[PATCH] Libsysfs updates

Please find attached a _BIG_ patch to update udev's libsysfs. Patch applies
on udev-021 and contains:

1. Updates to get udev's libsysfs to the latest (to be released) level.
2. Changes for C++ compatibility (use "char" and not "unsigned char"
	unless absolutely necessary).
3. More importantly, take care of buffer overflows. Libsysfs now uses a
        scaled down version of Kay's "safe" macros.

Tested using a usb-storage device.

I will send you a doc update shortly.

1 files changed, 121 insertions, 84 deletions

diff --git a/libsysfs/sysfs/libsysfs.h b/libsysfs/sysfs/libsysfs.h
index f3d2dd4d16..cbde2f5783 100644
--- a/libsysfs/sysfs/libsysfs.h
+++ b/libsysfs/sysfs/libsysfs.h
@@ -24,6 +24,25 @@
 #define _LIBSYSFS_H_
 
 #include <sys/types.h>
+#include <string.h>
+
+/* 
+ * Defines to prevent buffer overruns
+ */
+#define safestrcpy(to, from)	strncpy(to, from, sizeof(to)-1)
+#define safestrcat(to, from)	strncat(to, from, sizeof(to) - strlen(to)-1)
+
+#define safestrncpy(to, from, maxsize) \
+do { \
+	to[maxsize-1] = '\0'; \
+	strncpy(to, from, maxsize-1); \
+} while (0)
+
+#define safestrncat(to, from, maxsize) \
+do { \
+	to[maxsize-1] = '\0'; \
+	strncat(to, from, maxsize - strlen(to)-1); \
+} while (0)
 
 /*
  * Generic #defines go here..
@@ -46,25 +65,28 @@
 #define SYSFS_METHOD_SHOW	0x01	/* attr can be read by user */
 #define SYSFS_METHOD_STORE	0x02	/* attr can be changed by user */
 
-struct dlist;
+/*
+ * NOTE: We have the statically allocated "name" as the first element of all 
+ * the structures. This feature is used in the "sorter" function for dlists
+ */
 
 struct sysfs_attribute {
-	unsigned char *value;
+	char name[SYSFS_NAME_LEN];
+	char path[SYSFS_PATH_MAX];
+	char *value;
 	unsigned short len;		/* value length */
 	unsigned short method;		/* show and store */
-	unsigned char name[SYSFS_NAME_LEN];
-	unsigned char path[SYSFS_PATH_MAX];
 };
 
 struct sysfs_link {
-	unsigned char name[SYSFS_NAME_LEN];
-	unsigned char path[SYSFS_PATH_MAX];
-	unsigned char target[SYSFS_PATH_MAX];
+	char name[SYSFS_NAME_LEN];
+	char path[SYSFS_PATH_MAX];
+	char target[SYSFS_PATH_MAX];
 };
 
 struct sysfs_directory {
-	unsigned char name[SYSFS_NAME_LEN];
-	unsigned char path[SYSFS_PATH_MAX];
+	char name[SYSFS_NAME_LEN];
+	char path[SYSFS_PATH_MAX];
 
 	/* Private: for internal use only */
 	struct dlist *subdirs;	
@@ -73,8 +95,8 @@ struct sysfs_directory {
 };
 
 struct sysfs_driver {
-	unsigned char name[SYSFS_NAME_LEN];
-	unsigned char path[SYSFS_PATH_MAX];
+	char name[SYSFS_NAME_LEN];
+	char path[SYSFS_PATH_MAX];
 
 	/* Private: for internal use only */
 	struct dlist *devices;
@@ -82,11 +104,11 @@ struct sysfs_driver {
 };
 
 struct sysfs_device {
-	unsigned char name[SYSFS_NAME_LEN];
-	unsigned char bus_id[SYSFS_NAME_LEN];
-	unsigned char bus[SYSFS_NAME_LEN];
-	unsigned char driver_name[SYSFS_NAME_LEN];
-	unsigned char path[SYSFS_PATH_MAX];
+	char name[SYSFS_NAME_LEN];
+	char bus_id[SYSFS_NAME_LEN];
+	char bus[SYSFS_NAME_LEN];
+	char driver_name[SYSFS_NAME_LEN];
+	char path[SYSFS_PATH_MAX];
 
 	/* Private: for internal use only */
 	struct sysfs_device *parent;		
@@ -95,8 +117,8 @@ struct sysfs_device {
 };
 
 struct sysfs_root_device {
-	unsigned char name[SYSFS_NAME_LEN];
-	unsigned char path[SYSFS_PATH_MAX];
+	char name[SYSFS_NAME_LEN];
+	char path[SYSFS_PATH_MAX];
 
