htlcswitch: return hop.Payload from HopIterator

htlcswitch/hop/iterator.go

@@ -16,12 +16,13 @@ import (
 // interpret the forwarding information encoded within the HTLC packet, and hop
 // to encode the forwarding information for the _next_ hop.
 type Iterator interface {
-	// ForwardingInstructions returns the set of fields that detail exactly
+	// HopPayload returns the set of fields that detail exactly _how_ this
-	// _how_ this hop should forward the HTLC to the next hop.
+	// hop should forward the HTLC to the next hop.  Additionally, the
-	// Additionally, the information encoded within the returned
+	// information encoded within the returned ForwardingInfo is to be used
-	// ForwardingInfo is to be used by each hop to authenticate the
+	// by each hop to authenticate the information given to it by the prior
-	// information given to it by the prior hop.
+	// hop. The payload will also contain any additional TLV fields provided
-	ForwardingInstructions() (ForwardingInfo, error)
+	// by the sender.
+	HopPayload() (*Payload, error)
 
 	// ExtraOnionBlob returns the additional EOB data (if available).
 	ExtraOnionBlob() []byte
@@ -72,37 +73,31 @@ func (r *sphinxHopIterator) EncodeNextHop(w io.Writer) error {
 	return r.processedPacket.NextPacket.Encode(w)
 }
 
-// ForwardingInstructions returns the set of fields that detail exactly _how_
+// HopPayload returns the set of fields that detail exactly _how_ this hop
-// this hop should forward the HTLC to the next hop.  Additionally, the
+// should forward the HTLC to the next hop.  Additionally, the information
-// information encoded within the returned ForwardingInfo is to be used by each
+// encoded within the returned ForwardingInfo is to be used by each hop to
-// hop to authenticate the information given to it by the prior hop.
+// authenticate the information given to it by the prior hop. The payload will
+// also contain any additional TLV fields provided by the sender.
 //
 // NOTE: Part of the HopIterator interface.
-func (r *sphinxHopIterator) ForwardingInstructions() (ForwardingInfo, error) {
+func (r *sphinxHopIterator) HopPayload() (*Payload, error) {
 	switch r.processedPacket.Payload.Type {
+
 	// If this is the legacy payload, then we'll extract the information
 	// directly from the pre-populated ForwardingInstructions field.
 	case sphinx.PayloadLegacy:
 		fwdInst := r.processedPacket.ForwardingInstructions
-		p := NewLegacyPayload(fwdInst)
+		return NewLegacyPayload(fwdInst), nil
-
-		return p.ForwardingInfo(), nil
 
 	// Otherwise, if this is the TLV payload, then we'll make a new stream
 	// to decode only what we need to make routing decisions.
 	case sphinx.PayloadTLV:
-		p, err := NewPayloadFromReader(bytes.NewReader(
+		return NewPayloadFromReader(bytes.NewReader(
 			r.processedPacket.Payload.Payload,
 		))
-		if err != nil {
-			return ForwardingInfo{}, err
-		}
-
-		return p.ForwardingInfo(), nil
 
 	default:
-		return ForwardingInfo{}, fmt.Errorf("unknown "+
+		return nil, fmt.Errorf("unknown sphinx payload type: %v",
-			"sphinx payload type: %v",
 			r.processedPacket.Payload.Type)
 	}
 }

htlcswitch/hop/iterator_test.go

@@ -85,12 +85,13 @@ func TestSphinxHopIteratorForwardingInstructions(t *testing.T) {
 	for i, testCase := range testCases {
 		iterator.processedPacket = testCase.sphinxPacket
 
-		fwdInfo, err := iterator.ForwardingInstructions()
+		pld, err := iterator.HopPayload()
 		if err != nil {
 			t.Fatalf("#%v: unable to extract forwarding "+
 				"instructions: %v", i, err)
 		}
 
+		fwdInfo := pld.ForwardingInfo()
 		if fwdInfo != testCase.expectedFwdInfo {
 			t.Fatalf("#%v: wrong fwding info: expected %v, got %v",
 				i, spew.Sdump(testCase.expectedFwdInfo),

htlcswitch/link.go

@@ -2642,7 +2642,7 @@ func (l *channelLink) processRemoteAdds(fwdPkg *channeldb.FwdPkg,
 
 		heightNow := l.cfg.Switch.BestHeight()
 
-		fwdInfo, err := chanIterator.ForwardingInstructions()
+		pld, err := chanIterator.HopPayload()
 		if err != nil {
 			// If we're unable to process the onion payload, or we
 			// received invalid onion payload failure, then we
@@ -2671,6 +2671,8 @@ func (l *channelLink) processRemoteAdds(fwdPkg *channeldb.FwdPkg,
 			continue
 		}
 
