From 7aa4a7c7fcbbe5058960ad8edfea9a8228bd1c12 Mon Sep 17 00:00:00 2001
From: Joost Jager <joost.jager@gmail.com>
Date: Wed, 11 Dec 2019 10:20:55 +0100
Subject: [PATCH 1/5] channeldb/migration_01_to_11: isolate route structure

Before we change the Hop struct, isolate the code that is used in older
migrations to prevent breaking them.

route.go was taken from commit 6e463c1634061d595953f20813860207e5d485ce
---
 .../migration_09_legacy_serialization.go      |  15 +-
 .../migration_10_route_tlv_records.go         |  15 +-
 channeldb/migration_01_to_11/migrations.go    |   7 +-
 .../migration_01_to_11/migrations_test.go     |  15 +-
 channeldb/migration_01_to_11/payments.go      |  17 +-
 channeldb/migration_01_to_11/route.go         | 330 ++++++++++++++++++
 6 files changed, 362 insertions(+), 37 deletions(-)
 create mode 100644 channeldb/migration_01_to_11/route.go

diff --git a/channeldb/migration_01_to_11/migration_09_legacy_serialization.go b/channeldb/migration_01_to_11/migration_09_legacy_serialization.go
index cc6614c9..cc0568a3 100644
--- a/channeldb/migration_01_to_11/migration_09_legacy_serialization.go
+++ b/channeldb/migration_01_to_11/migration_09_legacy_serialization.go
@@ -10,7 +10,6 @@ import (
 	"github.com/coreos/bbolt"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
-	"github.com/lightningnetwork/lnd/routing/route"
 )
 
 var (
@@ -274,7 +273,7 @@ func serializePaymentAttemptInfoMigration9(w io.Writer, a *PaymentAttemptInfo) e
 	return nil
 }
 
-func serializeHopMigration9(w io.Writer, h *route.Hop) error {
+func serializeHopMigration9(w io.Writer, h *Hop) error {
 	if err := WriteElements(w,
 		h.PubKeyBytes[:], h.ChannelID, h.OutgoingTimeLock,
 		h.AmtToForward,
@@ -285,7 +284,7 @@ func serializeHopMigration9(w io.Writer, h *route.Hop) error {
 	return nil
 }
 
-func serializeRouteMigration9(w io.Writer, r route.Route) error {
+func serializeRouteMigration9(w io.Writer, r Route) error {
 	if err := WriteElements(w,
 		r.TotalTimeLock, r.TotalAmount, r.SourcePubKey[:],
 	); err != nil {
@@ -318,8 +317,8 @@ func deserializePaymentAttemptInfoMigration9(r io.Reader) (*PaymentAttemptInfo,
 	return a, nil
 }
 
-func deserializeRouteMigration9(r io.Reader) (route.Route, error) {
-	rt := route.Route{}
+func deserializeRouteMigration9(r io.Reader) (Route, error) {
+	rt := Route{}
 	if err := ReadElements(r,
 		&rt.TotalTimeLock, &rt.TotalAmount,
 	); err != nil {
@@ -337,7 +336,7 @@ func deserializeRouteMigration9(r io.Reader) (route.Route, error) {
 		return rt, err
 	}
 
-	var hops []*route.Hop
+	var hops []*Hop
 	for i := uint32(0); i < numHops; i++ {
 		hop, err := deserializeHopMigration9(r)
 		if err != nil {
@@ -350,8 +349,8 @@ func deserializeRouteMigration9(r io.Reader) (route.Route, error) {
 	return rt, nil
 }
 
-func deserializeHopMigration9(r io.Reader) (*route.Hop, error) {
-	h := &route.Hop{}
+func deserializeHopMigration9(r io.Reader) (*Hop, error) {
+	h := &Hop{}
 
 	var pub []byte
 	if err := ReadElements(r, &pub); err != nil {
diff --git a/channeldb/migration_01_to_11/migration_10_route_tlv_records.go b/channeldb/migration_01_to_11/migration_10_route_tlv_records.go
index 648d85ad..e404f575 100644
--- a/channeldb/migration_01_to_11/migration_10_route_tlv_records.go
+++ b/channeldb/migration_01_to_11/migration_10_route_tlv_records.go
@@ -5,7 +5,6 @@ import (
 	"io"
 
 	"github.com/coreos/bbolt"
-	"github.com/lightningnetwork/lnd/routing/route"
 )
 
 // MigrateRouteSerialization migrates the way we serialize routes across the
@@ -154,8 +153,8 @@ func serializePaymentAttemptInfoLegacy(w io.Writer, a *PaymentAttemptInfo) error
 	return nil
 }
 
-func deserializeHopLegacy(r io.Reader) (*route.Hop, error) {
-	h := &route.Hop{}
+func deserializeHopLegacy(r io.Reader) (*Hop, error) {
+	h := &Hop{}
 
 	var pub []byte
 	if err := ReadElements(r, &pub); err != nil {
@@ -172,7 +171,7 @@ func deserializeHopLegacy(r io.Reader) (*route.Hop, error) {
 	return h, nil
 }
 
-func serializeHopLegacy(w io.Writer, h *route.Hop) error {
+func serializeHopLegacy(w io.Writer, h *Hop) error {
 	if err := WriteElements(w,
 		h.PubKeyBytes[:], h.ChannelID, h.OutgoingTimeLock,
 		h.AmtToForward,
@@ -183,8 +182,8 @@ func serializeHopLegacy(w io.Writer, h *route.Hop) error {
 	return nil
 }
 
-func deserializeRouteLegacy(r io.Reader) (route.Route, error) {
-	rt := route.Route{}
+func deserializeRouteLegacy(r io.Reader) (Route, error) {
+	rt := Route{}
 	if err := ReadElements(r,
 		&rt.TotalTimeLock, &rt.TotalAmount,
 	); err != nil {
@@ -202,7 +201,7 @@ func deserializeRouteLegacy(r io.Reader) (route.Route, error) {
 		return rt, err
 	}
 
-	var hops []*route.Hop
+	var hops []*Hop
 	for i := uint32(0); i < numHops; i++ {
 		hop, err := deserializeHopLegacy(r)
 		if err != nil {
@@ -215,7 +214,7 @@ func deserializeRouteLegacy(r io.Reader) (route.Route, error) {
 	return rt, nil
 }
 
-func serializeRouteLegacy(w io.Writer, r route.Route) error {
+func serializeRouteLegacy(w io.Writer, r Route) error {
 	if err := WriteElements(w,
 		r.TotalTimeLock, r.TotalAmount, r.SourcePubKey[:],
 	); err != nil {
diff --git a/channeldb/migration_01_to_11/migrations.go b/channeldb/migration_01_to_11/migrations.go
index 3f841009..511633d8 100644
--- a/channeldb/migration_01_to_11/migrations.go
+++ b/channeldb/migration_01_to_11/migrations.go
@@ -9,7 +9,6 @@ import (
 	"github.com/btcsuite/btcd/btcec"
 	"github.com/coreos/bbolt"
 	"github.com/lightningnetwork/lnd/lnwire"
-	"github.com/lightningnetwork/lnd/routing/route"
 )
 
 // MigrateNodeAndEdgeUpdateIndex is a migration function that will update the
@@ -817,14 +816,14 @@ func MigrateOutgoingPayments(tx *bbolt.Tx) error {
 
