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grub/util/getroot.c

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/* getroot.c - Get root device */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 1999,2000,2001,2002,2003,2006,2007,2008,2009,2010,2011 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 <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 <grub/util/misc.h>
#include <grub/util/lvm.h>
#include <grub/cryptodisk.h>
#include <grub/i18n.h>
#ifdef __linux__
#include <sys/ioctl.h> /* ioctl */
#include <sys/mount.h>
#ifndef MAJOR
# ifndef MINORBITS
# define MINORBITS 8
# endif /* ! MINORBITS */
# define MAJOR(dev) ((unsigned) ((dev) >> MINORBITS))
#endif /* ! MAJOR */
#ifndef FLOPPY_MAJOR
# define FLOPPY_MAJOR 2
#endif /* ! FLOPPY_MAJOR */
#endif
#include <sys/types.h>
#if defined(HAVE_LIBZFS) && defined(HAVE_LIBNVPAIR)
# include <grub/util/libzfs.h>
# include <grub/util/libnvpair.h>
#endif
#include <grub/mm.h>
#include <grub/misc.h>
#include <grub/emu/misc.h>
#include <grub/emu/hostdisk.h>
#include <grub/emu/getroot.h>
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
# define MAJOR(dev) major(dev)
# define FLOPPY_MAJOR 2
#endif
#if defined (__FreeBSD__) || defined (__FreeBSD_kernel__)
#include <sys/mount.h>
#endif
#if defined(__NetBSD__) || defined(__OpenBSD__)
# include <sys/ioctl.h>
# include <sys/disklabel.h> /* struct disklabel */
# include <sys/disk.h> /* struct dkwedge_info */
#include <sys/param.h>
#include <sys/mount.h>
#endif /* defined(__NetBSD__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) */
#if defined(__NetBSD__) || defined(__OpenBSD__)
# define MAJOR(dev) major(dev)
# ifdef HAVE_GETRAWPARTITION
# include <util.h> /* getrawpartition */
# endif /* HAVE_GETRAWPARTITION */
#if defined(__NetBSD__)
# include <sys/fdio.h>
#endif
# ifndef FLOPPY_MAJOR
# define FLOPPY_MAJOR 2
# endif /* ! FLOPPY_MAJOR */
# ifndef RAW_FLOPPY_MAJOR
# define RAW_FLOPPY_MAJOR 9
# endif /* ! RAW_FLOPPY_MAJOR */
#endif /* defined(__NetBSD__) */
grub_disk_addr_t
grub_util_find_partition_start (const char *dev)
{
grub_disk_addr_t partition_start;
if (grub_util_device_is_mapped (dev)
&& grub_util_get_dm_node_linear_info (dev, 0, 0, &partition_start))
return partition_start;
return grub_util_find_partition_start_os (dev);
}
void
grub_util_pull_device (const char *os_dev)
{
enum grub_dev_abstraction_types ab;
ab = grub_util_get_dev_abstraction (os_dev);
switch (ab)
{
case GRUB_DEV_ABSTRACTION_LVM:
#if !defined (__MINGW32__) && !defined (__CYGWIN__)
grub_util_pull_lvm_by_command (os_dev);
#endif
/* Fallthrough in case that lvm-tools are unavailable. */
case GRUB_DEV_ABSTRACTION_LUKS:
grub_util_pull_devmapper (os_dev);
return;
default:
if (grub_util_pull_device_os (os_dev, ab))
return;
case GRUB_DEV_ABSTRACTION_NONE:
free (grub_util_biosdisk_get_grub_dev (os_dev));
return;
}
}
char *
grub_util_get_grub_dev (const char *os_dev)
{
char *ret;
grub_util_pull_device (os_dev);
ret = grub_util_get_devmapper_grub_dev (os_dev);
if (ret)
return ret;
ret = grub_util_get_grub_dev_os (os_dev);
if (ret)
return ret;
return grub_util_biosdisk_get_grub_dev (os_dev);
}
int
grub_util_get_dev_abstraction (const char *os_dev)
{
enum grub_dev_abstraction_types ret;
/* User explicitly claims that this drive is visible by BIOS. */
