channeld: fill in channel_update field in errors by asking gossipd.

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

channeld/Makefile

@@ -58,7 +58,12 @@ CHANNELD_COMMON_OBJS :=				\
 	common/timeout.o			\
 	common/type_to_string.o			\
 	common/utils.o				\
-	common/version.o
+	common/version.o			\
+	common/wireaddr.o			\
+	gossipd/gen_gossip_wire.o		\
+	lightningd/gossip_msg.o			\
+	wire/fromwire.o				\
+	wire/towire.o
 
 # Control daemon uses this:
 LIGHTNINGD_CHANNEL_CONTROL_HEADERS := $(LIGHTNINGD_CHANNEL_HEADERS_GEN)

channeld/channel.c

@@ -621,7 +621,7 @@ static u8 *master_wait_sync_reply(const tal_t *ctx,
 			       MASTER_FD, &peer->from_master, "master");
 }
 
-static UNNEEDED u8 *gossipd_wait_sync_reply(const tal_t *ctx,
+static u8 *gossipd_wait_sync_reply(const tal_t *ctx,
 				   struct peer *peer, const u8 *msg,
 				   enum gossip_wire_type replytype)
 {
@@ -1954,8 +1954,17 @@ static u8 *foreign_channel_update(const tal_t *ctx,
 				  struct peer *peer,
 				  const struct short_channel_id *scid)
 {
-	/* FIXME! */
-	return NULL;
+	tal_t *tmpctx = tal_tmpctx(ctx);
+	u8 *msg, *update;
+
+	msg = towire_gossip_get_update(tmpctx, scid);
+	msg = gossipd_wait_sync_reply(tmpctx, peer, take(msg),
+				      WIRE_GOSSIP_GET_UPDATE_REPLY);
+	if (!fromwire_gossip_get_update_reply(ctx, msg, NULL, &update))
+		status_failed(STATUS_FAIL_GOSSIP_IO,
+			      "Invalid update reply");
+	tal_free(tmpctx);
+	return update;
 }
 
 static u8 *make_failmsg(const tal_t *ctx,

gossipd/gossip.c

@@ -641,7 +641,7 @@ static void handle_get_update(struct peer *peer, const u8 *msg)
 
 reply:
 	msg = towire_gossip_get_update_reply(msg, update);
-	msg_enqueue(&peer->peer_out, take(msg));
+	daemon_conn_send(&peer->owner_conn, take(msg));
 }
 
 /**