package loopd import ( "bytes" "context" "encoding/hex" "errors" "fmt" "sort" "sync" "time" "github.com/btcsuite/btcd/btcec/v2" "github.com/btcsuite/btcd/btcutil" "github.com/btcsuite/btcd/chaincfg" "github.com/lightninglabs/aperture/lsat" "github.com/lightninglabs/lndclient" "github.com/lightninglabs/loop" "github.com/lightninglabs/loop/labels" "github.com/lightninglabs/loop/liquidity" "github.com/lightninglabs/loop/loopdb" clientrpc "github.com/lightninglabs/loop/looprpc" "github.com/lightninglabs/loop/swap" looprpc "github.com/lightninglabs/loop/swapserverrpc" "github.com/lightningnetwork/lnd/lnrpc/walletrpc" "github.com/lightningnetwork/lnd/lntypes" "github.com/lightningnetwork/lnd/queue" "github.com/lightningnetwork/lnd/routing/route" "github.com/lightningnetwork/lnd/zpay32" "google.golang.org/grpc/codes" "google.golang.org/grpc/status" ) const ( completedSwapsCount = 5 // minConfTarget is the minimum confirmation target we'll allow clients // to specify. This is driven by the minimum confirmation target allowed // by the backing fee estimator. minConfTarget = 2 defaultLoopdInitiator = "loopd" ) var ( // errIncorrectChain is returned when the format of the // destination address provided does not match the active chain. errIncorrectChain = errors.New("invalid address format for the " + "active chain") // errConfTargetTooLow is returned when the chosen confirmation target // is below the allowed minimum. errConfTargetTooLow = errors.New("confirmation target too low") // errBalanceTooLow is returned when the loop out amount can't be // satisfied given total balance of the selection of channels to loop // out on. errBalanceTooLow = errors.New( "channel balance too low for loop out amount", ) // errInvalidAddress is returned when the destination address is of // an unsupported format such as P2PK or P2TR addresses. errInvalidAddress = errors.New( "invalid or unsupported address", ) ) // swapClientServer implements the grpc service exposed by loopd. type swapClientServer struct { // Required by the grpc-gateway/v2 library for forward compatibility. clientrpc.UnimplementedSwapClientServer clientrpc.UnimplementedDebugServer config *Config network lndclient.Network impl *loop.Client liquidityMgr *liquidity.Manager lnd *lndclient.LndServices swaps map[lntypes.Hash]loop.SwapInfo subscribers map[int]chan<- interface{} statusChan chan loop.SwapInfo nextSubscriberID int swapsLock sync.Mutex mainCtx context.Context } // LoopOut initiates a loop out swap with the given parameters. The call returns // after the swap has been set up with the swap server. From that point onwards, // progress can be tracked via the LoopOutStatus stream that is returned from // Monitor(). func (s *swapClientServer) LoopOut(ctx context.Context, in *clientrpc.LoopOutRequest) ( *clientrpc.SwapResponse, error) { log.Infof("Loop out request received") var sweepAddr btcutil.Address var err error //nolint:lll switch { case in.Dest != "" && in.Account != "": return nil, fmt.Errorf("destination address and external " + "account address cannot be set at the same time") case in.Dest != "": // Decode the client provided destination address for the loop // out sweep. sweepAddr, err = btcutil.DecodeAddress( in.Dest, s.lnd.ChainParams, ) if err != nil { return nil, fmt.Errorf("decode address: %v", err) } case in.Account != "" && in.AccountAddrType == clientrpc.AddressType_ADDRESS_TYPE_UNKNOWN: return nil, liquidity.ErrAccountAndAddrType case in.Account != "": // Derive a new receiving address from the stated account. addrType, err := toWalletAddrType(in.AccountAddrType) if err != nil { return nil, err } // Check if account with address type exists. if !s.accountExists(ctx, in.Account, addrType) { return nil, fmt.Errorf("the provided account does " + "not exist") } sweepAddr, err = s.lnd.WalletKit.NextAddr( ctx, in.Account, addrType, false, ) if err != nil { return nil, fmt.Errorf("NextAddr from account error: "+ "%v", err) } default: // Generate sweep address if none specified. sweepAddr, err = s.lnd.WalletKit.NextAddr( context.Background(), "", walletrpc.AddressType_WITNESS_PUBKEY_HASH, false, ) if