*
* Generic device utility functions for libsysfs
*
- * Copyright (C) 2003 International Business Machines, Inc.
+ * Copyright (C) IBM Corp. 2003
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
#include "libsysfs.h"
#include "sysfs.h"
+/**
+ * sysfs_get_device_bus: retrieves the bus name the device is on, checks path
+ * to bus' link to make sure it has correct device.
+ * @dev: device to get busname.
+ * returns 0 with success and -1 with error.
+ */
+int sysfs_get_device_bus(struct sysfs_device *dev)
+{
+ unsigned char subsys[SYSFS_NAME_LEN], path[SYSFS_PATH_MAX];
+ unsigned char target[SYSFS_PATH_MAX], *bus = NULL, *c = NULL;
+ struct dlist *buslist = NULL;
+
+ if (dev == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ memset(subsys, 0, SYSFS_NAME_LEN);
+ strcat(subsys, "/");
+ strcpy(subsys, SYSFS_BUS_NAME); /* subsys = /bus */
+ buslist = sysfs_open_subsystem_list(subsys);
+ if (buslist != NULL) {
+ dlist_for_each_data(buslist, bus, char) {
+ memset(path, 0, SYSFS_PATH_MAX);
+ strcpy(path, dev->path);
+ c = strstr(path, "/devices");
+ if (c == NULL) {
+ dprintf("Invalid path to device %s\n", path);
+ sysfs_close_list(buslist);
+ return -1;
+ }
+ *c = '\0';
+ strcat(path, "/");
+ strcat(path, SYSFS_BUS_NAME);
+ strcat(path, "/");
+ strcat(path, bus);
+ strcat(path, "/");
+ strcat(path, SYSFS_DEVICES_NAME);
+ strcat(path, "/");
+ strcat(path, dev->bus_id);
+ if ((sysfs_path_is_link(path)) == 0) {
+ memset(target, 0, SYSFS_PATH_MAX);
+ if ((sysfs_get_link(path, target,
+ SYSFS_PATH_MAX)) != 0) {
+ dprintf("Error getting link target\n");
+ sysfs_close_list(buslist);
+ return -1;
+ }
+ if (!(strncmp(target, dev->path,
+ SYSFS_PATH_MAX))) {
+ strcpy(dev->bus, bus);
+ sysfs_close_list(buslist);
+ return 0;
+ }
+ }
+ }
+ sysfs_close_list(buslist);
+ }
+ return -1;
+}
+
+/**
+ * sysfs_close_device_tree: closes every device in the supplied tree,
+ * closing children only.
+ * @devroot: device root of tree.
+ */
+static void sysfs_close_device_tree(struct sysfs_device *devroot)
+{
+ if (devroot != NULL) {
+ if (devroot->children != NULL) {
+ struct sysfs_device *child = NULL;
+
+ dlist_for_each_data(devroot->children, child,
+ struct sysfs_device) {
+ sysfs_close_device_tree(child);
+ }
+ }
+ sysfs_close_device(devroot);
+ }
+}
+
+/**
+ * sysfs_close_dev_tree: routine for dlist integration
+ */
+static void sysfs_close_dev_tree(void *dev)
+{
+ sysfs_close_device_tree((struct sysfs_device *)dev);
+}
+
/**
* sysfs_close_device: closes and cleans up a device
* @dev = device to clean up
void sysfs_close_device(struct sysfs_device *dev)
{
if (dev != NULL) {
- dev->next = NULL;
- dev->driver = NULL;
+ if (dev->parent != NULL)
+ sysfs_close_device(dev->parent);
if (dev->directory != NULL)
sysfs_close_directory(dev->directory);
- dev->children = NULL;
+ if (dev->children != NULL && dev->children->count == 0)
+ dlist_destroy(dev->children);
free(dev);
}
}
}
/**
- * sysfs_get_device_attr: searches dev's attributes by name
- * @dev: device to look through
- * @name: attribute name to get
- * returns sysfs_attribute reference with success or NULL with error.
