lnwallet+funding: create CommitmentType enum

fundingmanager.go

@@ -1106,6 +1106,28 @@ func (f *fundingManager) processFundingOpen(msg *lnwire.OpenChannel,
 	}
 }
 
+// commitmentType returns the commitment type to use for the channel, based on
+// the features the two peers have available.
+func commitmentType(localFeatures,
+	remoteFeatures *lnwire.FeatureVector) lnwallet.CommitmentType {
+
+	localTweakless := localFeatures.HasFeature(
+		lnwire.StaticRemoteKeyOptional,
+	)
+	remoteTweakless := remoteFeatures.HasFeature(
+		lnwire.StaticRemoteKeyOptional,
+	)
+
+	// If both nodes are signaling the proper feature bit for tweakless
+	// copmmitments, we'll use that.
+	if localTweakless && remoteTweakless {
+		return lnwallet.CommitmentTypeTweakless
+	}
+
+	// Otherwise we'll fall back to the legacy type.
+	return lnwallet.CommitmentTypeLegacy
+}
+
 // handleFundingOpen creates an initial 'ChannelReservation' within the wallet,
 // then responds to the source peer with an accept channel message progressing
 // the funding workflow.
@@ -1228,13 +1250,9 @@ func (f *fundingManager) handleFundingOpen(fmsg *fundingOpenMsg) {
 	// negotiated the new tweakless commitment format. This is only the
 	// case if *both* us and the remote peer are signaling the proper
 	// feature bit.
-	localTweakless := fmsg.peer.LocalFeatures().HasFeature(
-		lnwire.StaticRemoteKeyOptional,
+	commitType := commitmentType(
+		fmsg.peer.LocalFeatures(), fmsg.peer.RemoteFeatures(),
 	)
-	remoteTweakless := fmsg.peer.RemoteFeatures().HasFeature(
-		lnwire.StaticRemoteKeyOptional,
-	)
-	tweaklessCommitment := localTweakless && remoteTweakless
 	chainHash := chainhash.Hash(msg.ChainHash)
 	req := &lnwallet.InitFundingReserveMsg{
 		ChainHash:        &chainHash,
@@ -1248,7 +1266,7 @@ func (f *fundingManager) handleFundingOpen(fmsg *fundingOpenMsg) {
 		PushMSat:         msg.PushAmount,
 		Flags:            msg.ChannelFlags,
 		MinConfs:         1,
-		Tweakless:        tweaklessCommitment,
+		CommitType:       commitType,
 	}
 
 	reservation, err := f.cfg.Wallet.InitChannelReservation(req)
@@ -1307,9 +1325,9 @@ func (f *fundingManager) handleFundingOpen(fmsg *fundingOpenMsg) {
 	reservation.SetOurUpfrontShutdown(shutdown)
 
 	fndgLog.Infof("Requiring %v confirmations for pendingChan(%x): "+
-		"amt=%v, push_amt=%v, tweakless=%v, upfrontShutdown=%x", numConfsReq,
+		"amt=%v, push_amt=%v, committype=%v, upfrontShutdown=%x", numConfsReq,
 		fmsg.msg.PendingChannelID, amt, msg.PushAmount,
-		tweaklessCommitment, msg.UpfrontShutdownScript)
+		commitType, msg.UpfrontShutdownScript)
 
 	// Generate our required constraints for the remote party.
 	remoteCsvDelay := f.cfg.RequiredRemoteDelay(amt)
@@ -2904,13 +2922,9 @@ func (f *fundingManager) handleInitFundingMsg(msg *initFundingMsg) {
 	// negotiated the new tweakless commitment format. This is only the
 	// case if *both* us and the remote peer are signaling the proper
 	// feature bit.
-	localTweakless := msg.peer.LocalFeatures().HasFeature(
-		lnwire.StaticRemoteKeyOptional,
+	commitType := commitmentType(
+		msg.peer.LocalFeatures(), msg.peer.RemoteFeatures(),
 	)
-	remoteTweakless := msg.peer.RemoteFeatures().HasFeature(
-		lnwire.StaticRemoteKeyOptional,
-	)
-	tweaklessCommitment := localTweakless && remoteTweakless
 	req := &lnwallet.InitFundingReserveMsg{
 		ChainHash:        &msg.chainHash,
 		PendingChanID:    chanID,
@@ -2924,7 +2938,7 @@ func (f *fundingManager) handleInitFundingMsg(msg *initFundingMsg) {
 		PushMSat:         msg.pushAmt,
 		Flags:            channelFlags,
 		MinConfs:         msg.minConfs,
-		Tweakless:        tweaklessCommitment,
+		CommitType:       commitType,
 		ChanFunder:       msg.chanFunder,
 	}
 
