Abort incoming channel after timeout

If a remote node starts opening a channel to us and then becomes
unresponsive, we abort the channel. This is particularly useful
when they're purchasing liquidity and we've locked utxos.

eclair-core/src/main/resources/reference.conf

@@ -109,6 +109,9 @@ eclair {
         max-attempts = 5 // maximum number of RBF attempts our peer is allowed to make
         attempt-delta-blocks = 6 // minimum number of blocks between RBF attempts
       }
+      // Duration after which we abort a channel creation. If our peer seems unresponsive and doesn't complete the
+      // funding protocol in time, they're likely buggy or malicious.
+      timeout = 60 seconds
     }
 
     dust-limit-satoshis = 546

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

@@ -591,6 +591,7 @@ object NodeParams extends Logging {
         channelOpenerWhitelist = channelOpenerWhitelist,
         maxPendingChannelsPerPeer = maxPendingChannelsPerPeer,
         maxTotalPendingChannelsPrivateNodes = maxTotalPendingChannelsPrivateNodes,
+        channelFundingTimeout = FiniteDuration(config.getDuration("channel.funding.timeout").getSeconds, TimeUnit.SECONDS),
         remoteRbfLimits = Channel.RemoteRbfLimits(config.getInt("channel.funding.remote-rbf-limits.max-attempts"), config.getInt("channel.funding.remote-rbf-limits.attempt-delta-blocks")),
         quiescenceTimeout = FiniteDuration(config.getDuration("channel.quiescence-timeout").getSeconds, TimeUnit.SECONDS),
         balanceThresholds = config.getConfigList("channel.channel-update.balance-thresholds").asScala.map(conf => BalanceThreshold(Satoshi(conf.getLong("available-sat")), Satoshi(conf.getLong("max-htlc-sat")))).toSeq,
@@ -683,7 +684,7 @@ object NodeParams extends Logging {
         batchSize = config.getInt("db.revoked-htlc-info-cleaner.batch-size"),
         interval = FiniteDuration(config.getDuration("db.revoked-htlc-info-cleaner.interval").getSeconds, TimeUnit.SECONDS)
       ),
-      liquidityAdsConfig = LiquidityAds.Config(willFundRates_opt, lockUtxos = config.getBoolean("liquidity-ads.lock-utxos-during-funding")),
+      liquidityAdsConfig = LiquidityAds.Config(rates_opt = willFundRates_opt, lockUtxos = config.getBoolean("liquidity-ads.lock-utxos-during-funding")),
       peerWakeUpConfig = PeerReadyNotifier.WakeUpConfig(
         enabled = config.getBoolean("peer-wake-up.enabled"),
         timeout = FiniteDuration(config.getDuration("peer-wake-up.timeout").getSeconds, TimeUnit.SECONDS),

eclair-core/src/main/scala/fr/acinq/eclair/channel/fsm/Channel.scala

@@ -102,6 +102,7 @@ object Channel {
                          channelOpenerWhitelist: Set[PublicKey],
                          maxPendingChannelsPerPeer: Int,
                          maxTotalPendingChannelsPrivateNodes: Int,
+                         channelFundingTimeout: FiniteDuration,
                          remoteRbfLimits: RemoteRbfLimits,
                          quiescenceTimeout: FiniteDuration,
                          balanceThresholds: Seq[BalanceThreshold],

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

@@ -198,7 +198,7 @@ class Peer(val nodeParams: NodeParams,
 
       case Event(SpawnChannelInitiator(replyTo, c, channelConfig, channelType, localParams), d: ConnectedData) =>
         val channel = spawnChannel()
-        c.timeout_opt.map(openTimeout => context.system.scheduler.scheduleOnce(openTimeout.duration, channel, Channel.TickChannelOpenTimeout)(context.dispatcher))
+        context.system.scheduler.scheduleOnce(c.timeout_opt.map(_.duration).getOrElse(nodeParams.channelConf.channelFundingTimeout), channel, Channel.TickChannelOpenTimeout)(context.dispatcher)
         val dualFunded = Features.canUseFeature(d.localFeatures, d.remoteFeatures, Features.DualFunding)
         val requireConfirmedInputs = c.requireConfirmedInputsOverride_opt.getOrElse(nodeParams.channelConf.requireConfirmedInputsForDualFunding)
         val temporaryChannelId = if (dualFunded) {
@@ -252,6 +252,7 @@ class Peer(val nodeParams: NodeParams,
               stay()
             case accept: OnTheFlyFunding.ValidationResult.Accept =>
               val channel = spawnChannel()
+              context.system.scheduler.scheduleOnce(nodeParams.channelConf.channelFundingTimeout, channel, Channel.TickChannelOpenTimeout)(context.dispatcher)
               log.info(s"accepting a new channel with type=$channelType temporaryChannelId=$temporaryChannelId localParams=$localParams")
               open match {
                 case Left(open) =>

