htlcswitch: expose custom channel blob from link

htlcswitch/link.go

@@ -31,6 +31,7 @@ import (
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/queue"
 	"github.com/lightningnetwork/lnd/ticker"
+	"github.com/lightningnetwork/lnd/tlv"
 )
 
 func init() {
@@ -4105,3 +4106,28 @@ func (l *channelLink) failf(linkErr LinkFailureError, format string,
 	l.failed = true
 	l.cfg.OnChannelFailure(l.ChanID(), l.ShortChanID(), linkErr)
 }
+
+// FundingCustomBlob returns the custom funding blob of the channel that this
+// link is associated with. The funding blob represents static information about
+// the channel that was created at channel funding time.
+func (l *channelLink) FundingCustomBlob() fn.Option[tlv.Blob] {
+	if l.channel == nil {
+		return fn.None[tlv.Blob]()
+	}
+
+	if l.channel.State() == nil {
+		return fn.None[tlv.Blob]()
+	}
+
+	return l.channel.State().CustomBlob
+}
+
+// CommitmentCustomBlob returns the custom blob of the current local commitment
+// of the channel that this link is associated with.
+func (l *channelLink) CommitmentCustomBlob() fn.Option[tlv.Blob] {
+	if l.channel == nil {
+		return fn.None[tlv.Blob]()
+	}
+
+	return l.channel.LocalCommitmentBlob()
+}