diff options
Diffstat (limited to 'libsysfs/sysfs_class.c')
| -rw-r--r-- | libsysfs/sysfs_class.c | 551 |
1 files changed, 551 insertions, 0 deletions
diff --git a/libsysfs/sysfs_class.c b/libsysfs/sysfs_class.c new file mode 100644 index 0000000..4fe0b82 --- /dev/null +++ b/libsysfs/sysfs_class.c @@ -0,0 +1,551 @@ +/* + * sysfs_class.c + * + * Generic class utility functions for libsysfs + * + * Copyright (C) IBM Corp. 2003-2005 + * + * 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_close_class_device: closes a single class device. + * @dev: class device to close. + */ +void sysfs_close_class_device(struct sysfs_class_device *dev) +{ + if (dev) { + if (dev->parent) + sysfs_close_class_device(dev->parent); + if (dev->sysdevice) + sysfs_close_device(dev->sysdevice); + if (dev->attrlist) + dlist_destroy(dev->attrlist); + free(dev); + } +} + +static void sysfs_close_cls_dev(void *dev) +{ + sysfs_close_class_device((struct sysfs_class_device *)dev); +} + +/** + * sysfs_close_class: close the given class + * @cls: sysfs_class to close + */ +void sysfs_close_class(struct sysfs_class *cls) +{ + if (cls) { + if (cls->devices) + dlist_destroy(cls->devices); + if (cls->attrlist) + dlist_destroy(cls->attrlist); + free(cls); + } +} + +static int cdev_name_equal(void *a, void *b) +{ + if (!a || !b) + return 0; + + if (strncmp((char *)a, ((struct sysfs_class_device *)b)->name, + strlen((char *)a)) == 0) + return 1; + + return 0; +} + +static struct sysfs_class *alloc_class(void) +{ + return (struct sysfs_class *) calloc(1, sizeof(struct sysfs_class)); +} + +/** + * alloc_class_device: mallocs and initializes new class device struct. + * returns sysfs_class_device or NULL. + */ +static struct sysfs_class_device *alloc_class_device(void) +{ + struct sysfs_class_device *dev; + + dev = calloc(1, sizeof(struct sysfs_class_device)); + return dev; +} + +/** + * set_classdev_classname: Grabs classname from path + * @cdev: class device to set + * Returns nothing + */ +static void set_classdev_classname(struct sysfs_class_device *cdev) +{ + char *c, *e, name[SYSFS_PATH_MAX], link[SYSFS_PATH_MAX]; + struct stat stats; + int count = 0; + + /* + * Newer driver core changes have a class:class_device representation. + * Check if this cdev belongs to the newer style subsystem and + * set the classname appropriately. + */ + memset(name, 0, SYSFS_PATH_MAX); + safestrcpy(name, cdev->name); + c = strchr(name, ':'); + if (c) { + safestrcpy(cdev->name, c+1); + *c = '\0'; + safestrcpy(cdev->classname, name); + return; + } + + c = strstr(cdev->path, SYSFS_CLASS_NAME); + if (c == NULL) + c = strstr(cdev->path, SYSFS_BLOCK_NAME); + else + c = strstr(c, "/"); + + if (c) { + if (*c == '/') + c++; + e = c; + while (e != NULL && *e != '/' && *e != '\0') { + e++; + count++; + } + strncpy(cdev->classname, c, count); + } else { + strcpy(link, cdev->path); + strcat(link, "/subsystem"); + sysfs_get_link(link, name, SYSFS_PATH_MAX); + if (lstat(name, &stats)) + safestrcpy(cdev->classname, SYSFS_UNKNOWN); + else { + c = strrchr(name, '/'); + if (c) + safestrcpy(cdev->classname, c+1); + else + safestrcpy(cdev->classname, SYSFS_UNKNOWN); + } + } +} + +/** + * sysfs_open_class_device_path: Opens and populates class device + * @path: path to class device. + * returns struct sysfs_class_device with success and NULL with error. + */ +struct