 		// Do the same for the PaymentAttemptInfo.
 		totalAmt := payment.Terms.Value + payment.Fee
-		rt := route.Route{
+		rt := Route{
 			TotalTimeLock: payment.TimeLockLength,
 			TotalAmount:   totalAmt,
 			SourcePubKey:  sourcePubKey,
-			Hops:          []*route.Hop{},
+			Hops:          []*Hop{},
 		}
 		for _, hop := range payment.Path {
-			rt.Hops = append(rt.Hops, &route.Hop{
+			rt.Hops = append(rt.Hops, &Hop{
 				PubKeyBytes:  hop,
 				AmtToForward: totalAmt,
 			})
diff --git a/channeldb/migration_01_to_11/migrations_test.go b/channeldb/migration_01_to_11/migrations_test.go
index 980b029c..fd2c2565 100644
--- a/channeldb/migration_01_to_11/migrations_test.go
+++ b/channeldb/migration_01_to_11/migrations_test.go
@@ -16,7 +16,6 @@ import (
 	"github.com/go-errors/errors"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
-	"github.com/lightningnetwork/lnd/routing/route"
 )
 
 // TestPaymentStatusesMigration checks that already completed payments will have
@@ -714,25 +713,25 @@ func makeRandPaymentCreationInfo() (*PaymentCreationInfo, error) {
 func TestPaymentRouteSerialization(t *testing.T) {
 	t.Parallel()
 
-	legacyHop1 := &route.Hop{
-		PubKeyBytes:      route.NewVertex(pub),
+	legacyHop1 := &Hop{
+		PubKeyBytes:      NewVertex(pub),
 		ChannelID:        12345,
 		OutgoingTimeLock: 111,
 		LegacyPayload:    true,
 		AmtToForward:     555,
 	}
-	legacyHop2 := &route.Hop{
-		PubKeyBytes:      route.NewVertex(pub),
+	legacyHop2 := &Hop{
+		PubKeyBytes:      NewVertex(pub),
 		ChannelID:        12345,
 		OutgoingTimeLock: 111,
 		LegacyPayload:    true,
 		AmtToForward:     555,
 	}
-	legacyRoute := route.Route{
+	legacyRoute := Route{
 		TotalTimeLock: 123,
 		TotalAmount:   1234567,
-		SourcePubKey:  route.NewVertex(pub),
-		Hops:          []*route.Hop{legacyHop1, legacyHop2},
+		SourcePubKey:  NewVertex(pub),
+		Hops:          []*Hop{legacyHop1, legacyHop2},
 	}
 
 	const numPayments = 4
diff --git a/channeldb/migration_01_to_11/payments.go b/channeldb/migration_01_to_11/payments.go
index 1195ca82..16e4a71c 100644
--- a/channeldb/migration_01_to_11/payments.go
+++ b/channeldb/migration_01_to_11/payments.go
@@ -14,7 +14,6 @@ import (
 	"github.com/coreos/bbolt"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
-	"github.com/lightningnetwork/lnd/routing/route"
 	"github.com/lightningnetwork/lnd/tlv"
 )
 
@@ -213,7 +212,7 @@ type PaymentAttemptInfo struct {
 	SessionKey *btcec.PrivateKey
 
 	// Route is the route attempted to send the HTLC.
-	Route route.Route
+	Route Route
 }
 
 // Payment is a wrapper around a payment's PaymentCreationInfo,
@@ -464,7 +463,7 @@ func deserializePaymentAttemptInfo(r io.Reader) (*PaymentAttemptInfo, error) {
 	return a, nil
 }
 
-func serializeHop(w io.Writer, h *route.Hop) error {
+func serializeHop(w io.Writer, h *Hop) error {
 	if err := WriteElements(w,
 		h.PubKeyBytes[:], h.ChannelID, h.OutgoingTimeLock,
 		h.AmtToForward,
@@ -513,8 +512,8 @@ func serializeHop(w io.Writer, h *route.Hop) error {
 // to read/write a TLV stream larger than this.
 const maxOnionPayloadSize = 1300
 
-func deserializeHop(r io.Reader) (*route.Hop, error) {
-	h := &route.Hop{}
+func deserializeHop(r io.Reader) (*Hop, error) {
+	h := &Hop{}
 
 	var pub []byte
 	if err := ReadElements(r, &pub); err != nil {
@@ -568,7 +567,7 @@ func deserializeHop(r io.Reader) (*route.Hop, error) {
 }
 
 // SerializeRoute serializes a route.
-func SerializeRoute(w io.Writer, r route.Route) error {
+func SerializeRoute(w io.Writer, r Route) error {
 	if err := WriteElements(w,
 		r.TotalTimeLock, r.TotalAmount, r.SourcePubKey[:],
 	); err != nil {
@@ -589,8 +588,8 @@ func SerializeRoute(w io.Writer, r route.Route) error {
 }
 
 // DeserializeRoute deserializes a route.
-func DeserializeRoute(r io.Reader) (route.Route, error) {
-	rt := route.Route{}
+func DeserializeRoute(r io.Reader) (Route, error) {
+	rt := Route{}
 	if err := ReadElements(r,
 		&rt.TotalTimeLock, &rt.TotalAmount,
 	); err != nil {
@@ -608,7 +607,7 @@ func DeserializeRoute(r io.Reader) (route.Route, error) {
 		return rt, err
 	}
 
