channeldb+lnwallet: add epoch history to OpenChannel

This commit takes the CommitChainEpochHistory defined in the last
commit and adds it to the OpenChannel structure. As of this commit
it is essentially redundant with the ChanCfgs but it will capture
the history of the ChanCfgs when we add the ability to update them.

Author: ProofOfKeags

channeldb/channel.go

@@ -260,6 +260,10 @@ type openChannelTlvData struct {
 	// customBlob is an optional TLV encoded blob of data representing
 	// custom channel funding information.
 	customBlob tlv.OptionalRecordT[tlv.TlvType7, tlv.Blob]
+
+	// commitChainEpochHistory is the optional TLV encoded blob of data
+	// representing the commit chain epoch history for the channel.
+	commitChainEpochHistory tlv.OptionalRecordT[tlv.TlvType8, CommitChainEpochHistory] //nolint:lll
 }
 
 // encode serializes the openChannelTlvData to the given io.Writer.
@@ -281,6 +285,11 @@ func (c *openChannelTlvData) encode(w io.Writer) error {
 	c.customBlob.WhenSome(func(blob tlv.RecordT[tlv.TlvType7, tlv.Blob]) {
 		tlvRecords = append(tlvRecords, blob.Record())
 	})
+	c.commitChainEpochHistory.WhenSome(
+		func(hist tlv.RecordT[tlv.TlvType8, CommitChainEpochHistory]) {
+			tlvRecords = append(tlvRecords, hist.Record())
+		},
+	)
 
 	// Create the tlv stream.
 	tlvStream, err := tlv.NewStream(tlvRecords...)
@@ -296,6 +305,7 @@ func (c *openChannelTlvData) decode(r io.Reader) error {
 	memo := c.memo.Zero()
 	tapscriptRoot := c.tapscriptRoot.Zero()
 	blob := c.customBlob.Zero()
+	commitChainEpochHistory := c.commitChainEpochHistory.Zero()
 
 	// Create the tlv stream.
 	tlvStream, err := tlv.NewStream(
@@ -306,6 +316,7 @@ func (c *openChannelTlvData) decode(r io.Reader) error {
 		memo.Record(),
 		tapscriptRoot.Record(),
 		blob.Record(),
+		commitChainEpochHistory.Record(),
 	)
 	if err != nil {
 		return err
@@ -325,6 +336,10 @@ func (c *openChannelTlvData) decode(r io.Reader) error {
 	if _, ok := tlvs[c.customBlob.TlvType()]; ok {
 		c.customBlob = tlv.SomeRecordT(blob)
 	}
+	if _, ok := tlvs[c.commitChainEpochHistory.TlvType()]; ok {
+		c.commitChainEpochHistory =
+			tlv.SomeRecordT(commitChainEpochHistory)
+	}
 
 	return nil
 }
@@ -947,6 +962,10 @@ type OpenChannel struct {
 	// commitment.
 	Commitments lntypes.Dual[ChannelCommitment]
 
+	// CommitChainEpochHistory is the history of the CommitmentParams for
+	// each side of the channel.
+	CommitChainEpochHistory CommitChainEpochHistory
+
 	// RemoteCurrentRevocation is the current revocation for their
 	// commitment transaction. However, since this the derived public key,
 	// we don't yet have the private key so we aren't yet able to verify
@@ -1207,6 +1226,11 @@ func (c *OpenChannel) amendTlvData(auxData openChannelTlvData) {
 	auxData.customBlob.WhenSomeV(func(blob tlv.Blob) {
 		c.CustomBlob = fn.Some(blob)
 	})
+	auxData.commitChainEpochHistory.WhenSomeV(
+		func(history CommitChainEpochHistory) {
+			c.CommitChainEpochHistory = history
+		},
+	)
 }
 
 // extractTlvData creates a new openChannelTlvData from the given channel.
@@ -1224,6 +1248,11 @@ func (c *OpenChannel) extractTlvData() openChannelTlvData {
 		realScid: tlv.NewRecordT[tlv.TlvType4](
 			c.confirmedScid,
 		),
+		commitChainEpochHistory: tlv.SomeRecordT(
+			tlv.NewRecordT[tlv.TlvType8](
+				c.CommitChainEpochHistory,
+			),
+		),
 	}
 
 	if len(c.Memo) != 0 {
@@ -4508,6 +4537,22 @@ func fetchChanInfo(chanBucket kvdb.RBucket, channel *OpenChannel) error {
 	// open channel.
 	channel.amendTlvData(auxData)
 
