[WIP] multi: add new draft key send mode for spontaneous payments

cmd/lncli/commands.go

@@ -2077,6 +2077,10 @@ var sendPaymentCommand = cli.Command{
 			Name:  "force, f",
 			Usage: "will skip payment request confirmation",
 		},
+		cli.BoolFlag{
+			Name:  "key_send",
+			Usage: "will generate a pre-image and encode it in the sphinx packet, a dest must be set",
+		},
 	},
 	Action: sendPayment,
 }
@@ -2215,11 +2219,12 @@ func sendPayment(ctx *cli.Context) error {
 		Dest:     destNode,
 		Amt:      amount,
 		FeeLimit: feeLimit,
+		KeySend:  ctx.Bool("key_send"),
 	}
 
 	if ctx.Bool("debug_send") && (ctx.IsSet("payment_hash") || args.Present()) {
 		return fmt.Errorf("do not provide a payment hash with debug send")
-	} else if !ctx.Bool("debug_send") {
+	} else if !ctx.Bool("debug_send") && !ctx.Bool("key_send") {
 		var rHash []byte
 
 		switch {

contractcourt/htlc_incoming_contest_resolver.go

@@ -166,7 +166,7 @@ func (h *htlcIncomingContestResolver) Resolve() (ContractResolver, error) {
 	// identical to HTLC resolution in the link.
 	event, err := h.Registry.NotifyExitHopHtlc(
 		h.payHash, h.htlcAmt, h.htlcExpiry, currentHeight,
-		hodlChan,
+		hodlChan, nil,
 	)
 	switch err {
 	case channeldb.ErrInvoiceNotFound:

contractcourt/interfaces.go

@@ -22,7 +22,8 @@ type Registry interface {
 	// the resolution is sent on the passed in hodlChan later.
 	NotifyExitHopHtlc(payHash lntypes.Hash, paidAmount lnwire.MilliSatoshi,
 		expiry uint32, currentHeight int32,
-		hodlChan chan<- interface{}) (*invoices.HodlEvent, error)
+		hodlChan chan<- interface{},
+		destEOB []byte) (*invoices.HodlEvent, error)
 
 	// HodlUnsubscribeAll unsubscribes from all hodl events.
 	HodlUnsubscribeAll(subscriber chan<- interface{})

go.mod

@@ -50,3 +50,5 @@ require (
 replace github.com/lightningnetwork/lnd/ticker => ./ticker
 
 replace github.com/lightningnetwork/lnd/queue => ./queue
+
+replace github.com/lightningnetwork/lightning-onion v0.0.0-20190430041606-751fb4dd8b72 => github.com/roasbeef/lightning-onion v0.0.0-20190111024907-b16e0e746d70d6f19176fe321d8c392e788f6168

go.sum

@@ -124,6 +124,8 @@ github.com/onsi/ginkgo v1.7.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+W
 github.com/onsi/gomega v1.4.1/go.mod h1:C1qb7wdrVGGVU+Z6iS04AVkA3Q65CEZX59MT0QO5uiA=
 github.com/onsi/gomega v1.4.3 h1:RE1xgDvH7imwFD45h+u2SgIfERHlS2yNG4DObb5BSKU=
 github.com/onsi/gomega v1.4.3/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
+github.com/roasbeef/lightning-onion v0.0.0-20190111024907-b16e0e746d70d6f19176fe321d8c392e788f6168 h1:CRdukCpvAHhnzm7stsLDSi88h26wcTCIUxFSDSso6Vg=
+github.com/roasbeef/lightning-onion v0.0.0-20190111024907-b16e0e746d70d6f19176fe321d8c392e788f6168/go.mod h1:Sooe/CoCqa85JxqHV+IBR2HW+6t2Cv+36awSmoccswM=
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af h1:gu+uRPtBe88sKxUCEXRoeCvVG90TJmwhiqRpvdhQFng=
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
 github.com/tv42/zbase32 v0.0.0-20160707012821-501572607d02 h1:tcJ6OjwOMvExLlzrAVZute09ocAGa7KqOON60++Gz4E=

