network.cpp

/*
 * network.cpp
 *
 *  Created on: Jul 29, 2017
 *      Author: wangyu
 */
#include "common.h"
#include "network.h"
#include "log.h"
#include "misc.h"

int g_fix_gro=0;

int raw_recv_fd=-1;
int raw_send_fd=-1;
u32_t link_level_header_len=0;//set it to 14 if SOCK_RAW is used in socket(PF_PACKET, SOCK_RAW, htons(ETH_P_IP));
int use_tcp_dummy_socket=0;

int seq_mode=3;
int max_seq_mode=4;
int random_drop=0;

int filter_port=-1;

int disable_bpf_filter=0;  //for test only,most time no need to disable this

//u32_t bind_address_uint32=0;

int lower_level=0;
int lower_level_manual=0;
int ifindex=-1;
char if_name[100]="";

char dev[100]="";

unsigned short g_ip_id_counter=0;
#ifdef UDP2RAW_LINUX
unsigned char dest_hw_addr[sizeof(sockaddr_ll::sll_addr)]=
    {0xff,0xff,0xff,0xff,0xff,0xff,0,0};
#endif

//{0x00,0x23,0x45,0x67,0x89,0xb9};

const u32_t receive_window_lower_bound=40960;
const u32_t receive_window_random_range=512;
const unsigned char wscale=0x05;

char g_packet_buf[huge_buf_len]; //looks dirty but works well
int g_packet_buf_len=-1;
int g_packet_buf_cnt=0;

#ifdef UDP2RAW_LINUX
union
{
	sockaddr_ll ll;
	sockaddr_in ipv4;
	sockaddr_in6 ipv6;
}g_sockaddr;
socklen_t g_sockaddr_len = -1;
#endif

#ifdef UDP2RAW_MP

#ifndef NO_LIBNET
libnet_t *libnet_handle;
libnet_ptag_t g_ptag=0;
int send_with_pcap=0;
#else
int send_with_pcap=1;
#endif

int pcap_header_captured=0;
int pcap_header_buf[buf_len];
int pcap_captured_full_len=-1;

pcap_t *pcap_handle;
int pcap_link_header_len=-1;
//int pcap_cnt=0;
queue_t my_queue;

pthread_mutex_t queue_mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_t pcap_mutex = PTHREAD_MUTEX_INITIALIZER;
int use_pcap_mutex=1;

ev_async async_watcher;

struct ev_loop* g_default_loop;

pthread_t pcap_recv_thread;

struct bpf_program g_filter;
long long g_filter_compile_cnt=0;

#endif

#ifdef UDP2RAW_LINUX

struct sock_filter code_tcp_old[] = {
		{ 0x28, 0, 0, 0x0000000c },//0
		{ 0x15, 0, 10, 0x00000800 },//1
		{ 0x30, 0, 0, 0x00000017 },//2
		{ 0x15, 0, 8, 0x00000006 },//3
		{ 0x28, 0, 0, 0x00000014 },//4
		{ 0x45, 6, 0, 0x00001fff },//5
		{ 0xb1, 0, 0, 0x0000000e },//6
		{ 0x48, 0, 0, 0x0000000e },//7
		{ 0x15, 2, 0, 0x0000ef32 },//8
		{ 0x48, 0, 0, 0x00000010 },//9
		{ 0x15, 0, 1, 0x0000ef32 },//10
		{ 0x6, 0, 0, 0x0000ffff },//11
		{ 0x6, 0, 0, 0x00000000 },//12
};
struct sock_filter code_tcp[] = {
//{ 0x5, 0, 0, 0x00000001 },//0    //jump to 2,dirty hack from tcpdump -d's output
//{ 0x5, 0, 0, 0x00000000 },//1
{ 0x30, 0, 0, 0x00000009 },//2
{ 0x15, 0, 6, 0x00000006 },//3
{ 0x28, 0, 0, 0x00000006 },//4
{ 0x45, 4, 0, 0x00001fff },//5
{ 0xb1, 0, 0, 0x00000000 },//6
{ 0x48, 0, 0, 0x00000002 },//7
{ 0x15, 0, 1, 0x0000fffe },//8   //modify this fffe to the port you listen on
{ 0x6, 0, 0, 0x0000ffff },//9
{ 0x6, 0, 0, 0x00000000 },//10
};
/*
{ 0x28, 0, 0, 0x0000000c },
{ 0x15, 0, 8, 0x00000800 },
{ 0x30, 0, 0, 0x00000017 },
{ 0x15, 0, 6, 0x00000006 },
{ 0x28, 0, 0, 0x00000014 },
{ 0x45, 4, 0, 0x00001fff },
{ 0xb1, 0, 0, 0x0000000e },
{ 0x48, 0, 0, 0x00000010 },
{ 0x15, 0, 1, 0x0000fffe },
{ 0x6, 0, 0, 0x0000ffff },
{ 0x6, 0, 0, 0x00000000 },
*/

int code_tcp_port_index=6;

//tcpdump -i ens33 ip6 and tcp and dst port 65534 -dd
struct sock_filter code_tcp6[] = {
//{ 0x28, 0, 0, 0x0000000c },//0
//{ 0x15, 0, 5, 0x000086dd },//1
{ 0x30, 0, 0, 0x00000006 },//2
{ 0x15, 0, 3, 0x00000006 },//3
{ 0x28, 0, 0, 0x0000002a },//4
{ 0x15, 0, 1, 0x0000fffe },//5
{ 0x6, 0, 0, 0x00040000 },//6
{ 0x6, 0, 0, 0x00000000 },//7
};//note: this filter doesnt support extension headers
/*
 { 0x30, 0, 0, 0x00000014 },//2
{ 0x15, 0, 3, 0x00000006 },//3
{ 0x28, 0, 0, 0x00000038 },//4
{ 0x15, 0, 1, 0x0000fffe },//5
{ 0x6, 0, 0, 0x00040000 },//6
{ 0x6, 0, 0, 0x00000000 },//7
*/

int code_tcp6_port_index=3;

struct sock_filter code_udp[] = {
//{ 0x5, 0, 0, 0x00000001 },
//{ 0x5, 0, 0, 0x00000000 },
{ 0x30, 0, 0, 0x00000009 },
{ 0x15, 0, 6, 0x00000011 },
{ 0x28, 0, 0, 0x00000006 },
{ 0x45, 4, 0, 0x00001fff },
{ 0xb1, 0, 0, 0x00000000 },
{ 0x48, 0, 0, 0x00000002 },
{ 0x15, 0, 1, 0x0000fffe },    //modify this fffe to the port you listen on
{ 0x6, 0, 0, 0x0000ffff },
{ 0x6, 0, 0, 0x00000000 },
};
int code_udp_port_index=6;

struct sock_filter code_udp6[] = {
//		{ 0x28, 0, 0, 0x0000000c },
//		{ 0x15, 0, 5, 0x000086dd },
		{ 0x30, 0, 0, 0x00000006 },
		{ 0x15, 0, 3, 0x00000011 },
		{ 0x28, 0, 0, 0x0000002a },
		{ 0x15, 0, 1, 0x0000fffe },
		{ 0x6, 0, 0, 0x00040000 },
		{ 0x6, 0, 0, 0x00000000 },

};
int code_udp6_port_index=3;

struct sock_filter code_icmp[] = {
//{ 0x5, 0, 0, 0x00000001 },
//{ 0x5, 0, 0, 0x00000000 },
{ 0x30, 0, 0, 0x00000009 },
{ 0x15, 0, 1, 0x00000001 },
{ 0x6, 0, 0, 0x0000ffff },
{ 0x6, 0, 0, 0x00000000 },
};

struct sock_filter code_icmp6[] = {
//		{ 0x28, 0, 0, 0x0000000c },
//		{ 0x15, 0, 6, 0x000086dd },
		{ 0x30, 0, 0, 0x00000006 },
		{ 0x15, 3, 0, 0x0000003a },
		{ 0x15, 0, 3, 0x0000002c },
		{ 0x30, 0, 0, 0x00000028 },
		{ 0x15, 0, 1, 0x0000003a },
		{ 0x6, 0, 0, 0x00040000 },
		{ 0x6, 0, 0, 0x00000000 },

};
/*

tcpdump -i eth1  ip and icmp -d
(000) ldh      [12]
(001) jeq      #0x800           jt 2    jf 5
(002) ldb      [23]
(003) jeq      #0x1             jt 4    jf 5
(004) ret      #65535
(005) ret      #0

tcpdump -i eth1  ip and icmp -dd
{ 0x28, 0, 0, 0x0000000c },
{ 0x15, 0, 3, 0x00000800 },
{ 0x30, 0, 0, 0x00000017 },
{ 0x15, 0, 1, 0x00000001 },
{ 0x6, 0, 0, 0x0000ffff },
{ 0x6, 0, 0, 0x00000000 },


 */
/*
  tcpdump -i eth1 ip and tcp and dst port 65534 -dd

{ 0x28, 0, 0, 0x0000000c },
{ 0x15, 0, 8, 0x00000800 },
{ 0x30, 0, 0, 0x00000017 },
{ 0x15, 0, 6, 0x00000006 },
{ 0x28, 0, 0, 0x00000014 },
{ 0x45, 4, 0, 0x00001fff },
{ 0xb1, 0, 0, 0x0000000e },
{ 0x48, 0, 0, 0x00000010 },
{ 0x15, 0, 1, 0x0000fffe },
{ 0x6, 0, 0, 0x0000ffff },
{ 0x6, 0, 0, 0x00000000 },

 (000) ldh      [12]
(001) jeq      #0x800           jt 2    jf 10
(002) ldb      [23]
(003) jeq      #0x6             jt 4    jf 10
(004) ldh      [20]
(005) jset     #0x1fff          jt 10   jf 6
(006) ldxb     4*([14]&0xf)
(007) ldh      [x + 16]
(008) jeq      #0xfffe          jt 9    jf 10
(009) ret      #65535
(010) ret      #0

 */
#endif

packet_info_t::packet_info_t()
{
	src_port=0;
	dst_port=0;
	if (raw_mode == mode_faketcp)
	{
		protocol = IPPROTO_TCP;
		ack_seq = get_true_random_number();
		seq = get_true_random_number();
		has_ts=0;
		ts_ack=0;
		syn=0;
		ack=1;
		ack_seq_counter=0;

		//mylog(log_info,"<cons ,ts_ack= %u>\n",ts_ack);
	}
	else if (raw_mode == mode_udp)
	{
		protocol = IPPROTO_UDP;
	}
	else if (raw_mode == mode_icmp)
	{
		if(raw_ip_version==AF_INET)
		{
			protocol = IPPROTO_ICMP;
		}
		else
		{
			assert(raw_ip_version==AF_INET6);
			protocol = IPPROTO_ICMPV6;
		}
		my_icmp_seq=0;
	}

}
#ifdef UDP2RAW_MP
void my_packet_handler(
    u_char *args,
    const struct pcap_pkthdr *packet_header,
    const u_char *pkt_data
)
{
	/*printf("<%d %d>\n",(int)packet_header->caplen,(int)packet_header->len );
	for(int i=0;i<sizeof(pcap_pkthdr);i++)
	{
		char *p=(char *) packet_header;
		printf("<%x>",int( p[i] ));
	}
	printf("\n");*/
	//mylog(log_debug,"received a packet!\n");
	assert(packet_header->caplen <= packet_header->len);
	assert(packet_header->caplen <= huge_data_len);
	//if(packet_header->caplen > max_data_len) return ;
	if(g_fix_gro==0&&packet_header->caplen<packet_header->len) return;

	if((int)packet_header->caplen<pcap_link_header_len) return;
	//mylog(log_debug,"and its vaild!\n");

	pthread_mutex_lock(&queue_mutex);
	if(!my_queue.full())
		my_queue.push_back((char *)pkt_data,(int)(packet_header->caplen));
	pthread_mutex_unlock(&queue_mutex);

	//pcap_cnt++;

	ev_async_send (g_default_loop,&async_watcher);
    return;
}

void *pcap_recv_thread_entry(void *none)
{
	struct pcap_pkthdr *packet_header;
	const u_char *pkt_data;

	while(1)
	{
		if(use_pcap_mutex) pthread_mutex_lock(&pcap_mutex);
		int ret=pcap_loop(pcap_handle, -1, my_packet_handler, NULL); //use -1 instead of 0 as cnt, since 0 is undefined in old versions
		if(use_pcap_mutex) pthread_mutex_unlock(&pcap_mutex);
		if(ret==-1)
			mylog(log_warn,"pcap_loop exited with value %d\n",ret);
		else
		{
			mylog(log_debug,"pcap_loop exited with value %d\n",ret);
		}
		ev_sleep(1.0);
		//myexit(-1);
	}
	/*
	while(1)
	{
		//printf("!!!\n");
		pthread_mutex_lock(&pcap_mutex);
		int ret=pcap_next_ex(pcap_handle,&packet_header,&pkt_data);
		pthread_mutex_unlock(&pcap_mutex);

		switch (ret)
		{
			case 0:
				continue;
			case 1:

				break;

			case -1:
				mylog(log_fatal,"pcap_next_ex error [%s]\n",pcap_geterr(pcap_handle));
				myexit(-1);
				break;
			case -2:
				assert(0==1);//
				break;
			default:
				assert(0==1);//
		}
	}
	myexit(-1);*/
	return 0;
}

extern void async_cb(struct ev_loop *loop, struct ev_async *watcher, int revents);
#endif

