int main(int argc, char const *argv[])
{
int family = AF_INET;
if (!(argc ==3 || argc ==4))
err_sys("input args: address port");
if (argc == 4)
family = AF_INET6;
struct sockaddr *serv_addr;
socklen_t serv_len;
if (family == AF_INET){
serv_addr = (struct sockaddr*)v4_addr(family, atoi(argv[2]), argv[1]);
serv_len = sizeof(struct sockaddr_in);
}
else {
serv_addr = (struct sockaddr*)v6_addr(family, atoi(argv[2]), argv[1]);
serv_len = sizeof(struct sockaddr_in6);
}
int clientfd = Socket(family, SOCK_STREAM, IPPROTO_TCP);
Connect(clientfd, serv_addr, serv_len);
struct sockaddr local_addr;
Getsockname(clientfd, &local_addr, &serv_len);
print_ip_addr(family, &local_addr, "local address \n");
select_do(clientfd);
Close(clientfd);
free(serv_addr);
return 0;
}
void
ip(struct pktinfo *pktinfo)
{
register const struct ip *ipv4 = NULL;
register int ipv4_p = 0; /* next header */
const struct in_addr *ipv4_src = NULL;
const struct in_addr *ipv4_dst = NULL;
struct addr_4 addr_ipv4;
struct udphdr *udphdr = NULL;
struct tcphdr *tcphdr = NULL;
struct pktinfo n_hdr;
u_int32_t src = 0;
u_int32_t dst = 0;
char *addr = NULL;
const u_char *pkt = pktinfo->pkt;
bpf_u_int32 len = pktinfo->len;
ipv4 = (const struct ip *)pkt;
/* next header type code */
ipv4_p = ipv4->ip_p;
/* IPv4 address */
ipv4_src = &ipv4->ip_src;
ipv4_dst = &ipv4->ip_dst;
src = htonl(ipv4_src->s_addr);
dst = htonl(ipv4_dst->s_addr);
addr_ipv4.src = src;
addr_ipv4.dst = dst;
len -= sizeof(struct ip);
pkt += sizeof(struct ip);
n_hdr.len = len;
n_hdr.pkt = pkt;
addr_ipv4.p_tcp = NULL;
addr_ipv4.p_udp = NULL;
addr_ipv4.nxtflag = 0;
if (ipv4_p == IPPROTO_TCP) {
tcphdr = (struct tcphdr *)pkt;
addr_ipv4.p_tcp = tcphdr;
addr_ipv4.nxtflag = 1;
}
else if (ipv4_p == IPPROTO_UDP) {
udphdr = (struct udphdr *)pkt;
addr_ipv4.p_udp = udphdr;
addr_ipv4.nxtflag = 2;
}
addr = v4_addr(&addr_ipv4, encap);
encap ++;
switch(ipv4_p) {
case IPPROTO_IPV4 : /* IP header */
ip(&n_hdr);
break;
case IPPROTO_TCP : /* tcp */
if (rflag != 1)
tcp(&n_hdr);
break;
case IPPROTO_UDP : /* user datagram protocol */
if (bflag != 1)
udp(&n_hdr);
break;
case IPPROTO_IPV6 : /* IP6 header */
ipv6(&n_hdr);
break;
default:
} /* end of switch */
} /* end of ip() */
