cmd: open channel command

Author: hieblmi

cmd/loop/openchannel.go

@@ -0,0 +1,364 @@
+package main
+
+import (
+	"context"
+	"encoding/hex"
+	"fmt"
+	"strconv"
+
+	"github.com/lightninglabs/loop/looprpc"
+	"github.com/urfave/cli/v3"
+)
+
+const (
+	defaultUtxoMinConf = 1
+)
+
+var (
+	channelTypeTweakless     = "tweakless"
+	channelTypeAnchors       = "anchors"
+	channelTypeSimpleTaproot = "taproot"
+)
+
+var openChannelCommand = &cli.Command{
+	Name:  "openchannel",
+	Usage: "Open a channel to a an existing peer.",
+	Description: `
+	Attempt to open a new channel to an existing peer with the key 
+	node-key.
+
+	The channel will be initialized with local-amt satoshis locally and
+	push-amt satoshis for the remote node. Note that the push-amt is
+	deducted from the specified local-amt which implies that the local-amt
+	must be greater than the push-amt. Also note that specifying push-amt
+	means you give that amount to the remote node as part of the channel
+	opening. Once the channel is open, a channelPoint (txid:vout) of the
+	funding output is returned.
+
+	If the remote peer supports the option upfront shutdown feature bit
+	(query listpeers to see their supported feature bits), an address to
+	enforce payout of funds on cooperative close can optionally be provided.
+	Note that if you set this value, you will not be able to cooperatively
+	close out to another address.
+
+	One can also specify a short string memo to record some useful
+	information about the channel using the --memo argument. This is stored
+	locally only, and is purely for reference. It has no bearing on the
+	channel's operation. Max allowed length is 500 characters.`,
+	Flags: []cli.Flag{
+		&cli.StringFlag{
+			Name: "node_key",
+			Usage: "the identity public key of the target " +
+				"node/peer serialized in compressed format",
+		},
+		&cli.IntFlag{
+			Name: "local_amt",
+			Usage: "the number of satoshis the wallet should " +
+				"commit to the channel",
+		},
+		&cli.Uint64Flag{
+			Name: "base_fee_msat",
+			Usage: "the base fee in milli-satoshis that will " +
+				"be charged for each forwarded HTLC, " +
+				"regardless of payment size",
+		},
+		&cli.Uint64Flag{
+			Name: "fee_rate_ppm",
+			Usage: "the fee rate ppm (parts per million) that " +
+				"will be charged proportionally based on the " +
+				"value of each forwarded HTLC, the lowest " +
+				"possible rate is 0 with a granularity of " +
+				"0.000001 (millionths)",
+		},
+		&cli.IntFlag{
+			Name: "push_amt",
+			Usage: "the number of satoshis to give the remote " +
+				"side as part of the initial commitment " +
+				"state, this is equivalent to first opening " +
+				"a channel and sending the remote party " +
+				"funds, but done all in one step",
+		},
+		&cli.Int64Flag{
+			Name:   "sat_per_byte",
+			Usage:  "Deprecated, use sat_per_vbyte instead.",
+			Hidden: true,
+		},
+		&cli.Int64Flag{
+			Name: "sat_per_vbyte",
+			Usage: "(optional) a manual fee expressed in " +
+				"sat/vbyte that should be used when crafting " +
+				"the transaction",
+		},
+		&cli.BoolFlag{
+			Name: "private",
+			Usage: "make the channel private, such that it won't " +
+				"be announced to the greater network, and " +
+				"nodes other than the two channel endpoints " +
+				"must be explicitly told about it to be able " +
+				"to route through it",
+		},
+		&cli.Int64Flag{
+			Name: "min_htlc_msat",
+			Usage: "(optional) the minimum value we will require " +
+				"for incoming HTLCs on the channel",
+		},
+		&cli.Uint64Flag{
+			Name: "remote_csv_delay",
+			Usage: "(optional) the number of blocks we will " +
+				"require our channel counterparty to wait " +
+				"before accessing its funds in case of " +
+				"unilateral close. If this is not set, we " +
+				"will scale the value according to the " +
+				"channel size",
+		},
+		&cli.Uint64Flag{
+			Name: "max_local_csv",
+			Usage: "(optional) the maximum number of blocks that " +
+				"we will allow the remote peer to require we " +
+				"wait before accessing our funds in the case " +
+				"of a unilateral close.",
+		},
+		&cli.StringFlag{
+			Name: "close_address",
+			Usage: "(optional) an address to enforce payout of " +
+				"our funds to on cooperative close. Note " +
+				"that if this value is set on channel open, " +
+				"you will *not* be able to cooperatively " +
