504 lines
13 KiB
C
504 lines
13 KiB
C
/*
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* sysfs_class.c
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*
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* Generic class 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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static void sysfs_close_cls_dev(void *dev)
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{
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sysfs_close_class_device((struct sysfs_class_device *)dev);
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}
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/**
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* class_name_equal: compares class_devices' name
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* @a: class_name looking for
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* @b: sysfs_class_device being compared
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*/
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static int class_name_equal(void *a, void *b)
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{
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if (a == NULL || b == NULL)
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return 0;
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if (strcmp(((unsigned char *)a), ((struct sysfs_class_device *)b)->name)
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== 0)
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return 1;
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return 0;
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}
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/**
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* sysfs_close_class_device: closes a single class device.
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* @dev: class device to close.
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*/
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void sysfs_close_class_device(struct sysfs_class_device *dev)
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{
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if (dev != NULL) {
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if (dev->directory != NULL)
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sysfs_close_directory(dev->directory);
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if (dev->sysdevice != NULL)
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sysfs_close_device(dev->sysdevice);
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if (dev->driver != NULL)
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sysfs_close_driver(dev->driver);
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free(dev);
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}
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}
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/**
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* sysfs_close_class: close single class
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* @class: class structure
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*/
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void sysfs_close_class(struct sysfs_class *cls)
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{
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if (cls != NULL) {
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if (cls->directory != NULL)
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sysfs_close_directory(cls->directory);
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if (cls->devices != NULL)
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dlist_destroy(cls->devices);
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free(cls);
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}
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}
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/**
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* alloc_class_device: mallocs and initializes new class device struct.
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* returns sysfs_class_device or NULL.
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*/
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static struct sysfs_class_device *alloc_class_device(void)
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{
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return (struct sysfs_class_device *)
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calloc(1, sizeof(struct sysfs_class_device));
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}
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/**
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* alloc_class: mallocs new class structure
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* returns sysfs_class struct or NULL
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*/
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static struct sysfs_class *alloc_class(void)
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{
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return (struct sysfs_class *)calloc(1, sizeof(struct sysfs_class));
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}
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/**
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* open_class_dir: opens up sysfs class directory
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* returns sysfs_directory struct with success and NULL with error
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*/
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static struct sysfs_directory *open_class_dir(const unsigned char *name)
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{
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struct sysfs_directory *classdir = NULL;
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unsigned char classpath[SYSFS_PATH_MAX];
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if (name == NULL) {
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errno = EINVAL;
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return NULL;
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}
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memset(classpath, 0, SYSFS_PATH_MAX);
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if ((sysfs_get_mnt_path(classpath, SYSFS_PATH_MAX)) != 0) {
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dprintf("Sysfs not supported on this system\n");
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return NULL;
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}
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if (sysfs_trailing_slash(classpath) == 0)
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strcat(classpath, "/");
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/*
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* We shall now treat "block" also as a class. Hence, check here
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* if "name" is "block" and proceed accordingly
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*/
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if (strcmp(name, SYSFS_BLOCK_NAME) == 0) {
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strcat(classpath, SYSFS_BLOCK_NAME);
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} else {
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strcat(classpath, SYSFS_CLASS_NAME);
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strcat(classpath, "/");
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strcat(classpath, name);
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}
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classdir = sysfs_open_directory(classpath);
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if (classdir == NULL) {
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errno = EINVAL;
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dprintf("Class %s not supported on this system\n", name);
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return NULL;
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}
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if ((sysfs_read_directory(classdir)) != 0) {
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dprintf("Error reading %s class dir %s\n", name, classpath);
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sysfs_close_directory(classdir);
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return NULL;
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}
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return classdir;
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}
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/**
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* set_classdev_classname: Grabs classname from path
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* @cdev: class device to set
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* Returns nothing
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*/
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static void set_classdev_classname(struct sysfs_class_device *cdev)
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{
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unsigned char *c = NULL, *e = NULL;
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int count = 0;
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c = strstr(cdev->path, SYSFS_CLASS_DIR);
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if (c == NULL)
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c = strstr(cdev->path, SYSFS_BLOCK_DIR);
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else {
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c++;
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while (c != NULL && *c != '/')
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c++;
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}
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if (c == NULL)
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strcpy(cdev->classname, SYSFS_UNKNOWN);
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else {
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c++;
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e = c;
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while (e != NULL && *e != '/' && *e != '\0') {
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e++;
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count++;
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}
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strncpy(cdev->classname, c, count);
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}
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}
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/**
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* sysfs_open_class_device: Opens and populates class device
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* @path: path to class device.
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* returns struct sysfs_class_device with success and NULL with error.