#ifdef UDP2RAW_LINUX
int init_raw_socket()
{
	assert(raw_ip_version==AF_INET||raw_ip_version==AF_INET6);

	g_ip_id_counter=get_true_random_number()%65535;
	if(lower_level==0)
	{
		raw_send_fd = socket(raw_ip_version , SOCK_RAW , IPPROTO_RAW);// IPPROTO_TCP??

	    if(raw_send_fd == -1) {
	    	mylog(log_fatal,"Failed to create raw_send_fd\n");
	        //perror("Failed to create raw_send_fd");
	        myexit(1);
	    }

	    /*ETH_P_IP
	    int one = 1;
	    const int *val = &one;
	    if (setsockopt (raw_send_fd, IPPROTO_IP, IP_HDRINCL, val, sizeof (one)) < 0) {
	    	mylog(log_fatal,"Error setting IP_HDRINCL %d\n",errno);
	        //perror("Error setting IP_HDRINCL");
	        myexit(2);
	    }*/


	}
	else
	{
		raw_send_fd = socket(PF_PACKET , SOCK_DGRAM , htons(ETH_P_IP));// todo  how to create a recv only raw socket?

	    if(raw_send_fd == -1) {
	    	mylog(log_fatal,"Failed to create raw_send_fd\n");
	        //perror("Failed to create raw_send_fd");
	        myexit(1);
	    }
		//init_ifindex(if_name);

	}

    int opt = 0;
    assert(setsockopt(raw_send_fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt))==0);// raw_send_fd is for send only, set its recv buffer to zero

	if(force_socket_buf)
	{
		if(setsockopt(raw_send_fd, SOL_SOCKET, SO_SNDBUFFORCE, &socket_buf_size, sizeof(socket_buf_size))<0)
		{
			mylog(log_fatal,"SO_SNDBUFFORCE fail  socket_buf_size=%d  errno=%s\n",socket_buf_size,strerror(errno));
			myexit(1);
		}
	}
	else
	{
		if(setsockopt(raw_send_fd, SOL_SOCKET, SO_SNDBUF, &socket_buf_size, sizeof(socket_buf_size))<0)
		{
			mylog(log_fatal,"SO_SNDBUF fail  socket_buf_size=%d  errno=%s\n",socket_buf_size,strerror(errno));
			myexit(1);
		}
	}



	//raw_fd = socket(AF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL));

	if(raw_ip_version==AF_INET)
		raw_recv_fd= socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
	else
		raw_recv_fd= socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IPV6));
	//ETH_P_IP doesnt read outgoing packets
	//   https://stackoverflow.com/questions/20264895/eth-p-ip-is-not-working-as-expected-i-can-only-receive-incoming-packets
	//   to capture both incoming and outgoing packets use ETH_P_ALL

    if(raw_recv_fd == -1) {
    	mylog(log_fatal,"Failed to create raw_recv_fd\n");
        //perror("");
        myexit(1);
    }
    if(strlen(dev)!=0)
    {
        struct sockaddr_ll bind_address;
        memset(&bind_address, 0, sizeof(bind_address));

        int index=-1;
        assert(init_ifindex(dev,raw_recv_fd,index)==0);

        bind_address.sll_family = AF_PACKET;
    	if(raw_ip_version==AF_INET)
    		bind_address.sll_protocol = htons(ETH_P_IP);
    	else
    		bind_address.sll_protocol = htons(ETH_P_IPV6);
        bind_address.sll_ifindex = index;

        if(bind(raw_recv_fd, (struct sockaddr *)&bind_address, sizeof(bind_address))==-1)
        {
        	mylog(log_fatal,"bind to dev [%s] failed\n",dev);
        	myexit(1);
        }
    }

	if(force_socket_buf)
	{
		if(setsockopt(raw_recv_fd, SOL_SOCKET, SO_RCVBUFFORCE, &socket_buf_size, sizeof(socket_buf_size))<0)
		{
			mylog(log_fatal,"SO_RCVBUFFORCE fail  socket_buf_size=%d  errno=%s\n",socket_buf_size,strerror(errno));
			myexit(1);
		}
	}
	else
	{
		if(setsockopt(raw_recv_fd, SOL_SOCKET, SO_RCVBUF, &socket_buf_size, sizeof(socket_buf_size))<0)
		{
			mylog(log_fatal,"SO_RCVBUF fail  socket_buf_size=%d  errno=%s\n",socket_buf_size,strerror(errno));
			myexit(1);
		}
	}

    //IP_HDRINCL to tell the kernel that headers are included in the packet



    setnonblocking(raw_send_fd); //not really necessary
    setnonblocking(raw_recv_fd);

	return 0;
}
#endif
#ifdef UDP2RAW_MP
int init_raw_socket()
{

#ifndef NO_LIBNET
	char libnet_errbuf[LIBNET_ERRBUF_SIZE];

	if(raw_ip_version==AF_INET)
	{
		libnet_handle = libnet_init(LIBNET_RAW4, dev, libnet_errbuf);
	}
	else
	{
		assert(raw_ip_version==AF_INET6);
		libnet_handle = libnet_init(LIBNET_RAW6, dev, libnet_errbuf);
	}

	if(libnet_handle==0)
	{
		mylog(log_fatal,"libnet_init failed bc of [%s]\n",libnet_errbuf);
		myexit(-1);
	}
	g_ptag=0;
    libnet_clear_packet(libnet_handle);
#endif

	char pcap_errbuf[PCAP_ERRBUF_SIZE];

	//pcap_handle=pcap_open_live(dev,max_data_len,0,1000,pcap_errbuf);

	pcap_handle = pcap_create( dev, pcap_errbuf );


	if(pcap_handle==0)
	{
		mylog(log_fatal,"pcap_create failed bc of [%s]\n",pcap_errbuf);
		myexit(-1);
	}

	assert( pcap_set_snaplen(pcap_handle, huge_data_len) ==0);
	assert( pcap_set_promisc(pcap_handle, 0) ==0);
	assert( pcap_set_timeout(pcap_handle, 1) ==0);
	assert( pcap_set_immediate_mode(pcap_handle,1) ==0);

	int ret = pcap_activate( pcap_handle );
	if( ret < 0 )
	{
		 printf("pcap_activate failed  %s\n", pcap_geterr(pcap_handle));
		 myexit(-1);
	}

	if(send_with_pcap)
	{
		ret=pcap_setdirection(pcap_handle,PCAP_D_INOUT);//must be used after being actived
		if(ret!=0) mylog(log_debug,"pcap_setdirection(pcap_handle,PCAP_D_INOUT) failed with value %d, %s\n",ret,pcap_geterr(pcap_handle));
	}
	else
	{
		ret=pcap_setdirection(pcap_handle,PCAP_D_IN);
		if(ret!=0) mylog(log_debug,"pcap_setdirection(pcap_handle,PCAP_D_IN) failed with value %d, %s\n",ret,pcap_geterr(pcap_handle));
	}


	ret=pcap_datalink(pcap_handle);

	if(ret==DLT_EN10MB)
	{
		pcap_link_header_len=14;
	}
	else if(ret==DLT_NULL)
	{
		pcap_link_header_len=4;
	}
	else if(ret==DLT_LINUX_SLL)
	{
		pcap_link_header_len=16;
	}
	else
	{
		mylog(log_fatal,"unknown pcap link type : %d\n",ret);
		myexit(-1);
	}

	char filter_exp[1000];

	address_t tmp_addr;
	if(get_src_adress2(tmp_addr,remote_addr)!=0)
	{
		mylog(log_error,"get_src_adress() failed, maybe you dont have internet\n");
		myexit(-1);
	}

	string src=tmp_addr.get_ip();
	string dst=remote_addr.get_ip();
	if(raw_ip_version==AF_INET)
	{
		//sprintf(filter_exp,"ip and src %s and dst %s and (tcp or udp or icmp)",my_ntoa(source_ip_uint32),dst.c_str());
		sprintf(filter_exp,"ip and src %s and dst %s and (tcp or udp or icmp)",src.c_str(),dst.c_str());
	}
	else
	{
		assert(raw_ip_version==AF_INET6);
		sprintf(filter_exp,"ip6 and src %s and dst %s and (tcp or udp or icmp6)",src.c_str(),dst.c_str());

	}

	 if (pcap_compile(pcap_handle, &g_filter, filter_exp, 0, PCAP_NETMASK_UNKNOWN ) == -1) {
		 printf("Bad filter - %s\n", pcap_geterr(pcap_handle));
		 myexit(-1);
	 }
	 g_filter_compile_cnt++;


	 if (pcap_setfilter(pcap_handle, &g_filter) == -1) {
		 printf("Error setting filter - %s\n", pcap_geterr(pcap_handle));
		 myexit(-1);
	 }

///////////////////////////////////////////////////////////////new thread created here
		if(pthread_create(&pcap_recv_thread, NULL, pcap_recv_thread_entry, 0)) {
			mylog(log_fatal, "Error creating thread\n");
			myexit(-1);
		}
////////////////////////////////////////////////////////////////////////////////


	g_ip_id_counter=get_true_random_number()%65535;

	/*
	if(lower_level==0)
	{
		raw_send_fd = socket(AF_INET , SOCK_RAW , IPPROTO_TCP);

	    if(raw_send_fd == -1) {
	    	mylog(log_fatal,"Failed to create raw_send_fd\n");
	        //perror("Failed to create raw_send_fd");
	        myexit(1);
	    }

	    int one = 1;
	    const int *val = &one;
	    if (setsockopt (raw_send_fd, IPPROTO_IP, IP_HDRINCL, val, sizeof (one)) < 0) {
	    	mylog(log_fatal,"Error setting IP_HDRINCL %d\n",errno);
	        //perror("Error setting IP_HDRINCL");
	        myexit(2);
	    }


	}
	else
	{
		raw_send_fd = socket(PF_PACKET , SOCK_DGRAM , htons(ETH_P_IP));

	    if(raw_send_fd == -1) {
	    	mylog(log_fatal,"Failed to create raw_send_fd\n");
	        //perror("Failed to create raw_send_fd");
	        myexit(1);
	    }
		//init_ifindex(if_name);

	}

	if(force_socket_buf)
	{
		if(setsockopt(raw_send_fd, SOL_SOCKET, SO_SNDBUFFORCE, &socket_buf_size, sizeof(socket_buf_size))<0)
		{
			mylog(log_fatal,"SO_SNDBUFFORCE fail  socket_buf_size=%d  errno=%s\n",socket_buf_size,strerror(errno));
			myexit(1);
		}
	}
	else
	{
		if(setsockopt(raw_send_fd, SOL_SOCKET, SO_SNDBUF, &socket_buf_size, sizeof(socket_buf_size))<0)
		{
			mylog(log_fatal,"SO_SNDBUF fail  socket_buf_size=%d  errno=%s\n",socket_buf_size,strerror(errno));
			myexit(1);
		}
	}



	//raw_fd = socket(AF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL));

	raw_recv_fd= socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));

    if(raw_recv_fd == -1) {
    	mylog(log_fatal,"Failed to create raw_recv_fd\n");
        //perror("");
        myexit(1);
    }

	if(force_socket_buf)
	{
		if(setsockopt(raw_recv_fd, SOL_SOCKET, SO_RCVBUFFORCE, &socket_buf_size, sizeof(socket_buf_size))<0)
		{
			mylog(log_fatal,"SO_RCVBUFFORCE fail  socket_buf_size=%d  errno=%s\n",socket_buf_size,strerror(errno));
			myexit(1);
		}
	}
	else
	{
		if(setsockopt(raw_recv_fd, SOL_SOCKET, SO_RCVBUF, &socket_buf_size, sizeof(socket_buf_size))<0)
		{
			mylog(log_fatal,"SO_RCVBUF fail  socket_buf_size=%d  errno=%s\n",socket_buf_size,strerror(errno));
			myexit(1);
		}
	}

    //IP_HDRINCL to tell the kernel that headers are included in the packet



    setnonblocking(raw_send_fd); //not really necessary
    setnonblocking(raw_recv_fd);*/

	return 0;
}
#endif
#ifdef UDP2RAW_LINUX
void init_filter(int port)
{
	sock_fprog bpf;
	assert(raw_ip_version==AF_INET||raw_ip_version==AF_INET6);
	if(raw_mode==mode_faketcp||raw_mode==mode_udp)
	{
		filter_port=port;
	}
	if(disable_bpf_filter) return;
	//if(raw_mode==mode_icmp) return ;
	//code_tcp[8].k=code_tcp[10].k=port;
	if(raw_mode==mode_faketcp)
	{
		if(raw_ip_version==AF_INET)
		{
			bpf.len = sizeof(code_tcp)/sizeof(code_tcp[0]);
			code_tcp[code_tcp_port_index].k=port;
			bpf.filter = code_tcp;
		}else
		{
			bpf.len = sizeof(code_tcp6)/sizeof(code_tcp6[0]);
			code_tcp6[code_tcp6_port_index].k=port;
			bpf.filter = code_tcp6;
		}
	}
	else if(raw_mode==mode_udp)
	{
		if(raw_ip_version==AF_INET)
		{
			bpf.len = sizeof(code_udp)/sizeof(code_udp[0]);
			code_udp[code_udp_port_index].k=port;
			bpf.filter = code_udp;
		}else
		{
			bpf.len = sizeof(code_udp6)/sizeof(code_udp6[0]);
			code_udp6[code_udp6_port_index].k=port;
			bpf.filter = code_udp6;
		}
	}
	else if(raw_mode==mode_icmp)
	{
		if(raw_ip_version==AF_INET)
		{
			bpf.len = sizeof(code_icmp)/sizeof(code_icmp[0]);
			bpf.filter = code_icmp;
		}else
		{
			bpf.len = sizeof(code_icmp6)/sizeof(code_icmp6[0]);
			bpf.filter = code_icmp6;
		}
	}

	int dummy;

	int ret=setsockopt(raw_recv_fd, SOL_SOCKET, SO_DETACH_FILTER, &dummy, sizeof(dummy)); //in case i forgot to remove
	if (ret != 0)
	{
		mylog(log_debug,"error remove fiter\n");
		//perror("filter");
		//exit(-1);
	}
	ret = setsockopt(raw_recv_fd, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf));
	if (ret != 0)
	{
		mylog(log_fatal,"error set fiter\n");
		//perror("filter");
		myexit(-1);
	}
}
#endif