+				"close to a different address.",
+		},
+		&cli.Uint64Flag{
+			Name: "remote_max_value_in_flight_msat",
+			Usage: "(optional) the maximum value in msat that " +
+				"can be pending within the channel at any " +
+				"given time",
+		},
+		&cli.StringFlag{
+			Name: "channel_type",
+			Usage: fmt.Sprintf("(optional) the type of channel to "+
+				"propose to the remote peer (%q, %q, %q)",
+				channelTypeTweakless, channelTypeAnchors,
+				channelTypeSimpleTaproot),
+		},
+		&cli.BoolFlag{
+			Name: "zero_conf",
+			Usage: "(optional) whether a zero-conf channel open " +
+				"should be attempted.",
+		},
+		&cli.BoolFlag{
+			Name: "scid_alias",
+			Usage: "(optional) whether a scid-alias channel type" +
+				" should be negotiated.",
+		},
+		&cli.Uint64Flag{
+			Name: "remote_reserve_sats",
+			Usage: "(optional) the minimum number of satoshis we " +
+				"require the remote node to keep as a direct " +
+				"payment. If not specified, a default of 1% " +
+				"of the channel capacity will be used.",
+		},
+		&cli.StringFlag{
+			Name: "memo",
+			Usage: `(optional) a note-to-self containing some useful
+				information about the channel. This is stored
+				locally only, and is purely for reference. It
+				has no bearing on the channel's operation. Max
+				allowed length is 500 characters`,
+		},
+		&cli.BoolFlag{
+			Name: "fundmax",
+			Usage: "if set, the wallet will attempt to commit " +
+				"the maximum possible local amount to the " +
+				"channel. This must not be set at the same " +
+				"time as local_amt",
+		},
+		&cli.StringSliceFlag{
+			Name: "utxo",
+			Usage: "a utxo specified as outpoint(tx:idx) which " +
+				"will be used to fund a channel. This flag " +
+				"can be repeatedly used to fund a channel " +
+				"with a selection of utxos. The selected " +
+				"funds can either be entirely spent by " +
+				"specifying the fundmax flag or partially by " +
+				"selecting a fraction of the sum of the " +
+				"outpoints in local_amt",
+		},
+	},
+	Action: openChannel,
+}
+
+func openChannel(ctx context.Context, cmd *cli.Command) error {
+	var (
+		args      = cmd.Args()
+		remaining []string
+		ctxb      = context.Background()
+		err       error
+	)
+
+	client, cleanup, err := getClient(ctx, cmd)
+	if err != nil {
+		return err
+	}
+	defer cleanup()
+
+	// Show command help if no arguments provided
+	if cmd.NArg() == 0 && cmd.NumFlags() == 0 {
+		_ = cli.ShowCommandHelp(ctx, cmd, "openchannel")
+		return nil
+	}
+
+	// Check that only the field sat_per_vbyte or the deprecated field
+	// sat_per_byte is used.
+	feeRateFlag, err := checkNotBothSet(
+		cmd, "sat_per_vbyte", "sat_per_byte",
+	)
+	if err != nil {
+		return err
+	}
+
+	minConfs := defaultUtxoMinConf
+	req := &looprpc.OpenChannelRequest{
+		SatPerVbyte:                cmd.Uint64(feeRateFlag),
+		FundMax:                    cmd.Bool("fundmax"),
+		MinHtlcMsat:                cmd.Int64("min_htlc_msat"),
+		RemoteCsvDelay:             uint32(cmd.Uint64("remote_csv_delay")),
+		MinConfs:                   int32(minConfs),
+		SpendUnconfirmed:           minConfs == 0,
+		CloseAddress:               cmd.String("close_address"),
+		RemoteMaxValueInFlightMsat: cmd.Uint64("remote_max_value_in_flight_msat"),
+		MaxLocalCsv:                uint32(cmd.Uint64("max_local_csv")),
+		ZeroConf:                   cmd.Bool("zero_conf"),
+		ScidAlias:                  cmd.Bool("scid_alias"),
+		RemoteChanReserveSat:       cmd.Uint64("remote_reserve_sats"),
+		Memo:                       cmd.String("memo"),
+	}
+
+	switch {
+	case cmd.IsSet("node_key"):
+		nodePubHex, err := hex.DecodeString(cmd.String("node_key"))
+		if err != nil {
+			return fmt.Errorf("unable to decode node public key: "+
+				"%v", err)
+		}
+		req.NodePubkey = nodePubHex
+
+	case args.Present():
+		nodePubHex, err := hex.DecodeString(args.First())
+		if err != nil {
+			return fmt.Errorf("unable to decode node public key: "+
+				"%v", err)
+		}
+		remaining = args.Tail()
+		req.NodePubkey = nodePubHex
+
+	default:
+		return fmt.Errorf("node id argument missing")
+	}
+
+	if cmd.IsSet("utxo") {
+		utxos := cmd.StringSlice("utxo")
+
+		outpoints, err := UtxosToOutpoints(utxos)
+		if err != nil {
+			return fmt.Errorf("unable to decode utxos: %w", err)
+		}
+
+		req.Outpoints = outpoints
+	}
+
+	// The fundmax flag is NOT allowed to be combined with local_amt above.
