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Systemd/src/libudev/libudev-device.c

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/***
This file is part of systemd.
Copyright 2008-2012 Kay Sievers <kay@vrfy.org>
systemd 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.
systemd 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <stdbool.h>
#include <errno.h>
#include <string.h>
#include <dirent.h>
#include <fcntl.h>
#include <ctype.h>
#include <net/if.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <linux/sockios.h>
#include "libudev.h"
#include "libudev-private.h"
static int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode);
/**
* 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 have
* a unique name inside that subsystem.
*/
/**
* 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;
mode_t devnode_mode;
uid_t devnode_uid;
gid_t devnode_gid;
char *subsystem;
char *devtype;
char *driver;
char *action;
char *devpath_old;
char *id_filename;
char **envp;
char *monitor_buf;
size_t monitor_buf_len;
struct udev_list devlinks_list;
struct udev_list properties_list;
struct udev_list sysattr_value_list;
struct udev_list sysattr_list;
struct udev_list tags_list;
unsigned long long int seqnum;
usec_t usec_initialized;
int devlink_priority;
int refcount;
dev_t devnum;
int ifindex;
int watch_handle;
int maj, min;
bool parent_set;
bool subsystem_set;
bool devtype_set;
bool devlinks_uptodate;
bool envp_uptodate;
bool tags_uptodate;
bool driver_set;
bool info_loaded;
bool db_loaded;
bool uevent_loaded;
bool is_initialized;
bool sysattr_list_read;
bool db_persist;
};
/**
* udev_device_get_seqnum:
* @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.
**/
_public_ unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device)
{
if (udev_device == NULL)
return 0;
return udev_device->seqnum;
}
static 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_get_ifindex(struct udev_device *udev_device)
{
if (!udev_device->info_loaded)
udev_device_read_uevent_file(udev_device);
return udev_device->ifindex;
}
static int udev_device_set_ifindex(struct udev_device *udev_device, int ifindex)
{
char num[32];
udev_device->ifindex = ifindex;
snprintf(num, sizeof(num), "%u", ifindex);
udev_device_add_property(udev_device, "IFINDEX", num);
return 0;
}
/**
* udev_device_get_devnum:
* @udev_device: udev device
*
* Get the device major/minor number.
*
* Returns: the dev_t number.
**/
_public_ dev_t udev_device_get_devnum(struct udev_device *udev_device)
{
if (udev_device == NULL)
return makedev(0, 0);
if (!udev_device->info_loaded)
udev_device_read_uevent_file(udev_device);
return udev_device->devnum;
}
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;
}
const char *udev_device_get_devpath_old(struct udev_device *udev_device)
{
return udev_device->devpath_old;
}
static int udev_device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old)
{
const char *pos;
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);
pos = strrchr(udev_device->devpath_old, '/');
if (pos == NULL)
return -EINVAL;
return 0;
}
/**
* udev_device_get_driver:
* @udev_device: udev device
*
* Get the kernel driver name.
*
* Returns: the driver name string, or #NULL if there is no driver attached.
**/
_public_ 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 = true;
if (util_get_sys_core_link_value(udev_device->udev, "driver", udev_device->syspath, driver, sizeof(driver)) > 0)
udev_device->driver = strdup(driver);
}
return udev_device->driver;
}
static 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 = true;
udev_device_add_property(udev_device, "DRIVER", udev_device->driver);
return 0;
}
/**
* 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
**/
_public_ 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 = true;
udev_device_read_uevent_file(udev_device);
}
return udev_device->devtype;
}
static 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 = true;
udev_device_add_property(udev_device, "DEVTYPE", udev_device->devtype);
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 = true;
udev_device_add_property(udev_device, "SUBSYSTEM", udev_device->subsystem);
return 0;
}
/**
* 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
**/
_public_ 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 = true;
/* read "subsystem" link */
if (util_get_sys_core_link_value(udev_device->udev, "subsystem", udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
udev_device_set_subsystem(udev_device, subsystem);
return udev_device->subsystem;
}
/* implicit names */
if (startswith(udev_device->devpath, "/module/")) {
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 (startswith(udev_device->devpath, "/subsystem/") ||
startswith(udev_device->devpath, "/class/") ||
startswith(udev_device->devpath, "/bus/")) {
udev_device_set_subsystem(udev_device, "subsystem");
return udev_device->subsystem;
}
}
return udev_device->subsystem;
}
mode_t udev_device_get_devnode_mode(struct udev_device *udev_device)
