From ddab82e52abc479044e792398f4f37f9ff788c02 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rados=C5=82aw=20Kapka?= <rkapka@wp.pl>
Date: Tue, 11 May 2021 19:11:34 +0200
Subject: [PATCH] Handle undiscovered peers when listing peers (#8882)

* Handle undiscovered peers when listing peers

* off by 1 fix
---
 beacon-chain/rpc/nodev1/node.go      | 17 +++++---
 beacon-chain/rpc/nodev1/node_test.go | 61 +++++++++++++++-------------
 2 files changed, 45 insertions(+), 33 deletions(-)

diff --git a/beacon-chain/rpc/nodev1/node.go b/beacon-chain/rpc/nodev1/node.go
index 3e8f4ffbd7..b2e266b938 100644
--- a/beacon-chain/rpc/nodev1/node.go
+++ b/beacon-chain/rpc/nodev1/node.go
@@ -300,9 +300,12 @@ func peerInfo(peerStatus *peers.Status, id peer.ID) (*ethpb.Peer, error) {
 	if err != nil {
 		return nil, errors.Wrap(err, "could not obtain ENR")
 	}
-	serializedEnr, err := p2p.SerializeENR(enr)
-	if err != nil {
-		return nil, errors.Wrap(err, "could not serialize ENR")
+	var serializedEnr string
+	if enr != nil {
+		serializedEnr, err = p2p.SerializeENR(enr)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not serialize ENR")
+		}
 	}
 	address, err := peerStatus.Address(id)
 	if err != nil {
@@ -318,11 +321,15 @@ func peerInfo(peerStatus *peers.Status, id peer.ID) (*ethpb.Peer, error) {
 	}
 	p := ethpb.Peer{
 		PeerId:    id.Pretty(),
-		Enr:       "enr:" + serializedEnr,
-		Address:   address.String(),
 		State:     ethpb.ConnectionState(connectionState),
 		Direction: ethpb.PeerDirection(direction),
 	}
+	if address != nil {
+		p.Address = address.String()
+	}
+	if serializedEnr != "" {
+		p.Enr = "enr:" + serializedEnr
+	}
 
 	return &p, nil
 }
diff --git a/beacon-chain/rpc/nodev1/node_test.go b/beacon-chain/rpc/nodev1/node_test.go
index fc92433d5c..3f2653bab1 100644
--- a/beacon-chain/rpc/nodev1/node_test.go
+++ b/beacon-chain/rpc/nodev1/node_test.go
@@ -212,41 +212,46 @@ func TestGetPeer(t *testing.T) {
 }
 
 func TestListPeers(t *testing.T) {
-	ids := libp2ptest.GeneratePeerIDs(8)
+	ids := libp2ptest.GeneratePeerIDs(9)
 	peerFetcher := &mockp2p.MockPeersProvider{}
 	peerFetcher.ClearPeers()
 	peerStatus := peerFetcher.Peers()
 
 	for i, id := range ids {
-		enrRecord := &enr.Record{}
-		err := enrRecord.SetSig(dummyIdentity{1}, []byte{42})
-		require.NoError(t, err)
-		enrRecord.Set(enr.IPv4{127, 0, 0, byte(i)})
-		err = enrRecord.SetSig(dummyIdentity{}, []byte{})
-		require.NoError(t, err)
-		var p2pAddr = "/ip4/127.0.0." + strconv.Itoa(i) + "/udp/30303/p2p/QmYyQSo1c1Ym7orWxLYvCrM2EmxFTANf8wXmmE7DWjhx5N"
-		p2pMultiAddr, err := ma.NewMultiaddr(p2pAddr)
-		require.NoError(t, err)
-
-		var direction network.Direction
-		if i%2 == 0 {
-			direction = network.DirInbound
+		// Make last peer undiscovered
+		if i == len(ids)-1 {
+			peerStatus.Add(nil, id, nil, network.DirUnknown)
 		} else {
-			direction = network.DirOutbound
-		}
-		peerStatus.Add(enrRecord, id, p2pMultiAddr, direction)
+			enrRecord := &enr.Record{}
+			err := enrRecord.SetSig(dummyIdentity{1}, []byte{42})
+			require.NoError(t, err)
+			enrRecord.Set(enr.IPv4{127, 0, 0, byte(i)})
+			err = enrRecord.SetSig(dummyIdentity{}, []byte{})
+			require.NoError(t, err)
+			var p2pAddr = "/ip4/127.0.0." + strconv.Itoa(i) + "/udp/30303/p2p/QmYyQSo1c1Ym7orWxLYvCrM2EmxFTANf8wXmmE7DWjhx5N"
+			p2pMultiAddr, err := ma.NewMultiaddr(p2pAddr)
+			require.NoError(t, err)
 
-		switch i {
-		case 0, 1:
-			peerStatus.SetConnectionState(id, peers.PeerConnecting)
-		case 2, 3:
-			peerStatus.SetConnectionState(id, peers.PeerConnected)
-		case 4, 5:
-			peerStatus.SetConnectionState(id, peers.PeerDisconnecting)
-		case 6, 7:
-			peerStatus.SetConnectionState(id, peers.PeerDisconnected)
-		default:
-			t.Fatalf("Failed to set connection state for peer")
+			var direction network.Direction
+			if i%2 == 0 {
+				direction = network.DirInbound
+			} else {
+				direction = network.DirOutbound
+			}
+			peerStatus.Add(enrRecord, id, p2pMultiAddr, direction)
+
+			switch i {
+			case 0, 1:
+				peerStatus.SetConnectionState(id, peers.PeerConnecting)
+			case 2, 3:
+				peerStatus.SetConnectionState(id, peers.PeerConnected)
+			case 4, 5:
+				peerStatus.SetConnectionState(id, peers.PeerDisconnecting)
+			case 6, 7:
+				peerStatus.SetConnectionState(id, peers.PeerDisconnected)
+			default:
+				t.Fatalf("Failed to set connection state for peer")
+			}
 		}
 	}