htlcswitch+hop: move ForwardingInfo to hop.ForwaringInfo

htlcswitch/hop/forwarding_info.go

@@ -0,0 +1,29 @@
+package hop
+
+import (
+	"github.com/lightningnetwork/lnd/lnwire"
+)
+
+// ForwardingInfo contains all the information that is necessary to forward and
+// incoming HTLC to the next hop encoded within a valid HopIterator instance.
+// Forwarding links are to use this information to authenticate the information
+// received within the incoming HTLC, to ensure that the prior hop didn't
+// tamper with the end-to-end routing information at all.
+type ForwardingInfo struct {
+	// Network is the target blockchain network that the HTLC will travel
+	// over next.
+	Network Network
+
+	// NextHop is the channel ID of the next hop. The received HTLC should
+	// be forwarded to this particular channel in order to continue the
+	// end-to-end route.
+	NextHop lnwire.ShortChannelID
+
+	// AmountToForward is the amount of milli-satoshis that the receiving
+	// node should forward to the next hop.
+	AmountToForward lnwire.MilliSatoshi
+
+	// OutgoingCTLV is the specified value of the CTLV timelock to be used
+	// in the outgoing HTLC.
+	OutgoingCTLV uint32
+}

htlcswitch/iterator.go

@@ -24,33 +24,6 @@ var (
 	sourceHop lnwire.ShortChannelID
 )
 
-// ForwardingInfo contains all the information that is necessary to forward and
-// incoming HTLC to the next hop encoded within a valid HopIterator instance.
-// Forwarding links are to use this information to authenticate the information
-// received within the incoming HTLC, to ensure that the prior hop didn't
-// tamper with the end-to-end routing information at all.
-type ForwardingInfo struct {
-	// Network is the target blockchain network that the HTLC will travel
-	// over next.
-	Network hop.Network
-
-	// NextHop is the channel ID of the next hop. The received HTLC should
-	// be forwarded to this particular channel in order to continue the
-	// end-to-end route.
-	NextHop lnwire.ShortChannelID
-
-	// AmountToForward is the amount of milli-satoshis that the receiving
-	// node should forward to the next hop.
-	AmountToForward lnwire.MilliSatoshi
-
-	// OutgoingCTLV is the specified value of the CTLV timelock to be used
-	// in the outgoing HTLC.
-	OutgoingCTLV uint32
-
-	// TODO(roasbeef): modify sphinx logic to not just discard the
-	// remaining bytes, instead should include the rest as excess
-}
-
 // HopIterator is an interface that abstracts away the routing information
 // included in HTLC's which includes the entirety of the payment path of an
 // HTLC. This interface provides two basic method which carry out: how to
@@ -62,7 +35,7 @@ type HopIterator interface {
 	// Additionally, the information encoded within the returned
 	// ForwardingInfo is to be used by each hop to authenticate the
 	// information given to it by the prior hop.
-	ForwardingInstructions() (ForwardingInfo, error)
+	ForwardingInstructions() (hop.ForwardingInfo, error)
 
 	// ExtraOnionBlob returns the additional EOB data (if available).
 	ExtraOnionBlob() []byte
@@ -119,7 +92,9 @@ func (r *sphinxHopIterator) EncodeNextHop(w io.Writer) error {
 // hop to authenticate the information given to it by the prior hop.
 //
 // NOTE: Part of the HopIterator interface.
-func (r *sphinxHopIterator) ForwardingInstructions() (ForwardingInfo, error) {
+func (r *sphinxHopIterator) ForwardingInstructions() (
+	hop.ForwardingInfo, error) {
+
 	var (
 		nextHop lnwire.ShortChannelID
 		amt     uint64
@@ -154,24 +129,25 @@ func (r *sphinxHopIterator) ForwardingInstructions() (ForwardingInfo, error) {
 			record.NewNextHopIDRecord(&cid),
 		)
 		if err != nil {
-			return ForwardingInfo{}, err
+			return hop.ForwardingInfo{}, err
 		}
 
 		err = tlvStream.Decode(bytes.NewReader(
 			r.processedPacket.Payload.Payload,
 		))
 		if err != nil {
-			return ForwardingInfo{}, err
+			return hop.ForwardingInfo{}, err
 		}
 
 		nextHop = lnwire.NewShortChanIDFromInt(cid)
 
 	default:
-		return ForwardingInfo{}, fmt.Errorf("unknown sphinx payload "+
+		return hop.ForwardingInfo{}, fmt.Errorf("unknown "+
-			"type: %v", r.processedPacket.Payload.Type)
+			"sphinx payload type: %v",
+			r.processedPacket.Payload.Type)
 	}
 
