lnwallet: make CreateCloseProposal take absolute fee instead of fee rate

lnwallet/channel.go

@@ -3671,14 +3671,14 @@ func (lc *LightningChannel) ForceClose() (*ForceCloseSummary, error) {
 //
 // TODO(roasbeef): caller should initiate signal to reject all incoming HTLCs,
 // settle any in flight.
-func (lc *LightningChannel) CreateCloseProposal(feeRate uint64,
+func (lc *LightningChannel) CreateCloseProposal(proposedFee uint64,
 	localDeliveryScript, remoteDeliveryScript []byte) ([]byte, uint64, error) {
 
 	lc.Lock()
 	defer lc.Unlock()
 
-	// If we're already closing the channel, then ignore this request.
+	// If we've already closed the channel, then ignore this request.
-	if lc.status == channelClosing || lc.status == channelClosed {
+	if lc.status == channelClosed {
 		// TODO(roasbeef): check to ensure no pending payments
 		return nil, 0, ErrChanClosing
 	}
@@ -3686,7 +3686,6 @@ func (lc *LightningChannel) CreateCloseProposal(feeRate uint64,
 	// Subtract the proposed fee from the appropriate balance, taking care
 	// not to persist the adjusted balance, as the feeRate may change
 	// during the channel closing process.
-	proposedFee := (feeRate * uint64(commitWeight)) / 1000
 	ourBalance := lc.channelState.LocalBalance
 	theirBalance := lc.channelState.RemoteBalance
 
@@ -3734,7 +3733,7 @@ func (lc *LightningChannel) CreateCloseProposal(feeRate uint64,
 // signatures including the proper sighash byte.
 func (lc *LightningChannel) CompleteCooperativeClose(localSig, remoteSig,
 	localDeliveryScript, remoteDeliveryScript []byte,
-	feeRate uint64) (*wire.MsgTx, error) {
+	proposedFee uint64) (*wire.MsgTx, error) {
 
 	lc.Lock()
 	defer lc.Unlock()
@@ -3748,7 +3747,6 @@ func (lc *LightningChannel) CompleteCooperativeClose(localSig, remoteSig,
 	// Subtract the proposed fee from the appropriate balance, taking care
 	// not to persist the adjusted balance, as the feeRate may change
 	// during the channel closing process.
-	proposedFee := (feeRate * uint64(commitWeight)) / 1000
 	ourBalance := lc.channelState.LocalBalance
 	theirBalance := lc.channelState.RemoteBalance
 
@@ -3947,3 +3945,9 @@ func CreateCooperativeCloseTx(fundingTxIn *wire.TxIn,
 
 	return closeTx
 }
+
+// CalcFee returns the commitment fee to use for the given
+// fee rate (fee-per-kw).
+func (lc *LightningChannel) CalcFee(feeRate uint64) uint64 {
+	return (feeRate * uint64(commitWeight)) / 1000
+}

lnwallet/channel_test.go

@@ -737,17 +737,19 @@ func TestCooperativeChannelClosure(t *testing.T) {
 	bobFeeRate := uint64(bobChannel.channelState.FeePerKw)
 
 	// We'll store with both Alice and Bob creating a new close proposal
-	// with the same fee rate.
+	// with the same fee.
+	aliceFee := aliceChannel.CalcFee(aliceFeeRate)
 	aliceSig, _, err := aliceChannel.CreateCloseProposal(
-		aliceFeeRate, aliceDeliveryScript, bobDeliveryScript,
+		aliceFee, aliceDeliveryScript, bobDeliveryScript,
 	)
 	if err != nil {
 		t.Fatalf("unable to create alice coop close proposal: %v", err)
 	}
 	aliceCloseSig := append(aliceSig, byte(txscript.SigHashAll))
 
+	bobFee := bobChannel.CalcFee(bobFeeRate)
 	bobSig, _, err := bobChannel.CreateCloseProposal(
-		bobFeeRate, bobDeliveryScript, aliceDeliveryScript,
+		bobFee, bobDeliveryScript, aliceDeliveryScript,
 	)
 	if err != nil {
 		t.Fatalf("unable to create bob coop close proposal: %v", err)
@@ -759,7 +761,7 @@ func TestCooperativeChannelClosure(t *testing.T) {
 	// transaction is well formed, and the signatures verify.
 	aliceCloseTx, err := bobChannel.CompleteCooperativeClose(
 		bobCloseSig, aliceCloseSig, bobDeliveryScript,
-		aliceDeliveryScript, bobFeeRate)
+		aliceDeliveryScript, bobFee)
 	if err != nil {
 		t.Fatalf("unable to complete alice cooperative close: %v", err)
 	}
@@ -767,7 +769,7 @@ func TestCooperativeChannelClosure(t *testing.T) {
 
