[thirdparty/systemd.git] / libudev / libudev.c

/*
 * libudev - interface to udev device information
 *
 * Copyright (C) 2008 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 <stdarg.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>

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

struct udev {
	int refcount;
	void (*log_fn)(struct udev *udev,
		       int priority, const char *file, int line, const char *fn,
		       const char *format, va_list args);
	void *userdata;
	char *sys_path;
	char *dev_path;
	char *rules_path;
	struct udev_list_node properties_list;
	int log_priority;
	int run;
};

void udev_log(struct udev *udev,
	      int priority, const char *file, int line, const char *fn,
	      const char *format, ...)
{
	va_list args;

	va_start(args, format);
	udev->log_fn(udev, priority, file, line, fn, format, args);
	va_end(args);
}

static void log_stderr(struct udev *udev,
		       int priority, const char *file, int line, const char *fn,
		       const char *format, va_list args)
{
	fprintf(stderr, "libudev: %s: ", fn);
	vfprintf(stderr, format, args);
}

void *udev_get_userdata(struct udev *udev)
{
	if (udev == NULL)
		return NULL;
	return udev->userdata;
}

void udev_set_userdata(struct udev *udev, void *userdata)
{
	if (udev == NULL)
		return;
	udev->userdata = userdata;
}

/**
 * udev_new:
 *
 * Create udev library context.
 *
 * The initial refcount is 1, and needs to be decremented to
 * release the resources of the udev library context.
 *
 * Returns: a new udev library context
 **/
struct udev *udev_new(void)
{
	struct udev *udev;
	const char *env;
	char *config_file;
	FILE *f;

	udev = calloc(1, sizeof(struct udev));
	if (udev == NULL)
		return NULL;
	udev->refcount = 1;
	udev->log_fn = log_stderr;
	udev->log_priority = LOG_ERR;
	udev_list_init(&udev->properties_list);
	udev->run = 1;
	udev->dev_path = strdup(UDEV_PREFIX "/dev");
	udev->sys_path = strdup("/sys");
	config_file = strdup(SYSCONFDIR "/udev/udev.conf");
	if (udev->dev_path == NULL ||
	    udev->sys_path == NULL ||
	    config_file == NULL)
		goto err;

	/* settings by environment and config file */
	env = getenv("SYSFS_PATH");
	if (env != NULL) {
		free(udev->sys_path);
		udev->sys_path = strdup(env);
		util_remove_trailing_chars(udev->sys_path, '/');
		udev_add_property(udev, "SYSFS_PATH", udev->sys_path);
	}

	env = getenv("UDEV_RUN");
	if (env != NULL && strcmp(env, "0") == 0)
		udev->run = 0;

	env = getenv("UDEV_CONFIG_FILE");
	if (env != NULL) {
		free(config_file);
		config_file = strdup(env);
		util_remove_trailing_chars(config_file, '/');
	}
	if (config_file == NULL)
		goto err;
	f = fopen(config_file, "r");
	if (f != NULL) {
		char line[UTIL_LINE_SIZE];
		int line_nr = 0;

		while (fgets(line, sizeof(line), f)) {
			size_t len;
			char *key;
			char *val;

			line_nr++;

			/* find key */
			key = line;
			while (isspace(key[0]))
				key++;

			/* comment or empty line */
			if (key[0] == '#' || key[0] == '\0')
				continue;

			/* split key/value */
			val = strchr(key, '=');
			if (val == NULL) {
				err(udev, "missing <key>=<value> in '%s'[%i], skip line\n", config_file, line_nr);
				continue;
			}
			val[0] = '\0';
			val++;

			/* find value */
			while (isspace(val[0]))
				val++;

			/* terminate key */
			len = strlen(key);
			if (len == 0)
				continue;
			while (isspace(key[len-1]))
				len--;
			key[len] = '\0';

			/* terminate value */
			len = strlen(val);
			if (len == 0)
				continue;
			while (isspace(val[len-1]))
				len--;
			val[len] = '\0';

			if (len == 0)
				continue;

