diff --git a/lualib/snax/gateserver.lua b/lualib/snax/gateserver.lua
index dfce2fa9..68f77b58 100644
--- a/lualib/snax/gateserver.lua
+++ b/lualib/snax/gateserver.lua
@@ -101,17 +101,24 @@ function gateserver.start(handler)
 	end
 
 	function MSG.close(fd)
-		if handler.disconnect then
-			handler.disconnect(fd)
+		if fd ~= socket then
+			if handler.disconnect then
+				handler.disconnect(fd)
+			end
+			close_fd(fd)
 		end
-		close_fd(fd)
 	end
 
 	function MSG.error(fd, msg)
-		if handler.error then
-			handler.error(fd, msg)
+		if fd == socket then
+			socketdriver.close(fd)
+			skynet.error(msg)
+		else
+			if handler.error then
+				handler.error(fd, msg)
+			end
+			close_fd(fd)
 		end
-		close_fd(fd)
 	end
 
 	function MSG.warning(fd, size)
diff --git a/lualib/socket.lua b/lualib/socket.lua
index c5fe7858..7f1d603b 100644
--- a/lualib/socket.lua
+++ b/lualib/socket.lua
@@ -106,16 +106,17 @@ socket_message[4] = function(id, newid, addr)
 end
 
 -- SKYNET_SOCKET_TYPE_ERROR = 5
-socket_message[5] = function(id)
+socket_message[5] = function(id, _, err)
 	local s = socket_pool[id]
 	if s == nil then
-		skynet.error("socket: error on unknown", id)
+		skynet.error("socket: error on unknown", id, err)
 		return
 	end
-	if s.connected then
-		skynet.error("socket: error on", id)
+	if s.connected or s.connecting then
+		skynet.error("socket: error on", id, err)
 	end
 	s.connected = false
+	driver.close(id)
 
 	wakeup(s)
 end
@@ -170,6 +171,7 @@ local function connect(id, func)
 		id = id,
 		buffer = newbuffer,
 		connected = false,
+		connecting = true,
 		read_required = false,
 		co = false,
 		callback = func,
@@ -177,6 +179,7 @@ local function connect(id, func)
 	}
 	socket_pool[id] = s
 	suspend(s)
+	s.connecting = nil
 	if s.connected then
 		return id
 	else
@@ -221,7 +224,7 @@ function socket.close(id)
 		return
 	end
 	if s.connected then
-		driver.close(s.id)
+		driver.close(id)
 		-- notice: call socket.close in __gc should be carefully,
 		-- because skynet.wait never return in __gc, so driver.clear may not be called
 		if s.co then
diff --git a/skynet-src/skynet_socket.c b/skynet-src/skynet_socket.c
index 9301419f..f6f8ec56 100644
--- a/skynet-src/skynet_socket.c
+++ b/skynet-src/skynet_socket.c
@@ -36,7 +36,11 @@ forward_message(int type, bool padding, struct socket_message * result) {
 	size_t sz = sizeof(*sm);
 	if (padding) {
 		if (result->data) {
-			sz += strlen(result->data);
+			size_t msg_sz = strlen(result->data);
+			if (msg_sz > 128) {
+				msg_sz = 128;
+			}
+			sz += msg_sz;
 		} else {
 			result->data = "";
 		}
@@ -86,7 +90,7 @@ skynet_socket_poll() {
 		forward_message(SKYNET_SOCKET_TYPE_CONNECT, true, &result);
 		break;
 	case SOCKET_ERROR:
-		forward_message(SKYNET_SOCKET_TYPE_ERROR, false, &result);
+		forward_message(SKYNET_SOCKET_TYPE_ERROR, true, &result);
 		break;
 	case SOCKET_ACCEPT:
 		forward_message(SKYNET_SOCKET_TYPE_ACCEPT, true, &result);
diff --git a/skynet-src/socket_server.c b/skynet-src/socket_server.c
index b2454d2e..7724a3c5 100644
--- a/skynet-src/socket_server.c
+++ b/skynet-src/socket_server.c
@@ -408,6 +408,7 @@ open_socket(struct socket_server *ss, struct request_open * request, struct sock
 
 	status = getaddrinfo( request->host, port, &ai_hints, &ai_list );
 	if ( status != 0 ) {
+		result->data = (void *)gai_strerror(status);
 		goto _failed;
 	}
 	int sock= -1;
@@ -428,12 +429,14 @@ open_socket(struct socket_server *ss, struct request_open * request, struct sock
 	}
 
 	if (sock < 0) {
+		result->data = strerror(errno);
 		goto _failed;
 	}
 
 	ns = new_fd(ss, id, sock, PROTOCOL_TCP, request->opaque, true);
 	if (ns == NULL) {
 		close(sock);
+		result->data = "reach skynet socket number limit";
 		goto _failed;
 	}
 
