grub/grub-core/osdep/devmapper/getroot.c
Andrei Borzenkov 3bca85b418 devmapper: check for valid device abstraction in get_grub_dev
This was lost when code was refactored. Patch restores previous behavior.

It is still not clear whether this is the right one. Due to the way we
detect DM abstraction, partitions on DM are skipped, we fall through to
generic detection which ends up in assuming parent device is BIOS disk.

It is useful to install GRUB on VM disk from the host. But it also means
that GRUB will mistakenly allow install on real system as well.

For now let's fix regression; future behavior needs to be discussed.

Closes: 45163
2015-12-26 21:45:22 +03:00

341 lines
7.1 KiB
C

/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 1999,2000,2001,2002,2003,2006,2007,2008,2009,2010,2011,2012,2013 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-util.h>
#include <config.h>
#include <grub/emu/getroot.h>
#include <grub/mm.h>
#ifdef HAVE_DEVICE_MAPPER
#include <sys/stat.h>
#include <sys/types.h>
#include <assert.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <dirent.h>
#include <errno.h>
#include <error.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#ifdef HAVE_LIMITS_H
#include <limits.h>
#endif
#include <libdevmapper.h>
#include <grub/types.h>
#include <grub/util/misc.h>
#include <grub/mm.h>
#include <grub/misc.h>
#include <grub/emu/misc.h>
#include <grub/emu/hostdisk.h>
static int
grub_util_open_dm (const char *os_dev, struct dm_tree **tree,
struct dm_tree_node **node)
{
uint32_t maj, min;
struct stat st;
*node = NULL;
*tree = NULL;
if (stat (os_dev, &st) < 0)
return 0;
maj = major (st.st_rdev);
min = minor (st.st_rdev);
if (!dm_is_dm_major (maj))
return 0;
*tree = dm_tree_create ();
if (! *tree)
{
grub_puts_ (N_("Failed to create `device-mapper' tree"));
grub_dprintf ("hostdisk", "dm_tree_create failed\n");
return 0;
}
if (! dm_tree_add_dev (*tree, maj, min))
{
grub_dprintf ("hostdisk", "dm_tree_add_dev failed\n");
dm_tree_free (*tree);
*tree = NULL;
return 0;
}
*node = dm_tree_find_node (*tree, maj, min);
if (! *node)
{
grub_dprintf ("hostdisk", "dm_tree_find_node failed\n");
dm_tree_free (*tree);
*tree = NULL;
return 0;
}
return 1;
}
static char *
get_dm_uuid (const char *os_dev)
{
struct dm_tree *tree;
struct dm_tree_node *node;
const char *node_uuid;
char *ret;
if (!grub_util_open_dm (os_dev, &tree, &node))
return NULL;
node_uuid = dm_tree_node_get_uuid (node);
if (! node_uuid)
{
grub_dprintf ("hostdisk", "%s has no DM uuid\n", os_dev);
dm_tree_free (tree);
return NULL;
}
ret = grub_strdup (node_uuid);
dm_tree_free (tree);
return ret;
}
enum grub_dev_abstraction_types
grub_util_get_dm_abstraction (const char *os_dev)
{
char *uuid;
uuid = get_dm_uuid (os_dev);
if (uuid == NULL)
return GRUB_DEV_ABSTRACTION_NONE;
if (strncmp (uuid, "LVM-", 4) == 0)
{
grub_free (uuid);
return GRUB_DEV_ABSTRACTION_LVM;
}
if (strncmp (uuid, "CRYPT-LUKS1-", 4) == 0)
{
grub_free (uuid);
return GRUB_DEV_ABSTRACTION_LUKS;
}
grub_free (uuid);
return GRUB_DEV_ABSTRACTION_NONE;
}
void
grub_util_pull_devmapper (const char *os_dev)
{
struct dm_tree *tree;
struct dm_tree_node *node;
struct dm_tree_node *child;
void *handle = NULL;
char *lastsubdev = NULL;
char *uuid;
uuid = get_dm_uuid (os_dev);
if (!grub_util_open_dm (os_dev, &tree, &node))
{
