mirror of
https://github.com/lightninglabs/loop
synced 2024-11-04 06:00:21 +00:00
540 lines
15 KiB
Go
540 lines
15 KiB
Go
package loop
|
|
|
|
import (
|
|
"context"
|
|
"crypto/tls"
|
|
"encoding/hex"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"net"
|
|
"strings"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/btcsuite/btcd/btcec"
|
|
"github.com/btcsuite/btcutil"
|
|
"github.com/lightninglabs/loop/loopdb"
|
|
"github.com/lightninglabs/loop/looprpc"
|
|
"github.com/lightninglabs/loop/lsat"
|
|
"github.com/lightningnetwork/lnd/lntypes"
|
|
"github.com/lightningnetwork/lnd/routing/route"
|
|
"github.com/lightningnetwork/lnd/tor"
|
|
"google.golang.org/grpc"
|
|
"google.golang.org/grpc/credentials"
|
|
)
|
|
|
|
var (
|
|
// errServerSubscriptionComplete is returned when our subscription to
|
|
// server updates exits because the server has no more updates to
|
|
// provide us, because its part in the swap is complete.
|
|
errServerSubscriptionComplete = errors.New("server finished serving " +
|
|
"updates")
|
|
|
|
// errSubscriptionFailed is returned when our subscription returns with
|
|
// and EOF, indicating that the server restarted, we had an unexpected
|
|
// network failure. Since we do not have restart-recovery, we note that
|
|
// we will not resume our subscription once this error occurs.
|
|
errSubscriptionFailed = errors.New("failed, no further updates will " +
|
|
"be provided")
|
|
)
|
|
|
|
type swapServerClient interface {
|
|
GetLoopOutTerms(ctx context.Context) (
|
|
*LoopOutTerms, error)
|
|
|
|
GetLoopOutQuote(ctx context.Context, amt btcutil.Amount, expiry int32,
|
|
swapPublicationDeadline time.Time) (
|
|
*LoopOutQuote, error)
|
|
|
|
GetLoopInTerms(ctx context.Context) (
|
|
*LoopInTerms, error)
|
|
|
|
GetLoopInQuote(ctx context.Context, amt btcutil.Amount) (
|
|
*LoopInQuote, error)
|
|
|
|
NewLoopOutSwap(ctx context.Context,
|
|
swapHash lntypes.Hash, amount btcutil.Amount, expiry int32,
|
|
receiverKey [33]byte, swapPublicationDeadline time.Time,
|
|
initiator string) (*newLoopOutResponse, error)
|
|
|
|
PushLoopOutPreimage(ctx context.Context,
|
|
preimage lntypes.Preimage) error
|
|
|
|
NewLoopInSwap(ctx context.Context,
|
|
swapHash lntypes.Hash, amount btcutil.Amount,
|
|
senderKey [33]byte, swapInvoice, probeInvoice string,
|
|
lastHop *route.Vertex, initiator string) (*newLoopInResponse,
|
|
error)
|
|
|
|
// SubscribeLoopOutUpdates subscribes to loop out server state.
|
|
SubscribeLoopOutUpdates(ctx context.Context,
|
|
hash lntypes.Hash) (<-chan *ServerUpdate, <-chan error, error)
|
|
|
|
// SubscribeLoopInUpdates subscribes to loop in server state.
|
|
SubscribeLoopInUpdates(ctx context.Context,
|
|
hash lntypes.Hash) (<-chan *ServerUpdate, <-chan error, error)
|
|
}
|
|
|
|
type grpcSwapServerClient struct {
|
|
server looprpc.SwapServerClient
|
|
conn *grpc.ClientConn
|
|
|
|
wg sync.WaitGroup
|
|
}
|
|
|
|
// stop sends the signal for the server's goroutines to shutdown and waits for
|
|
// them to complete.
|
|
func (s *grpcSwapServerClient) stop() {
|
|
if err := s.conn.Close(); err != nil {
|
|
log.Warnf("could not close connection: %v", err)
|
|
}
|
|
|
|
s.wg.Wait()
|
|
}
|
|
|
|
var _ swapServerClient = (*grpcSwapServerClient)(nil)
|
|
|
|
func newSwapServerClient(cfg *ClientConfig, lsatStore lsat.Store) (
|
|
*grpcSwapServerClient, error) {
|
|
|
|
// Create the server connection with the interceptor that will handle
|
|
// the LSAT protocol for us.