-	var hops []*route.Hop
+	var hops []*Hop
 	for i := uint32(0); i < numHops; i++ {
 		hop, err := deserializeHop(r)
 		if err != nil {
diff --git a/channeldb/migration_01_to_11/route.go b/channeldb/migration_01_to_11/route.go
new file mode 100644
index 00000000..1dbfff60
--- /dev/null
+++ b/channeldb/migration_01_to_11/route.go
@@ -0,0 +1,330 @@
+package migration_01_to_11
+
+import (
+	"bytes"
+	"encoding/binary"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+
+	"github.com/btcsuite/btcd/btcec"
+	sphinx "github.com/lightningnetwork/lightning-onion"
+	"github.com/lightningnetwork/lnd/lnwire"
+	"github.com/lightningnetwork/lnd/record"
+	"github.com/lightningnetwork/lnd/tlv"
+)
+
+// VertexSize is the size of the array to store a vertex.
+const VertexSize = 33
+
+// ErrNoRouteHopsProvided is returned when a caller attempts to construct a new
+// sphinx packet, but provides an empty set of hops for each route.
+var ErrNoRouteHopsProvided = fmt.Errorf("empty route hops provided")
+
+// Vertex is a simple alias for the serialization of a compressed Bitcoin
+// public key.
+type Vertex [VertexSize]byte
+
+// NewVertex returns a new Vertex given a public key.
+func NewVertex(pub *btcec.PublicKey) Vertex {
+	var v Vertex
+	copy(v[:], pub.SerializeCompressed())
+	return v
+}
+
+// NewVertexFromBytes returns a new Vertex based on a serialized pubkey in a
+// byte slice.
+func NewVertexFromBytes(b []byte) (Vertex, error) {
+	vertexLen := len(b)
+	if vertexLen != VertexSize {
+		return Vertex{}, fmt.Errorf("invalid vertex length of %v, "+
+			"want %v", vertexLen, VertexSize)
+	}
+
+	var v Vertex
+	copy(v[:], b)
+	return v, nil
+}
+
+// NewVertexFromStr returns a new Vertex given its hex-encoded string format.
+func NewVertexFromStr(v string) (Vertex, error) {
+	// Return error if hex string is of incorrect length.
+	if len(v) != VertexSize*2 {
+		return Vertex{}, fmt.Errorf("invalid vertex string length of "+
+			"%v, want %v", len(v), VertexSize*2)
+	}
+
+	vertex, err := hex.DecodeString(v)
+	if err != nil {
+		return Vertex{}, err
+	}
+
+	return NewVertexFromBytes(vertex)
+}
+
+// String returns a human readable version of the Vertex which is the
+// hex-encoding of the serialized compressed public key.
+func (v Vertex) String() string {
+	return fmt.Sprintf("%x", v[:])
+}
+
+// Hop represents an intermediate or final node of the route. This naming
+// is in line with the definition given in BOLT #4: Onion Routing Protocol.
+// The struct houses the channel along which this hop can be reached and
+// the values necessary to create the HTLC that needs to be sent to the
+// next hop. It is also used to encode the per-hop payload included within
+// the Sphinx packet.
+type Hop struct {
+	// PubKeyBytes is the raw bytes of the public key of the target node.
+	PubKeyBytes Vertex
+
+	// ChannelID is the unique channel ID for the channel. The first 3
+	// bytes are the block height, the next 3 the index within the block,
+	// and the last 2 bytes are the output index for the channel.
+	ChannelID uint64
+
+	// OutgoingTimeLock is the timelock value that should be used when
+	// crafting the _outgoing_ HTLC from this hop.
+	OutgoingTimeLock uint32
+
+	// AmtToForward is the amount that this hop will forward to the next
+	// hop. This value is less than the value that the incoming HTLC
+	// carries as a fee will be subtracted by the hop.
+	AmtToForward lnwire.MilliSatoshi
+
+	// TLVRecords if non-nil are a set of additional TLV records that
+	// should be included in the forwarding instructions for this node.
+	TLVRecords []tlv.Record
+
+	// LegacyPayload if true, then this signals that this node doesn't
+	// understand the new TLV payload, so we must instead use the legacy
+	// payload.
+	LegacyPayload bool
+}
+
+// PackHopPayload writes to the passed io.Writer, the series of byes that can
+// be placed directly into the per-hop payload (EOB) for this hop. This will
+// include the required routing fields, as well as serializing any of the
+// passed optional TLVRecords.  nextChanID is the unique channel ID that
+// references the _outgoing_ channel ID that follows this hop. This field
+// follows the same semantics as the NextAddress field in the onion: it should
+// be set to zero to indicate the terminal hop.
+func (h *Hop) PackHopPayload(w io.Writer, nextChanID uint64) error {
+	// If this is a legacy payload, then we'll exit here as this method
+	// shouldn't be called.
+	if h.LegacyPayload == true {
+		return fmt.Errorf("cannot pack hop payloads for legacy " +
+			"payloads")
+	}
+
+	// Otherwise, we'll need to make a new stream that includes our
+	// required routing fields, as well as these optional values.
+	var records []tlv.Record
+
+	// Every hop must have an amount to forward and CLTV expiry.
+	amt := uint64(h.AmtToForward)
+	records = append(records,
+		record.NewAmtToFwdRecord(&amt),
+		record.NewLockTimeRecord(&h.OutgoingTimeLock),
+	)
+
+	// BOLT 04 says the next_hop_id should be omitted for the final hop,
+	// but present for all others.
+	//
+	// TODO(conner): test using hop.Exit once available
+	if nextChanID != 0 {
+		records = append(records,
+			record.NewNextHopIDRecord(&nextChanID),
+		)
+	}
+
+	// Append any custom types destined for this hop.
+	records = append(records, h.TLVRecords...)
+
+	// To ensure we produce a canonical stream, we'll sort the records
+	// before encoding them as a stream in the hop payload.
+	tlv.SortRecords(records)
+
+	tlvStream, err := tlv.NewStream(records...)
+	if err != nil {
+		return err
+	}
+
+	return tlvStream.Encode(w)
+}
+
+// Route represents a path through the channel graph which runs over one or
+// more channels in succession. This struct carries all the information
+// required to craft the Sphinx onion packet, and send the payment along the
+// first hop in the path. A route is only selected as valid if all the channels
+// have sufficient capacity to carry the initial payment amount after fees are
+// accounted for.
+type Route struct {
+	// TotalTimeLock is the cumulative (final) time lock across the entire
+	// route. This is the CLTV value that should be extended to the first
+	// hop in the route. All other hops will decrement the time-lock as
+	// advertised, leaving enough time for all hops to wait for or present
+	// the payment preimage to complete the payment.
+	TotalTimeLock uint32
+
+	// TotalAmount is the total amount of funds required to complete a
+	// payment over this route. This value includes the cumulative fees at
+	// each hop. As a result, the HTLC extended to the first-hop in the
+	// route will need to have at least this many satoshis, otherwise the
+	// route will fail at an intermediate node due to an insufficient
+	// amount of fees.
+	TotalAmount lnwire.MilliSatoshi
+
+	// SourcePubKey is the pubkey of the node where this route originates
+	// from.
+	SourcePubKey Vertex
+
+	// Hops contains details concerning the specific forwarding details at
+	// each hop.
+	Hops []*Hop
+}
+
+// HopFee returns the fee charged by the route hop indicated by hopIndex.
+func (r *Route) HopFee(hopIndex int) lnwire.MilliSatoshi {
+	var incomingAmt lnwire.MilliSatoshi
+	if hopIndex == 0 {
+		incomingAmt = r.TotalAmount
+	} else {
+		incomingAmt = r.Hops[hopIndex-1].AmtToForward
+	}
+
+	// Fee is calculated as difference between incoming and outgoing amount.
+	return incomingAmt - r.Hops[hopIndex].AmtToForward
+}
+
+// TotalFees is the sum of the fees paid at each hop within the final route. In
+// the case of a one-hop payment, this value will be zero as we don't need to
+// pay a fee to ourself.
+func (r *Route) TotalFees() lnwire.MilliSatoshi {
+	if len(r.Hops) == 0 {
+		return 0
+	}
+
+	return r.TotalAmount - r.Hops[len(r.Hops)-1].AmtToForward
+}
+
+// NewRouteFromHops creates a new Route structure from the minimally required
+// information to perform the payment. It infers fee amounts and populates the
+// node, chan and prev/next hop maps.
+func NewRouteFromHops(amtToSend lnwire.MilliSatoshi, timeLock uint32,
+	sourceVertex Vertex, hops []*Hop) (*Route, error) {
+
+	if len(hops) == 0 {
+		return nil, ErrNoRouteHopsProvided
+	}
+
+	// First, we'll create a route struct and populate it with the fields
+	// for which the values are provided as arguments of this function.
+	// TotalFees is determined based on the difference between the amount
+	// that is send from the source and the final amount that is received
+	// by the destination.
+	route := &Route{
+		SourcePubKey:  sourceVertex,
+		Hops:          hops,
+		TotalTimeLock: timeLock,
+		TotalAmount:   amtToSend,
+	}
+
+	return route, nil
+}
+
+// ToSphinxPath converts a complete route into a sphinx PaymentPath that
+// contains the per-hop paylods used to encoding the HTLC routing data for each
+// hop in the route. This method also accepts an optional EOB payload for the
+// final hop.
+func (r *Route) ToSphinxPath() (*sphinx.PaymentPath, error) {
+	var path sphinx.PaymentPath
+
+	// For each hop encoded within the route, we'll convert the hop struct
+	// to an OnionHop with matching per-hop payload within the path as used
+	// by the sphinx package.
+	for i, hop := range r.Hops {
+		pub, err := btcec.ParsePubKey(
+			hop.PubKeyBytes[:], btcec.S256(),
+		)
+		if err != nil {
+			return nil, err
+		}
+
+		// As a base case, the next hop is set to all zeroes in order
+		// to indicate that the "last hop" as no further hops after it.
+		nextHop := uint64(0)
+
+		// If we aren't on the last hop, then we set the "next address"
+		// field to be the channel that directly follows it.
+		if i != len(r.Hops)-1 {
+			nextHop = r.Hops[i+1].ChannelID
+		}
+
+		var payload sphinx.HopPayload
+
+		// If this is the legacy payload, then we can just include the
+		// hop data as normal.
+		if hop.LegacyPayload {
+			// Before we encode this value, we'll pack the next hop
+			// into the NextAddress field of the hop info to ensure
+			// we point to the right now.
+			hopData := sphinx.HopData{
+				ForwardAmount: uint64(hop.AmtToForward),
+				OutgoingCltv:  hop.OutgoingTimeLock,
+			}
+			binary.BigEndian.PutUint64(
+				hopData.NextAddress[:], nextHop,
+			)
+
+			payload, err = sphinx.NewHopPayload(&hopData, nil)
+			if err != nil {
+				return nil, err
+			}
+		} else {
+			// For non-legacy payloads, we'll need to pack the
+			// routing information, along with any extra TLV
+			// information into the new per-hop payload format.
+			// We'll also pass in the chan ID of the hop this
+			// channel should be forwarded to so we can construct a
+			// valid payload.
+			var b bytes.Buffer
+			err := hop.PackHopPayload(&b, nextHop)
+			if err != nil {
+				return nil, err
+			}
+
+			// TODO(roasbeef): make better API for NewHopPayload?
+			payload, err = sphinx.NewHopPayload(nil, b.Bytes())
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		path[i] = sphinx.OnionHop{
+			NodePub:    *pub,
+			HopPayload: payload,
+		}
+	}
+
+	return &path, nil
+}
+
+// String returns a human readable representation of the route.
+func (r *Route) String() string {
+	var b strings.Builder
+
+	for i, hop := range r.Hops {
+		if i > 0 {
+			b.WriteString(",")
+		}
+		b.WriteString(strconv.FormatUint(hop.ChannelID, 10))
+	}
+
+	return fmt.Sprintf("amt=%v, fees=%v, tl=%v, chans=%v",
+		r.TotalAmount-r.TotalFees(), r.TotalFees(), r.TotalTimeLock,
+		b.String(),
+	)
+}