err != nil { return nil, fmt.Errorf("NextAddr error: %v", err) } } sweepConfTarget, err := validateLoopOutRequest( ctx, s.lnd.Client, s.lnd.ChainParams, in, sweepAddr, s.impl.LoopOutMaxParts, ) if err != nil { return nil, err } // Infer if the publication deadline is set in milliseconds. publicationDeadline := getPublicationDeadline(in.SwapPublicationDeadline) req := &loop.OutRequest{ Amount: btcutil.Amount(in.Amt), DestAddr: sweepAddr, MaxMinerFee: btcutil.Amount(in.MaxMinerFee), MaxPrepayAmount: btcutil.Amount(in.MaxPrepayAmt), MaxPrepayRoutingFee: btcutil.Amount(in.MaxPrepayRoutingFee), MaxSwapRoutingFee: btcutil.Amount(in.MaxSwapRoutingFee), MaxSwapFee: btcutil.Amount(in.MaxSwapFee), SweepConfTarget: sweepConfTarget, HtlcConfirmations: in.HtlcConfirmations, SwapPublicationDeadline: publicationDeadline, Label: in.Label, Initiator: in.Initiator, } switch { case in.LoopOutChannel != 0 && len(in.OutgoingChanSet) > 0: // nolint:staticcheck return nil, errors.New("loop_out_channel and outgoing_" + "chan_ids are mutually exclusive") case in.LoopOutChannel != 0: // nolint:staticcheck req.OutgoingChanSet = loopdb.ChannelSet{in.LoopOutChannel} // nolint:staticcheck default: req.OutgoingChanSet = in.OutgoingChanSet } info, err := s.impl.LoopOut(ctx, req) if err != nil { log.Errorf("LoopOut: %v", err) return nil, err } htlcAddress := info.HtlcAddress.String() resp := &clientrpc.SwapResponse{ Id: info.SwapHash.String(), IdBytes: info.SwapHash[:], HtlcAddress: htlcAddress, ServerMessage: info.ServerMessage, } if loopdb.CurrentProtocolVersion() < loopdb.ProtocolVersionHtlcV3 { resp.HtlcAddressP2Wsh = htlcAddress } else { resp.HtlcAddressP2Tr = htlcAddress } return resp, nil } // accountExists returns true if account under the address type exists in the // backing lnd instance and false otherwise. func (s *swapClientServer) accountExists(ctx context.Context, account string, addrType walletrpc.AddressType) bool { accounts, err := s.lnd.WalletKit.ListAccounts(ctx, account, addrType) if err != nil { return false } for _, a := range accounts { if a.Name == account { return true } } return false } func toWalletAddrType(addrType clientrpc.AddressType) (walletrpc.AddressType, error) { switch addrType { case clientrpc.AddressType_TAPROOT_PUBKEY: return walletrpc.AddressType_TAPROOT_PUBKEY, nil default: return walletrpc.AddressType_UNKNOWN, fmt.Errorf("unknown address type") } } func (s *swapClientServer) marshallSwap(loopSwap *loop.SwapInfo) ( *clientrpc.SwapStatus, error) { var ( state clientrpc.SwapState failureReason = clientrpc.FailureReason_FAILURE_REASON_NONE ) // Set our state var for non-failure states. If we get a failure, we // will update our failure reason. To remain backwards compatible with // previous versions where we squashed all failure reasons to a single // failure state, we set a failure reason for all our different failure // states, and set our failed state for all of them. switch loopSwap.State { case loopdb.StateInitiated: state = clientrpc.SwapState_INITIATED case loopdb.StatePreimageRevealed: state = clientrpc.SwapState_PREIMAGE_REVEALED case loopdb.StateHtlcPublished: state = clientrpc.SwapState_HTLC_PUBLISHED case loopdb.StateInvoiceSettled: state = clientrpc.SwapState_INVOICE_SETTLED case loopdb.StateSuccess: state = clientrpc.SwapState_SUCCESS case loopdb.StateFailOffchainPayments: failureReason = clientrpc.FailureReason_FAILURE_REASON_OFFCHAIN case loopdb.StateFailTimeout: failureReason = clientrpc.FailureReason_FAILURE_REASON_TIMEOUT case loopdb.StateFailSweepTimeout: failureReason = clientrpc.FailureReason_FAILURE_REASON_SWEEP_TIMEOUT case loopdb.StateFailInsufficientValue: failureReason = clientrpc.FailureReason_FAILURE_REASON_INSUFFICIENT_VALUE case loopdb.StateFailTemporary: failureReason = clientrpc.FailureReason_FAILURE_REASON_TEMPORARY case loopdb.StateFailIncorrectHtlcAmt: failureReason = clientrpc.FailureReason_FAILURE_REASON_INCORRECT_AMOUNT default: return nil, fmt.Errorf("unknown swap state: %v", loopSwap.State) } // If we have a failure