htlcswitch/interfaces.go

@@ -25,7 +25,8 @@ type InvoiceDatabase interface {
 	// the resolution is sent on the passed in hodlChan later.
 	NotifyExitHopHtlc(payHash lntypes.Hash, paidAmount lnwire.MilliSatoshi,
 		expiry uint32, currentHeight int32,
-		hodlChan chan<- interface{}) (*invoices.HodlEvent, error)
+		hodlChan chan<- interface{},
+		packetEOB []byte) (*invoices.HodlEvent, error)
 
 	// CancelInvoice attempts to cancel the invoice corresponding to the
 	// passed payment hash.

htlcswitch/iterator.go

@@ -87,6 +87,11 @@ type HopIterator interface {
 	// information given to it by the prior hop.
 	ForwardingInstructions() ForwardingInfo
 
+	// ExtraOnionBlob returns any parsed EOB data if any. If data is
+	// present, then the Type field will be anything other than
+	// sphinx.EOBEmpty.
+	ExtraOnionBlob() []byte
+
 	// EncodeNextHop encodes the onion packet destined for the next hop
 	// into the passed io.Writer.
 	EncodeNextHop(w io.Writer) error
@@ -159,6 +164,14 @@ func (r *sphinxHopIterator) ForwardingInstructions() ForwardingInfo {
 	}
 }
 
+// ExtraOnionBlob returns any parsed EOB data if any. If data is present, then
+// the Type field will be anything other than sphinx.EOBEmpty.
+//
+// NOTE: Part of the HopIterator interface.
+func (r *sphinxHopIterator) ExtraOnionBlob() []byte {
+	return r.processedPacket.ExtraOnionBlob
+}
+
 // ExtractErrorEncrypter decodes and returns the ErrorEncrypter for this hop,
 // along with a failure code to signal if the decoding was successful. The
 // ErrorEncrypter is used to encrypt errors back to the sender in the event that

htlcswitch/link.go

@@ -2565,6 +2565,7 @@ func (l *channelLink) processRemoteAdds(fwdPkg *channeldb.FwdPkg,
 		case exitHop:
 			updated, err := l.processExitHop(
 				pd, obfuscator, fwdInfo, heightNow,
+				chanIterator.ExtraOnionBlob(),
 			)
 			if err != nil {
 				l.fail(LinkFailureError{code: ErrInternalError},
@@ -2737,8 +2738,8 @@ 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, heightNow uint32) (
-	bool, error) {
+	obfuscator ErrorEncrypter, fwdInfo ForwardingInfo, heightNow uint32,
+	packetEOB []byte) (bool, error) {
 
 	// If hodl.ExitSettle is requested, we will not validate the final hop's
 	// ADD, nor will we settle the corresponding invoice or respond with the
@@ -2783,10 +2784,9 @@ func (l *channelLink) processExitHop(pd *lnwallet.PaymentDescriptor,
 	// after this, this code will be re-executed after restart. We will
 	// receive back a resolution event.
 	invoiceHash := lntypes.Hash(pd.RHash)
-
 	event, err := l.cfg.Registry.NotifyExitHopHtlc(
 		invoiceHash, pd.Amount, pd.Timeout, int32(heightNow),
-		l.hodlQueue.ChanIn(),
+		l.hodlQueue.ChanIn(), packetEOB,
 	)
 
 	switch err {

htlcswitch/mock.go

@@ -280,6 +280,10 @@ func (r *mockHopIterator) ForwardingInstructions() ForwardingInfo {
 	return h
 }
 
+func (r *mockHopIterator) ExtraOnionBlob() []byte {
+	return []byte{}
+}
+
 func (r *mockHopIterator) ExtractErrorEncrypter(
 	extracter ErrorEncrypterExtracter) (ErrorEncrypter, lnwire.FailCode) {
 
