lnd.xprv/lnrpc/routerrpc/router_backend.go
Olaoluwa Osuntokun 763cb6c09d
lnrpc+lnrpc/routerrpc: add a new TLV record field to the Hop proto
In this commit, we add a new field to the Hop proto to allow callers to
be able to specify TLV records for the SendToRoute call, and also to be
able to display TLV records that were used during regular path finding.

We also update SendPayment to support dest TLV records.
2019-08-22 18:53:03 -07:00

665 lines
18 KiB
Go

package routerrpc
import (
"encoding/hex"
"errors"
"fmt"
"time"
"github.com/btcsuite/btcd/btcec"
"github.com/btcsuite/btcd/chaincfg"
"github.com/btcsuite/btcutil"
"github.com/lightningnetwork/lnd/lnrpc"
"github.com/lightningnetwork/lnd/lnwire"
"github.com/lightningnetwork/lnd/routing"
"github.com/lightningnetwork/lnd/routing/route"
"github.com/lightningnetwork/lnd/tlv"
"github.com/lightningnetwork/lnd/zpay32"
context "golang.org/x/net/context"
)
// RouterBackend contains the backend implementation of the router rpc sub
// server calls.
type RouterBackend struct {
// MaxPaymentMSat is the largest payment permitted by the backend.
MaxPaymentMSat lnwire.MilliSatoshi
// SelfNode is the vertex of the node sending the payment.
SelfNode route.Vertex
// FetchChannelCapacity is a closure that we'll use the fetch the total
// capacity of a channel to populate in responses.
FetchChannelCapacity func(chanID uint64) (btcutil.Amount, error)
// FetchChannelEndpoints returns the pubkeys of both endpoints of the
// given channel id.
FetchChannelEndpoints func(chanID uint64) (route.Vertex,
route.Vertex, error)
// FindRoutes is a closure that abstracts away how we locate/query for
// routes.
FindRoute func(source, target route.Vertex,
amt lnwire.MilliSatoshi, restrictions *routing.RestrictParams,
destTlvRecords []tlv.Record,
finalExpiry ...uint16) (*route.Route, error)
MissionControl MissionControl
// ActiveNetParams are the network parameters of the primary network
// that the route is operating on. This is necessary so we can ensure
// that we receive payment requests that send to destinations on our
// network.
ActiveNetParams *chaincfg.Params
// Tower is the ControlTower instance that is used to track pending
// payments.
Tower routing.ControlTower
}
// MissionControl defines the mission control dependencies of routerrpc.
type MissionControl interface {
// GetProbability is expected to return the success probability of a
// payment from fromNode to toNode.
GetProbability(fromNode, toNode route.Vertex,
amt lnwire.MilliSatoshi) float64
// ResetHistory resets the history of MissionControl returning it to a
// state as if no payment attempts have been made.
ResetHistory() error
// GetHistorySnapshot takes a snapshot from the current mission control
// state and actual probability estimates.
GetHistorySnapshot() *routing.MissionControlSnapshot
}
// QueryRoutes attempts to query the daemons' Channel Router for a possible
// route to a target destination capable of carrying a specific amount of
// satoshis within the route's flow. The retuned route contains the full
// details required to craft and send an HTLC, also including the necessary
// information that should be present within the Sphinx packet encapsulated
// within the HTLC.
//
// TODO(roasbeef): should return a slice of routes in reality * create separate
// PR to send based on well formatted route
func (r *RouterBackend) QueryRoutes(ctx context.Context,
in *lnrpc.QueryRoutesRequest) (*lnrpc.QueryRoutesResponse, error) {
parsePubKey := func(key string) (route.Vertex, error) {
pubKeyBytes, err := hex.DecodeString(key)
if err != nil {
return route.Vertex{}, err
}
return route.NewVertexFromBytes(pubKeyBytes)
}
// Parse the hex-encoded source and target public keys into full public
// key objects we can properly manipulate.
targetPubKey, err := parsePubKey(in.PubKey)
if err != nil {
return nil, err
}
var sourcePubKey route.Vertex
if in.SourcePubKey != "" {
var err error
sourcePubKey, err = parsePubKey(in.SourcePubKey)
if err != nil {
return nil, err
}
} else {
// If no source is specified, use self.
