/* Basic test coverage for updwtmpx.

   Copyright (C) 2019 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public License as

   published by the Free Software Foundation; either version 2.1 of the

   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; see the file COPYING.LIB.  If

   not, see <http://www.gnu.org/licenses/>.  */

/* This program runs a series of tests.  Each one calls updwtmpx

   twice, to write two records, optionally with misalignment in the

   file, and reads back the results.  */

#include <errno.h>

#include <stdlib.h>

#include <support/check.h>

#include <support/descriptors.h>

#include <support/support.h>

#include <support/temp_file.h>

#include <support/test-driver.h>

#include <support/xunistd.h>

#include <unistd.h>

#include <utmpx.h>

static int

do_test (void)

{

  /* Two entries filled with an arbitrary bit pattern.  */

  struct utmpx entries[2];

  unsigned char pad;

  {

    unsigned char *p = (unsigned char *) &entries[0];

    for (size_t i = 0; i < sizeof (entries); ++i)

      {

        p[i] = i;

      }

    /* Make sure that the first and second entry and the padding are

       different.  */

    p[sizeof (struct utmpx)] = p[0] + 1;

    pad = p[0] + 2;

  }

  char *path;

  int fd = create_temp_file ("tst-updwtmpx-", &path);

  /* Used to check that updwtmpx does not leave an open file

     descriptor around.  */

  struct support_descriptors *descriptors = support_descriptors_list ();

  /* updwtmpx is expected to remove misalignment.  Optionally insert

     one byte of misalignment at the start and in the middle (after

     the first entry).  */

  for (int misaligned_start = 0; misaligned_start < 2; ++misaligned_start)

    for (int misaligned_middle = 0; misaligned_middle < 2; ++misaligned_middle)

      {

        if (test_verbose > 0)

          printf ("info: misaligned_start=%d misaligned_middle=%d\n",

                  misaligned_start, misaligned_middle);

        xftruncate (fd, 0);

        TEST_COMPARE (pwrite64 (fd, &pad, misaligned_start, 0),

                      misaligned_start);

        /* Write first entry and check it.  */

        errno = 0;

        updwtmpx (path, &entries[0]);

        TEST_COMPARE (errno, 0);

        support_descriptors_check (descriptors);

        TEST_COMPARE (xlseek (fd, 0, SEEK_END), sizeof (struct utmpx));

        struct utmpx buffer;

        TEST_COMPARE (pread64 (fd, &buffer, sizeof (buffer), 0),

                      sizeof (buffer));

        TEST_COMPARE_BLOB (&entries[0], sizeof (entries[0]),

                           &buffer, sizeof (buffer));

        /* Middle mis-alignmet.  */

        TEST_COMPARE (pwrite64 (fd, &pad, misaligned_middle,

                                sizeof (struct utmpx)), misaligned_middle);

        /* Write second entry and check both entries.  */

        errno = 0;

        updwtmpx (path, &entries[1]);

        TEST_COMPARE (errno, 0);

        support_descriptors_check (descriptors);

        TEST_COMPARE (xlseek (fd, 0, SEEK_END), 2 * sizeof (struct utmpx));

        TEST_COMPARE (pread64 (fd, &buffer, sizeof (buffer), 0),

                      sizeof (buffer));

        TEST_COMPARE_BLOB (&entries[0], sizeof (entries[0]),

                           &buffer, sizeof (buffer));

        TEST_COMPARE (pread64 (fd, &buffer, sizeof (buffer), sizeof (buffer)),

                      sizeof (buffer));

        TEST_COMPARE_BLOB (&entries[1], sizeof (entries[1]),

                           &buffer, sizeof (buffer));

      }

  support_descriptors_free (descriptors);

  free (path);

  xclose (fd);

  return 0;

}

#include <support/test-driver.c>