[6/?] StaticAddr: Quoting

client.go

@@ -645,9 +645,9 @@ func (s *Client) LoopIn(globalCtx context.Context,
 	return swapInfo, nil
 }
 
-// LoopInQuote takes an amount and returns a break down of estimated
-// costs for the client. Both the swap server and the on-chain fee estimator are
-// queried to get to build the quote response.
+// LoopInQuote takes an amount and returns a breakdown of estimated costs for
+// the client. Both the swap server and the on-chain fee estimator are queried
+// to get to build the quote response.
 func (s *Client) LoopInQuote(ctx context.Context,
 	request *LoopInQuoteRequest) (*LoopInQuote, error) {
 
@@ -693,7 +693,7 @@ func (s *Client) LoopInQuote(ctx context.Context,
 
 	quote, err := s.Server.GetLoopInQuote(
 		ctx, request.Amount, s.lndServices.NodePubkey, request.LastHop,
-		request.RouteHints, request.Initiator,
+		request.RouteHints, request.Initiator, request.NumDeposits,
 	)
 	if err != nil {
 		return nil, err
@@ -703,7 +703,9 @@ func (s *Client) LoopInQuote(ctx context.Context,
 
 	// We don't calculate the on-chain fee if the HTLC is going to be
 	// published externally.
-	if request.ExternalHtlc {
+	// We also don't calculate the on-chain fee if the loop in is funded by
+	// static address deposits because we don't publish the HTLC on-chain.
+	if request.ExternalHtlc || request.NumDeposits > 0 {
 		return &LoopInQuote{
 			SwapFee:  swapFee,
 			MinerFee: 0,

cmd/loop/quote.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"time"
 
+	"github.com/btcsuite/btcd/btcutil"
 	"github.com/lightninglabs/loop"
 	"github.com/lightninglabs/loop/looprpc"
 	"github.com/lightningnetwork/lnd/routing/route"
@@ -19,10 +20,11 @@ var quoteCommand = cli.Command{
 }
 
 var quoteInCommand = cli.Command{
-	Name:        "in",
-	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",
+	Name:      "in",
+	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." +
+		"Either specify an amount or deposit outpoints.",
 	Flags: []cli.Flag{
 		cli.StringFlag{
 			Name: lastHopFlag.Name,
@@ -33,20 +35,38 @@ var quoteInCommand = cli.Command{
 		verboseFlag,
 		privateFlag,
 		routeHintsFlag,
+		cli.StringSliceFlag{
+			Name: "deposit_outpoint",
+			Usage: "one or more static address deposit outpoints " +
+				"to quote for. Deposit outpoints are not to " +
+				"be used in combination with an amount. Each" +
+				"additional outpoint can be added by " +
+				"specifying --deposit_outpoint tx_id:idx",
+		},
 	},
 	Action: quoteIn,
 }
 
 func quoteIn(ctx *cli.Context) error {
 	// Show command help if the incorrect number arguments was provided.
-	if ctx.NArg() != 1 {
+	if ctx.NArg() != 1 && !ctx.IsSet("deposit_outpoint") {
 		return cli.ShowCommandHelp(ctx, "in")
 	}
 
-	args := ctx.Args()
-	amt, err := parseAmt(args[0])
-	if err != nil {
-		return err
+	var (
+		manualAmt        btcutil.Amount
+		depositAmt       btcutil.Amount
+		depositOutpoints []string
+		err              error
+		ctxb             = context.Background()
+	)
+
+	if ctx.NArg() == 1 {
+		args := ctx.Args()
+		manualAmt, err = parseAmt(args[0])
+		if err != nil {
+			return err
+		}
 	}
 
 	client, cleanup, err := getClient(ctx)
@@ -62,11 +82,20 @@ func quoteIn(ctx *cli.Context) error {
 		return err
 	}
 
+	if ctx.IsSet("deposit_outpoint") {
+		depositOutpoints = ctx.StringSlice("deposit_outpoint")
+		depositAmt, err = depositAmount(ctxb, client, depositOutpoints)
+		if err != nil {
+			return err
+		}
+	}
+
 	quoteReq := &looprpc.QuoteRequest{
-		Amt:              int64(amt),
+		Amt:              int64(manualAmt),
 		ConfTarget:       int32(ctx.Uint64("conf_target")),
 		LoopInRouteHints: hints,
 		Private:          ctx.Bool(privateFlag.Name),
+		DepositOutpoints: depositOutpoints,
 	}
 
 	if ctx.IsSet(lastHopFlag.Name) {
@@ -80,7 +109,6 @@ func quoteIn(ctx *cli.Context) error {
 		quoteReq.LoopInLastHop = lastHopVertex[:]
 	}
 
