sysdeps/unix/sysv/linux/bits/ipc-perm.h

   1 /* struct ipc_perm definition.
   2    Copyright (C) 2019-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C 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    The GNU C 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
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _SYS_IPC_H
  20 # error "Never use <bits/ipc-perm.h> directly; include <sys/ipc.h> instead."
  21 #endif
  22
  23 /* Data structure used to pass permission information to IPC operations.
  24    It follows the kernel ipc64_perm size so the syscall can be made directly
  25    without temporary buffer copy.  However, since glibc defines the MODE
  26    field as mode_t per POSIX definition (BZ#18231), it omits the __PAD1 field
  27    (since glibc does not export mode_t as 16-bit for any architecture).  */
  28 struct ipc_perm
  29 {
  30   __key_t __key;                                /* Key.  */
  31   __uid_t uid;                                  /* Owner's user ID.  */
  32   __gid_t gid;                                  /* Owner's group ID.  */
  33   __uid_t cuid;                                 /* Creator's user ID.  */
  34   __gid_t cgid;                                 /* Creator's group ID.  */
  35   __mode_t mode;                                /* Read/write permission.  */
  36   unsigned short int __seq;                     /* Sequence number.  */
  37   unsigned short int __pad2;
  38   __syscall_ulong_t __glibc_reserved1;
  39   __syscall_ulong_t __glibc_reserved2;
  40 };