diff --git a/client.go b/client.go index 7da3a9e..b709c8a 100644 --- a/client.go +++ b/client.go @@ -3,6 +3,7 @@ package loop import ( "context" "errors" + "fmt" "strings" "sync" "sync/atomic" @@ -33,20 +34,10 @@ var ( // more than the server maximum. ErrSwapAmountTooHigh = errors.New("swap amount too high") - // ErrExpiryTooSoon is returned when the server proposes an expiry that - // is too soon for us. - ErrExpiryTooSoon = errors.New("swap expiry too soon") - // ErrExpiryTooFar is returned when the server proposes an expiry that // is too soon for us. ErrExpiryTooFar = errors.New("swap expiry too far") - // ErrSweepConfTargetTooFar is returned when the client proposes a - // confirmation target to sweep the on-chain HTLC of a Loop Out that is - // beyond the expiration height proposed by the server. - ErrSweepConfTargetTooFar = errors.New("sweep confirmation target is " + - "beyond swap expiration height") - // serverRPCTimeout is the maximum time a gRPC request to the server // should be allowed to take. serverRPCTimeout = 30 * time.Second @@ -363,8 +354,21 @@ func (s *Client) LoopOut(globalCtx context.Context, return nil, err } - // Create a new swap object for this swap. + // Calculate htlc expiry height. + terms, err := s.Server.GetLoopOutTerms(globalCtx) + if err != nil { + return nil, err + } + initiationHeight := s.executor.height() + request.Expiry, err = s.getExpiry( + initiationHeight, terms, request.SweepConfTarget, + ) + if err != nil { + return nil, err + } + + // Create a new swap object for this swap. swapCfg := newSwapConfig(s.lndServices, s.Store, s.Server) initResult, err := newLoopOutSwap( globalCtx, swapCfg, initiationHeight, request, @@ -386,6 +390,24 @@ func (s *Client) LoopOut(globalCtx context.Context, }, nil } +// getExpiry returns an absolute expiry height based on the sweep confirmation +// target, constrained by the server terms. +func (s *Client) getExpiry(height int32, terms *LoopOutTerms, + confTarget int32) (int32, error) { + + switch { + case confTarget < terms.MinCltvDelta: + return height + terms.MinCltvDelta, nil + + case confTarget > terms.MaxCltvDelta: + return 0, fmt.Errorf("confirmation target %v exceeds maximum "+ + "server cltv delta of %v", confTarget, + terms.MaxCltvDelta) + } + + return height + confTarget, nil +} + // LoopOutQuote takes a LoopOut amount and returns a break down of estimated // costs for the client. Both the swap server and the on-chain fee estimator // are queried to get to build the quote response. @@ -405,8 +427,14 @@ func (s *Client) LoopOutQuote(ctx context.Context, return nil, ErrSwapAmountTooHigh } + height := s.executor.height() + expiry, err := s.getExpiry(height, terms, request.SweepConfTarget) + if err != nil { + return nil, err + } + quote, err := s.Server.GetLoopOutQuote( - ctx, request.Amount, request.SwapPublicationDeadline, + ctx, request.Amount, expiry, request.SwapPublicationDeadline, ) if err != nil { return nil, err @@ -440,7 +468,6 @@ func (s *Client) LoopOutQuote(ctx context.Context, MinerFee: minerFee, PrepayAmount: quote.PrepayAmount, SwapPaymentDest: quote.SwapPaymentDest, - CltvDelta: quote.CltvDelta, }, nil } diff --git a/interface.go b/interface.go index 0c0f1a9..a1be6d6 100644 --- a/interface.go +++ b/interface.go @@ -71,6 +71,9 @@ type OutRequest struct { // SwapPublicationDeadline can be