#define?__USE_BSD
#include?
#include?
#include?
#include?
#define?__FAVOR_BSD
#include?
#include?
#include?
#include?
#include?
#include?

struct?tcp_options
{
??u_int8_t?op0;
??u_int8_t?op1;
??u_int8_t?op2;
??u_int8_t?op3;
??u_int8_t?op4;
??u_int8_t?op5;
??u_int8_t?op6;
??u_int8_t?op7;
};

char?datagram[4096];		/*?datagram?buffer?*/
char?pheader[1024];		/*?pseudoheader?buffer?for?computing?tcp?checksum?*/

uint16_t
csum?（uint16_t?*?addr?int?len）
{
??int?nleft?=?len;
??uint32_t?sum?=?0;
??uint16_t?*w?=?addr;
??uint16_t?answer?=?0;

??while?（nleft?>?1）
??{
????sum?+=?*w++;
????nleft?-=?2;
??}
??if?（nleft?==?1）
??{
????*（unsigned?char?*）?（&answer）?=?*（unsigned?char?*）?w;
????sum?+=?answer;
??}
??sum?=?（sum?>>?16）?+?（sum?&?0xffff）;
??sum?+=?（sum?>>?16）;
??answer?=?~sum;
??return?（answer）;
}

int
main?（int?argc?char?**argv）
{

??int?flags?=?0?c?numtries?=?90;
??char?src_ip[17];
??char?dst_ip[17];
??short?dst_port?=?80;
??short?th_sport?=?1234;
??short?tcp_flags?=?TH_SYN;
??short?pig_ack?=?0;
??struct?ip?*iph?=?（struct?ip?*）?datagram;
??struct?tcphdr?*tcph?=?（struct?tcphdr?*）?（datagram?+?sizeof?（struct?ip））;
??struct?tcp_options?*tcpopt?=
????（struct?tcp_options?*）?（datagram?+?sizeof?（struct?ip）?+
			????sizeof?（struct?tcphdr））;
??struct?sockaddr_in?servaddr;
??memset?（datagram?0?4096）;	/*?zero?out?the?buffer?*/

??fprintf?（stderr?“sizeof?（struct?ip）=?%d\n“?sizeof?（struct?ip））;

??snprintf?（src_ip?16?“%s“?“192.168.8.12“）;	//default

??while?（（c?=?getopt?（argc?argv?“s:d:n:p:f:a:q:w:x:y:z:g:h:i:j:“））?!=?-1）
??{
????switch?（c）
????{
????case?‘s‘:
??????flags?|=?0x1;
??????snprintf?（src_ip?16?“%s“?optarg）;
??????break;
????case?‘d‘:
??????flags?|=?0x2;
??????snprintf?（dst_ip?16?“%s“?optarg）;
??????break;
????case?‘n‘:
??????flags?|=?0x4;
??????numtries?=?atoi?（optarg）;
??????break;
????case?‘p‘:
??????flags?|=?0x8;
??????dst_port?=?atoi?（optarg）;
??????break;
????case?‘f‘:
??????tcp_flags?=?atoi?（optarg）;
??????break;
????case?‘a‘:
??????pig_ack?=?atoi?（optarg）;
??????break;
????case?‘q‘:
??????th_sport?=?atoi?（optarg）;
??????break;
????case?‘w‘:
??????tcpopt->op0?=?atoi?（optarg）;
??????break;
????case?‘x‘:
??????tcpopt->op1?=?atoi?（optarg）;
??????break;
????case?‘y‘:
??????tcpopt->op2?=?atoi?（optarg）;
??????break;
????case?‘z‘:
??????tcpopt->op3?=?atoi?（optarg）;
??????break;
????case?‘g‘:
??????tcpopt->op4?=?atoi?（optarg）;
??????break;
????case?‘h‘:
??????tcpopt->op5?=?atoi?（optarg）;
??????break;
????case?‘i‘:
??????tcpopt->op6?=?atoi?（optarg）;
??????break;
????case?‘j‘:
??????tcpopt->op7?=?atoi?（optarg）;
??????break;
????case?‘?‘:
??????flags?|=?0x10;
??????fprintf?（stderr?“Unrecognized?option??\n“）;
??????break;
????}
??}

??if?（!（flags?&?0x2））
??{
????fprintf?（stderr
	?????“\nraws