gossip: Store channel deletions so we don't re-add them on restart

If we only remember the actions that added channels then we'd restore them when
re-reading the gossip_store, so put a tombstone in there to remember to delete
it. These will be cleared upon re-writing the store since the announcements wont
be written anymore.

Signed-off-by: Christian Decker <decker.christian@gmail.com>

gossipd/gossip.c

@@ -2007,6 +2007,7 @@ static struct io_plan *handle_outpoint_spent(struct io_conn *conn,
 		 * of the channel and the destructor takes care of unregistering
 		 * the channel */
 		tal_free(chan);
+		gossip_store_add_channel_delete(rstate->store, &scid);
 	}
 
 	return daemon_conn_read_next(conn, &daemon->master);
@@ -2096,6 +2097,7 @@ static struct io_plan *recv_req(struct io_conn *conn, struct daemon_conn *master
 	case WIRE_GOSSIP_STORE_CHANNEL_ANNOUNCEMENT:
 	case WIRE_GOSSIP_STORE_CHANNEL_UPDATE:
 	case WIRE_GOSSIP_STORE_NODE_ANNOUNCEMENT:
+	case WIRE_GOSSIP_STORE_CHANNEL_DELETE:
 		break;
 	}
 

gossipd/gossip_store.c

@@ -88,6 +88,14 @@ void gossip_store_add_node_announcement(struct gossip_store *gs,
 	tal_free(msg);
 }
 
+void gossip_store_add_channel_delete(struct gossip_store *gs,
+				     const struct short_channel_id *scid)
+{
+	u8 *msg = towire_gossip_store_channel_delete(NULL, scid);
+	gossip_store_append(gs, msg);
+	tal_free(msg);
+}
+
 bool gossip_store_read_next(struct routing_state *rstate,
 			    struct gossip_store *gs)
 {
@@ -96,6 +104,7 @@ bool gossip_store_read_next(struct routing_state *rstate,
 	u8 *msg, *gossip_msg;
 	u64 satoshis;
 	enum gossip_wire_type type;
+	struct short_channel_id scid;
 
 	/* Did we already reach the end of the gossip_store? */
 	if (gs->read_pos == -1)
@@ -135,6 +144,9 @@ bool gossip_store_read_next(struct routing_state *rstate,
 	} else if(type == WIRE_GOSSIP_STORE_NODE_ANNOUNCEMENT) {
 		fromwire_gossip_store_node_announcement(msg, msg, &gossip_msg);
 		routing_add_node_announcement(rstate, gossip_msg);
+	} else if(type == WIRE_GOSSIP_STORE_CHANNEL_DELETE) {
+		fromwire_gossip_store_channel_delete(msg, &scid);
+		tal_free(get_channel(rstate, &scid));
 	}
 	tal_free(msg);
 	return true;

gossipd/gossip_store.h

@@ -3,6 +3,7 @@
 
 #include "config.h"
 
+#include <bitcoin/short_channel_id.h>
 #include <ccan/short_types/short_types.h>
 #include <ccan/tal/tal.h>
 #include <gossipd/routing.h>
@@ -44,4 +45,10 @@ void gossip_store_add_channel_update(struct gossip_store *gs,
 void gossip_store_add_node_announcement(struct gossip_store *gs,
 					const u8 *gossip_msg);
 
+/**
+ * Remember that we deleted a channel as a result of its outpoint being spent
+ */
+void gossip_store_add_channel_delete(struct gossip_store *gs,
+				     const struct short_channel_id *scid);
+
 #endif /* LIGHTNING_GOSSIPD_GOSSIP_STORE_H */

gossipd/gossip_wire.csv

@@ -242,3 +242,6 @@ gossip_store_channel_update,,update,len*u8
 gossip_store_node_announcement,4098
 gossip_store_node_announcement,,len,u16
 gossip_store_node_announcement,,announcement,len*u8
+
+gossip_store_channel_delete,4099
+gossip_store_channel_delete,,short_channel_id,struct short_channel_id

gossipd/test/run-bench-find_route.c

@@ -65,6 +65,9 @@ bool fromwire_channel_update(const void *p UNNEEDED, secp256k1_ecdsa_signature *
 /* Generated stub for fromwire_gossip_store_channel_announcement */
 bool fromwire_gossip_store_channel_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, u8 **announcement UNNEEDED, u64 *satoshis UNNEEDED)
 { fprintf(stderr, "fromwire_gossip_store_channel_announcement called!\n"); abort(); }
+/* Generated stub for fromwire_gossip_store_channel_delete */
+bool fromwire_gossip_store_channel_delete(const void *p UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED)
+{ fprintf(stderr, "fromwire_gossip_store_channel_delete called!\n"); abort(); }
 /* Generated stub for fromwire_gossip_store_channel_update */
 bool fromwire_gossip_store_channel_update(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, u8 **update UNNEEDED)
 { fprintf(stderr, "fromwire_gossip_store_channel_update called!\n"); abort(); }
@@ -108,6 +111,9 @@ u8 *towire_errorfmt(const tal_t *ctx UNNEEDED,
 /* Generated stub for towire_gossip_store_channel_announcement */
 u8 *towire_gossip_store_channel_announcement(const tal_t *ctx UNNEEDED, const u8 *announcement UNNEEDED, u64 satoshis UNNEEDED)
 { fprintf(stderr, "towire_gossip_store_channel_announcement called!\n"); abort(); }
+/* Generated stub for towire_gossip_store_channel_delete */
+u8 *towire_gossip_store_channel_delete(const tal_t *ctx UNNEEDED, const struct short_channel_id *short_channel_id UNNEEDED)
+{ fprintf(stderr, "towire_gossip_store_channel_delete called!\n"); abort(); }
 /* Generated stub for towire_gossip_store_channel_update */
 u8 *towire_gossip_store_channel_update(const tal_t *ctx UNNEEDED, const u8 *update UNNEEDED)
 { fprintf(stderr, "towire_gossip_store_channel_update called!\n"); abort(); }

