+// 	}
+// 	for _, pr := range badPeers {
+// 		assert.NotNil(t, p.IsBad(pr), "peer with bad ip is not bad")
+// 	}
 
-	// Add in bad peers, so that our records are trimmed out
-	// from the peer store.
-	for i := 0; i < p.MaxPeerLimit()+100; i++ {
-		// Peer added to peer handler.
-		pid := addPeer(t, p, peers.Disconnected)
-		p.Scorers().BadResponsesScorer().Increment(pid)
-	}
-	p.Prune()
+// 	// Add in bad peers, so that our records are trimmed out
+// 	// from the peer store.
+// 	for i := 0; i < p.MaxPeerLimit()+100; i++ {
+// 		// Peer added to peer handler.
+// 		pid := addPeer(t, p, peers.PeerDisconnected)
+// 		p.Scorers().BadResponsesScorer().Increment(pid)
+// 	}
+// 	p.Prune()
 
-	for _, pr := range badPeers {
-		assert.NoError(t, p.IsBad(pr), "peer with good ip is regarded as bad")
-	}
-}
+// 	for _, pr := range badPeers {
+// 		assert.NoError(t, p.IsBad(pr), "peer with good ip is regarded as bad")
+// 	}
+// }
 
 func TestTrimmedOrderedPeers(t *testing.T) {
 	p := peers.NewStatus(context.Background(), &peers.StatusConfig{

beacon-chain/p2p/rpc_topic_mappings.go

@@ -61,6 +61,12 @@ const LightClientFinalityUpdateName = "/light_client_finality_update"
 // LightClientOptimisticUpdateName is the name for the LightClientOptimisticUpdate topic.
 const LightClientOptimisticUpdateName = "/light_client_optimistic_update"
 
+// DataColumnSidecarsByRootName is the name for the DataColumnSidecarsByRoot v1 message topic.
+const DataColumnSidecarsByRootName = "/data_column_sidecars_by_root"
+
+// DataColumnSidecarsByRangeName is the name for the DataColumnSidecarsByRange v1 message topic.
+const DataColumnSidecarsByRangeName = "/data_column_sidecars_by_range"
+
 const (
 	// V1 RPC Topics
 	// RPCStatusTopicV1 defines the v1 topic for the status rpc method.
@@ -92,6 +98,12 @@ const (
 	RPCLightClientFinalityUpdateTopicV1 = protocolPrefix + LightClientFinalityUpdateName + SchemaVersionV1
 	// RPCLightClientOptimisticUpdateTopicV1 is a topic for requesting a light client Optimistic update.
 	RPCLightClientOptimisticUpdateTopicV1 = protocolPrefix + LightClientOptimisticUpdateName + SchemaVersionV1
+	// RPCDataColumnSidecarsByRootTopicV1 is a topic for requesting data column sidecars by their block root.
+	// /eth2/beacon_chain/req/data_column_sidecars_by_root/1 - New in Fulu.
+	RPCDataColumnSidecarsByRootTopicV1 = protocolPrefix + DataColumnSidecarsByRootName + SchemaVersionV1
+	// RPCDataColumnSidecarsByRangeTopicV1 is a topic for requesting data column sidecars by their slot.
+	// /eth2/beacon_chain/req/data_column_sidecars_by_range/1 - New in Fulu.
+	RPCDataColumnSidecarsByRangeTopicV1 = protocolPrefix + DataColumnSidecarsByRangeName + SchemaVersionV1
 
 	// V2 RPC Topics
 	// RPCBlocksByRangeTopicV2 defines v2 the topic for the blocks by range rpc method.
@@ -139,6 +151,11 @@ var RPCTopicMappings = map[string]interface{}{
 	RPCLightClientUpdatesByRangeTopicV1:   new(pb.LightClientUpdatesByRangeRequest),
 	RPCLightClientFinalityUpdateTopicV1:   new(interface{}),
 	RPCLightClientOptimisticUpdateTopicV1: new(interface{}),
+
+	// DataColumnSidecarsByRange v1 Message
+	RPCDataColumnSidecarsByRangeTopicV1: new(pb.DataColumnSidecarsByRangeRequest),
+	// DataColumnSidecarsByRoot v1 Message
+	RPCDataColumnSidecarsByRootTopicV1: new(p2ptypes.DataColumnsByRootIdentifiers),
 }
 
 // Maps all registered protocol prefixes.
@@ -161,6 +178,8 @@ var messageMapping = map[string]bool{
 	LightClientUpdatesByRangeName:   true,
 	LightClientFinalityUpdateName:   true,
 	LightClientOptimisticUpdateName: true,
+	DataColumnSidecarsByRootName:    true,
+	DataColumnSidecarsByRangeName:   true,
 }
 
 // Maps all the RPC messages which are to updated in altair.

beacon-chain/p2p/service_test.go

@@ -10,8 +10,6 @@ import (
 
 	mock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/encoder"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
@@ -358,48 +356,49 @@ func initializeStateWithForkDigest(_ context.Context, t *testing.T, gs startup.C
 	return fd
 }
 
-func TestService_connectWithPeer(t *testing.T) {
-	params.SetupTestConfigCleanup(t)
-	tests := []struct {
-		name    string
-		peers   *peers.Status
-		info    peer.AddrInfo
-		wantErr string
-	}{
-		{
-			name: "bad peer",
-			peers: func() *peers.Status {
-				ps := peers.NewStatus(context.Background(), &peers.StatusConfig{
-					ScorerParams: &scorers.Config{},
-				})
-				for i := 0; i < 10; i++ {
-					ps.Scorers().BadResponsesScorer().Increment("bad")
-				}
-				return ps
-			}(),
-			info:    peer.AddrInfo{ID: "bad"},
-			wantErr: "refused to connect to bad peer",
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			h, _, _ := createHost(t, 34567)
-			defer func() {
-				if err := h.Close(); err != nil {
-					t.Fatal(err)
-				}
-			}()
-			ctx := context.Background()
-			s := &Service{
-				host:  h,
-				peers: tt.peers,
-			}
-			err := s.connectWithPeer(ctx, tt.info)
-			if len(tt.wantErr) > 0 {
-				require.ErrorContains(t, tt.wantErr, err)
-			} else {
-				require.NoError(t, err)
-			}
-		})
-	}
-}
+// TODO: Uncomment when out of devnet
+// func TestService_connectWithPeer(t *testing.T) {
+// 	params.SetupTestConfigCleanup(t)
+// 	tests := []struct {
+// 		name    string
+// 		peers   *peers.Status
+// 		info    peer.AddrInfo
+// 		wantErr string
+// 	}{
+// 		{
+// 			name: "bad peer",
+// 			peers: func() *peers.Status {
+// 				ps := peers.NewStatus(context.Background(), &peers.StatusConfig{
+// 					ScorerParams: &scorers.Config{},
+// 				})
+// 				for i := 0; i < 10; i++ {
+// 					ps.Scorers().BadResponsesScorer().Increment("bad")
+// 				}
+// 				return ps
+// 			}(),
+// 			info:    peer.AddrInfo{ID: "bad"},
+// 			wantErr: "refused to connect to bad peer",
+// 		},
+// 	}
+// 	for _, tt := range tests {
+// 		t.Run(tt.name, func(t *testing.T) {
+// 			h, _, _ := createHost(t, 34567)
+// 			defer func() {
+// 				if err := h.Close(); err != nil {
+// 					t.Fatal(err)
+// 				}
+// 			}()
+// 			ctx := context.Background()
+// 			s := &Service{
+// 				host:  h,
+// 				peers: tt.peers,
+// 			}
+// 			err := s.connectWithPeer(ctx, tt.info)
+// 			if len(tt.wantErr) > 0 {
+// 				require.ErrorContains(t, tt.wantErr, err)
+// 			} else {
+// 				require.NoError(t, err)
+// 			}
+// 		})
+// 	}
+// }

beacon-chain/p2p/types/rpc_errors.go

@@ -9,10 +9,13 @@ var (
 	ErrInvalidSequenceNum     = errors.New("invalid sequence number provided")
 	ErrGeneric                = errors.New("internal service error")
 
-	ErrRateLimited         = errors.New("rate limited")
-	ErrIODeadline          = errors.New("i/o deadline exceeded")
-	ErrInvalidRequest      = errors.New("invalid range, step or count")
-	ErrBlobLTMinRequest    = errors.New("blob epoch < minimum_request_epoch")
-	ErrMaxBlobReqExceeded  = errors.New("requested more than MAX_REQUEST_BLOB_SIDECARS")
+	ErrRateLimited      = errors.New("rate limited")
+	ErrIODeadline       = errors.New("i/o deadline exceeded")
+	ErrInvalidRequest   = errors.New("invalid range, step or count")
+	ErrBlobLTMinRequest = errors.New("blob epoch < minimum_request_epoch")
+
+	ErrMaxBlobReqExceeded       = errors.New("requested more than MAX_REQUEST_BLOB_SIDECARS")
+	ErrMaxDataColumnReqExceeded = errors.New("requested more than MAX_REQUEST_DATA_COLUMN_SIDECARS")
+
 	ErrResourceUnavailable = errors.New("resource requested unavailable")
 )

beacon-chain/p2p/types/types.go

@@ -206,8 +206,8 @@ func (s BlobSidecarsByRootReq) Swap(i, j int) {
 }
 
 // Len is the number of elements in the collection.
-func (s BlobSidecarsByRootReq) Len() int {
-	return len(s)
+func (s *BlobSidecarsByRootReq) Len() int {
+	return len(*s)
 }
 
 // ====================================

beacon-chain/p2p/types/types_test.go

@@ -221,7 +221,6 @@ func generateDataColumnIdentifiers(n int) []*eth.DataColumnsByRootIdentifier {
 
 func TestDataColumnSidecarsByRootReq_Marshal(t *testing.T) {
 	/*
-
 		SSZ encoding of DataColumnsByRootIdentifiers is tested in spectests.
 		However, encoding a list of DataColumnsByRootIdentifier is not.
 		We are testing it here.

beacon-chain/p2p/utils.go

@@ -201,6 +201,11 @@ func ConvertPeerIDToNodeID(pid peer.ID) (enode.ID, error) {
 		return [32]byte{}, errors.Wrap(err, "parse public key")
 	}
 
-	newPubkey := &ecdsa.PublicKey{Curve: gCrypto.S256(), X: pubKeyObjSecp256k1.X(), Y: pubKeyObjSecp256k1.Y()}
+	newPubkey := &ecdsa.PublicKey{
+		Curve: gCrypto.S256(),
+		X:     pubKeyObjSecp256k1.X(),
+		Y:     pubKeyObjSecp256k1.Y(),
+	}
+
 	return enode.PubkeyToIDV4(newPubkey), nil
 }

beacon-chain/rpc/eth/blob/handlers.go

@@ -97,18 +97,19 @@ func (s *Server) Blobs(w http.ResponseWriter, r *http.Request) {
 }
 
 // parseIndices filters out invalid and duplicate blob indices
-func parseIndices(url *url.URL, s primitives.Slot) ([]uint64, error) {
+func parseIndices(url *url.URL, s primitives.Slot) ([]int, error) {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(s)
 	rawIndices := url.Query()["indices"]
-	indices := make([]uint64, 0, params.BeaconConfig().MaxBlobsPerBlock(s))
+	indices := make([]int, 0, maxBlobsPerBlock)
 	invalidIndices := make([]string, 0)
 loop:
 	for _, raw := range rawIndices {
-		ix, err := strconv.ParseUint(raw, 10, 64)
+		ix, err := strconv.Atoi(raw)
 		if err != nil {
 			invalidIndices = append(invalidIndices, raw)
 			continue
 		}
-		if ix >= uint64(params.BeaconConfig().MaxBlobsPerBlock(s)) {
+		if !(0 <= ix && ix < maxBlobsPerBlock) {
 			invalidIndices = append(invalidIndices, raw)
 			continue
 		}

beacon-chain/rpc/eth/blob/handlers_test.go

@@ -520,13 +520,13 @@ func Test_parseIndices(t *testing.T) {
 	tests := []struct {
 		name    string
 		query   string
-		want    []uint64
+		want    []int
 		wantErr string
 	}{
 		{
 			name:  "happy path with duplicate indices within bound and other query parameters ignored",
 			query: "indices=1&indices=2&indices=1&indices=3&bar=bar",
-			want:  []uint64{1, 2, 3},
+			want:  []int{1, 2, 3},
 		},
 		{
 			name:    "out of bounds indices throws error",

beacon-chain/rpc/lookup/BUILD.bazel

@@ -10,11 +10,13 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//beacon-chain/blockchain:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/rpc/core:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/stategen:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
@@ -36,6 +38,7 @@ go_test(
     ],
     embed = [":go_default_library"],
     deps = [
+        "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/blockchain/testing:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
@@ -47,12 +50,16 @@ go_test(
         "//beacon-chain/verification:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
+        "@com_github_consensys_gnark_crypto//ecc/bls12-381/fr:go_default_library",
+        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
     ],
 )

beacon-chain/rpc/lookup/blocker.go

@@ -3,12 +3,15 @@ package lookup
 import (
 	"context"
 	"fmt"
+	"math"
 	"strconv"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/core"
+	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
@@ -40,7 +43,7 @@ func (e BlockIdParseError) Error() string {
 // Blocker is responsible for retrieving blocks.
 type Blocker interface {
 	Block(ctx context.Context, id []byte) (interfaces.ReadOnlySignedBeaconBlock, error)
-	Blobs(ctx context.Context, id string, indices []uint64) ([]*blocks.VerifiedROBlob, *core.RpcError)
+	Blobs(ctx context.Context, id string, indices []int) ([]*blocks.VerifiedROBlob, *core.RpcError)
 }
 
 // BeaconDbBlocker is an implementation of Blocker. It retrieves blocks from the beacon chain database.
@@ -49,6 +52,7 @@ type BeaconDbBlocker struct {
 	ChainInfoFetcher   blockchain.ChainInfoFetcher
 	GenesisTimeFetcher blockchain.TimeFetcher
 	BlobStorage        *filesystem.BlobStorage
+	DataColumnStorage  *filesystem.DataColumnStorage
 }
 
 // Block returns the beacon block for a given identifier. The identifier can be one of:
@@ -129,6 +133,137 @@ func (p *BeaconDbBlocker) Block(ctx context.Context, id []byte) (interfaces.Read
 	return blk, nil
 }
 
+// blobsFromStoredBlobs retrieves blobs corresponding to `indices` and `root` from the store.
+// This function expects blobs to be stored directly (aka. no data columns).
+func (p *BeaconDbBlocker) blobsFromStoredBlobs(indices []int, root []byte, commitments [][]byte) ([]*blocks.VerifiedROBlob, *core.RpcError) {
+	sum := p.BlobStorage.Summary(bytesutil.ToBytes32(root))
+
+	if len(indices) == 0 {
+		for index := range commitments {
+			if sum.HasIndex(uint64(index)) {
+				indices = append(indices, index)
+			}
+		}
+	} else {
+		for _, index := range indices {
+			if uint64(index) >= sum.MaxBlobsForEpoch() {
+				return nil, &core.RpcError{
+					Err:    fmt.Errorf("requested index %d is bigger than the maximum possible blob count %d", index, sum.MaxBlobsForEpoch()),
+					Reason: core.BadRequest,
+				}
+			}
+
+			if !sum.HasIndex(uint64(index)) {
+				return nil, &core.RpcError{
+					Err:    fmt.Errorf("requested index %d not found", index),
+					Reason: core.NotFound,
+				}
+			}
+		}
+	}
+
+	blobs := make([]*blocks.VerifiedROBlob, 0, len(indices))
+	for _, index := range indices {
+		vblob, err := p.BlobStorage.Get(bytesutil.ToBytes32(root), uint64(index))
+		if err != nil {
+			return nil, &core.RpcError{
+				Err:    fmt.Errorf("could not retrieve blob for block root %#x at index %d", root, index),
+				Reason: core.Internal,
+			}
+		}
+		blobs = append(blobs, &vblob)
+	}
+
+	return blobs, nil
+}
+
+// blobsFromStoredDataColumns retrieves data columns from the store, reconstruct the whole matrix if needed, convert the matrix to blobs,
+// and then returns blobs corresponding to `indices` and `root` from the store,
+// This function expects data columns to be stored (aka. no blobs).
+// If not enough data columns are available to extract blobs from them (either directly or after reconstruction), an error is returned.
+func (p *BeaconDbBlocker) blobsFromStoredDataColumns(block blocks.ROBlock, indices []int, rootBytes []byte) ([]*blocks.VerifiedROBlob, *core.RpcError) {
+	root := bytesutil.ToBytes32(rootBytes)
+
+	// Use all indices if none are provided.
+	if len(indices) == 0 {
+		commitments, err := block.Block().Body().BlobKzgCommitments()
+		if err != nil {
+			return nil, &core.RpcError{
+				Err:    errors.Wrap(err, "could not retrieve blob commitments"),
+				Reason: core.Internal,
+			}
+		}
+
+		for index := range commitments {
+			indices = append(indices, index)
+		}
+	}
+
+	// Count how many columns we have in the store.
+	summary := p.DataColumnStorage.Summary(root)
+	stored := summary.Stored()
+	count := uint64(len(stored))
+
+	if count < peerdas.MinimumColumnsCountToReconstruct() {
+		// There is no way to reconstruct the data columns.
+		return nil, &core.RpcError{
+			Err:    errors.Errorf("the node does not custody enough data columns to reconstruct blobs. Please start the beacon node with the `--%s` flag to ensure this call to success, or retry later if it is already the case.", flags.SubscribeAllDataSubnets.Name),
+			Reason: core.NotFound,
+		}
+	}
+
+	// Retrieve from the database needed data columns.
+	verifiedRoDataColumnSidecars, err := p.neededDataColumnSidecars(root, stored)
+	if err != nil {
+		return nil, &core.RpcError{
+			Err:    errors.Wrap(err, "needed data column sidecars"),
+			Reason: core.Internal,
+		}
+	}
+
+	verifiedRoBlobSidecars, err := peerdas.ReconstructBlobs(block, verifiedRoDataColumnSidecars, indices)
+	if err != nil {
+		return nil, &core.RpcError{
+			Err:    errors.Wrap(err, "blobs from data columns"),
+			Reason: core.Internal,
+		}
+	}
+
+	return verifiedRoBlobSidecars, nil
+}
+
+func (p *BeaconDbBlocker) neededDataColumnSidecars(root [fieldparams.RootLength]byte, stored map[uint64]bool) ([]blocks.VerifiedRODataColumn, error) {
+	// Check if we have all the non-extended data columns.
+	cellsPerBlob := fieldparams.CellsPerBlob
+	blobIndices := make([]uint64, 0, cellsPerBlob)
+	hasAllBlobColumns := true
+	for i := range uint64(cellsPerBlob) {
+		if !stored[i] {
+			hasAllBlobColumns = false
+			break
+		}
+		blobIndices = append(blobIndices, i)
+	}
+
+	if hasAllBlobColumns {
+		// Retrieve only the non-extended data columns.
+		verifiedRoSidecars, err := p.DataColumnStorage.Get(root, blobIndices)
+		if err != nil {
+			return nil, errors.Wrap(err, "data columns storage get")
+		}
+
+		return verifiedRoSidecars, nil
+	}
+
+	// Retrieve all the data columns.
+	verifiedRoSidecars, err := p.DataColumnStorage.Get(root, nil)
+	if err != nil {
+		return nil, errors.Wrap(err, "data columns storage get")
+	}
+
+	return verifiedRoSidecars, nil
+}
+
 // Blobs returns the blobs for a given block id identifier and blob indices. The identifier can be one of:
 //   - "head" (canonical head in node's view)
 //   - "genesis"
@@ -144,7 +279,7 @@ func (p *BeaconDbBlocker) Block(ctx context.Context, id []byte) (interfaces.Read
 //   - block exists, has commitments, inside retention period (greater of protocol- or user-specified) serve then w/ 200 unless we hit an error reading them.
 //     we are technically not supposed to import a block to forkchoice unless we have the blobs, so the nuance here is if we can't find the file and we are inside the protocol-defined retention period, then it's actually a 500.
 //   - block exists, has commitments, outside retention period (greater of protocol- or user-specified) - ie just like block exists, no commitment
-func (p *BeaconDbBlocker) Blobs(ctx context.Context, id string, indices []uint64) ([]*blocks.VerifiedROBlob, *core.RpcError) {
+func (p *BeaconDbBlocker) Blobs(ctx context.Context, id string, indices []int) ([]*blocks.VerifiedROBlob, *core.RpcError) {
 	var rootSlice []byte
 	switch id {
 	case "genesis":
@@ -212,64 +347,55 @@ func (p *BeaconDbBlocker) Blobs(ctx context.Context, id string, indices []uint64
 
 	root := bytesutil.ToBytes32(rootSlice)
 
-	b, err := p.BeaconDB.Block(ctx, root)
+	roSignedBlock, err := p.BeaconDB.Block(ctx, root)
 	if err != nil {
 		return nil, &core.RpcError{Err: errors.Wrapf(err, "failed to retrieve block %#x from db", rootSlice), Reason: core.Internal}
 	}
-	if b == nil {
+
+	if roSignedBlock == nil {
 		return nil, &core.RpcError{Err: fmt.Errorf("block %#x not found in db", rootSlice), Reason: core.NotFound}
 	}
 
-	// if block is not in the retention window, return 200 w/ empty list
-	if !p.BlobStorage.WithinRetentionPeriod(slots.ToEpoch(b.Block().Slot()), slots.ToEpoch(p.GenesisTimeFetcher.CurrentSlot())) {
+	// If block is not in the retention window, return 200 w/ empty list
+	if !p.BlobStorage.WithinRetentionPeriod(slots.ToEpoch(roSignedBlock.Block().Slot()), slots.ToEpoch(p.GenesisTimeFetcher.CurrentSlot())) {
 		return make([]*blocks.VerifiedROBlob, 0), nil
 	}
 
-	commitments, err := b.Block().Body().BlobKzgCommitments()
+	roBlock := roSignedBlock.Block()
+
+	commitments, err := roBlock.Body().BlobKzgCommitments()
 	if err != nil {
 		return nil, &core.RpcError{Err: errors.Wrapf(err, "failed to retrieve kzg commitments from block %#x", rootSlice), Reason: core.Internal}
 	}
+
 	// if there are no commitments return 200 w/ empty list
 	if len(commitments) == 0 {
 		return make([]*blocks.VerifiedROBlob, 0), nil
 	}
 
-	sum := p.BlobStorage.Summary(root)
+	// Get the slot of the block.
+	blockSlot := roBlock.Slot()
 
-	if len(indices) == 0 {
-		for i := range commitments {
-			if sum.HasIndex(uint64(i)) {
-				indices = append(indices, uint64(i))
-			}
-		}
-	} else {
-		for _, ix := range indices {
-			if ix >= sum.MaxBlobsForEpoch() {
-				return nil, &core.RpcError{
-					Err:    fmt.Errorf("requested index %d is bigger than the maximum possible blob count %d", ix, sum.MaxBlobsForEpoch()),
-					Reason: core.BadRequest,
-				}
-			}
-			if !sum.HasIndex(ix) {
-				return nil, &core.RpcError{
-					Err:    fmt.Errorf("requested index %d not found", ix),
-					Reason: core.NotFound,
-				}
-			}
-		}
-	}
+	// Get the first peerDAS epoch.
+	fuluForkEpoch := params.BeaconConfig().FuluForkEpoch
 
-	blobs := make([]*blocks.VerifiedROBlob, len(indices))
-	for i, index := range indices {
-		vblob, err := p.BlobStorage.Get(root, index)
+	// Compute the first peerDAS slot.
+	fuluForkSlot := primitives.Slot(math.MaxUint64)
+	if fuluForkEpoch != primitives.Epoch(math.MaxUint64) {
+		fuluForkSlot, err = slots.EpochStart(fuluForkEpoch)
 		if err != nil {
-			return nil, &core.RpcError{
-				Err:    fmt.Errorf("could not retrieve blob for block root %#x at index %d", rootSlice, index),
-				Reason: core.Internal,
-			}
+			return nil, &core.RpcError{Err: errors.Wrap(err, "could not calculate peerDAS start slot"), Reason: core.Internal}
 		}
-		blobs[i] = &vblob
 	}
 
-	return blobs, nil
+	if blockSlot >= fuluForkSlot {
+		roBlock, err := blocks.NewROBlockWithRoot(roSignedBlock, root)
+		if err != nil {
+			return nil, &core.RpcError{Err: errors.Wrapf(err, "failed to create roBlock with root %#x", root), Reason: core.Internal}
+		}
+
+		return p.blobsFromStoredDataColumns(roBlock, indices, rootSlice)
+	}
+
+	return p.blobsFromStoredBlobs(indices, rootSlice, commitments)
 }

beacon-chain/rpc/lookup/blocker_test.go

@@ -1,7 +1,10 @@
 package lookup
 
 import (
+	"bytes"
 	"context"
+	"crypto/sha256"
+	"encoding/binary"
 	"fmt"
 	"math"
 	"net/http"
@@ -9,6 +12,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	mockChain "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	testDB "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
@@ -17,12 +21,16 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
-	ethpbalpha "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
+	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
+	GoKZG "github.com/crate-crypto/go-kzg-4844"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/sirupsen/logrus"
 )
 
 func TestGetBlock(t *testing.T) {
@@ -51,7 +59,7 @@ func TestGetBlock(t *testing.T) {
 	b4.Block.ParentRoot = bytesutil.PadTo([]byte{8}, 32)
 	util.SaveBlock(t, ctx, beaconDB, b4)
 
-	wsb, err := blocks.NewSignedBeaconBlock(headBlock.Block.(*ethpbalpha.BeaconBlockContainer_Phase0Block).Phase0Block)
+	wsb, err := blocks.NewSignedBeaconBlock(headBlock.Block.(*ethpb.BeaconBlockContainer_Phase0Block).Phase0Block)
 	require.NoError(t, err)
 
 	fetcher := &BeaconDbBlocker{
@@ -60,7 +68,7 @@ func TestGetBlock(t *testing.T) {
 			DB:                  beaconDB,
 			Block:               wsb,
 			Root:                headBlock.BlockRoot,
-			FinalizedCheckPoint: &ethpbalpha.Checkpoint{Root: blkContainers[64].BlockRoot},
+			FinalizedCheckPoint: &ethpb.Checkpoint{Root: blkContainers[64].BlockRoot},
 			CanonicalRoots:      canonicalRoots,
 		},
 	}
@@ -71,13 +79,13 @@ func TestGetBlock(t *testing.T) {
 	tests := []struct {
 		name    string
 		blockID []byte
-		want    *ethpbalpha.SignedBeaconBlock
+		want    *ethpb.SignedBeaconBlock
 		wantErr bool
 	}{
 		{
 			name:    "slot",
 			blockID: []byte("30"),
-			want:    blkContainers[30].Block.(*ethpbalpha.BeaconBlockContainer_Phase0Block).Phase0Block,
+			want:    blkContainers[30].Block.(*ethpb.BeaconBlockContainer_Phase0Block).Phase0Block,
 		},
 		{
 			name:    "bad formatting",
@@ -87,7 +95,7 @@ func TestGetBlock(t *testing.T) {
 		{
 			name:    "canonical",
 			blockID: []byte("30"),
-			want:    blkContainers[30].Block.(*ethpbalpha.BeaconBlockContainer_Phase0Block).Phase0Block,
+			want:    blkContainers[30].Block.(*ethpb.BeaconBlockContainer_Phase0Block).Phase0Block,
 		},
 		{
 			name:    "non canonical",
@@ -97,12 +105,12 @@ func TestGetBlock(t *testing.T) {
 		{
 			name:    "head",
 			blockID: []byte("head"),
-			want:    headBlock.Block.(*ethpbalpha.BeaconBlockContainer_Phase0Block).Phase0Block,
+			want:    headBlock.Block.(*ethpb.BeaconBlockContainer_Phase0Block).Phase0Block,
 		},
 		{
 			name:    "finalized",
 			blockID: []byte("finalized"),
-			want:    blkContainers[64].Block.(*ethpbalpha.BeaconBlockContainer_Phase0Block).Phase0Block,
+			want:    blkContainers[64].Block.(*ethpb.BeaconBlockContainer_Phase0Block).Phase0Block,
 		},
 		{
 			name:    "genesis",
@@ -117,7 +125,7 @@ func TestGetBlock(t *testing.T) {
 		{
 			name:    "root",
 			blockID: blkContainers[20].BlockRoot,
-			want:    blkContainers[20].Block.(*ethpbalpha.BeaconBlockContainer_Phase0Block).Phase0Block,
+			want:    blkContainers[20].Block.(*ethpb.BeaconBlockContainer_Phase0Block).Phase0Block,
 		},
 		{
 			name:    "non-existent root",
@@ -127,7 +135,7 @@ func TestGetBlock(t *testing.T) {
 		{
 			name:    "hex",
 			blockID: []byte(hexutil.Encode(blkContainers[20].BlockRoot)),
-			want:    blkContainers[20].Block.(*ethpbalpha.BeaconBlockContainer_Phase0Block).Phase0Block,
+			want:    blkContainers[20].Block.(*ethpb.BeaconBlockContainer_Phase0Block).Phase0Block,
 		},
 		{
 			name:    "no block",
@@ -149,7 +157,7 @@ func TestGetBlock(t *testing.T) {
 			require.NoError(t, err)
 			pb, err := result.Proto()
 			require.NoError(t, err)
-			pbBlock, ok := pb.(*ethpbalpha.SignedBeaconBlock)
+			pbBlock, ok := pb.(*ethpb.SignedBeaconBlock)
 			require.Equal(t, true, ok)
 			if !reflect.DeepEqual(pbBlock, tt.want) {
 				t.Error("Expected blocks to equal")
@@ -158,6 +166,118 @@ func TestGetBlock(t *testing.T) {
 	}
 }
 
+func deterministicRandomness(seed int64) [32]byte {
+	// Converts an int64 to a byte slice
+	buf := new(bytes.Buffer)
+	err := binary.Write(buf, binary.BigEndian, seed)
+	if err != nil {
+		logrus.WithError(err).Error("Failed to write int64 to bytes buffer")
+		return [32]byte{}
+	}
+	bytes := buf.Bytes()
+
+	return sha256.Sum256(bytes)
+}
+
+// Returns a serialized random field element in big-endian
+func getRandFieldElement(seed int64) [32]byte {
+	bytes := deterministicRandomness(seed)
+	var r fr.Element
+	r.SetBytes(bytes[:])
+
+	return GoKZG.SerializeScalar(r)
+}
+
+// Returns a random blob using the passed seed as entropy
+func getRandBlob(seed int64) kzg.Blob {
+	var blob kzg.Blob
+	for i := 0; i < len(blob); i += 32 {
+		fieldElementBytes := getRandFieldElement(seed + int64(i))
+		copy(blob[i:i+32], fieldElementBytes[:])
+	}
+	return blob
+}
+
+func generateCommitmentAndProof(blob *kzg.Blob) (*kzg.Commitment, *kzg.Proof, error) {
+	commitment, err := kzg.BlobToKZGCommitment(blob)
+	if err != nil {
+		return nil, nil, err
+	}
+	proof, err := kzg.ComputeBlobKZGProof(blob, commitment)
+	if err != nil {
+		return nil, nil, err
+	}
+	return &commitment, &proof, err
+}
+
+func generateRandomBlocSignedBeaconBlockkAndVerifiedRoBlobs(t *testing.T, blobCount int) (interfaces.SignedBeaconBlock, []*blocks.VerifiedROBlob) {
+	// Create a protobuf signed beacon block.
+	signedBeaconBlockPb := util.NewBeaconBlockDeneb()
+
+	// Generate random blobs and their corresponding commitments and proofs.
+	blobs := make([]kzg.Blob, 0, blobCount)
+	blobKzgCommitments := make([]*kzg.Commitment, 0, blobCount)
+	blobKzgProofs := make([]*kzg.Proof, 0, blobCount)
+
+	for blobIndex := range blobCount {
+		// Create a random blob.
+		blob := getRandBlob(int64(blobIndex))
+		blobs = append(blobs, blob)
+
+		// Generate a blobKZGCommitment for the blob.
+		blobKZGCommitment, proof, err := generateCommitmentAndProof(&blob)
+		require.NoError(t, err)
+
+		blobKzgCommitments = append(blobKzgCommitments, blobKZGCommitment)
+		blobKzgProofs = append(blobKzgProofs, proof)
+	}
+
+	// Set the commitments into the block.
+	blobZkgCommitmentsBytes := make([][]byte, 0, blobCount)
+	for _, blobKZGCommitment := range blobKzgCommitments {
+		blobZkgCommitmentsBytes = append(blobZkgCommitmentsBytes, blobKZGCommitment[:])
+	}
+
+	signedBeaconBlockPb.Block.Body.BlobKzgCommitments = blobZkgCommitmentsBytes
+
+	// Generate verified RO blobs.
+	verifiedROBlobs := make([]*blocks.VerifiedROBlob, 0, blobCount)
+
+	// Create a signed beacon block from the protobuf.
+	signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+	require.NoError(t, err)
+
+	commitmentInclusionProof, err := blocks.MerkleProofKZGCommitments(signedBeaconBlock.Block().Body())
+	require.NoError(t, err)
+
+	for blobIndex := range blobCount {
+		blob := blobs[blobIndex]
+		blobKZGCommitment := blobKzgCommitments[blobIndex]
+		blobKzgProof := blobKzgProofs[blobIndex]
+
+		// Get the signed beacon block header.
+		signedBeaconBlockHeader, err := signedBeaconBlock.Header()
+		require.NoError(t, err)
+
+		blobSidecar := &ethpb.BlobSidecar{
+			Index:                    uint64(blobIndex),
+			Blob:                     blob[:],
+			KzgCommitment:            blobKZGCommitment[:],
+			KzgProof:                 blobKzgProof[:],
+			SignedBlockHeader:        signedBeaconBlockHeader,
+			CommitmentInclusionProof: commitmentInclusionProof,
+		}
+
+		roBlob, err := blocks.NewROBlob(blobSidecar)
+		require.NoError(t, err)
+
+		verifiedROBlob := blocks.NewVerifiedROBlob(roBlob)
+		verifiedROBlobs = append(verifiedROBlobs, &verifiedROBlob)
+	}
+
+	return signedBeaconBlock, verifiedROBlobs
+}
+
 func TestGetBlob(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	cfg := params.BeaconConfig().Copy()
@@ -218,7 +338,7 @@ func TestGetBlob(t *testing.T) {
 	})
 	t.Run("finalized", func(t *testing.T) {
 		blocker := &BeaconDbBlocker{
-			ChainInfoFetcher: &mockChain.ChainService{FinalizedCheckPoint: &ethpbalpha.Checkpoint{Root: blockRoot[:]}},
+			ChainInfoFetcher: &mockChain.ChainService{FinalizedCheckPoint: &ethpb.Checkpoint{Root: blockRoot[:]}},
 			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
 				Genesis: time.Now(),
 			},
@@ -232,7 +352,7 @@ func TestGetBlob(t *testing.T) {
 	})
 	t.Run("justified", func(t *testing.T) {
 		blocker := &BeaconDbBlocker{
-			ChainInfoFetcher: &mockChain.ChainService{CurrentJustifiedCheckPoint: &ethpbalpha.Checkpoint{Root: blockRoot[:]}},
+			ChainInfoFetcher: &mockChain.ChainService{CurrentJustifiedCheckPoint: &ethpb.Checkpoint{Root: blockRoot[:]}},
 			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
 				Genesis: time.Now(),
 			},
@@ -270,14 +390,14 @@ func TestGetBlob(t *testing.T) {
 	})
 	t.Run("one blob only", func(t *testing.T) {
 		blocker := &BeaconDbBlocker{
-			ChainInfoFetcher: &mockChain.ChainService{FinalizedCheckPoint: &ethpbalpha.Checkpoint{Root: blockRoot[:]}},
+			ChainInfoFetcher: &mockChain.ChainService{FinalizedCheckPoint: &ethpb.Checkpoint{Root: blockRoot[:]}},
 			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
 				Genesis: time.Now(),
 			},
 			BeaconDB:    db,
 			BlobStorage: bs,
 		}
-		verifiedBlobs, rpcErr := blocker.Blobs(ctx, "123", []uint64{2})
+		verifiedBlobs, rpcErr := blocker.Blobs(ctx, "123", []int{2})
 		assert.Equal(t, rpcErr == nil, true)
 		require.Equal(t, 1, len(verifiedBlobs))
 		sidecar := verifiedBlobs[0].BlobSidecar
@@ -289,7 +409,7 @@ func TestGetBlob(t *testing.T) {
 	})
 	t.Run("no blobs returns an empty array", func(t *testing.T) {
 		blocker := &BeaconDbBlocker{
-			ChainInfoFetcher: &mockChain.ChainService{FinalizedCheckPoint: &ethpbalpha.Checkpoint{Root: blockRoot[:]}},
+			ChainInfoFetcher: &mockChain.ChainService{FinalizedCheckPoint: &ethpb.Checkpoint{Root: blockRoot[:]}},
 			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
 				Genesis: time.Now(),
 			},
@@ -302,28 +422,28 @@ func TestGetBlob(t *testing.T) {
 	})
 	t.Run("no blob at index", func(t *testing.T) {
 		blocker := &BeaconDbBlocker{
-			ChainInfoFetcher: &mockChain.ChainService{FinalizedCheckPoint: &ethpbalpha.Checkpoint{Root: blockRoot[:]}},
+			ChainInfoFetcher: &mockChain.ChainService{FinalizedCheckPoint: &ethpb.Checkpoint{Root: blockRoot[:]}},
 			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
 				Genesis: time.Now(),
 			},
 			BeaconDB:    db,
 			BlobStorage: bs,
 		}
-		noBlobIndex := uint64(len(blobs)) + 1
-		_, rpcErr := blocker.Blobs(ctx, "123", []uint64{0, noBlobIndex})
+		noBlobIndex := len(blobs) + 1
+		_, rpcErr := blocker.Blobs(ctx, "123", []int{0, noBlobIndex})
 		require.NotNil(t, rpcErr)
 		assert.Equal(t, core.ErrorReason(core.NotFound), rpcErr.Reason)
 	})
 	t.Run("index too big", func(t *testing.T) {
 		blocker := &BeaconDbBlocker{
-			ChainInfoFetcher: &mockChain.ChainService{FinalizedCheckPoint: &ethpbalpha.Checkpoint{Root: blockRoot[:]}},
+			ChainInfoFetcher: &mockChain.ChainService{FinalizedCheckPoint: &ethpb.Checkpoint{Root: blockRoot[:]}},
 			GenesisTimeFetcher: &testutil.MockGenesisTimeFetcher{
 				Genesis: time.Now(),
 			},
 			BeaconDB:    db,
 			BlobStorage: bs,
 		}
-		_, rpcErr := blocker.Blobs(ctx, "123", []uint64{0, math.MaxUint})
+		_, rpcErr := blocker.Blobs(ctx, "123", []int{0, math.MaxInt})
 		require.NotNil(t, rpcErr)
 		assert.Equal(t, core.ErrorReason(core.BadRequest), rpcErr.Reason)
 	})

beacon-chain/rpc/prysm/v1alpha1/debug/p2p.go

@@ -109,6 +109,8 @@ func (ds *Server) getPeer(pid peer.ID) (*ethpb.DebugPeerResponse, error) {
 			peerInfo.MetadataV0 = metadata.MetadataObjV0()
 		case metadata.MetadataObjV1() != nil:
 			peerInfo.MetadataV1 = metadata.MetadataObjV1()
+		case metadata.MetadataObjV2() != nil:
+			peerInfo.MetadataV2 = metadata.MetadataObjV2()
 		}
 	}
 	addresses := peerStore.Addrs(pid)

beacon-chain/rpc/prysm/v1alpha1/validator/BUILD.bazel

@@ -1,3 +1,5 @@
+# gazelle:ignore
+
 load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 
 go_library(
@@ -36,6 +38,7 @@ go_library(
         "//api/client/builder:go_default_library",
         "//async/event:go_default_library",
         "//beacon-chain/blockchain:go_default_library",
+        "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/builder:go_default_library",
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/cache/depositsnapshot:go_default_library",
@@ -46,6 +49,7 @@ go_library(
         "//beacon-chain/core/feed/operation:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
@@ -179,7 +183,6 @@ common_deps = [
     "@org_golang_google_protobuf//types/known/emptypb:go_default_library",
 ]
 