{
if (!udev_device->info_loaded)
udev_device_read_uevent_file(udev_device);
return udev_device->devnode_mode;
}
static int udev_device_set_devnode_mode(struct udev_device *udev_device, mode_t mode)
{
char num[32];
udev_device->devnode_mode = mode;
snprintf(num, sizeof(num), "%#o", mode);
udev_device_add_property(udev_device, "DEVMODE", num);
return 0;
}
uid_t udev_device_get_devnode_uid(struct udev_device *udev_device)
{
if (!udev_device->info_loaded)
udev_device_read_uevent_file(udev_device);
return udev_device->devnode_uid;
}
static int udev_device_set_devnode_uid(struct udev_device *udev_device, uid_t uid)
{
char num[32];
udev_device->devnode_uid = uid;
snprintf(num, sizeof(num), "%u", uid);
udev_device_add_property(udev_device, "DEVUID", num);
return 0;
}
gid_t udev_device_get_devnode_gid(struct udev_device *udev_device)
{
if (!udev_device->info_loaded)
udev_device_read_uevent_file(udev_device);
return udev_device->devnode_gid;
}
static int udev_device_set_devnode_gid(struct udev_device *udev_device, gid_t gid)
{
char num[32];
udev_device->devnode_gid = gid;
snprintf(num, sizeof(num), "%u", gid);
udev_device_add_property(udev_device, "DEVGID", num);
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 = false;
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->properties_list, key, value);
}
static struct udev_list_entry *udev_device_add_property_from_string(struct udev_device *udev_device, const char *property)
{
char name[UTIL_LINE_SIZE];
char *val;
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);
}
/*
* parse property string, and if needed, update internal values accordingly
*
* udev_device_add_property_from_string_parse_finish() needs to be
* called after adding properties, and its return value checked
*
* udev_device_set_info_loaded() needs to be set, to avoid trying
* to use a device without a DEVPATH set
*/
void udev_device_add_property_from_string_parse(struct udev_device *udev_device, const char *property)
{
if (startswith(property, "DEVPATH=")) {
char path[UTIL_PATH_SIZE];
strscpyl(path, sizeof(path), "/sys", &property[8], NULL);
udev_device_set_syspath(udev_device, path);
} else if (startswith(property, "SUBSYSTEM=")) {
udev_device_set_subsystem(udev_device, &property[10]);
} else if (startswith(property, "DEVTYPE=")) {
udev_device_set_devtype(udev_device, &property[8]);
} else if (startswith(property, "DEVNAME=")) {
udev_device_set_devnode(udev_device, &property[8]);
} else if (startswith(property, "DEVLINKS=")) {
char devlinks[UTIL_PATH_SIZE];
char *slink;
char *next;
strscpy(devlinks, sizeof(devlinks), &property[9]);
slink = devlinks;
next = strchr(slink, ' ');
while (next != NULL) {
next[0] = '\0';
udev_device_add_devlink(udev_device, slink);
slink = &next[1];
next = strchr(slink, ' ');
}
if (slink[0] != '\0')
udev_device_add_devlink(udev_device, slink);
} else if (startswith(property, "TAGS=")) {
char tags[UTIL_PATH_SIZE];
char *next;
strscpy(tags, sizeof(tags), &property[5]);
next = strchr(tags, ':');
if (next != NULL) {
next++;
while (next[0] != '\0') {
char *tag;
tag = next;
next = strchr(tag, ':');
if (next == NULL)
break;
next[0] = '\0';
next++;
udev_device_add_tag(udev_device, tag);
}
}
} else if (startswith(property, "USEC_INITIALIZED=")) {
udev_device_set_usec_initialized(udev_device, strtoull(&property[19], NULL, 10));
} else if (startswith(property, "DRIVER=")) {
udev_device_set_driver(udev_device, &property[7]);
} else if (startswith(property, "ACTION=")) {
udev_device_set_action(udev_device, &property[7]);
} else if (startswith(property, "MAJOR=")) {
udev_device->maj = strtoull(&property[6], NULL, 10);
} else if (startswith(property, "MINOR=")) {
udev_device->min = strtoull(&property[6], NULL, 10);
} else if (startswith(property, "DEVPATH_OLD=")) {
udev_device_set_devpath_old(udev_device, &property[12]);
} else if (startswith(property, "SEQNUM=")) {
udev_device_set_seqnum(udev_device, strtoull(&property[7], NULL, 10));
} else if (startswith(property, "IFINDEX=")) {
udev_device_set_ifindex(udev_device, strtoull(&property[8], NULL, 10));
} else if (startswith(property, "DEVMODE=")) {
udev_device_set_devnode_mode(udev_device, strtoul(&property[8], NULL, 8));
} else if (startswith(property, "DEVUID=")) {
udev_device_set_devnode_uid(udev_device, strtoul(&property[7], NULL, 10));
} else if (startswith(property, "DEVGID=")) {
udev_device_set_devnode_gid(udev_device, strtoul(&property[7], NULL, 10));
} else {
udev_device_add_property_from_string(udev_device, property);
}
}
int udev_device_add_property_from_string_parse_finish(struct udev_device *udev_device)
{
if (udev_device->maj > 0)
udev_device_set_devnum(udev_device, makedev(udev_device->maj, udev_device->min));
udev_device->maj = 0;
udev_device->min = 0;
if (udev_device->devpath == NULL || udev_device->subsystem == NULL)
return -EINVAL;
return 0;
}
/**
* udev_device_get_property_value:
* @udev_device: udev device
* @key: property name
*
* Get the value of a given property.