+ * open_device_dir: opens up sysfs_directory for specific root dev
+ * @name: name of root
+ * returns struct sysfs_directory with success and NULL with error
*/
-struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
- const char *name)
+static struct sysfs_directory *open_device_dir(const unsigned char *path)
{
- struct sysfs_attribute *cur = NULL;
- char attrname[SYSFS_NAME_LEN];
+ struct sysfs_directory *rdir = NULL;
- if (dev == NULL || dev->directory == NULL || name == NULL) {
+ if (path == NULL) {
errno = EINVAL;
return NULL;
}
- for (cur = dev->directory->attributes; cur != NULL; cur = cur->next) {
- if ((sysfs_get_name_from_path(cur->path, attrname,
- SYSFS_NAME_LEN)) != 0)
- continue;
- if (strcmp(name, attrname) != 0)
- continue;
- return cur;
+ rdir = sysfs_open_directory(path);
+ if (rdir == NULL) {
+ errno = EINVAL;
+ dprintf ("Device %s not supported on this system\n", path);
+ return NULL;
}
-
- return NULL;
+ if ((sysfs_read_dir_subdirs(rdir)) != 0) {
+ dprintf ("Error reading device at dir %s\n", path);
+ sysfs_close_directory(rdir);
+ return NULL;
+ }
+
+ return rdir;
}
/**
- * sysfs_open_device: opens and populates device structure
+ * sysfs_open_device_path: opens and populates device structure
* @path: path to device, this is the /sys/devices/ path
* returns sysfs_device structure with success or NULL with error
*/
-struct sysfs_device *sysfs_open_device(const char *path)
+struct sysfs_device *sysfs_open_device_path(const unsigned char *path)
{
struct sysfs_device *dev = NULL;
- struct sysfs_directory *sdir = NULL;
- char *p = NULL;
if (path == NULL) {
errno = EINVAL;
return NULL;
}
+ if ((sysfs_path_is_dir(path)) != 0) {
+ dprintf("Incorrect path to device: %s\n", path);
+ return NULL;
+ }
dev = alloc_device();
if (dev == NULL) {
- dprintf(stderr, "Error allocating device at %s\n", path);
+ dprintf("Error allocating device at %s\n", path);
return NULL;
}
- sdir = sysfs_open_directory(path);
- if (sdir == NULL) {
- dprintf(stderr, "Invalid device at %s\n", path);
+ if ((sysfs_get_name_from_path(path, dev->bus_id,
+ SYSFS_NAME_LEN)) != 0) {
errno = EINVAL;
+ dprintf("Error getting device bus_id\n");
sysfs_close_device(dev);
return NULL;
}
- if ((sysfs_read_directory(sdir)) != 0) {
- dprintf(stderr, "Error reading device directory at %s\n", path);
- sysfs_close_directory(sdir);
+ strcpy(dev->path, path);
+ if ((sysfs_remove_trailing_slash(dev->path)) != 0) {
+ dprintf("Invalid path to device %s\n", dev->path);
sysfs_close_device(dev);
return NULL;
}
- dev->directory = sdir;
- sysfs_get_name_from_path(sdir->path, dev->bus_id, SYSFS_NAME_LEN);
- /* get device name */
- p = sysfs_get_value_from_attributes(sdir->attributes,
- SYSFS_NAME_ATTRIBUTE);
- if (p != NULL) {
- strncpy(dev->name, p, SYSFS_NAME_LEN);
- p = dev->name + strlen(dev->name) - 1;
- if ((strlen(dev->name) > 0) && *p == '\n')
- *p = '\0';
- }
+ /*
+ * The "name" attribute no longer exists... return the device's
+ * sysfs representation instead, in the "dev->name" field, which
+ * implies that the dev->name and dev->bus_id contain same data.
+ */
+ strncpy(dev->name, dev->bus_id, SYSFS_NAME_LEN);
+
+ if (sysfs_get_device_bus(dev) != 0)
+ dprintf("Could not get device bus\n");
return dev;
}
/**
- * sysfs_close_device_tree: closes every device in the supplied tree,
- * closing children only.
- * @devroot: device root of tree.
+ * sysfs_open_device_tree: opens root device and all of its children,
+ * creating a tree of devices. Only opens children.
+ * @path: sysfs path to devices
+ * returns struct sysfs_device and its children with success or NULL with
+ * error.