-	ctxb := context.Background()
 	quoteResp, err := client.GetLoopInQuote(ctxb, quoteReq)
 	if err != nil {
 		return err
@@ -98,10 +126,36 @@ func quoteIn(ctx *cli.Context) error {
 			"amount.\n")
 	}
 
+	// If the user specified static address deposits, we quoted for their
+	// total value and need to display that value instead of the manually
+	// selected one.
+	if manualAmt == 0 {
+		quoteReq.Amt = int64(depositAmt)
+	}
 	printQuoteInResp(quoteReq, quoteResp, ctx.Bool("verbose"))
 	return nil
 }
 
+func depositAmount(ctx context.Context, client looprpc.SwapClientClient,
+	depositOutpoints []string) (btcutil.Amount, error) {
+
+	addressSummary, err := client.GetStaticAddressSummary(
+		ctx, &looprpc.StaticAddressSummaryRequest{
+			Outpoints: depositOutpoints,
+		},
+	)
+	if err != nil {
+		return 0, err
+	}
+
+	var depositAmt btcutil.Amount
+	for _, deposit := range addressSummary.FilteredDeposits {
+		depositAmt += btcutil.Amount(deposit.Value)
+	}
+
+	return depositAmt, nil
+}
+
 var quoteOutCommand = cli.Command{
 	Name:        "out",
 	Usage:       "get a quote for the cost of a loop out swap",

interface.go

@@ -288,6 +288,12 @@ type LoopInQuoteRequest struct {
 	// initiated the swap (loop CLI, autolooper, LiT UI and so on) and is
 	// appended to the user agent string.
 	Initiator string
+
+	// The number of static address deposits the client wants to quote for.
+	// If the number of deposits exceeds one the server will apply a
+	// per-input service fee. This is to cover for the increased on-chain
+	// fee the server has to pay when the sweeping transaction is broadcast.
+	NumDeposits uint32
 }
 
 // LoopInQuote contains estimates for the fees making up the total swap cost

loopd/swapclient_server.go

@@ -748,13 +748,31 @@ func (s *swapClientServer) GetLoopInQuote(ctx context.Context,
 
 	log.Infof("Loop in quote request received")
 
+	var (
+		numDeposits = uint32(len(req.DepositOutpoints))
+		err         error
+	)
+
 	htlcConfTarget, err := validateLoopInRequest(
-		req.ConfTarget, req.ExternalHtlc,
+		req.ConfTarget, req.ExternalHtlc, numDeposits, req.Amt,
 	)
 	if err != nil {
 		return nil, err
 	}
 
+	// Retrieve deposits to calculate their total value.
+	var summary *clientrpc.StaticAddressSummaryResponse
+	if len(req.DepositOutpoints) > 0 {
+		summary, err = s.GetStaticAddressSummary(
+			ctx, &clientrpc.StaticAddressSummaryRequest{
+				Outpoints: req.DepositOutpoints,
+			},
+		)
+		if err != nil {
+			return nil, err
+		}
+	}
+
 	var (
 		routeHints [][]zpay32.HopHint
 		lastHop    *route.Vertex
@@ -777,14 +795,32 @@ func (s *swapClientServer) GetLoopInQuote(ctx context.Context,
 		}
 	}
 
+	// The requested amount should be 0 here if the request contained
+	// deposit outpoints.
+	amount := btcutil.Amount(req.Amt)
+	if amount != 0 && len(summary.FilteredDeposits) > 0 {
+		return nil, fmt.Errorf("amount should be 0 for deposit " +
+			"quotes")
+	}
+
+	// In case we quote for deposits we send the server both the total value
+	// and the number of deposits. This is so the server can probe the total
+	// amount and calculate the per input fee.
+	if amount == 0 && len(summary.FilteredDeposits) > 0 {
+		for _, deposit := range summary.FilteredDeposits {
+			amount += btcutil.Amount(deposit.Value)
+		}
+	}
+
 	quote, err := s.impl.LoopInQuote(ctx, &loop.LoopInQuoteRequest{
-		Amount:         btcutil.Amount(req.Amt),
+		Amount:         amount,
 		HtlcConfTarget: htlcConfTarget,
 		ExternalHtlc:   req.ExternalHtlc,
 		LastHop:        lastHop,
 		RouteHints:     routeHints,
 		Private:        req.Private,
 		Initiator:      defaultLoopdInitiator,
+		NumDeposits:    numDeposits,
 	})
 	if err != nil {
 		return nil, err
@@ -881,7 +917,7 @@ func (s *swapClientServer) LoopIn(ctx context.Context,
 	log.Infof("Loop in request received")
 
