Just had a quick look at the ARP cache code while going to lunch (rest was not checked):
+int ipv4_to_mac(struct interface *interface,
const alfred_addr *addr, struct ether_addr *mac)+{
ipv4_arp_request(interface, addr, mac);
if (!is_valid_ether_addr(mac->ether_addr_octet)) return -EINVAL;
[...]
+int ipv4_arp_request(struct interface *interface, const alfred_addr *addr,
struct ether_addr *mac)+{
- struct arpreq arpreq;
- struct sockaddr_in *sin;
- memset(&arpreq, 0, sizeof(arpreq));
- sin = (struct sockaddr_in *)&arpreq.arp_pa;
- sin->sin_family = AF_INET;
- sin->sin_addr.s_addr = addr->ipv4.s_addr;
- strcpy(arpreq.arp_dev, interface->interface);
- if (ioctl(interface->netsock, SIOCGARP, &arpreq) < 0)
return -1;- if (arpreq.arp_flags & ATF_COM) {
memcpy(mac, arpreq.arp_ha.sa_data, sizeof(*mac));- } else {
perror("arp: incomplete");return -1;- }
- return 0;
+}
This looks like you are not always initializing/setting the data for mac. And you are not checking the return value of ipv4_to_mac. So it is possible that your are accessing "random"/"uninitialized" data in is_valid_ether_addr. It can happen that your code accept bogus mac addresses (which are valid mac addresses but are not actually the mac address of the remote system) - which sounds wrong to me.
Kind regards, Sven