-# gazelle:ignore
 go_test(
     name = "go_default_test",
     timeout = "moderate",

beacon-chain/rpc/prysm/v1alpha1/validator/construct_generic_block.go

@@ -8,13 +8,18 @@ import (
 	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/pkg/errors"
 	"google.golang.org/protobuf/proto"
 )
 
 // constructGenericBeaconBlock constructs a `GenericBeaconBlock` based on the block version and other parameters.
-func (vs *Server) constructGenericBeaconBlock(sBlk interfaces.SignedBeaconBlock, blobsBundle *enginev1.BlobsBundle, winningBid primitives.Wei) (*ethpb.GenericBeaconBlock, error) {
+func (vs *Server) constructGenericBeaconBlock(
+	sBlk interfaces.SignedBeaconBlock,
+	blobsBundler enginev1.BlobsBundler,
+	winningBid primitives.Wei,
+) (*ethpb.GenericBeaconBlock, error) {
 	if sBlk == nil || sBlk.Block() == nil {
-		return nil, fmt.Errorf("block cannot be nil")
+		return nil, errors.New("block cannot be nil")
 	}
 
 	blockProto, err := sBlk.Block().Proto()
@@ -34,12 +39,21 @@ func (vs *Server) constructGenericBeaconBlock(sBlk interfaces.SignedBeaconBlock,
 		return vs.constructBellatrixBlock(blockProto, isBlinded, bidStr), nil
 	case version.Capella:
 		return vs.constructCapellaBlock(blockProto, isBlinded, bidStr), nil
-	case version.Deneb:
-		return vs.constructDenebBlock(blockProto, isBlinded, bidStr, blobsBundle), nil
-	case version.Electra:
-		return vs.constructElectraBlock(blockProto, isBlinded, bidStr, blobsBundle), nil
+	case version.Deneb, version.Electra:
+		bundle, ok := blobsBundler.(*enginev1.BlobsBundle)
+		if blobsBundler != nil && !ok {
+			return nil, fmt.Errorf("expected *BlobsBundler, got %T", blobsBundler)
+		}
+		if sBlk.Version() == version.Deneb {
+			return vs.constructDenebBlock(blockProto, isBlinded, bidStr, bundle), nil
+		}
+		return vs.constructElectraBlock(blockProto, isBlinded, bidStr, bundle), nil
 	case version.Fulu:
-		return vs.constructFuluBlock(blockProto, isBlinded, bidStr, blobsBundle), nil
+		bundle, ok := blobsBundler.(*enginev1.BlobsBundleV2)
+		if blobsBundler != nil && !ok {
+			return nil, fmt.Errorf("expected *BlobsBundleV2, got %T", blobsBundler)
+		}
+		return vs.constructFuluBlock(blockProto, isBlinded, bidStr, bundle), nil
 	default:
 		return nil, fmt.Errorf("unknown block version: %d", sBlk.Version())
 	}
@@ -92,7 +106,7 @@ func (vs *Server) constructElectraBlock(blockProto proto.Message, isBlinded bool
 	return &ethpb.GenericBeaconBlock{Block: &ethpb.GenericBeaconBlock_Electra{Electra: electraContents}, IsBlinded: false, PayloadValue: payloadValue}
 }
 
-func (vs *Server) constructFuluBlock(blockProto proto.Message, isBlinded bool, payloadValue string, bundle *enginev1.BlobsBundle) *ethpb.GenericBeaconBlock {
+func (vs *Server) constructFuluBlock(blockProto proto.Message, isBlinded bool, payloadValue string, bundle *enginev1.BlobsBundleV2) *ethpb.GenericBeaconBlock {
 	if isBlinded {
 		return &ethpb.GenericBeaconBlock{Block: &ethpb.GenericBeaconBlock_BlindedFulu{BlindedFulu: blockProto.(*ethpb.BlindedBeaconBlockFulu)}, IsBlinded: true, PayloadValue: payloadValue}
 	}

beacon-chain/rpc/prysm/v1alpha1/validator/construct_generic_block_test.go

@@ -29,12 +29,19 @@ func TestConstructGenericBeaconBlock(t *testing.T) {
 		require.NoError(t, err)
 		r1, err := eb.Block.HashTreeRoot()
 		require.NoError(t, err)
-		result, err := vs.constructGenericBeaconBlock(b, nil, primitives.ZeroWei())
+		bundle := &enginev1.BlobsBundleV2{
+			KzgCommitments: [][]byte{{1, 2, 3}},
+			Proofs:         [][]byte{{4, 5, 6}},
+			Blobs:          [][]byte{{7, 8, 9}},
+		}
+		result, err := vs.constructGenericBeaconBlock(b, bundle, primitives.ZeroWei())
 		require.NoError(t, err)
 		r2, err := result.GetFulu().Block.HashTreeRoot()
 		require.NoError(t, err)
 		require.Equal(t, r1, r2)
 		require.Equal(t, result.IsBlinded, false)
+		require.DeepEqual(t, bundle.Blobs, result.GetFulu().GetBlobs())
+		require.DeepEqual(t, bundle.Proofs, result.GetFulu().GetKzgProofs())
 	})
 
 	// Test for Electra version

beacon-chain/rpc/prysm/v1alpha1/validator/proposer.go

@@ -15,9 +15,13 @@ import (
 	blockfeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/block"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/operation"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	coreTime "github.com/OffchainLabs/prysm/v6/beacon-chain/core/time"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/kv"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
+	"github.com/OffchainLabs/prysm/v6/config/features"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
@@ -58,28 +62,31 @@ func (vs *Server) GetBeaconBlock(ctx context.Context, req *ethpb.BlockRequest) (
 	if err != nil {
 		log.WithError(err).Error("Could not convert slot to time")
 	}
-	log.WithFields(logrus.Fields{
-		"slot":               req.Slot,
-		"sinceSlotStartTime": time.Since(t),
-	}).Info("Begin building block")
+
+	log := log.WithField("slot", req.Slot)
+	log.WithField("sinceSlotStartTime", time.Since(t)).Info("Begin building block")
 
 	// A syncing validator should not produce a block.
 	if vs.SyncChecker.Syncing() {
+		log.Error("Fail to build block: node is syncing")
 		return nil, status.Error(codes.Unavailable, "Syncing to latest head, not ready to respond")
 	}
 	// An optimistic validator MUST NOT produce a block (i.e., sign across the DOMAIN_BEACON_PROPOSER domain).
 	if slots.ToEpoch(req.Slot) >= params.BeaconConfig().BellatrixForkEpoch {
 		if err := vs.optimisticStatus(ctx); err != nil {
+			log.WithError(err).Error("Fail to build block: node is optimistic")
 			return nil, status.Errorf(codes.Unavailable, "Validator is not ready to propose: %v", err)
 		}
 	}
 
 	head, parentRoot, err := vs.getParentState(ctx, req.Slot)
 	if err != nil {
+		log.WithError(err).Error("Fail to build block: could not get parent state")
 		return nil, err
 	}
 	sBlk, err := getEmptyBlock(req.Slot)
 	if err != nil {
+		log.WithError(err).Error("Fail to build block: could not get empty block")
 		return nil, status.Errorf(codes.Internal, "Could not prepare block: %v", err)
 	}
 	// Set slot, graffiti, randao reveal, and parent root.
@@ -91,6 +98,7 @@ func (vs *Server) GetBeaconBlock(ctx context.Context, req *ethpb.BlockRequest) (
 	// Set proposer index.
 	idx, err := helpers.BeaconProposerIndex(ctx, head)
 	if err != nil {
+		log.WithError(err).Error("Fail to build block: could not calculate proposer index")
 		return nil, fmt.Errorf("could not calculate proposer index %w", err)
 	}
 	sBlk.SetProposerIndex(idx)
@@ -101,7 +109,7 @@ func (vs *Server) GetBeaconBlock(ctx context.Context, req *ethpb.BlockRequest) (
 	}
 
 	resp, err := vs.BuildBlockParallel(ctx, sBlk, head, req.SkipMevBoost, builderBoostFactor)
-	log := log.WithFields(logrus.Fields{
+	log = log.WithFields(logrus.Fields{
 		"slot":               req.Slot,
 		"sinceSlotStartTime": time.Since(t),
 		"validator":          sBlk.Block().ProposerIndex(),
@@ -232,7 +240,7 @@ func (vs *Server) BuildBlockParallel(ctx context.Context, sBlk interfaces.Signed
 	}()
 
 	winningBid := primitives.ZeroWei()
-	var bundle *enginev1.BlobsBundle
+	var bundle enginev1.BlobsBundler
 	if sBlk.Version() >= version.Bellatrix {
 		local, err := vs.getLocalPayload(ctx, sBlk.Block(), head)
 		if err != nil {
@@ -274,7 +282,13 @@ func (vs *Server) BuildBlockParallel(ctx context.Context, sBlk interfaces.Signed
 // Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // ProposeBeaconBlock handles the proposal of beacon blocks.
+// TODO: Add tests
 func (vs *Server) ProposeBeaconBlock(ctx context.Context, req *ethpb.GenericSignedBeaconBlock) (*ethpb.ProposeResponse, error) {
+	var (
+		blobSidecars       []*ethpb.BlobSidecar
+		dataColumnSideCars []*ethpb.DataColumnSidecar
+	)
+
 	ctx, span := trace.StartSpan(ctx, "ProposerServer.ProposeBeaconBlock")
 	defer span.End()
 
@@ -286,12 +300,12 @@ func (vs *Server) ProposeBeaconBlock(ctx context.Context, req *ethpb.GenericSign
 	if err != nil {
 		return nil, status.Errorf(codes.InvalidArgument, "%s: %v", "decode block failed", err)
 	}
+	isPeerDASEnabled := coreTime.PeerDASIsActive(block.Block().Slot())
 
-	var sidecars []*ethpb.BlobSidecar
 	if block.IsBlinded() {
-		block, sidecars, err = vs.handleBlindedBlock(ctx, block)
+		block, blobSidecars, dataColumnSideCars, err = vs.handleBlindedBlock(ctx, block, isPeerDASEnabled)
 	} else if block.Version() >= version.Deneb {
-		sidecars, err = vs.blobSidecarsFromUnblindedBlock(block, req)
+		blobSidecars, dataColumnSideCars, err = vs.handleUnblindedBlock(block, req, isPeerDASEnabled)
 	}
 	if err != nil {
 		return nil, status.Errorf(codes.Internal, "%s: %v", "handle block failed", err)
@@ -302,9 +316,10 @@ func (vs *Server) ProposeBeaconBlock(ctx context.Context, req *ethpb.GenericSign
 		return nil, status.Errorf(codes.Internal, "Could not hash tree root: %v", err)
 	}
 
+	slot := block.Block().Slot()
+
 	var wg sync.WaitGroup
 	errChan := make(chan error, 1)
-
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
@@ -315,8 +330,14 @@ func (vs *Server) ProposeBeaconBlock(ctx context.Context, req *ethpb.GenericSign
 		errChan <- nil
 	}()
 
-	if err := vs.broadcastAndReceiveBlobs(ctx, sidecars, root); err != nil {
-		return nil, status.Errorf(codes.Internal, "Could not broadcast/receive blobs: %v", err)
+	if isPeerDASEnabled {
+		if err := vs.broadcastAndReceiveDataColumns(ctx, dataColumnSideCars, root, slot); err != nil {
+			return nil, status.Errorf(codes.Internal, "Could not broadcast/receive data columns: %v", err)
+		}
+	} else {
+		if err := vs.broadcastAndReceiveBlobs(ctx, blobSidecars, root); err != nil {
+			return nil, status.Errorf(codes.Internal, "Could not broadcast/receive blobs: %v", err)
+		}
 	}
 
 	wg.Wait()
@@ -328,46 +349,75 @@ func (vs *Server) ProposeBeaconBlock(ctx context.Context, req *ethpb.GenericSign
 }
 
 // handleBlindedBlock processes blinded beacon blocks.
-func (vs *Server) handleBlindedBlock(ctx context.Context, block interfaces.SignedBeaconBlock) (interfaces.SignedBeaconBlock, []*ethpb.BlobSidecar, error) {
+func (vs *Server) handleBlindedBlock(ctx context.Context, block interfaces.SignedBeaconBlock, isPeerDASEnabled bool) (interfaces.SignedBeaconBlock, []*ethpb.BlobSidecar, []*ethpb.DataColumnSidecar, error) {
 	if block.Version() < version.Bellatrix {
-		return nil, nil, errors.New("pre-Bellatrix blinded block")
+		return nil, nil, nil, errors.New("pre-Bellatrix blinded block")
 	}
+
 	if vs.BlockBuilder == nil || !vs.BlockBuilder.Configured() {
-		return nil, nil, errors.New("unconfigured block builder")
+		return nil, nil, nil, errors.New("unconfigured block builder")
 	}
 
 	copiedBlock, err := block.Copy()
 	if err != nil {
-		return nil, nil, err
+		return nil, nil, nil, errors.Wrap(err, "block copy")
 	}
 
 	payload, bundle, err := vs.BlockBuilder.SubmitBlindedBlock(ctx, block)
 	if err != nil {
-		return nil, nil, errors.Wrap(err, "submit blinded block failed")
+		return nil, nil, nil, errors.Wrap(err, "submit blinded block")
 	}
 
 	if err := copiedBlock.Unblind(payload); err != nil {
-		return nil, nil, errors.Wrap(err, "unblind failed")
+		return nil, nil, nil, errors.Wrap(err, "unblind")
 	}
 
-	sidecars, err := unblindBlobsSidecars(copiedBlock, bundle)
+	if isPeerDASEnabled {
+		dataColumnSideCars, err := peerdas.ConstructDataColumnSidecars(block, bundle.GetBlobs(), bundle.GetProofs())
+		if err != nil {
+			return nil, nil, nil, errors.Wrap(err, "construct data column sidecars")
+		}
+
+		return copiedBlock, nil, dataColumnSideCars, nil
+	}
+
+	blobSidecars, err := unblindBlobsSidecars(copiedBlock, bundle)
 	if err != nil {
-		return nil, nil, errors.Wrap(err, "unblind blobs sidecars: commitment value doesn't match block")
+		return nil, nil, nil, errors.Wrap(err, "unblind blobs sidecars: commitment value doesn't match block")
 	}
 
-	return copiedBlock, sidecars, nil
+	return copiedBlock, blobSidecars, nil, nil
 }
 
-func (vs *Server) blobSidecarsFromUnblindedBlock(block interfaces.SignedBeaconBlock, req *ethpb.GenericSignedBeaconBlock) ([]*ethpb.BlobSidecar, error) {
+func (vs *Server) handleUnblindedBlock(
+	block interfaces.SignedBeaconBlock,
+	req *ethpb.GenericSignedBeaconBlock,
+	isPeerDASEnabled bool,
+) ([]*ethpb.BlobSidecar, []*ethpb.DataColumnSidecar, error) {
 	rawBlobs, proofs, err := blobsAndProofs(req)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
-	return BuildBlobSidecars(block, rawBlobs, proofs)
+
+	if isPeerDASEnabled {
+		dataColumnSideCars, err := peerdas.ConstructDataColumnSidecars(block, rawBlobs, proofs)
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "construct data column sidecars")
+		}
+
+		return nil, dataColumnSideCars, nil
+	}
+
+	blobSidecars, err := BuildBlobSidecars(block, rawBlobs, proofs)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "build blob sidecars")
+	}
+
+	return blobSidecars, nil, nil
 }
 
 // broadcastReceiveBlock broadcasts a block and handles its reception.
-func (vs *Server) broadcastReceiveBlock(ctx context.Context, block interfaces.SignedBeaconBlock, root [32]byte) error {
+func (vs *Server) broadcastReceiveBlock(ctx context.Context, block interfaces.SignedBeaconBlock, root [fieldparams.RootLength]byte) error {
 	protoBlock, err := block.Proto()
 	if err != nil {
 		return errors.Wrap(err, "protobuf conversion failed")
@@ -383,7 +433,7 @@ func (vs *Server) broadcastReceiveBlock(ctx context.Context, block interfaces.Si
 }
 
 // broadcastAndReceiveBlobs handles the broadcasting and reception of blob sidecars.
-func (vs *Server) broadcastAndReceiveBlobs(ctx context.Context, sidecars []*ethpb.BlobSidecar, root [32]byte) error {
+func (vs *Server) broadcastAndReceiveBlobs(ctx context.Context, sidecars []*ethpb.BlobSidecar, root [fieldparams.RootLength]byte) error {
 	eg, eCtx := errgroup.WithContext(ctx)
 	for i, sc := range sidecars {
 		// Copy the iteration instance to a local variable to give each go-routine its own copy to play with.
@@ -412,6 +462,69 @@ func (vs *Server) broadcastAndReceiveBlobs(ctx context.Context, sidecars []*ethp
 	return eg.Wait()
 }
 
+// broadcastAndReceiveDataColumns handles the broadcasting and reception of data columns sidecars.
+func (vs *Server) broadcastAndReceiveDataColumns(
+	ctx context.Context,
+	sidecars []*ethpb.DataColumnSidecar,
+	root [fieldparams.RootLength]byte,
+	slot primitives.Slot,
+) error {
+	dataColumnsWithholdCount := features.Get().DataColumnsWithholdCount
+	verifiedRODataColumns := make([]blocks.VerifiedRODataColumn, 0, len(sidecars))
+
+	eg, _ := errgroup.WithContext(ctx)
+	for _, sd := range sidecars {
+		roDataColumn, err := blocks.NewRODataColumnWithRoot(sd, root)
+		if err != nil {
+			return errors.Wrap(err, "new read-only data column with root")
+		}
+
+		// We build this block ourselves, so we can upgrade the read only data column sidecar into a verified one.
+		verifiedRODataColumn := blocks.NewVerifiedRODataColumn(roDataColumn)
+		verifiedRODataColumns = append(verifiedRODataColumns, verifiedRODataColumn)
+
+		// Copy the iteration instance to a local variable to give each go-routine its own copy to play with.
+		// See https://golang.org/doc/faq#closures_and_goroutines for more details.
+		sidecar := sd
+		eg.Go(func() error {
+			if sidecar.Index < dataColumnsWithholdCount {
+				log.WithFields(logrus.Fields{
+					"root":  fmt.Sprintf("%#x", root),
+					"slot":  slot,
+					"index": sidecar.Index,
+				}).Warning("Withholding data column")
+
+				return nil
+			}
+
+			// Compute the subnet index based on the column index.
+			subnet := peerdas.ComputeSubnetForDataColumnSidecar(sidecar.Index)
+
+			if err := vs.P2P.BroadcastDataColumn(root, subnet, sidecar); err != nil {
+				return errors.Wrap(err, "broadcast data column")
+			}
+
+			return nil
+		})
+	}
+
+	if err := eg.Wait(); err != nil {
+		return errors.Wrap(err, "wait for data columns to be broadcasted")
+	}
+
+	if err := vs.DataColumnReceiver.ReceiveDataColumns(verifiedRODataColumns); err != nil {
+		return errors.Wrap(err, "receive data column")
+	}
+
+	for _, verifiedRODataColumn := range verifiedRODataColumns {
+		vs.OperationNotifier.OperationFeed().Send(&feed.Event{
+			Type: operation.DataColumnSidecarReceived,
+			Data: &operation.DataColumnSidecarReceivedData{DataColumn: &verifiedRODataColumn}, // #nosec G601
+		})
+	}
+	return nil
+}
+
 // Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // PrepareBeaconProposer caches and updates the fee recipient for the given proposer.

beacon-chain/rpc/prysm/v1alpha1/validator/proposer_bellatrix.go

@@ -54,7 +54,7 @@ const blockBuilderTimeout = 1 * time.Second
 const gasLimitAdjustmentFactor = 1024
 
 // Sets the execution data for the block. Execution data can come from local EL client or remote builder depends on validator registration and circuit breaker conditions.
-func setExecutionData(ctx context.Context, blk interfaces.SignedBeaconBlock, local *blocks.GetPayloadResponse, bid builder.Bid, builderBoostFactor primitives.Gwei) (primitives.Wei, *enginev1.BlobsBundle, error) {
+func setExecutionData(ctx context.Context, blk interfaces.SignedBeaconBlock, local *blocks.GetPayloadResponse, bid builder.Bid, builderBoostFactor primitives.Gwei) (primitives.Wei, enginev1.BlobsBundler, error) {
 	_, span := trace.StartSpan(ctx, "ProposerServer.setExecutionData")
 	defer span.End()
 
@@ -69,13 +69,13 @@ func setExecutionData(ctx context.Context, blk interfaces.SignedBeaconBlock, loc
 
 	// Use local payload if builder payload is nil.
 	if bid == nil {
-		return local.Bid, local.BlobsBundle, setLocalExecution(blk, local)
+		return local.Bid, local.BlobsBundler, setLocalExecution(blk, local)
 	}
 
 	builderPayload, err := bid.Header()
 	if err != nil {
 		log.WithError(err).Warn("Proposer: failed to retrieve header from BuilderBid")
-		return local.Bid, local.BlobsBundle, setLocalExecution(blk, local)
+		return local.Bid, local.BlobsBundler, setLocalExecution(blk, local)
 	}
 
 	switch {
@@ -84,7 +84,7 @@ func setExecutionData(ctx context.Context, blk interfaces.SignedBeaconBlock, loc
 		if err != nil {
 			tracing.AnnotateError(span, err)
 			log.WithError(err).Warn("Proposer: failed to match withdrawals root")
-			return local.Bid, local.BlobsBundle, setLocalExecution(blk, local)
+			return local.Bid, local.BlobsBundler, setLocalExecution(blk, local)
 		}
 
 		// Compare payload values between local and builder. Default to the local value if it is higher.
@@ -97,7 +97,7 @@ func setExecutionData(ctx context.Context, blk interfaces.SignedBeaconBlock, loc
 				"minBuilderBid":    minBid,
 				"builderGweiValue": builderValueGwei,
 			}).Warn("Proposer: using local execution payload because min bid not attained")
-			return local.Bid, local.BlobsBundle, setLocalExecution(blk, local)
+			return local.Bid, local.BlobsBundler, setLocalExecution(blk, local)
 		}
 
 		// Use local block if min difference is not attained
@@ -108,7 +108,7 @@ func setExecutionData(ctx context.Context, blk interfaces.SignedBeaconBlock, loc
 				"minBidDiff":       minDiff,
 				"builderGweiValue": builderValueGwei,
 			}).Warn("Proposer: using local execution payload because min difference with local value was not attained")
-			return local.Bid, local.BlobsBundle, setLocalExecution(blk, local)
+			return local.Bid, local.BlobsBundler, setLocalExecution(blk, local)
 		}
 
 		// Use builder payload if the following in true:
@@ -133,7 +133,7 @@ func setExecutionData(ctx context.Context, blk interfaces.SignedBeaconBlock, loc
 				bidDeneb, ok := bid.(builder.BidDeneb)
 				if !ok {
 					log.Warnf("bid type %T does not implement builder.BidDeneb", bid)
-					return local.Bid, local.BlobsBundle, setLocalExecution(blk, local)
+					return local.Bid, local.BlobsBundler, setLocalExecution(blk, local)
 				} else {
 					builderKzgCommitments = bidDeneb.BlobKzgCommitments()
 				}
@@ -144,14 +144,14 @@ func setExecutionData(ctx context.Context, blk interfaces.SignedBeaconBlock, loc
 				bidElectra, ok := bid.(builder.BidElectra)
 				if !ok {
 					log.Warnf("bid type %T does not implement builder.BidElectra", bid)
-					return local.Bid, local.BlobsBundle, setLocalExecution(blk, local)
+					return local.Bid, local.BlobsBundler, setLocalExecution(blk, local)
 				} else {
 					executionRequests = bidElectra.ExecutionRequests()
 				}
 			}
 			if err := setBuilderExecution(blk, builderPayload, builderKzgCommitments, executionRequests); err != nil {
 				log.WithError(err).Warn("Proposer: failed to set builder payload")
-				return local.Bid, local.BlobsBundle, setLocalExecution(blk, local)
+				return local.Bid, local.BlobsBundler, setLocalExecution(blk, local)
 			} else {
 				return bid.Value(), nil, nil
 			}
@@ -171,11 +171,11 @@ func setExecutionData(ctx context.Context, blk interfaces.SignedBeaconBlock, loc
 			trace.Int64Attribute("builderGweiValue", int64(builderValueGwei)),     // lint:ignore uintcast -- This is OK for tracing.
 			trace.Int64Attribute("builderBoostFactor", int64(builderBoostFactor)), // lint:ignore uintcast -- This is OK for tracing.
 		)
-		return local.Bid, local.BlobsBundle, setLocalExecution(blk, local)
+		return local.Bid, local.BlobsBundler, setLocalExecution(blk, local)
 	default: // Bellatrix case.
 		if err := setBuilderExecution(blk, builderPayload, nil, nil); err != nil {
 			log.WithError(err).Warn("Proposer: failed to set builder payload")
-			return local.Bid, local.BlobsBundle, setLocalExecution(blk, local)
+			return local.Bid, local.BlobsBundler, setLocalExecution(blk, local)
 		} else {
 			return bid.Value(), nil, nil
 		}
@@ -375,8 +375,8 @@ func matchingWithdrawalsRoot(local, builder interfaces.ExecutionData) (bool, err
 // It delegates to setExecution for the actual work.
 func setLocalExecution(blk interfaces.SignedBeaconBlock, local *blocks.GetPayloadResponse) error {
 	var kzgCommitments [][]byte
-	if local.BlobsBundle != nil {
-		kzgCommitments = local.BlobsBundle.KzgCommitments
+	if local.BlobsBundler != nil {
+		kzgCommitments = local.BlobsBundler.GetKzgCommitments()
 	}
 	if local.ExecutionRequests != nil {
 		if err := blk.SetExecutionRequests(local.ExecutionRequests); err != nil {

beacon-chain/rpc/prysm/v1alpha1/validator/proposer_bellatrix_test.go

@@ -520,7 +520,7 @@ func TestServer_setExecutionData(t *testing.T) {
 			PayloadIDBytes: id,
 			GetPayloadResponse: &blocks.GetPayloadResponse{
 				ExecutionData: ed,
-				BlobsBundle:   blobsBundle,
+				BlobsBundler:  blobsBundle,
 				Bid:           primitives.ZeroWei(),
 			},
 		}
@@ -528,7 +528,7 @@ func TestServer_setExecutionData(t *testing.T) {
 		res, err := vs.getLocalPayload(ctx, blk.Block(), capellaTransitionState)
 		require.NoError(t, err)
 		require.Equal(t, uint64(4), res.ExecutionData.BlockNumber())
-		require.DeepEqual(t, res.BlobsBundle, blobsBundle)
+		require.DeepEqual(t, res.BlobsBundler, blobsBundle)
 	})
 	t.Run("Can get builder payload and blobs in Deneb", func(t *testing.T) {
 		cfg := params.BeaconConfig().Copy()

beacon-chain/rpc/prysm/v1alpha1/validator/proposer_test.go

@@ -529,7 +529,7 @@ func TestServer_GetBeaconBlock_Deneb(t *testing.T) {
 		PayloadIDBytes: &enginev1.PayloadIDBytes{1},
 		GetPayloadResponse: &blocks.GetPayloadResponse{
 			ExecutionData: ed,
-			BlobsBundle:   bundle,
+			BlobsBundler:  bundle,
 		},
 	}
 

beacon-chain/rpc/prysm/v1alpha1/validator/server.go

@@ -67,6 +67,7 @@ type Server struct {
 	SyncCommitteePool       synccommittee.Pool
 	BlockReceiver           blockchain.BlockReceiver
 	BlobReceiver            blockchain.BlobReceiver
+	DataColumnReceiver      blockchain.DataColumnReceiver
 	MockEth1Votes           bool
 	Eth1BlockFetcher        execution.POWBlockFetcher
 	PendingDepositsFetcher  depositsnapshot.PendingDepositsFetcher

beacon-chain/rpc/service.go

@@ -89,6 +89,7 @@ type Config struct {
 	AttestationReceiver       blockchain.AttestationReceiver
 	BlockReceiver             blockchain.BlockReceiver
 	BlobReceiver              blockchain.BlobReceiver
+	DataColumnReceiver        blockchain.DataColumnReceiver
 	ExecutionChainService     execution.Chain
 	ChainStartFetcher         execution.ChainStartFetcher
 	ExecutionChainInfoFetcher execution.ChainInfoFetcher
@@ -120,6 +121,7 @@ type Config struct {
 	Router                    *http.ServeMux
 	ClockWaiter               startup.ClockWaiter
 	BlobStorage               *filesystem.BlobStorage
+	DataColumnStorage         *filesystem.DataColumnStorage
 	TrackedValidatorsCache    *cache.TrackedValidatorsCache
 	PayloadIDCache            *cache.PayloadIDCache
 	LCStore                   *lightClient.Store
@@ -196,6 +198,7 @@ func NewService(ctx context.Context, cfg *Config) *Service {
 		ChainInfoFetcher:   s.cfg.ChainInfoFetcher,
 		GenesisTimeFetcher: s.cfg.GenesisTimeFetcher,
 		BlobStorage:        s.cfg.BlobStorage,
+		DataColumnStorage:  s.cfg.DataColumnStorage,
 	}
 	rewardFetcher := &rewards.BlockRewardService{Replayer: ch, DB: s.cfg.BeaconDB}
 	coreService := &core.Service{
@@ -236,6 +239,7 @@ func NewService(ctx context.Context, cfg *Config) *Service {
 		P2P:                     s.cfg.Broadcaster,
 		BlockReceiver:           s.cfg.BlockReceiver,
 		BlobReceiver:            s.cfg.BlobReceiver,
+		DataColumnReceiver:      s.cfg.DataColumnReceiver,
 		MockEth1Votes:           s.cfg.MockEth1Votes,
 		Eth1BlockFetcher:        s.cfg.ExecutionChainService,
 		PendingDepositsFetcher:  s.cfg.PendingDepositFetcher,

beacon-chain/rpc/testutil/mock_blocker.go

@@ -36,6 +36,6 @@ func (m *MockBlocker) Block(_ context.Context, b []byte) (interfaces.ReadOnlySig
 }
 
 // Blobs --
-func (m *MockBlocker) Blobs(_ context.Context, _ string, _ []uint64) ([]*blocks.VerifiedROBlob, *core.RpcError) {
-	panic("implement me") // lint:nopanic -- Test code.
+func (*MockBlocker) Blobs(_ context.Context, _ string, _ []int) ([]*blocks.VerifiedROBlob, *core.RpcError) {
+	return nil, &core.RpcError{}
 }

beacon-chain/state/stategen/getter.go

@@ -259,7 +259,7 @@ func (s *State) latestAncestor(ctx context.Context, blockRoot [32]byte) (state.B
 	defer span.End()
 
 	if s.isFinalizedRoot(blockRoot) {
-		finalizedState := s.finalizedState()
+		finalizedState := s.FinalizedState()
 		if finalizedState != nil {
 			return finalizedState, nil
 		}
@@ -297,7 +297,7 @@ func (s *State) latestAncestor(ctx context.Context, blockRoot [32]byte) (state.B
 
 		// Does the state exist in finalized info cache.
 		if s.isFinalizedRoot(parentRoot) {
-			return s.finalizedState(), nil
+			return s.FinalizedState(), nil
 		}
 
 		// Does the state exist in epoch boundary cache.

beacon-chain/state/stategen/service.go

@@ -196,7 +196,7 @@ func (s *State) isFinalizedRoot(r [32]byte) bool {
 }
 
 // Returns the cached and copied finalized state.
-func (s *State) finalizedState() state.BeaconState {
+func (s *State) FinalizedState() state.BeaconState {
 	s.finalizedInfo.lock.RLock()
 	defer s.finalizedInfo.lock.RUnlock()
 	return s.finalizedInfo.state.Copy()

beacon-chain/state/stategen/service_test.go

@@ -33,5 +33,5 @@ func TestResume(t *testing.T) {
 	require.DeepSSZEqual(t, beaconState.ToProtoUnsafe(), resumeState.ToProtoUnsafe())
 	assert.Equal(t, params.BeaconConfig().SlotsPerEpoch, service.finalizedInfo.slot, "Did not get watned slot")
 	assert.Equal(t, service.finalizedInfo.root, root, "Did not get wanted root")
-	assert.NotNil(t, service.finalizedState(), "Wanted a non nil finalized state")
+	assert.NotNil(t, service.FinalizedState(), "Wanted a non nil finalized state")
 }

beacon-chain/sync/BUILD.bazel

@@ -7,6 +7,10 @@ go_library(
         "block_batcher.go",
         "broadcast_bls_changes.go",
         "context.go",
+        "data_column_assignment.go",
+        "data_columns.go",
+        "data_columns_reconstruct.go",
+        "data_columns_sampling.go",
         "deadlines.go",
         "decode_pubsub.go",
         "doc.go",
@@ -25,6 +29,8 @@ go_library(
         "rpc_blob_sidecars_by_range.go",
         "rpc_blob_sidecars_by_root.go",
         "rpc_chunked_response.go",
+        "rpc_data_column_sidecars_by_range.go",
+        "rpc_data_column_sidecars_by_root.go",
         "rpc_goodbye.go",
         "rpc_light_client.go",
         "rpc_metadata.go",
@@ -38,6 +44,7 @@ go_library(
         "subscriber_beacon_blocks.go",
         "subscriber_blob_sidecar.go",
         "subscriber_bls_to_execution_change.go",
+        "subscriber_data_column_sidecar.go",
         "subscriber_handlers.go",
         "subscriber_light_client.go",
         "subscriber_sync_committee_message.go",
@@ -55,6 +62,7 @@ go_library(
         "validate_sync_committee_message.go",
         "validate_sync_contribution_proof.go",
         "validate_voluntary_exit.go",
+        "validators_custody.go",
     ],
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/sync",
     visibility = [
@@ -76,7 +84,9 @@ go_library(
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/light-client:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/core/transition/interop:go_default_library",
         "//beacon-chain/db:go_default_library",
@@ -130,6 +140,7 @@ go_library(
         "//time:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_hashicorp_golang_lru//:go_default_library",
         "@com_github_libp2p_go_libp2p//core:go_default_library",
         "@com_github_libp2p_go_libp2p//core/host:go_default_library",
@@ -153,13 +164,15 @@ go_library(
 
 go_test(
     name = "go_default_test",
-    size = "small",
+    size = "medium",
     srcs = [
         "batch_verifier_test.go",
         "blobs_test.go",
         "block_batcher_test.go",
         "broadcast_bls_changes_test.go",
         "context_test.go",
+        "data_columns_sampling_test.go",
+        "data_columns_test.go",
         "decode_pubsub_test.go",
         "error_test.go",
         "fork_watcher_test.go",
@@ -197,19 +210,23 @@ go_test(
         "validate_sync_committee_message_test.go",
         "validate_sync_contribution_proof_test.go",
         "validate_voluntary_exit_test.go",
+        "validators_custody_test.go",
     ],
     embed = [":go_default_library"],
     shard_count = 4,
     deps = [
         "//async/abool:go_default_library",
         "//beacon-chain/blockchain:go_default_library",
+        "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/blockchain/testing:go_default_library",
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/core/altair:go_default_library",
         "//beacon-chain/core/feed:go_default_library",
         "//beacon-chain/core/feed/operation:go_default_library",
+        "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/light-client:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
@@ -247,6 +264,7 @@ go_test(
         "//container/leaky-bucket:go_default_library",
         "//container/slice:go_default_library",
         "//crypto/bls:go_default_library",
+        "//crypto/ecdsa:go_default_library",
         "//crypto/rand:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//encoding/ssz/equality:go_default_library",
@@ -261,13 +279,17 @@ go_test(
         "//testing/util:go_default_library",
         "//time:go_default_library",
         "//time/slots:go_default_library",
+        "@com_github_consensys_gnark_crypto//ecc/bls12-381/fr:go_default_library",
+        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
         "@com_github_d4l3k_messagediff//:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_ethereum_go_ethereum//core/types:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_ethereum_go_ethereum//p2p/enr:go_default_library",
         "@com_github_golang_snappy//:go_default_library",
         "@com_github_libp2p_go_libp2p//:go_default_library",
         "@com_github_libp2p_go_libp2p//core:go_default_library",
+        "@com_github_libp2p_go_libp2p//core/crypto:go_default_library",
         "@com_github_libp2p_go_libp2p//core/network:go_default_library",
         "@com_github_libp2p_go_libp2p//core/peer:go_default_library",
         "@com_github_libp2p_go_libp2p//core/protocol:go_default_library",

beacon-chain/sync/backfill/BUILD.bazel

@@ -6,6 +6,8 @@ go_library(
         "batch.go",
         "batcher.go",
         "blobs.go",
+        "columns.go",
+        "fulu_transition.go",
         "log.go",
         "metrics.go",
         "pool.go",
@@ -18,6 +20,7 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/das:go_default_library",
         "//beacon-chain/db:go_default_library",
@@ -41,6 +44,7 @@ go_library(
         "//runtime:go_default_library",
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_libp2p_go_libp2p//core/peer:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prometheus_client_golang//prometheus:go_default_library",
@@ -67,6 +71,7 @@ go_test(
         "//beacon-chain/das:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
+        "//beacon-chain/p2p/peers:go_default_library",
         "//beacon-chain/p2p/testing:go_default_library",
         "//beacon-chain/startup:go_default_library",
         "//beacon-chain/state:go_default_library",

beacon-chain/sync/backfill/batch.go

@@ -6,7 +6,6 @@ import (
 	"sort"
 	"time"
 
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/das"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/sync"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
@@ -38,8 +37,10 @@ func (s batchState) String() string {
 		return "import_complete"
 	case batchEndSequence:
 		return "end_sequence"
-	case batchBlobSync:
-		return "blob_sync"
+	case batchSyncBlobs:
+		return "sync_blobs"
+	case batchSyncColumns:
+		return "sync_columns"
 	default:
 		return "unknown"
 	}
@@ -50,7 +51,9 @@ const (
 	batchInit
 	batchSequenced
 	batchErrRetryable
-	batchBlobSync
+	batchErrFatal
+	batchSyncBlobs
+	batchSyncColumns
 	batchImportable
 	batchImportComplete
 	batchEndSequence
@@ -72,9 +75,12 @@ type batch struct {
 	err            error
 	state          batchState
 	busy           peer.ID
+	nextReqCols    []uint64
 	blockPid       peer.ID
 	blobPid        peer.ID
+	columnPid      peer.ID
 	bs             *blobSync
+	cs             *columnSync
 }
 
 func (b batch) logFields() logrus.Fields {
@@ -93,6 +99,9 @@ func (b batch) logFields() logrus.Fields {
 	if b.retries > 0 {
 		f["retryAfter"] = b.retryAfter.String()
 	}
+	if b.state == batchSyncColumns {
+		f["nextColumns"] = fmt.Sprintf("%v", b.nextReqCols)
+	}
 	return f
 }
 
@@ -136,22 +145,29 @@ func (b batch) blobRequest() *eth.BlobSidecarsByRangeRequest {
 	}
 }
 
-func (b batch) withResults(results verifiedROBlocks, bs *blobSync) batch {
+func (b batch) postBlockSync(results verifiedROBlocks, bs *blobSync, cs *columnSync) batch {
 	b.results = results
 	b.bs = bs
+	b.cs = cs
 	if bs.blobsNeeded() > 0 {
-		return b.withState(batchBlobSync)
+		return b.withState(batchSyncBlobs)
+	}
+	if len(cs.columnsNeeded()) > 0 {
+		return b.withState(batchSyncColumns)
 	}
 	return b.withState(batchImportable)
 }
 
