[PATCH] new version of libsysfs patch

Here's the patch applying the latest libsysfs.
	- adds the latest libsysfs code to udev
		* new code includes dlist implementation, a generic linked list
			implementation. Needed our own because LGPL
		* rearranged structures
		* provided more functions for accessing directory and attributes
	- gets rid of ->directory->path references in namedev.c
	- replaces sysfs_get_value_from_attributes with sysfs_get_classdev_attr

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;
 }