eclair-core/src/test/scala/fr/acinq/eclair/TestConstants.scala

@@ -145,6 +145,7 @@ object TestConstants {
         channelOpenerWhitelist = Set.empty,
         maxPendingChannelsPerPeer = 3,
         maxTotalPendingChannelsPrivateNodes = 99,
+        channelFundingTimeout = 30 seconds,
         remoteRbfLimits = RemoteRbfLimits(5, 0),
         quiescenceTimeout = 2 minutes,
         balanceThresholds = Nil,
@@ -323,6 +324,7 @@ object TestConstants {
         channelOpenerWhitelist = Set.empty,
         maxPendingChannelsPerPeer = 3,
         maxTotalPendingChannelsPrivateNodes = 99,
+        channelFundingTimeout = 30 seconds,
         remoteRbfLimits = RemoteRbfLimits(10, 0),
         quiescenceTimeout = 2 minutes,
         balanceThresholds = Nil,

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

@@ -28,6 +28,7 @@ import fr.acinq.eclair._
 import fr.acinq.eclair.blockchain.fee.{FeeratePerKw, FeeratesPerKw}
 import fr.acinq.eclair.blockchain.{CurrentFeerates, DummyOnChainWallet}
 import fr.acinq.eclair.channel._
+import fr.acinq.eclair.channel.fsm.Channel
 import fr.acinq.eclair.channel.states.ChannelStateTestsTags
 import fr.acinq.eclair.io.Peer._
 import fr.acinq.eclair.message.OnionMessages.{Recipient, buildMessage}
@@ -76,6 +77,7 @@ class PeerSpec extends FixtureSpec {
       .modify(_.features).setToIf(testData.tags.contains(ChannelStateTestsTags.DualFunding))(Features(StaticRemoteKey -> Optional, AnchorOutputs -> Optional, AnchorOutputsZeroFeeHtlcTx -> Optional, DualFunding -> Optional))
       .modify(_.channelConf.maxHtlcValueInFlightMsat).setToIf(testData.tags.contains("max-htlc-value-in-flight-percent"))(100_000_000 msat)
       .modify(_.channelConf.maxHtlcValueInFlightPercent).setToIf(testData.tags.contains("max-htlc-value-in-flight-percent"))(25)
+      .modify(_.channelConf.channelFundingTimeout).setToIf(testData.tags.contains("channel_funding_timeout"))(100 millis)
       .modify(_.autoReconnect).setToIf(testData.tags.contains("auto_reconnect"))(true)
 
     if (testData.tags.contains("with_node_announcement")) {
@@ -718,6 +720,17 @@ class PeerSpec extends FixtureSpec {
     assert(channelAborted.channelId == open.temporaryChannelId)
   }
 
+  test("abort incoming channel after funding timeout", Tag(ChannelStateTestsTags.DualFunding), Tag("channel_funding_timeout")) { f =>
+    import f._
+
+    connect(remoteNodeId, peer, peerConnection, switchboard, remoteInit = protocol.Init(Features(StaticRemoteKey -> Optional, AnchorOutputsZeroFeeHtlcTx -> Optional, DualFunding -> Optional)))
+    val open = createOpenDualFundedChannelMessage()
+    peerConnection.send(peer, open)
+    assert(channel.expectMsgType[INPUT_INIT_CHANNEL_NON_INITIATOR].dualFunded)
+    channel.expectMsg(open)
+    channel.expectMsg(Channel.TickChannelOpenTimeout)
+  }
+
   test("kill peer with no channels if connection dies before receiving `ConnectionReady`") { f =>
     import f._
     val probe = TestProbe()