157 lines
3.7 KiB
C
157 lines
3.7 KiB
C
/*
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* syfs_utils.c
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*
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* System utility functions for libsysfs
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*
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* Copyright (C) 2003 International Business Machines, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include "libsysfs.h"
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#include "sysfs.h"
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/**
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* sysfs_get_mnt_path: Gets the mount point for specified filesystem.
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* @fs_type: filesystem type to retrieve mount point
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* @mnt_path: place to put the retrieved mount path
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* @len: size of mnt_path
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* returns 0 with success and -1 with error.
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*/
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static int sysfs_get_fs_mnt_path(const char *fs_type, char *mnt_path,
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size_t len)
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{
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FILE *mnt;
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struct mntent *mntent;
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int ret = 0;
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size_t dirlen = 0;
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/* check arg */
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if (fs_type == NULL || mnt_path == NULL) {
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errno = EINVAL;
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return -1;
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}
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if ((mnt = setmntent(SYSFS_PROC_MNTS, "r")) == NULL) {
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dprintf(stderr, "Error getting mount information\n");
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return -1;
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}
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while (ret == 0 && dirlen == 0 && (mntent = getmntent(mnt)) != NULL) {
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if (strcmp(mntent->mnt_type, fs_type) == 0) {
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dirlen = strlen(mntent->mnt_dir);
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if (dirlen <= (len - 1)) {
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strcpy(mnt_path, mntent->mnt_dir);
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} else {
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dprintf(stderr,
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"Error - mount path too long\n");
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ret = -1;
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}
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}
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}
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endmntent(mnt);
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if (dirlen == 0 && ret == 0) {
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dprintf(stderr, "Filesystem %s not found!\n", fs_type);
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errno = EINVAL;
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ret = -1;
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}
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return ret;
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}
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/*
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* sysfs_get_mnt_path: Gets the sysfs mount point.
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* @mnt_path: place to put "sysfs" mount point
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* @len: size of mnt_path
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* returns 0 with success and -1 with error.
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*/
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int sysfs_get_mnt_path(char *mnt_path, size_t len)
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{
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int ret = -1;
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if (mnt_path != NULL)
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ret = sysfs_get_fs_mnt_path(SYSFS_FSTYPE_NAME, mnt_path, len);
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else
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errno = EINVAL;
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return ret;
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}
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/**
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* sysfs_get_name_from_path: returns last name from a "/" delimited path
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* @path: path to get name from
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* @name: where to put name
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* @len: size of name
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*/
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int sysfs_get_name_from_path(const char *path, char *name, size_t len)
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{
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char *n = NULL;
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if (path == NULL || name == NULL) {
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errno = EINVAL;
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return -1;
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}
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n = strrchr(path, '/');
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if (n == NULL) {
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errno = EINVAL;
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return -1;
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}
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n++;
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strncpy(name, n, len);
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return 0;
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}
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/**
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* sysfs_get_link: returns link source
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* @path: symbolic link's path
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* @target: where to put name
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* @len: size of name
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*/
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int sysfs_get_link(const char *path, char *target, size_t len)
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{
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char devdir[SYSFS_PATH_MAX];
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char linkpath[SYSFS_PATH_MAX];
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char *d = NULL;
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if (path == NULL || target == NULL) {
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errno = EINVAL;
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return -1;
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}
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memset(devdir, 0, SYSFS_PATH_MAX);
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memset(linkpath, 0, SYSFS_PATH_MAX);
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if ((sysfs_get_mnt_path(devdir, SYSFS_PATH_MAX)) != 0) {
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dprintf(stderr, "Sysfs not supported on this system\n");
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return -1;
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}
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if ((readlink(path, linkpath, SYSFS_PATH_MAX)) < 0) {
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return -1;
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}
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d = linkpath;
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/* getting rid of leading "../.." */
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while (*d == '/' || *d == '.')
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d++;
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d--;
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strcat(devdir, d);
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strncpy(target, devdir, len);
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return 0;
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}
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