*/
-void sysfs_close_device_tree(struct sysfs_device *devroot)
+static struct sysfs_device *sysfs_open_device_tree(const unsigned char *path)
{
- if (devroot != NULL) {
- if (devroot->children != NULL) {
- struct sysfs_device *child = NULL, *next = NULL;
-
- for (child = devroot->children; child != NULL;
- child = next) {
- next = child->next;
- sysfs_close_device_tree(child);
+ struct sysfs_device *rootdev = NULL, *new = NULL;
+ struct sysfs_directory *cur = NULL;
+
+ if (path == NULL) {
+ errno = EINVAL;
+ return NULL;
+ }
+ rootdev = sysfs_open_device_path(path);
+ if (rootdev == NULL) {
+ dprintf("Error opening root device at %s\n", path);
+ return NULL;
+ }
+ if (rootdev->directory == NULL) {
+ rootdev->directory = open_device_dir(rootdev->path);
+ if (rootdev->directory == NULL)
+ return NULL;
+ }
+ if (rootdev->directory->subdirs != NULL) {
+ dlist_for_each_data(rootdev->directory->subdirs, cur,
+ struct sysfs_directory) {
+ new = sysfs_open_device_tree(cur->path);
+ if (new == NULL) {
+ dprintf("Error opening device tree at %s\n",
+ cur->path);
+ sysfs_close_device_tree(rootdev);
+ return NULL;
}
+ if (rootdev->children == NULL)
+ rootdev->children = dlist_new_with_delete
+ (sizeof(struct sysfs_device),
+ sysfs_close_dev_tree);
+ dlist_unshift(rootdev->children, new);
}
- sysfs_close_device(devroot);
}
+
+ return rootdev;
}
/**
- * add_device_child_to_parent: adds child device to parent
- * @parent: parent device.
- * @child: child device to add.
+ * sysfs_close_root_device: closes root and all devices
+ * @root: root device to close
*/
-static void add_device_child_to_parent(struct sysfs_device *parent,
- struct sysfs_device *child)
+void sysfs_close_root_device(struct sysfs_root_device *root)
{
- if (parent != NULL && child != NULL) {
- child->next = parent->children;
- parent->children = child;
- child->parent = parent;
+ if (root != NULL) {
+ if (root->devices != NULL)
+ dlist_destroy(root->devices);
+ if (root->directory != NULL)
+ sysfs_close_directory(root->directory);
+ free(root);
}
}
/**
- * sysfs_open_device_tree: opens root device and all of its children,
- * creating a tree of devices. Only opens children.
- * @path: sysfs path to devices
- * returns struct sysfs_device and its children with success or NULL with
- * error.
+ * sysfs_get_root_devices: opens up all the devices under this root device
+ * @root: root device to open devices for
+ * returns dlist of devices with success and NULL with error
*/
-struct sysfs_device *sysfs_open_device_tree(const char *path)
+struct dlist *sysfs_get_root_devices(struct sysfs_root_device *root)
{
- struct sysfs_device *rootdev = NULL, *new = NULL;
+ struct sysfs_device *dev = NULL;
struct sysfs_directory *cur = NULL;
- if (path == NULL) {
+ if (root == NULL) {
errno = EINVAL;
return NULL;
}
- rootdev = sysfs_open_device(path);
- if (rootdev == NULL) {
- dprintf(stderr, "Error opening root device at %s\n", path);
+ if (root->directory == NULL) {
+ root->directory = open_device_dir(root->path);
+ if (root->directory == NULL)
+ return NULL;
+ }
+
+ if (root->directory->subdirs == NULL)
+ return 0;
+
+ dlist_for_each_data(root->directory->subdirs, cur,
+ struct sysfs_directory) {
+ dev = sysfs_open_device_tree(cur->path);
+ if (dev == NULL) {
+ dprintf ("Error opening device at %s\n", cur->path);
+ continue;
+ }
+ if (root->devices == NULL)
+ root->devices = dlist_new_with_delete
+ (sizeof(struct sysfs_device),
+ sysfs_close_dev_tree);
+ dlist_unshift(root->devices, dev);
+ }
+
+ return root->devices;
+}
+
+/**
+ * sysfs_open_root_device: opens sysfs devices root and all of its
+ * devices.