sourcePubKey = r.SelfNode
}
// Currently, within the bootstrap phase of the network, we limit the
// largest payment size allotted to (2^32) - 1 mSAT or 4.29 million
// satoshis.
amt := btcutil.Amount(in.Amt)
amtMSat := lnwire.NewMSatFromSatoshis(amt)
if amtMSat > r.MaxPaymentMSat {
return nil, fmt.Errorf("payment of %v is too large, max payment "+
"allowed is %v", amt, r.MaxPaymentMSat.ToSatoshis())
}
// Unmarshall restrictions from request.
feeLimit := calculateFeeLimit(in.FeeLimit, amtMSat)
ignoredNodes := make(map[route.Vertex]struct{})
for _, ignorePubKey := range in.IgnoredNodes {
ignoreVertex, err := route.NewVertexFromBytes(ignorePubKey)
if err != nil {
return nil, err
}
ignoredNodes[ignoreVertex] = struct{}{}
}
ignoredPairs := make(map[routing.DirectedNodePair]struct{})
// Convert deprecated ignoredEdges to pairs.
for _, ignoredEdge := range in.IgnoredEdges {
pair, err := r.rpcEdgeToPair(ignoredEdge)
if err != nil {
log.Warnf("Ignore channel %v skipped: %v",
ignoredEdge.ChannelId, err)
continue
}
ignoredPairs[pair] = struct{}{}
}
// Add ignored pairs to set.
for _, ignorePair := range in.IgnoredPairs {
from, err := route.NewVertexFromBytes(ignorePair.From)
if err != nil {
return nil, err
}
to, err := route.NewVertexFromBytes(ignorePair.To)
if err != nil {
return nil, err
}
pair := routing.NewDirectedNodePair(from, to)
ignoredPairs[pair] = struct{}{}
}
restrictions := &routing.RestrictParams{
FeeLimit: feeLimit,
ProbabilitySource: func(fromNode, toNode route.Vertex,
amt lnwire.MilliSatoshi) float64 {
if _, ok := ignoredNodes[fromNode]; ok {
return 0
}
pair := routing.DirectedNodePair{
From: fromNode,
To: toNode,
}
if _, ok := ignoredPairs[pair]; ok {
return 0
}
if !in.UseMissionControl {
return 1
}
return r.MissionControl.GetProbability(
fromNode, toNode, amt,
)
},
DestPayloadTLV: len(in.DestTlv) != 0,
}
// 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 := tlv.MapToRecords(in.DestTlv)
if err != nil {
return nil, err
}
// Query the channel router for a possible path to the destination that
// can carry `in.Amt` satoshis _including_ the total fee required on
// the route.
var (
route *route.Route
findErr error
)
if in.FinalCltvDelta == 0 {
route, findErr = r.FindRoute(
sourcePubKey, targetPubKey, amtMSat, restrictions,
destTlvRecords,
)
} else {
route, findErr = r.FindRoute(
sourcePubKey, targetPubKey, amtMSat, restrictions,
destTlvRecords, uint16(in.FinalCltvDelta),
)
}
if findErr != nil {
return nil, findErr
}
// For each valid route, we'll convert the result into the format
// required by the RPC system.
rpcRoute, err := r.MarshallRoute(route)
if err != nil {
return nil, err
}
routeResp := &lnrpc.QueryRoutesResponse{
Routes: []*lnrpc.Route{rpcRoute},
}
return routeResp, nil
}
// rpcEdgeToPair looks up the provided channel and returns the channel endpoints
// as a directed pair.
func (r *RouterBackend) rpcEdgeToPair(e *lnrpc.EdgeLocator) (
routing.DirectedNodePair, error) {
a, b, err := r.FetchChannelEndpoints(e.ChannelId)
if err != nil {
return routing.DirectedNodePair{}, err
}
var pair routing.DirectedNodePair
if e.DirectionReverse {
pair.From, pair.To = b, a
} else {
pair.From, pair.To = a, b
}
return pair, nil
}
// calculateFeeLimit returns the fee limit in millisatoshis. If a percentage
// based fee limit has been requested, we'll factor in the ratio provided with
// the amount of the payment.
