2 * libudev - interface to udev device information
4 * Copyright (C) 2008-2010 Kay Sievers <kay.sievers@vrfy.org>
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.
23 #include "libudev-private.h"
27 * @short_description: libudev context
29 * The context contains the default values read from the udev config file,
30 * and is passed to all library operations.
36 * Opaque object representing the library context.
40 void (*log_fn)(struct udev *udev,
41 int priority, const char *file, int line, const char *fn,
42 const char *format, va_list args);
47 unsigned long long rules_path_ts[4];
50 struct udev_list properties_list;
54 void udev_log(struct udev *udev,
55 int priority, const char *file, int line, const char *fn,
56 const char *format, ...)
60 va_start(args, format);
61 udev->log_fn(udev, priority, file, line, fn, format, args);
65 static void log_stderr(struct udev *udev,
66 int priority, const char *file, int line, const char *fn,
67 const char *format, va_list args)
69 fprintf(stderr, "libudev: %s: ", fn);
70 vfprintf(stderr, format, args);
75 * @udev: udev library context
77 * Retrieve stored data pointer from library context. This might be useful
78 * to access from callbacks like a custom logging function.
80 * Returns: stored userdata
82 _public_ void *udev_get_userdata(struct udev *udev)
86 return udev->userdata;
91 * @udev: udev library context
92 * @userdata: data pointer
94 * Store custom @userdata in the library context.
96 _public_ void udev_set_userdata(struct udev *udev, void *userdata)
100 udev->userdata = userdata;
103 static char *set_value(char **s, const char *v)
107 util_remove_trailing_chars(*s, '/');
114 * Create udev library context. This reads the udev configuration
115 * file, and fills in the default values.
117 * The initial refcount is 1, and needs to be decremented to
118 * release the resources of the udev library context.
120 * Returns: a new udev library context
122 _public_ struct udev *udev_new(void)
126 char *config_file = NULL;
129 udev = calloc(1, sizeof(struct udev));
133 udev->log_fn = log_stderr;
134 udev->log_priority = LOG_ERR;
135 udev_list_init(udev, &udev->properties_list, true);
137 /* custom config file */
138 env = getenv("UDEV_CONFIG_FILE");
140 if (set_value(&config_file, env) == NULL)
142 udev_add_property(udev, "UDEV_CONFIG_FILE", config_file);
145 /* default config file */
146 if (config_file == NULL)
147 config_file = strdup(SYSCONFDIR "/udev/udev.conf");
148 if (config_file == NULL)
151 f = fopen(config_file, "re");
153 char line[UTIL_LINE_SIZE];
156 while (fgets(line, sizeof(line), f)) {
165 while (isspace(key[0]))
168 /* comment or empty line */
169 if (key[0] == '#' || key[0] == '\0')
172 /* split key/value */
173 val = strchr(key, '=');
175 err(udev, "missing <key>=<value> in '%s'[%i], skip line\n", config_file, line_nr);
182 while (isspace(val[0]))
189 while (isspace(key[len-1]))
193 /* terminate value */
197 while (isspace(val[len-1]))
205 if (val[0] == '"' || val[0] == '\'') {
206 if (val[len-1] != val[0]) {
207 err(udev, "inconsistent quoting in '%s'[%i], skip line\n", config_file, line_nr);
214 if (strcmp(key, "udev_log") == 0) {
215 udev_set_log_priority(udev, util_log_priority(val));
218 if (strcmp(key, "udev_root") == 0) {
219 set_value(&udev->dev_path, val);
222 if (strcmp(key, "udev_run") == 0) {
223 set_value(&udev->run_path, val);
226 if (strcmp(key, "udev_sys") == 0) {
227 set_value(&udev->sys_path, val);
230 if (strcmp(key, "udev_rules") == 0) {
231 set_value(&udev->rules_path[0], val);
232 udev->rules_path_count = 1;
239 /* environment overrides config */
240 env = getenv("UDEV_LOG");
242 udev_set_log_priority(udev, util_log_priority(env));
245 if (udev->dev_path == NULL)
246 if (set_value(&udev->dev_path, "/dev") == NULL)
249 if (udev->sys_path == NULL)
250 if (set_value(&udev->sys_path, "/sys") == NULL)
253 if (udev->run_path == NULL)
254 if (set_value(&udev->run_path, "/run/udev") == NULL)
257 if (udev->rules_path[0] == NULL) {
258 /* /usr/lib/udev -- system rules */
259 udev->rules_path[0] = strdup(UDEVLIBEXECDIR "/rules.d");
260 if (!udev->rules_path[0])
263 /* /run/udev -- runtime rules */
264 if (asprintf(&udev->rules_path[1], "%s/rules.d", udev->run_path) < 0)
267 /* /etc/udev -- local administration rules */
268 udev->rules_path[2] = strdup(SYSCONFDIR "/udev/rules.d");
269 if (!udev->rules_path[2])
272 udev->rules_path_count = 3;
279 err(udev, "context creation failed\n");
286 * @udev: udev library context
288 * Take a reference of the udev library context.
