WIP

Author: t-bast

TODO.md

@@ -0,0 +1,14 @@
+# TODO
+
+- I removed `enable-trampoline-payments`, so the ACINQ node must:
+  - activate `trampoline_payment`
+  - activate `trampoline_payment_prototype` to support previous Phoenix versions
+- add trampoline to Bolt 12 features (can be requested in `invoice_request`)
+  - add blinded relay with trampoline onion (when intermediate node)
+  - write BOLT spec
+  - create official test vector for trampoline-to-blinded-path
+- add trampoline failures defined in the spec  
+- `lightning-kmp`:
+  - must support both options for a while (to allow being paid by older Phoenix)
+  - Bolt 11 invoices will simply set both feature bits
+  - Bolt 12 invoices will do it based on what the `invoice_request` contains

docs/TrampolinePayments.md

@@ -2,13 +2,7 @@
 
 Eclair started supporting [trampoline payments](https://github.com/lightning/bolts/pull/829) in v0.3.3.
 
-It is disabled by default, as it is still being reviewed for spec acceptance. However, if you want to experiment with it, here is what you can do.
-
-First of all, you need to activate the feature for any node that will act as a trampoline node. Update your `eclair.conf` with the following values:
-
-```conf
-eclair.trampoline-payments-enable=true
-```
+It is now active by default, since it has been added to the [BOLTs](https://github.com/lightning/bolts/pull/836).
 