|
|
clientInterceptor := lsat.NewInterceptor(
|
|
cfg.Lnd, lsatStore, serverRPCTimeout, cfg.MaxLsatCost,
|
|
cfg.MaxLsatFee,
|
|
)
|
|
serverConn, err := getSwapServerConn(
|
|
cfg.ServerAddress, cfg.ProxyAddress, cfg.SwapServerNoTLS,
|
|
cfg.TLSPathServer, clientInterceptor,
|
|
)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
server := looprpc.NewSwapServerClient(serverConn)
|
|
|
|
return &grpcSwapServerClient{
|
|
conn: serverConn,
|
|
server: server,
|
|
}, nil
|
|
}
|
|
|
|
func (s *grpcSwapServerClient) GetLoopOutTerms(ctx context.Context) (
|
|
*LoopOutTerms, error) {
|
|
|
|
rpcCtx, rpcCancel := context.WithTimeout(ctx, globalCallTimeout)
|
|
defer rpcCancel()
|
|
terms, err := s.server.LoopOutTerms(rpcCtx,
|
|
&looprpc.ServerLoopOutTermsRequest{
|
|
ProtocolVersion: loopdb.CurrentRPCProtocolVersion,
|
|
},
|
|
)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &LoopOutTerms{
|
|
MinSwapAmount: btcutil.Amount(terms.MinSwapAmount),
|
|
MaxSwapAmount: btcutil.Amount(terms.MaxSwapAmount),
|
|
MinCltvDelta: terms.MinCltvDelta,
|
|
MaxCltvDelta: terms.MaxCltvDelta,
|
|
}, nil
|
|
}
|
|
|
|
func (s *grpcSwapServerClient) GetLoopOutQuote(ctx context.Context,
|
|
amt btcutil.Amount, expiry int32, swapPublicationDeadline time.Time) (
|
|
*LoopOutQuote, error) {
|
|
|
|
rpcCtx, rpcCancel := context.WithTimeout(ctx, globalCallTimeout)
|
|
defer rpcCancel()
|
|
quoteResp, err := s.server.LoopOutQuote(rpcCtx,
|
|
&looprpc.ServerLoopOutQuoteRequest{
|
|
Amt: uint64(amt),
|
|
SwapPublicationDeadline: swapPublicationDeadline.Unix(),
|
|
ProtocolVersion: loopdb.CurrentRPCProtocolVersion,
|
|
Expiry: expiry,
|
|
},
|
|
)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
dest, err := hex.DecodeString(quoteResp.SwapPaymentDest)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if len(dest) != 33 {
|
|
return nil, errors.New("invalid payment dest")
|
|
}
|
|
var destArray [33]byte
|
|
copy(destArray[:], dest)
|
|
|
|
return &LoopOutQuote{
|
|
PrepayAmount: btcutil.Amount(quoteResp.PrepayAmt),
|
|
SwapFee: btcutil.Amount(quoteResp.SwapFee),
|
|
SwapPaymentDest: destArray,
|
|
}, nil
|
|
}
|
|
|
|
func (s *grpcSwapServerClient) GetLoopInTerms(ctx context.Context) (
|
|
*LoopInTerms, error) {
|
|
|
|
rpcCtx, rpcCancel := context.WithTimeout(ctx, globalCallTimeout)
|
|
defer rpcCancel()
|
|
terms, err := s.server.LoopInTerms(rpcCtx,
|
|
&looprpc.ServerLoopInTermsRequest{
|
|
ProtocolVersion: loopdb.CurrentRPCProtocolVersion,
|
|
},
|
|
)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &LoopInTerms{
|
|
MinSwapAmount: btcutil.Amount(terms.MinSwapAmount),
|
|
MaxSwapAmount: btcutil.Amount(terms.MaxSwapAmount),
|
|
}, nil
|
|
}
|
|
|
|
func (s *grpcSwapServerClient) GetLoopInQuote(ctx context.Context,
|
|
amt btcutil.Amount) (*LoopInQuote, error) {
|
|
|
|
rpcCtx, rpcCancel := context.WithTimeout(ctx, globalCallTimeout)
|
|
defer rpcCancel()
|
|
quoteResp, err := s.server.LoopInQuote(rpcCtx,
