lightningd: don't explicitly tell connectd to disconnect, have it do …

…it on sending error/warning.

Connectd already does this when we *receive* an error or warning, but
now do it on send.  This causes some slight behavior change: we don't
disconnect when we close a channel, for example (our behaviour here
has been inconsistent across versions, depending on the code).

When connectd is told to disconnect, it now does so immediately, and
doesn't wait for subds to drain etc.  That simplifies the manual
disconnect case, which now cleans up as it would from any other
disconnection when connectd says it's disconnected.

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

connectd/connectd.c

@@ -1868,7 +1868,7 @@ static void peer_discard(struct daemon *daemon, const u8 *msg)
 	if (peer->counter != counter)
 		return;
 	status_peer_debug(&id, "discard_peer");
-	drain_peer(peer);
+	tal_free(peer);
 }
 
 /* lightningd tells us to send a msg and disconnect. */

connectd/multiplex.c

@@ -109,7 +109,7 @@ static void close_subd_timeout(struct subd *subd)
 	io_close(subd->conn);
 }
 
-void drain_peer(struct peer *peer)
+static void drain_peer(struct peer *peer)
 {
 	status_debug("drain_peer");
 	assert(!peer->draining);
@@ -403,6 +403,12 @@ static bool is_urgent(enum peer_wire type)
 	return false;
 }
 
+/* io_sock_shutdown, but in format suitable for an io_plan callback */
+static struct io_plan *io_sock_shutdown_cb(struct io_conn *conn, struct peer *unused)
+{
+	return io_sock_shutdown(conn);
+}
+
 static struct io_plan *encrypt_and_send(struct peer *peer,
 					const u8 *msg TAKES,
 					struct io_plan *(*next)
@@ -438,6 +444,21 @@ static struct io_plan *encrypt_and_send(struct peer *peer,
 #endif
 	set_urgent_flag(peer, is_urgent(type));
 
+	/* BOLT #1:
+	 *
+	 * A sending node:
+	 *...
+	 *  - MAY close the connection after sending.
+	 */
+	if (type == WIRE_ERROR || type == WIRE_WARNING) {
+		/* Might already be draining... */
+		if (!peer->draining)
+			drain_peer(peer);
+
+		/* Close as soon as we've sent this. */
+		next = io_sock_shutdown_cb;
+	}
+
 	/* We free this and the encrypted version in next write_to_peer */
 	peer->sent_to_peer = cryptomsg_encrypt_msg(peer, &peer->cs, msg);
 	return io_write(peer->to_peer,

connectd/multiplex.h

@@ -22,10 +22,6 @@ void multiplex_final_msg(struct peer *peer,
  * this does io logging. */
 void inject_peer_msg(struct peer *peer, const u8 *msg TAKES);
 
-/* Start closing the peer: removes itself from hash table, frees itself
- * once done. */
-void drain_peer(struct peer *peer);
-
 void setup_peer_gossip_store(struct peer *peer,
 			     const struct feature_set *our_features,
 			     const u8 *their_features);

lightningd/channel.c

@@ -22,14 +22,10 @@
 void channel_set_owner(struct channel *channel, struct subd *owner)
 {
 	struct subd *old_owner = channel->owner;
-	bool was_connected = channel_is_connected(channel);
 	channel->owner = owner;
 
-	if (old_owner) {
+	if (old_owner)
 		subd_release_channel(old_owner, channel);
-		if (was_connected && !channel_is_connected(channel))
-			maybe_disconnect_peer(channel->peer->ld, channel->peer);
-	}
 }
 
 struct htlc_out *channel_has_htlc_out(struct channel *channel)

lightningd/connect_control.c

@@ -641,33 +641,6 @@ void connectd_activate(struct lightningd *ld)
 	assert(ret == ld->connectd);
 }
 
