lnd.xprv/lnrpc/routerrpc/router_server.go
carla b5a2d75465
htlcswitch+routing: type check on ClearTextError
Update the type check used for checking local payment
failures to check on the ClearTextError interface rather
than on the ForwardingError type. This change prepares
for splitting payment errors up into Link and Forwarding
errors.
2020-01-14 15:07:42 +02:00

746 lines
21 KiB
Go

// +build routerrpc
package routerrpc
import (
"context"
"errors"
"fmt"
"io/ioutil"
"os"
"path/filepath"
"github.com/btcsuite/btcutil"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/lightningnetwork/lnd/htlcswitch"
"github.com/lightningnetwork/lnd/lnrpc"
"github.com/lightningnetwork/lnd/lntypes"
"github.com/lightningnetwork/lnd/lnwire"
"github.com/lightningnetwork/lnd/routing"
"github.com/lightningnetwork/lnd/routing/route"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/status"
"gopkg.in/macaroon-bakery.v2/bakery"
)
const (
// subServerName is the name of the sub rpc server. We'll use this name
// to register ourselves, and we also require that the main
// SubServerConfigDispatcher instance recognize as the name of our
subServerName = "RouterRPC"
)
var (
// macaroonOps are the set of capabilities that our minted macaroon (if
// it doesn't already exist) will have.
macaroonOps = []bakery.Op{
{
Entity: "offchain",
Action: "read",
},
{
Entity: "offchain",
Action: "write",
},
}
// macPermissions maps RPC calls to the permissions they require.
macPermissions = map[string][]bakery.Op{
"/routerrpc.Router/SendPayment": {{
Entity: "offchain",
Action: "write",
}},
"/routerrpc.Router/SendToRoute": {{
Entity: "offchain",
Action: "write",
}},
"/routerrpc.Router/TrackPayment": {{
Entity: "offchain",
Action: "read",
}},
"/routerrpc.Router/EstimateRouteFee": {{
Entity: "offchain",
Action: "read",
}},
"/routerrpc.Router/QueryMissionControl": {{
Entity: "offchain",
Action: "read",
}},
"/routerrpc.Router/QueryProbability": {{
Entity: "offchain",
Action: "read",
}},
"/routerrpc.Router/ResetMissionControl": {{
Entity: "offchain",
Action: "write",
}},
"/routerrpc.Router/BuildRoute": {{
Entity: "offchain",
Action: "read",
}},
}
// DefaultRouterMacFilename is the default name of the router macaroon
// that we expect to find via a file handle within the main
// configuration file in this package.
DefaultRouterMacFilename = "router.macaroon"
)
// Server is a stand alone sub RPC server which exposes functionality that
// allows clients to route arbitrary payment through the Lightning Network.
type Server struct {
cfg *Config
}
// A compile time check to ensure that Server fully implements the RouterServer
// gRPC service.
var _ RouterServer = (*Server)(nil)
// fileExists reports whether the named file or directory exists.
func fileExists(name string) bool {
if _, err := os.Stat(name); err != nil {
if os.IsNotExist(err) {
return false
}
}
return true
}
// New creates a new instance of the RouterServer given a configuration struct
// that contains all external dependencies. If the target macaroon exists, and
// we're unable to create it, then an error will be returned. We also return
// the set of permissions that we require as a server. At the time of writing
// of this documentation, this is the same macaroon as as the admin macaroon.
func New(cfg *Config) (*Server, lnrpc.MacaroonPerms, error) {
// If the path of the router macaroon wasn't generated, then we'll
// assume that it's found at the default network directory.
if cfg.RouterMacPath == "" {
cfg.RouterMacPath = filepath.Join(
cfg.NetworkDir, DefaultRouterMacFilename,
)
}
// Now that we know the full path of the router macaroon, we can check
// to see if we need to create it or not.
