void check_arp()
{
struct ether_addr * dst_eth_addr = NULL;
static arp_resolv_count = 0;
dst_eth_addr = tw_search_arp_entry(ip); //checks if address exist in arp table against this IP.
if(dst_eth_addr == NULL)
{
tw_send_arp_request(tw_convert_ip_str_to_dec(ip), "tw0");
arp_resolv_count++;
}
else
{
printf("MAC address: %02X:%02X:%02X:%02X:%02X:%02X\n", dst_eth_addr->addr_bytes[0],
dst_eth_addr->addr_bytes[1], dst_eth_addr->addr_bytes[2],
dst_eth_addr->addr_bytes[3], dst_eth_addr->addr_bytes[4],
dst_eth_addr->addr_bytes[5]);
exit(0);
}
if(arp_flag == 1 && arp_resolv_count > 5)
{
printf("arp not resolved.\n");
exit(1);
}
}
void reply_payload(tw_rx_t * handle, tw_buf_t * buffer) {
struct ether_addr * dst_eth_addr;
struct ether_hdr * eth = buffer->data;
struct arp_hdr * arp_pkt =buffer->data + sizeof(struct ether_hdr);
switch (tw_be_to_cpu_16(eth->ether_type)) {
case ETHER_TYPE_ARP:
if (arp_flag == 1) {
tw_arp_parser(buffer, "tw0");
struct ether_addr * mac_addr = tw_search_arp_entry(ip);
if (mac_addr != NULL) {
dst_eth_addr = mac_addr;
printf("MAC address: %02X:%02X:%02X:%02X:%02X:%02X\n",
dst_eth_addr->addr_bytes[0],
dst_eth_addr->addr_bytes[1],
dst_eth_addr->addr_bytes[2],
dst_eth_addr->addr_bytes[3],
dst_eth_addr->addr_bytes[4],
dst_eth_addr->addr_bytes[5]);
arp_flag = -1;
exit(0);
}
}
}
tw_free_pkt(buffer);
}
