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-rw-r--r--libsysfs/sysfs_device.c487
1 files changed, 413 insertions, 74 deletions
diff --git a/libsysfs/sysfs_device.c b/libsysfs/sysfs_device.c
index 185b5cf378..89704dcd80 100644
--- a/libsysfs/sysfs_device.c
+++ b/libsysfs/sysfs_device.c
@@ -3,7 +3,7 @@
*
* 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
@@ -24,17 +24,52 @@
#include "sysfs.h"
/**
+ * 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_del_device: routine for dlist integration
+ */
+static void sysfs_del_device(void *dev)
+{
+ sysfs_close_device((struct sysfs_device *)dev);
+}
+
+/**
+ * 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->directory != NULL)
sysfs_close_directory(dev->directory);
- dev->children = NULL;
+ if (dev->children != NULL && dev->children->count == 0)
+ dlist_destroy(dev->children);
free(dev);
}
}
@@ -55,24 +90,20 @@ static struct sysfs_device *alloc_device(void)
* returns sysfs_attribute reference with success or NULL with error.
*/
struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
- const char *name)
+ const unsigned char *name)
{
struct sysfs_attribute *cur = NULL;
- char attrname[SYSFS_NAME_LEN];
- if (dev == NULL || dev->directory == NULL || name == NULL) {
+ if (dev == NULL || dev->directory == NULL
+ || dev->directory->attributes == NULL || name == 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;
-
+
+ cur = sysfs_get_directory_attribute(dev->directory,
+ (unsigned char *)name);
+ if (cur != NULL)
return cur;
- }
return NULL;
}
@@ -82,11 +113,10 @@ struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
* @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(const unsigned char *path)
{
struct sysfs_device *dev = NULL;
struct sysfs_directory *sdir = NULL;
- char *p = NULL;
if (path == NULL) {
errno = EINVAL;
@@ -94,106 +124,415 @@ struct sysfs_device *sysfs_open_device(const char *path)
}
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);
+ dprintf("Invalid device at %s\n", path);
errno = EINVAL;
sysfs_close_device(dev);
return NULL;
}
if ((sysfs_read_directory(sdir)) != 0) {
- dprintf(stderr, "Error reading device directory at %s\n", path);
+ dprintf("Error reading device directory at %s\n", path);
sysfs_close_directory(sdir);
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';
- }
+ strcpy(dev->bus_id, sdir->name);
+ strcpy(dev->path, sdir->path);
+
+ /*
+ * 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, sdir->name, SYSFS_NAME_LEN);
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);
+ if (rootdev == NULL) {
+ dprintf("Error opening root device at %s\n", path);
+ 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_del_device);
+ 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.
+ * open_root_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_device *sysfs_open_device_tree(const char *path)
+static struct sysfs_directory *open_root_device_dir(const unsigned char *name)
{
- struct sysfs_device *rootdev = NULL, *new = NULL;
+ struct sysfs_directory *rdir = 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, SYSFS_DEVICES_DIR);
+ strcat(rootpath, "/");
+ strcat(rootpath, name);
+ rdir = sysfs_open_directory(rootpath);
+ if (rdir == NULL) {
+ errno = EINVAL;
+ dprintf ("Root device %s not supported on this system\n",
+ name);
+ return NULL;
+ }
+ if (sysfs_read_directory(rdir) != 0) {
+ dprintf ("Error reading %s root device at dir %s\n", name,
+ rootpath);
+ sysfs_close_directory(rdir);
+ return NULL;
+ }
+
+ return rdir;
+}
+
+/**
+ * get_all_root_devices: opens up all the devices under this root device
+ * @root: root device to open devices for
+ * returns 0 with success and -1 with error
+ */
+static int get_all_root_devices(struct sysfs_root_device *root)
+{
+ struct sysfs_device *dev = NULL;
struct sysfs_directory *cur = NULL;
- if (path == NULL) {
+ if (root == NULL || root->directory == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+ 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 0;
+}
+
+/**
+ * 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;
+ struct sysfs_directory *rootdir = NULL;
+
+ if (name == NULL) {
errno = EINVAL;
return NULL;
}
- rootdev = sysfs_open_device(path);
- if (rootdev == NULL) {
- dprintf(stderr, "Error opening root device at %s\n", path);
+
+ root = (struct sysfs_root_device *)calloc
+ (1, sizeof(struct sysfs_root_device));
+ if (root == NULL) {
+ dprintf("calloc failure\n");
+ return NULL;
+ }
+ rootdir = open_root_device_dir(name);
+ if (rootdir == NULL) {
+ dprintf ("Invalid root device, %s not supported\n", name);
+ sysfs_close_root_device(root);
+ return NULL;
+ }
+ strcpy(root->path, rootdir->path);
+ root->directory = rootdir;
+ if (get_all_root_devices(root) != 0) {
+ dprintf ("Error retrieving devices for root %s\n", name);
+ 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 || device->directory == NULL)
+ return NULL;
+
+ return (device->directory->attributes);
+}
+
+/**
