Add wake-up step to channel and message relay

We allow relaying data to contain a wallet `node_id` instead of an scid.
When that's the case, we start by waking up that wallet node before we
try relaying onion messages or payments.

Author: t-bast

eclair-core/src/main/scala/fr/acinq/eclair/NodeParams.scala

@@ -87,7 +87,8 @@ case class NodeParams(nodeKeyManager: NodeKeyManager,
                       blockchainWatchdogSources: Seq[String],
                       onionMessageConfig: OnionMessageConfig,
                       purgeInvoicesInterval: Option[FiniteDuration],
-                      revokedHtlcInfoCleanerConfig: RevokedHtlcInfoCleaner.Config) {
+                      revokedHtlcInfoCleanerConfig: RevokedHtlcInfoCleaner.Config,
+                      wakeUpTimeout: FiniteDuration) {
   val privateKey: Crypto.PrivateKey = nodeKeyManager.nodeKey.privateKey
 
   val nodeId: PublicKey = nodeKeyManager.nodeId
@@ -610,7 +611,8 @@ object NodeParams extends Logging {
       revokedHtlcInfoCleanerConfig = RevokedHtlcInfoCleaner.Config(
         batchSize = config.getInt("db.revoked-htlc-info-cleaner.batch-size"),
         interval = FiniteDuration(config.getDuration("db.revoked-htlc-info-cleaner.interval").getSeconds, TimeUnit.SECONDS)
-      )
+      ),
+      wakeUpTimeout = 30 seconds,
     )
   }
 }

eclair-core/src/main/scala/fr/acinq/eclair/io/MessageRelay.scala

@@ -16,10 +16,10 @@
 
 package fr.acinq.eclair.io
 
-import akka.actor.typed.Behavior
 import akka.actor.typed.eventstream.EventStream
 import akka.actor.typed.scaladsl.adapter.TypedActorRefOps
 import akka.actor.typed.scaladsl.{ActorContext, Behaviors}
+import akka.actor.typed.{Behavior, SupervisorStrategy}
 import akka.actor.{ActorRef, typed}
 import fr.acinq.bitcoin.scalacompat.ByteVector32
 import fr.acinq.bitcoin.scalacompat.Crypto.PublicKey
@@ -32,6 +32,8 @@ import fr.acinq.eclair.router.Router
 import fr.acinq.eclair.wire.protocol.OnionMessage
 import fr.acinq.eclair.{EncodedNodeId, NodeParams, ShortChannelId}
 
+import scala.concurrent.duration.DurationInt
+
 object MessageRelay {
   // @formatter:off
   sealed trait Command
@@ -42,29 +44,18 @@ object MessageRelay {
                           policy: RelayPolicy,
                           replyTo_opt: Option[typed.ActorRef[Status]]) extends Command
   case class WrappedPeerInfo(peerInfo: PeerInfoResponse) extends Command
-  case class WrappedConnectionResult(result: PeerConnection.ConnectionResult) extends Command
-  case class WrappedOptionalNodeId(nodeId_opt: Option[PublicKey]) extends Command
+  private case class WrappedConnectionResult(result: PeerConnection.ConnectionResult) extends Command
+  private case class WrappedOptionalNodeId(nodeId_opt: Option[PublicKey]) extends Command
+  private case class WrappedPeerReadyResult(result: PeerReadyNotifier.Result) extends Command
 
-  sealed trait Status {
-    val messageId: ByteVector32
-  }
+  sealed trait Status { val messageId: ByteVector32 }
   case class Sent(messageId: ByteVector32) extends Status
   sealed trait Failure extends Status
-  case class AgainstPolicy(messageId: ByteVector32, policy: RelayPolicy) extends Failure {
-    override def toString: String = s"Relay prevented by policy $policy"
-  }
-  case class ConnectionFailure(messageId: ByteVector32, failure: PeerConnection.ConnectionResult.Failure) extends Failure {
-    override def toString: String = s"Can't connect to peer: ${failure.toString}"
-  }
-  case class Disconnected(messageId: ByteVector32) extends Failure {
-    override def toString: String = "Peer is not connected"
-  }
-  case class UnknownChannel(messageId: ByteVector32, channelId: ShortChannelId) extends Failure {
-    override def toString: String = s"Unknown channel: $channelId"
-  }
-  case class DroppedMessage(messageId: ByteVector32, reason: DropReason) extends Failure {
-    override def toString: String = s"Message dropped: $reason"
-  }
+  case class AgainstPolicy(messageId: ByteVector32, policy: RelayPolicy) extends Failure { override def toString: String = s"Relay prevented by policy $policy" }
+  case class ConnectionFailure(messageId: ByteVector32, failure: PeerConnection.ConnectionResult.Failure) extends Failure { override def toString: String = s"Can't connect to peer: ${failure.toString}" }
+  case class Disconnected(messageId: ByteVector32) extends Failure { override def toString: String = "Peer is not connected" }
+  case class UnknownChannel(messageId: ByteVector32, channelId: ShortChannelId) extends Failure { override def toString: String = s"Unknown channel: $channelId" }
+  case class DroppedMessage(messageId: ByteVector32, reason: DropReason) extends Failure { override def toString: String = s"Message dropped: $reason" }
 