-func (b batch) postBlobSync() batch {
+func (b batch) postSidecarSync() batch {
 	if b.blobsNeeded() > 0 {
 		log.WithFields(b.logFields()).WithField("blobsMissing", b.blobsNeeded()).Error("Batch still missing blobs after downloading from peer")
 		b.bs = nil
 		b.results = []blocks.ROBlock{}
 		return b.withState(batchErrRetryable)
 	}
+	if len(b.cs.columnsNeeded()) > 0 {
+		return b.withState(batchSyncColumns)
+	}
 	return b.withState(batchImportable)
 }
 
@@ -187,6 +203,11 @@ func (b batch) withRetryableError(err error) batch {
 	return b.withState(batchErrRetryable)
 }
 
+func (b batch) withFatalError(err error) batch {
+	b.err = errors.Wrap(err, "fatal erorr in batch")
+	return b.withState(batchErrFatal)
+}
+
 func (b batch) blobsNeeded() int {
 	return b.bs.blobsNeeded()
 }
@@ -195,8 +216,8 @@ func (b batch) blobResponseValidator() sync.BlobResponseValidation {
 	return b.bs.validateNext
 }
 
-func (b batch) availabilityStore() das.AvailabilityStore {
-	return b.bs.store
+func (b batch) validatingColumnRequest() *validatingColumnRequest {
+	return b.cs.newValidatingColumnRequest(b.nextReqCols)
 }
 
 var batchBlockUntil = func(ctx context.Context, untilRetry time.Duration, b batch) error {
@@ -223,6 +244,21 @@ func (b batch) waitUntilReady(ctx context.Context) error {
 	return nil
 }
 
+func (b batch) workComplete() bool {
+	if b.state == batchImportable {
+		return true
+	}
+	return false
+}
+
+func (b batch) selectPeer(matrix *sync.ColumnPeerRank, busy map[peer.ID]bool) (peer.ID, []uint64, error) {
+	if b.state == batchSyncColumns {
+		return matrix.HighestForIndices(b.cs.columnsNeeded(), busy)
+	}
+	peer, err := matrix.Lowest(busy)
+	return peer, nil, err
+}
+
 func sortBatchDesc(bb []batch) {
 	sort.Slice(bb, func(i, j int) bool {
 		return bb[i].end > bb[j].end

beacon-chain/sync/backfill/blobs.go

@@ -90,7 +90,10 @@ func (bs *blobSync) validateNext(rb blocks.ROBlob) error {
 	if err := v.SidecarKzgProofVerified(); err != nil {
 		return err
 	}
-	if err := bs.store.Persist(bs.current, rb); err != nil {
+
+	sc := blocks.NewSidecarFromBlobSidecar(rb)
+
+	if err := bs.store.Persist(bs.current, sc); err != nil {
 		return err
 	}
 

beacon-chain/sync/backfill/columns.go

@@ -0,0 +1,250 @@
+package backfill
+
+import (
+	"bytes"
+	"fmt"
+	"sort"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/das"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/sync"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/pkg/errors"
+)
+
+var (
+	errInvalidResponseOrder         = errors.New("out of order DataColumnSidecar response")
+	errColumnResponseSlotOutOfRange = errors.New("slot out of range for DataColumnSidecar response")
+	errColumnIndexNotRequested      = errors.New("index in DataColumnSidecar response not requested")
+)
+
+type columnBatch struct {
+	first              primitives.Slot
+	last               primitives.Slot
+	custodyRequirement peerdas.ColumnIndices
+	blockColumnsByRoot map[[32]byte]*blockColumns
+	peerRank           *sync.ColumnPeerRank
+}
+
+type blockColumns struct {
+	remaining   peerdas.ColumnIndices
+	commitments [][]byte
+}
+
+func (cs *columnBatch) needed() peerdas.ColumnIndices {
+	if len(cs.custodyRequirement) == 0 {
+		return nil
+	}
+	search := peerdas.CopyTrueIndices(cs.custodyRequirement)
+	ci := make(peerdas.ColumnIndices, len(search))
+	// avoid iterating every single block+index by only searching for indices
+	// we haven't found yet.
+	for _, v := range cs.blockColumnsByRoot {
+		for col := range search {
+			if v.remaining[col] {
+				ci[col] = true
+				// We found the column, so we can delete it from the search.
+				delete(search, col)
+			}
+		}
+	}
+	return ci
+}
+
+type columnSync struct {
+	*columnBatch
+	store   das.AvailabilityStore
+	current primitives.Slot
+}
+
+func newColumnSync(b batch, blks verifiedROBlocks, current primitives.Slot, p p2p.P2P, vbs verifiedROBlocks, cfg *workerCfg) (*columnSync, error) {
+	cb, err := buildColumnBatch(b, blks, p.NodeID(), cfg.custodyInfo)
+	if err != nil {
+		return nil, err
+	}
+	if cb == nil {
+		return &columnSync{}, nil
+	}
+	return &columnSync{
+		columnBatch: cb,
+		current:     current,
+		store:       das.NewLazilyPersistentStoreColumn(cfg.cfs, p.NodeID(), cfg.ndcv, cfg.custodyInfo),
+	}, nil
+}
+
+func (cs *columnSync) blockColumns(root [32]byte) *blockColumns {
+	if cs.columnBatch == nil {
+		return nil
+	}
+	return cs.columnBatch.blockColumnsByRoot[root]
+}
+
+func (cs *columnSync) columnsNeeded() peerdas.ColumnIndices {
+	if cs.columnBatch == nil {
+		return nil
+	}
+	return cs.columnBatch.needed()
+}
+
+func (cs *columnSync) request(reqCols []uint64) *ethpb.DataColumnSidecarsByRangeRequest {
+	return sync.DataColumnSidecarsByRangeRequest(reqCols, cs.first, cs.last)
+}
+
+func (cs *columnSync) newValidatingColumnRequest(cols []uint64) *validatingColumnRequest {
+	req := cs.request(cols)
+	if req == nil {
+		return nil
+	}
+	return &validatingColumnRequest{
+		req:     req,
+		columns: peerdas.ColumnIndicesFromSlice(cols),
+		cs:      cs,
+	}
+}
+
+type validatingColumnRequest struct {
+	last    primitives.Slot
+	req     *ethpb.DataColumnSidecarsByRangeRequest
+	columns map[uint64]bool
+	cs      *columnSync
+}
+
+func (v *validatingColumnRequest) validate(cd blocks.RODataColumn) bool {
+	return recordColumnSidecarDownload(cd, v.countedValidation(cd))
+}
+
+func recordColumnSidecarDownload(cd blocks.RODataColumn, valid bool) bool {
+	validity := "invalid"
+	if valid {
+		validity = "valid"
+	}
+	backfillDataColumnSidecarDownloaded.WithLabelValues(fmt.Sprintf("%d", cd.Index), validity).Inc()
+	backfillBytesDataColumnSidecar.Add(float64(cd.SizeSSZ()))
+	return valid
+}
+
+// When we call Persist we'll get the verification checks that are provided by the availability store.
+// In addition to those checks this function calls rpcValidity which maintains a state machine across
+// response values to ensure that the response is valid in the context of the overall request,
+// like making sure that the block roots is one of the ones we expect based on the blocks we used to
+// construct the request. It also does cheap sanity checks on the DataColumnSidecar values like
+// ensuring that the commitments line up with the block.
+func (v *validatingColumnRequest) countedValidation(cd blocks.RODataColumn) bool {
+	if err := v.rpcValidity(cd); err != nil {
+		log.WithError(err).WithField("slot", cd.Slot()).WithField("index", cd.Index).Error("invalid data column sidecar response")
+		return false
+	}
+	root := cd.BlockRoot()
+	expected := v.cs.blockColumns(root)
+	if expected == nil {
+		return false
+	}
+	// We don't need this column, but we trust the column state machine verified we asked for it as part of a range request.
+	// So we can just skip over it and not try to persist it.
+	if !expected.remaining[cd.Index] {
+		return true
+	}
+	if len(cd.KzgCommitments) != len(expected.commitments) {
+		log.WithField("slot", cd.Slot()).WithField("index", cd.Index).Error("unexpected number of commitments in data column sidecar")
+		return false
+	}
+	for i, cmt := range cd.KzgCommitments {
+		if !bytes.Equal(cmt, expected.commitments[i]) {
+			log.WithField("slot", cd.Slot()).WithField("index", cd.Index).WithField("cmtIndex", i).Error("commitment in data column sidecar does not match expected commitment")
+			return false
+		}
+	}
+	if err := v.cs.store.Persist(v.cs.current, blocks.NewSidecarFromDataColumnSidecar(cd)); err != nil {
+		log.WithError(err).Error("failed to persist data column")
+		return false
+	}
+	delete(expected.remaining, cd.Index)
+	return true
+}
+
+// rpcValidity checks that the individual DataColumnSidecar value is valid in the context of the overall response
+// respecting the p2p spec rules for DataColumnSidecarByRange responses:
+//   - values are in the requsted slot range
+//   - values are in slot order
+//   - block roots are canonical wrt the blocks we believe are canonical
+//     (assuming previous block response from another peer was honest)
+//   - there are not too many values in the response
+//   - the column index is one of the requested columns
+func (v *validatingColumnRequest) rpcValidity(col blocks.RODataColumn) error {
+	slot := col.Slot()
+	if v.last > slot {
+		return errInvalidResponseOrder
+	}
+	if slot < v.req.StartSlot {
+		return errors.Wrap(errColumnResponseSlotOutOfRange, "sidecar slot before request start")
+	}
+	if slot >= v.req.StartSlot+primitives.Slot(v.req.Count) {
+		return errors.Wrap(errColumnResponseSlotOutOfRange, "sidecar slot after request end")
+	}
+	// This is an important check because we may have already satisfied this column for a given
+	// block root but still requested it for the benefit of other blocks in the batch. So this check ensures
+	// that it was part ofthe overall batch request.
+	if !v.columns[col.Index] {
+		return errColumnIndexNotRequested
+	}
+	v.last = col.Slot()
+	return nil
+}
+
+func buildColumnBatch(b batch, fuluBlocks verifiedROBlocks, nodeID enode.ID, ci *peerdas.CustodyInfo) (*columnBatch, error) {
+	if len(fuluBlocks) == 0 {
+		return nil, nil
+	}
+
+	fuluStart := params.BeaconConfig().FuluForkEpoch
+	// If the batch end slot or last result block are pre-fulu, so are the rest.
+	if slots.ToEpoch(b.end) < fuluStart || slots.ToEpoch(fuluBlocks[len(fuluBlocks)-1].Block().Slot()) < fuluStart {
+		return nil, nil
+	}
+	// The last block in the batch is in fulu, but the first one is not.
+	// Find the index of the first fulu block to exclude the pre-fulu blocks.
+	if slots.ToEpoch(fuluBlocks[0].Block().Slot()) < fuluStart {
+		fuluStart := sort.Search(len(fuluBlocks), func(i int) bool {
+			return slots.ToEpoch(fuluBlocks[i].Block().Slot()) >= fuluStart
+		})
+		fuluBlocks = fuluBlocks[fuluStart:]
+	}
+	// Get the custody group sampling size for the node.
+	custodyGroupSamplingSize := ci.CustodyGroupSamplingSize(peerdas.Actual)
+	peerInfo, _, err := peerdas.Info(nodeID, custodyGroupSamplingSize)
+	if err != nil {
+		return nil, errors.Wrap(err, "peer info")
+	}
+	indices := peerdas.CopyTrueIndices(peerInfo.CustodyColumns)
+
+	summary := &columnBatch{
+		custodyRequirement: indices,
+		blockColumnsByRoot: make(map[[32]byte]*blockColumns, len(fuluBlocks)),
+	}
+	for _, b := range fuluBlocks {
+		cmts, err := b.Block().Body().BlobKzgCommitments()
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to get blob kzg commitments")
+		}
+		if len(cmts) == 0 {
+			continue
+		}
+		slot := b.Block().Slot()
+		if len(summary.blockColumnsByRoot) == 0 {
+			summary.first = slot
+		}
+		summary.blockColumnsByRoot[b.Root()] = &blockColumns{
+			remaining:   peerdas.CopyTrueIndices(indices),
+			commitments: cmts,
+		}
+		summary.last = slot
+	}
+
+	return summary, nil
+}

beacon-chain/sync/backfill/fulu_transition.go

@@ -0,0 +1,54 @@
+package backfill
+
+import (
+	"context"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/das"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/pkg/errors"
+)
+
+var errAvailabilityCheckerInvalid = errors.New("invalid availability checker state")
+
+type multiStore struct {
+	fuluStart   primitives.Slot
+	columnStore das.AvailabilityStore
+	blobStore   das.AvailabilityStore
+}
+
+// Persist implements das.AvailabilityStore.
+var _ das.AvailabilityChecker = &multiStore{}
+
+// IsDataAvailable implements the das.AvailabilityStore interface.
+func (m *multiStore) IsDataAvailable(ctx context.Context, current primitives.Slot, blk blocks.ROBlock) error {
+	if blk.Block().Slot() < m.fuluStart {
+		return m.checkAvailabilityWithFallback(ctx, m.blobStore, current, blk)
+	}
+	return m.checkAvailabilityWithFallback(ctx, m.columnStore, current, blk)
+}
+
+func (m *multiStore) checkAvailabilityWithFallback(ctx context.Context, ac das.AvailabilityChecker, current primitives.Slot, blk blocks.ROBlock) error {
+	if ac != nil {
+		return ac.IsDataAvailable(ctx, current, blk)
+	}
+	cmts, err := blk.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return err
+	}
+	if len(cmts) > 0 {
+		return errAvailabilityCheckerInvalid
+	}
+	return nil
+}
+
+func newMultiStore(fuluStart primitives.Slot, b batch) *multiStore {
+	s := &multiStore{fuluStart: fuluStart}
+	if b.bs != nil && b.bs.store != nil {
+		s.blobStore = b.bs.store
+	}
+	if b.cs != nil && b.cs.store != nil {
+		s.columnStore = b.cs.store
+	}
+	return s
+}

beacon-chain/sync/backfill/metrics.go

@@ -92,6 +92,33 @@ var (
 			Buckets: []float64{100, 300, 1000, 2000, 4000, 8000},
 		},
 	)
+	backfillBatchTimeDownloadingColumns = promauto.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "backfill_batch_columns_time_download",
+			Help:    "Time, in milliseconds, batch spent downloading DataColumnSidecars from peer.",
+			Buckets: []float64{100, 300, 1000, 2000, 4000, 8000},
+		},
+	)
+	backfillBatchTimeVerifyingColumns = promauto.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "backfill_batch_columns_time_verify",
+			Help:    "Time, in milliseconds, batch spent verifying DataColumnSidecars.",
+			Buckets: []float64{100, 300, 1000, 2000, 4000, 8000},
+		},
+	)
+	backfillBytesDataColumnSidecar = promauto.NewCounter(
+		prometheus.CounterOpts{
+			Name: "backfill_data_column_sidecar_bytes_downloaded",
+			Help: "DataColumnSidecar bytes downloaded from peers for backfill.",
+		},
+	)
+	backfillDataColumnSidecarDownloaded = promauto.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "backfill_data_column_sidecar_downloaded",
+			Help: "Number of DataColumnSidecar values downloaded from peers for backfill.",
+		},
+		[]string{"index", "validity"},
+	)
 )
 
 func blobValidationMetrics(_ blocks.ROBlob) error {

beacon-chain/sync/backfill/pool.go

@@ -2,22 +2,18 @@ package backfill
 
 import (
 	"context"
-	"math"
 	"time"
 
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/sync"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/pkg/errors"
 )
 
 type batchWorkerPool interface {
-	spawn(ctx context.Context, n int, clock *startup.Clock, a PeerAssigner, v *verifier, cm sync.ContextByteVersions, blobVerifier verification.NewBlobVerifier, bfs *filesystem.BlobStorage)
+	spawn(ctx context.Context, n int, a PeerAssigner, cfg *workerCfg)
 	todo(b batch)
 	complete() (batch, error)
 }
@@ -26,11 +22,11 @@ type worker interface {
 	run(context.Context)
 }
 
-type newWorker func(id workerId, in, out chan batch, c *startup.Clock, v *verifier, cm sync.ContextByteVersions, nbv verification.NewBlobVerifier, bfs *filesystem.BlobStorage) worker
+type newWorker func(id workerId, in, out chan batch, cfg *workerCfg) worker
 
 func defaultNewWorker(p p2p.P2P) newWorker {
-	return func(id workerId, in, out chan batch, c *startup.Clock, v *verifier, cm sync.ContextByteVersions, nbv verification.NewBlobVerifier, bfs *filesystem.BlobStorage) worker {
-		return newP2pWorker(id, p, in, out, c, v, cm, nbv, bfs)
+	return func(id workerId, in, out chan batch, cfg *workerCfg) worker {
+		return newP2pWorker(id, p, in, out, cfg)
 	}
 }
 
@@ -45,6 +41,8 @@ type p2pBatchWorkerPool struct {
 	endSeq      []batch
 	ctx         context.Context
 	cancel      func()
+	p2p         p2p.P2P
+	earliest    primitives.Slot
 }
 
 var _ batchWorkerPool = &p2pBatchWorkerPool{}
@@ -59,14 +57,15 @@ func newP2PBatchWorkerPool(p p2p.P2P, maxBatches int) *p2pBatchWorkerPool {
 		fromWorkers: make(chan batch),
 		maxBatches:  maxBatches,
 		shutdownErr: make(chan error),
+		p2p:         p,
 	}
 }
 
-func (p *p2pBatchWorkerPool) spawn(ctx context.Context, n int, c *startup.Clock, a PeerAssigner, v *verifier, cm sync.ContextByteVersions, nbv verification.NewBlobVerifier, bfs *filesystem.BlobStorage) {
+func (p *p2pBatchWorkerPool) spawn(ctx context.Context, n int, a PeerAssigner, cfg *workerCfg) {
 	p.ctx, p.cancel = context.WithCancel(ctx)
 	go p.batchRouter(a)
 	for i := 0; i < n; i++ {
-		go p.newWorker(workerId(i), p.toWorkers, p.fromWorkers, c, v, cm, nbv, bfs).run(p.ctx)
+		go p.newWorker(workerId(i), p.toWorkers, p.fromWorkers, cfg).run(p.ctx)
 	}
 }
 
@@ -103,7 +102,6 @@ func (p *p2pBatchWorkerPool) batchRouter(pa PeerAssigner) {
 	busy := make(map[peer.ID]bool)
 	todo := make([]batch, 0)
 	rt := time.NewTicker(time.Second)
-	earliest := primitives.Slot(math.MaxUint64)
 	for {
 		select {
 		case b := <-p.toRouter:
@@ -116,50 +114,72 @@ func (p *p2pBatchWorkerPool) batchRouter(pa PeerAssigner) {
 			// to retry failed assignments.
 		case b := <-p.fromWorkers:
 			pid := b.busy
-			busy[pid] = false
-			if b.state == batchBlobSync {
-				todo = append(todo, b)
-				sortBatchDesc(todo)
-			} else {
+			delete(busy, pid)
+			if b.workComplete() {
 				p.fromRouter <- b
+				break
 			}
+			todo = append(todo, b)
+			sortBatchDesc(todo)
 		case <-p.ctx.Done():
 			log.WithError(p.ctx.Err()).Info("p2pBatchWorkerPool context canceled, shutting down")
 			p.shutdown(p.ctx.Err())
 			return
 		}
-		if len(todo) == 0 {
-			continue
-		}
-		// Try to assign as many outstanding batches as possible to peers and feed the assigned batches to workers.
-		assigned, err := pa.Assign(busy, len(todo))
+		var err error
+		todo, err = p.processTodo(todo, pa, busy)
 		if err != nil {
-			if errors.Is(err, peers.ErrInsufficientSuitable) {
-				// Transient error resulting from insufficient number of connected peers. Leave batches in
-				// queue and get to them whenever the peer situation is resolved.
-				continue
-			}
 			p.shutdown(err)
-			return
-		}
-		for _, pid := range assigned {
-			if err := todo[0].waitUntilReady(p.ctx); err != nil {
-				log.WithError(p.ctx.Err()).Info("p2pBatchWorkerPool context canceled, shutting down")
-				p.shutdown(p.ctx.Err())
-				return
-			}
-			busy[pid] = true
-			todo[0].busy = pid
-			p.toWorkers <- todo[0].withPeer(pid)
-			if todo[0].begin < earliest {
-				earliest = todo[0].begin
-				oldestBatch.Set(float64(earliest))
-			}
-			todo = todo[1:]
 		}
 	}
 }
 
+func (p *p2pBatchWorkerPool) processTodo(todo []batch, pa PeerAssigner, busy map[peer.ID]bool) ([]batch, error) {
+	if len(todo) == 0 {
+		return todo, nil
+	}
+	notBusy, err := pa.Assign(peers.NotBusy(busy, -1))
+	if err != nil {
+		if errors.Is(err, peers.ErrInsufficientSuitable) {
+			// Transient error resulting from insufficient number of connected peers. Leave batches in
+			// queue and get to them whenever the peer situation is resolved.
+			return todo, nil
+		}
+		return nil, err
+	}
+	peerRank, err := sync.ComputeColumnPeerRank(notBusy, p.p2p)
+	if err != nil {
+		log.WithError(err).Error("Failed to compute column matrix for peer assignment")
+		return todo, nil
+	}
+	if len(notBusy) == 0 {
+		log.Warn("No suitable peers available for batch assignment")
+		return todo, nil
+	}
+	for i, b := range todo {
+		pid, cols, err := b.selectPeer(peerRank, busy)
+		if err != nil {
+			log.WithField("not_busy", len(notBusy)).WithError(err).WithFields(b.logFields()).Error("Failed to select peer for batch")
+			// Return the remaining todo items and allow the outer loop to control when we try again.
+			return todo[i:], nil
+		}
+		busy[pid] = true
+		b.busy = pid
+		b.nextReqCols = cols
+		p.toWorkers <- b.withPeer(pid)
+		p.updateEarliest(b.begin)
+	}
+	return []batch{}, nil
+}
+
+func (p *p2pBatchWorkerPool) updateEarliest(current primitives.Slot) {
+	if current >= p.earliest {
+		return
+	}
+	p.earliest = current
+	oldestBatch.Set(float64(p.earliest))
+}
+
 func (p *p2pBatchWorkerPool) shutdown(err error) {
 	p.cancel()
 	p.shutdownErr <- err

beacon-chain/sync/backfill/pool_test.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	p2ptest "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/sync"
@@ -24,7 +25,7 @@ type mockAssigner struct {
 
 // Assign satisfies the PeerAssigner interface so that mockAssigner can be used in tests
 // in place of the concrete p2p implementation of PeerAssigner.
-func (m mockAssigner) Assign(busy map[peer.ID]bool, n int) ([]peer.ID, error) {
+func (m mockAssigner) Assign(filter peers.AssignmentFilter) ([]peer.ID, error) {
 	if m.err != nil {
 		return nil, m.err
 	}
@@ -53,7 +54,8 @@ func TestPoolDetectAllEnded(t *testing.T) {
 	ctxMap, err := sync.ContextByteVersionsForValRoot(bytesutil.ToBytes32(st.GenesisValidatorsRoot()))
 	require.NoError(t, err)
 	bfs := filesystem.NewEphemeralBlobStorage(t)
-	pool.spawn(ctx, nw, startup.NewClock(time.Now(), [32]byte{}), ma, v, ctxMap, mockNewBlobVerifier, bfs)
+	wcfg := &workerCfg{c: startup.NewClock(time.Now(), [32]byte{}), nbv: mockNewBlobVerifier, v: v, cm: ctxMap, bfs: bfs}
+	pool.spawn(ctx, nw, ma, wcfg)
 	br := batcher{min: 10, size: 10}
 	endSeq := br.before(0)
 	require.Equal(t, batchEndSequence, endSeq.state)
@@ -72,7 +74,7 @@ type mockPool struct {
 	todoChan     chan batch
 }
 
-func (m *mockPool) spawn(_ context.Context, _ int, _ *startup.Clock, _ PeerAssigner, _ *verifier, _ sync.ContextByteVersions, _ verification.NewBlobVerifier, _ *filesystem.BlobStorage) {
+func (m *mockPool) spawn(_ context.Context, _ int, _ PeerAssigner, _ *workerCfg) {
 }
 
 func (m *mockPool) todo(b batch) {

beacon-chain/sync/backfill/service.go

@@ -4,11 +4,14 @@ import (
 	"context"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/sync"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
+	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
@@ -32,14 +35,16 @@ type Service struct {
 	batchSeq        *batchSequencer
 	batchSize       uint64
 	pool            batchWorkerPool
-	verifier        *verifier
 	ctxMap          sync.ContextByteVersions
 	p2p             p2p.P2P
 	pa              PeerAssigner
 	batchImporter   batchImporter
 	blobStore       *filesystem.BlobStorage
+	dcStore         *filesystem.DataColumnStorage
 	initSyncWaiter  func() error
 	complete        chan struct{}
+	workerCfg       *workerCfg
+	fuluStart       primitives.Slot
 }
 
 var _ runtime.Service = (*Service)(nil)
@@ -48,23 +53,13 @@ var _ runtime.Service = (*Service)(nil)
 // to service an RPC blockRequest. The Assign method takes a map of peers that should be excluded,
 // allowing the caller to avoid making multiple concurrent requests to the same peer.
 type PeerAssigner interface {
-	Assign(busy map[peer.ID]bool, n int) ([]peer.ID, error)
+	//Assign(busy map[peer.ID]bool, n int) ([]peer.ID, error)
+	Assign(filter peers.AssignmentFilter) ([]peer.ID, error)
 }
 
 type minimumSlotter func(primitives.Slot) primitives.Slot
 type batchImporter func(ctx context.Context, current primitives.Slot, b batch, su *Store) (*dbval.BackfillStatus, error)
 
-func defaultBatchImporter(ctx context.Context, current primitives.Slot, b batch, su *Store) (*dbval.BackfillStatus, error) {
-	status := su.status()
-	if err := b.ensureParent(bytesutil.ToBytes32(status.LowParentRoot)); err != nil {
-		return status, err
-	}
-	// Import blocks to db and update db state to reflect the newly imported blocks.
-	// Other parts of the beacon node may use the same StatusUpdater instance
-	// via the coverage.AvailableBlocker interface to safely determine if a given slot has been backfilled.
-	return su.fillBack(ctx, current, b.results, b.availabilityStore())
-}
-
 // ServiceOption represents a functional option for the backfill service constructor.
 type ServiceOption func(*Service) error
 
@@ -137,48 +132,43 @@ func WithMinimumSlot(s primitives.Slot) ServiceOption {
 	}
 }
 
+func WithCustodyInfo(custodyInfo *peerdas.CustodyInfo) ServiceOption {
+	return func(s *Service) error {
+		if s.workerCfg == nil {
+			s.workerCfg = &workerCfg{}
+		}
+		s.workerCfg.custodyInfo = custodyInfo
+		return nil
+	}
+}
+
 // NewService initializes the backfill Service. Like all implementations of the Service interface,
 // the service won't begin its runloop until Start() is called.
-func NewService(ctx context.Context, su *Store, bStore *filesystem.BlobStorage, cw startup.ClockWaiter, p p2p.P2P, pa PeerAssigner, opts ...ServiceOption) (*Service, error) {
+func NewService(ctx context.Context, su *Store, bStore *filesystem.BlobStorage, dcStore *filesystem.DataColumnStorage, cw startup.ClockWaiter, p p2p.P2P, pa PeerAssigner, opts ...ServiceOption) (*Service, error) {
 	s := &Service{
-		ctx:           ctx,
-		store:         su,
-		blobStore:     bStore,
-		cw:            cw,
-		ms:            minimumBackfillSlot,
-		p2p:           p,
-		pa:            pa,
-		batchImporter: defaultBatchImporter,
-		complete:      make(chan struct{}),
+		ctx:       ctx,
+		store:     su,
+		blobStore: bStore,
+		dcStore:   dcStore,
+		cw:        cw,
+		ms:        minimumBackfillSlot,
+		p2p:       p,
+		pa:        pa,
+		complete:  make(chan struct{}),
+		fuluStart: slots.SafeEpochStartOrMax(params.BeaconConfig().FuluForkEpoch),
 	}
+	s.batchImporter = s.defaultBatchImporter
 	for _, o := range opts {
 		if err := o(s); err != nil {
 			return nil, err
 		}
 	}
+
 	s.pool = newP2PBatchWorkerPool(p, s.nWorkers)
 
 	return s, nil
 }
 
-func (s *Service) initVerifier(ctx context.Context) (*verifier, sync.ContextByteVersions, error) {
-	cps, err := s.store.originState(ctx)
-	if err != nil {
-		return nil, nil, err
-	}
-	keys, err := cps.PublicKeys()
-	if err != nil {
-		return nil, nil, errors.Wrap(err, "unable to retrieve public keys for all validators in the origin state")
-	}
-	vr := cps.GenesisValidatorsRoot()
-	ctxMap, err := sync.ContextByteVersionsForValRoot(bytesutil.ToBytes32(vr))
-	if err != nil {
-		return nil, nil, errors.Wrapf(err, "unable to initialize context version map using genesis validator root %#x", vr)
-	}
-	v, err := newBackfillVerifier(vr, keys)
-	return v, ctxMap, err
-}
-
 func (s *Service) updateComplete() bool {
 	b, err := s.pool.complete()
 	if err != nil {
@@ -229,6 +219,18 @@ func (s *Service) importBatches(ctx context.Context) {
 	backfillRemainingBatches.Set(float64(nt))
 }
 
+func (s *Service) defaultBatchImporter(ctx context.Context, current primitives.Slot, b batch, su *Store) (*dbval.BackfillStatus, error) {
+	status := su.status()
+	if err := b.ensureParent(bytesutil.ToBytes32(status.LowParentRoot)); err != nil {
+		return status, err
+	}
+	// Import blocks to db and update db state to reflect the newly imported blocks.
+	// Other parts of the beacon node may use the same StatusUpdater instance
+	// via the coverage.AvailableBlocker interface to safely determine if a given slot has been backfilled.
+
+	return su.fillBack(ctx, current, b.results, newMultiStore(s.fuluStart, b))
+}
+
 func (s *Service) scheduleTodos() {
 	batches, err := s.batchSeq.sequence()
 	if err != nil {
@@ -260,25 +262,19 @@ func (s *Service) Start() {
 		log.Info("Backfill service is shutting down")
 		cancel()
 	}()
-	clock, err := s.cw.WaitForClock(ctx)
-	if err != nil {
-		log.WithError(err).Error("Backfill service failed to start while waiting for genesis data")
-		return
-	}
-	s.clock = clock
-	v, err := s.verifierWaiter.WaitForInitializer(ctx)
-	s.newBlobVerifier = newBlobVerifierFromInitializer(v)
-
-	if err != nil {
-		log.WithError(err).Error("Could not initialize blob verifier in backfill service")
-		return
-	}
 
 	if s.store.isGenesisSync() {
 		log.Info("Backfill short-circuit; node synced from genesis")
 		s.markComplete()
 		return
 	}
+
+	clock, err := s.cw.WaitForClock(ctx)
+	if err != nil {
+		log.WithError(err).Error("Backfill service failed to start while waiting for genesis data")
+		return
+	}
+	s.clock = clock
 	status := s.store.status()
 	// Exit early if there aren't going to be any batches to backfill.
 	if primitives.Slot(status.LowSlot) <= s.ms(s.clock.CurrentSlot()) {
@@ -288,11 +284,6 @@ func (s *Service) Start() {
 		s.markComplete()
 		return
 	}
-	s.verifier, s.ctxMap, err = s.initVerifier(ctx)
-	if err != nil {
-		log.WithError(err).Error("Unable to initialize backfill verifier")
-		return
-	}
 
 	if s.initSyncWaiter != nil {
 		log.Info("Backfill service waiting for initial-sync to reach head before starting")
@@ -301,7 +292,14 @@ func (s *Service) Start() {
 			return
 		}
 	}
-	s.pool.spawn(ctx, s.nWorkers, clock, s.pa, s.verifier, s.ctxMap, s.newBlobVerifier, s.blobStore)
+
+	wc, err := initWorkerCfg(ctx, s.workerCfg, s.clock, s.verifierWaiter, s.store, s.blobStore, s.dcStore)
+	if err != nil {
+		log.WithError(err).Error("Could not initialize blob verifier in backfill service")
+		return
+	}
+
+	s.pool.spawn(ctx, s.nWorkers, s.pa, wc)
 	s.batchSeq = newBatchSequencer(s.nWorkers, s.ms(s.clock.CurrentSlot()), primitives.Slot(status.LowSlot), primitives.Slot(s.batchSize))
 	if err = s.initBatches(); err != nil {
 		log.WithError(err).Error("Non-recoverable error in backfill service")
@@ -370,6 +368,12 @@ func newBlobVerifierFromInitializer(ini *verification.Initializer) verification.
 	}
 }
 
+func newDataColumnVerifierFromInitializer(ini *verification.Initializer) verification.NewDataColumnsVerifier {
+	return func(cols []blocks.RODataColumn, reqs []verification.Requirement) verification.DataColumnsVerifier {
+		return ini.NewDataColumnsVerifier(cols, reqs)
+	}
+}
+
 func (s *Service) markComplete() {
 	close(s.complete)
 	log.Info("Backfill service marked as complete")

beacon-chain/sync/backfill/service_test.go

@@ -57,7 +57,8 @@ func TestServiceInit(t *testing.T) {
 	pool := &mockPool{todoChan: make(chan batch, nWorkers), finishedChan: make(chan batch, nWorkers)}
 	p2pt := p2ptest.NewTestP2P(t)
 	bfs := filesystem.NewEphemeralBlobStorage(t)
-	srv, err := NewService(ctx, su, bfs, cw, p2pt, &mockAssigner{},
+	dcs := filesystem.NewEphemeralDataColumnStorage(t)
+	srv, err := NewService(ctx, su, bfs, dcs, cw, p2pt, &mockAssigner{},
 		WithBatchSize(batchSize), WithWorkerCount(nWorkers), WithEnableBackfill(true), WithVerifierWaiter(&mockInitalizerWaiter{}))
 	require.NoError(t, err)
 	srv.ms = mockMinimumSlotter{min: primitives.Slot(high - batchSize*uint64(nBatches))}.minimumSlot

beacon-chain/sync/backfill/status.go

@@ -74,7 +74,7 @@ func (s *Store) status() *dbval.BackfillStatus {
 // fillBack saves the slice of blocks and updates the BackfillStatus LowSlot/Root/ParentRoot tracker to the values
 // from the first block in the slice. This method assumes that the block slice has been fully validated and
 // sorted in slot order by the calling function.
-func (s *Store) fillBack(ctx context.Context, current primitives.Slot, blocks []blocks.ROBlock, store das.AvailabilityStore) (*dbval.BackfillStatus, error) {
+func (s *Store) fillBack(ctx context.Context, current primitives.Slot, blocks []blocks.ROBlock, store das.AvailabilityChecker) (*dbval.BackfillStatus, error) {
 	status := s.status()
 	if len(blocks) == 0 {
 		return status, nil

beacon-chain/sync/backfill/verify.go

@@ -5,7 +5,6 @@ import (
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/crypto/bls"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
@@ -23,18 +22,34 @@ var errUnknownDomain = errors.New("runtime error looking up signing domain for f
 type verifiedROBlocks []blocks.ROBlock
 
 func (v verifiedROBlocks) blobIdents(retentionStart primitives.Slot) ([]blobSummary, error) {
-	// early return if the newest block is outside the retention window
-	if len(v) > 0 && v[len(v)-1].Block().Slot() < retentionStart {
+	if len(v) == 0 {
 		return nil, nil
 	}
+	latest := v[len(v)-1].Block().Slot()
+	// early return if the newest block is outside the retention window
+	if latest < retentionStart {
+		return nil, nil
+	}
+	fuluStart := params.BeaconConfig().FuluForkEpoch
+	// If the batch end slot or last result block are pre-fulu, so are the rest.
+	if slots.ToEpoch(latest) < fuluStart {
+		return nil, nil
+	}
+
 	bs := make([]blobSummary, 0)
 	for i := range v {
-		if v[i].Block().Slot() < retentionStart {
+		slot := v[i].Block().Slot()
+		if slot < retentionStart {
 			continue
 		}
 		if v[i].Block().Version() < version.Deneb {
 			continue
 		}
+		// Assuming blocks are sorted, as soon as we see 1 fulu block we know the rest will also be fulu.
+		if slots.ToEpoch(slot) >= fuluStart {
+			return bs, nil
+		}
+
 		c, err := v[i].Block().Body().BlobKzgCommitments()
 		if err != nil {
 			return nil, errors.Wrapf(err, "unexpected error checking commitments for block root %#x", v[i].Root())
@@ -57,37 +72,31 @@ type verifier struct {
 	domain *domainCache
 }
 
-// TODO: rewrite this to use ROBlock.
-func (vr verifier) verify(blks []interfaces.ReadOnlySignedBeaconBlock) (verifiedROBlocks, error) {
+func (vr verifier) verify(blks []blocks.ROBlock) (verifiedROBlocks, error) {
 	var err error
-	result := make([]blocks.ROBlock, len(blks))
 	sigSet := bls.NewSet()
 	for i := range blks {
-		result[i], err = blocks.NewROBlock(blks[i])
-		if err != nil {
-			return nil, err
-		}
-		if i > 0 && result[i-1].Root() != result[i].Block().ParentRoot() {
-			p, b := result[i-1], result[i]
+		if i > 0 && blks[i-1].Root() != blks[i].Block().ParentRoot() {
+			p, b := blks[i-1], blks[i]
 			return nil, errors.Wrapf(errInvalidBatchChain,
 				"slot %d parent_root=%#x, slot %d root=%#x",
 				b.Block().Slot(), b.Block().ParentRoot(),
 				p.Block().Slot(), p.Root())
 		}
-		set, err := vr.blockSignatureBatch(result[i])
+		set, err := vr.blockSignatureBatch(blks[i])
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "block signature batch")
 		}
 		sigSet.Join(set)
 	}
 	v, err := sigSet.Verify()
 	if err != nil {
-		return nil, errors.Wrap(err, "block signature verification error")
+		return nil, errors.Wrap(err, "SignatureBatch Verify")
 	}
 	if !v {
-		return nil, errors.New("batch block signature verification failed")
+		return nil, errors.New("SignatureBatch Verify invalid")
 	}
-	return result, nil
+	return blks, nil
 }
 
 func (vr verifier) blockSignatureBatch(b blocks.ROBlock) (*bls.SignatureBatch, error) {

beacon-chain/sync/backfill/verify_test.go

@@ -8,7 +8,6 @@ import (
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/crypto/bls"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
@@ -72,12 +71,7 @@ func TestVerify(t *testing.T) {
 	}
 	v, err := newBackfillVerifier(vr, pubkeys)
 	require.NoError(t, err)
-	notrob := make([]interfaces.ReadOnlySignedBeaconBlock, len(blks))
-	// We have to unwrap the ROBlocks for this code because that's what it expects (for now).
-	for i := range blks {
-		notrob[i] = blks[i].ReadOnlySignedBeaconBlock
-	}
-	vbs, err := v.verify(notrob)
+	vbs, err := v.verify(blks)
 	require.NoError(t, err)
 	require.Equal(t, len(blks), len(vbs))
 }

beacon-chain/sync/backfill/worker.go

@@ -4,14 +4,63 @@ import (
 	"context"
 	"time"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/sync"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	"github.com/pkg/errors"
 )
 
