[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, 87 insertions, 70 deletions

diff --git a/libsysfs/sysfs_dir.c b/libsysfs/sysfs_dir.c
index 050e674038..be54a1cf86 100644
--- a/libsysfs/sysfs_dir.c
+++ b/libsysfs/sysfs_dir.c
@@ -58,9 +58,9 @@ static int dir_attribute_name_equal(void *a, void *b)
 	if (a == NULL || b == NULL)
 		return 0;
 
-	if (strcmp(((unsigned char *)a), ((struct sysfs_attribute *)b)->name) 
-	    == 0)
+	if (strcmp(((char *)a), ((struct sysfs_attribute *)b)->name) == 0)
 		return 1;
+
 	return 0;
 }
 
@@ -75,9 +75,9 @@ static int dir_link_name_equal(void *a, void *b)
 	if (a == NULL || b == NULL)
 		return 0;
 
-	if (strcmp(((unsigned char *)a), ((struct sysfs_link *)b)->name) 
-	    == 0)
+	if (strcmp(((char *)a), ((struct sysfs_link *)b)->name) == 0)
 		return 1;
+
 	return 0;
 }
 
@@ -92,9 +92,9 @@ static int dir_subdir_name_equal(void *a, void *b)
 	if (a == NULL || b == NULL)
 		return 0;
 
-	if (strcmp(((unsigned char *)a), ((struct sysfs_directory *)b)->name)
-	    == 0)
+	if (strcmp(((char *)a), ((struct sysfs_directory *)b)->name) == 0)
 		return 1;
+
 	return 0;
 }
 
@@ -126,7 +126,7 @@ static struct sysfs_attribute *alloc_attribute(void)
  * @path: path to attribute.
  * returns sysfs_attribute struct with success and NULL with error.
  */
-struct sysfs_attribute *sysfs_open_attribute(const unsigned char *path)
+struct sysfs_attribute *sysfs_open_attribute(const char *path)
 {
 	struct sysfs_attribute *sysattr = NULL;
 	struct stat fileinfo;
@@ -140,14 +140,13 @@ struct sysfs_attribute *sysfs_open_attribute(const unsigned char *path)
 		dprintf("Error allocating attribute at %s\n", path);
 		return NULL;
 	}
-	if (sysfs_get_name_from_path(path, sysattr->name, SYSFS_NAME_LEN) 
-	    != 0) {
-		dprintf("Error retrieving attribute name from path: %s\n", 
-			path);
+	if (sysfs_get_name_from_path(path, sysattr->name, 
+				SYSFS_NAME_LEN) != 0) {
+		dprintf("Error retrieving attrib name from path: %s\n", path);
 		sysfs_close_attribute(sysattr);
 		return NULL;
 	}
-	strncpy(sysattr->path, path, SYSFS_PATH_MAX);
+	safestrcpy(sysattr->path, path);
 	if ((stat(sysattr->path, &fileinfo)) != 0) {
 		dprintf("Stat failed: No such attribute?\n");
 		sysattr->method = 0;
@@ -171,7 +170,7 @@ struct sysfs_attribute *sysfs_open_attribute(const unsigned char *path)
  * returns 0 with success and -1 with error.
  */
 int sysfs_write_attribute(struct sysfs_attribute *sysattr,
-		const unsigned char *new_value, size_t len)
+		const char *new_value, size_t len)
 {
 	int fd;
 	int length;
@@ -184,6 +183,7 @@ int sysfs_write_attribute(struct sysfs_attribute *sysattr,
 	if (!(sysattr->method & SYSFS_METHOD_STORE)) {
 		dprintf ("Store method not supported for attribute %s\n",
 			sysattr->path);
+		errno = EACCES;
 		return -1;
 	}
 	if (sysattr->method & SYSFS_METHOD_SHOW) {
@@ -215,7 +215,7 @@ int sysfs_write_attribute(struct sysfs_attribute *sysattr,
 			sysattr->name);
 		close(fd);
 		return -1;
-	} else if (length != len) {
+	} else if ((unsigned int)length != len) {
 		dprintf("Could not write %d bytes to attribute %s\n", 
 					len, sysattr->name);
 		/* 
@@ -236,13 +236,13 @@ int sysfs_write_attribute(struct sysfs_attribute *sysattr,
 	 */ 
 	if (sysattr->method & SYSFS_METHOD_SHOW) {
 		if (length != sysattr->len) {
-			sysattr->value = (char *)realloc(sysattr->value, 
-								length);
+			sysattr->value = (char *)realloc
+				(sysattr->value, length);
 			sysattr->len = length;
-			strncpy(sysattr->value, new_value, length);
+			safestrncpy(sysattr->value, new_value, length);
 		} else {
 			/*"length" of the new value is same as old one */ 
-			strncpy(sysattr->value, new_value, length);
+			safestrncpy(sysattr->value, new_value, length);
 		}
 	}
 			