-void maybe_disconnect_peer(struct lightningd *ld, struct peer *peer)
-{
-	struct channel *channel;
-
-	/* Any channels left which want to talk? */
-	if (peer->uncommitted_channel)
-		return;
-
-	list_for_each(&peer->channels, channel, list)
-		if (channel_is_connected(channel))
-			return;
-
-	/* If shutting down, connectd no longer exists.
-	 * FIXME: Call peer_disconnect_done(), but nobody cares. */
-	if (!ld->connectd) {
-		peer->connected = PEER_DISCONNECTED;
-		return;
-	}
-
-	/* If connectd was the one who told us to cleanup peer, don't
-	 * tell it to discard again: it might have reconnected! */
-	if (peer->connected == PEER_CONNECTED)
-		subd_send_msg(ld->connectd,
-			      take(towire_connectd_discard_peer(NULL, &peer->id,
-								peer->connectd_counter)));
-}
-
 static struct command_result *json_sendcustommsg(struct command *cmd,
 						 const char *buffer,
 						 const jsmntok_t *obj UNNEEDED,

lightningd/connect_control.h

@@ -24,7 +24,4 @@ void connect_failed_disconnect(struct lightningd *ld,
 			       const struct node_id *id,
 			       const struct wireaddr_internal *addr);
 
-/* Disconnect a peer (if no subds want to talk any more) */
-void maybe_disconnect_peer(struct lightningd *ld, struct peer *peer);
-
 #endif /* LIGHTNING_LIGHTNINGD_CONNECT_CONTROL_H */

lightningd/opening_common.c

@@ -31,7 +31,6 @@ static void destroy_uncommitted_channel(struct uncommitted_channel *uc)
 
 	uc->peer->uncommitted_channel = NULL;
 
-	maybe_disconnect_peer(uc->peer->ld, uc->peer);
 	maybe_delete_peer(uc->peer);
 }
 

lightningd/peer_control.c

@@ -1539,11 +1539,6 @@ void peer_disconnect_done(struct lightningd *ld, const u8 *msg)
 		assert(p->connectd_counter == connectd_counter);
 		log_peer_debug(ld->log, &id, "peer_disconnect_done");
 		p->connected = PEER_DISCONNECTED;
-
-		/* If there are literally no channels, might as well
-		 * free immediately. */
-		if (!p->uncommitted_channel && list_empty(&p->channels))
-			p = tal_free(p);
 	}
 
 	/* If you were trying to connect, it failed. */
@@ -1561,6 +1556,10 @@ void peer_disconnect_done(struct lightningd *ld, const u8 *msg)
 		was_pending(command_success(i->cmd,
 					    json_stream_success(i->cmd)));
 	}
+
+	/* If connection was only thing keeping it, this will delete it. */
+	if (p)
+		maybe_delete_peer(p);
 }
 
 static bool check_funding_details(const struct bitcoin_tx *tx,
@@ -2084,9 +2083,8 @@ static struct command_result *json_disconnect(struct command *cmd,
 	struct node_id *id;
 	struct disconnect_command *dc;
 	struct peer *peer;
-	struct channel *channel, **channels;
+	struct channel *channel;
 	bool *force;
-	bool disconnected = false;
 
 	if (!param(cmd, buffer, params,
 		   p_req("id", param_node_id, &id),
@@ -2109,58 +2107,11 @@ static struct command_result *json_disconnect(struct command *cmd,
 				    channel_state_name(channel));
 	}
 
-	/* Careful here!  Disconnecting can free peer! */
-	channels = tal_arr(cmd, struct channel *, 0);
-	list_for_each(&peer->channels, channel, list) {
-		if (!channel->owner)
-			continue;
-		if (!channel->owner->talks_to_peer)
-			continue;
-
-		switch (channel->state) {
-		case DUALOPEND_OPEN_INIT:
-		case CHANNELD_AWAITING_LOCKIN:
-		case CHANNELD_NORMAL:
-		case CHANNELD_SHUTTING_DOWN:
-		case DUALOPEND_AWAITING_LOCKIN:
-		case CLOSINGD_SIGEXCHANGE:
-			tal_arr_expand(&channels, channel);
-			continue;
-		case CLOSINGD_COMPLETE:
-		case AWAITING_UNILATERAL:
-		case FUNDING_SPEND_SEEN:
-		case ONCHAIN:
-		case CLOSED:
-			/* We don't expect these to have owners who connect! */
-			log_broken(channel->log,
-				   "Don't expect owner %s in state %s",
-				   channel->owner->name,
-				   channel_state_name(channel));
-			continue;
-		}
-		abort();
-	}
-
-	/* This can free peer too! */
-	if (peer->uncommitted_channel) {
-		kill_uncommitted_channel(peer->uncommitted_channel,
-					 "disconnect command");
-		disconnected = true;
-	}
-
-	for (size_t i = 0; i < tal_count(channels); i++) {
-		if (channel_unsaved(channels[i]))
-			channel_unsaved_close_conn(channels[i],
-						   "disconnect command");
-		else
-			channel_fail_reconnect(channels[i],
-					       "disconnect command");
-		disconnected = true;
-	}
-
-	/* It's just sitting in connectd? */
-	if (!disconnected)
-		maybe_disconnect_peer(cmd->ld, peer);
+	/* If it's not already disconnecting, tell connectd to disconnect */
+	if (peer->connected == PEER_CONNECTED)
+		subd_send_msg(peer->ld->connectd,
+			      take(towire_connectd_discard_peer(NULL, &peer->id,
+								peer->connectd_counter)));
 
