Fees: add fractional sat/vB support (lncli) and sats_per_kw (RPC)

cmd/commands/cmd_open_channel.go

@@ -170,7 +170,7 @@ var openChannelCommand = cli.Command{
 			Usage:  "Deprecated, use sat_per_vbyte instead.",
 			Hidden: true,
 		},
-		cli.Int64Flag{
+		cli.Float64Flag{
 			Name: "sat_per_vbyte",
 			Usage: "(optional) a manual fee expressed in " +
 				"sat/vbyte that should be used when crafting " +
@@ -303,17 +303,22 @@ func openChannel(ctx *cli.Context) error {
 
 	// Check that only the field sat_per_vbyte or the deprecated field
 	// sat_per_byte is used.
-	feeRateFlag, err := checkNotBothSet(
+	_, err = checkNotBothSet(
 		ctx, "sat_per_vbyte", "sat_per_byte",
 	)
 	if err != nil {
 		return err
 	}
 
+	// Parse fee rate from --sat_per_vbyte and convert to sat/kw.
+	satPerKw, err := parseFeeRate(ctx, "sat_per_vbyte")
+	if err != nil {
+		return err
+	}
+
 	minConfs := int32(ctx.Uint64("min_confs"))
 	req := &lnrpc.OpenChannelRequest{
 		TargetConf:                 int32(ctx.Int64("conf_target")),
-		SatPerVbyte:                ctx.Uint64(feeRateFlag),
 		MinHtlcMsat:                ctx.Int64("min_htlc_msat"),
 		RemoteCsvDelay:             uint32(ctx.Uint64("remote_csv_delay")),
 		MinConfs:                   minConfs,
@@ -326,6 +331,7 @@ func openChannel(ctx *cli.Context) error {
 		RemoteChanReserveSat:       ctx.Uint64("remote_reserve_sats"),
 		FundMax:                    ctx.Bool("fundmax"),
 		Memo:                       ctx.String("memo"),
+		SatPerKw:                   satPerKw,
 	}
 
 	switch {
@@ -797,7 +803,7 @@ var batchOpenChannelCommand = cli.Command{
 				"transaction *should* confirm in, will be " +
 				"used for fee estimation",
 		},
-		cli.Int64Flag{
+		cli.Float64Flag{
 			Name: "sat_per_vbyte",
 			Usage: "(optional) a manual fee expressed in " +
 				"sat/vByte that should be used when crafting " +
@@ -850,14 +856,20 @@ func batchOpenChannel(ctx *cli.Context) error {
 		return err
 	}
 
+	// Parse fee rate from --sat_per_vbyte and convert to sat/kw.
+	satPerKw, err := parseFeeRate(ctx, "sat_per_vbyte")
+	if err != nil {
+		return err
+	}
+
 	minConfs := int32(ctx.Uint64("min_confs"))
 	req := &lnrpc.BatchOpenChannelRequest{
 		TargetConf:            int32(ctx.Int64("conf_target")),
-		SatPerVbyte:           int64(ctx.Uint64("sat_per_vbyte")),
 		MinConfs:              minConfs,
 		SpendUnconfirmed:      minConfs == 0,
 		Label:                 ctx.String("label"),
 		CoinSelectionStrategy: coinSelectionStrategy,
+		SatPerKw:              satPerKw,
 	}
 
 	// Let's try and parse the JSON part of the CLI now. Fortunately we can
@@ -1057,7 +1069,9 @@ func checkPsbtFlags(req *lnrpc.OpenChannelRequest) error {
 		return fmt.Errorf("specifying minimum confirmations for PSBT " +
 			"funding is not supported")
 	}
-	if req.TargetConf != 0 || req.SatPerByte != 0 || req.SatPerVbyte != 0 { // nolint:staticcheck
+	if req.TargetConf != 0 || req.SatPerByte != 0 || req.SatPerVbyte != 0 ||
+		req.SatPerKw != 0 {
+
 		return fmt.Errorf("setting fee estimation parameters not " +
 			"supported for PSBT funding")
 	}

cmd/commands/commands.go

@@ -483,7 +483,7 @@ var sendCoinsCommand = cli.Command{
 			Usage:  "Deprecated, use sat_per_vbyte instead.",
 			Hidden: true,
 		},
-		cli.Int64Flag{
+		cli.Float64Flag{
 			Name: "sat_per_vbyte",
 			Usage: "(optional) a manual fee expressed in " +
 				"sat/vbyte that should be used when crafting " +
@@ -639,6 +639,12 @@ func sendCoins(ctx *cli.Context) error {
 		}
 	}
 