			/* unquote */
			if (val[0] == '"' || val[0] == '\'') {
				if (val[len-1] != val[0]) {
					err(udev, "inconsistent quoting in '%s'[%i], skip line\n", config_file, line_nr);
					continue;
				}
				val[len-1] = '\0';
				val++;
			}

			if (strcmp(key, "udev_log") == 0) {
				udev_set_log_priority(udev, util_log_priority(val));
				continue;
			}
			if (strcmp(key, "udev_root") == 0) {
				free(udev->dev_path);
				udev->dev_path = strdup(val);
				util_remove_trailing_chars(udev->dev_path, '/');
				continue;
			}
			if (strcmp(key, "udev_rules") == 0) {
				free(udev->rules_path);
				udev->rules_path = strdup(val);
				util_remove_trailing_chars(udev->rules_path, '/');
				continue;
			}
		}
		fclose(f);
	}

	env = getenv("UDEV_ROOT");
	if (env != NULL) {
		free(udev->dev_path);
		udev->dev_path = strdup(env);
		util_remove_trailing_chars(udev->dev_path, '/');
		udev_add_property(udev, "UDEV_ROOT", udev->dev_path);
	}

	env = getenv("UDEV_LOG");
	if (env != NULL)
		udev_set_log_priority(udev, util_log_priority(env));

	if (udev->dev_path == NULL || udev->sys_path == NULL)
		goto err;
	dbg(udev, "context %p created\n", udev);
	dbg(udev, "log_priority=%d\n", udev->log_priority);
	dbg(udev, "config_file='%s'\n", config_file);
	dbg(udev, "dev_path='%s'\n", udev->dev_path);
	dbg(udev, "sys_path='%s'\n", udev->sys_path);
	if (udev->rules_path != NULL)
		dbg(udev, "rules_path='%s'\n", udev->rules_path);
	free(config_file);
	return udev;
err:
	free(config_file);
	err(udev, "context creation failed\n");
	udev_unref(udev);
	return NULL;
}

/**
 * udev_ref:
 * @udev: udev library context
 *
 * Take a reference of the udev library context.
 *
 * Returns: the passed udev library context
 **/
struct udev *udev_ref(struct udev *udev)
{
	if (udev == NULL)
		return NULL;
	udev->refcount++;
	return udev;
}

/**
 * udev_unref:
 * @udev: udev library context
 *
 * Drop a reference of the udev library context. If the refcount
 * reaches zero, the resources of the context will be released.
 *
 **/
void udev_unref(struct udev *udev)
{
	if (udev == NULL)
		return;
	udev->refcount--;
	if (udev->refcount > 0)
		return;
	udev_list_cleanup_entries(udev, &udev->properties_list);
	free(udev->dev_path);
	free(udev->sys_path);
	free(udev->rules_path);
	dbg(udev, "context %p released\n", udev);
	free(udev);
}

/**
 * udev_set_log_fn:
 * @udev: udev library context
 * @log_fn: function to be called for logging messages
 *
 * The built-in logging writes to stderr. It can be
 * overridden by a custom function, to plug log messages
 * into the users' logging functionality.
 *
 **/
void udev_set_log_fn(struct udev *udev,
		     void (*log_fn)(struct udev *udev,
				    int priority, const char *file, int line, const char *fn,
				    const char *format, va_list args))
{
	udev->log_fn = log_fn;
	info(udev, "custom logging function %p registered\n", udev);
}

int udev_get_log_priority(struct udev *udev)
{
	return udev->log_priority;
}

void udev_set_log_priority(struct udev *udev, int priority)
{
	char num[32];

	udev->log_priority = priority;
	snprintf(num, sizeof(num), "%u", udev->log_priority);
	udev_add_property(udev, "UDEV_LOG", num);
}

const char *udev_get_rules_path(struct udev *udev)
{
	return udev->rules_path;
}

int udev_get_run(struct udev *udev)
{
	return udev->run;
}

/**
 * udev_get_sys_path:
 * @udev: udev library context
 *
 * Retrieve the sysfs mount point. The default is "/sys". For
 * testing purposes, it can be overridden with the environment
 * variable SYSFS_PATH.
 *
 * Returns: the sys mount point
 **/
const char *udev_get_sys_path(struct udev *udev)
{
	if (udev == NULL)
		return NULL;
	return udev->sys_path;
}

/**
 * udev_get_dev_path:
 * @udev: udev library context
 *
 * Retrieve the device directory path. The default value is "/dev",
 * the actual value may be overridden in the udev configuration
 * file.
 *
 * Returns: the device directory path
 **/
const char *udev_get_dev_path(struct udev *udev)
{
	if (udev == NULL)
		return NULL;
	return udev->dev_path;
}

struct udev_list_entry *udev_add_property(struct udev *udev, const char *key, const char *value)
{
	if (value == NULL) {
		struct udev_list_entry *list_entry;

		list_entry = udev_get_properties_list_entry(udev);
		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, &udev->properties_list, key, value, 1, 0);
}

