src/udev/udevadm-hwdb.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2012 Kay Sievers <kay@vrfy.org>
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22 #include <getopt.h>
  23 #include <string.h>
  24
  25 #include "util.h"
  26 #include "strbuf.h"
  27 #include "conf-files.h"
  28
  29 #include "udev.h"
  30 #include "libudev-hwdb-def.h"
  31
  32 /*
  33  * Generic udev properties, key/value database based on modalias strings.
  34  * Uses a Patricia/radix trie to index all matches for efficient lookup.
  35  */
  36
  37 static const char * const conf_file_dirs[] = {
  38         "/etc/udev/hwdb.d",
  39         UDEVLIBEXECDIR "/hwdb.d",
  40         NULL
  41 };
  42
  43 /* in-memory trie objects */
  44 struct trie {
  45         struct trie_node *root;
  46         struct strbuf *strings;
  47
  48         size_t nodes_count;
  49         size_t children_count;
  50         size_t values_count;
  51 };
  52
  53 struct trie_node {
  54         /* prefix, common part for all children of this node */
  55         size_t prefix_off;
  56
  57         /* sorted array of pointers to children nodes */
  58         struct trie_child_entry *children;
  59         uint8_t children_count;
  60
  61         /* sorted array of key/value pairs */
  62         struct trie_value_entry *values;
  63         size_t values_count;
  64 };
  65
  66 /* children array item with char (0-255) index */
  67 struct trie_child_entry {
  68         uint8_t c;
  69         struct trie_node *child;
  70 };
  71
  72 /* value array item with key/value pairs */
  73 struct trie_value_entry {
  74         size_t key_off;
  75         size_t value_off;
  76 };
  77
  78 static int trie_children_cmp(const void *v1, const void *v2) {
  79         const struct trie_child_entry *n1 = v1;
  80         const struct trie_child_entry *n2 = v2;
  81
  82         return n1->c - n2->c;
  83 }
  84
  85 static int node_add_child(struct trie *trie, struct trie_node *node, struct trie_node *node_child, uint8_t c) {
  86         struct trie_child_entry *child;
  87         int err = 0;
  88
  89         /* extend array, add new entry, sort for bisection */
  90         child = realloc(node->children, (node->children_count + 1) * sizeof(struct trie_child_entry));
  91         if (!child) {
  92                 err = -ENOMEM;
  93                 goto out;
  94         }
  95         node->children = child;
  96         trie->children_count++;
  97         node->children[node->children_count].c = c;
  98         node->children[node->children_count].child = node_child;
  99         node->children_count++;
 100         qsort(node->children, node->children_count, sizeof(struct trie_child_entry), trie_children_cmp);
 101         trie->nodes_count++;
 102 out:
 103         return err;
 104 }
 105
 106 static struct trie_node *node_lookup(const struct trie_node *node, uint8_t c) {
 107         struct trie_child_entry *child;
 108         struct trie_child_entry search;
 109
 110         search.c = c;
 111         child = bsearch(&search, node->children, node->children_count, sizeof(struct trie_child_entry), trie_children_cmp);
 112         if (child)
 113                 return child->child;
 114         return NULL;
 115 }
 116
 117 static void trie_node_cleanup(struct trie_node *node) {
 118         size_t i;
 119
 120         for (i = 0; i < node->children_count; i++)
 121                 trie_node_cleanup(node->children[i].child);
 122         free(node->children);
 123         free(node->values);
 124         free(node);
 125 }
 126
 127 static int trie_values_cmp(const void *v1, const void *v2, void *arg) {
 128         const struct trie_value_entry *val1 = v1;
 129         const struct trie_value_entry *val2 = v2;
 130         struct trie *trie = arg;
 131
 132         return strcmp(trie->strings->buf + val1->key_off,
 133                       trie->strings->buf + val2->key_off);
 134 }
 135
 136 static int trie_node_add_value(struct trie *trie, struct trie_node *node,
 137                           const char *key, const char *value) {
 138         ssize_t k, v;
 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 (node->values_count) {
 149                 struct trie_value_entry search = {
 150                         .key_off = k,
 151                         .value_off = v,
 152                 };
 153
 154                 val = xbsearch_r(&search, node->values, node->values_count, sizeof(struct trie_value_entry), trie_values_cmp, trie);
 155                 if (val) {
 156                         /* replace existing earlier key with new value */
 157                         val->value_off = v;
 158                         return 0;
