lib/spawn_faction_addopen.c

   1 /* Copyright (C) 2000, 2009-2020 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 #include <config.h>
  18
  19 /* Specification.  */
  20 #include <spawn.h>
  21
  22 #include <errno.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26
  27 #if !_LIBC
  28 # define __sysconf(open_max) getdtablesize ()
  29 #endif
  30
  31 #if REPLACE_POSIX_SPAWN
  32 # include "spawn_int.h"
  33 #endif
  34
  35 /* Add an action to FILE-ACTIONS which tells the implementation to call
  36    'open' for the given file during the 'spawn' call.  */
  37 int
  38 posix_spawn_file_actions_addopen (posix_spawn_file_actions_t *file_actions,
  39                                   int fd, const char *path, int oflag,
  40                                   mode_t mode)
  41 #undef posix_spawn_file_actions_addopen
  42 {
  43   int maxfd = __sysconf (_SC_OPEN_MAX);
  44
  45   /* Test for the validity of the file descriptor.  */
  46   if (fd < 0 || fd >= maxfd)
  47     return EBADF;
  48
  49 #if !REPLACE_POSIX_SPAWN
  50   return posix_spawn_file_actions_addopen (file_actions, fd, path, oflag, mode);
  51 #else
  52   {
  53     /* Copy PATH, because the caller may free it before calling posix_spawn()
  54        or posix_spawnp().  */
  55     char *path_copy = strdup (path);
  56     if (path_copy == NULL)
  57       return ENOMEM;
  58
  59     /* Allocate more memory if needed.  */
  60     if (file_actions->_used == file_actions->_allocated
  61         && __posix_spawn_file_actions_realloc (file_actions) != 0)
  62       {
  63         /* This can only mean we ran out of memory.  */
  64         free (path_copy);
  65         return ENOMEM;
  66       }
  67
  68     {
  69       struct __spawn_action *rec;
  70
  71       /* Add the new value.  */
  72       rec = &file_actions->_actions[file_actions->_used];
  73       rec->tag = spawn_do_open;
  74       rec->action.open_action.fd = fd;
  75       rec->action.open_action.path = path_copy;
  76       rec->action.open_action.oflag = oflag;
  77       rec->action.open_action.mode = mode;
  78
  79       /* Account for the new entry.  */
  80       ++file_actions->_used;
  81
  82       return 0;
  83     }
  84   }
  85 #endif
  86 }