libudev.c revision cf0fbc49e67b55f8d346fc94de28c90113505297
/***
This file is part of systemd.
Copyright 2008-2014 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 <ctype.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "alloc-util.h"
#include "fd-util.h"
#include "libudev-private.h"
#include "libudev.h"
#include "missing.h"
#include "string-util.h"
/**
* SECTION:libudev
* @short_description: libudev context
*
* The context contains the default values read from the udev config file,
* and is passed to all library operations.
*/
/**
* udev:
*
* Opaque object representing the library context.
*/
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;
};
/**
* udev_get_userdata:
* @udev: udev library context
*
* Retrieve stored data pointer from library context. This might be useful
* to access from callbacks.
*
* Returns: stored userdata
**/
_public_ void *udev_get_userdata(struct udev *udev) {
if (udev == NULL)
return NULL;
return udev->userdata;
}
/**
* udev_set_userdata:
* @udev: udev library context
* @userdata: data pointer
*
* Store custom @userdata in the library context.
**/
_public_ void udev_set_userdata(struct udev *udev, void *userdata) {
if (udev == NULL)
return;
udev->userdata = userdata;
}
/**
* udev_new:
*
* Create udev library context. This reads the udev configuration
* file, and fills in the default values.
*
* 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
**/
_public_ struct udev *udev_new(void) {
struct udev *udev;
_cleanup_fclose_ FILE *f = NULL;
udev = new0(struct udev, 1);
if (udev == NULL)
return NULL;
udev->refcount = 1;
f = fopen("/etc/udev/udev.conf", "re");
if (f != NULL) {
char line[UTIL_LINE_SIZE];
unsigned 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) {
log_debug("/etc/udev/udev.conf:%u: missing assignment, skipping line.", 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]) {
log_debug("/etc/udev/udev.conf:%u: inconsistent quoting, skipping line.", line_nr);
continue;
}
val[len-1] = '\0';
val++;
}
if (streq(key, "udev_log")) {
int prio;
prio = util_log_priority(val);
if (prio < 0)
log_debug("/etc/udev/udev.conf:%u: invalid log level '%s', ignoring.", line_nr, val);
else
log_set_max_level(prio);
continue;
}
}
}
return udev;
}
/**
* udev_ref:
* @udev: udev library context
*
* Take a reference of the udev library context.
*
* Returns: the passed udev library context
**/
_public_ 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.
*
* Returns: the passed udev library context if it has still an active reference, or #NULL otherwise.
**/
_public_ struct udev *udev_unref(struct udev *udev) {
if (udev == NULL)
return NULL;
udev->refcount--;
if (udev->refcount > 0)
return udev;
free(udev);
return NULL;
}
/**
* udev_set_log_fn:
* @udev: udev library context
* @log_fn: function to be called for log messages
*
* This function is deprecated.
*
**/
_public_ 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)) {
return;
}
/**
* udev_get_log_priority:
* @udev: udev library context
*
* This function is deprecated.
*
**/
_public_ int udev_get_log_priority(struct udev *udev) {
return log_get_max_level();
}
/**
* udev_set_log_priority:
* @udev: udev library context
* @priority: the new log priority
*
* This function is deprecated.
*
**/
_public_ void udev_set_log_priority(struct udev *udev, int priority) {
log_set_max_level(priority);
}