lightningd: close channel ourselves, if we receive an error.

Previously, we would forward the message to a subd, but now we have
the case where the subd is gone, but we're still connected.  If the
peer anything but a reestablish in that state, we drop the connection.

Instead, an error should always make us fail the channel.

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

connectd/connectd_wire.csv

@@ -86,6 +86,8 @@ msgdata,connectd_peer_spoke,id,node_id,
 msgdata,connectd_peer_spoke,counter,u64,
 msgdata,connectd_peer_spoke,msgtype,u16,
 msgdata,connectd_peer_spoke,channel_id,channel_id,
+# If msgtype == WIRE_ERROR, this is the string.
+msgdata,connectd_peer_spoke,error,?wirestring,
 
 # master -> connectd: peer no longer wanted, you can disconnect.
 msgtype,connectd_discard_peer,2015

connectd/multiplex.c

@@ -1120,7 +1120,8 @@ static struct io_plan *read_body_from_peer_done(struct io_conn *peer_conn,
 				take(towire_connectd_peer_spoke(NULL, &peer->id,
 								peer->counter,
 								t,
-								&channel_id)));
+								&channel_id,
+								is_peer_error(tmpctx, decrypted))));
        }
 
        /* Even if we just created it, call this to catch open_channel2 */

lightningd/peer_control.c

@@ -1578,8 +1578,9 @@ void peer_spoke(struct lightningd *ld, const u8 *msg)
 	bool dual_fund;
 	u8 *error;
 	int fds[2];
+	char *errmsg;
 
-	if (!fromwire_connectd_peer_spoke(msg, &id, &connectd_counter, &msgtype, &channel_id))
+	if (!fromwire_connectd_peer_spoke(msg, msg, &id, &connectd_counter, &msgtype, &channel_id, &errmsg))
 		fatal("Connectd gave bad CONNECTD_PEER_SPOKE message %s",
 		      tal_hex(msg, msg));
 
@@ -1596,13 +1597,25 @@ void peer_spoke(struct lightningd *ld, const u8 *msg)
 			goto send_error;
 		}
 
-		/* If channel is active, we raced, so ignore this:
-		 * subd will get it soon. */
 		if (channel_state_wants_peercomms(channel->state)) {
-			log_debug(channel->log,
+			/* If they send an error, handle it immediately. */
-				  "channel already active");
+			if (errmsg) {
-			if (!channel->owner &&
+				channel_fail_permanent(channel, REASON_REMOTE,
-			    channel->state == DUALOPEND_AWAITING_LOCKIN) {
+						       "They sent %s", errmsg);
+				return;
+			}
+
+			/* If channel is active there are two possibilities:
+			 * 1. We have started subd, but channeld hasn't processed
+			 *    the connectd_peer_connect_subd message yet.
+			 * 2. subd exited */
+			if (channel->owner) {
+				/* We raced... */
+				return;
+			}
+
+			log_debug(channel->log, "channel already active");
+			if (channel->state == DUALOPEND_AWAITING_LOCKIN) {
 				if (socketpair(AF_LOCAL, SOCK_STREAM, 0, fds) != 0) {
 					log_broken(ld->log,
 						   "Failed to create socketpair: %s",

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

@@ -277,7 +277,7 @@ bool fromwire_connectd_peer_connected(const tal_t *ctx UNNEEDED, const void *p U
 bool fromwire_connectd_peer_disconnect_done(const void *p UNNEEDED, struct node_id *id UNNEEDED, u64 *counter UNNEEDED)
 { fprintf(stderr, "fromwire_connectd_peer_disconnect_done called!\n"); abort(); }
 /* Generated stub for fromwire_connectd_peer_spoke */
-bool fromwire_connectd_peer_spoke(const void *p UNNEEDED, struct node_id *id UNNEEDED, u64 *counter UNNEEDED, u16 *msgtype UNNEEDED, struct channel_id *channel_id UNNEEDED)
+bool fromwire_connectd_peer_spoke(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, struct node_id *id UNNEEDED, u64 *counter UNNEEDED, u16 *msgtype UNNEEDED, struct channel_id *channel_id UNNEEDED, wirestring **error UNNEEDED)
 { fprintf(stderr, "fromwire_connectd_peer_spoke called!\n"); abort(); }
 /* Generated stub for fromwire_dualopend_dev_memleak_reply */
 bool fromwire_dualopend_dev_memleak_reply(const void *p UNNEEDED, bool *leak UNNEEDED)

wallet/test/run-wallet.c

@@ -192,7 +192,7 @@ bool fromwire_connectd_peer_connected(const tal_t *ctx UNNEEDED, const void *p U
 bool fromwire_connectd_peer_disconnect_done(const void *p UNNEEDED, struct node_id *id UNNEEDED, u64 *counter UNNEEDED)
 { fprintf(stderr, "fromwire_connectd_peer_disconnect_done called!\n"); abort(); }
 /* Generated stub for fromwire_connectd_peer_spoke */
-bool fromwire_connectd_peer_spoke(const void *p UNNEEDED, struct node_id *id UNNEEDED, u64 *counter UNNEEDED, u16 *msgtype UNNEEDED, struct channel_id *channel_id UNNEEDED)
+bool fromwire_connectd_peer_spoke(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, struct node_id *id UNNEEDED, u64 *counter UNNEEDED, u16 *msgtype UNNEEDED, struct channel_id *channel_id UNNEEDED, wirestring **error UNNEEDED)
 { fprintf(stderr, "fromwire_connectd_peer_spoke called!\n"); abort(); }
 /* Generated stub for fromwire_dualopend_dev_memleak_reply */
 bool fromwire_dualopend_dev_memleak_reply(const void *p UNNEEDED, bool *leak UNNEEDED)