grub_free (uuid);
return;
}
while ((child = dm_tree_next_child (&handle, node, 0)))
{
const struct dm_info *dm = dm_tree_node_get_info (child);
char *subdev;
if (!dm)
continue;
subdev = grub_find_device ("/dev", makedev (dm->major, dm->minor));
if (subdev)
{
lastsubdev = subdev;
grub_util_pull_device (subdev);
}
}
if (uuid && strncmp (uuid, "CRYPT-LUKS1-", sizeof ("CRYPT-LUKS1-") - 1) == 0
&& lastsubdev)
{
char *grdev = grub_util_get_grub_dev (lastsubdev);
dm_tree_free (tree);
if (grdev)
{
grub_err_t err;
err = grub_cryptodisk_cheat_mount (grdev, os_dev);
if (err)
grub_util_error (_("can't mount encrypted volume `%s': %s"),
lastsubdev, grub_errmsg);
}
grub_free (grdev);
}
else
dm_tree_free (tree);
grub_free (uuid);
}
char *
grub_util_devmapper_part_to_disk (struct stat *st,
int *is_part, const char *path)
{
int major, minor;
if (grub_util_get_dm_node_linear_info (st->st_rdev,
&major, &minor, 0))
{
*is_part = 1;
return grub_find_device ("/dev", makedev (major, minor));
}
*is_part = 0;
return xstrdup (path);
}
char *
grub_util_get_devmapper_grub_dev (const char *os_dev)
{
char *uuid, *optr;
char *grub_dev;
uuid = get_dm_uuid (os_dev);
if (!uuid)
return NULL;
switch (grub_util_get_dev_abstraction (os_dev))
{
case GRUB_DEV_ABSTRACTION_LVM:
{
unsigned i;
int dashes[] = { 0, 6, 10, 14, 18, 22, 26, 32, 38, 42, 46, 50, 54, 58};
grub_dev = xmalloc (grub_strlen (uuid) + 40);
optr = grub_stpcpy (grub_dev, "lvmid/");
for (i = 0; i < ARRAY_SIZE (dashes) - 1; i++)
{
memcpy (optr, uuid + sizeof ("LVM-") - 1 + dashes[i],
dashes[i+1] - dashes[i]);
optr += dashes[i+1] - dashes[i];
*optr++ = '-';
}
optr = stpcpy (optr, uuid + sizeof ("LVM-") - 1 + dashes[i]);
*optr = '\0';
grub_dev[sizeof("lvmid/xxxxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx") - 1]
= '/';
free (uuid);
return grub_dev;
}
case GRUB_DEV_ABSTRACTION_LUKS:
{
char *dash;
dash = grub_strchr (uuid + sizeof ("CRYPT-LUKS1-") - 1, '-');
if (dash)
*dash = 0;
grub_dev = grub_xasprintf ("cryptouuid/%s",
uuid + sizeof ("CRYPT-LUKS1-") - 1);
grub_free (uuid);
return grub_dev;
}
default:
grub_free (uuid);
return NULL;
}
}
char *
grub_util_get_vg_uuid (const char *os_dev)
{
char *uuid, *vgid;
int dashes[] = { 0, 6, 10, 14, 18, 22, 26, 32};
unsigned i;
char *optr;
uuid = get_dm_uuid (os_dev);
if (!uuid)
return NULL;
vgid = xmalloc (grub_strlen (uuid));
optr = vgid;
for (i = 0; i < ARRAY_SIZE (dashes) - 1; i++)
{
memcpy (optr, uuid + sizeof ("LVM-") - 1 + dashes[i],
dashes[i+1] - dashes[i]);
optr += dashes[i+1] - dashes[i];
*optr++ = '-';
}
optr--;
*optr = '\0';
grub_free (uuid);
return vgid;
}
void
grub_util_devmapper_cleanup (void)
{
dm_lib_release ();
}
#else
void
grub_util_pull_devmapper (const char *os_dev __attribute__ ((unused)))
{
return;
}
void
grub_util_devmapper_cleanup (void)
{
}
enum grub_dev_abstraction_types
grub_util_get_dm_abstraction (const char *os_dev __attribute__ ((unused)))
{
return GRUB_DEV_ABSTRACTION_NONE;
}
char *
grub_util_get_vg_uuid (const char *os_dev __attribute__ ((unused)))
{
return NULL;
}
char *
grub_util_devmapper_part_to_disk (struct stat *st __attribute__ ((unused)),
int *is_part __attribute__ ((unused)),
const char *os_dev __attribute__ ((unused)))
{
return NULL;
}
char *
grub_util_get_devmapper_grub_dev (const char *os_dev __attribute__ ((unused)))
{
return NULL;
}
#endif