+	// Now that we've extracted the aux data, we can initialize the
+	// CommitChainEpochHistory. If we don't find it in the aux data,
+	// then we initialize it with the original CommitmentParams from
+	// the ChannelConfig.
+	histVal := auxData.commitChainEpochHistory.ValOpt()
+	channel.CommitChainEpochHistory = histVal.UnwrapOr(
+		BeginChainEpochHistory(
+			lntypes.MapDual(
+				channel.ChanCfgs,
+				func(cfg ChannelConfig) CommitmentParams {
+					return cfg.CommitmentParams
+				},
+			),
+		),
+	)
+
 	channel.Packager = NewChannelPackager(channel.ShortChannelID)
 
 	// Finally, read the optional shutdown scripts.

channeldb/channel_test.go

@@ -343,6 +343,12 @@ func createTestChannelState(t *testing.T, cdb *ChannelStateDB) *OpenChannel {
 			Local:  localCfg,
 			Remote: remoteCfg,
 		},
+		CommitChainEpochHistory: BeginChainEpochHistory(
+			lntypes.Dual[CommitmentParams]{
+				Local:  localRenderingParams,
+				Remote: remoteRenderingParams,
+			},
+		),
 		TotalMSatSent:     8,
 		TotalMSatReceived: 2,
 		Commitments: lntypes.Dual[ChannelCommitment]{

lnwallet/channel.go

@@ -7712,6 +7712,7 @@ func (lc *LightningChannel) ForceClose() (*LocalForceCloseSummary, error) {
 
 	return summary, nil
 }
+
 // NewLocalForceCloseSummary generates a LocalForceCloseSummary from the given
 // channel state.  The passed commitTx must be a fully signed commitment
 // transaction corresponding to localCommit.

lnwallet/test_utils.go

@@ -321,6 +321,12 @@ func CreateTestChannels(t *testing.T, chanType channeldb.ChannelType,
 			Local:  aliceCfg,
 			Remote: bobCfg,
 		},
+		CommitChainEpochHistory: channeldb.BeginChainEpochHistory(
+			lntypes.Dual[channeldb.CommitmentParams]{
+				Local:  aliceCfg.CommitmentParams,
+				Remote: bobCfg.CommitmentParams,
+			},
+		),
 		IdentityPub:             aliceKeys[0].PubKey(),
 		FundingOutpoint:         *prevOut,
 		ShortChannelID:          shortChanID,
@@ -343,6 +349,12 @@ func CreateTestChannels(t *testing.T, chanType channeldb.ChannelType,
 			Local:  bobCfg,
 			Remote: aliceCfg,
 		},
+		CommitChainEpochHistory: channeldb.BeginChainEpochHistory(
+			lntypes.Dual[channeldb.CommitmentParams]{
+				Local:  bobCfg.CommitmentParams,
+				Remote: aliceCfg.CommitmentParams,
+			},
+		),
 		IdentityPub:             bobKeys[0].PubKey(),
 		FundingOutpoint:         *prevOut,
 		ShortChannelID:          shortChanID,

lnwallet/wallet.go

@@ -2321,6 +2321,16 @@ func (l *LightningWallet) handleFundingCounterPartySigs(msg *addCounterPartySigs
 	// he stored within the database.
 	res.partialState.ChanCfgs.Local = res.ourContribution.toChanConfig()
 	res.partialState.ChanCfgs.Remote = res.theirContribution.toChanConfig()
+	res.partialState.CommitChainEpochHistory =
+		channeldb.BeginChainEpochHistory(
+			lntypes.MapDual(
+				res.partialState.ChanCfgs,
+				//nolint:lll
+				func(cfg channeldb.ChannelConfig) channeldb.CommitmentParams {
+					return cfg.CommitmentParams
+				},
+			),
+		)
 
 	// We'll also record the finalized funding txn, which will allow us to
 	// rebroadcast on startup in case we fail.
@@ -2532,6 +2542,16 @@ func (l *LightningWallet) handleSingleFunderSigs(req *addSingleFunderSigsMsg) {
 		pendingReservation.ourContribution.toChanConfig()
 	chanState.ChanCfgs.Remote =
 		pendingReservation.theirContribution.toChanConfig()
+	chanState.CommitChainEpochHistory =
+		channeldb.BeginChainEpochHistory(
+			lntypes.MapDual(
+				chanState.ChanCfgs,
+				//nolint:lll
+				func(cfg channeldb.ChannelConfig) channeldb.CommitmentParams {
+					return cfg.CommitmentParams
+				},
+			),
+		)
 
 	chanState.RevocationKeyLocator = pendingReservation.nextRevocationKeyLoc