set by the client to allow the server // delaying publication of the swap HTLC to save on chain fees. SwapPublicationDeadline time.Time + + // Expiry is the absolute expiry height of the on-chain htlc. + Expiry int32 } // Out contains the full details of a loop out request. This includes things @@ -146,10 +149,6 @@ type LoopOutQuote struct { // sweep the htlc. MinerFee btcutil.Amount - // Time lock delta relative to current block height that swap server - // will accept on the swap initiation call. - CltvDelta int32 - // SwapPaymentDest is the node pubkey where to swap payment needs to be // sent to. SwapPaymentDest [33]byte diff --git a/loopd/swapclient_server.go b/loopd/swapclient_server.go index 4bd2134..2720af6 100644 --- a/loopd/swapclient_server.go +++ b/loopd/swapclient_server.go @@ -373,7 +373,6 @@ func (s *swapClientServer) LoopOutQuote(ctx context.Context, PrepayAmtSat: int64(quote.PrepayAmount), SwapFeeSat: int64(quote.SwapFee), SwapPaymentDest: quote.SwapPaymentDest[:], - CltvDelta: quote.CltvDelta, }, nil } diff --git a/loopout.go b/loopout.go index e102cc9..5e26bc4 100644 --- a/loopout.go +++ b/loopout.go @@ -106,13 +106,14 @@ func newLoopOutSwap(globalCtx context.Context, cfg *swapConfig, // Post the swap parameters to the swap server. The response contains // the server revocation key and the swap and prepay invoices. - log.Infof("Initiating swap request at height %v", currentHeight) + log.Infof("Initiating swap request at height %v: amt=%v, expiry=%v", + currentHeight, request.Amount, request.Expiry) // The swap deadline will be given to the server for it to use as the // latest swap publication time. swapResp, err := cfg.server.NewLoopOutSwap( - globalCtx, swapHash, request.Amount, receiverKey, - request.SwapPublicationDeadline, + globalCtx, swapHash, request.Amount, request.Expiry, + receiverKey, request.SwapPublicationDeadline, ) if err != nil { return nil, fmt.Errorf("cannot initiate swap: %v", err) @@ -150,7 +151,7 @@ func newLoopOutSwap(globalCtx context.Context, cfg *swapConfig, SenderKey: swapResp.senderKey, Preimage: swapPreimage, AmountRequested: request.Amount, - CltvExpiry: swapResp.expiry, + CltvExpiry: request.Expiry, MaxMinerFee: request.MaxMinerFee, MaxSwapFee: request.MaxSwapFee, }, @@ -994,18 +995,5 @@ func validateLoopOutContract(lnd *lndclient.LndServices, return ErrPrepayAmountTooHigh } - if response.expiry-height < MinLoopOutPreimageRevealDelta { - log.Warnf("Proposed expiry %v (delta %v) too soon", - response.expiry, response.expiry-height) - - return ErrExpiryTooSoon - } - - // Ensure the client has provided a sweep confirmation target that does - // not exceed the height at which we revert back to using the default. - if height+request.SweepConfTarget >= response.expiry-DefaultSweepConfTargetDelta { - return ErrSweepConfTargetTooFar - } - return nil } diff --git a/loopout_test.go b/loopout_test.go index 0bc449d..80d1625 100644 --- a/loopout_test.go +++ b/loopout_test.go @@ -151,6 +151,8 @@ func TestLateHtlcPublish(t *testing.T) { cfg := newSwapConfig(&lnd.LndServices, store, server) + testRequest.Expiry = height + testLoopOutMinOnChainCltvDelta + initResult, err := newLoopOutSwap( context.Background(), cfg, height, testRequest, ) @@ -227,7 +229,7 @@ func TestCustomSweepConfTarget(t *testing.T) { // the default. testReq := *testRequest - testReq.SweepConfTarget = testLoopOutOnChainCltvDelta - + testReq.SweepConfTarget = testLoopOutMinOnChainCltvDelta - DefaultSweepConfTargetDelta - 1 // Set up custom fee estimates such that the lower confirmation target @@ -376,8 +378,8 @@ func TestCustomSweepConfTarget(t *testing.T) { // We'll then notify the height at which we begin using the default // confirmation target. - defaultConfTargetHeight := ctx.Lnd.Height + testLoopOutOnChainCltvDelta - - DefaultSweepConfTargetDelta + defaultConfTargetHeight := ctx.Lnd.Height + + testLoopOutMinOnChainCltvDelta - DefaultSweepConfTargetDelta blockEpochChan <- int32(defaultConfTargetHeight) expiryChan <- time.Now() @@ -427,8 +429,9 @@ func TestPreimagePush(t *testing.T) { // Start with a high confirmation delta which will have a very high fee // attached to it. testReq := *testRequest - testReq.SweepConfTarget = testLoopOutOnChainCltvDelta - + testReq.SweepConfTarget = testLoopOutMinOnChainCltvDelta - DefaultSweepConfTargetDelta - 1 + testReq.Expiry = ctx.Lnd.Height + testLoopOutMinOnChainCltvDelta // We set our mock fee estimate for our target sweep confs to be our // max miner fee *2, so that our fee will definitely be above what we @@ -520,7 +523,7 @@ func TestPreimagePush(t *testing.T) { // Now, we notify the height at which the client will start using the // default confirmation target. This has the effect of lowering our fees // so that the client still start sweeping. - defaultConfTargetHeight := ctx.Lnd.Height + testLoopOutOnChainCltvDelta - + defaultConfTargetHeight := ctx.Lnd.Height + testLoopOutMinOnChainCltvDelta - DefaultSweepConfTargetDelta blockEpochChan <- defaultConfTargetHeight diff --git a/server_mock_test.go b/server_mock_test.go index 7c8fdee..59010ab 100644 --- a/server_mock_test.go +++ b/server_mock_test.go @@ -18,12 +18,13 @@ import ( var ( testTime = time.Date(2018, time.January, 9, 14, 00, 00, 0, time.UTC) - testLoopOutOnChainCltvDelta = int32(30) - testChargeOnChainCltvDelta = int32(100) - testSwapFee = btcutil.Amount(210) - testFixedPrepayAmount = btcutil.Amount(100) - testMinSwapAmount = btcutil.Amount(10000) - testMaxSwapAmount = btcutil.Amount(1000000) + testLoopOutMinOnChainCltvDelta = int32(30) + testLoopOutMaxOnChainCltvDelta = int32(40) + testChargeOnChainCltvDelta = int32(100) + testSwapFee = btcutil.Amount(210) + testFixedPrepayAmount = btcutil.Amount(100) + testMinSwapAmount = btcutil.Amount(10000) + testMaxSwapAmount = btcutil.Amount(1000000) ) // serverMock is used in client unit tests to simulate swap server behaviour. @@ -58,7 +59,7 @@ func newServerMock() *serverMock { } func (s *serverMock) NewLoopOutSwap(ctx context.Context, - swapHash lntypes.Hash, amount btcutil.Amount, + swapHash lntypes.Hash, amount btcutil.Amount, expiry int32, receiverKey [33]byte, _ time.Time) ( *newLoopOutResponse, error) { @@ -87,7 +88,6 @@ func (s *serverMock) NewLoopOutSwap(ctx context.Context, senderKey: senderKeyArray, swapInvoice: swapPayReqString, prepayInvoice: prePayReqString, - expiry: s.height + testLoopOutOnChainCltvDelta, }, nil } @@ -97,18 +97,19 @@ func (s *serverMock) GetLoopOutTerms(ctx context.Context) ( return &LoopOutTerms{ MinSwapAmount: testMinSwapAmount, MaxSwapAmount: testMaxSwapAmount, + MinCltvDelta: testLoopOutMinOnChainCltvDelta, + MaxCltvDelta: testLoopOutMaxOnChainCltvDelta, }, nil } func (s *serverMock) GetLoopOutQuote(ctx context.Context, amt btcutil.Amount, - _ time.Time) (*LoopOutQuote, error) { + expiry int32, _ time.Time) (*LoopOutQuote, error) { dest := [33]byte{1, 2, 3} return &LoopOutQuote{ SwapFee: testSwapFee, SwapPaymentDest: dest, - CltvDelta: testLoopOutOnChainCltvDelta, PrepayAmount: testFixedPrepayAmount, }, nil } diff --git a/swap_server_client.go b/swap_server_client.go index d193b3b..2af795c 100644 --- a/swap_server_client.go +++ b/swap_server_client.go @@ -25,7 +25,7 @@ import ( // protocolVersion defines the version of the protocol that is currently // supported by the loop client. -const protocolVersion = looprpc.ProtocolVersion_PREIMAGE_PUSH_LOOP_OUT +const protocolVersion = looprpc.ProtocolVersion_USER_EXPIRY_LOOP_OUT var ( // errServerSubscriptionComplete is returned when our subscription to @@ -46,7 +46,7 @@ type swapServerClient interface { GetLoopOutTerms(ctx context.Context) ( *LoopOutTerms, error) - GetLoopOutQuote(ctx context.Context, amt btcutil.Amount, + GetLoopOutQuote(ctx context.Context, amt btcutil.Amount, expiry int32, swapPublicationDeadline time.Time) ( *LoopOutQuote, error) @@ -57,7 +57,7 @@ type swapServerClient interface { *LoopInQuote, error) NewLoopOutSwap(ctx context.Context, - swapHash lntypes.Hash, amount btcutil.Amount, + swapHash lntypes.Hash, amount btcutil.Amount, expiry int32, receiverKey [33]byte, swapPublicationDeadline time.Time) ( *newLoopOutResponse, error) @@ -146,7 +146,7 @@ func (s *grpcSwapServerClient) GetLoopOutTerms(ctx context.Context) ( } func (s *grpcSwapServerClient) GetLoopOutQuote(ctx context.Context, - amt btcutil.Amount, swapPublicationDeadline time.Time) ( + amt btcutil.Amount, expiry int32, swapPublicationDeadline time.Time) ( *LoopOutQuote, error) { rpcCtx, rpcCancel := context.WithTimeout(ctx, globalCallTimeout) @@ -156,6 +156,7 @@ func (s *grpcSwapServerClient) GetLoopOutQuote(ctx context.Context, Amt: uint64(amt), SwapPublicationDeadline: swapPublicationDeadline.Unix(), ProtocolVersion: protocolVersion, + Expiry: expiry, }, ) if err != nil { @@ -175,7 +176,6 @@ func (s *grpcSwapServerClient) GetLoopOutQuote(ctx context.Context, return &LoopOutQuote{ PrepayAmount: btcutil.Amount(quoteResp.PrepayAmt), SwapFee: btcutil.Amount(quoteResp.SwapFee), - CltvDelta: quoteResp.CltvDelta, SwapPaymentDest: destArray, }, nil } @@ -222,7 +222,7 @@ func (s *grpcSwapServerClient) GetLoopInQuote(ctx context.Context, } func (s *grpcSwapServerClient) NewLoopOutSwap(ctx context.Context, - swapHash lntypes.Hash, amount btcutil.Amount, + swapHash lntypes.Hash, amount btcutil.Amount, expiry int32, receiverKey [33]byte, swapPublicationDeadline time.Time) ( *newLoopOutResponse, error) { @@ -235,6 +235,7 @@ func (s *grpcSwapServerClient) NewLoopOutSwap(ctx context.Context, ReceiverKey: receiverKey[:], SwapPublicationDeadline: swapPublicationDeadline.Unix(), ProtocolVersion: protocolVersion, + Expiry: expiry, }, ) if err != nil { @@ -254,7 +255,6 @@ func (s *grpcSwapServerClient) NewLoopOutSwap(ctx context.Context, swapInvoice: swapResp.SwapInvoice, prepayInvoice: swapResp.PrepayInvoice, senderKey: senderKey, - expiry: swapResp.Expiry, serverMessage: swapResp.ServerMessage, }, nil } @@ -528,7 +528,6 @@ type newLoopOutResponse struct { swapInvoice string prepayInvoice string senderKey [33]byte - expiry int32 serverMessage string }