multi: add confirmation target to loop in

Author: carlaKC

cmd/loop/loopin.go

@@ -18,12 +18,29 @@ var (
 		Usage: "the pubkey of the last hop to use for this swap",
 	}
 
+	confTargetFlag = cli.Uint64Flag{
+		Name: "conf_target",
+		Usage: "the target number of blocks the on-chain " +
+			"htlc broadcast by the swap client should " +
+			"confirm within",
+	}
+
 	loopInCommand = cli.Command{
 		Name:      "in",
 		Usage:     "perform an on-chain to off-chain swap (loop in)",
 		ArgsUsage: "amt",
 		Description: `
-		Send the amount in satoshis specified by the amt argument off-chain.`,
+		Send the amount in satoshis specified by the amt argument 
+		off-chain.
+		
+		By default the swap client will create and broadcast the 
+		on-chain htlc. The fee priority of this transaction can 
+		optionally be set using the conf_target flag. 
+
+		The external flag can be set to publish the on chain htlc 
+		independently. Note that this flag cannot be set with the 
+		conf_target flag.
+		`,
 		Flags: []cli.Flag{
 			cli.Uint64Flag{
 				Name:  "amt",
@@ -33,6 +50,7 @@ var (
 				Name:  "external",
 				Usage: "expect htlc to be published externally",
 			},
+			confTargetFlag,
 			lastHopFlag,
 		},
 		Action: loopIn,
@@ -66,10 +84,21 @@ func loopIn(ctx *cli.Context) error {
 	defer cleanup()
 
 	external := ctx.Bool("external")
+	htlcConfTarget := int32(ctx.Uint64(confTargetFlag.Name))
+
+	// External and confirmation target are mutually exclusive; either the
+	// on chain htlc is being externally broadcast, or we are creating the
+	// on chain htlc with a desired confirmation target. Fail if both are
+	// set.
+	if external && htlcConfTarget != 0 {
+		return fmt.Errorf("external and conf_target both set")
+	}
+
 	quote, err := client.GetLoopInQuote(
 		context.Background(),
 		&looprpc.QuoteRequest{
 			Amt:          int64(amt),
+			ConfTarget:   htlcConfTarget,
 			ExternalHtlc: external,
 		},
 	)
@@ -96,10 +125,11 @@ func loopIn(ctx *cli.Context) error {
 	}
 
 	req := &looprpc.LoopInRequest{
-		Amt:          int64(amt),
-		MaxMinerFee:  int64(limits.maxMinerFee),
-		MaxSwapFee:   int64(limits.maxSwapFee),
-		ExternalHtlc: external,
+		Amt:            int64(amt),
+		MaxMinerFee:    int64(limits.maxMinerFee),
+		MaxSwapFee:     int64(limits.maxSwapFee),
+		ExternalHtlc:   external,
+		HtlcConfTarget: htlcConfTarget,
 	}
 
 	if ctx.IsSet(lastHopFlag.Name) {

cmd/loop/quote.go

@@ -22,15 +22,8 @@ var quoteInCommand = cli.Command{
 	Usage:       "get a quote for the cost of a loop in swap",
 	ArgsUsage:   "amt",
 	Description: "Allows to determine the cost of a swap up front",
-	Flags: []cli.Flag{
-		cli.Uint64Flag{
-			Name: "conf_target",
-			Usage: "the target number of blocks the on-chain " +
-				"htlc broadcast by the swap client should " +
-				"confirm within",
-		},
-	},
-	Action: quoteIn,
+	Flags:       []cli.Flag{confTargetFlag},
+	Action:      quoteIn,
 }
 
 func quoteIn(ctx *cli.Context) error {

loopd/swapclient_server.go

@@ -361,9 +361,16 @@ func (s *swapClientServer) GetLoopInQuote(ctx context.Context,
 
 	log.Infof("Loop in quote request received")
 
+	htlcConfTarget, err := validateLoopInRequest(
+		req.ConfTarget, req.ExternalHtlc,
+	)
+	if err != nil {
+		return nil, err
+	}
+
 	quote, err := s.impl.LoopInQuote(ctx, &loop.LoopInQuoteRequest{
 		Amount:         btcutil.Amount(req.Amt),
-		HtlcConfTarget: loop.DefaultHtlcConfTarget,
+		HtlcConfTarget: htlcConfTarget,
 		ExternalHtlc:   req.ExternalHtlc,
 	})
 	if err != nil {
@@ -381,11 +388,18 @@ func (s *swapClientServer) LoopIn(ctx context.Context,
 
 	log.Infof("Loop in request received")
 
+	htlcConfTarget, err := validateLoopInRequest(
+		in.HtlcConfTarget, in.ExternalHtlc,
+	)
+	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: loop.DefaultHtlcConfTarget,
+		HtlcConfTarget: htlcConfTarget,
 		ExternalHtlc:   in.ExternalHtlc,
 	}
 	if in.LastHop != nil {
@@ -489,3 +503,22 @@ func validateConfTarget(target, defaultTarget int32) (int32, error) {
 		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)
+}

loopd/swapclient_server_test.go

@@ -1,6 +1,10 @@
 package loopd
 
-import "testing"
+import (
+	"testing"
+
+	"github.com/lightninglabs/loop"
+)
 
 // TestValidateConfTarget tests all failure and success cases for our conf
 // target validation function, including the case where we replace a zero
@@ -70,3 +74,72 @@ func TestValidateConfTarget(t *testing.T) {
 		})
 	}
 }
+
+// TestValidateLoopInRequest tests validation of loop in requests.
+func TestValidateLoopInRequest(t *testing.T) {
+	tests := []struct {
+		name           string
+		external       bool
+		confTarget     int32
+		expectErr      bool
+		expectedTarget int32
+	}{
+		{
+			name:           "external and htlc conf set",
+			external:       true,
+			confTarget:     1,
+			expectErr:      true,
+			expectedTarget: 0,
+		},
+		{
+			name:           "external and no conf",
+			external:       true,
+			confTarget:     0,
+			expectErr:      false,
+			expectedTarget: 0,
+		},
+		{
+			name:           "not external, zero conf",
+			external:       false,
+			confTarget:     0,
+			expectErr:      false,
+			expectedTarget: loop.DefaultHtlcConfTarget,
+		},
+		{
+			name:           "not external, bad conf",
+			external:       false,
+			confTarget:     1,
+			expectErr:      true,
+			expectedTarget: 0,
+		},
+		{
+			name:           "not external, ok conf",
+			external:       false,
+			confTarget:     5,
+			expectErr:      false,
+			expectedTarget: 5,
+		},
+	}
+
+	for _, test := range tests {
+		test := test
+
+		t.Run(test.name, func(t *testing.T) {
+			external := test.external
+			conf, err := validateLoopInRequest(
+				test.confTarget, external,
+			)
+
+			haveErr := err != nil
+			if haveErr != test.expectErr {
+				t.Fatalf("expected err: %v, got: %v",
+					test.expectErr, err)
+			}
+
+			if conf != test.expectedTarget {
+				t.Fatalf("expected: %v, got: %v",
+					test.expectedTarget, conf)
+			}
+		})
+	}
+}