gossipd: don't shortcut dying phase for local channels.

This means that we won't complain to peers which gossip about our
channels, but it does mean that our channel graph (like other nodes on
the network) will show two channels, not one, for the duration.

For this reason, we need askrene to omit local dying channels.

Signed-off-by: Rusty Russell <[email protected]>

Author: rustyrussell

gossipd/gossmap_manage.c

@@ -1317,7 +1317,6 @@ void gossmap_manage_channel_spent(struct gossmap_manage *gm,
 				  struct short_channel_id scid)
 {
 	struct gossmap_chan *chan;
-	const struct gossmap_node *me;
 	const u8 *msg;
 	struct chan_dying cd;
 	struct gossmap *gossmap = gossmap_manage_get_gossmap(gm);
@@ -1326,14 +1325,6 @@ void gossmap_manage_channel_spent(struct gossmap_manage *gm,
 	if (!chan)
 		return;
 
-	me = gossmap_find_node(gossmap, &gm->daemon->id);
-	/* We delete our own channels immediately, since we have local knowledge */
-	if (gossmap_nth_node(gossmap, chan, 0) == me
-	    || gossmap_nth_node(gossmap, chan, 1) == me) {
-		kill_spent_channel(gm, gossmap, scid);
-		return;
-	}
-
 	/* Is it already dying?  It's lightningd re-telling us */
 	if (channel_already_dying(gm->dying_channels, scid))
 		return;

plugins/askrene/askrene.c

@@ -573,6 +573,7 @@ static struct command_result *do_getroutes(struct command *cmd,
 	struct route **routes;
 	struct flow **flows;
 	struct json_stream *response;
+	const struct gossmap_node *me;
 
 	/* update the gossmap */
 	if (gossmap_refresh(askrene->gossmap)) {
@@ -593,6 +594,30 @@ static struct command_result *do_getroutes(struct command *cmd,
 	rq->additional_costs = info->additional_costs;
 	rq->maxparts = info->maxparts;
 
+	/* We also eliminate any local channels we *know* are dying.
+	 * Most channels get 12 blocks grace in case it's a splice,
+	 * but if it's us, we know about the splice already. */
+	me = gossmap_find_node(rq->gossmap, &askrene->my_id);
+	if (me) {
+		for (size_t i = 0; i < me->num_chans; i++) {
+			struct short_channel_id_dir scidd;
+			const struct gossmap_chan *c = gossmap_nth_chan(rq->gossmap,
+									me, i, NULL);
+			if (!gossmap_chan_is_dying(rq->gossmap, c))
+				continue;
+
+			scidd.scid = gossmap_chan_scid(rq->gossmap, c);
+			/* Disable both directions */
+			for (scidd.dir = 0; scidd.dir < 2; scidd.dir++) {
+				bool enabled = false;
+				gossmap_local_updatechan(localmods,
+							 &scidd,
+							 &enabled,
+							 NULL, NULL, NULL, NULL, NULL);
+			}
+		}
+	}
+
 	/* apply selected layers to the localmods */
 	apply_layers(askrene, rq, &info->source, info->amount, localmods,
 		     info->layers, info->local_layer);

tests/test_closing.py

@@ -1851,8 +1851,8 @@ def test_onchaind_replay(node_factory, bitcoind):
 
     # Wait for nodes to notice the failure, this seach needle is after the
     # DB commit so we're sure the tx entries in onchaindtxs have been added
-    l1.daemon.wait_for_log("Deleting channel .* due to the funding outpoint being spent")
-    l2.daemon.wait_for_log("Deleting channel .* due to the funding outpoint being spent")
+    l1.daemon.wait_for_log("closing soon due to the funding outpoint being spent")
+    l2.daemon.wait_for_log("closing soon due to the funding outpoint being spent")
 
     # We should at least have the init tx now
     assert len(l1.db_query("SELECT * FROM channeltxs;")) > 0

tests/test_misc.py

@@ -1488,8 +1488,8 @@ def no_more_blocks(req):
 
     l1.rpc.close(l2.info['id'])
     bitcoind.generate_block(1, True)
-    l1.daemon.wait_for_log(r'Deleting channel')
-    l2.daemon.wait_for_log(r'Deleting channel')
+    l1.daemon.wait_for_log(r'closing soon due to the funding outpoint being spent')
+    l2.daemon.wait_for_log(r'closing soon due to the funding outpoint being spent')
 
 
 @pytest.mark.openchannel('v1')