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 "fd-util.h"
  10 #include "fileio.h"
  11 #include "fs-util.h"
  12 #include "hwdb-internal.h"
  13 #include "hwdb-util.h"
  14 #include "label.h"
  15 #include "mkdir-label.h"
  16 #include "nulstr-util.h"
  17 #include "path-util.h"
  18 #include "sort-util.h"
  19 #include "strbuf.h"
  20 #include "string-util.h"
  21 #include "strv.h"
  22 #include "tmpfile-util.h"
  23
  24 static const char *default_hwdb_bin_dir = "/etc/udev";
  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                 uint8_t 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         FILE *f;
 279         struct trie *trie;
 280         uint64_t strings_off;
 281
 282         uint64_t nodes_count;
 283         uint64_t children_count;
 284         uint64_t values_count;
 285 };
 286
 287 /* calculate the storage space for the nodes, children arrays, value arrays */
 288 static void trie_store_nodes_size(struct trie_f *trie, struct trie_node *node, bool compat) {
 289         for (uint64_t i = 0; i < node->children_count; i++)
 290                 trie_store_nodes_size(trie, node->children[i].child, compat);
 291
 292         trie->strings_off += sizeof(struct trie_node_f);
 293         for (uint64_t i = 0; i < node->children_count; i++)
 294                 trie->strings_off += sizeof(struct trie_child_entry_f);
 295         for (uint64_t i = 0; i < node->values_count; i++)
 296                 trie->strings_off += compat ? sizeof(struct trie_value_entry_f) : sizeof(struct trie_value_entry2_f);
 297 }
 298
 299 static int64_t trie_store_nodes(struct trie_f *trie, struct trie_node *node, bool compat) {
 300         struct trie_node_f n = {
 301                 .prefix_off = htole64(trie->strings_off + node->prefix_off),
 302                 .children_count = node->children_count,
 303                 .values_count = htole64(node->values_count),
 304         };
 305         _cleanup_free_ struct trie_child_entry_f *children = NULL;
 306         int64_t node_off;
 307
 308         if (node->children_count) {
 309                 children = new(struct trie_child_entry_f, node->children_count);
 310                 if (!children)
 311                         return -ENOMEM;
 312         }
 313
 314         /* post-order recursion */
 315         for (uint64_t i = 0; i < node->children_count; i++) {
 316                 int64_t child_off;
 317
 318                 child_off = trie_store_nodes(trie, node->children[i].child, compat);
 319                 if (child_off < 0)
 320                         return child_off;
 321
 322                 children[i] = (struct trie_child_entry_f) {
 323                         .c = node->children[i].c,
 324                         .child_off = htole64(child_off),
 325                 };
 326         }
 327
 328         /* write node */
 329         node_off = ftello(trie->f);
 330         fwrite(&n, sizeof(struct trie_node_f), 1, trie->f);
 331         trie->nodes_count++;
 332
 333         /* append children array */
 334         if (node->children_count) {
 335                 fwrite(children, sizeof(struct trie_child_entry_f), node->children_count, trie->f);
 336                 trie->children_count += node->children_count;
 337         }
 338
 339         /* append values array */
 340         for (uint64_t i = 0; i < node->values_count; i++) {
 341                 struct trie_value_entry2_f v = {
 342                         .key_off = htole64(trie->strings_off + node->values[i].key_off),
 343                         .value_off = htole64(trie->strings_off + node->values[i].value_off),
 344                         .filename_off = htole64(trie->strings_off + node->values[i].filename_off),
 345                         .line_number = htole32(node->values[i].line_number),
 346                         .file_priority = htole16(node->values[i].file_priority),
 347                 };
 348
 349                 fwrite(&v, compat ? sizeof(struct trie_value_entry_f) : sizeof(struct trie_value_entry2_f), 1, trie->f);
 350         }
 351         trie->values_count += node->values_count;
 352
 353         return node_off;
 354 }
 355
 356 static int trie_store(struct trie *trie, const char *filename, bool compat) {
 357         struct trie_f t = {
 358                 .trie = trie,
 359         };
 360         _cleanup_free_ char *filename_tmp = NULL;
 361         int64_t pos;
 362         int64_t root_off;
 363         int64_t size;
 364         struct trie_header_f h = {
 365                 .signature = HWDB_SIG,
 366                 .tool_version = htole64(PROJECT_VERSION),
 367                 .header_size = htole64(sizeof(struct trie_header_f)),