if (grub_util_biosdisk_is_present (os_dev))
return GRUB_DEV_ABSTRACTION_NONE;
/* Check for LVM and LUKS. */
ret = grub_util_get_dm_abstraction (os_dev);
if (ret != GRUB_DEV_ABSTRACTION_NONE)
return ret;
return grub_util_get_dev_abstraction_os (os_dev);
}
static char *
convert_system_partition_to_system_disk (const char *os_dev, struct stat *st,
int *is_part)
{
*is_part = 0;
if (grub_util_device_is_mapped_stat (st))
return grub_util_devmapper_part_to_disk (st, is_part, os_dev);
*is_part = 0;
return grub_util_part_to_disk (os_dev, st, is_part);
}
static const char *
find_system_device (const char *os_dev, struct stat *st, int convert, int add)
{
char *os_disk;
const char *drive;
int is_part;
if (convert)
os_disk = convert_system_partition_to_system_disk (os_dev, st, &is_part);
else
os_disk = xstrdup (os_dev);
if (! os_disk)
return NULL;
drive = grub_hostdisk_os_dev_to_grub_drive (os_disk, add);
free (os_disk);
return drive;
}
/*
* Note: we do not use the new partition naming scheme as dos_part does not
* necessarily correspond to an msdos partition.
*/
static char *
make_device_name (const char *drive, int dos_part, int bsd_part)
{
char *ret, *ptr, *end;
const char *iptr;
ret = xmalloc (strlen (drive) * 2
+ sizeof (",XXXXXXXXXXXXXXXXXXXXXXXXXX"
",XXXXXXXXXXXXXXXXXXXXXXXXXX"));
end = (ret + strlen (drive) * 2
+ sizeof (",XXXXXXXXXXXXXXXXXXXXXXXXXX"
",XXXXXXXXXXXXXXXXXXXXXXXXXX"));
ptr = ret;
for (iptr = drive; *iptr; iptr++)
{
if (*iptr == ',' || *iptr == '\\')
*ptr++ = '\\';
*ptr++ = *iptr;
}
*ptr = 0;
if (dos_part >= 0)
snprintf (ptr, end - ptr, ",%d", dos_part + 1);
ptr += strlen (ptr);
if (bsd_part >= 0)
snprintf (ptr, end - ptr, ",%d", bsd_part + 1);
return ret;
}
char *
grub_util_get_os_disk (const char *os_dev)
{
int is_part;
grub_util_info ("Looking for %s", os_dev);
#if !defined (__MINGW32__) && !defined (__CYGWIN__)
struct stat st;
if (stat (os_dev, &st) < 0)
{
const char *errstr = strerror (errno);
grub_error (GRUB_ERR_BAD_DEVICE, N_("cannot stat `%s': %s"),
os_dev, errstr);
grub_util_info (_("cannot stat `%s': %s"), os_dev, errstr);
return 0;
}
return convert_system_partition_to_system_disk (os_dev, &st, &is_part);
#else
return convert_system_partition_to_system_disk (os_dev, NULL, &is_part);
#endif
}
#if !defined(__APPLE__)
/* Context for grub_util_biosdisk_get_grub_dev. */
struct grub_util_biosdisk_get_grub_dev_ctx
{
char *partname;
grub_disk_addr_t start;
};
/* Helper for grub_util_biosdisk_get_grub_dev. */
static int
find_partition (grub_disk_t dsk __attribute__ ((unused)),
const grub_partition_t partition, void *data)
{
struct grub_util_biosdisk_get_grub_dev_ctx *ctx = data;
grub_disk_addr_t part_start = 0;
grub_util_info ("Partition %d starts from %" PRIuGRUB_UINT64_T,
partition->number, partition->start);
part_start = grub_partition_get_start (partition);
if (ctx->start == part_start)
{
ctx->partname = grub_partition_get_name (partition);
return 1;
}
return 0;
}
#endif
char *
grub_util_biosdisk_get_grub_dev (const char *os_dev)
{
#if !defined (__MINGW32__) && !defined (__CYGWIN__)
struct stat st;
#endif
const char *drive;
char *sys_disk;
int is_part;
grub_util_info ("Looking for %s", os_dev);
#if !defined (__MINGW32__) && !defined (__CYGWIN__)
if (stat (os_dev, &st) < 0)
{