 159                 }
 160         }
 161
 162         /* extend array, add new entry, sort for bisection */
 163         val = realloc(node->values, (node->values_count + 1) * sizeof(struct trie_value_entry));
 164         if (!val)
 165                 return -ENOMEM;
 166         trie->values_count++;
 167         node->values = val;
 168         node->values[node->values_count].key_off = k;
 169         node->values[node->values_count].value_off = v;
 170         node->values_count++;
 171         qsort_r(node->values, node->values_count, sizeof(struct trie_value_entry), trie_values_cmp, trie);
 172         return 0;
 173 }
 174
 175 static int trie_insert(struct trie *trie, struct trie_node *node, const char *search,
 176                        const char *key, const char *value) {
 177         size_t i = 0;
 178         int err = 0;
 179
 180         for (;;) {
 181                 size_t p;
 182                 uint8_t c;
 183                 struct trie_node *child;
 184
 185                 for (p = 0; (c = trie->strings->buf[node->prefix_off + p]); p++) {
 186                         char *s;
 187                         ssize_t off;
 188
 189                         if (c == search[i + p])
 190                                 continue;
 191
 192                         /* split node */
 193                         child = calloc(sizeof(struct trie_node), 1);
 194                         if (!child) {
 195                                 err = -ENOMEM;
 196                                 goto out;
 197                         }
 198
 199                         /* move values from parent to child */
 200                         child->prefix_off = node->prefix_off + p+1;
 201                         child->children = node->children;
 202                         child->children_count = node->children_count;
 203                         child->values = node->values;
 204                         child->values_count = node->values_count;
 205
 206                         /* update parent; use strdup() because the source gets realloc()d */
 207                         s = strndup(trie->strings->buf + node->prefix_off, p);
 208                         if (!s) {
 209                                 err = -ENOMEM;
 210                                 goto out;
 211                         }
 212                         off = strbuf_add_string(trie->strings, s, p);
 213                         free(s);
 214                         if (off < 0) {
 215                                 err = off;
 216                                 goto out;
 217                         }
 218                         node->prefix_off = off;
 219                         node->children = NULL;
 220                         node->children_count = 0;
 221                         node->values = NULL;
 222                         node->values_count = 0;
 223                         err = node_add_child(trie, node, child, c);
 224                         if (err)
 225                                 goto out;
 226                         break;
 227                 }
 228                 i += p;
 229
 230                 c = search[i];
 231                 if (c == '\0')
 232                         return trie_node_add_value(trie, node, key, value);
 233
 234                 child = node_lookup(node, c);
 235                 if (!child) {
 236                         ssize_t off;
 237
 238                         /* new child */
 239                         child = calloc(sizeof(struct trie_node), 1);
 240                         if (!child) {
 241                                 err = -ENOMEM;
 242                                 goto out;
 243                         }
 244                         off = strbuf_add_string(trie->strings, search + i+1, strlen(search + i+1));
 245                         if (off < 0) {
 246                                 err = off;
 247                                 goto out;
 248                         }
 249                         child->prefix_off = off;
 250                         err = node_add_child(trie, node, child, c);
 251                         if (err)
 252                                 goto out;
 253                         return trie_node_add_value(trie, child, key, value);
 254                 }
 255
 256                 node = child;
 257                 i++;
 258         }
 259 out:
 260         return err;
 261 }
 262
 263 struct trie_f {
 264         FILE *f;
 265         struct trie *trie;
 266         uint64_t strings_off;
 267
 268         uint64_t nodes_count;
 269         uint64_t children_count;
 270         uint64_t values_count;
 271 };
 272
