src/shared/bootspec.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2017 Zbigniew Jędrzejewski-Szmek
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <stdio.h>
  21 #include <linux/magic.h>
  22
  23 #include "sd-id128.h"
  24
  25 #include "alloc-util.h"
  26 #include "blkid-util.h"
  27 #include "bootspec.h"
  28 #include "conf-files.h"
  29 #include "def.h"
  30 #include "device-nodes.h"
  31 #include "efivars.h"
  32 #include "fd-util.h"
  33 #include "fileio.h"
  34 #include "parse-util.h"
  35 #include "stat-util.h"
  36 #include "string-util.h"
  37 #include "strv.h"
  38 #include "virt.h"
  39
  40 void boot_entry_free(BootEntry *entry) {
  41         assert(entry);
  42
  43         free(entry->filename);
  44         free(entry->title);
  45         free(entry->show_title);
  46         free(entry->version);
  47         free(entry->machine_id);
  48         free(entry->architecture);
  49         strv_free(entry->options);
  50         free(entry->kernel);
  51         free(entry->efi);
  52         strv_free(entry->initrd);
  53         free(entry->device_tree);
  54 }
  55
  56 int boot_entry_load(const char *path, BootEntry *entry) {
  57         _cleanup_(boot_entry_free) BootEntry tmp = {};
  58         _cleanup_fclose_ FILE *f = NULL;
  59         unsigned line = 1;
  60         char *b, *c;
  61         int r;
  62
  63         assert(path);
  64         assert(entry);
  65
  66         c = endswith_no_case(path, ".conf");
  67         if (!c) {
  68                 log_error("Invalid loader entry filename: %s", path);
  69                 return -EINVAL;
  70         }
  71
  72         b = basename(path);
  73         tmp.filename = strndup(b, c - b);
  74         if (!tmp.filename)
  75                 return log_oom();
  76
  77         f = fopen(path, "re");
  78         if (!f)
  79                 return log_error_errno(errno, "Failed to open \"%s\": %m", path);
  80
  81         for (;;) {
  82                 _cleanup_free_ char *buf = NULL;
  83                 char *p;
  84
  85                 r = read_line(f, LONG_LINE_MAX, &buf);
  86                 if (r == 0)
  87                         break;
  88                 if (r == -ENOBUFS)
  89                         return log_error_errno(r, "%s:%u: Line too long", path, line);
  90                 if (r < 0)
  91                         return log_error_errno(r, "%s:%u: Error while reading: %m", path, line);
  92
  93                 line++;
  94
  95                 if (IN_SET(*strstrip(buf), '#', '\0'))
  96                         continue;
  97
  98                 p = strchr(buf, ' ');
  99                 if (!p) {
 100                         log_warning("%s:%u: Bad syntax", path, line);
 101                         continue;
 102                 }
 103                 *p = '\0';
 104                 p = strstrip(p + 1);
 105
 106                 if (streq(buf, "title"))
 107                         r = free_and_strdup(&tmp.title, p);
 108                 else if (streq(buf, "version"))
 109                         r = free_and_strdup(&tmp.version, p);
 110                 else if (streq(buf, "machine-id"))
 111                         r = free_and_strdup(&tmp.machine_id, p);
 112                 else if (streq(buf, "architecture"))
 113                         r = free_and_strdup(&tmp.architecture, p);
 114                 else if (streq(buf, "options"))
 115                         r = strv_extend(&tmp.options, p);
 116                 else if (streq(buf, "linux"))
 117                         r = free_and_strdup(&tmp.kernel, p);
 118                 else if (streq(buf, "efi"))
 119                         r = free_and_strdup(&tmp.efi, p);
 120                 else if (streq(buf, "initrd"))
 121                         r = strv_extend(&tmp.initrd, p);
 122                 else if (streq(buf, "devicetree"))
 123                         r = free_and_strdup(&tmp.device_tree, p);
 124                 else {
 125                         log_notice("%s:%u: Unknown line \"%s\"", path, line, buf);
 126                         continue;
 127                 }
 128                 if (r < 0)
 129                         return log_error_errno(r, "%s:%u: Error while reading: %m", path, line);
 130         }
 131
 132         *entry = tmp;
 133         tmp = (BootEntry) {};
 134         return 0;
 135 }
 136
 137 void boot_config_free(BootConfig *config) {
 138         unsigned i;
 139
 140         assert(config);
 141
 142         free(config->default_pattern);
 143         free(config->timeout);
 144         free(config->editor);
 145         free(config->auto_entries);
 146         free(config->auto_firmware);
 147
 148         free(config->entry_oneshot);
 149         free(config->entry_default);
 150
 151         for (i = 0; i < config->n_entries; i++)
 152                 boot_entry_free(config->entries + i);
 153         free(config->entries);
 154 }
 155
 156 int boot_loader_read_conf(const char *path, BootConfig *config) {
 157         _cleanup_fclose_ FILE *f = NULL;
 158         unsigned line = 1;
 159         int r;
 160
 161         assert(path);
 162         assert(config);
 163
 164         f = fopen(path, "re");
 165         if (!f)
 166                 return log_error_errno(errno, "Failed to open \"%s\": %m", path);
 167
 168         for (;;) {
 169                 _cleanup_free_ char *buf = NULL;
 170                 char *p;
 171
 172                 r = read_line(f, LONG_LINE_MAX, &buf);
 173                 if (r == 0)
 174                         break;
 175                 if (r == -ENOBUFS)
 176                         return log_error_errno(r, "%s:%u: Line too long", path, line);
 177                 if (r < 0)
 178                         return log_error_errno(r, "%s:%u: Error while reading: %m", path, line);
 179
 180                 line++;
 181
 182                 if (IN_SET(*strstrip(buf), '#', '\0'))
 183                         continue;
 184
 185                 p = strchr(buf, ' ');
 186                 if (!p) {
 187                         log_warning("%s:%u: Bad syntax", path, line);
 188                         continue;
 189                 }
 190                 *p = '\0';
 191                 p = strstrip(p + 1);
 192
 193                 if (streq(buf, "default"))
 194                         r = free_and_strdup(&config->default_pattern, p);
 195                 else if (streq(buf, "timeout"))
 196                         r = free_and_strdup(&config->timeout, p);
 197                 else if (streq(buf, "editor"))
 198                         r = free_and_strdup(&config->editor, p);
 199                 else if (streq(buf, "auto-entries"))
 200                         r = free_and_strdup(&config->auto_entries, p);
 201                 else if (streq(buf, "auto-firmware"))
 202                         r = free_and_strdup(&config->auto_firmware, p);
 203                 else {
 204                         log_notice("%s:%u: Unknown line \"%s\"", path, line, buf);
 205                         continue;
 206                 }
 207                 if (r < 0)
 208                         return log_error_errno(r, "%s:%u: Error while reading: %m", path, line);
 209         }
 210
 211         return 0;
 212 }
 213
 214 static int boot_entry_compare(const void *a, const void *b) {
 215         const BootEntry *aa = a, *bb = b;
 216
 217         return str_verscmp(aa->filename, bb->filename);
 218 }
 219
 220 int boot_entries_find(const char *dir, BootEntry **ret_entries, size_t *ret_n_entries) {
 221         _cleanup_strv_free_ char **files = NULL;
 222         char **f;
 223         int r;
 224         BootEntry *array = NULL;
 225         size_t n_allocated = 0, n = 0;
 226
 227         assert(dir);
 228         assert(ret_entries);
 229         assert(ret_n_entries);
 230
 231         r = conf_files_list(&files, ".conf", NULL, 0, dir, NULL);
 232         if (r < 0)
 233                 return log_error_errno(r, "Failed to list files in \"%s\": %m", dir);
 234
 235         STRV_FOREACH(f, files) {
 236                 if (!GREEDY_REALLOC0(array, n_allocated, n + 1))
 237                         return log_oom();
 238
 239                 r = boot_entry_load(*f, array + n);
 240                 if (r < 0)
 241                         continue;
 242
 243                 n++;
 244         }
 245
 246         qsort_safe(array, n, sizeof(BootEntry), boot_entry_compare);
 247
 248         *ret_entries = array;
 249         *ret_n_entries = n;
 250
 251         return 0;
 252 }
 253
 254 static bool find_nonunique(BootEntry *entries, size_t n_entries, bool *arr) {
 255         unsigned i, j;
 256         bool non_unique = false;
 257
 258         assert(entries || n_entries == 0);
 259         assert(arr || n_entries == 0);
 260
 261         for (i = 0; i < n_entries; i++)
 262                 arr[i] = false;
 263
 264         for (i = 0; i < n_entries; i++)
 265                 for (j = 0; j < n_entries; j++)
 266                         if (i != j && streq(boot_entry_title(entries + i),
 267                                             boot_entry_title(entries + j)))
 268                                 non_unique = arr[i] = arr[j] = true;
 269
 270         return non_unique;
 271 }
 272
 273 static int boot_entries_uniquify(BootEntry *entries, size_t n_entries) {
 274         char *s;
 275         unsigned i;
 276         int r;
 277         bool arr[n_entries];
 278
 279         assert(entries || n_entries == 0);
 280
 281         /* Find _all_ non-unique titles */
 282         if (!find_nonunique(entries, n_entries, arr))
 283                 return 0;
 284
 285         /* Add version to non-unique titles */
 286         for (i = 0; i < n_entries; i++)
 287                 if (arr[i] && entries[i].version) {
 288                         r = asprintf(&s, "%s (%s)", boot_entry_title(entries + i), entries[i].version);
 289                         if (r < 0)
 290                                 return -ENOMEM;
 291
 292                         free_and_replace(entries[i].show_title, s);
 293                 }
 294
 295         if (!find_nonunique(entries, n_entries, arr))
 296                 return 0;
 297
 298         /* Add machine-id to non-unique titles */
 299         for (i = 0; i < n_entries; i++)
 300                 if (arr[i] && entries[i].machine_id) {
 301                         r = asprintf(&s, "%s (%s)", boot_entry_title(entries + i), entries[i].machine_id);
 302                         if (r < 0)
 303                                 return -ENOMEM;
 304
 305                         free_and_replace(entries[i].show_title, s);
 306                 }
 307
 308         if (!find_nonunique(entries, n_entries, arr))
 309                 return 0;
 310
 311         /* Add file name to non-unique titles */
 312         for (i = 0; i < n_entries; i++)
 313                 if (arr[i]) {
 314                         r = asprintf(&s, "%s (%s)", boot_entry_title(entries + i), entries[i].filename);
 315                         if (r < 0)
 316                                 return -ENOMEM;
 317
 318                         free_and_replace(entries[i].show_title, s);
 319                 }
 320
 321         return 0;
 322 }
 323
 324 static int boot_entries_select_default(const BootConfig *config) {
 325         int i;
 326
 327         assert(config);
 328
 329         if (config->entry_oneshot)
 330                 for (i = config->n_entries - 1; i >= 0; i--)
 331                         if (streq(config->entry_oneshot, config->entries[i].filename)) {
 332                                 log_debug("Found default: filename \"%s\" is matched by LoaderEntryOneShot",
 333                                           config->entries[i].filename);
 334                                 return i;
 335                         }
 336
 337         if (config->entry_default)
 338                 for (i = config->n_entries - 1; i >= 0; i--)
 339                         if (streq(config->entry_default, config->entries[i].filename)) {
 340                                 log_debug("Found default: filename \"%s\" is matched by LoaderEntryDefault",
 341                                           config->entries[i].filename);
 342                                 return i;
 343                         }
 344
 345         if (config->default_pattern)
 346                 for (i = config->n_entries - 1; i >= 0; i--)
 347                         if (fnmatch(config->default_pattern, config->entries[i].filename, FNM_CASEFOLD) == 0) {
 348                                 log_debug("Found default: filename \"%s\" is matched by pattern \"%s\"",
 349                                           config->entries[i].filename, config->default_pattern);
 350                                 return i;
 351                         }
 352
 353         if (config->n_entries > 0)
 354                 log_debug("Found default: last entry \"%s\"", config->entries[config->n_entries - 1].filename);
 355         else
 356                 log_debug("Found no default boot entry :(");
 357
 358         return config->n_entries - 1; /* -1 means "no default" */
 359 }
 360
 361 int boot_entries_load_config(const char *esp_path, BootConfig *config) {
 362         const char *p;
 363         int r;
 364
 365         assert(esp_path);
 366         assert(config);
 367
 368         p = strjoina(esp_path, "/loader/loader.conf");
 369         r = boot_loader_read_conf(p, config);
 370         if (r < 0)
 371                 return log_error_errno(r, "Failed to read boot config from \"%s\": %m", p);
 372
 373         p = strjoina(esp_path, "/loader/entries");
 374         r = boot_entries_find(p, &config->entries, &config->n_entries);
 375         if (r < 0)
 376                 return log_error_errno(r, "Failed to read boot entries from \"%s\": %m", p);
 377
 378         r = boot_entries_uniquify(config->entries, config->n_entries);
 379         if (r < 0)
 380                 return log_error_errno(r, "Failed to uniquify boot entries: %m");
 381
 382         r = efi_get_variable_string(EFI_VENDOR_LOADER, "LoaderEntryOneShot", &config->entry_oneshot);
 383         if (r < 0 && r != -ENOENT)
 384                 return log_error_errno(r, "Failed to read EFI var \"LoaderEntryOneShot\": %m");
 385
 386         r = efi_get_variable_string(EFI_VENDOR_LOADER, "LoaderEntryDefault", &config->entry_default);
 387         if (r < 0 && r != -ENOENT)
 388                 return log_error_errno(r, "Failed to read EFI var \"LoaderEntryDefault\": %m");
 389
 390         config->default_entry = boot_entries_select_default(config);
 391         return 0;
 392 }
 393
 394 /********************************************************************************/
 395
 396 static int verify_esp(
 397                 const char *p,
 398                 bool searching,
 399                 bool unprivileged_mode,
 400                 uint32_t *ret_part,
 401                 uint64_t *ret_pstart,
 402                 uint64_t *ret_psize,
 403                 sd_id128_t *ret_uuid) {
 404 #if HAVE_BLKID
 405         _cleanup_blkid_free_probe_ blkid_probe b = NULL;
 406         char t[DEV_NUM_PATH_MAX];
 407         const char *v;
 408 #endif
 409         uint64_t pstart = 0, psize = 0;
 410         struct stat st, st2;
 411         const char *t2;
 412         struct statfs sfs;
 413         sd_id128_t uuid = SD_ID128_NULL;
 414         uint32_t part = 0;
 415         int r;
 416
 417         assert(p);
 418
 419         /* Non-root user can only check the status, so if an error occured in the following, it does not cause any
 420          * issues. Let's also, silence the error messages. */
 421
 422         if (statfs(p, &sfs) < 0) {
 423                 /* If we are searching for the mount point, don't generate a log message if we can't find the path */
 424                 if (errno == ENOENT && searching)
 425                         return -ENOENT;
 426
 427                 return log_full_errno(unprivileged_mode && errno == EACCES ? LOG_DEBUG : LOG_ERR, errno,
 428                                       "Failed to check file system type of \"%s\": %m", p);
 429         }
 430
 431         if (!F_TYPE_EQUAL(sfs.f_type, MSDOS_SUPER_MAGIC)) {
 432                 if (searching)
 433                         return -EADDRNOTAVAIL;
 434
 435                 log_error("File system \"%s\" is not a FAT EFI System Partition (ESP) file system.", p);
 436                 return -ENODEV;
 437         }
 438
 439         if (stat(p, &st) < 0)
 440                 return log_full_errno(unprivileged_mode && errno == EACCES ? LOG_DEBUG : LOG_ERR, errno,
 441                                       "Failed to determine block device node of \"%s\": %m", p);
 442
 443         if (major(st.st_dev) == 0) {
 444                 log_error("Block device node of %p is invalid.", p);
 445                 return -ENODEV;
 446         }
 447
 448         t2 = strjoina(p, "/..");
 449         r = stat(t2, &st2);
 450         if (r < 0)
 451                 return log_full_errno(unprivileged_mode && errno == EACCES ? LOG_DEBUG : LOG_ERR, errno,
 452                                       "Failed to determine block device node of parent of \"%s\": %m", p);
 453
 454         if (st.st_dev == st2.st_dev) {
 455                 log_error("Directory \"%s\" is not the root of the EFI System Partition (ESP) file system.", p);
 456                 return -ENODEV;
 457         }
 458
 459         /* In a container we don't have access to block devices, skip this part of the verification, we trust the
 460          * container manager set everything up correctly on its own. Also skip the following verification for non-root user. */
 461         if (detect_container() > 0 || unprivileged_mode)
 462                 goto finish;
 463
 464 #if HAVE_BLKID
 465         xsprintf_dev_num_path(t, "block", st.st_dev);
 466         errno = 0;
 467         b = blkid_new_probe_from_filename(t);
 468         if (!b)
 469                 return log_error_errno(errno ?: ENOMEM, "Failed to open file system \"%s\": %m", p);
 470
 471         blkid_probe_enable_superblocks(b, 1);
 472         blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE);
 473         blkid_probe_enable_partitions(b, 1);
 474         blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS);
 475
 476         errno = 0;
 477         r = blkid_do_safeprobe(b);
 478         if (r == -2) {
 479                 log_error("File system \"%s\" is ambiguous.", p);
 480                 return -ENODEV;
 481         } else if (r == 1) {
 482                 log_error("File system \"%s\" does not contain a label.", p);
 483                 return -ENODEV;
 484         } else if (r != 0)
 485                 return log_error_errno(errno ?: EIO, "Failed to probe file system \"%s\": %m", p);
 486
 487         errno = 0;
 488         r = blkid_probe_lookup_value(b, "TYPE", &v, NULL);
 489         if (r != 0)
 490                 return log_error_errno(errno ?: EIO, "Failed to probe file system type \"%s\": %m", p);
 491         if (!streq(v, "vfat")) {
 492                 log_error("File system \"%s\" is not FAT.", p);
 493                 return -ENODEV;
 494         }
 495
 496         errno = 0;
 497         r = blkid_probe_lookup_value(b, "PART_ENTRY_SCHEME", &v, NULL);
 498         if (r != 0)
 499                 return log_error_errno(errno ?: EIO, "Failed to probe partition scheme \"%s\": %m", p);
 500         if (!streq(v, "gpt")) {
 501                 log_error("File system \"%s\" is not on a GPT partition table.", p);
 502                 return -ENODEV;
 503         }
 504
 505         errno = 0;
 506         r = blkid_probe_lookup_value(b, "PART_ENTRY_TYPE", &v, NULL);
 507         if (r != 0)
 508                 return log_error_errno(errno ?: EIO, "Failed to probe partition type UUID \"%s\": %m", p);
 509         if (!streq(v, "c12a7328-f81f-11d2-ba4b-00a0c93ec93b")) {
 510                 log_error("File system \"%s\" has wrong type for an EFI System Partition (ESP).", p);
 511                 return -ENODEV;
 512         }
 513
 514         errno = 0;
 515         r = blkid_probe_lookup_value(b, "PART_ENTRY_UUID", &v, NULL);
 516         if (r != 0)
 517                 return log_error_errno(errno ?: EIO, "Failed to probe partition entry UUID \"%s\": %m", p);
 518         r = sd_id128_from_string(v, &uuid);
 519         if (r < 0) {
 520                 log_error("Partition \"%s\" has invalid UUID \"%s\".", p, v);
 521                 return -EIO;
 522         }
 523
 524         errno = 0;
 525         r = blkid_probe_lookup_value(b, "PART_ENTRY_NUMBER", &v, NULL);
 526         if (r != 0)
 527                 return log_error_errno(errno ?: EIO, "Failed to probe partition number \"%s\": m", p);
 528         r = safe_atou32(v, &part);
 529         if (r < 0)
 530                 return log_error_errno(r, "Failed to parse PART_ENTRY_NUMBER field.");
 531
 532         errno = 0;
 533         r = blkid_probe_lookup_value(b, "PART_ENTRY_OFFSET", &v, NULL);
 534         if (r != 0)
 535                 return log_error_errno(errno ?: EIO, "Failed to probe partition offset \"%s\": %m", p);
 536         r = safe_atou64(v, &pstart);
 537         if (r < 0)
 538                 return log_error_errno(r, "Failed to parse PART_ENTRY_OFFSET field.");
 539
 540         errno = 0;
 541         r = blkid_probe_lookup_value(b, "PART_ENTRY_SIZE", &v, NULL);
 542         if (r != 0)
 543                 return log_error_errno(errno ?: EIO, "Failed to probe partition size \"%s\": %m", p);
 544         r = safe_atou64(v, &psize);
 545         if (r < 0)
 546                 return log_error_errno(r, "Failed to parse PART_ENTRY_SIZE field.");
 547 #endif
 548
 549 finish:
 550         if (ret_part)
 551                 *ret_part = part;
 552         if (ret_pstart)
 553                 *ret_pstart = pstart;
 554         if (ret_psize)
 555                 *ret_psize = psize;
 556         if (ret_uuid)
 557                 *ret_uuid = uuid;
 558
 559         return 0;
 560 }
 561
 562 int find_esp_and_warn(
 563                 const char *path,
 564                 bool unprivileged_mode,
 565                 char **ret_path,
 566                 uint32_t *ret_part,
 567                 uint64_t *ret_pstart,
 568                 uint64_t *ret_psize,
 569                 sd_id128_t *ret_uuid) {
 570
 571         int r;
 572
 573         /* This logs about all errors except:
 574          *
 575          *    -ENOKEY → when we can't find the partition
 576          *   -EACCESS → when unprivileged_mode is true, and we can't access something
 577          */
 578
 579         if (path) {
 580                 r = verify_esp(path, false, unprivileged_mode, ret_part, ret_pstart, ret_psize, ret_uuid);
 581                 if (r < 0)
 582                         return r;
 583
 584                 goto found;
 585         }
 586
 587         FOREACH_STRING(path, "/efi", "/boot", "/boot/efi") {
 588
 589                 r = verify_esp(path, true, unprivileged_mode, ret_part, ret_pstart, ret_psize, ret_uuid);
 590                 if (r >= 0)
 591                         goto found;
 592                 if (!IN_SET(r, -ENOENT, -EADDRNOTAVAIL)) /* This one is not it */
 593                         return r;
 594         }
 595
 596         /* No logging here */
 597         return -ENOKEY;
 598
 599 found:
 600         if (ret_path) {
 601                 char *c;
 602
 603                 c = strdup(path);
 604                 if (!c)
 605                         return log_oom();
 606
 607                 *ret_path = c;
 608         }
 609
 610         return 0;
 611 }