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mirror of https://github.com/systemd/systemd-stable.git synced 2024-10-30 14:55:26 +03:00
systemd-stable/udevdb.c

237 lines
5.2 KiB
C

/*
* udevdb.c - udev database library
*
* Userspace devfs
*
* Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2003 IBM Corp.
*
* 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.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stddef.h>
#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include <errno.h>
#include <signal.h>
#include "libsysfs/sysfs/libsysfs.h"
#include "udev.h"
#include "udev_lib.h"
#include "udev_version.h"
#include "logging.h"
#include "namedev.h"
#include "udevdb.h"
#include "tdb/tdb.h"
static TDB_CONTEXT *udevdb;
sig_atomic_t gotalarm;
int udevdb_add_dev(struct udevice *udev)
{
TDB_DATA key, data;
char keystr[SYSFS_PATH_MAX];
if (udev->test_run)
return 0;
if (udevdb == NULL)
return -1;
memset(keystr, 0x00, SYSFS_PATH_MAX);
strfieldcpy(keystr, udev->devpath);
key.dptr = keystr;
key.dsize = strlen(keystr) + 1;
data.dptr = (void *) udev;
data.dsize = UDEVICE_DB_LEN;
dbg("store key '%s' for device '%s'", keystr, udev->name);
return tdb_store(udevdb, key, data, TDB_REPLACE);
}
int udevdb_get_dev(const char *path, struct udevice *udev)
{
TDB_DATA key, data;
if (udevdb == NULL)
return -1;
if (path == NULL)
return -ENODEV;
key.dptr = (void *)path;
key.dsize = strlen(path) + 1;
data = tdb_fetch(udevdb, key);
if (data.dptr == NULL || data.dsize == 0)
return -ENODEV;
memset(udev, 0x00, sizeof(struct udevice));
memcpy(udev, data.dptr, UDEVICE_DB_LEN);
return 0;
}
int udevdb_delete_dev(const char *path)
{
TDB_DATA key;
char keystr[SYSFS_PATH_MAX];
if (udevdb == NULL)
return -1;
if (path == NULL)
return -EINVAL;
memset(keystr, 0, sizeof(keystr));
strfieldcpy(keystr, path);
key.dptr = keystr;
key.dsize = strlen(keystr) + 1;
return tdb_delete(udevdb, key);
}
/**
* udevdb_exit: closes database
*/
void udevdb_exit(void)
{
if (udevdb != NULL) {
tdb_close(udevdb);
udevdb = NULL;
}
}
/**
* udevdb_init: initializes database
* @init_flag: UDEVDB_INTERNAL - database stays in memory
* UDEVDB_DEFAULT - database is written to a file
*/
int udevdb_init(int init_flag)
{
if (init_flag != UDEVDB_DEFAULT && init_flag != UDEVDB_INTERNAL)
return -EINVAL;
tdb_set_lock_alarm(&gotalarm);
udevdb = tdb_open(udev_db_filename, 0, init_flag, O_RDWR | O_CREAT, 0644);
if (udevdb == NULL) {
if (init_flag == UDEVDB_INTERNAL)
dbg("unable to initialize in-memory database");
else
dbg("unable to initialize database at '%s'", udev_db_filename);
return -EACCES;
}
return 0;
}
/**
* udevdb_open_ro: open database for reading
*/
int udevdb_open_ro(void)
{
udevdb = tdb_open(udev_db_filename, 0, 0, O_RDONLY, 0);
if (udevdb == NULL) {
dbg("unable to open database at '%s'", udev_db_filename);
return -EACCES;
}
return 0;
}
static int (*user_record_callback) (const char *path, struct udevice *dev);
static int traverse_callback(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
{
return user_record_callback((char*) key.dptr, (struct udevice*) dbuf.dptr);
}
/**
* udevdb_call_foreach: dumps whole database by passing record data to user function
* @user_record_handler: user function called for every record in the database
*/
int udevdb_call_foreach(int (*user_record_handler) (const char *path, struct udevice *dev))
{
int retval = 0;
if (udevdb == NULL)
return -1;
if (user_record_handler == NULL) {
dbg("invalid user record handling function");
return -EINVAL;
}
user_record_callback = user_record_handler;
retval = tdb_traverse(udevdb, traverse_callback, NULL);
if (retval < 0)
return -ENODEV;
else
return 0;
}
static struct udevice *find_dev;
static char *find_path;
static const char *find_name;
static int find_found;
static int find_device_by_name(const char *path, struct udevice *udev)
{
char *pos;
int len;
if (strncmp(udev->name, find_name, sizeof(udev->name)) == 0) {
memcpy(find_dev, udev, sizeof(struct udevice));
strfieldcpymax(find_path, path, NAME_SIZE);
find_found = 1;
/* stop search */
return 1;
}
/* look for matching symlink*/
foreach_strpart(udev->symlink, " ", pos, len) {
if (strncmp(pos, find_name, len) != 0)
continue;
if (len != strlen(find_name))
continue;
memcpy(find_dev, udev, sizeof(struct udevice));
strfieldcpymax(find_path, path, NAME_SIZE);
find_found = 1;
return 1;
}
return 0;
}
/**
* udevdb_get_dev_byname: search device with given name by traversing the whole database
*/
int udevdb_get_dev_byname(const char *name, char *path, struct udevice *dev)
{
find_found = 0;
find_path = path;
find_dev = dev;
find_name = name;
udevdb_call_foreach(find_device_by_name);
if (find_found == 1)
return 0;
else
return -1;
}