-	return ForwardingInfo{
+	return hop.ForwardingInfo{
 		Network:         hop.BitcoinNetwork,
 		NextHop:         nextHop,
 		AmountToForward: lnwire.MilliSatoshi(amt),

htlcswitch/iterator_test.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/davecgh/go-spew/spew"
 	sphinx "github.com/lightningnetwork/lightning-onion"
+	"github.com/lightningnetwork/lnd/htlcswitch/hop"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/record"
 	"github.com/lightningnetwork/lnd/tlv"
@@ -29,7 +30,7 @@ func TestSphinxHopIteratorForwardingInstructions(t *testing.T) {
 	// Next, we'll make the hop forwarding information that we should
 	// extract each type, no matter the payload type.
 	nextAddrInt := binary.BigEndian.Uint64(hopData.NextAddress[:])
-	expectedFwdInfo := ForwardingInfo{
+	expectedFwdInfo := hop.ForwardingInfo{
 		NextHop:         lnwire.NewShortChanIDFromInt(nextAddrInt),
 		AmountToForward: lnwire.MilliSatoshi(hopData.ForwardAmount),
 		OutgoingCTLV:    hopData.OutgoingCltv,
@@ -53,7 +54,7 @@ func TestSphinxHopIteratorForwardingInstructions(t *testing.T) {
 
 	var testCases = []struct {
 		sphinxPacket    *sphinx.ProcessedPacket
-		expectedFwdInfo ForwardingInfo
+		expectedFwdInfo hop.ForwardingInfo
 	}{
 		// A regular legacy payload that signals more hops.
 		{

htlcswitch/link.go

@@ -16,6 +16,7 @@ import (
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/contractcourt"
 	"github.com/lightningnetwork/lnd/htlcswitch/hodl"
+	"github.com/lightningnetwork/lnd/htlcswitch/hop"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/invoices"
 	"github.com/lightningnetwork/lnd/lnpeer"
@@ -2849,7 +2850,7 @@ func (l *channelLink) processRemoteAdds(fwdPkg *channeldb.FwdPkg,
 // processExitHop handles an htlc for which this link is the exit hop. It
 // returns a boolean indicating whether the commitment tx needs an update.
 func (l *channelLink) processExitHop(pd *lnwallet.PaymentDescriptor,
-	obfuscator ErrorEncrypter, fwdInfo ForwardingInfo,
+	obfuscator ErrorEncrypter, fwdInfo hop.ForwardingInfo,
 	heightNow uint32, eob []byte) (bool, error) {
 
 	// If hodl.ExitSettle is requested, we will not validate the final hop's

htlcswitch/link_test.go

@@ -4308,7 +4308,7 @@ func generateHtlcAndInvoice(t *testing.T,
 
 	htlcAmt := lnwire.NewMSatFromSatoshis(10000)
 	htlcExpiry := testStartingHeight + testInvoiceCltvExpiry
-	hops := []ForwardingInfo{
+	hops := []hop.ForwardingInfo{
 		{
 			Network:         hop.BitcoinNetwork,
 			NextHop:         exitHop,

htlcswitch/mock.go

@@ -269,14 +269,16 @@ 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 []ForwardingInfo
+	hops []hop.ForwardingInfo
 }
 
-func newMockHopIterator(hops ...ForwardingInfo) HopIterator {
+func newMockHopIterator(hops ...hop.ForwardingInfo) HopIterator {
 	return &mockHopIterator{hops: hops}
 }
 
-func (r *mockHopIterator) ForwardingInstructions() (ForwardingInfo, error) {
+func (r *mockHopIterator) ForwardingInstructions() (
+	hop.ForwardingInfo, error) {
+
 	h := r.hops[0]
 	r.hops = r.hops[1:]
 	return h, nil
@@ -301,7 +303,7 @@ func (r *mockHopIterator) EncodeNextHop(w io.Writer) error {
 	}
 
 	for _, hop := range r.hops {
-		if err := hop.encode(w); err != nil {
+		if err := encodeFwdInfo(w, &hop); err != nil {
 			return err
 		}
 	}
@@ -309,7 +311,7 @@ func (r *mockHopIterator) EncodeNextHop(w io.Writer) error {
 	return nil
 }
 
