JSONRPC: getnodes: rename to listnodes.

Like listinvoice, and add optional 'id' parameter to ask about a
specific node.

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

gossipd/gossip.c

@@ -1095,23 +1095,40 @@ static struct io_plan *getchannels_req(struct io_conn *conn, struct daemon *daem
 	return daemon_conn_read_next(conn, &daemon->master);
 }
 
-static struct io_plan *getnodes(struct io_conn *conn, struct daemon *daemon)
+static void append_node(struct gossip_getnodes_entry **nodes,
+			const struct node *n)
+{
+	size_t num_nodes = tal_count(*nodes);
+	tal_resize(nodes, num_nodes + 1);
+	(*nodes)[num_nodes].nodeid = n->id;
+	(*nodes)[num_nodes].addresses = n->addresses;
+}
+
+static struct io_plan *getnodes(struct io_conn *conn, struct daemon *daemon,
+				const u8 *msg)
 {
 	tal_t *tmpctx = tal_tmpctx(daemon);
 	u8 *out;
 	struct node *n;
-	struct node_map_iter i;
 	struct gossip_getnodes_entry *nodes;
-	size_t node_count = 0;
+	struct pubkey *ids;
 
-	nodes = tal_arr(tmpctx, struct gossip_getnodes_entry, node_count);
-	n = node_map_first(daemon->rstate->nodes, &i);
-	while (n != NULL) {
-		tal_resize(&nodes, node_count + 1);
-		nodes[node_count].nodeid = n->id;
-		nodes[node_count].addresses = n->addresses;
-		node_count++;
-		n = node_map_next(daemon->rstate->nodes, &i);
+	fromwire_gossip_getnodes_request(tmpctx, msg, NULL, &ids);
+
+	nodes = tal_arr(tmpctx, struct gossip_getnodes_entry, 0);
+	if (ids) {
+		for (size_t i = 0; i < tal_count(ids); i++) {
+			n = node_map_get(daemon->rstate->nodes, &ids[i].pubkey);
+			if (n)
+				append_node(&nodes, n);
+		}
+	} else {
+		struct node_map_iter i;
+		n = node_map_first(daemon->rstate->nodes, &i);
+		while (n != NULL) {
+			append_node(&nodes, n);
+			n = node_map_next(daemon->rstate->nodes, &i);
+		}
 	}
 	out = towire_gossip_getnodes_reply(daemon, nodes);
 	daemon_conn_send(&daemon->master, take(out));
@@ -1749,7 +1766,7 @@ static struct io_plan *recv_req(struct io_conn *conn, struct daemon_conn *master
 		return release_peer(conn, daemon, master->msg_in);
 
 	case WIRE_GOSSIP_GETNODES_REQUEST:
-		return getnodes(conn, daemon);
+		return getnodes(conn, daemon, daemon->master.msg_in);
 
 	case WIRE_GOSSIP_GETROUTE_REQUEST:
 		return getroute_req(conn, daemon, daemon->master.msg_in);

gossipd/gossip_wire.csv

@@ -83,6 +83,9 @@ gossipctl_hand_back_peer,,msg,len*u8
 
 # Pass JSON-RPC getnodes call through
 gossip_getnodes_request,3005
+# Can be 0 or 1 currently
+gossip_getnodes_request,,num,u16
+gossip_getnodes_request,,id,num*struct pubkey
 
 #include <lightningd/gossip_msg.h>
 gossip_getnodes_reply,3105

lightningd/gossip_control.c

@@ -211,18 +211,38 @@ static void json_getnodes_reply(struct subd *gossip, const u8 *reply,
 	command_success(cmd, response);
 }
 
-static void json_getnodes(struct command *cmd, const char *buffer,
+static void json_listnodes(struct command *cmd, const char *buffer,
 			  const jsmntok_t *params)
 {
-	u8 *req = towire_gossip_getnodes_request(cmd);
+	u8 *req;
+	jsmntok_t *idtok = NULL;
+	struct pubkey *id = NULL;
+
+	if (!json_get_params(buffer, params,
+			     "?id", &idtok,
+			     NULL)) {
+		command_fail(cmd, "Invalid arguments");
+		return;
+	}
+
+	if (idtok) {
+		id = tal_arr(cmd, struct pubkey, 1);
+		if (!json_tok_pubkey(buffer, idtok, id)) {
+			command_fail(cmd, "Invalid id");
+			return;
+		}
+	}
+
+	req = towire_gossip_getnodes_request(cmd, id);
 	subd_req(cmd, cmd->ld->gossip, req, -1, 0, json_getnodes_reply, cmd);
 	command_still_pending(cmd);
 }
 
-static const struct json_command getnodes_command = {
-    "getnodes", json_getnodes, "Retrieve all nodes in our local network view",
+static const struct json_command listnodes_command = {
+    "listnodes", json_listnodes,
+    "List a nodes in our local network view (or all, if no {id})",
     "Returns a list of all nodes that we know about"};
-AUTODATA(json_command, &getnodes_command);
+AUTODATA(json_command, &listnodes_command);
 
 static void json_getroute_reply(struct subd *gossip, const u8 *reply, const int *fds,
 				struct command *cmd)

tests/test_lightningd.py

@@ -1412,9 +1412,15 @@ class LightningDTests(BaseLightningDTests):
                                  'Channel {}\\(1\\) was updated.'
                                  .format(channel_id)])
 
-        nodes = l1.rpc.getnodes()['nodes']
+        nodes = l1.rpc.listnodes()['nodes']
         assert set([n['nodeid'] for n in nodes]) == set([l1.info['id'], l2.info['id']])
 
+        # Test listnodes with an arg, while we're here.
+        n1 = l1.rpc.listnodes(l1.info['id'])['nodes'][0]
+        n2 = l1.rpc.listnodes(l2.info['id'])['nodes'][0]
+        assert n1['nodeid'] == l1.info['id']
+        assert n2['nodeid'] == l2.info['id']
+
         assert [c['active'] for c in l1.rpc.getchannels()['channels']] == [True, True]
         assert [c['public'] for c in l1.rpc.getchannels()['channels']] == [True, True]
         assert [c['active'] for c in l2.rpc.getchannels()['channels']] == [True, True]
@@ -1470,8 +1476,8 @@ class LightningDTests(BaseLightningDTests):
 
         assert scid2 not in [c['short_channel_id'] for c in l1.rpc.getchannels()['channels']]
         assert scid2 not in [c['short_channel_id'] for c in l2.rpc.getchannels()['channels']]
-        assert l3.info['id'] not in [n['nodeid'] for n in l1.rpc.getnodes()['nodes']]
-        assert l3.info['id'] not in [n['nodeid'] for n in l2.rpc.getnodes()['nodes']]
+        assert l3.info['id'] not in [n['nodeid'] for n in l1.rpc.listnodes()['nodes']]
+        assert l3.info['id'] not in [n['nodeid'] for n in l2.rpc.listnodes()['nodes']]
 
     def ping_tests(self, l1, l2):
         # 0-byte pong gives just type + length field.