*
* Returns: the property string, or #NULL if there is no such property.
**/
_public_ 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);
}
int udev_device_read_db(struct udev_device *udev_device, const char *dbfile)
{
char filename[UTIL_PATH_SIZE];
char line[UTIL_LINE_SIZE];
FILE *f;
/* providing a database file will always force-load it */
if (dbfile == NULL) {
const char *id;
if (udev_device->db_loaded)
return 0;
udev_device->db_loaded = true;
id = udev_device_get_id_filename(udev_device);
if (id == NULL)
return -1;
strscpyl(filename, sizeof(filename), "/run/udev/data/", id, NULL);
dbfile = filename;
}
f = fopen(dbfile, "re");
if (f == NULL) {
log_debug("no db file to read %s: %m\n", dbfile);
return -errno;
}
/* devices with a database entry are initialized */
udev_device->is_initialized = true;
while (fgets(line, sizeof(line), f)) {
ssize_t len;
const char *val;
struct udev_list_entry *entry;
len = strlen(line);
if (len < 4)
break;
line[len-1] = '\0';
val = &line[2];
switch(line[0]) {
case 'S':
strscpyl(filename, sizeof(filename), "/dev/", val, NULL);
udev_device_add_devlink(udev_device, filename);
break;
case 'L':
udev_device_set_devlink_priority(udev_device, atoi(val));
break;
case 'E':
entry = udev_device_add_property_from_string(udev_device, val);
udev_list_entry_set_num(entry, true);
break;
case 'G':
udev_device_add_tag(udev_device, val);
break;
case 'W':
udev_device_set_watch_handle(udev_device, atoi(val));
break;
case 'I':
udev_device_set_usec_initialized(udev_device, strtoull(val, NULL, 10));
break;
}
}
fclose(f);
log_debug("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;
if (udev_device->uevent_loaded)
return 0;
strscpyl(filename, sizeof(filename), udev_device->syspath, "/uevent", NULL);
f = fopen(filename, "re");
if (f == NULL)
return -errno;
udev_device->uevent_loaded = true;
while (fgets(line, sizeof(line), f)) {
char *pos;
pos = strchr(line, '\n');
if (pos == NULL)
continue;
pos[0] = '\0';
if (startswith(line, "DEVTYPE=")) {
udev_device_set_devtype(udev_device, &line[8]);
continue;
}
if (startswith(line, "IFINDEX=")) {
udev_device_set_ifindex(udev_device, strtoull(&line[8], NULL, 10));
continue;
}
if (startswith(line, "DEVNAME=")) {
udev_device_set_devnode(udev_device, &line[8]);
continue;
}
if (startswith(line, "MAJOR="))
maj = strtoull(&line[6], NULL, 10);
else if (startswith(line, "MINOR="))
min = strtoull(&line[6], NULL, 10);
else if (startswith(line, "DEVMODE="))
udev_device->devnode_mode = strtoul(&line[8], NULL, 8);
udev_device_add_property_from_string(udev_device, line);
}
udev_device->devnum = makedev(maj, min);
fclose(f);
return 0;
}
void udev_device_set_info_loaded(struct udev_device *device)
{
device->info_loaded = true;
}
struct udev_device *udev_device_new(struct udev *udev)
{
struct udev_device *udev_device;
struct udev_list_entry *list_entry;
if (udev == NULL) {
errno = EINVAL;
return NULL;
}
udev_device = new0(struct udev_device, 1);
if (udev_device == NULL) {
errno = ENOMEM;
return NULL;
}
udev_device->refcount = 1;
udev_device->udev = udev;
udev_list_init(udev, &udev_device->devlinks_list, true);
udev_list_init(udev, &udev_device->properties_list, true);
udev_list_init(udev, &udev_device->sysattr_value_list, true);
udev_list_init(udev, &udev_device->sysattr_list, false);
udev_list_init(udev, &udev_device->tags_list, true);
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));
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
**/
_public_ struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
{
const char *subdir;
char path[UTIL_PATH_SIZE];
char *pos;
struct stat statbuf;
struct udev_device *udev_device;
if (udev == NULL) {
errno = EINVAL;
return NULL;
}
if (syspath == NULL) {
errno = EINVAL;
return NULL;
}
/* path starts in sys */
if (!startswith(syspath, "/sys")) {
log_debug("not in sys :%s\n", syspath);
errno = EINVAL;
return NULL;
}
/* path is not a root directory */
subdir = syspath + strlen("/sys");
pos = strrchr(subdir, '/');
if (pos == NULL || pos[1] == '\0' || pos < &subdir[2]) {