 	bobCloseTx, err := aliceChannel.CompleteCooperativeClose(
 		aliceCloseSig, bobCloseSig, aliceDeliveryScript,
-		bobDeliveryScript, aliceFeeRate)
+		bobDeliveryScript, aliceFee)
 	if err != nil {
 		t.Fatalf("unable to complete bob cooperative close: %v", err)
 	}
@@ -1590,14 +1592,16 @@ func TestCooperativeCloseDustAdherence(t *testing.T) {
 	// Both sides currently have over 1 BTC settled as part of their
 	// balances. As a result, performing a cooperative closure now result
 	// in both sides having an output within the closure transaction.
-	aliceSig, _, err := aliceChannel.CreateCloseProposal(aliceFeeRate,
+	aliceFee := aliceChannel.CalcFee(aliceFeeRate)
+	aliceSig, _, err := aliceChannel.CreateCloseProposal(aliceFee,
 		aliceDeliveryScript, bobDeliveryScript)
 	if err != nil {
 		t.Fatalf("unable to close channel: %v", err)
 	}
 	aliceCloseSig := append(aliceSig, byte(txscript.SigHashAll))
 
-	bobSig, _, err := bobChannel.CreateCloseProposal(bobFeeRate,
+	bobFee := bobChannel.CalcFee(bobFeeRate)
+	bobSig, _, err := bobChannel.CreateCloseProposal(bobFee,
 		bobDeliveryScript, aliceDeliveryScript)
 	if err != nil {
 		t.Fatalf("unable to close channel: %v", err)
@@ -1606,7 +1610,7 @@ func TestCooperativeCloseDustAdherence(t *testing.T) {
 
 	closeTx, err := bobChannel.CompleteCooperativeClose(
 		bobCloseSig, aliceCloseSig,
-		bobDeliveryScript, aliceDeliveryScript, bobFeeRate)
+		bobDeliveryScript, aliceDeliveryScript, bobFee)
 	if err != nil {
 		t.Fatalf("unable to accept channel close: %v", err)
 	}
@@ -1628,14 +1632,14 @@ func TestCooperativeCloseDustAdherence(t *testing.T) {
 
 	// Attempt another cooperative channel closure. It should succeed
 	// without any issues.
-	aliceSig, _, err = aliceChannel.CreateCloseProposal(aliceFeeRate,
+	aliceSig, _, err = aliceChannel.CreateCloseProposal(aliceFee,
 		aliceDeliveryScript, bobDeliveryScript)
 	if err != nil {
 		t.Fatalf("unable to close channel: %v", err)
 	}
 	aliceCloseSig = append(aliceSig, byte(txscript.SigHashAll))
 
-	bobSig, _, err = bobChannel.CreateCloseProposal(bobFeeRate,
+	bobSig, _, err = bobChannel.CreateCloseProposal(bobFee,
 		bobDeliveryScript, aliceDeliveryScript)
 	if err != nil {
 		t.Fatalf("unable to close channel: %v", err)
@@ -1644,7 +1648,7 @@ func TestCooperativeCloseDustAdherence(t *testing.T) {
 
 	closeTx, err = bobChannel.CompleteCooperativeClose(
 		bobCloseSig, aliceCloseSig,
-		bobDeliveryScript, aliceDeliveryScript, bobFeeRate)
+		bobDeliveryScript, aliceDeliveryScript, bobFee)
 	if err != nil {
 		t.Fatalf("unable to accept channel close: %v", err)
 	}
@@ -1667,14 +1671,14 @@ func TestCooperativeCloseDustAdherence(t *testing.T) {
 
 	// Our final attempt at another cooperative channel closure. It should
 	// succeed without any issues.
-	aliceSig, _, err = aliceChannel.CreateCloseProposal(aliceFeeRate,
+	aliceSig, _, err = aliceChannel.CreateCloseProposal(aliceFee,
 		aliceDeliveryScript, bobDeliveryScript)
 	if err != nil {
 		t.Fatalf("unable to close channel: %v", err)
 	}
 	aliceCloseSig = append(aliceSig, byte(txscript.SigHashAll))
 
-	bobSig, _, err = bobChannel.CreateCloseProposal(bobFeeRate,
+	bobSig, _, err = bobChannel.CreateCloseProposal(bobFee,
 		bobDeliveryScript, aliceDeliveryScript)
 	if err != nil {
 		t.Fatalf("unable to close channel: %v", err)
@@ -1683,7 +1687,7 @@ func TestCooperativeCloseDustAdherence(t *testing.T) {
 
 	closeTx, err = bobChannel.CompleteCooperativeClose(
 		bobCloseSig, aliceCloseSig,
-		bobDeliveryScript, aliceDeliveryScript, bobFeeRate)
+		bobDeliveryScript, aliceDeliveryScript, bobFee)
 	if err != nil {
 		t.Fatalf("unable to accept channel close: %v", err)
 	}