lib/utils_blkid.c

   1 /*
   2  * blkid probe utilities
   3  *
   4  * Copyright (C) 2018-2020 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 <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26
  27 #include "utils_blkid.h"
  28 #include "utils_io.h"
  29
  30 #ifdef HAVE_BLKID
  31 #include <blkid/blkid.h>
  32 /* make bad checksums flag optional */
  33 #ifndef BLKID_SUBLKS_BADCSUM
  34 #define BLKID_SUBLKS_BADCSUM 0
  35 #endif
  36 struct blkid_handle {
  37         int fd;
  38         blkid_probe pr;
  39 };
  40 #ifndef HAVE_BLKID_WIPE
  41 static size_t crypt_getpagesize(void)
  42 {
  43         long r = sysconf(_SC_PAGESIZE);
  44         return r <= 0 ? 4096 : (size_t)r;
  45 }
  46 #endif
  47 #endif
  48
  49 void blk_set_chains_for_wipes(struct blkid_handle *h)
  50 {
  51 #ifdef HAVE_BLKID
  52         blkid_probe_enable_partitions(h->pr, 1);
  53         blkid_probe_set_partitions_flags(h->pr, 0
  54 #ifdef HAVE_BLKID_WIPE
  55         | BLKID_PARTS_MAGIC
  56 #endif
  57         );
  58
  59         blkid_probe_enable_superblocks(h->pr, 1);
  60         blkid_probe_set_superblocks_flags(h->pr, BLKID_SUBLKS_LABEL   |
  61                                                  BLKID_SUBLKS_UUID    |
  62                                                  BLKID_SUBLKS_TYPE    |
  63                                                  BLKID_SUBLKS_USAGE   |
  64                                                  BLKID_SUBLKS_VERSION |
  65                                                  BLKID_SUBLKS_MAGIC   |
  66                                                  BLKID_SUBLKS_BADCSUM);
  67 #endif
  68 }
  69
  70 void blk_set_chains_for_full_print(struct blkid_handle *h)
  71 {
  72         blk_set_chains_for_wipes(h);
  73 }
  74
  75 void blk_set_chains_for_fast_detection(struct blkid_handle *h)
  76 {
  77 #ifdef HAVE_BLKID
  78         blkid_probe_enable_partitions(h->pr, 1);
  79         blkid_probe_set_partitions_flags(h->pr, 0);
  80
  81         blkid_probe_enable_superblocks(h->pr, 1);
  82         blkid_probe_set_superblocks_flags(h->pr, BLKID_SUBLKS_TYPE);
  83 #endif
  84 }
  85
  86 int blk_init_by_path(struct blkid_handle **h, const char *path)
  87 {
  88         int r = -ENOTSUP;
  89 #ifdef HAVE_BLKID
  90         struct blkid_handle *tmp = malloc(sizeof(*tmp));
  91         if (!tmp)
  92                 return -ENOMEM;
  93
  94         tmp->fd = -1;
  95
  96         tmp->pr = blkid_new_probe_from_filename(path);
  97         if (!tmp->pr) {
  98                 free(tmp);
  99                 return -EINVAL;
 100         }
 101
 102         *h = tmp;
 103
 104         r = 0;
 105 #endif
 106         return r;
 107 }
 108
 109 int blk_init_by_fd(struct blkid_handle **h, int fd)
 110 {
 111         int r = -ENOTSUP;
 112 #ifdef HAVE_BLKID
 113         struct blkid_handle *tmp = malloc(sizeof(*tmp));
 114         if (!tmp)
 115                 return -ENOMEM;
 116
 117         tmp->pr = blkid_new_probe();
 118         if (!tmp->pr) {
 119                 free(tmp);
 120                 return -EINVAL;
 121         }
 122
 123         if (blkid_probe_set_device(tmp->pr, fd, 0, 0)) {
 124                 blkid_free_probe(tmp->pr);
 125                 free(tmp);
 126                 return -EINVAL;
 127         }
 128
 129         tmp->fd = fd;
 130
 131         *h = tmp;
 132
 133         r = 0;
 134 #endif
 135         return r;
 136 }
 137
 138 int blk_superblocks_filter_luks(struct blkid_handle *h)
 139 {
 140         int r = -ENOTSUP;
 141 #ifdef HAVE_BLKID
 142         char luks[] = "crypto_LUKS";
 143         char *luks_filter[] = {
 144                 luks,
 145                 NULL
 146         };
 147         r = blkid_probe_filter_superblocks_type(h->pr, BLKID_FLTR_NOTIN, luks_filter);
 148 #endif
 149         return r;
 150 }
 151
 152 blk_probe_status blk_probe(struct blkid_handle *h)
 153 {
 154         blk_probe_status pr = PRB_FAIL;
 155 #ifdef HAVE_BLKID
 156         int r = blkid_do_probe(h->pr);
 157
 158         if (r == 0)
 159                 pr = PRB_OK;
 160         else if (r == 1)
 161                 pr = PRB_EMPTY;
 162 #endif
 163         return pr;
 164 }
 165
 166 blk_probe_status blk_safeprobe(struct blkid_handle *h)
 167 {
 168         int r = -1;
 169 #ifdef HAVE_BLKID
 170         r = blkid_do_safeprobe(h->pr);
 171 #endif
 172         switch (r) {
 173         case -2:
