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mirror of https://github.com/lightninglabs/loop synced 2024-11-08 01:10:29 +00:00
loop/swap_server_client.go
carla 65c847674d
multi: add preimage push to loop out after sweep attempt
Once we have revealed our preimage to the world with a sweep attempt,
we can safely push our preimage to the server to speed up on chain
claim.

Rather than rely on the server, we use the state of our invoice in lnd
to determine whether we should continue trying to push the preimage to
the server.
2020-06-08 12:54:08 +02:00

343 lines
8.8 KiB
Go

package loop
import (
"context"
"crypto/tls"
"encoding/hex"
"errors"
"fmt"
"net"
"time"
"github.com/btcsuite/btcd/btcec"
"github.com/btcsuite/btcutil"
"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"
)
// protocolVersion defines the version of the protocol that is currently
// supported by the loop client.
const protocolVersion = looprpc.ProtocolVersion_PREIMAGE_PUSH_LOOP_OUT
type swapServerClient interface {
GetLoopOutTerms(ctx context.Context) (
*LoopOutTerms, error)
GetLoopOutQuote(ctx context.Context, amt btcutil.Amount,
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,
receiverKey [33]byte,
swapPublicationDeadline time.Time) (
*newLoopOutResponse, error)
PushLoopOutPreimage(ctx context.Context,
preimage lntypes.Preimage) error
NewLoopInSwap(ctx context.Context,
swapHash lntypes.Hash, amount btcutil.Amount,
senderKey [33]byte, swapInvoice string, lastHop *route.Vertex) (
*newLoopInResponse, error)
}
type grpcSwapServerClient struct {
server looprpc.SwapServerClient
conn *grpc.ClientConn
}
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.Insecure,
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: protocolVersion,
},
)
if err != nil {
return nil, err
}
return &LoopOutTerms{
MinSwapAmount: btcutil.Amount(terms.MinSwapAmount),
MaxSwapAmount: btcutil.Amount(terms.MaxSwapAmount),
}, nil
}
func (s *grpcSwapServerClient) GetLoopOutQuote(ctx context.Context,
amt btcutil.Amount, 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: protocolVersion,
},
)
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),
CltvDelta: quoteResp.CltvDelta,
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: protocolVersion,
},
)
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: protocolVersion,
},
)
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,
receiverKey [33]byte, swapPublicationDeadline time.Time) (
*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: protocolVersion,
},
)
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,
expiry: swapResp.Expiry,
}, 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: protocolVersion,
Preimage: preimage[:],
},
)
return err
}
func (s *grpcSwapServerClient) NewLoopInSwap(ctx context.Context,
swapHash lntypes.Hash, amount btcutil.Amount, senderKey [33]byte,
swapInvoice string, lastHop *route.Vertex) (*newLoopInResponse, error) {
rpcCtx, rpcCancel := context.WithTimeout(ctx, globalCallTimeout)
defer rpcCancel()
req := &looprpc.ServerLoopInRequest{
SwapHash: swapHash[:],
Amt: uint64(amount),
SenderKey: senderKey[:],
SwapInvoice: swapInvoice,
ProtocolVersion: protocolVersion,
}
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,
}, nil
}
func (s *grpcSwapServerClient) Close() {
s.conn.Close()
}
// 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,
)}
// 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
}
type newLoopOutResponse struct {
swapInvoice string
prepayInvoice string
senderKey [33]byte
expiry int32
}
type newLoopInResponse struct {
receiverKey [33]byte
expiry int32
}