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

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