X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=libsysfs%2Fsysfs_class.c;h=edf751b124c515f01c96f37409ba722714e6ba48;hb=d514329ee2d5614078649a425674d83e0211c1b9;hp=9d7d8b222711e541a1792827375b73ba7cd2954a;hpb=070f54223f66490e9d25719c495e074f77da8985;p=elogind.git

diff --git a/libsysfs/sysfs_class.c b/libsysfs/sysfs_class.c
index 9d7d8b222..edf751b12 100644
--- a/libsysfs/sysfs_class.c
+++ b/libsysfs/sysfs_class.c
@@ -3,7 +3,7 @@
  *
  * Generic class 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
@@ -29,209 +29,348 @@
  */
 void sysfs_close_class_device(struct sysfs_class_device *dev)
 {
-	if (dev != NULL) {
-		if (dev->directory != NULL)
-			sysfs_close_directory(dev->directory);
-		if (dev->sysdevice != NULL)
+	if (dev) {
+		if (dev->parent)
+			sysfs_close_class_device(dev->parent);
+		if (dev->sysdevice)
 			sysfs_close_device(dev->sysdevice);
-		if (dev->driver != NULL)
-			sysfs_close_driver(dev->driver);
+		if (dev->attrlist)
+			dlist_destroy(dev->attrlist);
 		free(dev);
 	}
 }
 
+static void sysfs_close_cls_dev(void *dev)
+{
+	sysfs_close_class_device((struct sysfs_class_device *)dev);
+}
+
 /**
- * sysfs_close_class: close single class
- * @class: class structure
- */
+ * sysfs_close_class: close the given class
+ * @cls: sysfs_class to close
+ */ 
 void sysfs_close_class(struct sysfs_class *cls)
 {
-	struct sysfs_class_device *cur = NULL, *next = NULL;
-
-	if (cls != NULL) {
-		if (cls->directory != NULL)
-			sysfs_close_directory(cls->directory);
-		for (cur = cls->devices; cur != NULL; cur = next) {
-			next = cur->next;
-			sysfs_close_class_device(cur);
-		}
+	if (cls) {
+		if (cls->devices)
+			dlist_destroy(cls->devices);
+		if (cls->attrlist)
+			dlist_destroy(cls->attrlist);
 		free(cls);
 	}
 }
 
+static int cdev_name_equal(void *a, void *b)
+{
+	if (!a || !b)
+		return 0;
+
+	if (strncmp((char *)a, ((struct sysfs_class_device *)b)->name, 
+				strlen((char *)a)) == 0)
+		return 1;
+
+	return 0;
+}
+
+static struct sysfs_class *alloc_class(void)
+{
+	return (struct sysfs_class *) calloc(1, sizeof(struct sysfs_class));
+}
+
 /**
  * alloc_class_device: mallocs and initializes new class device struct.
  * returns sysfs_class_device or NULL.
  */
 static struct sysfs_class_device *alloc_class_device(void)
 {
-	return (struct sysfs_class_device *)
-				calloc(1, sizeof(struct sysfs_class_device));
+	struct sysfs_class_device *dev;
+
+	dev = calloc(1, sizeof(struct sysfs_class_device));
+	return dev;
 }
 
 /**
- * alloc_class: mallocs new class structure
- * returns sysfs_class struct or NULL
+ * set_classdev_classname: Grabs classname from path
+ * @cdev: class device to set
+ * Returns nothing
  */
-static struct sysfs_class *alloc_class(void)
+static void set_classdev_classname(struct sysfs_class_device *cdev)
 {
-	return (struct sysfs_class *)calloc(1, sizeof(struct sysfs_class));
+	char *c, *e;
+	int count = 0;
+
+	c = strstr(cdev->path, SYSFS_CLASS_NAME);
+	if (c == NULL) {
+		c = strstr(cdev->path, SYSFS_BLOCK_NAME);
+	} else {
+		c = strstr(c, "/");
+	}
+
+	if (c == NULL)
+		safestrcpy(cdev->classname, SYSFS_UNKNOWN);
+	else {
+		if (*c == '/')
+			c++;
+		e = c;
+		while (e != NULL && *e != '/' && *e != '\0') {
+			e++;
+			count++;
+		}
+		strncpy(cdev->classname, c, count);
+	}
 }
 
 /**
- * open_class_dir: opens up sysfs class directory
- * returns sysfs_directory struct with success and NULL with error
+ * sysfs_open_class_device_path: Opens and populates class device
+ * @path: path to class device.
+ * returns struct sysfs_class_device with success and NULL with error.
  */
-static struct sysfs_directory *open_class_dir(const char *name)
+struct sysfs_class_device *sysfs_open_class_device_path(const char *path)
 {
-	struct sysfs_directory *classdir = NULL;
-	char classpath[SYSFS_PATH_MAX];
+	struct sysfs_class_device *cdev;
 
-	if (name == NULL) {
+	if (!path) {
 		errno = EINVAL;
 		return NULL;
 	}
-
-	memset(classpath, 0, SYSFS_PATH_MAX);
-	if ((sysfs_get_mnt_path(classpath, SYSFS_PATH_MAX)) != 0) {
-		dprintf(stderr, "Sysfs not supported on this system\n");
+	if (sysfs_path_is_dir(path)) {
+		dprintf("%s is not a valid path to a class device\n", path);
 		return NULL;
 	}
-
-	strcat(classpath, SYSFS_CLASS_DIR);
-	strcat(classpath, "/");
-	strcat(classpath, name);
-	classdir = sysfs_open_directory(classpath);
-	if (classdir == NULL) {
+	cdev = alloc_class_device();
+	if (!cdev) {
+		dprintf("calloc failed\n");
+		return NULL;
+	}
+	if (sysfs_get_name_from_path(path, cdev->name, SYSFS_NAME_LEN)) {
 		errno = EINVAL;
-		dprintf(stderr,"Class %s not supported on this system\n",
-			name);
+		dprintf("Error getting class device name\n");
+		sysfs_close_class_device(cdev);
 		return NULL;
 	}
-	if ((sysfs_read_directory(classdir)) != 0) {
-		dprintf(stderr, "Error reading %s class dir %s\n", name, 
-			classpath);
-		sysfs_close_directory(classdir);
+
+	safestrcpy(cdev->path, path);
+	if (sysfs_remove_trailing_slash(cdev->path)) {
+		dprintf("Invalid path to class device %s\n", cdev->path);
+		sysfs_close_class_device(cdev);
 		return NULL;
 	}
+	set_classdev_classname(cdev);
 
-	return classdir;
+	return cdev;
 }
 
-/**
- * sysfs_open_class_device: Opens and populates class device
- * @path: path to class device.
- * returns struct sysfs_class_device with success and NULL with error.
+/** 
+ * get_blockdev_parent: Get the parent class device for a "block" subsystem 
+ * 		device if present
+ * @clsdev: block subsystem class device whose parent needs to be found
+ * Returns 0 on success and 1 on error
  */
-struct sysfs_class_device *sysfs_open_class_device(const char *path)
+static int get_blockdev_parent(struct sysfs_class_device *clsdev)
 {
-	struct sysfs_class_device *cdev = NULL;
-	struct sysfs_directory *dir = NULL, *cur = NULL;
-	struct sysfs_dlink *curl = NULL;
-	struct sysfs_device *sdev = NULL;
-	struct sysfs_driver *drv = NULL;
-	char temp[SYSFS_NAME_LEN];
+	char parent_path[SYSFS_PATH_MAX];
+	char *c;
+
+	safestrcpy(parent_path, clsdev->path);
+	c = strstr(parent_path, SYSFS_BLOCK_NAME);
+	if (c == NULL) {
+		dprintf("Class device %s does not belong to BLOCK subsystem\n",
+				clsdev->name);
+		return 1;
+	}
+	c += strlen(SYSFS_BLOCK_NAME);
+	if (*c == '/')
+		c++;
+	else
+		goto errout;
+
+	/* validate whether the given class device is a partition or not */
+	if ((strncmp(c, clsdev->name, strlen(clsdev->name))) == 0) {
+		dprintf("%s not a partition\n", clsdev->name);
+		return 1;
+	}
 
