/*** This file is part of systemd. Copyright 2012 Kay Sievers <kay@vrfy.org> Copyright 2008 Alan Jenkins <alan.christopher.jenkins@googlemail.com> 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 <http://www.gnu.org/licenses/>. ***/ #include <stdio.h> #include <errno.h> #include <string.h> #include <inttypes.h> #include <ctype.h> #include <stdlib.h> #include <fnmatch.h> #include <getopt.h> #include <sys/mman.h> #include "libudev-private.h" #include "libudev-hwdb-def.h" /** * SECTION:libudev-hwdb * @short_description: retrieve properties from the hardware database * * Libudev hardware database interface. */ /** * udev_hwdb: * * Opaque object representing the hardware database. */ struct udev_hwdb { struct udev *udev; int refcount; FILE *f; struct stat st; union { struct trie_header_f *head; const char *map; }; struct udev_list properties_list; }; struct linebuf { char bytes[LINE_MAX]; size_t size; size_t len; }; static void linebuf_init(struct linebuf *buf) { buf->size = 0; buf->len = 0; } static const char *linebuf_get(struct linebuf *buf) { if (buf->len + 1 >= sizeof(buf->bytes)) return NULL; buf->bytes[buf->len] = '\0'; return buf->bytes; } static bool linebuf_add(struct linebuf *buf, const char *s, size_t len) { if (buf->len + len >= sizeof(buf->bytes)) return false; memcpy(buf->bytes + buf->len, s, len); buf->len += len; return true; } static bool linebuf_add_char(struct linebuf *buf, char c) { if (buf->len + 1 >= sizeof(buf->bytes)) return false; buf->bytes[buf->len++] = c; return true; } static void linebuf_rem(struct linebuf *buf, size_t count) { assert(buf->len >= count); buf->len -= count; } static void linebuf_rem_char(struct linebuf *buf) { linebuf_rem(buf, 1); } static const struct trie_child_entry_f *trie_node_children(struct udev_hwdb *hwdb, const struct trie_node_f *node) { return (const struct trie_child_entry_f *)((const char *)node + le64toh(hwdb->head->node_size)); } static const struct trie_value_entry_f *trie_node_values(struct udev_hwdb *hwdb, const struct trie_node_f *node) { const char *base = (const char *)node; base += le64toh(hwdb->head->node_size); base += node->children_count * le64toh(hwdb->head->child_entry_size); return (const struct trie_value_entry_f *)base; } static const struct trie_node_f *trie_node_from_off(struct udev_hwdb *hwdb, le64_t off) { return (const struct trie_node_f *)(hwdb->map + le64toh(off)); } static const char *trie_string(struct udev_hwdb *hwdb, le64_t off) { return hwdb->map + le64toh(off); } static int trie_children_cmp_f(const void *v1, const void *v2) { const struct trie_child_entry_f *n1 = v1; const struct trie_child_entry_f *n2 = v2; return n1->c - n2->c; } static const struct trie_node_f *node_lookup_f(struct udev_hwdb *hwdb, const struct trie_node_f *node, uint8_t c) { struct trie_child_entry_f *child; struct trie_child_entry_f search; search.c = c; child = bsearch(&search, trie_node_children(hwdb, node), node->children_count, le64toh(hwdb->head->child_entry_size), trie_children_cmp_f); if (child) return trie_node_from_off(hwdb, child->child_off); return NULL; } static int hwdb_add_property(struct udev_hwdb *hwdb, const char *key, const char *value) { /* TODO: add sub-matches (+) against DMI data */ if (key[0] != ' ') return 0; if (udev_list_entry_add(&hwdb->properties_list, key+1, value) == NULL) return -ENOMEM; return 0; } static int trie_fnmatch_f(struct udev_hwdb *hwdb, const struct trie_node_f *node, size_t p, struct linebuf *buf, const char *search) { size_t len; size_t i; const char *prefix; int err; prefix = trie_string(hwdb, node->prefix_off); len = strlen(prefix + p); linebuf_add(buf, prefix + p, len); for (i = 0; i < node->children_count; i++) { const struct trie_child_entry_f *child = &trie_node_children(hwdb, node)[i]; linebuf_add_char(buf, child->c); err = trie_fnmatch_f(hwdb, trie_node_from_off(hwdb, child->child_off), 0, buf, search); if (err < 0) return err; linebuf_rem_char(buf); } if (le64toh(node->values_count) && fnmatch(linebuf_get(buf), search, 0) == 0) for (i = 0; i < le64toh(node->values_count); i++) { err = hwdb_add_property(hwdb, trie_string(hwdb, trie_node_values(hwdb, node)[i].key_off), trie_string(hwdb, trie_node_values(hwdb, node)[i].value_off)); if (err < 0) return err; } linebuf_rem(buf, len); return 0; } static int trie_search_f(struct udev_hwdb *hwdb, const char *search) { struct linebuf buf; const struct trie_node_f *node; size_t i = 0; int err; linebuf_init(&buf); node = trie_node_from_off(hwdb, hwdb->head->nodes_root_off); while (node) { const struct trie_node_f *child; size_t p = 0; if (node->prefix_off) { uint8_t c; for (; (c = trie_string(hwdb, node->prefix_off)[p]); p++) { if (c == '*' || c == '?' || c == '[') return trie_fnmatch_f(hwdb, node, p, &buf, search + i + p); if (c != search[i + p]) return 0; } i += p; } child = node_lookup_f(hwdb, node, '*'); if (child) { linebuf_add_char(&buf, '*'); err = trie_fnmatch_f(hwdb, child, 0, &buf, search + i); if (err < 0) return err; linebuf_rem_char(&buf); } child = node_lookup_f(hwdb, node, '?'); if (child) { linebuf_add_char(&buf, '?'); err = trie_fnmatch_f(hwdb, child, 0, &buf, search + i); if (err < 0) return err; linebuf_rem_char(&buf); } child = node_lookup_f(hwdb, node, '['); if (child) { linebuf_add_char(&buf, '['); err = trie_fnmatch_f(hwdb, child, 0, &buf, search + i); if (err < 0) return err; linebuf_rem_char(&buf); } if (search[i] == '\0') { size_t n; for (n = 0; n < le64toh(node->values_count); n++) { err = hwdb_add_property(hwdb, trie_string(hwdb, trie_node_values(hwdb, node)[n].key_off), trie_string(hwdb, trie_node_values(hwdb, node)[n].value_off)); if (err < 0) return err; } return 0; } child = node_lookup_f(hwdb, node, search[i]); node = child; i++; } return 0; } /** * udev_hwdb_new: * @udev: udev library context * * Create a hardware database context to query properties for devices. * * Returns: a hwdb context. **/ _public_ struct udev_hwdb *udev_hwdb_new(struct udev *udev) { struct udev_hwdb *hwdb; const char sig[] = HWDB_SIG; hwdb = new0(struct udev_hwdb, 1); if (!hwdb) return NULL; hwdb->refcount = 1; udev_list_init(udev, &hwdb->properties_list, true); hwdb->f = fopen("/etc/udev/hwdb.bin", "re"); if (!hwdb->f) { log_debug("error reading /etc/udev/hwdb.bin: %m"); udev_hwdb_unref(hwdb); return NULL; } if (fstat(fileno(hwdb->f), &hwdb->st) < 0 || (size_t)hwdb->st.st_size < offsetof(struct trie_header_f, strings_len) + 8) { log_debug("error reading /etc/udev/hwdb.bin: %m"); udev_hwdb_unref(hwdb); return NULL; } hwdb->map = mmap(0, hwdb->st.st_size, PROT_READ, MAP_SHARED, fileno(hwdb->f), 0); if (hwdb->map == MAP_FAILED) { log_debug("error mapping /etc/udev/hwdb.bin: %m"); udev_hwdb_unref(hwdb); return NULL; } if (memcmp(hwdb->map, sig, sizeof(hwdb->head->signature)) != 0 || (size_t)hwdb->st.st_size != le64toh(hwdb->head->file_size)) { log_debug("error recognizing the format of /etc/udev/hwdb.bin"); udev_hwdb_unref(hwdb); return NULL; } log_debug("=== trie on-disk ===\n"); log_debug("tool version: %llu", (unsigned long long)le64toh(hwdb->head->tool_version)); log_debug("file size: %8llu bytes\n", (unsigned long long)hwdb->st.st_size); log_debug("header size %8llu bytes\n", (unsigned long long)le64toh(hwdb->head->header_size)); log_debug("strings %8llu bytes\n", (unsigned long long)le64toh(hwdb->head->strings_len)); log_debug("nodes %8llu bytes\n", (unsigned long long)le64toh(hwdb->head->nodes_len)); return hwdb; } /** * udev_hwdb_ref: * @hwdb: context * * Take a reference of a hwdb context. * * Returns: the passed enumeration context **/ _public_ struct udev_hwdb *udev_hwdb_ref(struct udev_hwdb *hwdb) { if (!hwdb) return NULL; hwdb->refcount++; return hwdb; } /** * udev_hwdb_unref: * @hwdb: context * * Drop a reference of a hwdb context. If the refcount reaches zero, * all resources of the hwdb context will be released. * * Returns: the passed hwdb context if it has still an active reference, or #NULL otherwise. **/ _public_ struct udev_hwdb *udev_hwdb_unref(struct udev_hwdb *hwdb) { if (!hwdb) return NULL; hwdb->refcount--; if (hwdb->refcount > 0) return hwdb; if (hwdb->map) munmap((void *)hwdb->map, hwdb->st.st_size); if (hwdb->f) fclose(hwdb->f); udev_list_cleanup(&hwdb->properties_list); free(hwdb); return NULL; } bool udev_hwdb_validate(struct udev_hwdb *hwdb) { struct stat st; if (!hwdb) return false; if (!hwdb->f) return false; if (fstat(fileno(hwdb->f), &st) < 0) return true; if (timespec_load(&hwdb->st.st_mtim) != timespec_load(&st.st_mtim)) return true; return false; } /** * udev_hwdb_get_properties_list_entry: * @hwdb: context * @modalias: modalias string * @flags: (unused) * * Lookup a matching device in the hardware database. The lookup key is a * modalias string, whose formats are defined for the Linux kernel modules. * Examples are: pci:v00008086d00001C2D*, usb:v04F2pB221*. The first entry * of a list of retrieved properties is returned. * * Returns: a udev_list_entry. */ _public_ struct udev_list_entry *udev_hwdb_get_properties_list_entry(struct udev_hwdb *hwdb, const char *modalias, unsigned int flags) { int err; if (!hwdb || !hwdb->f) { errno = EINVAL; return NULL; } udev_list_cleanup(&hwdb->properties_list); err = trie_search_f(hwdb, modalias); if (err < 0) { errno = -err; return NULL; } return udev_list_get_entry(&hwdb->properties_list); }