sysfs_class_device *sysfs_open_class_device_path(const char *path) +{ + struct sysfs_class_device *cdev; + char temp_path[SYSFS_PATH_MAX]; + + if (!path) { + errno = EINVAL; + return NULL; + } + + /* + * Post linux-2.6.14 driver model supports nested classes with + * links to the nested hierarchy at /sys/class/xxx/. Check for + * a link to the actual class device if a directory isn't found + */ + if (sysfs_path_is_dir(path)) { + dprintf("%s: Directory not found, checking for a link\n", path); + if (!sysfs_path_is_link(path)) { + if (sysfs_get_link(path, temp_path, SYSFS_PATH_MAX)) { + dprintf("Error retrieving link at %s\n", path); + return NULL; + } + } else { + dprintf("%s is not a valid class device path\n", path); + return NULL; + } + } else + safestrcpy(temp_path, path); + + cdev = alloc_class_device(); + if (!cdev) { + dprintf("calloc failed\n"); + return NULL; + } + if (sysfs_get_name_from_path(temp_path, cdev->name, SYSFS_NAME_LEN)) { + errno = EINVAL; + dprintf("Error getting class device name\n"); + sysfs_close_class_device(cdev); + return NULL; + } + + safestrcpy(cdev->path, temp_path); + if (sysfs_remove_trailing_slash(cdev->path)) { + dprintf("Invalid path to class device %s\n", cdev->path); + sysfs_close_class_device(cdev); + return NULL; + } + set_classdev_classname(cdev); + + return cdev; +} + +/** + * sysfs_get_classdev_parent: Retrieves the parent of a class device. + * eg., when working with hda1, this function can be used to retrieve the + * sysfs_class_device for hda + * + * @clsdev: class device whose parent details are required. + * Returns sysfs_class_device of the parent on success, NULL on failure + */ +struct sysfs_class_device *sysfs_get_classdev_parent + (struct sysfs_class_device *clsdev) +{ + char abs_path[SYSFS_PATH_MAX], tmp_path[SYSFS_PATH_MAX]; + char *c; + + if (!clsdev) { + errno = EINVAL; + return NULL; + } + + if (clsdev->parent) + return (clsdev->parent); + + memset(abs_path, 0, SYSFS_PATH_MAX); + memset(tmp_path, 0, SYSFS_PATH_MAX); + + safestrcpy(tmp_path, clsdev->path); + c = strstr(tmp_path, clsdev->classname); + c = strchr(c, '/'); + *c = '\0'; + + safestrcpy(abs_path, clsdev->path); + c = strrchr(abs_path, '/'); + *c = '\0'; + + if ((strncmp(tmp_path, abs_path, strlen(abs_path))) == 0) { + dprintf("Class device %s doesn't have a parent\n", + clsdev->name); + return NULL; + } + + clsdev->parent = sysfs_open_class_device_path(abs_path); + + return clsdev->parent; +} + +/** + * get_classdev_path: given the class and a device in the class, return the + * absolute path to the device + * @classname: name of the class + * @clsdev: the class device + * @path: buffer to return path + * @psize: size of "path" + * Returns 0 on SUCCESS or -1 on error + */ +static int get_classdev_path(const char *classname, const char *clsdev, + char *path, size_t len) +{ + char *c; + + if (!classname || !clsdev || !path) { + errno = EINVAL; + return -1; + } + if (sysfs_get_mnt_path(path, len) != 0) { + dprintf("Error getting sysfs mount path\n"); + return -1; + } + safestrcatmax(path, "/", len); + if (strncmp(classname, SYSFS_BLOCK_NAME, + sizeof(SYSFS_BLOCK_NAME)) == 0) { + safestrcatmax(path, SYSFS_BLOCK_NAME, len); + if (!sysfs_path_is_dir(path)) + goto done; + c = strrchr(path, '/'); + *(c+1) = '\0'; + } + safestrcatmax(path, SYSFS_CLASS_NAME, len); + safestrcatmax(path, "/", len); + safestrcatmax(path, classname, len); +done: + safestrcatmax(path, "/", len); + safestrcatmax(path, clsdev, len); + return 0; +} + +/** + * sysfs_open_class_device: Locates a specific class_device and returns it. + * Class_device must be closed using sysfs_close_class_device + * @classname: Class to search + * @name: name of the class_device + * + * NOTE: + * Call sysfs_close_class_device() to close the class device + */ +struct sysfs_class_device *sysfs_open_class_device + (const char *classname, const char *name) +{ + char devpath[SYSFS_PATH_MAX]; + struct sysfs_class_device *cdev; + + if (!classname || !name) { + errno = EINVAL; + return NULL; + } + + memset(devpath, 0, SYSFS_PATH_MAX); + if ((get_classdev_path(classname, name, devpath, + SYSFS_PATH_MAX)) != 0) { + dprintf("Error getting to device %s on class %s\n", + name, classname); + return NULL; + } + + cdev = sysfs_open_class_device_path(devpath); + if (!cdev) { + dprintf("Error getting class device %s from class %s\n", + name, classname); + return NULL; + } + return cdev; +} + +/** + * sysfs_get_classdev_attr: searches class device's attributes by name + * @clsdev: class device to look through + * @name: attribute name to get + * returns sysfs_attribute reference with success or NULL with error + */ +struct sysfs_attribute *sysfs_get_classdev_attr + (struct sysfs_class_device *clsdev, const char *name) +{ + if (!clsdev || !name) { + errno = EINVAL; + return NULL; + } + return get_attribute(clsdev, (char *)name); +} + +/** + * sysfs_get_classdev_attributes: gets list of classdev attributes + * @clsdev: class device whose attributes list is needed + * returns dlist of attributes on success or NULL on error + */ +struct dlist *sysfs_get_classdev_attributes(struct sysfs_class_device *clsdev) +{ + if (!clsdev) { + errno = EINVAL; + return NULL; + } + return get_dev_attributes_list(clsdev); +} + +/** + * sysfs_get_classdev_device: gets the sysfs_device associated with the + * given sysfs_class_device + * @clsdev: class device whose associated sysfs_device is needed + * returns struct sysfs_device * on success or NULL on error + */ +struct sysfs_device *sysfs_get_classdev_device + (struct sysfs_class_device *clsdev) +{ + char linkpath[SYSFS_PATH_MAX], devpath[SYSFS_PATH_MAX]; + + if (!clsdev) { + errno = EINVAL; + return NULL; + } + + if (clsdev->sysdevice) + return clsdev->sysdevice; + + memset(linkpath, 0, SYSFS_PATH_MAX); + safestrcpy(linkpath, clsdev->path); + safestrcat(linkpath, "/device"); + if (!sysfs_path_is_link(linkpath)) { + memset(devpath, 0, SYSFS_PATH_MAX); + if (!sysfs_get_link(linkpath, devpath, SYSFS_PATH_MAX)) + clsdev->sysdevice = sysfs_open_device_path(devpath); + } + return clsdev->sysdevice; +} + +/** + * sysfs_open_class: opens specific class and all its devices on system + * returns sysfs_class structure with success or NULL with error. + */ +struct sysfs_class *sysfs_open_class(const char *name) +{ + struct sysfs_class *cls = NULL; + char *c, classpath[SYSFS_PATH_MAX]; + + if (!name) { + errno = EINVAL; + return NULL; + } + + memset(classpath, 0, SYSFS_PATH_MAX); + if ((sysfs_get_mnt_path(classpath, SYSFS_PATH_MAX)) != 0) { + dprintf("Sysfs not supported on this system\n"); + return NULL; + } + + safestrcat(classpath, "/"); + if (strcmp(name, SYSFS_BLOCK_NAME) == 0) { + safestrcat(classpath, SYSFS_BLOCK_NAME); + if (!sysfs_path_is_dir(classpath)) + goto done; + c = strrchr(classpath, '/'); + *(c+1) = '\0'; + } + safestrcat(classpath, SYSFS_CLASS_NAME); + safestrcat(classpath, "/"); + safestrcat(classpath, name); +done: + if (sysfs_path_is_dir(classpath)) { + dprintf("Class %s not found on the system\n", name); + return NULL; + } + + cls = alloc_class(); + if (cls == NULL) { + dprintf("calloc failed\n"); + return NULL; + } + safestrcpy(cls->name, name); + safestrcpy(cls->path, classpath); + if ((sysfs_remove_trailing_slash(cls->path)) != 0) { + dprintf("Invalid path to class device %s\n", cls->path); + sysfs_close_class(cls); + return NULL; + } + + return cls; +} + +/** + * sysfs_get_class_device: get specific class device using the device's id + * @cls: sysfs_class to find the device on + * @name: name of the class device to look for + * + * Returns sysfs_class_device * on success and NULL on failure + */ +struct sysfs_class_device *sysfs_get_class_device(struct sysfs_class *cls, + const char *name) +{ + char path[SYSFS_PATH_MAX]; + struct sysfs_class_device *cdev = NULL; + + if (!cls || !name) { + errno = EINVAL; + return NULL; + } + + if (cls->devices) { + cdev = (struct sysfs_class_device *)dlist_find_custom + (cls->devices, (void *)name, cdev_name_equal); + if (cdev) + return cdev; + } + + safestrcpy(path, cls->path); + safestrcat(path, "/"); + safestrcat(path, name); + cdev = sysfs_open_class_device_path(path); + if (!cdev) { + dprintf("Error opening class device at %s\n", path); + return NULL; + } + if (!cls->devices) + cls->devices = dlist_new_with_delete + (sizeof(struct sysfs_class_device), + sysfs_close_cls_dev); + + dlist_unshift_sorted(cls->devices, cdev, sort_list); + return cdev; +} + +/** + * Add class devices to list + */ +static void add_cdevs_to_classlist(struct sysfs_class *cls, struct dlist *list) +{ + char path[SYSFS_PATH_MAX], *cdev_name; + struct sysfs_class_device *cdev = NULL; + + if (cls == NULL || list == NULL) + return; + + dlist_for_each_data(list, cdev_name, char) { + if (cls->devices) { + cdev = (struct sysfs_class_device *) + dlist_find_custom(cls->devices, + (void *)cdev_name, cdev_name_equal); + if (cdev) + continue; + } + safestrcpy(path, cls->path); + safestrcat(path, "/"); + safestrcat(path, cdev_name); + cdev = sysfs_open_class_device_path(path); + if (cdev) { + if (!cls->devices) + cls->devices = dlist_new_with_delete + (sizeof(struct sysfs_class_device), + sysfs_close_cls_dev); + dlist_unshift_sorted(cls->devices, cdev, + sort_list); + } + } +} + +/** + * sysfs_get_class_devices: get all class devices in the given class + * @cls: sysfs_class whose devices list is needed + * + * Returns a dlist of sysfs_class_device * on success and NULL on failure + */ +struct dlist *sysfs_get_class_devices(struct sysfs_class *cls) +{ + char path[SYSFS_PATH_MAX]; + struct dlist *dirlist, *linklist; + + if (!cls) { + errno = EINVAL; + return NULL; + } + + /* + * Post linux-2.6.14, we have nested classes and links under + * /sys/class/xxx/. are also valid class devices + */ + safestrcpy(path, cls->path); + dirlist = read_dir_subdirs(path); + if (dirlist) { + add_cdevs_to_classlist(cls, dirlist); + sysfs_close_list(dirlist); + } + + linklist = read_dir_links(path); + if (linklist) { + add_cdevs_to_classlist(cls, linklist); + sysfs_close_list(linklist); + } + + return cls->devices; +} |