 368                 .node_size = htole64(sizeof(struct trie_node_f)),
 369                 .child_entry_size = htole64(sizeof(struct trie_child_entry_f)),
 370                 .value_entry_size = htole64(compat ? sizeof(struct trie_value_entry_f) : sizeof(struct trie_value_entry2_f)),
 371         };
 372         int r;
 373
 374         /* calculate size of header, nodes, children entries, value entries */
 375         t.strings_off = sizeof(struct trie_header_f);
 376         trie_store_nodes_size(&t, trie->root, compat);
 377
 378         r = fopen_temporary(filename, &t.f, &filename_tmp);
 379         if (r < 0)
 380                 return r;
 381         (void) fchmod(fileno(t.f), 0444);
 382
 383         /* write nodes */
 384         if (fseeko(t.f, sizeof(struct trie_header_f), SEEK_SET) < 0)
 385                 goto error_fclose;
 386
 387         root_off = trie_store_nodes(&t, trie->root, compat);
 388         h.nodes_root_off = htole64(root_off);
 389         pos = ftello(t.f);
 390         h.nodes_len = htole64(pos - sizeof(struct trie_header_f));
 391
 392         /* write string buffer */
 393         fwrite(trie->strings->buf, trie->strings->len, 1, t.f);
 394         h.strings_len = htole64(trie->strings->len);
 395
 396         /* write header */
 397         size = ftello(t.f);
 398         h.file_size = htole64(size);
 399         if (fseeko(t.f, 0, SEEK_SET) < 0)
 400                 goto error_fclose;
 401         fwrite(&h, sizeof(struct trie_header_f), 1, t.f);
 402
 403         if (ferror(t.f))
 404                 goto error_fclose;
 405         if (fflush(t.f) < 0)
 406                 goto error_fclose;
 407         if (fsync(fileno(t.f)) < 0)
 408                 goto error_fclose;
 409         if (rename(filename_tmp, filename) < 0)
 410                 goto error_fclose;
 411
 412         /* write succeeded */
 413         fclose(t.f);
 414
 415         log_debug("=== trie on-disk ===");
 416         log_debug("size:             %8"PRIi64" bytes", size);
 417         log_debug("header:           %8zu bytes", sizeof(struct trie_header_f));
 418         log_debug("nodes:            %8"PRIu64" bytes (%8"PRIu64")",
 419                   t.nodes_count * sizeof(struct trie_node_f), t.nodes_count);
 420         log_debug("child pointers:   %8"PRIu64" bytes (%8"PRIu64")",
 421                   t.children_count * sizeof(struct trie_child_entry_f), t.children_count);
 422         log_debug("value pointers:   %8"PRIu64" bytes (%8"PRIu64")",
 423                   t.values_count * (compat ? sizeof(struct trie_value_entry_f) : sizeof(struct trie_value_entry2_f)), t.values_count);
 424         log_debug("string store:     %8zu bytes", trie->strings->len);
 425         log_debug("strings start:    %8"PRIu64, t.strings_off);
 426         return 0;
 427
 428  error_fclose:
 429         r = -errno;
 430         fclose(t.f);
 431         (void) unlink(filename_tmp);
 432         return r;
 433 }
 434
 435 static int insert_data(struct trie *trie, char **match_list, char *line, const char *filename,
 436                        uint16_t file_priority, uint32_t line_number, bool compat) {
 437         char *value;
 438
 439         assert(line[0] == ' ');
 440
 441         value = strchr(line, '=');
 442         if (!value)
 443                 return log_syntax(NULL, LOG_WARNING, filename, line_number, SYNTHETIC_ERRNO(EINVAL),
 444                                   "Key-value pair expected but got \"%s\", ignoring.", line);
 445
 446         value[0] = '\0';
 447         value++;
 448
 449         /* Replace multiple leading spaces by a single space */
 450         while (isblank(line[0]) && isblank(line[1]))
 451                 line++;
 452
 453         if (isempty(line + 1))
 454                 return log_syntax(NULL, LOG_WARNING, filename, line_number, SYNTHETIC_ERRNO(EINVAL),
 455                                   "Empty key in \"%s=%s\", ignoring.",
 456                                   line, value);
 457
 458         STRV_FOREACH(entry, match_list)
 459                 trie_insert(trie, trie->root, *entry, line, value, filename, file_priority, line_number, compat);
 460
 461         return 0;
 462 }
 463
 464 static int import_file(struct trie *trie, const char *filename, uint16_t file_priority, bool compat) {
 465         enum {
 466                 HW_NONE,
 467                 HW_MATCH,
 468                 HW_DATA,
 469         } state = HW_NONE;
 470         _cleanup_fclose_ FILE *f = NULL;
 471         _cleanup_strv_free_ char **match_list = NULL;
 472         uint32_t line_number = 0;
 473         int r, err;
 474
 475         f = fopen(filename, "re");
 476         if (!f)
