2 * libudev - interface to udev device information
4 * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
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.
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.
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/>.
31 #include <selinux/selinux.h>
35 #include "libudev-private.h"
39 void (*log_fn)(struct udev *udev,
40 int priority, const char *file, int line, const char *fn,
41 const char *format, va_list args);
48 security_context_t selinux_prev_scontext;
53 void udev_log(struct udev *udev,
54 int priority, const char *file, int line, const char *fn,
55 const char *format, ...)
59 if (priority > udev->log_priority)
62 va_start(args, format);
63 udev->log_fn(udev, priority, file, line, fn, format, args);
67 static void log_stderr(struct udev *udev,
68 int priority, const char *file, int line, const char *fn,
69 const char *format, va_list args)
71 fprintf(stderr, "libudev: %s: ", fn);
72 vfprintf(stderr, format, args);
75 static void selinux_init(struct udev *udev)
79 * record the present security context, for file-creation
80 * restoration creation purposes.
82 udev->selinux_enabled = (is_selinux_enabled() > 0);
83 info(udev, "selinux=%i\n", udev->selinux_enabled);
84 if (udev->selinux_enabled) {
85 matchpathcon_init_prefix(NULL, udev_get_dev_path(udev));
86 if (getfscreatecon(&udev->selinux_prev_scontext) < 0) {
87 err(udev, "getfscreatecon failed\n");
88 udev->selinux_prev_scontext = NULL;
94 static void selinux_exit(struct udev *udev)
97 if (udev->selinux_enabled) {
98 freecon(udev->selinux_prev_scontext);
99 udev->selinux_prev_scontext = NULL;
104 void udev_selinux_lsetfilecon(struct udev *udev, const char *file, unsigned int mode)
107 if (udev->selinux_enabled) {
108 security_context_t scontext = NULL;
110 if (matchpathcon(file, mode, &scontext) < 0) {
111 err(udev, "matchpathcon(%s) failed\n", file);
114 if (lsetfilecon(file, scontext) < 0)
115 err(udev, "setfilecon %s failed: %s\n", file, strerror(errno));
121 void udev_selinux_setfscreatecon(struct udev *udev, const char *file, unsigned int mode)
124 if (udev->selinux_enabled) {
125 security_context_t scontext = NULL;
127 if (matchpathcon(file, mode, &scontext) < 0) {
128 err(udev, "matchpathcon(%s) failed\n", file);
131 if (setfscreatecon(scontext) < 0)
132 err(udev, "setfscreatecon %s failed: %s\n", file, strerror(errno));
138 void udev_selinux_resetfscreatecon(struct udev *udev)
141 if (udev->selinux_enabled) {
142 if (setfscreatecon(udev->selinux_prev_scontext) < 0)
143 err(udev, "setfscreatecon failed: %s\n", strerror(errno));
151 * Create udev library context.
153 * The initial refcount is 1, and needs to be decremented to
154 * release the ressources of the udev library context.