macFilePath := cfg.RouterMacPath
if !fileExists(macFilePath) && cfg.MacService != nil {
log.Infof("Making macaroons for Router RPC Server at: %v",
macFilePath)
// At this point, we know that the router macaroon doesn't yet,
// exist, so we need to create it with the help of the main
// macaroon service.
routerMac, err := cfg.MacService.Oven.NewMacaroon(
context.Background(), bakery.LatestVersion, nil,
macaroonOps...,
)
if err != nil {
return nil, nil, err
}
routerMacBytes, err := routerMac.M().MarshalBinary()
if err != nil {
return nil, nil, err
}
err = ioutil.WriteFile(macFilePath, routerMacBytes, 0644)
if err != nil {
os.Remove(macFilePath)
return nil, nil, err
}
}
routerServer := &Server{
cfg: cfg,
}
return routerServer, macPermissions, nil
}
// Start launches any helper goroutines required for the rpcServer to function.
//
// NOTE: This is part of the lnrpc.SubServer interface.
func (s *Server) Start() error {
return nil
}
// Stop signals any active goroutines for a graceful closure.
//
// NOTE: This is part of the lnrpc.SubServer interface.
func (s *Server) Stop() error {
return nil
}
// Name returns a unique string representation of the sub-server. This can be
// used to identify the sub-server and also de-duplicate them.
//
// NOTE: This is part of the lnrpc.SubServer interface.
func (s *Server) Name() string {
return subServerName
}
// RegisterWithRootServer will be called by the root gRPC server to direct a
// sub RPC server to register itself with the main gRPC root server. Until this
// is called, each sub-server won't be able to have requests routed towards it.
//
// NOTE: This is part of the lnrpc.SubServer interface.
func (s *Server) RegisterWithRootServer(grpcServer *grpc.Server) error {
// We make sure that we register it with the main gRPC server to ensure
// all our methods are routed properly.
RegisterRouterServer(grpcServer, s)
log.Debugf("Router RPC server successfully register with root gRPC " +
"server")
return nil
}
// SendPayment attempts to route a payment described by the passed
// PaymentRequest to the final destination. If we are unable to route the
// payment, or cannot find a route that satisfies the constraints in the
// PaymentRequest, then an error will be returned. Otherwise, the payment
// pre-image, along with the final route will be returned.
func (s *Server) SendPayment(req *SendPaymentRequest,
stream Router_SendPaymentServer) error {
payment, err := s.cfg.RouterBackend.extractIntentFromSendRequest(req)
if err != nil {
return err
}
err = s.cfg.Router.SendPaymentAsync(payment)
if err != nil {
// Transform user errors to grpc code.
if err == channeldb.ErrPaymentInFlight ||
err == channeldb.ErrAlreadyPaid {
log.Debugf("SendPayment async result for hash %x: %v",
payment.PaymentHash, err)
return status.Error(
codes.AlreadyExists, err.Error(),
)
}
log.Errorf("SendPayment async error for hash %x: %v",
payment.PaymentHash, err)
return err
}
return s.trackPayment(payment.PaymentHash, stream)
}
// EstimateRouteFee allows callers to obtain a lower bound w.r.t how much it
// may cost to send an HTLC to the target end destination.
func (s *Server) EstimateRouteFee(ctx context.Context,
req *RouteFeeRequest) (*RouteFeeResponse, error) {
if len(req.Dest) != 33 {
return nil, errors.New("invalid length destination key")
}
var destNode route.Vertex
copy(destNode[:], req.Dest)
// Next, we'll convert the amount in satoshis to mSAT, which are the
// native unit of LN.
amtMsat := lnwire.NewMSatFromSatoshis(btcutil.Amount(req.AmtSat))
// Pick a fee limit
//
// TODO: Change this into behaviour that makes more sense.
feeLimit := lnwire.NewMSatFromSatoshis(btcutil.SatoshiPerBitcoin)
// Finally, we'll query for a route to the destination that can carry
// that target amount, we'll only request a single route. Set a
// restriction for the default CLTV limit, otherwise we can find a route
// that exceeds it and is useless to us.