+type workerCfg struct {
+	c           *startup.Clock
+	v           *verifier
+	cm          sync.ContextByteVersions
+	nbv         verification.NewBlobVerifier
+	ndcv        verification.NewDataColumnsVerifier
+	bfs         *filesystem.BlobStorage
+	cfs         *filesystem.DataColumnStorage
+	custodyInfo *peerdas.CustodyInfo
+}
+
+func initWorkerCfg(ctx context.Context, cfg *workerCfg, c *startup.Clock, vw InitializerWaiter, store *Store, bfs *filesystem.BlobStorage, cfs *filesystem.DataColumnStorage) (*workerCfg, error) {
+	vi, err := vw.WaitForInitializer(ctx)
+	if err != nil {
+		return nil, err
+	}
+	cps, err := store.originState(ctx)
+	if err != nil {
+		return nil, err
+	}
+	keys, err := cps.PublicKeys()
+	if err != nil {
+		return nil, errors.Wrap(err, "unable to retrieve public keys for all validators in the origin state")
+	}
+	vr := cps.GenesisValidatorsRoot()
+	cm, err := sync.ContextByteVersionsForValRoot(bytesutil.ToBytes32(vr))
+	if err != nil {
+		return nil, errors.Wrapf(err, "unable to initialize context version map using genesis validator root %#x", vr)
+	}
+	v, err := newBackfillVerifier(vr, keys)
+	if err != nil {
+		return nil, errors.Wrapf(err, "newBackfillVerifier failed")
+	}
+	if cfg == nil {
+		cfg = &workerCfg{}
+	}
+	cfg.c = c
+	cfg.v = v
+	cfg.cm = cm
+	cfg.bfs = bfs
+	cfg.cfs = cfs
+	cfg.nbv = newBlobVerifierFromInitializer(vi)
+	cfg.ndcv = newDataColumnVerifierFromInitializer(vi)
+	return cfg, nil
+}
+
 type workerId int
 
 type p2pWorker struct {
@@ -19,23 +68,38 @@ type p2pWorker struct {
 	todo chan batch
 	done chan batch
 	p2p  p2p.P2P
-	v    *verifier
-	c    *startup.Clock
-	cm   sync.ContextByteVersions
-	nbv  verification.NewBlobVerifier
-	bfs  *filesystem.BlobStorage
+	cfg  *workerCfg
+}
+
+func newP2pWorker(id workerId, p p2p.P2P, todo, done chan batch, cfg *workerCfg) *p2pWorker {
+	return &p2pWorker{
+		id:   id,
+		todo: todo,
+		done: done,
+		p2p:  p,
+		cfg:  cfg,
+	}
 }
 
 func (w *p2pWorker) run(ctx context.Context) {
 	for {
 		select {
 		case b := <-w.todo:
-			log.WithFields(b.logFields()).WithField("backfillWorker", w.id).Debug("Backfill worker received batch")
-			if b.state == batchBlobSync {
-				w.done <- w.handleBlobs(ctx, b)
-			} else {
-				w.done <- w.handleBlocks(ctx, b)
+			if err := b.waitUntilReady(ctx); err != nil {
+				log.WithField("batch_id", b.id()).WithError(ctx.Err()).Info("worker context canceled while waiting to retry")
+				continue
 			}
+			log.WithFields(b.logFields()).WithField("backfillWorker", w.id).Debug("Backfill worker received batch")
+			if b.state == batchSyncBlobs {
+				w.done <- w.handleSidecars(ctx, b)
+				continue
+			}
+			if b.state == batchSyncColumns {
+				w.done <- w.handleColumns(ctx, b)
+				continue
+			}
+
+			w.done <- w.handleBlocks(ctx, b)
 		case <-ctx.Done():
 			log.WithField("backfillWorker", w.id).Info("Backfill worker exiting after context canceled")
 			return
@@ -44,21 +108,27 @@ func (w *p2pWorker) run(ctx context.Context) {
 }
 
 func (w *p2pWorker) handleBlocks(ctx context.Context, b batch) batch {
-	cs := w.c.CurrentSlot()
-	blobRetentionStart, err := sync.BlobRPCMinValidSlot(cs)
+	current := w.cfg.c.CurrentSlot()
+	blobRetentionStart, err := sync.BlobRPCMinValidSlot(current)
 	if err != nil {
 		return b.withRetryableError(errors.Wrap(err, "configuration issue, could not compute minimum blob retention slot"))
 	}
 	b.blockPid = b.busy
 	start := time.Now()
-	results, err := sync.SendBeaconBlocksByRangeRequest(ctx, w.c, w.p2p, b.blockPid, b.blockRequest(), blockValidationMetrics)
-	dlt := time.Now()
-	backfillBatchTimeDownloadingBlocks.Observe(float64(dlt.Sub(start).Milliseconds()))
+	results, err := sync.SendBeaconBlocksByRangeRequest(ctx, w.cfg.c, w.p2p, b.blockPid, b.blockRequest(), blockValidationMetrics)
 	if err != nil {
 		log.WithError(err).WithFields(b.logFields()).Debug("Batch requesting failed")
 		return b.withRetryableError(err)
 	}
-	vb, err := w.v.verify(results)
+	dlt := time.Now()
+	backfillBatchTimeDownloadingBlocks.Observe(float64(dlt.Sub(start).Milliseconds()))
+	toVerify, err := blocks.NewROBlockSlice(results)
+	if err != nil {
+		log.WithError(err).WithFields(b.logFields()).Debug("Batch conversion to ROBlock failed")
+		return b.withRetryableError(err)
+	}
+
+	vb, err := w.cfg.v.verify(toVerify)
 	backfillBatchTimeVerifying.Observe(float64(time.Since(dlt).Milliseconds()))
 	if err != nil {
 		log.WithError(err).WithFields(b.logFields()).Debug("Batch validation failed")
@@ -73,19 +143,26 @@ func (w *p2pWorker) handleBlocks(ctx context.Context, b batch) batch {
 	}
 	backfillBlocksApproximateBytes.Add(float64(bdl))
 	log.WithFields(b.logFields()).WithField("dlbytes", bdl).Debug("Backfill batch block bytes downloaded")
-	bs, err := newBlobSync(cs, vb, &blobSyncConfig{retentionStart: blobRetentionStart, nbv: w.nbv, store: w.bfs})
+	bscfg := &blobSyncConfig{retentionStart: blobRetentionStart, nbv: w.cfg.nbv, store: w.cfg.bfs}
+	bs, err := newBlobSync(current, vb, bscfg)
 	if err != nil {
 		return b.withRetryableError(err)
 	}
-	return b.withResults(vb, bs)
+	w.cfg.custodyInfo.Mut.RLock()
+	defer w.cfg.custodyInfo.Mut.RUnlock()
+	cs, err := newColumnSync(b, vb, current, w.p2p, vb, w.cfg)
+	if err != nil {
+		return b.withFatalError(err)
+	}
+	return b.postBlockSync(vb, bs, cs)
 }
 
-func (w *p2pWorker) handleBlobs(ctx context.Context, b batch) batch {
+func (w *p2pWorker) handleSidecars(ctx context.Context, b batch) batch {
 	b.blobPid = b.busy
 	start := time.Now()
 	// we don't need to use the response for anything other than metrics, because blobResponseValidation
 	// adds each of them to a batch AvailabilityStore once it is checked.
-	blobs, err := sync.SendBlobsByRangeRequest(ctx, w.c, w.p2p, b.blobPid, w.cm, b.blobRequest(), b.blobResponseValidator(), blobValidationMetrics)
+	blobs, err := sync.SendBlobsByRangeRequest(ctx, w.cfg.c, w.p2p, b.blobPid, w.cfg.cm, b.blobRequest(), b.blobResponseValidator(), blobValidationMetrics)
 	if err != nil {
 		b.bs = nil
 		return b.withRetryableError(err)
@@ -98,19 +175,19 @@ func (w *p2pWorker) handleBlobs(ctx context.Context, b batch) batch {
 		backfillBlobsApproximateBytes.Add(float64(sz))
 		log.WithFields(b.logFields()).WithField("dlbytes", sz).Debug("Backfill batch blob bytes downloaded")
 	}
-	return b.postBlobSync()
+	return b.postSidecarSync()
 }
 
-func newP2pWorker(id workerId, p p2p.P2P, todo, done chan batch, c *startup.Clock, v *verifier, cm sync.ContextByteVersions, nbv verification.NewBlobVerifier, bfs *filesystem.BlobStorage) *p2pWorker {
-	return &p2pWorker{
-		id:   id,
-		todo: todo,
-		done: done,
-		p2p:  p,
-		v:    v,
-		c:    c,
-		cm:   cm,
-		nbv:  nbv,
-		bfs:  bfs,
+func (w *p2pWorker) handleColumns(ctx context.Context, b batch) batch {
+	b.columnPid = b.busy
+	start := time.Now()
+	vr := b.validatingColumnRequest()
+	// Response is dropped because the validation code adds the columns to the columnSync AvailabilityStore under the hood.
+	_, err := sync.SendDataColumnSidecarsByRangeRequest(ctx, w.cfg.c, w.p2p, b.busy, w.cfg.cm, vr.req, vr.validate)
+	if err != nil {
+		return b.withRetryableError(errors.Wrap(err, "failed to request data column sidecars"))
 	}
+	dlt := time.Now()
+	backfillBatchTimeDownloadingColumns.Observe(float64(dlt.Sub(start).Milliseconds()))
+	return b.postSidecarSync()
 }

beacon-chain/sync/blobs_test.go

@@ -181,7 +181,7 @@ func (c *blobsTestCase) setup(t *testing.T) (*Service, []blocks.ROBlob, func())
 		params.OverrideBeaconConfig(cfg)
 	}
 	maxBlobs := int(params.BeaconConfig().MaxBlobsPerBlock(0))
-	chain, clock := defaultMockChain(t)
+	chain, clock := defaultMockChain(t, 0)
 	if c.chain == nil {
 		c.chain = chain
 	}
@@ -279,7 +279,7 @@ func repositionFutureEpochs(cfg *params.BeaconChainConfig) {
 	}
 }
 
-func defaultMockChain(t *testing.T) (*mock.ChainService, *startup.Clock) {
+func defaultMockChain(t *testing.T, currentSlot uint64) (*mock.ChainService, *startup.Clock) {
 	de := params.BeaconConfig().DenebForkEpoch
 	df, err := forks.Fork(de)
 	require.NoError(t, err)
@@ -290,8 +290,14 @@ func defaultMockChain(t *testing.T) (*mock.ChainService, *startup.Clock) {
 	require.NoError(t, err)
 	now := time.Now()
 	genOffset := types.Slot(params.BeaconConfig().SecondsPerSlot) * cs
-	genesis := now.Add(-1 * time.Second * time.Duration(int64(genOffset)))
-	clock := startup.NewClock(genesis, [32]byte{})
+	genesisTime := now.Add(-1 * time.Second * time.Duration(int64(genOffset)))
+
+	clock := startup.NewClock(genesisTime, [32]byte{}, startup.WithNower(
+		func() time.Time {
+			return genesisTime.Add(time.Duration(currentSlot*params.BeaconConfig().SecondsPerSlot) * time.Second)
+		},
+	))
+
 	chain := &mock.ChainService{
 		FinalizedCheckPoint: &ethpb.Checkpoint{Epoch: fe},
 		Fork:                df,

beacon-chain/sync/block_batcher.go

@@ -78,9 +78,10 @@ func (bb *blockRangeBatcher) next(ctx context.Context, stream libp2pcore.Stream)
 	if !more {
 		return blockBatch{}, false
 	}
-	if err := bb.limiter.validateRequest(stream, bb.size); err != nil {
-		return blockBatch{err: errors.Wrap(err, "throttled by rate limiter")}, false
-	}
+	// TODO: Uncomment out of devnet.
+	// if err := bb.limiter.validateRequest(stream, bb.size); err != nil {
+	// 	return blockBatch{err: errors.Wrap(err, "throttled by rate limiter")}, false
+	// }
 
 	// Wait for the ticker before doing anything expensive, unless this is the first batch.
 	if bb.ticker != nil && bb.current != nil {

beacon-chain/sync/data_column_assignment.go

@@ -0,0 +1,211 @@
+package sync
+
+import (
+	"slices"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/crypto/rand"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/pkg/errors"
+)
+
+type columnRankedPeer struct {
+	peerID    peer.ID
+	nodeID    enode.ID
+	custodied []uint64
+	cov       float64
+}
+
+func (p *columnRankedPeer) covered(needed peerdas.ColumnIndices) []uint64 {
+	covered := make([]uint64, 0, len(p.custodied))
+	for col, want := range needed {
+		if want && p.custodied[col] == 1 {
+			covered = append(covered, uint64(col))
+		}
+	}
+	return covered
+}
+
+func (p *columnRankedPeer) coverageScore(rarity []float64) float64 {
+	if p.cov == 0 {
+		p.cov = coverageScore(p.custodied, rarity)
+	}
+	return p.cov
+}
+
+type ColumnPeerRank struct {
+	peers        map[peer.ID]*columnRankedPeer
+	freq         []colFreq
+	rarity       []float64
+	rg           rand.Rand
+	covScoreRank []*columnRankedPeer
+}
+
+func coverageScore(covered []uint64, rarity []float64) float64 {
+	score := 0.0
+	for _, col := range covered {
+		if col >= uint64(len(rarity)) {
+			continue
+		}
+		score += rarity[col]
+	}
+	return score
+}
+
+func (m *ColumnPeerRank) HighestForIndices(needed peerdas.ColumnIndices, busy map[peer.ID]bool) (peer.ID, []uint64, error) {
+	// - find the custodied column with the lowest frequency
+	// - collect all the peers that have custody of that column
+	// - score the peers by how many other of the needed columns they ave
+	// -- or, score them by the rank of the columns they have??
+	for _, cf := range m.freq {
+		if !needed[cf.col] {
+			continue
+		}
+		if cf.freq() == 0 {
+			continue
+		}
+		var best *columnRankedPeer
+		bestScore, bestCoverage := 0.0, make([]uint64, 1)
+		for _, p := range cf.custodians {
+			if busy[p.peerID] {
+				continue
+			}
+			coverage := p.covered(needed)
+			if len(coverage) == 0 {
+				continue
+			}
+			pscore := coverageScore(coverage, m.rarity)
+			if pscore > bestScore {
+				best, bestScore, bestCoverage = p, pscore, coverage
+			}
+		}
+		if best != nil {
+			return best.peerID, bestCoverage, nil
+		}
+	}
+
+	return "", nil, errors.New("no peers able to cover needed columns")
+}
+
+func NeededCoveredIntersection(needed peerdas.ColumnIndices, covered []uint64) []uint64 {
+	intersection := make([]uint64, 0, len(covered))
+	for _, col := range covered {
+		if needed[col] {
+			intersection = append(intersection, col)
+		}
+	}
+	return intersection
+}
+
+// Lowest returns the lowest scoring peer in the set. This can be used to pick a peer
+// for block requests, preserving the peers that have the highest coverage scores
+// for column requests.
+func (m *ColumnPeerRank) Lowest(busy map[peer.ID]bool) (peer.ID, error) {
+	for i := len(m.covScoreRank) - 1; i >= 0; i-- {
+		p := m.covScoreRank[i]
+		if !busy[p.peerID] {
+			return p.peerID, nil
+		}
+	}
+	return "", errors.New("no peers available")
+}
+
+type colFreq struct {
+	col        uint64
+	custodians []*columnRankedPeer
+}
+
+func (f colFreq) rarity() float64 {
+	if f.freq() == 0 {
+		return 1
+	}
+	return 1 / float64(f.freq())
+}
+
+func (f colFreq) freq() int {
+	return len(f.custodians)
+}
+
+type colFreqs []colFreq
+
+func (s colFreqs) rarity() []float64 {
+	ra := make([]float64, len(s))
+	for _, f := range s {
+		ra[f.col] = f.rarity()
+	}
+	return ra
+}
+
+// ColumnMatrix computes a grid of column custody x peer.
+func ComputeColumnPeerRank(peers []peer.ID, p2pSvc p2p.P2P) (*ColumnPeerRank, error) {
+	nc := params.BeaconConfig().NumberOfColumns
+	grid := make(map[peer.ID]*columnRankedPeer, len(peers))
+	freqByColumn := make([]colFreq, nc)
+	for i := range freqByColumn {
+		freqByColumn[i].col = uint64(i)
+	}
+	for _, peer := range peers {
+		nodeID, err := p2p.ConvertPeerIDToNodeID(peer)
+		if err != nil {
+			log.WithField("peerID", peer).WithError(err).Debug("Failed to convert peer ID to node ID.")
+			continue
+		}
+		dasInfo, _, err := peerdas.Info(nodeID, p2pSvc.CustodyGroupCountFromPeer(peer))
+		if err != nil {
+			log.WithField("peerID", peer).WithField("nodeID", nodeID).WithError(err).Debug("Failed to derive custody groups from peer.")
+			return nil, errors.Wrap(err, "custody groups")
+		}
+		p := &columnRankedPeer{
+			peerID:    peer,
+			nodeID:    nodeID,
+			custodied: make([]uint64, nc),
+		}
+		for c, v := range dasInfo.CustodyColumns {
+			if c > nc-1 {
+				return nil, errors.Errorf("column %d is out of bounds", c)
+			}
+			if v {
+				p.custodied[c] = 1
+				freqByColumn[c].custodians = append(freqByColumn[c].custodians, p)
+			}
+		}
+		grid[peer] = p
+	}
+
+	var colByFreq colFreqs
+	colByFreq = slices.SortedFunc(slices.Values(freqByColumn), func(a, b colFreq) int {
+		if a.freq() == b.freq() {
+			return 0
+		}
+		if a.freq() < b.freq() {
+			return -1
+		}
+		return 1
+	})
+	rarity := colByFreq.rarity()
+
+	covScoreRank := make([]*columnRankedPeer, 0, len(grid))
+	for _, p := range grid {
+		covScoreRank = append(covScoreRank, p)
+	}
+	slices.SortFunc(covScoreRank, func(a, b *columnRankedPeer) int {
+		if a.coverageScore(rarity) == b.coverageScore(rarity) {
+			return 0
+		}
+		if a.coverageScore(rarity) < b.coverageScore(rarity) {
+			return -1
+		}
+		return 1
+	})
+
+	return &ColumnPeerRank{
+		peers:        grid,
+		freq:         colByFreq,
+		rg:           *rand.NewGenerator(),
+		rarity:       rarity,
+		covScoreRank: covScoreRank,
+	}, nil
+}

beacon-chain/sync/data_columns.go

@@ -0,0 +1,940 @@
+package sync
+
+import (
+	"context"
+	"fmt"
+	"sort"
+	"time"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/types"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	leakybucket "github.com/OffchainLabs/prysm/v6/container/leaky-bucket"
+	eth "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/libp2p/go-libp2p/core"
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+// RequestDataColumnSidecarsByRoot is an opinionated, high level function which, for each data column in `dataColumnsToFetch`:
+//   - Greedily selects, among `peers`, the peers that can provide the requested data columns, to minimize the number of requests.
+//   - Request the data column sidecars from the selected peers.
+//   - In case of peers unable to actually provide all the requested data columns, retry with other peers.
+//
+// This function:
+//   - returns on success when all the initially missing sidecars in `dataColumnsToFetch` are retrieved, or
+//   - returns an error if all peers in `peers` are exhausted and at least one data column sidecar is still missing.
+//
+// TODO: In case at least one column is still missing after peer exhaustion,
+//
+//	but `peers` custody more than 64 columns, then try to fetch enough columns to reconstruct needed ones.
+func RequestDataColumnSidecarsByRoot(
+	ctx context.Context,
+	dataColumnsToFetch []uint64,
+	block blocks.ROBlock,
+	peers []core.PeerID,
+	clock *startup.Clock,
+	p2p p2p.P2P,
+	ctxMap ContextByteVersions,
+	newColumnsVerifier verification.NewDataColumnsVerifier,
+) ([]blocks.VerifiedRODataColumn, error) {
+	if len(dataColumnsToFetch) == 0 {
+		return nil, nil
+	}
+
+	// Assemble the peers who can provide the needed data columns.
+	dataColumnsByAdmissiblePeer, _, _, err := AdmissiblePeersForDataColumns(peers, dataColumnsToFetch, p2p)
+	if err != nil {
+		return nil, errors.Wrap(err, "couldn't get admissible peers for data columns")
+	}
+
+	verifiedSidecars := make([]blocks.VerifiedRODataColumn, 0, len(dataColumnsToFetch))
+	remainingMissingColumns := make(map[uint64]bool, len(dataColumnsToFetch))
+	for _, column := range dataColumnsToFetch {
+		remainingMissingColumns[column] = true
+	}
+
+	blockRoot := block.Root()
+
+	for len(dataColumnsByAdmissiblePeer) > 0 {
+		peersToFetchFrom, err := SelectPeersToFetchDataColumnsFrom(sliceFromMap(remainingMissingColumns, true /*sorted*/), dataColumnsByAdmissiblePeer)
+		if err != nil {
+			return nil, errors.Wrap(err, "select peers to fetch data columns from")
+		}
+
+		// Request the data columns from each peer.
+		successfulColumns := make(map[uint64]bool, len(remainingMissingColumns))
+		for peer, peerRequestedColumns := range peersToFetchFrom {
+			log := log.WithFields(logrus.Fields{"peer": peer.String(), "blockRoot": fmt.Sprintf("%#x", blockRoot)})
+
+			// Build the requests for the data columns.
+			byRootRequest := &eth.DataColumnsByRootIdentifier{BlockRoot: blockRoot[:], Columns: peerRequestedColumns}
+
+			// Send the requests to the peer.
+			peerSidecars, err := SendDataColumnSidecarsByRootRequest(ctx, clock, p2p, peer, ctxMap, &types.DataColumnsByRootIdentifiers{byRootRequest})
+			if err != nil {
+				// Remove this peer since it failed to respond correctly.
+				delete(dataColumnsByAdmissiblePeer, peer)
+
+				log.WithFields(logrus.Fields{
+					"peer":      peer.String(),
+					"blockRoot": fmt.Sprintf("%#x", block.Root()),
+				}).WithError(err).Debug("Failed to request data columns from peer")
+
+				continue
+			}
+
+			// Check if returned data columns align with the block.
+			if err := peerdas.DataColumnsAlignWithBlock(block, peerSidecars); err != nil {
+				// Remove this peer since it failed to respond correctly.
+				delete(dataColumnsByAdmissiblePeer, peer)
+				log.WithError(err).Debug("Align with block failed")
+				continue
+			}
+
+			// Verify the received sidecars.
+			verifier := newColumnsVerifier(peerSidecars, verification.ByRootRequestDataColumnSidecarRequirements)
+
+			if err := verifier.ValidFields(); err != nil {
+				// Remove this peer if the verification failed.
+				delete(dataColumnsByAdmissiblePeer, peer)
+				log.WithError(err).Debug("Valid verification failed")
+				continue
+			}
+
+			if err := verifier.SidecarInclusionProven(); err != nil {
+				// Remove this peer if the verification failed.
+				delete(dataColumnsByAdmissiblePeer, peer)
+				log.WithError(err).Debug("Sidecar inclusion proof verification failed")
+				continue
+			}
+
+			if err := verifier.SidecarKzgProofVerified(); err != nil {
+				// Remove this peer if the verification failed.
+				delete(dataColumnsByAdmissiblePeer, peer)
+				log.WithError(err).Debug("Sidecar KZG proof verification failed")
+				continue
+			}
+
+			// Upgrade the sidecars to verified sidecars.
+			verifiedPeerSidecars, err := verifier.VerifiedRODataColumns()
+			if err != nil {
+				// This should never happen.
+				return nil, errors.Wrap(err, "verified data columns")
+			}
+
+			// Mark columns as successful
+			for _, sidecar := range verifiedPeerSidecars {
+				successfulColumns[sidecar.Index] = true
+			}
+
+			// Check if all requested columns were successfully returned.
+			peerMissingColumns := make(map[uint64]bool)
+			for _, index := range peerRequestedColumns {
+				if !successfulColumns[index] {
+					peerMissingColumns[index] = true
+				}
+			}
+
+			if len(peerMissingColumns) > 0 {
+				// Remove this peer if some requested columns were not correctly returned.
+				delete(dataColumnsByAdmissiblePeer, peer)
+				log.WithField("missingColumns", sliceFromMap(peerMissingColumns, true /*sorted*/)).Debug("Peer did not provide all requested data columns")
+			}
+
+			verifiedSidecars = append(verifiedSidecars, verifiedPeerSidecars...)
+		}
+
+		// Update remaining columns for the next retry.
+		for col := range successfulColumns {
+			delete(remainingMissingColumns, col)
+		}
+
+		if len(remainingMissingColumns) > 0 {
+			// Some columns are still missing, retry with the remaining peers.
+			continue
+		}
+
+		return verifiedSidecars, nil
+	}
+
+	// If we still have remaining columns after all retries, return error
+	return nil, errors.Errorf("failed to retrieve all requested data columns after retries for block root=%#x, missing columns=%v", blockRoot, sliceFromMap(remainingMissingColumns, true /*sorted*/))
+}
+
+// RequestMissingDataColumnsByRange is an opinionated, high level function which, for each block in `blks`:
+//   - Computes all data column sidecars we should store and which are missing (according to our node ID and `groupCount`),
+//   - Builds an optimized set of data column sidecars by range requests in order to never request a data column that is already stored in the DB,
+//     and in order to minimize the number of total requests, while not exceeding `batchSize` sidecars per requests.
+//   - Greedily selects, among `peers`, the peers that can provide the requested data columns, to minimize the number of requests.
+//   - Request the data column sidecars from the selected peers.
+//   - In case of peers unable to actually provide all the requested data columns, retry with other peers.
+//
+// This function:
+//   - returns on success when all the initially missing sidecars for `blks` are retrieved, or
+//   - returns an error if no progress at all is made after 5 consecutives trials.
+//     (If at least one additional data column sidecar is retrieved between two trials, the counter is reset.)
+//
+// In case of success, initially missing data columns grouped by block root are returned.
+// This function expects blocks to be sorted by slot.
+//
+// TODO: In case at least one column is still missing after all allowed retries,
+//
+//	but `peers` custody more than 64 columns, then try to fetch enough columns to reconstruct needed ones.
+func RequestMissingDataColumnsByRange(
+	ctx context.Context,
+	clock *startup.Clock,
+	ctxMap ContextByteVersions,
+	p2p p2p.P2P,
+	rateLimiter *leakybucket.Collector,
+	groupCount uint64,
+	dataColumnsStorage filesystem.DataColumnStorageSummarizer,
+	blks []blocks.ROBlock,
+	batchSize int,
+) (map[[fieldparams.RootLength]byte][]blocks.RODataColumn, error) {
+	const maxAllowedStall = 5 // Number of trials before giving up.
+
+	if len(blks) == 0 {
+		return nil, nil
+	}
+
+	// Get the current slot.
+	currentSlot := clock.CurrentSlot()
+
+	// Compute the minimum slot for which we should serve data columns.
+	minimumSlot, err := DataColumnsRPCMinValidSlot(currentSlot)
+	if err != nil {
+		return nil, errors.Wrap(err, "data columns RPC min valid slot")
+	}
+
+	// Get blocks by root and compute all missing columns by root.
+	blockByRoot := make(map[[fieldparams.RootLength]byte]blocks.ROBlock, len(blks))
+	missingColumnsByRoot := make(map[[fieldparams.RootLength]byte]map[uint64]bool, len(blks))
+	for _, blk := range blks {
+		// Extract the block root and the block slot
+		blockRoot, blockSlot := blk.Root(), blk.Block().Slot()
+
+		// Populate the block by root.
+		blockByRoot[blockRoot] = blk
+
+		// Skip blocks that are not in the retention period.
+		if blockSlot < minimumSlot {
+			continue
+		}
+
+		missingColumns, err := MissingDataColumns(blk, p2p.NodeID(), groupCount, dataColumnsStorage)
+		if err != nil {
+			return nil, errors.Wrap(err, "missing data columns")
+		}
+
+		for _, column := range missingColumns {
+			if _, ok := missingColumnsByRoot[blockRoot]; !ok {
+				missingColumnsByRoot[blockRoot] = make(map[uint64]bool)
+			}
+			missingColumnsByRoot[blockRoot][column] = true
+		}
+	}
+
+	// Return early if there are no missing data columns.
+	if len(missingColumnsByRoot) == 0 {
+		return nil, nil
+	}
+
+	// Compute the number of missing data columns.
+	previousMissingDataColumnsCount := itemsCount(missingColumnsByRoot)
+
+	// Count the number of retries for the same amount of missing data columns.
+	stallCount := 0
+
+	// Add log fields.
+	log := log.WithFields(logrus.Fields{
+		"initialMissingColumnsCount": previousMissingDataColumnsCount,
+		"blockCount":                 len(blks),
+		"firstSlot":                  blks[0].Block().Slot(),
+		"lastSlot":                   blks[len(blks)-1].Block().Slot(),
+	})
+
+	// Log the start of the process.
+	start := time.Now()
+	log.Debug("Requesting data column sidecars - start")
+
+	alignedDataColumnsByRoot := make(map[[fieldparams.RootLength]byte][]blocks.RODataColumn, len(blks))
+	for len(missingColumnsByRoot) > 0 {
+		// Build requests.
+		requests, err := buildDataColumnByRangeRequests(blks, missingColumnsByRoot, batchSize)
+		if err != nil {
+			return nil, errors.Wrap(err, "build data column by range requests")
+		}
+
+		// Requests data column sidecars from peers.
+		retrievedDataColumnsByRoot := make(map[[fieldparams.RootLength]byte][]blocks.RODataColumn)
+		for _, request := range requests {
+			roDataColumns, err := fetchDataColumnsFromPeers(ctx, clock, p2p, rateLimiter, ctxMap, request)
+			if err != nil {
+				return nil, errors.Wrap(err, "fetch data columns from peers")
+			}
+
+			for _, roDataColumn := range roDataColumns {
+				root := roDataColumn.BlockRoot()
+				if _, ok := blockByRoot[root]; !ok {
+					// It may happen if the peer which sent the data columns is on a different fork.
+					continue
+				}
+
+				retrievedDataColumnsByRoot[root] = append(retrievedDataColumnsByRoot[root], roDataColumn)
+			}
+		}
+
+		for root, dataColumns := range retrievedDataColumnsByRoot {
+			// Retrieve the block from the root.
+			block, ok := blockByRoot[root]
+			if !ok {
+				return nil, errors.New("block not found - this should never happen")
+			}
+
+			// Check if the data columns align with blocks.
+			if err := peerdas.DataColumnsAlignWithBlock(block, dataColumns); err != nil {
+				log.WithField("root", root).WithError(err).Debug("Data columns do not align with block")
+				continue
+			}
+
+			alignedDataColumnsByRoot[root] = append(alignedDataColumnsByRoot[root], dataColumns...)
+
+			// Remove aligned data columns from the missing columns.
+			for _, dataColumn := range dataColumns {
+				delete(missingColumnsByRoot[root], dataColumn.Index)
+				if len(missingColumnsByRoot[root]) == 0 {
+					delete(missingColumnsByRoot, root)
+				}
+			}
+		}
+
+		missingDataColumnsCount := itemsCount(missingColumnsByRoot)
+		if missingDataColumnsCount == previousMissingDataColumnsCount {
+			stallCount++
+		} else {
+			stallCount = 0
+		}
+
+		previousMissingDataColumnsCount = missingDataColumnsCount
+
+		if missingDataColumnsCount > 0 {
+			log := log.WithFields(logrus.Fields{
+				"remainingMissingColumnsCount": missingDataColumnsCount,
+				"stallCount":                   stallCount,
+				"maxAllowedStall":              maxAllowedStall,
+			})
+
+			if stallCount >= maxAllowedStall {
+				// It is very likely `bwbs` contains orphaned blocks, for which no peer has the data columns.
+				// We give up and let the state machine handle the situation.
+				const message = "Requesting data column sidecars - no progress, giving up"
+				log.Warning(message)
+				return nil, errors.New(message)
+			}
+
+			log.WithFields(logrus.Fields{
+				"remainingMissingColumnsCount": missingDataColumnsCount,
+				"stallCount":                   stallCount,
+			}).Debug("Requesting data column sidecars - continue")
+		}
+	}
+
+	log.WithField("duration", time.Since(start)).Debug("Requesting data column sidecars - success")
+	return alignedDataColumnsByRoot, nil
+}
+
+// MissingDataColumns looks at the data columns we should store for a given block regarding `custodyGroupCount`,
+// and returns the indices of the missing ones.
+func MissingDataColumns(block blocks.ROBlock, nodeID enode.ID, custodyGroupCount uint64, dataColumnStorage filesystem.DataColumnStorageSummarizer) ([]uint64, error) {
+	// Blocks before Fulu have no data columns.
+	if block.Version() < version.Fulu {
+		return nil, nil
+	}
+
+	// Get the blob commitments from the block.
+	commitments, err := block.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return nil, errors.Wrap(err, "blob KZG commitments")
+	}
+
+	// Nothing to build if there are no commitments.
+	if len(commitments) == 0 {
+		return nil, nil
+	}
+
+	// Compute the expected columns.
+	peerInfo, _, err := peerdas.Info(nodeID, custodyGroupCount)
+	if err != nil {
+		return nil, errors.Wrap(err, "peer info")
+	}
+
+	expectedColumns := peerInfo.CustodyColumns
+
+	// Get the stored columns.
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	summary := dataColumnStorage.Summary(block.Root())
+
+	storedColumns := make(map[uint64]bool, numberOfColumns)
+	for i := range numberOfColumns {
+		if summary.HasIndex(i) {
+			storedColumns[i] = true
+		}
+	}
+
+	// Compute the missing columns.
+	missingColumns := make([]uint64, 0, len(expectedColumns))
+	for column := range expectedColumns {
+		if !storedColumns[column] {
+			missingColumns = append(missingColumns, column)
+		}
+	}
+
+	return missingColumns, nil
+}
+
+// SelectPeersToFetchDataColumnsFrom implements greedy algorithm in order to select peers to fetch data columns from.
+// https://en.wikipedia.org/wiki/Set_cover_problem#Greedy_algorithm
+func SelectPeersToFetchDataColumnsFrom(neededDataColumns []uint64, dataColumnsByPeer map[peer.ID]map[uint64]bool) (map[peer.ID][]uint64, error) {
+	// Copy the provided needed data columns into a set that we will remove elements from.
+	remainingDataColumns := make(map[uint64]bool, len(neededDataColumns))
+	for _, dataColumn := range neededDataColumns {
+		remainingDataColumns[dataColumn] = true
+	}
+
+	dataColumnsFromSelectedPeers := make(map[peer.ID][]uint64)
+
+	// Filter `dataColumnsByPeer` to only contain needed data columns.
+	neededDataColumnsByPeer := make(map[peer.ID]map[uint64]bool, len(dataColumnsByPeer))
+	for pid, dataColumns := range dataColumnsByPeer {
+		for dataColumn := range dataColumns {
+			if remainingDataColumns[dataColumn] {
+				if _, ok := neededDataColumnsByPeer[pid]; !ok {
+					neededDataColumnsByPeer[pid] = make(map[uint64]bool, len(neededDataColumns))
+				}
+
+				neededDataColumnsByPeer[pid][dataColumn] = true
+			}
+		}
+	}
+
+	maxRequestDataColumnSidecars := params.BeaconConfig().MaxRequestDataColumnSidecars
+
+	for len(remainingDataColumns) > 0 {
+		// Check if at least one peer remains. If not, it means that we don't have enough peers to fetch all needed data columns.
+		if len(neededDataColumnsByPeer) == 0 {
+			missingDataColumnsSortedSlice := sliceFromMap(remainingDataColumns, true /*sorted*/)
+			return dataColumnsFromSelectedPeers, errors.Errorf("no peer to fetch the following data columns: %v", missingDataColumnsSortedSlice)
+		}
+
+		// Select the peer that custody the most needed data columns (greedy selection).
+		var bestPeer peer.ID
+		for peer, dataColumns := range neededDataColumnsByPeer {
+			if len(dataColumns) > len(neededDataColumnsByPeer[bestPeer]) {
+				bestPeer = peer
+			}
+		}
+
+		dataColumnsSortedSlice := sliceFromMap(neededDataColumnsByPeer[bestPeer], true /*sorted*/)
+		if uint64(len(dataColumnsSortedSlice)) > maxRequestDataColumnSidecars {
+			dataColumnsSortedSlice = dataColumnsSortedSlice[:maxRequestDataColumnSidecars]
+		}
+		dataColumnsFromSelectedPeers[bestPeer] = dataColumnsSortedSlice
+
+		// Remove the selected peer from the list of peers.
+		delete(neededDataColumnsByPeer, bestPeer)
+
+		// Remove the selected peer's data columns from the list of remaining data columns.
+		for _, dataColumn := range dataColumnsSortedSlice {
+			delete(remainingDataColumns, dataColumn)
+		}
+
+		// Remove the selected peer's data columns from the list of needed data columns by peer.
+		for _, dataColumn := range dataColumnsSortedSlice {
+			for peer, dataColumns := range neededDataColumnsByPeer {
+				delete(dataColumns, dataColumn)
+
+				if len(dataColumns) == 0 {
+					delete(neededDataColumnsByPeer, peer)
+				}
+			}
+		}
+	}
+
+	return dataColumnsFromSelectedPeers, nil
+}
+
+// AdmissiblePeersForCustodyGroup returns a map of peers that custody at least one custody group listed in `neededCustodyGroups`.
+//
+// It returns:
+// - A map, where the key of the map is the peer, the value is the custody groups of the peer.
+// - A map, where the key of the map is the custody group, the value is a list of peers that custody the group.
+// - A slice of descriptions for non admissible peers.
+// - An error if any.
+//
+// NOTE: distributeSamplesToPeer from the DataColumnSampler implements similar logic,
+// but with only one column queried in each request.
+func AdmissiblePeersForDataColumns(
+	peers []peer.ID,
+	neededDataColumns []uint64,
+	p2p p2p.P2P,
+) (map[peer.ID]map[uint64]bool, map[uint64][]peer.ID, []string, error) {
+	peerCount := len(peers)
+	neededDataColumnsCount := uint64(len(neededDataColumns))
+
+	// Create description slice for non admissible peers.
+	descriptions := make([]string, 0, peerCount)
+
+	// Compute custody columns for each peer.
+	dataColumnsByPeer, err := custodyColumnsFromPeers(p2p, peers)
+	if err != nil {
+		return nil, nil, nil, errors.Wrap(err, "custody columns from peers")
+	}
+
+	// Filter peers which custody at least one needed data column.
+	dataColumnsByAdmissiblePeer, localDescriptions := filterPeerWhichCustodyAtLeastOneDataColumn(neededDataColumns, dataColumnsByPeer)
+	descriptions = append(descriptions, localDescriptions...)
+
+	// Compute a map from needed data columns to their peers.
+	admissiblePeersByDataColumn := make(map[uint64][]peer.ID, neededDataColumnsCount)
+	for peerId, peerDataColumns := range dataColumnsByAdmissiblePeer {
+		for _, dataColumn := range neededDataColumns {
+			if peerDataColumns[dataColumn] {
+				admissiblePeersByDataColumn[dataColumn] = append(admissiblePeersByDataColumn[dataColumn], peerId)
+			}
+		}
+	}
+
+	return dataColumnsByAdmissiblePeer, admissiblePeersByDataColumn, descriptions, nil
+}
+
+// custodyColumnsFromPeers computes all the custody columns indexed by peer.
+func custodyColumnsFromPeers(p2pIface p2p.P2P, peers []peer.ID) (map[peer.ID]map[uint64]bool, error) {
+	peerCount := len(peers)
+
+	custodyColumnsByPeer := make(map[peer.ID]map[uint64]bool, peerCount)
+	for _, peer := range peers {
+		// Get the node ID from the peer ID.
+		nodeID, err := p2p.ConvertPeerIDToNodeID(peer)
+		if err != nil {
+			return nil, errors.Wrap(err, "convert peer ID to node ID")
+		}
+
+		// Get the custody group count of the peer.
+		custodyGroupCount := p2pIface.CustodyGroupCountFromPeer(peer)
+
+		// Get peerdas info of the peer.
+		dasInfo, _, err := peerdas.Info(nodeID, custodyGroupCount)
+		if err != nil {
+			return nil, errors.Wrap(err, "peerdas info")
+		}
+
+		custodyColumnsByPeer[peer] = dasInfo.CustodyColumns
+	}
+
+	return custodyColumnsByPeer, nil
+}
+
+// `filterPeerWhichCustodyAtLeastOneDataColumn` filters peers which custody at least one data column
+// specified in `neededDataColumns`. It returns also a list of descriptions for non admissible peers.
+func filterPeerWhichCustodyAtLeastOneDataColumn(neededDataColumns []uint64, inputDataColumnsByPeer map[peer.ID]map[uint64]bool) (map[peer.ID]map[uint64]bool, []string) {
+	// Create pretty needed data columns for logs.
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	outputDataColumnsByPeer := make(map[peer.ID]map[uint64]bool, len(inputDataColumnsByPeer))
+	descriptions := make([]string, 0)
+
+outerLoop:
+	for peer, peerCustodyDataColumns := range inputDataColumnsByPeer {
+		for _, neededDataColumn := range neededDataColumns {
+			if peerCustodyDataColumns[neededDataColumn] {
+				outputDataColumnsByPeer[peer] = peerCustodyDataColumns
+
+				continue outerLoop
+			}
+		}
+
+		peerCustodyColumnsCount := uint64(len(peerCustodyDataColumns))
+		var peerCustodyColumnsLog interface{} = "all"
+
+		if peerCustodyColumnsCount < numberOfColumns {
+			peerCustodyColumnsLog = sliceFromMap(peerCustodyDataColumns, true /*sorted*/)
+		}
+
+		description := fmt.Sprintf("peer %s: does not custody any needed column, custody columns: %v", peer, peerCustodyColumnsLog)
+		descriptions = append(descriptions, description)
+	}
+
+	return outputDataColumnsByPeer, descriptions
+}
+
+// buildDataColumnByRangeRequests builds an optimized slices of data column by range requests:
+// 1. It will never request a data column that is already stored in the DB if there is no "hole" in `roBlocks` other than missed slots.
+// 2. It will minimize the number of requests.
+// It expects blocks to be sorted by slot.
+func buildDataColumnByRangeRequests(roBlocks []blocks.ROBlock, missingColumnsByRoot map[[fieldparams.RootLength]byte]map[uint64]bool, batchSize int) ([]*eth.DataColumnSidecarsByRangeRequest, error) {
+	batchSizeSlot := primitives.Slot(batchSize)
+
+	// Return early if there are no blocks to process.
+	if len(roBlocks) == 0 {
+		return nil, nil
+	}
+
+	// It's safe to get the first item of the slice since we've already checked that it's not empty.
+	firstROBlock, lastROBlock := roBlocks[0], roBlocks[len(roBlocks)-1]
+	firstBlockSlot, lastBlockSlot := firstROBlock.Block().Slot(), lastROBlock.Block().Slot()
+	firstBlockRoot := firstROBlock.Root()
+
+	previousMissingDataColumns := make(map[uint64]bool, len(missingColumnsByRoot[firstBlockRoot]))
+
+	if missing, ok := missingColumnsByRoot[firstBlockRoot]; ok {
+		for key, value := range missing {
+			previousMissingDataColumns[key] = value
+		}
+	}
+
+	previousBlockSlot, previousStartBlockSlot := firstBlockSlot, firstBlockSlot
+
+	result := make([]*eth.DataColumnSidecarsByRangeRequest, 0, 1)
+	for index := 1; index < len(roBlocks); index++ {
+		roBlock := roBlocks[index]
+
+		// Extract the block from the RO-block.
+		block := roBlock.Block()
+
+		// Extract the slot from the block.
+		blockRoot, blockSlot := roBlock.Root(), block.Slot()
+
+		if blockSlot <= previousBlockSlot {
+			return nil, errors.Errorf("blocks are not strictly sorted by slot. Previous block slot: %d, current block slot: %d", previousBlockSlot, blockSlot)
+		}
+
+		// Extract KZG commitments count from the current block body
+		blockKzgCommitments, err := block.Body().BlobKzgCommitments()
+		if err != nil {
+			return nil, errors.Wrap(err, "blob KZG commitments")
+		}
+
+		// Compute the count of KZG commitments.
+		blockKzgCommitmentCount := len(blockKzgCommitments)
+
+		// Skip blocks without commitments.
+		if blockKzgCommitmentCount == 0 {
+			previousBlockSlot = blockSlot
+			continue
+		}
+
+		// Get the missing data columns for the current block.
+		missingDataColumns := make(map[uint64]bool, len(missingColumnsByRoot[blockRoot]))
+		for key, value := range missingColumnsByRoot[blockRoot] {
+			missingDataColumns[key] = value
+		}
+
+		// Compute if the missing data columns differ.
+		missingDataColumnsDiffer := uint64MapDiffer(previousMissingDataColumns, missingDataColumns)
+
+		// Compute if the batch size is reached.
+		batchSizeReached := blockSlot-previousStartBlockSlot >= batchSizeSlot
+
+		if missingDataColumnsDiffer || batchSizeReached {
+			// Append the slice to the result.
+			request := &eth.DataColumnSidecarsByRangeRequest{
+				StartSlot: previousStartBlockSlot,
+				Count:     uint64(blockSlot - previousStartBlockSlot),
+				Columns:   sliceFromMap(previousMissingDataColumns, true /*sorted*/),
+			}
+
+			result = append(result, request)
+
+			previousStartBlockSlot, previousMissingDataColumns = blockSlot, missingDataColumns
+		}
+
+		previousBlockSlot = blockSlot
+	}
+
+	lastRequest := &eth.DataColumnSidecarsByRangeRequest{
+		StartSlot: previousStartBlockSlot,
+		Count:     uint64(lastBlockSlot - previousStartBlockSlot + 1),
+		Columns:   sliceFromMap(previousMissingDataColumns, true /*sorted*/),
+	}
+
+	result = append(result, lastRequest)
+
+	return result, nil
+}
+
+// fetchDataColumnsFromPeers requests data columns by range to relevant peers
+func fetchDataColumnsFromPeers(
+	ctx context.Context,
+	clock *startup.Clock,
+	p2p p2p.P2P,
+	rateLimiter *leakybucket.Collector,
+	ctxMap ContextByteVersions,
+	targetRequest *eth.DataColumnSidecarsByRangeRequest,
+) ([]blocks.RODataColumn, error) {
+	// Filter out requests with no data columns.
+	if len(targetRequest.Columns) == 0 {
+		return nil, nil
+	}
+
+	// Get all admissible peers with the data columns they custody.
+	dataColumnsByAdmissiblePeer, err := waitForPeersForDataColumns(p2p, rateLimiter, targetRequest)
+	if err != nil {
+		return nil, errors.Wrap(err, "wait for peers for data columns")
+	}
+
+	// Select the peers that will be requested.
+	dataColumnsToFetchByPeer, err := SelectPeersToFetchDataColumnsFrom(targetRequest.Columns, dataColumnsByAdmissiblePeer)
+	if err != nil {
+		// This should never happen.
+		return nil, errors.Wrap(err, "select peers to fetch data columns from")
+	}
+
+	var roDataColumns []blocks.RODataColumn
+	for peer, columnsToFetch := range dataColumnsToFetchByPeer {
+		// Build the request.
+		request := &eth.DataColumnSidecarsByRangeRequest{
+			StartSlot: targetRequest.StartSlot,
+			Count:     targetRequest.Count,
+			Columns:   columnsToFetch,
+		}
+
+		peerRoDataColumns, err := SendDataColumnSidecarsByRangeRequest(ctx, clock, p2p, peer, ctxMap, request)
+		if err != nil {
+			return nil, errors.Wrap(err, "send data column sidecars by range request")
+		}
+
+		roDataColumns = append(roDataColumns, peerRoDataColumns...)
+	}
+
+	return roDataColumns, nil
+}
+
+// waitForPeersForDataColumns returns a map, where the key of the map is the peer, the value is the custody columns of the peer.
+// It uses only peers
+// - synced up to `lastSlot`, and
+// - have bandwidth to serve `blockCount` blocks.
+// It waits until at least one peer per data column is available.
+func waitForPeersForDataColumns(p2p p2p.P2P, rateLimiter *leakybucket.Collector, request *eth.DataColumnSidecarsByRangeRequest) (map[peer.ID]map[uint64]bool, error) {
+	const delay = 5 * time.Second
+
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	// Build nice log fields.
+	lastSlot := request.StartSlot.Add(request.Count).Sub(1)
+
+	var neededDataColumnsLog interface{} = "all"
+	neededDataColumnCount := uint64(len(request.Columns))
+	if neededDataColumnCount < numberOfColumns {
+		neededDataColumnsLog = request.Columns
+	}
+
+	log := log.WithFields(logrus.Fields{
+		"start":             request.StartSlot,
+		"targetSlot":        lastSlot,
+		"neededDataColumns": neededDataColumnsLog,
+	})
+
+	// Keep only peers with head epoch greater than or equal to the epoch corresponding to the target slot, and
+	// keep only peers with enough bandwidth.
+	filteredPeers, descriptions, err := filterPeersByTargetSlotAndBandwidth(p2p, rateLimiter, lastSlot, request.Count)
+	if err != nil {
+		return nil, errors.Wrap(err, "filter eers by target slot and bandwidth")
+	}
+
+	// Get the peers that are admissible for the data columns.
+	dataColumnsByAdmissiblePeer, admissiblePeersByDataColumn, moreDescriptions, err := AdmissiblePeersForDataColumns(filteredPeers, request.Columns, p2p)
+	if err != nil {
+		return nil, errors.Wrap(err, "admissible peers for data columns")
+	}
+
+	descriptions = append(descriptions, moreDescriptions...)
+
+	// Compute data columns without any peer.
+	dataColumnsWithoutPeers := computeDataColumnsWithoutPeers(request.Columns, admissiblePeersByDataColumn)
+
+	// Wait if no suitable peers are available.
+	for len(dataColumnsWithoutPeers) > 0 {
+		// Build a nice log fields.
+		var dataColumnsWithoutPeersLog interface{} = "all"
+		dataColumnsWithoutPeersCount := uint64(len(dataColumnsWithoutPeers))
+		if dataColumnsWithoutPeersCount < numberOfColumns {
+			dataColumnsWithoutPeersLog = sliceFromMap(dataColumnsWithoutPeers, true /*sorted*/)
+		}
+
+		log.WithField("columnsWithoutPeer", dataColumnsWithoutPeersLog).Warning("Fetch data columns from peers - no available peers, retrying later")
+		for _, description := range descriptions {
+			log.Debug(description)
+		}
+
+		for pid, peerDataColumns := range dataColumnsByAdmissiblePeer {
+			var peerDataColumnsLog interface{} = "all"
+			peerDataColumnsCount := uint64(len(peerDataColumns))
+			if peerDataColumnsCount < numberOfColumns {
+				peerDataColumnsLog = sliceFromMap(peerDataColumns, true /*sorted*/)
+			}
+
+			log.WithFields(logrus.Fields{
+				"peer":            pid,
+				"peerDataColumns": peerDataColumnsLog,
+			}).Debug("Peer data columns")
+		}
+
+		time.Sleep(delay)
+
+		// Filter for peers with head epoch greater than or equal to our target epoch for ByRange requests.
+		filteredPeers, descriptions, err = filterPeersByTargetSlotAndBandwidth(p2p, rateLimiter, lastSlot, request.Count)
+		if err != nil {
+			return nil, errors.Wrap(err, "filter peers by target slot and bandwidth")
+		}
+
+		// Get the peers that are admissible for the data columns.
+		dataColumnsByAdmissiblePeer, admissiblePeersByDataColumn, moreDescriptions, err = AdmissiblePeersForDataColumns(filteredPeers, request.Columns, p2p)
+		if err != nil {
+			return nil, errors.Wrap(err, "admissible peers for data columns")
+		}
+
+		descriptions = append(descriptions, moreDescriptions...)
+
+		// Compute data columns without any peer.
+		dataColumnsWithoutPeers = computeDataColumnsWithoutPeers(request.Columns, admissiblePeersByDataColumn)
+	}
+
+	return dataColumnsByAdmissiblePeer, nil
+}
+
+// Filter peers to ensure they are synced to the target slot and have sufficient bandwidth to serve the request.
+func filterPeersByTargetSlotAndBandwidth(p2p p2p.P2P, rateLimiter *leakybucket.Collector, lastSlot primitives.Slot, blockCount uint64) ([]peer.ID, []string, error) {
+	peers := p2p.Peers().Connected()
+
+	slotPeers, descriptions, err := filterPeersByTargetSlot(p2p, peers, lastSlot)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "peers with slot and data columns")
+	}
+
+	// Filter for peers with sufficient bandwidth to serve the request.
+	slotAndBandwidthPeers := hasSufficientBandwidth(rateLimiter, slotPeers, blockCount)
+
+	// Add debugging logs for the filtered peers.
+	peerWithSufficientBandwidthMap := make(map[peer.ID]bool, len(peers))
+	for _, peer := range slotAndBandwidthPeers {
+		peerWithSufficientBandwidthMap[peer] = true
+	}
+
+	for _, peer := range slotPeers {
+		if !peerWithSufficientBandwidthMap[peer] {
+			description := fmt.Sprintf("peer %s: does not have sufficient bandwidth", peer)
+			descriptions = append(descriptions, description)
+		}
+	}
+	return slotAndBandwidthPeers, descriptions, nil
+}
+
+func hasSufficientBandwidth(rateLimiter *leakybucket.Collector, peers []peer.ID, count uint64) []peer.ID {
+	var filteredPeers []peer.ID
+
+	for _, p := range peers {
+		if uint64(rateLimiter.Remaining(p.String())) < count {
+			continue
+		}
+		copiedP := p
+		filteredPeers = append(filteredPeers, copiedP)
+	}
+	return filteredPeers
+}
+
+func computeDataColumnsWithoutPeers(neededColumns []uint64, peersByColumn map[uint64][]peer.ID) map[uint64]bool {
+	result := make(map[uint64]bool)
+	for _, column := range neededColumns {
+		if _, ok := peersByColumn[column]; !ok {
+			result[column] = true
+		}
+	}
+
+	return result
+}
+
+// Filter peers with head epoch lower than our target epoch for ByRange requests.
+func filterPeersByTargetSlot(p2p p2p.P2P, peers []peer.ID, targetSlot primitives.Slot) ([]peer.ID, []string, error) {
+	filteredPeers := make([]peer.ID, 0, len(peers))
+	descriptions := make([]string, 0, len(peers))
+	// Compute the target epoch from the target slot.
+	targetEpoch := slots.ToEpoch(targetSlot)
+
+	for _, peer := range peers {
+		peerChainState, err := p2p.Peers().ChainState(peer)
+		if err != nil {
+			description := fmt.Sprintf("peer %s: error: %s", peer, err)
+			descriptions = append(descriptions, description)
+			continue
+		}
+
+		if peerChainState == nil {
+			description := fmt.Sprintf("peer %s: chain state is nil", peer)
+			descriptions = append(descriptions, description)
+			continue
+		}
+
+		peerHeadEpoch := slots.ToEpoch(peerChainState.HeadSlot)
+
+		if peerHeadEpoch < targetEpoch {
+			description := fmt.Sprintf("peer %s: peer head epoch %d < our target epoch %d", peer, peerHeadEpoch, targetEpoch)
+			descriptions = append(descriptions, description)
+			continue
+		}
+
+		filteredPeers = append(filteredPeers, peer)
+	}
+
+	return filteredPeers, descriptions, nil
+}
+
+// itemsCount returns the total count of items
+func itemsCount(missingColumnsByRoot map[[fieldparams.RootLength]byte]map[uint64]bool) int {
+	count := 0
+	for _, columns := range missingColumnsByRoot {
+		count += len(columns)
+	}
+	return count
+}
+
+// uint64MapDiffer returns true if the two maps differ.
+func uint64MapDiffer(left, right map[uint64]bool) bool {
+	if len(left) != len(right) {
+		return true
+	}
+
+	for k := range left {
+		if !right[k] {
+			return true
+		}
+	}
+
+	return false
+}
+
+func DataColumnSidecarsByRangeRequest(columns []uint64, start, end primitives.Slot) *eth.DataColumnSidecarsByRangeRequest {
+	sort.Slice(columns, func(i, j int) bool {
+		return columns[i] < columns[j]
+	})
+	return &eth.DataColumnSidecarsByRangeRequest{
+		StartSlot: start,
+		Count:     uint64(end-start) + 1,
+		Columns:   columns,
+	}
+}
+
+func RequestDataColumnsByRoot(ctx context.Context, ctxMap ContextByteVersions, pid peer.ID, reqs types.DataColumnsByRootIdentifiers) ([]blocks.RODataColumn, error) {
+	return nil, nil
+}