#ifdef UDP2RAW_MP
void init_filter(int port)
{
	/*
	sock_fprog bpf;*/
	if(raw_mode==mode_faketcp||raw_mode==mode_udp)
	{
		filter_port=port;
	}



	 char filter_exp[1000];

	if(raw_ip_version==AF_INET)
	{
		if(raw_mode==mode_faketcp)
		{
			sprintf(filter_exp,"ip and tcp and src %s and src port %d and dst port %d",remote_addr.get_ip(),remote_addr.get_port(),port);
		}
		else if(raw_mode==mode_udp)
		{
			sprintf(filter_exp,"ip and udp and src %s and src port %d and dst port %d",remote_addr.get_ip(),remote_addr.get_port(),port);
		}
		else if(raw_mode==mode_icmp)
		{
			sprintf(filter_exp,"ip and icmp and src %s",remote_addr.get_ip());
		}
		else
		{
			mylog(log_fatal,"unknow raw mode\n");
			myexit(-1);
		}
	}
	else
	{
		assert(raw_ip_version==AF_INET6);
		if(raw_mode==mode_faketcp)
		{
			sprintf(filter_exp,"ip6 and tcp and src %s and src port %d and dst port %d",remote_addr.get_ip(),remote_addr.get_port(),port);
		}
		else if(raw_mode==mode_udp)
		{
			sprintf(filter_exp,"ip6 and udp and src %s and src port %d and dst port %d",remote_addr.get_ip(),remote_addr.get_port(),port);
		}
		else if(raw_mode==mode_icmp)
		{
			sprintf(filter_exp,"ip6 and icmp6 and src %s",remote_addr.get_ip());
		}
		else
		{
			mylog(log_fatal,"unknow raw mode\n");
			myexit(-1);
		}
	}

	mylog(log_info,"filter expression is [%s]\n",filter_exp);

	//pthread_mutex_lock(&pcap_mutex);//not sure if mutex is needed here

	long long tmp_cnt=0;
	if(use_pcap_mutex)
	{
		while(pthread_mutex_trylock(&pcap_mutex)!=0)
		{
			tmp_cnt++;
			pcap_breakloop(pcap_handle);
			if(tmp_cnt==100)
			{
				mylog(log_warn,"%lld attempts of pcap_breakloop()\n", tmp_cnt);
			}
			if(tmp_cnt%1000==0)
			{
				mylog(log_warn,"%lld attempts of pcap_breakloop()\n", tmp_cnt);
				if(tmp_cnt>5000)
				{
					 mylog(log_fatal,"we might have already run into a deadlock\n");
				}
			}
			ev_sleep(0.001);
		}
		mylog(log_info,"breakloop() succeed after %lld attempt(s)\n", tmp_cnt);
	}

	if(1)
	{
		int ret=pcap_setdirection(pcap_handle,PCAP_D_IN);
		if(ret!=0) mylog(log_debug,"pcap_setdirection(pcap_handle,PCAP_D_IN) failed with value %d, %s\n",ret,pcap_geterr(pcap_handle));
	}

	assert(g_filter_compile_cnt!=0);
	pcap_freecode(&g_filter);

	 if (pcap_compile(pcap_handle, &g_filter, filter_exp, 0, PCAP_NETMASK_UNKNOWN ) == -1) {
		 mylog(log_fatal,"Bad filter - %s\n", pcap_geterr(pcap_handle));
		 myexit(-1);
	 }
	 g_filter_compile_cnt++;

	 if (pcap_setfilter(pcap_handle, &g_filter) == -1)
	 {
		 mylog(log_fatal,"Error setting filter - %s\n", pcap_geterr(pcap_handle));
		 myexit(-1);
	 }


	if(use_pcap_mutex) pthread_mutex_unlock(&pcap_mutex);
	/*
	if(disable_bpf_filter) return;
	//if(raw_mode==mode_icmp) return ;
	//code_tcp[8].k=code_tcp[10].k=port;
	if(raw_mode==mode_faketcp)
	{
		bpf.len = sizeof(code_tcp)/sizeof(code_tcp[0]);
		code_tcp[code_tcp_port_index].k=port;
		bpf.filter = code_tcp;
	}
	else if(raw_mode==mode_udp)
	{
		bpf.len = sizeof(code_udp)/sizeof(code_udp[0]);
		code_udp[code_udp_port_index].k=port;
		bpf.filter = code_udp;
	}
	else if(raw_mode==mode_icmp)
	{
		bpf.len = sizeof(code_icmp)/sizeof(code_icmp[0]);
		bpf.filter = code_icmp;
	}

	int dummy;

	int ret=setsockopt(raw_recv_fd, SOL_SOCKET, SO_DETACH_FILTER, &dummy, sizeof(dummy)); //in case i forgot to remove
	if (ret != 0)
	{
		mylog(log_debug,"error remove fiter\n");
		//perror("filter");
		//exit(-1);
	}
	ret = setsockopt(raw_recv_fd, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf));
	if (ret != 0)
	{
		mylog(log_fatal,"error set fiter\n");
		//perror("filter");
		myexit(-1);
	}*/
}
#endif

void remove_filter()
{
	filter_port=0;
#ifdef UDP2RAW_LINUX
	int dummy;
	int ret=setsockopt(raw_recv_fd, SOL_SOCKET, SO_DETACH_FILTER, &dummy, sizeof(dummy));
	if (ret != 0)
	{
		mylog(log_debug,"error remove fiter\n");
		//perror("filter");
		//exit(-1);
	}
#endif
}

int init_ifindex(const char * if_name,int fd,int &index)
{
#ifdef UDP2RAW_LINUX
	struct ifreq ifr;
	size_t if_name_len=strlen(if_name);
	if (if_name_len<sizeof(ifr.ifr_name)) {
		memcpy(ifr.ifr_name,if_name,if_name_len);
		ifr.ifr_name[if_name_len]=0;
	} else {
		mylog(log_fatal,"interface name is too long\n");
		myexit(-1);
	}
	if (ioctl(fd,SIOCGIFINDEX,&ifr)==-1) {

		mylog(log_fatal,"SIOCGIFINDEX fail ,%s\n",strerror(errno));
		myexit(-1);
	}
	index=ifr.ifr_ifindex;
	mylog(log_info,"ifname:%s  ifindex:%d\n",if_name,index);
#endif
	return 0;
}

#ifdef UDP2RAW_LINUX
bool interface_has_arp(const char * interface) {
    struct ifreq ifr;
   // int sock = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
    int sock=raw_send_fd;
    memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name, interface);
    if (ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
            //perror("SIOCGIFFLAGS");
    		mylog(log_fatal,"ioctl(sock, SIOCGIFFLAGS, &ifr) failed for interface %s,errno %s\n",interface,strerror(errno));
            myexit(-1);
    }
    //close(sock);
    return !(ifr.ifr_flags & IFF_NOARP);
}
struct route_info_t
{
	string if_name;
	u32_t dest;
	u32_t mask;
	u32_t gw;
	u32_t flag;

};
int dest_idx=1;
int gw_idx=2;
int if_idx=0;
int mask_idx=7;
int flag_idx=3;
vector<int> find_route_entry(const vector<route_info_t> &route_info_vec,u32_t ip)
{
	vector<int> res;
	for(u32_t i=0;i<=32;i++)
	{
		u32_t mask=0xffffffff;
		//mask >>=i;
		//if(i==32) mask=0;  //why 0xffffffff>>32  equals 0xffffffff??

		mask <<=i;
		if(i==32) mask=0;
		log_bare(log_debug,"(mask:%x)",mask);
		for(u32_t j=0;j<route_info_vec.size();j++)
		{
			const route_info_t & info=route_info_vec[j];
			if(info.mask!=mask)
				continue;
			log_bare(log_debug,"<<%d,%d>>",i,j);
			if((info.dest&mask)==(ip&mask))
			{
				log_bare(log_debug,"found!");
				res.push_back(j);
			}
		}
		if(res.size()!=0)
		{
			return res;
		}
	}
	return res;
}
int find_direct_dest(const vector<route_info_t> &route_info_vec,u32_t ip,u32_t &dest_ip,string &if_name)
{
	vector<int> res;
	for(int i=0;i<1000;i++)
	{
		res=find_route_entry(route_info_vec,ip);
		log_bare(log_debug,"<entry:%u>",(u32_t)res.size());
		if(res.size()==0)
		{
			mylog(log_error,"cant find route entry\n");
			return -1;
		}
		if(res.size()>1)
		{
			mylog(log_error,"found duplicated entries\n");
			return -1;
		}
		if((route_info_vec[res[0]].flag&2)==0)
		{
			dest_ip=ip;
			if_name=route_info_vec[res[0]].if_name;
			return 0;
		}
		else
		{
			ip=route_info_vec[res[0]].gw;
		}
	}
	mylog(log_error,"dead loop in find_direct_dest\n");
	return -1;
}
struct arp_info_t
{
	u32_t ip;
	string hw;
	string if_name;
};
int arp_ip_idx=0;
int arp_hw_idx=3;
int arp_if_idx=5;


int find_arp(const vector<arp_info_t> &arp_info_vec,u32_t ip,string if_name,string &hw)
{
	int pos=-1;
	int count=0;
	for(u32_t i=0;i<arp_info_vec.size();i++)
	{
		const arp_info_t & info=arp_info_vec[i];
		if(info.if_name!=if_name) continue;
		if(info.ip==ip)
		{
			count++;
			pos=i;
		}
	}
	if(count==0)
	{
		//mylog(log_warn,"cant find arp entry for %s %s,using 00:00:00:00:00:00\n",my_ntoa(ip),if_name.c_str());
		//hw="00:00:00:00:00:00";
		mylog(log_error,"cant find arp entry for %s %s\n",my_ntoa(ip),if_name.c_str());
		return -1;
	}
	if(count>1)
	{
		mylog(log_error,"find multiple arp entry for %s %s\n",my_ntoa(ip),if_name.c_str());
		return -1;
	}
	hw=arp_info_vec[pos].hw;
	return 0;
}
int find_lower_level_info(u32_t ip,u32_t &dest_ip,string &if_name,string &hw)
{
	ip=htonl(ip);
	if(ip==htonl(inet_addr("127.0.0.1")))
	{
		dest_ip=ntohl(ip);
		if_name="lo";
		hw="00:00:00:00:00:00";
		return 0;
	}

	string route_file;
	if(read_file("/proc/net/route",route_file)!=0) return -1;
	string arp_file;
	if(read_file("/proc/net/arp",arp_file)!=0) return -1;

	log_bare(log_debug,"/proc/net/route:<<%s>>\n",route_file.c_str());
	log_bare(log_debug,"/proc/net/arp:<<%s>>\n",route_file.c_str());

	auto route_vec2=string_to_vec2(route_file.c_str());
	vector<route_info_t> route_info_vec;
	for(u32_t i=1;i<route_vec2.size();i++)
	{
		log_bare(log_debug,"<size:%u>",(u32_t)route_vec2[i].size());
		if(route_vec2[i].size()!=11)
		{
			mylog(log_error,"route coloum %d !=11 \n",int(route_vec2[i].size()));
			return -1;
		}
		route_info_t tmp;
		tmp.if_name=route_vec2[i][if_idx];
		if(hex_to_u32_with_endian(route_vec2[i][dest_idx],tmp.dest)!=0) return -1;
		if(hex_to_u32_with_endian(route_vec2[i][gw_idx],tmp.gw)!=0) return -1;
		if(hex_to_u32_with_endian(route_vec2[i][mask_idx],tmp.mask)!=0) return -1;
		if(hex_to_u32(route_vec2[i][flag_idx],tmp.flag)!=0)return -1;
		route_info_vec.push_back(tmp);
		for(u32_t j=0;j<route_vec2[i].size();j++)
		{
			log_bare(log_debug,"<%s>",route_vec2[i][j].c_str());
		}
		log_bare(log_debug,"%s dest:%x mask:%x gw:%x flag:%x",tmp.if_name.c_str(),tmp.dest,tmp.mask,tmp.gw,tmp.flag);
		log_bare(log_debug,"\n");
	}

	if(find_direct_dest(route_info_vec,ip,dest_ip,if_name)!=0)
	{
		mylog(log_error,"find_direct_dest failed for ip %s\n",my_ntoa(ntohl(ip)));
		return -1;
	}


	log_bare(log_debug,"========\n");
	auto arp_vec2=string_to_vec2(arp_file.c_str());
	vector<arp_info_t> arp_info_vec;
	for(u32_t i=1;i<arp_vec2.size();i++)
	{
		log_bare(log_debug,"<<arp_vec2[i].size(): %d>>",(int)arp_vec2[i].size());

