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/*
* 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 <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"
static ssize_t get_sys_link(struct udev *udev, const char *slink, const char *devpath, char *subsystem, size_t size)
{
char path[PATH_SIZE];
ssize_t len;
const char *pos;
strlcpy(path, udev_get_sys_path(udev), sizeof(path));
strlcat(path, devpath, sizeof(path));
strlcat(path, "/", sizeof(path));
strlcat(path, slink, sizeof(path));
len = readlink(path, path, sizeof(path));
if (len < 0 || len >= (ssize_t) sizeof(path))
return -1;
path[len] = '\0';
pos = strrchr(path, '/');
if (pos == NULL)
return -1;
pos = &pos[1];
return strlcpy(subsystem, pos, size);
}
ssize_t util_get_sys_subsystem(struct udev *udev, const char *devpath, char *subsystem, size_t size)
{
return get_sys_link(udev, "subsystem", devpath, subsystem, size);
}
ssize_t util_get_sys_driver(struct udev *udev, const char *devpath, char *driver, size_t size)
{
return get_sys_link(udev, "driver", devpath, driver, size);
}
int util_resolve_sys_link(struct udev *udev, char *devpath, size_t size)
{
char link_path[PATH_SIZE];
char link_target[PATH_SIZE];
int len;
int i;
int back;
strlcpy(link_path, udev_get_sys_path(udev), sizeof(link_path));
strlcat(link_path, devpath, sizeof(link_path));
len = readlink(link_path, link_target, sizeof(link_target));
if (len <= 0)
return -1;
link_target[len] = '\0';
dbg(udev, "path link '%s' points to '%s'\n", devpath, link_target);
for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++)
;
dbg(udev, "base '%s', tail '%s', back %i\n", devpath, &link_target[back * 3], back);
for (i = 0; i <= back; i++) {
char *pos = strrchr(devpath, '/');
if (pos == NULL)
return -1;
pos[0] = '\0';
}
dbg(udev, "after moving back '%s'\n", devpath);
strlcat(devpath, "/", size);
strlcat(devpath, &link_target[back * 3], size);
return 0;
}
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