 	/* Connectd tells us when it's finally disconnected */
 	dc = tal(cmd, struct disconnect_command);

lightningd/test/run-invoice-select-inchan.c

@@ -387,7 +387,9 @@ void json_add_short_channel_id(struct json_stream *response UNNEEDED,
 			       const struct short_channel_id *id UNNEEDED)
 { fprintf(stderr, "json_add_short_channel_id called!\n"); abort(); }
 /* Generated stub for json_add_string */
-void json_add_string(struct json_stream *result UNNEEDED, const char *fieldname UNNEEDED, const char *value TAKES UNNEEDED)
+void json_add_string(struct json_stream *js UNNEEDED,
+		     const char *fieldname UNNEEDED,
+		     const char *str TAKES UNNEEDED)
 { fprintf(stderr, "json_add_string called!\n"); abort(); }
 /* Generated stub for json_add_stringn */
 void json_add_stringn(struct json_stream *result UNNEEDED, const char *fieldname UNNEEDED,
@@ -509,9 +511,6 @@ void log_(struct log *log UNNEEDED, enum log_level level UNNEEDED,
 	  const char *fmt UNNEEDED, ...)
 
 { fprintf(stderr, "log_ called!\n"); abort(); }
-/* Generated stub for maybe_disconnect_peer */
-void maybe_disconnect_peer(struct lightningd *ld UNNEEDED, struct peer *peer UNNEEDED)
-{ fprintf(stderr, "maybe_disconnect_peer called!\n"); abort(); }
 /* Generated stub for merkle_tlv */
 void merkle_tlv(const struct tlv_field *fields UNNEEDED, struct sha256 *merkle UNNEEDED)
 { fprintf(stderr, "merkle_tlv called!\n"); abort(); }
@@ -716,6 +715,9 @@ u8 *towire_channeld_dev_memleak(const tal_t *ctx UNNEEDED)
 /* Generated stub for towire_channeld_dev_reenable_commit */
 u8 *towire_channeld_dev_reenable_commit(const tal_t *ctx UNNEEDED)
 { fprintf(stderr, "towire_channeld_dev_reenable_commit called!\n"); abort(); }
+/* Generated stub for towire_connectd_discard_peer */
+u8 *towire_connectd_discard_peer(const tal_t *ctx UNNEEDED, const struct node_id *id UNNEEDED, u64 counter UNNEEDED)
+{ fprintf(stderr, "towire_connectd_discard_peer called!\n"); abort(); }
 /* Generated stub for towire_connectd_peer_connect_subd */
 u8 *towire_connectd_peer_connect_subd(const tal_t *ctx UNNEEDED, const struct node_id *id UNNEEDED, u64 counter UNNEEDED, const struct channel_id *channel_id UNNEEDED)
 { fprintf(stderr, "towire_connectd_peer_connect_subd called!\n"); abort(); }

lightningd/test/run-log-pruning.c

@@ -47,7 +47,9 @@ void json_add_str_fmt(struct json_stream *js UNNEEDED,
 		      const char *fmt UNNEEDED, ...)
 { fprintf(stderr, "json_add_str_fmt called!\n"); abort(); }
 /* Generated stub for json_add_string */
-void json_add_string(struct json_stream *result UNNEEDED, const char *fieldname UNNEEDED, const char *value TAKES UNNEEDED)
+void json_add_string(struct json_stream *js UNNEEDED,
+		     const char *fieldname UNNEEDED,
+		     const char *str TAKES UNNEEDED)
 { fprintf(stderr, "json_add_string called!\n"); abort(); }
 /* Generated stub for json_add_time */
 void json_add_time(struct json_stream *result UNNEEDED, const char *fieldname UNNEEDED,

