*
* Generic device utility functions for libsysfs
*
- * Copyright (C) 2003 International Business Machines, Inc.
+ * 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
#include "sysfs.h"
/**
- * sysfs_close_device: closes and cleans up a device
- * @dev = device to clean up
+ * get_dev_driver: fills in the dev->driver_name field
+ * Returns 0 on SUCCESS and -1 on error
*/
-void sysfs_close_device(struct sysfs_device *dev)
+static int get_dev_driver(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;
- free(dev);
+ struct dlist *drvlist;
+ char path[SYSFS_PATH_MAX];
+ char devpath[SYSFS_PATH_MAX];
+ char *drv = NULL, *c;
+
+ if (!dev) {
+ errno = EINVAL;
+ return -1;
}
+
+ memset(path, 0, SYSFS_PATH_MAX);
+ memset(devpath, 0, SYSFS_PATH_MAX);
+ safestrcpymax(path, dev->path, SYSFS_PATH_MAX);
+ safestrcatmax(path, "/driver", SYSFS_PATH_MAX);
+ if (!sysfs_path_is_link(path)) {
+ if (!sysfs_get_link(path, devpath, SYSFS_PATH_MAX)) {
+ if (sysfs_get_name_from_path(devpath,
+ dev->driver_name, SYSFS_NAME_LEN))
+ return -1;
+ }
+ return 0;
+ }
+
+ /*
+ * Devices on on earlier kernels do not have the "driver" link.
+ * Look it up in the bus directory.
+ */
+ if (dev->bus[0] == '\0')
+ return -1;
+ memset(path, 0, SYSFS_PATH_MAX);
+ memset(devpath, 0, SYSFS_PATH_MAX);
+ safestrcpy(path, dev->path);
+ c = strstr(path, SYSFS_DEVICES_NAME);
+ if (c == NULL) {
+ dprintf("Invalid path to device - %s\n", dev->path);
+ return -1;
+ } else
+ *c = '\0';
+ safestrcat(path, SYSFS_BUS_NAME);
+ safestrcat(path, "/");
+ safestrcat(path, dev->bus);
+ safestrcat(path, "/");
+ safestrcat(path, SYSFS_DRIVERS_NAME);
+
+ drvlist = sysfs_open_directory_list(path);
+ if (drvlist) {
+ dlist_for_each_data(drvlist, drv, char) {
+ safestrcpy(devpath, path);
+ safestrcat(devpath, "/");
+ safestrcat(devpath, drv);
+ safestrcat(devpath, "/");
+ safestrcat(devpath, dev->bus_id);
+ if (sysfs_path_is_link(devpath) == 0) {
+ safestrcpy(dev->driver_name, drv);
+ sysfs_close_list(drvlist);
+ return 0;
+ }
+ }
+ sysfs_close_list(drvlist);
+ }
+ return -1;
}
/**
- * alloc_device: allocates and initializes device structure
- * returns struct sysfs_device
+ * 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.
*/
-static struct sysfs_device *alloc_device(void)
+int sysfs_get_device_bus(struct sysfs_device *dev)
{
- return (struct sysfs_device *)calloc(1, sizeof(struct sysfs_device));
+ char devpath[SYSFS_PATH_MAX];
+ char subsys[SYSFS_NAME_LEN];
+ char path[SYSFS_PATH_MAX];
+ char target[SYSFS_PATH_MAX];
+ char *bus = NULL, *c;
+ struct dlist *buslist;
+
+ if (!dev) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ memset(path, 0, SYSFS_PATH_MAX);
+ memset(devpath, 0, SYSFS_PATH_MAX);
+ safestrcpymax(path, dev->path, SYSFS_PATH_MAX);
+ safestrcatmax(path, "/bus", SYSFS_PATH_MAX);
+ if (!sysfs_path_is_link(path)) {
+ if (!sysfs_get_link(path, devpath, SYSFS_PATH_MAX)) {
+ if (sysfs_get_name_from_path(devpath,
+ dev->bus, SYSFS_NAME_LEN))
+ return -1;
+ }
+ return 0;
+ }
+
+ /*
+ * Devices on on earlier kernels do not have the "bus" link.
+ * Look it up in the bus directory.