+		fwdInfo := pld.ForwardingInfo()
+
 		switch fwdInfo.NextHop {
 		case hop.Exit:
 			updated, err := l.processExitHop(

htlcswitch/link_test.go

@@ -22,6 +22,7 @@ import (
 	"github.com/coreos/bbolt"
 	"github.com/davecgh/go-spew/spew"
 	"github.com/go-errors/errors"
+	sphinx "github.com/lightningnetwork/lightning-onion"
 	"github.com/lightningnetwork/lnd/build"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/contractcourt"
@@ -563,7 +564,7 @@ func TestExitNodeTimelockPayloadMismatch(t *testing.T) {
 	// per-hop payload for outgoing time lock to be the incorrect value.
 	// The proper value of the outgoing CLTV should be the policy set by
 	// the receiving node, instead we set it to be a random value.
-	hops[0].OutgoingCTLV = 500
+	hops[0].FwdInfo.OutgoingCTLV = 500
 	firstHop := n.firstBobChannelLink.ShortChanID()
 	_, err = makePayment(
 		n.aliceServer, n.bobServer, firstHop, hops, amount, htlcAmt,
@@ -616,7 +617,7 @@ func TestExitNodeAmountPayloadMismatch(t *testing.T) {
 	// per-hop payload for amount to be the incorrect value.  The proper
 	// value of the amount to forward should be the amount that the
 	// receiving node expects to receive.
-	hops[0].AmountToForward = 1
+	hops[0].FwdInfo.AmountToForward = 1
 	firstHop := n.firstBobChannelLink.ShortChanID()
 	_, err = makePayment(
 		n.aliceServer, n.bobServer, firstHop, hops, amount, htlcAmt,
@@ -4354,13 +4355,13 @@ func generateHtlcAndInvoice(t *testing.T,
 
 	htlcAmt := lnwire.NewMSatFromSatoshis(10000)
 	htlcExpiry := testStartingHeight + testInvoiceCltvExpiry
-	hops := []hop.ForwardingInfo{
+	hops := []*hop.Payload{
-		{
+		hop.NewLegacyPayload(&sphinx.HopData{
-			Network:         hop.BitcoinNetwork,
+			Realm:         [1]byte{}, // hop.BitcoinNetwork
-			NextHop:         hop.Exit,
+			NextAddress:   [8]byte{}, // hop.Exit,
-			AmountToForward: htlcAmt,
+			ForwardAmount: uint64(htlcAmt),
-			OutgoingCTLV:    uint32(htlcExpiry),
+			OutgoingCltv:  uint32(htlcExpiry),
-		},
+		}),
 	}
 	blob, err := generateRoute(hops...)
 	if err != nil {

htlcswitch/mock.go

@@ -265,16 +265,14 @@ func (s *mockServer) QuitSignal() <-chan struct{} {
 // mockHopIterator represents the test version of hop iterator which instead
 // of encrypting the path in onion blob just stores the path as a list of hops.
 type mockHopIterator struct {
-	hops []hop.ForwardingInfo
+	hops []*hop.Payload
 }
 
-func newMockHopIterator(hops ...hop.ForwardingInfo) hop.Iterator {
+func newMockHopIterator(hops ...*hop.Payload) hop.Iterator {
 	return &mockHopIterator{hops: hops}
 }
 
-func (r *mockHopIterator) ForwardingInstructions() (
+func (r *mockHopIterator) HopPayload() (*hop.Payload, error) {
-	hop.ForwardingInfo, error) {
-
 	h := r.hops[0]
 	r.hops = r.hops[1:]
 	return h, nil
@@ -300,7 +298,8 @@ func (r *mockHopIterator) EncodeNextHop(w io.Writer) error {
 	}
 
 	for _, hop := range r.hops {
-		if err := encodeFwdInfo(w, &hop); err != nil {
+		fwdInfo := hop.ForwardingInfo()
+		if err := encodeFwdInfo(w, &fwdInfo); err != nil {
 			return err
 		}
 	}
@@ -434,14 +433,22 @@ func (p *mockIteratorDecoder) DecodeHopIterator(r io.Reader, rHash []byte,
 	}
 	hopLength := binary.BigEndian.Uint32(b[:])
 
-	hops := make([]hop.ForwardingInfo, hopLength)
+	hops := make([]*hop.Payload, hopLength)
 	for i := uint32(0); i < hopLength; i++ {
-		f := &hop.ForwardingInfo{}
+		var f hop.ForwardingInfo
-		if err := decodeFwdInfo(r, f); err != nil {
+		if err := decodeFwdInfo(r, &f); err != nil {
 			return nil, lnwire.CodeTemporaryChannelFailure
 		}
 