struct udev_list_entry *udev_get_properties_list_entry(struct udev *udev)
{
	return udev_list_get_entry(&udev->properties_list);
}
Commit	Line	Data
33a5cc29 KS	1	/*
	2	* libudev - interface to udev device information
	3	*
	4	* Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
	5	*
4061ab9f KS	6	* This library is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU Lesser General Public
	8	* License as published by the Free Software Foundation; either
	9	* version 2.1 of the License, or (at your option) any later version.
33a5cc29 KS	10	*/
33a5cc29 KS	11
33a5cc29 KS	12	#include <stdio.h>
	13	#include <stdlib.h>
	14	#include <stddef.h>
4cf23685	15	#include <stdarg.h>
33a5cc29 KS	16	#include <unistd.h>
	17	#include <errno.h>
	18	#include <string.h>
7d563a17	19	#include <ctype.h>
33a5cc29 KS	20
	21	#include "libudev.h"
	22	#include "libudev-private.h"
33a5cc29	23
ba6929f6 KS	24	struct udev {
	25	int refcount;
	26	void (log_fn)(struct udev udev,
	27	int priority, const char file, int line, const char fn,
	28	const char *format, va_list args);
c8e32461	29	void *userdata;
7d563a17 KS	30	char *sys_path;
	31	char *dev_path;
	32	char *rules_path;
f183b6ed	33	struct udev_list_node properties_list;
7d563a17	34	int log_priority;
6bd1c78a	35	int run;
ba6929f6 KS	36	};
ba6929f6 KS	37
33a5cc29 KS	38	void udev_log(struct udev *udev,
	39	int priority, const char file, int line, const char fn,
	40	const char *format, ...)
	41	{
	42	va_list args;
	43
	44	va_start(args, format);
	45	udev->log_fn(udev, priority, file, line, fn, format, args);
	46	va_end(args);
	47	}
	48
	49	static void log_stderr(struct udev *udev,
	50	int priority, const char file, int line, const char fn,
	51	const char *format, va_list args)
	52	{
7d563a17 KS	53	fprintf(stderr, "libudev: %s: ", fn);
7d563a17 KS	54	vfprintf(stderr, format, args);
33a5cc29	55	}
33a5cc29	56
c8e32461 KS	57	void udev_get_userdata(struct udev udev)
	58	{
	59	if (udev == NULL)
	60	return NULL;
	61	return udev->userdata;
	62	}
	63
	64	void udev_set_userdata(struct udev udev, void userdata)
	65	{
	66	if (udev == NULL)
	67	return;
	68	udev->userdata = userdata;
	69	}
	70
33a5cc29 KS	71	/**
	72	* udev_new:
	73	*
	74	* Create udev library context.
	75	*
	76	* The initial refcount is 1, and needs to be decremented to
be7de409	77	* release the resources of the udev library context.
33a5cc29 KS	78	*
	79	* Returns: a new udev library context
	80	**/
	81	struct udev *udev_new(void)
	82	{
	83	struct udev *udev;
7d563a17 KS	84	const char *env;
	85	char *config_file;
	86	FILE *f;
33a5cc29	87
b29a5e4a	88	udev = calloc(1, sizeof(struct udev));
33a5cc29 KS	89	if (udev == NULL)
33a5cc29 KS	90	return NULL;
33a5cc29 KS	91	udev->refcount = 1;
33a5cc29 KS	92	udev->log_fn = log_stderr;
7d563a17	93	udev->log_priority = LOG_ERR;
f183b6ed	94	udev_list_init(&udev->properties_list);
7d563a17 KS	95	udev->run = 1;
	96	udev->dev_path = strdup(UDEV_PREFIX "/dev");
	97	udev->sys_path = strdup("/sys");
	98	config_file = strdup(SYSCONFDIR "/udev/udev.conf");
a035bf27 KS	99	if (udev->dev_path == NULL \|\|
	100	udev->sys_path == NULL \|\|
	101	config_file == NULL)
7d563a17 KS	102	goto err;
	103
	104	/* settings by environment and config file */
	105	env = getenv("SYSFS_PATH");
	106	if (env != NULL) {
	107	free(udev->sys_path);
	108	udev->sys_path = strdup(env);
7a01f11a	109	util_remove_trailing_chars(udev->sys_path, '/');
f183b6ed	110	udev_add_property(udev, "SYSFS_PATH", udev->sys_path);
7d563a17 KS	111	}
	112
	113	env = getenv("UDEV_RUN");
7a01f11a	114	if (env != NULL && strcmp(env, "0") == 0)
7d563a17 KS	115	udev->run = 0;
	116
	117	env = getenv("UDEV_CONFIG_FILE");
	118	if (env != NULL) {
	119	free(config_file);
	120	config_file = strdup(env);
7a01f11a	121	util_remove_trailing_chars(config_file, '/');
7d563a17 KS	122	}
	123	if (config_file == NULL)
	124	goto err;
	125	f = fopen(config_file, "r");
	126	if (f != NULL) {
3eb46ec6	127	char line[UTIL_LINE_SIZE];
7d563a17 KS	128	int line_nr = 0;
	129
	130	while (fgets(line, sizeof(line), f)) {
	131	size_t len;
	132	char *key;
	133	char *val;
	134
	135	line_nr++;
	136
	137	/* find key */
	138	key = line;
	139	while (isspace(key[0]))
	140	key++;
	141
	142	/* comment or empty line */
	143	if (key[0] == '#' \|\| key[0] == '\0')
	144	continue;
	145
	146	/* split key/value */
	147	val = strchr(key, '=');
	148	if (val == NULL) {
	149	err(udev, "missing <key>=<value> in '%s'[%i], skip line\n", config_file, line_nr);
	150	continue;
	151	}
	152	val[0] = '\0';
	153	val++;
	154
	155	/* find value */
	156	while (isspace(val[0]))
	157	val++;
	158
	159	/* terminate key */
	160	len = strlen(key);
	161	if (len == 0)
	162	continue;
	163	while (isspace(key[len-1]))
	164	len--;
	165	key[len] = '\0';
	166
	167	/* terminate value */
	168	len = strlen(val);
	169	if (len == 0)
	170	continue;
	171	while (isspace(val[len-1]))
	172	len--;
	173	val[len] = '\0';
	174
	175	if (len == 0)
	176	continue;
	177
	178	/* unquote */
	179	if (val[0] == '"' \|\| val[0] == '\'') {
	180	if (val[len-1] != val[0]) {
	181	err(udev, "inconsistent quoting in '%s'[%i], skip line\n", config_file, line_nr);
	182	continue;
	183	}
	184	val[len-1] = '\0';
	185	val++;
	186	}
	187
bd75fddb	188	if (strcmp(key, "udev_log") == 0) {
3fb629fd	189	udev_set_log_priority(udev, util_log_priority(val));
7d563a17 KS	190	continue;
7d563a17 KS	191	}
bd75fddb	192	if (strcmp(key, "udev_root") == 0) {
7d563a17 KS	193	free(udev->dev_path);
7d563a17 KS	194	udev->dev_path = strdup(val);
7a01f11a	195	util_remove_trailing_chars(udev->dev_path, '/');
7d563a17 KS	196	continue;
7d563a17 KS	197	}
bd75fddb	198	if (strcmp(key, "udev_rules") == 0) {
7d563a17 KS	199	free(udev->rules_path);
7d563a17 KS	200	udev->rules_path = strdup(val);
7a01f11a	201	util_remove_trailing_chars(udev->rules_path, '/');
7d563a17 KS	202	continue;
	203	}
	204	}
	205	fclose(f);
	206	}
7d563a17 KS	207
	208	env = getenv("UDEV_ROOT");
	209	if (env != NULL) {
	210	free(udev->dev_path);
	211	udev->dev_path = strdup(env);
7a01f11a	212	util_remove_trailing_chars(udev->dev_path, '/');
f183b6ed	213	udev_add_property(udev, "UDEV_ROOT", udev->dev_path);
7d563a17 KS	214	}
	215
	216	env = getenv("UDEV_LOG");
	217	if (env != NULL)
f183b6ed	218	udev_set_log_priority(udev, util_log_priority(env));
7d563a17 KS	219
	220	if (udev->dev_path == NULL \|\| udev->sys_path == NULL)
	221	goto err;
86b57788 KS	222	dbg(udev, "context %p created\n", udev);
	223	dbg(udev, "log_priority=%d\n", udev->log_priority);
	224	dbg(udev, "config_file='%s'\n", config_file);
	225	dbg(udev, "dev_path='%s'\n", udev->dev_path);
	226	dbg(udev, "sys_path='%s'\n", udev->sys_path);
7d563a17	227	if (udev->rules_path != NULL)
86b57788	228	dbg(udev, "rules_path='%s'\n", udev->rules_path);
a035bf27	229	free(config_file);
33a5cc29	230	return udev;
7d563a17	231	err:
a035bf27	232	free(config_file);
7d563a17 KS	233	err(udev, "context creation failed\n");
	234	udev_unref(udev);
	235	return NULL;
33a5cc29 KS	236	}
	237
	238	/**
	239	* udev_ref:
	240	* @udev: udev library context
	241	*
	242	* Take a reference of the udev library context.
	243	*
	244	* Returns: the passed udev library context
	245	**/
	246	struct udev udev_ref(struct udev udev)
	247	{
ba6929f6 KS	248	if (udev == NULL)
ba6929f6 KS	249	return NULL;