 174                 return PRB_AMBIGUOUS;
 175         case 1:
 176                 return PRB_EMPTY;
 177         case 0:
 178                 return PRB_OK;
 179         default:
 180                 return PRB_FAIL;
 181         }
 182 }
 183
 184 int blk_is_partition(struct blkid_handle *h)
 185 {
 186         int r = 0;
 187 #ifdef HAVE_BLKID
 188         r = blkid_probe_has_value(h->pr, "PTTYPE");
 189 #endif
 190         return r;
 191 }
 192
 193 int blk_is_superblock(struct blkid_handle *h)
 194 {
 195         int r = 0;
 196 #ifdef HAVE_BLKID
 197         r = blkid_probe_has_value(h->pr, "TYPE");
 198 #endif
 199         return r;
 200 }
 201
 202 const char *blk_get_partition_type(struct blkid_handle *h)
 203 {
 204         const char *value = NULL;
 205 #ifdef HAVE_BLKID
 206         (void) blkid_probe_lookup_value(h->pr, "PTTYPE", &value, NULL);
 207 #endif
 208         return value;
 209 }
 210
 211 const char *blk_get_superblock_type(struct blkid_handle *h)
 212 {
 213         const char *value = NULL;
 214 #ifdef HAVE_BLKID
 215         (void) blkid_probe_lookup_value(h->pr, "TYPE", &value, NULL);
 216 #endif
 217         return value;
 218 }
 219
 220 void blk_free(struct blkid_handle *h)
 221 {
 222 #ifdef HAVE_BLKID
 223         if (!h)
 224                 return;
 225
 226         if (h->pr)
 227                 blkid_free_probe(h->pr);
 228
 229         free(h);
 230 #endif
 231 }
 232
 233 #ifdef HAVE_BLKID
 234 #ifndef HAVE_BLKID_WIPE
 235 static int blk_step_back(struct blkid_handle *h)
 236 {
 237 #ifdef HAVE_BLKID_STEP_BACK
 238         return blkid_probe_step_back(h->pr);
 239 #else
 240         blkid_reset_probe(h->pr);
 241         blkid_probe_set_device(h->pr, h->fd, 0, 0);
 242         return 0;
 243 #endif
 244 }
 245 #endif /* not HAVE_BLKID_WIPE */
 246 #endif /* HAVE_BLKID */
 247
 248 int blk_do_wipe(struct blkid_handle *h)
 249 {
 250 #ifdef HAVE_BLKID
 251 #ifdef HAVE_BLKID_WIPE
 252         return blkid_do_wipe(h->pr, 0);
 253 #else
 254         const char *offset;
 255         off_t offset_val;
 256         void *buf;
 257         ssize_t ret;
 258         size_t alignment, len, bsize = blkid_probe_get_sectorsize(h->pr);
 259
 260         if (h->fd < 0 || !bsize)
 261                 return -EINVAL;
 262
 263         if (blk_is_partition(h)) {
 264                 if (blkid_probe_lookup_value(h->pr, "PTMAGIC_OFFSET", &offset, NULL))
 265                         return -EINVAL;
 266                 if (blkid_probe_lookup_value(h->pr, "PTMAGIC", NULL, &len))
 267                         return -EINVAL;
 268         } else if (blk_is_superblock(h)) {
 269                 if (blkid_probe_lookup_value(h->pr, "SBMAGIC_OFFSET", &offset, NULL))
 270                         return -EINVAL;
 271                 if (blkid_probe_lookup_value(h->pr, "SBMAGIC", NULL, &len))
 272                         return -EINVAL;
 273         } else
 274                 return 0;
 275
 276         alignment = crypt_getpagesize();
 277
 278         if (posix_memalign(&buf, alignment, len))
 279                 return -EINVAL;
 280         memset(buf, 0, len);
 281
 282         offset_val = strtoll(offset, NULL, 10);
 283
 284         /* TODO: missing crypt_wipe_fd() */
 285         ret = write_lseek_blockwise(h->fd, bsize, alignment, buf, len, offset_val);
 286         free(buf);
 287         if (ret < 0)
 288                 return -EIO;
 289
 290         if ((size_t)ret == len) {
 291                 blk_step_back(h);
 292                 return 0;
 293         }
 294
 295         return -EIO;
 296 #endif
 297 #else /* HAVE_BLKID */
 298         return -ENOTSUP;
 299 #endif
 300 }
 301
 302 int blk_supported(void)
 303 {
 304         int r = 0;
 305 #ifdef HAVE_BLKID
 306         r = 1;
 307 #endif
 308         return r;
 309 }
 310
 311 off_t blk_get_offset(struct blkid_handle *h)
 312 {
 313         off_t offset_value = -1;
 314 #ifdef HAVE_BLKID
 315         const char *offset;
 316         if (blk_is_superblock(h)) {
 317                 if (!blkid_probe_lookup_value(h->pr, "SBMAGIC_OFFSET", &offset, NULL))
 318                         offset_value = strtoll(offset, NULL, 10);
 319         } else if (blk_is_partition(h) && !blkid_probe_lookup_value(h->pr, "PTMAGIC_OFFSET", &offset, NULL))
 320                 offset_value = strtoll(offset, NULL, 10);
 321 #endif
 322         return offset_value;
 323 }