 ## Sending trampoline payments
 

docs/release-notes/eclair-vnext.md

@@ -17,6 +17,10 @@ To enable CoinGrinder at all fee rates and prevent the automatic consolidation o
 consolidatefeerate=0
 ```
 
+### Trampoline payments
+
+TODO: link to final spec
+
 ### API changes
 
 <insert changes>

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

@@ -47,7 +47,6 @@ eclair {
   node-alias = "eclair"
   node-color = "49daaa"
 
-  trampoline-payments-enable = false // TODO: @t-bast: once spec-ed this should use a global feature flag
   // see https://github.com/lightningnetwork/lightning-rfc/blob/master/09-features.md
   features {
     // option_upfront_shutdown_script is not activated by default.
@@ -81,6 +80,7 @@ eclair {
     // node that you trust using override-init-features (see below).
     option_zeroconf = disabled
     keysend = disabled
+    trampoline_routing = optional
     trampoline_payment_prototype = disabled
     async_payment_prototype = disabled
   }

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

@@ -300,13 +300,15 @@ object Features {
     val mandatory = 54
   }
 
-  // TODO: @t-bast: update feature bits once spec-ed (currently reserved here: https://github.com/lightningnetwork/lightning-rfc/issues/605)
-  // We're not advertising these bits yet in our announcements, clients have to assume support.
-  // This is why we haven't added them yet to `areSupported`.
-  // The version of trampoline enabled by this feature bit does not match the latest spec PR: once the spec is accepted,
-  // we will introduce a new version of trampoline that will work in parallel to this legacy one, until we can safely
-  // deprecate it.
-  case object TrampolinePaymentPrototype extends Feature with InitFeature with NodeFeature with Bolt11Feature {
+  case object TrampolinePayment extends Feature with InitFeature with NodeFeature with Bolt11Feature {
+    val rfcName = "trampoline_routing"
+    val mandatory = 56
+  }
+
+  // We don't advertise this feature bit in our announcements (clients assumed support).
+  // We should keep supporting this version until clients have all migrated to the official version above.
+  // TODO: remove this and the related onion TLVs once it is unused.
+  case object TrampolinePaymentPrototype extends Feature with InitFeature with Bolt11Feature {
     val rfcName = "trampoline_payment_prototype"
     val mandatory = 148
   }
@@ -346,6 +348,7 @@ object Features {
     PaymentMetadata,
     ZeroConf,
     KeySend,
+    TrampolinePayment,
     TrampolinePaymentPrototype,
     AsyncPaymentPrototype,
     SplicePrototype,
@@ -361,6 +364,7 @@ object Features {
     RouteBlinding -> (VariableLengthOnion :: Nil),
     TrampolinePaymentPrototype -> (PaymentSecret :: Nil),
     KeySend -> (VariableLengthOnion :: Nil),
+    TrampolinePayment -> (BasicMultiPartPayment :: Nil),
     AsyncPaymentPrototype -> (TrampolinePaymentPrototype :: Nil)
   )
 

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

@@ -81,7 +81,6 @@ case class NodeParams(nodeKeyManager: NodeKeyManager,
                       socksProxy_opt: Option[Socks5ProxyParams],
                       maxPaymentAttempts: Int,
                       paymentFinalExpiry: PaymentFinalExpiryConf,
-                      enableTrampolinePayment: Boolean,
                       balanceCheckInterval: FiniteDuration,
                       blockchainWatchdogThreshold: Int,
                       blockchainWatchdogSources: Seq[String],
@@ -596,7 +595,6 @@ object NodeParams extends Logging {
       socksProxy_opt = socksProxy_opt,
       maxPaymentAttempts = config.getInt("max-payment-attempts"),
       paymentFinalExpiry = PaymentFinalExpiryConf(CltvExpiryDelta(config.getInt("send.recipient-final-expiry.min-delta")), CltvExpiryDelta(config.getInt("send.recipient-final-expiry.max-delta"))),
-      enableTrampolinePayment = config.getBoolean("trampoline-payments-enable"),
       balanceCheckInterval = FiniteDuration(config.getDuration("balance-check-interval").getSeconds, TimeUnit.SECONDS),
       blockchainWatchdogThreshold = config.getInt("blockchain-watchdog.missing-blocks-threshold"),
       blockchainWatchdogSources = config.getStringList("blockchain-watchdog.sources").asScala.toSeq,

eclair-core/src/main/scala/fr/acinq/eclair/payment/receive/MultiPartHandler.scala

@@ -329,11 +329,6 @@ object MultiPartHandler {
             val paymentHash = Crypto.sha256(paymentPreimage)
             val expirySeconds = r.expirySeconds_opt.getOrElse(nodeParams.invoiceExpiry.toSeconds)
             val paymentMetadata = hex"2a"
-            val featuresTrampolineOpt = if (nodeParams.enableTrampolinePayment) {
-              nodeParams.features.bolt11Features().add(Features.TrampolinePaymentPrototype, FeatureSupport.Optional)
-            } else {
-              nodeParams.features.bolt11Features()
-            }
             val invoice = Bolt11Invoice(
               nodeParams.chainHash,
               r.amount_opt,
@@ -345,7 +340,7 @@ object MultiPartHandler {
               expirySeconds = Some(expirySeconds),
               extraHops = r.extraHops,
               paymentMetadata = Some(paymentMetadata),
-              features = featuresTrampolineOpt
+              features = nodeParams.features.bolt11Features()
             )
             context.log.debug("generated invoice={} from amount={}", invoice.toString, r.amount_opt)
             nodeParams.db.payments.addIncomingPayment(invoice, paymentPreimage, r.paymentType)

eclair-core/src/main/scala/fr/acinq/eclair/payment/relay/Relayer.scala

@@ -29,7 +29,7 @@ import fr.acinq.eclair.channel._
 import fr.acinq.eclair.db.PendingCommandsDb
 import fr.acinq.eclair.payment._
 import fr.acinq.eclair.wire.protocol._
-import fr.acinq.eclair.{CltvExpiryDelta, Logs, MilliSatoshi, NodeParams}
+import fr.acinq.eclair.{CltvExpiryDelta, Features, Logs, MilliSatoshi, NodeParams}
 import grizzled.slf4j.Logging
 
 import scala.concurrent.Promise
@@ -71,7 +71,7 @@ class Relayer(nodeParams: NodeParams, router: ActorRef, register: ActorRef, paym
         case Right(r: IncomingPaymentPacket.ChannelRelayPacket) =>
           channelRelayer ! ChannelRelayer.Relay(r)
         case Right(r: IncomingPaymentPacket.NodeRelayPacket) =>
-          if (!nodeParams.enableTrampolinePayment) {
+          if (!nodeParams.features.hasFeature(Features.TrampolinePayment) && !nodeParams.features.hasFeature(Features.TrampolinePaymentPrototype)) {
             log.warning(s"rejecting htlc #${add.id} from channelId=${add.channelId} reason=trampoline disabled")
             PendingCommandsDb.safeSend(register, nodeParams.db.pendingCommands, add.channelId, CMD_FAIL_HTLC(add.id, Right(RequiredNodeFeatureMissing()), commit = true))
           } else {

eclair-core/src/main/scala/fr/acinq/eclair/payment/send/PaymentInitiator.scala

@@ -84,7 +84,7 @@ class PaymentInitiator(nodeParams: NodeParams, outgoingPaymentFactory: PaymentIn
       r.trampolineAttempts match {
         case Nil =>
           r.replyTo ! PaymentFailed(paymentId, r.paymentHash, LocalFailure(r.recipientAmount, Nil, TrampolineFeesMissing) :: Nil)
-        case _ if !r.invoice.features.hasFeature(Features.TrampolinePaymentPrototype) && r.invoice.amount_opt.isEmpty =>
+        case _ if !r.invoice.features.hasFeature(Features.TrampolinePayment) && r.invoice.amount_opt.isEmpty =>
           r.replyTo ! PaymentFailed(paymentId, r.paymentHash, LocalFailure(r.recipientAmount, Nil, TrampolineLegacyAmountLessInvoice) :: Nil)
         case (trampolineFees, trampolineExpiryDelta) :: remainingAttempts =>
           log.info(s"sending trampoline payment with trampoline fees=$trampolineFees and expiry delta=$trampolineExpiryDelta")

eclair-core/src/main/scala/fr/acinq/eclair/payment/send/Recipient.scala

@@ -241,7 +241,9 @@ case class TrampolineRecipient(invoice: Invoice,
   private def createTrampolinePacket(paymentHash: ByteVector32, trampolineHop: NodeHop): Either[OutgoingPaymentError, Sphinx.PacketAndSecrets] = {
     invoice match {
       case invoice: Bolt11Invoice =>
-        if (invoice.features.hasFeature(Features.TrampolinePaymentPrototype)) {
+        if (invoice.features.hasFeature(Features.TrampolinePayment)) {
+          ???
+        } else if (invoice.features.hasFeature(Features.TrampolinePaymentPrototype)) {
           // This is the payload the final recipient will receive, so we use the invoice's payment secret.
           val finalPayload = NodePayload(nodeId, FinalPayload.Standard.createPayload(totalAmount, totalAmount, expiry, invoice.paymentSecret, invoice.paymentMetadata, customTlvs))
           val trampolinePayload = NodePayload(trampolineHop.nodeId, IntermediatePayload.NodeRelay.Standard(totalAmount, expiry, nodeId))