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*/
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struct sysfs_class_device *sysfs_open_class_device(const unsigned char *path)
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{
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struct sysfs_class_device *cdev = NULL;
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struct sysfs_directory *dir = NULL;
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struct sysfs_link *curl = NULL;
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struct sysfs_device *sdev = NULL;
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struct sysfs_driver *drv = NULL;
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if (path == NULL) {
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errno = EINVAL;
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return NULL;
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}
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cdev = alloc_class_device();
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if (cdev == NULL) {
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dprintf("calloc failed\n");
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return NULL;
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}
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if ((sysfs_get_name_from_path(path, cdev->name, SYSFS_NAME_LEN)) != 0) {
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errno = EINVAL;
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dprintf("Invalid class device path %s\n", path);
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sysfs_close_class_device(cdev);
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return NULL;
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}
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dir = sysfs_open_directory(path);
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if (dir == NULL) {
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dprintf("Error opening class device at %s\n", path);
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sysfs_close_class_device(cdev);
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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 class device at %s\n", path);
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sysfs_close_directory(dir);
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sysfs_close_class_device(cdev);
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return NULL;
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}
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sysfs_read_all_subdirs(dir);
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cdev->directory = dir;
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strcpy(cdev->path, dir->path);
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set_classdev_classname(cdev);
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/* get driver and device, if implemented */
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if (cdev->directory->links != NULL) {
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dlist_for_each_data(cdev->directory->links, curl,
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struct sysfs_link) {
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if (strncmp(curl->name, SYSFS_DEVICES_NAME, 6) == 0) {
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sdev = sysfs_open_device(curl->target);
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if (sdev != NULL) {
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cdev->sysdevice = sdev;
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if (cdev->driver != NULL)
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strncpy(sdev->driver_name,
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cdev->driver->name,
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SYSFS_NAME_LEN);
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}
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} else if (strncmp(curl->name,
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SYSFS_DRIVERS_NAME, 6) == 0) {
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drv = sysfs_open_driver(curl->target);
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if (drv != NULL) {
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cdev->driver = drv;
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if (cdev->sysdevice != NULL) {
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strncpy(cdev->sysdevice->name,
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drv->name,
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SYSFS_NAME_LEN);
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if (drv->devices == NULL)
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drv->devices =
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dlist_new
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(sizeof(struct
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sysfs_device));
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dlist_unshift(drv->devices,
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cdev->sysdevice);
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}
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}
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}
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}
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}
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return cdev;
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}
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/**
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* get_all_class_devices: gets all devices for class
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* @class: class to get devices for
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* returns 0 with success and -1 with failure
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*/
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static int get_all_class_devices(struct sysfs_class *cls)
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{
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struct sysfs_class_device *dev = NULL;
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struct sysfs_directory *cur = NULL;
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if (cls == NULL || cls->directory == NULL) {
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errno = EINVAL;
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return -1;
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}
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if (cls->directory->subdirs == NULL)
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return 0;
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dlist_for_each_data(cls->directory->subdirs, cur,
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struct sysfs_directory) {
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dev = sysfs_open_class_device(cur->path);
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if (dev == NULL) {
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dprintf("Error opening device at %s\n", cur->path);
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continue;
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}
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if (cls->devices == NULL)
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cls->devices = dlist_new_with_delete
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(sizeof(struct sysfs_class_device),
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sysfs_close_cls_dev);
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dlist_unshift(cls->devices, dev);
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}
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return 0;
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}
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/**
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* sysfs_open_class: opens specific class and all its devices on system
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* returns sysfs_class structure with success or NULL with error.
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*/
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struct sysfs_class *sysfs_open_class(const unsigned char *name)
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{
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struct sysfs_class *cls = NULL;
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struct sysfs_directory *classdir = NULL;
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if (name == NULL) {
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errno = EINVAL;
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return NULL;
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}
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cls = alloc_class();
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if (cls == NULL) {
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dprintf("calloc failed\n");
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return NULL;
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}
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strcpy(cls->name, name);
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classdir = open_class_dir(name);
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if (classdir == NULL) {
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dprintf("Invalid class, %s not supported on this system\n",
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name);
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sysfs_close_class(cls);
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return NULL;
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}
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cls->directory = classdir;
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strcpy(cls->path, classdir->path);
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if ((get_all_class_devices(cls)) != 0) {
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dprintf("Error reading %s class devices\n", name);
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sysfs_close_class(cls);
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return NULL;
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}
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return cls;
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}
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/**
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* sysfs_get_class_device: Get specific class device using the device's id
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* @class: class to find device on
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* @name: class name of the device
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*/
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struct sysfs_class_device *sysfs_get_class_device(struct sysfs_class *class,
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unsigned char *name)
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{
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if (class == NULL || name == NULL) {
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errno = EINVAL;
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return NULL;
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}
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return (struct sysfs_class_device *)dlist_find_custom(class->devices,
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name, class_name_equal);
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}
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/**
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* get_classdev_path: given the class and a device in the class, return the
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* absolute path to the device
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* @classname: name of the class
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* @clsdev: the class device
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* @path: buffer to return path
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* @psize: size of "path"
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* Returns 0 on SUCCESS or -1 on error
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*/
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static int get_classdev_path(const unsigned char *classname,
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const unsigned char *clsdev, unsigned char *path, size_t len)
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{
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if (classname == NULL || clsdev == NULL || path == NULL) {
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errno = EINVAL;
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return -1;
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}
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if (sysfs_get_mnt_path(path, len) != 0) {
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dprintf("Error getting sysfs mount path\n");
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return -1;
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}
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if (sysfs_trailing_slash(path) == 0)
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strcat(path, "/");
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if (strcmp(classname, SYSFS_BLOCK_NAME) == 0) {
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strcat(path, SYSFS_BLOCK_NAME);
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} else {
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strcat(path, SYSFS_CLASS_NAME);
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strcat(path, "/");
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strcat(path, classname);
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}
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strcat(path, "/");
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strcat(path, clsdev);
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return 0;
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}
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/**
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* sysfs_open_class_device_by_name: Locates a specific class_device and returns it.