beacon-chain/sync/data_columns_reconstruct.go

@@ -0,0 +1,205 @@
+package sync
+
+import (
+	"context"
+	"fmt"
+	"slices"
+	"time"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+const broadCastMissingDataColumnsTimeIntoSlot = 3 * time.Second
+
+func (s *Service) reconstructDataColumns(ctx context.Context, verifiedRODataColumn blocks.VerifiedRODataColumn) error {
+	blockRoot := verifiedRODataColumn.BlockRoot()
+	proposerIndex := verifiedRODataColumn.ProposerIndex()
+	slot := verifiedRODataColumn.Slot()
+
+	// Get the columns we store.
+	storedDataColumns := s.cfg.dataColumnStorage.Summary(blockRoot)
+	storedColumnsCount := storedDataColumns.Count()
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	// If reconstruction is not possible or if all columns are already stored, exit early.
+	if storedColumnsCount < peerdas.MinimumColumnsCountToReconstruct() || storedColumnsCount == numberOfColumns {
+		return nil
+	}
+
+	// Lock to prevent concurrent reconstruction.
+	if !s.dataColumsnReconstructionLock.TryLock() {
+		// If the mutex is already locked, it means that another goroutine is already reconstructing the data columns.
+		// In this case, no need to reconstruct again.
+		// TODO: Implement the (pathological) case where we want to reconstruct data columns corresponding to different blocks at the same time.
+		//       This should be a rare case and we can ignore it for now, but it needs to be addressed in the future.
+		return nil
+	}
+
+	defer s.dataColumsnReconstructionLock.Unlock()
+
+	// Retrieve the node ID.
+	nodeID := s.cfg.p2p.NodeID()
+
+	// Prevent custody group count to change during the rest of the function.
+	s.cfg.custodyInfo.Mut.RLock()
+	defer s.cfg.custodyInfo.Mut.RUnlock()
+
+	// Compute the custody group count.
+	custodyGroupCount := s.cfg.custodyInfo.ActualGroupCount()
+
+	// Retrieve our local node info.
+	localNodeInfo, _, err := peerdas.Info(nodeID, custodyGroupCount)
+	if err != nil {
+		return errors.Wrap(err, "peer info")
+	}
+
+	// Load all the possible data columns sidecars, to minimize reconstruction time.
+	verifiedSidecars, err := s.cfg.dataColumnStorage.Get(blockRoot, nil)
+	if err != nil {
+		return errors.Wrap(err, "get data column sidecars")
+	}
+
+	// Recover cells and proofs.
+	reconstructedSidecars, err := peerdas.ReconstructDataColumnSidecars(verifiedSidecars)
+	if err != nil {
+		return errors.Wrap(err, "reconstruct data column sidecars")
+	}
+
+	// Filter reconstructed sidecars to save.
+	custodyColumns := localNodeInfo.CustodyColumns
+	toSaveSidecars := make([]blocks.VerifiedRODataColumn, 0, len(custodyColumns))
+
+	for _, sidecar := range reconstructedSidecars {
+		if custodyColumns[sidecar.Index] {
+			toSaveSidecars = append(toSaveSidecars, sidecar)
+		}
+	}
+
+	// Save the data columns sidecars in the database.
+	// Note: We do not call `receiveDataColumn`, because it will ignore
+	// incoming data columns via gossip while we did not broadcast (yet) the reconstructed data columns.
+	if err := s.cfg.dataColumnStorage.Save(toSaveSidecars); err != nil {
+		return errors.Wrap(err, "save data column sidecars")
+	}
+
+	// Schedule the broadcast.
+	if err := s.scheduleReconstructedDataColumnsBroadcast(ctx, blockRoot, proposerIndex, slot); err != nil {
+		return errors.Wrap(err, "schedule reconstructed data columns broadcast")
+	}
+
+	log.WithFields(logrus.Fields{
+		"root":             fmt.Sprintf("%#x", blockRoot),
+		"slot":             slot,
+		"fromColumnsCount": storedColumnsCount,
+	}).Debug("Data columns reconstructed and saved")
+
+	return nil
+}
+
+func (s *Service) scheduleReconstructedDataColumnsBroadcast(
+	ctx context.Context,
+	root [fieldparams.RootLength]byte,
+	proposerIndex primitives.ValidatorIndex,
+	slot primitives.Slot,
+) error {
+	log := log.WithFields(logrus.Fields{
+		"root": fmt.Sprintf("%x", root),
+		"slot": slot,
+	})
+
+	// Get the time corresponding to the start of the slot.
+	genesisTime := uint64(s.cfg.chain.GenesisTime().Unix())
+	slotStartTime, err := slots.ToTime(genesisTime, slot)
+	if err != nil {
+		return errors.Wrap(err, "to time")
+	}
+
+	// Compute when to broadcast the missing data columns.
+	broadcastTime := slotStartTime.Add(broadCastMissingDataColumnsTimeIntoSlot)
+
+	// Compute the waiting time. This could be negative. In such a case, broadcast immediately.
+	waitingTime := time.Until(broadcastTime)
+
+	time.AfterFunc(waitingTime, func() {
+		s.dataColumsnReconstructionLock.Lock()
+		defer s.dataColumsnReconstructionLock.Unlock()
+
+		// Get the node ID.
+		nodeID := s.cfg.p2p.NodeID()
+
+		// Prevent custody group count to change during the rest of the function.
+		s.cfg.custodyInfo.Mut.RLock()
+		defer s.cfg.custodyInfo.Mut.RUnlock()
+
+		// Get the custody group count.
+		custodyGroupCount := s.cfg.custodyInfo.ActualGroupCount()
+
+		// Retrieve the local node info.
+		localNodeInfo, _, err := peerdas.Info(nodeID, custodyGroupCount)
+		if err != nil {
+			log.WithError(err).Error("Peer info")
+			return
+		}
+
+		// Get the data columns we actually store.
+		summary := s.cfg.dataColumnStorage.Summary(root)
+
+		// Compute the missing data columns (data columns we should custody but we do not have received via gossip.)
+		missingColumns := make([]uint64, 0, len(localNodeInfo.CustodyColumns))
+		for column := range localNodeInfo.CustodyColumns {
+			if !s.hasSeenDataColumnIndex(slot, proposerIndex, column) {
+				missingColumns = append(missingColumns, column)
+			}
+		}
+
+		// Exit early if there are no missing data columns.
+		// This is the happy path.
+		if len(missingColumns) == 0 {
+			return
+		}
+
+		for _, column := range missingColumns {
+			if !summary.HasIndex(column) {
+				// This column was not received nor reconstructed. This should not happen.
+				log.WithField("column", column).Error("Data column not received nor reconstructed")
+			}
+		}
+
+		// Get the non received but reconstructed data column.
+		verifiedRODataColumnSidecars, err := s.cfg.dataColumnStorage.Get(root, missingColumns)
+		if err != nil {
+			log.WithError(err).Error("get data column sidecars")
+			return
+		}
+
+		for _, verifiedRODataColumn := range verifiedRODataColumnSidecars {
+			// Compute the subnet for this column.
+			subnet := peerdas.ComputeSubnetForDataColumnSidecar(verifiedRODataColumn.Index)
+
+			// Broadcast the missing data column.
+			if err := s.cfg.p2p.BroadcastDataColumn(root, subnet, verifiedRODataColumn.DataColumnSidecar); err != nil {
+				log.WithError(err).Error("Broadcast data column")
+			}
+
+			// Now, we can set the data column as seen.
+			s.setSeenDataColumnIndex(slot, proposerIndex, verifiedRODataColumn.Index)
+		}
+
+		// Sort the missing data columns.
+		slices.Sort[[]uint64](missingColumns)
+
+		log.WithFields(logrus.Fields{
+			"timeIntoSlot": broadCastMissingDataColumnsTimeIntoSlot,
+			"columns":      missingColumns,
+		}).Debug("Start broadcasting not seen via gossip but reconstructed data columns")
+	})
+
+	return nil
+}

beacon-chain/sync/data_columns_sampling.go

@@ -0,0 +1,627 @@
+package sync
+
+import (
+	"context"
+	"fmt"
+	"slices"
+	"sync"
+	"time"
+
+	"github.com/OffchainLabs/prysm/v6/async"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed"
+	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/types"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/crypto/rand"
+	eth "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+const PeerRefreshInterval = 1 * time.Minute
+
+type roundSummary struct {
+	RequestedColumns []uint64
+	MissingColumns   map[uint64]bool
+}
+
+// DataColumnSampler defines the interface for sampling data columns from peers for requested block root and samples count.
+type DataColumnSampler interface {
+	// Run starts the data column sampling service.
+	Run(ctx context.Context)
+}
+
+var _ DataColumnSampler = (*dataColumnSampler1D)(nil)
+
+// dataColumnSampler1D implements the DataColumnSampler interface for PeerDAS 1D.
+type dataColumnSampler1D struct {
+	sync.RWMutex
+
+	p2p           p2p.P2P
+	clock         *startup.Clock
+	ctxMap        ContextByteVersions
+	stateNotifier statefeed.Notifier
+
+	// nonCustodyGroups is a set of groups that are not custodied by the node.
+	nonCustodyGroups map[uint64]bool
+
+	// groupsByPeer maps a peer to the groups it is responsible for custody.
+	groupsByPeer map[peer.ID]map[uint64]bool
+
+	// peersByCustodyGroup maps a group to the peer responsible for custody.
+	peersByCustodyGroup map[uint64]map[peer.ID]bool
+
+	// columnVerifier verifies a column according to the specified requirements.
+	columnVerifier verification.NewDataColumnsVerifier
+
+	// custodyInfo contains the custody information of the node.
+	custodyInfo *peerdas.CustodyInfo
+}
+
+// newDataColumnSampler1D creates a new 1D data column sampler.
+func newDataColumnSampler1D(
+	p2p p2p.P2P,
+	clock *startup.Clock,
+	ctxMap ContextByteVersions,
+	stateNotifier statefeed.Notifier,
+	colVerifier verification.NewDataColumnsVerifier,
+	custodyInfo *peerdas.CustodyInfo,
+) *dataColumnSampler1D {
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
+	peersByCustodyGroup := make(map[uint64]map[peer.ID]bool, numberOfCustodyGroups)
+
+	for i := range numberOfCustodyGroups {
+		peersByCustodyGroup[i] = make(map[peer.ID]bool)
+	}
+
+	return &dataColumnSampler1D{
+		p2p:                 p2p,
+		clock:               clock,
+		ctxMap:              ctxMap,
+		stateNotifier:       stateNotifier,
+		groupsByPeer:        make(map[peer.ID]map[uint64]bool),
+		peersByCustodyGroup: peersByCustodyGroup,
+		columnVerifier:      colVerifier,
+		custodyInfo:         custodyInfo,
+	}
+}
+
+// Run implements DataColumnSampler.
+func (d *dataColumnSampler1D) Run(ctx context.Context) {
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
+
+	// Get the node ID.
+	nodeID := d.p2p.NodeID()
+
+	// Verify if we need to run sampling or not, if not, return directly.
+	// TODO: Rework this part to take into account dynamic custody group count with peer sampling.
+	custodyGroupCount := d.custodyInfo.ActualGroupCount()
+
+	// Retrieve our local node info.
+	localNodeInfo, _, err := peerdas.Info(nodeID, custodyGroupCount)
+	if err != nil {
+		log.WithError(err).Error("peer info")
+		return
+	}
+
+	// TODO: custody group count != data column group count
+	if custodyGroupCount >= peerdas.MinimumColumnsCountToReconstruct() {
+		log.WithFields(logrus.Fields{
+			"custodyGroupCount": custodyGroupCount,
+			"totalGroups":       numberOfCustodyGroups,
+		}).Debug("The node custodies at least the half of the groups, no need to sample")
+		return
+	}
+
+	// Initialize non custody groups.
+	d.nonCustodyGroups = make(map[uint64]bool)
+	for i := range numberOfCustodyGroups {
+		if !localNodeInfo.CustodyGroups[i] {
+			d.nonCustodyGroups[i] = true
+		}
+	}
+
+	// Initialize peer info first.
+	d.refreshPeerInfo()
+
+	// periodically refresh peer info to keep peer <-> column mapping up to date.
+	async.RunEvery(ctx, PeerRefreshInterval, d.refreshPeerInfo)
+
+	// start the sampling loop.
+	d.samplingRoutine(ctx)
+}
+
+func (d *dataColumnSampler1D) samplingRoutine(ctx context.Context) {
+	stateCh := make(chan *feed.Event, 1)
+	stateSub := d.stateNotifier.StateFeed().Subscribe(stateCh)
+	defer stateSub.Unsubscribe()
+
+	for {
+		select {
+		case evt := <-stateCh:
+			d.handleStateNotification(ctx, evt)
+		case err := <-stateSub.Err():
+			log.WithError(err).Error("DataColumnSampler1D subscription to state feed failed")
+		case <-ctx.Done():
+			log.Debug("Context canceled, exiting data column sampling loop.")
+			return
+		}
+	}
+}
+
+// Refresh peer information.
+func (d *dataColumnSampler1D) refreshPeerInfo() {
+	d.Lock()
+	defer d.Unlock()
+
+	activePeers := d.p2p.Peers().Active()
+	d.prunePeerInfo(activePeers)
+
+	for _, pid := range activePeers {
+		// Retrieve the custody group count of the peer.
+		retrievedCustodyGroupCount := d.p2p.CustodyGroupCountFromPeer(pid)
+
+		// Look into our store the custody storedGroups for this peer.
+		storedGroups, ok := d.groupsByPeer[pid]
+		storedGroupsCount := uint64(len(storedGroups))
+
+		if ok && storedGroupsCount == retrievedCustodyGroupCount {
+			// No change for this peer.
+			continue
+		}
+
+		nodeID, err := p2p.ConvertPeerIDToNodeID(pid)
+		if err != nil {
+			log.WithError(err).WithField("peerID", pid).Error("Failed to convert peer ID to node ID")
+			continue
+		}
+
+		// Retrieve the peer info.
+		peerInfo, _, err := peerdas.Info(nodeID, retrievedCustodyGroupCount)
+		if err != nil {
+			log.WithError(err).WithField("peerID", pid.String()).Error("Failed to determine peer info")
+		}
+
+		d.groupsByPeer[pid] = peerInfo.CustodyGroups
+		for group := range peerInfo.CustodyGroups {
+			d.peersByCustodyGroup[group][pid] = true
+		}
+	}
+
+	groupsWithoutPeers := make([]uint64, 0)
+	for group, peers := range d.peersByCustodyGroup {
+		if len(peers) == 0 {
+			groupsWithoutPeers = append(groupsWithoutPeers, group)
+		}
+	}
+
+	if len(groupsWithoutPeers) > 0 {
+		slices.Sort[[]uint64](groupsWithoutPeers)
+		log.WithField("groups", groupsWithoutPeers).Warn("Some groups have no peers responsible for custody")
+	}
+}
+
+// prunePeerInfo prunes inactive peers from peerByGroup and groupByPeer.
+// This should not be called outside of refreshPeerInfo without being locked.
+func (d *dataColumnSampler1D) prunePeerInfo(activePeers []peer.ID) {
+	active := make(map[peer.ID]bool)
+	for _, pid := range activePeers {
+		active[pid] = true
+	}
+
+	for pid := range d.groupsByPeer {
+		if !active[pid] {
+			d.prunePeer(pid)
+		}
+	}
+}
+
+// prunePeer removes a peer from stored peer info map, it should be called with lock held.
+func (d *dataColumnSampler1D) prunePeer(pid peer.ID) {
+	delete(d.groupsByPeer, pid)
+	for _, peers := range d.peersByCustodyGroup {
+		delete(peers, pid)
+	}
+}
+
+func (d *dataColumnSampler1D) handleStateNotification(ctx context.Context, event *feed.Event) {
+	if event.Type != statefeed.BlockProcessed {
+		return
+	}
+
+	data, ok := event.Data.(*statefeed.BlockProcessedData)
+	if !ok {
+		log.Error("Event feed data is not of type *statefeed.BlockProcessedData")
+		return
+	}
+
+	if !data.Verified {
+		// We only process blocks that have been verified
+		log.Error("Data is not verified")
+		return
+	}
+
+	if data.SignedBlock.Version() < version.Fulu {
+		log.Debug("Pre Fulu block, skipping data column sampling")
+		return
+	}
+
+	// Determine if we need to sample data columns for this block.
+	beaconConfig := params.BeaconConfig()
+	samplesPerSlots := beaconConfig.SamplesPerSlot
+	halfOfCustodyGroups := beaconConfig.NumberOfCustodyGroups / 2
+	nonCustodyGroupsCount := uint64(len(d.nonCustodyGroups))
+
+	if nonCustodyGroupsCount <= halfOfCustodyGroups {
+		// Nothing to sample.
+		return
+	}
+
+	// Get the commitments for this block.
+	commitments, err := data.SignedBlock.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		log.WithError(err).Error("Failed to get blob KZG commitments")
+		return
+	}
+
+	// Skip if there are no commitments.
+	if len(commitments) == 0 {
+		log.Debug("No commitments in block, skipping data column sampling")
+		return
+	}
+
+	// Randomize columns for sample selection.
+	randomizedColumns, err := randomizeColumns(d.nonCustodyGroups)
+	if err != nil {
+		log.WithError(err).Error("Failed to randomize columns")
+		return
+	}
+
+	samplesCount := min(samplesPerSlots, nonCustodyGroupsCount-halfOfCustodyGroups)
+
+	// TODO: Use the first output of `incrementalDAS` as input of the fork choice rule.
+	_, _, err = d.incrementalDAS(ctx, data, randomizedColumns, samplesCount)
+	if err != nil {
+		log.WithError(err).Error("Failed to run incremental DAS")
+	}
+}
+
+// incrementalDAS samples data columns from active peers using incremental DAS.
+// https://ethresear.ch/t/lossydas-lossy-incremental-and-diagonal-sampling-for-data-availability/18963#incrementaldas-dynamically-increase-the-sample-size-10
+// According to https://github.com/ethereum/consensus-specs/issues/3825, we're going to select query samples exclusively from the non custody columns.
+func (d *dataColumnSampler1D) incrementalDAS(
+	ctx context.Context,
+	blockProcessedData *statefeed.BlockProcessedData,
+	columns []uint64,
+	sampleCount uint64,
+) (bool, []roundSummary, error) {
+	allowedFailures := uint64(0)
+	firstColumnToSample, extendedSampleCount := uint64(0), peerdas.ExtendedSampleCount(sampleCount, allowedFailures)
+	roundSummaries := make([]roundSummary, 0, 1) // We optimistically allocate only one round summary.
+	blockRoot := blockProcessedData.BlockRoot
+	columnsCount := uint64(len(columns))
+
+	start := time.Now()
+
+	for round := 1; ; /*No exit condition */ round++ {
+		if extendedSampleCount > columnsCount {
+			// We already tried to sample all possible columns, this is the unhappy path.
+			log.WithFields(logrus.Fields{
+				"root":  fmt.Sprintf("%#x", blockRoot),
+				"round": round - 1,
+			}).Warning("Some columns are still missing after trying to sample all possible columns")
+			return false, roundSummaries, nil
+		}
+
+		// Get the columns to sample for this round.
+		columnsToSample := columns[firstColumnToSample:extendedSampleCount]
+		columnsToSampleCount := extendedSampleCount - firstColumnToSample
+
+		log.WithFields(logrus.Fields{
+			"root":    fmt.Sprintf("%#x", blockRoot),
+			"columns": columnsToSample,
+			"round":   round,
+		}).Debug("Start data columns sampling")
+
+		// Sample data columns from peers in parallel.
+		retrievedSamples, err := d.sampleDataColumns(ctx, blockProcessedData, columnsToSample)
+		if err != nil {
+			return false, nil, errors.Wrap(err, "sample data columns")
+		}
+
+		missingSamples := make(map[uint64]bool)
+		for _, column := range columnsToSample {
+			if !retrievedSamples[column] {
+				missingSamples[column] = true
+			}
+		}
+
+		roundSummaries = append(roundSummaries, roundSummary{
+			RequestedColumns: columnsToSample,
+			MissingColumns:   missingSamples,
+		})
+
+		retrievedSampleCount := uint64(len(retrievedSamples))
+		if retrievedSampleCount == columnsToSampleCount {
+			// All columns were correctly sampled, this is the happy path.
+			log.WithFields(logrus.Fields{
+				"root":         fmt.Sprintf("%#x", blockRoot),
+				"neededRounds": round,
+				"duration":     time.Since(start),
+			}).Debug("All columns were successfully sampled")
+			return true, roundSummaries, nil
+		}
+
+		if retrievedSampleCount > columnsToSampleCount {
+			// This should never happen.
+			return false, nil, errors.New("retrieved more columns than requested")
+		}
+
+		// There is still some missing columns, extend the samples.
+		allowedFailures += columnsToSampleCount - retrievedSampleCount
+		oldExtendedSampleCount := extendedSampleCount
+		firstColumnToSample = extendedSampleCount
+		extendedSampleCount = peerdas.ExtendedSampleCount(sampleCount, allowedFailures)
+
+		log.WithFields(logrus.Fields{
+			"root":                fmt.Sprintf("%#x", blockRoot),
+			"round":               round,
+			"missingColumnsCount": allowedFailures,
+			"currentSampleIndex":  oldExtendedSampleCount,
+			"nextSampleIndex":     extendedSampleCount,
+		}).Debug("Some columns are still missing after sampling this round.")
+	}
+}
+
+func (d *dataColumnSampler1D) sampleDataColumns(
+	ctx context.Context,
+	blockProcessedData *statefeed.BlockProcessedData,
+	columns []uint64,
+) (map[uint64]bool, error) {
+	// distribute samples to peer
+	peerToColumns, err := d.distributeSamplesToPeer(columns)
+	if err != nil {
+		return nil, errors.Wrap(err, "distribute samples to peer")
+	}
+
+	var (
+		mu sync.Mutex
+		wg sync.WaitGroup
+	)
+
+	res := make(map[uint64]bool)
+
+	sampleFromPeer := func(pid peer.ID, cols map[uint64]bool) {
+		defer wg.Done()
+		retrieved := d.sampleDataColumnsFromPeer(ctx, pid, blockProcessedData, cols)
+
+		mu.Lock()
+		for col := range retrieved {
+			res[col] = true
+		}
+		mu.Unlock()
+	}
+
+	// sample from peers in parallel
+	for pid, cols := range peerToColumns {
+		wg.Add(1)
+		go sampleFromPeer(pid, cols)
+	}
+
+	wg.Wait()
+	return res, nil
+}
+
+// distributeSamplesToPeer distributes samples to peers based on the columns they are responsible for.
+// Currently it randomizes peer selection for a column and did not take into account whole peer distribution balance. It could be improved if needed.
+func (d *dataColumnSampler1D) distributeSamplesToPeer(columns []uint64) (map[peer.ID]map[uint64]bool, error) {
+	dist := make(map[peer.ID]map[uint64]bool)
+
+	for _, column := range columns {
+		custodyGroup, err := peerdas.ComputeCustodyGroupForColumn(column)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute custody group for column")
+		}
+
+		peers := d.peersByCustodyGroup[custodyGroup]
+		if len(peers) == 0 {
+			log.WithField("column", column).Warning("No peers responsible for custody of column")
+			continue
+		}
+
+		pid, err := selectRandomPeer(peers)
+		if err != nil {
+			return nil, errors.Wrap(err, "select random peer")
+		}
+
+		if _, ok := dist[pid]; !ok {
+			dist[pid] = make(map[uint64]bool)
+		}
+
+		dist[pid][column] = true
+	}
+
+	return dist, nil
+}
+
+func (d *dataColumnSampler1D) sampleDataColumnsFromPeer(
+	ctx context.Context,
+	pid peer.ID,
+	blockProcessedData *statefeed.BlockProcessedData,
+	requestedColumns map[uint64]bool,
+) map[uint64]bool {
+	retrievedColumns := make(map[uint64]bool)
+
+	cols := make([]uint64, 0, len(requestedColumns))
+	for col := range requestedColumns {
+		cols = append(cols, col)
+	}
+	req := &eth.DataColumnsByRootIdentifier{
+		BlockRoot: blockProcessedData.BlockRoot[:],
+		Columns:   cols,
+	}
+
+	// Send the request to the peer.
+	roDataColumns, err := SendDataColumnSidecarsByRootRequest(ctx, d.clock, d.p2p, pid, d.ctxMap, &types.DataColumnsByRootIdentifiers{req})
+	if err != nil {
+		log.WithError(err).Error("Failed to send data column sidecar by root")
+		return nil
+	}
+
+	// TODO: Once peer sampling is used, we should verify all sampled data columns in a single batch instead of looping over columns.
+	for _, roDataColumn := range roDataColumns {
+		if verifyColumn(roDataColumn, blockProcessedData, pid, requestedColumns, d.columnVerifier) {
+			retrievedColumns[roDataColumn.Index] = true
+		}
+	}
+
+	if len(retrievedColumns) == len(requestedColumns) {
+		log.WithFields(logrus.Fields{
+			"peerID":           pid,
+			"root":             fmt.Sprintf("%#x", blockProcessedData.BlockRoot),
+			"requestedColumns": sliceFromMap(requestedColumns, true /*sorted*/),
+		}).Debug("Sampled columns from peer successfully")
+	} else {
+		log.WithFields(logrus.Fields{
+			"peerID":           pid,
+			"root":             fmt.Sprintf("%#x", blockProcessedData.BlockRoot),
+			"requestedColumns": sliceFromMap(requestedColumns, true /*sorted*/),
+			"retrievedColumns": sliceFromMap(retrievedColumns, true /*sorted*/),
+		}).Debug("Sampled columns from peer with some errors")
+	}
+
+	return retrievedColumns
+}
+
+// randomizeColumns returns a slice containing randomly ordered columns belonging to the input `groups`.
+func randomizeColumns(custodyGroups map[uint64]bool) ([]uint64, error) {
+	// Compute the number of columns per group.
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
+	columnsPerGroup := numberOfColumns / numberOfCustodyGroups
+
+	// Compute the number of columns.
+	groupCount := uint64(len(custodyGroups))
+	expectedColumnCount := groupCount * columnsPerGroup
+
+	// Compute the columns.
+	columns := make([]uint64, 0, expectedColumnCount)
+	for group := range custodyGroups {
+		columnsGroup, err := peerdas.ComputeColumnsForCustodyGroup(group)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute columns for custody group")
+		}
+
+		columns = append(columns, columnsGroup...)
+	}
+
+	actualColumnCount := len(columns)
+
+	// Safety check.
+	if uint64(actualColumnCount) != expectedColumnCount {
+		return nil, errors.New("invalid number of columns, should never happen")
+	}
+
+	// Shuffle the columns.
+	rand.NewGenerator().Shuffle(actualColumnCount, func(i, j int) {
+		columns[i], columns[j] = columns[j], columns[i]
+	})
+
+	return columns, nil
+}
+
+// sliceFromMap returns a sorted list of keys from a map.
+func sliceFromMap(m map[uint64]bool, sorted ...bool) []uint64 {
+	result := make([]uint64, 0, len(m))
+	for k := range m {
+		result = append(result, k)
+	}
+
+	if len(sorted) > 0 && sorted[0] {
+		slices.Sort(result)
+	}
+
+	return result
+}
+
+// selectRandomPeer returns a random peer from the given list of peers.
+func selectRandomPeer(peers map[peer.ID]bool) (peer.ID, error) {
+	peersCount := uint64(len(peers))
+	pick := rand.NewGenerator().Uint64() % peersCount
+
+	for peer := range peers {
+		if pick == 0 {
+			return peer, nil
+		}
+
+		pick--
+	}
+
+	// This should never be reached.
+	return peer.ID(""), errors.New("failed to select random peer")
+}
+
+// verifyColumn verifies the retrieved column against the root, the index,
+// the KZG inclusion and the KZG proof.
+func verifyColumn(
+	roDataColumn blocks.RODataColumn,
+	blockProcessedData *statefeed.BlockProcessedData,
+	pid peer.ID,
+	requestedColumns map[uint64]bool,
+	newDataColumnsVerifier verification.NewDataColumnsVerifier,
+) bool {
+	retrievedColumn := roDataColumn.Index
+
+	// Filter out columns that were not requested.
+	if !requestedColumns[retrievedColumn] {
+		columnsToSampleList := sliceFromMap(requestedColumns, true /*sorted*/)
+
+		log.WithFields(logrus.Fields{
+			"peerID":           pid,
+			"requestedColumns": columnsToSampleList,
+			"retrievedColumn":  retrievedColumn,
+		}).Debug("Retrieved column was not requested")
+
+		return false
+	}
+
+	roBlock, err := blocks.NewROBlock(blockProcessedData.SignedBlock)
+	if err != nil {
+		log.WithError(err).WithField("peerID", pid).Error("Failed to create ROBlock")
+	}
+
+	roDataColumns := []blocks.RODataColumn{roDataColumn}
+
+	if err := peerdas.DataColumnsAlignWithBlock(roBlock, roDataColumns); err != nil {
+		return false
+	}
+
+	// https://github.com/ethereum/consensus-specs/blob/dev/specs/fulu/p2p-interface.md#datacolumnsidecarsbyroot-v1
+	verifier := newDataColumnsVerifier(roDataColumns, verification.ByRootRequestDataColumnSidecarRequirements)
+
+	if err := verifier.ValidFields(); err != nil {
+		log.WithError(err).WithField("peerID", pid).Error("Failed to verify data column")
+	}
+
+	if err := verifier.SidecarInclusionProven(); err != nil {
+		log.WithError(err).WithField("peerID", pid).Error("Failed to prove inclusion")
+	}
+
+	if err := verifier.SidecarKzgProofVerified(); err != nil {
+		log.WithError(err).WithField("peerID", pid).Error("Failed to verify KZG proof")
+	}
+
+	_, err = verifier.VerifiedRODataColumns()
+	if err != nil {
+		log.WithError(err).WithField("peerID", pid).Error("Failed to upgrade RODataColumns to VerifiedRODataColumns - should never happen")
+	}
+
+	return true
+}