		for(u32_t j=0;j<arp_vec2[i].size();j++)
		{
			log_bare(log_debug,"<%s>",arp_vec2[i][j].c_str());
		}
		if(arp_vec2[i].size()!=6)
		{
			mylog(log_error,"arp coloum %d !=11 \n",int(arp_vec2[i].size()));
			return -1;
		}
		arp_info_t tmp;
		tmp.if_name=arp_vec2[i][arp_if_idx];
		tmp.hw=arp_vec2[i][arp_hw_idx];
		tmp.ip=htonl(inet_addr(arp_vec2[i][arp_ip_idx].c_str()));
		arp_info_vec.push_back(tmp);
		log_bare(log_debug,"\n");
	}
	if(!interface_has_arp(if_name.c_str()))
	{
		mylog(log_info,"%s is a noarp interface,using 00:00:00:00:00:00\n",if_name.c_str());
		hw="00:00:00:00:00:00";
	}
	else if(find_arp(arp_info_vec,dest_ip,if_name,hw)!=0)
	{
		mylog(log_error,"find_arp failed for dest_ip %s ,if_name %s\n",my_ntoa(ntohl(ip)),if_name.c_str());
		return -1;
	}
	//printf("%s\n",hw.c_str());

	dest_ip=ntohl(dest_ip);
	return 0;
}
#endif

#ifdef UDP2RAW_LINUX
int send_raw_packet(raw_info_t &raw_info,const char * packet,int len)
{
	const packet_info_t &send_info=raw_info.send_info;
	const packet_info_t &recv_info=raw_info.recv_info;

    int ret;
    if(lower_level==0)
    {
    	if(raw_ip_version==AF_INET)
    	{
			struct sockaddr_in sin={0};
			sin.sin_family = raw_ip_version;
			//sin.sin_port = htons(info.dst_port); //dont need this
			sin.sin_addr.s_addr = send_info.new_dst_ip.v4;
			ret = sendto(raw_send_fd, packet, len ,  0, (struct sockaddr *) &sin, sizeof (sin));
    	}
    	else if(raw_ip_version==AF_INET6)
    	{
			struct sockaddr_in6 sin={0};
			sin.sin6_family = raw_ip_version;
			//sin.sin_port = htons(info.dst_port); //dont need this
			sin.sin6_addr = send_info.new_dst_ip.v6;
			ret = sendto(raw_send_fd, packet, len ,  0, (struct sockaddr *) &sin, sizeof (sin));
    	}else
    	{
    		assert(0==1);
    	}

    }
    else
    {

    	struct sockaddr_ll addr={0};  //={0} not necessary
    	memcpy(&addr,&send_info.addr_ll,sizeof(addr));

    	ret = sendto(raw_send_fd, packet, len ,  0, (struct sockaddr *) &addr, sizeof (addr));
    }
    if(ret==-1)
    {

    	mylog(log_trace,"sendto failed\n");
    	//perror("why?");
    	return -1;
    }
    else
    {
    	//mylog(log_info,"sendto succ\n");
    }
    return 0;
}
#endif

#ifdef UDP2RAW_MP

int send_raw_packet(raw_info_t &raw_info,const char * packet,int len)
{
	const packet_info_t &send_info=raw_info.send_info;
	const packet_info_t &recv_info=raw_info.recv_info;

    if(! send_with_pcap)
    {
#ifndef NO_LIBNET

		//g_ptag=libnet_build_ipv4(ip_tot_len, iph->tos, ntohs(iph->id), ntohs(iph->frag_off),
		//	iph->ttl , iph->protocol , iph->check , iph->saddr, iph->daddr,
		//	(const unsigned char *)payload, payloadlen, libnet_handle, g_ptag);

		//assert(g_ptag!=-1 &&g_ptag!=0);

		//int ret;
		//ret= libnet_write(libnet_handle);

		//assert(ret!=-1);


		//iph->tot_len=htons(ip_tot_len);
		//iph->check =csum ((unsigned short *) send_raw_ip_buf, iph->ihl*4);
    	if(raw_ip_version==AF_INET)
    	{
    		libnet_write_raw_ipv4(libnet_handle,(const unsigned char *)packet,len);  //todo, this api is marked as internal, maybe we should avoid using it.
    	}
    	else
    	{
    		assert(raw_ip_version==AF_INET6);
    		libnet_write_raw_ipv6(libnet_handle,(const unsigned char *)packet,len);
    	}
#endif
    }
    else
    {
    	char buf[buf_len];
    	assert(pcap_header_captured==1);
    	assert(pcap_link_header_len!=-1);
    	memcpy(buf,pcap_header_buf,pcap_link_header_len);
    	memcpy(buf+pcap_link_header_len,packet,len);
    	//pthread_mutex_lock(&pcap_mutex); looks like this is not necessary, and it harms performance
    	int ret=pcap_sendpacket(pcap_handle,(const unsigned char *)buf,len+pcap_link_header_len);
		if(ret!=0)
		{
			mylog(log_warn,"pcap_sendpcaket failed with vaule %d,%s, data_len=%d\n",ret,pcap_geterr(pcap_handle),len);
			//pthread_mutex_unlock(&pcap_mutex);
			//myexit(-1);
		}
    	//pthread_mutex_unlock(&pcap_mutex);
		/*
	unsigned char *p=(unsigned char *)send_raw_ip_buf0;
	for(int i=0;i<ip_tot_len+pcap_link_header_len;i++)
		printf("<%02x>",int(p[i]));
	printf("\n");
    	assert(pcap_sendpacket(pcap_handle,(const unsigned char *)pcap_header_buf,cap_len)==0);
	p=(unsigned char *)pcap_header_buf;
	for(int i=0;i<cap_len;i++)
		printf("<%02x>",int(p[i]));
	printf("\n");
	printf("pcap send!\n");*/
    }
    return 0;
}
#endif

int send_raw_ip(raw_info_t &raw_info,const char * payload,int payloadlen)
{
	const packet_info_t &send_info=raw_info.send_info;
	const packet_info_t &recv_info=raw_info.recv_info;
	char send_raw_ip_buf[buf_len];

	if(raw_info.disabled)
	{
		mylog(log_debug,"[%s,%d]connection disabled, no packet will be sent\n",recv_info.new_src_ip.get_str1(),recv_info.src_port);
		assert(max_rst_allowed>=0);
		return 0;
	}

    uint16_t ip_tot_len;
    if(raw_ip_version==AF_INET)
    {
    	struct my_iphdr *iph = (struct my_iphdr *) send_raw_ip_buf;
        memset(iph,0,sizeof(my_iphdr));

        iph->ihl = sizeof(my_iphdr)/4;  //we dont use ip options,so the length is just sizeof(iphdr)
        iph->version = 4;
        iph->tos = 0;

		if(lower_level)
		{
			//iph->id=0;
			iph->id = htons (g_ip_id_counter++); //Id of this packet
		}
		else//no need to else?
		{
			iph->id = htons (g_ip_id_counter++); //Id of this packet
			//iph->id = 0; //Id of this packet  ,kernel will auto fill this if id is zero  ,or really?????// todo //seems like there is a problem
		}

		iph->frag_off = htons(0x4000); //DF set,others are zero
	   // iph->frag_off = htons(0x0000); //DF set,others are zero
		iph->ttl = (unsigned char)ttl_value;
		iph->protocol = send_info.protocol;
		iph->check = 0; //Set to 0 before calculating checksum
		iph->saddr = send_info.new_src_ip.v4;    //Spoof the source ip address
		iph->daddr = send_info.new_dst_ip.v4;

		ip_tot_len=sizeof (struct my_iphdr)+payloadlen;
#ifdef UDP2RAW_LINUX
		if(lower_level)iph->tot_len = htons(ip_tot_len);            //this is not necessary ,kernel will always auto fill this  //http://man7.org/linux/man-pages/man7/raw.7.html
		else
			iph->tot_len = 0;
#endif

#ifdef UDP2RAW_MP
		iph->tot_len = htons(ip_tot_len);//always fill for mp version
#endif

		memcpy(send_raw_ip_buf+sizeof(my_iphdr) , payload, payloadlen);

#ifdef UDP2RAW_LINUX
		if(lower_level) iph->check =
				csum ((unsigned short *) send_raw_ip_buf, iph->ihl*4); //this is not necessary ,kernel will always auto fill this
		else
			iph->check=0;
#endif

#ifdef UDP2RAW_MP
		iph->check =csum((unsigned short *) send_raw_ip_buf, iph->ihl*4);//always cal checksum for mp version
#endif
    }
    else
    {
    	assert(raw_ip_version==AF_INET6);

    	struct my_ip6hdr *ip6h = (struct my_ip6hdr *) send_raw_ip_buf;
        memset(ip6h,0,sizeof(my_ip6hdr));

        ip6h->version=6;
        ip6h->payload_len=htons(payloadlen);
        ip6h->next_header=send_info.protocol;
        ip6h->hop_limit=(unsigned char)ttl_value;
        ip6h->src=send_info.new_src_ip.v6;
        ip6h->dst=send_info.new_dst_ip.v6;

        ip_tot_len=sizeof (struct my_ip6hdr)+payloadlen;
        memcpy(send_raw_ip_buf+sizeof(my_ip6hdr) , payload, payloadlen);
    }


    return send_raw_packet(raw_info,send_raw_ip_buf,ip_tot_len);
}

int pre_recv_raw_packet()
{
#ifdef UDP2RAW_LINUX
	assert(g_packet_buf_cnt==0);

	g_sockaddr_len=sizeof(g_sockaddr.ll);
	g_packet_buf_len = recvfrom(raw_recv_fd, g_packet_buf, huge_data_len+1, 0 ,(sockaddr*)&g_sockaddr , &g_sockaddr_len);
	//assert(g_sockaddr_len==sizeof(g_sockaddr.ll)); //g_sockaddr_len=18, sizeof(g_sockaddr.ll)=20, why its not equal? maybe its bc sll_halen is 6?

	//assert(g_addr_ll_size==sizeof(g_addr_ll));

	if(g_packet_buf_len==huge_data_len+1)
	{
		if(g_fix_gro==0)
		{
		mylog(log_warn,"huge packet, data_len %d > %d,dropped\n",g_packet_buf_len,huge_data_len);
		return -1;
		}
		else
		{
			mylog(log_debug,"huge packet, data_len %d > %d,not dropped\n",g_packet_buf_len,huge_data_len);  
			g_packet_buf_len=huge_data_len;
		}
	}

    if(g_packet_buf_len>= max_data_len+1)
    {
        if(g_fix_gro==0)
        {
            mylog(log_warn, "huge packet, data_len %d > %d(max_data_len) dropped, maybe you need to turn down mtu at upper level, or you may take a look at --fix-gro\n", g_packet_buf_len,
                  max_data_len);
            return -1;
        }
        else
        {
            mylog(log_debug, "huge packet, data_len %d > %d(max_data_len) not dropped\n", g_packet_buf_len,
                  max_data_len);
            //return -1;
        }

    }

	if(g_packet_buf_len<0)
	{
		mylog(log_trace,"recv_len %d\n",g_packet_buf_len);
		return -1;
	}
	g_packet_buf_cnt++;
#endif
	return 0;
}
int discard_raw_packet()
{
	assert(g_packet_buf_cnt==1);
	g_packet_buf_cnt--;
	return 0;
}
#ifdef UDP2RAW_LINUX
int recv_raw_packet(char * &packet,int &len,int peek)
{
	assert(g_packet_buf_cnt==1);
	if(!peek)
		g_packet_buf_cnt--;

	if(g_packet_buf_len<int(link_level_header_len))
	{
		mylog(log_trace,"packet len %d shorter than link_level_header_len %d\n",g_packet_buf_len,int(link_level_header_len));
		return -1;
	}

	if(link_level_header_len ==14)
	{
		unsigned char a=g_packet_buf[12];
		unsigned char b=g_packet_buf[13];

		if(! ((a==0x08&&b==0x00) ||(a==0x86&&b==0xdd))   )
		{
			mylog(log_trace,"not an ipv4 or ipv6 packet!\n");
			return -1;
		}

	}
	packet=g_packet_buf+int(link_level_header_len);
	len=g_packet_buf_len-int(link_level_header_len);
	return 0;
}
#endif
#ifdef UDP2RAW_MP
int recv_raw_packet(char * &packet,int &len,int peek)
{
	assert(g_packet_buf_cnt==1);
	if(!peek)
		g_packet_buf_cnt--;

	packet=g_packet_buf;
	len=g_packet_buf_len;
	return 0;
}
#endif
int recv_raw_ip(raw_info_t &raw_info,char * &payload,int &payloadlen)
{
	char *raw_packet_buf;
	//static char recv_raw_ip_buf[buf_len];
	int raw_packet_len;

	if(recv_raw_packet(raw_packet_buf,raw_packet_len,raw_info.peek)!=0) return -1;

