#include <dirent.h>

#include <fcntl.h>

#include <stdbool.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

static void prepare (void);

#define PREPARE(argc, argv) prepare ()

static int do_test (void);

#define TEST_FUNCTION do_test ()

#include "../test-skeleton.c"

static int dir_fd;

static void

prepare (void)

{

  size_t test_dir_len = strlen (test_dir);

  static const char dir_name[] = "/tst-openat.XXXXXX";

  size_t dirbuflen = test_dir_len + sizeof (dir_name);

  char *dirbuf = malloc (dirbuflen);

  if (dirbuf == NULL)

    {

      puts ("out of memory");

      exit (1);

    }

  snprintf (dirbuf, dirbuflen, "%s%s", test_dir, dir_name);

  if (mkdtemp (dirbuf) == NULL)

    {

      puts ("cannot create temporary directory");

      exit (1);

    }

  add_temp_file (dirbuf);

  dir_fd = open (dirbuf, O_RDONLY | O_DIRECTORY);

  if (dir_fd == -1)

    {

      puts ("cannot open directory");

      exit (1);

    }

}

static int

do_test (void)

{

  /* fdopendir takes over the descriptor, make a copy.  */

  int dupfd = dup (dir_fd);

  if (dupfd == -1)

    {

      puts ("dup failed");

      return 1;

    }

  if (lseek (dupfd, 0, SEEK_SET) != 0)

    {

      puts ("1st lseek failed");

      return 1;

    }

  /* The directory should be empty safe the . and .. files.  */

  DIR *dir = fdopendir (dupfd);

  if (dir == NULL)

    {

      puts ("fdopendir failed");

      return 1;

    }

  struct dirent64 *d;

  while ((d = readdir64 (dir)) != NULL)

    if (strcmp (d->d_name, ".") != 0 && strcmp (d->d_name, "..") != 0)

      {

	printf ("temp directory contains file \"%s\"\n", d->d_name);

	return 1;

      }

  closedir (dir);

  /* Try to create a file.  */

  int fd = openat (dir_fd, "some-file", O_CREAT|O_RDWR|O_EXCL, 0666);

  if (fd == -1)

    {

      if (errno == ENOSYS)

	{

	  puts ("*at functions not supported");

	  return 0;

	}

      puts ("file creation failed");

      return 1;

    }

  write (fd, "hello", 5);

  /* Before closing the file, try using this file descriptor to open

     another file.  This must fail.  */

  int fd2 = openat (fd, "should-not-work", O_CREAT|O_RDWR, 0666);

  if (fd2 != -1)

    {

      puts ("openat using descriptor for normal file worked");

      return 1;

    }

  if (errno != ENOTDIR)

    {

      puts ("error for openat using descriptor for normal file not ENOTDIR ");

      return 1;

    }

  close (fd);

  puts ("file created");

  /* fdopendir takes over the descriptor, make a copy.  */

  dupfd = dup (dir_fd);

  if (dupfd == -1)

    {

      puts ("dup failed");

      return 1;

    }

  if (lseek (dupfd, 0, SEEK_SET) != 0)

    {

      puts ("2nd lseek failed");

      return 1;

    }

  /* The directory should be empty safe the . and .. files.  */

  dir = fdopendir (dupfd);

  if (dir == NULL)

    {

      puts ("fdopendir failed");

      return 1;

    }

  bool seen_file = false;

  while ((d = readdir64 (dir)) != NULL)

    if (strcmp (d->d_name, ".") != 0 && strcmp (d->d_name, "..") != 0)

      {

	if (strcmp (d->d_name, "some-file") != 0)

	  {

	    printf ("temp directory contains file \"%s\"\n", d->d_name);

	    return 1;

	  }

	seen_file = true;

      }

  closedir (dir);

  if (!seen_file)

    {

      puts ("file not created in correct directory");

      return 1;

    }

  int cwdfd = open (".", O_RDONLY | O_DIRECTORY);

  if (cwdfd == -1)

    {

      puts ("cannot get descriptor for cwd");

      return 1;

    }

  if (fchdir (dir_fd) != 0)

    {

      puts ("1st fchdir failed");

      return 1;

    }

  if (unlink ("some-file") != 0)

    {

      puts ("unlink failed");

      return 1;

    }

  if (fchdir (cwdfd) != 0)

    {

      puts ("2nd fchdir failed");

      return 1;

    }

  close (dir_fd);

  close (cwdfd);

  /* With the file descriptor closed the next call must fail.  */

  fd = openat (dir_fd, "some-file", O_CREAT|O_RDWR|O_EXCL, 0666);

  if (fd != -1)

    {

      puts ("openat using closed descriptor succeeded");

      return 1;

    }

  if (errno != EBADF)

    {

      puts ("openat using closed descriptor did not set EBADF");

      return 1;

    }

  fd = openat (-1, "some-file", O_CREAT|O_RDWR|O_EXCL, 0666);

  if (fd != -1)

    {

      puts ("openat using -1 descriptor succeeded");

      return 1;

    }

  if (errno != EBADF)

    {

      puts ("openat using -1 descriptor did not set EBADF");

      return 1;

    }

  return 0;

}