beacon-chain/sync/data_columns_sampling_test.go

@@ -0,0 +1,554 @@
+package sync
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"encoding/binary"
+	"fmt"
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	mock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
+	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
+	p2ptest "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
+	p2pTypes "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/types"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
+	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
+	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	"github.com/ethereum/go-ethereum/p2p/enr"
+	"github.com/libp2p/go-libp2p"
+	"github.com/libp2p/go-libp2p/core/crypto"
+	"github.com/libp2p/go-libp2p/core/network"
+)
+
+func TestRandomizeColumns(t *testing.T) {
+	const count uint64 = 128
+
+	// Generate groups.
+	groups := make(map[uint64]bool, count)
+	for i := uint64(0); i < count; i++ {
+		groups[i] = true
+	}
+
+	// Randomize columns.
+	randomizedColumns, err := randomizeColumns(groups)
+	require.NoError(t, err)
+
+	// Convert back to a map.
+	randomizedColumnsMap := make(map[uint64]bool, count)
+	for _, column := range randomizedColumns {
+		randomizedColumnsMap[column] = true
+	}
+
+	// Check duplicates and missing columns.
+	require.Equal(t, len(groups), len(randomizedColumnsMap))
+
+	// Check the values.
+	for column := range randomizedColumnsMap {
+		require.Equal(t, true, column < count)
+	}
+}
+
+// createAndConnectPeer creates a peer with a private key `offset` fixed.
+// The peer is added and connected to `p2pService`.
+// If a `RPCDataColumnSidecarsByRootTopicV1` request is made with column index `i`,
+// then the peer will respond with the `dataColumnSidecars[i]` if it is not in `columnsNotToRespond`.
+// (If `len(dataColumnSidecars) < i`, then this function will panic.)
+func createAndConnectPeer(
+	t *testing.T,
+	p2pService *p2ptest.TestP2P,
+	chainService *mock.ChainService,
+	dataColumnSidecars []*ethpb.DataColumnSidecar,
+	custodyGroupCount uint64,
+	columnsNotToRespond map[uint64]bool,
+	offset int,
+) *p2ptest.TestP2P {
+	// Create the private key, depending on the offset.
+	privateKeyBytes := make([]byte, 32)
+	for i := 0; i < 32; i++ {
+		privateKeyBytes[i] = byte(offset + i)
+	}
+
+	privateKey, err := crypto.UnmarshalSecp256k1PrivateKey(privateKeyBytes)
+	require.NoError(t, err)
+
+	// Create the peer.
+	peer := p2ptest.NewTestP2P(t, libp2p.Identity(privateKey))
+
+	peer.SetStreamHandler(p2p.RPCDataColumnSidecarsByRootTopicV1+"/ssz_snappy", func(stream network.Stream) {
+		// Decode the request.
+		req := new(p2pTypes.DataColumnsByRootIdentifiers)
+		err := peer.Encoding().DecodeWithMaxLength(stream, req)
+		require.NoError(t, err)
+
+		for _, identifier := range *req {
+			for _, column := range identifier.Columns {
+				// Filter out the columns not to respond.
+				if columnsNotToRespond[column] {
+					continue
+				}
+
+				// Create the response.
+				resp := dataColumnSidecars[column]
+
+				// Send the response.
+				err := WriteDataColumnSidecarChunk(stream, chainService, p2pService.Encoding(), resp)
+				require.NoError(t, err)
+			}
+		}
+
+		// Close the stream.
+		closeStream(stream, log)
+	})
+
+	// Create the record and set the custody count.
+	enr := &enr.Record{}
+	enr.Set(peerdas.Cgc(custodyGroupCount))
+
+	// Add the peer and connect it.
+	p2pService.Peers().Add(enr, peer.PeerID(), nil, network.DirOutbound)
+	p2pService.Peers().SetConnectionState(peer.PeerID(), peers.Connected)
+	p2pService.Connect(peer)
+
+	return peer
+}
+
+type dataSamplerTest struct {
+	ctx                context.Context
+	p2pSvc             *p2ptest.TestP2P
+	peers              []*p2ptest.TestP2P
+	ctxMap             map[[4]byte]int
+	chainSvc           *mock.ChainService
+	blockProcessedData *statefeed.BlockProcessedData
+	blobs              []kzg.Blob
+	kzgCommitments     [][]byte
+	kzgProofs          [][]byte
+	dataColumnSidecars []*ethpb.DataColumnSidecar
+}
+
+func setupDefaultDataColumnSamplerTest(t *testing.T) (*dataSamplerTest, *dataColumnSampler1D) {
+	const (
+		blobCount          uint64 = 3
+		custodyRequirement uint64 = 4
+	)
+
+	test, sampler := setupDataColumnSamplerTest(t, blobCount)
+
+	// Custody columns: [6, 38, 70, 102]
+	p1 := createAndConnectPeer(t, test.p2pSvc, test.chainSvc, test.dataColumnSidecars, custodyRequirement, map[uint64]bool{}, 1)
+
+	// Custody columns: [3, 35, 67, 99]
+	p2 := createAndConnectPeer(t, test.p2pSvc, test.chainSvc, test.dataColumnSidecars, custodyRequirement, map[uint64]bool{}, 2)
+
+	// Custody columns: [12, 44, 76, 108]
+	p3 := createAndConnectPeer(t, test.p2pSvc, test.chainSvc, test.dataColumnSidecars, custodyRequirement, map[uint64]bool{}, 3)
+
+	test.peers = []*p2ptest.TestP2P{p1, p2, p3}
+
+	return test, sampler
+}
+
+func setupDataColumnSamplerTest(t *testing.T, blobCount uint64) (*dataSamplerTest, *dataColumnSampler1D) {
+	require.NoError(t, kzg.Start())
+
+	// Generate random blobs, commitments and inclusion proofs.
+	blobs := make([]kzg.Blob, blobCount)
+	kzgCommitments := make([][]byte, blobCount)
+	kzgProofs := make([][]byte, blobCount)
+
+	for i := uint64(0); i < blobCount; i++ {
+		blob := getRandBlob(t, int64(i))
+
+		kzgCommitment, kzgProof, err := generateCommitmentAndProof(&blob)
+		require.NoError(t, err)
+
+		blobs[i] = blob
+		kzgCommitments[i] = kzgCommitment[:]
+		kzgProofs[i] = kzgProof[:]
+	}
+
+	dbBlock := util.NewBeaconBlockDeneb()
+	dbBlock.Block.Body.BlobKzgCommitments = kzgCommitments
+	sBlock, err := blocks.NewSignedBeaconBlock(dbBlock)
+	require.NoError(t, err)
+
+	cellsAndProofs := util.GenerateCellsAndProofs(t, blobs)
+	dataColumnSidecars, err := peerdas.DataColumnSidecars(sBlock, cellsAndProofs)
+	require.NoError(t, err)
+
+	blockRoot, err := dataColumnSidecars[0].GetSignedBlockHeader().Header.HashTreeRoot()
+	require.NoError(t, err)
+
+	blockProcessedData := &statefeed.BlockProcessedData{
+		BlockRoot:   blockRoot,
+		SignedBlock: sBlock,
+	}
+
+	p2pSvc := p2ptest.NewTestP2P(t)
+	chainSvc, clock := defaultMockChain(t, 0)
+
+	test := &dataSamplerTest{
+		ctx:                context.Background(),
+		p2pSvc:             p2pSvc,
+		peers:              []*p2ptest.TestP2P{},
+		ctxMap:             map[[4]byte]int{{245, 165, 253, 66}: version.Fulu},
+		chainSvc:           chainSvc,
+		blockProcessedData: blockProcessedData,
+		blobs:              blobs,
+		kzgCommitments:     kzgCommitments,
+		kzgProofs:          kzgProofs,
+		dataColumnSidecars: dataColumnSidecars,
+	}
+	clockSync := startup.NewClockSynchronizer()
+	require.NoError(t, clockSync.SetClock(clock))
+	iniWaiter := verification.NewInitializerWaiter(clockSync, nil, nil)
+	ini, err := iniWaiter.WaitForInitializer(context.Background())
+	require.NoError(t, err)
+	sampler := newDataColumnSampler1D(p2pSvc, clock, test.ctxMap, nil, newDataColumnsVerifierFromInitializer(ini), &peerdas.CustodyInfo{})
+
+	return test, sampler
+}
+
+func TestDataColumnSampler1D_PeerManagement(t *testing.T) {
+	testCases := []struct {
+		name               string
+		numPeers           int
+		custodyRequirement uint64
+		expectedColumns    [][]uint64
+		prunePeers         map[int]bool // Peers to prune.
+	}{
+		{
+			name:               "custodyRequirement=4",
+			numPeers:           3,
+			custodyRequirement: 4,
+			expectedColumns: [][]uint64{
+				{6, 37, 48, 113},
+				{35, 79, 92, 109},
+				{31, 44, 58, 97},
+			},
+			prunePeers: map[int]bool{
+				0: true,
+			},
+		},
+		{
+			name:               "custodyRequirement=8",
+			numPeers:           3,
+			custodyRequirement: 8,
+			expectedColumns: [][]uint64{
+				{1, 6, 37, 48, 51, 87, 112, 113},
+				{24, 25, 35, 52, 79, 92, 109, 126},
+				{31, 44, 58, 64, 91, 97, 116, 127},
+			},
+			prunePeers: map[int]bool{
+				0: true,
+			},
+		},
+	}
+
+	params.SetupTestConfigCleanup(t)
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			cfg := params.BeaconConfig()
+			cfg.CustodyRequirement = tc.custodyRequirement
+			params.OverrideBeaconConfig(cfg)
+			test, sampler := setupDataColumnSamplerTest(t, uint64(tc.numPeers))
+			for i := 0; i < tc.numPeers; i++ {
+				p := createAndConnectPeer(t, test.p2pSvc, test.chainSvc, test.dataColumnSidecars, tc.custodyRequirement, nil, i+1)
+				test.peers = append(test.peers, p)
+			}
+
+			// confirm everything works
+			sampler.refreshPeerInfo()
+			require.Equal(t, params.BeaconConfig().NumberOfColumns, uint64(len(sampler.peersByCustodyGroup)))
+
+			require.Equal(t, tc.numPeers, len(sampler.groupsByPeer))
+			for i, peer := range test.peers {
+				// confirm peer has the expected columns
+				require.Equal(t, len(tc.expectedColumns[i]), len(sampler.groupsByPeer[peer.PeerID()]))
+				for _, column := range tc.expectedColumns[i] {
+					require.Equal(t, true, sampler.groupsByPeer[peer.PeerID()][column])
+				}
+
+				// confirm column to peer mapping are correct
+				for _, column := range tc.expectedColumns[i] {
+					require.Equal(t, true, sampler.peersByCustodyGroup[column][peer.PeerID()])
+				}
+			}
+
+			// prune peers
+			for peer := range tc.prunePeers {
+				err := test.p2pSvc.Disconnect(test.peers[peer].PeerID())
+				test.p2pSvc.Peers().SetConnectionState(test.peers[peer].PeerID(), peers.Disconnected)
+				require.NoError(t, err)
+			}
+			sampler.refreshPeerInfo()
+
+			require.Equal(t, tc.numPeers-len(tc.prunePeers), len(sampler.groupsByPeer))
+			for i, peer := range test.peers {
+				for _, column := range tc.expectedColumns[i] {
+					expected := true
+					if tc.prunePeers[i] {
+						expected = false
+					}
+					require.Equal(t, expected, sampler.peersByCustodyGroup[column][peer.PeerID()])
+				}
+			}
+		})
+	}
+}
+
+func TestDataColumnSampler1D_SampleDistribution(t *testing.T) {
+	// TODO: Use `t.Run`.
+	testCases := []struct {
+		numPeers             int
+		custodyRequirement   uint64
+		columnsToDistribute  [][]uint64
+		expectedDistribution []map[int][]uint64
+	}{
+		{
+			numPeers:           3,
+			custodyRequirement: 4,
+			// peer custody maps
+			// p0: {6, 37, 48, 113},
+			// p1: {35, 79, 92, 109},
+			// p2: {31, 44, 58, 97},
+			columnsToDistribute: [][]uint64{
+				{6, 35, 31},
+				{6, 48, 79, 109, 31, 97},
+				{6, 37, 113},
+				{11},
+			},
+			expectedDistribution: []map[int][]uint64{
+				{
+					0: {6},  // p0
+					1: {35}, // p1
+					2: {31}, // p2
+				},
+				{
+					0: {6, 48},   // p0
+					1: {79, 109}, // p1
+					2: {31, 97},  // p2
+				},
+				{
+					0: {6, 37, 113}, // p0
+				},
+				{},
+			},
+		},
+		{
+			numPeers:           3,
+			custodyRequirement: 8,
+			// peer custody maps
+			// p0: {6, 37, 48, 113, 1, 112, 87, 51},
+			// p1: {35, 79, 92, 109, 52, 126, 25, 24},
+			// p2: {31, 44, 58, 97, 116, 91, 64, 127},
+			columnsToDistribute: [][]uint64{
+				{6, 48, 79, 25, 24, 97}, // all covered by peers
+				{6, 35, 31, 32},         // `32` is not in covered by peers
+			},
+			expectedDistribution: []map[int][]uint64{
+				{
+					0: {6, 48},      // p0
+					1: {79, 25, 24}, // p1
+					2: {97},         // p2
+				},
+				{
+					0: {6},  // p0
+					1: {35}, // p1
+					2: {31}, // p2
+				},
+			},
+		},
+	}
+	params.SetupTestConfigCleanup(t)
+	for _, tc := range testCases {
+		cfg := params.BeaconConfig()
+		cfg.CustodyRequirement = tc.custodyRequirement
+		params.OverrideBeaconConfig(cfg)
+		test, sampler := setupDataColumnSamplerTest(t, uint64(tc.numPeers))
+		for i := 0; i < tc.numPeers; i++ {
+			p := createAndConnectPeer(t, test.p2pSvc, test.chainSvc, test.dataColumnSidecars, tc.custodyRequirement, nil, i+1)
+			test.peers = append(test.peers, p)
+		}
+		sampler.refreshPeerInfo()
+
+		for idx, columns := range tc.columnsToDistribute {
+			result, err := sampler.distributeSamplesToPeer(columns)
+			require.NoError(t, err)
+			require.Equal(t, len(tc.expectedDistribution[idx]), len(result), fmt.Sprintf("%v - %v", tc.expectedDistribution[idx], result))
+
+			for peerIdx, dist := range tc.expectedDistribution[idx] {
+				for _, column := range dist {
+					peerID := test.peers[peerIdx].PeerID()
+					require.Equal(t, true, result[peerID][column])
+				}
+			}
+		}
+	}
+}
+
+func TestDataColumnSampler1D_SampleDataColumns(t *testing.T) {
+	test, sampler := setupDefaultDataColumnSamplerTest(t)
+	sampler.refreshPeerInfo()
+
+	t.Run("sample all columns", func(t *testing.T) {
+		sampleColumns := []uint64{6, 35, 31, 37, 79, 44, 48, 92, 58, 113, 109, 97}
+		retrieved, err := sampler.sampleDataColumns(test.ctx, test.blockProcessedData, sampleColumns)
+		require.NoError(t, err)
+		require.Equal(t, 12, len(retrieved))
+		for _, column := range sampleColumns {
+			require.Equal(t, true, retrieved[column])
+		}
+	})
+
+	t.Run("sample a subset of columns", func(t *testing.T) {
+		sampleColumns := []uint64{35, 31, 79, 48, 113, 97}
+		retrieved, err := sampler.sampleDataColumns(test.ctx, test.blockProcessedData, sampleColumns)
+		require.NoError(t, err)
+		require.Equal(t, 6, len(retrieved))
+		for _, column := range sampleColumns {
+			require.Equal(t, true, retrieved[column])
+		}
+	})
+
+	t.Run("sample a subset of columns with missing columns", func(t *testing.T) {
+		sampleColumns := []uint64{35, 31, 100, 79}
+		retrieved, err := sampler.sampleDataColumns(test.ctx, test.blockProcessedData, sampleColumns)
+		require.NoError(t, err)
+		require.Equal(t, 3, len(retrieved))
+		require.DeepEqual(t, map[uint64]bool{35: true, 31: true, 79: true}, retrieved)
+	})
+}
+
+func TestDataColumnSampler1D_IncrementalDAS(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig()
+	cfg.DataColumnSidecarSubnetCount = 32
+	params.OverrideBeaconConfig(cfg)
+
+	testCases := []struct {
+		name                     string
+		samplesCount             uint64
+		possibleColumnsToRequest []uint64
+		columnsNotToRespond      map[uint64]bool
+		expectedSuccess          bool
+		expectedRoundSummaries   []roundSummary
+	}{
+		{
+			name:                     "All columns are correctly sampled in a single round",
+			samplesCount:             5,
+			possibleColumnsToRequest: []uint64{6, 35, 31, 37, 79, 44, 48, 92, 58, 113, 109, 97},
+			columnsNotToRespond:      map[uint64]bool{},
+			expectedSuccess:          true,
+			expectedRoundSummaries: []roundSummary{
+				{
+					RequestedColumns: []uint64{6, 35, 31, 37, 79},
+					MissingColumns:   map[uint64]bool{},
+				},
+			},
+		},
+		{
+			name:                     "Two missing columns in the first round, ok in the second round",
+			samplesCount:             5,
+			possibleColumnsToRequest: []uint64{6, 35, 31, 37, 79, 44, 48, 92, 58, 113, 109, 97},
+			columnsNotToRespond:      map[uint64]bool{6: true, 31: true},
+			expectedSuccess:          true,
+			expectedRoundSummaries: []roundSummary{
+				{
+					RequestedColumns: []uint64{6, 35, 31, 37, 79},
+					MissingColumns:   map[uint64]bool{6: true, 31: true},
+				},
+				{
+					RequestedColumns: []uint64{44, 48, 92, 58, 113, 109},
+					MissingColumns:   map[uint64]bool{},
+				},
+			},
+		},
+		{
+			name:                     "Two missing columns in the first round, one missing in the second round. Fail to sample.",
+			samplesCount:             5,
+			possibleColumnsToRequest: []uint64{6, 35, 31, 37, 79, 44, 48, 92, 58, 113, 109, 97},
+			columnsNotToRespond:      map[uint64]bool{6: true, 31: true, 48: true},
+			expectedSuccess:          false,
+			expectedRoundSummaries: []roundSummary{
+				{
+					RequestedColumns: []uint64{6, 35, 31, 37, 79},
+					MissingColumns:   map[uint64]bool{6: true, 31: true},
+				},
+				{
+					RequestedColumns: []uint64{44, 48, 92, 58, 113, 109},
+					MissingColumns:   map[uint64]bool{48: true},
+				},
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			test, sampler := setupDataColumnSamplerTest(t, 3)
+			p1 := createAndConnectPeer(t, test.p2pSvc, test.chainSvc, test.dataColumnSidecars, params.BeaconConfig().CustodyRequirement, tc.columnsNotToRespond, 1)
+			p2 := createAndConnectPeer(t, test.p2pSvc, test.chainSvc, test.dataColumnSidecars, params.BeaconConfig().CustodyRequirement, tc.columnsNotToRespond, 2)
+			p3 := createAndConnectPeer(t, test.p2pSvc, test.chainSvc, test.dataColumnSidecars, params.BeaconConfig().CustodyRequirement, tc.columnsNotToRespond, 3)
+			test.peers = []*p2ptest.TestP2P{p1, p2, p3}
+
+			sampler.refreshPeerInfo()
+
+			success, summaries, err := sampler.incrementalDAS(test.ctx, test.blockProcessedData, tc.possibleColumnsToRequest, tc.samplesCount)
+			require.NoError(t, err)
+			require.Equal(t, tc.expectedSuccess, success)
+			require.DeepEqual(t, tc.expectedRoundSummaries, summaries)
+		})
+	}
+}
+
+func deterministicRandomness(t *testing.T, seed int64) [32]byte {
+	// Converts an int64 to a byte slice
+	buf := new(bytes.Buffer)
+	err := binary.Write(buf, binary.BigEndian, seed)
+	require.NoError(t, err)
+	bytes := buf.Bytes()
+
+	return sha256.Sum256(bytes)
+}
+
+// Returns a serialized random field element in big-endian
+func getRandFieldElement(t *testing.T, seed int64) [32]byte {
+	bytes := deterministicRandomness(t, seed)
+	var r fr.Element
+	r.SetBytes(bytes[:])
+
+	return GoKZG.SerializeScalar(r)
+}
+
+// Returns a random blob using the passed seed as entropy
+func getRandBlob(t *testing.T, seed int64) kzg.Blob {
+	var blob kzg.Blob
+	for i := 0; i < len(blob); i += 32 {
+		fieldElementBytes := getRandFieldElement(t, seed+int64(i))
+		copy(blob[i:i+32], fieldElementBytes[:])
+	}
+	return blob
+}
+
+func generateCommitmentAndProof(blob *kzg.Blob) (*kzg.Commitment, *kzg.Proof, error) {
+	commitment, err := kzg.BlobToKZGCommitment(blob)
+	if err != nil {
+		return nil, nil, err
+	}
+	proof, err := kzg.ComputeBlobKZGProof(blob, commitment)
+	if err != nil {
+		return nil, nil, err
+	}
+	return &commitment, &proof, err
+}

beacon-chain/sync/fork_watcher_test.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/async/abool"
 	mockChain "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
 	p2ptest "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
@@ -46,6 +47,7 @@ func TestService_CheckForNextEpochFork(t *testing.T) {
 						chain:       chainService,
 						clock:       startup.NewClock(gt, vr),
 						initialSync: &mockSync.Sync{IsSyncing: false},
+						custodyInfo: &peerdas.CustodyInfo{},
 					},
 					chainStarted: abool.New(),
 					subHandler:   newSubTopicHandler(),
@@ -81,6 +83,7 @@ func TestService_CheckForNextEpochFork(t *testing.T) {
 						chain:       chainService,
 						clock:       startup.NewClock(gt, vr),
 						initialSync: &mockSync.Sync{IsSyncing: false},
+						custodyInfo: &peerdas.CustodyInfo{},
 					},
 					chainStarted: abool.New(),
 					subHandler:   newSubTopicHandler(),
@@ -125,6 +128,7 @@ func TestService_CheckForNextEpochFork(t *testing.T) {
 						chain:       chainService,
 						clock:       startup.NewClock(chainService.Genesis, chainService.ValidatorsRoot),
 						initialSync: &mockSync.Sync{IsSyncing: false},
+						custodyInfo: &peerdas.CustodyInfo{},
 					},
 					chainStarted: abool.New(),
 					subHandler:   newSubTopicHandler(),
@@ -167,6 +171,7 @@ func TestService_CheckForNextEpochFork(t *testing.T) {
 						chain:       chainService,
 						clock:       startup.NewClock(gt, vr),
 						initialSync: &mockSync.Sync{IsSyncing: false},
+						custodyInfo: &peerdas.CustodyInfo{},
 					},
 					chainStarted: abool.New(),
 					subHandler:   newSubTopicHandler(),
@@ -211,6 +216,7 @@ func TestService_CheckForNextEpochFork(t *testing.T) {
 						chain:       chainService,
 						clock:       startup.NewClock(gt, vr),
 						initialSync: &mockSync.Sync{IsSyncing: false},
+						custodyInfo: &peerdas.CustodyInfo{},
 					},
 					chainStarted: abool.New(),
 					subHandler:   newSubTopicHandler(),
@@ -255,6 +261,7 @@ func TestService_CheckForNextEpochFork(t *testing.T) {
 						chain:       chainService,
 						clock:       startup.NewClock(gt, vr),
 						initialSync: &mockSync.Sync{IsSyncing: false},
+						custodyInfo: &peerdas.CustodyInfo{},
 					},
 					chainStarted: abool.New(),
 					subHandler:   newSubTopicHandler(),
@@ -274,6 +281,7 @@ func TestService_CheckForNextEpochFork(t *testing.T) {
 				}
 				assert.Equal(t, true, rpcMap[p2p.RPCBlobSidecarsByRangeTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()], "topic doesn't exist")
 				assert.Equal(t, true, rpcMap[p2p.RPCBlobSidecarsByRootTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()], "topic doesn't exist")
+				assert.Equal(t, true, rpcMap[p2p.RPCMetaDataTopicV3+s.cfg.p2p.Encoding().ProtocolSuffix()], "topic doesn't exist")
 			},
 		},
 	}

beacon-chain/sync/initial-sync/BUILD.bazel

@@ -20,6 +20,7 @@ go_library(
         "//beacon-chain/blockchain:go_default_library",
         "//beacon-chain/core/feed/block:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/das:go_default_library",
         "//beacon-chain/db:go_default_library",
@@ -73,6 +74,7 @@ go_test(
         "//async/abool:go_default_library",
         "//beacon-chain/blockchain:go_default_library",
         "//beacon-chain/blockchain/testing:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/das:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",

beacon-chain/sync/initial-sync/blocks_fetcher.go

@@ -8,6 +8,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
@@ -15,6 +16,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	prysmsync "github.com/OffchainLabs/prysm/v6/beacon-chain/sync"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/sync/verify"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
 	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
 	"github.com/OffchainLabs/prysm/v6/config/features"
 	"github.com/OffchainLabs/prysm/v6/config/params"
@@ -23,7 +25,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	leakybucket "github.com/OffchainLabs/prysm/v6/container/leaky-bucket"
 	"github.com/OffchainLabs/prysm/v6/crypto/rand"
-	"github.com/OffchainLabs/prysm/v6/math"
+	mathPrysm "github.com/OffchainLabs/prysm/v6/math"
 	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
 	p2ppb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
@@ -34,7 +36,6 @@ import (
 )
 
 const (
-
 	// maxPendingRequests limits how many concurrent fetch request one can initiate.
 	maxPendingRequests = 64
 	// peersPercentagePerRequest caps percentage of peers to be used in a request.
@@ -78,6 +79,10 @@ type blocksFetcherConfig struct {
 	peerFilterCapacityWeight float64
 	mode                     syncMode
 	bs                       filesystem.BlobStorageSummarizer
+	dcs                      filesystem.DataColumnStorageSummarizer
+	bv                       verification.NewBlobVerifier
+	cv                       verification.NewDataColumnsVerifier
+	custodyInfo              *peerdas.CustodyInfo
 }
 
 // blocksFetcher is a service to fetch chain data from peers.
@@ -94,6 +99,9 @@ type blocksFetcher struct {
 	p2p             p2p.P2P
 	db              db.ReadOnlyDatabase
 	bs              filesystem.BlobStorageSummarizer
+	dcs             filesystem.DataColumnStorageSummarizer
+	bv              verification.NewBlobVerifier
+	cv              verification.NewDataColumnsVerifier
 	blocksPerPeriod uint64
 	rateLimiter     *leakybucket.Collector
 	peerLocks       map[peer.ID]*peerLock
@@ -102,6 +110,7 @@ type blocksFetcher struct {
 	capacityWeight  float64       // how remaining capacity affects peer selection
 	mode            syncMode      // allows to use fetcher in different sync scenarios
 	quit            chan struct{} // termination notifier
+	custodyInfo     *peerdas.CustodyInfo
 }
 
 // peerLock restricts fetcher actions on per peer basis. Currently, used for rate limiting.
@@ -124,7 +133,7 @@ type fetchRequestResponse struct {
 	blobsFrom  peer.ID
 	start      primitives.Slot
 	count      uint64
-	bwb        []blocks.BlockWithROBlobs
+	bwb        []blocks.BlockWithROSidecars
 	err        error
 }
 
@@ -162,6 +171,9 @@ func newBlocksFetcher(ctx context.Context, cfg *blocksFetcherConfig) *blocksFetc
 		p2p:             cfg.p2p,
 		db:              cfg.db,
 		bs:              cfg.bs,
+		dcs:             cfg.dcs,
+		bv:              cfg.bv,
+		cv:              cfg.cv,
 		blocksPerPeriod: uint64(blocksPerPeriod),
 		rateLimiter:     rateLimiter,
 		peerLocks:       make(map[peer.ID]*peerLock),
@@ -170,6 +182,7 @@ func newBlocksFetcher(ctx context.Context, cfg *blocksFetcherConfig) *blocksFetc
 		capacityWeight:  capacityWeight,
 		mode:            cfg.mode,
 		quit:            make(chan struct{}),
+		custodyInfo:     cfg.custodyInfo,
 	}
 }
 
@@ -181,7 +194,7 @@ func maxBatchLimit() int {
 	if params.DenebEnabled() {
 		maxLimit = params.BeaconConfig().MaxRequestBlocksDeneb
 	}
-	castedMaxLimit, err := math.Int(maxLimit)
+	castedMaxLimit, err := mathPrysm.Int(maxLimit)
 	if err != nil {
 		// Should be impossible to hit this case.
 		log.WithError(err).Error("Unable to calculate the max batch limit")
@@ -298,7 +311,7 @@ func (f *blocksFetcher) handleRequest(ctx context.Context, start primitives.Slot
 	response := &fetchRequestResponse{
 		start: start,
 		count: count,
-		bwb:   []blocks.BlockWithROBlobs{},
+		bwb:   []blocks.BlockWithROSidecars{},
 		err:   nil,
 	}
 
@@ -317,30 +330,96 @@ func (f *blocksFetcher) handleRequest(ctx context.Context, start primitives.Slot
 	if f.mode == modeStopOnFinalizedEpoch {
 		highestFinalizedSlot := params.BeaconConfig().SlotsPerEpoch.Mul(uint64(targetEpoch + 1))
 		if start > highestFinalizedSlot {
-			response.err = fmt.Errorf("%w, slot: %d, highest finalized slot: %d",
-				errSlotIsTooHigh, start, highestFinalizedSlot)
+			response.err = fmt.Errorf(
+				"%w, slot: %d, highest finalized slot: %d",
+				errSlotIsTooHigh, start, highestFinalizedSlot,
+			)
+
 			return response
 		}
 	}
 
 	response.bwb, response.blocksFrom, response.err = f.fetchBlocksFromPeer(ctx, start, count, peers)
 	if response.err == nil {
-		pid, bwb, err := f.fetchBlobsFromPeer(ctx, response.bwb, response.blocksFrom, peers)
+		pid, err := f.fetchSidecars(ctx, response.blocksFrom, peers, response.bwb)
 		if err != nil {
 			response.err = err
 		}
-		response.bwb = bwb
+
 		response.blobsFrom = pid
 	}
+
 	return response
 }
 
-// fetchBlocksFromPeer fetches blocks from a single randomly selected peer.
+// fetchSidecars fetches sidecars corresponding to blocks in `response.bwb`.
+// It mutates `Blobs` and `Columns` fields of `response.bwb` with fetched sidecars.
+func (f *blocksFetcher) fetchSidecars(ctx context.Context, pid peer.ID, peers []peer.ID, bwScs []blocks.BlockWithROSidecars) (peer.ID, error) {
+	const batchSize = 32
+
+	// Find the first block with a slot greater than or equal to the first Fulu slot.
+	// (Blocks are sorted by slot.)
+	firstFuluIndex := sort.Search(len(bwScs), func(i int) bool {
+		return bwScs[i].Block.Version() >= version.Fulu
+	})
+
+	blocksWithBlobs := bwScs[:firstFuluIndex]
+	blocksWithDataColumns := bwScs[firstFuluIndex:]
+
+	if len(blocksWithBlobs) == 0 && len(blocksWithDataColumns) == 0 {
+		return "", nil
+	}
+
+	var (
+		blobsPid peer.ID
+		err      error
+	)
+
+	if len(blocksWithBlobs) > 0 {
+		// Fetch blob sidecars.
+		blobsPid, err = f.fetchBlobsFromPeer(ctx, blocksWithBlobs, pid, peers)
+		if err != nil {
+			return "", errors.Wrap(err, "fetch blobs from peer")
+		}
+	}
+
+	if len(blocksWithDataColumns) == 0 {
+		return blobsPid, nil
+	}
+
+	// Extract blocks.
+	dataColumnBlocks := make([]blocks.ROBlock, 0, len(blocksWithBlobs))
+	for _, blockWithSidecars := range blocksWithDataColumns {
+		block := blockWithSidecars.Block
+		dataColumnBlocks = append(dataColumnBlocks, block)
+	}
+
+	// Fetch data column sidecars.
+	actualGroupCount := f.custodyInfo.ActualGroupCount()
+	fetchedDataColumnsByRoot, err := prysmsync.RequestMissingDataColumnsByRange(ctx, f.clock, f.ctxMap, f.p2p, f.rateLimiter, actualGroupCount, f.dcs, dataColumnBlocks, batchSize)
+	if err != nil {
+		return blobsPid, errors.Wrap(err, "fetch missing data columns from peers")
+	}
+
+	// Populate the response.
+	for i := range bwScs {
+		bwSc := &bwScs[i]
+		root := bwSc.Block.Root()
+		if columns, ok := fetchedDataColumnsByRoot[root]; ok {
+			bwSc.Columns = columns
+		}
+	}
+
+	// TODO: Return the (multiple) peer IDs that provided the data columns and not only the one for blobs.
+	return blobsPid, nil
+}
+
+// fetchBlocksFromPeer fetches blocks from a single randomly selected peer, sorted by slot.
 func (f *blocksFetcher) fetchBlocksFromPeer(
 	ctx context.Context,
 	start primitives.Slot, count uint64,
 	peers []peer.ID,
-) ([]blocks.BlockWithROBlobs, peer.ID, error) {
+) ([]blocks.BlockWithROSidecars, peer.ID, error) {
 	ctx, span := trace.StartSpan(ctx, "initialsync.fetchBlocksFromPeer")
 	defer span.End()
 
