Increase default max-cltv value (#2677)

LND and CLN already use 2016 blocks. The network is generally raising the
values of `cltv_expiry_delta` to account for high on-chain fees, so we'll
need to allow longer maximum deltas to avoid rejecting payments.

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

@@ -125,6 +125,7 @@ eclair {
     max-to-local-delay-blocks = 2016 // maximum number of blocks that we are ready to accept for our own delayed outputs (2016 ~ 2 weeks)
     mindepth-blocks = 3
     expiry-delta-blocks = 144
+    max-expiry-delta-blocks = 2016 // we won't forward HTLCs with timeouts greater than this delta
     // When we receive the preimage for an HTLC and want to fulfill it but the upstream peer stops responding, we want to
     // avoid letting its HTLC-timeout transaction become enforceable on-chain (otherwise there is a race condition between
     // our HTLC-success and their HTLC-timeout).
@@ -312,7 +313,7 @@ eclair {
 
         boundaries {
           max-route-length = 6         // max route length for the 'first pass', if none is found then a second pass is made with no limit
-          max-cltv = 1008              // max acceptable cltv expiry for the payment (1008 ~ 1 week)
+          max-cltv = 2016              // max acceptable cltv expiry for the payment (2016 ~ 2 weeks)
           // the route must have a fee that's below max-fee-flat-sat OR below max-fee-proportional-percent / 100 * total-amount
           max-fee-flat-sat = 21
           max-fee-proportional-percent = 3 // that's 3%

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

@@ -299,9 +299,10 @@ object NodeParams extends Logging {
 
     val maxToLocalCLTV = CltvExpiryDelta(config.getInt("channel.max-to-local-delay-blocks"))
     val offeredCLTV = CltvExpiryDelta(config.getInt("channel.to-remote-delay-blocks"))
-    require(maxToLocalCLTV <= Channel.MAX_TO_SELF_DELAY && offeredCLTV <= Channel.MAX_TO_SELF_DELAY, s"CLTV delay values too high, max is ${Channel.MAX_TO_SELF_DELAY}")
 
     val expiryDelta = CltvExpiryDelta(config.getInt("channel.expiry-delta-blocks"))
+    val maxExpiryDelta = CltvExpiryDelta(config.getInt("channel.max-expiry-delta-blocks"))
+    require(expiryDelta < maxExpiryDelta, "channel.max-expiry-delta-blocks must be at least a few times larger than channel.expiry-delta-blocks, otherwise you will fail to relay payments")
     val fulfillSafetyBeforeTimeout = CltvExpiryDelta(config.getInt("channel.fulfill-safety-before-timeout-blocks"))
     require(fulfillSafetyBeforeTimeout * 2 < expiryDelta, "channel.fulfill-safety-before-timeout-blocks must be smaller than channel.expiry-delta-blocks / 2 because it effectively reduces that delta; if you want to increase this value, you may want to increase expiry-delta-blocks as well")
     val minFinalExpiryDelta = CltvExpiryDelta(config.getInt("channel.min-final-expiry-delta-blocks"))
@@ -479,6 +480,7 @@ object NodeParams extends Logging {
         maxToLocalDelay = maxToLocalCLTV,
         minDepthBlocks = config.getInt("channel.mindepth-blocks"),
         expiryDelta = expiryDelta,
+        maxExpiryDelta = maxExpiryDelta,
         fulfillSafetyBeforeTimeout = fulfillSafetyBeforeTimeout,
         minFinalExpiryDelta = minFinalExpiryDelta,
         maxBlockProcessingDelay = FiniteDuration(config.getDuration("channel.max-block-processing-delay").getSeconds, TimeUnit.SECONDS),

