1  /* glib-unixprivate.h - Unix specific integration private functions
       2   *
       3   * SPDX-License-Identifier: LGPL-2.1-or-later
       4   *
       5   * This library is free software; you can redistribute it and/or
       6   * modify it under the terms of the GNU Lesser General Public
       7   * License as published by the Free Software Foundation; either
       8   * version 2.1 of the License, or (at your option) any later version.
       9   *
      10   * This library is distributed in the hope that it will be useful,
      11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
      12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13   * Lesser General Public License for more details.
      14   *
      15   * You should have received a copy of the GNU Lesser General Public License
      16   * along with this library; if not, see <http://www.gnu.org/licenses/>.
      17   */
      18  
      19  #ifndef __G_UNIXPRIVATE_H__
      20  #define __G_UNIXPRIVATE_H__
      21  
      22  #include "config.h"
      23  
      24  #ifndef G_OS_UNIX
      25  #error "This header may only be used on UNIX"
      26  #endif
      27  
      28  /* To make bionic export pipe2() */
      29  #ifndef _GNU_SOURCE
      30  #define _GNU_SOURCE 1
      31  #endif
      32  
      33  #include "gmacros.h"
      34  #include "gtypes.h"
      35  
      36  #include <errno.h>
      37  #include <fcntl.h>
      38  #include <unistd.h>
      39  
      40  G_BEGIN_DECLS
      41  
      42  static inline gboolean
      43  g_unix_open_pipe_internal (int *fds,
      44                             gboolean close_on_exec,
      45                             gboolean nonblock)
      46    {
      47  #ifdef HAVE_PIPE2
      48    do
      49      {
      50        int ecode;
      51        int flags = 0;
      52  
      53        if (close_on_exec)
      54          flags |= O_CLOEXEC;
      55        if (nonblock)
      56          flags |= O_NONBLOCK;
      57  
      58        /* Atomic */
      59        ecode = pipe2 (fds, flags);
      60        if (ecode == -1 && errno != ENOSYS)
      61          return FALSE;
      62        else if (ecode == 0)
      63          return TRUE;
      64        /* Fall through on -ENOSYS, we must be running on an old kernel */
      65      }
      66    while (FALSE);
      67  #endif
      68  
      69    if (pipe (fds) == -1)
      70      return FALSE;
      71  
      72    if (close_on_exec)
      73      {
      74        if (fcntl (fds[0], F_SETFD, FD_CLOEXEC) == -1 ||
      75            fcntl (fds[1], F_SETFD, FD_CLOEXEC) == -1)
      76          {
      77            int saved_errno = errno;
      78  
      79            close (fds[0]);
      80            close (fds[1]);
      81            fds[0] = -1;
      82            fds[1] = -1;
      83  
      84            errno = saved_errno;
      85            return FALSE;
      86          }
      87      }
      88  
      89    if (nonblock)
      90      {
      91  #ifdef O_NONBLOCK
      92        int flags = O_NONBLOCK;
      93  #else
      94        int flags = O_NDELAY;
      95  #endif
      96  
      97        if (fcntl (fds[0], F_SETFL, flags) == -1 ||
      98            fcntl (fds[1], F_SETFL, flags) == -1)
      99          {
     100            int saved_errno = errno;
     101  
     102            close (fds[0]);
     103            close (fds[1]);
     104            fds[0] = -1;
     105            fds[1] = -1;
     106  
     107            errno = saved_errno;
     108            return FALSE;
     109          }
     110      }
     111  
     112    return TRUE;
     113  }
     114  
     115  G_END_DECLS
     116  
     117  #endif  /* __G_UNIXPRIVATE_H__ */