@@ -3012,7 +3026,7 @@ func (f *fundingManager) handleInitFundingMsg(msg *initFundingMsg) {
 	maxHtlcs := f.cfg.RequiredRemoteMaxHTLCs(capacity)
 
 	fndgLog.Infof("Starting funding workflow with %v for pending_id(%x), "+
-		"tweakless=%v", msg.peer.Address(), chanID, tweaklessCommitment)
+		"committype=%v", msg.peer.Address(), chanID, commitType)
 
 	fundingOpen := lnwire.OpenChannel{
 		ChainHash:             *f.cfg.Wallet.Cfg.NetParams.GenesisHash,

lnwallet/interface_test.go

@@ -700,7 +700,8 @@ func testCancelNonExistentReservation(miner *rpctest.Harness,
 	// Create our own reservation, give it some ID.
 	res, err := lnwallet.NewChannelReservation(
 		10000, 10000, feePerKw, alice, 22, 10, &testHdSeed,
-		lnwire.FFAnnounceChannel, true, nil, [32]byte{},
+		lnwire.FFAnnounceChannel, lnwallet.CommitmentTypeTweakless,
+		nil, [32]byte{},
 	)
 	if err != nil {
 		t.Fatalf("unable to create res: %v", err)
@@ -738,7 +739,7 @@ func testReservationInitiatorBalanceBelowDustCancel(miner *rpctest.Harness,
 		FundingFeePerKw:  1000,
 		PushMSat:         0,
 		Flags:            lnwire.FFAnnounceChannel,
-		Tweakless:        true,
+		CommitType:       lnwallet.CommitmentTypeTweakless,
 	}
 	_, err = alice.InitChannelReservation(req)
 	switch {
@@ -793,7 +794,8 @@ func assertContributionInitPopulated(t *testing.T, c *lnwallet.ChannelContributi
 }
 
 func testSingleFunderReservationWorkflow(miner *rpctest.Harness,
-	alice, bob *lnwallet.LightningWallet, t *testing.T, tweakless bool,
+	alice, bob *lnwallet.LightningWallet, t *testing.T,
+	commitType lnwallet.CommitmentType,
 	aliceChanFunder chanfunding.Assembler,
 	fetchFundingTx func() *wire.MsgTx, pendingChanID [32]byte) {
 
@@ -823,7 +825,7 @@ func testSingleFunderReservationWorkflow(miner *rpctest.Harness,
 		FundingFeePerKw:  feePerKw,
 		PushMSat:         pushAmt,
 		Flags:            lnwire.FFAnnounceChannel,
-		Tweakless:        tweakless,
+		CommitType:       commitType,
 		ChanFunder:       aliceChanFunder,
 	}
 	aliceChanReservation, err := alice.InitChannelReservation(aliceReq)
@@ -874,7 +876,7 @@ func testSingleFunderReservationWorkflow(miner *rpctest.Harness,
 		FundingFeePerKw:  feePerKw,
 		PushMSat:         pushAmt,
 		Flags:            lnwire.FFAnnounceChannel,
-		Tweakless:        tweakless,
+		CommitType:       commitType,
 	}
 	bobChanReservation, err := bob.InitChannelReservation(bobReq)
 	if err != nil {
@@ -2543,7 +2545,8 @@ var walletTests = []walletTestCase{
 			bob *lnwallet.LightningWallet, t *testing.T) {
 
 			testSingleFunderReservationWorkflow(
-				miner, alice, bob, t, false, nil, nil,
+				miner, alice, bob, t,
+				lnwallet.CommitmentTypeLegacy, nil, nil,
 				[32]byte{},
 			)
 		},
@@ -2554,7 +2557,8 @@ var walletTests = []walletTestCase{
 			bob *lnwallet.LightningWallet, t *testing.T) {
 
