libnet TCP示例

[root@TD18 tmp]#gcc -o 1 1.c -lnet
[root@TD18 tmp]#./1
please enter Host address
11.11.11.11
please enter local address:
22.22.22.22
wrote 126 byte TCP packet
[root@TD18 tmp]#cat 1.c
#include<stdio.h>
#include<string.h>
#include<pcap.h>
#include<libnet.h>

main(void)
{ int c ;
   u_char *cp;
   libnet_t *l;
   libnet_ptag_t t;
   char *payload;
   u_char HostAddr[255],MyAddr[255];
   u_short payload_s;
   u_long src_ip,dst_ip;
   u_short src_prt,dst_prt;


   char errbuf[LIBNET_ERRBUF_SIZE];
   printf("please enter Host address\n");
  scanf("%s",HostAddr);
   printf("please enter local address:\n");
  scanf("%s",MyAddr);
   l=libnet_init( LIBNET_LINK,NULL,errbuf);
  if(l==NULL)
    {
       printf("libnet failed: %s",errbuf);
       exit(EXIT_FAILURE);
    }
  dst_ip=inet_addr(HostAddr);
  src_ip=inet_addr(MyAddr);
  dst_prt=0;
  src_prt=0;

  payload="adafhafhasfjashfasjfasjkfhsadjkfajskfjasdhfjaksfjkaf";
  payload_s=strlen(payload);
t=libnet_build_tcp_options("\003\003\012\001\002\004\001\011\010\012\077\077\077\077\000\000\000\000\000\000",20,l,0);
if(t==-1)
   {printf("cant build TCP options: %s\n",libnet_geterror(l));
   goto bad;}

   t=libnet_build_tcp(src_prt,dst_prt,0x01010101,0x02020202,TH_SYN,32767,0,10,
                   LIBNET_TCP_H+20+payload_s,payload,payload_s,l,0 );
if(t==-1)
          {
             printf("cant build TCP header:%s\n",libnet_geterror(l));
             goto bad;
          }

    t=libnet_build_ipv4(LIBNET_IPV4_H+LIBNET_TCP_H+20+payload_s,0,242,0,64,IPPROTO_TCP,0,src_ip,dst_ip,NULL,0,l,0);

if(t==-1)
  {
   printf("cant build IP header:%s\n",libnet_geterror(l));
   goto bad;
  }
  t=libnet_build_ethernet("00:0B:6A:63:5E:11","00:0B:6A:63:5E:22",ETHERTYPE_IP,NULL,0,l,0);

if(t==-1)
{printf("cant buid ethernet header:%s\n",libnet_geterror(l));
  goto bad;
}
  c=libnet_write(l);
if(c==-1)
  {printf("write error:%s\n",libnet_geterror(l));
   goto bad;
  }
else { printf("wrote %d byte TCP packet\n",c);
     }
libnet_destroy(l);
return(EXIT_SUCCESS);
bad:
   libnet_destroy(l);
   return(EXIT_FAILURE);

}