	//const packet_info_t &send_info=raw_info.send_info;
	packet_info_t &recv_info=raw_info.recv_info;


	my_iphdr *  iph;
	my_ip6hdr * ip6h;
	int flag=0;
	//int recv_len = recvfrom(raw_recv_fd, recv_raw_ip_buf, max_data_len+1, flag ,(sockaddr*)&saddr , &saddr_size);

	char *ip_begin=raw_packet_buf;  //14 is eth net header


	if(raw_packet_len<1)
	{
		mylog(log_trace,"raw_packet_len <1, dropped\n");
		return -1;
	}
	iph = (struct my_iphdr *) (ip_begin);
	ip6h= (struct my_ip6hdr *) (ip_begin);
	if(raw_ip_version==AF_INET)
	{
		if(iph->version!=4)
		{
			mylog(log_trace,"expect ipv4 packet, but got something else: %02x\n",iph->version);
			return -1;
		}
		if(raw_packet_len<(int)sizeof(my_iphdr))
		{
			mylog(log_trace,"raw_packet_len<sizeof(iphdr)\n");
			return -1;
		}
	}
	else
	{
		assert(raw_ip_version==AF_INET6);
		if(ip6h->version!=6)
		{
			mylog(log_trace,"expect ipv6 packet, but got something else: %02x\n",ip6h->version);
			return -1;
		}
		if(raw_packet_len<(int)sizeof(my_ip6hdr))
		{
			mylog(log_trace,"raw_packet_len<sizeof(ip6_hdr)\n");
			return -1;
		}
	}
#ifdef UDP2RAW_LINUX
	if(lower_level)
	{
		memcpy(&recv_info.addr_ll,&g_sockaddr.ll,sizeof(recv_info.addr_ll));
	}
#endif



	unsigned short iphdrlen;
	int ip_len;
	if(raw_ip_version==AF_INET)
	{
		recv_info.new_src_ip.v4=iph->saddr;
		recv_info.new_dst_ip.v4=iph->daddr;
		recv_info.protocol=iph->protocol;
		iphdrlen =iph->ihl*4;
		ip_len=ntohs(iph->tot_len);
	}
	else
	{
		//todo flow id
		assert(raw_ip_version==AF_INET6);
		recv_info.new_src_ip.v6=ip6h->src;
		recv_info.new_dst_ip.v6=ip6h->dst;
		iphdrlen=40;
		recv_info.protocol=ip6h->next_header;  //todo handle extension headers;
		ip_len=ntohs(ip6h->payload_len)+iphdrlen;
	}

	if(bind_addr_used && !recv_info.new_dst_ip.equal(bind_addr))
	{
		mylog(log_trace,"bind adress doenst match %s %s, dropped\n",recv_info.new_dst_ip.get_str1(), bind_addr.get_str2());
		//printf(" bind adress doenst match, dropped\n");
		return -1;
	}

    //if (!(iph->ihl > 0 && iph->ihl <=60)) {
    //	mylog(log_trace,"iph ihl error\n");
    //   return -1;
    // }


	if(raw_packet_len <ip_len)
	{
		mylog(log_debug,"incomplete packet\n");
		return -1;
	}

	if(raw_ip_version==AF_INET)
	{
		if(raw_info.peek==0)// avoid cal it twice
		{
			u32_t ip_chk=csum ((unsigned short *) ip_begin, iphdrlen);

			if(ip_chk!=0)
			{
				mylog(log_debug,"ip header error %x\n",ip_chk);
				return -1;
			}
		}
	}
	else
	{
		//do nothing
	}

    payload=ip_begin+iphdrlen;

    payloadlen=ip_len-iphdrlen;

    if(payloadlen<0)
    {
    	mylog(log_warn,"error payload len\n");
    	return -1;
    }

	return 0;
}

int peek_raw(raw_info_t &raw_info)
{
	//static char peek_raw_buf[buf_len];
	//assert(g_packet_buf_cnt==1);
	//g_packet_buf_cnt--;
	//char * peek_raw_buf=g_packet_buf;
	//int recv_len=g_packet_buf_len;

	//char *ip_begin=peek_raw_buf+link_level_header_len;
	//struct sockaddr saddr={0};
	//socklen_t saddr_size=sizeof(saddr);
	//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)))
	//{
	//	mylog(log_trace,"failed here %d %d\n",recv_len,int(sizeof(iphdr)));
	//	mylog(log_trace,"%s\n ",strerror(errno));
	//	return -1;
	//}
	//peek_info.new_src_ip.v4=iph->saddr;
    //unsigned short iphdrlen =iph->ihl*4;
    //char *payload=ip_begin+iphdrlen;

	packet_info_t &recv_info=raw_info.recv_info;

	char *payload;int payload_len;
	if(recv_raw_ip(raw_info,payload,payload_len)!=0)
		return -1;
	//mylog(log_info,"protocol %d\n",iph->protocol);
    switch(raw_mode)
    {
    	case mode_faketcp:
    	{
    		if(recv_info.protocol!=IPPROTO_TCP)
    		{
    			mylog(log_trace,"failed here");
    			return -1;
    		}
    		struct my_tcphdr *tcph=(my_tcphdr *)payload;
    		if(payload_len<int(sizeof(my_tcphdr) ))
    		{
    			mylog(log_trace,"failed here");
    			return -1;
    		}
    		recv_info.src_port=ntohs(tcph->source);
    		recv_info.syn=tcph->syn;
			break;
    	}
    	case mode_udp:
    	{
    		if(recv_info.protocol!=IPPROTO_UDP) return -1;
    		struct my_udphdr *udph=(my_udphdr *)payload;
    		if(payload_len<int(sizeof(my_udphdr)))
    			return -1;
    		recv_info.src_port=ntohs(udph->source);
			break;
    	}
    	case mode_icmp:
    	{
    		if(raw_ip_version==AF_INET)
    		{
    			if(recv_info.protocol!=IPPROTO_ICMP) return -1;
    		}else
    		{
    			assert(raw_ip_version==AF_INET6);
    			if(recv_info.protocol!=IPPROTO_ICMPV6) return -1;
    		}
    		struct my_icmphdr *icmph=(my_icmphdr *)payload;
    		if(payload_len<int(sizeof(my_udphdr)))
    			return -1;
    		recv_info.src_port=ntohs(icmph->id);
			break;
    	}
    	default:return -1;
    }
    return 0;
}
int send_raw_icmp(raw_info_t &raw_info, const char * payload, int payloadlen)
{
	const packet_info_t &send_info=raw_info.send_info;
	const packet_info_t &recv_info=raw_info.recv_info;

	char send_raw_icmp_buf[buf_len];
	my_icmphdr *icmph=(struct my_icmphdr *) (send_raw_icmp_buf);
	memset(icmph,0,sizeof(my_icmphdr));
	if(raw_ip_version==AF_INET)
	{
		if(program_mode==client_mode)
		{
			icmph->type=8;
		}
		else
		{
			icmph->type=0;
		}
	}
	else
	{
		assert(raw_ip_version==AF_INET6);
		if(program_mode==client_mode)
		{
			icmph->type=128;
		}
		else
		{
			icmph->type=129;
		}
	}
	icmph->code=0;
	icmph->id=htons(send_info.src_port);

	icmph->seq=htons(send_info.my_icmp_seq);   /////////////modify

	memcpy(send_raw_icmp_buf+sizeof(my_icmphdr),payload,payloadlen);

	if(raw_ip_version==AF_INET)
	{
		icmph->check_sum = csum( (unsigned short*) send_raw_icmp_buf, sizeof(my_icmphdr)+payloadlen);
	}
	else
	{
		assert(raw_ip_version==AF_INET6);

		pseudo_header6 v6;
		struct pseudo_header6 *psh = &v6;

		psh->src=send_info.new_src_ip.v6;
		psh->dst=send_info.new_dst_ip.v6;
		psh->next_header=IPPROTO_ICMPV6;
		psh->tcp_length=htons(sizeof(my_icmphdr)+payloadlen);
		psh->placeholder1 = 0;
		psh->placeholder2 = 0;

		icmph->check_sum = csum_with_header((char *)psh,sizeof(pseudo_header6), (unsigned short*) send_raw_icmp_buf, sizeof(my_icmphdr)+payloadlen);
	}
	if(send_raw_ip(raw_info,send_raw_icmp_buf,sizeof(my_icmphdr)+payloadlen)!=0)
	{
		return -1;
	}

	/*if(program_mode==client_mode)
	{
		send_info.icmp_seq++;
	}*/

	return 0;
}

int send_raw_udp(raw_info_t &raw_info, const char * payload, int payloadlen)
{
	const packet_info_t &send_info=raw_info.send_info;
	const packet_info_t &recv_info=raw_info.recv_info;

	char send_raw_udp_buf[buf_len];

	my_udphdr *udph=(struct my_udphdr *) (send_raw_udp_buf);

	memset(udph,0,sizeof(my_udphdr));

	udph->source = htons(send_info.src_port);
	udph->dest = htons(send_info.dst_port);

	int udp_tot_len=payloadlen+sizeof(my_udphdr);


	if(udp_tot_len>65535)
	{
		mylog(log_debug,"invalid len\n");
		return -1;
	}
	mylog(log_trace,"udp_len:%d %d\n",udp_tot_len,udph->len);
	udph->len=htons(uint16_t(udp_tot_len));

	memcpy(send_raw_udp_buf+sizeof(my_udphdr),payload,payloadlen);




	if(raw_ip_version==AF_INET)
	{
		pseudo_header v4;
		struct pseudo_header *psh = &v4;

		psh->source_address = send_info.new_src_ip.v4;
		psh->dest_address = send_info.new_dst_ip.v4;
		psh->placeholder = 0;
		psh->protocol = IPPROTO_UDP;
		psh->tcp_length = htons(udp_tot_len);

		udph->check  = csum_with_header((char *)psh,sizeof(pseudo_header), (unsigned short*) send_raw_udp_buf, udp_tot_len);
	}
	else
	{
		assert(raw_ip_version==AF_INET6);
		pseudo_header6 v6;
		struct pseudo_header6 *psh = &v6;

		psh->src=send_info.new_src_ip.v6;
		psh->dst=send_info.new_dst_ip.v6;
		psh->next_header=IPPROTO_UDP;
		psh->tcp_length=htons(udp_tot_len);

		psh->placeholder1 = 0;
		psh->placeholder2 = 0;


		udph->check  = csum_with_header((char *)psh,sizeof(pseudo_header6), (unsigned short*) send_raw_udp_buf, udp_tot_len);
	}


	if(send_raw_ip(raw_info,send_raw_udp_buf,udp_tot_len)!=0)
	{
		return -1;
	}
	return 0;
}

int send_raw_tcp(raw_info_t &raw_info,const char * payload, int payloadlen) {  	//TODO seq increase


	const packet_info_t &send_info=raw_info.send_info;
	const packet_info_t &recv_info=raw_info.recv_info;

	//mylog(log_debug,"syn %d\n",send_info.syn);

	char send_raw_tcp_buf[buf_len];
	//char *send_raw_tcp_buf=send_raw_tcp_buf0;

	struct my_tcphdr *tcph = (struct my_tcphdr *) (send_raw_tcp_buf);

	memset(tcph,0,sizeof(my_tcphdr));

	//TCP Header
	tcph->source = htons(send_info.src_port);
	tcph->dest = htons(send_info.dst_port);

	tcph->seq = htonl(send_info.seq);
	tcph->ack_seq = htonl(send_info.ack_seq);

	tcph->fin = 0;
	tcph->syn = send_info.syn;
	tcph->rst = 0;
	tcph->psh = send_info.psh;
	tcph->ack = send_info.ack;

	if (tcph->syn == 1) {
		tcph->doff = 10;  //tcp header size
		int i = sizeof(my_tcphdr);
		send_raw_tcp_buf[i++] = 0x02;  //mss
		send_raw_tcp_buf[i++] = 0x04;
		send_raw_tcp_buf[i++] = 0x05;
		send_raw_tcp_buf[i++] = (char)0xb4;

		//raw_send_buf[i++]=0x01;
		//raw_send_buf[i++]=0x01;
		send_raw_tcp_buf[i++] = 0x04; //sack ok
		send_raw_tcp_buf[i++] = 0x02; //sack ok

		send_raw_tcp_buf[i++] = 0x08;   //ts   i=6
		send_raw_tcp_buf[i++] = 0x0a;   //i=7

		//*(u32_t*) (&send_raw_tcp_buf[i]) = htonl(
			//	(u32_t) get_current_time());

		u32_t ts=htonl((u32_t) get_current_time());
		memcpy(&send_raw_tcp_buf[i],&ts,sizeof(ts));

		i += 4;

		//mylog(log_info,"[syn]<send_info.ts_ack= %u>\n",send_info.ts_ack);

		//*(u32_t*) (&send_raw_tcp_buf[i]) = htonl(send_info.ts_ack);
		u32_t ts_ack=htonl(send_info.ts_ack);
		memcpy(&send_raw_tcp_buf[i],&ts_ack,sizeof(ts_ack));

		i += 4;

		send_raw_tcp_buf[i++] = 0x01;
		send_raw_tcp_buf[i++] = 0x03;
		send_raw_tcp_buf[i++] = 0x03;
		send_raw_tcp_buf[i++] = wscale;
	} else {
		tcph->doff = 8;
		int i = sizeof(my_tcphdr);

		send_raw_tcp_buf[i++] = 0x01;
		send_raw_tcp_buf[i++] = 0x01;

		send_raw_tcp_buf[i++] = 0x08;  //ts   //i=2
		send_raw_tcp_buf[i++] = 0x0a; 		  //i=3;

		//*(u32_t*) (&send_raw_tcp_buf[i]) = htonl(
			//	(u32_t) get_current_time());

		u32_t ts=htonl((u32_t) get_current_time());
		memcpy(&send_raw_tcp_buf[i],&ts,sizeof(ts));

		i += 4;

		//mylog(log_info,"<send_info.ts_ack= %u>\n",send_info.ts_ack);

