multi: add OutAddr parameter for autoloop loop out

Author: GeorgeTsagk

cmd/loop/liquidity.go

@@ -286,6 +286,12 @@ var setParamsCommand = cli.Command{
 				"of swaps, limited to the budget set by " +
 				"autobudget",
 		},
+		cli.StringFlag{
+			Name: "destaddr",
+			Usage: "custom address to be used as destination for " +
+				"autoloop loop out, set to \"default\" in " +
+				"order to revert to default behavior",
+		},
 		cli.Uint64Flag{
 			Name: "autobudget",
 			Usage: "the maximum amount of fees in satoshis that " +
@@ -429,6 +435,11 @@ func setParams(ctx *cli.Context) error {
 		flagSet = true
 	}
 
+	if ctx.IsSet("destaddr") {
+		params.AutoloopDestAddress = ctx.String("destaddr")
+		flagSet = true
+	}
+
 	if ctx.IsSet("budgetstart") {
 		params.AutoloopBudgetStartSec = ctx.Uint64("budgetstart")
 		flagSet = true

liquidity/liquidity.go

@@ -380,6 +380,13 @@ func (m *Manager) autoloop(ctx context.Context) error {
 
 		// Create a copy of our range var so that we can reference it.
 		swap := swap
+
+		// Check if the parameter for custom address is defined for loop
+		// outs.
+		if m.params.DestAddr != nil {
+			swap.DestAddr = m.params.DestAddr
+		}
+
 		loopOut, err := m.cfg.LoopOut(ctx, &swap)
 		if err != nil {
 			return err

liquidity/parameters.go

@@ -18,9 +18,10 @@ import (
 
 var (
 	// defaultParameters contains the default parameters that we start our
-	// liquidity manger with.
+	// liquidity manager with.
 	defaultParameters = Parameters{
 		AutoFeeBudget:   defaultBudget,
+		DestAddr:        nil,
 		MaxAutoInFlight: defaultMaxInFlight,
 		ChannelRules:    make(map[lnwire.ShortChannelID]*SwapRule),
 		PeerRules:       make(map[route.Vertex]*SwapRule),
@@ -37,6 +38,10 @@ type Parameters struct {
 	// Autoloop enables automatic dispatch of swaps.
 	Autoloop bool
 
+	// DestAddr is the address to be used for sweeping the on-chain HTLC that
+	// is related with a loop out.
+	DestAddr btcutil.Address
+
 	// AutoFeeBudget is the total amount we allow to be spent on
 	// automatically dispatched swaps. Once this budget has been used, we
 	// will stop dispatching swaps until the budget is increased or the
@@ -347,12 +352,25 @@ func rpcToParameters(req *clientrpc.LiquidityParameters) (*Parameters,
 		return nil, err
 	}
 
+	var destaddr btcutil.Address
+	if len(req.AutoloopDestAddress) != 0 {
+		if req.AutoloopDestAddress == "default" {
+			destaddr = nil
+		} else {
+			destaddr, err = btcutil.DecodeAddress(req.AutoloopDestAddress, nil)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+
 	params := &Parameters{
 		FeeLimit:        feeLimit,
 		SweepConfTarget: req.SweepConfTarget,
 		FailureBackOff: time.Duration(req.FailureBackoffSec) *
 			time.Second,
 		Autoloop:        req.Autoloop,
+		DestAddr:        destaddr,
 		AutoFeeBudget:   btcutil.Amount(req.AutoloopBudgetSat),
 		MaxAutoInFlight: int(req.AutoMaxInFlight),
 		ChannelRules: make(

loopd/swapclient_server.go

@@ -747,12 +747,18 @@ func (s *swapClientServer) GetLiquidityParams(_ context.Context,
 
 	totalRules := len(cfg.ChannelRules) + len(cfg.PeerRules)
 
+	var destaddr string
+	if cfg.DestAddr != nil {
+		destaddr = cfg.DestAddr.String()
+	}
+
 	rpcCfg := &clientrpc.LiquidityParameters{
-		SweepConfTarget:   cfg.SweepConfTarget,
-		FailureBackoffSec: uint64(cfg.FailureBackOff.Seconds()),
-		Autoloop:          cfg.Autoloop,
-		AutoloopBudgetSat: uint64(cfg.AutoFeeBudget),
-		AutoMaxInFlight:   uint64(cfg.MaxAutoInFlight),
+		SweepConfTarget:     cfg.SweepConfTarget,
+		FailureBackoffSec:   uint64(cfg.FailureBackOff.Seconds()),
+		Autoloop:            cfg.Autoloop,
+		AutoloopBudgetSat:   uint64(cfg.AutoFeeBudget),
+		AutoMaxInFlight:     uint64(cfg.MaxAutoInFlight),
+		AutoloopDestAddress: destaddr,
 		Rules: make(
 			[]*clientrpc.LiquidityRule, 0, totalRules,
 		),