multi: expose confirmation target for loop out HTLC sweep

Author: wpaulino

cmd/loop/loopout.go

@@ -36,6 +36,13 @@ var loopOutCommand = cli.Command{
 			Name:  "amt",
 			Usage: "the amount in satoshis to loop out",
 		},
+		cli.Uint64Flag{
+			Name: "conf_target",
+			Usage: "the number of blocks from the swap " +
+				"initiation height that the on-chain HTLC " +
+				"should be swept within",
+			Value: uint64(loop.DefaultSweepConfTarget),
+		},
 	},
 	Action: loopOut,
 }
@@ -75,8 +82,10 @@ func loopOut(ctx *cli.Context) error {
 	}
 	defer cleanup()
 
+	sweepConfTarget := int32(ctx.Uint64("conf_target"))
 	quoteReq := &looprpc.QuoteRequest{
-		Amt: int64(amt),
+		Amt:        int64(amt),
+		ConfTarget: sweepConfTarget,
 	}
 	quote, err := client.LoopOutQuote(context.Background(), quoteReq)
 	if err != nil {
@@ -103,6 +112,7 @@ func loopOut(ctx *cli.Context) error {
 		MaxPrepayRoutingFee: int64(*limits.maxPrepayRoutingFee),
 		MaxSwapRoutingFee:   int64(*limits.maxSwapRoutingFee),
 		LoopOutChannel:      unchargeChannel,
+		SweepConfTarget:     sweepConfTarget,
 	})
 	if err != nil {
 		return err

cmd/loopd/swapclient_server.go

@@ -41,6 +41,13 @@ func (s *swapClientServer) LoopOut(ctx context.Context,
 
 	logger.Infof("Loop out request received")
 
+	sweepConfTarget, err := validateConfTarget(
+		in.SweepConfTarget, loop.DefaultSweepConfTarget,
+	)
+	if err != nil {
+		return nil, err
+	}
+
 	var sweepAddr btcutil.Address
 	if in.Dest == "" {
 		// Generate sweep address if none specified.
@@ -67,7 +74,7 @@ func (s *swapClientServer) LoopOut(ctx context.Context,
 		MaxPrepayRoutingFee: btcutil.Amount(in.MaxPrepayRoutingFee),
 		MaxSwapRoutingFee:   btcutil.Amount(in.MaxSwapRoutingFee),
 		MaxSwapFee:          btcutil.Amount(in.MaxSwapFee),
-		SweepConfTarget:     defaultConfTarget,
+		SweepConfTarget:     sweepConfTarget,
 	}
 	if in.LoopOutChannel != 0 {
 		req.LoopOutChannel = &in.LoopOutChannel
@@ -249,7 +256,9 @@ func (s *swapClientServer) LoopOutTerms(ctx context.Context,
 func (s *swapClientServer) LoopOutQuote(ctx context.Context,
 	req *looprpc.QuoteRequest) (*looprpc.QuoteResponse, error) {
 
-	confTarget, err := validateConfTarget(req.ConfTarget, defaultConfTarget)
+	confTarget, err := validateConfTarget(
+		req.ConfTarget, loop.DefaultSweepConfTarget,
+	)
 	if err != nil {
 		return nil, err
 	}

loopout.go

@@ -20,7 +20,11 @@ import (
 var (
 	// MinLoopOutPreimageRevealDelta configures the minimum number of
 	// remaining blocks before htlc expiry required to reveal preimage.
-	MinLoopOutPreimageRevealDelta = int32(20)
+	MinLoopOutPreimageRevealDelta int32 = 20
+
+	// DefaultSweepConfTarget is the default confirmation target we'll use
+	// when sweeping on-chain HTLCs.
+	DefaultSweepConfTarget int32 = 6
 )
 
 // loopOutSwap contains all the in-memory state related to a pending loop out

looprpc/client.pb.go

@@ -127,6 +127,12 @@ message LoopOutRequest {
     lowest routing fee for the swap payment to the server.
     */
     uint64 loop_out_channel = 8;
+
+    /**
+    The number of blocks from the on-chain HTLC's confirmation height that it
+    should be swept within.
+    */
+    int32 sweep_conf_target = 9;
 }
 
 message LoopInRequest {

looprpc/client.proto

@@ -136,6 +136,11 @@
           "type": "string",
           "format": "uint64",
           "description": "*\nThe channel to loop out, the channel to loop out is selected based on the\nlowest routing fee for the swap payment to the server."
+        },
+        "sweep_conf_target": {
+          "type": "integer",
+          "format": "int32",
+          "description": "*\nThe number of blocks from the on-chain HTLC's confirmation height that it\nshould be swept within."
         }
       }
     },