-		hops[i] = *f
+		var nextHopBytes [8]byte
+		binary.BigEndian.PutUint64(nextHopBytes[:], f.NextHop.ToUint64())
+
+		hops[i] = hop.NewLegacyPayload(&sphinx.HopData{
+			Realm:         [1]byte{}, // hop.BitcoinNetwork
+			NextAddress:   nextHopBytes,
+			ForwardAmount: uint64(f.AmountToForward),
+			OutgoingCltv:  f.OutgoingCTLV,
+		})
 	}
 
 	return newMockHopIterator(hops...), lnwire.CodeNone

htlcswitch/test_utils.go

@@ -23,6 +23,7 @@ import (
 	"github.com/btcsuite/fastsha256"
 	"github.com/coreos/bbolt"
 	"github.com/go-errors/errors"
+	sphinx "github.com/lightningnetwork/lightning-onion"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/contractcourt"
 	"github.com/lightningnetwork/lnd/htlcswitch/hop"
@@ -601,7 +602,7 @@ func generatePayment(invoiceAmt, htlcAmt lnwire.MilliSatoshi, timelock uint32,
 }
 
 // generateRoute generates the path blob by given array of peers.
-func generateRoute(hops ...hop.ForwardingInfo) (
+func generateRoute(hops ...*hop.Payload) (
 	[lnwire.OnionPacketSize]byte, error) {
 
 	var blob [lnwire.OnionPacketSize]byte
@@ -642,13 +643,12 @@ type threeHopNetwork struct {
 // also the time lock value needed to route an HTLC with the target amount over
 // the specified path.
 func generateHops(payAmt lnwire.MilliSatoshi, startingHeight uint32,
-	path ...*channelLink) (lnwire.MilliSatoshi, uint32,
+	path ...*channelLink) (lnwire.MilliSatoshi, uint32, []*hop.Payload) {
-	[]hop.ForwardingInfo) {
 
 	totalTimelock := startingHeight
 	runningAmt := payAmt
 
-	hops := make([]hop.ForwardingInfo, len(path))
+	hops := make([]*hop.Payload, len(path))
 	for i := len(path) - 1; i >= 0; i-- {
 		// If this is the last hop, then the next hop is the special
 		// "exit node". Otherwise, we look to the "prior" hop.
@@ -676,7 +676,7 @@ func generateHops(payAmt lnwire.MilliSatoshi, startingHeight uint32,
 		amount := payAmt
 		if i != len(path)-1 {
 			prevHop := hops[i+1]
-			prevAmount := prevHop.AmountToForward
+			prevAmount := prevHop.ForwardingInfo().AmountToForward
 
 			fee := ExpectedFee(path[i].cfg.FwrdingPolicy, prevAmount)
 			runningAmt += fee
@@ -687,12 +687,15 @@ func generateHops(payAmt lnwire.MilliSatoshi, startingHeight uint32,
 			amount = runningAmt - fee
 		}
 
-		hops[i] = hop.ForwardingInfo{
+		var nextHopBytes [8]byte
-			Network:         hop.BitcoinNetwork,
+		binary.BigEndian.PutUint64(nextHopBytes[:], nextHop.ToUint64())
-			NextHop:         nextHop,
+
-			AmountToForward: amount,
+		hops[i] = hop.NewLegacyPayload(&sphinx.HopData{
-			OutgoingCTLV:    timeLock,
+			Realm:         [1]byte{}, // hop.BitcoinNetwork
-		}
+			NextAddress:   nextHopBytes,
+			ForwardAmount: uint64(amount),
+			OutgoingCltv:  timeLock,
+		})
 	}
 
 	return runningAmt, totalTimelock, hops
@@ -739,7 +742,7 @@ func waitForPayFuncResult(payFunc func() error, d time.Duration) error {
 // * from Alice to Carol through the Bob
 // * from Alice to some another peer through the Bob
 func makePayment(sendingPeer, receivingPeer lnpeer.Peer,
-	firstHop lnwire.ShortChannelID, hops []hop.ForwardingInfo,
+	firstHop lnwire.ShortChannelID, hops []*hop.Payload,
 	invoiceAmt, htlcAmt lnwire.MilliSatoshi,
 	timelock uint32) *paymentResponse {
 
@@ -773,7 +776,7 @@ func makePayment(sendingPeer, receivingPeer lnpeer.Peer,
 // preparePayment creates an invoice at the receivingPeer and returns a function
 // that, when called, launches the payment from the sendingPeer.
 func preparePayment(sendingPeer, receivingPeer lnpeer.Peer,
-	firstHop lnwire.ShortChannelID, hops []hop.ForwardingInfo,
+	firstHop lnwire.ShortChannelID, hops []*hop.Payload,
 	invoiceAmt, htlcAmt lnwire.MilliSatoshi,
 	timelock uint32) (*channeldb.Invoice, func() error, error) {
 
@@ -1265,7 +1268,7 @@ func (n *twoHopNetwork) stop() {
 }
 
 func (n *twoHopNetwork) makeHoldPayment(sendingPeer, receivingPeer lnpeer.Peer,
-	firstHop lnwire.ShortChannelID, hops []hop.ForwardingInfo,
+	firstHop lnwire.ShortChannelID, hops []*hop.Payload,
 	invoiceAmt, htlcAmt lnwire.MilliSatoshi,
 	timelock uint32, preimage lntypes.Preimage) chan error {