 273 /* calculate the storage space for the nodes, children arrays, value arrays */
 274 static void trie_store_nodes_size(struct trie_f *trie, struct trie_node *node) {
 275         uint64_t i;
 276
 277         for (i = 0; i < node->children_count; i++)
 278                 trie_store_nodes_size(trie, node->children[i].child);
 279
 280         trie->strings_off += sizeof(struct trie_node_f);
 281         for (i = 0; i < node->children_count; i++)
 282                 trie->strings_off += sizeof(struct trie_child_entry_f);
 283         for (i = 0; i < node->values_count; i++)
 284                 trie->strings_off += sizeof(struct trie_value_entry_f);
 285 }
 286
 287 static int64_t trie_store_nodes(struct trie_f *trie, struct trie_node *node) {
 288         uint64_t i;
 289         struct trie_node_f n = {
 290                 .prefix_off = htole64(trie->strings_off + node->prefix_off),
 291                 .children_count = node->children_count,
 292                 .values_count = htole64(node->values_count),
 293         };
 294         struct trie_child_entry_f *children = NULL;
 295         int64_t node_off;
 296
 297         if (node->children_count) {
 298                 children = new0(struct trie_child_entry_f, node->children_count);
 299                 if (!children)
 300                         return -ENOMEM;
 301         }
 302
 303         /* post-order recursion */
 304         for (i = 0; i < node->children_count; i++) {
 305                 int64_t child_off;
 306
 307                 child_off = trie_store_nodes(trie, node->children[i].child);
 308                 if (child_off < 0)
 309                         return child_off;
 310                 children[i].c = node->children[i].c;
 311                 children[i].child_off = htole64(child_off);
 312         }
 313
 314         /* write node */
 315         node_off = ftello(trie->f);
 316         fwrite(&n, sizeof(struct trie_node_f), 1, trie->f);
 317         trie->nodes_count++;
 318
 319         /* append children array */
 320         if (node->children_count) {
 321                 fwrite(children, sizeof(struct trie_child_entry_f), node->children_count, trie->f);
 322                 trie->children_count += node->children_count;
 323                 free(children);
 324         }
 325
 326         /* append values array */
 327         for (i = 0; i < node->values_count; i++) {
 328                 struct trie_value_entry_f v = {
 329                         .key_off = htole64(trie->strings_off + node->values[i].key_off),
 330                         .value_off = htole64(trie->strings_off + node->values[i].value_off),
 331                 };
 332
 333                 fwrite(&v, sizeof(struct trie_value_entry_f), 1, trie->f);
 334                 trie->values_count++;
 335         }
 336
 337         return node_off;
 338 }
 339
 340 static int trie_store(struct trie *trie, const char *filename) {
 341         struct trie_f t = {
 342                 .trie = trie,
 343         };
 344         char *filename_tmp;
 345         int64_t pos;
 346         int64_t root_off;
 347         int64_t size;
 348         struct trie_header_f h = {
 349                 .signature = HWDB_SIG,
 350                 .tool_version = htole64(atoi(VERSION)),
 351                 .header_size = htole64(sizeof(struct trie_header_f)),
 352                 .node_size = htole64(sizeof(struct trie_node_f)),
 353                 .child_entry_size = htole64(sizeof(struct trie_child_entry_f)),
 354                 .value_entry_size = htole64(sizeof(struct trie_value_entry_f)),
 355         };
 356         int err;
 357
 358         /* calculate size of header, nodes, children entries, value entries */
 359         t.strings_off = sizeof(struct trie_header_f);
 360         trie_store_nodes_size(&t, trie->root);
 361
 362         err = fopen_temporary(filename , &t.f, &filename_tmp);
 363         if (err < 0)
 364                 return err;
 365         fchmod(fileno(t.f), 0444);
 366
 367         /* write nodes */
 368         fseeko(t.f, sizeof(struct trie_header_f), SEEK_SET);
 369         root_off = trie_store_nodes(&t, trie->root);
 370         h.nodes_root_off = htole64(root_off);
 371         pos = ftello(t.f);
 372         h.nodes_len = htole64(pos - sizeof(struct trie_header_f));
 373
 374         /* write string buffer */
 375         fwrite(trie->strings->buf, trie->strings->len, 1, t.f);
 376         h.strings_len = htole64(trie->strings->len);
 377
 378         /* write header */
 379         size = ftello(t.f);
 380         h.file_size = htole64(size);
 381         fseeko(t.f, 0, SEEK_SET);
 382         fwrite(&h, sizeof(struct trie_header_f), 1, t.f);
