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mirror of https://github.com/systemd/systemd-stable.git synced 2024-10-31 07:51:08 +03:00
systemd-stable/udev.c
kay.sievers@vrfy.org 5472beeea5 [PATCH] udev - advanced user query options
This patch improves the user options for udev.
It is possible now to query for the name, the symlinks or owner/group.
If asked for the name of the node we are able to prepend the udev_root
with the -r option.

SAMPLE:

  kay@pim:~/src/udev.test$ ./udev -V
  udev, version 012_bk

  kay@pim:~/src/udev.test$ ./udev -h
  Usage: [-qrVh]
    -q <name>  query database for the specified value
    -p <path>  device path used for query
    -r         print udev root
    -V         print udev version
    -h         print this help text

  kay@pim:~/src/udev.test$ ./udev -r
  /udev/

  kay@pim:~/src/udev.test$ ./udev -q name -p /class/video4linux/video0
  video/webcam0

  kay@pim:~/src/udev.test$ ./udev -q symlink -p /class/video4linux/video0
  camera0 kamera0

  kay@pim:~/src/udev.test$ ./udev -q owner -p /class/video4linux/video0
  501

  kay@pim:~/src/udev.test$ ./udev -r -q name -p /class/video4linux/video0
  /udev/video/webcam0
2005-04-26 21:13:15 -07:00

330 lines
6.0 KiB
C

/*
* udev.c
*
* Userspace devfs
*
* Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
*
*
* 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 <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <ctype.h>
#include <signal.h>
#include <stdarg.h>
#include "udev.h"
#include "udev_version.h"
#include "udev_dbus.h"
#include "namedev.h"
#include "udevdb.h"
#include "libsysfs/libsysfs.h"
/* global variables */
char **main_argv;
char **main_envp;
static void sig_handler(int signum)
{
dbg("caught signal %d", signum);
switch (signum) {
case SIGINT:
case SIGTERM:
case SIGKILL:
sysbus_disconnect();
udevdb_exit();
exit(20 + signum);
break;
default:
dbg("unhandled signal");
}
}
static inline char *get_action(void)
{
char *action;
action = getenv("ACTION");
return action;
}
static inline char *get_devpath(void)
{
char *devpath;
devpath = getenv("DEVPATH");
return devpath;
}
static inline char *get_seqnum(void)
{
char *seqnum;
seqnum = getenv("SEQNUM");
return seqnum;
}
enum query_type {
NONE,
NAME,
SYMLINK,
OWNER,
GROUP
};
static inline int udev_user(int argc, char **argv)
{
static const char short_options[] = "p:q:rVh";
int option;
int retval = -EINVAL;
struct udevice dev;
int root = 0;
enum query_type query = NONE;
char result[NAME_SIZE] = "";
char path[NAME_SIZE] = "";
/* get command line options */
while (1) {
option = getopt(argc, argv, short_options);
if (option == -1)
break;
dbg("option '%c'", option);
switch (option) {
case 'p':
dbg("udev path: %s\n", optarg);
strfieldcpy(path, optarg);
break;
case 'q':
dbg("udev query: %s\n", optarg);
if (strcmp(optarg, "name") == 0) {
query = NAME;
break;
}
if (strcmp(optarg, "symlink") == 0) {
query = SYMLINK;
break;
}
if (strcmp(optarg, "owner") == 0) {
query = OWNER;
break;
}
if (strcmp(optarg, "group") == 0) {
query = GROUP;
break;
}
printf("unknown query type\n");
return -EINVAL;
case 'r':
root = 1;
break;
case 'V':
printf("udev, version %s\n", UDEV_VERSION);
return 0;
case 'h':
retval = 0;
case '?':
default:
goto help;
}
}
/* process options */
if (query != NONE) {
if (path[0] == '\0') {
printf("query needs device path specified\n");
return -EINVAL;
}
retval = udevdb_open_ro();
if (retval != 0) {
printf("unable to open udev database\n");
return -EACCES;
}
retval = udevdb_get_dev(path, &dev);
if (retval == 0) {
switch(query) {
case NAME:
if (root)
strfieldcpy(result, udev_root);
strncat(result, dev.name, sizeof(result));
break;
case SYMLINK:
strfieldcpy(result, dev.symlink);
break;
case GROUP:
strfieldcpy(result, dev.group);
break;
case OWNER:
strfieldcpy(result, dev.owner);
break;
default:
break;
}
printf("%s\n", result);
} else {
printf("device not found in udev database\n");
}
udevdb_exit();
return retval;
}
if (root) {
printf("%s\n", udev_root);
return 0;
}
help:
printf("Usage: [-qrVh]\n"
" -q <name> query database for the specified value\n"
" -p <path> device path used for query\n"
" -r print udev root\n"
" -V print udev version\n"
" -h print this help text\n"
"\n");
return retval;
}
static char *subsystem_blacklist[] = {
"net",
"scsi_host",
"scsi_device",
"",
};
static inline int udev_hotplug(int argc, char **argv)
{
char *action;
char *devpath;
char *subsystem;
int retval = -EINVAL;
int i;
subsystem = argv[1];
devpath = get_devpath();
if (!devpath) {
dbg ("no devpath?");
goto exit;
}
dbg("looking at '%s'", devpath);
/* we only care about class devices and block stuff */
if (!strstr(devpath, "class") &&
!strstr(devpath, "block")) {
dbg("not a block or class device");
goto exit;
}
/* skip blacklisted subsystems */
i = 0;
while (subsystem_blacklist[i][0] != '\0') {
if (strcmp(subsystem, subsystem_blacklist[i]) == 0) {
dbg("don't care about '%s' devices", subsystem);
goto exit;
}
i++;
}
action = get_action();
if (!action) {
dbg ("no action?");
goto exit;
}
/* connect to the system message bus */
sysbus_connect();
/* initialize udev database */
retval = udevdb_init(UDEVDB_DEFAULT);
if (retval != 0) {
dbg("unable to initialize database");
goto exit_sysbus;
}
/* set up a default signal handler for now */
signal(SIGINT, sig_handler);
signal(SIGTERM, sig_handler);
signal(SIGKILL, sig_handler);
/* initialize the naming deamon */
namedev_init();
if (strcmp(action, "add") == 0)
retval = udev_add_device(devpath, subsystem);
else if (strcmp(action, "remove") == 0)
retval = udev_remove_device(devpath, subsystem);
else {
dbg("unknown action '%s'", action);
retval = -EINVAL;
}
udevdb_exit();
exit_sysbus:
/* disconnect from the system message bus */
sysbus_disconnect();
exit:
if (retval > 0)
retval = 0;
return -retval;
}
int main(int argc, char **argv, char **envp)
{
int retval;
main_argv = argv;
main_envp = envp;
dbg("version %s", UDEV_VERSION);
/* initialize our configuration */
udev_init_config();
if (argc == 2 && argv[1][0] != '-') {
dbg("called by hotplug");
retval = udev_hotplug(argc, argv);
} else {
dbg("called by user");
retval = udev_user(argc, argv);
}
return retval;
}