/* this is one */
/* it prints to stdout everything, it sniffes */
#include <sys/socket.h>
#include <netinet/in.h>
#include <net/if.h>
#include <unistd.h>
#include <signal.h>
#include <stdio.h>

static volatile int done;

void handler(int signum)
{
  done = 1;
}

int main(int argc, char **argv)
{
  char buff[0x10000];
  struct ifreq ifr;
  int s, n;

  if (argc < 2)
  {
    fprintf(stderr, "Usage: %s <interface>\n", argv[0]);
    return 1;
  }

  s = socket(PF_INET, SOCK_PACKET, htons(0x0003));
  if (s == -1)
  {
    perror("socket");
    return 1;
  }

  strcpy(ifr.ifr_name, argv[1]);

  if (ioctl(s, SIOCGIFFLAGS, &ifr) < 0)
  {
    perror("ioctl(SIOCGIFFLAGS)");
    return 1;
  }

  ifr.ifr_flags |= IFF_PROMISC;

  if (ioctl(s, SIOCSIFFLAGS, &ifr) < 0)
  {
    perror("ioctl(SIOCGIFFLAGS)");
    return 1;
  }

  signal(SIGINT, handler);
  
       puts("starting capturing:\n");
       fflush(stdout);
  for (done = 0; !done; )
  {
    n = read(s, buff, sizeof(buff));
    if ( n!=-1 ) write(STDOUT_FILENO, buff, n);
  }

  ifr.ifr_flags &= ~IFF_PROMISC;

  if (ioctl(s, SIOCSIFFLAGS, &ifr) < 0)
  {
    perror("ioctl(SIOCGIFFLAGS)");
    return 1;
  }

  close(s);
        printf("Finished\n");


  return 0;
}