|
|
&looprpc.ServerLoopInQuoteRequest{
|
|
Amt: uint64(amt),
|
|
ProtocolVersion: loopdb.CurrentRPCProtocolVersion,
|
|
},
|
|
)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &LoopInQuote{
|
|
SwapFee: btcutil.Amount(quoteResp.SwapFee),
|
|
CltvDelta: quoteResp.CltvDelta,
|
|
}, nil
|
|
}
|
|
|
|
func (s *grpcSwapServerClient) NewLoopOutSwap(ctx context.Context,
|
|
swapHash lntypes.Hash, amount btcutil.Amount, expiry int32,
|
|
receiverKey [33]byte, swapPublicationDeadline time.Time,
|
|
initiator string) (*newLoopOutResponse, error) {
|
|
|
|
rpcCtx, rpcCancel := context.WithTimeout(ctx, globalCallTimeout)
|
|
defer rpcCancel()
|
|
swapResp, err := s.server.NewLoopOutSwap(rpcCtx,
|
|
&looprpc.ServerLoopOutRequest{
|
|
SwapHash: swapHash[:],
|
|
Amt: uint64(amount),
|
|
ReceiverKey: receiverKey[:],
|
|
SwapPublicationDeadline: swapPublicationDeadline.Unix(),
|
|
ProtocolVersion: loopdb.CurrentRPCProtocolVersion,
|
|
Expiry: expiry,
|
|
UserAgent: UserAgent(initiator),
|
|
},
|
|
)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
var senderKey [33]byte
|
|
copy(senderKey[:], swapResp.SenderKey)
|
|
|
|
// Validate sender key.
|
|
_, err = btcec.ParsePubKey(senderKey[:], btcec.S256())
|
|
if err != nil {
|
|
return nil, fmt.Errorf("invalid sender key: %v", err)
|
|
}
|
|
|
|
return &newLoopOutResponse{
|
|
swapInvoice: swapResp.SwapInvoice,
|
|
prepayInvoice: swapResp.PrepayInvoice,
|
|
senderKey: senderKey,
|
|
serverMessage: swapResp.ServerMessage,
|
|
}, nil
|
|
}
|
|
|
|
// PushLoopOutPreimage pushes a preimage to the server.
|
|
func (s *grpcSwapServerClient) PushLoopOutPreimage(ctx context.Context,
|
|
preimage lntypes.Preimage) error {
|
|
|
|
rpcCtx, rpcCancel := context.WithTimeout(ctx, globalCallTimeout)
|
|
defer rpcCancel()
|
|
|
|
_, err := s.server.LoopOutPushPreimage(rpcCtx,
|
|
&looprpc.ServerLoopOutPushPreimageRequest{
|
|
ProtocolVersion: loopdb.CurrentRPCProtocolVersion,
|
|
Preimage: preimage[:],
|
|
},
|
|
)
|
|
|
|
return err
|
|
}
|
|
|
|
func (s *grpcSwapServerClient) NewLoopInSwap(ctx context.Context,
|
|
swapHash lntypes.Hash, amount btcutil.Amount, senderKey [33]byte,
|
|
swapInvoice, probeInvoice string, lastHop *route.Vertex,
|
|
initiator string) (*newLoopInResponse, error) {
|
|
|
|
rpcCtx, rpcCancel := context.WithTimeout(ctx, globalCallTimeout)
|
|
defer rpcCancel()
|
|
|
|
req := &looprpc.ServerLoopInRequest{
|
|
SwapHash: swapHash[:],
|
|
Amt: uint64(amount),
|
|
SenderKey: senderKey[:],
|
|
SwapInvoice: swapInvoice,
|
|
ProtocolVersion: loopdb.CurrentRPCProtocolVersion,
|
|
ProbeInvoice: probeInvoice,
|
|
UserAgent: UserAgent(initiator),
|
|
}
|
|
if lastHop != nil {
|
|
req.LastHop = lastHop[:]
|
|
}
|
|
|
|
swapResp, err := s.server.NewLoopInSwap(rpcCtx, req)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
var receiverKey [33]byte
|
|
copy(receiverKey[:], swapResp.ReceiverKey)
|
|
|
|
// Validate receiver key.
