#include <arpa/inet.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <unistd.h>

#define ETH_P_CUSTOM 0x8888

int main(int argc, char** argv) {
  int sfd,sfdS, i, ifindex,ifindexS;
  ssize_t len;
  char* frame;
  char* fdata;
  struct ethhdr* fhead;
  struct ifreq ifr, ifrS;
  struct sockaddr_ll sall, sallS;
  struct sockaddr_ll sallnew;
  socklen_t sl;

  sfd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_CUSTOM));
  strncpy(ifr.ifr_name, argv[1], IFNAMSIZ);
  ioctl(sfd, SIOCGIFINDEX, &ifr);
  ifindex = ifr.ifr_ifindex;
  ioctl(sfd, SIOCGIFHWADDR, &ifr);
  memset(&sall, 0, sizeof(struct sockaddr_ll));
  sall.sll_family = AF_PACKET;
  sall.sll_protocol = htons(ETH_P_CUSTOM);
  sall.sll_ifindex = ifr.ifr_ifindex;
  sall.sll_hatype = ARPHRD_ETHER;
  sall.sll_pkttype = PACKET_HOST;
  sall.sll_halen = ETH_ALEN;
  bind(sfd, (struct sockaddr*) &sall, sizeof(struct sockaddr_ll));

  sfdS = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_CUSTOM));
  strncpy(ifrS.ifr_name, argv[1], IFNAMSIZ);
  ioctl(sfdS, SIOCGIFINDEX, &ifrS);
  ifindexS = ifrS.ifr_ifindex;
  ioctl(sfdS, SIOCGIFHWADDR, &ifrS);
  memset(&sallS, 0, sizeof(struct sockaddr_ll));
  sallS.sll_family = AF_PACKET;
  sallS.sll_protocol = htons(ETH_P_CUSTOM);
  sallS.sll_ifindex = ifr.ifr_ifindex;
  sallS.sll_hatype = ARPHRD_ETHER;
  sallS.sll_pkttype = PACKET_HOST;
  sallS.sll_halen = ETH_ALEN;
  bind(sfd, (struct sockaddr*) &sallS, sizeof(struct sockaddr_ll));

  while(1) {
      //receive
    frame = malloc(ETH_FRAME_LEN);
    memset(frame, 0, ETH_FRAME_LEN);
    fhead = (struct ethhdr*) frame;
    fdata = frame + ETH_HLEN;
    len = recvfrom(sfd, frame, ETH_FRAME_LEN, 0, (struct sockaddr*) &sall, &sl);

    printf("%d %d",sall.sll_pkttype,sall.sll_hatype);

    printf("[%dB] %02x:%02x:%02x:%02x:%02x:%02x -> ", (int)len,
           fhead->h_source[0], fhead->h_source[1], fhead->h_source[2],
           fhead->h_source[3], fhead->h_source[4], fhead->h_source[5]);
    printf("%02x:%02x:%02x:%02x:%02x:%02x | ",
           fhead->h_dest[0], fhead->h_dest[1], fhead->h_dest[2],
           fhead->h_dest[3], fhead->h_dest[4], fhead->h_dest[5]);
    printf("%s\n", fdata);
    for (i = 0; i < len ; i++) {
      printf("%02x ", (unsigned char) frame[i]);
      if ((i + 1) % 16 == 0)
        printf("\n");
    }
    printf("\n\n");
    //send

    sscanf(argv[2], "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
         &sallS.sll_addr[0], &sallS.sll_addr[1], &sallS.sll_addr[2],
         &sallS.sll_addr[3], &sallS.sll_addr[4], &sallS.sll_addr[5]);
    memcpy(fhead->h_dest, &sallS.sll_addr, ETH_ALEN);
    memcpy(fhead->h_source, &ifrS.ifr_hwaddr.sa_data, ETH_ALEN);
    fhead->h_proto = htons(ETH_P_CUSTOM);
    memcpy(fdata, fdata, len);
    sendto(sfdS, frame, ETH_HLEN + len, 0,
         (struct sockaddr*) &sallS, sizeof(struct sockaddr_ll));
    free(frame);
  }
  close(sfd);
  close(sfdS);
  return EXIT_SUCCESS;
}