From 8b5bb0ac639c96a5bd165dde568a0a073c5e6394 Mon Sep 17 00:00:00 2001
From: Joost Jager <joost.jager@gmail.com>
Date: Thu, 12 Dec 2019 00:01:55 +0100
Subject: [PATCH 2/5] record: move CustomRecordSet

---
 channeldb/invoice_test.go         | 10 +++++-----
 channeldb/invoices.go             |  5 +++--
 htlcswitch/hop/payload.go         | 25 +++++++++----------------
 htlcswitch/hop/payload_test.go    |  2 +-
 invoices/interface.go             |  3 +--
 invoices/invoiceregistry_test.go  |  5 ++---
 invoices/update.go                |  4 +---
 lnrpc/routerrpc/router_backend.go |  5 ++---
 record/custom_records.go          | 10 ++++++++++
 9 files changed, 34 insertions(+), 35 deletions(-)
 create mode 100644 record/custom_records.go

diff --git a/channeldb/invoice_test.go b/channeldb/invoice_test.go
index 24eaf180..b38c5cad 100644
--- a/channeldb/invoice_test.go
+++ b/channeldb/invoice_test.go
@@ -7,9 +7,9 @@ import (
 	"time"
 
 	"github.com/davecgh/go-spew/spew"
-	"github.com/lightningnetwork/lnd/htlcswitch/hop"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
+	"github.com/lightningnetwork/lnd/record"
 )
 
 var (
@@ -212,7 +212,7 @@ func TestInvoiceCancelSingleHtlc(t *testing.T) {
 	key := CircuitKey{ChanID: lnwire.NewShortChanIDFromInt(1), HtlcID: 4}
 	htlc := HtlcAcceptDesc{
 		Amt:           500,
-		CustomRecords: make(hop.CustomRecordSet),
+		CustomRecords: make(record.CustomSet),
 	}
 	invoice, err := db.UpdateInvoice(paymentHash,
 		func(invoice *Invoice) (*InvoiceUpdateDesc, error) {
@@ -439,7 +439,7 @@ func TestDuplicateSettleInvoice(t *testing.T) {
 			AcceptTime:    time.Unix(1, 0),
 			ResolveTime:   time.Unix(1, 0),
 			State:         HtlcStateSettled,
-			CustomRecords: make(hop.CustomRecordSet),
+			CustomRecords: make(record.CustomSet),
 		},
 	}
 
@@ -751,7 +751,7 @@ func getUpdateInvoice(amt lnwire.MilliSatoshi) InvoiceUpdateCallback {
 			return nil, ErrInvoiceAlreadySettled
 		}
 
-		noRecords := make(hop.CustomRecordSet)
+		noRecords := make(record.CustomSet)
 
 		update := &InvoiceUpdateDesc{
 			State: &InvoiceStateUpdateDesc{
@@ -795,7 +795,7 @@ func TestCustomRecords(t *testing.T) {
 	// Accept an htlc with custom records on this invoice.
 	key := CircuitKey{ChanID: lnwire.NewShortChanIDFromInt(1), HtlcID: 4}
 
-	records := hop.CustomRecordSet{
+	records := record.CustomSet{
 		100000: []byte{},
 		100001: []byte{1, 2},
 	}
diff --git a/channeldb/invoices.go b/channeldb/invoices.go
index 106c0e41..8ded522f 100644
--- a/channeldb/invoices.go
+++ b/channeldb/invoices.go
@@ -12,6 +12,7 @@ import (
 	"github.com/lightningnetwork/lnd/htlcswitch/hop"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
+	"github.com/lightningnetwork/lnd/record"
 	"github.com/lightningnetwork/lnd/tlv"
 )
 
@@ -317,7 +318,7 @@ type InvoiceHTLC struct {
 
 	// CustomRecords contains the custom key/value pairs that accompanied
 	// the htlc.
-	CustomRecords hop.CustomRecordSet
+	CustomRecords record.CustomSet
 }
 
 // HtlcAcceptDesc describes the details of a newly accepted htlc.
@@ -337,7 +338,7 @@ type HtlcAcceptDesc struct {
 
 	// CustomRecords contains the custom key/value pairs that accompanied
 	// the htlc.
-	CustomRecords hop.CustomRecordSet
+	CustomRecords record.CustomSet
 }
 
 // InvoiceUpdateDesc describes the changes that should be applied to the
diff --git a/htlcswitch/hop/payload.go b/htlcswitch/hop/payload.go
index 523ffbad..d8aafd9c 100644
--- a/htlcswitch/hop/payload.go
+++ b/htlcswitch/hop/payload.go
@@ -29,12 +29,6 @@ const (
 	RequiredViolation
 )
 
-const (
-	// CustomTypeStart is the start of the custom tlv type range as defined
-	// in BOLT 01.
-	CustomTypeStart = 65536
-)
-
 // String returns a human-readable description of the violation as a verb.
 func (v PayloadViolation) String() string {
 	switch v {
@@ -79,9 +73,6 @@ func (e ErrInvalidPayload) Error() string {
 		hopType, e.Violation, e.Type)
 }
 
-// CustomRecordSet stores a set of custom key/value pairs.
-type CustomRecordSet map[uint64][]byte
-
 // Payload encapsulates all information delivered to a hop in an onion payload.
 // A Hop can represent either a TLV or legacy payload. The primary forwarding
 // instruction can be accessed via ForwardingInfo, and additional records can be
@@ -97,7 +88,7 @@ type Payload struct {
 
 	// customRecords are user-defined records in the custom type range that
 	// were included in the payload.
-	customRecords CustomRecordSet
+	customRecords record.CustomSet
 }
 