		//*(u32_t*) (&send_raw_tcp_buf[i]) = htonl(send_info.ts_ack);
		u32_t ts_ack=htonl(send_info.ts_ack);
		memcpy(&send_raw_tcp_buf[i],&ts_ack,sizeof(ts_ack));
		i += 4;
	}

	tcph->urg = 0;
	//tcph->window = htons((uint16_t)(1024));
	tcph->window = htons((uint16_t) (receive_window_lower_bound + get_true_random_number() % receive_window_random_range));

	tcph->check = 0; //leave checksum 0 now, filled later by pseudo header
	tcph->urg_ptr = 0;

	char *tcp_data = send_raw_tcp_buf+ + tcph->doff * 4;

	memcpy(tcp_data, payload, payloadlen);
	int tcp_totlen=tcph->doff*4 + payloadlen;

	if(raw_ip_version==AF_INET)
	{
		pseudo_header v4;
		struct pseudo_header *psh = &v4;

		psh->source_address = send_info.new_src_ip.v4;
		psh->dest_address = send_info.new_dst_ip.v4;
		psh->placeholder = 0;
		psh->protocol = IPPROTO_TCP;
		psh->tcp_length = htons(tcp_totlen);

		tcph->check = csum_with_header((char *)psh,sizeof(pseudo_header), (unsigned short*) send_raw_tcp_buf, tcp_totlen);
	}
	else
	{
		assert(raw_ip_version==AF_INET6);

		pseudo_header6 v6;
		struct pseudo_header6 *psh = &v6;

		psh->src=send_info.new_src_ip.v6;
		psh->dst=send_info.new_dst_ip.v6;
		psh->next_header=IPPROTO_TCP;
		psh->tcp_length=htons(tcp_totlen);
		psh->placeholder1 = 0;
		psh->placeholder2 = 0;

		tcph->check = csum_with_header((char *)psh,sizeof(pseudo_header6), (unsigned short*) send_raw_tcp_buf, tcp_totlen);
	}


	if(send_raw_ip(raw_info,send_raw_tcp_buf,tcp_totlen)!=0)
	{
		return -1;
	}


	raw_info.send_info.data_len=payloadlen;
	return 0;
}
/*
int send_raw_tcp_deprecated(const packet_info_t &info,const char * payload,int payloadlen)
{
	static uint16_t ip_id=1;
	char raw_send_buf[buf_len];
	char raw_send_buf2[buf_len];

	//if((prog_mode==client_mode&& payloadlen!=9)  ||(prog_mode==server_mode&& payloadlen!=5 )  )
	mylog(log_trace,"send raw from to %d %d %d %d\n",info.src_ip,info.src_port,info.dst_ip,info.dst_port);

	char *data;

    memset(raw_send_buf,0,payloadlen+100);

    struct iphdr *iph = (struct iphdr *) raw_send_buf;

    //TCP header
    struct tcphdr *tcph = (struct tcphdr *) (raw_send_buf + sizeof (struct ip));

    struct sockaddr_in sin;
    struct pseudo_header psh;

    //some address resolution
    sin.sin_family = AF_INET;
    sin.sin_port = htons(info.dst_port);
    sin.sin_addr.s_addr = info.dst_ip;

    //Fill in the IP Header
    iph->ihl = 5;
    iph->version = 4;
    iph->tos = 0;

    iph->id = htonl (ip_id++); //Id of this packet
    iph->frag_off = htons(0x4000); //DF set,others are zero
    iph->ttl = (unsigned char)ttl_value;
    iph->protocol = IPPROTO_TCP;
    iph->check = 0; //Set to 0 before calculating checksum
    iph->saddr = info.src_ip;    //Spoof the source ip address
    iph->daddr = info.dst_ip;

    //TCP Header
    tcph->source = htons(info.src_port);
    tcph->dest = htons(info.dst_port);

    tcph->seq =htonl(info.seq);
    tcph->ack_seq = htonl(info.ack_seq);

    tcph->fin=0;
    tcph->syn=info.syn;
    tcph->rst=0;
    tcph->psh=info.psh;
    tcph->ack=info.ack;

    if(tcph->syn==1)
    {
    	tcph->doff = 10;  //tcp header size
    	int i=sizeof (struct iphdr)+20;
    	raw_send_buf[i++]=0x02;//mss
    	raw_send_buf[i++]=0x04;
    	raw_send_buf[i++]=0x05;
    	raw_send_buf[i++]=0xb4;

    	//raw_send_buf[i++]=0x01;
    	//raw_send_buf[i++]=0x01;
    	raw_send_buf[i++]=0x04; //sack ok
    	raw_send_buf[i++]=0x02; //sack ok


    	raw_send_buf[i++]=0x08;   //i=6;
    	raw_send_buf[i++]=0x0a;

    	*(uint32_t*)(& raw_send_buf[i])=htonl((uint32_t)get_current_time());

    	i+=4;

    	*(uint32_t*)(& raw_send_buf[i])=htonl(info.ts_ack);
    	i+=4;

    	raw_send_buf[i++]=0x01;
    	raw_send_buf[i++]=0x03;
    	raw_send_buf[i++]=0x03;
    	raw_send_buf[i++]=0x05;
    }
    else
    {
    	tcph->doff=8;
    	int i=sizeof (struct iphdr)+20;

    	raw_send_buf[i++]=0x01;
    	raw_send_buf[i++]=0x01;

    	raw_send_buf[i++]=0x08;   //i=0;
    	raw_send_buf[i++]=0x0a;

    	*(uint32_t*)(& raw_send_buf[i])=htonl((uint32_t)get_current_time());

    	i+=4;

    	*(uint32_t*)(& raw_send_buf[i])=htonl(info.ts_ack);
    	i+=4;


    }



    tcph->urg=0;
    //tcph->window = htons((uint16_t)(1024));
    tcph->window = htons((uint16_t)(10240+random()%100));


    tcph->check = 0; //leave checksum 0 now, filled later by pseudo header
    tcph->urg_ptr = 0;


    //Data part
    data = raw_send_buf + sizeof(struct iphdr) + tcph->doff*4;

    iph->tot_len = sizeof (struct iphdr) + tcph->doff*4 + payloadlen;

    memcpy(data , payload, payloadlen);

    psh.source_address = info.src_ip;
    psh.dest_address = sin.sin_addr.s_addr;
    psh.placeholder = 0;
    psh.protocol = IPPROTO_TCP;
    psh.tcp_length = htons(tcph->doff*4 + payloadlen );

    int psize = sizeof(struct pseudo_header) + tcph->doff*4 + payloadlen;

     memcpy(raw_send_buf2 , (char*) &psh , sizeof (struct pseudo_header));
     memcpy(raw_send_buf2 + sizeof(struct pseudo_header) , tcph , tcph->doff*4 + payloadlen);

     tcph->check = csum( (unsigned short*) raw_send_buf2, psize);

     //Ip checksum
     iph->check = csum ((unsigned short *) raw_send_buf, iph->tot_len);

     mylog(log_trace,"sent seq  ack_seq len<%u %u %d>\n",g_packet_info_send.seq,g_packet_info_send.ack_seq,payloadlen);

     int ret = sendto(raw_send_fd, raw_send_buf, iph->tot_len ,  0, (struct sockaddr *) &sin, sizeof (sin));

     if(g_packet_info_send.syn==0&&g_packet_info_send.ack==1&&payloadlen!=0)
     {
    	 if(seq_mode==0)
    	 {


    	 }
    	 else if(seq_mode==1)
    	 {
    		 g_packet_info_send.seq+=payloadlen;
    	 }
    	 else if(seq_mode==2)
    	 {
    		 if(random()% 5==3 )
    			 g_packet_info_send.seq+=payloadlen;
    	 }
     }
     mylog(log_trace,"<ret:%d>\n",ret);
	 if(ret<0)
     {
	    	mylog(log_fatal,"");
    	 perror("raw send error\n");
    	 //printf("send error\n");
     }
     return 0;
}
*/

int recv_raw_icmp(raw_info_t &raw_info, char *&payload, int &payloadlen)
{
	const packet_info_t &send_info=raw_info.send_info;
	packet_info_t &recv_info=raw_info.recv_info;
	static char recv_raw_icmp_buf[buf_len];

	char * ip_payload;
	int ip_payloadlen;

	if(recv_raw_ip(raw_info,ip_payload,ip_payloadlen)!=0)
	{
		mylog(log_debug,"recv_raw_ip error\n");
		return -1;
	}
	mylog(log_trace,"ip_payloadlen=%d\n",ip_payloadlen);
	if(raw_ip_version==AF_INET)
	{
		if(recv_info.protocol!=IPPROTO_ICMP)
		{
			//printf("not udp protocol\n");
			return -1;
		}
	}
	else
	{
		assert(raw_ip_version==AF_INET6);
		if(recv_info.protocol!=IPPROTO_ICMPV6)
		{
			//printf("not udp protocol\n");
			return -1;
		}
	}

	if(ip_payloadlen<int( sizeof(my_icmphdr) ))
	{
		mylog(log_debug,"too short to hold icmp header\n");
		return -1;
	}



	my_icmphdr *icmph=(struct my_icmphdr *) (ip_payload);

	if(ntohs(icmph->id)!=send_info.src_port)
	{
		mylog(log_debug,"icmp id mis-match,ignored\n");
		return -1;
	}

	recv_info.src_port=recv_info.dst_port=ntohs(icmph->id);
	recv_info.my_icmp_seq=ntohs(icmph->seq);

	if(icmph->code!=0)
		return -1;

	unsigned short check ;
	if(raw_ip_version==AF_INET)
	{
		if(program_mode==client_mode)
		{
			if(icmph->type!=0)
				return -1;
		}
		else
		{
			if(icmph->type!=8)
				return -1;
		}
		check= csum( (unsigned short*) ip_payload, ip_payloadlen);
	}
	else
	{
		assert(raw_ip_version==AF_INET6);
		if(program_mode==client_mode)
		{
			if(icmph->type!=129)
				return -1;
		}
		else
		{
			if(icmph->type!=128)
				return -1;
		}

		pseudo_header6 tmp_header;
		struct pseudo_header6 *psh=&tmp_header ;

		psh->src = recv_info.new_src_ip.v6;
		psh->dst = recv_info.new_dst_ip.v6;
		psh->placeholder1 = 0;
		psh->placeholder2 = 0;
		psh->next_header = IPPROTO_ICMPV6;
		psh->tcp_length = htons(ip_payloadlen);

		check = csum_with_header((char *)psh,sizeof(pseudo_header6), (unsigned short*) ip_payload, ip_payloadlen);
	}


	if(check!=0)
	{
		mylog(log_debug,"icmp checksum fail %x\n",check);
		return -1;
	}
	//mylog(log_info,"program_mode=%d\n",program_mode);
/*
	if(program_mode==server_mode)
	{
		send_info.icmp_seq=ntohs(icmph->seq);
		//mylog(log_info,"send_info.seq=%d\n",send_info.seq);
	}*/

	payload=ip_payload+sizeof(my_icmphdr);
	payloadlen=ip_payloadlen-sizeof(my_icmphdr);
	mylog(log_trace,"get a packet len=%d\n",payloadlen);

    return 0;
}

int recv_raw_udp(raw_info_t &raw_info, char *&payload, int &payloadlen)
{
	const packet_info_t &send_info=raw_info.send_info;
	packet_info_t &recv_info=raw_info.recv_info;
	//static char recv_raw_udp_buf[buf_len];
	char * ip_payload;
	int ip_payloadlen;

	if(recv_raw_ip(raw_info,ip_payload,ip_payloadlen)!=0)
	{
		mylog(log_debug,"recv_raw_ip error\n");
		return -1;
	}
	if(recv_info.protocol!=IPPROTO_UDP)
	{
		//printf("not udp protocol\n");
		return -1;
	}
	if(ip_payloadlen<int( sizeof(my_udphdr) ))
	{
		mylog(log_debug,"too short to hold udpheader\n");
		return -1;
	}
	my_udphdr *udph=(struct my_udphdr*)ip_payload;

	if(int(ntohs(udph->len))!=ip_payloadlen)
	{

		mylog(log_debug,"udp length error %d %d \n",ntohs(udph->len),ip_payloadlen);
		return -1;
	}

    if(udph->dest!=ntohs(uint16_t(filter_port)))
    {
    	//printf("%x %x",tcph->dest,);
    	return -1;
    }

    //memcpy(recv_raw_udp_buf+ sizeof(struct pseudo_header) , ip_payload , ip_payloadlen);

    /*
    pseudo_header tmp_header={0};
    struct pseudo_header *psh=&tmp_header ;

    psh->source_address = recv_info.new_src_ip.v4;
    psh->dest_address = recv_info.new_dst_ip.v4;
    psh->placeholder = 0;
    psh->protocol = IPPROTO_UDP;
    psh->tcp_length = htons(ip_payloadlen);

    int csum_len=ip_payloadlen;
    uint16_t udp_chk = csum_with_header((char *)psh,sizeof(pseudo_header), (unsigned short*) ip_payload, csum_len);
    */
    uint16_t udp_chk;
	int csum_len=ip_payloadlen;
	if(raw_ip_version==AF_INET)
	{
		pseudo_header tmp_header;
		struct pseudo_header *psh=&tmp_header ;

		psh->source_address = recv_info.new_src_ip.v4;
		psh->dest_address = recv_info.new_dst_ip.v4;
		psh->placeholder = 0;
		psh->protocol = IPPROTO_UDP;
		psh->tcp_length = htons(ip_payloadlen);

		udp_chk = csum_with_header((char *)psh,sizeof(pseudo_header), (unsigned short*) ip_payload, csum_len);
	}
	else
	{
		assert(raw_ip_version==AF_INET6);

		pseudo_header6 tmp_header;
		struct pseudo_header6 *psh=&tmp_header ;

		psh->src = recv_info.new_src_ip.v6;
		psh->dst = recv_info.new_dst_ip.v6;
		psh->placeholder1 = 0;
		psh->placeholder2 = 0;
		psh->next_header = IPPROTO_UDP;
		psh->tcp_length = htons(ip_payloadlen);

		udp_chk = csum_with_header((char *)psh,sizeof(pseudo_header6), (unsigned short*) ip_payload, csum_len);
	}

    if(udp_chk!=0)
    {
    	mylog(log_debug,"udp_chk:%x\n",udp_chk);
    	mylog(log_debug,"udp header error\n");
    	return -1;