route, err := s.cfg.Router.FindRoute(
s.cfg.RouterBackend.SelfNode, destNode, amtMsat,
&routing.RestrictParams{
FeeLimit: feeLimit,
CltvLimit: s.cfg.RouterBackend.MaxTotalTimelock,
}, nil,
)
if err != nil {
return nil, err
}
return &RouteFeeResponse{
RoutingFeeMsat: int64(route.TotalFees()),
TimeLockDelay: int64(route.TotalTimeLock),
}, nil
}
// SendToRoute sends a payment through a predefined route. The response of this
// call contains structured error information.
func (s *Server) SendToRoute(ctx context.Context,
req *SendToRouteRequest) (*SendToRouteResponse, error) {
if req.Route == nil {
return nil, fmt.Errorf("unable to send, no routes provided")
}
route, err := s.cfg.RouterBackend.UnmarshallRoute(req.Route)
if err != nil {
return nil, err
}
hash, err := lntypes.MakeHash(req.PaymentHash)
if err != nil {
return nil, err
}
preimage, err := s.cfg.Router.SendToRoute(hash, route)
// In the success case, return the preimage.
if err == nil {
return &SendToRouteResponse{
Preimage: preimage[:],
}, nil
}
// In the failure case, marshall the failure message to the rpc format
// before returning it to the caller.
rpcErr, err := marshallError(err)
if err != nil {
return nil, err
}
return &SendToRouteResponse{
Failure: rpcErr,
}, nil
}
// marshallError marshall an error as received from the switch to rpc structs
// suitable for returning to the caller of an rpc method.
//
// Because of difficulties with using protobuf oneof constructs in some
// languages, the decision was made here to use a single message format for all
// failure messages with some fields left empty depending on the failure type.
func marshallError(sendError error) (*Failure, error) {
response := &Failure{}
if sendError == htlcswitch.ErrUnreadableFailureMessage {
response.Code = Failure_UNREADABLE_FAILURE
return response, nil
}
rtErr, ok := sendError.(htlcswitch.ClearTextError)
if !ok {
return nil, sendError
}
switch onionErr := rtErr.WireMessage().(type) {
case *lnwire.FailIncorrectDetails:
response.Code = Failure_INCORRECT_OR_UNKNOWN_PAYMENT_DETAILS
response.Height = onionErr.Height()
case *lnwire.FailIncorrectPaymentAmount:
response.Code = Failure_INCORRECT_PAYMENT_AMOUNT
case *lnwire.FailFinalIncorrectCltvExpiry:
response.Code = Failure_FINAL_INCORRECT_CLTV_EXPIRY
response.CltvExpiry = onionErr.CltvExpiry
case *lnwire.FailFinalIncorrectHtlcAmount:
response.Code = Failure_FINAL_INCORRECT_HTLC_AMOUNT
response.HtlcMsat = uint64(onionErr.IncomingHTLCAmount)
case *lnwire.FailFinalExpiryTooSoon:
response.Code = Failure_FINAL_EXPIRY_TOO_SOON
case *lnwire.FailInvalidRealm:
response.Code = Failure_INVALID_REALM
case *lnwire.FailExpiryTooSoon:
response.Code = Failure_EXPIRY_TOO_SOON
response.ChannelUpdate = marshallChannelUpdate(&onionErr.Update)
case *lnwire.FailExpiryTooFar:
response.Code = Failure_EXPIRY_TOO_FAR
case *lnwire.FailInvalidOnionVersion:
response.Code = Failure_INVALID_ONION_VERSION
response.OnionSha_256 = onionErr.OnionSHA256[:]
case *lnwire.FailInvalidOnionHmac:
response.Code = Failure_INVALID_ONION_HMAC
response.OnionSha_256 = onionErr.OnionSHA256[:]
