grub-core/osdep/devmapper/getroot.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 1999,2000,2001,2002,2003,2006,2007,2008,2009,2010,2011,2012,2013  Free Software Foundation, Inc.
   4  *
   5  *  GRUB is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  GRUB is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <config-util.h>
  20 #include <config.h>
  21
  22 #include <grub/emu/getroot.h>
  23 #include <grub/mm.h>
  24
  25 #ifdef HAVE_DEVICE_MAPPER
  26
  27 #include <sys/stat.h>
  28 #include <sys/types.h>
  29 #include <assert.h>
  30 #include <fcntl.h>
  31 #include <unistd.h>
  32 #include <string.h>
  33 #include <dirent.h>
  34 #include <errno.h>
  35 #include <error.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <stdint.h>
  39 #ifdef HAVE_LIMITS_H
  40 #include <limits.h>
  41 #endif
  42
  43 #if defined(MAJOR_IN_MKDEV)
  44 #include <sys/mkdev.h>
  45 #elif defined(MAJOR_IN_SYSMACROS)
  46 #include <sys/sysmacros.h>
  47 #endif
  48
  49 #include <libdevmapper.h>
  50
  51 #include <grub/types.h>
  52 #include <grub/util/misc.h>
  53
  54 #include <grub/mm.h>
  55 #include <grub/misc.h>
  56 #include <grub/emu/misc.h>
  57 #include <grub/emu/hostdisk.h>
  58
  59 static int
  60 grub_util_open_dm (const char *os_dev, struct dm_tree **tree,
  61                    struct dm_tree_node **node)
  62 {
  63   uint32_t maj, min;
  64   struct stat st;
  65
  66   *node = NULL;
  67   *tree = NULL;
  68
  69   if (stat (os_dev, &st) < 0)
  70     return 0;
  71
  72   maj = major (st.st_rdev);
  73   min = minor (st.st_rdev);
  74
  75   if (!dm_is_dm_major (maj))
  76     return 0;
  77
  78   *tree = dm_tree_create ();
  79   if (! *tree)
  80     {
  81       grub_puts_ (N_("Failed to create `device-mapper' tree"));
  82       grub_dprintf ("hostdisk", "dm_tree_create failed\n");
  83       return 0;
  84     }
  85
  86   if (! dm_tree_add_dev (*tree, maj, min))
  87     {
  88       grub_dprintf ("hostdisk", "dm_tree_add_dev failed\n");
  89       dm_tree_free (*tree);
  90       *tree = NULL;
  91       return 0;
  92     }
  93
  94   *node = dm_tree_find_node (*tree, maj, min);
  95   if (! *node)
  96     {
  97       grub_dprintf ("hostdisk", "dm_tree_find_node failed\n");
  98       dm_tree_free (*tree);
  99       *tree = NULL;
 100       return 0;
 101     }
 102   return 1;
 103 }
 104
 105 static char *
 106 get_dm_uuid (const char *os_dev)
 107 {
 108   struct dm_tree *tree;
 109   struct dm_tree_node *node;
 110   const char *node_uuid;
 111   char *ret;
 112
 113   if (!grub_util_open_dm (os_dev, &tree, &node))
 114     return NULL;
 115
 116   node_uuid = dm_tree_node_get_uuid (node);
 117   if (! node_uuid)
 118     {
 119       grub_dprintf ("hostdisk", "%s has no DM uuid\n", os_dev);
 120       dm_tree_free (tree);
 121       return NULL;
 122     }
 123
 124   ret = grub_strdup (node_uuid);
 125
 126   dm_tree_free (tree);
 127
 128   return ret;
 129 }
 130
 131 enum grub_dev_abstraction_types
 132 grub_util_get_dm_abstraction (const char *os_dev)
 133 {
 134   char *uuid;
 135
 136   uuid = get_dm_uuid (os_dev);
 137
 138   if (uuid == NULL)
 139     return GRUB_DEV_ABSTRACTION_NONE;
 140
 141   if (strncmp (uuid, "LVM-", 4) == 0)
 142     {
 143       grub_free (uuid);
 144       return GRUB_DEV_ABSTRACTION_LVM;
 145     }
 146   if (strncmp (uuid, "CRYPT-LUKS1-", 12) == 0)
 147     {
 148       grub_free (uuid);
 149       return GRUB_DEV_ABSTRACTION_LUKS;
 150     }
 151
 152   grub_free (uuid);
 153   return GRUB_DEV_ABSTRACTION_NONE;
 154 }
 155
 156 void
 157 grub_util_pull_devmapper (const char *os_dev)
 158 {
 159   struct dm_tree *tree;
 160   struct dm_tree_node *node;
 161   struct dm_tree_node *child;
 162   void *handle = NULL;
 163   char *lastsubdev = NULL;
 164   char *uuid;
 165
 166   uuid = get_dm_uuid (os_dev);
 167
 168   if (!grub_util_open_dm (os_dev, &tree, &node))
 169     {
 170       grub_free (uuid);
 171       return;
 172     }
 173
 174   while ((child = dm_tree_next_child (&handle, node, 0)))
 175     {
 176       const struct dm_info *dm = dm_tree_node_get_info (child);
 177       char *subdev;
 178       if (!dm)
 179         continue;
 180       subdev = grub_find_device ("/dev", makedev (dm->major, dm->minor));
 181       if (subdev)
 182         {
 183           lastsubdev = subdev;
 184           grub_util_pull_device (subdev);
 185         }
 186     }
 187   if (uuid && strncmp (uuid, "CRYPT-LUKS1-", sizeof ("CRYPT-LUKS1-") - 1) == 0