reason, we have a failure state, so should use // our catchall failed state. if failureReason != clientrpc.FailureReason_FAILURE_REASON_NONE { state = clientrpc.SwapState_FAILED } var swapType clientrpc.SwapType var ( htlcAddress string htlcAddressP2TR string htlcAddressP2WSH string ) var outGoingChanSet []uint64 var lastHop []byte switch loopSwap.SwapType { case swap.TypeIn: swapType = clientrpc.SwapType_LOOP_IN if loopSwap.HtlcAddressP2TR != nil { htlcAddressP2TR = loopSwap.HtlcAddressP2TR.EncodeAddress() htlcAddress = htlcAddressP2TR } else { htlcAddressP2WSH = loopSwap.HtlcAddressP2WSH.EncodeAddress() htlcAddress = htlcAddressP2WSH } if loopSwap.LastHop != nil { lastHop = loopSwap.LastHop[:] } case swap.TypeOut: swapType = clientrpc.SwapType_LOOP_OUT if loopSwap.HtlcAddressP2WSH != nil { htlcAddressP2WSH = loopSwap.HtlcAddressP2WSH.EncodeAddress() htlcAddress = htlcAddressP2WSH } else { htlcAddressP2TR = loopSwap.HtlcAddressP2TR.EncodeAddress() htlcAddress = htlcAddressP2TR } outGoingChanSet = loopSwap.OutgoingChanSet default: return nil, errors.New("unknown swap type") } return &clientrpc.SwapStatus{ Amt: int64(loopSwap.AmountRequested), Id: loopSwap.SwapHash.String(), IdBytes: loopSwap.SwapHash[:], State: state, FailureReason: failureReason, InitiationTime: loopSwap.InitiationTime.UnixNano(), LastUpdateTime: loopSwap.LastUpdate.UnixNano(), HtlcAddress: htlcAddress, HtlcAddressP2Tr: htlcAddressP2TR, HtlcAddressP2Wsh: htlcAddressP2WSH, Type: swapType, CostServer: int64(loopSwap.Cost.Server), CostOnchain: int64(loopSwap.Cost.Onchain), CostOffchain: int64(loopSwap.Cost.Offchain), Label: loopSwap.Label, LastHop: lastHop, OutgoingChanSet: outGoingChanSet, }, nil } // Monitor will return a stream of swap updates for currently active swaps. func (s *swapClientServer) Monitor(in *clientrpc.MonitorRequest, server clientrpc.SwapClient_MonitorServer) error { log.Infof("Monitor request received") send := func(info loop.SwapInfo) error { rpcSwap, err := s.marshallSwap(&info) if err != nil { return err } return server.Send(rpcSwap) } // Start a notification queue for this subscriber. queue := queue.NewConcurrentQueue(20) queue.Start() // Add this subscriber to the global subscriber list. Also create a // snapshot of all pending and completed swaps within the lock, to // prevent subscribers from receiving duplicate updates. s.swapsLock.Lock() id := s.nextSubscriberID s.nextSubscriberID++ s.subscribers[id] = queue.ChanIn() var pendingSwaps, completedSwaps []loop.SwapInfo for _, swap := range s.swaps { if swap.State.Type() == loopdb.StateTypePending { pendingSwaps = append(pendingSwaps, swap) } else { completedSwaps = append(completedSwaps, swap) } } s.swapsLock.Unlock() defer func() { s.swapsLock.Lock() delete(s.subscribers, id) s.swapsLock.Unlock() queue.Stop() }() // Sort completed swaps new to old. sort.Slice(completedSwaps, func(i, j int) bool { return completedSwaps[i].LastUpdate.After( completedSwaps[j].LastUpdate, ) }) // Discard all but top x latest. if len(completedSwaps) > completedSwapsCount { completedSwaps = completedSwaps[:completedSwapsCount] } // Concatenate both sets. filteredSwaps := append(pendingSwaps, completedSwaps...) // nolint: gocritic // Sort again, but this time old to new. sort.Slice(filteredSwaps, func(i, j int) bool { return filteredSwaps[i].LastUpdate.Before( filteredSwaps[j].LastUpdate, ) }) // Return swaps to caller. for _, swap := range filteredSwaps { if err := send(swap); err != nil { return err } } // As long as the client is connected, keep passing through swap // updates. for { select { case queueItem, ok := <-queue.ChanOut(): if !ok { return nil } swap := queueItem.