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mirror of https://github.com/systemd/systemd-stable.git synced 2024-10-30 23:21:08 +03:00
systemd-stable/udev_db.c

344 lines
8.6 KiB
C

/*
* Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation version 2 of the License.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "udev.h"
static size_t devpath_to_db_path(const char *devpath, char *filename, size_t len)
{
size_t start;
/* translate to location of db file */
strlcpy(filename, udev_root, len);
start = strlcat(filename, "/"DB_DIR"/", len);
strlcat(filename, devpath, len);
return path_encode(&filename[start], len - start);
}
/* reverse mapping from the device file name to the devpath */
static int name_index(const char *devpath, const char *name, int add)
{
char device[PATH_SIZE];
char filename[PATH_SIZE * 2];
size_t start;
int fd;
/* directory with device name */
strlcpy(filename, udev_root, sizeof(filename));
start = strlcat(filename, "/"DB_NAME_INDEX_DIR"/", sizeof(filename));
strlcat(filename, name, sizeof(filename));
path_encode(&filename[start], sizeof(filename) - start);
/* entry with the devpath */
strlcpy(device, devpath, sizeof(device));
path_encode(device, sizeof(device));
strlcat(filename, "/", sizeof(filename));
strlcat(filename, device, sizeof(filename));
if (add) {
info("creating index: '%s'", filename);
create_path(filename);
fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
if (fd > 0)
close(fd);
} else {
info("removing index: '%s'", filename);
unlink(filename);
delete_path(filename);
}
return 0;
}
int udev_db_get_devices_by_name(const char *name, struct list_head *name_list)
{
char dirname[PATH_MAX];
size_t start;
DIR *dir;
int rc = 0;
strlcpy(dirname, udev_root, sizeof(dirname));
start = strlcat(dirname, "/"DB_NAME_INDEX_DIR"/", sizeof(dirname));
strlcat(dirname, name, sizeof(dirname));
path_encode(&dirname[start], sizeof(dirname) - start);
dir = opendir(dirname);
if (dir == NULL) {
info("no index directory '%s': %s", dirname, strerror(errno));
rc = -1;
goto out;
}
info("found index directory '%s'", dirname);
while (1) {
struct dirent *ent;
char device[PATH_SIZE];
ent = readdir(dir);
if (ent == NULL || ent->d_name[0] == '\0')
break;
if (ent->d_name[0] == '.')
continue;
strlcpy(device, ent->d_name, sizeof(device));
path_decode(device);
name_list_add(name_list, device, 0);
rc++;
}
closedir(dir);
out:
return rc;
}
int udev_db_rename(const char *devpath_old, const char *devpath)
{
char filename[PATH_SIZE];
char filename_old[PATH_SIZE];
devpath_to_db_path(devpath_old, filename_old, sizeof(filename_old));
devpath_to_db_path(devpath, filename, sizeof(filename));
return rename(filename_old, filename);
}
int udev_db_add_device(struct udevice *udev)
{
char filename[PATH_SIZE];
if (udev->test_run)
return 0;
devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
create_path(filename);
unlink(filename);
/*
* don't waste tmpfs memory pages, if we don't have any data to store
* create fake db-file; store the node-name in a symlink target
*/
if (list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
!udev->partitions && !udev->ignore_remove) {
dbg("nothing interesting to store, create symlink");
if (symlink(udev->name, filename) != 0) {
err("unable to create db link '%s': %s", filename, strerror(errno));
return -1;
}
} else {
FILE *f;
struct name_entry *name_loop;
f = fopen(filename, "w");
if (f == NULL) {
err("unable to create db file '%s': %s", filename, strerror(errno));
return -1;
}
dbg("storing data for device '%s' in '%s'", udev->dev->devpath, filename);
fprintf(f, "N:%s\n", udev->name);
list_for_each_entry(name_loop, &udev->symlink_list, node) {
fprintf(f, "S:%s\n", name_loop->name);
/* add symlink-name to index */
name_index(udev->dev->devpath, name_loop->name, 1);
}
fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
if (udev->link_priority != 0)
fprintf(f, "L:%u\n", udev->link_priority);
if (udev->partitions != 0)
fprintf(f, "A:%u\n", udev->partitions);
if (udev->ignore_remove)
fprintf(f, "R:%u\n", udev->ignore_remove);
list_for_each_entry(name_loop, &udev->env_list, node)
fprintf(f, "E:%s\n", name_loop->name);
fclose(f);
}
/* add name to index */
name_index(udev->dev->devpath, udev->name, 1);
return 0;
}
int udev_db_get_device(struct udevice *udev, const char *devpath)
{
struct stat stats;
char filename[PATH_SIZE];
char line[PATH_SIZE];
unsigned int maj, min;
char *bufline;
char *buf;
size_t bufsize;
size_t cur;
size_t count;
sysfs_device_set_values(udev->dev, devpath, NULL, NULL);
devpath_to_db_path(devpath, filename, sizeof(filename));
if (lstat(filename, &stats) != 0) {
info("no db file to read %s: %s", filename, strerror(errno));
return -1;
}
if ((stats.st_mode & S_IFMT) == S_IFLNK) {
char target[NAME_SIZE];
int target_len;
info("found a symlink as db file");
target_len = readlink(filename, target, sizeof(target));
if (target_len > 0)
target[target_len] = '\0';
else {
info("error reading db link %s: %s", filename, strerror(errno));
return -1;
}
dbg("db link points to '%s'", target);
strlcpy(udev->name, target, sizeof(udev->name));
return 0;
}
if (file_map(filename, &buf, &bufsize) != 0) {
info("error reading db file %s: %s", filename, strerror(errno));
return -1;
}
cur = 0;
while (cur < bufsize) {
count = buf_get_line(buf, bufsize, cur);
bufline = &buf[cur];
cur += count+1;
switch(bufline[0]) {
case 'N':
if (count > sizeof(udev->name))
count = sizeof(udev->name);
memcpy(udev->name, &bufline[2], count-2);
udev->name[count-2] = '\0';
break;
case 'M':
if (count > sizeof(line))
count = sizeof(line);
memcpy(line, &bufline[2], count-2);
line[count-2] = '\0';
sscanf(line, "%u:%u", &maj, &min);
udev->devt = makedev(maj, min);
break;
case 'S':
if (count > sizeof(line))
count = sizeof(line);
memcpy(line, &bufline[2], count-2);
line[count-2] = '\0';
name_list_add(&udev->symlink_list, line, 0);
break;
case 'L':
if (count > sizeof(line))
count = sizeof(line);
memcpy(line, &bufline[2], count-2);
line[count-2] = '\0';
udev->link_priority = atoi(line);
break;
case 'A':
if (count > sizeof(line))
count = sizeof(line);
memcpy(line, &bufline[2], count-2);
line[count-2] = '\0';
udev->partitions = atoi(line);
break;
case 'R':
if (count > sizeof(line))
count = sizeof(line);
memcpy(line, &bufline[2], count-2);
line[count-2] = '\0';
udev->ignore_remove = atoi(line);
break;
case 'E':
if (count > sizeof(line))
count = sizeof(line);
memcpy(line, &bufline[2], count-2);
line[count-2] = '\0';
name_list_add(&udev->env_list, line, 0);
break;
}
}
file_unmap(buf, bufsize);
if (udev->name[0] == '\0')
return -1;
return 0;
}
int udev_db_delete_device(struct udevice *udev)
{
char filename[PATH_SIZE];
struct name_entry *name_loop;
if (udev->test_run)
return 0;
devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
unlink(filename);
name_index(udev->dev->devpath, udev->name, 0);
list_for_each_entry(name_loop, &udev->symlink_list, node)
name_index(udev->dev->devpath, name_loop->name, 0);
return 0;
}
int udev_db_get_all_entries(struct list_head *name_list)
{
char dbpath[PATH_MAX];
DIR *dir;
strlcpy(dbpath, udev_root, sizeof(dbpath));
strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
dir = opendir(dbpath);
if (dir == NULL) {
info("no udev_db available '%s': %s", dbpath, strerror(errno));
return -1;
}
while (1) {
struct dirent *ent;
char device[PATH_SIZE];
ent = readdir(dir);
if (ent == NULL || ent->d_name[0] == '\0')
break;
if (ent->d_name[0] == '.')
continue;
strlcpy(device, ent->d_name, sizeof(device));
path_decode(device);
name_list_add(name_list, device, 1);
dbg("added '%s'", device);
}
closedir(dir);
return 0;
}