 // NewLegacyPayload builds a Payload from the amount, cltv, and next hop
@@ -112,7 +103,7 @@ func NewLegacyPayload(f *sphinx.HopData) *Payload {
 			AmountToForward: lnwire.MilliSatoshi(f.ForwardAmount),
 			OutgoingCTLV:    f.OutgoingCltv,
 		},
-		customRecords: make(CustomRecordSet),
+		customRecords: make(record.CustomSet),
 	}
 }
 
@@ -188,10 +179,10 @@ func (h *Payload) ForwardingInfo() ForwardingInfo {
 
 // NewCustomRecords filters the types parsed from the tlv stream for custom
 // records.
-func NewCustomRecords(parsedTypes tlv.TypeMap) CustomRecordSet {
-	customRecords := make(CustomRecordSet)
+func NewCustomRecords(parsedTypes tlv.TypeMap) record.CustomSet {
+	customRecords := make(record.CustomSet)
 	for t, parseResult := range parsedTypes {
-		if parseResult == nil || t < CustomTypeStart {
+		if parseResult == nil || t < record.CustomTypeStart {
 			continue
 		}
 		customRecords[uint64(t)] = parseResult
@@ -261,7 +252,7 @@ func (h *Payload) MultiPath() *record.MPP {
 
 // CustomRecords returns the custom tlv type records that were parsed from the
 // payload.
-func (h *Payload) CustomRecords() CustomRecordSet {
+func (h *Payload) CustomRecords() record.CustomSet {
 	return h.customRecords
 }
 
@@ -280,7 +271,9 @@ func getMinRequiredViolation(set tlv.TypeMap) *tlv.Type {
 		//
 		// We always accept custom fields, because a higher level
 		// application may understand them.
-		if parseResult == nil || t%2 != 0 || t >= CustomTypeStart {
+		if parseResult == nil || t%2 != 0 ||
+			t >= record.CustomTypeStart {
+
 			continue
 		}
 
diff --git a/htlcswitch/hop/payload_test.go b/htlcswitch/hop/payload_test.go
index f8c0df21..b0a92534 100644
--- a/htlcswitch/hop/payload_test.go
+++ b/htlcswitch/hop/payload_test.go
@@ -244,7 +244,7 @@ func testDecodeHopPayloadValidation(t *testing.T, test decodePayloadTest) {
 
 	// Convert expected nil map to empty map, because we always expect an
 	// initiated map from the payload.
-	expCustomRecords := make(hop.CustomRecordSet)
+	expCustomRecords := make(record.CustomSet)
 	if test.expCustomRecords != nil {
 		expCustomRecords = test.expCustomRecords
 	}
diff --git a/invoices/interface.go b/invoices/interface.go
index bf7f0ed9..c511dded 100644
--- a/invoices/interface.go
+++ b/invoices/interface.go
@@ -1,7 +1,6 @@
 package invoices
 
 import (
-	"github.com/lightningnetwork/lnd/htlcswitch/hop"
 	"github.com/lightningnetwork/lnd/record"
 )
 
@@ -14,5 +13,5 @@ type Payload interface {
 
 	// CustomRecords returns the custom tlv type records that were parsed
 	// from the payload.
-	CustomRecords() hop.CustomRecordSet
+	CustomRecords() record.CustomSet
 }
diff --git a/invoices/invoiceregistry_test.go b/invoices/invoiceregistry_test.go
index 8b992258..eabb2ba2 100644
--- a/invoices/invoiceregistry_test.go
+++ b/invoices/invoiceregistry_test.go
@@ -7,7 +7,6 @@ import (
 	"time"
 
 	"github.com/lightningnetwork/lnd/channeldb"
-	"github.com/lightningnetwork/lnd/htlcswitch/hop"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/record"
@@ -690,8 +689,8 @@ func (p *mockPayload) MultiPath() *record.MPP {
 	return p.mpp
 }
 
-func (p *mockPayload) CustomRecords() hop.CustomRecordSet {
-	return make(hop.CustomRecordSet)
+func (p *mockPayload) CustomRecords() record.CustomSet {
+	return make(record.CustomSet)
 }
 
 // TestSettleMpp tests settling of an invoice with multiple partial payments.
diff --git a/invoices/update.go b/invoices/update.go
index 3175efa6..913caeb0 100644
--- a/invoices/update.go
+++ b/invoices/update.go
@@ -3,8 +3,6 @@ package invoices
 import (
 	"errors"
 
-	"github.com/lightningnetwork/lnd/htlcswitch/hop"
-
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/record"
@@ -105,7 +103,7 @@ type invoiceUpdateCtx struct {
 	expiry               uint32
 	currentHeight        int32
 	finalCltvRejectDelta int32
-	customRecords        hop.CustomRecordSet
+	customRecords        record.CustomSet
 	mpp                  *record.MPP
 }
 
diff --git a/lnrpc/routerrpc/router_backend.go b/lnrpc/routerrpc/router_backend.go
index 38c4a1b7..b9de9617 100644
--- a/lnrpc/routerrpc/router_backend.go
+++ b/lnrpc/routerrpc/router_backend.go
@@ -13,7 +13,6 @@ import (
 	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/btcsuite/btcutil"
 	"github.com/lightningnetwork/lnd/channeldb"
-	"github.com/lightningnetwork/lnd/htlcswitch/hop"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
@@ -385,9 +384,9 @@ func UnmarshallCustomRecords(rpcRecords map[uint64][]byte) ([]tlv.Record,
 
 	// tlvRecords is sorted, so we only need to check that the first
 	// element is within the custom range.
-	if uint64(tlvRecords[0].Type()) < hop.CustomTypeStart {
+	if uint64(tlvRecords[0].Type()) < record.CustomTypeStart {
 		return nil, fmt.Errorf("no custom records with types "+
-			"below %v allowed", hop.CustomTypeStart)
+			"below %v allowed", record.CustomTypeStart)
 	}
 
 	return tlvRecords, nil
diff --git a/record/custom_records.go b/record/custom_records.go
new file mode 100644
index 00000000..36e9e5ac
--- /dev/null
+++ b/record/custom_records.go
@@ -0,0 +1,10 @@
+package record
+
+const (
+	// CustomTypeStart is the start of the custom tlv type range as defined
+	// in BOLT 01.
+	CustomTypeStart = 65536
+)
+
+// CustomSet stores a set of custom key/value pairs.
+type CustomSet map[uint64][]byte

From d02de70d20e2af8a43ce9397a1b71fb63122a99d Mon Sep 17 00:00:00 2001
From: Joost Jager <joost.jager@gmail.com>
Date: Wed, 11 Dec 2019 10:52:27 +0100
Subject: [PATCH 3/5] multi: do not use tlv.Record outside wire format handling

This commit prepares for more manipulation of custom records. A list of
tlv.Record types is more difficult to use than the more basic
map[uint64][]byte.

Furthermore fields and variables are renamed to make them more
consistent.
---
 channeldb/payments.go                  |  6 +-
 channeldb/payments_test.go             | 78 ++------------------------
 lnrpc/routerrpc/router_backend.go      | 49 ++++++----------
 lnrpc/routerrpc/router_backend_test.go |  4 +-
 routing/pathfind.go                    |  8 +--
 routing/payment_session.go             |  2 +-
 routing/route/route.go                 |  7 ++-
 routing/router.go                      | 10 ++--
 rpcserver.go                           |  9 +--
 9 files changed, 46 insertions(+), 127 deletions(-)

diff --git a/channeldb/payments.go b/channeldb/payments.go
index 3d8c6e34..0e2b865d 100644
--- a/channeldb/payments.go
+++ b/channeldb/payments.go
@@ -606,7 +606,9 @@ func serializeHop(w io.Writer, h *route.Hop) error {
 	if h.MPP != nil {
 		records = append(records, h.MPP.Record())
 	}
-	records = append(records, h.TLVRecords...)
+
+	tlvRecords := tlv.MapToRecords(h.CustomRecords)
+	records = append(records, tlvRecords...)
 