plugins/test/run-route-overlong.c

@@ -75,7 +75,9 @@ void json_add_short_channel_id(struct json_stream *response UNNEEDED,
 			       const struct short_channel_id *id UNNEEDED)
 { fprintf(stderr, "json_add_short_channel_id called!\n"); abort(); }
 /* Generated stub for json_add_string */
-void json_add_string(struct json_stream *result UNNEEDED, const char *fieldname UNNEEDED, const char *value TAKES UNNEEDED)
+void json_add_string(struct json_stream *js UNNEEDED,
+		     const char *fieldname UNNEEDED,
+		     const char *str TAKES UNNEEDED)
 { fprintf(stderr, "json_add_string called!\n"); abort(); }
 /* Generated stub for json_add_timeabs */
 void json_add_timeabs(struct json_stream *result UNNEEDED, const char *fieldname UNNEEDED,
@@ -155,12 +157,10 @@ bool json_to_u16(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
                  uint16_t *num UNNEEDED)
 { fprintf(stderr, "json_to_u16 called!\n"); abort(); }
 /* Generated stub for json_to_u32 */
-bool json_to_u32(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		 uint32_t *num UNNEEDED)
+bool json_to_u32(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED, u32 *num UNNEEDED)
 { fprintf(stderr, "json_to_u32 called!\n"); abort(); }
 /* Generated stub for json_to_u64 */
-bool json_to_u64(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
-		 uint64_t *num UNNEEDED)
+bool json_to_u64(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED, u64 *num UNNEEDED)
 { fprintf(stderr, "json_to_u64 called!\n"); abort(); }
 /* Generated stub for json_tok_bin_from_hex */
 u8 *json_tok_bin_from_hex(const tal_t *ctx UNNEEDED, const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED)

tests/test_closing.py

@@ -550,7 +550,7 @@ def test_penalty_inhtlc(node_factory, bitcoind, executor, chainparams):
     bitcoind.generate_block(100)
 
     sync_blockheight(bitcoind, [l1, l2])
-    wait_for(lambda: len(l2.rpc.listpeers()['peers']) == 0)
+    wait_for(lambda: only_one(l2.rpc.listpeers()['peers'])['channels'] == [])
 
     # Do one last pass over the logs to extract the reactions l2 sent
     l2.daemon.logsearch_start = needle
@@ -679,7 +679,7 @@ def test_penalty_outhtlc(node_factory, bitcoind, executor, chainparams):
     bitcoind.generate_block(100)
 
     sync_blockheight(bitcoind, [l1, l2])
-    wait_for(lambda: len(l2.rpc.listpeers()['peers']) == 0)
+    wait_for(lambda: only_one(l2.rpc.listpeers()['peers'])['channels'] == [])
 
     # Do one last pass over the logs to extract the reactions l2 sent
     l2.daemon.logsearch_start = needle
@@ -3447,10 +3447,8 @@ def test_you_forgot_closed_channel(node_factory, executor):
     wait_for(lambda: only_one(only_one(l2.rpc.listpeers()['peers'])['channels'])['state'] == 'CLOSINGD_COMPLETE')
     assert only_one(only_one(l1.rpc.listpeers()['peers'])['channels'])['state'] == 'CLOSINGD_SIGEXCHANGE'
 
-    # l2 closes on us.
-    wait_for(lambda: only_one(l1.rpc.listpeers()['peers'])['connected'] is False)
-
-    # l1 reconnects, it should succeed.
+    # l1 won't send anything else until we reconnect, then it should succeed.
+    l1.rpc.disconnect(l2.info['id'], force=True)
     l1.rpc.connect(l2.info['id'], 'localhost', l2.port)
     fut.result(TIMEOUT)
 
@@ -3486,8 +3484,7 @@ def no_new_blocks(req):
     wait_for(lambda: only_one(only_one(l2.rpc.listpeers()['peers'])['channels'])['state'] == 'ONCHAIN')
 
     # l1 reconnects, it should succeed.
-    # l1 will disconnect once it sees block
-    wait_for(lambda: only_one(l1.rpc.listpeers()['peers'])['connected'] is False)
+    l1.rpc.disconnect(l2.info['id'], force=True)
     l1.rpc.connect(l2.info['id'], 'localhost', l2.port)
     fut.result(TIMEOUT)