errno = EINVAL;
return NULL;
}
/* resolve possible symlink to real path */
strscpy(path, sizeof(path), syspath);
util_resolve_sys_link(udev, path, sizeof(path));
if (startswith(path + strlen("/sys"), "/devices/")) {
char file[UTIL_PATH_SIZE];
/* all "devices" require a "uevent" file */
strscpyl(file, sizeof(file), path, "/uevent", NULL);
if (stat(file, &statbuf) != 0)
return NULL;
} else {
/* everything else just needs to be a directory */
if (stat(path, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode))
return NULL;
}
udev_device = udev_device_new(udev);
if (udev_device == NULL)
return NULL;
udev_device_set_syspath(udev_device, path);
log_debug("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 and type. Character and block device
* numbers are not unique across the two types.
*
* 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
**/
_public_ 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;
if (type == 'b')
type_str = "block";
else if (type == 'c')
type_str = "char";
else {
errno = EINVAL;
return NULL;
}
/* use /sys/dev/{block,char}/<maj>:<min> link */
snprintf(path, sizeof(path), "/sys/dev/%s/%u:%u",
type_str, major(devnum), minor(devnum));
return udev_device_new_from_syspath(udev, path);
}
/**
* udev_device_new_from_device_id:
* @udev: udev library context
* @id: text string identifying a kernel device
*
* Create new udev device, and fill in information from the sys
* device and the udev database entry. The device is looked-up
* by a special string:
* b8:2 - block device major:minor
* c128:1 - char device major:minor
* n3 - network device ifindex
* +sound:card29 - kernel driver core subsystem:device name
*
* 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
**/
_public_ struct udev_device *udev_device_new_from_device_id(struct udev *udev, const char *id)
{
char type;
int maj, min;
char subsys[UTIL_PATH_SIZE];
char *sysname;
switch(id[0]) {
case 'b':
case 'c':
if (sscanf(id, "%c%i:%i", &type, &maj, &min) != 3)
return NULL;
return udev_device_new_from_devnum(udev, type, makedev(maj, min));
case 'n': {
int sk;
struct ifreq ifr;
struct udev_device *dev;
int ifindex;
ifindex = strtoul(&id[1], NULL, 10);
if (ifindex <= 0) {
errno = EINVAL;
return NULL;
}
sk = socket(PF_INET, SOCK_DGRAM, 0);
if (sk < 0)
return NULL;
memzero(&ifr, sizeof(struct ifreq));
ifr.ifr_ifindex = ifindex;
if (ioctl(sk, SIOCGIFNAME, &ifr) != 0) {
close(sk);
return NULL;
}
close(sk);
dev = udev_device_new_from_subsystem_sysname(udev, "net", ifr.ifr_name);
if (dev == NULL)
return NULL;
if (udev_device_get_ifindex(dev) == ifindex)
return dev;
/* this is racy, so we may end up with the wrong device */
udev_device_unref(dev);
errno = ENODEV;
return NULL;
}
case '+':
strscpy(subsys, sizeof(subsys), &id[1]);
sysname = strchr(subsys, ':');
if (sysname == NULL) {
errno = EINVAL;
return NULL;
}
sysname[0] = '\0';
sysname = &sysname[1];
return udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
default:
errno = EINVAL;
return NULL;
}
}
/**
* 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
**/
_public_ struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname)
{
char path[UTIL_PATH_SIZE];
struct stat statbuf;
if (streq(subsystem, "subsystem")) {
strscpyl(path, sizeof(path), "/sys/subsystem/", sysname, NULL);
if (stat(path, &statbuf) == 0)
goto found;
strscpyl(path, sizeof(path), "/sys/bus/", sysname, NULL);
if (stat(path, &statbuf) == 0)
goto found;
strscpyl(path, sizeof(path), "/sys/class/", sysname, NULL);
if (stat(path, &statbuf) == 0)
goto found;
goto out;
}
if (streq(subsystem, "module")) {
strscpyl(path, sizeof(path), "/sys/module/", sysname, NULL);
if (stat(path, &statbuf) == 0)
goto found;
goto out;
}
if (streq(subsystem, "drivers")) {
char subsys[UTIL_NAME_SIZE];
char *driver;
strscpy(subsys, sizeof(subsys), sysname);
driver = strchr(subsys, ':');
if (driver != NULL) {
driver[0] = '\0';
driver = &driver[1];
strscpyl(path, sizeof(path), "/sys/subsystem/", subsys, "/drivers/", driver, NULL);
if (stat(path, &statbuf) == 0)