@@ -355,39 +434,38 @@ func (f *blocksFetcher) fetchBlocksFromPeer(
 	// peers are dialed first.
 	peers = append(bestPeers, peers...)
 	peers = dedupPeers(peers)
-	for i := 0; i < len(peers); i++ {
-		p := peers[i]
-		blocks, err := f.requestBlocks(ctx, req, p)
+	for _, peer := range peers {
+		blocks, err := f.requestBlocks(ctx, req, peer)
 		if err != nil {
-			log.WithField("peer", p).WithError(err).Debug("Could not request blocks by range from peer")
+			log.WithField("peer", peer).WithError(err).Debug("Could not request blocks by range from peer")
 			continue
 		}
-		f.p2p.Peers().Scorers().BlockProviderScorer().Touch(p)
+		f.p2p.Peers().Scorers().BlockProviderScorer().Touch(peer)
 		robs, err := sortedBlockWithVerifiedBlobSlice(blocks)
 		if err != nil {
-			log.WithField("peer", p).WithError(err).Debug("invalid BeaconBlocksByRange response")
+			log.WithField("peer", peer).WithError(err).Debug("invalid BeaconBlocksByRange response")
 			continue
 		}
 		if len(features.Get().BlacklistedRoots) > 0 {
 			for _, b := range robs {
 				if features.BlacklistedBlock(b.Block.Root()) {
-					return nil, p, prysmsync.ErrInvalidFetchedData
+					return nil, peer, prysmsync.ErrInvalidFetchedData
 				}
 			}
 		}
-		return robs, p, err
+		return robs, peer, err
 	}
 	return nil, "", errNoPeersAvailable
 }
 
-func sortedBlockWithVerifiedBlobSlice(bs []interfaces.ReadOnlySignedBeaconBlock) ([]blocks.BlockWithROBlobs, error) {
-	rb := make([]blocks.BlockWithROBlobs, len(bs))
-	for i, b := range bs {
+func sortedBlockWithVerifiedBlobSlice(blks []interfaces.ReadOnlySignedBeaconBlock) ([]blocks.BlockWithROSidecars, error) {
+	rb := make([]blocks.BlockWithROSidecars, len(blks))
+	for i, b := range blks {
 		ro, err := blocks.NewROBlock(b)
 		if err != nil {
 			return nil, err
 		}
-		rb[i] = blocks.BlockWithROBlobs{Block: ro}
+		rb[i] = blocks.BlockWithROSidecars{Block: ro}
 	}
 	sort.Sort(blocks.BlockWithROBlobsSlice(rb))
 	return rb, nil
@@ -403,7 +481,7 @@ type commitmentCountList []commitmentCount
 
 // countCommitments makes a list of all blocks that have commitments that need to be satisfied.
 // This gives us a representation to finish building the request that is lightweight and readable for testing.
-func countCommitments(bwb []blocks.BlockWithROBlobs, retentionStart primitives.Slot) commitmentCountList {
+func countCommitments(bwb []blocks.BlockWithROSidecars, retentionStart primitives.Slot) commitmentCountList {
 	if len(bwb) == 0 {
 		return nil
 	}
@@ -485,7 +563,9 @@ func (r *blobRange) Request() *p2ppb.BlobSidecarsByRangeRequest {
 var errBlobVerification = errors.New("peer unable to serve aligned BlobSidecarsByRange and BeaconBlockSidecarsByRange responses")
 var errMissingBlobsForBlockCommitments = errors.Wrap(errBlobVerification, "blobs unavailable for processing block with kzg commitments")
 
-func verifyAndPopulateBlobs(bwb []blocks.BlockWithROBlobs, blobs []blocks.ROBlob, req *p2ppb.BlobSidecarsByRangeRequest, bss filesystem.BlobStorageSummarizer) ([]blocks.BlockWithROBlobs, error) {
+// verifyAndPopulateBlobs mutate the input `bwb` argument by adding verified blobs.
+// This function mutates the input `bwb` argument.
+func verifyAndPopulateBlobs(bwb []blocks.BlockWithROSidecars, blobs []blocks.ROBlob, req *p2ppb.BlobSidecarsByRangeRequest, bss filesystem.BlobStorageSummarizer) error {
 	blobsByRoot := make(map[[32]byte][]blocks.ROBlob)
 	for i := range blobs {
 		if blobs[i].Slot() < req.StartSlot {
@@ -495,46 +575,53 @@ func verifyAndPopulateBlobs(bwb []blocks.BlockWithROBlobs, blobs []blocks.ROBlob
 		blobsByRoot[br] = append(blobsByRoot[br], blobs[i])
 	}
 	for i := range bwb {
-		bwi, err := populateBlock(bwb[i], blobsByRoot[bwb[i].Block.Root()], req, bss)
+		err := populateBlock(&bwb[i], blobsByRoot[bwb[i].Block.Root()], req, bss)
 		if err != nil {
 			if errors.Is(err, errDidntPopulate) {
 				continue
 			}
-			return bwb, err
+			return err
 		}
-		bwb[i] = bwi
 	}
-	return bwb, nil
+	return nil
 }
 
 var errDidntPopulate = errors.New("skipping population of block")
 
-func populateBlock(bw blocks.BlockWithROBlobs, blobs []blocks.ROBlob, req *p2ppb.BlobSidecarsByRangeRequest, bss filesystem.BlobStorageSummarizer) (blocks.BlockWithROBlobs, error) {
+// populateBlock verifies and populates blobs for a block.
+// This function mutates the input `bw` argument.
+func populateBlock(bw *blocks.BlockWithROSidecars, blobs []blocks.ROBlob, req *p2ppb.BlobSidecarsByRangeRequest, bss filesystem.BlobStorageSummarizer) error {
 	blk := bw.Block
 	if blk.Version() < version.Deneb || blk.Block().Slot() < req.StartSlot {
-		return bw, errDidntPopulate
+		return errDidntPopulate
 	}
+
 	commits, err := blk.Block().Body().BlobKzgCommitments()
 	if err != nil {
-		return bw, errDidntPopulate
+		return errDidntPopulate
 	}
+
 	if len(commits) == 0 {
-		return bw, errDidntPopulate
+		return errDidntPopulate
 	}
+
 	// Drop blobs on the floor if we already have them.
 	if bss != nil && bss.Summary(blk.Root()).AllAvailable(len(commits)) {
-		return bw, errDidntPopulate
+		return errDidntPopulate
 	}
+
 	if len(commits) != len(blobs) {
-		return bw, missingCommitError(blk.Root(), blk.Block().Slot(), commits)
+		return missingCommitError(blk.Root(), blk.Block().Slot(), commits)
 	}
+
 	for ci := range commits {
 		if err := verify.BlobAlignsWithBlock(blobs[ci], blk); err != nil {
-			return bw, err
+			return err
 		}
 	}
+
 	bw.Blobs = blobs
-	return bw, nil
+	return nil
 }
 
 func missingCommitError(root [32]byte, slot primitives.Slot, missing [][]byte) error {
@@ -547,29 +634,34 @@ func missingCommitError(root [32]byte, slot primitives.Slot, missing [][]byte) e
 }
 
 // fetchBlobsFromPeer fetches blocks from a single randomly selected peer.
-func (f *blocksFetcher) fetchBlobsFromPeer(ctx context.Context, bwb []blocks.BlockWithROBlobs, pid peer.ID, peers []peer.ID) (peer.ID, []blocks.BlockWithROBlobs, error) {
+// This function mutates the input `bwb` argument.
+func (f *blocksFetcher) fetchBlobsFromPeer(ctx context.Context, bwb []blocks.BlockWithROSidecars, pid peer.ID, peers []peer.ID) (peer.ID, error) {
+	if len(bwb) == 0 {
+		return "", nil
+	}
+
 	ctx, span := trace.StartSpan(ctx, "initialsync.fetchBlobsFromPeer")
 	defer span.End()
 	if slots.ToEpoch(f.clock.CurrentSlot()) < params.BeaconConfig().DenebForkEpoch {
-		return "", bwb, nil
+		return "", nil
 	}
 	blobWindowStart, err := prysmsync.BlobRPCMinValidSlot(f.clock.CurrentSlot())
 	if err != nil {
-		return "", nil, err
+		return "", err
 	}
 	// Construct request message based on observed interval of blocks in need of blobs.
 	req := countCommitments(bwb, blobWindowStart).blobRange(f.bs).Request()
 	if req == nil {
-		return "", bwb, nil
+		return "", nil
 	}
 	peers = f.filterPeers(ctx, peers, peersPercentagePerRequest)
 	// We dial the initial peer first to ensure that we get the desired set of blobs.
-	wantedPeers := append([]peer.ID{pid}, peers...)
-	bestPeers := f.hasSufficientBandwidth(wantedPeers, req.Count)
+	peers = append([]peer.ID{pid}, peers...)
+	peers = f.hasSufficientBandwidth(peers, req.Count)
 	// We append the best peers to the front so that higher capacity
 	// peers are dialed first. If all of them fail, we fallback to the
 	// initial peer we wanted to request blobs from.
-	peers = append(bestPeers, pid)
+	peers = append(peers, pid)
 	for i := 0; i < len(peers); i++ {
 		p := peers[i]
 		blobs, err := f.requestBlobs(ctx, req, p)
@@ -578,16 +670,31 @@ func (f *blocksFetcher) fetchBlobsFromPeer(ctx context.Context, bwb []blocks.Blo
 			continue
 		}
 		f.p2p.Peers().Scorers().BlockProviderScorer().Touch(p)
-		robs, err := verifyAndPopulateBlobs(bwb, blobs, req, f.bs)
-		if err != nil {
+		if err := verifyAndPopulateBlobs(bwb, blobs, req, f.bs); err != nil {
 			log.WithField("peer", p).WithError(err).Debug("Invalid BeaconBlobsByRange response")
 			continue
 		}
-		return p, robs, err
+		return p, err
 	}
-	return "", nil, errNoPeersAvailable
+	return "", errNoPeersAvailable
 }
 
+// sortedSliceFromMap returns a sorted slice of keys from a map.
+func sortedSliceFromMap(m map[uint64]bool) []uint64 {
+	result := make([]uint64, 0, len(m))
+	for k := range m {
+		result = append(result, k)
+	}
+
+	sort.Slice(result, func(i, j int) bool {
+		return result[i] < result[j]
+	})
+
+	return result
+}
+
+// waitForPeersFo
+
 // requestBlocks is a wrapper for handling BeaconBlocksByRangeRequest requests/streams.
 func (f *blocksFetcher) requestBlocks(
 	ctx context.Context,
@@ -642,6 +749,7 @@ func (f *blocksFetcher) requestBlobs(ctx context.Context, req *p2ppb.BlobSidecar
 	}
 	f.rateLimiter.Add(pid.String(), int64(req.Count))
 	l.Unlock()
+
 	return prysmsync.SendBlobsByRangeRequest(ctx, f.clock, f.p2p, pid, f.ctxMap, req)
 }
 
@@ -682,7 +790,7 @@ func (f *blocksFetcher) waitForBandwidth(pid peer.ID, count uint64) error {
 		// Exit early if we have sufficient capacity
 		return nil
 	}
-	intCount, err := math.Int(count)
+	intCount, err := mathPrysm.Int(count)
 	if err != nil {
 		return err
 	}
@@ -699,7 +807,8 @@ func (f *blocksFetcher) waitForBandwidth(pid peer.ID, count uint64) error {
 }
 
 func (f *blocksFetcher) hasSufficientBandwidth(peers []peer.ID, count uint64) []peer.ID {
-	filteredPeers := []peer.ID{}
+	var filteredPeers []peer.ID
+
 	for _, p := range peers {
 		if uint64(f.rateLimiter.Remaining(p.String())) < count {
 			continue

beacon-chain/sync/initial-sync/blocks_fetcher_test.go

@@ -12,8 +12,8 @@ import (
 	mock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	dbtest "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
-	p2pm "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
-	p2pt "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
+	p2ptest "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	beaconsync "github.com/OffchainLabs/prysm/v6/beacon-chain/sync"
 	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
@@ -266,7 +266,7 @@ func TestBlocksFetcher_RoundRobin(t *testing.T) {
 
 			beaconDB := dbtest.SetupDB(t)
 
-			p := p2pt.NewTestP2P(t)
+			p := p2ptest.NewTestP2P(t)
 			connectPeers(t, p, tt.peers, p.Peers())
 			cache.RLock()
 			genesisRoot := cache.rootCache[0]
@@ -307,9 +307,9 @@ func TestBlocksFetcher_RoundRobin(t *testing.T) {
 				fetcher.stop()
 			}()
 
-			processFetchedBlocks := func() ([]blocks.BlockWithROBlobs, error) {
+			processFetchedBlocks := func() ([]blocks.BlockWithROSidecars, error) {
 				defer cancel()
-				var unionRespBlocks []blocks.BlockWithROBlobs
+				var unionRespBlocks []blocks.BlockWithROSidecars
 
 				for {
 					select {
@@ -398,6 +398,7 @@ func TestBlocksFetcher_scheduleRequest(t *testing.T) {
 			fetcher.scheduleRequest(context.Background(), 1, blockBatchLimit))
 	})
 }
+
 func TestBlocksFetcher_handleRequest(t *testing.T) {
 	blockBatchLimit := flags.Get().BlockBatchLimit
 	chainConfig := struct {
@@ -455,7 +456,7 @@ func TestBlocksFetcher_handleRequest(t *testing.T) {
 			}
 		}()
 
-		var bwb []blocks.BlockWithROBlobs
+		var bwb []blocks.BlockWithROSidecars
 		select {
 		case <-ctx.Done():
 			t.Error(ctx.Err())
@@ -531,9 +532,9 @@ func TestBlocksFetcher_requestBeaconBlocksByRange(t *testing.T) {
 }
 
 func TestBlocksFetcher_RequestBlocksRateLimitingLocks(t *testing.T) {
-	p1 := p2pt.NewTestP2P(t)
-	p2 := p2pt.NewTestP2P(t)
-	p3 := p2pt.NewTestP2P(t)
+	p1 := p2ptest.NewTestP2P(t)
+	p2 := p2ptest.NewTestP2P(t)
+	p3 := p2ptest.NewTestP2P(t)
 	p1.Connect(p2)
 	p1.Connect(p3)
 	require.Equal(t, 2, len(p1.BHost.Network().Peers()), "Expected peers to be connected")
@@ -543,7 +544,7 @@ func TestBlocksFetcher_RequestBlocksRateLimitingLocks(t *testing.T) {
 		Count:     64,
 	}
 
-	topic := p2pm.RPCBlocksByRangeTopicV1
+	topic := p2p.RPCBlocksByRangeTopicV1
 	protocol := libp2pcore.ProtocolID(topic + p2.Encoding().ProtocolSuffix())
 	streamHandlerFn := func(stream network.Stream) {
 		assert.NoError(t, stream.Close())
@@ -602,15 +603,15 @@ func TestBlocksFetcher_RequestBlocksRateLimitingLocks(t *testing.T) {
 }
 
 func TestBlocksFetcher_WaitForBandwidth(t *testing.T) {
-	p1 := p2pt.NewTestP2P(t)
-	p2 := p2pt.NewTestP2P(t)
+	p1 := p2ptest.NewTestP2P(t)
+	p2 := p2ptest.NewTestP2P(t)
 	p1.Connect(p2)
 	require.Equal(t, 1, len(p1.BHost.Network().Peers()), "Expected peers to be connected")
 	req := &ethpb.BeaconBlocksByRangeRequest{
 		Count: 64,
 	}
 
-	topic := p2pm.RPCBlocksByRangeTopicV1
+	topic := p2p.RPCBlocksByRangeTopicV1
 	protocol := libp2pcore.ProtocolID(topic + p2.Encoding().ProtocolSuffix())
 	streamHandlerFn := func(stream network.Stream) {
 		assert.NoError(t, stream.Close())
@@ -638,7 +639,7 @@ func TestBlocksFetcher_WaitForBandwidth(t *testing.T) {
 }
 
 func TestBlocksFetcher_requestBlocksFromPeerReturningInvalidBlocks(t *testing.T) {
-	p1 := p2pt.NewTestP2P(t)
+	p1 := p2ptest.NewTestP2P(t)
 	tests := []struct {
 		name         string
 		req          *ethpb.BeaconBlocksByRangeRequest
@@ -883,7 +884,7 @@ func TestBlocksFetcher_requestBlocksFromPeerReturningInvalidBlocks(t *testing.T)
 		},
 	}
 
-	topic := p2pm.RPCBlocksByRangeTopicV1
+	topic := p2p.RPCBlocksByRangeTopicV1
 	protocol := libp2pcore.ProtocolID(topic + p1.Encoding().ProtocolSuffix())
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -893,7 +894,7 @@ func TestBlocksFetcher_requestBlocksFromPeerReturningInvalidBlocks(t *testing.T)
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			p2 := p2pt.NewTestP2P(t)
+			p2 := p2ptest.NewTestP2P(t)
 			p1.Connect(p2)
 
 			p2.BHost.SetStreamHandler(protocol, tt.handlerGenFn(tt.req))
@@ -993,7 +994,7 @@ func TestBlobRangeForBlocks(t *testing.T) {
 func TestBlobRequest(t *testing.T) {
 	var nilReq *ethpb.BlobSidecarsByRangeRequest
 	// no blocks
-	req := countCommitments([]blocks.BlockWithROBlobs{}, 0).blobRange(nil).Request()
+	req := countCommitments([]blocks.BlockWithROSidecars{}, 0).blobRange(nil).Request()
 	require.Equal(t, nilReq, req)
 	blks, _ := util.ExtendBlocksPlusBlobs(t, []blocks.ROBlock{}, 10)
 	sbbs := make([]interfaces.ReadOnlySignedBeaconBlock, len(blks))
@@ -1026,22 +1027,16 @@ func TestBlobRequest(t *testing.T) {
 }
 
 func TestCountCommitments(t *testing.T) {
-	// no blocks
-	// blocks before retention start filtered
-	// blocks without commitments filtered
-	// pre-deneb filtered
-	// variety of commitment counts are accurate, from 1 to max
 	type testcase struct {
-		name      string
-		bwb       func(t *testing.T, c testcase) []blocks.BlockWithROBlobs
-		numBlocks int
-		retStart  primitives.Slot
-		resCount  int
+		name     string
+		bwb      func(t *testing.T, c testcase) []blocks.BlockWithROSidecars
+		retStart primitives.Slot
+		resCount int
 	}
 	cases := []testcase{
 		{
 			name: "nil blocks is safe",
-			bwb: func(t *testing.T, c testcase) []blocks.BlockWithROBlobs {
+			bwb: func(t *testing.T, c testcase) []blocks.BlockWithROSidecars {
 				return nil
 			},
 			retStart: 0,
@@ -1179,7 +1174,7 @@ func TestCommitmentCountList(t *testing.T) {
 	}
 }
 
-func testSequenceBlockWithBlob(t *testing.T, nblocks int) ([]blocks.BlockWithROBlobs, []blocks.ROBlob) {
+func testSequenceBlockWithBlob(t *testing.T, nblocks int) ([]blocks.BlockWithROSidecars, []blocks.ROBlob) {
 	blks, blobs := util.ExtendBlocksPlusBlobs(t, []blocks.ROBlock{}, nblocks)
 	sbbs := make([]interfaces.ReadOnlySignedBeaconBlock, len(blks))
 	for i := range blks {
@@ -1190,7 +1185,7 @@ func testSequenceBlockWithBlob(t *testing.T, nblocks int) ([]blocks.BlockWithROB
 	return bwb, blobs
 }
 
-func testReqFromResp(bwb []blocks.BlockWithROBlobs) *ethpb.BlobSidecarsByRangeRequest {
+func testReqFromResp(bwb []blocks.BlockWithROSidecars) *ethpb.BlobSidecarsByRangeRequest {
 	return &ethpb.BlobSidecarsByRangeRequest{
 		StartSlot: bwb[0].Block.Block().Slot(),
 		Count:     uint64(bwb[len(bwb)-1].Block.Block().Slot()-bwb[0].Block.Block().Slot()) + 1,
@@ -1207,7 +1202,7 @@ func TestVerifyAndPopulateBlobs(t *testing.T) {
 		}
 		require.Equal(t, len(blobs), len(expectedCommits))
 
-		bwb, err := verifyAndPopulateBlobs(bwb, blobs, testReqFromResp(bwb), nil)
+		err := verifyAndPopulateBlobs(bwb, blobs, testReqFromResp(bwb), nil)
 		require.NoError(t, err)
 		for _, bw := range bwb {
 			commits, err := bw.Block.Block().Body().BlobKzgCommitments()
@@ -1228,7 +1223,7 @@ func TestVerifyAndPopulateBlobs(t *testing.T) {
 	})
 	t.Run("missing blobs", func(t *testing.T) {
 		bwb, blobs := testSequenceBlockWithBlob(t, 10)
-		_, err := verifyAndPopulateBlobs(bwb, blobs[1:], testReqFromResp(bwb), nil)
+		err := verifyAndPopulateBlobs(bwb, blobs[1:], testReqFromResp(bwb), nil)
 		require.ErrorIs(t, err, errMissingBlobsForBlockCommitments)
 	})
 	t.Run("no blobs for last block", func(t *testing.T) {
@@ -1240,7 +1235,7 @@ func TestVerifyAndPopulateBlobs(t *testing.T) {
 		blobs = blobs[0 : len(blobs)-len(cmts)]
 		lastBlk, _ = util.GenerateTestDenebBlockWithSidecar(t, lastBlk.Block().ParentRoot(), lastBlk.Block().Slot(), 0)
 		bwb[lastIdx].Block = lastBlk
-		_, err = verifyAndPopulateBlobs(bwb, blobs, testReqFromResp(bwb), nil)
+		err = verifyAndPopulateBlobs(bwb, blobs, testReqFromResp(bwb), nil)
 		require.NoError(t, err)
 	})
 	t.Run("blobs not copied if all locally available", func(t *testing.T) {
@@ -1254,7 +1249,7 @@ func TestVerifyAndPopulateBlobs(t *testing.T) {
 			r7: {0, 1, 2, 3, 4, 5},
 		}
 		bss := filesystem.NewMockBlobStorageSummarizer(t, onDisk)
-		bwb, err := verifyAndPopulateBlobs(bwb, blobs, testReqFromResp(bwb), bss)
+		err := verifyAndPopulateBlobs(bwb, blobs, testReqFromResp(bwb), bss)
 		require.NoError(t, err)
 		require.Equal(t, 6, len(bwb[i1].Blobs))
 		require.Equal(t, 0, len(bwb[i7].Blobs))
@@ -1302,3 +1297,11 @@ func TestBlockFetcher_HasSufficientBandwidth(t *testing.T) {
 	}
 	assert.Equal(t, 2, len(receivedPeers))
 }
+
+func TestSortedSliceFromMap(t *testing.T) {
+	m := map[uint64]bool{1: true, 3: true, 2: true, 4: true}
+	expected := []uint64{1, 2, 3, 4}
+
+	actual := sortedSliceFromMap(m)
+	require.DeepSSZEqual(t, expected, actual)
+}

beacon-chain/sync/initial-sync/blocks_fetcher_utils.go

@@ -24,7 +24,7 @@ import (
 type forkData struct {
 	blocksFrom peer.ID
 	blobsFrom  peer.ID
-	bwb        []blocks.BlockWithROBlobs
+	bwb        []blocks.BlockWithROSidecars
 }
 
 // nonSkippedSlotAfter checks slots after the given one in an attempt to find a non-empty future slot.
@@ -188,7 +188,7 @@ func (f *blocksFetcher) findFork(ctx context.Context, slot primitives.Slot) (*fo
 			"peer": pid,
 			"step": fmt.Sprintf("%d/%d", i+1, len(peers)),
 		}).Debug("Searching for alternative blocks")
-		fork, err := f.findForkWithPeer(ctx, pid, slot)
+		fork, err := f.findForkWithPeer(ctx, pid, peers, slot)
 		if err != nil {
 			log.WithFields(logrus.Fields{
 				"peer":  pid,
@@ -208,7 +208,7 @@ func findForkReqRangeSize() uint64 {
 }
 
 // findForkWithPeer loads some blocks from a peer in an attempt to find alternative blocks.
-func (f *blocksFetcher) findForkWithPeer(ctx context.Context, pid peer.ID, slot primitives.Slot) (*forkData, error) {
+func (f *blocksFetcher) findForkWithPeer(ctx context.Context, pid peer.ID, peers []peer.ID, slot primitives.Slot) (*forkData, error) {
 	reqCount := findForkReqRangeSize()
 	// Safe-guard, since previous epoch is used when calculating.
 	if uint64(slot) < reqCount {
@@ -237,21 +237,21 @@ func (f *blocksFetcher) findForkWithPeer(ctx context.Context, pid peer.ID, slot
 		Count:     reqCount,
 		Step:      1,
 	}
-	blocks, err := f.requestBlocks(ctx, req, pid)
+	reqBlocks, err := f.requestBlocks(ctx, req, pid)
 	if err != nil {
 		return nil, fmt.Errorf("cannot fetch blocks: %w", err)
 	}
-	if len(blocks) == 0 {
+	if len(reqBlocks) == 0 {
 		return nil, errNoAlternateBlocks
 	}
 
 	// If the first block is not connected to the current canonical chain, we'll stop processing this batch.
 	// Instead, we'll work backwards from the first block until we find a common ancestor,
 	// and then begin processing from there.
-	first := blocks[0]
+	first := reqBlocks[0]
 	if !f.chain.HasBlock(ctx, first.Block().ParentRoot()) {
 		// Backtrack on a root, to find a common ancestor from which we can resume syncing.
-		fork, err := f.findAncestor(ctx, pid, first)
+		fork, err := f.findAncestor(ctx, pid, peers, first)
 		if err != nil {
 			return nil, fmt.Errorf("failed to find common ancestor: %w", err)
 		}
@@ -261,8 +261,8 @@ func (f *blocksFetcher) findForkWithPeer(ctx context.Context, pid peer.ID, slot
 	// Traverse blocks, and if we've got one that doesn't have parent in DB, backtrack on it.
 	// Note that we start from the second element in the array, because we know that the first element is in the db,
 	// otherwise we would have gone into the findAncestor early return path above.
-	for i := 1; i < len(blocks); i++ {
-		block := blocks[i]
+	for i := 1; i < len(reqBlocks); i++ {
+		block := reqBlocks[i]
 		parentRoot := block.Block().ParentRoot()
 		// Step through blocks until we find one that is not in the chain. The goal is to find the point where the
 		// chain observed in the peer diverges from the locally known chain, and then collect up the remainder of the
@@ -275,25 +275,27 @@ func (f *blocksFetcher) findForkWithPeer(ctx context.Context, pid peer.ID, slot
 			"slot": block.Block().Slot(),
 			"root": fmt.Sprintf("%#x", parentRoot),
 		}).Debug("Block with unknown parent root has been found")
-		altBlocks, err := sortedBlockWithVerifiedBlobSlice(blocks[i-1:])
+		bwb, err := sortedBlockWithVerifiedBlobSlice(reqBlocks[i-1:])
 		if err != nil {
 			return nil, errors.Wrap(err, "invalid blocks received in findForkWithPeer")
 		}
+
+		sidecarsPid, err := f.fetchSidecars(ctx, pid, peers, bwb)
+		if err != nil {
+			return nil, errors.Wrap(err, "fetch sidecars")
+		}
+
 		// We need to fetch the blobs for the given alt-chain if any exist, so that we can try to verify and import
 		// the blocks.
-		bpid, bwb, err := f.fetchBlobsFromPeer(ctx, altBlocks, pid, []peer.ID{pid})
-		if err != nil {
-			return nil, errors.Wrap(err, "unable to retrieve blobs for blocks found in findForkWithPeer")
-		}
 		// The caller will use the BlocksWith VerifiedBlobs in bwb as the starting point for
 		// round-robin syncing the alternate chain.
-		return &forkData{blocksFrom: pid, blobsFrom: bpid, bwb: bwb}, nil
+		return &forkData{blocksFrom: pid, blobsFrom: sidecarsPid, bwb: bwb}, nil
 	}
 	return nil, errNoAlternateBlocks
 }
 
 // findAncestor tries to figure out common ancestor slot that connects a given root to known block.
-func (f *blocksFetcher) findAncestor(ctx context.Context, pid peer.ID, b interfaces.ReadOnlySignedBeaconBlock) (*forkData, error) {
+func (f *blocksFetcher) findAncestor(ctx context.Context, pid peer.ID, peers []peer.ID, b interfaces.ReadOnlySignedBeaconBlock) (*forkData, error) {
 	outBlocks := []interfaces.ReadOnlySignedBeaconBlock{b}
 	for i := uint64(0); i < backtrackingMaxHops; i++ {
 		parentRoot := outBlocks[len(outBlocks)-1].Block().ParentRoot()
@@ -303,15 +305,14 @@ func (f *blocksFetcher) findAncestor(ctx context.Context, pid peer.ID, b interfa
 			if err != nil {
 				return nil, errors.Wrap(err, "received invalid blocks in findAncestor")
 			}
-			var bpid peer.ID
-			bpid, bwb, err = f.fetchBlobsFromPeer(ctx, bwb, pid, []peer.ID{pid})
+			sidecarsPid, err := f.fetchSidecars(ctx, pid, peers, bwb)
 			if err != nil {
-				return nil, errors.Wrap(err, "unable to retrieve blobs for blocks found in findAncestor")
+				return nil, errors.Wrap(err, "fetch sidecars")
 			}
 			return &forkData{
 				blocksFrom: pid,
 				bwb:        bwb,
-				blobsFrom:  bpid,
+				blobsFrom:  sidecarsPid,
 			}, nil
 		}
 		// Request block's parent.
@@ -350,9 +351,12 @@ func (f *blocksFetcher) calculateHeadAndTargetEpochs() (headEpoch, targetEpoch p
 		cp := f.chain.FinalizedCheckpt()
 		headEpoch = cp.Epoch
 		targetEpoch, peers = f.p2p.Peers().BestFinalized(params.BeaconConfig().MaxPeersToSync, headEpoch)
-	} else {
-		headEpoch = slots.ToEpoch(f.chain.HeadSlot())
-		targetEpoch, peers = f.p2p.Peers().BestNonFinalized(flags.Get().MinimumSyncPeers, headEpoch)
+
+		return headEpoch, targetEpoch, peers
 	}
+
+	headEpoch = slots.ToEpoch(f.chain.HeadSlot())
+	targetEpoch, peers = f.p2p.Peers().BestNonFinalized(flags.Get().MinimumSyncPeers, headEpoch)
+
 	return headEpoch, targetEpoch, peers
 }

beacon-chain/sync/initial-sync/blocks_fetcher_utils_test.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	mock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	dbtest "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
 	p2pm "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
 	p2pt "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
@@ -188,10 +189,11 @@ func TestBlocksFetcher_findFork(t *testing.T) {
 	fetcher := newBlocksFetcher(
 		ctx,
 		&blocksFetcherConfig{
-			chain: mc,
-			clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
-			p2p:   p2p,
-			db:    beaconDB,
+			chain:       mc,
+			clock:       startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
+			p2p:         p2p,
+			db:          beaconDB,
+			custodyInfo: &peerdas.CustodyInfo{},
 		},
 	)
 	fetcher.rateLimiter = leakybucket.NewCollector(6400, 6400, 1*time.Second, false)
@@ -356,10 +358,11 @@ func TestBlocksFetcher_findForkWithPeer(t *testing.T) {
 	fetcher := newBlocksFetcher(
 		ctx,
 		&blocksFetcherConfig{
-			chain: mc,
-			clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
-			p2p:   p1,
-			db:    beaconDB,
+			chain:       mc,
+			clock:       startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
+			p2p:         p1,
+			db:          beaconDB,
+			custodyInfo: &peerdas.CustodyInfo{},
 		},
 	)
 	fetcher.rateLimiter = leakybucket.NewCollector(6400, 6400, 1*time.Second, false)
@@ -371,13 +374,13 @@ func TestBlocksFetcher_findForkWithPeer(t *testing.T) {
 
 	t.Run("slot is too early", func(t *testing.T) {
 		p2 := p2pt.NewTestP2P(t)
-		_, err := fetcher.findForkWithPeer(ctx, p2.PeerID(), 0)
+		_, err := fetcher.findForkWithPeer(ctx, p2.PeerID(), nil, 0)
 		assert.ErrorContains(t, "slot is too low to backtrack", err)
 	})
 
 	t.Run("no peer status", func(t *testing.T) {
 		p2 := p2pt.NewTestP2P(t)
-		_, err := fetcher.findForkWithPeer(ctx, p2.PeerID(), 64)
+		_, err := fetcher.findForkWithPeer(ctx, p2.PeerID(), nil, 64)
 		assert.ErrorContains(t, "cannot obtain peer's status", err)
 	})
 
@@ -391,7 +394,7 @@ func TestBlocksFetcher_findForkWithPeer(t *testing.T) {
 			HeadRoot: nil,
 			HeadSlot: 0,
 		})
-		_, err := fetcher.findForkWithPeer(ctx, p2.PeerID(), 64)
+		_, err := fetcher.findForkWithPeer(ctx, p2.PeerID(), nil, 64)
 		assert.ErrorContains(t, "cannot locate non-empty slot for a peer", err)
 	})
 
@@ -401,7 +404,7 @@ func TestBlocksFetcher_findForkWithPeer(t *testing.T) {
 		defer func() {
 			assert.NoError(t, p1.Disconnect(p2))
 		}()
-		_, err := fetcher.findForkWithPeer(ctx, p2, 64)
+		_, err := fetcher.findForkWithPeer(ctx, p2, nil, 64)
 		assert.ErrorContains(t, "no alternative blocks exist within scanned range", err)
 	})
 
@@ -413,7 +416,7 @@ func TestBlocksFetcher_findForkWithPeer(t *testing.T) {
 		defer func() {
 			assert.NoError(t, p1.Disconnect(p2))
 		}()
-		fork, err := fetcher.findForkWithPeer(ctx, p2, 64)
+		fork, err := fetcher.findForkWithPeer(ctx, p2, nil, 64)
 		require.NoError(t, err)
 		require.Equal(t, 10, len(fork.bwb))
 		assert.Equal(t, forkedSlot, fork.bwb[0].Block.Block().Slot(), "Expected slot %d to be ancestor", forkedSlot)
@@ -426,7 +429,7 @@ func TestBlocksFetcher_findForkWithPeer(t *testing.T) {
 		defer func() {
 			assert.NoError(t, p1.Disconnect(p2))
 		}()
-		_, err := fetcher.findForkWithPeer(ctx, p2, 64)
+		_, err := fetcher.findForkWithPeer(ctx, p2, nil, 64)
 		require.ErrorContains(t, "failed to find common ancestor", err)
 	})
 
@@ -438,7 +441,7 @@ func TestBlocksFetcher_findForkWithPeer(t *testing.T) {
 		defer func() {
 			assert.NoError(t, p1.Disconnect(p2))
 		}()
-		fork, err := fetcher.findForkWithPeer(ctx, p2, 64)
+		fork, err := fetcher.findForkWithPeer(ctx, p2, nil, 64)
 		require.NoError(t, err)
 
 		reqEnd := testForkStartSlot(t, 64) + primitives.Slot(findForkReqRangeSize())
@@ -512,7 +515,7 @@ func TestBlocksFetcher_findAncestor(t *testing.T) {
 
 		wsb, err := blocks.NewSignedBeaconBlock(knownBlocks[4])
 		require.NoError(t, err)
-		_, err = fetcher.findAncestor(ctx, p2.PeerID(), wsb)
+		_, err = fetcher.findAncestor(ctx, p2.PeerID(), nil, wsb)
 		assert.ErrorContains(t, "protocols not supported", err)
 	})
 
@@ -525,7 +528,7 @@ func TestBlocksFetcher_findAncestor(t *testing.T) {
 		wsb, err := blocks.NewSignedBeaconBlock(knownBlocks[4])
 		require.NoError(t, err)
 
-		fork, err := fetcher.findAncestor(ctx, p2.PeerID(), wsb)
+		fork, err := fetcher.findAncestor(ctx, p2.PeerID(), nil, wsb)
 		assert.ErrorContains(t, "no common ancestor found", err)
 		assert.Equal(t, (*forkData)(nil), fork)
 	})

beacon-chain/sync/initial-sync/blocks_queue.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"time"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
@@ -72,6 +73,10 @@ type blocksQueueConfig struct {
 	db                  db.ReadOnlyDatabase
 	mode                syncMode
 	bs                  filesystem.BlobStorageSummarizer
+	dcs                 filesystem.DataColumnStorageSummarizer
+	bv                  verification.NewBlobVerifier
+	cv                  verification.NewDataColumnsVerifier
+	custodyInfo         *peerdas.CustodyInfo
 }
 
 // blocksQueue is a priority queue that serves as a intermediary between block fetchers (producers)
@@ -96,7 +101,7 @@ type blocksQueue struct {
 type blocksQueueFetchedData struct {
 	blocksFrom peer.ID
 	blobsFrom  peer.ID
-	bwb        []blocks.BlockWithROBlobs
+	bwb        []blocks.BlockWithROSidecars
 }
 
 // newBlocksQueue creates initialized priority queue.
@@ -109,12 +114,16 @@ func newBlocksQueue(ctx context.Context, cfg *blocksQueueConfig) *blocksQueue {
 			log.Warn("rpc fetcher starting without blob availability cache, duplicate blobs may be requested.")
 		}
 		blocksFetcher = newBlocksFetcher(ctx, &blocksFetcherConfig{
-			ctxMap: cfg.ctxMap,
-			chain:  cfg.chain,
-			p2p:    cfg.p2p,
-			db:     cfg.db,
-			clock:  cfg.clock,
-			bs:     cfg.bs,
+			ctxMap:      cfg.ctxMap,
+			chain:       cfg.chain,
+			p2p:         cfg.p2p,
+			db:          cfg.db,
+			clock:       cfg.clock,
+			bs:          cfg.bs,
+			dcs:         cfg.dcs,
+			bv:          cfg.bv,
+			cv:          cfg.cv,
+			custodyInfo: cfg.custodyInfo,
 		})
 	}
 	highestExpectedSlot := cfg.highestExpectedSlot

beacon-chain/sync/initial-sync/blocks_queue_test.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	mock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	dbtest "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	p2pt "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
@@ -36,9 +37,10 @@ func TestBlocksQueue_InitStartStop(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 	fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
-		chain: mc,
-		p2p:   p2p,
-		clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
+		chain:       mc,
+		p2p:         p2p,
+		clock:       startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
+		custodyInfo: &peerdas.CustodyInfo{},
 	})
 
 	t.Run("stop without start", func(t *testing.T) {
@@ -253,9 +255,10 @@ func TestBlocksQueue_Loop(t *testing.T) {
 			defer cancel()
 
 			fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
-				chain: mc,
-				p2p:   p2p,
-				clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
+				chain:       mc,
+				p2p:         p2p,
+				clock:       startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
+				custodyInfo: &peerdas.CustodyInfo{},
 			})
 			queue := newBlocksQueue(ctx, &blocksQueueConfig{
 				blocksFetcher:       fetcher,
@@ -263,7 +266,7 @@ func TestBlocksQueue_Loop(t *testing.T) {
 				highestExpectedSlot: tt.highestExpectedSlot,
 			})
 			assert.NoError(t, queue.start())
-			processBlock := func(b blocks.BlockWithROBlobs) error {
+			processBlock := func(b blocks.BlockWithROSidecars) error {
 				block := b.Block
 				if !beaconDB.HasBlock(ctx, block.Block().ParentRoot()) {
 					return fmt.Errorf("%w: %#x", errParentDoesNotExist, block.Block().ParentRoot())
@@ -275,7 +278,7 @@ func TestBlocksQueue_Loop(t *testing.T) {
 				return mc.ReceiveBlock(ctx, block, root, nil)
 			}
 