|
|
_, err = btcec.ParsePubKey(receiverKey[:], btcec.S256())
|
|
if err != nil {
|
|
return nil, fmt.Errorf("invalid sender key: %v", err)
|
|
}
|
|
|
|
return &newLoopInResponse{
|
|
receiverKey: receiverKey,
|
|
expiry: swapResp.Expiry,
|
|
serverMessage: swapResp.ServerMessage,
|
|
}, nil
|
|
}
|
|
|
|
// ServerUpdate summarizes an update from the swap server.
|
|
type ServerUpdate struct {
|
|
// State is the state that the server has sent us.
|
|
State looprpc.ServerSwapState
|
|
|
|
// Timestamp is the time of the server state update.
|
|
Timestamp time.Time
|
|
}
|
|
|
|
// SubscribeLoopInUpdates subscribes to loop in server state and pipes updates
|
|
// into the channel provided.
|
|
func (s *grpcSwapServerClient) SubscribeLoopInUpdates(ctx context.Context,
|
|
hash lntypes.Hash) (<-chan *ServerUpdate, <-chan error, error) {
|
|
|
|
resp, err := s.server.SubscribeLoopInUpdates(
|
|
ctx, &looprpc.SubscribeUpdatesRequest{
|
|
ProtocolVersion: loopdb.CurrentRPCProtocolVersion,
|
|
SwapHash: hash[:],
|
|
},
|
|
)
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
|
|
receive := func() (*ServerUpdate, error) {
|
|
response, err := resp.Recv()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &ServerUpdate{
|
|
State: response.State,
|
|
Timestamp: time.Unix(0, response.TimestampNs),
|
|
}, nil
|
|
}
|
|
|
|
updateChan, errChan := s.makeServerUpdate(ctx, receive)
|
|
return updateChan, errChan, nil
|
|
}
|
|
|
|
// SubscribeLoopOutUpdates subscribes to loop out server state and pipes updates
|
|
// into the channel provided.
|
|
func (s *grpcSwapServerClient) SubscribeLoopOutUpdates(ctx context.Context,
|
|
hash lntypes.Hash) (<-chan *ServerUpdate, <-chan error, error) {
|
|
|
|
resp, err := s.server.SubscribeLoopOutUpdates(
|
|
ctx, &looprpc.SubscribeUpdatesRequest{
|
|
ProtocolVersion: loopdb.CurrentRPCProtocolVersion,
|
|
SwapHash: hash[:],
|
|
},
|
|
)
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
|
|
receive := func() (*ServerUpdate, error) {
|
|
response, err := resp.Recv()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &ServerUpdate{
|
|
State: response.State,
|
|
Timestamp: time.Unix(0, response.TimestampNs),
|
|
}, nil
|
|
}
|
|
|
|
updateChan, errChan := s.makeServerUpdate(ctx, receive)
|
|
return updateChan, errChan, nil
|
|
}
|
|
|
|
// makeServerUpdate takes a stream receive function and a channel that it
|
|
// should pipe updates into. It sends events into the updates channel until
|
|
// the client cancels, server client shuts down or the subscription is cancelled
|
|
// server side.
|
|
func (s *grpcSwapServerClient) makeServerUpdate(ctx context.Context,
|
|
receive func() (*ServerUpdate, error)) (<-chan *ServerUpdate,
|
|
<-chan error) {
|
|
|
|
// We will return exactly one error from this function so we buffer
|
|
// our error channel so that the function exit is not dependent on
|
|
// the error being read.
|
|
errChan := make(chan error, 1)
|
|
updateChan := make(chan *ServerUpdate)
|
|
|
|
// Create a goroutine that will pipe updates in to our updates channel.
|
|
s.wg.Add(1)
|
|
go func() {
|
|
defer s.wg.Done()
|
|
|
|
for {
|
|
// Try to receive from our stream. If there are no items
|
|
// to consume, this call will block. If our stream is
|
|
// cancelled by the server we will receive an error.
|
|
response, err := receive()
|
|
switch err {
|
|
// If we get a nil error, we proceed with to delivering
|
|
// the update we have just received.