goto found;
strscpyl(path, sizeof(path), "/sys/bus/", subsys, "/drivers/", driver, NULL);
if (stat(path, &statbuf) == 0)
goto found;
} else
errno = EINVAL;
goto out;
}
strscpyl(path, sizeof(path), "/sys/subsystem/", subsystem, "/devices/", sysname, NULL);
if (stat(path, &statbuf) == 0)
goto found;
strscpyl(path, sizeof(path), "/sys/bus/", subsystem, "/devices/", sysname, NULL);
if (stat(path, &statbuf) == 0)
goto found;
strscpyl(path, sizeof(path), "/sys/class/", subsystem, "/", sysname, NULL);
if (stat(path, &statbuf) == 0)
goto found;
out:
return NULL;
found:
return udev_device_new_from_syspath(udev, path);
}
/**
* udev_device_new_from_environment
* @udev: udev library context
*
* Create new udev device, and fill in information from the
* current process environment. This only works reliable if
* the process is called from a udev rule. It is usually used
* for tools executed from IMPORT= rules.
*
* 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
**/
_public_ struct udev_device *udev_device_new_from_environment(struct udev *udev)
{
int i;
struct udev_device *udev_device;
udev_device = udev_device_new(udev);
if (udev_device == NULL)
return NULL;
udev_device_set_info_loaded(udev_device);
for (i = 0; environ[i] != NULL; i++)
udev_device_add_property_from_string_parse(udev_device, environ[i]);
if (udev_device_add_property_from_string_parse_finish(udev_device) < 0) {
log_debug("missing values, invalid device\n");
udev_device_unref(udev_device);
udev_device = NULL;
}
return udev_device;
}
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;
strscpy(path, sizeof(path), udev_device->syspath);
subdir = path + strlen("/sys/");
for (;;) {
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;
}
errno = ENOENT;
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.
*
* Returned 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.
**/
_public_ struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
{
if (udev_device == NULL) {
errno = EINVAL;
return NULL;
}
if (!udev_device->parent_set) {
udev_device->parent_set = true;
udev_device->parent_device = device_new_from_parent(udev_device);
}
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.
*
* If devtype is #NULL, only subsystem is checked, and any devtype will
* match.
*
* Returned 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.
**/
_public_ 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) {
errno = EINVAL;
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 && streq(parent_subsystem, subsystem)) {
if (devtype == NULL)
break;
parent_devtype = udev_device_get_devtype(parent);
if (parent_devtype != NULL && streq(parent_devtype, devtype))
break;
}
parent = udev_device_get_parent(parent);
}
if (!parent)
errno = ENOENT;
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
**/
_public_ 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
**/
_public_ 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.
*
* Returns: #NULL
**/
_public_ struct udev_device *udev_device_unref(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
udev_device->refcount--;
if (udev_device->refcount > 0)
return NULL;
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(&udev_device->devlinks_list);
udev_list_cleanup(&udev_device->properties_list);
udev_list_cleanup(&udev_device->sysattr_value_list);
udev_list_cleanup(&udev_device->sysattr_list);
udev_list_cleanup(&udev_device->tags_list);
free(udev_device->action);
free(udev_device->driver);
free(udev_device->devpath_old);
free(udev_device->id_filename);
free(udev_device->envp);
free(udev_device->monitor_buf);
free(udev_device);
return NULL;
}
/**
* 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
**/
_public_ 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
**/
_public_ 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
*
* Get the kernel device name in /sys.
*
* Returns: the name string of the device device
**/
_public_ 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
*
* Get the instance number of the device.
*
* Returns: the trailing number string of the device name
**/
_public_ 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
**/
_public_ const char *udev_device_get_devnode(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
if (udev_device->devnode != NULL)
return udev_device->devnode;
if (!udev_device->info_loaded)
udev_device_read_uevent_file(udev_device);
return udev_device->devnode;
}
/**
* 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_get_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
**/
_public_ 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)
udev_device_read_db(udev_device, NULL);
return udev_list_get_entry(&udev_device->devlinks_list);
}
void udev_device_cleanup_devlinks_list(struct udev_device *udev_device)
{
udev_device->devlinks_uptodate = false;
udev_list_cleanup(&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_get_next(),
* which returns #NULL if no more entries exist. The property name
* can be retrieved from the list entry by udev_list_entry_get_name(),
* the property value by udev_list_entry_get_value().
*
* Returns: the first entry of the property list
**/
_public_ 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) {
udev_device_read_uevent_file(udev_device);
udev_device_read_db(udev_device, NULL);
}
if (!udev_device->devlinks_uptodate) {
char symlinks[UTIL_PATH_SIZE];
struct udev_list_entry *list_entry;
udev_device->devlinks_uptodate = true;
list_entry = udev_device_get_devlinks_list_entry(udev_device);
if (list_entry != NULL) {
char *s;
size_t l;
s = symlinks;
l = 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 = strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry), NULL);
udev_device_add_property(udev_device, "DEVLINKS", symlinks);
}
}
if (!udev_device->tags_uptodate) {
udev_device->tags_uptodate = true;
if (udev_device_get_tags_list_entry(udev_device) != NULL) {
char tags[UTIL_PATH_SIZE];
struct udev_list_entry *list_entry;
char *s;
size_t l;
s = tags;
l = strpcpyl(&s, sizeof(tags), ":", NULL);
udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device))
l = strpcpyl(&s, l, udev_list_entry_get_name(list_entry), ":", NULL);
udev_device_add_property(udev_device, "TAGS", tags);
}
}
return udev_list_get_entry(&udev_device->properties_list);
}
/**
* 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.
**/
_public_ const char *udev_device_get_action(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
return udev_device->action;
}
/**
* udev_device_get_usec_since_initialized:
* @udev_device: udev device
*
* Return the number of microseconds passed since udev set up the
* device for the first time.
*
* This is only implemented for devices with need to store properties
* in the udev database. All other devices return 0 here.
*
* Returns: the number of microseconds since the device was first seen.
**/
_public_ unsigned long long int udev_device_get_usec_since_initialized(struct udev_device *udev_device)
{
usec_t now_ts;
if (udev_device == NULL)
return 0;
if (!udev_device->info_loaded)
udev_device_read_db(udev_device, NULL);
if (udev_device->usec_initialized == 0)
return 0;
now_ts = now(CLOCK_MONOTONIC);
if (now_ts == 0)
return 0;
return now_ts - udev_device->usec_initialized;
}
usec_t udev_device_get_usec_initialized(struct udev_device *udev_device)
{
return udev_device->usec_initialized;
}
void udev_device_set_usec_initialized(struct udev_device *udev_device, usec_t usec_initialized)
{
char num[32];
udev_device->usec_initialized = usec_initialized;
snprintf(num, sizeof(num), USEC_FMT, usec_initialized);
udev_device_add_property(udev_device, "USEC_INITIALIZED", num);
}
/**
* 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.
**/
_public_ 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 */
list_entry = udev_list_get_entry(&udev_device->sysattr_value_list);
list_entry = udev_list_entry_get_by_name(list_entry, sysattr);
if (list_entry != NULL)
return udev_list_entry_get_value(list_entry);
strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", sysattr, NULL);
if (lstat(path, &statbuf) != 0) {
udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, NULL);
goto out;
}
if (S_ISLNK(statbuf.st_mode)) {
/*
* Some core links return only the last element of the target path,
* these are just values, the paths should not be exposed.
*/
if (streq(sysattr, "driver") ||
streq(sysattr, "subsystem") ||
streq(sysattr, "module")) {
if (util_get_sys_core_link_value(udev_device->udev, sysattr,
udev_device->syspath, value, sizeof(value)) < 0)
return NULL;
list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value);
val = udev_list_entry_get_value(list_entry);
goto out;
}
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|O_CLOEXEC);
if (fd < 0)
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');
list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value);
val = udev_list_entry_get_value(list_entry);
out:
return val;
}
/**
* udev_device_set_sysattr_value:
* @udev_device: udev device
* @sysattr: attribute name
* @value: new value to be set
*
* Update the contents of the sys attribute and the cached value of the device.
*
* Returns: Negative error code on failure or 0 on success.