(loop.SwapInfo) if err := send(swap); err != nil { return err } // The client cancels the subscription. case <-server.Context().Done(): return nil // The server is shutting down. case <-s.mainCtx.Done(): return fmt.Errorf("server is shutting down") } } } // ListSwaps returns a list of all currently known swaps and their current // status. func (s *swapClientServer) ListSwaps(_ context.Context, _ *clientrpc.ListSwapsRequest) (*clientrpc.ListSwapsResponse, error) { var ( rpcSwaps = make([]*clientrpc.SwapStatus, len(s.swaps)) idx = 0 err error ) s.swapsLock.Lock() defer s.swapsLock.Unlock() // We can just use the server's in-memory cache as that contains the // most up-to-date state including temporary failures which aren't // persisted to disk. The swaps field is a map, that's why we need an // additional index. for _, swp := range s.swaps { swp := swp rpcSwaps[idx], err = s.marshallSwap(&swp) if err != nil { return nil, err } idx++ } return &clientrpc.ListSwapsResponse{Swaps: rpcSwaps}, nil } // SwapInfo returns all known details about a single swap. func (s *swapClientServer) SwapInfo(_ context.Context, req *clientrpc.SwapInfoRequest) (*clientrpc.SwapStatus, error) { swapHash, err := lntypes.MakeHash(req.Id) if err != nil { return nil, fmt.Errorf("error parsing swap hash: %v", err) } // Just return the server's in-memory cache here too as we also want to // return temporary failures to the client. swp, ok := s.swaps[swapHash] if !ok { return nil, fmt.Errorf("swap with hash %s not found", req.Id) } return s.marshallSwap(&swp) } // LoopOutTerms returns the terms that the server enforces for loop out swaps. func (s *swapClientServer) LoopOutTerms(ctx context.Context, req *clientrpc.TermsRequest) (*clientrpc.OutTermsResponse, error) { log.Infof("Loop out terms request received") terms, err := s.impl.LoopOutTerms(ctx, defaultLoopdInitiator) if err != nil { log.Errorf("Terms request: %v", err) return nil, err } return &clientrpc.OutTermsResponse{ MinSwapAmount: int64(terms.MinSwapAmount), MaxSwapAmount: int64(terms.MaxSwapAmount), MinCltvDelta: terms.MinCltvDelta, MaxCltvDelta: terms.MaxCltvDelta, }, nil } // LoopOutQuote returns a quote for a loop out swap with the provided // parameters. func (s *swapClientServer) LoopOutQuote(ctx context.Context, req *clientrpc.QuoteRequest) (*clientrpc.OutQuoteResponse, error) { confTarget, err := validateConfTarget( req.ConfTarget, loop.DefaultSweepConfTarget, ) if err != nil { return nil, err } publicactionDeadline := getPublicationDeadline(req.SwapPublicationDeadline) quote, err := s.impl.LoopOutQuote(ctx, &loop.LoopOutQuoteRequest{ Amount: btcutil.Amount(req.Amt), SweepConfTarget: confTarget, SwapPublicationDeadline: publicactionDeadline, Initiator: defaultLoopdInitiator, }) if err != nil { return nil, err } return &clientrpc.OutQuoteResponse{ HtlcSweepFeeSat: int64(quote.MinerFee), PrepayAmtSat: int64(quote.PrepayAmount), SwapFeeSat: int64(quote.SwapFee), SwapPaymentDest: quote.SwapPaymentDest[:], ConfTarget: confTarget, }, nil } // GetTerms returns the terms that the server enforces for swaps. func (s *swapClientServer) GetLoopInTerms(ctx context.Context, req *clientrpc.TermsRequest) (*clientrpc.InTermsResponse, error) { log.Infof("Loop in terms request received") terms, err := s.impl.LoopInTerms(ctx, defaultLoopdInitiator) if err != nil { log.Errorf("Terms request: %v", err) return nil, err } return &clientrpc.InTermsResponse{ MinSwapAmount: int64(terms.MinSwapAmount), MaxSwapAmount: int64(terms.MaxSwapAmount), }, nil } // GetQuote returns a quote for a swap with the provided parameters. func (s *swapClientServer) GetLoopInQuote(ctx context.Context, req *clientrpc.QuoteRequest) (*clientrpc.InQuoteResponse, error) { log.Infof("Loop in quote request received") htlcConfTarget, err := validateLoopInRequest( req.ConfTarget, req.ExternalHtlc, ) if err != nil { return nil, err } var ( routeHints [][]zpay32.HopHint lastHop *route.Vertex ) if req.LoopInLastHop != nil { lastHopVertex, err := route.NewVertexFromBytes( req.LoopInLastHop, ) if err != nil { return nil, err } lastHop = &lastHopVertex } if len(req.LoopInRouteHints) != 0 { routeHints, err = unmarshallRouteHints(req.LoopInRouteHints) if err != nil { return nil, err } } quote, err := s.impl.LoopInQuote(ctx, &loop.LoopInQuoteRequest{ Amount: btcutil.Amount(req.Amt), HtlcConfTarget: htlcConfTarget, ExternalHtlc: req.ExternalHtlc, LastHop: lastHop, RouteHints: routeHints, Private: req.Private, Initiator: defaultLoopdInitiator, }) if err != nil { return nil, err } return &clientrpc.InQuoteResponse{ HtlcPublishFeeSat: int64(quote.MinerFee), SwapFeeSat: int64(quote.SwapFee), ConfTarget: htlcConfTarget, }, nil } // unmarshallRouteHints unmarshalls a list of route hints. func unmarshallRouteHints(rpcRouteHints []*looprpc.RouteHint) ( [][]zpay32.HopHint, error) { routeHints := make([][]zpay32.HopHint, 0, len(rpcRouteHints)) for _, rpcRouteHint := range rpcRouteHints { routeHint := make( []zpay32.HopHint, 0, len(rpcRouteHint.HopHints), ) for _, rpcHint := range rpcRouteHint.HopHints { hint, err := unmarshallHopHint(rpcHint) if err != nil { return nil, err } routeHint = append(routeHint, hint) } routeHints = append(routeHints, routeHint) } return routeHints, nil } // unmarshallHopHint unmarshalls a single hop hint. func unmarshallHopHint(rpcHint *looprpc.HopHint) (zpay32.HopHint, error) { pubBytes, err := hex.DecodeString(rpcHint.NodeId) if err != nil { return zpay32.HopHint{}, err } pubkey, err := btcec.ParsePubKey(pubBytes) if err != nil { return zpay32.HopHint{}, err } return zpay32.HopHint{ NodeID: pubkey, ChannelID: rpcHint.ChanId, FeeBaseMSat: rpcHint.FeeBaseMsat, FeeProportionalMillionths: rpcHint.FeeProportionalMillionths, CLTVExpiryDelta: uint16(rpcHint.CltvExpiryDelta), }, nil } // Probe requests the server to probe the client's node to test inbound // liquidity. func (s *swapClientServer) Probe(ctx context.Context, req *clientrpc.ProbeRequest) (*clientrpc.ProbeResponse, error) { log.Infof("Probe request received") var lastHop *route.Vertex if req.LastHop != nil { lastHopVertex, err := route.NewVertexFromBytes(req.LastHop) if err != nil { return nil, err } lastHop = &lastHopVertex } routeHints, err := unmarshallRouteHints(req.RouteHints) if err != nil { return nil, err } err = s.impl.Probe(ctx, &loop.ProbeRequest{ Amount: btcutil.Amount(req.Amt), LastHop: lastHop, RouteHints: routeHints, }) if err != nil { return nil, err } return &clientrpc.ProbeResponse{}, nil } func (s *swapClientServer) LoopIn(ctx context.Context, in *clientrpc.LoopInRequest) (*clientrpc.SwapResponse, error) { log.Infof("Loop in request received") htlcConfTarget, err := validateLoopInRequest( in.HtlcConfTarget, in.ExternalHtlc, ) if err != nil { return nil, err } // Check that the label is valid. if err := labels.Validate(in.Label); err != nil { return nil, err } routeHints, err := unmarshallRouteHints(in.RouteHints) if err != nil { return nil, err } req := &loop.LoopInRequest{ Amount: btcutil.Amount(in.Amt), MaxMinerFee: btcutil.Amount(in.MaxMinerFee), MaxSwapFee: btcutil.Amount(in.MaxSwapFee), HtlcConfTarget: htlcConfTarget, ExternalHtlc: in.ExternalHtlc, Label: in.Label, Initiator: in.Initiator, Private: in.Private, RouteHints: routeHints, } if in.LastHop != nil { lastHop, err := route.NewVertexFromBytes(in.LastHop) if err != nil { return nil, err } req.LastHop = &lastHop } swapInfo, err := s.impl.LoopIn(ctx, req) if err != nil { log.Errorf("Loop in: %v", err) return nil, err } response := &clientrpc.SwapResponse{ Id: swapInfo.SwapHash.String(), IdBytes: swapInfo.SwapHash[:], ServerMessage: swapInfo.ServerMessage, } if loopdb.CurrentProtocolVersion() < loopdb.ProtocolVersionHtlcV3 { p2wshAddr := swapInfo.HtlcAddressP2WSH.String() response.HtlcAddress = p2wshAddr response.HtlcAddressP2Wsh = p2wshAddr } else { p2trAddr := swapInfo.HtlcAddressP2TR.String() response.HtlcAddress = p2trAddr response.HtlcAddressP2Tr = p2trAddr } return response, nil } // GetLsatTokens returns all tokens that are contained in the LSAT token store. func (s *swapClientServer) GetLsatTokens(ctx context.Context, _ *clientrpc.TokensRequest) (*clientrpc.TokensResponse, error) { log.Infof("Get LSAT tokens request received") tokens, err := s.impl.LsatStore.AllTokens() if err != nil { return nil, err } rpcTokens := make([]*clientrpc.LsatToken, len(tokens)) idx := 0 for key, token := range tokens { macBytes, err := token.BaseMacaroon().MarshalBinary() if err != nil { return nil, err } id, err := lsat.DecodeIdentifier( bytes.NewReader(token.BaseMacaroon().Id()), ) if err != nil { return nil, err } rpcTokens[idx] = &clientrpc.LsatToken{ BaseMacaroon: macBytes, PaymentHash: token.PaymentHash[:], PaymentPreimage: token.Preimage[:], AmountPaidMsat: int64(token.AmountPaid), RoutingFeePaidMsat: int64(token.RoutingFeePaid), TimeCreated: token.TimeCreated.Unix(), Expired: !token.IsValid(), StorageName: key, Id: hex.EncodeToString( id.TokenID[:], ), } idx++ } return &clientrpc.TokensResponse{Tokens: rpcTokens}, nil } // GetInfo returns basic information about the loop daemon and details to swaps // from the swap store. func (s *swapClientServer) GetInfo(ctx context.Context, _ *clientrpc.GetInfoRequest) (*clientrpc.GetInfoResponse, error) { // Fetch loop-outs from the loop db. outSwaps, err := s.impl.Store.FetchLoopOutSwaps(ctx) if err != nil { return nil, err } // Collect loop-out stats. loopOutStats := &clientrpc.LoopStats{} for _, out := range outSwaps { switch out.State().State.Type() { case loopdb.StateTypeSuccess: loopOutStats.SuccessCount++ loopOutStats.SumSucceededAmt += int64( out.Contract.AmountRequested, ) case loopdb.StateTypePending: loopOutStats.PendingCount++ loopOutStats.SumPendingAmt += int64( out.Contract.AmountRequested, ) case loopdb.StateTypeFail: loopOutStats.FailCount++ } } // Fetch loop-ins from the loop db. inSwaps, err := s.impl.Store.FetchLoopInSwaps(ctx) if err != nil { return nil, err } // Collect loop-in stats. loopInStats := &clientrpc.LoopStats{} for _, in := range inSwaps { switch in.State().State.Type() { case loopdb.StateTypeSuccess: loopInStats.SuccessCount++ loopInStats.SumSucceededAmt += int64( in.Contract.AmountRequested, ) case loopdb.StateTypePending: loopInStats.PendingCount++ loopInStats.SumPendingAmt += int64( in.Contract.AmountRequested, ) case loopdb.StateTypeFail: loopInStats.FailCount++ } } return &clientrpc.GetInfoResponse{ Version: loop.Version(), Network: s.config.Network, RpcListen: s.config.RPCListen, RestListen: s.config.RESTListen, MacaroonPath: s.config.MacaroonPath, TlsCertPath: s.config.TLSCertPath, LoopOutStats: loopOutStats, LoopInStats: loopInStats, }, nil } // GetLiquidityParams gets our current liquidity manager's parameters. func (s *swapClientServer) GetLiquidityParams(_ context.Context, _ *clientrpc.GetLiquidityParamsRequest) (*clientrpc.LiquidityParameters, error) { cfg := s.liquidityMgr.GetParameters() rpcCfg, err := liquidity.ParametersToRpc(cfg) if err != nil { return nil, err } return rpcCfg, nil } // SetLiquidityParams attempts to set our current liquidity manager's // parameters. func (s *swapClientServer) SetLiquidityParams(ctx context.Context, in *clientrpc.SetLiquidityParamsRequest) (*clientrpc.SetLiquidityParamsResponse, error) { err := s.liquidityMgr.SetParameters(ctx, in.Parameters) if err != nil { return nil, err } return &clientrpc.SetLiquidityParamsResponse{}, nil } // SuggestSwaps provides a list of suggested swaps based on lnd's current // channel balances and rules set by the liquidity manager. func (s *swapClientServer) SuggestSwaps(ctx context.Context, _ *clientrpc.SuggestSwapsRequest) (*clientrpc.SuggestSwapsResponse, error) { suggestions, err := s.liquidityMgr.SuggestSwaps(ctx) switch err { case liquidity.ErrNoRules: return nil, status.Error(codes.FailedPrecondition, err.Error()) case nil: default: return nil, err } resp := &clientrpc.SuggestSwapsResponse{ LoopOut: make( []*clientrpc.LoopOutRequest, len(suggestions.OutSwaps), ), LoopIn: make( []*clientrpc.LoopInRequest, len(suggestions.InSwaps), ), } for i, swap := range suggestions.OutSwaps { resp.LoopOut[i] = &clientrpc.LoopOutRequest{ Amt: int64(swap.Amount), OutgoingChanSet: swap.OutgoingChanSet, MaxSwapFee: int64(swap.MaxSwapFee), MaxMinerFee: int64(swap.MaxMinerFee), MaxPrepayAmt: int64(swap.MaxPrepayAmount), MaxSwapRoutingFee: int64(swap.MaxSwapRoutingFee), MaxPrepayRoutingFee: int64(swap.MaxPrepayRoutingFee), SweepConfTarget: swap.SweepConfTarget, } } for i, swap := range suggestions.InSwaps { loopIn := &clientrpc.LoopInRequest{ Amt: int64(swap.Amount), MaxSwapFee: int64(swap.MaxSwapFee), MaxMinerFee: int64(swap.MaxMinerFee), HtlcConfTarget: swap.HtlcConfTarget, } if swap.LastHop != nil { loopIn.LastHop = swap.LastHop[:] } resp.LoopIn[i] = loopIn } for id, reason := range suggestions.DisqualifiedChans { autoloopReason, err := rpcAutoloopReason(reason) if err != nil { return nil, err } exclChan := &clientrpc.Disqualified{ Reason: autoloopReason, ChannelId: id.ToUint64(), } resp.Disqualified = append(resp.Disqualified, exclChan) } for pubkey, reason := range suggestions.DisqualifiedPeers { autoloopReason, err := rpcAutoloopReason(reason) if err != nil { return nil, err } clonedPubkey := route.Vertex{} copy(clonedPubkey[:], pubkey[:]) exclChan := &clientrpc.Disqualified{ Reason: autoloopReason, Pubkey: clonedPubkey[:], } resp.Disqualified = append(resp.Disqualified, exclChan) } return resp, nil } func rpcAutoloopReason(reason liquidity.Reason) (clientrpc.AutoReason, error) { switch reason { case liquidity.ReasonNone: return clientrpc.AutoReason_AUTO_REASON_UNKNOWN, nil case liquidity.ReasonBudgetNotStarted: return clientrpc.AutoReason_AUTO_REASON_BUDGET_NOT_STARTED, nil case liquidity.ReasonSweepFees: return clientrpc.AutoReason_AUTO_REASON_SWEEP_FEES, nil case liquidity.ReasonBudgetElapsed: return clientrpc.AutoReason_AUTO_REASON_BUDGET_ELAPSED, nil case liquidity.ReasonInFlight: return clientrpc.AutoReason_AUTO_REASON_IN_FLIGHT, nil case liquidity.ReasonSwapFee: return clientrpc.AutoReason_AUTO_REASON_SWAP_FEE, nil case liquidity.ReasonMinerFee: return clientrpc.AutoReason_AUTO_REASON_MINER_FEE, nil case liquidity.ReasonPrepay: return clientrpc.AutoReason_AUTO_REASON_PREPAY, nil case liquidity.ReasonFailureBackoff: return clientrpc.AutoReason_AUTO_REASON_FAILURE_BACKOFF, nil case liquidity.ReasonLoopOut: return clientrpc.AutoReason_AUTO_REASON_LOOP_OUT, nil case liquidity.ReasonLoopIn: return clientrpc.AutoReason_AUTO_REASON_LOOP_IN, nil case liquidity.ReasonLiquidityOk: return clientrpc.AutoReason_AUTO_REASON_LIQUIDITY_OK, nil case liquidity.ReasonBudgetInsufficient: return clientrpc.AutoReason_AUTO_REASON_BUDGET_INSUFFICIENT, nil case liquidity.ReasonFeePPMInsufficient: return clientrpc.AutoReason_AUTO_REASON_SWAP_FEE, nil default: return 0, fmt.Errorf("unknown autoloop reason: %v", reason) } } // processStatusUpdates reads updates on the status channel and processes them. // // NOTE: This must run inside a goroutine as it blocks until the main context // shuts down. func (s *swapClientServer) processStatusUpdates(mainCtx context.Context) { for { select { // On updates, refresh the server's in-memory state and inform // subscribers about the changes. case swp := <-s.statusChan: s.swapsLock.Lock() s.swaps[swp.SwapHash] = swp for _, subscriber := range s.subscribers { select { case subscriber <- swp: case <-mainCtx.Done(): s.swapsLock.Unlock() return } } s.swapsLock.Unlock() // Server is shutting down. case <-mainCtx.Done(): return } } } // validateConfTarget ensures the given confirmation target is valid. If one // isn't specified (0 value), then the default target is used. func validateConfTarget(target, defaultTarget int32) (int32, error) { switch { case target == 0: return defaultTarget, nil // Ensure the target respects our minimum threshold. case target < minConfTarget: return 0, fmt.Errorf("%w: A confirmation target of at "+ "least %v must be provided", errConfTargetTooLow, minConfTarget) default: return target, nil } } // validateLoopInRequest fails if the mutually exclusive conf target and // external parameters are both set. func validateLoopInRequest(htlcConfTarget int32, external bool) (int32, error) { // If the htlc is going to be externally set, the htlcConfTarget should // not be set, because it has no relevance when the htlc is external. if external && htlcConfTarget != 0 { return 0, errors.New("external and htlc conf target cannot " + "both be set") } // If the htlc is being externally published, we do not need to set a // confirmation target. if external { return 0, nil } return validateConfTarget(htlcConfTarget, loop.DefaultHtlcConfTarget) } // validateLoopOutRequest validates the confirmation target, destination // address and label of the loop out request. It also checks that the requested // loop amount is valid given the available balance. func validateLoopOutRequest(ctx context.Context, lnd lndclient.LightningClient, chainParams *chaincfg.Params, req *clientrpc.LoopOutRequest, sweepAddr btcutil.Address, maxParts uint32) (int32, error) { // Check that the provided destination address has the correct format // for the active network. if !sweepAddr.IsForNet(chainParams) { return 0, fmt.Errorf("%w: Current active network is %s", errIncorrectChain, chainParams.Name) } // Check that the provided destination address is a supported // address format. switch sweepAddr.