+ * sysfs_open_device_by_id: 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
+ * @bsize: size of the bus buffer
+ * 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_by_id(const unsigned char *bus_id,
+ const unsigned char *bus, size_t bsize)
+{
+ char sysfs_path[SYSFS_PATH_MAX], device_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 ((sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX)) != 0) {
+ dprintf("Error getting sysfs mount path\n");
+ return NULL;
+ }
+ strcat(sysfs_path, SYSFS_BUS_DIR);
+ strcat(sysfs_path, "/");
+ strncat(sysfs_path, bus, bsize);
+ strcat(sysfs_path, SYSFS_DEVICES_DIR);
+ strcat(sysfs_path, "/");
+ strcat(sysfs_path, bus_id);
+
+ /* devices under /sys/bus/xxx/devices are links to devices subsystem */
+ if ((sysfs_get_link(sysfs_path, device_path, SYSFS_PATH_MAX)) < 0) {
+ dprintf("Error getting device path\n");
+ return NULL;
+ }
+
+ device = sysfs_open_device(device_path);
+ if (device == NULL) {
+ dprintf("Error opening device %s\n", bus_id);
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);
- return NULL;
+
+ return device;
+}
+
+/**
+ * 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,
+ unsigned char *path, size_t psize)
+{
+ unsigned char bus_name[SYSFS_NAME_LEN], bus_path[SYSFS_PATH_MAX];
+
+ if (device == NULL || path == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ memset(bus_name, 0, SYSFS_NAME_LEN);
+ memset(bus_path, 0, SYSFS_NAME_LEN);
+ if ((sysfs_find_device_bus(device, bus_name, SYSFS_NAME_LEN)) != 0) {
+ dprintf("Device %s not found\n", device);
+ return -1;
+ }
+ if (sysfs_get_mnt_path(bus_path, SYSFS_PATH_MAX) != 0) {
+ dprintf ("Sysfs not supported on this system\n");
+ return -1;
+ }
+ strcat(bus_path, SYSFS_BUS_DIR);
+ strcat(bus_path, "/");
+ strcat(bus_path, bus_name);
+ strcat(bus_path, SYSFS_DEVICES_DIR);
+ 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_write_device_attr: modify a "writable" attribute for the given device
+ * @dev: device bus_id for which attribute has to be changed
+ * @attrib: attribute to change
+ * @value: value to change to
+ * @len: "value" length to write
+ * Returns 0 on success -1 on error
+ */
+int sysfs_write_device_attr(unsigned char *dev, unsigned char *attrib,
+ unsigned char *value, size_t len)
+{
+ struct sysfs_attribute *attribute = NULL;
+ unsigned char devpath[SYSFS_PATH_MAX];
+
+ if (dev == NULL || attrib == NULL || value == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ memset(devpath, 0, SYSFS_PATH_MAX);
+ if ((get_device_absolute_path(dev, devpath, SYSFS_PATH_MAX)) != 0) {
+ dprintf("Error finding absolute path to device %s\n", dev);
+ return -1;
+ }
+ strcat(devpath, "/");
+ strcat(devpath, attrib);
+ attribute = sysfs_open_attribute(devpath);
+ if (attribute == NULL) {
+ dprintf("Attribute %s could not be retrieved for device %s\n",
+ attrib, dev);
+ return -1;
+ }
+ if (attribute->method & SYSFS_METHOD_SHOW) {
+ if ((sysfs_read_attribute(attribute)) != 0) {
+ dprintf("Error reading attribute %s for device %s\n",
+ attrib, dev);
+ sysfs_close_attribute(attribute);
+ return -1;
}
- add_device_child_to_parent(rootdev, new);
- cur = cur->next;
}
+ if ((sysfs_write_attribute(attribute, value, len)) < 0) {
+ dprintf("Error setting %s to %s\n", attrib, value);
+ sysfs_close_attribute(attribute);
+ return -1;
+ }
+ sysfs_close_attribute(attribute);
+ return 0;
+}
- return rootdev;
+/**
+ * sysfs_read_device_attr: read an attribute of the given device
+ * @dev: device bus_id for which attribute has to be changed
+ * @attrib: attribute to read
+ * @value: buffer to return value in
+ * @len: size of buffer available
+ * Returns 0 on success -1 on error
+ */
+int sysfs_read_device_attr(unsigned char *dev, unsigned char *attrib,
+ unsigned char *value, size_t len)
+{
+ struct sysfs_attribute *attribute = NULL;
+ unsigned char devpath[SYSFS_PATH_MAX];
+
+ if (dev == NULL || attrib == NULL || value == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ memset(devpath, 0, SYSFS_PATH_MAX);
+ if ((get_device_absolute_path(dev, devpath, SYSFS_PATH_MAX)) != 0) {
+ dprintf("Error finding absolute path to device %s\n", dev);
+ return -1;
+ }
+ strcat(devpath, "/");
+ strcat(devpath, attrib);
+ attribute = sysfs_open_attribute(devpath);
+ if (attribute == NULL) {
+ dprintf("Error opening attribute %s for device %s\n",
+ attrib, dev);
+ return -1;
+ }
+ if (!(attribute->method & SYSFS_METHOD_SHOW)) {
+ dprintf("Show method not supported for attribute %s\n",
+ attrib);
+ sysfs_close_attribute(attribute);
+ return -1;
+ }
+ if ((sysfs_read_attribute(attribute)) != 0) {
+ dprintf("Error reading attribute %s for device %s\n",
+ attrib, dev);
+ sysfs_close_attribute(attribute);
+ return -1;
+ }
+ if (attribute->len > len) {
+ dprintf("Value length %d is larger than supplied buffer %d\n",
+ attribute->len, len);
+ sysfs_close_attribute(attribute);
+ return -1;
+ }
+ strncpy(value, attribute->value, attribute->len);
+ value[(attribute->len)+1] = 0;
+ sysfs_close_attribute(attribute);
+ return 0;
}