From 796b06c21b62d13c9021e2fbd9c58a5c6edb2764 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Mon, 22 Oct 2012 18:23:08 +0200 Subject: udev: add hardware database support --- src/udev/udevadm-hwdb.c | 548 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 548 insertions(+) create mode 100644 src/udev/udevadm-hwdb.c (limited to 'src/udev/udevadm-hwdb.c') diff --git a/src/udev/udevadm-hwdb.c b/src/udev/udevadm-hwdb.c new file mode 100644 index 0000000000..52fe1d4ebc --- /dev/null +++ b/src/udev/udevadm-hwdb.c @@ -0,0 +1,548 @@ +/*** + This file is part of systemd. + + Copyright 2012 Kay Sievers + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see . +***/ + +#include +#include +#include +#include + +#include "util.h" +#include "strbuf.h" +#include "conf-files.h" + +#include "udev.h" +#include "udev-hwdb.h" + +/* + * Generic udev properties, key/value database based on modalias strings. + * Uses a Patricia/radix trie to index all matches for efficient lookup. + */ + +static const char * const conf_file_dirs[] = { + SYSCONFDIR "/udev/hwdb.d", + UDEVLIBEXECDIR "/hwdb.d", + NULL +}; + +/* in-memory trie objects */ +struct trie { + struct trie_node *root; + struct strbuf *strings; + + size_t nodes_count; + size_t children_count; + size_t values_count; +}; + +struct trie_node { + /* prefix, common part for all children of this node */ + size_t prefix_off; + + /* sorted array of pointers to children nodes */ + struct trie_child_entry *children; + uint8_t children_count; + + /* sorted array of key/value pairs */ + struct trie_value_entry *values; + size_t values_count; +}; + +/* children array item with char (0-255) index */ +struct trie_child_entry { + uint8_t c; + struct trie_node *child; +}; + +/* value array item with key/value pairs */ +struct trie_value_entry { + size_t key_off; + size_t value_off; +}; + +static int trie_children_cmp(const void *v1, const void *v2) { + const struct trie_child_entry *n1 = v1; + const struct trie_child_entry *n2 = v2; + + return n1->c - n2->c; +} + +static int node_add_child(struct trie *trie, struct trie_node *node, struct trie_node *node_child, uint8_t c) { + struct trie_child_entry *child; + int err = 0; + + /* extend array, add new entry, sort for bisection */ + child = realloc(node->children, (node->children_count + 1) * sizeof(struct trie_child_entry)); + if (!child) { + err = -ENOMEM; + goto out; + } + node->children = child; + trie->children_count++; + node->children[node->children_count].c = c; + node->children[node->children_count].child = node_child; + node->children_count++; + qsort(node->children, node->children_count, sizeof(struct trie_child_entry), trie_children_cmp); + trie->nodes_count++; +out: + return err; +} + +static struct trie_node *node_lookup(const struct trie_node *node, uint8_t c) { + struct trie_child_entry *child; + struct trie_child_entry search; + + search.c = c; + child = bsearch(&search, node->children, node->children_count, sizeof(struct trie_child_entry), trie_children_cmp); + if (child) + return child->child; + return NULL; +} + +static void trie_node_cleanup(struct trie_node *node) { + size_t i; + + for (i = 0; i < node->children_count; i++) + trie_node_cleanup(node->children[i].child); + free(node->children); + free(node->values); + free(node); +} + +static int trie_values_cmp(const void *v1, const void *v2, void *arg) { + const struct trie_value_entry *val1 = v1; + const struct trie_value_entry *val2 = v2; + struct trie *trie = arg; + + return strcmp(trie->strings->buf + val1->key_off, + trie->strings->buf + val2->key_off); +} + +static