case *lnwire.FailInvalidOnionKey:
response.Code = Failure_INVALID_ONION_KEY
response.OnionSha_256 = onionErr.OnionSHA256[:]
case *lnwire.FailAmountBelowMinimum:
response.Code = Failure_AMOUNT_BELOW_MINIMUM
response.ChannelUpdate = marshallChannelUpdate(&onionErr.Update)
response.HtlcMsat = uint64(onionErr.HtlcMsat)
case *lnwire.FailFeeInsufficient:
response.Code = Failure_FEE_INSUFFICIENT
response.ChannelUpdate = marshallChannelUpdate(&onionErr.Update)
response.HtlcMsat = uint64(onionErr.HtlcMsat)
case *lnwire.FailIncorrectCltvExpiry:
response.Code = Failure_INCORRECT_CLTV_EXPIRY
response.ChannelUpdate = marshallChannelUpdate(&onionErr.Update)
response.CltvExpiry = onionErr.CltvExpiry
case *lnwire.FailChannelDisabled:
response.Code = Failure_CHANNEL_DISABLED
response.ChannelUpdate = marshallChannelUpdate(&onionErr.Update)
response.Flags = uint32(onionErr.Flags)
case *lnwire.FailTemporaryChannelFailure:
response.Code = Failure_TEMPORARY_CHANNEL_FAILURE
response.ChannelUpdate = marshallChannelUpdate(onionErr.Update)
case *lnwire.FailRequiredNodeFeatureMissing:
response.Code = Failure_REQUIRED_NODE_FEATURE_MISSING
case *lnwire.FailRequiredChannelFeatureMissing:
response.Code = Failure_REQUIRED_CHANNEL_FEATURE_MISSING
case *lnwire.FailUnknownNextPeer:
response.Code = Failure_UNKNOWN_NEXT_PEER
case *lnwire.FailTemporaryNodeFailure:
response.Code = Failure_TEMPORARY_NODE_FAILURE
case *lnwire.FailPermanentNodeFailure:
response.Code = Failure_PERMANENT_NODE_FAILURE
case *lnwire.FailPermanentChannelFailure:
response.Code = Failure_PERMANENT_CHANNEL_FAILURE
case *lnwire.FailMPPTimeout:
response.Code = Failure_MPP_TIMEOUT
case nil:
response.Code = Failure_UNKNOWN_FAILURE
default:
return nil, fmt.Errorf("cannot marshall failure %T", onionErr)
}
// If the ClearTextError received is a ForwardingError, the error
// originated from a node along the route, not locally on our outgoing
// link. We set failureSourceIdx to the index of the node where the
// failure occurred. If the error is not a ForwardingError, the failure
// occurred at our node, so we leave the index as 0 to indicate that
// we failed locally.
fErr, ok := rtErr.(*htlcswitch.ForwardingError)
if ok {
response.FailureSourceIndex = uint32(fErr.FailureSourceIdx)
}
return response, nil
}
// marshallChannelUpdate marshalls a channel update as received over the wire to
// the router rpc format.
func marshallChannelUpdate(update *lnwire.ChannelUpdate) *ChannelUpdate {
if update == nil {
return nil
}
return &ChannelUpdate{
Signature: update.Signature[:],
ChainHash: update.ChainHash[:],
ChanId: update.ShortChannelID.ToUint64(),
Timestamp: update.Timestamp,
MessageFlags: uint32(update.MessageFlags),
ChannelFlags: uint32(update.ChannelFlags),
TimeLockDelta: uint32(update.TimeLockDelta),
HtlcMinimumMsat: uint64(update.HtlcMinimumMsat),
BaseFee: update.BaseFee,
FeeRate: update.FeeRate,
HtlcMaximumMsat: uint64(update.HtlcMaximumMsat),
ExtraOpaqueData: update.ExtraOpaqueData,
}
}
// ResetMissionControl clears all mission control state and starts with a clean
// slate.
