listpeers: expose peer features as 'local_features' and 'global_features'

For now, just the connected peers.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

gossipd/gossip.c

@@ -2104,6 +2104,8 @@ static struct io_plan *getchannels_req(struct io_conn *conn, struct daemon *daem
 
 static void append_node(const struct gossip_getnodes_entry ***nodes,
 			const struct pubkey *nodeid,
+			const u8 *gfeatures,
+			const u8 *lfeatures,
 			/* If non-NULL, contains more information */
 			const struct node *n)
 {
@@ -2112,6 +2114,10 @@ static void append_node(const struct gossip_getnodes_entry ***nodes,
 
 	new = tal(*nodes, struct gossip_getnodes_entry);
 	new->nodeid = *nodeid;
+	new->global_features = tal_dup_arr(*nodes, u8, gfeatures,
+					   tal_len(gfeatures), 0);
+	new->local_features = tal_dup_arr(*nodes, u8, lfeatures,
+					  tal_len(lfeatures), 0);
 	if (!n || n->last_timestamp < 0) {
 		new->last_timestamp = -1;
 		new->addresses = NULL;
@@ -2140,13 +2146,15 @@ static struct io_plan *getnodes(struct io_conn *conn, struct daemon *daemon,
 		for (size_t i = 0; i < tal_count(ids); i++) {
 			n = get_node(daemon->rstate, &ids[i]);
 			if (n)
-				append_node(&nodes, &ids[i], n);
+				/* FIXME: Keep global features from node_announcement! */
+				append_node(&nodes, &ids[i], NULL, NULL, n);
 		}
 	} else {
 		struct node_map_iter i;
 		n = node_map_first(daemon->rstate->nodes, &i);
 		while (n != NULL) {
-			append_node(&nodes, &n->id, n);
+			/* FIXME: Keep global features from node_announcement! */
+			append_node(&nodes, &n->id, NULL, NULL, n);
 			n = node_map_next(daemon->rstate->nodes, &i);
 		}
 	}
@@ -3433,7 +3441,7 @@ static struct io_plan *get_peers(struct io_conn *conn,
 	size_t n = 0;
 	struct pubkey *id = tal_arr(conn, struct pubkey, n);
 	struct wireaddr_internal *wireaddr = tal_arr(conn, struct wireaddr_internal, n);
-	const struct gossip_getnodes_entry **nodes = tal_arr(conn, const struct gossip_getnodes_entry *, 0);
+	const struct gossip_getnodes_entry **nodes = tal_arr(conn, const struct gossip_getnodes_entry *, n);
 	struct pubkey *specific_id = NULL;
 
 	if (!fromwire_gossip_getpeers_request(msg, msg, &specific_id))
@@ -3448,6 +3456,7 @@ static struct io_plan *get_peers(struct io_conn *conn,
 		id[n] = peer->id;
 		wireaddr[n] = peer->addr;
 		append_node(&nodes, &peer->id,
+			    peer->gfeatures, peer->lfeatures,
 			    get_node(daemon->rstate, &peer->id));
 		n++;
 	}

lightningd/gossip_msg.c

@@ -7,11 +7,19 @@ struct gossip_getnodes_entry *fromwire_gossip_getnodes_entry(const tal_t *ctx,
 {
 	u8 numaddresses, i;
 	struct gossip_getnodes_entry *entry;
+	u16 flen;
 
 	entry = tal(ctx, struct gossip_getnodes_entry);
 	fromwire_pubkey(pptr, max, &entry->nodeid);
-	entry->last_timestamp = fromwire_u64(pptr, max);
+	flen = fromwire_u16(pptr, max);
+	entry->local_features = tal_arr(entry, u8, flen);
+	fromwire_u8_array(pptr, max, entry->local_features, flen);
 
+	flen = fromwire_u16(pptr, max);
+	entry->global_features = tal_arr(entry, u8, flen);
+	fromwire_u8_array(pptr, max, entry->global_features, flen);
+
+	entry->last_timestamp = fromwire_u64(pptr, max);
 	if (entry->last_timestamp < 0) {
 		entry->addresses = NULL;
 		entry->alias = NULL;
@@ -30,6 +38,7 @@ struct gossip_getnodes_entry *fromwire_gossip_getnodes_entry(const tal_t *ctx,
 	entry->alias = tal_arr(entry, u8, fromwire_u8(pptr, max));
 	fromwire(pptr, max, entry->alias, tal_len(entry->alias));
 	fromwire(pptr, max, entry->color, sizeof(entry->color));
+
 	return entry;
 }
 
@@ -38,6 +47,12 @@ void towire_gossip_getnodes_entry(u8 **pptr,
 {
 	u8 i, numaddresses = tal_count(entry->addresses);
 	towire_pubkey(pptr, &entry->nodeid);
+	towire_u16(pptr, tal_count(entry->local_features));
+	towire_u8_array(pptr, entry->local_features,
+			tal_count(entry->local_features));
+	towire_u16(pptr, tal_count(entry->global_features));
+	towire_u8_array(pptr, entry->global_features,
+			tal_count(entry->global_features));
 	towire_u64(pptr, entry->last_timestamp);
 
 	if (entry->last_timestamp < 0)

lightningd/gossip_msg.h

@@ -6,6 +6,8 @@
 
 struct gossip_getnodes_entry {
 	struct pubkey nodeid;
+	/* We'll only have non-empty local_features if it's a direct peer. */
+	u8 *local_features, *global_features;
 	s64 last_timestamp; /* -1 means never: following fields ignored */
 	struct wireaddr *addresses;
 	u8 *alias;

lightningd/peer_control.c

@@ -708,6 +708,16 @@ static void json_add_node_decoration(struct json_result *response,
 {
 	struct json_escaped *esc;
 
+	if (node->local_features)
+		json_add_hex(response, "local_features",
+			     node->local_features,
+			     tal_len(node->local_features));
+
+	if (node->global_features)
+		json_add_hex(response, "global_features",
+			     node->global_features,
+			     tal_len(node->global_features));
+
 	/* If node announcement hasn't been received yet, no alias information.
 	 */
 	if (node->last_timestamp < 0)
@@ -780,6 +790,7 @@ static void gossipd_getpeers_complete(struct subd *gossip, const u8 *msg,
 		json_array_start(response, "channels");
 		json_add_uncommitted_channel(response, p->uncommitted_channel);
 
+		/* FIXME: Add their local and global features */
 		list_for_each(&p->channels, channel, list) {
 			struct channel_id cid;
 			u64 our_reserve_msat = channel->channel_info.their_config.channel_reserve_satoshis * 1000;

tests/test_lightningd.py

@@ -426,6 +426,12 @@ class LightningDTests(BaseLightningDTests):
                                 .format(l1.daemon.lightning_dir, leaks))
         l1.rpc.stop()
 
+    def test_features(self):
+        l1, l2 = self.connect()
+
+        # LOCAL_INITIAL_ROUTING_SYNC + LOCAL_GOSSIP_QUERIES
+        assert l1.rpc.listpeers()['peers'][0]['local_features'] == '88'
+
     def test_autocleaninvoice(self):
         l1 = self.node_factory.get_node()