[thirdparty/systemd.git] / udev / lib / libudev-device.c

/*
 * libudev - interface to udev device information
 *
 * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <dirent.h>
#include <sys/stat.h>

#include "libudev.h"
#include "libudev-private.h"
#include "../udev.h"

struct udev_device *device_init(struct udev *udev)
{
	struct udev_device *udev_device;

	if (udev == NULL)
		return NULL;

	udev_device = malloc(sizeof(struct udev_device));
	if (udev_device == NULL)
		return NULL;
	memset(udev_device, 0x00, sizeof(struct udev_device));
	udev_device->refcount = 1;
	udev_device->udev = udev;
	INIT_LIST_HEAD(&udev_device->link_list);
	INIT_LIST_HEAD(&udev_device->env_list);
	log_info(udev_device->udev, "udev_device: %p created\n", udev_device);
	return udev_device;
}

/**
 * udev_device_new_from_devpath:
 * @udev: udev library context
 * @devpath: sys device path
 *
 * Create new udev device, and fill in information from the sysfs
 * device and the udev database entry. The devpath must not contain
 * the sysfs mount path, and must contain a leading '/'.
 *
 * The initial refcount is 1, and needs to be decremented to
 * release the ressources of the udev device.
 *
 * Returns: a new udev device, or #NULL, if it does not exist
 **/
struct udev_device *udev_device_new_from_devpath(struct udev *udev, const char *devpath)
{
	char path[PATH_SIZE];
	struct stat statbuf;
	struct udev_device *udev_device;
	struct udevice *udevice;
	struct name_entry *name_loop;
	int err;

	if (udev == NULL)
		return NULL;
	if (devpath == NULL)
		return NULL;

	strlcpy(path, udev_get_sys_path(udev), sizeof(path));
	strlcat(path, devpath, sizeof(path));
	if (stat(path, &statbuf) != 0)
		return NULL;
	if (!S_ISDIR(statbuf.st_mode))
		return NULL;

	udev_device = device_init(udev);
	if (udev_device == NULL)
		return NULL;

	udevice = udev_device_init(NULL);
	if (udevice == NULL) {
		free(udev_device);
		return NULL;
	}

	/* resolve possible symlink to real path */
	strlcpy(path, devpath, sizeof(path));
	sysfs_resolve_link(path, sizeof(path));
	udev_device->devpath = strdup(path);
	log_info(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));

	err = udev_db_get_device(udevice, path);
	if (err >= 0)
		log_info(udev, "device %p filled with udev database data\n", udev_device);

	if (udevice->name[0] != '\0')
		asprintf(&udev_device->devname, "%s/%s", udev_get_dev_path(udev), udevice->name);

	list_for_each_entry(name_loop, &udevice->symlink_list, node) {
		char name[PATH_SIZE];

		strlcpy(name, udev_get_dev_path(udev), sizeof(name));
		strlcat(name, "/", sizeof(name));
		strlcat(name, name_loop->name, sizeof(name));
		name_list_add(&udev_device->link_list, name, 0);
	}

	list_for_each_entry(name_loop, &udevice->env_list, node)
		name_list_add(&udev_device->env_list, name_loop->name, 0);

	udev_device_cleanup(udevice);
	return udev_device;
}

/**
 * udev_device_get_udev:
 *
 * 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 ressources 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;
	free(udev_device->devpath);
	free(udev_device->devname);
	free(udev_device->subsystem);
	name_list_cleanup(&udev_device->link_list);
	name_list_cleanup(&udev_device->env_list);
	log_info(udev_device->udev, "udev_device: %p released\n", udev_device);
	free(udev_device);
}

/**
 * udev_device_get_devpath:
 * @udev_device: udev device
 *
 * Retrieve the sys path of the udev device. The path does not contain
 * the sys mount point.
 *
 * Returns: the sys path 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_devname:
 * @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_devname(struct udev_device *udev_device)
{
	if (udev_device == NULL)
		return NULL;
	return udev_device->devname;
}

/**
 * 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[NAME_SIZE];

	if (udev_device == NULL)
		return NULL;
	if (udev_device->subsystem != NULL)
		return udev_device->subsystem;
	if (util_get_sys_subsystem(udev_device->udev, udev_device->devpath, subsystem, sizeof(subsystem)) < 2)
		return NULL;
	udev_device->subsystem = strdup(subsystem);
	return udev_device->subsystem;
}

