1 files changed, 424 insertions, 0 deletions
diff --git a/libsysfs/sysfs_device.c b/libsysfs/sysfs_device.c
new file mode 100644
index 0000000..b783ec5
--- /dev/null
+++ b/libsysfs/sysfs_device.c
@@ -0,0 +1,424 @@
+/*
+ * sysfs_device.c
+ *
+ * Generic device 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"
+
+/**
+ * get_dev_driver: fills in the dev->driver_name field
+ * Returns 0 on SUCCESS and -1 on error
+ */
+static int get_dev_driver(struct sysfs_device *dev)
+{
+	char path[SYSFS_PATH_MAX], devpath[SYSFS_PATH_MAX];
+
+	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 0;
+		}
+	}
+	return -1;
+}
+
+/**
+ * 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)
+{
+	char devpath[SYSFS_PATH_MAX], path[SYSFS_PATH_MAX];
+
+	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 0;
+		}
+	}
+	return -1;
+}
+
+/**
+ * get_dev_subsystem: fills in the dev->subsystem field
+ * Returns 0 on SUCCESS and -1 on error
+ */
+static int get_dev_subsystem(struct sysfs_device *dev)
+{
+	char path[SYSFS_PATH_MAX], devpath[SYSFS_PATH_MAX];
+
+	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, "/subsystem", 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->subsystem, SYSFS_NAME_LEN))
+				return 0;
+		}
+	}
+	return -1;
+}
+/**
+ * sysfs_close_dev_tree: routine for dlist integration
+ */
+void sysfs_close_dev_tree(void *dev)
+{
+	sysfs_close_device_tree((struct sysfs_device *)dev);
+}
+
+/**
+ * sysfs_close_device_tree: closes every device in the supplied tree,
+ * 	closing children only.
+ * @devroot: device root of tree.
+ */
+void sysfs_close_device_tree(struct sysfs_device *devroot)
+{
+	if (devroot) {
+		if (devroot->children) {
+			struct sysfs_device *child = NULL;
+
+			dlist_for_each_data(devroot->children, child,
+					struct sysfs_device)
+				sysfs_close_device_tree(child);
+		}
+		devroot->children = NULL;
+		sysfs_close_device(devroot);
+	}
+}
+
+/**
+ * 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);
+	}
+}
+
+/**
+ * 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_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_path(const char *path)
+{
+	struct sysfs_device *dev;
+
+	if (!path) {
+		errno = EINVAL;
+		return NULL;
+	}
+	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;
+	}
+	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;
+	}
+	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;
+	}
+	/*
+	 * 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);
+	}
+
+	if (get_dev_subsystem(dev)) {
+		dprintf("Could not get device %s's subsystem\n", dev->bus_id);
+		safestrcpy(dev->subsystem, SYSFS_UNKNOWN);
+	}
+	return dev;
+}
+
+/**
+ * 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.
+ */
+struct sysfs_device *sysfs_open_device_tree(const char *path)
+{
+	struct sysfs_device *rootdev = NULL, *new = NULL;
+	struct sysfs_device *cur = NULL;
+	struct sysfs_device *devlist;
+
+	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;
+	}
+
+	devlist = sysfs_read_dir_subdirs(path);
+        if (devlist->children) {
+		dlist_for_each_data(devlist->children, cur,
+				struct sysfs_device) {
+			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_sorted(rootdev->children, new, sort_list);
+		}
+	}
+
+	return rootdev;
+}
+
+/**
+ * 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 char *name)
+{
+	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_dev_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;
+}
+
+/**
+ * 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
+ */
+struct sysfs_device *sysfs_open_device(const char *bus,	const char *bus_id)
+{
+	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_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)
+{
+	char ppath[SYSFS_PATH_MAX], dpath[SYSFS_PATH_MAX], *tmp;
+
+	if (!dev) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	if (dev->parent)
+		return (dev->parent);
+
+	memset(ppath, 0, SYSFS_PATH_MAX);
+	memset(dpath, 0, SYSFS_PATH_MAX);
+	safestrcpy(ppath, dev->path);
+	tmp = strrchr(ppath, '/');
+	if (!tmp) {
+		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;
+		}
+	}
+	*tmp = '\0';
+
+	/* Make sure we're at the top of the device tree */
+	if (sysfs_get_mnt_path(dpath, SYSFS_PATH_MAX) != 0) {
+		dprintf("Sysfs not supported on this system\n");
+		return NULL;
+	}
+	safestrcat(dpath, "/");
+	safestrcat(dpath, SYSFS_DEVICES_NAME);
+
+	if (strcmp(dpath, ppath) == 0) {
+		dprintf("Device at %s does not have a parent\n", dev->path);
+		return NULL;
+	}
+
+	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);
+}