+	// Parse fee rate from --sat_per_vbyte and convert to sat/kw.
+	satPerKw, err := parseFeeRate(ctx, "sat_per_vbyte")
+	if err != nil {
+		return err
+	}
+
 	// Ask for confirmation if we're on an actual terminal and the output is
 	// not being redirected to another command. This prevents existing shell
 	// scripts from breaking.
@@ -656,13 +662,13 @@ func sendCoins(ctx *cli.Context) error {
 		Addr:                  addr,
 		Amount:                amt,
 		TargetConf:            int32(ctx.Int64("conf_target")),
-		SatPerVbyte:           ctx.Uint64(feeRateFlag),
 		SendAll:               ctx.Bool("sweepall"),
 		Label:                 ctx.String(txLabelFlag.Name),
 		MinConfs:              minConfs,
 		SpendUnconfirmed:      minConfs == 0,
 		CoinSelectionStrategy: coinSelectionStrategy,
 		Outpoints:             outpoints,
+		SatPerKw:              satPerKw,
 	}
 	txid, err := client.SendCoins(ctxc, req)
 	if err != nil {
@@ -822,7 +828,7 @@ var sendManyCommand = cli.Command{
 			Usage:  "Deprecated, use sat_per_vbyte instead.",
 			Hidden: true,
 		},
-		cli.Int64Flag{
+		cli.Float64Flag{
 			Name: "sat_per_vbyte",
 			Usage: "(optional) a manual fee expressed in " +
 				"sat/vbyte that should be used when crafting " +
@@ -874,15 +880,21 @@ func sendMany(ctx *cli.Context) error {
 	client, cleanUp := getClient(ctx)
 	defer cleanUp()
 
+	// Parse fee rate from --sat_per_vbyte and convert to sat/kw.
+	satPerKw, err := parseFeeRate(ctx, "sat_per_vbyte")
+	if err != nil {
+		return err
+	}
+
 	minConfs := int32(ctx.Uint64("min_confs"))
 	txid, err := client.SendMany(ctxc, &lnrpc.SendManyRequest{
 		AddrToAmount:          amountToAddr,
 		TargetConf:            int32(ctx.Int64("conf_target")),
-		SatPerVbyte:           ctx.Uint64(feeRateFlag),
 		Label:                 ctx.String(txLabelFlag.Name),
 		MinConfs:              minConfs,
 		SpendUnconfirmed:      minConfs == 0,
 		CoinSelectionStrategy: coinSelectionStrategy,
+		SatPerKw:              satPerKw,
 	})
 	if err != nil {
 		return err
@@ -1073,7 +1085,7 @@ var closeChannelCommand = cli.Command{
 			Usage:  "Deprecated, use sat_per_vbyte instead.",
 			Hidden: true,
 		},
-		cli.Int64Flag{
+		cli.Float64Flag{
 			Name: "sat_per_vbyte",
 			Usage: "(optional) a manual fee expressed in " +
 				"sat/vbyte that should be used when crafting " +
@@ -1087,7 +1099,7 @@ var closeChannelCommand = cli.Command{
 				"be used if an upfront shutdown address is not " +
 				"already set",
 		},
-		cli.Uint64Flag{
+		cli.Float64Flag{
 			Name: "max_fee_rate",
 			Usage: "(optional) maximum fee rate in sat/vbyte " +
 				"accepted during the negotiation (default is " +
@@ -1112,7 +1124,7 @@ func closeChannel(ctx *cli.Context) error {
 
 	// Check that only the field sat_per_vbyte or the deprecated field
 	// sat_per_byte is used.
-	feeRateFlag, err := checkNotBothSet(
+	_, err := checkNotBothSet(
 		ctx, "sat_per_vbyte", "sat_per_byte",
 	)
 	if err != nil {
@@ -1124,14 +1136,26 @@ func closeChannel(ctx *cli.Context) error {
 		return err
 	}
 
+	// Parse fee rate from --sat_per_vbyte and convert to sat/kw.
+	satPerKw, err := parseFeeRate(ctx, "sat_per_vbyte")
+	if err != nil {
+		return err
+	}
+
+	// Parse fee rate from --max_fee_rate and convert to sat/kw.
+	maxFeePerKw, err := parseFeeRate(ctx, "max_fee_rate")
+	if err != nil {
+		return err
+	}
+
 	// TODO(roasbeef): implement time deadline within server
 	req := &lnrpc.CloseChannelRequest{
 		ChannelPoint:    channelPoint,
 		Force:           ctx.Bool("force"),
 		TargetConf:      int32(ctx.Int64("conf_target")),
-		SatPerVbyte:     ctx.Uint64(feeRateFlag),
+		SatPerKw:        satPerKw,
 		DeliveryAddress: ctx.String("delivery_addr"),
-		MaxFeePerVbyte:  ctx.Uint64("max_fee_rate"),
+		MaxFeePerKw:     maxFeePerKw,
 		// This makes sure that a coop close will also be executed if
 		// active HTLCs are present on the channel.
 		NoWait: true,
@@ -1277,7 +1301,7 @@ var closeAllChannelsCommand = cli.Command{
 			Usage:  "Deprecated, use sat_per_vbyte instead.",
 			Hidden: true,
 		},
-		cli.Int64Flag{
+		cli.Float64Flag{
 			Name: "sat_per_vbyte",
 			Usage: "(optional) a manual fee expressed in " +
 				"sat/vbyte that should be used when crafting " +
@@ -1299,13 +1323,19 @@ func closeAllChannels(ctx *cli.Context) error {
 