+ */
+ memset(subsys, 0, SYSFS_NAME_LEN);
+ safestrcpy(subsys, dev->path);
+ c = strstr(subsys, SYSFS_DEVICES_NAME);
+ if (c == NULL) {
+ dprintf("Invalid path to device - %s\n", dev->path);
+ return -1;
+ } else
+ *c = '\0';
+ safestrcat(subsys, SYSFS_BUS_NAME);
+ buslist = sysfs_open_directory_list(subsys);
+ if (buslist) {
+ dlist_for_each_data(buslist, bus, char) {
+ memset(path, 0, SYSFS_PATH_MAX);
+ safestrcpy(path, subsys);
+ safestrcat(path, "/");
+ safestrcat(path, bus);
+ safestrcat(path, "/");
+ safestrcat(path, SYSFS_DEVICES_NAME);
+ safestrcat(path, "/");
+ safestrcat(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)) {
+ dprintf("Error getting link target\n");
+ sysfs_close_list(buslist);
+ return -1;
+ }
+ if (!(strncmp(target, dev->path,
+ SYSFS_PATH_MAX))) {
+ safestrcpy(dev->bus, bus);
+ sysfs_close_list(buslist);
+ return 0;
+ }
+ }
+ }
+ sysfs_close_list(buslist);
+ }
+ return -1;
}
/**
- * 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.
+ * sysfs_close_device_tree: closes every device in the supplied tree,
+ * closing children only.
+ * @devroot: device root of tree.
*/
-struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
- const char *name)
+void sysfs_close_device_tree(struct sysfs_device *devroot)
{
- struct sysfs_attribute *cur = NULL;
- char attrname[SYSFS_NAME_LEN];
+ if (devroot) {
+ if (devroot->children) {
+ struct sysfs_device *child = NULL;
- if (dev == NULL || dev->directory == NULL || name == NULL) {
- errno = EINVAL;
- return NULL;
+ dlist_for_each_data(devroot->children, child,
+ struct sysfs_device) {
+ sysfs_close_device_tree(child);
+ }
+ }
+ sysfs_close_device(devroot);
}
- 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;
+/**
+ * sysfs_close_device: closes and cleans up a device
+ * @dev = device to clean up
+ */
+void sysfs_close_device(struct sysfs_device *dev)
+{
+ if (dev) {
+ if (dev->parent)
+ sysfs_close_device(dev->parent);
+ if (dev->children && dev->children->count)
+ dlist_destroy(dev->children);
+ if (dev->attrlist)
+ dlist_destroy(dev->attrlist);
+ free(dev);
}
+}
- return NULL;
+/**
+ * alloc_device: allocates and initializes device structure
+ * returns struct sysfs_device
+ */
+static struct sysfs_device *alloc_device(void)
+{
+ return (struct sysfs_device *) calloc(1, sizeof(struct sysfs_device));
}
/**
- * 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 char *path)
{
- struct sysfs_device *dev = NULL;
- struct sysfs_directory *sdir = NULL;
- char *p = NULL;
+ struct sysfs_device *dev;
- if (path == NULL) {
+ if (!path) {
errno = EINVAL;
return NULL;
}
- dev = alloc_device();
- if (dev == NULL) {
- dprintf(stderr, "Error allocating device at %s\n", path);
+ if (sysfs_path_is_dir(path)) {
+ dprintf("Incorrect path to device: %s\n", path);
+ return NULL;
+ }
+ dev = alloc_device();
+ if (!dev) {
+ 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)) {
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);
+ safestrcpy(dev->path, path);
+ if (sysfs_remove_trailing_slash(dev->path)) {
+ 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.
+ */
+ safestrcpy(dev->name, dev->bus_id);
+
+ if (sysfs_get_device_bus(dev))
+ dprintf("Could not get device bus\n");
+
+ if (get_dev_driver(dev)) {
+ dprintf("Could not get device %s's driver\n", dev->bus_id);
+ safestrcpy(dev->driver_name, SYSFS_UNKNOWN);
}
return dev;
}
/**
- * sysfs_close_device_tree: closes every device in the supplied tree,
- * closing children only.
- * @devroot: device root of tree.
+ * 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.