33a5cc29 KS	250	udev->refcount++;
	251	return udev;
	252	}
	253
	254	/**
	255	* udev_unref:
	256	* @udev: udev library context
	257	*
	258	* Drop a reference of the udev library context. If the refcount
be7de409	259	* reaches zero, the resources of the context will be released.
33a5cc29 KS	260	*
	261	**/
	262	void udev_unref(struct udev *udev)
	263	{
ba6929f6 KS	264	if (udev == NULL)
ba6929f6 KS	265	return;
33a5cc29 KS	266	udev->refcount--;
	267	if (udev->refcount > 0)
	268	return;
eb8837e1	269	udev_list_cleanup_entries(udev, &udev->properties_list);
7d563a17 KS	270	free(udev->dev_path);
7d563a17 KS	271	free(udev->sys_path);
a035bf27	272	free(udev->rules_path);
86b57788	273	dbg(udev, "context %p released\n", udev);
33a5cc29 KS	274	free(udev);
	275	}
	276
	277	/**
	278	* udev_set_log_fn:
	279	* @udev: udev library context
	280	* @log_fn: function to be called for logging messages
	281	*
be7de409	282	* The built-in logging writes to stderr. It can be
33a5cc29	283	* overridden by a custom function, to plug log messages
be7de409	284	* into the users' logging functionality.
33a5cc29 KS	285	*
	286	**/
	287	void udev_set_log_fn(struct udev *udev,
	288	void (log_fn)(struct udev udev,
	289	int priority, const char file, int line, const char fn,
	290	const char *format, va_list args))
	291	{
	292	udev->log_fn = log_fn;
7d563a17 KS	293	info(udev, "custom logging function %p registered\n", udev);
	294	}
	295
	296	int udev_get_log_priority(struct udev *udev)
	297	{
	298	return udev->log_priority;
	299	}
	300
	301	void udev_set_log_priority(struct udev *udev, int priority)
	302	{
f183b6ed KS	303	char num[32];
f183b6ed KS	304
7d563a17	305	udev->log_priority = priority;
f183b6ed KS	306	snprintf(num, sizeof(num), "%u", udev->log_priority);
f183b6ed KS	307	udev_add_property(udev, "UDEV_LOG", num);
7d563a17 KS	308	}
	309
	310	const char udev_get_rules_path(struct udev udev)
	311	{
	312	return udev->rules_path;
	313	}
	314
	315	int udev_get_run(struct udev *udev)
	316	{
	317	return udev->run;
33a5cc29 KS	318	}
	319
	320	/**
	321	* udev_get_sys_path:
	322	* @udev: udev library context
	323	*
	324	* Retrieve the sysfs mount point. The default is "/sys". For
	325	* testing purposes, it can be overridden with the environment
	326	* variable SYSFS_PATH.
	327	*
	328	* Returns: the sys mount point
	329	**/
	330	const char udev_get_sys_path(struct udev udev)
	331	{
ba6929f6 KS	332	if (udev == NULL)
ba6929f6 KS	333	return NULL;
7d563a17	334	return udev->sys_path;
33a5cc29 KS	335	}
	336
	337	/**
	338	* udev_get_dev_path:
	339	* @udev: udev library context
	340	*
	341	* Retrieve the device directory path. The default value is "/dev",
	342	* the actual value may be overridden in the udev configuration
	343	* file.
	344	*
	345	* Returns: the device directory path
	346	**/
	347	const char udev_get_dev_path(struct udev udev)
	348	{
ba6929f6 KS	349	if (udev == NULL)
ba6929f6 KS	350	return NULL;
7d563a17	351	return udev->dev_path;
33a5cc29	352	}
f183b6ed KS	353
	354	struct udev_list_entry udev_add_property(struct udev udev, const char key, const char value)
	355	{
	356	if (value == NULL) {
	357	struct udev_list_entry *list_entry;
	358
	359	list_entry = udev_get_properties_list_entry(udev);
	360	list_entry = udev_list_entry_get_by_name(list_entry, key);
	361	if (list_entry != NULL)
1e78dcbe	362	udev_list_entry_delete(list_entry);
f183b6ed KS	363	return NULL;
	364	}
	365	return udev_list_entry_add(udev, &udev->properties_list, key, value, 1, 0);
	366	}
	367
	368	struct udev_list_entry udev_get_properties_list_entry(struct udev udev)
	369	{
	370	return udev_list_get_entry(&udev->properties_list);
	371	}