func (s *Server) ResetMissionControl(ctx context.Context,
req *ResetMissionControlRequest) (*ResetMissionControlResponse, error) {
err := s.cfg.RouterBackend.MissionControl.ResetHistory()
if err != nil {
return nil, err
}
return &ResetMissionControlResponse{}, nil
}
// QueryMissionControl exposes the internal mission control state to callers. It
// is a development feature.
func (s *Server) QueryMissionControl(ctx context.Context,
req *QueryMissionControlRequest) (*QueryMissionControlResponse, error) {
snapshot := s.cfg.RouterBackend.MissionControl.GetHistorySnapshot()
rpcPairs := make([]*PairHistory, 0, len(snapshot.Pairs))
for _, p := range snapshot.Pairs {
// Prevent binding to loop variable.
pair := p
rpcPair := PairHistory{
NodeFrom: pair.Pair.From[:],
NodeTo: pair.Pair.To[:],
History: toRPCPairData(&pair.TimedPairResult),
}
rpcPairs = append(rpcPairs, &rpcPair)
}
response := QueryMissionControlResponse{
Pairs: rpcPairs,
}
return &response, nil
}
// toRPCPairData marshalls mission control pair data to the rpc struct.
func toRPCPairData(data *routing.TimedPairResult) *PairData {
rpcData := PairData{
FailAmtSat: int64(data.FailAmt.ToSatoshis()),
FailAmtMsat: int64(data.FailAmt),
SuccessAmtSat: int64(data.SuccessAmt.ToSatoshis()),
SuccessAmtMsat: int64(data.SuccessAmt),
}
if !data.FailTime.IsZero() {
rpcData.FailTime = data.FailTime.Unix()
}
if !data.SuccessTime.IsZero() {
rpcData.SuccessTime = data.SuccessTime.Unix()
}
return &rpcData
}
// QueryProbability returns the current success probability estimate for a
// given node pair and amount.
func (s *Server) QueryProbability(ctx context.Context,
req *QueryProbabilityRequest) (*QueryProbabilityResponse, error) {
fromNode, err := route.NewVertexFromBytes(req.FromNode)
if err != nil {
return nil, err
}
toNode, err := route.NewVertexFromBytes(req.ToNode)
if err != nil {
return nil, err
}
amt := lnwire.MilliSatoshi(req.AmtMsat)
mc := s.cfg.RouterBackend.MissionControl
prob := mc.GetProbability(fromNode, toNode, amt)
history := mc.GetPairHistorySnapshot(fromNode, toNode)
return &QueryProbabilityResponse{
Probability: prob,
History: toRPCPairData(&history),
}, nil
}
// TrackPayment returns a stream of payment state updates. The stream is
// closed when the payment completes.
func (s *Server) TrackPayment(request *TrackPaymentRequest,
stream Router_TrackPaymentServer) error {
paymentHash, err := lntypes.MakeHash(request.PaymentHash)
if err != nil {
return err
}
log.Debugf("TrackPayment called for payment %v", paymentHash)
return s.trackPayment(paymentHash, stream)
}
// trackPayment writes payment status updates to the provided stream.
func (s *Server) trackPayment(paymentHash lntypes.Hash,
stream Router_TrackPaymentServer) error {
router := s.cfg.RouterBackend
// Subscribe to the outcome of this payment.
inFlight, resultChan, err := router.Tower.SubscribePayment(
paymentHash,
)
switch {
case err == channeldb.ErrPaymentNotInitiated:
return status.Error(codes.NotFound, err.Error())
case err != nil:
return err
}
// If it is in flight, send a state update to the client. Payment status
// update streams are expected to always send the current payment state
// immediately.
if inFlight {
err = stream.Send(&PaymentStatus{
State: PaymentState_IN_FLIGHT,
})
if err != nil {
return err
}
}
// Wait for the outcome of the payment. For payments that have
// completed, the result should already be waiting on the channel.
select {
case result := <-resultChan:
// Marshall result to rpc type.
var status PaymentStatus
if result.Success {
log.Debugf("Payment %v successfully completed",
paymentHash)
status.State = PaymentState_SUCCEEDED
status.Preimage = result.Preimage[:]
} else {
state, err := marshallFailureReason(
result.FailureReason,
)
if err != nil {
return err
}
status.State = state
}
// Extract the last route from the given list of HTLCs. This
// will populate the legacy route field for backwards
// compatibility.