 188       && lastsubdev)
 189     {
 190       char *grdev = grub_util_get_grub_dev (lastsubdev);
 191       dm_tree_free (tree);
 192       if (grdev)
 193         {
 194           grub_err_t err;
 195           err = grub_cryptodisk_cheat_mount (grdev, os_dev);
 196           if (err)
 197             grub_util_error (_("can't mount encrypted volume `%s': %s"),
 198                              lastsubdev, grub_errmsg);
 199         }
 200       grub_free (grdev);
 201     }
 202   else
 203     dm_tree_free (tree);
 204   grub_free (uuid);
 205 }
 206
 207 char *
 208 grub_util_devmapper_part_to_disk (struct stat *st,
 209                                   int *is_part, const char *path)
 210 {
 211   int major, minor;
 212
 213   if (grub_util_get_dm_node_linear_info (st->st_rdev,
 214                                          &major, &minor, 0))
 215     {
 216       *is_part = 1;
 217       return grub_find_device ("/dev", makedev (major, minor));
 218     }
 219   *is_part = 0;
 220   return xstrdup (path);
 221 }
 222
 223 char *
 224 grub_util_get_devmapper_grub_dev (const char *os_dev)
 225 {
 226   char *uuid, *optr;
 227   char *grub_dev;
 228
 229   uuid = get_dm_uuid (os_dev);
 230   if (!uuid)
 231     return NULL;
 232
 233   switch (grub_util_get_dev_abstraction (os_dev))
 234     {
 235     case GRUB_DEV_ABSTRACTION_LVM:
 236       {
 237         unsigned i;
 238         int dashes[] = { 0, 6, 10, 14, 18, 22, 26, 32, 38, 42, 46, 50, 54, 58};
 239
 240         grub_dev = xmalloc (grub_strlen (uuid) + 40);
 241         optr = grub_stpcpy (grub_dev, "lvmid/");
 242         for (i = 0; i < ARRAY_SIZE (dashes) - 1; i++)
 243           {
 244             memcpy (optr, uuid + sizeof ("LVM-") - 1 + dashes[i],
 245                     dashes[i+1] - dashes[i]);
 246             optr += dashes[i+1] - dashes[i];
 247             *optr++ = '-';
 248           }
 249         optr = stpcpy (optr, uuid + sizeof ("LVM-") - 1 + dashes[i]);
 250         *optr = '\0';
 251         grub_dev[sizeof("lvmid/xxxxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx") - 1]
 252           = '/';
 253         free (uuid);
 254         return grub_dev;
 255       }
 256
 257     case GRUB_DEV_ABSTRACTION_LUKS:
 258       {
 259         char *dash;
 260
 261         dash = grub_strchr (uuid + sizeof ("CRYPT-LUKS1-") - 1, '-');
 262         if (dash)
 263           *dash = 0;
 264         grub_dev = grub_xasprintf ("cryptouuid/%s",
 265                                    uuid + sizeof ("CRYPT-LUKS1-") - 1);
 266         grub_free (uuid);
 267         return grub_dev;
 268       }
 269
 270     default:
 271       grub_free (uuid);
 272       return NULL;
 273     }
 274 }
 275
 276 char *
 277 grub_util_get_vg_uuid (const char *os_dev)
 278 {
 279   char *uuid, *vgid;
 280   int dashes[] = { 0, 6, 10, 14, 18, 22, 26, 32};
 281   unsigned i;
 282   char *optr;
 283
 284   uuid = get_dm_uuid (os_dev);
 285   if (!uuid)
 286     return NULL;
 287
 288   vgid = xmalloc (grub_strlen (uuid));
 289   optr = vgid;
 290   for (i = 0; i < ARRAY_SIZE (dashes) - 1; i++)
 291     {
 292       memcpy (optr, uuid + sizeof ("LVM-") - 1 + dashes[i],
 293               dashes[i+1] - dashes[i]);
 294       optr += dashes[i+1] - dashes[i];
 295       *optr++ = '-';
 296     }
 297   optr--;
 298   *optr = '\0';
 299   grub_free (uuid);
 300   return vgid;
 301 }
 302
 303 void
 304 grub_util_devmapper_cleanup (void)
 305 {
 306   dm_lib_release ();
 307 }
 308
 309 #else
 310 void
 311 grub_util_pull_devmapper (const char *os_dev __attribute__ ((unused)))
 312 {
 313   return;
 314 }
 315
 316 void
 317 grub_util_devmapper_cleanup (void)
 318 {
 319 }
 320
 321 enum grub_dev_abstraction_types
 322 grub_util_get_dm_abstraction (const char *os_dev __attribute__ ((unused)))
 323 {
 324   return GRUB_DEV_ABSTRACTION_NONE;
 325 }
 326
 327 char *
 328 grub_util_get_vg_uuid (const char *os_dev __attribute__ ((unused)))
 329 {
 330   return NULL;
 331 }
 332
 333 char *
 334 grub_util_devmapper_part_to_disk (struct stat *st __attribute__ ((unused)),
 335                                   int *is_part __attribute__ ((unused)),
 336                                   const char *os_dev __attribute__ ((unused)))
 337 {
 338   return NULL;
 339 }
 340
 341 char *
 342 grub_util_get_devmapper_grub_dev (const char *os_dev __attribute__ ((unused)))
 343 {
 344   return NULL;
 345 }
 346
 347 #endif