int trie_node_add_value(struct trie *trie, struct trie_node *node, + const char *key, const char *value) { + size_t k, v; + struct trie_value_entry *val; + struct trie_value_entry search; + + k = strbuf_add_string(trie->strings, key, strlen(key)); + v = strbuf_add_string(trie->strings, value, strlen(value)); + + /* replace existing earlier key with new value */ + search.value_off = k; + val = xbsearch_r(&search, node->values, node->values_count, sizeof(struct trie_value_entry), trie_values_cmp, trie); + if (val) { + val->value_off = v; + return 0; + } + + /* extend array, add new entry, sort for bisection */ + val = realloc(node->values, (node->values_count + 1) * sizeof(struct trie_value_entry)); + if (!val) + return -ENOMEM; + trie->values_count++; + node->values = val; + node->values[node->values_count].key_off = k; + node->values[node->values_count].value_off = v; + node->values_count++; + qsort_r(node->values, node->values_count, sizeof(struct trie_value_entry), trie_values_cmp, trie); + return 0; +} + +static int trie_insert(struct trie *trie, struct trie_node *node, const char *search, + const char *key, const char *value) { + size_t i = 0; + int err = 0; + + for (;;) { + size_t p; + uint8_t c; + struct trie_node *child; + + for (p = 0; (c = trie->strings->buf[node->prefix_off + p]); p++) { + char *s; + ssize_t off; + + if (c == search[i + p]) + continue; + + /* split node */ + child = calloc(sizeof(struct trie_node), 1); + if (!child) { + err = -ENOMEM; + goto out; + } + + /* move values from parent to child */ + child->prefix_off = node->prefix_off + p+1; + child->children = node->children; + child->children_count = node->children_count; + child->values = node->values; + child->values_count = node->values_count; + + /* update parent; use strdup() because the source gets realloc()d */ + s = strndup(trie->strings->buf + node->prefix_off, p); + if (!s) { + err = -ENOMEM; + goto out; + } + off = strbuf_add_string(trie->strings, s, p); + free(s); + if (off < 0) { + err = off; + goto out; + } + node->prefix_off = off; + node->children = NULL; + node->children_count = 0; + node->values = NULL; + node->values_count = 0; + err = node_add_child(trie, node, child, c); + if (err) + goto out; + break; + } + i += p; + + c = search[i]; + if (c == '\0') + return trie_node_add_value(trie, node, key, value); + + child = node_lookup(node, c); + if (!child) { + ssize_t off; + + /* new child */ + child = calloc(sizeof(struct trie_node), 1); + if (!child) { + err = -ENOMEM; + goto out; + } + off = strbuf_add_string(trie->strings, search + i+1, strlen(search + i+1)); + if (off < 0) { + err = off; + goto out; + } + child->prefix_off = off; + err = node_add_child(trie, node, child, c); + if (err) + goto out; + return trie_node_add_value(trie, child, key, value); + } + + node = child; + i++; + } +out: + return err; +} + +struct trie_f { + FILE *f; + struct trie *trie; + uint64_t strings_off; + + uint64_t nodes_count; + uint64_t children_count; + uint64_t values_count; +}; + +/* calculate the storage space for the nodes, children arrays, value arrays */ +static void trie_store_nodes_size(struct trie_f *trie, struct trie_node *node) { + uint64_t i; + + for (i = 0; i < node->children_count; i++) + trie_store_nodes_size(trie, node->children[i].child); + + trie->strings_off += sizeof(struct trie_node_f); + for (i = 0; i < node->children_count; i++) + trie->strings_off += sizeof(struct trie_child_entry_f); + for (i = 0; i < node->values_count; i++) + trie->strings_off += sizeof(struct trie_value_entry_f); +} + +static