eclair-core/src/main/scala/fr/acinq/eclair/channel/Commitments.scala

@@ -8,6 +8,7 @@ import fr.acinq.eclair.blockchain.fee.{FeeratePerKw, OnChainFeeConf}
 import fr.acinq.eclair.channel.Helpers.Closing
 import fr.acinq.eclair.channel.Monitoring.Metrics
 import fr.acinq.eclair.channel.fsm.Channel
+import fr.acinq.eclair.channel.fsm.Channel.ChannelConf
 import fr.acinq.eclair.channel.fund.InteractiveTxBuilder.SharedTransaction
 import fr.acinq.eclair.crypto.keymanager.ChannelKeyManager
 import fr.acinq.eclair.crypto.{Generators, ShaChain}
@@ -808,15 +809,15 @@ case class Commitments(params: ChannelParams,
    * @param cmd add HTLC command
    * @return either Left(failure, error message) where failure is a failure message (see BOLT #4 and the Failure Message class) or Right(new commitments, updateAddHtlc)
    */
-  def sendAdd(cmd: CMD_ADD_HTLC, currentHeight: BlockHeight, feeConf: OnChainFeeConf): Either[ChannelException, (Commitments, UpdateAddHtlc)] = {
+  def sendAdd(cmd: CMD_ADD_HTLC, currentHeight: BlockHeight, channelConf: ChannelConf, feeConf: OnChainFeeConf): Either[ChannelException, (Commitments, UpdateAddHtlc)] = {
     // we must ensure we're not relaying htlcs that are already expired, otherwise the downstream channel will instantly close
     // NB: we add a 3 blocks safety to reduce the probability of running into this when our bitcoin node is slightly outdated
     val minExpiry = CltvExpiry(currentHeight + 3)
     if (cmd.cltvExpiry < minExpiry) {
       return Left(ExpiryTooSmall(channelId, minimum = minExpiry, actual = cmd.cltvExpiry, blockHeight = currentHeight))
     }
     // we don't want to use too high a refund timeout, because our funds will be locked during that time if the payment is never fulfilled
-    val maxExpiry = Channel.MAX_CLTV_EXPIRY_DELTA.toCltvExpiry(currentHeight)
+    val maxExpiry = channelConf.maxExpiryDelta.toCltvExpiry(currentHeight)
     if (cmd.cltvExpiry >= maxExpiry) {
       return Left(ExpiryTooBig(channelId, maximum = maxExpiry, actual = cmd.cltvExpiry, blockHeight = currentHeight))
     }

eclair-core/src/main/scala/fr/acinq/eclair/channel/Helpers.scala

@@ -95,7 +95,7 @@ object Helpers {
     if (open.pushMsat > open.fundingSatoshis) return Left(InvalidPushAmount(open.temporaryChannelId, open.pushMsat, open.fundingSatoshis.toMilliSatoshi))
 
     // BOLT #2: The receiving node MUST fail the channel if: to_self_delay is unreasonably large.
-    if (open.toSelfDelay > Channel.MAX_TO_SELF_DELAY || open.toSelfDelay > nodeParams.channelConf.maxToLocalDelay) return Left(ToSelfDelayTooHigh(open.temporaryChannelId, open.toSelfDelay, nodeParams.channelConf.maxToLocalDelay))
+    if (open.toSelfDelay > nodeParams.channelConf.maxToLocalDelay) return Left(ToSelfDelayTooHigh(open.temporaryChannelId, open.toSelfDelay, nodeParams.channelConf.maxToLocalDelay))
 
     // BOLT #2: The receiving node MUST fail the channel if: max_accepted_htlcs is greater than 483.
     if (open.maxAcceptedHtlcs > Channel.MAX_ACCEPTED_HTLCS) return Left(InvalidMaxAcceptedHtlcs(open.temporaryChannelId, open.maxAcceptedHtlcs, Channel.MAX_ACCEPTED_HTLCS))
@@ -144,7 +144,7 @@ object Helpers {
     if (open.pushAmount > open.fundingAmount) return Left(InvalidPushAmount(open.temporaryChannelId, open.pushAmount, open.fundingAmount.toMilliSatoshi))
 
     // BOLT #2: The receiving node MUST fail the channel if: to_self_delay is unreasonably large.
-    if (open.toSelfDelay > Channel.MAX_TO_SELF_DELAY || open.toSelfDelay > nodeParams.channelConf.maxToLocalDelay) return Left(ToSelfDelayTooHigh(open.temporaryChannelId, open.toSelfDelay, nodeParams.channelConf.maxToLocalDelay))
+    if (open.toSelfDelay > nodeParams.channelConf.maxToLocalDelay) return Left(ToSelfDelayTooHigh(open.temporaryChannelId, open.toSelfDelay, nodeParams.channelConf.maxToLocalDelay))
 
