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mirror of https://github.com/lightninglabs/loop synced 2024-11-04 06:00:21 +00:00
loop/lndclient/router_client.go
2019-11-21 14:14:28 +01:00

326 lines
8.5 KiB
Go

package lndclient
import (
"context"
"encoding/hex"
"fmt"
"time"
"github.com/btcsuite/btcutil"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/lightningnetwork/lnd/lnrpc"
"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
"github.com/lightningnetwork/lnd/lntypes"
"github.com/lightningnetwork/lnd/lnwire"
"github.com/lightningnetwork/lnd/routing/route"
"github.com/lightningnetwork/lnd/zpay32"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/status"
)
// RouterClient exposes payment functionality.
type RouterClient interface {
// SendPayment attempts to route a payment to the final destination. The
// call returns a payment update stream and an error stream.
SendPayment(ctx context.Context, request SendPaymentRequest) (
chan PaymentStatus, chan error, error)
// TrackPayment picks up a previously started payment and returns a
// payment update stream and an error stream.
TrackPayment(ctx context.Context, hash lntypes.Hash) (
chan PaymentStatus, chan error, error)
}
// PaymentStatus describe the state of a payment.
type PaymentStatus struct {
State routerrpc.PaymentState
Preimage lntypes.Preimage
Fee lnwire.MilliSatoshi
Route *route.Route
}
// SendPaymentRequest defines the payment parameters for a new payment.
type SendPaymentRequest struct {
// Invoice is an encoded payment request. The individual payment
// parameters Target, Amount, PaymentHash, FinalCLTVDelta and RouteHints
// are only processed when the Invoice field is empty.
Invoice string
MaxFee btcutil.Amount
MaxCltv *int32
OutgoingChannel *uint64
Timeout time.Duration
// Target is the node in which the payment should be routed towards.
Target route.Vertex
// Amount is the value of the payment to send through the network in
// satoshis.
Amount btcutil.Amount
// PaymentHash is the r-hash value to use within the HTLC extended to
// the first hop.
PaymentHash [32]byte
// FinalCLTVDelta is the CTLV expiry delta to use for the _final_ hop
// in the route. This means that the final hop will have a CLTV delta
// of at least: currentHeight + FinalCLTVDelta.
FinalCLTVDelta uint16
// RouteHints represents the different routing hints that can be used to
// assist a payment in reaching its destination successfully. These
// hints will act as intermediate hops along the route.
//
// NOTE: This is optional unless required by the payment. When providing
// multiple routes, ensure the hop hints within each route are chained
// together and sorted in forward order in order to reach the
// destination successfully.
RouteHints [][]zpay32.HopHint
}
// routerClient is a wrapper around the generated routerrpc proxy.
type routerClient struct {
client routerrpc.RouterClient
routerKitMac serializedMacaroon
}
func newRouterClient(conn *grpc.ClientConn,
routerKitMac serializedMacaroon) *routerClient {
return &routerClient{
client: routerrpc.NewRouterClient(conn),
routerKitMac: routerKitMac,
}
}
// SendPayment attempts to route a payment to the final destination. The call
// returns a payment update stream and an error stream.
func (r *routerClient) SendPayment(ctx context.Context,
request SendPaymentRequest) (chan PaymentStatus, chan error, error) {
rpcCtx := r.routerKitMac.WithMacaroonAuth(ctx)
rpcReq := &routerrpc.SendPaymentRequest{
FeeLimitSat: int64(request.MaxFee),
PaymentRequest: request.Invoice,
TimeoutSeconds: int32(request.Timeout.Seconds()),
}
if request.MaxCltv != nil {
rpcReq.CltvLimit = *request.MaxCltv
}
if request.OutgoingChannel != nil {
rpcReq.OutgoingChanId = *request.OutgoingChannel
}
// Only if there is no payment request set, we will parse the individual
// payment parameters.
if request.Invoice == "" {
rpcReq.Dest = request.Target[:]
rpcReq.Amt = int64(request.Amount)
rpcReq.PaymentHash = request.PaymentHash[:]
rpcReq.FinalCltvDelta = int32(request.FinalCLTVDelta)
routeHints, err := marshallRouteHints(request.RouteHints)
if err != nil {
return nil, nil, err
}
rpcReq.RouteHints = routeHints
}
stream, err := r.client.SendPayment(rpcCtx, rpcReq)
if err != nil {
return nil, nil, err
}
return r.trackPayment(ctx, stream)
}
// TrackPayment picks up a previously started payment and returns a payment
// update stream and an error stream.