290 * Returns: the passed udev library context
292 _public_ struct udev *udev_ref(struct udev *udev)
302 * @udev: udev library context
304 * Drop a reference of the udev library context. If the refcount
305 * reaches zero, the resources of the context will be released.
308 _public_ void udev_unref(struct udev *udev)
313 if (udev->refcount > 0)
315 udev_list_cleanup(&udev->properties_list);
316 free(udev->dev_path);
317 free(udev->sys_path);
318 free(udev->rules_path[0]);
319 free(udev->rules_path[1]);
320 free(udev->rules_path[2]);
321 free(udev->run_path);
327 * @udev: udev library context
328 * @log_fn: function to be called for logging messages
330 * The built-in logging writes to stderr. It can be
331 * overridden by a custom function, to plug log messages
332 * into the users' logging functionality.
335 _public_ void udev_set_log_fn(struct udev *udev,
336 void (*log_fn)(struct udev *udev,
337 int priority, const char *file, int line, const char *fn,
338 const char *format, va_list args))
340 udev->log_fn = log_fn;
341 dbg(udev, "custom logging function %p registered\n", log_fn);
345 * udev_get_log_priority:
346 * @udev: udev library context
348 * The initial logging priority is read from the udev config file
351 * Returns: the current logging priority
353 _public_ int udev_get_log_priority(struct udev *udev)
355 return udev->log_priority;
359 * udev_set_log_priority:
360 * @udev: udev library context
361 * @priority: the new logging priority
363 * Set the current logging priority. The value controls which messages
366 _public_ void udev_set_log_priority(struct udev *udev, int priority)
370 udev->log_priority = priority;
371 snprintf(num, sizeof(num), "%u", udev->log_priority);
372 udev_add_property(udev, "UDEV_LOG", num);
375 int udev_get_rules_path(struct udev *udev, char **path[], unsigned long long *stamp_usec[])
377 *path = udev->rules_path;
379 *stamp_usec = udev->rules_path_ts;
380 return udev->rules_path_count;
385 * @udev: udev library context
387 * Retrieve the sysfs mount point. The default is "/sys". For
388 * testing purposes, it can be overridden with udev_sys=
389 * in the udev configuration file.
391 * Returns: the sys mount point
393 _public_ const char *udev_get_sys_path(struct udev *udev)
397 return udev->sys_path;
402 * @udev: udev library context
404 * Retrieve the device directory path. The default value is "/dev",
405 * the actual value may be overridden in the udev configuration
408 * Returns: the device directory path
410 _public_ const char *udev_get_dev_path(struct udev *udev)
414 return udev->dev_path;
419 * @udev: udev library context
421 * Retrieve the udev runtime directory path. The default is "/run/udev".
423 * Returns: the runtime directory path
425 _public_ const char *udev_get_run_path(struct udev *udev)
429 return udev->run_path;
432 struct udev_list_entry *udev_add_property(struct udev *udev, const char *key, const char *value)
435 struct udev_list_entry *list_entry;
437 list_entry = udev_get_properties_list_entry(udev);
438 list_entry = udev_list_entry_get_by_name(list_entry, key);
439 if (list_entry != NULL)
440 udev_list_entry_delete(list_entry);
443 return udev_list_entry_add(&udev->properties_list, key, value);
446 struct udev_list_entry *udev_get_properties_list_entry(struct udev *udev)
448 return udev_list_get_entry(&udev->properties_list);