diff --git a/common.cpp b/common.cpp
index 160e5e7..aafff5b 100644
--- a/common.cpp
+++ b/common.cpp
@@ -20,9 +20,9 @@ int delay_capacity=0;
 char iptables_rule[200]="";
 //int is_client = 0, is_server = 0;
 
-program_mode_t program_mode=unset_mode;//0 unset; 1client 2server
-
+program_mode_t client_or_server=unset_mode;//0 unset; 1client 2server
 
+working_mode_t working_mode=unset_mode;
 
 struct random_fd_t
 {
diff --git a/common.h b/common.h
index 8eb69af..7d143c8 100644
--- a/common.h
+++ b/common.h
@@ -115,9 +115,12 @@ extern int about_to_exit;
 enum raw_mode_t{mode_faketcp=0,mode_udp,mode_icmp,mode_end};
 extern raw_mode_t raw_mode;
 enum program_mode_t {unset_mode=0,client_mode,server_mode};
-extern program_mode_t program_mode;
+extern program_mode_t client_or_server;
 extern unordered_map<int, const char*> raw_mode_tostring ;
 
+enum working_mode_t {unset_mode=0,tunnel_mode,tun_dev_mode};
+extern working_mode_t working_mode;
+
 extern int delay_capacity;
 
 
diff --git a/connection.cpp b/connection.cpp
index d5d6a3b..a1c8416 100644
--- a/connection.cpp
+++ b/connection.cpp
@@ -47,7 +47,7 @@ void conv_manager_t::clear()
 {
 	//if(disable_conv_clear) return ;//////what was the purpose of this code?
 
-	if(program_mode==server_mode)
+	if(client_or_server==server_mode)
 	{
 		for(auto it=conv_to_u64.begin();it!=conv_to_u64.end();it++)
 		{
@@ -111,7 +111,7 @@ int conv_manager_t::erase_conv(u32_t conv)
 	//if(disable_conv_clear) return 0;
 	assert(conv_last_active_time.find(conv)!=conv_last_active_time.end());
 	u64_t u64=conv_to_u64[conv];
-	if(program_mode==server_mode)
+	if(client_or_server==server_mode)
 	{
 		server_clear_function(u64);
 	}
diff --git a/main.cpp b/main.cpp
index 8b0c31e..c39353c 100644
--- a/main.cpp
+++ b/main.cpp
@@ -14,20 +14,9 @@ using namespace std;
 
 int main(int argc, char *argv[])
 {
+	working_mode=tun_dev_mode;
+
 
-	/*
-	if(argc==1||argc==0)
-	{
-		printf("this_program classic\n");
-		printf("this_program fec\n");
-		return 0;
-	}*/
-	/*
-	if(argc>=2&&strcmp(argv[1],"fec")!=0)
-	{
-		printf("running into classic mode!\n");
-		return classic::main(argc,argv);
-	}*/
 
 	assert(sizeof(u64_t)==8);
 	assert(sizeof(i64_t)==8);
@@ -43,13 +32,25 @@ int main(int argc, char *argv[])
 	local_ip_uint32=inet_addr(local_ip);
 	remote_ip_uint32=inet_addr(remote_ip);
 
-	if(program_mode==client_mode)
+	if(working_mode==tunnel_mode)
 	{
-		client_event_loop();
+		if(client_or_server==client_mode)
+		{
+			tunnel_client_event_loop();
+		}
+		else
+		{
+			tunnel_server_event_loop();
+		}
 	}
 	else
 	{
-		server_event_loop();
+		if(client_or_server==client_mode)
+		{
+		}
+		else
+		{
+		}
 	}
 
 	return 0;
diff --git a/misc.cpp b/misc.cpp
index aee9a87..70ce0c5 100644
--- a/misc.cpp
+++ b/misc.cpp
@@ -41,7 +41,6 @@ int time_mono_test=0;
 int socket_buf_size=1024*1024;
 
 
-
 int from_normal_to_fec(conn_info_t & conn_info,char *data,int len,int & out_n,char **&out_arr,int *&out_len,my_time_t *&out_delay)
 {
 
@@ -899,11 +898,11 @@ void process_arg(int argc, char *argv[])
 	}
 	if(is_client==1)
 	{
-		program_mode=client_mode;
+		client_or_server=client_mode;
 	}
 	else
 	{
-		program_mode=server_mode;
+		client_or_server=server_mode;
 	}
 
 	print_parameter();
diff --git a/tunnel.cpp b/tunnel.cpp
index 62d2585..b8469c8 100644
--- a/tunnel.cpp
+++ b/tunnel.cpp
@@ -65,7 +65,7 @@ int new_connected_socket(int &fd,u32_t ip,int port)
 	return 0;
 }
 
-int client_event_loop()
+int tunnel_client_event_loop()
 {
 	//char buf[buf_len];
 	int i, j, k;int ret;
@@ -392,7 +392,7 @@ int client_event_loop()
 	return 0;
 }
 
-int server_event_loop()
+int tunnel_server_event_loop()
 {
 	//char buf[buf_len];
 	int i, j, k;int ret;
diff --git a/tunnel.h b/tunnel.h
index 288b3b2..a074154 100644
--- a/tunnel.h
+++ b/tunnel.h
@@ -11,7 +11,7 @@
 
 #include "misc.h"
 
-int client_event_loop();
-int server_event_loop();
+int tunnel_client_event_loop();
+int tunnel_server_event_loop();
 
 #endif /* TUNNEL_H_ */