grub/commands/loadenv.c

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/* loadenv.c - command to load/save environment variable. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2008 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/normal.h>
#include <grub/dl.h>
#include <grub/mm.h>
#include <grub/arg.h>
#include <grub/file.h>
#include <grub/disk.h>
#include <grub/misc.h>
#include <grub/env.h>
#include <grub/partition.h>
#include <grub/lib/envblk.h>
static const struct grub_arg_option options[] =
{
{"file", 'f', 0, "specify filename", 0, ARG_TYPE_PATHNAME},
{0, 0, 0, 0, 0, 0}
};
char buffer[GRUB_ENVBLK_MAXLEN];
grub_envblk_t envblk;
static grub_file_t
read_envblk_file (char *filename, void NESTED_FUNC_ATTR read_hook (grub_disk_addr_t sector, unsigned offset, unsigned length))
{
char *buf = 0;
grub_file_t file;
if (! filename)
{
char *prefix;
prefix = grub_env_get ("prefix");
if (prefix)
{
int len;
len = grub_strlen (prefix);
buf = grub_malloc (len + 1 + sizeof (GRUB_ENVBLK_DEFCFG));
grub_strcpy (buf, prefix);
buf[len] = '/';
grub_strcpy (buf + len + 1, GRUB_ENVBLK_DEFCFG);
filename = buf;
}
else
{
grub_error (GRUB_ERR_FILE_NOT_FOUND, "prefix is not found");
return 0;
}
}
file = grub_file_open (filename);
grub_free (buf);
if (! file)
return 0;
if (read_hook)
{
if (! file->device->disk)
{
grub_file_close (file);
grub_error (GRUB_ERR_BAD_DEVICE,
"this command is available only for disk devices.");
return 0;
}
file->read_hook = read_hook;
}
if (grub_file_read (file, buffer, GRUB_ENVBLK_MAXLEN) != GRUB_ENVBLK_MAXLEN)
{
grub_file_close (file);
grub_error (GRUB_ERR_BAD_FILE_TYPE, "file too short");
return 0;
}
envblk = grub_envblk_find (buffer);
if (! envblk)
{
grub_file_close (file);
grub_error (GRUB_ERR_BAD_FILE_TYPE, "environment block not found");
return 0;
}
return file;
}
static grub_err_t
grub_cmd_load_env (struct grub_arg_list *state,
int argc __attribute__ ((unused)), char **args __attribute__ ((unused)))
{
grub_file_t file;
auto int hook (char *name, char *value);
int hook (char *name, char *value)
{
grub_env_set (name, value);
return 0;
}
file = read_envblk_file ((state[0].set) ? state[0].arg : 0, 0);
if (! file)
return grub_errno;
grub_file_close (file);
grub_envblk_iterate (envblk, hook);
return grub_errno;
}
static grub_err_t
grub_cmd_list_env (struct grub_arg_list *state,
int argc __attribute__ ((unused)), char **args __attribute__ ((unused)))
{
grub_file_t file;
auto int hook (char *name, char *value);
int hook (char *name, char *value)
{
grub_printf ("%s=%s\n", name, value);
return 0;
}
file = read_envblk_file ((state[0].set) ? state[0].arg : 0, 0);
if (! file)
return grub_errno;
grub_file_close (file);
grub_envblk_iterate (envblk, hook);
return grub_errno;
}
static grub_err_t
grub_cmd_save_env (struct grub_arg_list *state, int argc, char **args)
{
grub_file_t file;
grub_disk_t disk;
grub_disk_addr_t addr[GRUB_ENVBLK_MAXLEN >> GRUB_DISK_SECTOR_BITS];
char buf[GRUB_DISK_SECTOR_SIZE];
grub_disk_addr_t part_start = 0;
int num = 0;
auto void NESTED_FUNC_ATTR hook (grub_disk_addr_t sector, unsigned offset,
unsigned length);
void NESTED_FUNC_ATTR hook (grub_disk_addr_t sector,
unsigned offset, unsigned length)
{
if ((offset != 0) || (length != GRUB_DISK_SECTOR_SIZE))
return;
if (num < (GRUB_ENVBLK_MAXLEN >> GRUB_DISK_SECTOR_BITS))
addr[num++] = sector;
}
if (! argc)
return grub_error (GRUB_ERR_BAD_ARGUMENT, "No variable is specified");
file = read_envblk_file ((state[0].set) ? state[0].arg : 0, hook);
if (! file)
return grub_errno;
file->read_hook = 0;
if (num != GRUB_ENVBLK_MAXLEN >> GRUB_DISK_SECTOR_BITS)
{
grub_error (GRUB_ERR_BAD_DEVICE, "invalid blocklist");
goto quit;
}
disk = file->device->disk;
if (disk->partition)
part_start = grub_partition_get_start (disk->partition);
for (num = 0; num < (GRUB_ENVBLK_MAXLEN >> GRUB_DISK_SECTOR_BITS); num++)
{
if (grub_disk_read (disk, addr[num] - part_start, 0,
GRUB_DISK_SECTOR_SIZE, buf))
goto quit;
if (grub_memcmp (&buffer[num << GRUB_DISK_SECTOR_BITS], buf,
GRUB_DISK_SECTOR_SIZE))
{
grub_error (GRUB_ERR_BAD_DEVICE, "invalid blocklist");
goto quit;
}
}
while (argc)
{
char *value;
value = grub_env_get (args[0]);
if (value)
{
if (grub_envblk_insert (envblk, args[0], value))
{
grub_error (GRUB_ERR_BAD_ARGUMENT, "environment block too small");
goto quit;
}
}
argc--;
args++;
}
for (num = 0; num < (GRUB_ENVBLK_MAXLEN >> GRUB_DISK_SECTOR_BITS); num++)
if (grub_disk_write (disk, addr[num] - part_start, 0,
GRUB_DISK_SECTOR_SIZE,
&buffer[num << GRUB_DISK_SECTOR_BITS]))
goto quit;
quit:
grub_file_close (file);
return grub_errno;
}
GRUB_MOD_INIT(loadenv)
{
(void) mod;
grub_register_command ("load_env", grub_cmd_load_env, GRUB_COMMAND_FLAG_BOTH,
"load_env [-f FILE]", "Load variables from environment block file.", options);
grub_register_command ("list_env", grub_cmd_list_env, GRUB_COMMAND_FLAG_BOTH,
"list_env [-f FILE]", "List variables from environment block file.", options);
grub_register_command ("save_env", grub_cmd_save_env, GRUB_COMMAND_FLAG_BOTH,
"save_env [-f FILE] variable_name [...]", "Save variables to environment block file.", options);
}
GRUB_MOD_FINI(loadenv)
{
grub_unregister_command ("load_env");
grub_unregister_command ("list_env");
grub_unregister_command ("save_env");
}