     // BOLT #2: The receiving node MUST fail the channel if: max_accepted_htlcs is greater than 483.
     if (open.maxAcceptedHtlcs > Channel.MAX_ACCEPTED_HTLCS) return Left(InvalidMaxAcceptedHtlcs(open.temporaryChannelId, open.maxAcceptedHtlcs, Channel.MAX_ACCEPTED_HTLCS))
@@ -198,7 +198,7 @@ object Helpers {
 
     // if minimum_depth is unreasonably large:
     // MAY reject the channel.
-    if (accept.toSelfDelay > Channel.MAX_TO_SELF_DELAY || accept.toSelfDelay > nodeParams.channelConf.maxToLocalDelay) return Left(ToSelfDelayTooHigh(accept.temporaryChannelId, accept.toSelfDelay, nodeParams.channelConf.maxToLocalDelay))
+    if (accept.toSelfDelay > nodeParams.channelConf.maxToLocalDelay) return Left(ToSelfDelayTooHigh(accept.temporaryChannelId, accept.toSelfDelay, nodeParams.channelConf.maxToLocalDelay))
 
     // if channel_reserve_satoshis is less than dust_limit_satoshis within the open_channel message:
     //  MUST reject the channel.
@@ -236,7 +236,7 @@ object Helpers {
 
     // if minimum_depth is unreasonably large:
     // MAY reject the channel.
-    if (accept.toSelfDelay > Channel.MAX_TO_SELF_DELAY || accept.toSelfDelay > nodeParams.channelConf.maxToLocalDelay) return Left(ToSelfDelayTooHigh(accept.temporaryChannelId, accept.toSelfDelay, nodeParams.channelConf.maxToLocalDelay))
+    if (accept.toSelfDelay > nodeParams.channelConf.maxToLocalDelay) return Left(ToSelfDelayTooHigh(accept.temporaryChannelId, accept.toSelfDelay, nodeParams.channelConf.maxToLocalDelay))
 
     val channelFeatures = ChannelFeatures(channelType, localFeatures, remoteFeatures, open.channelFlags.announceChannel)
     extractShutdownScript(accept.temporaryChannelId, localFeatures, remoteFeatures, accept.upfrontShutdownScript_opt).map(script_opt => (channelFeatures, script_opt))

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

@@ -80,6 +80,7 @@ object Channel {
                          maxToLocalDelay: CltvExpiryDelta,
                          minDepthBlocks: Int,
                          expiryDelta: CltvExpiryDelta,
+                         maxExpiryDelta: CltvExpiryDelta,
                          fulfillSafetyBeforeTimeout: CltvExpiryDelta,
                          minFinalExpiryDelta: CltvExpiryDelta,
                          maxBlockProcessingDelay: FiniteDuration,
@@ -127,10 +128,6 @@ object Channel {
   val MAX_NEGOTIATION_ITERATIONS = 20
 
   val MIN_CLTV_EXPIRY_DELTA: CltvExpiryDelta = Bolt11Invoice.DEFAULT_MIN_CLTV_EXPIRY_DELTA
-  val MAX_CLTV_EXPIRY_DELTA: CltvExpiryDelta = CltvExpiryDelta(7 * 144) // one week
-
-  // since BOLT 1.1, there is a max value for the refund delay of the main commitment tx
-  val MAX_TO_SELF_DELAY: CltvExpiryDelta = CltvExpiryDelta(2016)
 