    }

    char *udp_begin=ip_payload;

    recv_info.src_port=ntohs(udph->source);
    recv_info.dst_port=ntohs(udph->dest);

    payloadlen = ip_payloadlen-sizeof(my_udphdr);

    payload=udp_begin+sizeof(my_udphdr);

    return 0;
}
int parse_tcp_option(char * option_begin,char * option_end,packet_info_t &recv_info)
{
    recv_info.has_ts=0;
    recv_info.ts=0;

    char *ptr=option_begin;
    //char *option_end=tcp_begin+tcp_hdr_len;
    while(ptr<option_end)
    {
    	if(*ptr==0)
    	{
    		return  0;
    	}
    	else if(*ptr==1)
    	{
    		ptr++;
    	}
    	else if(*ptr==8)
    	{
    		if(ptr+1>=option_end)
    		{
    			mylog(log_trace,"invaild option ptr+1==option_end,for ts\n");
    			return -1;
    		}
    		if(*(ptr+1)!=10)
    		{
    			mylog(log_trace,"invaild ts len\n");
    			return -1;
    		}
    		if(ptr+10>option_end)
    		{
    			mylog(log_trace,"ptr+10>option_end for ts\n");
    			return -1;
    		}

    		recv_info.has_ts=1;

    		recv_info.ts= read_u32(ptr+2);
    		recv_info.ts_ack=read_u32(ptr+6);

    		//printf("<%d %d>!\n",recv_info.ts,recv_info.ts_ack);

    		//return 0;//we currently only parse ts, so just return after its found
    		ptr+=10;
    	}
    	else
    	{
    		if(ptr+1>=option_end)
    		{
    			mylog(log_trace,"invaild option ptr+1==option_end\n");
    			return -1;
    		}
    		else
    		{
    			int len=(unsigned char)*(ptr+1);
    			if(len<=1)
    			{
    				mylog(log_trace,"invaild option len %d\n",len);
    				return -1;
    			}
    			//omit check
    			ptr+=len;
    		}
    	}
    	//printf("!");
    }
    //printf("\n");

	return 0;
}
int recv_raw_tcp(raw_info_t &raw_info,char * &payload,int &payloadlen)
{
	const packet_info_t &send_info=raw_info.send_info;
	packet_info_t &recv_info=raw_info.recv_info;

	//static char recv_raw_tcp_buf[buf_len];

	char * ip_payload;
	int ip_payloadlen;


	if(recv_raw_ip(raw_info,ip_payload,ip_payloadlen)!=0)
	{
		mylog(log_debug,"recv_raw_ip error\n");
		return -1;
	}

	if(recv_info.protocol!=IPPROTO_TCP)
	{
		//printf("not tcp protocol\n");
		return -1;
	}


	my_tcphdr * tcph=(struct my_tcphdr*)ip_payload;

    unsigned short tcphdrlen = tcph->doff*4;

    if (!(tcphdrlen > 0 && tcphdrlen <=60)) {
    	mylog(log_debug,"tcph error\n");
    	return 0;
    }

    if (tcphdrlen >ip_payloadlen) {
    	mylog(log_debug,"error,tcphdrlen >ip_payloadlen\n");
    	return 0;
    }


    if(tcph->dest!=ntohs(uint16_t(filter_port)))
    {
    	//printf("%x %x",tcph->dest,);
    	return -1;
    }

   // memcpy(recv_raw_tcp_buf+ sizeof(struct pseudo_header) , ip_payload , ip_payloadlen);
    uint16_t tcp_chk;
	int csum_len=ip_payloadlen;
	if(raw_ip_version==AF_INET)
	{
		pseudo_header tmp_header;
		struct pseudo_header *psh=&tmp_header ;

		psh->source_address = recv_info.new_src_ip.v4;
		psh->dest_address = recv_info.new_dst_ip.v4;
		psh->placeholder = 0;
		psh->protocol = IPPROTO_TCP;
		psh->tcp_length = htons(ip_payloadlen);

		tcp_chk = csum_with_header((char *)psh,sizeof(pseudo_header), (unsigned short*) ip_payload, csum_len);
	}
	else
	{
		assert(raw_ip_version==AF_INET6);

		pseudo_header6 tmp_header;
		struct pseudo_header6 *psh=&tmp_header ;

		psh->src = recv_info.new_src_ip.v6;
		psh->dst = recv_info.new_dst_ip.v6;
		psh->placeholder1 = 0;
		psh->placeholder2 = 0;
		psh->next_header = IPPROTO_TCP;
		psh->tcp_length = htons(ip_payloadlen);

		tcp_chk = csum_with_header((char *)psh,sizeof(pseudo_header6), (unsigned short*) ip_payload, csum_len);
	}
    /*for(int i=0;i<csum_len;i++)
    {
    	printf("<%d>",int(ip_payload[i]));
    }
    printf("\n");*/

    if(tcp_chk!=0)
    {
    	mylog(log_debug,"tcp_chk:%x, tcp checksum failed, ignored\n",tcp_chk);
    	//return -1;

    }

    char *tcp_begin=ip_payload;  //ip packet's data part

    char *tcp_option=ip_payload+sizeof(my_tcphdr);
    char *option_end=ip_payload+tcphdrlen;

    /*
    //old ts parse code
    recv_info.has_ts=0;
    recv_info.ts=0;
    if(tcph->doff==10)
    {
    	if(tcp_option[6]==0x08 &&tcp_option[7]==0x0a)
    	{
    		recv_info.has_ts=1;
    		//recv_info.ts=ntohl(*(u32_t*)(&tcp_option[8]));
    		memcpy(&recv_info.ts,&tcp_option[8],sizeof(recv_info.ts));
    		recv_info.ts=ntohl(recv_info.ts);

    		//recv_info.ts_ack=ntohl(*(u32_t*)(&tcp_option[12]));
    		memcpy(&recv_info.ts_ack,&tcp_option[12],sizeof(recv_info.ts_ack));
    		recv_info.ts_ack=ntohl(recv_info.ts_ack);

    		//g_packet_info_send.ts_ack= ntohl(*(uint32_t*)(&tcp_option[8]));
    	}
    	else
    	{
    	//	mylog(log_info,"\n");
    	}
    }
    else if(tcph->doff==8)
    {
    	if(tcp_option[2]==0x08 &&tcp_option[3]==0x0a)
    	{
    		recv_info.has_ts=1;
    		//recv_info.ts=ntohl(*(u32_t*)(&tcp_option[4]));
    		memcpy(&recv_info.ts,&tcp_option[4],sizeof(recv_info.ts));
    		recv_info.ts=ntohl(recv_info.ts);
    		//recv_info.ts_ack=ntohl(*(u32_t*)(&tcp_option[8]));
    		memcpy(&recv_info.ts_ack,&tcp_option[8],sizeof(recv_info.ts_ack));
    		recv_info.ts_ack=ntohl(recv_info.ts_ack);
    		//g_packet_info_send.ts_ack= ntohl(*(uint32_t*)(&tcp_option[0]));
    	}
    	else
    	{
    		//mylog(log_info,"!!!\n");
    	}
    }
    else
    {
    	//mylog(log_info,"tcph->doff= %u\n",tcph->doff);
    }
    printf("<%d %d>\n",recv_info.ts,recv_info.ts_ack);
    */
    parse_tcp_option(tcp_option,option_end,recv_info);

    recv_info.ack=tcph->ack;
    recv_info.syn=tcph->syn;
    recv_info.rst=tcph->rst;
    recv_info.src_port=ntohs(tcph->source);
    recv_info.dst_port=ntohs(tcph->dest);

    recv_info.seq=ntohl(tcph->seq);

   // recv_info.last_last_ack_seq=recv_info.last_ack_seq;
    //recv_info.last_ack_seq=recv_info.ack_seq;
    u32_t last_ack_seq=recv_info.ack_seq;
    recv_info.ack_seq=ntohl(tcph->ack_seq);
    if(recv_info.ack_seq==last_ack_seq)
    {
    	recv_info.ack_seq_counter++;
    }
    else
    {
    	recv_info.ack_seq_counter=0;
    }

    recv_info.psh=tcph->psh;

    if(tcph->rst==1)
    {
		raw_info.rst_received++;

    	if(max_rst_to_show>0)
    	{
    		if(raw_info.rst_received < max_rst_to_show)
    		{
    			mylog(log_warn,"[%s,%d]rst==1,cnt=%d\n",recv_info.new_src_ip.get_str1(),recv_info.src_port,(int)raw_info.rst_received);
    		}
    		else if(raw_info.rst_received == max_rst_to_show)
    		{
    			mylog(log_warn,"[%s,%d]rst==1,cnt=%d >=max_rst_to_show, this log will be muted for current connection\n",recv_info.new_src_ip.get_str1(),recv_info.src_port,(int)raw_info.rst_received);
    		}
    		else
    		{
    			mylog(log_debug,"[%s,%d]rst==1,cnt=%d\n",recv_info.new_src_ip.get_str1(),recv_info.src_port,(int)raw_info.rst_received);
    		}
    	}
    	else if(max_rst_to_show==0)
    	{
    		mylog(log_debug,"[%s,%d]rst==1,cnt=%d\n",recv_info.new_src_ip.get_str1(),recv_info.src_port,(int)raw_info.rst_received);
    	}
    	else
    	{
    		mylog(log_warn,"[%s,%d]rst==1,cnt=%d\n",recv_info.new_src_ip.get_str1(),recv_info.src_port,(int)raw_info.rst_received);
    	}

		if(max_rst_allowed>=0 && raw_info.rst_received==max_rst_allowed+1 )
		{
			mylog(log_warn,"[%s,%d]connection disabled because of rst_received=%d > max_rst_allow=%d\n",recv_info.new_src_ip.get_str1(),recv_info.src_port,(int)raw_info.rst_received,(int)max_rst_allowed );
			raw_info.disabled=1;
		}
    }

   /* if(recv_info.has_ts)
    {
    	send_info.ts_ack=recv_info.ts;   //////////////////////////////////////////////modify
    }*/

    payloadlen = ip_payloadlen-tcphdrlen;

    payload=tcp_begin+tcphdrlen;

	/*if (recv_info.syn == 0 && recv_info.ack == 1&& payloadlen != 0)   //only modify   send_info when the packet is not part of handshake
	{
		send_info.ack_seq=recv_info.seq;
	}*/
    raw_info.recv_info.data_len=payloadlen;
    return 0;
}
/*
int recv_raw_tcp_deprecated(packet_info_t &info,char * &payload,int &payloadlen)
{
	static char buf[buf_len];

	char raw_recv_buf[buf_len];
	char raw_recv_buf2[buf_len];
	char raw_recv_buf3[buf_len];

	iphdr *  iph;
	tcphdr * tcph;
	int size;
	struct sockaddr saddr;
	socklen_t saddr_size;
	saddr_size = sizeof(saddr);

	mylog(log_trace,"raw!\n");

	size = recvfrom(raw_recv_fd, buf, max_data_len, 0 ,&saddr , &saddr_size);

	if(buf[12]!=8||buf[13]!=0)
	{
		mylog(log_debug,"not an ipv4 packet!\n");
		return -1;
	}

	char *ip_begin=buf+14;

	iph = (struct iphdr *) (ip_begin);


    if (!(iph->ihl > 0 && iph->ihl <=60)) {
    	mylog(log_debug,"iph ihl error");
        return -1;
    }

    if (iph->protocol != IPPROTO_TCP) {
    	mylog(log_debug,"iph protocal != tcp\n");
    	return -1;
    }


	int ip_len=ntohs(iph->tot_len);

    unsigned short iphdrlen =iph->ihl*4;
    tcph=(struct tcphdr*)(ip_begin+ iphdrlen);
    unsigned short tcphdrlen = tcph->doff*4;

    if (!(tcph->doff > 0 && tcph->doff <=60)) {
    	mylog(log_debug,"tcph error");
    	return 0;
    }


    if(tcph->dest!=ntohs(uint16_t(filter_port)))
    {
    	//printf("%x %x",tcph->dest,);
    	return -1;
    }
    /////ip
    uint32_t ip_chk=csum ((unsigned short *) ip_begin, iphdrlen);

    int psize = sizeof(struct pseudo_header) + ip_len-iphdrlen;
    /////ip end


    ///tcp
    struct pseudo_header psh;

    psh.source_address = iph->saddr;
    psh.dest_address = iph->daddr;
    psh.placeholder = 0;
    psh.protocol = IPPROTO_TCP;
    psh.tcp_length = htons(ip_len-iphdrlen);

    memcpy(raw_recv_buf2 , (char*) &psh , sizeof (struct pseudo_header));
    memcpy(raw_recv_buf2 + sizeof(struct pseudo_header) , ip_begin+ iphdrlen , ip_len-iphdrlen);

    uint16_t tcp_chk = csum( (unsigned short*) raw_recv_buf2, psize);


   if(ip_chk!=0)
    {
	   mylog(log_debug,"ip header error %d\n",ip_chk);
    	return -1;
    }
    if(tcp_chk!=0)
    {
    	mylog(log_debug,"tcp_chk:%x\n",tcp_chk);
    	mylog(log_debug,"tcp header error\n");
    	return -1;