 	/* Private: for internal use only */
 	struct dlist *devices;
@@ -104,8 +126,8 @@ struct sysfs_root_device {
 };
 
 struct sysfs_bus {
-	unsigned char name[SYSFS_NAME_LEN];
-	unsigned char path[SYSFS_PATH_MAX];
+	char name[SYSFS_NAME_LEN];
+	char path[SYSFS_PATH_MAX];
 
 	/* Private: for internal use only */
 	struct dlist *drivers;
@@ -114,9 +136,9 @@ struct sysfs_bus {
 };
 
 struct sysfs_class_device {
-	unsigned char name[SYSFS_NAME_LEN];
-	unsigned char classname[SYSFS_NAME_LEN];
-	unsigned char path[SYSFS_PATH_MAX];
+	char name[SYSFS_NAME_LEN];
+	char classname[SYSFS_NAME_LEN];
+	char path[SYSFS_PATH_MAX];
 
 	/* Private: for internal use only */
 	struct sysfs_class_device *parent;	
@@ -126,8 +148,8 @@ struct sysfs_class_device {
 };
 
 struct sysfs_class {
-	unsigned char name[SYSFS_NAME_LEN];
-	unsigned char path[SYSFS_PATH_MAX];
+	char name[SYSFS_NAME_LEN];
+	char path[SYSFS_PATH_MAX];
 
 	/* Private: for internal use only */
 	struct dlist *devices;
@@ -141,49 +163,47 @@ extern "C" {
 /*
  * Function Prototypes
  */
-extern int sysfs_get_mnt_path(unsigned char *mnt_path, size_t len);
-extern int sysfs_remove_trailing_slash(unsigned char *path);
-extern int sysfs_get_name_from_path(const unsigned char *path, 
-					unsigned char *name, size_t len);
-extern int sysfs_path_is_dir(const unsigned char *path);
-extern int sysfs_path_is_link(const unsigned char *path);
-extern int sysfs_path_is_file(const unsigned char *path);
-extern int sysfs_get_link(const unsigned char *path, unsigned char *target, 
-								size_t len);
-extern struct dlist *sysfs_open_subsystem_list(unsigned char *name);
-extern struct dlist *sysfs_open_bus_devices_list(unsigned char *name);
+extern int sysfs_get_mnt_path(char *mnt_path, size_t len);
+extern int sysfs_remove_trailing_slash(char *path);
+extern int sysfs_get_name_from_path(const char *path, char *name, size_t len);
+extern int sysfs_path_is_dir(const char *path);
+extern int sysfs_path_is_link(const char *path);
+extern int sysfs_path_is_file(const char *path);
+extern int sysfs_get_link(const char *path, char *target, size_t len);
+extern struct dlist *sysfs_open_subsystem_list(char *name);
+extern struct dlist *sysfs_open_bus_devices_list(char *name);
 extern void sysfs_close_list(struct dlist *list);
 