 	// Otherwise, we'll transform our slice of records into a map of the
 	// raw bytes, then serialize them in-line with a length (number of
@@ -710,7 +712,7 @@ func deserializeHop(r io.Reader) (*route.Hop, error) {
 		h.MPP = mpp
 	}
 
-	h.TLVRecords = tlv.MapToRecords(tlvMap)
+	h.CustomRecords = tlvMap
 
 	return h, nil
 }
diff --git a/channeldb/payments_test.go b/channeldb/payments_test.go
index bec8e528..8eba5e5a 100644
--- a/channeldb/payments_test.go
+++ b/channeldb/payments_test.go
@@ -2,7 +2,6 @@ package channeldb
 
 import (
 	"bytes"
-	"errors"
 	"fmt"
 	"math/rand"
 	"reflect"
@@ -28,9 +27,9 @@ var (
 		ChannelID:        12345,
 		OutgoingTimeLock: 111,
 		AmtToForward:     555,
-		TLVRecords: []tlv.Record{
-			tlv.MakeStaticRecord(1, nil, 3, tlvEncoder, nil),
-			tlv.MakeStaticRecord(2, nil, 3, tlvEncoder, nil),
+		CustomRecords: record.CustomSet{
+			1: []byte{},
+			2: []byte{},
 		},
 		MPP: record.NewMPP(32, [32]byte{0x42}),
 	}
@@ -144,25 +143,7 @@ func TestSentPaymentSerialization(t *testing.T) {
 // assertRouteEquals compares to routes for equality and returns an error if
 // they are not equal.
 func assertRouteEqual(a, b *route.Route) error {
-	err := assertRouteHopRecordsEqual(a, b)
-	if err != nil {
-		return err
-	}
-
-	// TLV records have already been compared and need to be cleared to
-	// properly compare the remaining fields using DeepEqual.
-	copyRouteNoHops := func(r *route.Route) *route.Route {
-		copy := *r
-		copy.Hops = make([]*route.Hop, len(r.Hops))
-		for i, hop := range r.Hops {
-			hopCopy := *hop
-			hopCopy.TLVRecords = nil
-			copy.Hops[i] = &hopCopy
-		}
-		return &copy
-	}
-
-	if !reflect.DeepEqual(copyRouteNoHops(a), copyRouteNoHops(b)) {
+	if !reflect.DeepEqual(a, b) {
 		return fmt.Errorf("PaymentAttemptInfos don't match: %v vs %v",
 			spew.Sdump(a), spew.Sdump(b))
 	}
@@ -170,57 +151,6 @@ func assertRouteEqual(a, b *route.Route) error {
 	return nil
 }
 
-func assertRouteHopRecordsEqual(r1, r2 *route.Route) error {
-	if len(r1.Hops) != len(r2.Hops) {
-		return errors.New("route hop count mismatch")
-	}
-
-	for i := 0; i < len(r1.Hops); i++ {
-		records1 := r1.Hops[i].TLVRecords
-		records2 := r2.Hops[i].TLVRecords
-		if len(records1) != len(records2) {
-			return fmt.Errorf("route record count for hop %v "+
-				"mismatch", i)
-		}
-
-		for j := 0; j < len(records1); j++ {
-			expectedRecord := records1[j]
-			newRecord := records2[j]
-
-			err := assertHopRecordsEqual(expectedRecord, newRecord)
-			if err != nil {
-				return fmt.Errorf("route record mismatch: %v", err)
-			}
-		}
-	}
-
-	return nil
-}
-
-func assertHopRecordsEqual(h1, h2 tlv.Record) error {
-	if h1.Type() != h2.Type() {
-		return fmt.Errorf("wrong type: expected %v, got %v", h1.Type(),
-			h2.Type())
-	}
-
-	var b bytes.Buffer
-	if err := h2.Encode(&b); err != nil {
-		return fmt.Errorf("unable to encode record: %v", err)
-	}
-
-	if !bytes.Equal(b.Bytes(), tlvBytes) {
-		return fmt.Errorf("wrong raw record: expected %x, got %x",
-			tlvBytes, b.Bytes())
-	}
-
-	if h1.Size() != h2.Size() {
-		return fmt.Errorf("wrong size: expected %v, "+
-			"got %v", h1.Size(), h2.Size())
-	}
-
-	return nil
-}
-
 func TestRouteSerialization(t *testing.T) {
 	t.Parallel()
 
diff --git a/lnrpc/routerrpc/router_backend.go b/lnrpc/routerrpc/router_backend.go
index b9de9617..dd918f54 100644
--- a/lnrpc/routerrpc/router_backend.go
+++ b/lnrpc/routerrpc/router_backend.go
@@ -19,7 +19,6 @@ import (
 	"github.com/lightningnetwork/lnd/record"
 	"github.com/lightningnetwork/lnd/routing"
 	"github.com/lightningnetwork/lnd/routing/route"
-	"github.com/lightningnetwork/lnd/tlv"
 	"github.com/lightningnetwork/lnd/zpay32"
 )
 
@@ -45,7 +44,7 @@ type RouterBackend struct {
 	// routes.
 	FindRoute func(source, target route.Vertex,
 		amt lnwire.MilliSatoshi, restrictions *routing.RestrictParams,
-		destTlvRecords []tlv.Record,
+		destCustomRecords record.CustomSet,
 		finalExpiry ...uint16) (*route.Route, error)
 
 	MissionControl MissionControl
@@ -232,7 +231,7 @@ func (r *RouterBackend) QueryRoutes(ctx context.Context,
 	// If we have any TLV records destined for the final hop, then we'll
 	// attempt to decode them now into a form that the router can more
 	// easily manipulate.
-	destTlvRecords, err := UnmarshallCustomRecords(in.DestCustomRecords)
+	err = ValidateCustomRecords(in.DestCustomRecords)
 	if err != nil {
 		return nil, err
 	}
@@ -242,7 +241,7 @@ func (r *RouterBackend) QueryRoutes(ctx context.Context,
 	// the route.
 	route, err := r.FindRoute(
 		sourcePubKey, targetPubKey, amt, restrictions,
-		destTlvRecords, finalCLTVDelta,
+		in.DestCustomRecords, finalCLTVDelta,
 	)
 	if err != nil {
 		return nil, err
@@ -346,11 +345,6 @@ func (r *RouterBackend) MarshallRoute(route *route.Route) (*lnrpc.Route, error)
 			}
 		}
 
-		tlvMap, err := tlv.RecordsToMap(hop.TLVRecords)
-		if err != nil {
-			return nil, err
-		}
-
 		resp.Hops[i] = &lnrpc.Hop{
 			ChanId:           hop.ChannelID,
 			ChanCapacity:     int64(chanCapacity),
@@ -362,7 +356,7 @@ func (r *RouterBackend) MarshallRoute(route *route.Route) (*lnrpc.Route, error)
 			PubKey: hex.EncodeToString(
 				hop.PubKeyBytes[:],
 			),
-			CustomRecords: tlvMap,
+			CustomRecords: hop.CustomRecords,
 			TlvPayload:    !hop.LegacyPayload,
 			MppRecord:     mpp,
 		}
@@ -372,24 +366,16 @@ func (r *RouterBackend) MarshallRoute(route *route.Route) (*lnrpc.Route, error)
 	return resp, nil
 }
 
