peer: make connect command an async command.

So it can return failure.

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

daemon/peer.c

@@ -15,6 +15,12 @@
 #include <sys/socket.h>
 #include <sys/types.h>
 
+struct json_connecting {
+	/* This owns us, so we're freed after command_fail or command_success */
+	struct command *cmd;
+	const char *name, *port;
+};
+
 /* Send and receive (encrypted) hello message. */
 static struct io_plan *peer_test_check(struct io_conn *conn, struct peer *peer)
 {
@@ -82,15 +88,24 @@ static struct peer *new_peer(struct lightningd_state *state,
 
 static struct io_plan *peer_connected_out(struct io_conn *conn,
 					  struct lightningd_state *state,
-					  char *dest)
+					  struct json_connecting *connect)
 {
+	struct json_result *response;
 	struct peer *peer = new_peer(state, conn, SOCK_STREAM, IPPROTO_TCP,
 				     "out");
 	if (!peer) {
-		log_unusual(peer->log, "Failed to make peer for %s", dest);
+		command_fail(connect->cmd, "Failed to make peer for %s:%s",
+			     connect->name, connect->port);
 		return io_close(conn);
 	}
-	log_info(peer->log, "Connected out to %s", dest);
+	log_info(peer->log, "Connected out to %s:%s",
+		 connect->name, connect->port);
+
+	response = new_json_result(connect);	
+	json_object_start(response, NULL);
+	json_object_end(response);
+	command_success(connect->cmd, response);
+
 	return peer_crypto_setup(conn, peer, peer_test);
 }
 
@@ -190,19 +205,19 @@ void setup_listeners(struct lightningd_state *state, unsigned int portnum)
 		fatal("Could not bind to a network address");
 }
 
-static void peer_failed(struct lightningd_state *state, char *dest)
+static void peer_failed(struct lightningd_state *state,
+			struct json_connecting *connect)
 {
 	/* FIXME: Better diagnostics! */
-	log_unusual(state->base_log, "Connect to %s failed", dest);
+	command_fail(connect->cmd, "Failed to connect to peer %s:%s",
+		     connect->name, connect->port);
 }
 
 static void json_connect(struct command *cmd,
 			const char *buffer, const jsmntok_t *params)
 {
-	struct json_result *response;
+	struct json_connecting *connect;
 	jsmntok_t *host, *port;
-	const char *hoststr, *portstr;
-	char *dest;
 
 	json_get_params(buffer, params, "host", &host, "port", &port, NULL);
 
@@ -211,26 +226,22 @@ static void json_connect(struct command *cmd,
 		return;
 	}
 
-	hoststr = tal_strndup(cmd->state, buffer + host->start,
-			      host->end - host->start);
-	portstr = tal_strndup(cmd->state, buffer + port->start,
-			      port->end - port->start);
-	dest = tal_fmt(cmd->state, "%s:%s", hoststr, portstr);
-	if (!dns_resolve_and_connect(cmd->state, hoststr, portstr,
-				     peer_connected_out, peer_failed, dest)) {
+	connect = tal(cmd, struct json_connecting);
+	connect->cmd = cmd;
+	connect->name = tal_strndup(connect, buffer + host->start,
+				    host->end - host->start);
+	connect->port = tal_strndup(connect, buffer + port->start,
+				    port->end - port->start);
+	if (!dns_resolve_and_connect(cmd->state, connect->name, connect->port,
+				     peer_connected_out, peer_failed, connect)) {
 		command_fail(cmd, "DNS failed");
 		return;
 	}
-
-	response = new_json_result(cmd);
-	json_object_start(response, NULL);
-	json_object_end(response);
-	command_success(cmd, response);
 }
 
 const struct json_command connect_command = {
 	"connect",
 	json_connect,
 	"Connect to a {host} at {port}",
-	"Returns an empty result (meaning connection in progress)"
+	"Returns an empty result on success"
 };