 	// Check that only the field sat_per_vbyte or the deprecated field
 	// sat_per_byte is used.
-	feeRateFlag, err := checkNotBothSet(
+	_, err := checkNotBothSet(
 		ctx, "sat_per_vbyte", "sat_per_byte",
 	)
 	if err != nil {
 		return err
 	}
 
+	// Parse fee rate from --sat_per_vbyte and convert to sat/kw.
+	satPerKw, err := parseFeeRate(ctx, "sat_per_vbyte")
+	if err != nil {
+		return err
+	}
+
 	prompt := "Do you really want to close ALL channels? (yes/no): "
 	if !ctx.Bool("skip_confirmation") && !promptForConfirmation(prompt) {
 		return errors.New("action aborted by user")
@@ -1437,9 +1467,9 @@ func closeAllChannels(ctx *cli.Context) error {
 					},
 					OutputIndex: uint32(index),
 				},
-				Force:       !channel.GetActive(),
-				TargetConf:  int32(ctx.Int64("conf_target")),
-				SatPerVbyte: ctx.Uint64(feeRateFlag),
+				Force:      !channel.GetActive(),
+				TargetConf: int32(ctx.Int64("conf_target")),
+				SatPerKw:   satPerKw,
 			}
 
 			txidChan := make(chan string, 1)

cmd/commands/main.go

@@ -14,6 +14,7 @@ import (
 	"strings"
 	"syscall"
 
+	"github.com/btcsuite/btcd/blockchain"
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/lightningnetwork/lnd"
@@ -328,6 +329,24 @@ func extractPathArgs(ctx *cli.Context) (string, string, error) {
 	return tlsCertPath, macPath, nil
 }
 
+// parseFeeRate converts a fee from sat/vB to sat/kw using float64 math.
+// We round up to avoid underpaying due to floating point truncation.
+func parseFeeRate(ctx *cli.Context, flagName string) (uint64, error) {
+	if !ctx.IsSet(flagName) {
+		return 0, nil
+	}
+
+	satPerVb := ctx.Float64(flagName)
+	if satPerVb <= 0 {
+		return 0, fmt.Errorf("invalid --%s", flagName)
+	}
+
+	scaleFactor := float64(blockchain.WitnessScaleFactor)
+	satPerKw := uint64((satPerVb*1000 + scaleFactor - 1) / scaleFactor)
+
+	return satPerKw, nil
+}
+
 // checkNotBothSet accepts two flag names, a and b, and checks that only flag a
 // or flag b can be set, but not both. It returns the name of the flag or an
 // error.

cmd/commands/walletrpc_active.go

@@ -283,7 +283,7 @@ var bumpFeeCommand = cli.Command{
 			Usage:  "Deprecated, use immediate instead.",
 			Hidden: true,
 		},
-		cli.Uint64Flag{
+		cli.Float64Flag{
 			Name: "sat_per_vbyte",
 			Usage: `
 	The starting fee rate, expressed in sat/vbyte, that will be used to
@@ -352,13 +352,19 @@ func bumpFee(ctx *cli.Context) error {
 		immediate = true
 	}
 
+	// Parse fee rate from --sat_per_vbyte and convert to sat/kw.
+	satPerKw, err := parseFeeRate(ctx, "sat_per_vbyte")
+	if err != nil {
+		return err
+	}
+
 	resp, err := client.BumpFee(ctxc, &walletrpc.BumpFeeRequest{
 		Outpoint:      protoOutPoint,
 		TargetConf:    uint32(ctx.Uint64("conf_target")),
 		Immediate:     immediate,
 		Budget:        ctx.Uint64("budget"),
-		SatPerVbyte:   ctx.Uint64("sat_per_vbyte"),
 		DeadlineDelta: uint32(ctx.Uint64("deadline_delta")),
+		SatPerKw:      satPerKw,
 	})
 	if err != nil {
 		return err