+ * @name: name of /sys/devices/root to open
+ * returns struct sysfs_root_device if success and NULL with error
+ */
+struct sysfs_root_device *sysfs_open_root_device(const unsigned char *name)
+{
+ struct sysfs_root_device *root = NULL;
+ unsigned char rootpath[SYSFS_PATH_MAX];
+
+ if (name == NULL) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ memset(rootpath, 0, SYSFS_PATH_MAX);
+ if (sysfs_get_mnt_path(rootpath, SYSFS_PATH_MAX) != 0) {
+ dprintf ("Sysfs not supported on this system\n");
+ return NULL;
+ }
+
+ strcat(rootpath, "/");
+ strcat(rootpath, SYSFS_DEVICES_NAME);
+ strcat(rootpath, "/");
+ strcat(rootpath, name);
+ if ((sysfs_path_is_dir(rootpath)) != 0) {
+ errno = EINVAL;
+ dprintf("Invalid root device: %s\n", name);
return NULL;
}
- cur = rootdev->directory->subdirs;
- while (cur != NULL) {
- new = sysfs_open_device_tree(cur->path);
- if (new == NULL) {
- dprintf(stderr, "Error opening device tree at %s\n",
- cur->path);
- sysfs_close_device_tree(rootdev);
+ root = (struct sysfs_root_device *)calloc
+ (1, sizeof(struct sysfs_root_device));
+ if (root == NULL) {
+ dprintf("calloc failure\n");
+ return NULL;
+ }
+ strcpy(root->name, name);
+ strcpy(root->path, rootpath);
+ if ((sysfs_remove_trailing_slash(root->path)) != 0) {
+ dprintf("Invalid path to root device %s\n", root->path);
+ sysfs_close_root_device(root);
+ return NULL;
+ }
+ return root;
+}
+
+/**
+ * sysfs_get_device_attributes: returns a dlist of attributes corresponding to
+ * the specific device
+ * @device: struct sysfs_device * for which attributes are to be returned
+ */
+struct dlist *sysfs_get_device_attributes(struct sysfs_device *device)
+{
+ if (device == NULL)
+ return NULL;
+
+ if (device->directory == NULL) {
+ device->directory = sysfs_open_directory(device->path);
+ if (device->directory == NULL)
+ return NULL;
+ }
+ if (device->directory->attributes == NULL) {
+ if ((sysfs_read_dir_attributes(device->directory)) != 0)
+ return NULL;
+ }
+ return (device->directory->attributes);
+}
+
+/**
+ * sysfs_refresh_device_attributes: refreshes the device's list of attributes
+ * @device: sysfs_device whose attributes to refresh
+ *
+ * NOTE: Upon return, prior references to sysfs_attributes for this device
+ * _may_ not be valid
+ *
+ * Returns list of attributes on success and NULL on failure
+ */
+struct dlist *sysfs_refresh_device_attributes(struct sysfs_device *device)
+{
+ if (device == NULL) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ if (device->directory == NULL)
+ return (sysfs_get_device_attributes(device));
+
+ if ((sysfs_refresh_dir_attributes(device->directory)) != 0) {
+ dprintf("Error refreshing device attributes\n");
+ return NULL;
+ }
+
+ return (device->directory->attributes);
+}
+
+/**
+ * sysfs_get_device_attr: searches dev's attributes by name
+ * @dev: device to look through
+ * @name: attribute name to get
+ * returns sysfs_attribute reference with success or NULL with error.
+ */
+struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
+ const unsigned char *name)
+{
+ struct dlist *attrlist = NULL;
+
+ if (dev == NULL || name == NULL) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ attrlist = sysfs_get_device_attributes(dev);
+ if (attrlist == NULL)
+ return NULL;
+
+ return sysfs_get_directory_attribute(dev->directory,
+ (unsigned char *)name);
+}
+
+/**
+ * get_device_absolute_path: looks up the bus the device is on, gets
+ * absolute path to the device
+ * @device: device for which path is needed
+ * @path: buffer to store absolute path
+ * @psize: size of "path"
+ * Returns 0 on success -1 on failure
+ */
+static int get_device_absolute_path(const unsigned char *device,
+ const unsigned char *bus, unsigned char *path, size_t psize)
+{
+ unsigned char bus_path[SYSFS_PATH_MAX];
+
+ if (device == NULL || path == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ memset(bus_path, 0, SYSFS_PATH_MAX);
+ if (sysfs_get_mnt_path(bus_path, SYSFS_PATH_MAX) != 0) {
+ dprintf ("Sysfs not supported on this system\n");
+ return -1;
+ }
+ strcat(bus_path, "/");
+ strcat(bus_path, SYSFS_BUS_NAME);
+ strcat(bus_path, "/");
+ strcat(bus_path, bus);
+ strcat(bus_path, "/");
+ strcat(bus_path, SYSFS_DEVICES_NAME);
+ strcat(bus_path, "/");
+ strcat(bus_path, device);
+ /*
+ * We now are at /sys/bus/"bus_name"/devices/"device" which is a link.
+ * Now read this link to reach to the device.