/**
 * udev_device_get_devlinks:
 * @udev_device: udev device
 * @cb: function to be called for every device link found
 * @data: data to be passed to the function
 *
 * Retrieve the device links pointing to the device file of the
 * udev device. For every device link, the passed function will be
 * called with the device link string.
 * The path is an absolute path, and starts with the device directory.
 * If the function returns 1, remaning device links will be ignored.
 *
 * Returns: the number of device links passed to the caller, or a negative value on error
 **/
int udev_device_get_devlinks(struct udev_device *udev_device,
			      int (*cb)(struct udev_device *udev_device, const char *value, void *data),
			      void *data)
{
	struct name_entry *name_loop;
	int count = 0;

	if (udev_device == NULL)
		return -1;
	list_for_each_entry(name_loop, &udev_device->link_list, node) {
		count++;
		if (cb(udev_device, name_loop->name, data) != 0)
			break;
	}
	return count;
}

/**
 * udev_device_get_properties:
 * @udev_device: udev device
 * @cb: function to be called for every property found
 * @data: data to be passed to the function
 *
 * Retrieve the property key/value pairs belonging to the
 * udev device. For every key/value pair, the passed function will be
 * called. If the function returns 1, remaning properties will be
 * ignored.
 *
 * Returns: the number of properties passed to the caller, or a negative value on error
 **/
int udev_device_get_properties(struct udev_device *udev_device,
				int (*cb)(struct udev_device *udev_device, const char *key, const char *value, void *data),
				void *data)
{
	struct name_entry *name_loop;
	int count = 0;

	if (udev_device == NULL)
		return -1;
	list_for_each_entry(name_loop, &udev_device->env_list, node) {
		char name[PATH_SIZE];
		char *val;