 477                 return -errno;
 478
 479         for (;;) {
 480                 _cleanup_free_ char *line = NULL;
 481                 size_t len;
 482                 char *pos;
 483
 484                 r = read_line_full(f, LONG_LINE_MAX, READ_LINE_NOT_A_TTY, &line);
 485                 if (r < 0)
 486                         return r;
 487                 if (r == 0)
 488                         break;
 489
 490                 line_number ++;
 491
 492                 /* comment line */
 493                 if (line[0] == '#')
 494                         continue;
 495
 496                 /* strip trailing comment */
 497                 pos = strchr(line, '#');
 498                 if (pos)
 499                         pos[0] = '\0';
 500
 501                 /* strip trailing whitespace */
 502                 len = strlen(line);
 503                 while (len > 0 && isspace(line[len-1]))
 504                         len--;
 505                 line[len] = '\0';
 506
 507                 switch (state) {
 508                 case HW_NONE:
 509                         if (len == 0)
 510                                 break;
 511
 512                         if (line[0] == ' ') {
 513                                 r = log_syntax(NULL, LOG_WARNING, filename, line_number, SYNTHETIC_ERRNO(EINVAL),
 514                                                "Match expected but got indented property \"%s\", ignoring line.", line);
 515                                 break;
 516                         }
 517
 518                         /* start of record, first match */
 519                         state = HW_MATCH;
 520
 521                         err = strv_extend(&match_list, line);
 522                         if (err < 0)
 523                                 return err;
 524
 525                         break;
 526
 527                 case HW_MATCH:
 528                         if (len == 0) {
 529                                 r = log_syntax(NULL, LOG_WARNING, filename, line_number, SYNTHETIC_ERRNO(EINVAL),
 530                                                "Property expected, ignoring record with no properties.");
 531                                 state = HW_NONE;
 532                                 match_list = strv_free(match_list);
 533                                 break;
 534                         }
 535
 536                         if (line[0] != ' ') {
 537                                 /* another match */
 538                                 err = strv_extend(&match_list, line);
 539                                 if (err < 0)
 540                                         return err;
 541
 542                                 break;
 543                         }
 544
 545                         /* first data */
 546                         state = HW_DATA;
 547                         err = insert_data(trie, match_list, line, filename, file_priority, line_number, compat);
 548                         if (err < 0)
 549                                 r = err;
 550                         break;
 551
 552                 case HW_DATA:
 553                         if (len == 0) {
 554                                 /* end of record */
 555                                 state = HW_NONE;
 556                                 match_list = strv_free(match_list);
 557                                 break;
 558                         }
 559
 560                         if (line[0] != ' ') {
 561                                 r = log_syntax(NULL, LOG_WARNING, filename, line_number, SYNTHETIC_ERRNO(EINVAL),
 562                                                "Property or empty line expected, got \"%s\", ignoring record.", line);
 563                                 state = HW_NONE;
 564                                 match_list = strv_free(match_list);
 565                                 break;
 566                         }
 567
 568                         err = insert_data(trie, match_list, line, filename, file_priority, line_number, compat);
 569                         if (err < 0)
 570                                 r = err;
 571                         break;
 572                 };
 573         }
 574
 575         if (state == HW_MATCH)
 576                 log_syntax(NULL, LOG_WARNING, filename, line_number, 0,
 577                            "Property expected, ignoring record with no properties.");
 578
 579         return r;
 580 }
 581
 582 int hwdb_update(const char *root, const char *hwdb_bin_dir, bool strict, bool compat) {
 583         _cleanup_free_ char *hwdb_bin = NULL;
 584         _cleanup_(trie_freep) struct trie *trie = NULL;
 585         _cleanup_strv_free_ char **files = NULL;
