Optimistic sync: prysm validator rpcs

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

@@ -37,6 +37,18 @@ func (vs *Server) GetAttestationData(ctx context.Context, req *ethpb.Attestation
 		return nil, status.Errorf(codes.Unavailable, "Syncing to latest head, not ready to respond")
 	}
 
+	optimistic, err := vs.HeadFetcher.IsOptimistic(ctx)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "Could not determine if the node is a optimistic node: %v", err)
+	}
+	if optimistic {
+		root, err := vs.HeadFetcher.HeadRoot(ctx)
+		if err != nil {
+			return nil, status.Errorf(codes.Internal, "Could not get head root: %v", err)
+		}
+		return nil, status.Errorf(codes.Unavailable, "The node is currently optimistic and cannot serve attestations. Head root: %#x", root)
+	}
+
 	if err := helpers.ValidateAttestationTime(req.Slot, vs.TimeFetcher.GenesisTime(),
 		params.BeaconNetworkConfig().MaximumGossipClockDisparity); err != nil {
 		return nil, status.Error(codes.InvalidArgument, fmt.Sprintf("invalid request: %v", err))

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

@@ -48,6 +48,18 @@ func (vs *Server) GetBeaconBlock(ctx context.Context, req *ethpb.BlockRequest) (
 		return &ethpb.GenericBeaconBlock{Block: &ethpb.GenericBeaconBlock_Altair{Altair: blk}}, nil
 	}
 
+	optimistic, err := vs.HeadFetcher.IsOptimistic(ctx)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "Could not determine if the node is a optimistic node: %v", err)
+	}
+	if optimistic {
+		root, err := vs.HeadFetcher.HeadRoot(ctx)
+		if err != nil {
+			return nil, status.Errorf(codes.Internal, "Could not get head root: %v", err)
+		}
+		return nil, status.Errorf(codes.Unavailable, "The node is currently optimistic and cannot serve blocks. Head root: %#x", root)
+	}
+
 	blk, err := vs.getBellatrixBeaconBlock(ctx, req)
 	if err != nil {
 		return nil, status.Errorf(codes.Internal, "Could not fetch Bellatrix beacon block: %v", err)

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

@@ -26,6 +26,13 @@ func (vs *Server) GetSyncMessageBlockRoot(
 	if err != nil {
 		return nil, status.Errorf(codes.Internal, "Could not retrieve head root: %v", err)
 	}
+	optimistic, err := vs.HeadFetcher.IsOptimistic(ctx)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "Could not determine if the node is a optimistic node: %v", err)
+	}
+	if optimistic {
+		return nil, status.Errorf(codes.Unavailable, "The node is currently optimistic and cannot serve blocks. Head root: %#x", r)
+	}
 
 	return &ethpb.SyncMessageBlockRootResponse{
 		Root: r,