Merge pull request #3338 from g11tech/update-max-blobs-limit-mainnet

Update block's `blob_kzg_commitments` size limit to MAX_BLOB_COMMITMENTS_PER_BLOCK (4096)

presets/mainnet/deneb.yaml

@@ -4,5 +4,7 @@
 # ---------------------------------------------------------------
 # `uint64(4096)`
 FIELD_ELEMENTS_PER_BLOB: 4096
+# `uint64(2**12)` (= 4096)
+MAX_BLOB_COMMITMENTS_PER_BLOCK: 4096
 # `uint64(2**2)` (= 4)
 MAX_BLOBS_PER_BLOCK: 4

presets/minimal/deneb.yaml

@@ -4,5 +4,7 @@
 # ---------------------------------------------------------------
 # [customized]
 FIELD_ELEMENTS_PER_BLOB: 4
+# [customized]
+MAX_BLOB_COMMITMENTS_PER_BLOCK: 16
 # `uint64(2**2)` (= 4)
 MAX_BLOBS_PER_BLOCK: 4

specs/_features/eip6110/beacon-chain.md

@@ -244,6 +244,8 @@ def process_execution_payload(state: BeaconState, body: BeaconBlockBody, executi
     assert payload.prev_randao == get_randao_mix(state, get_current_epoch(state))
     # Verify timestamp
     assert payload.timestamp == compute_timestamp_at_slot(state, state.slot)
+    # Verify commitments are under limit
+    assert len(body.blob_kzg_commitments) <= MAX_BLOBS_PER_BLOCK
     # Verify the execution payload is valid
     versioned_hashes = [kzg_commitment_to_versioned_hash(commitment) for commitment in body.blob_kzg_commitments]
     assert execution_engine.verify_and_notify_new_payload(

specs/deneb/beacon-chain.md

@@ -43,6 +43,8 @@
 
 This upgrade adds blobs to the beacon chain as part of Deneb. This is an extension of the Capella upgrade.
 
+The blob transactions are packed into the execution payload by the EL/builder with their corresponding blobs being independently transmitted and are limited by `MAX_DATA_GAS_PER_BLOCK // DATA_GAS_PER_BLOB`. However the CL limit is independently defined by `MAX_BLOBS_PER_BLOCK`.
+
 ## Custom types
 
 | Name | SSZ equivalent | Description |
@@ -71,7 +73,8 @@ This upgrade adds blobs to the beacon chain as part of Deneb. This is an extensi
 
 | Name | Value |
 | - | - |
-| `MAX_BLOBS_PER_BLOCK` | `uint64(2**2)` (= 4) |
+| `MAX_BLOB_COMMITMENTS_PER_BLOCK` | `uint64(2**12)` (= 4096) | hardfork independent fixed theoretical limit same as `LIMIT_BLOBS_PER_TX` (see EIP 4844) |
+| `MAX_BLOBS_PER_BLOCK`            | `uint64(2**2)` (= 4)     | Maximum number of blobs in a single block limited by `MAX_BLOB_COMMITMENTS_PER_BLOCK` |
 
