lib/utils_blkid.c

   1 /*
   2  * blkid probe utilities
   3  *
   4  * Copyright (C) 2018-2023 Red Hat, Inc. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <errno.h>
  22 #include <stdbool.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27
  28 #include "utils_blkid.h"
  29 #include "utils_io.h"
  30
  31 #ifdef HAVE_BLKID
  32 #include <blkid/blkid.h>
  33 /* make bad checksums flag optional */
  34 #ifndef BLKID_SUBLKS_BADCSUM
  35 #define BLKID_SUBLKS_BADCSUM 0
  36 #endif
  37 struct blkid_handle {
  38         int fd;
  39         blkid_probe pr;
  40 };
  41 #ifndef HAVE_BLKID_WIPE
  42 static size_t crypt_getpagesize(void)
  43 {
  44         long r = sysconf(_SC_PAGESIZE);
  45         return r <= 0 ? 4096 : (size_t)r;
  46 }
  47 #endif
  48 #endif
  49
  50 void blk_set_chains_for_wipes(struct blkid_handle *h)
  51 {
  52 #ifdef HAVE_BLKID
  53         blkid_probe_enable_partitions(h->pr, 1);
  54         blkid_probe_set_partitions_flags(h->pr, 0
  55 #ifdef HAVE_BLKID_WIPE
  56         | BLKID_PARTS_MAGIC
  57 #endif
  58         );
  59
  60         blkid_probe_enable_superblocks(h->pr, 1);
  61         blkid_probe_set_superblocks_flags(h->pr, BLKID_SUBLKS_LABEL   |
  62                                                  BLKID_SUBLKS_UUID    |
  63                                                  BLKID_SUBLKS_TYPE    |
  64                                                  BLKID_SUBLKS_USAGE   |
  65                                                  BLKID_SUBLKS_VERSION |
  66                                                  BLKID_SUBLKS_MAGIC   |
  67                                                  BLKID_SUBLKS_BADCSUM);
  68 #endif
  69 }
  70
  71 void blk_set_chains_for_full_print(struct blkid_handle *h)
  72 {
  73         blk_set_chains_for_wipes(h);
  74 }
  75
  76 void blk_set_chains_for_superblocks(struct blkid_handle *h)
  77 {
  78 #ifdef HAVE_BLKID
  79         blkid_probe_enable_superblocks(h->pr, 1);
  80         blkid_probe_set_superblocks_flags(h->pr, BLKID_SUBLKS_TYPE);
  81 #endif
  82 }
  83
  84 void blk_set_chains_for_fast_detection(struct blkid_handle *h)
  85 {
  86 #ifdef HAVE_BLKID
  87         blkid_probe_enable_partitions(h->pr, 1);
  88         blkid_probe_set_partitions_flags(h->pr, 0);
  89         blk_set_chains_for_superblocks(h);
  90 #endif
  91 }
  92
  93 int blk_init_by_path(struct blkid_handle **h, const char *path)
  94 {
  95         int r = -ENOTSUP;
  96 #ifdef HAVE_BLKID
  97         struct blkid_handle *tmp = malloc(sizeof(*tmp));
  98         if (!tmp)
  99                 return -ENOMEM;
 100
 101         tmp->fd = -1;
 102
 103         tmp->pr = blkid_new_probe_from_filename(path);
 104         if (!tmp->pr) {
 105                 free(tmp);
 106                 return -EINVAL;
 107         }
 108
 109         *h = tmp;
 110
 111         r = 0;
 112 #endif
 113         return r;
 114 }
 115
 116 int blk_init_by_fd(struct blkid_handle **h, int fd)
 117 {
 118         int r = -ENOTSUP;
 119 #ifdef HAVE_BLKID
 120         struct blkid_handle *tmp = malloc(sizeof(*tmp));
 121         if (!tmp)
 122                 return -ENOMEM;
 123
 124         tmp->pr = blkid_new_probe();
 125         if (!tmp->pr) {
 126                 free(tmp);
 127                 return -EINVAL;
 128         }
 129
 130         if (blkid_probe_set_device(tmp->pr, fd, 0, 0)) {
 131                 blkid_free_probe(tmp->pr);
 132                 free(tmp);
 133                 return -EINVAL;
 134         }
 135
 136         tmp->fd = fd;
 137
 138         *h = tmp;
 139
 140         r = 0;
 141 #endif
 142         return r;
 143 }
 144
 145 #ifdef HAVE_BLKID
 146 static int blk_superblocks_luks(struct blkid_handle *h, bool enable)
 147 {
 148         char luks[] = "crypto_LUKS";
 149         char *luks_filter[] = {
 150                 luks,
 151                 NULL
 152         };
 153         return blkid_probe_filter_superblocks_type(h->pr,
 154                         enable ? BLKID_FLTR_ONLYIN : BLKID_FLTR_NOTIN,
 155                         luks_filter);
 156 }
 157 #endif
 158
 159 int blk_superblocks_filter_luks(struct blkid_handle *h)
 160 {
 161         int r = -ENOTSUP;
 162 #ifdef HAVE_BLKID
 163         r = blk_superblocks_luks(h, false);
 164 #endif
 165         return r;
 166 }
 167
 168 int blk_superblocks_only_luks(struct blkid_handle *h)
 169 {
 170         int r = -ENOTSUP;
 171 #ifdef HAVE_BLKID
 172         r = blk_superblocks_luks(h, true);
 173 #endif
 174         return r;
 175 }
 176
 177 blk_probe_status blk_probe(struct blkid_handle *h)
 178 {
 179         blk_probe_status pr = PRB_FAIL;
 180 #ifdef HAVE_BLKID
 181         int r = blkid_do_probe(h->pr);