const char *errstr = strerror (errno);
grub_error (GRUB_ERR_BAD_DEVICE, N_("cannot stat `%s': %s"), os_dev,
errstr);
grub_util_info (_("cannot stat `%s': %s"), os_dev, errstr);
return 0;
}
drive = find_system_device (os_dev, &st, 1, 1);
#if GRUB_DISK_DEVS_ARE_CHAR
if (! S_ISCHR (st.st_mode))
#else
if (! S_ISBLK (st.st_mode))
#endif
return make_device_name (drive, -1, -1);
sys_disk = convert_system_partition_to_system_disk (os_dev, &st, &is_part);
#else
drive = find_system_device (os_dev, NULL, 1, 1);
sys_disk = convert_system_partition_to_system_disk (os_dev, NULL, &is_part);
#endif
if (!sys_disk)
return 0;
grub_util_info ("%s is a parent of %s", sys_disk, os_dev);
if (!is_part)
{
free (sys_disk);
return make_device_name (drive, -1, -1);
}
free (sys_disk);
#if defined(__APPLE__)
/* Apple uses "/dev/r?disk[0-9]+(s[0-9]+)?". */
{
const char *p;
int disk = (grub_memcmp (os_dev, "/dev/disk", sizeof ("/dev/disk") - 1)
== 0);
int rdisk = (grub_memcmp (os_dev, "/dev/rdisk", sizeof ("/dev/rdisk") - 1)
== 0);
if (!disk && !rdisk)
return make_device_name (drive, -1, -1);
p = os_dev + sizeof ("/dev/disk") + rdisk - 1;
while (*p >= '0' && *p <= '9')
p++;
if (*p != 's')
return make_device_name (drive, -1, -1);
p++;
return make_device_name (drive, strtol (p, NULL, 10) - 1, -1);
}
#else
/* Linux counts partitions uniformly, whether a BSD partition or a DOS
partition, so mapping them to GRUB devices is not trivial.
Here, get the start sector of a partition by HDIO_GETGEO, and
compare it with each partition GRUB recognizes.
Cygwin /dev/sdXN emulation uses Windows partition mapping. It
does not count the extended partition and missing primary
partitions. Use same method as on Linux here.
For NetBSD and FreeBSD, proceed as for Linux, except that the start
sector is obtained from the disk label. */
{
char *name;
grub_disk_t disk;
struct grub_util_biosdisk_get_grub_dev_ctx ctx;
name = make_device_name (drive, -1, -1);
# ifdef FLOPPY_MAJOR
if (MAJOR (st.st_rdev) == FLOPPY_MAJOR)
return name;
# else
/* Since os_dev and convert_system_partition_to_system_disk (os_dev) are
* different, we know that os_dev cannot be a floppy device. */
# endif
ctx.start = grub_util_find_partition_start (os_dev);
if (grub_errno != GRUB_ERR_NONE)
{
free (name);
return 0;
}
#if defined(__GNU__)
/* Some versions of Hurd use badly glued Linux code to handle partitions
resulting in partitions being promoted to disks. */
/* GNU uses "/dev/[hs]d[0-9]+(s[0-9]+[a-z]?)?". */
if (ctx.start == (grub_disk_addr_t) -1)
{
char *p;
int dos_part = -1;
int bsd_part = -1;
p = strrchr (os_dev + sizeof ("/dev/hd") - 1, 's');
if (p)
{
long int n;
char *q;
p++;
n = strtol (p, &q, 10);
if (p != q && n != GRUB_LONG_MIN && n != GRUB_LONG_MAX)
{
dos_part = (int) n - 1;
if (*q >= 'a' && *q <= 'g')
bsd_part = *q - 'a';
}
}
return make_device_name (drive, dos_part, bsd_part);
}
#endif
grub_util_info ("%s starts from %" PRIuGRUB_UINT64_T, os_dev, ctx.start);
if (ctx.start == 0 && !is_part)
return name;
grub_util_info ("opening the device %s", name);
disk = grub_disk_open (name);
free (name);
if (! disk)
{
/* We already know that the partition exists. Given that we already
checked the device map above, we can only get
GRUB_ERR_UNKNOWN_DEVICE at this point if the disk does not exist.
