gossipd: Check features in `node_announcement` and `channel_announcement`.

Fixes: #548

gossipd/Makefile

@@ -40,6 +40,7 @@ GOSSIPD_COMMON_OBJS :=				\
 	common/cryptomsg.o			\
 	common/daemon_conn.o			\
 	common/dev_disconnect.o			\
+	common/features.o			\
 	common/io_debug.o			\
 	common/msg_queue.o			\
 	common/ping.o				\

gossipd/routing.c

@@ -7,6 +7,7 @@
 #include <ccan/endian/endian.h>
 #include <ccan/structeq/structeq.h>
 #include <ccan/tal/str/str.h>
+#include <common/features.h>
 #include <common/pseudorand.h>
 #include <common/status.h>
 #include <common/type_to_string.h>
@@ -554,6 +555,20 @@ const struct short_channel_id *handle_channel_announcement(
 	tag = type_to_string(pending, struct short_channel_id,
 			     &pending->short_channel_id);
 
+	/* BOLT #7:
+	 *
+	 * If there is an unknown even bit in the `features` field the
+	 * receiving node MUST NOT parse the remainder of the message
+	 * and MUST NOT add the channel to its local network view, and
+	 * SHOULD NOT forward the announcement.
+	 */
+	if (unsupported_features(features, NULL)) {
+		status_trace("Ignoring channel announcement, unsupported features %s.",
+			     tal_hex(pending, features));
+		tal_free(pending);
+		return NULL;
+	}
+
 	/* BOLT #7:
 	 *
 	 * The receiving node MUST ignore the message if the specified
@@ -568,8 +583,6 @@ const struct short_channel_id *handle_channel_announcement(
 		return NULL;
 	}
 
-	// FIXME: Check features!
-
 	if (!check_channel_announcement(&pending->node_id_1, &pending->node_id_2,
 					&pending->bitcoin_key_1,
 					&pending->bitcoin_key_2,
@@ -873,7 +886,19 @@ void handle_node_announcement(
 		return;
 	}
 
-	// FIXME: Check features!
+	/* BOLT #7:
+	 *
+	 * If the `features` field contains unknown even bits the
+	 * receiving node MUST NOT parse the remainder of the message
+	 * and MAY discard the message altogether.
+	 */
+	if (unsupported_features(features, NULL)) {
+		status_trace("Ignoring node announcement, unsupported features %s.",
+			     tal_hex(tmpctx, features));
+		tal_free(tmpctx);
+		return;
+	}
+
 	status_trace("Received node_announcement for node %s",
 		     type_to_string(trc, struct pubkey, &node_id));
 

gossipd/test/Makefile

@@ -7,6 +7,7 @@ GOSSIPD_TEST_OBJS := $(GOSSIPD_TEST_SRC:.c=.o)
 GOSSIPD_TEST_PROGRAMS := $(GOSSIPD_TEST_OBJS:.o=)
 
 GOSSIPD_TEST_COMMON_OBJS :=			\
+	common/features.o			\
 	common/pseudorand.o			\
 	common/type_to_string.o			\
 	common/utils.o