2 This file is part of systemd.
4 Copyright 2012 Kay Sievers <kay.sievers@vrfy.org>
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.
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.
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/>.
27 #include "conf-files.h"
30 #include "udev-hwdb.h"
33 * Generic udev properties, key/value database based on modalias strings.
34 * Uses a Patricia/radix trie to index all matches for efficient lookup.
37 static const char * const conf_file_dirs[] = {
38 SYSCONFDIR "/udev/hwdb.d",
39 UDEVLIBEXECDIR "/hwdb.d",
43 /* in-memory trie objects */
45 struct trie_node *root;
46 struct strbuf *strings;
49 size_t children_count;
54 /* prefix, common part for all children of this node */
57 /* sorted array of pointers to children nodes */
58 struct trie_child_entry *children;
59 uint8_t children_count;
61 /* sorted array of key/value pairs */
62 struct trie_value_entry *values;
66 /* children array item with char (0-255) index */
67 struct trie_child_entry {
69 struct trie_node *child;
72 /* value array item with key/value pairs */
73 struct trie_value_entry {
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;
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;
89 /* extend array, add new entry, sort for bisection */
90 child = realloc(node->children, (node->children_count + 1) * sizeof(struct trie_child_entry));
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);
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;
111 child = bsearch(&search, node->children, node->children_count, sizeof(struct trie_child_entry), trie_children_cmp);
117 static void trie_node_cleanup(struct trie_node *node) {
120 for (i = 0; i < node->children_count; i++)
121 trie_node_cleanup(node->children[i].child);
122 free(node->children);
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;
132 return strcmp(trie->strings->buf + val1->key_off,
133 trie->strings->buf + val2->key_off);
136 static int trie_node_add_value(struct trie *trie, struct trie_node *node,
137 const char *key, const char *value) {
139 struct trie_value_entry *val;
140 struct trie_value_entry search;
142 k = strbuf_add_string(trie->strings, key, strlen(key));
143 v = strbuf_add_string(trie->strings, value, strlen(value));
145 /* replace existing earlier key with new value */
146 search.value_off = k;
147 val = xbsearch_r(&search, node->values, node->values_count, sizeof(struct trie_value_entry), trie_values_cmp, trie);
153 /* extend array, add new entry, sort for bisection */
154 val = realloc(node->values, (node->values_count + 1) * sizeof(struct trie_value_entry));
157 trie->values_count++;
159 node->values[node->values_count].key_off = k;
160 node->values[node->values_count].value_off = v;
161 node->values_count++;
162 qsort_r(node->values, node->values_count, sizeof(struct trie_value_entry), trie_values_cmp, trie);
166 static int trie_insert(struct trie *trie, struct trie_node *node, const char *search,
167 const char *key, const char *value) {
174 struct trie_node *child;
176 for (p = 0; (c = trie->strings->buf[node->prefix_off + p]); p++) {
180 if (c == search[i + p])
184 child = calloc(sizeof(struct trie_node), 1);
190 /* move values from parent to child */
191 child->prefix_off = node->prefix_off + p+1;
192 child->children = node->children;
193 child->children_count = node->children_count;
194 child->values = node->values;
195 child->values_count = node->values_count;
197 /* update parent; use strdup() because the source gets realloc()d */
198 s = strndup(trie->strings->buf + node->prefix_off, p);
203 off = strbuf_add_string(trie->strings, s, p);
209 node->prefix_off = off;
210 node->children = NULL;
211 node->children_count = 0;
213 node->values_count = 0;
214 err = node_add_child(trie, node, child, c);
223 return trie_node_add_value(trie, node, key, value);
225 child = node_lookup(node, c);
230 child = calloc(sizeof(struct trie_node), 1);
235 off = strbuf_add_string(trie->strings, search + i+1, strlen(search + i+1));
240 child->prefix_off = off;
241 err = node_add_child(trie, node, child, c);
244 return trie_node_add_value(trie, child, key, value);
257 uint64_t strings_off;
259 uint64_t nodes_count;
260 uint64_t children_count;
261 uint64_t values_count;
264 /* calculate the storage space for the nodes, children arrays, value arrays */
265 static void trie_store_nodes_size(struct trie_f *trie, struct trie_node *node) {
268 for (i = 0; i < node->children_count; i++)
269 trie_store_nodes_size(trie, node->children[i].child);
271 trie->strings_off += sizeof(struct trie_node_f);
272 for (i = 0; i < node->children_count; i++)
273 trie->strings_off += sizeof(struct trie_child_entry_f);
274 for (i = 0; i < node->values_count; i++)
275 trie->strings_off += sizeof(struct trie_value_entry_f);
278 static int64_t trie_store_nodes(struct trie_f *trie, struct trie_node *node) {
280 struct trie_node_f n = {
281 .prefix_off = htole64(trie->strings_off + node->prefix_off),
282 .children_count = node->children_count,
283 .values_count = htole64(node->values_count),
285 struct trie_child_entry_f *children;
288 if (node->children_count) {