 586         uint16_t file_priority = 1;
 587         int r = 0, err;
 588
 589         /* The argument 'compat' controls the format version of database. If false, then hwdb.bin will be
 590          * created with additional information such that priority, line number, and filename of database
 591          * source. If true, then hwdb.bin will be created without the information. systemd-hwdb command
 592          * should set the argument false, and 'udevadm hwdb' command should set it true. */
 593
 594         trie = new0(struct trie, 1);
 595         if (!trie)
 596                 return -ENOMEM;
 597
 598         /* string store */
 599         trie->strings = strbuf_new();
 600         if (!trie->strings)
 601                 return -ENOMEM;
 602
 603         /* index */
 604         trie->root = new0(struct trie_node, 1);
 605         if (!trie->root)
 606                 return -ENOMEM;
 607
 608         trie->nodes_count++;
 609
 610         err = conf_files_list_strv(&files, ".hwdb", root, 0, conf_file_dirs);
 611         if (err < 0)
 612                 return log_error_errno(err, "Failed to enumerate hwdb files: %m");
 613
 614         STRV_FOREACH(f, files) {
 615                 log_debug("Reading file \"%s\"", *f);
 616                 err = import_file(trie, *f, file_priority++, compat);
 617                 if (err < 0 && strict)
 618                         r = err;
 619         }
 620
 621         strbuf_complete(trie->strings);
 622
 623         log_debug("=== trie in-memory ===");
 624         log_debug("nodes:            %8zu bytes (%8zu)",
 625                   trie->nodes_count * sizeof(struct trie_node), trie->nodes_count);
 626         log_debug("children arrays:  %8zu bytes (%8zu)",
 627                   trie->children_count * sizeof(struct trie_child_entry), trie->children_count);
 628         log_debug("values arrays:    %8zu bytes (%8zu)",
 629                   trie->values_count * sizeof(struct trie_value_entry), trie->values_count);
 630         log_debug("strings:          %8zu bytes",
 631                   trie->strings->len);
 632         log_debug("strings incoming: %8zu bytes (%8zu)",
 633                   trie->strings->in_len, trie->strings->in_count);
 634         log_debug("strings dedup'ed: %8zu bytes (%8zu)",
 635                   trie->strings->dedup_len, trie->strings->dedup_count);
 636
 637         hwdb_bin = path_join(root, hwdb_bin_dir ?: default_hwdb_bin_dir, "hwdb.bin");
 638         if (!hwdb_bin)
 639                 return -ENOMEM;
 640
 641         (void) mkdir_parents_label(hwdb_bin, 0755);
 642         err = trie_store(trie, hwdb_bin, compat);
 643         if (err < 0)
 644                 return log_error_errno(err, "Failed to write database %s: %m", hwdb_bin);
 645
 646         err = label_fix(hwdb_bin, 0);
 647         if (err < 0)
 648                 return err;
 649
 650         return r;
 651 }
 652
 653 int hwdb_query(const char *modalias, const char *root) {
 654         _cleanup_(sd_hwdb_unrefp) sd_hwdb *hwdb = NULL;
 655         const char *key, *value, *p;
 656         int r;
 657
 658         assert(modalias);
 659
 660         if (!isempty(root))
 661                 NULSTR_FOREACH(p, hwdb_bin_paths) {
 662                         _cleanup_free_ char *hwdb_bin = NULL;
 663
 664                         hwdb_bin = path_join(root, p);
 665                         if (!hwdb_bin)
 666                                 return -ENOMEM;
 667
 668                         r = sd_hwdb_new_from_path(hwdb_bin, &hwdb);
 669                         if (r >= 0)
 670                                 break;
 671                 }
 672         else
 673                 r = sd_hwdb_new(&hwdb);
 674         if (r < 0)
 675                 return r;
 676
 677         SD_HWDB_FOREACH_PROPERTY(hwdb, modalias, key, value)
 678                 printf("%s=%s\n", key, value);
 679
 680         return 0;
 681 }
 682
 683 bool hwdb_should_reload(sd_hwdb *hwdb) {
 684         bool found = false;
 685         const char* p;
 686         struct stat st;
 687
 688         if (!hwdb)
 689                 return false;
 690         if (!hwdb->f)
 691                 return false;
 692
 693         /* if hwdb.bin doesn't exist anywhere, we need to update */
 694         NULSTR_FOREACH(p, hwdb_bin_paths)
 695                 if (stat(p, &st) >= 0) {
 696                         found = true;
 697                         break;
 698                 }
 699         if (!found)
 700                 return true;
 701
 702         if (timespec_load(&hwdb->st.st_mtim) != timespec_load(&st.st_mtim))
 703                 return true;
 704         return false;
 705 }