   // as a non-initiator, we will wait that many blocks for the funding tx to confirm (initiator will rely on the funding tx being double-spent)
   val FUNDING_TIMEOUT_FUNDEE = 2016
@@ -387,7 +384,7 @@ class Channel(val nodeParams: NodeParams, val wallet: OnChainChannelFunder with
       handleAddHtlcCommandError(c, error, Some(d.channelUpdate))
 
     case Event(c: CMD_ADD_HTLC, d: DATA_NORMAL) =>
-      d.commitments.sendAdd(c, nodeParams.currentBlockHeight, nodeParams.onChainFeeConf) match {
+      d.commitments.sendAdd(c, nodeParams.currentBlockHeight, nodeParams.channelConf, nodeParams.onChainFeeConf) match {
         case Right((commitments1, add)) =>
           if (c.commit) self ! CMD_SIGN()
           context.system.eventStream.publish(AvailableBalanceChanged(self, d.channelId, d.shortIds, commitments1))

eclair-core/src/main/scala/fr/acinq/eclair/router/RouteCalculation.scala

@@ -240,8 +240,8 @@ object RouteCalculation {
   /** https://github.com/lightningnetwork/lightning-rfc/blob/master/04-onion-routing.md#clarifications */
   val ROUTE_MAX_LENGTH = 20
 
-  /** Max allowed CLTV for a route (one week) */
-  val DEFAULT_ROUTE_MAX_CLTV = CltvExpiryDelta(1008)
+  /** Max allowed CLTV for a route (two weeks) */
+  val DEFAULT_ROUTE_MAX_CLTV = CltvExpiryDelta(2016)
 
   /** The default number of routes we'll search for when findRoute is called with randomize = true */
   val DEFAULT_ROUTES_COUNT = 3

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

@@ -110,6 +110,7 @@ object TestConstants {
         maxHtlcValueInFlightPercent = 100,
         maxAcceptedHtlcs = 100,
         expiryDelta = CltvExpiryDelta(144),
+        maxExpiryDelta = CltvExpiryDelta(2016),
         fulfillSafetyBeforeTimeout = CltvExpiryDelta(6),
         minFinalExpiryDelta = CltvExpiryDelta(18),
         maxBlockProcessingDelay = 10 millis,
@@ -265,6 +266,7 @@ object TestConstants {
         maxHtlcValueInFlightPercent = 100,
         maxAcceptedHtlcs = 30,
         expiryDelta = CltvExpiryDelta(144),
+        maxExpiryDelta = CltvExpiryDelta(2016),
         fulfillSafetyBeforeTimeout = CltvExpiryDelta(6),
         minFinalExpiryDelta = CltvExpiryDelta(18),
         maxBlockProcessingDelay = 10 millis,

eclair-core/src/test/scala/fr/acinq/eclair/channel/CommitmentsSpec.scala

@@ -79,7 +79,7 @@ class CommitmentsSpec extends TestKitBaseClass with FixtureAnyFunSuiteLike with
     assert(bc0.availableBalanceForReceive == a)
 
     val (payment_preimage, cmdAdd) = makeCmdAdd(p, bob.underlyingActor.nodeParams.nodeId, currentBlockHeight)
-    val Right((ac1, add)) = ac0.sendAdd(cmdAdd, currentBlockHeight, alice.underlyingActor.nodeParams.onChainFeeConf)
+    val Right((ac1, add)) = ac0.sendAdd(cmdAdd, currentBlockHeight, alice.underlyingActor.nodeParams.channelConf, alice.underlyingActor.nodeParams.onChainFeeConf)
     assert(ac1.availableBalanceForSend == a - p - htlcOutputFee) // as soon as htlc is sent, alice sees its balance decrease (more than the payment amount because of the commitment fees)
     assert(ac1.availableBalanceForReceive == b)
 
@@ -164,7 +164,7 @@ class CommitmentsSpec extends TestKitBaseClass with FixtureAnyFunSuiteLike with
     assert(bc0.availableBalanceForReceive == a)
 
     val (_, cmdAdd) = makeCmdAdd(p, bob.underlyingActor.nodeParams.nodeId, currentBlockHeight)
-    val Right((ac1, add)) = ac0.sendAdd(cmdAdd, currentBlockHeight, alice.underlyingActor.nodeParams.onChainFeeConf)
+    val Right((ac1, add)) = ac0.sendAdd(cmdAdd, currentBlockHeight, alice.underlyingActor.nodeParams.channelConf, alice.underlyingActor.nodeParams.onChainFeeConf)
     assert(ac1.availableBalanceForSend == a - p - htlcOutputFee) // as soon as htlc is sent, alice sees its balance decrease (more than the payment amount because of the commitment fees)
     assert(ac1.availableBalanceForReceive == b)
 
