/* Basic test for gethostid.

   Copyright (C) 2018 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; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <gnu/lib-names.h>

#include <nss.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <support/namespace.h>

#include <support/support.h>

#include <support/temp_file.h>

#include <support/xdlfcn.h>

#include <support/xstdio.h>

#include <support/xunistd.h>

#include <unistd.h>

/* Initial test is run outside a chroot, to increase the likelihood of

   success.  */

static void

outside_chroot (void *closure)

{

  long id = gethostid ();

  printf ("info: host ID outside chroot: 0x%lx\n", id);

}

/* The same, but this time perform a chroot operation.  */

static void

in_chroot (void *closure)

{

  const char *chroot_path = closure;

  xchroot (chroot_path);

  long id = gethostid ();

  printf ("info: host ID in chroot: 0x%lx\n", id);

}

static int

do_test (void)

{

  support_isolate_in_subprocess (outside_chroot, NULL);

  /* Now run the test inside a chroot.  */

  support_become_root ();

  if (!support_can_chroot ())

    /* Cannot perform further tests.  */

    return 0;

  /* Only use nss_files.  */

  __nss_configure_lookup ("hosts", "files");

  /* Load the DSO outside of the chroot.  */

  xdlopen (LIBNSS_FILES_SO, RTLD_LAZY);

  char *chroot_dir = support_create_temp_directory ("tst-gethostid-");

  support_isolate_in_subprocess (in_chroot, chroot_dir);

  /* Tests with /etc/hosts in the chroot.  */

  {

    char *path = xasprintf ("%s/etc", chroot_dir);

    add_temp_file (path);

    xmkdir (path, 0777);

    free (path);

    path = xasprintf ("%s/etc/hosts", chroot_dir);

    add_temp_file (path);

    FILE *fp = xfopen (path, "w");

    xfclose (fp);

    printf ("info: chroot test with an empty /etc/hosts file\n");

    support_isolate_in_subprocess (in_chroot, chroot_dir);

    char hostname[1024];

    int ret = gethostname (hostname, sizeof (hostname));

    if (ret < 0)

      printf ("warning: invalid result from gethostname: %d\n", ret);

    else if (strlen (hostname) == 0)

      puts ("warning: gethostname returned empty string");

    else

      {

        printf ("info: chroot test with IPv6 address in /etc/hosts for: %s\n",

                hostname);

        fp = xfopen (path, "w");

        /* Use an IPv6 address to induce another lookup failure.  */

        fprintf (fp, "2001:db8::1 %s\n", hostname);

        xfclose (fp);

        support_isolate_in_subprocess (in_chroot, chroot_dir);

      }

    free (path);

  }

  free (chroot_dir);

  return 0;

}

#include <support/test-driver.c>