func calculateFeeLimit(feeLimit *lnrpc.FeeLimit,
amount lnwire.MilliSatoshi) lnwire.MilliSatoshi {
switch feeLimit.GetLimit().(type) {
case *lnrpc.FeeLimit_Fixed:
return lnwire.NewMSatFromSatoshis(
btcutil.Amount(feeLimit.GetFixed()),
)
case *lnrpc.FeeLimit_Percent:
return amount * lnwire.MilliSatoshi(feeLimit.GetPercent()) / 100
default:
// If a fee limit was not specified, we'll use the payment's
// amount as an upper bound in order to avoid payment attempts
// from incurring fees higher than the payment amount itself.
return amount
}
}
// MarshallRoute marshalls an internal route to an rpc route struct.
func (r *RouterBackend) MarshallRoute(route *route.Route) (*lnrpc.Route, error) {
resp := &lnrpc.Route{
TotalTimeLock: route.TotalTimeLock,
TotalFees: int64(route.TotalFees().ToSatoshis()),
TotalFeesMsat: int64(route.TotalFees()),
TotalAmt: int64(route.TotalAmount.ToSatoshis()),
TotalAmtMsat: int64(route.TotalAmount),
Hops: make([]*lnrpc.Hop, len(route.Hops)),
}
incomingAmt := route.TotalAmount
for i, hop := range route.Hops {
fee := route.HopFee(i)
// Channel capacity is not a defining property of a route. For
// backwards RPC compatibility, we retrieve it here from the
// graph.
chanCapacity, err := r.FetchChannelCapacity(hop.ChannelID)
if err != nil {
// If capacity cannot be retrieved, this may be a
// not-yet-received or private channel. Then report
// amount that is sent through the channel as capacity.
chanCapacity = incomingAmt.ToSatoshis()
}
tlvMap, err := tlv.RecordsToMap(hop.TLVRecords)
if err != nil {
return nil, err
}
resp.Hops[i] = &lnrpc.Hop{
ChanId: hop.ChannelID,
ChanCapacity: int64(chanCapacity),
AmtToForward: int64(hop.AmtToForward.ToSatoshis()),
AmtToForwardMsat: int64(hop.AmtToForward),
Fee: int64(fee.ToSatoshis()),
FeeMsat: int64(fee),
Expiry: uint32(hop.OutgoingTimeLock),
PubKey: hex.EncodeToString(
hop.PubKeyBytes[:],
),
TlvRecords: tlvMap,
TlvPayload: !hop.LegacyPayload,
}
incomingAmt = hop.AmtToForward
}
return resp, nil
}
// UnmarshallHopByChannelLookup unmarshalls an rpc hop for which the pub key is
// not known. This function will query the channel graph with channel id to
// retrieve both endpoints and determine the hop pubkey using the previous hop
// pubkey. If the channel is unknown, an error is returned.
func (r *RouterBackend) UnmarshallHopByChannelLookup(hop *lnrpc.Hop,
prevPubKeyBytes [33]byte) (*route.Hop, error) {
// Discard edge policies, because they may be nil.
node1, node2, err := r.FetchChannelEndpoints(hop.ChanId)
if err != nil {
return nil, err
}
var pubKeyBytes [33]byte
switch {
case prevPubKeyBytes == node1:
pubKeyBytes = node2
case prevPubKeyBytes == node2:
pubKeyBytes = node1
default:
return nil, fmt.Errorf("channel edge does not match expected node")
}
tlvRecords, err := tlv.MapToRecords(hop.TlvRecords)
if err != nil {
return nil, err
}
return &route.Hop{
OutgoingTimeLock: hop.Expiry,
AmtToForward: lnwire.MilliSatoshi(hop.AmtToForwardMsat),
PubKeyBytes: pubKeyBytes,
ChannelID: hop.ChanId,
TLVRecords: tlvRecords,
LegacyPayload: !hop.TlvPayload,
}, nil
}
// UnmarshallKnownPubkeyHop unmarshalls an rpc hop that contains the hop pubkey.
