GRUB2/MOD_SRC/grub-2.04/grub-core/commands/loadenv.h

   1 /* loadenv.c - command to load/save environment variable.  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2008,2009,2010  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 static grub_envblk_t UNUSED
  21 read_envblk_file (grub_file_t file)
  22 {
  23   grub_off_t offset = 0;
  24   char *buf;
  25   grub_size_t size = grub_file_size (file);
  26   grub_envblk_t envblk;
  27
  28   buf = grub_malloc (size);
  29   if (! buf)
  30     return 0;
  31
  32   while (size > 0)
  33     {
  34       grub_ssize_t ret;
  35
  36       ret = grub_file_read (file, buf + offset, size);
  37       if (ret <= 0)
  38         {
  39           grub_free (buf);
  40           return 0;
  41         }
  42
  43       size -= ret;
  44       offset += ret;
  45     }
  46
  47   envblk = grub_envblk_open (buf, offset);
  48   if (! envblk)
  49     {
  50       grub_free (buf);
  51       grub_error (GRUB_ERR_BAD_FILE_TYPE, "invalid environment block");
  52       return 0;
  53     }
  54
  55   return envblk;
  56 }
  57
  58 struct grub_env_whitelist
  59 {
  60   grub_size_t len;
  61   char **list;
  62 };
  63 typedef struct grub_env_whitelist grub_env_whitelist_t;
  64
  65 static int UNUSED
  66 test_whitelist_membership (const char* name,
  67                            const grub_env_whitelist_t* whitelist)
  68 {
  69   grub_size_t i;
  70
  71   for (i = 0; i < whitelist->len; i++)
  72     if (grub_strcmp (name, whitelist->list[i]) == 0)
  73       return 1;  /* found it */
  74
  75   return 0;  /* not found */
  76 }
  77
  78 /* Helper for grub_cmd_load_env.  */
  79 static int UNUSED
  80 set_var (const char *name, const char *value, void *whitelist)
  81 {
  82   if (! whitelist)
  83     {
  84       grub_env_set (name, value);
  85       return 0;
  86     }
  87
  88   if (test_whitelist_membership (name,
  89                                  (const grub_env_whitelist_t *) whitelist))
  90     grub_env_set (name, value);
  91
  92   return 0;
  93 }