void
handle_ip(const struct ip *ip, int len, void *userdata)
{
/* note: ip->ip_v does not work if header is not int-aligned */
/* fprintf(stderr, "IPv %d\n", (*(uint8_t *) ip) >> 4); */
switch ((*(uint8_t *) ip) >> 4) {
case 4:
handle_ipv4(ip, len, userdata);
break;
case 6:
handle_ipv6((struct ip6_hdr *)ip, len, userdata);
break;
default:
break;
}
}
dns_message *
handle_ip(const struct ip * ip, int len)
{
switch(ip->ip_v) {
case 4:
return handle_ipv4(ip, len);
break;
#if USE_IPV6
case 6:
return handle_ipv6((struct ip6_hdr *)ip, len);
break;
#endif
default:
return NULL;
break;
}
}
/**
* Ethernet: Receives an ethernet-packet and handles it according to
* Receive-handle diagram.
*
* @return ZERO - packet was handled or no packets received;
* NON ZERO - error condition occurs.
*/
int32_t
receive_ether(void) {
int32_t bytes_received;
struct ethhdr * ethh;
memset(ether_packet, 0, ETH_MTU_SIZE);
bytes_received = recv(0, ether_packet, ETH_MTU_SIZE, 0);
if (!bytes_received) // No messages
return 0;
if (bytes_received < sizeof(struct ethhdr))
return -1; // packet is too small
ethh = (struct ethhdr *) ether_packet;
if(memcmp(ethh->dest_mac, broadcast_mac, 6) != 0
&& memcmp(ethh->dest_mac, multicast_mac, 3) != 0
&& memcmp(ethh->dest_mac, own_mac, 6 ) != 0
&& !is_multicast_mac(ethh->dest_mac))
return -1; // packet is too small
switch (htons(ethh -> type)) {
case ETHERTYPE_IP:
return handle_ipv4((uint8_t*) (ethh + 1),
bytes_received - sizeof(struct ethhdr));
/*
case ETHERTYPE_IPv6:
return handle_ipv6(ether_packet + sizeof(struct ethhdr),
bytes_received - sizeof(struct ethhdr));
*/
case ETHERTYPE_ARP:
return handle_arp((uint8_t*) (ethh + 1),
bytes_received - sizeof(struct ethhdr));
default:
break;
}
return -1; // unknown protocol
}