-			var blocks []blocks.BlockWithROBlobs
+			var blocks []blocks.BlockWithROSidecars
 			for data := range queue.fetchedData {
 				for _, b := range data.bwb {
 					if err := processBlock(b); err != nil {
@@ -311,8 +314,9 @@ func TestBlocksQueue_onScheduleEvent(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 	fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
-		chain: mc,
-		p2p:   p2p,
+		chain:       mc,
+		p2p:         p2p,
+		custodyInfo: &peerdas.CustodyInfo{},
 	})
 
 	t.Run("expired context", func(t *testing.T) {
@@ -406,8 +410,9 @@ func TestBlocksQueue_onDataReceivedEvent(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 	fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
-		chain: mc,
-		p2p:   p2p,
+		chain:       mc,
+		p2p:         p2p,
+		custodyInfo: &peerdas.CustodyInfo{},
 	})
 
 	t.Run("expired context", func(t *testing.T) {
@@ -538,7 +543,7 @@ func TestBlocksQueue_onDataReceivedEvent(t *testing.T) {
 		require.NoError(t, err)
 		response := &fetchRequestResponse{
 			blocksFrom: "abc",
-			bwb: []blocks.BlockWithROBlobs{
+			bwb: []blocks.BlockWithROSidecars{
 				{Block: blocks.ROBlock{ReadOnlySignedBeaconBlock: wsb}},
 				{Block: blocks.ROBlock{ReadOnlySignedBeaconBlock: wsbCopy}},
 			},
@@ -565,8 +570,9 @@ func TestBlocksQueue_onReadyToSendEvent(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 	fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
-		chain: mc,
-		p2p:   p2p,
+		chain:       mc,
+		p2p:         p2p,
+		custodyInfo: &peerdas.CustodyInfo{},
 	})
 
 	t.Run("expired context", func(t *testing.T) {
@@ -624,8 +630,9 @@ func TestBlocksQueue_onReadyToSendEvent(t *testing.T) {
 	const pidDataParsed = "abc"
 	t.Run("send from the first machine", func(t *testing.T) {
 		fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
-			chain: mc,
-			p2p:   p2p,
+			chain:       mc,
+			p2p:         p2p,
+			custodyInfo: &peerdas.CustodyInfo{},
 		})
 		queue := newBlocksQueue(ctx, &blocksQueueConfig{
 			blocksFetcher:       fetcher,
@@ -640,7 +647,7 @@ func TestBlocksQueue_onReadyToSendEvent(t *testing.T) {
 		queue.smm.machines[256].fetched.blocksFrom = pidDataParsed
 		rwsb, err := blocks.NewROBlock(wsb)
 		require.NoError(t, err)
-		queue.smm.machines[256].fetched.bwb = []blocks.BlockWithROBlobs{
+		queue.smm.machines[256].fetched.bwb = []blocks.BlockWithROSidecars{
 			{Block: rwsb},
 		}
 
@@ -653,8 +660,9 @@ func TestBlocksQueue_onReadyToSendEvent(t *testing.T) {
 
 	t.Run("previous machines are not processed - do not send", func(t *testing.T) {
 		fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
-			chain: mc,
-			p2p:   p2p,
+			chain:       mc,
+			p2p:         p2p,
+			custodyInfo: &peerdas.CustodyInfo{},
 		})
 		queue := newBlocksQueue(ctx, &blocksQueueConfig{
 			blocksFetcher:       fetcher,
@@ -674,7 +682,7 @@ func TestBlocksQueue_onReadyToSendEvent(t *testing.T) {
 		queue.smm.machines[320].fetched.blocksFrom = pidDataParsed
 		rwsb, err := blocks.NewROBlock(wsb)
 		require.NoError(t, err)
-		queue.smm.machines[320].fetched.bwb = []blocks.BlockWithROBlobs{
+		queue.smm.machines[320].fetched.bwb = []blocks.BlockWithROSidecars{
 			{Block: rwsb},
 		}
 
@@ -688,8 +696,9 @@ func TestBlocksQueue_onReadyToSendEvent(t *testing.T) {
 
 	t.Run("previous machines are processed - send", func(t *testing.T) {
 		fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
-			chain: mc,
-			p2p:   p2p,
+			chain:       mc,
+			p2p:         p2p,
+			custodyInfo: &peerdas.CustodyInfo{},
 		})
 		queue := newBlocksQueue(ctx, &blocksQueueConfig{
 			blocksFetcher:       fetcher,
@@ -705,7 +714,7 @@ func TestBlocksQueue_onReadyToSendEvent(t *testing.T) {
 		queue.smm.machines[320].fetched.blocksFrom = pidDataParsed
 		rwsb, err := blocks.NewROBlock(wsb)
 		require.NoError(t, err)
-		queue.smm.machines[320].fetched.bwb = []blocks.BlockWithROBlobs{
+		queue.smm.machines[320].fetched.bwb = []blocks.BlockWithROSidecars{
 			{Block: rwsb},
 		}
 
@@ -723,8 +732,9 @@ func TestBlocksQueue_onProcessSkippedEvent(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 	fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
-		chain: mc,
-		p2p:   p2p,
+		chain:       mc,
+		p2p:         p2p,
+		custodyInfo: &peerdas.CustodyInfo{},
 	})
 
 	t.Run("expired context", func(t *testing.T) {
@@ -852,8 +862,9 @@ func TestBlocksQueue_onProcessSkippedEvent(t *testing.T) {
 			{blocks: makeSequence(1, 160), finalizedEpoch: 5, headSlot: 128},
 		}, p.Peers())
 		fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
-			chain: mc,
-			p2p:   p,
+			chain:       mc,
+			p2p:         p,
+			custodyInfo: &peerdas.CustodyInfo{},
 		})
 		queue := newBlocksQueue(ctx, &blocksQueueConfig{
 			blocksFetcher:       fetcher,
@@ -879,8 +890,9 @@ func TestBlocksQueue_onProcessSkippedEvent(t *testing.T) {
 			{blocks: makeSequence(200, 320), finalizedEpoch: 8, headSlot: 300},
 		}, p.Peers())
 		fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
-			chain: mc,
-			p2p:   p,
+			chain:       mc,
+			p2p:         p,
+			custodyInfo: &peerdas.CustodyInfo{},
 		})
 		queue := newBlocksQueue(ctx, &blocksQueueConfig{
 			blocksFetcher:       fetcher,
@@ -929,8 +941,9 @@ func TestBlocksQueue_onProcessSkippedEvent(t *testing.T) {
 			{blocks: makeSequence(200, 320), finalizedEpoch: 8, headSlot: 320},
 		}, p.Peers())
 		fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
-			chain: mc,
-			p2p:   p,
+			chain:       mc,
+			p2p:         p,
+			custodyInfo: &peerdas.CustodyInfo{},
 		})
 		queue := newBlocksQueue(ctx, &blocksQueueConfig{
 			blocksFetcher:       fetcher,
@@ -1060,10 +1073,11 @@ func TestBlocksQueue_stuckInUnfavourableFork(t *testing.T) {
 	fetcher := newBlocksFetcher(
 		ctx,
 		&blocksFetcherConfig{
-			chain: mc,
-			p2p:   p2p,
-			db:    beaconDB,
-			clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
+			chain:       mc,
+			p2p:         p2p,
+			db:          beaconDB,
+			clock:       startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
+			custodyInfo: &peerdas.CustodyInfo{},
 		},
 	)
 	fetcher.rateLimiter = leakybucket.NewCollector(6400, 6400, 1*time.Second, false)
@@ -1282,10 +1296,11 @@ func TestBlocksQueue_stuckWhenHeadIsSetToOrphanedBlock(t *testing.T) {
 	fetcher := newBlocksFetcher(
 		ctx,
 		&blocksFetcherConfig{
-			chain: mc,
-			p2p:   p2p,
-			db:    beaconDB,
-			clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
+			chain:       mc,
+			p2p:         p2p,
+			db:          beaconDB,
+			clock:       startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
+			custodyInfo: &peerdas.CustodyInfo{},
 		},
 	)
 	fetcher.rateLimiter = leakybucket.NewCollector(6400, 6400, 1*time.Second, false)

beacon-chain/sync/initial-sync/round_robin.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/hex"
 	"fmt"
+	"sort"
 	"time"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
@@ -13,6 +14,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/paulbellamy/ratecounter"
 	"github.com/pkg/errors"
@@ -77,6 +79,9 @@ func (s *Service) startBlocksQueue(ctx context.Context, highestSlot primitives.S
 		highestExpectedSlot: highestSlot,
 		mode:                mode,
 		bs:                  s.cfg.BlobStorage,
+		dcs:                 s.cfg.DataColumnStorage,
+		cv:                  s.newDataColumnsVerifier,
+		custodyInfo:         s.cfg.CustodyInfo,
 	}
 	queue := newBlocksQueue(ctx, cfg)
 	if err := queue.start(); err != nil {
@@ -156,30 +161,75 @@ func (s *Service) processFetchedDataRegSync(ctx context.Context, data *blocksQue
 		log.WithError(err).Debug("batch did not contain a valid sequence of unprocessed blocks")
 		return 0, err
 	}
+
 	if len(bwb) == 0 {
 		return 0, nil
 	}
-	bv := verification.NewBlobBatchVerifier(s.newBlobVerifier, verification.InitsyncBlobSidecarRequirements)
-	avs := das.NewLazilyPersistentStore(s.cfg.BlobStorage, bv)
-	batchFields := logrus.Fields{
-		"firstSlot":        data.bwb[0].Block.Block().Slot(),
-		"firstUnprocessed": bwb[0].Block.Block().Slot(),
+
+	nodeID := s.cfg.P2P.NodeID()
+
+	// Separate blocks with blobs from blocks with data columns.
+	fistDataColumnIndex := sort.Search(len(bwb), func(i int) bool {
+		return bwb[i].Block.Version() >= version.Fulu
+	})
+
+	blocksWithBlobs := bwb[:fistDataColumnIndex]
+	blocksWithDataColumns := bwb[fistDataColumnIndex:]
+
+	blobBatchVerifier := verification.NewBlobBatchVerifier(s.newBlobVerifier, verification.InitsyncBlobSidecarRequirements)
+	lazilyPersistentStoreBlobs := das.NewLazilyPersistentStore(s.cfg.BlobStorage, blobBatchVerifier)
+	lazilyPersistentStoreColumn := das.NewLazilyPersistentStoreColumn(s.cfg.DataColumnStorage, nodeID, s.newDataColumnsVerifier, s.cfg.CustodyInfo)
+
+	log := log.WithField("firstSlot", data.bwb[0].Block.Block().Slot())
+	logBlobs, logDataColumns := log, log
+
+	if len(blocksWithBlobs) > 0 {
+		logBlobs = logBlobs.WithField("firstUnprocessed", blocksWithBlobs[0].Block.Block().Slot())
 	}
-	for i, b := range bwb {
-		if err := avs.Persist(s.clock.CurrentSlot(), b.Blobs...); err != nil {
-			log.WithError(err).WithFields(batchFields).WithFields(syncFields(b.Block)).Warn("Batch failure due to BlobSidecar issues")
+
+	for i, b := range blocksWithBlobs {
+		sidecars := blocks.NewSidecarsFromBlobSidecars(b.Blobs)
+
+		if err := lazilyPersistentStoreBlobs.Persist(s.clock.CurrentSlot(), sidecars...); err != nil {
+			logBlobs.WithError(err).WithFields(syncFields(b.Block)).Warning("Batch failure due to BlobSidecar issues")
 			return uint64(i), err
 		}
-		if err := s.processBlock(ctx, s.genesisTime, b, s.cfg.Chain.ReceiveBlock, avs); err != nil {
+
+		if err := s.processBlock(ctx, s.genesisTime, b, s.cfg.Chain.ReceiveBlock, lazilyPersistentStoreBlobs); err != nil {
 			if errors.Is(err, errParentDoesNotExist) {
-				log.WithFields(batchFields).WithField("missingParent", fmt.Sprintf("%#x", b.Block.Block().ParentRoot())).
+				logBlobs.WithField("missingParent", fmt.Sprintf("%#x", b.Block.Block().ParentRoot())).
 					WithFields(syncFields(b.Block)).Debug("Could not process batch blocks due to missing parent")
 			} else {
-				log.WithError(err).WithFields(batchFields).WithFields(syncFields(b.Block)).Warn("Block processing failure")
+				logBlobs.WithError(err).WithFields(syncFields(b.Block)).Warn("Block processing failure")
 			}
+
 			return uint64(i), err
 		}
 	}
+
+	for i, b := range blocksWithDataColumns {
+		logDataColumns := logDataColumns.WithFields(syncFields(b.Block))
+
+		sicecars := blocks.NewSidecarsFromDataColumnSidecars(b.Columns)
+
+		if err := lazilyPersistentStoreColumn.Persist(s.clock.CurrentSlot(), sicecars...); err != nil {
+			logDataColumns.WithError(err).Warning("Batch failure due to DataColumnSidecar issues")
+			return uint64(i), err
+		}
+
+		if err := s.processBlock(ctx, s.genesisTime, b, s.cfg.Chain.ReceiveBlock, lazilyPersistentStoreColumn); err != nil {
+			switch {
+			case errors.Is(err, errParentDoesNotExist):
+				logDataColumns.
+					WithField("missingParent", fmt.Sprintf("%#x", b.Block.Block().ParentRoot())).
+					Debug("Could not process batch blocks due to missing parent")
+				return uint64(i), err
+			default:
+				logDataColumns.WithError(err).Warning("Block processing failure")
+				return uint64(i), err
+			}
+		}
+	}
 	return uint64(len(bwb)), nil
 }
 
@@ -191,12 +241,18 @@ func syncFields(b blocks.ROBlock) logrus.Fields {
 }
 
 // highestFinalizedEpoch returns the absolute highest finalized epoch of all connected peers.
-// Note this can be lower than our finalized epoch if we have no peers or peers that are all behind us.
+// It returns `0` if no peers are connected.
+// Note this can be lower than our finalized epoch if our connected peers are all behind us.
 func (s *Service) highestFinalizedEpoch() primitives.Epoch {
 	highest := primitives.Epoch(0)
 	for _, pid := range s.cfg.P2P.Peers().Connected() {
 		peerChainState, err := s.cfg.P2P.Peers().ChainState(pid)
-		if err == nil && peerChainState != nil && peerChainState.FinalizedEpoch > highest {
+
+		if err != nil || peerChainState == nil {
+			continue
+		}
+
+		if peerChainState.FinalizedEpoch > highest {
 			highest = peerChainState.FinalizedEpoch
 		}
 	}
@@ -248,7 +304,7 @@ func (s *Service) logBatchSyncStatus(firstBlk blocks.ROBlock, nBlocks int) {
 func (s *Service) processBlock(
 	ctx context.Context,
 	genesis time.Time,
-	bwb blocks.BlockWithROBlobs,
+	bwb blocks.BlockWithROSidecars,
 	blockReceiver blockReceiverFn,
 	avs das.AvailabilityStore,
 ) error {
@@ -267,7 +323,7 @@ func (s *Service) processBlock(
 
 type processedChecker func(context.Context, blocks.ROBlock) bool
 
-func validUnprocessed(ctx context.Context, bwb []blocks.BlockWithROBlobs, headSlot primitives.Slot, isProc processedChecker) ([]blocks.BlockWithROBlobs, error) {
+func validUnprocessed(ctx context.Context, bwb []blocks.BlockWithROSidecars, headSlot primitives.Slot, isProc processedChecker) ([]blocks.BlockWithROSidecars, error) {
 	// use a pointer to avoid confusing the zero-value with the case where the first element is processed.
 	var processed *int
 	for i := range bwb {
@@ -297,40 +353,100 @@ func validUnprocessed(ctx context.Context, bwb []blocks.BlockWithROBlobs, headSl
 	return bwb[nonProcessedIdx:], nil
 }
 
-func (s *Service) processBatchedBlocks(ctx context.Context, bwb []blocks.BlockWithROBlobs, bFunc batchBlockReceiverFn) (uint64, error) {
-	if len(bwb) == 0 {
+func (s *Service) processBatchedBlocks(ctx context.Context, bwb []blocks.BlockWithROSidecars, bFunc batchBlockReceiverFn) (uint64, error) {
+	bwbCount := uint64(len(bwb))
+	if bwbCount == 0 {
 		return 0, errors.New("0 blocks provided into method")
 	}
+
 	headSlot := s.cfg.Chain.HeadSlot()
-	var err error
-	bwb, err = validUnprocessed(ctx, bwb, headSlot, s.isProcessedBlock)
+	bwb, err := validUnprocessed(ctx, bwb, headSlot, s.isProcessedBlock)
 	if err != nil {
 		return 0, err
 	}
-	if len(bwb) == 0 {
-		return 0, nil
-	}
 
-	first := bwb[0].Block
-	if !s.cfg.Chain.HasBlock(ctx, first.Block().ParentRoot()) {
+	firstBlock := bwb[0].Block
+	if !s.cfg.Chain.HasBlock(ctx, firstBlock.Block().ParentRoot()) {
 		return 0, fmt.Errorf("%w: %#x (in processBatchedBlocks, slot=%d)",
-			errParentDoesNotExist, first.Block().ParentRoot(), first.Block().Slot())
+			errParentDoesNotExist, firstBlock.Block().ParentRoot(), firstBlock.Block().Slot())
 	}
 
-	bv := verification.NewBlobBatchVerifier(s.newBlobVerifier, verification.InitsyncBlobSidecarRequirements)
-	avs := das.NewLazilyPersistentStore(s.cfg.BlobStorage, bv)
-	s.logBatchSyncStatus(first, len(bwb))
-	for _, bb := range bwb {
-		if len(bb.Blobs) == 0 {
+	// Seaerate blocks with blobs from blocks with data columns.
+	fistDataColumnIndex := sort.Search(len(bwb), func(i int) bool {
+		return bwb[i].Block.Version() >= version.Fulu
+	})
+
+	blocksWithBlobs := bwb[:fistDataColumnIndex]
+	blocksWithDataColumns := bwb[fistDataColumnIndex:]
+
+	if err := s.processBlocksWithBlobs(ctx, blocksWithBlobs, bFunc, firstBlock); err != nil {
+		return 0, errors.Wrap(err, "processing blocks with blobs")
+	}
+
+	if err := s.processBlocksWithDataColumns(ctx, blocksWithDataColumns, bFunc, firstBlock); err != nil {
+		return 0, errors.Wrap(err, "processing blocks with data columns")
+	}
+
+	return bwbCount, nil
+}
+
+func (s *Service) processBlocksWithBlobs(ctx context.Context, bwbs []blocks.BlockWithROSidecars, bFunc batchBlockReceiverFn, firstBlock blocks.ROBlock) error {
+	bwbCount := len(bwbs)
+	if bwbCount == 0 {
+		return nil
+	}
+
+	batchVerifier := verification.NewBlobBatchVerifier(s.newBlobVerifier, verification.InitsyncBlobSidecarRequirements)
+	persistentStore := das.NewLazilyPersistentStore(s.cfg.BlobStorage, batchVerifier)
+	s.logBatchSyncStatus(firstBlock, bwbCount)
+
+	for _, bwb := range bwbs {
+		if len(bwb.Blobs) == 0 {
 			continue
 		}
-		if err := avs.Persist(s.clock.CurrentSlot(), bb.Blobs...); err != nil {
-			return 0, err
+
+		sidecars := blocks.NewSidecarsFromBlobSidecars(bwb.Blobs)
+
+		if err := persistentStore.Persist(s.clock.CurrentSlot(), sidecars...); err != nil {
+			return errors.Wrap(err, "persisting blobs")
 		}
 	}
 
-	robs := blocks.BlockWithROBlobsSlice(bwb).ROBlocks()
-	return uint64(len(bwb)), bFunc(ctx, robs, avs)
+	robs := blocks.BlockWithROBlobsSlice(bwbs).ROBlocks()
+	if err := bFunc(ctx, robs, persistentStore); err != nil {
+		return errors.Wrap(err, "processing blocks with blobs")
+	}
+
+	return nil
+}
+
+func (s *Service) processBlocksWithDataColumns(ctx context.Context, bwbs []blocks.BlockWithROSidecars, bFunc batchBlockReceiverFn, firstBlock blocks.ROBlock) error {
+	bwbCount := len(bwbs)
+	if bwbCount == 0 {
+		return nil
+	}
+
+	persistentStoreColumn := das.NewLazilyPersistentStoreColumn(s.cfg.DataColumnStorage, s.cfg.P2P.NodeID(), s.newDataColumnsVerifier, s.cfg.CustodyInfo)
+	s.logBatchSyncStatus(firstBlock, bwbCount)
+
+	for _, bwb := range bwbs {
+		if len(bwb.Columns) == 0 {
+			continue
+		}
+
+		sidecars := blocks.NewSidecarsFromDataColumnSidecars(bwb.Columns)
+
+		if err := persistentStoreColumn.Persist(s.clock.CurrentSlot(), sidecars...); err != nil {
+			return errors.Wrap(err, "persisting columns")
+		}
+	}
+
+	robs := blocks.BlockWithROBlobsSlice(bwbs).ROBlocks()
+	if err := bFunc(ctx, robs, persistentStoreColumn); err != nil {
+		return errors.Wrap(err, "process post-Fulu blocks")
+	}
+
+	return nil
 }
 
 func isPunishableError(err error) bool {

beacon-chain/sync/initial-sync/round_robin_test.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/async/abool"
 	mock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/das"
 	dbtest "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
 	p2pt "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
@@ -309,7 +310,7 @@ func TestService_roundRobinSync(t *testing.T) {
 			clock := startup.NewClock(gt, vr)
 			s := &Service{
 				ctx:          context.Background(),
-				cfg:          &Config{Chain: mc, P2P: p, DB: beaconDB},
+				cfg:          &Config{Chain: mc, P2P: p, DB: beaconDB, CustodyInfo: &peerdas.CustodyInfo{}},
 				synced:       abool.New(),
 				chainStarted: abool.NewBool(true),
 				clock:        clock,
@@ -373,7 +374,7 @@ func TestService_processBlock(t *testing.T) {
 		require.NoError(t, err)
 		rowsb, err := blocks.NewROBlock(wsb)
 		require.NoError(t, err)
-		err = s.processBlock(ctx, genesis, blocks.BlockWithROBlobs{Block: rowsb}, func(
+		err = s.processBlock(ctx, genesis, blocks.BlockWithROSidecars{Block: rowsb}, func(
 			ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, _ das.AvailabilityStore) error {
 			assert.NoError(t, s.cfg.Chain.ReceiveBlock(ctx, block, blockRoot, nil))
 			return nil
@@ -385,7 +386,7 @@ func TestService_processBlock(t *testing.T) {
 		require.NoError(t, err)
 		rowsb, err = blocks.NewROBlock(wsb)
 		require.NoError(t, err)
-		err = s.processBlock(ctx, genesis, blocks.BlockWithROBlobs{Block: rowsb}, func(
+		err = s.processBlock(ctx, genesis, blocks.BlockWithROSidecars{Block: rowsb}, func(
 			ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, _ das.AvailabilityStore) error {
 			return nil
 		}, nil)
@@ -396,7 +397,7 @@ func TestService_processBlock(t *testing.T) {
 		require.NoError(t, err)
 		rowsb, err = blocks.NewROBlock(wsb)
 		require.NoError(t, err)
-		err = s.processBlock(ctx, genesis, blocks.BlockWithROBlobs{Block: rowsb}, func(
+		err = s.processBlock(ctx, genesis, blocks.BlockWithROSidecars{Block: rowsb}, func(
 			ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, _ das.AvailabilityStore) error {
 			assert.NoError(t, s.cfg.Chain.ReceiveBlock(ctx, block, blockRoot, nil))
 			return nil
@@ -432,7 +433,7 @@ func TestService_processBlockBatch(t *testing.T) {
 	s.genesisTime = genesis
 
 	t.Run("process non-linear batch", func(t *testing.T) {
-		var batch []blocks.BlockWithROBlobs
+		var batch []blocks.BlockWithROSidecars
 		currBlockRoot := genesisBlkRoot
 		for i := primitives.Slot(1); i < 10; i++ {
 			parentRoot := currBlockRoot
@@ -446,11 +447,11 @@ func TestService_processBlockBatch(t *testing.T) {
 			require.NoError(t, err)
 			rowsb, err := blocks.NewROBlock(wsb)
 			require.NoError(t, err)
-			batch = append(batch, blocks.BlockWithROBlobs{Block: rowsb})
+			batch = append(batch, blocks.BlockWithROSidecars{Block: rowsb})
 			currBlockRoot = blk1Root
 		}
 
-		var batch2 []blocks.BlockWithROBlobs
+		var batch2 []blocks.BlockWithROSidecars
 		for i := primitives.Slot(10); i < 20; i++ {
 			parentRoot := currBlockRoot
 			blk1 := util.NewBeaconBlock()
@@ -463,7 +464,7 @@ func TestService_processBlockBatch(t *testing.T) {
 			require.NoError(t, err)
 			rowsb, err := blocks.NewROBlock(wsb)
 			require.NoError(t, err)
-			batch2 = append(batch2, blocks.BlockWithROBlobs{Block: rowsb})
+			batch2 = append(batch2, blocks.BlockWithROSidecars{Block: rowsb})
 			currBlockRoot = blk1Root
 		}
 
@@ -485,7 +486,7 @@ func TestService_processBlockBatch(t *testing.T) {
 		assert.ErrorContains(t, "block is already processed", err)
 		require.Equal(t, uint64(0), count)
 
-		var badBatch2 []blocks.BlockWithROBlobs
+		var badBatch2 []blocks.BlockWithROSidecars
 		for i, b := range batch2 {
 			// create a non-linear batch
 			if i%3 == 0 && i != 0 {
@@ -569,7 +570,7 @@ func TestService_blockProviderScoring(t *testing.T) {
 	clock := startup.NewClock(gt, vr)
 	s := &Service{
 		ctx:          context.Background(),
-		cfg:          &Config{Chain: mc, P2P: p, DB: beaconDB},
+		cfg:          &Config{Chain: mc, P2P: p, DB: beaconDB, CustodyInfo: &peerdas.CustodyInfo{}},
 		synced:       abool.New(),
 		chainStarted: abool.NewBool(true),
 		clock:        clock,
@@ -638,7 +639,7 @@ func TestService_syncToFinalizedEpoch(t *testing.T) {
 	}
 	s := &Service{
 		ctx:          context.Background(),
-		cfg:          &Config{Chain: mc, P2P: p, DB: beaconDB},
+		cfg:          &Config{Chain: mc, P2P: p, DB: beaconDB, CustodyInfo: &peerdas.CustodyInfo{}},
 		synced:       abool.New(),
 		chainStarted: abool.NewBool(true),
 		counter:      ratecounter.NewRateCounter(counterSeconds * time.Second),
@@ -685,7 +686,7 @@ func TestService_ValidUnprocessed(t *testing.T) {
 	require.NoError(t, err)
 	util.SaveBlock(t, context.Background(), beaconDB, genesisBlk)
 
-	var batch []blocks.BlockWithROBlobs
+	var batch []blocks.BlockWithROSidecars
 	currBlockRoot := genesisBlkRoot
 	for i := primitives.Slot(1); i < 10; i++ {
 		parentRoot := currBlockRoot
@@ -699,7 +700,7 @@ func TestService_ValidUnprocessed(t *testing.T) {
 		require.NoError(t, err)
 		rowsb, err := blocks.NewROBlock(wsb)
 		require.NoError(t, err)
-		batch = append(batch, blocks.BlockWithROBlobs{Block: rowsb})
+		batch = append(batch, blocks.BlockWithROSidecars{Block: rowsb})
 		currBlockRoot = blk1Root
 	}
 

beacon-chain/sync/initial-sync/service.go

@@ -12,6 +12,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain"
 	blockfeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/block"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/das"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
@@ -53,22 +54,25 @@ type Config struct {
 	ClockWaiter         startup.ClockWaiter
 	InitialSyncComplete chan struct{}
 	BlobStorage         *filesystem.BlobStorage
+	DataColumnStorage   *filesystem.DataColumnStorage
+	CustodyInfo         *peerdas.CustodyInfo
 }
 
 // Service service.
 type Service struct {
-	cfg             *Config
-	ctx             context.Context
-	cancel          context.CancelFunc
-	synced          *abool.AtomicBool
-	chainStarted    *abool.AtomicBool
-	counter         *ratecounter.RateCounter
-	genesisChan     chan time.Time
-	clock           *startup.Clock
-	verifierWaiter  *verification.InitializerWaiter
-	newBlobVerifier verification.NewBlobVerifier
-	ctxMap          sync.ContextByteVersions
-	genesisTime     time.Time
+	cfg                    *Config
+	ctx                    context.Context
+	cancel                 context.CancelFunc
+	synced                 *abool.AtomicBool
+	chainStarted           *abool.AtomicBool
+	counter                *ratecounter.RateCounter
+	genesisChan            chan time.Time
+	clock                  *startup.Clock
+	verifierWaiter         *verification.InitializerWaiter
+	newBlobVerifier        verification.NewBlobVerifier
+	newDataColumnsVerifier verification.NewDataColumnsVerifier
+	ctxMap                 sync.ContextByteVersions
+	genesisTime            time.Time
 }
 
 // Option is a functional option for the initial-sync Service.
@@ -149,6 +153,7 @@ func (s *Service) Start() {
 		return
 	}
 	s.newBlobVerifier = newBlobVerifierFromInitializer(v)
+	s.newDataColumnsVerifier = newDataColumnsVerifierFromInitializer(v)
 
 	gt := clock.GenesisTime()
 	if gt.IsZero() {
@@ -175,20 +180,22 @@ func (s *Service) Start() {
 	}
 	s.chainStarted.Set()
 	log.Info("Starting initial chain sync...")
+
 	// Are we already in sync, or close to it?
 	if slots.ToEpoch(s.cfg.Chain.HeadSlot()) == slots.ToEpoch(currentSlot) {
 		log.Info("Already synced to the current chain head")
 		s.markSynced()
 		return
 	}
+
 	peers, err := s.waitForMinimumPeers()
 	if err != nil {
 		log.WithError(err).Error("Error waiting for minimum number of peers")
 		return
 	}
-	if err := s.fetchOriginBlobs(peers); err != nil {
-		log.WithError(err).Error("Failed to fetch missing blobs for checkpoint origin")
-		return
+
+	if err := s.fetchOriginSidecars(peers); err != nil {
+		log.WithError(err).Error("Error fetching origin sidecars")
 	}
 	if err := s.roundRobinSync(); err != nil {
 		if errors.Is(s.ctx.Err(), context.Canceled) {
@@ -200,6 +207,47 @@ func (s *Service) Start() {
 	s.markSynced()
 }
 
+// fetchOriginSidecars fetches origin sidecars
+func (s *Service) fetchOriginSidecars(peers []peer.ID) error {
+	blockRoot, err := s.cfg.DB.OriginCheckpointBlockRoot(s.ctx)
+	if errors.Is(err, db.ErrNotFoundOriginBlockRoot) {
+		return nil
+	}
+
+	block, err := s.cfg.DB.Block(s.ctx, blockRoot)
+	if err != nil {
+		return errors.Wrap(err, "block")
+	}
+
+	currentSlot, blockSlot := s.clock.CurrentSlot(), block.Block().Slot()
+	currentEpoch, blockEpoch := slots.ToEpoch(currentSlot), slots.ToEpoch(blockSlot)
+
+	if !params.WithinDAPeriod(blockEpoch, currentEpoch) {
+		return nil
+	}
+
+	roBlock, err := blocks.NewROBlockWithRoot(block, blockRoot)
+	if err != nil {
+		return errors.Wrap(err, "new ro block with root")
+	}
+
+	beaconConfig := params.BeaconConfig()
+
+	if blockEpoch >= beaconConfig.FuluForkEpoch {
+		if err := s.fetchOriginColumns(peers, roBlock); err != nil {
+			return errors.Wrap(err, "fetch origin columns")
+		}
+	}
+
+	if blockEpoch >= beaconConfig.DenebForkEpoch {
+		if err := s.fetchOriginBlobs(peers, roBlock); err != nil {
+			return errors.Wrap(err, "fetch origin blobs")
+		}
+	}
+
+	return nil
+}
+
 // Stop initial sync.
 func (s *Service) Stop() error {
 	s.cancel()
@@ -304,23 +352,9 @@ func missingBlobRequest(blk blocks.ROBlock, store *filesystem.BlobStorage) (p2pt
 	return req, nil
 }
 
-func (s *Service) fetchOriginBlobs(pids []peer.ID) error {
-	r, err := s.cfg.DB.OriginCheckpointBlockRoot(s.ctx)
-	if errors.Is(err, db.ErrNotFoundOriginBlockRoot) {
-		return nil
-	}
-	blk, err := s.cfg.DB.Block(s.ctx, r)
-	if err != nil {
-		log.WithField("root", fmt.Sprintf("%#x", r)).Error("Block for checkpoint sync origin root not found in db")
-		return err
-	}
-	if !params.WithinDAPeriod(slots.ToEpoch(blk.Block().Slot()), slots.ToEpoch(s.clock.CurrentSlot())) {
-		return nil
-	}
-	rob, err := blocks.NewROBlockWithRoot(blk, r)
-	if err != nil {
-		return err
-	}
+func (s *Service) fetchOriginBlobs(pids []peer.ID, rob blocks.ROBlock) error {
+	r := rob.Root()
+
 	req, err := missingBlobRequest(rob, s.cfg.BlobStorage)
 	if err != nil {
 		return err
@@ -331,10 +365,13 @@ func (s *Service) fetchOriginBlobs(pids []peer.ID) error {
 	}
 	shufflePeers(pids)
 	for i := range pids {
-		sidecars, err := sync.SendBlobSidecarByRoot(s.ctx, s.clock, s.cfg.P2P, pids[i], s.ctxMap, &req, rob.Block().Slot())
+		blobSidecars, err := sync.SendBlobSidecarByRoot(s.ctx, s.clock, s.cfg.P2P, pids[i], s.ctxMap, &req, rob.Block().Slot())
 		if err != nil {
 			continue
 		}
+
+		sidecars := blocks.NewSidecarsFromBlobSidecars(blobSidecars)
+
 		if len(sidecars) != len(req) {
 			continue
 		}
@@ -344,6 +381,7 @@ func (s *Service) fetchOriginBlobs(pids []peer.ID) error {
 		if err := avs.Persist(current, sidecars...); err != nil {
 			return err
 		}
+
 		if err := avs.IsDataAvailable(s.ctx, current, rob); err != nil {
 			log.WithField("root", fmt.Sprintf("%#x", r)).WithField("peerID", pids[i]).Warn("Blobs from peer for origin block were unusable")
 			continue
@@ -354,6 +392,29 @@ func (s *Service) fetchOriginBlobs(pids []peer.ID) error {
 	return fmt.Errorf("no connected peer able to provide blobs for checkpoint sync block %#x", r)
 }
 
+func (s *Service) fetchOriginColumns(pids []peer.ID, roBlock blocks.ROBlock) error {
+	actualSamplingSize := s.cfg.CustodyInfo.CustodyGroupSamplingSize(peerdas.Actual)
+	nodeID := s.cfg.P2P.NodeID()
+	storage := s.cfg.DataColumnStorage
+
+	missingColumns, err := sync.MissingDataColumns(roBlock, nodeID, actualSamplingSize, storage)
+	if err != nil {
+		return errors.Wrap(err, "missing data columns")
+	}
+
+	sidecars, err := sync.RequestDataColumnSidecarsByRoot(s.ctx, missingColumns, roBlock, pids, s.clock, s.cfg.P2P, s.ctxMap, s.newDataColumnsVerifier)
+	if err != nil {
+		return errors.Wrap(err, "request data column sidecars")
+	}
+
+	log.WithFields(logrus.Fields{
+		"blockRoot":   fmt.Sprintf("%#x", roBlock.Root()),
+		"columnCount": len(sidecars),
+	}).Info("Successfully downloaded data columns for checkpoint sync block")
+
+	return nil
+}
+
 func shufflePeers(pids []peer.ID) {
 	rg := rand.NewGenerator()
 	rg.Shuffle(len(pids), func(i, j int) {
@@ -366,3 +427,9 @@ func newBlobVerifierFromInitializer(ini *verification.Initializer) verification.
 		return ini.NewBlobVerifier(b, reqs)
 	}
 }
+
+func newDataColumnsVerifierFromInitializer(ini *verification.Initializer) verification.NewDataColumnsVerifier {
+	return func(roDataColumns []blocks.RODataColumn, reqs []verification.Requirement) verification.DataColumnsVerifier {
+		return ini.NewDataColumnsVerifier(roDataColumns, reqs)
+	}
+}

beacon-chain/sync/initial-sync/service_test.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/async/abool"
 	mock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/kv"
 	dbtest "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
@@ -161,6 +162,7 @@ func TestService_InitStartStop(t *testing.T) {
 				ClockWaiter:         gs,
 				StateNotifier:       &mock.MockStateNotifier{},
 				InitialSyncComplete: make(chan struct{}),
+				CustodyInfo:         &peerdas.CustodyInfo{},
 			})
 			s.verifierWaiter = verification.NewInitializerWaiter(gs, nil, nil)
 			time.Sleep(500 * time.Millisecond)
@@ -197,7 +199,7 @@ func TestService_waitForStateInitialization(t *testing.T) {
 		cs := startup.NewClockSynchronizer()
 		ctx, cancel := context.WithCancel(ctx)
 		s := &Service{
-			cfg:          &Config{Chain: mc, StateNotifier: mc.StateNotifier(), ClockWaiter: cs, InitialSyncComplete: make(chan struct{})},
+			cfg:          &Config{Chain: mc, StateNotifier: mc.StateNotifier(), ClockWaiter: cs, InitialSyncComplete: make(chan struct{}), CustodyInfo: &peerdas.CustodyInfo{}},
 			ctx:          ctx,
 			cancel:       cancel,
 			synced:       abool.New(),
@@ -305,6 +307,7 @@ func TestService_markSynced(t *testing.T) {
 		Chain:               mc,
 		StateNotifier:       mc.StateNotifier(),
 		InitialSyncComplete: make(chan struct{}),
+		CustodyInfo:         &peerdas.CustodyInfo{},
 	})
 	require.NotNil(t, s)
 	assert.Equal(t, false, s.chainStarted.IsSet())
@@ -390,6 +393,7 @@ func TestService_Resync(t *testing.T) {
 				Chain:         mc,
 				StateNotifier: mc.StateNotifier(),
 				BlobStorage:   filesystem.NewEphemeralBlobStorage(t),
+				CustodyInfo:   &peerdas.CustodyInfo{},
 			})
 			assert.NotNil(t, s)
 			assert.Equal(t, primitives.Slot(0), s.cfg.Chain.HeadSlot())
@@ -409,6 +413,7 @@ func TestService_Resync(t *testing.T) {
 func TestService_Initialized(t *testing.T) {
 	s := NewService(context.Background(), &Config{
 		StateNotifier: &mock.MockStateNotifier{},
+		CustodyInfo:   &peerdas.CustodyInfo{},
 	})
 	s.chainStarted.Set()
 	assert.Equal(t, true, s.Initialized())
@@ -495,8 +500,8 @@ func TestOriginOutsideRetention(t *testing.T) {
 	bdb := dbtest.SetupDB(t)
 	genesis := time.Unix(0, 0)
 	secsPerEpoch := params.BeaconConfig().SecondsPerSlot * uint64(params.BeaconConfig().SlotsPerEpoch)
-	retentionPeriod := time.Second * time.Duration(uint64(params.BeaconConfig().MinEpochsForBlobsSidecarsRequest+1)*secsPerEpoch)
-	outsideRetention := genesis.Add(retentionPeriod)
+	retentionDuration := time.Second * time.Duration(uint64(params.BeaconConfig().MinEpochsForBlobsSidecarsRequest+1)*secsPerEpoch)
+	outsideRetention := genesis.Add(retentionDuration)
 	now := func() time.Time {
 		return outsideRetention
 	}
@@ -509,5 +514,6 @@ func TestOriginOutsideRetention(t *testing.T) {
 	require.NoError(t, concreteDB.SaveOriginCheckpointBlockRoot(ctx, blk.Root()))
 	// This would break due to missing service dependencies, but will return nil fast due to being outside retention.
 	require.Equal(t, false, params.WithinDAPeriod(slots.ToEpoch(blk.Block().Slot()), slots.ToEpoch(clock.CurrentSlot())))
-	require.NoError(t, s.fetchOriginBlobs([]peer.ID{}))
+
+	require.NoError(t, s.fetchOriginSidecars([]peer.ID{}))
 }