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mirror of https://github.com/systemd/systemd-stable.git synced 2024-10-30 14:55:26 +03:00
systemd-stable/udev/lib/libudev.c
2008-08-30 23:07:50 +02:00

200 lines
4.5 KiB
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 <stdarg.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 {
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 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)
{
static int log = -1;
if (log == -1) {
if (getenv("LIBUDEV_DEBUG") != NULL)
log = 1;
else
log = 0;
}
if (log == 1) {
fprintf(stderr, "libudev: %s: ", fn);
vfprintf(stderr, format, args);
}
}
/* glue to udev logging, needed until udev logging code is "fixed" */
#ifdef USE_LOG
void log_message(int priority, const char *format, ...)
{
va_list args;
va_start(args, format);
log_stderr(NULL, priority, NULL, 0, "", format, args);
va_end(args);
}
#endif
/**
* udev_new:
*
* Create udev library context.
*
* The initial refcount is 1, and needs to be decremented to
* release the ressources of the udev library context.
*
* Returns: a new udev library context
**/
struct udev *udev_new(void)
{
struct udev *udev;
udev = malloc(sizeof(struct udev));
if (udev == NULL)
return NULL;
memset(udev, 0x00, (sizeof(struct udev)));
udev->refcount = 1;
udev->log_fn = log_stderr;
udev_config_init();
sysfs_init();
log_info(udev, "context %p created\n", udev);
return udev;
}
/**
* 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 ressources of the context will be released.
*
**/
void udev_unref(struct udev *udev)
{
if (udev == NULL)
return;
udev->refcount--;
if (udev->refcount > 0)
return;
sysfs_cleanup();
log_info(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, which writes to stderr if the
* LIBUDEV_DEBUG environment variable is set, 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;
log_info(udev, "custom logging function %p registered\n", udev);
}
/**
* 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 sysfs_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_root;
}