Merge pull request #3702 from carlaKC/lnrpc-addcloseaddress

Add optional close address

chancloser.go

@@ -28,10 +28,10 @@ var (
 	// a message while it is in an unknown state.
 	ErrInvalidState = fmt.Errorf("invalid state")
 
-	// errUpfrontShutdownScriptMismatch is returned when our peer sends us a
-	// shutdown message with a script that does not match the upfront shutdown
-	// script previously set.
-	errUpfrontShutdownScriptMismatch = fmt.Errorf("peer's shutdown " +
+	// errUpfrontShutdownScriptMismatch is returned when a peer or end user
+	// provides a script to cooperatively close out to which does not match
+	// the upfront shutdown script previously set for that party.
+	errUpfrontShutdownScriptMismatch = fmt.Errorf("shutdown " +
 		"script does not match upfront shutdown script")
 )
 

cmd/lncli/commands.go

@@ -835,11 +835,16 @@ var closeChannelCommand = cli.Command{
 	transaction will be broadcast to the network. As a result, any settled
 	funds will be time locked for a few blocks before they can be spent.
 
-	In the case of a cooperative closure, One can manually set the fee to
+	In the case of a cooperative closure, one can manually set the fee to
 	be used for the closing transaction via either the --conf_target or
 	--sat_per_byte arguments. This will be the starting value used during
 	fee negotiation. This is optional.
 
+	In the case of a cooperative closure, one can manually set the address
+	to deliver funds to upon closure. This is optional, and may only be used
+	if an upfront shutdown address has not already been set. If neither are
+	set the funds will be delivered to a new wallet address.
+
 	To view which funding_txids/output_indexes can be used for a channel close,
 	see the channel_point values within the listchannels command output.
 	The format for a channel_point is 'funding_txid:output_index'.`,
@@ -874,6 +879,13 @@ var closeChannelCommand = cli.Command{
 				"sat/byte that should be used when crafting " +
 				"the transaction",
 		},
+		cli.StringFlag{
+			Name: "delivery_addr",
+			Usage: "(optional) an address to deliver funds " +
+				"upon cooperative channel closing, may only " +
+				"be used if an upfront shutdown addresss is not" +
+				"already set",
+		},
 	},
 	Action: actionDecorator(closeChannel),
 }
@@ -895,10 +907,11 @@ func closeChannel(ctx *cli.Context) error {
 
 	// TODO(roasbeef): implement time deadline within server
 	req := &lnrpc.CloseChannelRequest{
-		ChannelPoint: channelPoint,
-		Force:        ctx.Bool("force"),
-		TargetConf:   int32(ctx.Int64("conf_target")),
-		SatPerByte:   ctx.Int64("sat_per_byte"),
+		ChannelPoint:    channelPoint,
+		Force:           ctx.Bool("force"),
+		TargetConf:      int32(ctx.Int64("conf_target")),
+		SatPerByte:      ctx.Int64("sat_per_byte"),
+		DeliveryAddress: ctx.String("delivery_addr"),
 	}
 
 	// After parsing the request, we'll spin up a goroutine that will

htlcswitch/switch.go

@@ -105,6 +105,9 @@ type ChanClose struct {
 	// process for the cooperative closure transaction kicks off.
 	TargetFeePerKw chainfee.SatPerKWeight
 
+	// DeliveryScript is an optional delivery script to pay funds out to.
+	DeliveryScript lnwire.DeliveryAddress
+
 	// Updates is used by request creator to receive the notifications about
 	// execution of the close channel request.
 	Updates chan interface{}
@@ -1365,12 +1368,13 @@ func (s *Switch) teardownCircuit(pkt *htlcPacket) error {
 }
 
 // CloseLink creates and sends the close channel command to the target link
-// directing the specified closure type. If the closure type if CloseRegular,
-// then the last parameter should be the ideal fee-per-kw that will be used as
-// a starting point for close negotiation.
-func (s *Switch) CloseLink(chanPoint *wire.OutPoint, closeType ChannelCloseType,
-	targetFeePerKw chainfee.SatPerKWeight) (chan interface{},
-	chan error) {
+// directing the specified closure type. If the closure type is CloseRegular,
+// targetFeePerKw parameter should be the ideal fee-per-kw that will be used as
+// a starting point for close negotiation. The deliveryScript parameter is an
+// optional parameter which sets a user specified script to close out to.
+func (s *Switch) CloseLink(chanPoint *wire.OutPoint,
+	closeType ChannelCloseType, targetFeePerKw chainfee.SatPerKWeight,
+	deliveryScript lnwire.DeliveryAddress) (chan interface{}, chan error) {
 
 	// TODO(roasbeef) abstract out the close updates.
 	updateChan := make(chan interface{}, 2)
@@ -1381,6 +1385,7 @@ func (s *Switch) CloseLink(chanPoint *wire.OutPoint, closeType ChannelCloseType,
 		ChanPoint:      chanPoint,
 		Updates:        updateChan,
 		TargetFeePerKw: targetFeePerKw,
+		DeliveryScript: deliveryScript,
 		Err:            errChan,
 	}