289 children = new0(struct trie_child_entry_f, node->children_count);
294 /* post-order recursion */
295 for (i = 0; i < node->children_count; i++) {
298 child_off = trie_store_nodes(trie, node->children[i].child);
301 children[i].c = node->children[i].c;
302 children[i].child_off = htole64(child_off);
306 node_off = ftello(trie->f);
307 fwrite(&n, sizeof(struct trie_node_f), 1, trie->f);
310 /* append children array */
311 if (node->children_count) {
312 fwrite(children, sizeof(struct trie_child_entry_f), node->children_count, trie->f);
313 trie->children_count += node->children_count;
317 /* append values array */
318 for (i = 0; i < node->values_count; i++) {
319 struct trie_value_entry_f v = {
320 .key_off = htole64(trie->strings_off + node->values[i].key_off),
321 .value_off = htole64(trie->strings_off + node->values[i].value_off),
324 fwrite(&v, sizeof(struct trie_value_entry_f), 1, trie->f);
325 trie->values_count++;
331 static int trie_store(struct trie *trie, const char *filename) {
339 struct trie_header_f h = {
340 .signature = HWDB_SIG,
341 .tool_version = htole64(atoi(VERSION)),
342 .header_size = htole64(sizeof(struct trie_header_f)),
343 .node_size = htole64(sizeof(struct trie_node_f)),
344 .child_entry_size = htole64(sizeof(struct trie_child_entry_f)),
345 .value_entry_size = htole64(sizeof(struct trie_value_entry_f)),
349 /* calculate size of header, nodes, children entries, value entries */
350 t.strings_off = sizeof(struct trie_header_f);
351 trie_store_nodes_size(&t, trie->root);
353 err = fopen_temporary(filename , &t.f, &filename_tmp);
356 fchmod(fileno(t.f), 0444);
359 fseeko(t.f, sizeof(struct trie_header_f), SEEK_SET);
360 root_off = trie_store_nodes(&t, trie->root);
361 h.nodes_root_off = htole64(root_off);
363 h.nodes_len = htole64(pos - sizeof(struct trie_header_f));
365 /* write string buffer */
366 fwrite(trie->strings->buf, trie->strings->len, 1, t.f);
367 h.strings_len = htole64(trie->strings->len);
371 h.file_size = htole64(size);
372 fseeko(t.f, 0, SEEK_SET);
373 fwrite(&h, sizeof(struct trie_header_f), 1, t.f);
378 if (err < 0 || rename(filename_tmp, filename) < 0) {
379 unlink(filename_tmp);
383 log_debug("=== trie on-disk ===\n");
384 log_debug("size: %8zi bytes\n", size);
385 log_debug("header: %8zu bytes\n", sizeof(struct trie_header_f));
386 log_debug("nodes: %8zu bytes (%8zi)\n", t.nodes_count * sizeof(struct trie_node_f), t.nodes_count);
387 log_debug("child pointers: %8zu bytes (%8zi)\n", t.children_count * sizeof(struct trie_child_entry_f), t.children_count);
388 log_debug("value pointers: %8zu bytes (%8zi)\n", t.values_count * sizeof(struct trie_value_entry_f), t.values_count);
389 log_debug("string store: %8zu bytes\n", trie->strings->len);
390 log_debug("strings start: %8llu\n", (unsigned long long) t.strings_off);
396 static int import_file(struct trie *trie, const char *filename) {
399 char match[LINE_MAX];
401 f = fopen(filename, "re");
406 while (fgets(line, sizeof(line), f)) {
412 /* new line, new record */
413 if (line[0] == '\n') {
424 /* start of new record */
425 if (match[0] == '\0') {
431 if (line[0] == ' ') {
434 value = strchr(line, '=');
439 trie_insert(trie, trie->root, match, line, value);
446 static void help(void) {
447 printf("Usage: udevadm hwdb [--create] [--help]\n"
448 " --update update the hardware database\n"
452 static int adm_hwdb(struct udev *udev, int argc, char *argv[]) {
453 static const struct option options[] = {
454 { "update", no_argument, NULL, 'u' },
455 { "help", no_argument, NULL, 'h' },
462 int rc = EXIT_SUCCESS;
467 option = getopt_long(argc, argv, "ch", options, NULL);
486 trie = calloc(sizeof(struct trie), 1);
493 trie->strings = strbuf_new();
494 if (!trie->strings) {
500 trie->root = calloc(sizeof(struct trie_node), 1);
507 err = conf_files_list_strv(&files, ".hwdb", (const char **)conf_file_dirs);
509 log_error("failed to enumerate hwdb files: %s\n", strerror(-err));
513 STRV_FOREACH(f, files) {
514 log_debug("reading file '%s'", *f);
515 import_file(trie, *f);
519 strbuf_complete(trie->strings);
521 log_debug("=== trie in-memory ===\n");
522 log_debug("nodes: %8zu bytes (%8zu)\n", trie->nodes_count * sizeof(struct trie_node), trie->nodes_count);
523 log_debug("children arrays: %8zu bytes (%8zu)\n", trie->children_count * sizeof(struct trie_child_entry), trie->children_count);
524 log_debug("values arrays: %8zu bytes (%8zu)\n", trie->values_count * sizeof(struct trie_value_entry), trie->values_count);
525 log_debug("strings: %8zu bytes\n", trie->strings->len);
526 log_debug("strings incoming: %8zu bytes (%8zu)\n", trie->strings->in_len, trie->strings->in_count);
527 log_debug("strings dedup'ed: %8zu bytes (%8zu)\n", trie->strings->dedup_len, trie->strings->dedup_count);
529 mkdir_parents(SYSCONFDIR "/udev/hwdb.bin", 0755);
530 err = trie_store(trie, SYSCONFDIR "/udev/hwdb.bin");
532 log_error("Failure writing hardware database '%s': %s", SYSCONFDIR "/udev/hwdb.bin", strerror(-err));
538 trie_node_cleanup(trie->root);
539 strbuf_cleanup(trie->strings);
544 const struct udevadm_cmd udevadm_hwdb = {
547 .help = "maintain the hardware database index",