**/
_public_ int udev_device_set_sysattr_value(struct udev_device *udev_device, const char *sysattr, char *value)
{
struct udev_device *dev;
char path[UTIL_PATH_SIZE];
struct stat statbuf;
int fd;
ssize_t size, value_len;
int ret = 0;
if (udev_device == NULL)
return -EINVAL;
dev = udev_device;
if (sysattr == NULL)
return -EINVAL;
if (value == NULL)
value_len = 0;
else
value_len = strlen(value);
strscpyl(path, sizeof(path), udev_device_get_syspath(dev), "/", sysattr, NULL);
if (lstat(path, &statbuf) != 0) {
udev_list_entry_add(&dev->sysattr_value_list, sysattr, NULL);
ret = -ENXIO;
goto out;
}
if (S_ISLNK(statbuf.st_mode)) {
ret = -EINVAL;
goto out;
}
/* skip directories */
if (S_ISDIR(statbuf.st_mode)) {
ret = -EISDIR;
goto out;
}
/* skip non-readable files */
if ((statbuf.st_mode & S_IRUSR) == 0) {
ret = -EACCES;
goto out;
}
/* Value is limited to 4k */
if (value_len > 4096) {
ret = -EINVAL;
goto out;
}
util_remove_trailing_chars(value, '\n');
/* write attribute value */
fd = open(path, O_WRONLY|O_CLOEXEC);
if (fd < 0) {
ret = -errno;
goto out;
}
size = write(fd, value, value_len);
close(fd);
if (size < 0) {
ret = -errno;
goto out;
}
if (size < value_len) {
ret = -EIO;
goto out;
}
/* wrote a valid value, store it in cache and return it */
udev_list_entry_add(&dev->sysattr_value_list, sysattr, value);
out:
if (dev != udev_device)
udev_device_unref(dev);
return ret;
}
static int udev_device_sysattr_list_read(struct udev_device *udev_device)
{
struct dirent *dent;
DIR *dir;
int num = 0;
if (udev_device == NULL)
return -EINVAL;
if (udev_device->sysattr_list_read)
return 0;
dir = opendir(udev_device_get_syspath(udev_device));
if (!dir)
return -errno;
for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
char path[UTIL_PATH_SIZE];
struct stat statbuf;
/* only handle symlinks and regular files */
if (dent->d_type != DT_LNK && dent->d_type != DT_REG)
continue;
strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", dent->d_name, NULL);
if (lstat(path, &statbuf) != 0)
continue;
if ((statbuf.st_mode & S_IRUSR) == 0)
continue;
udev_list_entry_add(&udev_device->sysattr_list, dent->d_name, NULL);
num++;
}
closedir(dir);
udev_device->sysattr_list_read = true;
return num;
}
/**
* udev_device_get_sysattr_list_entry:
* @udev_device: udev device
*
* Retrieve the list of available sysattrs, with value being empty;
* This just return all available sysfs attributes for a particular
* device without reading their values.
*
* Returns: the first entry of the property list
**/
_public_ struct udev_list_entry *udev_device_get_sysattr_list_entry(struct udev_device *udev_device)
{
if (!udev_device->sysattr_list_read) {
int ret;
ret = udev_device_sysattr_list_read(udev_device);
if (0 > ret)
return NULL;
}
return udev_list_get_entry(&udev_device->sysattr_list);
}
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("/sys");
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;
}
static int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode)
{
free(udev_device->devnode);
if (devnode[0] != '/') {
if (asprintf(&udev_device->devnode, "/dev/%s", devnode) < 0)
udev_device->devnode = NULL;
} else {
udev_device->devnode = strdup(devnode);
}
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)
{
struct udev_list_entry *list_entry;
udev_device->devlinks_uptodate = false;
list_entry = udev_list_entry_add(&udev_device->devlinks_list, devlink, NULL);
if (list_entry == NULL)
return -ENOMEM;
return 0;
}
const char *udev_device_get_id_filename(struct udev_device *udev_device)
{
if (udev_device->id_filename == NULL) {
if (udev_device_get_subsystem(udev_device) == NULL)
return NULL;
if (major(udev_device_get_devnum(udev_device)) > 0) {
/* use dev_t -- b259:131072, c254:0 */
if (asprintf(&udev_device->id_filename, "%c%u:%u",
streq(udev_device_get_subsystem(udev_device), "block") ? 'b' : 'c',
major(udev_device_get_devnum(udev_device)),
minor(udev_device_get_devnum(udev_device))) < 0)
udev_device->id_filename = NULL;
} else if (udev_device_get_ifindex(udev_device) > 0) {
/* use netdev ifindex -- n3 */
if (asprintf(&udev_device->id_filename, "n%u", udev_device_get_ifindex(udev_device)) < 0)
udev_device->id_filename = NULL;
} else {
/*
* use $subsys:$syname -- pci:0000:00:1f.2
* sysname() has '!' translated, get it from devpath
*/
const char *sysname;
sysname = strrchr(udev_device->devpath, '/');
if (sysname == NULL)
return NULL;
sysname = &sysname[1];
if (asprintf(&udev_device->id_filename, "+%s:%s", udev_device_get_subsystem(udev_device), sysname) < 0)
udev_device->id_filename = NULL;
}
}
return udev_device->id_filename;
}
/**
* udev_device_get_is_initialized:
* @udev_device: udev device
*
* Check if udev has already handled the device and has set up
* device node permissions and context, or has renamed a network
* device.
