#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <net/ethernet.h>
#include <linux/if_arp.h>
#include <unistd.h>

#include "connect.h"
#include "buffer.h"

int sd, if_sd;
struct sockaddr_ll *bc;

/* Return raw 802.2 socket */
int open_802_2(char *ifname) {
  sd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_802_2));
  if(sd < 0) {
    perror("Failed to open socket: ");
    exit(EXIT_FAILURE);
  }
  if(create_broadcast(ifname) == NULL) {
    fputs("Failed to create ethernet broadcast.\n", stderr);
    exit(EXIT_FAILURE);
  }
  return sd;
}

/* Get interface ID for sockaddr_ll */
int get_interface(char *name) {
  struct ifreq ifr;

  if_sd = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
  if(if_sd == -1) {
    perror(name);
    exit(EXIT_FAILURE);
  }

  strncpy(ifr.ifr_name, name, sizeof ifr.ifr_name);
  if(ioctl(if_sd, SIOCGIFINDEX, &ifr) < 0) {
    perror("Failed ioctl");
    exit(EXIT_FAILURE);
  }
  close(if_sd);
  return ifr.ifr_ifindex;
}

struct sockaddr_ll *create_broadcast(char *ifname) {
  bc = malloc(sizeof *bc);
  if(bc == NULL)
    return NULL;

 /* Setup broadcast */
  bc->sll_family   = AF_PACKET;
  bc->sll_protocol = 1;
  bc->sll_ifindex  = get_interface(ifname);
  bc->sll_hatype   = ARPHRD_IEEE802;
  bc->sll_pkttype  = PACKET_BROADCAST;
  bc->sll_halen    = IFHWADDRLEN;
  memset(bc->sll_addr, 0, sizeof bc->sll_addr);
  memset(bc->sll_addr, 0xFF, IFHWADDRLEN);
  return bc;
}

int send_buffer(Buffer *b) {
  if(b == NULL || b->data == NULL || b->used == 0)
    return -2;

  if(sendto(sd, b->data, b->used, 0, (struct sockaddr *) bc, sizeof *bc) == -1) {
    perror("Failed broadcast");
    return -1;
  }

  return 1;
}