   sealed trait RelayPolicy
   case object RelayChannelsOnly extends RelayPolicy
@@ -100,15 +91,15 @@ private class MessageRelay(nodeParams: NodeParams,
   def queryNextNodeId(msg: OnionMessage, nextNode: Either[ShortChannelId, EncodedNodeId]): Behavior[Command] = {
     nextNode match {
       case Left(outgoingChannelId) if outgoingChannelId == ShortChannelId.toSelf =>
-        withNextNodeId(msg, nodeParams.nodeId)
+        withNextNodeId(msg, EncodedNodeId.WithPublicKey.Plain(nodeParams.nodeId))
       case Left(outgoingChannelId) =>
         register ! Register.GetNextNodeId(context.messageAdapter(WrappedOptionalNodeId), outgoingChannelId)
         waitForNextNodeId(msg, outgoingChannelId)
       case Right(EncodedNodeId.ShortChannelIdDir(isNode1, scid)) =>
         router ! Router.GetNodeId(context.messageAdapter(WrappedOptionalNodeId), scid, isNode1)
         waitForNextNodeId(msg, scid)
       case Right(encodedNodeId: EncodedNodeId.WithPublicKey) =>
-        withNextNodeId(msg, encodedNodeId.publicKey)
+        withNextNodeId(msg, encodedNodeId)
     }
   }
 
@@ -118,33 +109,39 @@ private class MessageRelay(nodeParams: NodeParams,
         replyTo_opt.foreach(_ ! UnknownChannel(messageId, channelId))
         Behaviors.stopped
       case WrappedOptionalNodeId(Some(nextNodeId)) =>
-        withNextNodeId(msg, nextNodeId)
+        withNextNodeId(msg, EncodedNodeId.WithPublicKey.Plain(nextNodeId))
     }
   }
 
-  private def withNextNodeId(msg: OnionMessage, nextNodeId: PublicKey): Behavior[Command] = {
-    if (nextNodeId == nodeParams.nodeId) {
-      OnionMessages.process(nodeParams.privateKey, msg) match {
-        case OnionMessages.DropMessage(reason) =>
-          replyTo_opt.foreach(_ ! DroppedMessage(messageId, reason))
-          Behaviors.stopped
-        case OnionMessages.SendMessage(nextNode, nextMessage) =>
-          // We need to repeat the process until we identify the (real) next node, or find out that we're the recipient.
-          queryNextNodeId(nextMessage, nextNode)
-        case received: OnionMessages.ReceiveMessage =>
-          context.system.eventStream ! EventStream.Publish(received)
-          replyTo_opt.foreach(_ ! Sent(messageId))
-          Behaviors.stopped
-      }
-    } else {
-      policy match {
-        case RelayChannelsOnly =>
-          switchboard ! GetPeerInfo(context.messageAdapter(WrappedPeerInfo), prevNodeId)
-          waitForPreviousPeerForPolicyCheck(msg, nextNodeId)
-        case RelayAll =>
-          switchboard ! Peer.Connect(nextNodeId, None, context.messageAdapter(WrappedConnectionResult).toClassic, isPersistent = false)
-          waitForConnection(msg)
-      }
+  private def withNextNodeId(msg: OnionMessage, nextNodeId: EncodedNodeId.WithPublicKey): Behavior[Command] = {
+    nextNodeId match {
+      case EncodedNodeId.WithPublicKey.Plain(nodeId) if nodeId == nodeParams.nodeId =>
+        OnionMessages.process(nodeParams.privateKey, msg) match {
+          case OnionMessages.DropMessage(reason) =>
+            replyTo_opt.foreach(_ ! DroppedMessage(messageId, reason))
+            Behaviors.stopped
+          case OnionMessages.SendMessage(nextNode, nextMessage) =>
+            // We need to repeat the process until we identify the (real) next node, or find out that we're the recipient.
+            queryNextNodeId(nextMessage, nextNode)
+          case received: OnionMessages.ReceiveMessage =>
+            context.system.eventStream ! EventStream.Publish(received)
+            replyTo_opt.foreach(_ ! Sent(messageId))
+            Behaviors.stopped
+        }
+      case EncodedNodeId.WithPublicKey.Plain(nodeId) =>
+        policy match {
+          case RelayChannelsOnly =>
+            switchboard ! GetPeerInfo(context.messageAdapter(WrappedPeerInfo), prevNodeId)
+            waitForPreviousPeerForPolicyCheck(msg, nodeId)
+          case RelayAll =>
+            switchboard ! Peer.Connect(nodeId, None, context.messageAdapter(WrappedConnectionResult).toClassic, isPersistent = false)
+            waitForConnection(msg)
+        }
+      case EncodedNodeId.WithPublicKey.Wallet(nodeId) =>
+        context.log.info("trying to wake up next peer to relay onion message (nodeId={})", nodeId)
+        val notifier = context.spawnAnonymous(Behaviors.supervise(PeerReadyNotifier(nodeId, timeout_opt = Some(Left(nodeParams.wakeUpTimeout)))).onFailure(SupervisorStrategy.stop))
+        notifier ! PeerReadyNotifier.NotifyWhenPeerReady(context.messageAdapter(WrappedPeerReadyResult))
+        waitForWalletNodeUp(msg)
     }
   }
 