// The channel graph doesn't need to be queried because all information required
// for sending the payment is present.
func UnmarshallKnownPubkeyHop(hop *lnrpc.Hop) (*route.Hop, error) {
pubKey, err := hex.DecodeString(hop.PubKey)
if err != nil {
return nil, fmt.Errorf("cannot decode pubkey %s", hop.PubKey)
}
var pubKeyBytes [33]byte
copy(pubKeyBytes[:], pubKey)
var tlvRecords []tlv.Record
if hop.TlvRecords != nil {
tlvRecords, err = tlv.MapToRecords(hop.TlvRecords)
if err != nil {
return nil, err
}
}
return &route.Hop{
OutgoingTimeLock: hop.Expiry,
AmtToForward: lnwire.MilliSatoshi(hop.AmtToForwardMsat),
PubKeyBytes: pubKeyBytes,
ChannelID: hop.ChanId,
TLVRecords: tlvRecords,
LegacyPayload: !hop.TlvPayload,
}, nil
}
// UnmarshallHop unmarshalls an rpc hop that may or may not contain a node
// pubkey.
func (r *RouterBackend) UnmarshallHop(hop *lnrpc.Hop,
prevNodePubKey [33]byte) (*route.Hop, error) {
if hop.PubKey == "" {
// If no pub key is given of the hop, the local channel
// graph needs to be queried to complete the information
// necessary for routing.
return r.UnmarshallHopByChannelLookup(hop, prevNodePubKey)
}
return UnmarshallKnownPubkeyHop(hop)
}
// UnmarshallRoute unmarshalls an rpc route. For hops that don't specify a
// pubkey, the channel graph is queried.
func (r *RouterBackend) UnmarshallRoute(rpcroute *lnrpc.Route) (
*route.Route, error) {
prevNodePubKey := r.SelfNode
hops := make([]*route.Hop, len(rpcroute.Hops))
for i, hop := range rpcroute.Hops {
routeHop, err := r.UnmarshallHop(hop, prevNodePubKey)
if err != nil {
return nil, err
}
hops[i] = routeHop
prevNodePubKey = routeHop.PubKeyBytes
}
route, err := route.NewRouteFromHops(
lnwire.MilliSatoshi(rpcroute.TotalAmtMsat),
rpcroute.TotalTimeLock,
r.SelfNode,
hops,
)
if err != nil {
return nil, err
}
return route, nil
}
// extractIntentFromSendRequest attempts to parse the SendRequest details
// required to dispatch a client from the information presented by an RPC
// client.
func (r *RouterBackend) extractIntentFromSendRequest(
rpcPayReq *SendPaymentRequest) (*routing.LightningPayment, error) {
payIntent := &routing.LightningPayment{}
// Pass along an outgoing channel restriction if specified.
if rpcPayReq.OutgoingChanId != 0 {
payIntent.OutgoingChannelID = &rpcPayReq.OutgoingChanId
}
// Take cltv limit from request if set.
if rpcPayReq.CltvLimit != 0 {
cltvLimit := uint32(rpcPayReq.CltvLimit)
payIntent.CltvLimit = &cltvLimit
}
// Take fee limit from request.
payIntent.FeeLimit = lnwire.NewMSatFromSatoshis(
btcutil.Amount(rpcPayReq.FeeLimitSat),
)
// Set payment attempt timeout.
if rpcPayReq.TimeoutSeconds == 0 {
return nil, errors.New("timeout_seconds must be specified")
}
if len(rpcPayReq.DestTlv) != 0 {
var err error
payIntent.FinalDestRecords, err = tlv.MapToRecords(
rpcPayReq.DestTlv,
)
if err != nil {
return nil, err
}
}
payIntent.PayAttemptTimeout = time.Second *
time.Duration(rpcPayReq.TimeoutSeconds)
// Route hints.
routeHints, err := unmarshallRouteHints(
rpcPayReq.RouteHints,
)
if err != nil {
return nil, err
}
payIntent.RouteHints = routeHints
// If the payment request field isn't blank, then the details of the
// invoice are encoded entirely within the encoded payReq. So we'll
// attempt to decode it, populating the payment accordingly.
if rpcPayReq.PaymentRequest != "" {
switch {
case len(rpcPayReq.Dest) > 0:
return nil, errors.New("dest and payment_request " +
"cannot appear together")
case len(rpcPayReq.PaymentHash) > 0:
return nil, errors.New("dest and payment_hash " +
"cannot appear together")
case rpcPayReq.FinalCltvDelta != 0:
return nil, errors.New("dest and final_cltv_delta " +
"cannot appear together")
}
payReq, err := zpay32.Decode(
rpcPayReq.PaymentRequest, r.ActiveNetParams,
)
if err != nil {
return nil, err
}
// Next, we'll ensure that this payreq hasn't already expired.
err = ValidatePayReqExpiry(payReq)
if err != nil {
return nil, err
}
// If the amount was not included in the invoice, then we let
// the payee specify the amount of satoshis they wish to send.
