config: make total payment timeout and retries configurable

Author: bhandras

client.go

@@ -108,6 +108,14 @@ type ClientConfig struct {
 	// for a loop out swap. When greater than one, a multi-part payment may
 	// be attempted.
 	LoopOutMaxParts uint32
+
+	// TotalPaymentTimeout is the total amount of time until we time out
+	// off-chain payments (used in loop out).
+	TotalPaymentTimeout time.Duration
+
+	// MaxPaymentRetries is the maximum times we retry an off-chain payment
+	// (used in loop out).
+	MaxPaymentRetries int
 }
 
 // NewClient returns a new instance to initiate swaps with.
@@ -142,12 +150,14 @@ func NewClient(dbDir string, cfg *ClientConfig) (*Client, func(), error) {
 	}
 
 	executor := newExecutor(&executorConfig{
-		lnd:               cfg.Lnd,
-		store:             store,
-		sweeper:           sweeper,
-		createExpiryTimer: config.CreateExpiryTimer,
-		loopOutMaxParts:   cfg.LoopOutMaxParts,
-		cancelSwap:        swapServerClient.CancelLoopOutSwap,
+		lnd:                 cfg.Lnd,
+		store:               store,
+		sweeper:             sweeper,
+		createExpiryTimer:   config.CreateExpiryTimer,
+		loopOutMaxParts:     cfg.LoopOutMaxParts,
+		totalPaymentTimeout: cfg.TotalPaymentTimeout,
+		maxPaymentRetries:   cfg.MaxPaymentRetries,
+		cancelSwap:          swapServerClient.CancelLoopOutSwap,
 	})
 
 	client := &Client{

executor.go

@@ -26,6 +26,10 @@ type executorConfig struct {
 
 	loopOutMaxParts uint32
 
+	totalPaymentTimeout time.Duration
+
+	maxPaymentRetries int
+
 	cancelSwap func(ctx context.Context, details *outCancelDetails) error
 }
 
@@ -141,12 +145,14 @@ func (s *executor) run(mainCtx context.Context,
 				defer s.wg.Done()
 
 				err := newSwap.execute(mainCtx, &executeConfig{
-					statusChan:      statusChan,
-					sweeper:         s.sweeper,
-					blockEpochChan:  queue.ChanOut(),
-					timerFactory:    s.executorConfig.createExpiryTimer,
-					loopOutMaxParts: s.executorConfig.loopOutMaxParts,
-					cancelSwap:      s.executorConfig.cancelSwap,
+					statusChan:         statusChan,
+					sweeper:            s.sweeper,
+					blockEpochChan:     queue.ChanOut(),
+					timerFactory:       s.executorConfig.createExpiryTimer,
+					loopOutMaxParts:    s.executorConfig.loopOutMaxParts,
+					totalPaymentTimout: s.executorConfig.totalPaymentTimeout,
+					maxPaymentRetries:  s.executorConfig.maxPaymentRetries,
+					cancelSwap:         s.executorConfig.cancelSwap,
 				}, height)
 				if err != nil && err != context.Canceled {
 					log.Errorf("Execute error: %v", err)

loopd/config.go

@@ -33,9 +33,11 @@ var (
 		LoopDirBase, DefaultNetwork, defaultConfigFilename,
 	)
 
-	defaultMaxLogFiles     = 3
-	defaultMaxLogFileSize  = 10
-	defaultLoopOutMaxParts = uint32(5)
+	defaultMaxLogFiles         = 3
+	defaultMaxLogFileSize      = 10
+	defaultLoopOutMaxParts     = uint32(5)
+	defaultTotalPaymentTimeout = time.Minute * 60
+	defaultMaxPaymentRetries   = 3
 
 	// DefaultTLSCertFilename is the default file name for the autogenerated
 	// TLS certificate.
@@ -144,6 +146,9 @@ type Config struct {
 
 	LoopOutMaxParts uint32 `long:"loopoutmaxparts" description:"The maximum number of payment parts that may be used for a loop out swap."`
 
+	TotalPaymentTimeout time.Duration `long:"totalpaymenttimeout" description:"The timeout to use for off-chain payments."`
+	MaxPaymentRetries   int           `long:"maxpaymentretries" description:"The maximum number of times an off-chain payment may be retried."`
+
 	Lnd *lndConfig `group:"lnd" namespace:"lnd"`
 
 	Server *loopServerConfig `group:"server" namespace:"server"`
@@ -165,19 +170,21 @@ func DefaultConfig() Config {
 		Server: &loopServerConfig{
 			NoTLS: false,
 		},
-		LoopDir:         LoopDirBase,
-		ConfigFile:      defaultConfigFile,
-		DataDir:         LoopDirBase,
-		LogDir:          defaultLogDir,
-		MaxLogFiles:     defaultMaxLogFiles,
-		MaxLogFileSize:  defaultMaxLogFileSize,
-		DebugLevel:      defaultLogLevel,
-		TLSCertPath:     DefaultTLSCertPath,
-		TLSKeyPath:      DefaultTLSKeyPath,
-		MacaroonPath:    DefaultMacaroonPath,
-		MaxLSATCost:     lsat.DefaultMaxCostSats,
-		MaxLSATFee:      lsat.DefaultMaxRoutingFeeSats,
-		LoopOutMaxParts: defaultLoopOutMaxParts,
+		LoopDir:             LoopDirBase,
+		ConfigFile:          defaultConfigFile,
+		DataDir:             LoopDirBase,
+		LogDir:              defaultLogDir,
+		MaxLogFiles:         defaultMaxLogFiles,
+		MaxLogFileSize:      defaultMaxLogFileSize,
+		DebugLevel:          defaultLogLevel,
+		TLSCertPath:         DefaultTLSCertPath,
+		TLSKeyPath:          DefaultTLSKeyPath,
+		MacaroonPath:        DefaultMacaroonPath,
+		MaxLSATCost:         lsat.DefaultMaxCostSats,
+		MaxLSATFee:          lsat.DefaultMaxRoutingFeeSats,
+		LoopOutMaxParts:     defaultLoopOutMaxParts,
+		TotalPaymentTimeout: defaultTotalPaymentTimeout,
+		MaxPaymentRetries:   defaultMaxPaymentRetries,
 		Lnd: &lndConfig{
 			Host:         "localhost:10009",
 			MacaroonPath: DefaultLndMacaroonPath,
@@ -299,6 +306,17 @@ func Validate(cfg *Config) error {
 		return fmt.Errorf("must specify --lnd.macaroonpath")
 	}
 
