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mirror of https://github.com/systemd/systemd.git synced 2024-12-23 21:35:11 +03:00
systemd/libudev/libudev-device.c

1405 lines
38 KiB
C

/*
* libudev - interface to udev device information
*
* Copyright (C) 2008-2009 Kay Sievers <kay.sievers@vrfy.org>
*
* This library 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.
*/
#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 <sys/stat.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 subsytem.
*/
/**
* udev_device:
*
* Opaque object representing one kernel sys device.
*/
struct udev_device {
struct udev *udev;
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 *knodename;
char **envp;
char *monitor_buf;
size_t monitor_buf_len;
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;
dev_t devnum;
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;
};
static size_t devpath_to_db_path(struct udev *udev, const char *devpath, char *filename, size_t len)
{
char *s;
size_t l;
s = filename;
l = util_strpcpyl(&s, len, udev_get_dev_path(udev), "/.udev/db/", NULL);
return util_path_encode(devpath, s, l);
}
int udev_device_read_db(struct udev_device *udev_device)
{
struct stat stats;
char filename[UTIL_PATH_SIZE];
char line[UTIL_LINE_SIZE];
FILE *f;
devpath_to_db_path(udev_device->udev, udev_device->devpath, filename, sizeof(filename));
if (lstat(filename, &stats) != 0) {
dbg(udev_device->udev, "no db file to read %s: %m\n", filename);
return -1;
}
if ((stats.st_mode & S_IFMT) == S_IFLNK) {
char target[UTIL_PATH_SIZE];
char devnode[UTIL_PATH_SIZE];
int target_len;
char *next;
target_len = readlink(filename, target, sizeof(target));
if (target_len > 0)
target[target_len] = '\0';
else {
dbg(udev_device->udev, "error reading db link %s: %m\n", filename);
return -1;
}
next = strchr(target, ' ');
if (next != NULL) {
next[0] = '\0';
next = &next[1];
}
util_strscpyl(devnode, sizeof(devnode), udev_get_dev_path(udev_device->udev), "/", target, NULL);
udev_device_set_devnode(udev_device, devnode);
while (next != NULL) {
char devlink[UTIL_PATH_SIZE];
const char *lnk;
lnk = next;
next = strchr(next, ' ');
if (next != NULL) {
next[0] = '\0';
next = &next[1];
}
util_strscpyl(devlink, sizeof(devlink), udev_get_dev_path(udev_device->udev), "/", lnk, NULL);
udev_device_add_devlink(udev_device, devlink);
}
info(udev_device->udev, "device %p filled with db symlink data '%s'\n", udev_device, udev_device->devnode);
return 0;
}
f = fopen(filename, "r");
if (f == NULL) {
dbg(udev_device->udev, "error reading db file %s: %m\n", filename);
return -1;
}
while (fgets(line, sizeof(line), f)) {
ssize_t len;
const char *val;
len = strlen(line);
if (len < 4)
break;
line[len-1] = '\0';
val = &line[2];
switch(line[0]) {
case 'N':
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_device->udev), "/", val, NULL);
udev_device_set_devnode(udev_device, filename);
break;
case 'S':
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_device->udev), "/", val, NULL);
udev_device_add_devlink(udev_device, filename);
break;
case 'L':
udev_device_set_devlink_priority(udev_device, atoi(val));
break;
case 'T':
udev_device_set_event_timeout(udev_device, atoi(val));
break;
case 'A':
udev_device_set_num_fake_partitions(udev_device, atoi(val));
break;
case 'R':
udev_device_set_ignore_remove(udev_device, atoi(val));
break;
case 'E':
udev_device_add_property_from_string(udev_device, val);
break;
case 'W':
udev_device_set_watch_handle(udev_device, atoi(val));
break;
}
}
fclose(f);
info(udev_device->udev, "device %p filled with db file data\n", udev_device);
return 0;
}
int udev_device_read_uevent_file(struct udev_device *udev_device)
{
char filename[UTIL_PATH_SIZE];
FILE *f;
char line[UTIL_LINE_SIZE];
int maj = 0;
int min = 0;
util_strscpyl(filename, sizeof(filename), udev_device->syspath, "/uevent", NULL);
f = fopen(filename, "r");
if (f == NULL)
return -1;
while (fgets(line, sizeof(line), f)) {
char *pos;
pos = strchr(line, '\n');
if (pos == NULL)
continue;
pos[0] = '\0';
if (strncmp(line, "DEVTYPE=", 8) == 0)
udev_device_set_devtype(udev_device, &line[8]);
else if (strncmp(line, "MAJOR=", 6) == 0)
maj = strtoull(&line[6], NULL, 10);
else if (strncmp(line, "MINOR=", 6) == 0)
min = strtoull(&line[6], NULL, 10);
else if (strncmp(line, "DEVNAME=", 8) == 0)
udev_device_set_knodename(udev_device, &line[8]);
udev_device_add_property_from_string(udev_device, line);
}
udev_device->devnum = makedev(maj, min);
fclose(f);
return 0;
}
static void device_load_info(struct udev_device *device)
{
device->info_loaded = 1;
udev_device_read_uevent_file(device);
udev_device_read_db(device);
}
void udev_device_set_info_loaded(struct udev_device *device)
{
device->info_loaded = 1;
}
struct udev_device *udev_device_new(struct udev *udev)
{
struct udev_device *udev_device;
struct udev_list_entry *list_entry;
if (udev == NULL)
return NULL;
udev_device = calloc(1, sizeof(struct udev_device));
if (udev_device == NULL)
return NULL;
udev_device->refcount = 1;
udev_device->udev = udev;
udev_list_init(&udev_device->devlinks_list);
udev_list_init(&udev_device->properties_list);
udev_list_init(&udev_device->sysattr_list);
udev_device->event_timeout = -1;
udev_device->watch_handle = -1;
/* copy global properties */
udev_list_entry_foreach(list_entry, udev_get_properties_list_entry(udev))
udev_device_add_property(udev_device,
udev_list_entry_get_name(list_entry),
udev_list_entry_get_value(list_entry));
dbg(udev_device->udev, "udev_device: %p created\n", udev_device);
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 sypath 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
**/
struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
{
size_t len;
const char *subdir;
char path[UTIL_PATH_SIZE];
char *pos;
struct stat statbuf;
struct udev_device *udev_device;
if (udev == NULL)
return NULL;
if (syspath == NULL)
return NULL;
/* path starts in sys */
len = strlen(udev_get_sys_path(udev));
if (strncmp(syspath, udev_get_sys_path(udev), len) != 0) {
info(udev, "not in sys :%s\n", syspath);
return NULL;
}
/* path is not a root directory */
subdir = &syspath[len+1];
pos = strrchr(subdir, '/');
if (pos == NULL || pos[1] == '\0' || pos < &subdir[2]) {
dbg(udev, "not a subdir :%s\n", syspath);
return NULL;
}
/* resolve possible symlink to real path */
util_strscpy(path, sizeof(path), syspath);
util_resolve_sys_link(udev, path, sizeof(path));
/* try to resolve the silly block layout if needed */
if (strncmp(&path[len], "/block/", 7) == 0) {
char block[UTIL_PATH_SIZE];
char part[UTIL_PATH_SIZE];
util_strscpy(block, sizeof(block), path);
pos = strrchr(block, '/');
if (pos == NULL)
return NULL;
util_strscpy(part, sizeof(part), pos);
pos[0] = '\0';
if (util_resolve_sys_link(udev, block, sizeof(block)) == 0)
util_strscpyl(path, sizeof(path), block, part, NULL);
}
/* path exists in sys */
if (strncmp(&syspath[len], "/devices/", 9) == 0 ||
strncmp(&syspath[len], "/class/", 7) == 0 ||
strncmp(&syspath[len], "/block/", 7) == 0) {
char file[UTIL_PATH_SIZE];
/* all "devices" require a "uevent" file */
util_strscpyl(file, sizeof(file), path, "/uevent", NULL);
if (stat(file, &statbuf) != 0) {
dbg(udev, "not a device: %s\n", syspath);
return NULL;
}
} else {
/* everything else just needs to be a directory */
if (stat(path, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode)) {
dbg(udev, "directory not found: %s\n", syspath);
return NULL;
}
}
udev_device = udev_device_new(udev);
if (udev_device == NULL)
return NULL;
udev_device_set_syspath(udev_device, path);
info(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
return udev_device;
}
/**
* udev_device_new_from_devnum:
* @udev: udev library context
* @type: char or block device
* @devnum: device major/minor number
*
* Create new udev device, and fill in information from the sys
* device and the udev database entry. The device is looked up
* by its major/minor number. Character and block device numbers
* 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
**/
struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum)
{
char path[UTIL_PATH_SIZE];
const char *type_str;
struct udev_enumerate *udev_enumerate;
struct udev_list_entry *list_entry;
struct udev_device *device = NULL;
if (type == 'b')
type_str = "block";
else if (type == 'c')
type_str = "char";
else
return NULL;
/* /sys/dev/{block,char}/<maj>:<min> link */
snprintf(path, sizeof(path), "%s/dev/%s/%u:%u", udev_get_sys_path(udev),
type_str, major(devnum), minor(devnum));
if (util_resolve_sys_link(udev, path, sizeof(path)) == 0)
return udev_device_new_from_syspath(udev, path);
udev_enumerate = udev_enumerate_new(udev);
if (udev_enumerate == NULL)
return NULL;
/* fallback to search sys devices for the major/minor */
if (type == 'b')
udev_enumerate_add_match_subsystem(udev_enumerate, "block");
else if (type == 'c')
udev_enumerate_add_nomatch_subsystem(udev_enumerate, "block");
udev_enumerate_scan_devices(udev_enumerate);
udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
struct udev_device *device_loop;
device_loop = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
if (device_loop != NULL) {
if (udev_device_get_devnum(device_loop) == devnum) {
if (type == 'b' && strcmp(udev_device_get_subsystem(device_loop), "block") != 0)
continue;
if (type == 'c' && strcmp(udev_device_get_subsystem(device_loop), "block") == 0)
continue;
device = device_loop;
break;
}
udev_device_unref(device_loop);
}
}
udev_enumerate_unref(udev_enumerate);
return device;
}
/**
* udev_device_new_from_subsystem_sysname:
* @udev: udev library context
* @subsystem: the subsytem 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 subsytem 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;
struct stat statbuf;
path = path_full;
l = util_strpcpyl(&path, sizeof(path_full), udev_get_sys_path(udev), NULL);
if (strcmp(subsystem, "subsystem") == 0) {
util_strscpyl(path, l, "/subsystem/", sysname, NULL);
if (stat(path_full, &statbuf) == 0)
goto found;
util_strscpyl(path, l, "/bus/", sysname, NULL);
if (stat(path_full, &statbuf) == 0)
goto found;
util_strscpyl(path, l, "/class/", sysname, NULL);
if (stat(path_full, &statbuf) == 0)
goto found;
goto out;
}
if (strcmp(subsystem, "module") == 0) {
util_strscpyl(path, l, "/module/", sysname, NULL);
if (stat(path_full, &statbuf) == 0)
goto found;
goto out;
}
if (strcmp(subsystem, "drivers") == 0) {
char subsys[UTIL_NAME_SIZE];
char *driver;
util_strscpy(subsys, sizeof(subsys), sysname);
driver = strchr(subsys, ':');
if (driver != NULL) {
driver[0] = '\0';
driver = &driver[1];
util_strscpyl(path, l, "/subsystem/", subsys, "/drivers/", driver, NULL);
if (stat(path_full, &statbuf) == 0)
goto found;
util_strscpyl(path, l, "/bus/", subsys, "/drivers/", driver, NULL);
if (stat(path_full, &statbuf) == 0)
goto found;
}
goto out;
}
util_strscpyl(path, l, "/subsystem/", subsystem, "/devices/", sysname, NULL);
if (stat(path_full, &statbuf) == 0)
goto found;
util_strscpyl(path, l, "/bus/", subsystem, "/devices/", sysname, NULL);
if (stat(path_full, &statbuf) == 0)
goto found;
util_strscpyl(path, l, "/class/", subsystem, "/", sysname, NULL);
if (stat(path_full, &statbuf) == 0)
goto found;
out:
return NULL;
found:
return udev_device_new_from_syspath(udev, path_full);
}
static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
{
struct udev_device *udev_device_parent = NULL;
char path[UTIL_PATH_SIZE];
const char *subdir;
/* follow "device" link in deprecated sys layout */
if (strncmp(udev_device->devpath, "/class/", 7) == 0 ||
strncmp(udev_device->devpath, "/block/", 7) == 0) {
util_strscpyl(path, sizeof(path), udev_device->syspath, "/device", NULL);
if (util_resolve_sys_link(udev_device->udev, path, sizeof(path)) == 0) {
udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
if (udev_device_parent != NULL)
return udev_device_parent;
}
}
util_strscpy(path, sizeof(path), udev_device->syspath);
subdir = &path[strlen(udev_get_sys_path(udev_device->udev))+1];
while (1) {
char *pos;
pos = strrchr(subdir, '/');
if (pos == NULL || pos < &subdir[2])
break;
pos[0] = '\0';
udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
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 neccessarily 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.
**/
struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
if (!udev_device->parent_set) {
udev_device->parent_set = 1;
udev_device->parent_device = device_new_from_parent(udev_device);
}
if (udev_device->parent_device != NULL)
dbg(udev_device->udev, "returning existing parent %p\n", udev_device->parent_device);
return udev_device->parent_device;
}
/**
* udev_device_get_parent_with_subsystem_devtype:
* @udev_device: udev device to start searching from
* @subsystem: the subsytem 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;
if (subsystem == NULL)
return NULL;
parent = udev_device_get_parent(udev_device);
while (parent != NULL) {
const char *parent_subsystem;
const char *parent_devtype;
parent_subsystem = udev_device_get_subsystem(parent);
if (parent_subsystem != NULL && strcmp(parent_subsystem, subsystem) == 0) {
if (devtype == NULL)
break;
parent_devtype = udev_device_get_devtype(parent);
if (parent_devtype != NULL && strcmp(parent_devtype, devtype) == 0)
break;
}
parent = udev_device_get_parent(parent);
}
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
**/
struct udev *udev_device_get_udev(struct udev_device *udev_device)
{
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
**/
struct udev_device *udev_device_ref(struct udev_device *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.
*
**/
void udev_device_unref(struct udev_device *udev_device)
{
if (udev_device == NULL)
return;
udev_device->refcount--;
if (udev_device->refcount > 0)
return;
if (udev_device->parent_device != NULL)
udev_device_unref(udev_device->parent_device);
free(udev_device->syspath);
free(udev_device->sysname);
free(udev_device->devnode);
free(udev_device->subsystem);
free(udev_device->devtype);
udev_list_cleanup_entries(udev_device->udev, &udev_device->devlinks_list);
udev_list_cleanup_entries(udev_device->udev, &udev_device->properties_list);
free(udev_device->action);
free(udev_device->driver);
free(udev_device->devpath_old);
free(udev_device->knodename);
udev_list_cleanup_entries(udev_device->udev, &udev_device->sysattr_list);
free(udev_device->envp);
free(udev_device->monitor_buf);
dbg(udev_device->udev, "udev_device: %p released\n", udev_device);
free(udev_device);
}
/**
* 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
**/
const char *udev_device_get_devpath(struct udev_device *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
**/
const char *udev_device_get_syspath(struct udev_device *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
**/
const char *udev_device_get_sysname(struct udev_device *udev_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
**/
const char *udev_device_get_sysnum(struct udev_device *udev_device)
{
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
**/
const char *udev_device_get_devnode(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
if (!udev_device->info_loaded)
device_load_info(udev_device);
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
**/
const char *udev_device_get_subsystem(struct udev_device *udev_device)
{
char subsystem[UTIL_NAME_SIZE];
if (udev_device == NULL)
return NULL;
if (!udev_device->subsystem_set) {
udev_device->subsystem_set = 1;
/* read "subsytem" link */
if (util_get_sys_subsystem(udev_device->udev, udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
udev_device_set_subsystem(udev_device, subsystem);
return udev_device->subsystem;
}
/* implicit names */
if (strncmp(udev_device->devpath, "/module/", 8) == 0) {
udev_device_set_subsystem(udev_device, "module");
return udev_device->subsystem;
}
if (strstr(udev_device->devpath, "/drivers/") != NULL) {
udev_device_set_subsystem(udev_device, "drivers");
return udev_device->subsystem;
}
if (strncmp(udev_device->devpath, "/subsystem/", 11) == 0 ||
strncmp(udev_device->devpath, "/class/", 7) == 0 ||
strncmp(udev_device->devpath, "/bus/", 5) == 0) {
udev_device_set_subsystem(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
**/
const char *udev_device_get_devtype(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
if (!udev_device->devtype_set) {
udev_device->devtype_set = 1;
if (!udev_device->info_loaded)
udev_device_read_uevent_file(udev_device);
}
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
**/
struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
if (!udev_device->info_loaded)
device_load_info(udev_device);
return udev_list_get_entry(&udev_device->devlinks_list);
}
void udev_device_cleanup_devlinks_list(struct udev_device *udev_device)
{
udev_device->devlinks_uptodate = 0;
udev_list_cleanup_entries(udev_device->udev, &udev_device->devlinks_list);
}
/**
* udev_device_get_properties_list_entry:
* @udev_device: udev device
*
* Retrieve the list of key/value device properties 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 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
**/
struct udev_list_entry *udev_device_get_properties_list_entry(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
if (!udev_device->info_loaded)
device_load_info(udev_device);
if (!udev_device->devlinks_uptodate) {
char symlinks[UTIL_PATH_SIZE];
struct udev_list_entry *list_entry;
udev_device->devlinks_uptodate = 1;
list_entry = udev_device_get_devlinks_list_entry(udev_device);
if (list_entry != NULL) {
char *s;
size_t l;
s = symlinks;
l = util_strpcpyl(&s, sizeof(symlinks), udev_list_entry_get_name(list_entry), NULL);
udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
l = util_strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry), NULL);
udev_device_add_property(udev_device, "DEVLINKS", symlinks);
}
}
return udev_list_get_entry(&udev_device->properties_list);
}
/**
* udev_device_get_driver:
* @udev_device: udev device
*
* Returns: the driver string, or #NULL if there is no driver attached.
**/
const char *udev_device_get_driver(struct udev_device *udev_device)
{
char driver[UTIL_NAME_SIZE];
if (udev_device == NULL)
return NULL;
if (!udev_device->driver_set) {
udev_device->driver_set = 1;
if (util_get_sys_driver(udev_device->udev, udev_device->syspath, driver, sizeof(driver)) > 0)
udev_device->driver = strdup(driver);
}
return udev_device->driver;
}
/**
* udev_device_get_devnum:
* @udev_device: udev device
*
* Returns: the device major/minor number.
**/
dev_t udev_device_get_devnum(struct udev_device *udev_device)
{
if (udev_device == NULL)
return makedev(0, 0);
if (!udev_device->info_loaded)
device_load_info(udev_device);
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.
**/
const char *udev_device_get_action(struct udev_device *udev_device)
{
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.
**/
unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device)
{
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.
**/
const char *udev_device_get_sysattr_value(struct udev_device *udev_device, const char *sysattr)
{
struct udev_list_entry *list_entry;
char path[UTIL_PATH_SIZE];
char value[4096];
struct stat statbuf;
int fd;
ssize_t size;
const char *val = NULL;
if (udev_device == NULL)
return NULL;
if (sysattr == NULL)
return NULL;
/* look for possibly already cached result */
udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_device->sysattr_list)) {
if (strcmp(udev_list_entry_get_name(list_entry), sysattr) == 0) {
dbg(udev_device->udev, "got '%s' (%s) from cache\n",
sysattr, udev_list_entry_get_value(list_entry));
return udev_list_entry_get_value(list_entry);
}
}
util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", sysattr, NULL);
if (lstat(path, &statbuf) != 0) {
dbg(udev_device->udev, "no attribute '%s', keep negative entry\n", path);
udev_list_entry_add(udev_device->udev, &udev_device->sysattr_list, sysattr, NULL, 0, 0);
goto out;
}
if (S_ISLNK(statbuf.st_mode)) {
char target[UTIL_NAME_SIZE];
int len;
char *pos;
/* some core links return the last element of the target path */
if (strcmp(sysattr, "driver") != 0 &&
strcmp(sysattr, "subsystem") != 0 &&
strcmp(sysattr, "module") != 0)
goto out;
len = readlink(path, target, sizeof(target));
if (len > 0) {
target[len] = '\0';
pos = strrchr(target, '/');
if (pos != NULL) {
pos = &pos[1];
dbg(udev_device->udev, "cache '%s' with link value '%s'\n", sysattr, pos);
list_entry = udev_list_entry_add(udev_device->udev, &udev_device->sysattr_list, sysattr, pos, 0, 0);
val = udev_list_entry_get_value(list_entry);
}
}
goto out;
}
/* skip directories */
if (S_ISDIR(statbuf.st_mode))
goto out;
/* skip non-readable files */
if ((statbuf.st_mode & S_IRUSR) == 0)
goto out;
/* read attribute value */
fd = open(path, O_RDONLY);
if (fd < 0) {
dbg(udev_device->udev, "attribute '%s' can not be opened\n", path);
goto out;
}
size = read(fd, value, sizeof(value));
close(fd);
if (size < 0)
goto out;
if (size == sizeof(value))
goto out;
/* got a valid value, store it in cache and return it */
value[size] = '\0';
util_remove_trailing_chars(value, '\n');
dbg(udev_device->udev, "'%s' has attribute value '%s'\n", path, value);
list_entry = udev_list_entry_add(udev_device->udev, &udev_device->sysattr_list, sysattr, value, 0, 0);
val = udev_list_entry_get_value(list_entry);
out:
return val;
}
int udev_device_set_syspath(struct udev_device *udev_device, const char *syspath)
{
const char *pos;
size_t len;
free(udev_device->syspath);
udev_device->syspath = strdup(syspath);
if (udev_device->syspath == NULL)
return -ENOMEM;
udev_device->devpath = &udev_device->syspath[strlen(udev_get_sys_path(udev_device->udev))];
udev_device_add_property(udev_device, "DEVPATH", udev_device->devpath);
pos = strrchr(udev_device->syspath, '/');
if (pos == NULL)
return -EINVAL;
udev_device->sysname = strdup(&pos[1]);
if (udev_device->sysname == NULL)
return -ENOMEM;
/* some devices have '!' in their name, change that to '/' */
len = 0;
while (udev_device->sysname[len] != '\0') {
if (udev_device->sysname[len] == '!')
udev_device->sysname[len] = '/';
len++;
}
/* trailing number */
while (len > 0 && isdigit(udev_device->sysname[--len]))
udev_device->sysnum = &udev_device->sysname[len];
/* sysname is completely numeric */
if (len == 0)
udev_device->sysnum = NULL;
return 0;
}
int udev_device_set_subsystem(struct udev_device *udev_device, const char *subsystem)
{
free(udev_device->subsystem);
udev_device->subsystem = strdup(subsystem);
if (udev_device->subsystem == NULL)
return -ENOMEM;
udev_device->subsystem_set = 1;
udev_device_add_property(udev_device, "SUBSYSTEM", udev_device->subsystem);
return 0;
}
int udev_device_set_devtype(struct udev_device *udev_device, const char *devtype)
{
free(udev_device->devtype);
udev_device->devtype = strdup(devtype);
if (udev_device->devtype == NULL)
return -ENOMEM;
udev_device->devtype_set = 1;
udev_device_add_property(udev_device, "DEVTYPE", udev_device->devtype);
return 0;
}
int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode)
{
free(udev_device->devnode);
udev_device->devnode = strdup(devnode);
if (devnode == NULL)
return 0;
if (udev_device->devnode == NULL)
return -ENOMEM;
udev_device_add_property(udev_device, "DEVNAME", udev_device->devnode);
return 0;
}
int udev_device_add_devlink(struct udev_device *udev_device, const char *devlink)
{
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;
if (value == NULL) {
struct udev_list_entry *list_entry;
list_entry = udev_device_get_properties_list_entry(udev_device);
list_entry = udev_list_entry_get_by_name(list_entry, key);
if (list_entry != NULL)
udev_list_entry_delete(list_entry);
return NULL;
}
return udev_list_entry_add(udev_device->udev, &udev_device->properties_list, key, value, 1, 0);
}
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;
util_strscpy(name, sizeof(name), property);
val = strchr(name, '=');
if (val == NULL)
return NULL;
val[0] = '\0';
val = &val[1];
if (val[0] == '\0')
val = NULL;
return udev_device_add_property(udev_device, name, val);
}
/**
* 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.
**/
const char *udev_device_get_property_value(struct udev_device *udev_device, const char *key)
{
struct udev_list_entry *list_entry;
if (udev_device == NULL)
return NULL;
if (key == NULL)
return NULL;
list_entry = udev_device_get_properties_list_entry(udev_device);
list_entry = udev_list_entry_get_by_name(list_entry, key);
return udev_list_entry_get_value(list_entry);
}
#define ENVP_SIZE 128
#define MONITOR_BUF_SIZE 4096
static int update_envp_monitor_buf(struct udev_device *udev_device)
{
struct udev_list_entry *list_entry;
char *s;
size_t l;
unsigned int i;
/* monitor buffer of property strings */
free(udev_device->monitor_buf);
udev_device->monitor_buf_len = 0;
udev_device->monitor_buf = malloc(MONITOR_BUF_SIZE);
if (udev_device->monitor_buf == NULL)
return -ENOMEM;
/* envp array, strings will point into monitor buffer */
if (udev_device->envp == NULL)
udev_device->envp = malloc(sizeof(char *) * ENVP_SIZE);
if (udev_device->envp == NULL)
return -ENOMEM;
i = 0;
s = udev_device->monitor_buf;
l = MONITOR_BUF_SIZE;
udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
const char *key;
key = udev_list_entry_get_name(list_entry);
/* 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 */
l = util_strpcpyl(&s, l, key, "=", udev_list_entry_get_value(list_entry), NULL);
if (l == 0)
return -EINVAL;
s++;
}
udev_device->envp[i] = NULL;
udev_device->monitor_buf_len = s - udev_device->monitor_buf;
udev_device->envp_uptodate = 1;
dbg(udev_device->udev, "filled envp/monitor buffer, %u properties, %zu bytes\n",
i, udev_device->monitor_buf_len);
return 0;
}
char **udev_device_get_properties_envp(struct udev_device *udev_device)
{
if (!udev_device->envp_uptodate)
if (update_envp_monitor_buf(udev_device) != 0)
return NULL;
return udev_device->envp;
}
ssize_t udev_device_get_properties_monitor_buf(struct udev_device *udev_device, const char **buf)
{
if (!udev_device->envp_uptodate)
if (update_envp_monitor_buf(udev_device) != 0)
return -EINVAL;
*buf = udev_device->monitor_buf;
return udev_device->monitor_buf_len;
}
int udev_device_set_action(struct udev_device *udev_device, const char *action)
{
free(udev_device->action);
udev_device->action = strdup(action);
if (udev_device->action == NULL)
return -ENOMEM;
udev_device_add_property(udev_device, "ACTION", udev_device->action);
return 0;
}
int udev_device_set_driver(struct udev_device *udev_device, const char *driver)
{
free(udev_device->driver);
udev_device->driver = strdup(driver);
if (udev_device->driver == NULL)
return -ENOMEM;
udev_device->driver_set = 1;
udev_device_add_property(udev_device, "DRIVER", udev_device->driver);
return 0;
}
const char *udev_device_get_devpath_old(struct udev_device *udev_device)
{
return udev_device->devpath_old;
}
int udev_device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old)
{
free(udev_device->devpath_old);
udev_device->devpath_old = strdup(devpath_old);
if (udev_device->devpath_old == NULL)
return -ENOMEM;
udev_device_add_property(udev_device, "DEVPATH_OLD", udev_device->devpath_old);
return 0;
}
const char *udev_device_get_knodename(struct udev_device *udev_device)
{
return udev_device->knodename;
}
int udev_device_set_knodename(struct udev_device *udev_device, const char *knodename)
{
free(udev_device->knodename);
udev_device->knodename = strdup(knodename);
if (udev_device->knodename == NULL)
return -ENOMEM;
udev_device_add_property(udev_device, "DEVNAME", udev_device->knodename);
return 0;
}
int udev_device_get_timeout(struct udev_device *udev_device)
{
return udev_device->timeout;
}
int udev_device_set_timeout(struct udev_device *udev_device, int timeout)
{
udev_device->timeout = timeout;
return 0;
}
int udev_device_get_event_timeout(struct udev_device *udev_device)
{
if (!udev_device->info_loaded)
device_load_info(udev_device);
return udev_device->event_timeout;
}
int udev_device_set_event_timeout(struct udev_device *udev_device, int event_timeout)
{
udev_device->event_timeout = event_timeout;
return 0;
}
int udev_device_set_seqnum(struct udev_device *udev_device, unsigned long long int seqnum)
{
char num[32];
udev_device->seqnum = seqnum;
snprintf(num, sizeof(num), "%llu", seqnum);
udev_device_add_property(udev_device, "SEQNUM", num);
return 0;
}
int udev_device_set_devnum(struct udev_device *udev_device, dev_t devnum)
{
char num[32];
udev_device->devnum = devnum;
snprintf(num, sizeof(num), "%u", major(devnum));
udev_device_add_property(udev_device, "MAJOR", num);
snprintf(num, sizeof(num), "%u", minor(devnum));
udev_device_add_property(udev_device, "MINOR", num);
return 0;
}
int udev_device_get_num_fake_partitions(struct udev_device *udev_device)
{
if (!udev_device->info_loaded)
device_load_info(udev_device);
return udev_device->num_fake_partitions;
}
int udev_device_set_num_fake_partitions(struct udev_device *udev_device, int num)
{
udev_device->num_fake_partitions = num;
return 0;
}
int udev_device_get_devlink_priority(struct udev_device *udev_device)
{
if (!udev_device->info_loaded)
device_load_info(udev_device);
return udev_device->devlink_priority;
}
int udev_device_set_devlink_priority(struct udev_device *udev_device, int prio)
{
udev_device->devlink_priority = prio;
return 0;
}
int udev_device_get_ignore_remove(struct udev_device *udev_device)
{
if (!udev_device->info_loaded)
device_load_info(udev_device);
return udev_device->ignore_remove;
}
int udev_device_set_ignore_remove(struct udev_device *udev_device, int ignore)
{
udev_device->ignore_remove = ignore;
return 0;
}
int udev_device_get_watch_handle(struct udev_device *udev_device)
{
if (!udev_device->info_loaded)
device_load_info(udev_device);
return udev_device->watch_handle;
}
int udev_device_set_watch_handle(struct udev_device *udev_device, int handle)
{
udev_device->watch_handle = handle;
return 0;
}