static void arp_input(const uint8_t *pkt, int pkt_len)
{
struct ethhdr *eh = (struct ethhdr *)pkt;
struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN);
uint8_t arp_reply[ETH_HLEN + sizeof(struct arphdr)];
struct ethhdr *reh = (struct ethhdr *)arp_reply;
struct arphdr *rah = (struct arphdr *)(arp_reply + ETH_HLEN);
int ar_op;
struct ex_list *ex_ptr;
ar_op = ntohs(ah->ar_op);
switch(ar_op) {
uint32_t ar_tip_ip;
case ARPOP_REQUEST:
ar_tip_ip = ip_read32h(ah->ar_tip);
if ((ar_tip_ip & 0xffffff00) == special_addr_ip) {
uint32_t ar_tip_low = ar_tip_ip & 0xff;
if ( CTL_IS_DNS(ar_tip_low) || ar_tip_low == CTL_ALIAS)
goto arp_ok;
for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
if (ex_ptr->ex_addr == ar_tip_low)
goto arp_ok;
}
return;
arp_ok:
memcpy(client_ethaddr, eh->h_source, ETH_ALEN);
memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN);
memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 1);
reh->h_source[5] = ar_tip_low;
reh->h_proto = htons(ETH_P_ARP);
rah->ar_hrd = htons(1);
rah->ar_pro = htons(ETH_P_IP);
rah->ar_hln = ETH_ALEN;
rah->ar_pln = 4;
rah->ar_op = htons(ARPOP_REPLY);
memcpy(rah->ar_sha, reh->h_source, ETH_ALEN);
memcpy(rah->ar_sip, ah->ar_tip, 4);
memcpy(rah->ar_tha, ah->ar_sha, ETH_ALEN);
memcpy(rah->ar_tip, ah->ar_sip, 4);
slirp_output(arp_reply, sizeof(arp_reply));
}
break;
case ARPOP_REPLY:
if (!memcmp(client_ethaddr, zero_ethaddr, ETH_ALEN) &&
ip_equal( ip_read(ah->ar_sip), client_ip )) {
memcpy(client_ethaddr, ah->ar_sha, ETH_ALEN);
}
break;
default:
break;
}
}
/*
* sendto() a socket
*/
int
sosendto(struct socket *so, struct mbuf *m)
{
int ret;
SockAddress addr;
uint32_t addr_ip;
uint16_t addr_port;
DEBUG_CALL("sosendto");
DEBUG_ARG("so = %lx", (long)so);
DEBUG_ARG("m = %lx", (long)m);
if ((so->so_faddr_ip & 0xffffff00) == special_addr_ip) {
/* It's an alias */
int low = so->so_faddr_ip & 0xff;
if ( CTL_IS_DNS(low) )
addr_ip = dns_addr[low - CTL_DNS];
else
addr_ip = loopback_addr_ip;
} else
addr_ip = so->so_faddr_ip;
addr_port = so->so_faddr_port;
/*
* test for generic forwarding; this function replaces the arguments
* only on success
*/
unsigned long faddr = addr_ip;
int fport = addr_port;
if (slirp_should_net_forward(faddr, fport, &faddr, &fport)) {
time_t timestamp = time(NULL);
slirp_drop_log(
"Redirected UDP: src: 0x%08lx:0x%04x org dst: 0x%08lx:0x%04x "
"new dst: 0x%08lx:0x%04x %ld\n",
so->so_laddr_ip, so->so_laddr_port,
addr_ip, addr_port,
faddr, fport, timestamp
);
}
addr_ip = faddr;
addr_port = fport;
sock_address_init_inet(&addr, addr_ip, addr_port);
DEBUG_MISC((dfd, " sendto()ing, addr.sin_port=%d, addr.sin_addr.s_addr=%08x\n", addr_port, addr_ip));
/* Don't care what port we get */
ret = socket_sendto(so->s, m->m_data, m->m_len,&addr);
if (ret < 0)
return -1;
/*
* Kill the socket if there's no reply in 4 minutes,
* but only if it's an expirable socket
*/
if (so->so_expire)
so->so_expire = curtime + SO_EXPIRE;
so->so_state = SS_ISFCONNECTED; /* So that it gets select()ed */
return 0;
}