(type) { case *btcutil.AddressTaproot, *btcutil.AddressWitnessScriptHash, *btcutil.AddressWitnessPubKeyHash, *btcutil.AddressScriptHash, *btcutil.AddressPubKeyHash: default: return 0, errInvalidAddress } // Check that the label is valid. if err := labels.Validate(req.Label); err != nil { return 0, err } channels, err := lnd.ListChannels(ctx, false, false) if err != nil { return 0, err } unlimitedChannels := len(req.OutgoingChanSet) == 0 outgoingChanSetMap := make(map[uint64]bool) for _, chanID := range req.OutgoingChanSet { outgoingChanSetMap[chanID] = true } var activeChannelSet []lndclient.ChannelInfo for _, c := range channels { // Don't bother looking at inactive channels. if !c.Active { continue } // If no outgoing channel set was specified then all active // channels are considered. However, if a channel set was // specified then only the specified channels are considered. if unlimitedChannels || outgoingChanSetMap[c.ChannelID] { activeChannelSet = append(activeChannelSet, c) } } // Determine if the loop out request is theoretically possible given // the amount requested, the maximum possible routing fees, // the available channel set and the fact that equal splitting is // used for MPP. requiredBalance := btcutil.Amount(req.Amt + req.MaxSwapRoutingFee) isRoutable, _ := hasBandwidth(activeChannelSet, requiredBalance, int(maxParts)) if !isRoutable { return 0, fmt.Errorf("%w: Requested swap amount of %d "+ "sats along with the maximum routing fee of %d sats "+ "is more than what can be routed given current state "+ "of the channel set", errBalanceTooLow, req.Amt, req.MaxSwapRoutingFee) } return validateConfTarget( req.SweepConfTarget, loop.DefaultSweepConfTarget, ) } // hasBandwidth simulates the MPP splitting logic that will be used by LND when // attempting to route the payment. This function is used to evaluate if a // payment will be routable given the splitting logic used by LND. // It returns true if the amount is routable given the channel set and the // maximum number of shards allowed. If the amount is routable then the number // of shards used is also returned. This function makes an assumption that the // minimum loop amount divided by max parts will not be less than the minimum // shard amount. If the MPP logic changes, then this function should be updated. func hasBandwidth(channels []lndclient.ChannelInfo, amt btcutil.Amount, maxParts int) (bool, int) { scratch := make([]btcutil.Amount, len(channels)) var totalBandwidth btcutil.Amount for i, channel := range channels { scratch[i] = channel.LocalBalance totalBandwidth += channel.LocalBalance } if totalBandwidth < amt { return false, 0 } split := amt for shard := 0; shard <= maxParts; { paid := false for i := 0; i < len(scratch); i++ { if scratch[i] >= split { scratch[i] -= split amt -= split paid = true shard++ break } } if amt == 0 { return true, shard } if !paid { split /= 2 } else { split = amt } } return false, 0 } // getPublicationDeadline returns the publication deadline for a swap given the // unix timestamp. If the timestamp is believed to be in milliseconds, then it // is converted to seconds. func getPublicationDeadline(unixTimestamp uint64) time.Time { length := len(fmt.Sprintf("%d", unixTimestamp)) if length >= 13 { // Likely a millisecond timestamp secs := unixTimestamp / 1000 nsecs := (unixTimestamp % 1000) * 1e6 return time.Unix(int64(secs), int64(nsecs)) } else { // Likely a second timestamp return time.Unix(int64(unixTimestamp), 0) } }