Implement change in BOLT11 r field (#277)

* update link to bolt11 spec

* BOLT11: implement change in r field
see lightning/bolts#317

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

@@ -21,9 +21,9 @@ object PaymentHop {
     * @param msat        an amount to send to a payment recipient
     * @return a sequence of extra hops with a pre-calculated fee for a given msat amount
     */
-  def buildExtra(reversePath: Seq[Hop], msat: Long): Seq[ExtraHop] = (List.empty[ExtraHop] /: reversePath) {
-    case (Nil, hop) => ExtraHop(hop.nodeId, hop.shortChannelId, hop.nextFee(msat), hop.cltvExpiryDelta) :: Nil
-    case (head :: rest, hop) => ExtraHop(hop.nodeId, hop.shortChannelId, hop.nextFee(msat + head.fee), hop.cltvExpiryDelta) :: head :: rest
+  def buildExtra(reversePath: Seq[Hop], msat: Long): Seq[ExtraHop] = reversePath.foldLeft(List.empty[ExtraHop]) {
+    case (Nil, hop) => ExtraHop(hop.nodeId, hop.shortChannelId, hop.feeBaseMsat, hop.feeProportionalMillionths, hop.cltvExpiryDelta) :: Nil
+    case (head :: rest, hop) => ExtraHop(hop.nodeId, hop.shortChannelId, hop.feeBaseMsat, hop.feeProportionalMillionths, hop.cltvExpiryDelta) :: head :: rest
   }
 }
 
@@ -40,6 +40,10 @@ trait PaymentHop {
 case class Hop(nodeId: PublicKey, nextNodeId: PublicKey, lastUpdate: ChannelUpdate) extends PaymentHop {
   def nextFee(msat: Long): Long = PaymentHop.nodeFee(lastUpdate.feeBaseMsat, lastUpdate.feeProportionalMillionths, msat)
 
+  def feeBaseMsat: Long = lastUpdate.feeBaseMsat
+
+  def feeProportionalMillionths: Long = lastUpdate.feeProportionalMillionths
+
   def cltvExpiryDelta: Int = lastUpdate.cltvExpiryDelta
 
   def shortChannelId: Long = lastUpdate.shortChannelId

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

@@ -15,7 +15,7 @@ import scala.util.Try
 
 /**
   * Lightning Payment Request
-  * see https://github.com/lightningnetwork/lightning-rfc/pull/183
+  * see https://github.com/lightningnetwork/lightning-rfc/blob/master/11-payment-encoding.md
   *
   * @param prefix    currency prefix; lnbc for bitcoin, lntb for bitcoin testnet
   * @param amount    amount to pay (empty string means no amount is specified)
@@ -217,15 +217,16 @@ object PaymentRequest {
     *
     * @param nodeId          node id
     * @param shortChannelId  channel id
-    * @param fee             node fee
+    * @param feeBaseMast   node fixed fee
+    * @param feeProportionalMillionths  node proportional fee
     * @param cltvExpiryDelta node cltv expiry delta
     */
-  case class ExtraHop(nodeId: PublicKey, shortChannelId: Long, fee: Long, cltvExpiryDelta: Int) extends PaymentHop {
+  case class ExtraHop(nodeId: PublicKey, shortChannelId: Long, feeBaseMast: Long, feeProportionalMillionths: Long, cltvExpiryDelta: Int) extends PaymentHop {
     def pack: Seq[Byte] = nodeId.toBin ++ Protocol.writeUInt64(shortChannelId, ByteOrder.BIG_ENDIAN) ++
-      Protocol.writeUInt64(fee, ByteOrder.BIG_ENDIAN) ++ Protocol.writeUInt16(cltvExpiryDelta, ByteOrder.BIG_ENDIAN)
+      Protocol.writeUInt32(feeBaseMast, ByteOrder.BIG_ENDIAN) ++ Protocol.writeUInt32(feeProportionalMillionths, ByteOrder.BIG_ENDIAN) ++ Protocol.writeUInt16(cltvExpiryDelta, ByteOrder.BIG_ENDIAN)
 
     // Fee is already pre-calculated for extra hops
-    def nextFee(msat: Long): Long = fee
+    def nextFee(msat: Long): Long = PaymentHop.nodeFee(feeBaseMast, feeProportionalMillionths, msat)
   }
 
   /**
@@ -244,15 +245,16 @@ object PaymentRequest {
     def parse(data: Seq[Byte]) = {
       val pubkey = data.slice(0, 33)
       val shortChannelId = Protocol.uint64(data.slice(33, 33 + 8), ByteOrder.BIG_ENDIAN)
-      val fee = Protocol.uint64(data.slice(33 + 8, 33 + 8 + 8), ByteOrder.BIG_ENDIAN)
+      val fee_base_msat = Protocol.uint32(data.slice(33 + 8, 33 + 8 + 4), ByteOrder.BIG_ENDIAN)
+      val fee_proportional_millionths = Protocol.uint32(data.slice(33 + 8 + 4, 33 + 8 + 8), ByteOrder.BIG_ENDIAN)
       val cltv = Protocol.uint16(data.slice(33 + 8 + 8, chunkLength), ByteOrder.BIG_ENDIAN)
-      ExtraHop(PublicKey(pubkey), shortChannelId, fee, cltv)
+      ExtraHop(PublicKey(pubkey), shortChannelId, fee_base_msat, fee_proportional_millionths, cltv)
     }
 
     def parseAll(data: Seq[Byte]): Seq[ExtraHop] =
       data.grouped(chunkLength).map(parse).toList
 
