udevadm-hwdb.c revision 23b7245397ac3d21b2386e7b33d9e4ae3db3c8a1
/***
This file is part of systemd.
Copyright 2012 Kay Sievers <kay.sievers@vrfy.org>
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 <stdlib.h>
#include <unistd.h>
#include <getopt.h>
#include <string.h>
#include "util.h"
#include "strbuf.h"
#include "conf-files.h"
#include "udev.h"
#include "libudev-hwdb-def.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[] = {
"/etc/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) {
ssize_t k, v;
struct trie_value_entry *val;
k = strbuf_add_string(trie->strings, key, strlen(key));
if (k < 0)
return k;
v = strbuf_add_string(trie->strings, value, strlen(value));
if (v < 0)
return v;
if (node->values_count) {
struct trie_value_entry search = {
.key_off = k,
.value_off = v,
};
val = xbsearch_r(&search, node->values, node->values_count, sizeof(struct trie_value_entry), trie_values_cmp, trie);
if (val) {
/* replace existing earlier key with new value */
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 = NULL;
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: %8llu bytes\n", (unsigned long long)size);
log_debug("header: %8zu bytes\n", sizeof(struct trie_header_f));
log_debug("nodes: %8llu bytes (%8llu)\n",
(unsigned long long)t.nodes_count * sizeof(struct trie_node_f), (unsigned long long)t.nodes_count);
log_debug("child pointers: %8llu bytes (%8llu)\n",
(unsigned long long)t.children_count * sizeof(struct trie_child_entry_f), (unsigned long long)t.children_count);
log_debug("value pointers: %8llu bytes (%8llu)\n",
(unsigned long long)t.values_count * sizeof(struct trie_value_entry_f), (unsigned long long)t.values_count);
log_debug("string store: %8llu bytes\n", (unsigned long long)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];
char cond[LINE_MAX];
f = fopen(filename, "re");
if (f == NULL)
return -errno;
match[0] = '\0';
cond[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';
cond[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);
cond[0] = '\0';
continue;
}
if (line[0] == '+') {
strcpy(cond, line);
continue;
}
/* TODO: support +; skip the entire record until we support it */
if (cond[0] != '\0')
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"
" --test <modalias> query database and print result\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' },
{ "test", required_argument, NULL, 't' },
{ "help", no_argument, NULL, 'h' },
{}
};
const char *test = NULL;
bool update = false;
struct trie *trie = NULL;
int err;
int rc = EXIT_SUCCESS;
for (;;) {
int option;
option = getopt_long(argc, argv, "ut:h", options, NULL);
if (option == -1)
break;
switch (option) {
case 'u':
update = true;
break;
case 't':
test = optarg;
break;
case 'h':
help();
return EXIT_SUCCESS;
}
}
if (!update && !test) {
help();
return EXIT_SUCCESS;
}
if (update) {
char **files, **f;
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("/etc/udev/hwdb.bin", 0755);
err = trie_store(trie, "/etc/udev/hwdb.bin");
if (err < 0) {
log_error("Failure writing hardware database '%s': %s", "/etc/udev/hwdb.bin", strerror(-err));
rc = EXIT_FAILURE;
}
}
if (test) {
struct udev_hwdb *hwdb = udev_hwdb_new(udev);
if (hwdb) {
struct udev_list_entry *entry;
udev_list_entry_foreach(entry, udev_hwdb_get_properties_list_entry(hwdb, test, 0))
printf("%s=%s\n", udev_list_entry_get_name(entry), udev_list_entry_get_value(entry));
hwdb = udev_hwdb_unref(hwdb);
}
}
out:
if (trie) {
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",
};