-	if (path == NULL) {
+	c = strchr(c, '/');
+	if (c == NULL)
+		goto errout;
+
+	*c = '\0';
+
+	clsdev->parent = sysfs_open_class_device_path(parent_path);
+	if (!clsdev->parent) {
+		dprintf("Error opening the parent class device at %s\n", 
+								parent_path);
+		return 1;
+	}
+	return 0;
+
+errout:
+	dprintf("Invalid path %s\n", clsdev->path);
+	return 1;
+}
+
+/**
+ * sysfs_get_classdev_parent: Retrieves the parent of a class device. 
+ * 	eg., when working with hda1, this function can be used to retrieve the
+ * 		sysfs_class_device for hda
+ * 		
+ * @clsdev: class device whose parent details are required.
+ * Returns sysfs_class_device of the parent on success, NULL on failure
+ */ 
+struct sysfs_class_device *sysfs_get_classdev_parent
+				(struct sysfs_class_device *clsdev)
+{
+	if (!clsdev) {
 		errno = EINVAL;
 		return NULL;
 	}
-	cdev = alloc_class_device();
-	if (cdev == NULL) {
-		perror("malloc");
-		return NULL;
+	if (clsdev->parent)
+		return (clsdev->parent);
+
+	/*
+	 * As of now, only block devices have a parent child heirarchy in sysfs
+	 * We do not know, if, in the future, more classes will have a similar
+	 * structure. Hence, we now call a specialized function for block and
+	 * later we can add support functions for other subsystems as required.
+	 */
+	if (!(strncmp(clsdev->classname, SYSFS_BLOCK_NAME, 
+					sizeof(SYSFS_BLOCK_NAME)))) {
+		if ((get_blockdev_parent(clsdev)) == 0) 
+			return (clsdev->parent);
 	}
-	memset(temp, 0, SYSFS_NAME_LEN);
-	if ((sysfs_get_name_from_path(path, temp, SYSFS_NAME_LEN)) != 0) {
+	return NULL;
+}
+
+/**
+ * get_classdev_path: given the class and a device in the class, return the
+ * 		absolute path to the device
+ * @classname: name of the class
+ * @clsdev: the class device
+ * @path: buffer to return path
+ * @psize: size of "path"
+ * Returns 0 on SUCCESS or -1 on error
+ */
+static int get_classdev_path(const char *classname, const char *clsdev, 
+		char *path, size_t len)
+{
+	if (!classname || !clsdev || !path) {
 		errno = EINVAL;
-		dprintf(stderr, "Invalid class device path %s\n", path);
-		sysfs_close_class_device(cdev);
-		return NULL;
+		return -1;
+	}
+	if (sysfs_get_mnt_path(path, len) != 0) {
+		dprintf("Error getting sysfs mount path\n");
+		return -1;
+	}
+	if (strncmp(classname, SYSFS_BLOCK_NAME,
+				sizeof(SYSFS_BLOCK_NAME)) == 0) {
+		safestrcatmax(path, "/", len);
+		safestrcatmax(path, SYSFS_BLOCK_NAME, len);
+	} else {
+		safestrcatmax(path, "/", len);
+		safestrcatmax(path, SYSFS_CLASS_NAME, len);
+		safestrcatmax(path, "/", len);
+		safestrcatmax(path, classname, len);
 	}
-	strcpy(cdev->name, temp);
+	safestrcatmax(path, "/", len);
+	safestrcatmax(path, clsdev, len);
+	return 0;
+}
 
-	dir = sysfs_open_directory(path);
-	if (dir == NULL) {
-		dprintf(stderr, "Error opening class device at %s\n", path);
-		sysfs_close_class_device(cdev);
+/**
+ * sysfs_open_class_device: Locates a specific class_device and returns it.
+ * Class_device must be closed using sysfs_close_class_device
+ * @classname: Class to search
+ * @name: name of the class_device
+ * 
+ * NOTE:
+ * 	Call sysfs_close_class_device() to close the class device
+ */
+struct sysfs_class_device *sysfs_open_class_device
+		(const char *classname, const char *name)
+{
+	char devpath[SYSFS_PATH_MAX];
+	struct sysfs_class_device *cdev;
+
+	if (!classname || !name) {
+		errno = EINVAL;
 		return NULL;
 	}
-	if ((sysfs_read_directory(dir)) != 0) {
-		dprintf(stderr, "Error reading class device at %s\n", path);
-		sysfs_close_directory(dir);
-		sysfs_close_class_device(cdev);
+	
+	memset(devpath, 0, SYSFS_PATH_MAX);
+	if ((get_classdev_path(classname, name, devpath, 
+					SYSFS_PATH_MAX)) != 0) {
+		dprintf("Error getting to device %s on class %s\n",
+							name, classname);
 		return NULL;
 	}
-	cdev->directory = dir;
-
-	cur = cdev->directory->subdirs;
-	while(cur != NULL) {
-		sysfs_read_directory(cur);
-		cur = cur->next;
-	}
-	/* get driver and device, if implemented */
-	curl = cdev->directory->links;
-	while (curl != NULL) {
-		if (strncmp(curl->name, SYSFS_DEVICES_NAME, 6) == 0) {
-			sdev = sysfs_open_device(curl->target->path);
-			if (sdev != NULL) {
-				cdev->sysdevice = sdev;
-				if (cdev->driver != NULL) 
-					sdev->driver = cdev->driver;
-			}
-		} else if (strncmp(curl->name, SYSFS_DRIVERS_NAME, 6) == 0) {
-			drv = sysfs_open_driver(curl->target->path);
-			if (drv != NULL) {
-				cdev->driver = drv;
-				if (cdev->sysdevice != NULL) 
-					drv->device = cdev->sysdevice;
-			}
-		}
-		curl = curl->next;
+
+	cdev = sysfs_open_class_device_path(devpath);
+	if (!cdev) {
+		dprintf("Error getting class device %s from class %s\n",
+				name, classname);
+		return NULL;
 	}
 	return cdev;
 }
 
 /**
- * add_dev_to_class: adds a class device to class list
- * @class: class to add the device
- * @dev: device to add
+ * sysfs_get_classdev_attr: searches class device's attributes by name
+ * @clsdev: class device to look through
+ * @name: attribute name to get
+ * returns sysfs_attribute reference with success or NULL with error
+ */
+struct sysfs_attribute *sysfs_get_classdev_attr
+		(struct sysfs_class_device *clsdev, const char *name)
+{
+	if (!clsdev || !name) {
+		errno = EINVAL;
+		return NULL;
+	}
+	return get_attribute(clsdev, (char *)name);
+}
+
+/**
+ * sysfs_get_classdev_attributes: gets list of classdev attributes
+ * @clsdev: class device whose attributes list is needed
+ * returns dlist of attributes on success or NULL on error
  */
-static void add_dev_to_class(struct sysfs_class *cls, 
-					struct sysfs_class_device *dev)
+struct dlist *sysfs_get_classdev_attributes(struct sysfs_class_device *clsdev)
 {
-	if (cls != NULL && dev != NULL) {
-		dev->next = cls->devices;
-		cls->devices = dev;
+	if (!clsdev) {
+		errno = EINVAL;
+		return NULL;
 	}
+	return get_attributes_list(clsdev);
 }
 
 /**
- * get_all_class_devices: gets all devices for class
- * @class: class to get devices for
- * returns 0 with success and -1 with failure
+ * sysfs_get_classdev_device: gets the sysfs_device associated with the
+ * 	given sysfs_class_device
+ * @clsdev: class device whose associated sysfs_device is needed
+ * returns struct sysfs_device * on success or NULL on error
  */
-static int get_all_class_devices(struct sysfs_class *cls)
+struct sysfs_device *sysfs_get_classdev_device
+		(struct sysfs_class_device *clsdev)
 {
-	struct sysfs_class_device *dev = NULL;
-	struct sysfs_directory *cur = NULL, *next = NULL;
+	char linkpath[SYSFS_PATH_MAX], devpath[SYSFS_PATH_MAX];
 
-	if (cls == NULL || cls->directory == NULL) {
+	if (!clsdev) {
 		errno = EINVAL;
-		return -1;
+		return NULL;
 	}
-	for (cur = cls->directory->subdirs; cur != NULL; cur = next) {
-		next = cur->next;
-		dev = sysfs_open_class_device(cur->path);
-		if (dev == NULL) {
-			dprintf(stderr, "Error opening device at %s\n",
-				cur->path);
-			continue;
-		}
-		add_dev_to_class(cls, dev);
+
+	if (clsdev->sysdevice)
+		return clsdev->sysdevice;
+
+	memset(linkpath, 0, SYSFS_PATH_MAX);
+	safestrcpy(linkpath, clsdev->path);
+	safestrcat(linkpath, "/device");
+	if (!sysfs_path_is_link(linkpath)) {
+		memset(devpath, 0, SYSFS_PATH_MAX);
+		if (!sysfs_get_link(linkpath, devpath, SYSFS_PATH_MAX))
+			clsdev->sysdevice = sysfs_open_device_path(devpath);
 	}
-			
-	return 0;
+	return clsdev->sysdevice;
 }
 
 /**
@@ -241,33 +380,142 @@ static int get_all_class_devices(struct sysfs_class *cls)
 struct sysfs_class *sysfs_open_class(const char *name)
 {
 	struct sysfs_class *cls = NULL;
-	struct sysfs_directory *classdir = NULL;
+	char classpath[SYSFS_PATH_MAX];
 
