/* Copyright (C) 2014-2018 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 <stdio.h>

#include <errno.h>

#include <pthread.h>

#include <stdbool.h>

#include <unistd.h>

/* The test must run under a non-privileged user ID.  */

static const uid_t test_uid = 1;

static pthread_barrier_t barrier1;

static pthread_barrier_t barrier2;

#define FAIL(fmt, ...) \

  do { printf ("FAIL: " fmt "\n", __VA_ARGS__); _exit (1); } while (0)

#define FAIL_ERR(fmt, ...) \

  do { printf ("FAIL: " fmt ": %m\n", __VA_ARGS__); _exit (1); } while (0)

/* True if x is not a successful return code from pthread_barrier_wait.  */

static inline bool

is_invalid_barrier_ret (int x)

{

  return x != 0 && x != PTHREAD_BARRIER_SERIAL_THREAD;

}

static void *

thread_func (void *ctx __attribute__ ((unused)))

{

  int ret = pthread_barrier_wait (&barrier1);

  if (is_invalid_barrier_ret (ret))

    FAIL ("pthread_barrier_wait (barrier1) (on thread): %d", ret);

  ret = pthread_barrier_wait (&barrier2);

  if (is_invalid_barrier_ret (ret))

    FAIL ("pthread_barrier_wait (barrier2) (on thread): %d", ret);

  return NULL;

}

static void

setuid_failure (int phase)

{

  int ret = setuid (0);

  switch (ret)

    {

    case 0:

      FAIL ("setuid succeeded unexpectedly in phase %d", phase);

    case -1:

      if (errno != EPERM)

	FAIL_ERR ("setuid phase %d", phase);

      break;

    default:

      FAIL ("invalid setuid return value in phase %d: %d", phase, ret);

    }

}

static int

do_test (void)

{

  if (getuid () == 0)

    if (setuid (test_uid) != 0)

      FAIL_ERR ("setuid (%u)", (unsigned) test_uid);

  if (setuid (getuid ()))

    FAIL_ERR ("setuid (%s)", "getuid ()");

  setuid_failure (1);

  int ret = pthread_barrier_init (&barrier1, NULL, 2);

  if (ret != 0)

    FAIL ("pthread_barrier_init (barrier1): %d", ret);

  ret = pthread_barrier_init (&barrier2, NULL, 2);

  if (ret != 0)

    FAIL ("pthread_barrier_init (barrier2): %d", ret);

  pthread_t thread;

  ret = pthread_create (&thread, NULL, thread_func, NULL);

  if (ret != 0)

    FAIL ("pthread_create: %d", ret);

  /* Ensure that the thread is running properly.  */

  ret = pthread_barrier_wait (&barrier1);

  if (is_invalid_barrier_ret (ret))

    FAIL ("pthread_barrier_wait (barrier1): %d", ret);

  setuid_failure (2);

  /* Check success case. */

  if (setuid (getuid ()) != 0)

    FAIL_ERR ("setuid (%s)", "getuid ()");

  /* Shutdown.  */

  ret = pthread_barrier_wait (&barrier2);

  if (is_invalid_barrier_ret (ret))

    FAIL ("pthread_barrier_wait (barrier2): %d", ret);

  ret = pthread_join (thread, NULL);

  if (ret != 0)

    FAIL ("pthread_join: %d", ret);

  return 0;

}

#define TEST_FUNCTION do_test ()

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