grub/grub-core/osdep/devmapper/getroot.c
2013-10-08 17:30:22 +02:00

451 lines
10 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/util/lvm.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))
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);
}
char *
grub_util_devmapper_part_to_disk (struct stat *st,
int *is_part, const char *path)
{
struct dm_tree *tree;
uint32_t maj, min;
struct dm_tree_node *node = NULL, *child;
void *handle;
const char *node_uuid, *mapper_name = NULL, *child_uuid, *child_name;
tree = dm_tree_create ();
if (! tree)
{
grub_util_info ("dm_tree_create failed");
goto devmapper_out;
}
maj = major (st->st_rdev);
min = minor (st->st_rdev);
if (! dm_tree_add_dev (tree, maj, min))
{
grub_util_info ("dm_tree_add_dev failed");
goto devmapper_out;
}
node = dm_tree_find_node (tree, maj, min);
if (! node)
{
grub_util_info ("dm_tree_find_node failed");
goto devmapper_out;
}
reiterate:
node_uuid = dm_tree_node_get_uuid (node);
if (! node_uuid)
{
grub_util_info ("%s has no DM uuid", path);
goto devmapper_out;
}
if (strncmp (node_uuid, "LVM-", 4) == 0)
{
grub_util_info ("%s is an LVM", path);
goto devmapper_out;
}
if (strncmp (node_uuid, "mpath-", 6) == 0)
{
/* Multipath partitions have partN-mpath-* UUIDs, and are
linear mappings so are handled by
grub_util_get_dm_node_linear_info. Multipath disks are not
linear mappings and must be handled specially. */
grub_util_info ("%s is a multipath disk", path);
goto devmapper_out;
}
if (strncmp (node_uuid, "DMRAID-", 7) != 0)
{
int major, minor;
const char *node_name;
grub_util_info ("%s is not DM-RAID", path);
if ((node_name = dm_tree_node_get_name (node))
&& grub_util_get_dm_node_linear_info (node_name,
&major, &minor, 0))
{
*is_part = 1;
if (tree)
dm_tree_free (tree);
char *ret = grub_find_device ("/dev",
(major << 8) | minor);
return ret;
}
goto devmapper_out;
}
handle = NULL;
/* Counter-intuitively, device-mapper refers to the disk-like
device containing a DM-RAID partition device as a "child" of
the partition device. */
child = dm_tree_next_child (&handle, node, 0);
if (! child)
{
grub_util_info ("%s has no DM children", path);
goto devmapper_out;
}
child_uuid = dm_tree_node_get_uuid (child);
if (! child_uuid)
{
grub_util_info ("%s child has no DM uuid", path);
goto devmapper_out;
}
else if (strncmp (child_uuid, "DMRAID-", 7) != 0)
{
grub_util_info ("%s child is not DM-RAID", path);
goto devmapper_out;
}
child_name = dm_tree_node_get_name (child);
if (! child_name)
{
grub_util_info ("%s child has no DM name", path);
goto devmapper_out;
}
mapper_name = child_name;
*is_part = 1;
node = child;
goto reiterate;
devmapper_out:
if (! mapper_name && node)
{
/* This is a DM-RAID disk, not a partition. */
mapper_name = dm_tree_node_get_name (node);
if (! mapper_name)
grub_util_info ("%s has no DM name", path);
}
char *ret;
if (mapper_name)
ret = xasprintf ("/dev/mapper/%s", mapper_name);
else
ret = NULL;
if (tree)
dm_tree_free (tree);
return ret;
}
int
grub_util_device_is_mapped_stat (struct stat *st)
{
if (!grub_device_mapper_supported ())
return 0;
return dm_is_dm_major (major (st->st_rdev));
}
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;
if (strncmp (uuid, "LVM-", sizeof ("LVM-") - 1) == 0)
{
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;
}
if (strncmp (uuid, "CRYPT-LUKS1-", sizeof ("CRYPT-LUKS1-") - 1) == 0)
{
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;
}
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';
return vgid;
}
void
grub_util_devmapper_cleanup (void)
{
dm_lib_release ();
}
#else
void
grub_util_pull_devmapper (const char *os_dev __attribute__ ((unused)))
{
return;
}
int
grub_util_device_is_mapped_stat (struct stat *st __attribute__ ((unused)))
{
return 0;
}
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