@@ -787,10 +791,11 @@ func (i *mockInvoiceRegistry) SettleHodlInvoice(preimage lntypes.Preimage) error
 
 func (i *mockInvoiceRegistry) NotifyExitHopHtlc(rhash lntypes.Hash,
 	amt lnwire.MilliSatoshi, expiry uint32, currentHeight int32,
-	hodlChan chan<- interface{}) (*invoices.HodlEvent, error) {
+	hodlChan chan<- interface{},
+	packetEOB []byte) (*invoices.HodlEvent, error) {
 
 	event, err := i.registry.NotifyExitHopHtlc(
-		rhash, amt, expiry, currentHeight, hodlChan,
+		rhash, amt, expiry, currentHeight, hodlChan, packetEOB,
 	)
 	if err != nil {
 		return nil, err

invoices/invoiceregistry.go

@@ -14,6 +14,8 @@ import (
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/queue"
+	"github.com/lightningnetwork/lnd/tlv"
+	"github.com/lightningnetwork/lnd/watchtower/wtwire"
 )
 
 var (
@@ -563,7 +565,7 @@ func (i *InvoiceRegistry) checkHtlcParameters(invoice *channeldb.Invoice,
 // prevent deadlock.
 func (i *InvoiceRegistry) NotifyExitHopHtlc(rHash lntypes.Hash,
 	amtPaid lnwire.MilliSatoshi, expiry uint32, currentHeight int32,
-	hodlChan chan<- interface{}) (*HodlEvent, error) {
+	hodlChan chan<- interface{}, packetEOB []byte) (*HodlEvent, error) {
 
 	i.Lock()
 	defer i.Unlock()
@@ -572,6 +574,7 @@ func (i *InvoiceRegistry) NotifyExitHopHtlc(rHash lntypes.Hash,
 		log.Debugf("Invoice(%x): %v, amt=%v, expiry=%v",
 			rHash[:], s, amtPaid, expiry)
 	}
+
 	// First check the in-memory debug invoice index to see if this is an
 	// existing invoice added for debugging.
 	if invoice, ok := i.debugInvoices[rHash]; ok {
@@ -585,6 +588,46 @@ func (i *InvoiceRegistry) NotifyExitHopHtlc(rHash lntypes.Hash,
 		}, nil
 	}
 
+	// If any EOB data was provided, then we'll attempt to decode the TLV
+	// information included, as it may modify when/how we settle the HTLC.
+	if len(packetEOB) != 0 {
+		log.Infof("TLV packet other: %x", packetEOB)
+
+		// Atm, the only TLV field that we care about is the one that
+		// denotes a pre-image has been sent to us in the encrypted EOB, so
+		// we'll attempt to parse that out.
+		var (
+			preImage      [32]byte
+			blankPreImage [32]byte
+		)
+		tlvStream := tlv.NewStream(
+			wtwire.WriteElement, wtwire.ReadElement,
+			tlv.MakePrimitiveRecord(PreimageTLV, &preImage),
+		)
+		err := tlvStream.Decode(
+			bytes.NewReader(packetEOB), tlv.ParseModeRetain,
+		)
+		if err != nil {
+			return nil, err
+		}
+
+		// If something was acutally specified for this tag, then we'll
+		// check to see if it matches up with the payment hash.
+		paymentSecret := lntypes.Preimage(preImage)
+		if preImage != blankPreImage && paymentSecret.Matches(rHash) {
+
+			debugLog("settled")
+
+			// TODO(roasbeef): record settled spontaneous payment
+			// in DB
+
+			return &HodlEvent{
+				Hash:     rHash,
+				Preimage: &paymentSecret,
+			}, nil
+		}
+	}
+
 	// If this isn't a debug invoice, then we'll attempt to settle an
 	// invoice matching this rHash on disk (if one exists).
 	invoice, err := i.cdb.AcceptOrSettleInvoice(

invoices/tlv_types.go

@@ -0,0 +1,6 @@
+package invoices
+
+const (
+	// PreimageTLV...
+	PreimageTLV = 128
+)