		strncpy(name, name_loop->name, PATH_SIZE);
		name[PATH_SIZE-1] = '\0';
		val = strchr(name, '=');
		if (val == NULL)
			continue;
		val[0] = '\0';
		val = &val[1];
		count++;
		if (cb(udev_device, name, val, data) != 0)
			break;
	}
	return count;
}
Commit	Line	Data
eb1f0e66 KS	1	/*
	2	* libudev - interface to udev device information
	3	*
	4	* Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
	5	*
	6	* This program is free software: you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation, either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	18	*/
	19
	20	#include "config.h"
	21
	22	#include <stdio.h>
	23	#include <stdlib.h>
	24	#include <stddef.h>
	25	#include <unistd.h>
	26	#include <errno.h>
	27	#include <string.h>
	28	#include <dirent.h>
	29	#include <sys/stat.h>
	30
	31	#include "libudev.h"
	32	#include "libudev-private.h"
	33	#include "../udev.h"
	34
ba6929f6	35	struct udev_device device_init(struct udev udev)
eb1f0e66 KS	36	{
	37	struct udev_device *udev_device;
	38
ba6929f6 KS	39	if (udev == NULL)
	40	return NULL;
	41
eb1f0e66 KS	42	udev_device = malloc(sizeof(struct udev_device));
	43	if (udev_device == NULL)
	44	return NULL;
	45	memset(udev_device, 0x00, sizeof(struct udev_device));
	46	udev_device->refcount = 1;
	47	udev_device->udev = udev;
ba6929f6 KS	48	INIT_LIST_HEAD(&udev_device->link_list);
	49	INIT_LIST_HEAD(&udev_device->env_list);
	50	log_info(udev_device->udev, "udev_device: %p created\n", udev_device);
eb1f0e66 KS	51	return udev_device;
	52	}
	53
	54	/**
	55	* udev_device_new_from_devpath:
	56	* @udev: udev library context
	57	* @devpath: sys device path
	58	*
	59	* Create new udev device, and fill in information from the sysfs
	60	* device and the udev database entry. The devpath must not contain
	61	* the sysfs mount path, and must contain a leading '/'.
	62	*
	63	* The initial refcount is 1, and needs to be decremented to
	64	* release the ressources of the udev device.
	65	*
	66	* Returns: a new udev device, or #NULL, if it does not exist
	67	**/
	68	struct udev_device udev_device_new_from_devpath(struct udev udev, const char *devpath)
	69	{
	70	char path[PATH_SIZE];
	71	struct stat statbuf;
	72	struct udev_device *udev_device;
ba6929f6 KS	73	struct udevice *udevice;
ba6929f6 KS	74	struct name_entry *name_loop;
eb1f0e66 KS	75	int err;
eb1f0e66 KS	76
ba6929f6 KS	77	if (udev == NULL)
	78	return NULL;
	79	if (devpath == NULL)
	80	return NULL;
	81
eb1f0e66 KS	82	strlcpy(path, udev_get_sys_path(udev), sizeof(path));
	83	strlcat(path, devpath, sizeof(path));
	84	if (stat(path, &statbuf) != 0)
	85	return NULL;
	86	if (!S_ISDIR(statbuf.st_mode))
	87	return NULL;
	88
	89	udev_device = device_init(udev);
	90	if (udev_device == NULL)
	91	return NULL;
	92
ba6929f6 KS	93	udevice = udev_device_init(NULL);
ba6929f6 KS	94	if (udevice == NULL) {
eb1f0e66 KS	95	free(udev_device);
	96	return NULL;
	97	}
eb1f0e66	98
ba6929f6	99	/* resolve possible symlink to real path */
eb1f0e66 KS	100	strlcpy(path, devpath, sizeof(path));
eb1f0e66 KS	101	sysfs_resolve_link(path, sizeof(path));
ba6929f6 KS	102	udev_device->devpath = strdup(path);
ba6929f6 KS	103	log_info(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
eb1f0e66	104
ba6929f6	105	err = udev_db_get_device(udevice, path);
eb1f0e66 KS	106	if (err >= 0)
eb1f0e66 KS	107	log_info(udev, "device %p filled with udev database data\n", udev_device);
ba6929f6 KS	108
	109	if (udevice->name[0] != '\0')
	110	asprintf(&udev_device->devname, "%s/%s", udev_get_dev_path(udev), udevice->name);
	111
	112	list_for_each_entry(name_loop, &udevice->symlink_list, node) {
	113	char name[PATH_SIZE];
	114
	115	strlcpy(name, udev_get_dev_path(udev), sizeof(name));
	116	strlcat(name, "/", sizeof(name));
	117	strlcat(name, name_loop->name, sizeof(name));
	118	name_list_add(&udev_device->link_list, name, 0);
	119	}
	120
	121	list_for_each_entry(name_loop, &udevice->env_list, node)
	122	name_list_add(&udev_device->env_list, name_loop->name, 0);
	123
	124	udev_device_cleanup(udevice);
eb1f0e66 KS	125	return udev_device;
	126	}
	127
	128	/**
	129	* udev_device_get_udev:
	130	*
	131	* Retrieve the udev library context the device was created with.
	132	*
	133	* Returns: the udev library context
	134	**/
	135	struct udev udev_device_get_udev(struct udev_device udev_device)
	136	{
ba6929f6 KS	137	if (udev_device == NULL)
ba6929f6 KS	138	return NULL;
eb1f0e66 KS	139	return udev_device->udev;
	140	}
	141
	142	/**
	143	* udev_device_ref:
	144	* @udev_device: udev device
	145	*
	146	* Take a reference of a udev device.
	147	*
	148	* Returns: the passed udev device
	149	**/
	150	struct udev_device udev_device_ref(struct udev_device udev_device)
	151	{
ba6929f6 KS	152	if (udev_device == NULL)
ba6929f6 KS	153	return NULL;
eb1f0e66 KS	154	udev_device->refcount++;
	155	return udev_device;
	156	}
	157
	158	/**
	159	* udev_device_unref:
	160	* @udev_device: udev device
	161	*