*
* This is only implemented for devices with a device node
* or network interfaces. All other devices return 1 here.
*
* Returns: 1 if the device is set up. 0 otherwise.
**/
_public_ int udev_device_get_is_initialized(struct udev_device *udev_device)
{
if (!udev_device->info_loaded)
udev_device_read_db(udev_device, NULL);
return udev_device->is_initialized;
}
void udev_device_set_is_initialized(struct udev_device *udev_device)
{
udev_device->is_initialized = true;
}
static bool is_valid_tag(const char *tag)
{
return !strchr(tag, ':') && !strchr(tag, ' ');
}
int udev_device_add_tag(struct udev_device *udev_device, const char *tag)
{
if (!is_valid_tag(tag))
return -EINVAL;
udev_device->tags_uptodate = false;
if (udev_list_entry_add(&udev_device->tags_list, tag, NULL) != NULL)
return 0;
return -ENOMEM;
}
void udev_device_remove_tag(struct udev_device *udev_device, const char *tag)
{
struct udev_list_entry *e;
if (!is_valid_tag(tag))
return;
e = udev_list_get_entry(&udev_device->tags_list);
e = udev_list_entry_get_by_name(e, tag);
if (e) {
udev_device->tags_uptodate = false;
udev_list_entry_delete(e);
}
}
void udev_device_cleanup_tags_list(struct udev_device *udev_device)
{
udev_device->tags_uptodate = false;
udev_list_cleanup(&udev_device->tags_list);
}
/**
* udev_device_get_tags_list_entry:
* @udev_device: udev device
*
* Retrieve the list of tags attached to the udev device. The next
* list entry can be retrieved with udev_list_entry_get_next(),
* which returns #NULL if no more entries exist. The tag string
* can be retrieved from the list entry by udev_list_entry_get_name().
*
* Returns: the first entry of the tag list
**/
_public_ struct udev_list_entry *udev_device_get_tags_list_entry(struct udev_device *udev_device)
{
if (udev_device == NULL)
return NULL;
if (!udev_device->info_loaded)
udev_device_read_db(udev_device, NULL);
return udev_list_get_entry(&udev_device->tags_list);
}
/**
* udev_device_has_tag:
* @udev_device: udev device
* @tag: tag name
*
* Check if a given device has a certain tag associated.
*
* Returns: 1 if the tag is found. 0 otherwise.
**/
_public_ int udev_device_has_tag(struct udev_device *udev_device, const char *tag)
{
struct udev_list_entry *list_entry;
if (udev_device == NULL)
return false;
if (!udev_device->info_loaded)
udev_device_read_db(udev_device, NULL);
list_entry = udev_device_get_tags_list_entry(udev_device);
if (udev_list_entry_get_by_name(list_entry, tag) != NULL)
return true;
return false;
}
#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 = strpcpyl(&s, l, key, "=", udev_list_entry_get_value(list_entry), NULL);
if (l == 0)
return -EINVAL;
/* advance past the trailing '\0' that strpcpyl() guarantees */
s++;
l--;
}
udev_device->envp[i] = NULL;
udev_device->monitor_buf_len = s - udev_device->monitor_buf;
udev_device->envp_uptodate = true;
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_get_devlink_priority(struct udev_device *udev_device)
{
if (!udev_device->info_loaded)
udev_device_read_db(udev_device, NULL);
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_watch_handle(struct udev_device *udev_device)
{
if (!udev_device->info_loaded)
udev_device_read_db(udev_device, NULL);
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;
}
bool udev_device_get_db_persist(struct udev_device *udev_device)
{
return udev_device->db_persist;
}
void udev_device_set_db_persist(struct udev_device *udev_device)
{
udev_device->db_persist = true;
}
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