This can happen on Xen, where disk images in the host can be
assigned to devices that have partition-like names in the guest
but are really more like disks. */
if (grub_errno == GRUB_ERR_UNKNOWN_DEVICE)
{
char *canon;
grub_util_warn
(_("disk does not exist, so falling back to partition device %s"),
os_dev);
grub_errno = GRUB_ERR_NONE;
canon = canonicalize_file_name (os_dev);
#if !defined (__MINGW32__) && !defined (__CYGWIN__)
drive = find_system_device (canon ? : os_dev, &st, 0, 1);
#else
drive = find_system_device (canon ? : os_dev, NULL, 0, 1);
#endif
if (canon)
free (canon);
return make_device_name (drive, -1, -1);
}
else
return 0;
}
name = grub_util_get_ldm (disk, ctx.start);
if (name)
return name;
ctx.partname = NULL;
grub_partition_iterate (disk, find_partition, &ctx);
if (grub_errno != GRUB_ERR_NONE)
{
grub_disk_close (disk);
return 0;
}
if (ctx.partname == NULL)
{
grub_disk_close (disk);
grub_util_info ("cannot find the partition of `%s'", os_dev);
grub_error (GRUB_ERR_BAD_DEVICE,
"cannot find the partition of `%s'", os_dev);
return 0;
}
name = grub_xasprintf ("%s,%s", disk->name, ctx.partname);
free (ctx.partname);
grub_disk_close (disk);
return name;
}
#endif
}
int
grub_util_biosdisk_is_present (const char *os_dev)
{
struct stat st;
if (stat (os_dev, &st) < 0)
return 0;
int ret= (find_system_device (os_dev, &st, 1, 0) != NULL);
grub_util_info ((ret ? "%s is present" : "%s is not present"),
os_dev);
return ret;
}
const char *
grub_util_check_block_device (const char *blk_dev)
{
struct stat st;
if (stat (blk_dev, &st) < 0)
grub_util_error (_("cannot stat `%s': %s"), blk_dev,
strerror (errno));
if (S_ISBLK (st.st_mode))
return (blk_dev);
else
return 0;
}
const char *
grub_util_check_char_device (const char *blk_dev)
{
struct stat st;
if (stat (blk_dev, &st) < 0)
grub_util_error (_("cannot stat `%s': %s"), blk_dev, strerror (errno));
if (S_ISCHR (st.st_mode))
return (blk_dev);
else
return 0;
}
#ifdef HAVE_LIBZFS
static libzfs_handle_t *__libzfs_handle;
static void
fini_libzfs (void)
{
libzfs_fini (__libzfs_handle);
}
libzfs_handle_t *
grub_get_libzfs_handle (void)
{
if (! __libzfs_handle)
{
__libzfs_handle = libzfs_init ();
if (__libzfs_handle)
atexit (fini_libzfs);
}
return __libzfs_handle;
}
#endif /* HAVE_LIBZFS */
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