|
|
case nil:
|
|
|
|
// If we get an EOF error, the server is finished
|
|
// sending us updates, so we return with a non-nil
|
|
// a subscription complete error to inform the caller
|
|
// that they will no longer receive updates.
|
|
case io.EOF:
|
|
errChan <- errServerSubscriptionComplete
|
|
return
|
|
|
|
// If we receive a non-nil error, we exit.
|
|
default:
|
|
// If we get a transport is closing error, we
|
|
// send a server restarting error so that the
|
|
// caller is informed that we will not get
|
|
// any more updates from the server (since we
|
|
// don't have retry logic yet).
|
|
if isErrConClosing(err) {
|
|
errChan <- errSubscriptionFailed
|
|
} else {
|
|
errChan <- err
|
|
}
|
|
|
|
return
|
|
}
|
|
|
|
select {
|
|
// Try to send our update to the update channel.
|
|
case updateChan <- response:
|
|
|
|
// If the client cancels their context, we exit with
|
|
// no error.
|
|
case <-ctx.Done():
|
|
errChan <- nil
|
|
return
|
|
}
|
|
}
|
|
}()
|
|
|
|
return updateChan, errChan
|
|
}
|
|
|
|
// getSwapServerConn returns a connection to the swap server. A non-empty
|
|
// proxyAddr indicates that a SOCKS proxy found at the address should be used to
|
|
// establish the connection.
|
|
func getSwapServerConn(address, proxyAddress string, insecure bool,
|
|
tlsPath string, interceptor *lsat.Interceptor) (*grpc.ClientConn, error) {
|
|
|
|
// Create a dial options array.
|
|
opts := []grpc.DialOption{
|
|
grpc.WithUnaryInterceptor(
|
|
interceptor.UnaryInterceptor,
|
|
),
|
|
grpc.WithStreamInterceptor(
|
|
interceptor.StreamInterceptor,
|
|
),
|
|
}
|
|
|
|
// There are three options to connect to a swap server, either insecure,
|
|
// using a self-signed certificate or with a certificate signed by a
|
|
// public CA.
|
|
switch {
|
|
case insecure:
|
|
opts = append(opts, grpc.WithInsecure())
|
|
|
|
case tlsPath != "":
|
|
// Load the specified TLS certificate and build
|
|
// transport credentials
|
|
creds, err := credentials.NewClientTLSFromFile(tlsPath, "")
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
opts = append(opts, grpc.WithTransportCredentials(creds))
|
|
|
|
default:
|
|
creds := credentials.NewTLS(&tls.Config{})
|
|
opts = append(opts, grpc.WithTransportCredentials(creds))
|
|
}
|
|
|
|
// If a SOCKS proxy address was specified, then we should dial through
|
|
// it.
|
|
if proxyAddress != "" {
|
|
log.Infof("Proxying connection to %v over Tor SOCKS proxy %v",
|
|
address, proxyAddress)
|
|
torDialer := func(_ context.Context, addr string) (net.Conn, error) {
|
|
return tor.Dial(addr, proxyAddress, false)
|
|
}
|
|
opts = append(opts, grpc.WithContextDialer(torDialer))
|
|
}
|
|
|
|
conn, err := grpc.Dial(address, opts...)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("unable to connect to RPC server: %v",
|
|
err)
|
|
}
|
|
|
|
return conn, nil
|
|
}
|
|
|
|
// isErrConClosing identifies whether we have received a "transport is closing"
|
|
// error from a grpc stream, indicating that the server has shutdown. We need
|
|
// to string match this error because ErrConnClosing is part of an internal
|
|
// grpc package, so cannot be used directly.
|
|
func isErrConClosing(err error) bool {
|
|
if err == nil {
|
|
return false
|
|
}
|
|
|
|
return strings.Contains(err.Error(), "transport is closing")
|
|
}
|
|
|
|
type newLoopOutResponse struct {
|
|
swapInvoice string
|
|
prepayInvoice string
|
|
senderKey [33]byte
|
|
serverMessage string
|
|
}
|
|
|
|
type newLoopInResponse struct {
|
|
receiverKey [33]byte
|
|
expiry int32
|
|
serverMessage string
|
|
}
|