Allow broadcasting "ignored" gossip messages

Validator clients such as Vouch can be configured to work with multiple
beacon nodes simultaneously. In this configuration, the validator client
will try to broadcast the gossip messages through each of the connected
beacon nodes which may lead to a situation where some of the nodes see a
message arriving from the network before it arrives through the REST API.

This should not be considered an error and the beacon node should still
broadcast the message as the intented purpose of the Vouch strategy is
to ensure that the message will reach as many peers as possible.

beacon_chain/validators/validator_duties.nim

@@ -179,6 +179,17 @@ proc isSynced*(node: BeaconNode, head: BlockRef): bool =
   else:
     true
 
+func isGoodForSending(validationResult: ValidationRes): bool =
+  # Validator clients such as Vouch can be configured to work with multiple
+  # beacon nodes simultaneously. In this configuration, the validator client
+  # will try to broadcast the gossip messages through each of the connected
+  # beacon nodes which may lead to a situation where some of the nodes see a
+  # message arriving from the network before it arrives through the REST API.
+  # This should not be considered an error and the beacon node should still
+  # broadcast the message as the intented purpose of the Vouch strategy is
+  # to ensure that the message will reach as many peers as possible.
+  validationResult.isOk() or validationResult.error[0] == ValidationResult.Ignore
+
 proc sendAttestation*(
     node: BeaconNode, attestation: Attestation,
     subnet_id: SubnetId, checkSignature: bool): Future[SendResult] {.async.} =
@@ -190,7 +201,7 @@ proc sendAttestation*(
     attestation, subnet_id, checkSignature)
 
   return
-    if res.isOk():
+    if res.isGoodForSending:
       node.network.broadcastAttestation(subnet_id, attestation)
       beacon_attestations_sent.inc()
       if not(isNil(node.onAttestationSent)):
@@ -211,9 +222,9 @@ proc sendSyncCommitteeMessage*(
   # message pool. Notably, although libp2p calls the data handler for
   # any subscription on the subnet topic, it does not perform validation.
   let res = node.processor.syncCommitteeMessageValidator(msg, subcommitteeIdx,
-                                                     checkSignature)
+                                                         checkSignature)
   return
-    if res.isOk():
+    if res.isGoodForSending:
       node.network.broadcastSyncCommitteeMessage(msg, subcommitteeIdx)
       beacon_sync_committee_messages_sent.inc()
       SendResult.ok()
@@ -312,7 +323,7 @@ proc sendSyncCommitteeContribution*(
     msg, checkSignature)
 
   return
-    if res.isOk():
+    if res.isGoodForSending:
       node.network.broadcastSignedContributionAndProof(msg)
       beacon_sync_committee_contributions_sent.inc()
       ok()
@@ -1094,7 +1105,7 @@ proc sendAggregateAndProof*(node: BeaconNode,
   # REST/JSON-RPC API helper procedure.
   let res = await node.processor.aggregateValidator(proof)
   return
-    if res.isOk():
+    if res.isGoodForSending:
       node.network.broadcastAggregateAndProof(proof)
 
       notice "Aggregated attestation sent",
@@ -1113,7 +1124,7 @@ proc sendVoluntaryExit*(node: BeaconNode,
                         exit: SignedVoluntaryExit): SendResult =
   # REST/JSON-RPC API helper procedure.
   let res = node.processor[].voluntaryExitValidator(exit)
-  if res.isOk():
+  if res.isGoodForSending:
     node.network.broadcastVoluntaryExit(exit)
     ok()
   else:
@@ -1125,7 +1136,7 @@ proc sendAttesterSlashing*(node: BeaconNode,
                            slashing: AttesterSlashing): SendResult =
   # REST/JSON-RPC API helper procedure.
   let res = node.processor[].attesterSlashingValidator(slashing)
-  if res.isOk():
+  if res.isGoodForSending:
     node.network.broadcastAttesterSlashing(slashing)
     ok()
   else:
@@ -1137,7 +1148,7 @@ proc sendProposerSlashing*(node: BeaconNode,
                            slashing: ProposerSlashing): SendResult =
   # REST/JSON-RPC API helper procedure.
   let res = node.processor[].proposerSlashingValidator(slashing)
-  if res.isOk():
+  if res.isGoodForSending:
     node.network.broadcastProposerSlashing(slashing)
     ok()
   else: