libudev-device.c revision 2ffc9cc1917b1bb6fe86881a94a47dce9aa15168
/*
* libudev - interface to udev device information
*
* Copyright (C) 2008-2009 Kay Sievers <kay.sievers@vrfy.org>
*
* 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.
*/
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <dirent.h>
#include <fcntl.h>
#include <ctype.h>
#include "libudev.h"
#include "libudev-private.h"
/**
* SECTION:libudev-device
* @short_description: kernel sys devices
*
* Representation of kernel sys devices. Devices are uniquely identified
* by their syspath, every device has exactly one path in the kernel sys
* filesystem. Devices usually belong to a kernel subsystem, and and have
* a unique name inside that subsystem.
*/
/**
* udev_device:
*
* Opaque object representing one kernel sys device.
*/
struct udev_device {
struct udev_device *parent_device;
char *syspath;
const char *devpath;
char *sysname;
const char *sysnum;
char *devnode;
char *subsystem;
char *devtype;
char *driver;
char *action;
char *devpath_old;
char *sysname_old;
char *knodename;
char **envp;
char *monitor_buf;
struct udev_list_node devlinks_list;
struct udev_list_node properties_list;
struct udev_list_node sysattr_list;
unsigned long long int seqnum;
int event_timeout;
int timeout;
int num_fake_partitions;
int devlink_priority;
int refcount;
int watch_handle;
unsigned int parent_set:1;
unsigned int subsystem_set:1;
unsigned int devtype_set:1;
unsigned int devlinks_uptodate:1;
unsigned int envp_uptodate:1;
unsigned int driver_set:1;
unsigned int info_loaded:1;
unsigned int ignore_remove:1;
};
{
char filename[UTIL_PATH_SIZE];
char line[UTIL_LINE_SIZE];
FILE *f;
return -1;
}
char target[UTIL_PATH_SIZE];
char devnode[UTIL_PATH_SIZE];
int target_len;
char *next;
if (target_len > 0)
else {
return -1;
}
next[0] = '\0';
}
char devlink[UTIL_PATH_SIZE];
const char *lnk;
next[0] = '\0';
}
}
info(udev_device->udev, "device %p filled with db symlink data '%s'\n", udev_device, udev_device->devnode);
return 0;
}
if (f == NULL) {
return -1;
}
const char *val;
if (len < 4)
break;
switch(line[0]) {
case 'N':
break;
case 'S':
break;
case 'L':
break;
case 'T':
break;
case 'A':
break;
case 'R':
break;
case 'E':
break;
case 'W':
break;
}
}
fclose(f);
return 0;
}
{
char filename[UTIL_PATH_SIZE];
FILE *f;
char line[UTIL_LINE_SIZE];
int maj = 0;
int min = 0;
if (f == NULL)
return -1;
char *pos;
continue;
pos[0] = '\0';
}
fclose(f);
return 0;
}
{
}
{
}
{
struct udev_device *udev_device;
struct udev_list_entry *list_entry;
return NULL;
if (udev_device == NULL)
return NULL;
/* copy global properties */
return udev_device;
}
/**
* udev_device_new_from_syspath:
* @udev: udev library context
* @syspath: sys device path including sys directory
*
* Create new udev device, and fill in information from the sys
* device and the udev database entry. The syspath is the absolute
* path to the device, including the sys mount point.
*
* The initial refcount is 1, and needs to be decremented to
* release the resources of the udev device.
*
* Returns: a new udev device, or #NULL, if it does not exist
**/
{
const char *subdir;
char path[UTIL_PATH_SIZE];
char *pos;
struct udev_device *udev_device;
return NULL;
return NULL;
/* path starts in sys */
return NULL;
}
/* path is not a root directory */
return NULL;
}
/* resolve possible symlink to real path */
/* try to resolve the silly block layout if needed */
char block[UTIL_PATH_SIZE];
char part[UTIL_PATH_SIZE];
return NULL;
pos[0] = '\0';
}
/* path exists in sys */
char file[UTIL_PATH_SIZE];
/* all "devices" require a "uevent" file */
return NULL;
}
} else {
/* everything else just needs to be a directory */
return NULL;
}
}
if (udev_device == NULL)
return NULL;
return udev_device;
}
/**
* udev_device_new_from_devnum:
* @udev: udev library context
* @type: char or block device
*
* Create new udev device, and fill in information from the sys
* device and the udev database entry. The device is looked up
* are not unique across the two types, they do not share the same
* range of numbers.
*
* The initial refcount is 1, and needs to be decremented to
* release the resources of the udev device.
*
* Returns: a new udev device, or #NULL, if it does not exist
**/
{
char path[UTIL_PATH_SIZE];
const char *type_str;
struct udev_enumerate *udev_enumerate;
struct udev_list_entry *list_entry;
if (type == 'b')
type_str = "block";
else if (type == 'c')
type_str = "char";
else
return NULL;
if (udev_enumerate == NULL)
return NULL;
if (type == 'b')
else if (type == 'c')
struct udev_device *device_loop;
if (device_loop != NULL) {
continue;
continue;
break;
}
}
}
return device;
}
/**
* udev_device_new_from_subsystem_sysname:
* @udev: udev library context
* @subsystem: the subsystem of the device
* @sysname: the name of the device
*
* Create new udev device, and fill in information from the sys
* device and the udev database entry. The device is looked up
* by the subsystem and name string of the device, like "mem",
* "zero", or "block", "sda".
*
* The initial refcount is 1, and needs to be decremented to
* release the resources of the udev device.
*
* Returns: a new udev device, or #NULL, if it does not exist
**/
struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname)
{
char path_full[UTIL_PATH_SIZE];
char *path;
size_t l;
goto found;
goto found;
goto found;
goto out;
}
goto found;
goto out;
}
char subsys[UTIL_NAME_SIZE];
char *driver;
driver[0] = '\0';
goto found;
goto found;
}
goto out;
}
goto found;
goto found;
goto found;
out:
return NULL;
}
{
char path[UTIL_PATH_SIZE];
const char *subdir;
/* follow "device" link in deprecated sys layout */
if (udev_device_parent != NULL)
return udev_device_parent;
}
}
while (1) {
char *pos;
break;
pos[0] = '\0';
if (udev_device_parent != NULL)
return udev_device_parent;
}
return NULL;
}
/**
* udev_device_get_parent:
* @udev_device: the device to start searching from
*
* Find the next parent device, and fill in information from the sys
* device and the udev database entry.
*
* The returned the device is not referenced. It is attached to the
* child device, and will be cleaned up when the child device
* is cleaned up.
*
* It is not necessarily just the upper level directory, empty or not
* recognized sys directories are ignored.
*
* It can be called as many times as needed, without caring about
* references.
*
* Returns: a new udev device, or #NULL, if it no parent exist.
**/
{
if (udev_device == NULL)
return NULL;
if (!udev_device->parent_set) {
}
return udev_device->parent_device;
}
/**
* udev_device_get_parent_with_subsystem_devtype:
* @udev_device: udev device to start searching from
* @subsystem: the subsystem of the device
* @devtype: the type (DEVTYPE) of the device
*
* Find the next parent device, with a matching subsystem and devtype
* value, and fill in information from the sys device and the udev
* database entry.
*
* The returned the device is not referenced. It is attached to the
* child device, and will be cleaned up when the child device
* is cleaned up.
*
* It can be called as many times as needed, without caring about
* references.
*
* Returns: a new udev device, or #NULL if no matching parent exists.
**/
struct udev_device *udev_device_get_parent_with_subsystem_devtype(struct udev_device *udev_device, const char *subsystem, const char *devtype)
{
struct udev_device *parent;
return NULL;
const char *parent_subsystem;
const char *parent_devtype;
break;
break;
}
}
return parent;
}
/**
* udev_device_get_udev:
* @udev_device: udev device
*
* Retrieve the udev library context the device was created with.
*
* Returns: the udev library context
**/
{
if (udev_device == NULL)
return NULL;
return udev_device->udev;
}
/**
* udev_device_ref:
* @udev_device: udev device
*
* Take a reference of a udev device.
*
* Returns: the passed udev device
**/
{
if (udev_device == NULL)
return NULL;
udev_device->refcount++;
return udev_device;
}
/**
* udev_device_unref:
* @udev_device: udev device
*
* Drop a reference of a udev device. If the refcount reaches zero,
* the resources of the device will be released.
*
**/
{
if (udev_device == NULL)
return;
udev_device->refcount--;
if (udev_device->refcount > 0)
return;
}
/**
* udev_device_get_devpath:
* @udev_device: udev device
*
* Retrieve the kernel devpath value of the udev device. The path
* does not contain the sys mount point, and starts with a '/'.
*
* Returns: the devpath of the udev device
**/
{
if (udev_device == NULL)
return NULL;
return udev_device->devpath;
}
/**
* udev_device_get_syspath:
* @udev_device: udev device
*
* Retrieve the sys path of the udev device. The path is an
* absolute path and starts with the sys mount point.
*
* Returns: the sys path of the udev device
**/
{
if (udev_device == NULL)
return NULL;
return udev_device->syspath;
}
/**
* udev_device_get_sysname:
* @udev_device: udev device
*
* Returns: the sys name of the device device
**/
{
if (udev_device == NULL)
return NULL;
return udev_device->sysname;
}
/**
* udev_device_get_sysnum:
* @udev_device: udev device
*
* Returns: the trailing number of of the device name
**/
{
if (udev_device == NULL)
return NULL;
return udev_device->sysnum;
}
/**
* udev_device_get_devnode:
* @udev_device: udev device
*
* Retrieve the device node file name belonging to the udev device.
* The path is an absolute path, and starts with the device directory.
*
* Returns: the device node file name of the udev device, or #NULL if no device node exists
**/
{
if (udev_device == NULL)
return NULL;
if (!udev_device->info_loaded)
return udev_device->devnode;
}
/**
* udev_device_get_subsystem:
* @udev_device: udev device
*
* Retrieve the subsystem string of the udev device. The string does not
* contain any "/".
*
* Returns: the subsystem name of the udev device, or #NULL if it can not be determined
**/
{
char subsystem[UTIL_NAME_SIZE];
if (udev_device == NULL)
return NULL;
if (!udev_device->subsystem_set) {
/* read "subsystem" link */
if (util_get_sys_subsystem(udev_device->udev, udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
return udev_device->subsystem;
}
/* implicit names */
return udev_device->subsystem;
}
return udev_device->subsystem;
}
return udev_device->subsystem;
}
}
return udev_device->subsystem;
}
/**
* udev_device_get_devtype:
* @udev_device: udev device
*
* Retrieve the devtype string of the udev device.
*
* Returns: the devtype name of the udev device, or #NULL if it can not be determined
**/
{
if (udev_device == NULL)
return NULL;
if (!udev_device->devtype_set) {
if (!udev_device->info_loaded)
}
return udev_device->devtype;
}
/**
* udev_device_get_devlinks_list_entry:
* @udev_device: udev device
*
* Retrieve the list of device links pointing to the device file of
* the udev device. The next list entry can be retrieved with
* udev_list_entry_next(), which returns #NULL if no more entries exist.
* The devlink path can be retrieved from the list entry by
* udev_list_entry_get_name(). The path is an absolute path, and starts with
* the device directory.
*
* Returns: the first entry of the device node link list
**/
{
if (udev_device == NULL)
return NULL;
if (!udev_device->info_loaded)
}
{
udev_device->devlinks_uptodate = 0;
}
/**
* udev_device_get_properties_list_entry:
* @udev_device: udev device
*
* device. The next list entry can be retrieved with udev_list_entry_next(),
* which returns #NULL if no more entries exist. The property name
* can be retrieved from the list entry by udev_list_get_name(),
* the property value by udev_list_get_value().
*
* Returns: the first entry of the property list
**/
{
if (udev_device == NULL)
return NULL;
if (!udev_device->info_loaded)
if (!udev_device->devlinks_uptodate) {
char symlinks[UTIL_PATH_SIZE];
struct udev_list_entry *list_entry;
if (list_entry != NULL) {
char *s;
size_t l;
s = symlinks;
}
}
}
/**
* udev_device_get_driver:
* @udev_device: udev device
*
* Returns: the driver string, or #NULL if there is no driver attached.
**/
{
char driver[UTIL_NAME_SIZE];
if (udev_device == NULL)
return NULL;
if (!udev_device->driver_set) {
}
return udev_device->driver;
}
/**
* udev_device_get_devnum:
* @udev_device: udev device
*
**/
{
if (udev_device == NULL)
return makedev(0, 0);
if (!udev_device->info_loaded)
return udev_device->devnum;
}
/**
* udev_device_get_action:
* @udev_device: udev device
*
* This is only valid if the device was received through a monitor. Devices read from
* sys do not have an action string. Usual actions are: add, remove, change, online,
* offline.
*
* Returns: the kernel action value, or #NULL if there is no action value available.
**/
{
if (udev_device == NULL)
return NULL;
return udev_device->action;
}
/**
* udev_device_get_devnum:
* @udev_device: udev device
*
* This is only valid if the device was received through a monitor. Devices read from
* sys do not have a sequence number.
*
* Returns: the kernel event sequence number, or 0 if there is no sequence number available.
**/
{
if (udev_device == NULL)
return 0;
return udev_device->seqnum;
}
/**
* udev_device_get_sysattr_value:
* @udev_device: udev device
* @sysattr: attribute name
*
* The retrieved value is cached in the device. Repeated calls will return the same
* value and not open the attribute again.
*
* Returns: the content of a sys attribute file, or #NULL if there is no sys attribute value.