*/
-void sysfs_close_device_tree(struct sysfs_device *devroot)
+struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
+ const char *name)
{
- 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);
- }
- }
- sysfs_close_device(devroot);
+ if (!dev || !name) {
+ errno = EINVAL;
+ return NULL;
+ }
+ return get_attribute(dev, (char *)name);
+}
+
+/**
+ * sysfs_get_device_attributes: gets list of device attributes
+ * @dev: device whose attributes list is needed
+ * returns dlist of attributes on success or NULL on error
+ */
+struct dlist *sysfs_get_device_attributes(struct sysfs_device *dev)
+{
+ if (!dev) {
+ errno = EINVAL;
+ return NULL;
+ }
+ return get_attributes_list(dev);
+}
+
+/**
+ * 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 char *device, const char *bus,
+ char *path, size_t psize)
+{
+ char bus_path[SYSFS_PATH_MAX];
+
+ if (!device || !path) {
+ errno = EINVAL;
+ return -1;
}
+
+ memset(bus_path, 0, SYSFS_PATH_MAX);
+ if (sysfs_get_mnt_path(bus_path, SYSFS_PATH_MAX)) {
+ dprintf ("Sysfs not supported on this system\n");
+ return -1;
+ }
+ safestrcat(bus_path, "/");
+ safestrcat(bus_path, SYSFS_BUS_NAME);
+ safestrcat(bus_path, "/");
+ safestrcat(bus_path, bus);
+ safestrcat(bus_path, "/");
+ safestrcat(bus_path, SYSFS_DEVICES_NAME);
+ safestrcat(bus_path, "/");
+ safestrcat(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, psize)) {
+ dprintf("Error getting to device %s\n", device);
+ return -1;
+ }
+ return 0;
}
/**
- * add_device_child_to_parent: adds child device to parent
- * @parent: parent device.
- * @child: child device to add.
+ * sysfs_open_device: open a device by id (use the "bus" subsystem)
+ * @bus: bus the device belongs to
+ * @bus_id: bus_id of the device to open - has to be the "bus_id" in
+ * /sys/bus/xxx/devices
+ * 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
*/
-static void add_device_child_to_parent(struct sysfs_device *parent,
- struct sysfs_device *child)
+struct sysfs_device *sysfs_open_device(const char *bus, const char *bus_id)
{
- if (parent != NULL && child != NULL) {
- child->next = parent->children;
- parent->children = child;
- child->parent = parent;
+ char sysfs_path[SYSFS_PATH_MAX];
+ struct sysfs_device *device;
+
+ if (!bus_id || !bus) {
+ errno = EINVAL;
+ return NULL;
+ }
+ memset(sysfs_path, 0, SYSFS_PATH_MAX);
+ if (get_device_absolute_path(bus_id, bus, sysfs_path,
+ SYSFS_PATH_MAX)) {
+ dprintf("Error getting to device %s\n", bus_id);
+ return NULL;
+ }
+
+ device = sysfs_open_device_path(sysfs_path);
+ if (!device) {
+ dprintf("Error opening device %s\n", bus_id);
+ return NULL;
}
+
+ return device;
}
/**
- * 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_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_open_device_tree(const char *path)
+struct sysfs_device *sysfs_get_device_parent(struct sysfs_device *dev)
{
- struct sysfs_device *rootdev = NULL, *new = NULL;
- struct sysfs_directory *cur = NULL;
+ char ppath[SYSFS_PATH_MAX], *tmp;
- if (path == NULL) {
+ if (!dev) {
errno = EINVAL;
return NULL;
}
- rootdev = sysfs_open_device(path);
- if (rootdev == NULL) {
- dprintf(stderr, "Error opening root device at %s\n", path);
+
+ if (dev->parent)
+ return (dev->parent);
+
+ memset(ppath, 0, SYSFS_PATH_MAX);
+ safestrcpy(ppath, dev->path);
+ tmp = strrchr(ppath, '/');
+ if (!tmp) {
+ dprintf("Invalid path to device %s\n", ppath);
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);
+ 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';
- return rootdev;
+ /*
+ * All "devices" have the "detach_state" attribute - validate here
+ */
+ safestrcat(ppath, "/detach_state");
+ if (sysfs_path_is_file(ppath)) {
+ 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) {
+ dprintf("Error opening device %s's parent at %s\n",
+ dev->bus_id, ppath);
+ return NULL;
+ }
+ return (dev->parent);
}
~ianmdlvl / elogind.git / blobdiff