	162	* Drop a reference of a udev device. If the refcount reaches zero,
	163	* the ressources of the device will be released.
	164	*
	165	**/
	166	void udev_device_unref(struct udev_device *udev_device)
	167	{
ba6929f6 KS	168	if (udev_device == NULL)
ba6929f6 KS	169	return;
eb1f0e66 KS	170	udev_device->refcount--;
	171	if (udev_device->refcount > 0)
	172	return;
ba6929f6 KS	173	free(udev_device->devpath);
	174	free(udev_device->devname);
	175	free(udev_device->subsystem);
	176	name_list_cleanup(&udev_device->link_list);
	177	name_list_cleanup(&udev_device->env_list);
	178	log_info(udev_device->udev, "udev_device: %p released\n", udev_device);
eb1f0e66 KS	179	free(udev_device);
	180	}
	181
	182	/**
	183	* udev_device_get_devpath:
	184	* @udev_device: udev device
	185	*
	186	* Retrieve the sys path of the udev device. The path does not contain
	187	* the sys mount point.
	188	*
	189	* Returns: the sys path of the udev device
	190	**/
	191	const char udev_device_get_devpath(struct udev_device udev_device)
	192	{
ba6929f6 KS	193	if (udev_device == NULL)
	194	return NULL;
	195	return udev_device->devpath;
eb1f0e66 KS	196	}
	197
	198	/**
	199	* udev_device_get_devname:
	200	* @udev_device: udev device
	201	*
	202	* Retrieve the device node file name belonging to the udev device.
ba6929f6	203	* The path is an absolute path, and starts with the device directory.
eb1f0e66 KS	204	*
	205	* Returns: the device node file name of the udev device, or #NULL if no device node exists
	206	**/
	207	const char udev_device_get_devname(struct udev_device udev_device)
	208	{
ba6929f6	209	if (udev_device == NULL)
eb1f0e66	210	return NULL;
ba6929f6	211	return udev_device->devname;
eb1f0e66 KS	212	}
	213
	214	/**
	215	* udev_device_get_subsystem:
	216	* @udev_device: udev device
	217	*
	218	* Retrieve the subsystem string of the udev device. The string does not
	219	* contain any "/".
	220	*
	221	* Returns: the subsystem name of the udev device, or #NULL if it can not be determined
	222	**/
	223	const char udev_device_get_subsystem(struct udev_device udev_device)
	224	{
ba6929f6 KS	225	char subsystem[NAME_SIZE];
	226
	227	if (udev_device == NULL)
	228	return NULL;
	229	if (udev_device->subsystem != NULL)
	230	return udev_device->subsystem;
	231	if (util_get_sys_subsystem(udev_device->udev, udev_device->devpath, subsystem, sizeof(subsystem)) < 2)
eb1f0e66	232	return NULL;
ba6929f6 KS	233	udev_device->subsystem = strdup(subsystem);
ba6929f6 KS	234	return udev_device->subsystem;
eb1f0e66 KS	235	}
	236
	237	/**
	238	* udev_device_get_devlinks:
	239	* @udev_device: udev device
	240	* @cb: function to be called for every device link found
	241	* @data: data to be passed to the function
	242	*
	243	* Retrieve the device links pointing to the device file of the
	244	* udev device. For every device link, the passed function will be
ba6929f6 KS	245	* called with the device link string.
	246	* The path is an absolute path, and starts with the device directory.
	247	* If the function returns 1, remaning device links will be ignored.
eb1f0e66 KS	248	*
	249	* Returns: the number of device links passed to the caller, or a negative value on error
	250	**/
	251	int udev_device_get_devlinks(struct udev_device *udev_device,
	252	int (cb)(struct udev_device udev_device, const char value, void data),
	253	void *data)
	254	{
	255	struct name_entry *name_loop;
	256	int count = 0;
	257
ba6929f6 KS	258	if (udev_device == NULL)
	259	return -1;
	260	list_for_each_entry(name_loop, &udev_device->link_list, node) {
eb1f0e66 KS	261	count++;
	262	if (cb(udev_device, name_loop->name, data) != 0)
	263	break;
	264	}
	265	return count;
	266	}
	267
	268	/**
	269	* udev_device_get_properties:
	270	* @udev_device: udev device
	271	* @cb: function to be called for every property found
	272	* @data: data to be passed to the function
	273	*
	274	* Retrieve the property key/value pairs belonging to the
	275	* udev device. For every key/value pair, the passed function will be
	276	* called. If the function returns 1, remaning properties will be
	277	* ignored.
	278	*
	279	* Returns: the number of properties passed to the caller, or a negative value on error
	280	**/
	281	int udev_device_get_properties(struct udev_device *udev_device,
	282	int (cb)(struct udev_device udev_device, const char key, const char value, void *data),
	283	void *data)
	284	{
	285	struct name_entry *name_loop;
	286	int count = 0;
	287
ba6929f6 KS	288	if (udev_device == NULL)
	289	return -1;
	290	list_for_each_entry(name_loop, &udev_device->env_list, node) {
eb1f0e66 KS	291	char name[PATH_SIZE];
	292	char *val;
	293
	294	strncpy(name, name_loop->name, PATH_SIZE);
	295	name[PATH_SIZE-1] = '\0';
	296	val = strchr(name, '=');
	297	if (val == NULL)
	298	continue;
	299	val[0] = '\0';
	300	val = &val[1];
ba6929f6	301	count++;
eb1f0e66 KS	302	if (cb(udev_device, name, val, data) != 0)
	303	break;
	304	}
	305	return count;
	306	}