grub2/util/grub-mknetdir.c
Dimitri John Ledkov 8ddbdc3bc2 grub-install: Add backup and restore
Refactor clean_grub_dir() to create a backup of all the files, instead
of just irrevocably removing them as the first action. If available,
register atexit() handler to restore the backup if errors occur before
point of no return, or remove the backup if everything was successful.
If atexit() is not available, the backup remains on disk for manual
recovery.

Some platforms defined a point of no return, i.e. after modules & core
images were updated. Failures from any commands after that stage are
ignored, and backup is cleaned up. For example, on EFI platforms update
is not reverted when efibootmgr fails.

Extra care is taken to ensure atexit() handler is only invoked by the
parent process and not any children forks. Some older GRUB codebases
can invoke parent atexit() hooks from forks, which can mess up the
backup.

This allows safer upgrades of MBR & modules, such that
modules/images/fonts/translations are consistent with MBR in case of
errors. For example accidental grub-install /dev/non-existent-disk
currently clobbers and upgrades modules in /boot/grub, despite not
actually updating any MBR.

This patch only handles backup and restore of files copied to /boot/grub.
This patch does not perform backup (or restoration) of MBR itself or
blocklists. Thus when installing i386-pc platform, corruption may still
occur with MBR and blocklists which will not be attempted to be
automatically recovered.

Also add modinfo.sh and *.efi to the cleanup/backup/restore code path,
to ensure it is also cleaned, backed up and restored.

Signed-off-by: Dimitri John Ledkov <xnox@ubuntu.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2021-06-01 17:20:20 +02:00