-    val chunkLength: Int = 33 + 8 + 8 + 2
+    val chunkLength: Int = 33 + 8 + 4 + 4 + 2
   }
 
   /**

eclair-core/src/test/scala/fr/acinq/eclair/payment/PaymentRequestSpec.scala

@@ -97,7 +97,7 @@ class PaymentRequestSpec extends FunSuite {
   }
 
   test("On mainnet, with fallback address 1RustyRX2oai4EYYDpQGWvEL62BBGqN9T with extra routing info to go via nodes 029e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255 then 039e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255") {
-    val ref = "lnbc20m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqhp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy043l2ahrqsfpp3qjmp7lwpagxun9pygexvgpjdc4jdj85fr9yq20q82gphp2nflc7jtzrcazrra7wwgzxqc8u7754cdlpfrmccae92qgzqvzq2ps8pqqqqqqqqqqqq9qqqvpeuqafqxu92d8lr6fvg0r5gv0heeeqgcrqlnm6jhphu9y00rrhy4grqszsvpcgpy9qqqqqqqqqqqq7qqzqfnlkwydm8rg30gjku7wmxmk06sevjp53fmvrcfegvwy7d5443jvyhxsel0hulkstws7vqv400q4j3wgpk4crg49682hr4scqvmad43cqd5m7tf"
+    val ref = "lnbc20m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqhp58yjmdan79s6qqdhdzgynm4zwqd5d7xmw5fk98klysy043l2ahrqsfpp3qjmp7lwpagxun9pygexvgpjdc4jdj85fr9yq20q82gphp2nflc7jtzrcazrra7wwgzxqc8u7754cdlpfrmccae92qgzqvzq2ps8pqqqqqqpqqqqq9qqqvpeuqafqxu92d8lr6fvg0r5gv0heeeqgcrqlnm6jhphu9y00rrhy4grqszsvpcgpy9qqqqqqgqqqqq7qqzqj9n4evl6mr5aj9f58zp6fyjzup6ywn3x6sk8akg5v4tgn2q8g4fhx05wf6juaxu9760yp46454gpg5mtzgerlzezqcqvjnhjh8z3g2qqdhhwkj"
     val pr = PaymentRequest.read(ref)
     assert(pr.prefix == "lnbc")
     assert(pr.amount === Some(MilliSatoshi(2000000000L)))
@@ -106,9 +106,12 @@ class PaymentRequestSpec extends FunSuite {
     assert(pr.nodeId == PublicKey(BinaryData("03e7156ae33b0a208d0744199163177e909e80176e55d97a2f221ede0f934dd9ad")))
     assert(pr.description == Right(Crypto.sha256("One piece of chocolate cake, one icecream cone, one pickle, one slice of swiss cheese, one slice of salami, one lollypop, one piece of cherry pie, one sausage, one cupcake, and one slice of watermelon".getBytes)))
     assert(pr.fallbackAddress === Some("1RustyRX2oai4EYYDpQGWvEL62BBGqN9T"))
-    assert(pr.routingInfo() === List(RoutingInfoTag(List(ExtraHop(PublicKey("029e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255"), 72623859790382856L, 20, 3), ExtraHop(PublicKey("039e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255"), 217304205466536202L, 30, 4)))))
-    assert(BinaryData(Protocol.writeUInt64(72623859790382856L, ByteOrder.BIG_ENDIAN)) == BinaryData("0102030405060708"))
-    assert(BinaryData(Protocol.writeUInt64(217304205466536202L, ByteOrder.BIG_ENDIAN)) == BinaryData("030405060708090a"))
+    assert(pr.routingInfo() === List(RoutingInfoTag(List(
+      ExtraHop(PublicKey("029e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255"), 72623859790382856L, 1, 20, 3),
+      ExtraHop(PublicKey("039e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255"), 217304205466536202L, 2, 30, 4)
+    ))))
+    assert(BinaryData(Protocol.writeUInt64(0x0102030405060708L, ByteOrder.BIG_ENDIAN)) == BinaryData("0102030405060708"))
+    assert(BinaryData(Protocol.writeUInt64(0x030405060708090aL, ByteOrder.BIG_ENDIAN)) == BinaryData("030405060708090a"))
     assert(pr.tags.size == 4)
     assert(PaymentRequest.write(pr.sign(priv)) == ref)
   }

eclair-core/src/test/scala/fr/acinq/eclair/router/RouteCalculationSpec.scala

@@ -200,8 +200,10 @@ class RouteCalculationSpec extends FunSuite {
     val reverseRoute = List(hopBA, hopCB)
     val extraRoute = PaymentHop.buildExtra(reverseRoute, amount.amount)
 
-    assert(extraRoute === List(ExtraHop(PublicKey("02f0b230e53723ccc331db140edc518be1ee5ab29a508104a4be2f5be922c928e8"), 24412456671576064L, 547005, 144),
-      ExtraHop(PublicKey("032b4af42b5e8089a7a06005ead9ac4667527390ee39c998b7b0307f0d81d7f4ac"), 23366821113626624L, 547000, 144)))
+    assert(extraRoute === List(
+      ExtraHop(PublicKey("02f0b230e53723ccc331db140edc518be1ee5ab29a508104a4be2f5be922c928e8"), 24412456671576064L, 546000, 10, 144),
+      ExtraHop(PublicKey("032b4af42b5e8089a7a06005ead9ac4667527390ee39c998b7b0307f0d81d7f4ac"), 23366821113626624L, 546000, 10, 144))
+    )
 
     // Sender side