@@ -252,17 +252,17 @@ class CommitmentsSpec extends TestKitBaseClass with FixtureAnyFunSuiteLike with
     assert(bc0.availableBalanceForReceive == a)
 
     val (payment_preimage1, cmdAdd1) = makeCmdAdd(p1, bob.underlyingActor.nodeParams.nodeId, currentBlockHeight)
-    val Right((ac1, add1)) = ac0.sendAdd(cmdAdd1, currentBlockHeight, alice.underlyingActor.nodeParams.onChainFeeConf)
+    val Right((ac1, add1)) = ac0.sendAdd(cmdAdd1, currentBlockHeight, alice.underlyingActor.nodeParams.channelConf, alice.underlyingActor.nodeParams.onChainFeeConf)
     assert(ac1.availableBalanceForSend == a - p1 - htlcOutputFee) // as soon as htlc is sent, alice sees its balance decrease (more than the payment amount because of the commitment fees)
     assert(ac1.availableBalanceForReceive == b)
 
     val (_, cmdAdd2) = makeCmdAdd(p2, bob.underlyingActor.nodeParams.nodeId, currentBlockHeight)
-    val Right((ac2, add2)) = ac1.sendAdd(cmdAdd2, currentBlockHeight, alice.underlyingActor.nodeParams.onChainFeeConf)
+    val Right((ac2, add2)) = ac1.sendAdd(cmdAdd2, currentBlockHeight, alice.underlyingActor.nodeParams.channelConf, alice.underlyingActor.nodeParams.onChainFeeConf)
     assert(ac2.availableBalanceForSend == a - p1 - htlcOutputFee - p2 - htlcOutputFee) // as soon as htlc is sent, alice sees its balance decrease (more than the payment amount because of the commitment fees)
     assert(ac2.availableBalanceForReceive == b)
 
     val (payment_preimage3, cmdAdd3) = makeCmdAdd(p3, alice.underlyingActor.nodeParams.nodeId, currentBlockHeight)
-    val Right((bc1, add3)) = bc0.sendAdd(cmdAdd3, currentBlockHeight, bob.underlyingActor.nodeParams.onChainFeeConf)
+    val Right((bc1, add3)) = bc0.sendAdd(cmdAdd3, currentBlockHeight, bob.underlyingActor.nodeParams.channelConf, bob.underlyingActor.nodeParams.onChainFeeConf)
     assert(bc1.availableBalanceForSend == b - p3) // bob doesn't pay the fee
     assert(bc1.availableBalanceForReceive == a)
 
@@ -383,22 +383,22 @@ class CommitmentsSpec extends TestKitBaseClass with FixtureAnyFunSuiteLike with
     val isInitiator = true
     val c = CommitmentsSpec.makeCommitments(100000000 msat, 50000000 msat, FeeratePerKw(2500 sat), 546 sat, isInitiator)
     val (_, cmdAdd) = makeCmdAdd(c.availableBalanceForSend, randomKey().publicKey, f.currentBlockHeight)
-    val Right((c1, _)) = c.sendAdd(cmdAdd, f.currentBlockHeight, feeConfNoMismatch)
+    val Right((c1, _)) = c.sendAdd(cmdAdd, f.currentBlockHeight, TestConstants.Alice.nodeParams.channelConf, feeConfNoMismatch)
     assert(c1.availableBalanceForSend == 0.msat)
 
     // We should be able to handle a fee increase.
     val Right((c2, _)) = c1.sendFee(CMD_UPDATE_FEE(FeeratePerKw(3000 sat)), feeConfNoMismatch)
 
