diff --git a/common.h b/common.h
index 89d5f46..0436cf9 100644
--- a/common.h
+++ b/common.h
@@ -59,7 +59,7 @@ typedef int i32_t;
 
 
 const int max_data_len=1600;
-const int buf_len=max_data_len+200;
+const int buf_len=max_data_len+400;
 const u32_t max_handshake_conn_num=10000;
 const u32_t max_ready_conn_num=1000;
 const u32_t anti_replay_window_size=1000;
diff --git a/encrypt.h b/encrypt.h
index 8495ca8..b1b4e63 100755
--- a/encrypt.h
+++ b/encrypt.h
@@ -29,10 +29,6 @@ enum cipher_mode_t {cipher_none=0,cipher_aes128cbc,cipher_xor,cipher_end};
 extern auth_mode_t auth_mode;
 extern cipher_mode_t cipher_mode;
 
-struct a
-{
-	char * buf[buf_len];
-};
 extern unordered_map<int, const char *> auth_mode_tostring;
 extern unordered_map<int, const char *> cipher_mode_tostring;
 
diff --git a/main.cpp b/main.cpp
index a44d5be..b2d21d7 100755
--- a/main.cpp
+++ b/main.cpp
@@ -2034,7 +2034,7 @@ int client_event_loop()
 
 				int recv_len;
 				struct sockaddr_in udp_new_addr_in;
-				if ((recv_len = recvfrom(udp_fd, buf, buf_len, 0,
+				if ((recv_len = recvfrom(udp_fd, buf, max_data_len, 0,
 						(struct sockaddr *) &udp_new_addr_in, &slen)) == -1) {
 					mylog(log_error,"recv_from error,this shouldnt happen at client\n");
 					myexit(1);
@@ -2307,7 +2307,7 @@ int server_event_loop()
 
 				u32_t conv_id=conn_info.blob->conv_manager.find_conv_by_u64(fd);
 
-				int recv_len=recv(fd,buf,buf_len,0);
+				int recv_len=recv(fd,buf,max_data_len,0);
 
 				mylog(log_trace,"received a packet from udp_fd,len:%d\n",recv_len);
 
diff --git a/makefile b/makefile
index 670669a..1b868ef 100755
--- a/makefile
+++ b/makefile
@@ -4,7 +4,7 @@ FLAGS2= -O3
 all:
 	sudo killall udp2raw||true
 	sleep 0.2
-	gcc main.cpp -o udp2raw  -static  -ggdb -I. lib/aes.c lib/md5.c encrypt.cpp log.cpp network.cpp common.cpp -lrt -std=c++11    ${FLAGS} ${FLAGS2}
+	g++ main.cpp -o udp2raw  -static  -ggdb -I. lib/aes.c lib/md5.c encrypt.cpp log.cpp network.cpp common.cpp -lrt -std=c++11    ${FLAGS} ${FLAGS2}
 #	${ccmips} main.cpp -o udp2raw_ar71xx  -lrt -I. lib/aes.c lib/md5.c encrypt.cpp log.cpp network.cpp common.cpp -std=c++11 ${FLAGS} ${FLAGS2}
 fast:
 	sudo killall udp2raw||true
diff --git a/network.cpp b/network.cpp
index 3e7c48b..be84833 100644
--- a/network.cpp
+++ b/network.cpp
@@ -391,7 +391,7 @@ int peek_raw(packet_info_t &peek_info)
 	char *ip_begin=peek_raw_buf+link_level_header_len;
 	struct sockaddr saddr;
 	socklen_t saddr_size;
-	int recv_len = recvfrom(raw_recv_fd, peek_raw_buf,buf_len, MSG_PEEK ,&saddr , &saddr_size);//change buf_len to something smaller,we only need header here
+	int recv_len = recvfrom(raw_recv_fd, peek_raw_buf,max_data_len, MSG_PEEK ,&saddr , &saddr_size);//change max_data_len to something smaller,we only need header here
 	iphdr * iph = (struct iphdr *) (ip_begin);
 	//mylog(log_info,"recv_len %d\n",recv_len);
 	if(recv_len<int(sizeof(iphdr)))
@@ -450,7 +450,7 @@ int recv_raw_ip(raw_info_t &raw_info,char * &payload,int &payloadlen)
 	saddr_size = sizeof(saddr);
 	int flag=0;
 
-	int recv_len = recvfrom(raw_recv_fd, recv_raw_ip_buf, buf_len, flag ,&saddr , &saddr_size);
+	int recv_len = recvfrom(raw_recv_fd, recv_raw_ip_buf, max_data_len, flag ,&saddr , &saddr_size);
 
 	if(recv_len<0)
 	{
@@ -1183,7 +1183,7 @@ int recv_raw_tcp_deprecated(packet_info_t &info,char * &payload,int &payloadlen)
 
 	mylog(log_trace,"raw!\n");
 
-	size = recvfrom(raw_recv_fd, buf, buf_len, 0 ,&saddr , &saddr_size);
+	size = recvfrom(raw_recv_fd, buf, max_data_len, 0 ,&saddr , &saddr_size);
 
 	if(buf[12]!=8||buf[13]!=0)
 	{