multi: add tapscript root to chan ann (temp)

Needed so the router can validate the musig2 output w/ a custom tweak.

channeldb/models/channel_edge_info.go

@@ -8,6 +8,7 @@ import (
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
+	"github.com/lightningnetwork/lnd/fn"
 )
 
 // ChannelEdgeInfo represents a fully authenticated channel along with all its
@@ -62,6 +63,8 @@ type ChannelEdgeInfo struct {
 	// the value output in the outpoint that created this channel.
 	Capacity btcutil.Amount
 
+	TapscriptRoot fn.Option[chainhash.Hash]
+
 	// ExtraOpaqueData is the set of data that was appended to this
 	// message, some of which we may not actually know how to iterate or
 	// parse. By holding onto this data, we ensure that we're able to

discovery/gossiper.go

@@ -20,6 +20,7 @@ import (
 	"github.com/lightningnetwork/lnd/chainntnfs"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/channeldb/models"
+	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/keychain"
 	"github.com/lightningnetwork/lnd/kvdb"
 	"github.com/lightningnetwork/lnd/lnpeer"
@@ -82,9 +83,10 @@ var (
 // can provide that serve useful when processing a specific network
 // announcement.
 type optionalMsgFields struct {
-	capacity     *btcutil.Amount
-	channelPoint *wire.OutPoint
-	remoteAlias  *lnwire.ShortChannelID
+	capacity      *btcutil.Amount
+	channelPoint  *wire.OutPoint
+	remoteAlias   *lnwire.ShortChannelID
+	tapscriptRoot fn.Option[chainhash.Hash]
 }
 
 // apply applies the optional fields within the functional options.
@@ -115,6 +117,12 @@ func ChannelPoint(op wire.OutPoint) OptionalMsgField {
 	}
 }
 
+func TapscriptRoot(root fn.Option[chainhash.Hash]) OptionalMsgField {
+	return func(f *optionalMsgFields) {
+		f.tapscriptRoot = root
+	}
+}
+
 // RemoteAlias is an optional field that lets the gossiper know that a locally
 // sent channel update is actually an update for the peer that should replace
 // the ShortChannelID field with the remote's alias. This is only used for
@@ -2500,6 +2508,7 @@ func (d *AuthenticatedGossiper) handleChanAnnouncement(nMsg *networkMsg,
 		BitcoinKey2Bytes: ann.BitcoinKey2,
 		AuthProof:        proof,
 		Features:         featureBuf.Bytes(),
+		TapscriptRoot:    nMsg.optionalMsgFields.tapscriptRoot,
 		ExtraOpaqueData:  ann.ExtraOpaqueData,
 	}
 

funding/manager.go

@@ -3478,6 +3478,7 @@ func (f *Manager) addToRouterGraph(completeChan *channeldb.OpenChannel,
 	errChan := f.cfg.SendAnnouncement(
 		ann.chanAnn, discovery.ChannelCapacity(completeChan.Capacity),
 		discovery.ChannelPoint(completeChan.FundingOutpoint),
+		discovery.TapscriptRoot(completeChan.TapscriptRoot),
 	)
 	select {
 	case err := <-errChan:
@@ -4406,9 +4407,9 @@ func (f *Manager) announceChannel(localIDKey, remoteIDKey *btcec.PublicKey,
 	//
 	// We can pass in zeroes for the min and max htlc policy, because we
 	// only use the channel announcement message from the returned struct.
-	ann, err := f.newChanAnnouncement(localIDKey, remoteIDKey,
-		localFundingKey, remoteFundingKey, shortChanID, chanID,
-		0, 0, nil, chanType,
+	ann, err := f.newChanAnnouncement(
+		localIDKey, remoteIDKey, localFundingKey, remoteFundingKey,
+		shortChanID, chanID, 0, 0, nil, chanType,
 	)
 	if err != nil {
 		log.Errorf("can't generate channel announcement: %v", err)

routing/router.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/btcsuite/btcd/btcutil"
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/davecgh/go-spew/spew"
 	"github.com/go-errors/errors"
@@ -22,6 +23,7 @@ import (
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/clock"
+	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/htlcswitch"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/kvdb"
@@ -1503,8 +1505,8 @@ func (r *ChannelRouter) addZombieEdge(chanID uint64) error {
 // segwit v1 (taproot) channels.
 //
 // TODO(roasbeef: export and use elsewhere?
-func makeFundingScript(bitcoinKey1, bitcoinKey2 []byte,
-	chanFeatures []byte) ([]byte, error) {
+func makeFundingScript(bitcoinKey1, bitcoinKey2 []byte, chanFeatures []byte,
+	tapscriptRoot fn.Option[chainhash.Hash]) ([]byte, error) {
 
 	legacyFundingScript := func() ([]byte, error) {
 		witnessScript, err := input.GenMultiSigScript(
@@ -1550,8 +1552,15 @@ func makeFundingScript(bitcoinKey1, bitcoinKey2 []byte,
 			return nil, err
 		}
 
+		var fundingOpts []input.FundingScriptOpt
+		tapscriptRoot.WhenSome(func(root chainhash.Hash) {
+			fundingOpts = append(
+				fundingOpts, input.WithTapscriptRoot(root),
+			)
+		})
+
 		fundingScript, _, _, err := input.GenTaprootFundingScript(
-			pubKey1, pubKey2, 0,
+			pubKey1, pubKey2, 0, fundingOpts...,
 		)
 		if err != nil {
 			return nil, err
@@ -1676,7 +1685,7 @@ func (r *ChannelRouter) processUpdate(msg interface{},
 		// reality.
 		fundingPkScript, err := makeFundingScript(
 			msg.BitcoinKey1Bytes[:], msg.BitcoinKey2Bytes[:],
-			msg.Features,
+			msg.Features, msg.TapscriptRoot,
 		)
 		if err != nil {
 			return err