@@ -180,4 +177,15 @@ private class MessageRelay(nodeParams: NodeParams,
         Behaviors.stopped
     }
   }
+
+  private def waitForWalletNodeUp(msg: OnionMessage): Behavior[Command] = {
+    Behaviors.receiveMessagePartial {
+      case WrappedPeerReadyResult(r: PeerReadyNotifier.PeerReady) =>
+        r.peer ! Peer.RelayOnionMessage(messageId, msg, replyTo_opt)
+        Behaviors.stopped
+      case WrappedPeerReadyResult(_: PeerReadyNotifier.PeerUnavailable) =>
+        replyTo_opt.foreach(_ ! Disconnected(messageId))
+        Behaviors.stopped
+    }
+  }
 }

eclair-core/src/main/scala/fr/acinq/eclair/io/PeerReadyNotifier.scala

@@ -83,7 +83,7 @@ object PeerReadyNotifier {
       case WrappedListing(Switchboard.SwitchboardServiceKey.Listing(listings)) =>
         listings.headOption match {
           case Some(switchboard) =>
-              waitForPeerConnected(replyTo, remoteNodeId, switchboard, context, timers)
+            waitForPeerConnected(replyTo, remoteNodeId, switchboard, context, timers)
           case None =>
             context.log.error("no switchboard found")
             replyTo ! PeerUnavailable(remoteNodeId)

eclair-core/src/main/scala/fr/acinq/eclair/payment/Monitoring.scala

@@ -115,6 +115,7 @@ object Monitoring {
     val Failure = "failure"
 
     object FailureType {
+      val WakeUp = "WakeUp"
       val Remote = "Remote"
       val Malformed = "MalformedHtlc"
 

eclair-core/src/main/scala/fr/acinq/eclair/payment/PaymentPacket.scala

@@ -128,7 +128,7 @@ object IncomingPaymentPacket {
             decryptEncryptedRecipientData(add, privateKey, payload, encrypted.data).flatMap {
               case DecodedEncryptedRecipientData(blindedPayload, nextBlinding) =>
                 validateBlindedChannelRelayPayload(add, payload, blindedPayload, nextBlinding, nextPacket).flatMap {
-                  case ChannelRelayPacket(_, payload, nextPacket) if payload.outgoingChannelId == ShortChannelId.toSelf =>
+                  case ChannelRelayPacket(_, payload, nextPacket) if payload.outgoing == Right(ShortChannelId.toSelf) =>
                     decrypt(add.copy(onionRoutingPacket = nextPacket, tlvStream = add.tlvStream.copy(records = Set(UpdateAddHtlcTlv.BlindingPoint(nextBlinding)))), privateKey, features)
                   case relayPacket => Right(relayPacket)
                 }