 ## Configuration
 
@@ -99,7 +102,7 @@ class BeaconBlockBody(Container):
     # Execution
     execution_payload: ExecutionPayload  # [Modified in Deneb]
     bls_to_execution_changes: List[SignedBLSToExecutionChange, MAX_BLS_TO_EXECUTION_CHANGES]
-    blob_kzg_commitments: List[KZGCommitment, MAX_BLOBS_PER_BLOCK]  # [New in Deneb]
+    blob_kzg_commitments: List[KZGCommitment, MAX_BLOB_COMMITMENTS_PER_BLOCK]  # [New in Deneb]
 ```
 
 #### `ExecutionPayload`
@@ -226,8 +229,12 @@ def process_execution_payload(state: BeaconState, body: BeaconBlockBody, executi
     assert payload.prev_randao == get_randao_mix(state, get_current_epoch(state))
     # Verify timestamp
     assert payload.timestamp == compute_timestamp_at_slot(state, state.slot)
+
+    # [New in Deneb] Verify commitments are under limit
+    assert len(body.blob_kzg_commitments) <= MAX_BLOBS_PER_BLOCK
+
     # Verify the execution payload is valid
-    # [Modified in Deneb]
+    # [Modified in Deneb] Pass `versioned_hashes` to Engine API 
     versioned_hashes = [kzg_commitment_to_versioned_hash(commitment) for commitment in body.blob_kzg_commitments]
     assert execution_engine.verify_and_notify_new_payload(
         NewPayloadRequest(execution_payload=payload, versioned_hashes=versioned_hashes)

specs/deneb/p2p-interface.md

@@ -117,6 +117,11 @@ Deneb introduces new global topics for blob sidecars.
 
 The *type* of the payload of this topic changes to the (modified) `SignedBeaconBlock` found in deneb.
 
+New validation:
+
+- _[REJECT]_ The length of KZG commitments is less than or equal to the limitation defined in Consensus Layer --
+  i.e. validate that `len(body.signed_beacon_block.message.blob_kzg_commitments) <= MAX_BLOBS_PER_BLOCK`
+
 ###### `blob_sidecar_{subnet_id}`
 
 This topic is used to propagate signed blob sidecars, where each blob index maps to some `subnet_id`.

tests/core/pyspec/eth2spec/test/deneb/block_processing/test_process_execution_payload.py

@@ -190,3 +190,16 @@ def test_invalid_correct_input__execution_invalid(spec, state):
 
     yield from run_execution_payload_processing(spec, state, execution_payload, blob_kzg_commitments,
                                                 valid=False, execution_valid=False)
+
+
+@with_deneb_and_later
+@spec_state_test
+def test_invalid_exceed_max_blobs_per_block(spec, state):
+    execution_payload = build_empty_execution_payload(spec, state)
+
+    opaque_tx, _, blob_kzg_commitments, _ = get_sample_opaque_tx(spec, blob_count=spec.MAX_BLOBS_PER_BLOCK + 1)
+
+    execution_payload.transactions = [opaque_tx]
+    execution_payload.block_hash = compute_el_block_hash(spec, execution_payload)
+
+    yield from run_execution_payload_processing(spec, state, execution_payload, blob_kzg_commitments, valid=False)

tests/core/pyspec/eth2spec/test/deneb/sanity/test_blocks.py

@@ -16,7 +16,7 @@ from eth2spec.test.helpers.sharding import (
 )
 
 
-def run_block_with_blobs(spec, state, blob_count, excess_data_gas=1):
+def run_block_with_blobs(spec, state, blob_count, excess_data_gas=1, valid=True):
     yield 'pre', state
 
     block = build_empty_block_for_next_slot(spec, state)
@@ -25,10 +25,16 @@ def run_block_with_blobs(spec, state, blob_count, excess_data_gas=1):
     block.body.execution_payload.transactions = [opaque_tx]
     block.body.execution_payload.excess_data_gas = excess_data_gas
     block.body.execution_payload.block_hash = compute_el_block_hash(spec, block.body.execution_payload)
-    signed_block = state_transition_and_sign_block(spec, state, block)
+
+    print(len(block.body.blob_kzg_commitments))
+
+    if valid:
+        signed_block = state_transition_and_sign_block(spec, state, block)
+    else:
+        signed_block = state_transition_and_sign_block(spec, state, block, expect_fail=True)
 
     yield 'blocks', [signed_block]
-    yield 'post', state
+    yield 'post', state if valid else None
 
 
 @with_deneb_and_later
@@ -45,5 +51,11 @@ def test_one_blob(spec, state):
 
 @with_deneb_and_later
 @spec_state_test
-def test_max_blobs(spec, state):
+def test_max_blobs_per_block(spec, state):
     yield from run_block_with_blobs(spec, state, blob_count=spec.MAX_BLOBS_PER_BLOCK)
+
+
+@with_deneb_and_later
+@spec_state_test
+def test_invalid_exceed_max_blobs_per_block(spec, state):
+    yield from run_block_with_blobs(spec, state, blob_count=spec.MAX_BLOBS_PER_BLOCK + 1, valid=False)

tests/core/pyspec/eth2spec/test/deneb/unittests/test_config_invariants.py

@@ -0,0 +1,12 @@
+from eth2spec.test.context import (
+    single_phase,
+    spec_test,
+    with_deneb_and_later,
+)
+
+
+@with_deneb_and_later
+@spec_test
+@single_phase
+def test_length(spec):
+    assert spec.MAX_BLOBS_PER_BLOCK < spec.MAX_BLOB_COMMITMENTS_PER_BLOCK