#include <dirent.h>

#include <fcntl.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <sys/stat.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-linkat.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);

  puts ("file created");

  struct stat64 st1;

  if (fstat64 (fd, &st1) != 0)

    {

      puts ("fstat64 failed");

      return 1;

    }

  close (fd);

  if (linkat (dir_fd, "some-file", dir_fd, "another-file", 0) != 0)

    {

      puts ("symlinkat failed");

      return 1;

    }

  struct stat64 st2;

  if (fstatat64 (dir_fd, "some-file", &st2, 0) != 0)

    {

      puts ("fstatat64 failed");

      return 1;

    }

  if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)

    {

      puts ("file changed after symlinkat");

      return 1;

    }

  if (fstatat64 (dir_fd, "another-file", &st2, AT_SYMLINK_NOFOLLOW) != 0)

    {

      puts ("2nd fstatat64 failed");

      return 1;

    }

  if (S_ISLNK (st2.st_mode))

    {

      puts ("2nd fstatat64 shows file is a symlink");

      return 1;

    }

  if (st1.st_dev != st2.st_dev

      || st1.st_ino != st2.st_ino

      || st1.st_size != st2.st_size)

    {

      puts ("stat results for linked file do not match");

      return 1;

    }

  if (fstatat64 (dir_fd, "another-file", &st2, 0) != 0)

    {

      puts ("3rd fstatat64 failed");

      return 1;

    }

  if (st1.st_dev != st2.st_dev

      || st1.st_ino != st2.st_ino

      || st1.st_size != st2.st_size)

    {

      puts ("stat results do not match");

      return 1;

    }

  if (unlinkat (dir_fd, "another-file", 0) != 0)

    {

      puts ("unlinkat failed");

      return 1;

    }

  if (unlinkat (dir_fd, "some-file", 0) != 0)

    {

      puts ("2nd unlinkat failed");

      return 1;

    }

  close (dir_fd);

  return 0;

}