 /* sysfs directory and file access */
 extern void sysfs_close_attribute(struct sysfs_attribute *sysattr);
-extern struct sysfs_attribute *sysfs_open_attribute(const unsigned char *path);
+extern struct sysfs_attribute *sysfs_open_attribute(const char *path);
 extern int sysfs_read_attribute(struct sysfs_attribute *sysattr);
-extern int sysfs_read_attribute_value(const unsigned char *attrpath, 
-				unsigned char *value, size_t vsize);
+extern int sysfs_read_attribute_value(const char *attrpath, 
+		char *value, size_t vsize);
 extern int sysfs_write_attribute(struct sysfs_attribute *sysattr,
-		const unsigned char *new_value, size_t len);
-extern unsigned char *sysfs_get_value_from_attributes(struct dlist *attr, 
-						const unsigned char * name);
+		const char *new_value, size_t len);
+extern char *sysfs_get_value_from_attributes(struct dlist *attr, 
+		const char *name);
 extern int sysfs_refresh_dir_attributes(struct sysfs_directory *sysdir);
 extern int sysfs_refresh_dir_links(struct sysfs_directory *sysdir);
 extern int sysfs_refresh_dir_subdirs(struct sysfs_directory *sysdir);
 extern void sysfs_close_directory(struct sysfs_directory *sysdir);
-extern struct sysfs_directory *sysfs_open_directory(const unsigned char *path);
+extern struct sysfs_directory *sysfs_open_directory(const char *path);
 extern int sysfs_read_dir_attributes(struct sysfs_directory *sysdir);
 extern int sysfs_read_dir_links(struct sysfs_directory *sysdir);
 extern int sysfs_read_dir_subdirs(struct sysfs_directory *sysdir);
 extern int sysfs_read_directory(struct sysfs_directory *sysdir);
 extern int sysfs_read_all_subdirs(struct sysfs_directory *sysdir);
 extern struct sysfs_directory *sysfs_get_subdirectory
-			(struct sysfs_directory *dir, unsigned char *subname);
+	(struct sysfs_directory *dir, char *subname);
 extern void sysfs_close_link(struct sysfs_link *ln);
-extern struct sysfs_link *sysfs_open_link(const unsigned char *lnpath);
-extern struct sysfs_link *sysfs_get_directory_link(struct sysfs_directory *dir,
-						unsigned char *linkname);
+extern struct sysfs_link *sysfs_open_link(const char *lnpath);
+extern struct sysfs_link *sysfs_get_directory_link
+	(struct sysfs_directory *dir, char *linkname);
 extern struct sysfs_link *sysfs_get_subdirectory_link
-			(struct sysfs_directory *dir, unsigned char *linkname);
+	(struct sysfs_directory *dir, char *linkname);
 extern struct sysfs_attribute *sysfs_get_directory_attribute
-			(struct sysfs_directory *dir, unsigned char *attrname);
+	(struct sysfs_directory *dir, char *attrname);
 extern struct dlist *sysfs_get_dir_attributes(struct sysfs_directory *dir);
 extern struct dlist *sysfs_get_dir_links(struct sysfs_directory *dir);
 extern struct dlist *sysfs_get_dir_subdirs(struct sysfs_directory *dir);
@@ -191,84 +211,101 @@ extern struct dlist *sysfs_get_dir_subdirs(struct sysfs_directory *dir);
 /* sysfs driver access */
 extern void sysfs_close_driver(struct sysfs_driver *driver);
 extern struct sysfs_driver *sysfs_open_driver
-	(const unsigned char *drv_name, const unsigned char *bus_name);
-extern struct sysfs_driver *sysfs_open_driver_path(const unsigned char *path);
+	(const char *bus_name, const char *drv_name);
+extern struct sysfs_driver *sysfs_open_driver_path(const char *path);
 extern struct sysfs_attribute *sysfs_get_driver_attr
-		(struct sysfs_driver *drv, const unsigned char *name);
+	(struct sysfs_driver *drv, const char *name);
 extern struct dlist *sysfs_get_driver_attributes(struct sysfs_driver *driver);
 extern struct dlist *sysfs_get_driver_devices(struct sysfs_driver *driver);
 extern struct dlist *sysfs_refresh_driver_devices(struct sysfs_driver *driver);
 extern struct dlist *sysfs_get_driver_links(struct sysfs_driver *driver);
 extern struct sysfs_device *sysfs_get_driver_device
-	(struct sysfs_driver *driver, const unsigned char *name);
+	(struct sysfs_driver *driver, const char *name);
 extern struct dlist *sysfs_refresh_driver_attributes
-			(struct sysfs_driver *driver);
-extern struct sysfs_attribute *sysfs_open_driver_attr(const unsigned char *bus, 
-		const unsigned char *drv, const unsigned char *attrib);
+	(struct sysfs_driver *driver);
+extern struct sysfs_attribute *sysfs_open_driver_attr
+	(const char *bus, const char *drv, const char *attrib);
 
 /* generic sysfs device access */
 extern void sysfs_close_root_device(struct sysfs_root_device *root);
-extern struct sysfs_root_device *sysfs_open_root_device
-						(const unsigned char *name);
+extern struct sysfs_root_device *sysfs_open_root_device(const char *name);
 extern struct dlist *sysfs_get_root_devices(struct sysfs_root_device *root);
+extern void sysfs_close_device_tree(struct sysfs_device *device);
+extern struct sysfs_device *sysfs_open_device_tree(const char *path);
 extern void sysfs_close_device(struct sysfs_device *dev);
 extern struct sysfs_device *sysfs_open_device
-		(const unsigned char *bus_id, const unsigned char *bus);
+	(const char *bus, const char *bus_id);
 extern struct sysfs_device *sysfs_get_device_parent(struct sysfs_device *dev);
-extern struct sysfs_device *sysfs_open_device_path(const unsigned char *path);
+extern struct sysfs_device *sysfs_open_device_path(const char *path);
 extern int sysfs_get_device_bus(struct sysfs_device *dev);
 extern struct sysfs_attribute *sysfs_get_device_attr
-			(struct sysfs_device *dev, const unsigned char *name);
+	(struct sysfs_device *dev, const char *name);
 extern struct dlist *sysfs_get_device_attributes(struct sysfs_device *device);
 extern struct dlist *sysfs_refresh_device_attributes
-			(struct sysfs_device *device);
-extern struct sysfs_attribute *sysfs_open_device_attr(const unsigned char *bus, 
-		const unsigned char *bus_id, const unsigned char *attrib);
+	(struct sysfs_device *device);
+extern struct sysfs_attribute *sysfs_open_device_attr(const char *bus, 
+		const char *bus_id, const char *attrib);
 