    }
    char *tcp_begin=raw_recv_buf2+sizeof(struct pseudo_header);  //ip packet's data part

    char *tcp_option=raw_recv_buf2+sizeof(struct pseudo_header)+sizeof(tcphdr);

    info.has_ts=0;

    if(tcph->doff==10)
    {
    	if(tcp_option[6]==0x08 &&tcp_option[7]==0x0a)
    	{
    		info.has_ts=1;
    		info.ts=ntohl(*(uint32_t*)(&tcp_option[8]));
    		info.ts_ack=ntohl(*(uint32_t*)(&tcp_option[12]));
    		//g_packet_info_send.ts_ack= ntohl(*(uint32_t*)(&tcp_option[8]));
    	}
    }
    else if(tcph->doff==8)
    {
    	if(tcp_option[3]==0x08 &&tcp_option[4]==0x0a)
    	{
    		info.has_ts=1;
    		info.ts=ntohl(*(uint32_t*)(&tcp_option[0]));
    		info.ts_ack=ntohl(*(uint32_t*)(&tcp_option[4]));
    		//g_packet_info_send.ts_ack= ntohl(*(uint32_t*)(&tcp_option[0]));
    	}
    }

    if(tcph->rst==1)
    {
    	mylog(log_warn,"%%%%%%%%%%rst==1%%%%%%%%%%%%%\n");
    }


    info.ack=tcph->ack;
    info.syn=tcph->syn;
    info.rst=tcph->rst;
    info.src_port=ntohs(tcph->source);
    info.src_ip=iph->saddr;
    info.seq=ntohl(tcph->seq);
    info.ack_seq=ntohl(tcph->ack_seq);
    info.psh=tcph->psh;
    if(info.has_ts)
    {
    	g_packet_info_send.ts_ack=info.ts;
    }
    ////tcp end


    payloadlen = ip_len-tcphdrlen-iphdrlen;

    payload=ip_begin+tcphdrlen+iphdrlen;

    if(payloadlen>0&&payload[0]=='h')
    {
    	mylog(log_debug,"recvd <%u %u %d>\n",ntohl(tcph->seq ),ntohl(tcph->ack_seq), payloadlen);
    }

    if(payloadlen>0&&tcph->syn==0&&tcph->ack==1)
    {
    	//if(seq_increse)
    		g_packet_info_send.ack_seq=ntohl(tcph->seq)+(uint32_t)payloadlen;
    }


    //printf("%d\n",ip_len);

    mylog(log_trace,"<%u,%u,%u,%u,%d>\n",(unsigned int)iphdrlen,(unsigned int)tcphdrlen,(unsigned int)tcph->syn,(unsigned int)tcph->ack,payloadlen);


	return 0;
}*/
int send_raw0(raw_info_t &raw_info,const char * payload,int payloadlen)
{
	if (random_drop != 0) {
		if (get_true_random_number() % 10000 < (u32_t) random_drop) {
			return 0;
		}
	}

	packet_info_t &send_info=raw_info.send_info;
	packet_info_t &recv_info=raw_info.recv_info;
	mylog(log_trace,"send_raw : from %s %d  to %s %d\n",send_info.new_src_ip.get_str1(),send_info.src_port,send_info.new_dst_ip.get_str2(),send_info.dst_port);
	switch(raw_mode)
	{
		case mode_faketcp:return send_raw_tcp(raw_info,payload,payloadlen);
		case mode_udp: return send_raw_udp(raw_info,payload,payloadlen);
		case mode_icmp: return send_raw_icmp(raw_info,payload,payloadlen);
		default:return -1;
	}

}
int recv_raw0(raw_info_t &raw_info,char * &payload,int &payloadlen)
{
	packet_info_t &send_info=raw_info.send_info;
	packet_info_t &recv_info=raw_info.recv_info;
	switch(raw_mode)
	{
		case mode_faketcp:return recv_raw_tcp(raw_info,payload,payloadlen);
		case mode_udp: return recv_raw_udp(raw_info,payload,payloadlen);
		case mode_icmp: return recv_raw_icmp(raw_info,payload,payloadlen);
		default:	return -1;
	}

}

int after_send_raw0(raw_info_t &raw_info)
{
	packet_info_t &send_info=raw_info.send_info;
	packet_info_t &recv_info=raw_info.recv_info;

	if(raw_mode==mode_faketcp)
	{
		if (send_info.syn == 0 && send_info.ack == 1&& raw_info.send_info.data_len != 0)   //only modify   send_info when the packet is not part of handshake
		{
			if (seq_mode == 0)
			{

			} else if (seq_mode == 1)
			{
				send_info.seq += raw_info.send_info.data_len;    //////////////////modify
			} else if (seq_mode == 2)
			{
				if (get_true_random_number() % 5 == 3)
					send_info.seq += raw_info.send_info.data_len; //////////////////modify
			}
			else if(seq_mode==3||seq_mode==4)
			{
				send_info.seq += raw_info.send_info.data_len;

				u32_t window_size;

				if(seq_mode==3)
				{
					window_size=(u32_t)((u32_t)receive_window_lower_bound<<(u32_t)wscale);
				}
				else//seq_mode==4
				{
					window_size=(u32_t)((u32_t)receive_window_lower_bound);
				}

				if(larger_than_u32(send_info.seq+max_data_len,recv_info.ack_seq+window_size))
				{
					send_info.seq=raw_info.recv_info.ack_seq;
				}
				if(recv_info.ack_seq_counter>=3) //simulate tcp fast re-transmit
				{
					recv_info.ack_seq_counter=0;
					send_info.seq=raw_info.recv_info.ack_seq;
				}
				if(larger_than_u32(raw_info.recv_info.ack_seq,send_info.seq))  //for further use,currently no effect.
				{
					send_info.seq=raw_info.recv_info.ack_seq;
				}
			}
		}
	}
	if(raw_mode==mode_icmp)
	{
		if(program_mode==client_mode)
		{
			send_info.my_icmp_seq++;
		}
	}
	return 0;
}
int after_recv_raw0(raw_info_t &raw_info)
{
	packet_info_t &send_info=raw_info.send_info;
	packet_info_t &recv_info=raw_info.recv_info;

	if(raw_mode==mode_faketcp)
	{
		if(recv_info.has_ts)
			send_info.ts_ack=recv_info.ts;
		if (recv_info.syn == 0 && recv_info.ack == 1 && raw_info.recv_info.data_len != 0) //only modify   send_info when the packet is not part of handshake
		{
			if(seq_mode==0||seq_mode==1||seq_mode==2)
			{
				if(larger_than_u32(recv_info.seq+raw_info.recv_info.data_len,send_info.ack_seq))
					send_info.ack_seq = recv_info.seq+raw_info.recv_info.data_len;//TODO only update if its larger
			}
			else if(seq_mode==3||seq_mode==4)
			{
				if(recv_info.seq==send_info.ack_seq)
				{
					send_info.ack_seq=recv_info.seq+raw_info.recv_info.data_len;//currently we dont remembr tcp segments,this is the simplest way
					//TODO implement tcp segment remembering and SACK.
				}
			}
		}
	}
	if(raw_mode==mode_icmp)
	{
		if(program_mode==server_mode)
		{
			if(larger_than_u16(recv_info.my_icmp_seq,send_info.my_icmp_seq))
				send_info.my_icmp_seq = recv_info.my_icmp_seq;  //TODO only update if its larger
		}
	}
	return 0;
}

/*
int send_raw(raw_info_t &raw_info,const char * payload,int payloadlen)
{
	packet_info_t &send_info=raw_info.send_info;
	packet_info_t &recv_info=raw_info.recv_info;
	int ret=send_raw0(raw_info,payload,payloadlen);
	if(ret<0) return ret;
	else
	{
		after_send_raw0(raw_info);
		return ret;
	}
}

int recv_raw(raw_info_t &raw_info,char *& payload,int & payloadlen)
{
	packet_info_t &send_info=raw_info.send_info;
	packet_info_t &recv_info=raw_info.recv_info;
	int ret=recv_raw0(raw_info,payload,payloadlen);
	if(ret<0) return ret;
	else
	{
		after_recv_raw0(raw_info);
		return ret;
	}
}*/

/*
int get_src_adress(u32_t &ip,u32_t remote_ip_uint32,int remote_port)  //a trick to get src adress for a dest adress,so that we can use the src address in raw socket as source ip
{
	struct sockaddr_in remote_addr_in={0};

	socklen_t slen = sizeof(sockaddr_in);
	//memset(&remote_addr_in, 0, sizeof(remote_addr_in));
	remote_addr_in.sin_family = AF_INET;
	remote_addr_in.sin_port = htons(remote_port);
	remote_addr_in.sin_addr.s_addr = remote_ip_uint32;


	int new_udp_fd=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
	if(new_udp_fd<0)
	{
		mylog(log_warn,"create udp_fd error\n");
		return -1;
	}
	//set_buf_size(new_udp_fd);

	mylog(log_debug,"created new udp_fd %d\n",new_udp_fd);
	int ret = connect(new_udp_fd, (struct sockaddr *) &remote_addr_in, slen);
	if(ret!=0)
	{
		mylog(log_warn,"udp fd connect fail\n");
		close(new_udp_fd);
		return -1;
	}

	struct sockaddr_in my_addr={0};
	socklen_t len=sizeof(my_addr);

    if(getsockname(new_udp_fd, (struct sockaddr *) &my_addr, &len)!=0){close(new_udp_fd); return -1;}

    ip=my_addr.sin_addr.s_addr;

    close(new_udp_fd);

    return 0;
}*/

int get_src_adress2(address_t &output_addr,address_t remote_addr)
{
	int new_udp_fd=remote_addr.new_connected_udp_fd();
	if(new_udp_fd<0)
	{
		mylog(log_warn,"create udp_fd error\n");
		return -1;
	}

	socklen_t len=sizeof(output_addr.inner);

    if(getsockname(new_udp_fd, (struct sockaddr *) &output_addr.inner, &len)!=0) {close(new_udp_fd); return -1;}

    assert(output_addr.get_type()==remote_addr.get_type());

    close(new_udp_fd);

	return 0;
}
/*
int try_to_list_and_bind(int &fd,u32_t local_ip_uint32,int port)  //try to bind to a port,may fail.
{
	 int old_bind_fd=fd;

	 if(raw_mode==mode_faketcp)
	 {
		 fd=socket(AF_INET,SOCK_STREAM,0);
	 }
	 else  if(raw_mode==mode_udp||raw_mode==mode_icmp)
	 {
		 fd=socket(AF_INET,SOCK_DGRAM,0);
	 }
     if(old_bind_fd!=-1)
     {
    	 close(old_bind_fd);
     }

	 struct sockaddr_in temp_bind_addr={0};
     //bzero(&temp_bind_addr, sizeof(temp_bind_addr));

     temp_bind_addr.sin_family = AF_INET;
     temp_bind_addr.sin_port = htons(port);
     temp_bind_addr.sin_addr.s_addr = local_ip_uint32;

     if (bind(fd, (struct sockaddr*)&temp_bind_addr, sizeof(temp_bind_addr)) !=0)
     {
    	 mylog(log_debug,"bind fail\n");
    	 return -1;
     }
	 if(raw_mode==mode_faketcp)
	 {

		if (listen(fd, SOMAXCONN) != 0) {
			mylog(log_warn,"listen fail\n");
			return -1;
		}
	 }
     return 0;
}*/
int try_to_list_and_bind2(int &fd,address_t address)  //try to bind to a port,may fail.
{
	if(fd!=-1)
	{
		close(fd);
	}
	if(raw_mode==mode_faketcp)
	{
		fd=socket(address.get_type(),SOCK_STREAM,0);
	}
	else  if(raw_mode==mode_udp||raw_mode==mode_icmp)
	{
		fd=socket(address.get_type(),SOCK_DGRAM,0);
	}

	if(fd==-1)
	{
		mylog(log_debug,"create fd fail\n");
		return -1;
	}
	/*struct sockaddr_in temp_bind_addr={0};
	//bzero(&temp_bind_addr, sizeof(temp_bind_addr));

	temp_bind_addr.sin_family = AF_INET;
	temp_bind_addr.sin_port = htons(port);
	temp_bind_addr.sin_addr.s_addr = local_ip_uint32;*/

	if (::bind(fd, (struct sockaddr*)&address.inner, address.get_len()) !=0)
	{
		mylog(log_debug,"bind fail\n");
		return -1;
	}
	if(raw_mode==mode_faketcp&&!use_tcp_dummy_socket)
	{

		if (listen(fd, SOMAXCONN) != 0) {
			mylog(log_warn,"listen fail\n");
			return -1;
		}
	}
	return 0;
}
/*
int client_bind_to_a_new_port(int &fd,u32_t local_ip_uint32)//find a free port and bind to it.
{
	int raw_send_port=10000+get_true_random_number()%(65535-10000);
	for(int i=0;i<1000;i++)//try 1000 times at max,this should be enough
	{
		if (try_to_list_and_bind(fd,local_ip_uint32,raw_send_port)==0)
		{
			return raw_send_port;
		}
	}
	mylog(log_fatal,"bind port fail\n");
	myexit(-1);
	return -1;////for compiler check
}*/

int client_bind_to_a_new_port2(int &fd,const address_t& address)//find a free port and bind to it.
{
	address_t tmp=address;
	for(int i=0;i<1000;i++)//try 1000 times at max,this should be enough
	{
		int raw_send_port=10000+get_true_random_number()%(65535-10000);
		tmp.set_port(raw_send_port);
		if (try_to_list_and_bind2(fd,tmp)==0)
		{
			return raw_send_port;
		}
	}
	mylog(log_fatal,"bind port fail\n");
	myexit(-1);
	return -1;////for compiler check
}