cmd/commands/walletrpc_types.go

@@ -13,8 +13,10 @@ type PendingSweep struct {
 	WitnessType          string   `json:"witness_type"`
 	AmountSat            uint32   `json:"amount_sat"`
 	SatPerVByte          uint32   `json:"sat_per_vbyte"`
+	SatPerKw             uint64   `json:"sat_per_kw"`
 	BroadcastAttempts    uint32   `json:"broadcast_attempts"`
 	RequestedSatPerVByte uint32   `json:"requested_sat_per_vbyte"`
+	RequestedSatPerKw    uint64   `json:"requested_sat_per_kw"`
 	Immediate            bool     `json:"immediate"`
 	Budget               uint64   `json:"budget"`
 	DeadlineHeight       uint32   `json:"deadline_height"`
@@ -33,8 +35,10 @@ func NewPendingSweepFromProto(pendingSweep *walletrpc.PendingSweep) *PendingSwee
 		WitnessType:          pendingSweep.WitnessType.String(),
 		AmountSat:            pendingSweep.AmountSat,
 		SatPerVByte:          uint32(pendingSweep.SatPerVbyte),
+		SatPerKw:             pendingSweep.SatPerKw,
 		BroadcastAttempts:    pendingSweep.BroadcastAttempts,
 		RequestedSatPerVByte: uint32(pendingSweep.RequestedSatPerVbyte),
+		RequestedSatPerKw:    pendingSweep.RequestedSatPerKw,
 		Immediate:            pendingSweep.Immediate,
 		Budget:               pendingSweep.Budget,
 		DeadlineHeight:       pendingSweep.DeadlineHeight,

docs/release-notes/release-notes-0.21.0.md

@@ -26,8 +26,18 @@
 
 ## RPC Additions
 
+* [Add sat_per_kw option for more fine granular control of transaction 
+  fees](https://github.com/lightningnetwork/lnd/pull/10067). This option is added for the sendcoins, sendmany, openchannel, batchopenchannel,
+  closechannel, closeallchannels and wallet bumpfee commands. Also add
+  max_fee_per_kw for closechannel command.
+
 ## lncli Additions
 
+* The [--sat_per_vbyte](https://github.com/lightningnetwork/lnd/pull/10067) 
+  option now supports fractional values (e.g. 1.05).
+  This option is added for the sendcoins, sendmany, openchannel,
+  batchopenchannel, closechannel, closeallchannels and wallet bumpfee commands. The max_fee_rate argument for closechannel also supports fractional values.
+
 # Improvements
 ## Functional Updates
 
@@ -41,6 +51,10 @@
 
 ## Deprecations
 
+### ⚠️ **Warning:** The deprecated fee rate option --sat_per_byte will be removed in release version **0.22**
+
+  The following RPCs will be impacted: sendcoins, sendmany, openchannel, closechannel, closeallchannels and wallet bumpfee.
+
 # Technical and Architectural Updates
 ## BOLT Spec Updates
 
@@ -53,3 +67,5 @@
 ## Tooling and Documentation
 
 # Contributors (Alphabetical Order)
+
+Pins

funding/batch.go

@@ -233,6 +233,7 @@ func (b *Batcher) BatchFund(ctx context.Context,
 		//nolint:ll
 		fundingReq, err := b.cfg.RequestParser(&lnrpc.OpenChannelRequest{
 			SatPerVbyte:                uint64(req.SatPerVbyte),
+			SatPerKw:                   req.SatPerKw,
 			TargetConf:                 req.TargetConf,
 			MinConfs:                   req.MinConfs,
 			SpendUnconfirmed:           req.SpendUnconfirmed,
@@ -331,14 +332,14 @@ func (b *Batcher) BatchFund(ctx context.Context,
 	// settings from the first request as all of them should be equal
 	// anyway.
 	firstReq := b.channels[0].fundingReq
-	feeRateSatPerVByte := firstReq.FundingFeePerKw.FeePerVByte()
+	feeRateSatPerKw := firstReq.FundingFeePerKw
 	changeType := walletrpc.ChangeAddressType_CHANGE_ADDRESS_TYPE_P2TR
 	fundPsbtReq := &walletrpc.FundPsbtRequest{
 		Template: &walletrpc.FundPsbtRequest_Raw{
 			Raw: txTemplate,
 		},
-		Fees: &walletrpc.FundPsbtRequest_SatPerVbyte{
-			SatPerVbyte: uint64(feeRateSatPerVByte),
+		Fees: &walletrpc.FundPsbtRequest_SatPerKw{
+			SatPerKw: uint64(feeRateSatPerKw),
 		},
 		MinConfs:              firstReq.MinConfs,
 		SpendUnconfirmed:      firstReq.MinConfs == 0,