func (r *routerClient) TrackPayment(ctx context.Context,
hash lntypes.Hash) (chan PaymentStatus, chan error, error) {
ctx = r.routerKitMac.WithMacaroonAuth(ctx)
stream, err := r.client.TrackPayment(
ctx, &routerrpc.TrackPaymentRequest{
PaymentHash: hash[:],
},
)
if err != nil {
return nil, nil, err
}
return r.trackPayment(ctx, stream)
}
// trackPayment takes an update stream from either a SendPayment or a
// TrackPayment rpc call and converts it into distinct update and error streams.
func (r *routerClient) trackPayment(ctx context.Context,
stream routerrpc.Router_TrackPaymentClient) (chan PaymentStatus,
chan error, error) {
statusChan := make(chan PaymentStatus)
errorChan := make(chan error, 1)
go func() {
for {
rpcStatus, err := stream.Recv()
if err != nil {
switch status.Convert(err).Code() {
// NotFound is only expected as a response to
// TrackPayment.
case codes.NotFound:
err = channeldb.ErrPaymentNotInitiated
// NotFound is only expected as a response to
// SendPayment.
case codes.AlreadyExists:
err = channeldb.ErrAlreadyPaid
}
errorChan <- err
return
}
status, err := unmarshallPaymentStatus(rpcStatus)
if err != nil {
errorChan <- err
return
}
select {
case statusChan <- *status:
case <-ctx.Done():
return
}
}
}()
return statusChan, errorChan, nil
}
// unmarshallPaymentStatus converts an rpc status update to the PaymentStatus
// type that is used throughout the application.
func unmarshallPaymentStatus(rpcStatus *routerrpc.PaymentStatus) (
*PaymentStatus, error) {
status := PaymentStatus{
State: rpcStatus.State,
}
if status.State == routerrpc.PaymentState_SUCCEEDED {
preimage, err := lntypes.MakePreimage(
rpcStatus.Preimage,
)
if err != nil {
return nil, err
}
status.Preimage = preimage
status.Fee = lnwire.MilliSatoshi(
rpcStatus.Route.TotalFeesMsat,
)
if rpcStatus.Route != nil {
route, err := unmarshallRoute(rpcStatus.Route)
if err != nil {
return nil, err
}
status.Route = route
}
}
return &status, nil
}
// unmarshallRoute unmarshalls an rpc route.
func unmarshallRoute(rpcroute *lnrpc.Route) (
*route.Route, error) {
hops := make([]*route.Hop, len(rpcroute.Hops))
for i, hop := range rpcroute.Hops {
routeHop, err := unmarshallHop(hop)
if err != nil {
return nil, err
}
hops[i] = routeHop
}
// TODO(joostjager): Fetch self node from lnd.
selfNode := route.Vertex{}
route, err := route.NewRouteFromHops(
lnwire.MilliSatoshi(rpcroute.TotalAmtMsat),
rpcroute.TotalTimeLock,
selfNode,
hops,
)
if err != nil {
return nil, err
}
return route, nil
}
// unmarshallKnownPubkeyHop unmarshalls an rpc hop.
func unmarshallHop(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)
return &route.Hop{
OutgoingTimeLock: hop.Expiry,
AmtToForward: lnwire.MilliSatoshi(hop.AmtToForwardMsat),
PubKeyBytes: pubKeyBytes,
ChannelID: hop.ChanId,
}, nil
}
// marshallRouteHints marshalls a list of route hints.
func marshallRouteHints(routeHints [][]zpay32.HopHint) (
[]*lnrpc.RouteHint, error) {
rpcRouteHints := make([]*lnrpc.RouteHint, 0, len(routeHints))
for _, routeHint := range routeHints {
rpcRouteHint := make(
[]*lnrpc.HopHint, 0, len(routeHint),
)
for _, hint := range routeHint {
rpcHint, err := marshallHopHint(hint)
if err != nil {
return nil, err
}
rpcRouteHint = append(rpcRouteHint, rpcHint)
}
rpcRouteHints = append(rpcRouteHints, &lnrpc.RouteHint{
HopHints: rpcRouteHint,
})
}
return rpcRouteHints, nil
}
// marshallHopHint marshalls a single hop hint.
func marshallHopHint(hint zpay32.HopHint) (*lnrpc.HopHint, error) {
nodeID, err := route.NewVertexFromBytes(
hint.NodeID.SerializeCompressed(),
)
if err != nil {
return nil, err
}
return &lnrpc.HopHint{
ChanId: hint.ChannelID,
CltvExpiryDelta: uint32(hint.CLTVExpiryDelta),
FeeBaseMsat: hint.FeeBaseMSat,
FeeProportionalMillionths: hint.FeeProportionalMillionths,
NodeId: nodeID.String(),
}, nil
}