gossipd/test/run-find_route-specific.c

@@ -29,6 +29,9 @@ bool fromwire_channel_update(const void *p UNNEEDED, secp256k1_ecdsa_signature *
 /* Generated stub for fromwire_gossip_store_channel_announcement */
 bool fromwire_gossip_store_channel_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, u8 **announcement UNNEEDED, u64 *satoshis UNNEEDED)
 { fprintf(stderr, "fromwire_gossip_store_channel_announcement called!\n"); abort(); }
+/* Generated stub for fromwire_gossip_store_channel_delete */
+bool fromwire_gossip_store_channel_delete(const void *p UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED)
+{ fprintf(stderr, "fromwire_gossip_store_channel_delete called!\n"); abort(); }
 /* Generated stub for fromwire_gossip_store_channel_update */
 bool fromwire_gossip_store_channel_update(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, u8 **update UNNEEDED)
 { fprintf(stderr, "fromwire_gossip_store_channel_update called!\n"); abort(); }
@@ -72,6 +75,9 @@ u8 *towire_errorfmt(const tal_t *ctx UNNEEDED,
 /* Generated stub for towire_gossip_store_channel_announcement */
 u8 *towire_gossip_store_channel_announcement(const tal_t *ctx UNNEEDED, const u8 *announcement UNNEEDED, u64 satoshis UNNEEDED)
 { fprintf(stderr, "towire_gossip_store_channel_announcement called!\n"); abort(); }
+/* Generated stub for towire_gossip_store_channel_delete */
+u8 *towire_gossip_store_channel_delete(const tal_t *ctx UNNEEDED, const struct short_channel_id *short_channel_id UNNEEDED)
+{ fprintf(stderr, "towire_gossip_store_channel_delete called!\n"); abort(); }
 /* Generated stub for towire_gossip_store_channel_update */
 u8 *towire_gossip_store_channel_update(const tal_t *ctx UNNEEDED, const u8 *update UNNEEDED)
 { fprintf(stderr, "towire_gossip_store_channel_update called!\n"); abort(); }

gossipd/test/run-find_route.c

@@ -27,6 +27,9 @@ bool fromwire_channel_update(const void *p UNNEEDED, secp256k1_ecdsa_signature *
 /* Generated stub for fromwire_gossip_store_channel_announcement */
 bool fromwire_gossip_store_channel_announcement(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, u8 **announcement UNNEEDED, u64 *satoshis UNNEEDED)
 { fprintf(stderr, "fromwire_gossip_store_channel_announcement called!\n"); abort(); }
+/* Generated stub for fromwire_gossip_store_channel_delete */
+bool fromwire_gossip_store_channel_delete(const void *p UNNEEDED, struct short_channel_id *short_channel_id UNNEEDED)
+{ fprintf(stderr, "fromwire_gossip_store_channel_delete called!\n"); abort(); }
 /* Generated stub for fromwire_gossip_store_channel_update */
 bool fromwire_gossip_store_channel_update(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, u8 **update UNNEEDED)
 { fprintf(stderr, "fromwire_gossip_store_channel_update called!\n"); abort(); }
@@ -70,6 +73,9 @@ u8 *towire_errorfmt(const tal_t *ctx UNNEEDED,
 /* Generated stub for towire_gossip_store_channel_announcement */
 u8 *towire_gossip_store_channel_announcement(const tal_t *ctx UNNEEDED, const u8 *announcement UNNEEDED, u64 satoshis UNNEEDED)
 { fprintf(stderr, "towire_gossip_store_channel_announcement called!\n"); abort(); }
+/* Generated stub for towire_gossip_store_channel_delete */
+u8 *towire_gossip_store_channel_delete(const tal_t *ctx UNNEEDED, const struct short_channel_id *short_channel_id UNNEEDED)
+{ fprintf(stderr, "towire_gossip_store_channel_delete called!\n"); abort(); }
 /* Generated stub for towire_gossip_store_channel_update */
 u8 *towire_gossip_store_channel_update(const tal_t *ctx UNNEEDED, const u8 *update UNNEEDED)
 { fprintf(stderr, "towire_gossip_store_channel_update called!\n"); abort(); }

lightningd/gossip_control.c

@@ -153,6 +153,7 @@ static unsigned gossip_msg(struct subd *gossip, const u8 *msg, const int *fds)
 	case WIRE_GOSSIP_STORE_CHANNEL_ANNOUNCEMENT:
 	case WIRE_GOSSIP_STORE_CHANNEL_UPDATE:
 	case WIRE_GOSSIP_STORE_NODE_ANNOUNCEMENT:
+	case WIRE_GOSSIP_STORE_CHANNEL_DELETE:
 		break;
 	/* These are inter-daemon messages, not received by us */
 	case WIRE_GOSSIP_LOCAL_ADD_CHANNEL: