src/shared/hwdb-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <ctype.h>
   4 #include <stdio.h>
   5 #include <sys/stat.h>
   6
   7 #include "alloc-util.h"
   8 #include "conf-files.h"
   9 #include "env-util.h"
  10 #include "fd-util.h"
  11 #include "fileio.h"
  12 #include "fs-util.h"
  13 #include "hwdb-internal.h"
  14 #include "hwdb-util.h"
  15 #include "label-util.h"
  16 #include "mkdir-label.h"
  17 #include "nulstr-util.h"
  18 #include "path-util.h"
  19 #include "sort-util.h"
  20 #include "strbuf.h"
  21 #include "string-util.h"
  22 #include "strv.h"
  23 #include "tmpfile-util.h"
  24
  25 static const char* const conf_file_dirs[] = {
  26         "/etc/udev/hwdb.d",
  27         UDEVLIBEXECDIR "/hwdb.d",
  28         NULL
  29 };
  30
  31 /*
  32  * Generic udev properties, key-value database based on modalias strings.
  33  * Uses a Patricia/radix trie to index all matches for efficient lookup.
  34  */
  35
  36 /* in-memory trie objects */
  37 struct trie {
  38         struct trie_node *root;
  39         struct strbuf *strings;
  40
  41         size_t nodes_count;
  42         size_t children_count;
  43         size_t values_count;
  44 };
  45
  46 struct trie_node {
  47         /* prefix, common part for all children of this node */
  48         size_t prefix_off;
  49
  50         /* sorted array of pointers to children nodes */
  51         struct trie_child_entry *children;
  52         uint8_t children_count;
  53
  54         /* sorted array of key-value pairs */
  55         struct trie_value_entry *values;
  56         size_t values_count;
  57 };
  58
  59 /* children array item with char (0-255) index */
  60 struct trie_child_entry {
  61         uint8_t c;
  62         struct trie_node *child;
  63 };
  64
  65 /* value array item with key-value pairs */
  66 struct trie_value_entry {
  67         size_t key_off;
  68         size_t value_off;
  69         size_t filename_off;
  70         uint32_t line_number;
  71         uint16_t file_priority;
  72 };
  73
  74 static int trie_children_cmp(const struct trie_child_entry *a, const struct trie_child_entry *b) {
  75         return CMP(a->c, b->c);
  76 }
  77
  78 static int node_add_child(struct trie *trie, struct trie_node *node, struct trie_node *node_child, uint8_t c) {
  79         struct trie_child_entry *child;
  80
  81         /* extend array, add new entry, sort for bisection */
  82         child = reallocarray(node->children, node->children_count + 1, sizeof(struct trie_child_entry));
  83         if (!child)
  84                 return -ENOMEM;
  85
  86         node->children = child;
  87         trie->children_count++;
  88         node->children[node->children_count].c = c;
  89         node->children[node->children_count].child = node_child;
  90         node->children_count++;
  91         typesafe_qsort(node->children, node->children_count, trie_children_cmp);
  92         trie->nodes_count++;
  93
  94         return 0;
  95 }
  96
  97 static struct trie_node *node_lookup(const struct trie_node *node, uint8_t c) {
  98         struct trie_child_entry *child;
  99         struct trie_child_entry search;
 100
 101         search.c = c;
 102         child = typesafe_bsearch(&search, node->children, node->children_count, trie_children_cmp);
 103         if (child)
 104                 return child->child;
 105         return NULL;
 106 }
 107
 108 static void trie_node_cleanup(struct trie_node *node) {
 109         if (!node)
 110                 return;
 111
 112         for (size_t i = 0; i < node->children_count; i++)
 113                 trie_node_cleanup(node->children[i].child);
 114         free(node->children);
 115         free(node->values);
 116         free(node);
 117 }
 118
 119 static struct trie* trie_free(struct trie *trie) {
 120         if (!trie)
 121                 return NULL;
 122
 123         trie_node_cleanup(trie->root);
 124         strbuf_free(trie->strings);
 125         return mfree(trie);
 126 }
 127
 128 DEFINE_TRIVIAL_CLEANUP_FUNC(struct trie*, trie_free);
 129
 130 static int trie_values_cmp(const struct trie_value_entry *a, const struct trie_value_entry *b, struct trie *trie) {
 131         return strcmp(trie->strings->buf + a->key_off,
 132                       trie->strings->buf + b->key_off);
 133 }
 134
 135 static int trie_node_add_value(struct trie *trie, struct trie_node *node,
 136                                const char *key, const char *value,
 137                                const char *filename, uint16_t file_priority, uint32_t line_number, bool compat) {
 138         ssize_t k, v, fn = 0;
 139         struct trie_value_entry *val;
 140
 141         k = strbuf_add_string(trie->strings, key, strlen(key));
 142         if (k < 0)
 143                 return k;
 144         v = strbuf_add_string(trie->strings, value, strlen(value));
 145         if (v < 0)
 146                 return v;
 147
 148         if (!compat) {
 149                 fn = strbuf_add_string(trie->strings, filename, strlen(filename));
 150                 if (fn < 0)
 151                         return fn;
 152         }
 153
 154         if (node->values_count) {
 155                 struct trie_value_entry search = {
 156                         .key_off = k,
 157                         .value_off = v,
 158                 };
 159
 160                 val = typesafe_bsearch_r(&search, node->values, node->values_count, trie_values_cmp, trie);
 161                 if (val) {
 162                         /* At this point we have 2 identical properties on the same match-string.
 163                          * Since we process files in order, we just replace the previous value. */
 164                         val->value_off = v;
 165                         val->filename_off = fn;
 166                         val->file_priority = file_priority;
 167                         val->line_number = line_number;
 168                         return 0;
 169                 }
 170         }
 171
 172         /* extend array, add new entry, sort for bisection */
 173         val = reallocarray(node->values, node->values_count + 1, sizeof(struct trie_value_entry));
 174         if (!val)
 175                 return -ENOMEM;
 176         trie->values_count++;
 177         node->values = val;
 178         node->values[node->values_count] = (struct trie_value_entry) {
 179                 .key_off = k,
 180                 .value_off = v,
 181                 .filename_off = fn,
 182                 .file_priority = file_priority,
 183                 .line_number = line_number,
 184         };
 185         node->values_count++;
 186         typesafe_qsort_r(node->values, node->values_count, trie_values_cmp, trie);
 187         return 0;
 188 }
 189
 190 static int trie_insert(struct trie *trie, struct trie_node *node, const char *search,
 191                        const char *key, const char *value,
 192                        const char *filename, uint16_t file_priority, uint32_t line_number, bool compat) {
 193         int r = 0;
 194
 195         for (size_t i = 0;; i++) {
 196                 size_t p;
 197                 char c;
 198                 struct trie_node *child;
 199
 200                 for (p = 0; (c = trie->strings->buf[node->prefix_off + p]); p++) {
 201                         _cleanup_free_ struct trie_node *new_child = NULL;
 202                         _cleanup_free_ char *s = NULL;
 203                         ssize_t off;
 204
 205                         if (c == search[i + p])
 206                                 continue;
 207
 208                         /* split node */
 209                         new_child = new(struct trie_node, 1);
 210                         if (!new_child)
 211                                 return -ENOMEM;
 212
 213                         /* move values from parent to child */
 214                         *new_child = (struct trie_node) {
 215                                 .prefix_off = node->prefix_off + p+1,
 216                                 .children = node->children,
 217                                 .children_count = node->children_count,
 218                                 .values = node->values,
 219                                 .values_count = node->values_count,
 220                         };
 221
 222                         /* update parent; use strdup() because the source gets realloc()d */
 223                         s = strndup(trie->strings->buf + node->prefix_off, p);
 224                         if (!s)
 225                                 return -ENOMEM;
 226
 227                         off = strbuf_add_string(trie->strings, s, p);
 228                         if (off < 0)
 229                                 return off;
 230
 231                         *node = (struct trie_node) {
 232                                 .prefix_off = off,
 233                         };
 234                         r = node_add_child(trie, node, new_child, c);
 235                         if (r < 0)
 236                                 return r;
 237
 238                         new_child = NULL; /* avoid cleanup */
 239                         break;
 240                 }
 241                 i += p;
 242
 243                 c = search[i];
 244                 if (c == '\0')
 245                         return trie_node_add_value(trie, node, key, value, filename, file_priority, line_number, compat);
 246
 247                 child = node_lookup(node, c);
 248                 if (!child) {
 249                         _cleanup_free_ struct trie_node *new_child = NULL;
 250                         ssize_t off;
 251
 252                         /* new child */
 253                         new_child = new(struct trie_node, 1);
 254                         if (!new_child)
 255                                 return -ENOMEM;
 256
 257                         off = strbuf_add_string(trie->strings, search + i+1, strlen(search + i+1));
 258                         if (off < 0)
 259                                 return off;
 260
 261                         *new_child = (struct trie_node) {
 262                                 .prefix_off = off,
 263                         };
 264
 265                         r = node_add_child(trie, node, new_child, c);
 266                         if (r < 0)
 267                                 return r;
 268
 269                         child = TAKE_PTR(new_child);
 270                         return trie_node_add_value(trie, child, key, value, filename, file_priority, line_number, compat);
 271                 }
 272
 273                 node = child;
 274         }
 275 }
 276
 277 struct trie_f {
 278         struct trie *trie;
 279         uint64_t strings_off;
 280
 281         uint64_t nodes_count;
 282         uint64_t children_count;
 283         uint64_t values_count;
 284 };
 285
 286 /* calculate the storage space for the nodes, children arrays, value arrays */
 287 static void trie_store_nodes_size(struct trie_f *trie, struct trie_node *node, bool compat) {
 288         for (uint64_t i = 0; i < node->children_count; i++)
 289                 trie_store_nodes_size(trie, node->children[i].child, compat);
 290
 291         trie->strings_off += sizeof(struct trie_node_f);
 292         for (uint64_t i = 0; i < node->children_count; i++)
 293                 trie->strings_off += sizeof(struct trie_child_entry_f);
 294         for (uint64_t i = 0; i < node->values_count; i++)
 295                 trie->strings_off += compat ? sizeof(struct trie_value_entry_f) : sizeof(struct trie_value_entry2_f);
 296 }
 297
 298 static int64_t trie_store_nodes(struct trie_f *trie, FILE *f, struct trie_node *node, bool compat) {
 299         _cleanup_free_ struct trie_child_entry_f *children = NULL;
 300         int64_t node_off;
 301
 302         assert(trie);
 303         assert(f);
 304         assert(node);
 305
 306         if (node->children_count) {
 307                 children = new(struct trie_child_entry_f, node->children_count);
 308                 if (!children)
 309                         return -ENOMEM;
 310         }
 311
 312         /* post-order recursion */
 313         for (uint64_t i = 0; i < node->children_count; i++) {
 314                 int64_t child_off;
 315
 316                 child_off = trie_store_nodes(trie, f, node->children[i].child, compat);
 317                 if (child_off < 0)
 318                         return child_off;
 319
 320                 children[i] = (struct trie_child_entry_f) {
 321                         .c = node->children[i].c,
 322                         .child_off = htole64(child_off),
 323                 };
 324         }
 325
 326         struct trie_node_f n = {
 327                 .prefix_off = htole64(trie->strings_off + node->prefix_off),
 328                 .children_count = node->children_count,
 329                 .values_count = htole64(node->values_count),
 330         };
 331
 332         /* write node */
 333         node_off = ftello(f);
 334         fwrite(&n, sizeof(struct trie_node_f), 1, f);
 335         trie->nodes_count++;
 336
 337         /* append children array */
 338         if (node->children_count) {
 339                 fwrite(children, sizeof(struct trie_child_entry_f), node->children_count, f);
 340                 trie->children_count += node->children_count;
 341         }
 342
 343         /* append values array */
 344         for (uint64_t i = 0; i < node->values_count; i++) {
 345                 struct trie_value_entry2_f v = {
 346                         .key_off = htole64(trie->strings_off + node->values[i].key_off),
 347                         .value_off = htole64(trie->strings_off + node->values[i].value_off),
 348                         .filename_off = htole64(trie->strings_off + node->values[i].filename_off),
 349                         .line_number = htole32(node->values[i].line_number),
 350                         .file_priority = htole16(node->values[i].file_priority),
 351                 };
 352
 353                 fwrite(&v, compat ? sizeof(struct trie_value_entry_f) : sizeof(struct trie_value_entry2_f), 1, f);
 354         }
 355         trie->values_count += node->values_count;
 356
 357         return node_off;
 358 }
 359
 360 static int trie_store(struct trie *trie, const char *filename, bool compat) {
 361         struct trie_f t = {
 362                 .trie = trie,
 363                 .strings_off = sizeof(struct trie_header_f),
 364         };
 365         _cleanup_(unlink_and_freep) char *filename_tmp = NULL;
 366         _cleanup_fclose_ FILE *f = NULL;
 367         int64_t pos, root_off, size;
 368         int r;
 369
 370         assert(trie);
 371         assert(filename);
 372
 373         /* calculate size of header, nodes, children entries, value entries */
 374         trie_store_nodes_size(&t, trie->root, compat);
 375
 376         r = fopen_tmpfile_linkable(filename, O_WRONLY|O_CLOEXEC, &filename_tmp, &f);
 377         if (r < 0)
 378                 return r;
 379
 380         if (fchmod(fileno(f), 0444) < 0)
 381                 return -errno;
 382
 383         struct trie_header_f h = {
 384                 .signature = HWDB_SIG,
 385                 .tool_version = htole64(PROJECT_VERSION),
 386                 .header_size = htole64(sizeof(struct trie_header_f)),
 387                 .node_size = htole64(sizeof(struct trie_node_f)),
 388                 .child_entry_size = htole64(sizeof(struct trie_child_entry_f)),
 389                 .value_entry_size = htole64(compat ? sizeof(struct trie_value_entry_f) : sizeof(struct trie_value_entry2_f)),
 390         };
 391
 392         /* write nodes */
 393         if (fseeko(f, sizeof(struct trie_header_f), SEEK_SET) < 0)
 394                 return -errno;
 395
 396         root_off = trie_store_nodes(&t, f, trie->root, compat);
 397         h.nodes_root_off = htole64(root_off);
 398         pos = ftello(f);
 399         h.nodes_len = htole64(pos - sizeof(struct trie_header_f));
 400
 401         /* write string buffer */
 402         fwrite(trie->strings->buf, trie->strings->len, 1, f);
 403         h.strings_len = htole64(trie->strings->len);
 404
 405         /* write header */
 406         size = ftello(f);
 407         h.file_size = htole64(size);
 408         if (fseeko(f, 0, SEEK_SET) < 0)
 409                 return -errno;
 410         fwrite(&h, sizeof(struct trie_header_f), 1, f);
 411
 412         r = flink_tmpfile(f, filename_tmp, filename, LINK_TMPFILE_REPLACE|LINK_TMPFILE_SYNC);
 413         if (r < 0)
 414                 return r;
 415
 416         /* write succeeded */
 417
 418         log_debug("=== trie on-disk ===");
 419         log_debug("size:             %8"PRIi64" bytes", size);
 420         log_debug("header:           %8zu bytes", sizeof(struct trie_header_f));
 421         log_debug("nodes:            %8"PRIu64" bytes (%8"PRIu64")",
 422                   t.nodes_count * sizeof(struct trie_node_f), t.nodes_count);
 423         log_debug("child pointers:   %8"PRIu64" bytes (%8"PRIu64")",
 424                   t.children_count * sizeof(struct trie_child_entry_f), t.children_count);
 425         log_debug("value pointers:   %8"PRIu64" bytes (%8"PRIu64")",
 426                   t.values_count * (compat ? sizeof(struct trie_value_entry_f) : sizeof(struct trie_value_entry2_f)), t.values_count);
 427         log_debug("string store:     %8zu bytes", trie->strings->len);
 428         log_debug("strings start:    %8"PRIu64, t.strings_off);
 429         return 0;
 430 }
 431
 432 static int insert_data(struct trie *trie, char **match_list, char *line, const char *filename,
 433                        uint16_t file_priority, uint32_t line_number, bool compat) {
 434         char *value;
 435
 436         assert(line[0] == ' ');
 437
 438         value = strchr(line, '=');
 439         if (!value)
 440                 return log_syntax(NULL, LOG_WARNING, filename, line_number, SYNTHETIC_ERRNO(EINVAL),
 441                                   "Key-value pair expected but got \"%s\", ignoring.", line);
 442
 443         value[0] = '\0';
 444         value++;
 445
 446         /* Replace multiple leading spaces by a single space */
 447         while (isblank(line[0]) && isblank(line[1]))
 448                 line++;
 449
 450         if (isempty(line + 1))
 451                 return log_syntax(NULL, LOG_WARNING, filename, line_number, SYNTHETIC_ERRNO(EINVAL),
 452                                   "Empty key in \"%s=%s\", ignoring.",
 453                                   line, value);
 454
 455         STRV_FOREACH(entry, match_list)
 456                 trie_insert(trie, trie->root, *entry, line, value, filename, file_priority, line_number, compat);
 457
 458         return 0;
 459 }
 460
 461 static int import_file(struct trie *trie, const char *filename, uint16_t file_priority, bool compat) {
 462         enum {
 463                 HW_NONE,
 464                 HW_MATCH,
 465                 HW_DATA,
 466         } state = HW_NONE;
 467         _cleanup_fclose_ FILE *f = NULL;
 468         _cleanup_strv_free_ char **match_list = NULL;
 469         uint32_t line_number = 0;
 470         int r, err;
 471
 472         f = fopen(filename, "re");
 473         if (!f)
 474                 return -errno;
 475
 476         for (;;) {
 477                 _cleanup_free_ char *line = NULL;
 478                 size_t len;
 479                 char *pos;
 480
 481                 r = read_line_full(f, LONG_LINE_MAX, READ_LINE_NOT_A_TTY, &line);
 482                 if (r < 0)
 483                         return r;
 484                 if (r == 0)
 485                         break;
 486
 487                 line_number++;
 488
 489                 /* comment line */
 490                 if (line[0] == '#')
 491                         continue;
 492
 493                 /* strip trailing comment */
 494                 pos = strchr(line, '#');
 495                 if (pos)
 496                         pos[0] = '\0';
 497
 498                 /* strip trailing whitespace */
 499                 len = strlen(line);
 500                 while (len > 0 && isspace(line[len-1]))
 501                         len--;
 502                 line[len] = '\0';
 503
 504                 switch (state) {
 505                 case HW_NONE:
 506                         if (len == 0)
 507                                 break;
 508
 509                         if (line[0] == ' ') {
 510                                 r = log_syntax(NULL, LOG_WARNING, filename, line_number, SYNTHETIC_ERRNO(EINVAL),
 511                                                "Match expected but got indented property \"%s\", ignoring line.", line);
 512                                 break;
 513                         }
 514
 515                         /* start of record, first match */
 516                         state = HW_MATCH;
 517
 518                         err = strv_extend(&match_list, line);
 519                         if (err < 0)
 520                                 return err;
 521
 522                         break;
 523
 524                 case HW_MATCH:
 525                         if (len == 0) {
 526                                 r = log_syntax(NULL, LOG_WARNING, filename, line_number, SYNTHETIC_ERRNO(EINVAL),
 527                                                "Property expected, ignoring record with no properties.");
 528                                 state = HW_NONE;
 529                                 match_list = strv_free(match_list);
 530                                 break;
 531                         }
 532
 533                         if (line[0] != ' ') {
 534                                 /* another match */
 535                                 err = strv_extend(&match_list, line);
 536                                 if (err < 0)
 537                                         return err;
 538
 539                                 break;
 540                         }
 541
 542                         /* first data */
 543                         state = HW_DATA;
 544                         err = insert_data(trie, match_list, line, filename, file_priority, line_number, compat);
 545                         if (err < 0)
 546                                 r = err;
 547                         break;
 548
 549                 case HW_DATA:
 550                         if (len == 0) {
 551                                 /* end of record */
 552                                 state = HW_NONE;
 553                                 match_list = strv_free(match_list);
 554                                 break;
 555                         }
 556
 557                         if (line[0] != ' ') {
 558                                 r = log_syntax(NULL, LOG_WARNING, filename, line_number, SYNTHETIC_ERRNO(EINVAL),
 559                                                "Property or empty line expected, got \"%s\", ignoring record.", line);
 560                                 state = HW_NONE;
 561                                 match_list = strv_free(match_list);
 562                                 break;
 563                         }
 564
 565                         err = insert_data(trie, match_list, line, filename, file_priority, line_number, compat);
 566                         if (err < 0)
 567                                 r = err;
 568                         break;
 569                 };
 570         }
 571
 572         if (state == HW_MATCH)
 573                 log_syntax(NULL, LOG_WARNING, filename, line_number, 0,
 574                            "Property expected, ignoring record with no properties.");
 575
 576         return r;
 577 }
 578
 579 int hwdb_update(const char *root, const char *hwdb_bin_dir, bool strict, bool compat) {
 580         _cleanup_free_ char *hwdb_bin = NULL;
 581         _cleanup_(trie_freep) struct trie *trie = NULL;
 582         _cleanup_strv_free_ char **files = NULL;
 583         uint16_t file_priority = 1;
 584         int r = 0, err;
 585
 586         /* The argument 'compat' controls the format version of database. If false, then hwdb.bin will be
 587          * created with additional information such that priority, line number, and filename of database
 588          * source. If true, then hwdb.bin will be created without the information. systemd-hwdb command
 589          * should set the argument false, and 'udevadm hwdb' command should set it true. */
 590
 591         hwdb_bin = path_join(root, hwdb_bin_dir ?: "/etc/udev", "hwdb.bin");
 592         if (!hwdb_bin)
 593                 return -ENOMEM;
 594
 595         trie = new0(struct trie, 1);
 596         if (!trie)
 597                 return -ENOMEM;
 598
 599         /* string store */
 600         trie->strings = strbuf_new();
 601         if (!trie->strings)
 602                 return -ENOMEM;
 603
 604         /* index */
 605         trie->root = new0(struct trie_node, 1);
 606         if (!trie->root)
 607                 return -ENOMEM;
 608
 609         trie->nodes_count++;
 610
 611         err = conf_files_list_strv(&files, ".hwdb", root, 0, conf_file_dirs);
 612         if (err < 0)
 613                 return log_error_errno(err, "Failed to enumerate hwdb files: %m");
 614
 615         if (strv_isempty(files)) {
 616                 if (unlink(hwdb_bin) < 0) {