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* Class_device must be closed using sysfs_close_class_device
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* @classname: Class to search
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* @name: name of the class_device
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*
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* NOTE:
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* Call sysfs_close_class_device() to close the class device
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*/
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struct sysfs_class_device *sysfs_open_class_device_by_name
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(const unsigned char *classname, const unsigned char *name)
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{
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unsigned char devpath[SYSFS_PATH_MAX];
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struct sysfs_class_device *cdev = NULL;
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if (classname == NULL || name == NULL) {
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errno = EINVAL;
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return NULL;
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}
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memset(devpath, 0, SYSFS_PATH_MAX);
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if ((get_classdev_path(classname, name, devpath,
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SYSFS_PATH_MAX)) != 0) {
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dprintf("Error getting to device %s on class %s\n",
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name, classname);
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return NULL;
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}
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cdev = sysfs_open_class_device(devpath);
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if (cdev == NULL) {
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dprintf("Error getting class device %s from class %s\n",
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name, classname);
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return NULL;
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}
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return cdev;
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}
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/**
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* sysfs_get_classdev_attributes: returns a dlist of attributes for
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* the requested class_device
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* @cdev: sysfs_class_dev for which attributes are needed
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* returns a dlist of attributes if exists, NULL otherwise
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*/
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struct dlist *sysfs_get_classdev_attributes(struct sysfs_class_device *cdev)
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{
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if (cdev == NULL || cdev->directory == NULL)
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return NULL;
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return (cdev->directory->attributes);
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}
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/**
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* sysfs_get_classdev_attr: searches class device's attributes by name
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* @clsdev: class device to look through
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* @name: attribute name to get
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* returns sysfs_attribute reference with success or NULL with error
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*/
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struct sysfs_attribute *sysfs_get_classdev_attr
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(struct sysfs_class_device *clsdev, const unsigned char *name)
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{
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struct sysfs_attribute *cur = NULL;
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if (clsdev == NULL || clsdev->directory == NULL ||
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clsdev->directory->attributes == NULL || name == NULL) {
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errno = EINVAL;
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return NULL;
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}
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cur = sysfs_get_directory_attribute(clsdev->directory,
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(unsigned char *)name);
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if (cur != NULL)
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return cur;
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return NULL;
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}
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/**
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* sysfs_open_classdev_attr: read an attribute for a given class device
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* @classname: name of the class on which to look
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* @dev: class device name for which the attribute has to be read
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* @attrib: attribute to read
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* Returns sysfs_attribute * on SUCCESS and NULL on error
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*
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* NOTE:
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* A call to sysfs_close_attribute() is required to close the
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* attribute returned and to free memory
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*/
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struct sysfs_attribute *sysfs_open_classdev_attr(const unsigned char *classname,
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const unsigned char *dev, const unsigned char *attrib)
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{
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struct sysfs_attribute *attribute = NULL;
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unsigned char path[SYSFS_PATH_MAX];
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if (classname == NULL || dev == NULL || attrib == NULL) {
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errno = EINVAL;
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return NULL;
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}
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memset(path, 0, SYSFS_PATH_MAX);
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if ((get_classdev_path(classname, dev, path, SYSFS_PATH_MAX)) != 0) {
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dprintf("Error getting to device %s on class %s\n",
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dev, classname);
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return NULL;
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}
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strcat(path, "/");
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strcat(path, attrib);
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attribute = sysfs_open_attribute(path);
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if (attribute == NULL) {
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dprintf("Error opening attribute %s on class device %s\n",
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attrib, dev);
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return NULL;
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}
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if ((sysfs_read_attribute(attribute)) != 0) {
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dprintf("Error reading attribute %s for class device %s\n",
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attrib, dev);
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sysfs_close_attribute(attribute);
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return NULL;
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}
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return attribute;
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}
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