void do_ip(void *p)
{
struct iphdr *ip = p;
g.packet_ip++;
if(g.print_flag_ip)
print_ip(ip);
void *data = ip;
data += ip->ihl << 2;
switch(ip->protocol)
{
case IPPROTO_TCP:
do_tcp(data);
break;
case IPPROTO_UDP:
do_udp(data);
break;
case IPPROTO_ICMP:
do_icmp(data);
break;
case IPPROTO_IGMP:
do_igmp(data);
break;
}
}
void do_ip( char * data )
{
global.packet_ip ++;
struct iphdr *pip;
pip = ( struct iphdr * ) data; /* pip = point to ip layer */
if( global.print_flag_ip )
print_ip( pip );
char * pdata = data + pip->ihl * 4;
switch( pip->protocol ){
case IPPROTO_ICMP:
do_icmp( pdata );
break;
case IPPROTO_IGMP:
do_igmp( pdata );
break;
case IPPROTO_TCP:
do_tcp( pdata );
break;
case IPPROTO_UDP:
do_udp( pdata );
break;
default:
printf("IP: 未知其上层协议.\n");
break;
}
}
int
main(int argc, char **argv)
{
int cc;
uint32_t port;
uint32_t udp;
struct sockaddr_in addr;
socklen_t one;
/* bah default port
*/
port = 8765;
udp = 0;
while ((cc = getopt(argc, argv, "hup:")) != EOF) {
switch (cc) {
case 'h':
usage();
return -1;
case 'p':
port = atoi(optarg);
break;
case 'u':
udp = 1;
break;
case '?':
usage();
return -1;
}
}
/* Get the mother socket
*/
if (udp)
Sock = socket(AF_INET, SOCK_DGRAM, 0);
else
Sock = socket(AF_INET, SOCK_STREAM, 0);
if (Sock < 0) {
perror("socket()");
return -1;
}
one = 1;
setsockopt(Sock,
SOL_SOCKET,
SO_REUSEADDR,
&one,
sizeof(socklen_t));
for (cc = 0; cc < MAXCONN; cc++)
conn[cc] = -1;
/* bind() it to a specified port
*/
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = htonl(INADDR_ANY);
cc = bind(Sock,
(struct sockaddr *)&addr,
sizeof(struct sockaddr_in));
if (cc < 0) {
perror("bind()");
return -1;
}
fprintf(stderr, "\
%d:%lu: socket %d to port %d bind() all right\n",
getpid(), time(NULL), Sock, port);
if (!udp)
listen(Sock, SOMAXCONN);
if (udp)
do_udp();
else
do_tcp();
return 0;
}
