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8d8172514d
Here's a quick patch to: 1) Add an environment variable "SYSFS_PATH" that libsysfs will check for when getting mount point before searching system's sysfs mount point. 2) A quick fix to sysfs_get_link where the bug was. I have tested this out with libsysfs and with udev. I couldn't test with klibc because I haven't got the tree to build with klibc without my changes either. I made the link but get an error finding linux/linits.h. I will figure that out. Please have a look at the patch. If it's agreeable, please test it. I really want to add some generic path manipulation functions for the sysfs_get_link error, rather than my patch's hack. But, I haven't had time yet to do that. You really sounded like you needed this for testing, so I'm sending it out to you. I should probably add a function to set the env variable(?).
314 lines
7.3 KiB
C
314 lines
7.3 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) IBM Corp. 2003
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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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#ifndef __KLIBC__
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#include <mntent.h>
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#endif
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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 unsigned char *fs_type,
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unsigned char *mnt_path, size_t len)
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{
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#ifdef __KLIBC__
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strcpy(mnt_path, "/sys");
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return 0;
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#else
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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("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("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("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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#endif
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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(unsigned char *mnt_path, size_t len)
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{
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char *sysfs_path = NULL;
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int ret = 0;
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if (mnt_path == NULL) {
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errno = EINVAL;
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return -1;
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}
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sysfs_path = getenv(SYSFS_PATH_ENV);
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if (sysfs_path != NULL)
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strncpy(mnt_path, sysfs_path, len);
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else
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ret = sysfs_get_fs_mnt_path(SYSFS_FSTYPE_NAME, mnt_path, len);
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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 unsigned char *path, unsigned char *name,
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size_t len)
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{
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unsigned 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 unsigned char *path, unsigned char *target, size_t len)
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{
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unsigned char devdir[SYSFS_PATH_MAX];
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unsigned char linkpath[SYSFS_PATH_MAX];
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unsigned char *d = NULL, *s = NULL;
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int slashes = 0, count = 0;
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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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strncpy(devdir, path, SYSFS_PATH_MAX);
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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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if (*d == '/')
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slashes++;
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d++;
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}
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d--;
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s = &devdir[strlen(devdir)-1];
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while (s != NULL && count != (slashes+1)) {
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s--;
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if (*s == '/')
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count++;
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}
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if (s == NULL)
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return -1;
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strncpy(s, d, (SYSFS_PATH_MAX-strlen(devdir)));
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strncpy(target, devdir, len);
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return 0;
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}
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/**
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* sysfs_del_name: free function for sysfs_open_subsystem_list
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* @name: memory area to be freed
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*/
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void sysfs_del_name(void *name)
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{
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free(name);
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}
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/**
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* sysfs_close_list: generic list free routine
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* @list: dlist to free
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* Returns nothing
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*/
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void sysfs_close_list(struct dlist *list)
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{
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if (list != NULL)
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dlist_destroy(list);
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}
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/**
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* sysfs_open_subsystem_list: gets a list of all supported "name" subsystem
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* details from the system
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* @name: name of the subsystem, eg., "bus", "class", "devices"
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* Returns a dlist of supported names or NULL if subsystem not supported
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*/
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struct dlist *sysfs_open_subsystem_list(unsigned char *name)
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{
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unsigned char sysfs_path[SYSFS_PATH_MAX], *subsys_name = NULL;
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struct sysfs_directory *dir = NULL, *cur = NULL;
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struct dlist *list = NULL;
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if (name == NULL)
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return NULL;
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if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) {
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dprintf("Error getting sysfs mount point\n");
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return NULL;
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}
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strcat(sysfs_path, name);
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dir = sysfs_open_directory(sysfs_path);
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if (dir == NULL) {
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dprintf("Error opening sysfs_directory at %s\n", sysfs_path);
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return NULL;
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}
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if (sysfs_read_directory(dir) != 0) {
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dprintf("Error reading sysfs_directory at %s\n", sysfs_path);
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sysfs_close_directory(dir);
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return NULL;
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}
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if (dir->subdirs != NULL) {
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list = dlist_new_with_delete(SYSFS_NAME_LEN,
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sysfs_del_name);
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if (list == NULL) {
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dprintf("Error creating list\n");
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sysfs_close_directory(dir);
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return NULL;
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}
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dlist_for_each_data(dir->subdirs, cur,
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struct sysfs_directory) {
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subsys_name = (char *)calloc(1, SYSFS_NAME_LEN);
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strcpy(subsys_name, cur->name);
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dlist_unshift(list, subsys_name);
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}
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}
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sysfs_close_directory(dir);
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return list;
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}
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/**
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* sysfs_open_bus_devices_list: gets a list of all devices on "name" bus
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* @name: name of the subsystem, eg., "pci", "scsi", "usb"
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* Returns a dlist of supported names or NULL if subsystem not supported
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*/
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struct dlist *sysfs_open_bus_devices_list(unsigned char *name)
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{
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unsigned char sysfs_path[SYSFS_PATH_MAX], *device_name = NULL;
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struct sysfs_directory *dir = NULL;
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struct sysfs_link *cur = NULL;
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struct dlist *list = NULL;
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if (name == NULL)
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return NULL;
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if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) {
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dprintf("Error getting sysfs mount point\n");
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return NULL;
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}
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strcat(sysfs_path, SYSFS_BUS_DIR);
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strcat(sysfs_path, "/");
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strcat(sysfs_path, name);
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strcat(sysfs_path, SYSFS_DEVICES_DIR);
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dir = sysfs_open_directory(sysfs_path);
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if (dir == NULL) {
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dprintf("Error opening sysfs_directory at %s\n", sysfs_path);
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return NULL;
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}
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if (sysfs_read_directory(dir) != 0) {
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dprintf("Error reading sysfs_directory at %s\n", sysfs_path);
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sysfs_close_directory(dir);
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return NULL;
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}
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if (dir->links != NULL) {
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list = dlist_new_with_delete(SYSFS_NAME_LEN,
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sysfs_del_name);
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if (list == NULL) {
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dprintf("Error creating list\n");
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sysfs_close_directory(dir);
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return NULL;
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}
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dlist_for_each_data(dir->links, cur,
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struct sysfs_link) {
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device_name = (char *)calloc(1, SYSFS_NAME_LEN);
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strcpy(device_name, cur->name);
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dlist_unshift(list, device_name);
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}
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}
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sysfs_close_directory(dir);
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return list;
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}
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