//
// NOTE: For now there will be at most one HTLC, this code
// should be revisted or the field removed when multiple HTLCs
// are permitted.
var legacyRoute *route.Route
for _, htlc := range result.HTLCs {
switch {
case htlc.Settle != nil:
legacyRoute = &htlc.Route
// Only display the route for failed payments if we got
// an incorrect payment details error, so that it can be
// used for probing or fee estimation.
case htlc.Failure != nil && result.FailureReason ==
channeldb.FailureReasonPaymentDetails:
legacyRoute = &htlc.Route
}
}
if legacyRoute != nil {
status.Route, err = router.MarshallRoute(legacyRoute)
if err != nil {
return err
}
}
// Marshal our list of HTLCs that have been tried for this
// payment.
htlcs := make([]*lnrpc.HTLCAttempt, 0, len(result.HTLCs))
for _, dbHtlc := range result.HTLCs {
htlc, err := router.MarshalHTLCAttempt(dbHtlc)
if err != nil {
return err
}
htlcs = append(htlcs, htlc)
}
status.Htlcs = htlcs
// Send event to the client.
err = stream.Send(&status)
if err != nil {
return err
}
case <-stream.Context().Done():
log.Debugf("Payment status stream %v canceled", paymentHash)
return stream.Context().Err()
}
return nil
}
// marshallFailureReason marshalls the failure reason to the corresponding rpc
// type.
func marshallFailureReason(reason channeldb.FailureReason) (
PaymentState, error) {
switch reason {
case channeldb.FailureReasonTimeout:
return PaymentState_FAILED_TIMEOUT, nil
case channeldb.FailureReasonNoRoute:
return PaymentState_FAILED_NO_ROUTE, nil
case channeldb.FailureReasonError:
return PaymentState_FAILED_ERROR, nil
case channeldb.FailureReasonPaymentDetails:
return PaymentState_FAILED_INCORRECT_PAYMENT_DETAILS, nil
case channeldb.FailureReasonInsufficientBalance:
return PaymentState_FAILED_INSUFFICIENT_BALANCE, nil
}
return 0, errors.New("unknown failure reason")
}
// BuildRoute builds a route from a list of hop addresses.
func (s *Server) BuildRoute(ctx context.Context,
req *BuildRouteRequest) (*BuildRouteResponse, error) {
// Unmarshall hop list.
hops := make([]route.Vertex, len(req.HopPubkeys))
for i, pubkeyBytes := range req.HopPubkeys {
pubkey, err := route.NewVertexFromBytes(pubkeyBytes)
if err != nil {
return nil, err
}
hops[i] = pubkey
}
// Prepare BuildRoute call parameters from rpc request.
var amt *lnwire.MilliSatoshi
if req.AmtMsat != 0 {
rpcAmt := lnwire.MilliSatoshi(req.AmtMsat)
amt = &rpcAmt
}
var outgoingChan *uint64
if req.OutgoingChanId != 0 {
outgoingChan = &req.OutgoingChanId
}
// Build the route and return it to the caller.
route, err := s.cfg.Router.BuildRoute(
amt, hops, outgoingChan, req.FinalCltvDelta,
)
if err != nil {
return nil, err
}
rpcRoute, err := s.cfg.RouterBackend.MarshallRoute(route)
if err != nil {
return nil, err
}
routeResp := &BuildRouteResponse{
Route: rpcRoute,
}
return routeResp, nil
}