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/*
* syfs_utils.c
*
* System utility functions for libsysfs
*
* Copyright (C) 2003 International Business Machines, Inc.
*
* This library 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.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include "libsysfs.h"
#include "sysfs.h"
/**
* sysfs_get_mnt_path: Gets the mount point for specified filesystem.
* @fs_type: filesystem type to retrieve mount point
* @mnt_path: place to put the retrieved mount path
* @len: size of mnt_path
* returns 0 with success and -1 with error.
*/
static int sysfs_get_fs_mnt_path(const char *fs_type, char *mnt_path,
size_t len)
{
FILE *mnt;
struct mntent *mntent;
int ret = 0;
size_t dirlen = 0;
/* check arg */
if (fs_type == NULL || mnt_path == NULL) {
errno = EINVAL;
return -1;
}
if ((mnt = setmntent(SYSFS_PROC_MNTS, "r")) == NULL) {
dprintf(stderr, "Error getting mount information\n");
return -1;
}
while (ret == 0 && dirlen == 0 && (mntent = getmntent(mnt)) != NULL) {
if (strcmp(mntent->mnt_type, fs_type) == 0) {
dirlen = strlen(mntent->mnt_dir);
if (dirlen <= (len - 1)) {
strcpy(mnt_path, mntent->mnt_dir);
} else {
dprintf(stderr,
"Error - mount path too long\n");
ret = -1;
}
}
}
endmntent(mnt);
if (dirlen == 0 && ret == 0) {
dprintf(stderr, "Filesystem %s not found!\n", fs_type);
errno = EINVAL;
ret = -1;
}
return ret;
}
/*
* sysfs_get_mnt_path: Gets the sysfs mount point.
* @mnt_path: place to put "sysfs" mount point
* @len: size of mnt_path
* returns 0 with success and -1 with error.
*/
int sysfs_get_mnt_path(char *mnt_path, size_t len)
{
int ret = -1;
if (mnt_path != NULL)
ret = sysfs_get_fs_mnt_path(SYSFS_FSTYPE_NAME, mnt_path, len);
else
errno = EINVAL;
return ret;
}
/**
* sysfs_get_name_from_path: returns last name from a "/" delimited path
* @path: path to get name from
* @name: where to put name
* @len: size of name
*/
int sysfs_get_name_from_path(const char *path, char *name, size_t len)
{
char *n = NULL;
if (path == NULL || name == NULL) {
errno = EINVAL;
return -1;
}
n = strrchr(path, '/');
if (n == NULL) {
errno = EINVAL;
return -1;
}
n++;
strncpy(name, n, len);
return 0;
}
/**
* sysfs_get_link: returns link source
* @path: symbolic link's path
* @target: where to put name
* @len: size of name
*/
int sysfs_get_link(const char *path, char *target, size_t len)
{
char devdir[SYSFS_PATH_MAX];
char linkpath[SYSFS_PATH_MAX];
char *d = NULL;
if (path == NULL || target == NULL) {
errno = EINVAL;
return -1;
}
memset(devdir, 0, SYSFS_PATH_MAX);
memset(linkpath, 0, SYSFS_PATH_MAX);
if ((sysfs_get_mnt_path(devdir, SYSFS_PATH_MAX)) != 0) {
dprintf(stderr, "Sysfs not supported on this system\n");
return -1;
}
if ((readlink(path, linkpath, SYSFS_PATH_MAX)) < 0) {
return -1;
}
d = linkpath;
/* getting rid of leading "../.." */
while (*d == '/' || *d == '.')
d++;
d--;
strcat(devdir, d);
strncpy(target, devdir, len);
return 0;
}
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