 			testSingleFunderReservationWorkflow(
-				miner, alice, bob, t, true, nil, nil,
+				miner, alice, bob, t,
+				lnwallet.CommitmentTypeTweakless, nil, nil,
 				[32]byte{},
 			)
 		},
@@ -2809,8 +2813,8 @@ func testSingleFunderExternalFundingTx(miner *rpctest.Harness,
 	// pending channel ID generated above to allow Alice and Bob to track
 	// the funding flow externally.
 	testSingleFunderReservationWorkflow(
-		miner, alice, bob, t, true, aliceExternalFunder,
-		func() *wire.MsgTx {
+		miner, alice, bob, t, lnwallet.CommitmentTypeTweakless,
+		aliceExternalFunder, func() *wire.MsgTx {
 			return fundingTx
 		}, pendingChanID,
 	)

lnwallet/reservation.go

@@ -15,6 +15,32 @@ import (
 	"github.com/lightningnetwork/lnd/lnwire"
 )
 
+// CommitmentType is an enum indicating the commitment type we should use for
+// the channel we are opening.
+type CommitmentType int
+
+const (
+	// CommitmentTypeLegacy is the legacy commitment format with a tweaked
+	// to_remote key.
+	CommitmentTypeLegacy = iota
+
+	// CommitmentTypeTweakless is a newer commitment format where the
+	// to_remote key is static.
+	CommitmentTypeTweakless
+)
+
+// String returns the name of the CommitmentType.
+func (c CommitmentType) String() string {
+	switch c {
+	case CommitmentTypeLegacy:
+		return "legacy"
+	case CommitmentTypeTweakless:
+		return "tweakless"
+	default:
+		return "invalid"
+	}
+}
+
 // ChannelContribution is the primary constituent of the funding workflow
 // within lnwallet. Each side first exchanges their respective contributions
 // along with channel specific parameters like the min fee/KB. Once
@@ -136,7 +162,7 @@ type ChannelReservation struct {
 func NewChannelReservation(capacity, localFundingAmt btcutil.Amount,
 	commitFeePerKw chainfee.SatPerKWeight, wallet *LightningWallet,
 	id uint64, pushMSat lnwire.MilliSatoshi, chainHash *chainhash.Hash,
-	flags lnwire.FundingFlag, tweaklessCommit bool,
+	flags lnwire.FundingFlag, commitType CommitmentType,
 	fundingAssembler chanfunding.Assembler,
 	pendingChanID [32]byte) (*ChannelReservation, error) {
 
@@ -231,7 +257,7 @@ func NewChannelReservation(capacity, localFundingAmt btcutil.Amount,
 	// non-zero push amt (there's no pushing for dual funder), then this is
 	// a single-funder channel.
 	if ourBalance == 0 || theirBalance == 0 || pushMSat != 0 {
-		if tweaklessCommit {
+		if commitType == CommitmentTypeTweakless {
 			chanType |= channeldb.SingleFunderTweaklessBit
 		} else {
 			chanType |= channeldb.SingleFunderBit

lnwallet/wallet.go

@@ -98,9 +98,9 @@ type InitFundingReserveMsg struct {
 	// output selected to fund the channel should satisfy.
 	MinConfs int32
 
-	// Tweakless indicates if the channel should use the new tweakless
-	// commitment format or not.
-	Tweakless bool
+	// CommitType indicates what type of commitment type the channel should
+	// be using, like tweakless or anchors.
+	CommitType CommitmentType
 
 	// ChanFunder is an optional channel funder that allows the caller to
 	// control exactly how the channel funding is carried out. If not
@@ -568,7 +568,7 @@ func (l *LightningWallet) handleFundingReserveRequest(req *InitFundingReserveMsg
 	reservation, err := NewChannelReservation(
 		capacity, localFundingAmt, req.CommitFeePerKw, l, id,
 		req.PushMSat, l.Cfg.NetParams.GenesisHash, req.Flags,
-		req.Tweakless, req.ChanFunder, req.PendingChanID,
+		req.CommitType, req.ChanFunder, req.PendingChanID,
 	)
 	if err != nil {
 		if fundingIntent != nil {