Networks in Init message

And receive other peer's network, disconnect if incompatible.

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

@@ -101,7 +101,7 @@ class Peer(val nodeParams: NodeParams, remoteNodeId: PublicKey, authenticator: A
       transport ! TransportHandler.Listener(self)
       context watch transport
       val localInit = nodeParams.overrideFeatures.get(remoteNodeId) match {
-        case Some(f) => wire.Init(f)
+        case Some(f) => wire.Init(f, TlvStream(InitTlv.Networks(nodeParams.chainHash :: Nil)))
         case None =>
           // Eclair-mobile thinks feature bit 15 (payment_secret) is gossip_queries_ex which creates issues, so we mask
           // off basic_mpp and payment_secret. As long as they're provided in the invoice it's not an issue.
@@ -116,7 +116,7 @@ class Peer(val nodeParams: NodeParams, remoteNodeId: PublicKey, authenticator: A
             // ... and leave the others untouched
             case (value, _) => value
           }).reverse.bytes.dropWhile(_ == 0)
-          wire.Init(tweakedFeatures)
+          wire.Init(tweakedFeatures, TlvStream(InitTlv.Networks(nodeParams.chainHash :: Nil)))
       }
       log.info(s"using features=${localInit.features.toBin}")
       transport ! localInit
@@ -148,9 +148,19 @@ class Peer(val nodeParams: NodeParams, remoteNodeId: PublicKey, authenticator: A
     case Event(remoteInit: wire.Init, d: InitializingData) =>
       d.transport ! TransportHandler.ReadAck(remoteInit)
 
-      log.info(s"peer is using features=${remoteInit.features.toBin}")
+      log.info(s"peer is using features=${remoteInit.features.toBin}, network=${remoteInit.networks}")
 
-      if (Features.areSupported(remoteInit.features)) {
+      if (remoteInit.networks.nonEmpty && !remoteInit.networks.contains(nodeParams.chainHash)) {
+        log.warning(s"incompatible networks (${remoteInit.networks}), disconnecting")
+        d.origin_opt.foreach(origin => origin ! Status.Failure(new RuntimeException("incompatible networks")))
+        d.transport ! PoisonPill
+        stay
+      } else if (!Features.areSupported(remoteInit.features)) {
+        log.warning("incompatible features, disconnecting")
+        d.origin_opt.foreach(origin => origin ! Status.Failure(new RuntimeException("incompatible features")))
+        d.transport ! PoisonPill
+        stay
+      } else {
         d.origin_opt.foreach(origin => origin ! "connected")
 
         def localHasFeature(f: Feature): Boolean = Features.hasFeature(d.localInit.features, f)
@@ -181,11 +191,6 @@ class Peer(val nodeParams: NodeParams, remoteNodeId: PublicKey, authenticator: A
         val rebroadcastDelay = Random.nextInt(nodeParams.routerConf.routerBroadcastInterval.toSeconds.toInt).seconds
         log.info(s"rebroadcast will be delayed by $rebroadcastDelay")
         goto(CONNECTED) using ConnectedData(d.address_opt, d.transport, d.localInit, remoteInit, d.channels.map { case (k: ChannelId, v) => (k, v) }, rebroadcastDelay) forMax (30 seconds) // forMax will trigger a StateTimeout
-      } else {
-        log.warning(s"incompatible features, disconnecting")
-        d.origin_opt.foreach(origin => origin ! Status.Failure(new RuntimeException("incompatible features")))
-        d.transport ! PoisonPill
-        stay
       }
 
     case Event(Authenticator.Authenticated(connection, _, _, _, _, origin_opt), _) =>

eclair-core/src/main/scala/fr/acinq/eclair/wire/InitTlv.scala

@@ -40,10 +40,6 @@ object InitTlvCodecs {
 
   import InitTlv._
 
-  // TODO:
-  //  * Send the chainHash from nodeParams when creating Init
-  //  * Add logic to Peer.scala to fail connections to others that don't offer my chainHash
-
   private val networks: Codec[Networks] = variableSizeBytesLong(varintoverflow, list(bytes32)).as[Networks]
 
   val initTlvCodec = TlvCodecs.tlvStream(discriminated[InitTlv].by(varint)

eclair-core/src/test/scala/fr/acinq/eclair/io/PeerSpec.scala

@@ -21,6 +21,7 @@ import java.net.{Inet4Address, InetAddress, InetSocketAddress, ServerSocket}
 import akka.actor.FSM.{CurrentState, SubscribeTransitionCallBack, Transition}
 import akka.actor.{ActorRef, PoisonPill}
 import akka.testkit.{TestFSMRef, TestProbe}
+import fr.acinq.bitcoin.Block
 import fr.acinq.bitcoin.Crypto.PublicKey
 import fr.acinq.eclair.TestConstants._
 import fr.acinq.eclair._
@@ -31,7 +32,7 @@ import fr.acinq.eclair.crypto.TransportHandler
 import fr.acinq.eclair.io.Peer._
 import fr.acinq.eclair.router.RoutingSyncSpec.makeFakeRoutingInfo
 import fr.acinq.eclair.router.{Rebroadcast, RoutingSyncSpec, SendChannelQuery}
-import fr.acinq.eclair.wire.{ChannelCodecsSpec, Color, EncodedShortChannelIds, EncodingType, Error, IPv4, LightningMessageCodecs, NodeAddress, NodeAnnouncement, Ping, Pong, QueryShortChannelIds, TlvStream}
+import fr.acinq.eclair.wire.{ChannelCodecsSpec, Color, EncodedShortChannelIds, EncodingType, Error, IPv4, InitTlv, LightningMessageCodecs, NodeAddress, NodeAnnouncement, Ping, Pong, QueryShortChannelIds, TlvStream}
 import org.scalatest.{Outcome, Tag}
 import scodec.bits.{ByteVector, _}
 
@@ -81,7 +82,8 @@ class PeerSpec extends TestkitBaseClass with StateTestsHelperMethods {
     probe.send(peer, Peer.Init(None, channels))
     authenticator.send(peer, Authenticator.Authenticated(connection.ref, transport.ref, remoteNodeId, fakeIPAddress.socketAddress, outgoing = true, None))
     transport.expectMsgType[TransportHandler.Listener]
-    transport.expectMsgType[wire.Init]
+    val localInit = transport.expectMsgType[wire.Init]
+    assert(localInit.networks === List(Block.RegtestGenesisBlock.hash))
     transport.send(peer, remoteInit)
     transport.expectMsgType[TransportHandler.ReadAck]
     if (expectSync) {
@@ -255,6 +257,19 @@ class PeerSpec extends TestkitBaseClass with StateTestsHelperMethods {
       assert(init.features === sentFeatures.bytes)
     }
   }
+
+  test("disconnect if incompatible networks") { f =>
+    import f._
+    val probe = TestProbe()
+    probe.watch(transport.ref)
+    probe.send(peer, Peer.Init(None, Set.empty))
+    authenticator.send(peer, Authenticator.Authenticated(connection.ref, transport.ref, remoteNodeId, new InetSocketAddress("1.2.3.4", 42000), outgoing = true, None))
+    transport.expectMsgType[TransportHandler.Listener]
+    transport.expectMsgType[wire.Init]
+    transport.send(peer, wire.Init(Bob.nodeParams.features, TlvStream(InitTlv.Networks(Block.LivenetGenesisBlock.hash :: Block.SegnetGenesisBlock.hash :: Nil))))
+    transport.expectMsgType[TransportHandler.ReadAck]
+    probe.expectTerminated(transport.ref)
+  }
 
   test("handle disconnect in status INITIALIZING") { f =>
     import f._