 383         err = ferror(t.f);
 384         if (err)
 385                 err = -errno;
 386         fclose(t.f);
 387         if (err < 0 || rename(filename_tmp, filename) < 0) {
 388                 unlink(filename_tmp);
 389                 goto out;
 390         }
 391
 392         log_debug("=== trie on-disk ===\n");
 393         log_debug("size:             %8llu bytes\n", (unsigned long long)size);
 394         log_debug("header:           %8zu bytes\n", sizeof(struct trie_header_f));
 395         log_debug("nodes:            %8llu bytes (%8llu)\n",
 396                   (unsigned long long)t.nodes_count * sizeof(struct trie_node_f), (unsigned long long)t.nodes_count);
 397         log_debug("child pointers:   %8llu bytes (%8llu)\n",
 398                   (unsigned long long)t.children_count * sizeof(struct trie_child_entry_f), (unsigned long long)t.children_count);
 399         log_debug("value pointers:   %8llu bytes (%8llu)\n",
 400                   (unsigned long long)t.values_count * sizeof(struct trie_value_entry_f), (unsigned long long)t.values_count);
 401         log_debug("string store:     %8llu bytes\n", (unsigned long long)trie->strings->len);
 402         log_debug("strings start:    %8llu\n", (unsigned long long) t.strings_off);
 403 out:
 404         free(filename_tmp);
 405         return err;
 406 }
 407
 408 static int import_file(struct trie *trie, const char *filename) {
 409         FILE *f;
 410         char line[LINE_MAX];
 411         char match[LINE_MAX];
 412         char cond[LINE_MAX];
 413
 414         f = fopen(filename, "re");
 415         if (f == NULL)
 416                 return -errno;
 417
 418         match[0] = '\0';
 419         cond[0] = '\0';
 420         while (fgets(line, sizeof(line), f)) {
 421                 size_t len;
 422
 423                 if (line[0] == '#')
 424                         continue;
 425
 426                 /* new line, new record */
 427                 if (line[0] == '\n') {
 428                         match[0] = '\0';
 429                         cond[0] = '\0';
 430                         continue;
 431                 }
 432
 433                 /* remove newline */
 434                 len = strlen(line);
 435                 if (len < 2)
 436                         continue;
 437                 line[len-1] = '\0';
 438
 439                 /* start of new record */
 440                 if (match[0] == '\0') {
 441                         strcpy(match, line);
 442                         cond[0] = '\0';
 443                         continue;
 444                 }
 445
 446                 if (line[0] == '+') {
 447                         strcpy(cond, line);
 448                         continue;
 449                 }
 450
 451                 /* TODO: support +; skip the entire record until we support it */
 452                 if (cond[0] != '\0')
 453                         continue;
 454
 455                 /* value lines */
 456                 if (line[0] == ' ') {
 457                         char *value;
 458
 459                         value = strchr(line, '=');
 460                         if (!value)
 461                                 continue;
 462                         value[0] = '\0';
 463                         value++;
 464                         trie_insert(trie, trie->root, match, line, value);
 465                 }
 466         }
 467         fclose(f);
 468         return 0;
 469 }
 470
 471 static void help(void) {
 472         printf("Usage: udevadm hwdb OPTIONS\n"
 473                "  --update            update the hardware database\n"
 474                "  --test=<modalias>   query database and print result\n"
 475                "  --root=<path>       alternative root path in the filesystem\n"
 476                "  --help\n\n");
 477 }
 478
 479 static int adm_hwdb(struct udev *udev, int argc, char *argv[]) {
 480         static const struct option options[] = {
 481                 { "update", no_argument, NULL, 'u' },
 482                 { "root", required_argument, NULL, 'r' },
 483                 { "test", required_argument, NULL, 't' },
 484                 { "help", no_argument, NULL, 'h' },
 485                 {}
 486         };
 487         const char *test = NULL;
 488         const char *root = "";
 489         bool update = false;
 490         struct trie *trie = NULL;
 491         int err;
 492         int rc = EXIT_SUCCESS;
 493
 494         for (;;) {
 495                 int option;
 496
 497                 option = getopt_long(argc, argv, "ut:r:h", options, NULL);
 498                 if (option == -1)
 499                         break;
 500
