src/libsystemd/sd-hwdb/hwdb-util.c

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