-// UnmarshallCustomRecords unmarshall rpc custom records to tlv records.
-func UnmarshallCustomRecords(rpcRecords map[uint64][]byte) ([]tlv.Record,
-	error) {
-
-	if len(rpcRecords) == 0 {
-		return nil, nil
+// ValidateCustomRecords checks that all custom records are in the custom type
+// range.
+func ValidateCustomRecords(rpcRecords map[uint64][]byte) error {
+	for key := range rpcRecords {
+		if key < record.CustomTypeStart {
+			return fmt.Errorf("no custom records with types "+
+				"below %v allowed", record.CustomTypeStart)
+		}
 	}
-
-	tlvRecords := tlv.MapToRecords(rpcRecords)
-
-	// tlvRecords is sorted, so we only need to check that the first
-	// element is within the custom range.
-	if uint64(tlvRecords[0].Type()) < record.CustomTypeStart {
-		return nil, fmt.Errorf("no custom records with types "+
-			"below %v allowed", record.CustomTypeStart)
-	}
-
-	return tlvRecords, nil
+	return nil
 }
 
 // UnmarshallHopWithPubkey unmarshalls an rpc hop for which the pubkey has
@@ -397,7 +383,7 @@ func UnmarshallCustomRecords(rpcRecords map[uint64][]byte) ([]tlv.Record,
 func UnmarshallHopWithPubkey(rpcHop *lnrpc.Hop, pubkey route.Vertex) (*route.Hop,
 	error) {
 
-	tlvRecords, err := UnmarshallCustomRecords(rpcHop.CustomRecords)
+	err := ValidateCustomRecords(rpcHop.CustomRecords)
 	if err != nil {
 		return nil, err
 	}
@@ -412,7 +398,7 @@ func UnmarshallHopWithPubkey(rpcHop *lnrpc.Hop, pubkey route.Vertex) (*route.Hop
 		AmtToForward:     lnwire.MilliSatoshi(rpcHop.AmtToForwardMsat),
 		PubKeyBytes:      pubkey,
 		ChannelID:        rpcHop.ChanId,
-		TLVRecords:       tlvRecords,
+		CustomRecords:    rpcHop.CustomRecords,
 		LegacyPayload:    !rpcHop.TlvPayload,
 		MPP:              mpp,
 	}, nil
@@ -540,12 +526,11 @@ func (r *RouterBackend) extractIntentFromSendRequest(
 		return nil, errors.New("timeout_seconds must be specified")
 	}
 
-	payIntent.FinalDestRecords, err = UnmarshallCustomRecords(
-		rpcPayReq.DestCustomRecords,
-	)
+	err = ValidateCustomRecords(rpcPayReq.DestCustomRecords)
 	if err != nil {
 		return nil, err
 	}
+	payIntent.DestCustomRecords = rpcPayReq.DestCustomRecords
 
 	payIntent.PayAttemptTimeout = time.Second *
 		time.Duration(rpcPayReq.TimeoutSeconds)
diff --git a/lnrpc/routerrpc/router_backend_test.go b/lnrpc/routerrpc/router_backend_test.go
index 6e55e5ad..f6dfc2cc 100644
--- a/lnrpc/routerrpc/router_backend_test.go
+++ b/lnrpc/routerrpc/router_backend_test.go
@@ -8,9 +8,9 @@ import (
 
 	"github.com/btcsuite/btcutil"
 	"github.com/lightningnetwork/lnd/lnwire"
+	"github.com/lightningnetwork/lnd/record"
 	"github.com/lightningnetwork/lnd/routing"
 	"github.com/lightningnetwork/lnd/routing/route"
-	"github.com/lightningnetwork/lnd/tlv"
 
 	"github.com/lightningnetwork/lnd/lnrpc"
 )
@@ -92,7 +92,7 @@ func testQueryRoutes(t *testing.T, useMissionControl bool, useMsat bool) {
 
 	findRoute := func(source, target route.Vertex,
 		amt lnwire.MilliSatoshi, restrictions *routing.RestrictParams,
-		_ []tlv.Record,
+		_ record.CustomSet,
 		finalExpiry ...uint16) (*route.Route, error) {
 
 		if int64(amt) != amtSat*1000 {
diff --git a/routing/pathfind.go b/routing/pathfind.go
index 3f4f8f60..e8db244a 100644
--- a/routing/pathfind.go
+++ b/routing/pathfind.go
@@ -11,8 +11,8 @@ import (
 	"github.com/coreos/bbolt"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/lnwire"
+	"github.com/lightningnetwork/lnd/record"
 	"github.com/lightningnetwork/lnd/routing/route"
-	"github.com/lightningnetwork/lnd/tlv"
 )
 
 const (
@@ -100,7 +100,7 @@ type edgePolicyWithSource struct {
 func newRoute(amtToSend lnwire.MilliSatoshi, sourceVertex route.Vertex,
 	pathEdges []*channeldb.ChannelEdgePolicy, currentHeight uint32,
 	finalCLTVDelta uint16,
-	finalDestRecords []tlv.Record) (*route.Route, error) {
+	destCustomRecords record.CustomSet) (*route.Route, error) {
 
 	var (
 		hops []*route.Hop
@@ -198,8 +198,8 @@ func newRoute(amtToSend lnwire.MilliSatoshi, sourceVertex route.Vertex,
 
 		// If this is the last hop, then we'll populate any TLV records
 		// destined for it.
-		if i == len(pathEdges)-1 && len(finalDestRecords) != 0 {
-			currentHop.TLVRecords = finalDestRecords
+		if i == len(pathEdges)-1 && len(destCustomRecords) != 0 {
+			currentHop.CustomRecords = destCustomRecords
 		}
 
 		hops = append([]*route.Hop{currentHop}, hops...)
diff --git a/routing/payment_session.go b/routing/payment_session.go
index 979b7a7a..124becbd 100644
--- a/routing/payment_session.go
+++ b/routing/payment_session.go
@@ -129,7 +129,7 @@ func (p *paymentSession) RequestRoute(payment *LightningPayment,
 	sourceVertex := route.Vertex(ss.SelfNode.PubKeyBytes)
 	route, err := newRoute(
 		payment.Amount, sourceVertex, path, height, finalCltvDelta,
-		payment.FinalDestRecords,
+		payment.DestCustomRecords,
 	)
 	if err != nil {
 		// TODO(roasbeef): return which edge/vertex didn't work
diff --git a/routing/route/route.go b/routing/route/route.go
index 6858f3b8..1444b9df 100644
--- a/routing/route/route.go
+++ b/routing/route/route.go
@@ -107,9 +107,9 @@ type Hop struct {
 	// only be set for the final hop.
 	MPP *record.MPP
 
-	// TLVRecords if non-nil are a set of additional TLV records that
+	// CustomRecords if non-nil are a set of additional TLV records that
 	// should be included in the forwarding instructions for this node.
-	TLVRecords []tlv.Record
+	CustomRecords record.CustomSet
 
 	// LegacyPayload if true, then this signals that this node doesn't
 	// understand the new TLV payload, so we must instead use the legacy
@@ -165,7 +165,8 @@ func (h *Hop) PackHopPayload(w io.Writer, nextChanID uint64) error {
 	}
 
 	// Append any custom types destined for this hop.
-	records = append(records, h.TLVRecords...)
+	tlvRecords := tlv.MapToRecords(h.CustomRecords)
+	records = append(records, tlvRecords...)
 