 182
 183         if (r == 0)
 184                 pr = PRB_OK;
 185         else if (r == 1)
 186                 pr = PRB_EMPTY;
 187 #endif
 188         return pr;
 189 }
 190
 191 blk_probe_status blk_safeprobe(struct blkid_handle *h)
 192 {
 193         int r = -1;
 194 #ifdef HAVE_BLKID
 195         r = blkid_do_safeprobe(h->pr);
 196 #endif
 197         switch (r) {
 198         case -2:
 199                 return PRB_AMBIGUOUS;
 200         case 1:
 201                 return PRB_EMPTY;
 202         case 0:
 203                 return PRB_OK;
 204         default:
 205                 return PRB_FAIL;
 206         }
 207 }
 208
 209 int blk_is_partition(struct blkid_handle *h)
 210 {
 211         int r = 0;
 212 #ifdef HAVE_BLKID
 213         r = blkid_probe_has_value(h->pr, "PTTYPE");
 214 #endif
 215         return r;
 216 }
 217
 218 int blk_is_superblock(struct blkid_handle *h)
 219 {
 220         int r = 0;
 221 #ifdef HAVE_BLKID
 222         r = blkid_probe_has_value(h->pr, "TYPE");
 223 #endif
 224         return r;
 225 }
 226
 227 const char *blk_get_partition_type(struct blkid_handle *h)
 228 {
 229         const char *value = NULL;
 230 #ifdef HAVE_BLKID
 231         (void) blkid_probe_lookup_value(h->pr, "PTTYPE", &value, NULL);
 232 #endif
 233         return value;
 234 }
 235
 236 const char *blk_get_superblock_type(struct blkid_handle *h)
 237 {
 238         const char *value = NULL;
 239 #ifdef HAVE_BLKID
 240         (void) blkid_probe_lookup_value(h->pr, "TYPE", &value, NULL);
 241 #endif
 242         return value;
 243 }
 244
 245 void blk_free(struct blkid_handle *h)
 246 {
 247 #ifdef HAVE_BLKID
 248         if (!h)
 249                 return;
 250
 251         if (h->pr)
 252                 blkid_free_probe(h->pr);
 253
 254         free(h);
 255 #endif
 256 }
 257
 258 #ifdef HAVE_BLKID
 259 #ifndef HAVE_BLKID_WIPE
 260 static int blk_step_back(struct blkid_handle *h)
 261 {
 262 #ifdef HAVE_BLKID_STEP_BACK
 263         return blkid_probe_step_back(h->pr);
 264 #else
 265         blkid_reset_probe(h->pr);
 266         blkid_probe_set_device(h->pr, h->fd, 0, 0);
 267         return 0;
 268 #endif
 269 }
 270 #endif /* not HAVE_BLKID_WIPE */
 271 #endif /* HAVE_BLKID */
 272
 273 int blk_do_wipe(struct blkid_handle *h)
 274 {
 275 #ifdef HAVE_BLKID
 276 #ifdef HAVE_BLKID_WIPE
 277         return blkid_do_wipe(h->pr, 0);
 278 #else
 279         const char *offset;
 280         off_t offset_val;
 281         void *buf;
 282         ssize_t ret;
 283         size_t alignment, len, bsize = blkid_probe_get_sectorsize(h->pr);
 284
 285         if (h->fd < 0 || !bsize)
 286                 return -EINVAL;
 287
 288         if (blk_is_partition(h)) {
 289                 if (blkid_probe_lookup_value(h->pr, "PTMAGIC_OFFSET", &offset, NULL))
 290                         return -EINVAL;
 291                 if (blkid_probe_lookup_value(h->pr, "PTMAGIC", NULL, &len))
 292                         return -EINVAL;
 293         } else if (blk_is_superblock(h)) {
 294                 if (blkid_probe_lookup_value(h->pr, "SBMAGIC_OFFSET", &offset, NULL))
 295                         return -EINVAL;
 296                 if (blkid_probe_lookup_value(h->pr, "SBMAGIC", NULL, &len))
 297                         return -EINVAL;
 298         } else
 299                 return 0;
 300
 301         alignment = crypt_getpagesize();
 302
 303         if (posix_memalign(&buf, alignment, len))
 304                 return -EINVAL;
 305         memset(buf, 0, len);
 306
 307         offset_val = strtoll(offset, NULL, 10);
 308
 309         /* TODO: missing crypt_wipe_fd() */
 310         ret = write_lseek_blockwise(h->fd, bsize, alignment, buf, len, offset_val);
 311         free(buf);
 312         if (ret < 0)
 313                 return -EIO;
 314
 315         if ((size_t)ret == len) {
 316                 blk_step_back(h);
 317                 return 0;
 318         }
 319
 320         return -EIO;
 321 #endif
 322 #else /* HAVE_BLKID */
 323         return -ENOTSUP;
 324 #endif
 325 }
 326
 327 int blk_supported(void)
 328 {
 329         int r = 0;
 330 #ifdef HAVE_BLKID
 331         r = 1;
 332 #endif
 333         return r;
 334 }
 335
 336 unsigned blk_get_block_size(struct blkid_handle *h)
 337 {
 338         unsigned block_size = 0;
 339 #ifdef HAVE_BLKID
 340         const char *data;
 341         if (!blk_is_superblock(h) || !blkid_probe_has_value(h->pr, "BLOCK_SIZE") ||
 342             blkid_probe_lookup_value(h->pr, "BLOCK_SIZE", &data, NULL) ||
 343             sscanf(data, "%u", &block_size) != 1)
 344                 block_size = 0;
 345 #endif
 346         return block_size;
 347 }