156 * Returns: a new udev library context
158 struct udev *udev_new(void)
165 udev = malloc(sizeof(struct udev));
168 memset(udev, 0x00, (sizeof(struct udev)));
170 udev->log_fn = log_stderr;
171 udev->log_priority = LOG_ERR;
173 udev->dev_path = strdup(UDEV_PREFIX "/dev");
174 udev->sys_path = strdup("/sys");
175 config_file = strdup(SYSCONFDIR "/udev/udev.conf");
176 if (udev->dev_path == NULL ||
177 udev->sys_path == NULL ||
181 /* settings by environment and config file */
182 env = getenv("SYSFS_PATH");
184 free(udev->sys_path);
185 udev->sys_path = strdup(env);
186 util_remove_trailing_chars(udev->sys_path, '/');
189 env = getenv("UDEV_RUN");
190 if (env != NULL && strcmp(env, "0") == 0)
193 env = getenv("UDEV_CONFIG_FILE");
196 config_file = strdup(env);
197 util_remove_trailing_chars(config_file, '/');
199 if (config_file == NULL)
201 f = fopen(config_file, "r");
203 char line[UTIL_LINE_SIZE];
206 while (fgets(line, sizeof(line), f)) {
215 while (isspace(key[0]))
218 /* comment or empty line */
219 if (key[0] == '#' || key[0] == '\0')
222 /* split key/value */
223 val = strchr(key, '=');
225 err(udev, "missing <key>=<value> in '%s'[%i], skip line\n", config_file, line_nr);
232 while (isspace(val[0]))
239 while (isspace(key[len-1]))
243 /* terminate value */
247 while (isspace(val[len-1]))
255 if (val[0] == '"' || val[0] == '\'') {
256 if (val[len-1] != val[0]) {
257 err(udev, "inconsistent quoting in '%s'[%i], skip line\n", config_file, line_nr);
264 if (strcasecmp(key, "udev_log") == 0) {
265 udev->log_priority = util_log_priority(val);
268 if (strcasecmp(key, "udev_root") == 0) {
269 free(udev->dev_path);
270 udev->dev_path = strdup(val);
271 util_remove_trailing_chars(udev->dev_path, '/');
274 if (strcasecmp(key, "udev_rules") == 0) {
275 free(udev->rules_path);
276 udev->rules_path = strdup(val);
277 util_remove_trailing_chars(udev->rules_path, '/');
284 env = getenv("UDEV_ROOT");
286 free(udev->dev_path);
287 udev->dev_path = strdup(env);
288 util_remove_trailing_chars(udev->dev_path, '/');
291 env = getenv("UDEV_LOG");
293 udev->log_priority = util_log_priority(env);
295 if (udev->dev_path == NULL || udev->sys_path == NULL)
298 info(udev, "context %p created\n", udev);
299 info(udev, "log_priority=%d\n", udev->log_priority);
300 info(udev, "config_file='%s'\n", config_file);
301 info(udev, "dev_path='%s'\n", udev->dev_path);
302 info(udev, "sys_path='%s'\n", udev->sys_path);
303 if (udev->rules_path != NULL)
304 info(udev, "rules_path='%s'\n", udev->rules_path);
309 err(udev, "context creation failed\n");
316 * @udev: udev library context
318 * Take a reference of the udev library context.
320 * Returns: the passed udev library context
322 struct udev *udev_ref(struct udev *udev)
332 * @udev: udev library context
334 * Drop a reference of the udev library context. If the refcount
335 * reaches zero, the ressources of the context will be released.
338 void udev_unref(struct udev *udev)
343 if (udev->refcount > 0)
346 free(udev->dev_path);
347 free(udev->sys_path);
348 free(udev->rules_path);
349 info(udev, "context %p released\n", udev);
355 * @udev: udev library context
356 * @log_fn: function to be called for logging messages
358 * The built-in logging, which writes to stderr if the
359 * LIBUDEV_DEBUG environment variable is set, can be
360 * overridden by a custom function, to plug log messages
361 * into the users logging functionality.
364 void udev_set_log_fn(struct udev *udev,
365 void (*log_fn)(struct udev *udev,
366 int priority, const char *file, int line, const char *fn,
367 const char *format, va_list args))
369 udev->log_fn = log_fn;
370 info(udev, "custom logging function %p registered\n", udev);
373 int udev_get_log_priority(struct udev *udev)
375 return udev->log_priority;
378 void udev_set_log_priority(struct udev *udev, int priority)
380 udev->log_priority = priority;
383 const char *udev_get_rules_path(struct udev *udev)
385 return udev->rules_path;
388 int udev_get_run(struct udev *udev)
395 * @udev: udev library context
397 * Retrieve the sysfs mount point. The default is "/sys". For
398 * testing purposes, it can be overridden with the environment
399 * variable SYSFS_PATH.
401 * Returns: the sys mount point
403 const char *udev_get_sys_path(struct udev *udev)
407 return udev->sys_path;
412 * @udev: udev library context
414 * Retrieve the device directory path. The default value is "/dev",
415 * the actual value may be overridden in the udev configuration
418 * Returns: the device directory path
420 const char *udev_get_dev_path(struct udev *udev)
424 return udev->dev_path;