-func (f *ForwardingInfo) encode(w io.Writer) error {
+func encodeFwdInfo(w io.Writer, f *hop.ForwardingInfo) error {
 	if _, err := w.Write([]byte{byte(f.Network)}); err != nil {
 		return err
 	}
@@ -430,10 +432,10 @@ func (p *mockIteratorDecoder) DecodeHopIterator(r io.Reader, rHash []byte,
 	}
 	hopLength := binary.BigEndian.Uint32(b[:])
 
-	hops := make([]ForwardingInfo, hopLength)
+	hops := make([]hop.ForwardingInfo, hopLength)
 	for i := uint32(0); i < hopLength; i++ {
-		f := &ForwardingInfo{}
+		f := &hop.ForwardingInfo{}
-		if err := f.decode(r); err != nil {
+		if err := decodeFwdInfo(r, f); err != nil {
 			return nil, lnwire.CodeTemporaryChannelFailure
 		}
 
@@ -481,7 +483,7 @@ func (p *mockIteratorDecoder) DecodeHopIterators(id []byte,
 	return resps, nil
 }
 
-func (f *ForwardingInfo) decode(r io.Reader) error {
+func decodeFwdInfo(r io.Reader, f *hop.ForwardingInfo) error {
 	var net [1]byte
 	if _, err := r.Read(net[:]); err != nil {
 		return err

htlcswitch/test_utils.go

@@ -597,7 +597,9 @@ func generatePayment(invoiceAmt, htlcAmt lnwire.MilliSatoshi, timelock uint32,
 }
 
 // generateRoute generates the path blob by given array of peers.
-func generateRoute(hops ...ForwardingInfo) ([lnwire.OnionPacketSize]byte, error) {
+func generateRoute(hops ...hop.ForwardingInfo) (
+	[lnwire.OnionPacketSize]byte, error) {
+
 	var blob [lnwire.OnionPacketSize]byte
 	if len(hops) == 0 {
 		return blob, errors.New("empty path")
@@ -636,12 +638,13 @@ 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, []ForwardingInfo) {
+	path ...*channelLink) (lnwire.MilliSatoshi, uint32,
+	[]hop.ForwardingInfo) {
 
 	totalTimelock := startingHeight
 	runningAmt := payAmt
 
-	hops := make([]ForwardingInfo, len(path))
+	hops := make([]hop.ForwardingInfo, 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.
@@ -680,7 +683,7 @@ func generateHops(payAmt lnwire.MilliSatoshi, startingHeight uint32,
 			amount = runningAmt - fee
 		}
 
-		hops[i] = ForwardingInfo{
+		hops[i] = hop.ForwardingInfo{
 			Network:         hop.BitcoinNetwork,
 			NextHop:         nextHop,
 			AmountToForward: amount,
@@ -732,7 +735,7 @@ 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 []ForwardingInfo,
+	firstHop lnwire.ShortChannelID, hops []hop.ForwardingInfo,
 	invoiceAmt, htlcAmt lnwire.MilliSatoshi,
 	timelock uint32) *paymentResponse {
 
@@ -766,7 +769,7 @@ 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 []ForwardingInfo,
+	firstHop lnwire.ShortChannelID, hops []hop.ForwardingInfo,
 	invoiceAmt, htlcAmt lnwire.MilliSatoshi,
 	timelock uint32) (*channeldb.Invoice, func() error, error) {
 
@@ -1247,7 +1250,7 @@ func (n *twoHopNetwork) stop() {
 }
 
 func (n *twoHopNetwork) makeHoldPayment(sendingPeer, receivingPeer lnpeer.Peer,
-	firstHop lnwire.ShortChannelID, hops []ForwardingInfo,
+	firstHop lnwire.ShortChannelID, hops []hop.ForwardingInfo,
 	invoiceAmt, htlcAmt lnwire.MilliSatoshi,
 	timelock uint32, preimage lntypes.Preimage) chan error {