+	// Allow at most 2x the default total payment timeout.
+	if cfg.TotalPaymentTimeout > 2*defaultTotalPaymentTimeout {
+		return fmt.Errorf("max total payment timeout allowed is at "+
+			"most %v", 2*defaultTotalPaymentTimeout)
+	}
+
+	// At least one retry.
+	if cfg.MaxPaymentRetries < 1 {
+		return fmt.Errorf("max payment retries must be positive")
+	}
+
 	return nil
 }
 

loopd/utils.go

@@ -17,14 +17,16 @@ func getClient(config *Config, lnd *lndclient.LndServices) (*loop.Client,
 	func(), error) {
 
 	clientConfig := &loop.ClientConfig{
-		ServerAddress:   config.Server.Host,
-		ProxyAddress:    config.Server.Proxy,
-		SwapServerNoTLS: config.Server.NoTLS,
-		TLSPathServer:   config.Server.TLSPath,
-		Lnd:             lnd,
-		MaxLsatCost:     btcutil.Amount(config.MaxLSATCost),
-		MaxLsatFee:      btcutil.Amount(config.MaxLSATFee),
-		LoopOutMaxParts: config.LoopOutMaxParts,
+		ServerAddress:       config.Server.Host,
+		ProxyAddress:        config.Server.Proxy,
+		SwapServerNoTLS:     config.Server.NoTLS,
+		TLSPathServer:       config.Server.TLSPath,
+		Lnd:                 lnd,
+		MaxLsatCost:         btcutil.Amount(config.MaxLSATCost),
+		MaxLsatFee:          btcutil.Amount(config.MaxLSATFee),
+		LoopOutMaxParts:     config.LoopOutMaxParts,
+		TotalPaymentTimeout: config.TotalPaymentTimeout,
+		MaxPaymentRetries:   config.MaxPaymentRetries,
 	}
 
 	swapClient, cleanUp, err := loop.NewClient(config.DataDir, clientConfig)

loopout.go

@@ -52,15 +52,6 @@ var (
 	//
 	// TODO(wilmer): tune?
 	DefaultSweepConfTargetDelta = DefaultSweepConfTarget * 2
-
-	// totalPaymentTimeout is the total timeout used for the loop out
-	// offchain payment.
-	totalPaymentTimeout = time.Minute * 60
-
-	// maxPaymentRetries is the maximum number of times the client will
-	// attempt to pay the invoice before failing the swap. This retry limit
-	// only applies to when the client uses a routing helper plugin.
-	maxPaymentRetries = 3
 )
 
 // loopOutSwap contains all the in-memory state related to a pending loop out
@@ -87,12 +78,14 @@ type loopOutSwap struct {
 
 // executeConfig contains extra configuration to execute the swap.
 type executeConfig struct {
-	sweeper         *sweep.Sweeper
-	statusChan      chan<- SwapInfo
-	blockEpochChan  <-chan interface{}
-	timerFactory    func(d time.Duration) <-chan time.Time
-	loopOutMaxParts uint32
-	cancelSwap      func(context.Context, *outCancelDetails) error
+	sweeper            *sweep.Sweeper
+	statusChan         chan<- SwapInfo
+	blockEpochChan     <-chan interface{}
+	timerFactory       func(d time.Duration) <-chan time.Time
+	loopOutMaxParts    uint32
+	totalPaymentTimout time.Duration
+	maxPaymentRetries  int
+	cancelSwap         func(context.Context, *outCancelDetails) error
 }
 
 // loopOutInitResult contains information about a just-initiated loop out swap.
@@ -683,6 +676,8 @@ func (s *loopOutSwap) payInvoiceAsync(ctx context.Context,
 	}
 
 	maxRetries := 1
+	paymentTimeout := s.executeConfig.totalPaymentTimout
+
 	// Attempt to acquire and initialize the routing plugin.
 	routingPlugin, err := AcquireRoutingPlugin(
 		ctx, pluginType, *s.lnd, target, nil, amt,
@@ -695,11 +690,11 @@ func (s *loopOutSwap) payInvoiceAsync(ctx context.Context,
 		s.log.Infof("Acquired routing plugin %v for payment %v",
 			pluginType, hash.String())
 
-		maxRetries = maxPaymentRetries
+		maxRetries = s.executeConfig.maxPaymentRetries
+		paymentTimeout /= time.Duration(maxRetries)
 		defer ReleaseRoutingPlugin(ctx)
 	}
 
-	paymentTimeout := totalPaymentTimeout / time.Duration(maxRetries)
 	req := lndclient.SendPaymentRequest{
 		MaxFee:          maxFee,
 		Invoice:         invoice,