 /* generic sysfs bus access */
 extern void sysfs_close_bus(struct sysfs_bus *bus);
-extern struct sysfs_bus *sysfs_open_bus(const unsigned char *name);
-extern struct sysfs_device *sysfs_get_bus_device(struct sysfs_bus *bus,
-						unsigned char *id);
+extern struct sysfs_bus *sysfs_open_bus(const char *name);
+extern struct sysfs_device *sysfs_get_bus_device(struct sysfs_bus *bus, 
+		char *id);
 extern struct sysfs_driver *sysfs_get_bus_driver(struct sysfs_bus *bus,
-						unsigned char *drvname);
+		char *drvname);
 extern struct dlist *sysfs_get_bus_drivers(struct sysfs_bus *bus);
 extern struct dlist *sysfs_get_bus_devices(struct sysfs_bus *bus);
 extern struct dlist *sysfs_get_bus_attributes(struct sysfs_bus *bus);
 extern struct dlist *sysfs_refresh_bus_attributes(struct sysfs_bus *bus);
-extern struct sysfs_attribute *sysfs_get_bus_attribute(struct sysfs_bus *bus,
-						unsigned char *attrname);
-extern struct sysfs_device *sysfs_open_bus_device(unsigned char *busname, 
-							unsigned char *dev_id);
-extern int sysfs_find_driver_bus(const unsigned char *driver, 
-					unsigned char *busname,	size_t bsize);
+extern struct sysfs_attribute *sysfs_get_bus_attribute
+	(struct sysfs_bus *bus,	char *attrname);
+extern int sysfs_find_driver_bus(const char *driver, char *busname, 
+		size_t bsize);
 
 /* generic sysfs class access */
 extern void sysfs_close_class_device(struct sysfs_class_device *dev);
 extern struct sysfs_class_device *sysfs_open_class_device_path
-					(const unsigned char *path);
+	(const char *path);
 extern struct sysfs_class_device *sysfs_open_class_device
-	(const unsigned char *class, const unsigned char *name);
+	(const char *classname, const char *name);
 extern struct sysfs_device *sysfs_get_classdev_device
-				(struct sysfs_class_device *clsdev);
+	(struct sysfs_class_device *clsdev);
 extern struct sysfs_driver *sysfs_get_classdev_driver
-				(struct sysfs_class_device *clsdev);
+	(struct sysfs_class_device *clsdev);
 extern struct sysfs_class_device *sysfs_get_classdev_parent
-				(struct sysfs_class_device *clsdev);
+	(struct sysfs_class_device *clsdev);
 extern void sysfs_close_class(struct sysfs_class *cls);
-extern struct sysfs_class *sysfs_open_class(const unsigned char *name);
+extern struct sysfs_class *sysfs_open_class(const char *name);
 extern struct dlist *sysfs_get_class_devices(struct sysfs_class *cls);
 extern struct sysfs_class_device *sysfs_get_class_device
-	(struct sysfs_class *class, unsigned char *name);
+	(struct sysfs_class *cls, char *name);
 extern struct dlist *sysfs_get_classdev_attributes
 	(struct sysfs_class_device *cdev);
 extern struct dlist *sysfs_refresh_classdev_attributes
 	(struct sysfs_class_device *cdev);
 extern struct sysfs_attribute *sysfs_get_classdev_attr
-	(struct sysfs_class_device *clsdev, const unsigned char *name);
+	(struct sysfs_class_device *clsdev, const char *name);
 extern struct sysfs_attribute *sysfs_open_classdev_attr
-	(const unsigned char *classname, const unsigned char *dev, 
-	 					const unsigned char *attrib); 
+	(const char *classname, const char *dev, 
+	 					const char *attrib); 
+
+/**
+ * sort_list: sorter function to keep list elements sorted in alphabetical 
+ * 	order. Just does a strncmp as you can see :)
+ * 	
+ * Returns 1 if less than 0 otherwise
+ *
+ * NOTE: We take care to have a statically allocated "name" as the first 
+ * 	lement of all libsysfs structures. Hence, this function will work 
+ * 	AS IS for _ALL_ the lists that have to be sorted.
+ */
+static inline int sort_list(void *new_elem, void *old_elem)
+{
+        return ((strncmp(((struct sysfs_attribute *)new_elem)->name,
+		((struct sysfs_attribute *)old_elem)->name,
+		strlen(((struct sysfs_attribute *)new_elem)->name))) < 0 ? 1 : 0);
+}
+
 
 #ifdef __cplusplus
 }