-	if (name == NULL) {
+	if (!name) {
 		errno = EINVAL;
 		return NULL;
 	}
 
+	memset(classpath, 0, SYSFS_PATH_MAX);
+        if ((sysfs_get_mnt_path(classpath, SYSFS_PATH_MAX)) != 0) {
+                dprintf("Sysfs not supported on this system\n");
+                return NULL;
+        }
+
+	/* 
+	 * We shall now treat "block" also as a class. Hence, check here
+	 * if "name" is "block" and proceed accordingly
+	 */
+	if (strcmp(name, SYSFS_BLOCK_NAME) == 0) {
+		safestrcat(classpath, "/");
+		safestrcat(classpath, SYSFS_BLOCK_NAME);
+	} else {
+		safestrcat(classpath, "/");
+		safestrcat(classpath, SYSFS_CLASS_NAME);
+		safestrcat(classpath, "/");
+		safestrcat(classpath, name);
+	}
+	if (sysfs_path_is_dir(classpath)) {
+		dprintf("Class %s not found on the system\n", name);
+		return NULL;
+	}
+
 	cls = alloc_class();
 	if (cls == NULL) {
-		perror("malloc");
+		dprintf("calloc failed\n");
 		return NULL;
 	}
-	strcpy(cls->name, name);	
-	classdir = open_class_dir(name);
-	if (classdir == NULL) {
-		dprintf(stderr,
-			"Invalid class, %s not supported on this system\n",
-			name);
+	safestrcpy(cls->name, name);	
+	safestrcpy(cls->path, classpath);
+	if ((sysfs_remove_trailing_slash(cls->path)) != 0) {
+		dprintf("Invalid path to class device %s\n", cls->path);
 		sysfs_close_class(cls);
 		return NULL;
 	}
-	cls->directory = classdir;
-	if ((get_all_class_devices(cls)) != 0) {
-		dprintf(stderr, "Error reading %s class devices\n", name);
-		sysfs_close_class(cls);
+
+	return cls;
+}
+
+/**
+ * sysfs_get_class_device: get specific class device using the device's id
+ * @cls: sysfs_class to find the device on
+ * @name: name of the class device to look for
+ * 
+ * Returns sysfs_class_device * on success and NULL on failure
+ */ 
+struct sysfs_class_device *sysfs_get_class_device(struct sysfs_class *cls,
+		const char *name)
+{
+	char path[SYSFS_PATH_MAX];
+	struct sysfs_class_device *cdev = NULL;
+
+	if (!cls || !name) {
+		errno = EINVAL;
 		return NULL;
 	}
 
-	return cls;
+	if (cls->devices) {
+		cdev = (struct sysfs_class_device *)dlist_find_custom
+			(cls->devices, (void *)name, cdev_name_equal);
+		if (cdev)
+			return cdev;
+	}
+
+	safestrcpy(path, cls->path);
+	safestrcat(path, "/");
+	safestrcat(path, name);
+	if (!sysfs_path_is_dir(path)) {
+		cdev = sysfs_open_class_device_path(path);
+		if (!cdev) {
+			dprintf("Error opening class device at %s\n", path);
+			return NULL;
+		}
+	}
+	if (!cls->devices)
+		cls->devices = dlist_new_with_delete
+			(sizeof(struct sysfs_class_device),
+				 sysfs_close_cls_dev);
+	
+	dlist_unshift_sorted(cls->devices, cdev, sort_list);
+	return cdev;
 }
+
+/**
+ * sysfs_get_class_devices: get all class devices in the given class
+ * @cls: sysfs_class whose devices list is needed
+ *
+ * Returns a dlist of sysfs_class_device * on success and NULL on failure
+ */
+struct dlist *sysfs_get_class_devices(struct sysfs_class *cls)
+{
+	char path[SYSFS_PATH_MAX];
+	char *cdev_name;
+	struct sysfs_class_device *cdev = NULL;
+	struct dlist *dirlist;
+
+	if (!cls) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	safestrcpy(path, cls->path);
+	dirlist = read_dir_subdirs(path);
+	if (dirlist) {
+		dlist_for_each_data(dirlist, cdev_name, char) {
+			if (cls->devices) {
+				cdev = (struct sysfs_class_device *)
+					dlist_find_custom(cls->devices, 
+					(void *)cdev_name, cdev_name_equal);
+				if (cdev)
+					continue;
+			}
+			safestrcpy(path, cls->path);
+			safestrcat(path, "/");
+			safestrcat(path, cdev_name);
+			cdev = sysfs_open_class_device_path(path);
+			if (cdev) {
+				if (!cls->devices)
+					cls->devices = dlist_new_with_delete
+					(sizeof(struct sysfs_class_device),
+					 sysfs_close_cls_dev);
+				dlist_unshift_sorted(cls->devices, cdev,
+						sort_list);
+			}
+		}
+		sysfs_close_list(dirlist);
+	}
+	
+	return cls->devices;
+}
+