/* test_sockets.c */
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>

typedef enum { FALSE, TRUE } Boolean;

#define SOCK_PATH "test_sockets_socket"
#define USE_SOCK_DGRAM
//#undef USE_SOCK_DGRAM

#define handle_error(msg) \
  do { perror(msg); exit(EXIT_FAILURE); } while (0)

int
main(int argc, char *argv[])
{
  struct sockaddr_un addr = { 0 };
  const char *path = SOCK_PATH;

#ifdef USE_SOCK_DGRAM
  int sfd;
  int type = SOCK_DGRAM;
#else
  int sfd, cfd;
  int type = SOCK_STREAM;
#define LISTEN_BACKLOG 50
  struct sockaddr_un peer_addr = { 0 };
  socklen_t peer_addr_size;
#endif

  /* Create a UNIX domain socket and bind it to 'path'.
   Return the socket descriptor on success, or -1 on error. */

  /* Create socket bound to well-known address */
  if (remove(SOCK_PATH) == -1 && errno != ENOENT)
    handle_error("remove-SOCK_PATH");

  addr.sun_family = AF_UNIX;
  if (strlen(path) < sizeof(addr.sun_path))
    strncpy(addr.sun_path, path, sizeof(addr.sun_path) - 1);
  else
    handle_error("strncpy");

  sfd = socket(AF_UNIX, type, 0);
  if (sfd == -1)
    handle_error("socket");

  if (bind(sfd, (struct sockaddr *) &addr, sizeof(struct sockaddr_un)) == -1)
    {
      close(sfd);
      handle_error("bind");
    }

  /* Temporary test: make socket world readable */
  //Does not work? chmod (path, S_IRUSR || S_IWUSR || S_IROTH || S_IWOTH);
  chmod (path, 0444);
  //chmod (path, 0644);
  //chmod (path, 0666);

#ifdef USE_SOCK_DGRAM
  fprintf(stderr, "Receiving via datagram socket\n");
#else
  fprintf(stderr, "Receiving via stream socket\n");
  if (listen(sfd, LISTEN_BACKLOG) == -1)
    handle_error("listen");

  peer_addr_size = sizeof(struct sockaddr_un);
  cfd = accept(sfd, (struct sockaddr *) &peer_addr,
    &peer_addr_size);
  if (cfd == -1)
    handle_error("accept");
#endif

  exit(EXIT_SUCCESS);
}