funding: fund channel with selected utxos

cmd/lncli/cmd_open_channel.go

@@ -122,6 +122,17 @@ var openChannelCommand = cli.Command{
 				"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",
+		},
 		cli.Uint64Flag{
 			Name: "base_fee_msat",
 			Usage: "the base fee in milli-satoshis that will " +
@@ -391,6 +402,17 @@ func openChannel(ctx *cli.Context) error {
 			"to commit the maximum amount out of the wallet")
 	}
 
+	if ctx.IsSet("utxo") {
+		utxos := ctx.StringSlice("utxo")
+
+		outpoints, err := utxosToOutpoints(utxos)
+		if err != nil {
+			return fmt.Errorf("unable to decode utxos: %w", err)
+		}
+
+		req.Outpoints = outpoints
+	}
+
 	if ctx.IsSet("push_amt") {
 		req.PushSat = int64(ctx.Int("push_amt"))
 	} else if args.Present() {
@@ -1109,3 +1131,21 @@ func decodePsbt(psbt string) ([]byte, error) {
 		return nil, fmt.Errorf("not a PSBT")
 	}
 }
+
+// parseUtxos parses a comma separated list of utxos into outpoints that are
+// passed to the server.
+func utxosToOutpoints(utxos []string) ([]*lnrpc.OutPoint, error) {
+	var outpoints []*lnrpc.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
+}

docs/release-notes/release-notes-0.17.0.md

@@ -109,6 +109,10 @@ on the old value of 10000](https://github.com/lightningnetwork/lnd/pull/7780).
   key scopes. The non-deterministic behaviours linked to this case are fixed,
   and users can no longer create two custom accounts with the same name.
 
+* `OpenChannel` adds a new `utxo` flag that allows the specification of multiple
+  UTXOs [as a basis for funding a channel 
+  opening.](https://github.com/lightningnetwork/lnd/pull/7516)
+
 ## Misc
 
 * [Generate default macaroons

funding/manager.go

@@ -276,6 +276,13 @@ type InitFundingMsg struct {
 	// minimum amount to commit to.
 	MinFundAmt btcutil.Amount
 
+	// Outpoints is a list of client-selected outpoints that should be used
+	// for funding a channel. If LocalFundingAmt is specified then this
+	// amount is allocated from the sum of outpoints towards funding. If
+	// the FundUpToMaxAmt is specified the entirety of selected funds is
+	// allocated towards channel funding.
+	Outpoints []wire.OutPoint
+
 	// ChanFunder is an optional channel funder that allows the caller to
 	// control exactly how the channel funding is carried out. If not
 	// specified, then the default chanfunding.WalletAssembler will be
@@ -3973,6 +3980,7 @@ func (f *Manager) handleInitFundingMsg(msg *InitFundingMsg) {
 		maxHtlcs       = msg.MaxHtlcs
 		maxCSV         = msg.MaxLocalCsv
 		chanReserve    = msg.RemoteChanReserve
+		outpoints      = msg.Outpoints
 	)
 
 	// If no maximum CSV delay was set for this channel, we use our default
@@ -4101,6 +4109,7 @@ func (f *Manager) handleInitFundingMsg(msg *InitFundingMsg) {
 		FundUpToMaxAmt:    msg.FundUpToMaxAmt,
 		MinFundAmt:        msg.MinFundAmt,
 		RemoteChanReserve: chanReserve,
+		Outpoints:         outpoints,
 		CommitFeePerKw:    commitFeePerKw,
 		FundingFeePerKw:   msg.FundingFeePerKw,
 		PushMSat:          msg.PushAmt,

itest/list_on_test.go

@@ -542,4 +542,8 @@ var allTestCases = []*lntest.TestCase{
 		Name:     "custom features",
 		TestFunc: testCustomFeatures,
 	},
+	{
+		Name:     "utxo selection funding",
+		TestFunc: testChannelUtxoSelection,
+	},
 }