 501                 switch (option) {
 502                 case 'u':
 503                         update = true;
 504                         break;
 505                 case 't':
 506                         test = optarg;
 507                         break;
 508                 case 'r':
 509                         root = optarg;
 510                         break;
 511                 case 'h':
 512                         help();
 513                         return EXIT_SUCCESS;
 514                 }
 515         }
 516
 517         if (!update && !test) {
 518                 help();
 519                 return EXIT_SUCCESS;
 520         }
 521
 522         if (update) {
 523                 char **files, **f;
 524                 _cleanup_free_ char *hwdb_bin = NULL;
 525
 526                 trie = calloc(sizeof(struct trie), 1);
 527                 if (!trie) {
 528                         rc = EXIT_FAILURE;
 529                         goto out;
 530                 }
 531
 532                 /* string store */
 533                 trie->strings = strbuf_new();
 534                 if (!trie->strings) {
 535                         rc = EXIT_FAILURE;
 536                         goto out;
 537                 }
 538
 539                 /* index */
 540                 trie->root = calloc(sizeof(struct trie_node), 1);
 541                 if (!trie->root) {
 542                         rc = EXIT_FAILURE;
 543                         goto out;
 544                 }
 545                 trie->nodes_count++;
 546
 547                 err = conf_files_list_strv(&files, ".hwdb", root, conf_file_dirs);
 548                 if (err < 0) {
 549                         log_error("failed to enumerate hwdb files: %s\n", strerror(-err));
 550                         rc = EXIT_FAILURE;
 551                         goto out;
 552                 }
 553                 STRV_FOREACH(f, files) {
 554                         log_debug("reading file '%s'", *f);
 555                         import_file(trie, *f);
 556                 }
 557                 strv_free(files);
 558
 559                 strbuf_complete(trie->strings);
 560
 561                 log_debug("=== trie in-memory ===\n");
 562                 log_debug("nodes:            %8zu bytes (%8zu)\n",
 563                           trie->nodes_count * sizeof(struct trie_node), trie->nodes_count);
 564                 log_debug("children arrays:  %8zu bytes (%8zu)\n",
 565                           trie->children_count * sizeof(struct trie_child_entry), trie->children_count);
 566                 log_debug("values arrays:    %8zu bytes (%8zu)\n",
 567                           trie->values_count * sizeof(struct trie_value_entry), trie->values_count);
 568                 log_debug("strings:          %8zu bytes\n",
 569                           trie->strings->len);
 570                 log_debug("strings incoming: %8zu bytes (%8zu)\n",
 571                           trie->strings->in_len, trie->strings->in_count);
 572                 log_debug("strings dedup'ed: %8zu bytes (%8zu)\n",
 573                           trie->strings->dedup_len, trie->strings->dedup_count);
 574
 575                 if (asprintf(&hwdb_bin, "%s/etc/udev/hwdb.bin", root) < 0) {
 576                         rc = EXIT_FAILURE;
 577                         goto out;
 578                 }
 579                 mkdir_parents(hwdb_bin, 0755);
 580                 err = trie_store(trie, hwdb_bin);
 581                 if (err < 0) {
 582                         log_error("Failure writing database %s: %s", hwdb_bin, strerror(-err));
 583                         rc = EXIT_FAILURE;
 584                 }
 585         }
 586
 587         if (test) {
 588                 struct udev_hwdb *hwdb = udev_hwdb_new(udev);
 589
 590                 if (hwdb) {
 591                         struct udev_list_entry *entry;
 592
 593                         udev_list_entry_foreach(entry, udev_hwdb_get_properties_list_entry(hwdb, test, 0))
 594                                 printf("%s=%s\n", udev_list_entry_get_name(entry), udev_list_entry_get_value(entry));
 595                         hwdb = udev_hwdb_unref(hwdb);
 596                 }
 597         }
 598 out:
 599         if (trie) {
 600                 if (trie->root)
 601                         trie_node_cleanup(trie->root);
 602                 strbuf_cleanup(trie->strings);
 603                 free(trie);
 604         }
 605         return rc;
 606 }
 607
 608 const struct udevadm_cmd udevadm_hwdb = {
 609         .name = "hwdb",
 610         .cmd = adm_hwdb,
 611         .help = "maintain the hardware database index",
 612 };