 617                         if (errno != ENOENT)
 618                                 return log_error_errno(errno, "Failed to remove compiled hwdb database %s: %m", hwdb_bin);
 619
 620                         log_info("No hwdb files found, skipping.");
 621                 } else
 622                         log_info("No hwdb files found, compiled hwdb database %s removed.", hwdb_bin);
 623
 624                 return 0;
 625         }
 626
 627         STRV_FOREACH(f, files) {
 628                 log_debug("Reading file \"%s\"", *f);
 629                 err = import_file(trie, *f, file_priority++, compat);
 630                 if (err < 0 && strict)
 631                         r = err;
 632         }
 633
 634         strbuf_complete(trie->strings);
 635
 636         log_debug("=== trie in-memory ===");
 637         log_debug("nodes:            %8zu bytes (%8zu)",
 638                   trie->nodes_count * sizeof(struct trie_node), trie->nodes_count);
 639         log_debug("children arrays:  %8zu bytes (%8zu)",
 640                   trie->children_count * sizeof(struct trie_child_entry), trie->children_count);
 641         log_debug("values arrays:    %8zu bytes (%8zu)",
 642                   trie->values_count * sizeof(struct trie_value_entry), trie->values_count);
 643         log_debug("strings:          %8zu bytes",
 644                   trie->strings->len);
 645         log_debug("strings incoming: %8zu bytes (%8zu)",
 646                   trie->strings->in_len, trie->strings->in_count);
 647         log_debug("strings dedup'ed: %8zu bytes (%8zu)",
 648                   trie->strings->dedup_len, trie->strings->dedup_count);
 649
 650         (void) mkdir_parents_label(hwdb_bin, 0755);
 651         err = trie_store(trie, hwdb_bin, compat);
 652         if (err < 0)
 653                 return log_error_errno(err, "Failed to write database %s: %m", hwdb_bin);
 654
 655         err = label_fix(hwdb_bin, 0);
 656         if (err < 0)
 657                 return err;
 658
 659         return r;
 660 }
 661
 662 int hwdb_query(const char *modalias, const char *root) {
 663         _cleanup_(sd_hwdb_unrefp) sd_hwdb *hwdb = NULL;
 664         const char *key, *value;
 665         int r;
 666
 667         assert(modalias);
 668
 669         if (!isempty(root))
 670                 NULSTR_FOREACH(p, hwdb_bin_paths) {
 671                         _cleanup_free_ char *hwdb_bin = NULL;
 672
 673                         hwdb_bin = path_join(root, p);
 674                         if (!hwdb_bin)
 675                                 return -ENOMEM;
 676
 677                         r = sd_hwdb_new_from_path(hwdb_bin, &hwdb);
 678                         if (r >= 0)
 679                                 break;
 680                 }
 681         else
 682                 r = sd_hwdb_new(&hwdb);
 683         if (r < 0)
 684                 return r;
 685
 686         SD_HWDB_FOREACH_PROPERTY(hwdb, modalias, key, value)
 687                 printf("%s=%s\n", key, value);
 688
 689         return 0;
 690 }
 691
 692 bool hwdb_should_reload(sd_hwdb *hwdb) {
 693         bool found = false;
 694         struct stat st;
 695
 696         if (!hwdb)
 697                 return false;
 698         if (!hwdb->f)
 699                 return false;
 700
 701         /* if hwdb.bin doesn't exist anywhere, we need to update */
 702         NULSTR_FOREACH(p, hwdb_bin_paths)
 703                 if (stat(p, &st) >= 0) {
 704                         found = true;
 705                         break;
 706                 }
 707         if (!found)
 708                 return true;
 709
 710         if (timespec_load(&hwdb->st.st_mtim) != timespec_load(&st.st_mtim))
 711                 return true;
 712         return false;
 713 }
 714
 715 int hwdb_bypass(void) {
 716         int r;
 717
 718         r = getenv_bool("SYSTEMD_HWDB_UPDATE_BYPASS");
 719         if (r < 0 && r != -ENXIO)
 720                 log_debug_errno(r, "Failed to parse $SYSTEMD_HWDB_UPDATE_BYPASS, assuming no.");
 721         if (r <= 0)
 722                 return false;
 723
 724         log_debug("$SYSTEMD_HWDB_UPDATE_BYPASS is enabled, skipping execution.");
 725         return true;
 726 }