+ */
+ if ((sysfs_get_link(bus_path, path, SYSFS_PATH_MAX)) != 0) {
+ dprintf("Error getting to device %s\n", device);
+ return -1;
+ }
+ return 0;
+}
+
+/**
+ * sysfs_open_device: open a device by id (use the "bus" subsystem)
+ * @bus_id: bus_id of the device to open - has to be the "bus_id" in
+ * /sys/bus/xxx/devices
+ * @bus: bus the device belongs to
+ * returns struct sysfs_device if found, NULL otherwise
+ * NOTE:
+ * 1. Use sysfs_close_device to close the device
+ * 2. Bus the device is on must be supplied
+ * Use sysfs_find_device_bus to get the bus name
+ */
+struct sysfs_device *sysfs_open_device(const unsigned char *bus_id,
+ const unsigned char *bus)
+{
+ char sysfs_path[SYSFS_PATH_MAX];
+ struct sysfs_device *device = NULL;
+
+ if (bus_id == NULL || bus == NULL) {
+ errno = EINVAL;
+ return NULL;
+ }
+ memset(sysfs_path, 0, SYSFS_PATH_MAX);
+ if ((get_device_absolute_path(bus_id, bus, sysfs_path,
+ SYSFS_PATH_MAX)) != 0) {
+ dprintf("Error getting to device %s\n", bus_id);
+ return NULL;
+ }
+
+ device = sysfs_open_device_path(sysfs_path);
+ if (device == NULL) {
+ dprintf("Error opening device %s\n", bus_id);
+ return NULL;
+ }
+
+ return device;
+}
+
+/**
+ * sysfs_get_device_parent: opens up given device's parent and returns a
+ * reference to its sysfs_device
+ * @dev: sysfs_device whose parent is requested
+ * Returns sysfs_device of the parent on success and NULL on failure
+ */
+struct sysfs_device *sysfs_get_device_parent(struct sysfs_device *dev)
+{
+ unsigned char ppath[SYSFS_PATH_MAX], *tmp = NULL;
+
+ if (dev == NULL) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ if (dev->parent != NULL)
+ return (dev->parent);
+
+ memset(ppath, 0, SYSFS_PATH_MAX);
+ strcpy(ppath, dev->path);
+ tmp = strrchr(ppath, '/');
+ if (tmp == NULL) {
+ dprintf("Invalid path to device %s\n", ppath);
+ return NULL;
+ }
+ if (*(tmp +1) == '\0') {
+ *tmp = '\0';
+ tmp = strrchr(tmp, '/');
+ if (tmp == NULL) {
+ dprintf("Invalid path to device %s\n", ppath);
return NULL;
}
- add_device_child_to_parent(rootdev, new);
- cur = cur->next;
}
+ *tmp = '\0';
+
+ /*
+ * All "devices" have the "detach_state" attribute - validate here
+ */
+ strcat(ppath, "/detach_state");
+ if ((sysfs_path_is_file(ppath)) != 0) {
+ dprintf("Device at %s does not have a parent\n", dev->path);
+ return NULL;
+ }
+ tmp = strrchr(ppath, '/');
+ *tmp = '\0';
+ dev->parent = sysfs_open_device_path(ppath);
+ if (dev->parent == NULL) {
+ dprintf("Error opening device %s's parent at %s\n",
+ dev->bus_id, ppath);
+ return NULL;
+ }
+ return (dev->parent);
+}
- return rootdev;
+/*
+ * sysfs_open_device_attr: open the given device's attribute
+ * @bus: Bus on which to look
+ * @dev_id: device for which attribute is required
+ * @attrname: name of the attribute to look for
+ * Returns struct sysfs_attribute on success and NULL on failure
+ *
+ * NOTE:
+ * A call to sysfs_close_attribute() is required to close
+ * the attribute returned and free memory.
+ */
+struct sysfs_attribute *sysfs_open_device_attr(const unsigned char *bus,
+ const unsigned char *bus_id, const unsigned char *attrib)
+{
+ struct sysfs_attribute *attribute = NULL;
+ unsigned char devpath[SYSFS_PATH_MAX];
+
+ if (bus == NULL || bus_id == NULL || attrib == NULL) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ memset(devpath, 0, SYSFS_PATH_MAX);
+ if ((get_device_absolute_path(bus_id, bus, devpath,
+ SYSFS_PATH_MAX)) != 0) {
+ dprintf("Error getting to device %s\n", bus_id);
+ return NULL;
+ }
+ strcat(devpath, "/");
+ strcat(devpath, attrib);
+ attribute = sysfs_open_attribute(devpath);
+ if (attribute == NULL) {
+ dprintf("Error opening attribute %s for device %s\n",
+ attrib, bus_id);
+ return NULL;
+ }
+ if ((sysfs_read_attribute(attribute)) != 0) {
+ dprintf("Error reading attribute %s for device %s\n",
+ attrib, bus_id);
+ sysfs_close_attribute(attribute);
+ return NULL;
+ }
+ return attribute;
}
+
~ianmdlvl / elogind.git / blobdiff