     // Now we shouldn't be able to send until we receive enough to handle the updated commit tx fee (even trimmed HTLCs shouldn't be sent).
     val (_, cmdAdd1) = makeCmdAdd(100 msat, randomKey().publicKey, f.currentBlockHeight)
-    val Left(_: InsufficientFunds) = c2.sendAdd(cmdAdd1, f.currentBlockHeight, feeConfNoMismatch)
+    val Left(_: InsufficientFunds) = c2.sendAdd(cmdAdd1, f.currentBlockHeight, TestConstants.Alice.nodeParams.channelConf, feeConfNoMismatch)
   }
 
   test("can send availableForSend") { f =>
     for (isInitiator <- Seq(true, false)) {
       val c = CommitmentsSpec.makeCommitments(702000000 msat, 52000000 msat, FeeratePerKw(2679 sat), 546 sat, isInitiator)
       val (_, cmdAdd) = makeCmdAdd(c.availableBalanceForSend, randomKey().publicKey, f.currentBlockHeight)
-      val result = c.sendAdd(cmdAdd, f.currentBlockHeight, feeConfNoMismatch)
+      val result = c.sendAdd(cmdAdd, f.currentBlockHeight, TestConstants.Alice.nodeParams.channelConf, feeConfNoMismatch)
       assert(result.isRight, result)
     }
   }
@@ -428,14 +428,14 @@ class CommitmentsSpec extends TestKitBaseClass with FixtureAnyFunSuiteLike with
       for (_ <- 1 to t.pendingHtlcs) {
         val amount = Random.nextInt(maxPendingHtlcAmount.toLong.toInt).msat.max(1 msat)
         val (_, cmdAdd) = makeCmdAdd(amount, randomKey().publicKey, f.currentBlockHeight)
-        c.sendAdd(cmdAdd, f.currentBlockHeight, feeConfNoMismatch) match {
+        c.sendAdd(cmdAdd, f.currentBlockHeight, TestConstants.Alice.nodeParams.channelConf, feeConfNoMismatch) match {
           case Right((cc, _)) => c = cc
           case Left(e) => ignore(s"$t -> could not setup initial htlcs: $e")
         }
       }
       if (c.availableBalanceForSend > 0.msat) {
         val (_, cmdAdd) = makeCmdAdd(c.availableBalanceForSend, randomKey().publicKey, f.currentBlockHeight)
-        val result = c.sendAdd(cmdAdd, f.currentBlockHeight, feeConfNoMismatch)
+        val result = c.sendAdd(cmdAdd, f.currentBlockHeight, TestConstants.Alice.nodeParams.channelConf, feeConfNoMismatch)
         assert(result.isRight, s"$t -> $result")
       }
     }

eclair-core/src/test/scala/fr/acinq/eclair/channel/states/e/NormalStateSpec.scala

@@ -163,10 +163,11 @@ class NormalStateSpec extends TestKitBaseClass with FixtureAnyFunSuiteLike with
     import f._
     val sender = TestProbe()
     val initialState = alice.stateData.asInstanceOf[DATA_NORMAL]
-    val expiryTooBig = (Channel.MAX_CLTV_EXPIRY_DELTA + 1).toCltvExpiry(currentBlockHeight)
+    val maxAllowedExpiryDelta = alice.underlyingActor.nodeParams.channelConf.maxExpiryDelta
+    val expiryTooBig = (maxAllowedExpiryDelta + 1).toCltvExpiry(currentBlockHeight)
     val add = CMD_ADD_HTLC(sender.ref, 500000000 msat, randomBytes32(), expiryTooBig, TestConstants.emptyOnionPacket, None, localOrigin(sender.ref))
     alice ! add
-    val error = ExpiryTooBig(channelId(alice), maximum = Channel.MAX_CLTV_EXPIRY_DELTA.toCltvExpiry(currentBlockHeight), actual = expiryTooBig, blockHeight = currentBlockHeight)
+    val error = ExpiryTooBig(channelId(alice), maximum = maxAllowedExpiryDelta.toCltvExpiry(currentBlockHeight), actual = expiryTooBig, blockHeight = currentBlockHeight)
     sender.expectMsg(RES_ADD_FAILED(add, error, Some(initialState.channelUpdate)))
     alice2bob.expectNoMessage(200 millis)
   }