 	htlcConfTarget, err := validateLoopInRequest(
-		in.HtlcConfTarget, in.ExternalHtlc,
+		in.HtlcConfTarget, in.ExternalHtlc, 0, in.Amt,
 	)
 	if err != nil {
 		return nil, err
@@ -1710,7 +1746,13 @@ func validateConfTarget(target, defaultTarget int32) (int32, error) {
 
 // validateLoopInRequest fails if the mutually exclusive conf target and
 // external parameters are both set.
-func validateLoopInRequest(htlcConfTarget int32, external bool) (int32, error) {
+func validateLoopInRequest(htlcConfTarget int32, external bool,
+	numDeposits uint32, amount int64) (int32, error) {
+
+	if amount == 0 && numDeposits == 0 {
+		return 0, errors.New("either amount or deposits must be set")
+	}
+
 	// 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 {
@@ -1724,6 +1766,12 @@ func validateLoopInRequest(htlcConfTarget int32, external bool) (int32, error) {
 		return 0, nil
 	}
 
+	// If the loop in uses static address deposits, we do not need to set a
+	// confirmation target since the HTLC won't be published by the client.
+	if numDeposits > 0 {
+		return 0, nil
+	}
+
 	return validateConfTarget(htlcConfTarget, loop.DefaultHtlcConfTarget)
 }
 

loopd/swapclient_server_test.go

@@ -145,55 +145,76 @@ func TestValidateConfTarget(t *testing.T) {
 func TestValidateLoopInRequest(t *testing.T) {
 	tests := []struct {
 		name           string
+		amount         int64
+		numDeposits    uint32
 		external       bool
 		confTarget     int32
 		expectErr      bool
 		expectedTarget int32
 	}{
 		{
 			name:           "external and htlc conf set",
+			amount:         100_000,
 			external:       true,
 			confTarget:     1,
 			expectErr:      true,
 			expectedTarget: 0,
 		},
 		{
 			name:           "external and no conf",
+			amount:         100_000,
 			external:       true,
 			confTarget:     0,
 			expectErr:      false,
 			expectedTarget: 0,
 		},
 		{
 			name:           "not external, zero conf",
+			amount:         100_000,
 			external:       false,
 			confTarget:     0,
 			expectErr:      false,
 			expectedTarget: loop.DefaultHtlcConfTarget,
 		},
 		{
 			name:           "not external, bad conf",
+			amount:         100_000,
 			external:       false,
 			confTarget:     1,
 			expectErr:      true,
 			expectedTarget: 0,
 		},
 		{
 			name:           "not external, ok conf",
+			amount:         100_000,
 			external:       false,
 			confTarget:     5,
 			expectErr:      false,
 			expectedTarget: 5,
 		},
+		{
+			name:           "not external, amount no deposit",
+			amount:         100_000,
+			numDeposits:    0,
+			external:       false,
+			expectErr:      false,
+			expectedTarget: loop.DefaultHtlcConfTarget,
+		},
+		{
+			name:        "not external, deposit no amount",
+			amount:      100_000,
+			numDeposits: 1,
+			external:    false,
+			expectErr:   false,
+		},
 	}
 
 	for _, test := range tests {
-		test := test
-
 		t.Run(test.name, func(t *testing.T) {
 			external := test.external
 			conf, err := validateLoopInRequest(
-				test.confTarget, external,
+				test.confTarget, external, test.numDeposits,
+				test.amount,
 			)
 
 			if test.expectErr {

loopin.go

@@ -128,7 +128,7 @@ func newLoopInSwap(globalCtx context.Context, cfg *swapConfig,
 	// hints.
 	quote, err := cfg.server.GetLoopInQuote(
 		globalCtx, request.Amount, cfg.lnd.NodePubkey, request.LastHop,
-		request.RouteHints, request.Initiator,
+		request.RouteHints, request.Initiator, 0,
 	)
 	if err != nil {
 		return nil, wrapGrpcError("loop in terms", err)