**/
{
struct udev_list_entry *list_entry;
char path[UTIL_PATH_SIZE];
char value[4096];
int fd;
if (udev_device == NULL)
return NULL;
return NULL;
/* look for possibly already cached result */
return udev_list_entry_get_value(list_entry);
}
}
goto out;
}
char target[UTIL_NAME_SIZE];
int len;
char *pos;
/* some core links return the last element of the target path */
goto out;
if (len > 0) {
list_entry = udev_list_entry_add(udev_device->udev, &udev_device->sysattr_list, sysattr, pos, 0, 0);
}
}
goto out;
}
/* skip directories */
goto out;
/* skip non-readable files */
goto out;
/* read attribute value */
if (fd < 0) {
goto out;
}
if (size < 0)
goto out;
goto out;
/* got a valid value, store it in cache and return it */
list_entry = udev_list_entry_add(udev_device->udev, &udev_device->sysattr_list, sysattr, value, 0, 0);
out:
return val;
}
{
const char *pos;
return -ENOMEM;
return -EINVAL;
return -ENOMEM;
/* some devices have '!' in their name, change that to '/' */
len = 0;
len++;
}
/* trailing number */
/* sysname is completely numeric */
if (len == 0)
return 0;
}
{
return -ENOMEM;
return 0;
}
{
return -ENOMEM;
return 0;
}
{
return 0;
return -ENOMEM;
return 0;
}
{
udev_device->devlinks_uptodate = 0;
if (udev_list_entry_add(udev_device->udev, &udev_device->devlinks_list, devlink, NULL, 1, 0) == NULL)
return -ENOMEM;
return 0;
}
struct udev_list_entry *udev_device_add_property(struct udev_device *udev_device, const char *key, const char *value)
{
udev_device->envp_uptodate = 0;
struct udev_list_entry *list_entry;
if (list_entry != NULL)
return NULL;
}
}
struct udev_list_entry *udev_device_add_property_from_string(struct udev_device *udev_device, const char *property)
{
char name[UTIL_PATH_SIZE];
char *val;
return NULL;
val[0] = '\0';
if (val[0] == '\0')
}
/**
* udev_device_get_property_value:
* @udev_device: udev device
* @key: property name
*
* Returns: the value of a device property, or #NULL if there is no such property.
**/
{
struct udev_list_entry *list_entry;
if (udev_device == NULL)
return NULL;
return NULL;
return udev_list_entry_get_value(list_entry);
}
#define ENVP_SIZE 128
#define MONITOR_BUF_SIZE 4096
{
struct udev_list_entry *list_entry;
char *s;
size_t l;
unsigned int i;
/* monitor buffer of property strings */
udev_device->monitor_buf_len = 0;
return -ENOMEM;
/* envp array, strings will point into monitor buffer */
return -ENOMEM;
i = 0;
s = udev_device->monitor_buf;
l = MONITOR_BUF_SIZE;
const char *key;
/* skip private variables */
if (key[0] == '.')
continue;
/* add string to envp array */
udev_device->envp[i++] = s;
if (i+1 >= ENVP_SIZE)
return -EINVAL;
/* add property string to monitor buffer */
if (l == 0)
return -EINVAL;
s++;
}
i, udev_device->monitor_buf_len);
return 0;
}
{
if (!udev_device->envp_uptodate)
if (update_envp_monitor_buf(udev_device) != 0)
return NULL;
return udev_device->envp;
}
{
if (!udev_device->envp_uptodate)
if (update_envp_monitor_buf(udev_device) != 0)
return -EINVAL;
return udev_device->monitor_buf_len;
}
{
return -ENOMEM;
return 0;
}
{
return -ENOMEM;
return 0;
}
{
return udev_device->devpath_old;
}
{
const char *pos;
return -ENOMEM;
return -EINVAL;
return -ENOMEM;
/* some devices have '!' in their name, change that to '/' */
len = 0;
len++;
}
return 0;
}
{
if (udev_device == NULL)
return NULL;
return udev_device->sysname_old;
}
{
return udev_device->knodename;
}
{
return -ENOMEM;
return 0;
}
{
return udev_device->timeout;
}
{
return 0;
}
{
if (!udev_device->info_loaded)
return udev_device->event_timeout;
}
{
return 0;
}
{
char num[32];
return 0;
}
{
char num[32];
return 0;
}
{
if (!udev_device->info_loaded)
return udev_device->num_fake_partitions;
}
{
return 0;
}
{
if (!udev_device->info_loaded)
return udev_device->devlink_priority;
}
{
return 0;
}
{
if (!udev_device->info_loaded)
return udev_device->ignore_remove;
}
{
return 0;
}
{
if (!udev_device->info_loaded)
return udev_device->watch_handle;
}
{
return 0;
}