gossipd: don't try to handle padding inside fromwire_ipaddr.

It makes it impossible to embed an ipaddr in another structure, since we
always try to skip over any zeroes, which may swallow a following field.

Do the skip specially for the case where we're parsing routing messages:
we never use padding for our own internal messages anyway.

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

gossipd/routing.c

@@ -637,6 +637,10 @@ static struct ipaddr *read_addresses(const tal_t *ctx, const u8 *ser)
 	while (cursor && cursor < ser + max) {
 		struct ipaddr ipaddr;
 
+		/* Skip any padding */
+		while (max && cursor[0] == ADDR_TYPE_PADDING)
+			fromwire_u8(&cursor, &max);
+
 		/* BOLT #7:
 		 *
 		 * The receiving node SHOULD ignore the first `address

gossipd/test/run-find_route-specific.c

@@ -31,6 +31,9 @@ bool fromwire_ipaddr(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct ip
 /* Generated stub for fromwire_node_announcement */
 bool fromwire_node_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, size_t *plen UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, u8 **features UNNEEDED, u32 *timestamp UNNEEDED, struct pubkey *node_id UNNEEDED, u8 rgb_color[3] UNNEEDED, u8 alias[32] UNNEEDED, u8 **addresses UNNEEDED)
 { fprintf(stderr, "fromwire_node_announcement called!\n"); abort(); }
+/* Generated stub for fromwire_u8 */
+u8 fromwire_u8(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+{ fprintf(stderr, "fromwire_u8 called!\n"); abort(); }
 /* Generated stub for queue_broadcast */
 void queue_broadcast(struct broadcast_state *bstate UNNEEDED,
 			     const int type UNNEEDED,

gossipd/test/run-find_route.c

@@ -24,6 +24,9 @@ bool fromwire_ipaddr(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct ip
 /* Generated stub for fromwire_node_announcement */
 bool fromwire_node_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, size_t *plen UNNEEDED, secp256k1_ecdsa_signature *signature UNNEEDED, u8 **features UNNEEDED, u32 *timestamp UNNEEDED, struct pubkey *node_id UNNEEDED, u8 rgb_color[3] UNNEEDED, u8 alias[32] UNNEEDED, u8 **addresses UNNEEDED)
 { fprintf(stderr, "fromwire_node_announcement called!\n"); abort(); }
+/* Generated stub for fromwire_u8 */
+u8 fromwire_u8(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+{ fprintf(stderr, "fromwire_u8 called!\n"); abort(); }
 /* Generated stub for queue_broadcast */
 void queue_broadcast(struct broadcast_state *bstate UNNEEDED,
 			     const int type UNNEEDED,

lightningd/test/run-find_my_path.c

@@ -40,12 +40,6 @@ struct log_book *new_log_book(const tal_t *ctx UNNEEDED,
 /* Generated stub for new_topology */
 struct chain_topology *new_topology(const tal_t *ctx UNNEEDED, struct log *log UNNEEDED)
 { fprintf(stderr, "new_topology called!\n"); abort(); }
-/* Generated stub for opt_subd_debug */
-char *opt_subd_debug(const char *optarg UNNEEDED, struct lightningd *ld UNNEEDED)
-{ fprintf(stderr, "opt_subd_debug called!\n"); abort(); }
-/* Generated stub for opt_subd_dev_disconnect */
-char *opt_subd_dev_disconnect(const char *optarg UNNEEDED, struct lightningd *ld UNNEEDED)
-{ fprintf(stderr, "opt_subd_dev_disconnect called!\n"); abort(); }
 /* Generated stub for populate_peer */
 void populate_peer(struct lightningd *ld UNNEEDED, struct peer *peer UNNEEDED)
 { fprintf(stderr, "populate_peer called!\n"); abort(); }

wire/fromwire.c

@@ -198,10 +198,6 @@ bool fromwire_ipaddr(const u8 **cursor, size_t *max, struct ipaddr *addr)
 	fromwire(cursor, max, addr->addr, addr->addrlen);
 	addr->port = fromwire_u16(cursor, max);
 
-	/* Skip any post-padding */
-	while (*max && (*cursor)[0] == ADDR_TYPE_PADDING)
-		fromwire_u8(cursor, max);
-
 	return *cursor != NULL;
 }