gossipd: flag zombie channels when loading from gossip_store

Without inheriting zombie status, gossipd would allow regular channel updates
into the store until the pruning cycle hits (and the channel is properly
flagged) which is 3.5 days. Applying zombie status when reading channel
updates from the store prevents this.

Changelog-None

gossipd/gossip_store.c

@@ -778,6 +778,7 @@ u32 gossip_store_load(struct routing_state *rstate, struct gossip_store *gs)
 	gs->writable = false;
 	while (pread(gs->fd, &hdr, sizeof(hdr), gs->len) == sizeof(hdr)) {
 		bool spam;
+		bool zombie;
 
 		msglen = be16_to_cpu(hdr.len);
 		checksum = be32_to_cpu(hdr.crc);
@@ -802,6 +803,7 @@ u32 gossip_store_load(struct routing_state *rstate, struct gossip_store *gs)
 			goto next;
 		}
 		spam = (be16_to_cpu(hdr.flags) & GOSSIP_STORE_RATELIMIT_BIT);
+		zombie = (be16_to_cpu(hdr.flags) & GOSSIP_STORE_ZOMBIE_BIT);
 
 		switch (fromwire_peektype(msg)) {
 		case WIRE_GOSSIP_STORE_PRIVATE_CHANNEL: {
@@ -872,7 +874,8 @@ u32 gossip_store_load(struct routing_state *rstate, struct gossip_store *gs)
 		case WIRE_CHANNEL_UPDATE:
 			if (!routing_add_channel_update(rstate,
 							take(msg), gs->len,
-							NULL, false, spam)) {
+							NULL, false,
+							spam, zombie)) {
 				bad = "Bad channel_update";
 				goto badmsg;
 			}

gossipd/routing.c

@@ -980,10 +980,10 @@ bool routing_add_channel_announcement(struct routing_state *rstate,
 	/* If we had private updates, they'll immediately create the channel. */
 	if (private_updates[0])
 		routing_add_channel_update(rstate, take(private_updates[0]), 0,
-					   peer, false, false);
+					   peer, false, false, false);
 	if (private_updates[1])
 		routing_add_channel_update(rstate, take(private_updates[1]), 0,
-					   peer, false, false);
+					   peer, false, false, false);
 
 	/* Now we can finish cleanup of gossip store, so there's no window where
 	 * channel (or nodes) vanish. */
@@ -1327,7 +1327,8 @@ bool routing_add_channel_update(struct routing_state *rstate,
 				u32 index,
 				struct peer *peer,
 				bool ignore_timestamp,
-				bool force_spam_flag)
+				bool force_spam_flag,
+				bool force_zombie_flag)
 {
 	secp256k1_ecdsa_signature signature;
 	struct short_channel_id short_channel_id;
@@ -1373,7 +1374,8 @@ bool routing_add_channel_update(struct routing_state *rstate,
 			return false;
 		}
 		sat = uc->sat;
-		zombie = false;
+		/* When loading zombies from the store. */
+		zombie = force_zombie_flag;
 	}
 
 	/* Reject update if the `htlc_maximum_msat` is greater
@@ -1396,6 +1398,9 @@ bool routing_add_channel_update(struct routing_state *rstate,
 		assert(!chan);
 		chan = new_chan(rstate, &short_channel_id,
 				&uc->id[0], &uc->id[1], sat);
+		/* Assign zombie flag if loading zombie from store */
+		if (force_zombie_flag)
+			chan->half[direction].zombie = true;
 	}
 
 	/* Discard older updates */
@@ -1735,7 +1740,8 @@ u8 *handle_channel_update(struct routing_state *rstate, const u8 *update TAKES,
 		return warn;
 	}
 
-	routing_add_channel_update(rstate, take(serialized), 0, peer, force, false);
+	routing_add_channel_update(rstate, take(serialized), 0, peer, force,
+				   false, false);
 	return NULL;
 }
 
@@ -2009,20 +2015,21 @@ u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann,
 
 /* Set zombie flags in gossip_store and tombstone the channel for any
  * gossip_store consumers. Remove any orphaned node_announcements. */
-static void zombify_channel(struct gossip_store *gs, struct chan *channel)
+static void zombify_channel(struct routing_state *rstate, struct chan *channel)
 {
 	struct half_chan *half;
 	assert(!is_chan_zombie(channel));
-	gossip_store_mark_channel_zombie(gs, &channel->bcast);
-	gossip_store_mark_channel_deleted(gs, &channel->scid);
+	gossip_store_mark_channel_zombie(rstate->gs, &channel->bcast);
+	gossip_store_mark_channel_deleted(rstate->gs, &channel->scid);
 	for (int i = 0; i < 2; i++) {
 		half = &channel->half[i];
 		half->zombie = true;
 		if (half->bcast.index) {
-			gossip_store_mark_cupdate_zombie(gs, &half->bcast);
+			gossip_store_mark_cupdate_zombie(rstate->gs, &half->bcast);
 			/* Channel may also have a spam entry */
 			if (half->bcast.index != half->rgraph.index)
-				gossip_store_mark_cupdate_zombie(gs, &half->rgraph);
+				gossip_store_mark_cupdate_zombie(rstate->gs,
+								 &half->rgraph);
 		}
 	}
 	status_debug("Channel %s zombified",
@@ -2044,9 +2051,9 @@ static void zombify_channel(struct gossip_store *gs, struct chan *channel)
 			continue;
 		}
 		if (node->rgraph.index != node->bcast.index)
-			gossip_store_delete(gs, &node->rgraph,
+			gossip_store_delete(rstate->gs, &node->rgraph,
 					    WIRE_NODE_ANNOUNCEMENT);
-		gossip_store_delete(gs, &node->bcast,
+		gossip_store_delete(rstate->gs, &node->bcast,
 				    WIRE_NODE_ANNOUNCEMENT);
 		node->rgraph.index = node->bcast.index = 0;
 	}
@@ -2110,7 +2117,7 @@ void route_prune(struct routing_state *rstate)
 	 * stashed away for later use. If all remaining channels for a node are
 	 * zombies, the node is zombified too. */
 	for (size_t i = 0; i < tal_count(pruned); i++) {
-		zombify_channel(rstate->gs, pruned[i]);
+		zombify_channel(rstate, pruned[i]);
 	}
 }
 

gossipd/routing.h

@@ -370,7 +370,8 @@ bool routing_add_channel_update(struct routing_state *rstate,
 				u32 index,
 				struct peer *peer,
 				bool ignore_timestamp,
-				bool force_spam_flag);
+				bool force_spam_flag,
+				bool force_zombie_flag);
 /**
  * Add a node_announcement to the network view without checking it
  *