+	// It is allowed to be combined with push_amt, but only if explicitly
+	// set.
+	if cmd.Bool("fundmax") && req.LocalFundingAmount != 0 {
+		return fmt.Errorf("local amount cannot be set if attempting " +
+			"to commit the maximum amount out of the wallet")
+	}
+
+	switch {
+	case cmd.IsSet("local_amt"):
+		req.LocalFundingAmount = int64(cmd.Int("local_amt"))
+
+	case !cmd.Bool("fundmax"):
+		return fmt.Errorf("either local_amt or fundmax must be " +
+			"specified")
+	}
+
+	if cmd.IsSet("push_amt") {
+		req.PushSat = int64(cmd.Int("push_amt"))
+	} else if len(remaining) > 0 {
+		req.PushSat, err = strconv.ParseInt(remaining[0], 10, 64)
+		if err != nil {
+			return fmt.Errorf("unable to decode push amt: %w", err)
+		}
+	}
+
+	if cmd.IsSet("base_fee_msat") {
+		req.BaseFee = cmd.Uint64("base_fee_msat")
+		req.UseBaseFee = true
+	}
+
+	if cmd.IsSet("fee_rate_ppm") {
+		req.FeeRate = cmd.Uint64("fee_rate_ppm")
+		req.UseFeeRate = true
+	}
+
+	req.Private = cmd.Bool("private")
+
+	// Parse the channel type and map it to its RPC representation.
+	channelType := cmd.String("channel_type")
+	switch channelType {
+	case "":
+		break
+	case channelTypeTweakless:
+		req.CommitmentType = looprpc.CommitmentType_STATIC_REMOTE_KEY
+
+	case channelTypeAnchors:
+		req.CommitmentType = looprpc.CommitmentType_ANCHORS
+
+	case channelTypeSimpleTaproot:
+		req.CommitmentType = looprpc.CommitmentType_SIMPLE_TAPROOT
+	default:
+		return fmt.Errorf("unsupported channel type %v", channelType)
+	}
+
+	resp, err := client.StaticOpenChannel(ctxb, req)
+
+	printRespJSON(resp)
+
+	return err
+}
+
+// UtxosToOutpoints converts a slice of UTXO strings into a slice of OutPoint
+// protobuf objects. It returns an error if no UTXOs are specified or if any
+// UTXO string cannot be parsed into an OutPoint.
+func UtxosToOutpoints(utxos []string) ([]*looprpc.OutPoint, error) {
+	var outpoints []*looprpc.OutPoint
+	if len(utxos) == 0 {
+		return nil, fmt.Errorf("no utxos specified")
+	}
+	for _, utxo := range utxos {
+		outpoint, err := NewProtoOutPoint(utxo)
+		if err != nil {
+			return nil, err
+		}
+		outpoints = append(outpoints, outpoint)
+	}
+
+	return outpoints, 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.
+func checkNotBothSet(cmd *cli.Command, a, b string) (string, error) {
+	if cmd.IsSet(a) && cmd.IsSet(b) {
+		return "", fmt.Errorf(
+			"either %s or %s should be set, but not both", a, b,
+		)
+	}
+
+	if cmd.IsSet(a) {
+		return a, nil
+	}
+
+	return b, nil
+}