gossipd: preserve unannounced channels across store compaction.

Otherwise we'd forget them on restart, again.

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

CHANGELOG.md

@@ -25,6 +25,7 @@ changes.
 ### Fixed
 
 - `--bind-addr=<path>` fixed for nodes using local sockets (eg. testing).
+- Unannounced local channels were forgotten for routing on restart until reconnection occurred.
 
 ### Security
 

gossipd/gossip_store.c

@@ -150,6 +150,46 @@ static bool gossip_store_append(int fd, struct routing_state *rstate, const u8 *
 		write(fd, msg, msglen) == msglen);
 }
 
+/* Local unannounced channels don't appear in broadcast map, but we need to
+ * remember them anyway, so we manually append to the store.
+ *
+ * Note these do *not* add to gs->count, since that's compared with
+ * the broadcast map count.
+*/
+static bool add_local_unnannounced(int fd,
+				   struct routing_state *rstate,
+				   struct node *self)
+{
+	struct chan_map_iter i;
+	struct chan *c;
+
+	for (c = chan_map_first(&self->chans, &i);
+	     c;
+	     c = chan_map_next(&self->chans, &i)) {
+		struct node *peer = other_node(self, c);
+		const u8 *msg;
+
+		/* Ignore already announced. */
+		if (c->channel_announce)
+			continue;
+
+		msg = towire_gossipd_local_add_channel(tmpctx, &c->scid,
+						       &peer->id, c->sat);
+		if (!gossip_store_append(fd, rstate, msg))
+			return false;
+
+		for (size_t i = 0; i < 2; i++) {
+			msg = c->half[i].channel_update;
+			if (!msg)
+				continue;
+			if (!gossip_store_append(fd, rstate, msg))
+				return false;
+		}
+	}
+
+	return true;
+}
+
 /**
  * Rewrite the on-disk gossip store, compacting it along the way
  *
@@ -162,6 +202,7 @@ bool gossip_store_compact(struct gossip_store *gs)
 	u64 index = 0;
 	int fd;
 	const u8 *msg;
+	struct node *self;
 
 	assert(gs->broadcast);
 	status_trace(
@@ -187,11 +228,18 @@ bool gossip_store_compact(struct gossip_store *gs)
 			status_broken("Failed writing to gossip store: %s",
 				      strerror(errno));
 			goto unlink_disable;
-
 		}
 		count++;
 	}
 
+	/* Local unannounced channels are not in the store! */
+	self = get_node(gs->rstate, &gs->rstate->local_id);
+	if (self && !add_local_unnannounced(fd, gs->rstate, self)) {
+		status_broken("Failed writing unannounced to gossip store: %s",
+			      strerror(errno));
+		goto unlink_disable;
+	}
+
 	if (rename(GOSSIP_STORE_TEMP_FILENAME, GOSSIP_STORE_FILENAME) == -1) {
 		status_broken(
 		    "Error swapping compacted gossip_store into place: %s",

gossipd/test/run-bench-find_route.c

@@ -95,6 +95,9 @@ u8 *towire_errorfmt(const tal_t *ctx UNNEEDED,
 		    const struct channel_id *channel UNNEEDED,
 		    const char *fmt UNNEEDED, ...)
 { fprintf(stderr, "towire_errorfmt called!\n"); abort(); }
+/* Generated stub for towire_gossipd_local_add_channel */
+u8 *towire_gossipd_local_add_channel(const tal_t *ctx UNNEEDED, const struct short_channel_id *short_channel_id UNNEEDED, const struct pubkey *remote_node_id UNNEEDED, struct amount_sat satoshis UNNEEDED)
+{ fprintf(stderr, "towire_gossipd_local_add_channel called!\n"); abort(); }
 /* Generated stub for towire_gossip_store_channel_announcement */
 u8 *towire_gossip_store_channel_announcement(const tal_t *ctx UNNEEDED, const u8 *announcement UNNEEDED, struct amount_sat satoshis UNNEEDED)
 { fprintf(stderr, "towire_gossip_store_channel_announcement called!\n"); abort(); }

gossipd/test/run-find_route-specific.c

@@ -84,6 +84,9 @@ u8 *towire_errorfmt(const tal_t *ctx UNNEEDED,
 		    const struct channel_id *channel UNNEEDED,
 		    const char *fmt UNNEEDED, ...)
 { fprintf(stderr, "towire_errorfmt called!\n"); abort(); }
+/* Generated stub for towire_gossipd_local_add_channel */
+u8 *towire_gossipd_local_add_channel(const tal_t *ctx UNNEEDED, const struct short_channel_id *short_channel_id UNNEEDED, const struct pubkey *remote_node_id UNNEEDED, struct amount_sat satoshis UNNEEDED)
+{ fprintf(stderr, "towire_gossipd_local_add_channel called!\n"); abort(); }
 /* Generated stub for towire_gossip_store_channel_announcement */
 u8 *towire_gossip_store_channel_announcement(const tal_t *ctx UNNEEDED, const u8 *announcement UNNEEDED, struct amount_sat satoshis UNNEEDED)
 { fprintf(stderr, "towire_gossip_store_channel_announcement called!\n"); abort(); }

gossipd/test/run-find_route.c

@@ -82,6 +82,9 @@ u8 *towire_errorfmt(const tal_t *ctx UNNEEDED,
 		    const struct channel_id *channel UNNEEDED,
 		    const char *fmt UNNEEDED, ...)
 { fprintf(stderr, "towire_errorfmt called!\n"); abort(); }
+/* Generated stub for towire_gossipd_local_add_channel */
+u8 *towire_gossipd_local_add_channel(const tal_t *ctx UNNEEDED, const struct short_channel_id *short_channel_id UNNEEDED, const struct pubkey *remote_node_id UNNEEDED, struct amount_sat satoshis UNNEEDED)
+{ fprintf(stderr, "towire_gossipd_local_add_channel called!\n"); abort(); }
 /* Generated stub for towire_gossip_store_channel_announcement */
 u8 *towire_gossip_store_channel_announcement(const tal_t *ctx UNNEEDED, const u8 *announcement UNNEEDED, struct amount_sat satoshis UNNEEDED)
 { fprintf(stderr, "towire_gossip_store_channel_announcement called!\n"); abort(); }

tests/test_gossip.py

@@ -1033,7 +1033,6 @@ def test_getroute_exclude(node_factory, bitcoind):
         l1.rpc.getroute(l4.info['id'], 1, 1, exclude=[chan_l2l3, chan_l2l4])
 
 
-@pytest.mark.xfail(strict=True)
 @unittest.skipIf(not DEVELOPER, "need dev-compact-gossip-store")
 def test_gossip_store_local_channels(node_factory, bitcoind):
     l1, l2 = node_factory.line_graph(2, wait_for_announce=False)
@@ -1059,7 +1058,6 @@ def test_gossip_store_local_channels(node_factory, bitcoind):
     assert len(chans) == 2
 
 
-@pytest.mark.xfail(strict=True)
 @unittest.skipIf(not DEVELOPER, "need dev-compact-gossip-store")
 def test_gossip_store_private_channels(node_factory, bitcoind):
     l1, l2 = node_factory.line_graph(2, announce_channels=False)