 	// To ensure we produce a canonical stream, we'll sort the records
 	// before encoding them as a stream in the hop payload.
diff --git a/routing/router.go b/routing/router.go
index 5020aefc..f157b7bd 100644
--- a/routing/router.go
+++ b/routing/router.go
@@ -24,10 +24,10 @@ import (
 	"github.com/lightningnetwork/lnd/lnwallet/chanvalidate"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/multimutex"
+	"github.com/lightningnetwork/lnd/record"
 	"github.com/lightningnetwork/lnd/routing/chainview"
 	"github.com/lightningnetwork/lnd/routing/route"
 	"github.com/lightningnetwork/lnd/ticker"
-	"github.com/lightningnetwork/lnd/tlv"
 	"github.com/lightningnetwork/lnd/zpay32"
 )
 
@@ -1401,7 +1401,7 @@ type routingMsg struct {
 // factoring in channel capacities and cumulative fees along the route.
 func (r *ChannelRouter) FindRoute(source, target route.Vertex,
 	amt lnwire.MilliSatoshi, restrictions *RestrictParams,
-	destTlvRecords []tlv.Record,
+	destCustomRecords record.CustomSet,
 	finalExpiry ...uint16) (*route.Route, error) {
 
 	var finalCLTVDelta uint16
@@ -1455,7 +1455,7 @@ func (r *ChannelRouter) FindRoute(source, target route.Vertex,
 	// Create the route with absolute time lock values.
 	route, err := newRoute(
 		amt, source, path, uint32(currentHeight), finalCLTVDelta,
-		destTlvRecords,
+		destCustomRecords,
 	)
 	if err != nil {
 		return nil, err
@@ -1608,11 +1608,11 @@ type LightningPayment struct {
 	// attempting to complete.
 	PaymentRequest []byte
 
-	// FinalDestRecords are TLV records that are to be sent to the final
+	// DestCustomRecords are TLV records that are to be sent to the final
 	// hop in the new onion payload format. If the destination does not
 	// understand this new onion payload format, then the payment will
 	// fail.
-	FinalDestRecords []tlv.Record
+	DestCustomRecords record.CustomSet
 }
 
 // SendPayment attempts to send a payment as described within the passed
diff --git a/rpcserver.go b/rpcserver.go
index 225fdf00..fd2ef044 100644
--- a/rpcserver.go
+++ b/rpcserver.go
@@ -50,11 +50,11 @@ import (
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/macaroons"
 	"github.com/lightningnetwork/lnd/monitoring"
+	"github.com/lightningnetwork/lnd/record"
 	"github.com/lightningnetwork/lnd/routing"
 	"github.com/lightningnetwork/lnd/routing/route"
 	"github.com/lightningnetwork/lnd/signal"
 	"github.com/lightningnetwork/lnd/sweep"
-	"github.com/lightningnetwork/lnd/tlv"
 	"github.com/lightningnetwork/lnd/watchtower"
 	"github.com/lightningnetwork/lnd/zpay32"
 	"github.com/tv42/zbase32"
@@ -3099,7 +3099,7 @@ type rpcPaymentIntent struct {
 	lastHop           *route.Vertex
 	payReq            []byte
 
-	destTLV []tlv.Record
+	destCustomRecords record.CustomSet
 
 	route *route.Route
 }
@@ -3158,12 +3158,13 @@ func (r *rpcServer) extractPaymentIntent(rpcPayReq *rpcPaymentRequest) (rpcPayme
 	}
 	payIntent.cltvLimit = cltvLimit
 
-	payIntent.destTLV, err = routerrpc.UnmarshallCustomRecords(
+	err = routerrpc.ValidateCustomRecords(
 		rpcPayReq.DestCustomRecords,
 	)
 	if err != nil {
 		return payIntent, err
 	}
+	payIntent.destCustomRecords = rpcPayReq.DestCustomRecords
 
 	validateDest := func(dest route.Vertex) error {
 		if rpcPayReq.AllowSelfPayment {
@@ -3348,7 +3349,7 @@ func (r *rpcServer) dispatchPaymentIntent(
 			LastHop:           payIntent.lastHop,
 			PaymentRequest:    payIntent.payReq,
 			PayAttemptTimeout: routing.DefaultPayAttemptTimeout,
-			FinalDestRecords:  payIntent.destTLV,
+			DestCustomRecords: payIntent.destCustomRecords,
 		}
 
 		preImage, route, routerErr = r.server.chanRouter.SendPayment(

From c37289cd94520a44e94b4ec9de1bc15e60387c35 Mon Sep 17 00:00:00 2001
From: Joost Jager <joost.jager@gmail.com>
Date: Wed, 11 Dec 2019 11:49:03 +0100
Subject: [PATCH 4/5] routing: pass custom records into pathfinding

---
 lnrpc/routerrpc/router_backend.go | 4 ++--
 routing/pathfind.go               | 9 ++++-----
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/lnrpc/routerrpc/router_backend.go b/lnrpc/routerrpc/router_backend.go
index dd918f54..63bec96e 100644
--- a/lnrpc/routerrpc/router_backend.go
+++ b/lnrpc/routerrpc/router_backend.go
@@ -224,8 +224,8 @@ func (r *RouterBackend) QueryRoutes(ctx context.Context,
 				fromNode, toNode, amt,
 			)
 		},
-		DestPayloadTLV: len(in.DestCustomRecords) != 0,
-		CltvLimit:      cltvLimit,
+		DestCustomRecords: record.CustomSet(in.DestCustomRecords),
+		CltvLimit:         cltvLimit,
 	}
 
 	// If we have any TLV records destined for the final hop, then we'll
diff --git a/routing/pathfind.go b/routing/pathfind.go
index e8db244a..3fa48355 100644
--- a/routing/pathfind.go
+++ b/routing/pathfind.go
@@ -289,10 +289,9 @@ type RestrictParams struct {
 	// all cltv expiry heights with the required final cltv delta.
 	CltvLimit uint32
 
-	// DestPayloadTLV should be set to true if we need to drop off a TLV
-	// payload at the final hop in order to properly complete this payment
-	// attempt.
-	DestPayloadTLV bool
+	// DestCustomRecords contains the custom records to drop off at the
+	// final hop, if any.
+	DestCustomRecords record.CustomSet
 }
 
 // PathFindingConfig defines global parameters that control the trade-off in
@@ -396,7 +395,7 @@ func findPath(g *graphParams, r *RestrictParams, cfg *PathFindingConfig,
 		defer tx.Rollback()
 	}
 
-	if r.DestPayloadTLV {
+	if len(r.DestCustomRecords) > 0 {
 		// Check if the target has TLV enabled
 
 		targetKey, err := btcec.ParsePubKey(target[:], btcec.S256())

From 75aa4e7061c57c095f8d3910cab7261ca2b2fab1 Mon Sep 17 00:00:00 2001
From: Joost Jager <joost.jager@gmail.com>
Date: Wed, 11 Dec 2019 10:54:11 +0100
Subject: [PATCH 5/5] routing: require tlv capability for custom record
 payments

Previously if a payment was sent with custom records attached, path
finding wouldn't perform a check whether the final node was capable of
receiving custom records in a tlv payload.
---
 routing/payment_session.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/routing/payment_session.go b/routing/payment_session.go
index 124becbd..5168ba28 100644
--- a/routing/payment_session.go
+++ b/routing/payment_session.go
@@ -97,6 +97,7 @@ func (p *paymentSession) RequestRoute(payment *LightningPayment,
 		OutgoingChannelID: payment.OutgoingChannelID,
 		LastHop:           payment.LastHop,
 		CltvLimit:         cltvLimit,
+		DestCustomRecords: payment.DestCustomRecords,
 	}
 
 	// We'll also obtain a set of bandwidthHints from the lower layer for