channeldb: add new ExtraOpaqueData to edge policy+update and node ann

In this commit, we add a mirror set of fields to the ones we recently
added to the set of gossip wire messages. With these set of fields in
place, we ensure that we'll be able to properly store and re-validate
gossip messages that contain a set of extra/optional fields.

channeldb/graph.go

@@ -1694,6 +1694,14 @@ type LightningNode struct {
 	// Features is the list of protocol features supported by this node.
 	Features *lnwire.FeatureVector
 
+	// 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
+	// properly validate the set of signatures that cover these new fields,
+	// and ensure we're able to make upgrades to the network in a forwards
+	// compatible manner.
+	ExtraOpaqueData []byte
+
 	db *DB
 
 	// TODO(roasbeef): discovery will need storage to keep it's last IP
@@ -1978,6 +1986,14 @@ type ChannelEdgeInfo struct {
 	// the value output in the outpoint that created this channel.
 	Capacity btcutil.Amount
 
+	// 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
+	// properly validate the set of signatures that cover these new fields,
+	// and ensure we're able to make upgrades to the network in a forwards
+	// compatible manner.
+	ExtraOpaqueData []byte
+
 	db *DB
 }
 
@@ -2322,6 +2338,14 @@ type ChannelEdgePolicy struct {
 	// this pointer the channel graph can further be traversed.
 	Node *LightningNode
 
+	// 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
+	// properly validate the set of signatures that cover these new fields,
+	// and ensure we're able to make upgrades to the network in a forwards
+	// compatible manner.
+	ExtraOpaqueData []byte
+
 	db *DB
 }
 
@@ -2691,6 +2715,11 @@ func putLightningNode(nodeBucket *bolt.Bucket, aliasBucket *bolt.Bucket,
 		return err
 	}
 
+	err = wire.WriteVarBytes(&b, 0, node.ExtraOpaqueData)
+	if err != nil {
+		return err
+	}
+
 	if err := aliasBucket.Put(nodePub, []byte(node.Alias)); err != nil {
 		return err
 	}
@@ -2815,6 +2844,13 @@ func deserializeLightningNode(r io.Reader) (LightningNode, error) {
 		return LightningNode{}, err
 	}
 
+	// We'll try and see if there are any opaque bytes left, if not, then
+	// we'll ignore the EOF error and return the node as is.
+	node.ExtraOpaqueData, err = wire.ReadVarBytes(r, 0, 1000, "blob")
+	if err != nil && err != io.ErrUnexpectedEOF {
+		return LightningNode{}, err
+	}
+
 	return node, nil
 }
 
@@ -2873,6 +2909,11 @@ func putChanEdgeInfo(edgeIndex *bolt.Bucket, edgeInfo *ChannelEdgeInfo, chanID [
 		return err
 	}
 
+	err := wire.WriteVarBytes(&b, 0, edgeInfo.ExtraOpaqueData)
+	if err != nil {
+		return err
+	}
+
 	return edgeIndex.Put(chanID[:], b.Bytes())
 }
 
@@ -2950,6 +2991,13 @@ func deserializeChanEdgeInfo(r io.Reader) (ChannelEdgeInfo, error) {
 		return ChannelEdgeInfo{}, err
 	}
 
+	// We'll try and see if there are any opaque bytes left, if not, then
+	// we'll ignore the EOF error and return the edge as is.
+	edgeInfo.ExtraOpaqueData, err = wire.ReadVarBytes(r, 0, 1000, "blob")
+	if err != nil && err != io.ErrUnexpectedEOF {
+		return ChannelEdgeInfo{}, err
+	}
+
 	return edgeInfo, nil
 }
 
@@ -2998,6 +3046,10 @@ func putChanEdgePolicy(edges, nodes *bolt.Bucket, edge *ChannelEdgePolicy,
 		return err
 	}
 
+	if err := wire.WriteVarBytes(&b, 0, edge.ExtraOpaqueData); err != nil {
+		return err
+	}
+
 	// Before we write out the new edge, we'll create a new entry in the
 	// update index in order to keep it fresh.
 	var indexKey [8 + 8]byte
@@ -3182,6 +3234,13 @@ func deserializeChanEdgePolicy(r io.Reader,
 			pub[:], err)
 	}
 
+	// We'll try and see if there are any opaque bytes left, if not, then
+	// we'll ignore the EOF error and return the edge as is.
+	edge.ExtraOpaqueData, err = wire.ReadVarBytes(r, 0, 1000, "blob")
+	if err != nil && err != io.ErrUnexpectedEOF {
+		return nil, err
+	}
+
 	edge.Node = &node
 	return edge, nil
 }