openingd: tell gossipd that the peer is important once funding tx in place.

And on channel_fail_permanent and closing (the two places we drop to
chain), we tell gossipd it's no longer important.

Fixes: #1316
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

gossipd/gossip.c

@@ -84,6 +84,9 @@ struct daemon {
 
 	/* To make sure our node_announcement timestamps increase */
 	u32 last_announce_timestamp;
+
+	/* Only matters if DEVELOPER defined */
+	bool no_reconnect;
 };
 
 /* Peers we're trying to reach. */
@@ -185,6 +188,10 @@ static bool try_reach_peer(struct daemon *daemon, const struct pubkey *id,
 static void destroy_peer(struct peer *peer)
 {
 	list_del_from(&peer->daemon->peers, &peer->list);
+#if DEVELOPER
+	if (peer->daemon->no_reconnect)
+		return;
+#endif
 	if (peer->keep_connected)
 		try_reach_peer(peer->daemon, &peer->id, true);
 }
@@ -1498,7 +1505,7 @@ static struct io_plan *gossip_init(struct daemon_conn *master,
 		daemon, msg, &daemon->broadcast_interval, &chain_hash,
 		&daemon->id, &port, &daemon->globalfeatures,
 		&daemon->localfeatures, &daemon->wireaddrs, daemon->rgb,
-		daemon->alias, &update_channel_interval)) {
+		daemon->alias, &update_channel_interval, &daemon->no_reconnect)) {
 		master_badmsg(WIRE_GOSSIPCTL_INIT, msg);
 	}
 	/* Prune time is twice update time */
@@ -1825,6 +1832,12 @@ static struct io_plan *peer_important(struct io_conn *conn,
 	if (p)
 		p->keep_connected = important;
 
+#if DEVELOPER
+	/* With --dev-no-reconnect, we only want explicit connects */
+	if (daemon->no_reconnect)
+		important = false;
+#endif
+
 	/* If it's important and we're not connected/connecting, do so now. */
 	if (important && !r && !p)
 		try_reach_peer(daemon, &id, true);

gossipd/gossip_wire.csv

@@ -18,6 +18,8 @@ gossipctl_init,,wireaddrs,num_wireaddrs*struct wireaddr
 gossipctl_init,,rgb,3*u8
 gossipctl_init,,alias,32*u8
 gossipctl_init,,update_channel_interval,u32
+# DEVELOPER only
+gossipctl_init,,no_reconnect,bool
 
 # Gossipd->master, I am ready.
 gossipctl_init_reply,3100

lightningd/channel.c

@@ -309,6 +309,7 @@ void channel_fail_permanent(struct channel *channel, const char *fmt, ...)
 	va_list ap;
 	char *why;
 	struct channel_id cid;
+	u8 *msg;
 
 	va_start(ap, fmt);
 	why = tal_vfmt(channel, fmt, ap);
@@ -333,6 +334,10 @@ void channel_fail_permanent(struct channel *channel, const char *fmt, ...)
 		channel->error = towire_errorfmt(channel, &cid, "%s", why);
 	}
 
+	/* Tell gossipd we no longer need to keep connection to this peer */
+	msg = towire_gossipctl_peer_important(NULL, &channel->peer->id, false);
+	subd_send_msg(ld->gossip, take(msg));
+
 	channel_set_owner(channel, NULL);
 	/* Drop non-cooperatively (unilateral) to chain. */
 	drop_to_chain(ld, channel, false);
@@ -397,8 +402,4 @@ void channel_fail_transient(struct channel *channel, const char *fmt, ...)
 #endif
 
 	channel_set_owner(channel, NULL);
-
-	/* Reconnect unless we've dropped/are dropping to chain. */
-	if (channel_active(channel))
-		try_reconnect(channel->peer);
 }

lightningd/closing_control.c

@@ -4,6 +4,7 @@
 #include <common/initial_commit_tx.h>
 #include <common/utils.h>
 #include <errno.h>
+#include <gossipd/gen_gossip_wire.h>
 #include <inttypes.h>
 #include <lightningd/chaintopology.h>
 #include <lightningd/channel.h>
@@ -93,6 +94,10 @@ static void peer_closing_complete(struct channel *channel, const u8 *msg)
 	if (channel->state == CLOSINGD_COMPLETE)
 		return;
 
