tests: add dev-query-scids

And write the test for it.

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

contrib/pylightning/lightning/lightning.py

@@ -249,6 +249,16 @@ class LightningRpc(UnixDomainSocketRpc):
         """
         return self.call("dev-crash")
 
+    def dev_query_scids(self, id, scids):
+        """
+        Ask peer for a particular set of scids
+        """
+        payload = {
+            "id": id,
+            "scids": scids
+        }
+        return self.call("dev-query-scids", payload)
+
     def getinfo(self):
         """
         Show information about this node

lightningd/gossip_control.c

@@ -545,3 +545,88 @@ static const struct json_command listchannels_command = {
 	"Show channel {short_channel_id} (or all known channels, if no {short_channel_id})"
 };
 AUTODATA(json_command, &listchannels_command);
+
+#if DEVELOPER
+static void json_scids_reply(struct subd *gossip UNUSED, const u8 *reply,
+			     const int *fds UNUSED, struct command *cmd)
+{
+	bool ok, complete;
+	struct json_result *response = new_json_result(cmd);
+
+	if (!fromwire_gossip_scids_reply(reply, &ok, &complete)) {
+		command_fail(cmd, LIGHTNINGD,
+			     "Gossip gave bad gossip_scids_reply");
+		return;
+	}
+
+	if (!ok) {
+		command_fail(cmd, LIGHTNINGD,
+			     "Gossip refused to query peer");
+		return;
+	}
+
+	json_object_start(response, NULL);
+	json_add_bool(response, "complete", complete);
+	json_object_end(response);
+	command_success(cmd, response);
+}
+
+static void json_dev_query_scids(struct command *cmd,
+				 const char *buffer, const jsmntok_t *params)
+{
+	u8 *msg;
+	jsmntok_t *idtok, *scidstok;
+	const jsmntok_t *t, *end;
+	struct pubkey id;
+	struct short_channel_id *scids;
+	size_t i;
+
+	if (!json_get_params(cmd, buffer, params,
+			     "id", &idtok,
+			     "scids", &scidstok,
+			     NULL)) {
+		return;
+	}
+
+	if (!json_tok_pubkey(buffer, idtok, &id)) {
+		command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			     "'%.*s' is not a valid id",
+			     idtok->end - idtok->start,
+			     buffer + idtok->start);
+		return;
+	}
+
+	if (scidstok->type != JSMN_ARRAY) {
+		command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+			     "'%.*s' is not an array",
+			     scidstok->end - scidstok->start,
+			     buffer + scidstok->start);
+		return;
+	}
+
+	scids = tal_arr(cmd, struct short_channel_id, scidstok->size);
+	end = json_next(scidstok);
+	for (i = 0, t = scidstok + 1; t < end; t = json_next(t), i++) {
+		if (!json_tok_short_channel_id(buffer, t, &scids[i])) {
+			command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+				     "scid %zu '%.*s' is not an scid",
+				     i, t->end - t->start,
+				     buffer + t->start);
+			return;
+		}
+	}
+
+	/* Tell gossipd, since this is a gossip query. */
+	msg = towire_gossip_query_scids(cmd, &id, scids);
+	subd_req(cmd->ld->gossip, cmd->ld->gossip,
+		 take(msg), -1, 0, json_scids_reply, cmd);
+	command_still_pending(cmd);
+}
+
+static const struct json_command dev_query_scids_command = {
+	"dev-query-scids",
+	json_dev_query_scids,
+	"Query {peerid} for [scids]"
+};
+AUTODATA(json_command, &dev_query_scids_command);
+#endif /* DEVELOPER */

tests/test_lightningd.py

@@ -2622,6 +2622,65 @@ class LightningDTests(BaseLightningDTests):
             l1.daemon.wait_for_log('Got pong 1000 bytes \({}\.\.\.\)'
                                    .format(l2.info['version']))
 
+    @unittest.skipIf(not DEVELOPER, "needs DEVELOPER=1")
+    def test_query_short_channel_id(self):
+        l1 = self.node_factory.get_node(options={'log-level': 'io'})
+        l2 = self.node_factory.get_node()
+        l3 = self.node_factory.get_node()
+        l1.rpc.connect(l2.info['id'], 'localhost', l2.port)
+        l2.rpc.connect(l3.info['id'], 'localhost', l3.port)
+
+        # Need full IO logging so we can see gossip (from gossipd and channeld)
+        subprocess.run(['kill', '-USR1', l1.subd_pid('gossipd')])
+
+        # Empty result tests.
+        reply = l1.rpc.dev_query_scids(l2.info['id'], ['1:1:1', '2:2:2'])
+        # 0x0105 = query_short_channel_ids
+        l1.daemon.wait_for_log('\[OUT\] 0105.*0000000100000100010000020000020002')
+        assert reply['complete']
+
+        # Make channels public.
+        scid12 = self.fund_channel(l1, l2, 10**5)
+        scid23 = self.fund_channel(l2, l3, 10**5)
+        bitcoind.generate_block(5)
+        sync_blockheight([l1, l2, l3])
+
+        # It will know about everything.
+        l1.daemon.wait_for_log('Received node_announcement for node {}'.format(l3.info['id']))
+        subprocess.run(['kill', '-USR1', l1.subd_pid('channeld')])
+
+        # This query should get channel announcements, channel updates, and node announcements.
+        reply = l1.rpc.dev_query_scids(l2.info['id'], [scid23])
+        # 0x0105 = query_short_channel_ids
+        l1.daemon.wait_for_log('\[OUT\] 0105')
+        assert reply['complete']
+
+        # 0x0100 = channel_announcement
+        l1.daemon.wait_for_log('\[IN\] 0100')
+        # 0x0102 = channel_update
+        l1.daemon.wait_for_log('\[IN\] 0102')
+        l1.daemon.wait_for_log('\[IN\] 0102')
+        # 0x0101 = node_announcement
+        l1.daemon.wait_for_log('\[IN\] 0101')
+        l1.daemon.wait_for_log('\[IN\] 0101')
+
+        reply = l1.rpc.dev_query_scids(l2.info['id'], [scid12, scid23])
+        assert reply['complete']
+        # Technically, this order could be different, but this matches code.
+        # 0x0100 = channel_announcement
+        l1.daemon.wait_for_log('\[IN\] 0100')
+        # 0x0102 = channel_update
+        l1.daemon.wait_for_log('\[IN\] 0102')
+        l1.daemon.wait_for_log('\[IN\] 0102')
+        # 0x0100 = channel_announcement
+        l1.daemon.wait_for_log('\[IN\] 0100')
+        # 0x0102 = channel_update
+        l1.daemon.wait_for_log('\[IN\] 0102')
+        l1.daemon.wait_for_log('\[IN\] 0102')
+        # 0x0101 = node_announcement
+        l1.daemon.wait_for_log('\[IN\] 0101')
+        l1.daemon.wait_for_log('\[IN\] 0101')
+
     @unittest.skipIf(not DEVELOPER, "needs DEVELOPER=1")
     def test_routing_gossip_reconnect(self):
         # Connect two peers, reconnect and then see if we resume the