posix/shm-directory.c

   1 /* Determine directory for shm/sem files.  Generic POSIX version.
   2    Copyright (C) 2014-2023 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    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <unistd.h>
  20
  21 #if _POSIX_MAPPED_FILES
  22
  23 #include <alloc_buffer.h>
  24 #include <shm-directory.h>
  25 #include <string.h>
  26
  27 int
  28 __shm_get_name (struct shmdir_name *result, const char *name, bool sem_prefix)
  29 {
  30   while (name[0] == '/')
  31     ++name;
  32   size_t namelen = strlen (name);
  33
  34   struct alloc_buffer buffer
  35     = alloc_buffer_create (result->name, sizeof (result->name));
  36   alloc_buffer_copy_bytes (&buffer, SHMDIR, strlen (SHMDIR));
  37   if (sem_prefix)
  38     alloc_buffer_copy_bytes (&buffer, "sem.", strlen ("sem."));
  39   alloc_buffer_copy_bytes (&buffer, name, namelen + 1);
  40   if (namelen == 0 || memchr (name, '/', namelen) != NULL
  41       || alloc_buffer_has_failed (&buffer))
  42     return -1;
  43   return 0;
  44 }
  45 libc_hidden_def (__shm_get_name)
  46
  47 #endif