@@ -762,7 +765,7 @@ _failed:
 	result->opaque = request->opaque;
 	result->id = id;
 	result->ud = 0;
-	result->data = NULL;
+	result->data = "reach skynet socket number limit";
 	ss->slot[HASH_ID(id)].type = SOCKET_TYPE_INVALID;
 
 	return SOCKET_ERROR;
@@ -803,7 +806,7 @@ bind_socket(struct socket_server *ss, struct request_bind *request, struct socke
 	result->ud = 0;
 	struct socket *s = new_fd(ss, id, request->fd, PROTOCOL_TCP, request->opaque, true);
 	if (s == NULL) {
-		result->data = NULL;
+		result->data = "reach skynet socket number limit";
 		return SOCKET_ERROR;
 	}
 	sp_nonblocking(request->fd);
@@ -821,11 +824,13 @@ start_socket(struct socket_server *ss, struct request_start *request, struct soc
 	result->data = NULL;
 	struct socket *s = &ss->slot[HASH_ID(id)];
 	if (s->type == SOCKET_TYPE_INVALID || s->id !=id) {
+		result->data = "invalid socket";
 		return SOCKET_ERROR;
 	}
 	if (s->type == SOCKET_TYPE_PACCEPT || s->type == SOCKET_TYPE_PLISTEN) {
 		if (sp_add(ss->event_fd, s->fd, s)) {
 			s->type = SOCKET_TYPE_INVALID;
+			result->data = strerror(errno);
 			return SOCKET_ERROR;
 		}
 		s->type = (s->type == SOCKET_TYPE_PACCEPT) ? SOCKET_TYPE_CONNECTED : SOCKET_TYPE_LISTEN;
@@ -913,7 +918,7 @@ set_udp_address(struct socket_server *ss, struct request_setudp *request, struct
 		result->opaque = s->opaque;
 		result->id = s->id;
 		result->ud = 0;
-		result->data = NULL;
+		result->data = "protocol mismatch";
 
 		return SOCKET_ERROR;
 	}
@@ -995,6 +1000,7 @@ forward_message_tcp(struct socket_server *ss, struct socket *s, struct socket_me
 		default:
 			// close when error
 			force_close(ss, s, result);
+			result->data = strerror(errno);
 			return SOCKET_ERROR;
 		}
 		return -1;
@@ -1055,6 +1061,7 @@ forward_message_udp(struct socket_server *ss, struct socket *s, struct socket_me
 		default:
 			// close when error
 			force_close(ss, s, result);
+			result->data = strerror(errno);
 			return SOCKET_ERROR;
 		}
 		return -1;
@@ -1088,6 +1095,7 @@ report_connect(struct socket_server *ss, struct socket *s, struct socket_message
 	int code = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, &error, &len);  
 	if (code < 0 || error) {  
 		force_close(ss,s, result);
+		result->data = strerror(errno);
 		return SOCKET_ERROR;
 	} else {
 		s->type = SOCKET_TYPE_CONNECTED;
@@ -1111,14 +1119,22 @@ report_connect(struct socket_server *ss, struct socket *s, struct socket_message
 	}
 }
 
-// return 0 when failed
+// return 0 when failed, or -1 when file limit
 static int
 report_accept(struct socket_server *ss, struct socket *s, struct socket_message *result) {
 	union sockaddr_all u;
 	socklen_t len = sizeof(u);
 	int client_fd = accept(s->fd, &u.s, &len);
 	if (client_fd < 0) {
-		return 0;
+		if (errno == EMFILE || errno == ENFILE) {
+			result->opaque = s->opaque;
+			result->id = s->id;
+			result->ud = 0;
+			result->data = strerror(errno);
+			return -1;
+		} else {
+			return 0;
+		}
 	}
 	int id = reserve_id(ss);
 	if (id < 0) {
@@ -1203,11 +1219,16 @@ socket_server_poll(struct socket_server *ss, struct socket_message * result, int
 		switch (s->type) {
 		case SOCKET_TYPE_CONNECTING:
 			return report_connect(ss, s, result);
-		case SOCKET_TYPE_LISTEN:
-			if (report_accept(ss, s, result)) {
+		case SOCKET_TYPE_LISTEN: {
+			int ok = report_accept(ss, s, result);
+			if (ok > 0) {
 				return SOCKET_ACCEPT;
-			} 
+			} if (ok < 0 ) {
+				return SOCKET_ERROR;
+			}
+			// when ok == 0, retry
 			break;
+		}
 		case SOCKET_TYPE_INVALID:
 			fprintf(stderr, "socket-server: invalid socket\n");
 			break;