+	/* Tell gossipd we no longer need to keep connection to this peer */
+	msg = towire_gossipctl_peer_important(NULL, &channel->peer->id, false);
+	subd_send_msg(channel->peer->ld->gossip, take(msg));
+
 	/* Channel gets dropped to chain cooperatively. */
 	drop_to_chain(channel->peer->ld, channel, true);
 	channel_set_state(channel, CLOSINGD_SIGEXCHANGE, CLOSINGD_COMPLETE);

lightningd/gossip_control.c

@@ -194,6 +194,11 @@ void gossip_init(struct lightningd *ld)
 	u8 *msg;
 	int hsmfd;
 	u64 capabilities = HSM_CAP_ECDH | HSM_CAP_SIGN_GOSSIP;
+#if DEVELOPER
+	bool no_reconnect = ld->no_reconnect;
+#else
+	bool no_reconnect = false;
+#endif
 
 	msg = towire_hsm_client_hsmfd(tmpctx, &ld->id, capabilities);
 	if (!wire_sync_write(ld->hsm_fd, msg))
@@ -218,7 +223,7 @@ void gossip_init(struct lightningd *ld)
 	    &get_chainparams(ld)->genesis_blockhash, &ld->id, ld->portnum,
 	    get_offered_global_features(tmpctx),
 	    get_offered_local_features(tmpctx), ld->wireaddrs, ld->rgb,
-	    ld->alias, ld->config.channel_update_interval);
+	    ld->alias, ld->config.channel_update_interval, no_reconnect);
 	subd_req(ld->gossip, ld->gossip, msg, -1, 0, gossip_init_done, NULL);
 
 	/* Wait for init done */

lightningd/opening_control.c

@@ -255,6 +255,23 @@ static void funding_broadcast_failed(struct channel *channel,
 			       exitstatus, err);
 }
 
+static void tell_gossipd_peer_is_important(struct lightningd *ld,
+					   const struct channel *channel)
+{
+	u8 *msg;
+
+#if DEVELOPER
+	/* Don't schedule an attempt if we disabled reconnections with
+	 * the `--dev-no-reconnect` flag */
+	if (ld->no_reconnect)
+		return;
+#endif /* DEVELOPER */
+
+	/* Tell gossipd we need to keep connection to this peer */
+	msg = towire_gossipctl_peer_important(NULL, &channel->peer->id, true);
+	subd_send_msg(ld->gossip, take(msg));
+}
+
 static void opening_funder_finished(struct subd *openingd, const u8 *resp,
 				    const int *fds,
 				    struct funding_channel *fc)
@@ -410,6 +427,8 @@ static void opening_funder_finished(struct subd *openingd, const u8 *resp,
 
 	channel_watch_funding(ld, channel);
 
+	tell_gossipd_peer_is_important(ld, channel);
+
 	/* Start normal channel daemon. */
 	peer_start_channeld(channel, &cs, gossip_index,
 			    fds[0], fds[1], NULL, false);
@@ -515,6 +534,8 @@ static void opening_fundee_finished(struct subd *openingd,
 
 	channel_watch_funding(ld, channel);
 
+	tell_gossipd_peer_is_important(ld, channel);
+
 	/* On to normal operation! */
 	peer_start_channeld(channel, &cs, gossip_index,
 			    fds[0], fds[1], funding_signed, false);

lightningd/peer_control.c

@@ -1090,7 +1090,7 @@ static const struct json_command close_command = {
 };
 AUTODATA(json_command, &close_command);
 
-void try_reconnect(struct peer *peer)
+static void try_reconnect(struct peer *peer)
 {
 	struct lightningd *ld = peer->ld;
 	u8 *msg;

lightningd/peer_control.h

@@ -61,9 +61,6 @@ struct peer *new_peer(struct lightningd *ld, u64 dbid,
 /* Also removes from db. */
 void delete_peer(struct peer *peer);
 
-/* Tell gossipd to try to reconnect (unless --dev-no-reconnect) */
-void try_reconnect(struct peer *peer);
-
 struct peer *peer_by_id(struct lightningd *ld, const struct pubkey *id);
 struct peer *peer_from_json(struct lightningd *ld,
 			    const char *buffer,

wallet/test/run-wallet.c

@@ -387,6 +387,9 @@ u8 *towire_gossipctl_peer_addrhint(const tal_t *ctx UNNEEDED, const struct pubke
 /* Generated stub for towire_gossipctl_peer_disconnect */
 u8 *towire_gossipctl_peer_disconnect(const tal_t *ctx UNNEEDED, const struct pubkey *id UNNEEDED)
 { fprintf(stderr, "towire_gossipctl_peer_disconnect called!\n"); abort(); }
+/* Generated stub for towire_gossipctl_peer_important */
+u8 *towire_gossipctl_peer_important(const tal_t *ctx UNNEEDED, const struct pubkey *id UNNEEDED, bool important UNNEEDED)
+{ fprintf(stderr, "towire_gossipctl_peer_important called!\n"); abort(); }
 /* Generated stub for towire_gossipctl_reach_peer */
 u8 *towire_gossipctl_reach_peer(const tal_t *ctx UNNEEDED, const struct pubkey *id UNNEEDED)
 { fprintf(stderr, "towire_gossipctl_reach_peer called!\n"); abort(); }