int64_t trie_store_nodes(struct trie_f *trie, struct trie_node *node) { + uint64_t i; + struct trie_node_f n = { + .prefix_off = htole64(trie->strings_off + node->prefix_off), + .children_count = node->children_count, + .values_count = htole64(node->values_count), + }; + struct trie_child_entry_f *children; + int64_t node_off; + + if (node->children_count) { + children = new0(struct trie_child_entry_f, node->children_count); + if (!children) + return -ENOMEM; + } + + /* post-order recursion */ + for (i = 0; i < node->children_count; i++) { + int64_t child_off; + + child_off = trie_store_nodes(trie, node->children[i].child); + if (child_off < 0) + return child_off; + children[i].c = node->children[i].c; + children[i].child_off = htole64(child_off); + } + + /* write node */ + node_off = ftello(trie->f); + fwrite(&n, sizeof(struct trie_node_f), 1, trie->f); + trie->nodes_count++; + + /* append children array */ + if (node->children_count) { + fwrite(children, sizeof(struct trie_child_entry_f), node->children_count, trie->f); + trie->children_count += node->children_count; + free(children); + } + + /* append values array */ + for (i = 0; i < node->values_count; i++) { + struct trie_value_entry_f v = { + .key_off = htole64(trie->strings_off + node->values[i].key_off), + .value_off = htole64(trie->strings_off + node->values[i].value_off), + }; + + fwrite(&v, sizeof(struct trie_value_entry_f), 1, trie->f); + trie->values_count++; + } + + return node_off; +} + +static int trie_store(struct trie *trie, const char *filename) { + struct trie_f t = { + .trie = trie, + }; + char *filename_tmp; + int64_t pos; + int64_t root_off; + int64_t size; + struct trie_header_f h = { + .signature = HWDB_SIG, + .tool_version = htole64(atoi(VERSION)), + .header_size = htole64(sizeof(struct trie_header_f)), + .node_size = htole64(sizeof(struct trie_node_f)), + .child_entry_size = htole64(sizeof(struct trie_child_entry_f)), + .value_entry_size = htole64(sizeof(struct trie_value_entry_f)), + }; + int err; + + /* calculate size of header, nodes, children entries, value entries */ + t.strings_off = sizeof(struct trie_header_f); + trie_store_nodes_size(&t, trie->root); + + err = fopen_temporary(filename , &t.f, &filename_tmp); + if (err < 0) + return err; + fchmod(fileno(t.f), 0444); + + /* write nodes */ + fseeko(t.f, sizeof(struct trie_header_f), SEEK_SET); + root_off = trie_store_nodes(&t, trie->root); + h.nodes_root_off = htole64(root_off); + pos = ftello(t.f); + h.nodes_len = htole64(pos - sizeof(struct trie_header_f)); + + /* write string buffer */ + fwrite(trie->strings->buf, trie->strings->len, 1, t.f); + h.strings_len = htole64(trie->strings->len); + + /* write header */ + size = ftello(t.f); + h.file_size = htole64(size); + fseeko(t.f, 0, SEEK_SET); + fwrite(&h, sizeof(struct trie_header_f), 1, t.f); + err = ferror(t.f); + if (err) + err = -errno; + fclose(t.f); + if (err < 0 || rename(filename_tmp, filename) < 0) { + unlink(filename_tmp); + goto out; + } + + log_debug("=== trie on-disk ===\n"); + log_debug("size: %8zi bytes\n", size); + log_debug("header: %8zu bytes\n", sizeof(struct trie_header_f)); + log_debug("nodes: %8zu bytes (%8zi)\n", t.nodes_count * sizeof(struct trie_node_f), t.nodes_count); + log_debug("child pointers: %8zu bytes (%8zi)\n", t.children_count * sizeof(struct trie_child_entry_f), t.children_count); + log_debug("value pointers: %8zu bytes (%8zi)\n", t.values_count * sizeof(struct trie_value_entry_f), t.values_count); + log_debug("string store: %8zu bytes\n", trie->strings->len); + log_debug("strings start: %8llu\n", (unsigned long long) t.strings_off); +out: + free(filename_tmp); + return err; +} + +static int import_file(struct trie *trie, const char *filename) { + FILE *f; + char line[LINE_MAX]; + char match[LINE_MAX]; + + f = fopen(filename, "re"); + if (f == NULL) + return -errno; + + match[0] = '\0'; + while (fgets(line, sizeof(line), f)) { + size_t len; + + if (line[0] == '#') + continue; + + /* new line, new record */ + if (line[0] == '\n') { + match[0] = '\0'; + continue; + } + + /* remove newline */ + len = strlen(line); + if (len < 2) + continue; + line[len-1] = '\0'; + + /* start of new record */ + if (match[0] == '\0') { + strcpy(match, line); + continue; + } + + /* value lines */ + if (line[0] == ' ') { + char *value; + + value = strchr(line, '='); + if (!value) + continue; + value[0] = '\0'; + value++; + trie_insert(trie, trie->root, match, line, value); + } + } + fclose(f); + return 0; +} + +static void help(void) { + printf("Usage: udevadm hwdb [--create] [--help]\n" + " --update update the hardware database\n" + " --help\n\n"); +} + +static int adm_hwdb(struct udev *udev, int argc, char *argv[]) { + static const struct option options[] = { + { "update", no_argument, NULL, 'u' }, + { "help", no_argument, NULL, 'h' }, + {} + }; + bool update = false; + struct trie *trie; + char **files, **f; + int err; + int rc = EXIT_SUCCESS; + + for (;;) { + int option; + + option = getopt_long(argc, argv, "ch", options, NULL); + if (option == -1) + break; + + switch (option) { + case 'u': + update = true; + break; + case 'h': + help(); + return EXIT_SUCCESS; + } + } + + if (!update) { + help(); + return EXIT_SUCCESS; + } + + trie = calloc(sizeof(struct trie), 1); + if (!trie) { + rc = EXIT_FAILURE; + goto out; + } + + /* string store */ + trie->strings = strbuf_new(); + if (!trie->strings) { + rc = EXIT_FAILURE; + goto out; + } + + /* index */ + trie->root = calloc(sizeof(struct trie_node), 1); + if (!trie->root) { + rc = EXIT_FAILURE; + goto out; + } + trie->nodes_count++; + + err = conf_files_list_strv(&files, ".hwdb", (const char **)conf_file_dirs); + if (err < 0) { + log_error("failed to enumerate hwdb files: %s\n", strerror(-err)); + rc = EXIT_FAILURE; + goto out; + } + STRV_FOREACH(f, files) { + log_debug("reading file '%s'", *f); + import_file(trie, *f); + } + strv_free(files); + + strbuf_complete(trie->strings); + + log_debug("=== trie in-memory ===\n"); + log_debug("nodes: %8zu bytes (%8zu)\n", trie->nodes_count * sizeof(struct trie_node), trie->nodes_count); + log_debug("children arrays: %8zu bytes (%8zu)\n", trie->children_count * sizeof(struct trie_child_entry), trie->children_count); + log_debug("values arrays: %8zu bytes (%8zu)\n", trie->values_count * sizeof(struct trie_value_entry), trie->values_count); + log_debug("strings: %8zu bytes\n", trie->strings->len); + log_debug("strings incoming: %8zu bytes (%8zu)\n", trie->strings->in_len, trie->strings->in_count); + log_debug("strings dedup'ed: %8zu bytes (%8zu)\n", trie->strings->dedup_len, trie->strings->dedup_count); + + mkdir_parents(SYSCONFDIR "/udev/hwdb.bin", 0755); + err = trie_store(trie, SYSCONFDIR "/udev/hwdb.bin"); + if (err < 0) { + log_error("Failure writing hardware database '%s': %s", SYSCONFDIR "/udev/hwdb.bin", strerror(-err)); + rc = EXIT_FAILURE; + } + +out: + if (trie->root) + trie_node_cleanup(trie->root); + strbuf_cleanup(trie->strings); + free(trie); + return rc; +} + +const struct udevadm_cmd udevadm_hwdb = { + .name = "hwdb", + .cmd = adm_hwdb, + .help = "maintain the hardware database index", +}; -- cgit v1.2.3-54-g00ecf