228 lines
6.4 KiB
C

/*
* Copyright (C) 1999,2000,2001,2002,2003,2004,2005,2006,2007,2008,2009,2010,2013 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 <config.h>
#include <grub/util/install.h>
#include <grub/emu/config.h>
#include <grub/util/misc.h>
#include <string.h>
#include <errno.h>
#pragma GCC diagnostic ignored "-Wmissing-prototypes"
#pragma GCC diagnostic ignored "-Wmissing-declarations"
#include <argp.h>
#pragma GCC diagnostic error "-Wmissing-prototypes"
#pragma GCC diagnostic error "-Wmissing-declarations"
static char *rootdir = NULL, *subdir = NULL;
static char *debug_image = NULL;
enum
{
OPTION_NET_DIRECTORY = 0x301,
OPTION_SUBDIR,
OPTION_DEBUG,
OPTION_DEBUG_IMAGE
};
static struct argp_option options[] = {
GRUB_INSTALL_OPTIONS,
{"net-directory", OPTION_NET_DIRECTORY, N_("DIR"),
0, N_("root directory of TFTP server"), 2},
{"subdir", OPTION_SUBDIR, N_("DIR"),
0, N_("relative subdirectory on network server"), 2},
{"debug", OPTION_DEBUG, 0, OPTION_HIDDEN, 0, 2},
{"debug-image", OPTION_DEBUG_IMAGE, N_("STRING"), OPTION_HIDDEN, 0, 2},
{0, 0, 0, 0, 0, 0}
};
static error_t
argp_parser (int key, char *arg, struct argp_state *state)
{
if (grub_install_parse (key, arg))
return 0;
switch (key)
{
case OPTION_NET_DIRECTORY:
free (rootdir);
rootdir = xstrdup (arg);
return 0;
case OPTION_SUBDIR:
free (subdir);
subdir = xstrdup (arg);
return 0;
/* This is an undocumented feature... */
case OPTION_DEBUG:
verbosity++;
return 0;
case OPTION_DEBUG_IMAGE:
free (debug_image);
debug_image = xstrdup (arg);
return 0;
case ARGP_KEY_ARG:
default:
return ARGP_ERR_UNKNOWN;
}
}
struct argp argp = {
options, argp_parser, NULL,
"\v"N_("Prepares GRUB network boot images at net_directory/subdir "
"assuming net_directory being TFTP root."),
NULL, grub_install_help_filter, NULL
};
static char *base;
static const struct
{
const char *mkimage_target;
const char *netmodule;
const char *ext;
} targets[GRUB_INSTALL_PLATFORM_MAX] =
{
[GRUB_INSTALL_PLATFORM_I386_PC] = { "i386-pc-pxe", "pxe", ".0" },
[GRUB_INSTALL_PLATFORM_SPARC64_IEEE1275] = { "sparc64-ieee1275-aout", "ofnet", ".img" },
[GRUB_INSTALL_PLATFORM_I386_IEEE1275] = { "i386-ieee1275", "ofnet", ".elf" },
[GRUB_INSTALL_PLATFORM_POWERPC_IEEE1275] = { "powerpc-ieee1275", "ofnet", ".elf" },
[GRUB_INSTALL_PLATFORM_I386_EFI] = { "i386-efi", "efinet", ".efi" },
[GRUB_INSTALL_PLATFORM_X86_64_EFI] = { "x86_64-efi", "efinet", ".efi" },
[GRUB_INSTALL_PLATFORM_IA64_EFI] = { "ia64-efi", "efinet", ".efi" },
[GRUB_INSTALL_PLATFORM_ARM_EFI] = { "arm-efi", "efinet", ".efi" },
[GRUB_INSTALL_PLATFORM_ARM64_EFI] = { "arm64-efi", "efinet", ".efi" },
[GRUB_INSTALL_PLATFORM_RISCV32_EFI] = { "riscv32-efi", "efinet", ".efi" },
[GRUB_INSTALL_PLATFORM_RISCV64_EFI] = { "riscv64-efi", "efinet", ".efi" },
};
static void
process_input_dir (const char *input_dir, enum grub_install_plat platform)
{
char *platsub = grub_install_get_platform_name (platform);
char *grubdir = grub_util_path_concat (3, rootdir, subdir, platsub);
char *load_cfg = grub_util_path_concat (2, grubdir, "load.cfg");
char *prefix;
char *output;
char *grub_cfg;
FILE *cfg;
grub_install_copy_files (input_dir, base, platform);
grub_util_unlink (load_cfg);
if (debug_image)
{
FILE *f = grub_util_fopen (load_cfg, "wb");
if (!f)
grub_util_error (_("cannot open `%s': %s"), load_cfg,
strerror (errno));
fprintf (f, "set debug='%s'\n", debug_image);
fclose (f);
}
else
{
free (load_cfg);
load_cfg = 0;
}
prefix = xasprintf ("/%s", subdir);
if (!targets[platform].mkimage_target)
grub_util_error (_("unsupported platform %s"), platsub);
grub_cfg = grub_util_path_concat (2, grubdir, "grub.cfg");
cfg = grub_util_fopen (grub_cfg, "wb");
if (!cfg)
grub_util_error (_("cannot open `%s': %s"), grub_cfg,
strerror (errno));
fprintf (cfg, "source %s/grub.cfg", subdir);
fclose (cfg);
grub_install_push_module (targets[platform].netmodule);
output = grub_util_path_concat_ext (2, grubdir, "core", targets[platform].ext);
grub_install_make_image_wrap (input_dir, prefix, output,
0, load_cfg,
targets[platform].mkimage_target, 0);
grub_set_install_backup_ponr ();
grub_install_pop_module ();
/* TRANSLATORS: First %s is replaced by platform name. Second one by filename. */
printf (_("Netboot directory for %s created. Configure your DHCP server to point to %s\n"),
platsub, output);
free (platsub);
free (output);
free (prefix);
free (grub_cfg);
free (grubdir);
}
int
main (int argc, char *argv[])
{
const char *pkglibdir;
grub_util_host_init (&argc, &argv);
grub_util_disable_fd_syncs ();
rootdir = xstrdup ("/srv/tftp");
pkglibdir = grub_util_get_pkglibdir ();
subdir = grub_util_path_concat (2, GRUB_BOOT_DIR_NAME, GRUB_DIR_NAME);
argp_parse (&argp, argc, argv, 0, 0, 0);
base = grub_util_path_concat (2, rootdir, subdir);
/* Create the GRUB directory if it is not present. */
grub_install_mkdir_p (base);
grub_install_push_module ("tftp");
if (!grub_install_source_directory)
{
enum grub_install_plat plat;
for (plat = 0; plat < GRUB_INSTALL_PLATFORM_MAX; plat++)
if (targets[plat].mkimage_target)
{
char *platdir = grub_util_path_concat (2, pkglibdir,
grub_install_get_platform_name (plat));
grub_util_info ("Looking for `%s'", platdir);
if (!grub_util_is_directory (platdir))
{
free (platdir);
continue;
}
process_input_dir (platdir, plat);
}
}
else
{
enum grub_install_plat plat;
plat = grub_install_get_target (grub_install_source_directory);
process_input_dir (grub_install_source_directory, plat);
}
return 0;
}