// We override the amount to pay with the amount provided from
// the payment request.
if payReq.MilliSat == nil {
if rpcPayReq.Amt == 0 {
return nil, errors.New("amount must be " +
"specified when paying a zero amount " +
"invoice")
}
payIntent.Amount = lnwire.NewMSatFromSatoshis(
btcutil.Amount(rpcPayReq.Amt),
)
} else {
if rpcPayReq.Amt != 0 {
return nil, errors.New("amount must not be " +
"specified when paying a non-zero " +
" amount invoice")
}
payIntent.Amount = *payReq.MilliSat
}
copy(payIntent.PaymentHash[:], payReq.PaymentHash[:])
destKey := payReq.Destination.SerializeCompressed()
copy(payIntent.Target[:], destKey)
payIntent.FinalCLTVDelta = uint16(payReq.MinFinalCLTVExpiry())
payIntent.RouteHints = append(
payIntent.RouteHints, payReq.RouteHints...,
)
} else {
// Otherwise, If the payment request field was not specified
// (and a custom route wasn't specified), construct the payment
// from the other fields.
// Payment destination.
target, err := route.NewVertexFromBytes(rpcPayReq.Dest)
if err != nil {
return nil, err
}
payIntent.Target = target
// Final payment CLTV delta.
if rpcPayReq.FinalCltvDelta != 0 {
payIntent.FinalCLTVDelta =
uint16(rpcPayReq.FinalCltvDelta)
} else {
payIntent.FinalCLTVDelta = zpay32.DefaultFinalCLTVDelta
}
// Amount.
if rpcPayReq.Amt == 0 {
return nil, errors.New("amount must be specified")
}
payIntent.Amount = lnwire.NewMSatFromSatoshis(
btcutil.Amount(rpcPayReq.Amt),
)
// Payment hash.
copy(payIntent.PaymentHash[:], rpcPayReq.PaymentHash)
}
// Currently, within the bootstrap phase of the network, we limit the
// largest payment size allotted to (2^32) - 1 mSAT or 4.29 million
// satoshis.
if payIntent.Amount > r.MaxPaymentMSat {
// In this case, we'll send an error to the caller, but
// continue our loop for the next payment.
return payIntent, fmt.Errorf("payment of %v is too large, "+
"max payment allowed is %v", payIntent.Amount,
r.MaxPaymentMSat)
}
return payIntent, nil
}
// unmarshallRouteHints unmarshalls a list of route hints.
func unmarshallRouteHints(rpcRouteHints []*lnrpc.RouteHint) (
[][]zpay32.HopHint, error) {
routeHints := make([][]zpay32.HopHint, 0, len(rpcRouteHints))
for _, rpcRouteHint := range rpcRouteHints {
routeHint := make(
[]zpay32.HopHint, 0, len(rpcRouteHint.HopHints),
)
for _, rpcHint := range rpcRouteHint.HopHints {
hint, err := unmarshallHopHint(rpcHint)
if err != nil {
return nil, err
}
routeHint = append(routeHint, hint)
}
routeHints = append(routeHints, routeHint)
}
return routeHints, nil
}
// unmarshallHopHint unmarshalls a single hop hint.
func unmarshallHopHint(rpcHint *lnrpc.HopHint) (zpay32.HopHint, error) {
pubBytes, err := hex.DecodeString(rpcHint.NodeId)
if err != nil {
return zpay32.HopHint{}, err
}
pubkey, err := btcec.ParsePubKey(pubBytes, btcec.S256())
if err != nil {
return zpay32.HopHint{}, err
}
return zpay32.HopHint{
NodeID: pubkey,
ChannelID: rpcHint.ChanId,
FeeBaseMSat: rpcHint.FeeBaseMsat,
FeeProportionalMillionths: rpcHint.FeeProportionalMillionths,
CLTVExpiryDelta: uint16(rpcHint.CltvExpiryDelta),
}, nil
}
// ValidatePayReqExpiry checks if the passed payment request has expired. In
// the case it has expired, an error will be returned.
func ValidatePayReqExpiry(payReq *zpay32.Invoice) error {
expiry := payReq.Expiry()
validUntil := payReq.Timestamp.Add(expiry)
if time.Now().After(validUntil) {
return fmt.Errorf("invoice expired. Valid until %v", validUntil)
}
return nil
}