@@ -250,7 +250,6 @@ int sysfs_write_attribute(struct sysfs_attribute *sysattr,
 	return 0;
 }
 
-
 /**
  * sysfs_read_attribute: reads value from attribute
  * @sysattr: attribute to read
@@ -258,8 +257,8 @@ int sysfs_write_attribute(struct sysfs_attribute *sysattr,
  */
 int sysfs_read_attribute(struct sysfs_attribute *sysattr)
 {
-	unsigned char *fbuf = NULL;
-	unsigned char *vbuf = NULL;
+	char *fbuf = NULL;
+	char *vbuf = NULL;
 	ssize_t length = 0;
 	long pgsize = 0;
 	int fd;
@@ -271,11 +270,11 @@ int sysfs_read_attribute(struct sysfs_attribute *sysattr)
 	if (!(sysattr->method & SYSFS_METHOD_SHOW)) {
 		dprintf("Show method not supported for attribute %s\n",
 			sysattr->path);
+		errno = EACCES;
 		return -1;
 	}
-
 	pgsize = getpagesize();
-	fbuf = (unsigned char *)calloc(1, pgsize+1);
+	fbuf = (char *)calloc(1, pgsize+1);
 	if (fbuf == NULL) {
 		dprintf("calloc failed\n");
 		return -1;
@@ -296,13 +295,14 @@ int sysfs_read_attribute(struct sysfs_attribute *sysattr)
 		if ((sysattr->len == length) && 
 				(!(strncmp(sysattr->value, fbuf, length)))) {
 			close(fd);
+			free(fbuf);
 			return 0;
 		}
 		free(sysattr->value);
 	}
 	sysattr->len = length;
 	close(fd);
-	vbuf = (unsigned char *)realloc(fbuf, length+1);
+	vbuf = (char *)realloc(fbuf, length+1);
 	if (vbuf == NULL) {
 		dprintf("realloc failed\n");
 		free(fbuf);
@@ -322,13 +322,13 @@ int sysfs_read_attribute(struct sysfs_attribute *sysattr)
  * @vsize: size of value buffer
  * returns 0 with success and -1 with error.
  */
-int sysfs_read_attribute_value(const unsigned char *attrpath, 
-					unsigned char *value, size_t vsize)
+int sysfs_read_attribute_value(const char *attrpath, 
+					char *value, size_t vsize)
 {
 	struct sysfs_attribute *attr = NULL;
 	size_t length = 0;
 
-	if (attrpath == NULL || value == NULL) {
+	if (attrpath == NULL || value == NULL || vsize == 0) {
 		errno = EINVAL;
 		return -1;
 	}
@@ -348,7 +348,7 @@ int sysfs_read_attribute_value(const unsigned char *attrpath,
 	if (length > vsize) 
 		dprintf("Value length %d is larger than supplied buffer %d\n",
 			length, vsize);
-	strncpy(value, attr->value, vsize);
+	safestrncpy(value, attr->value, vsize);
 	sysfs_close_attribute(attr);
 
 	return 0;
@@ -359,10 +359,9 @@ int sysfs_read_attribute_value(const unsigned char *attrpath,
  * 	attribute name, return its value
  * @attr: attribute to search
  * @name: name to look for
- * returns unsigned char * value - could be NULL
+ * returns char * value - could be NULL
  */
-unsigned char *sysfs_get_value_from_attributes(struct dlist *attr, 
-					const unsigned char *name)
+char *sysfs_get_value_from_attributes(struct dlist *attr, const char *name)
 {	
 	struct sysfs_attribute *cur = NULL;
 	
@@ -432,6 +431,7 @@ static struct sysfs_link *alloc_link(void)
 int sysfs_read_all_subdirs(struct sysfs_directory *sysdir)
 {
 	struct sysfs_directory *cursub = NULL;
+	int retval = 0;
 
 	if (sysdir == NULL) {
 		errno = EINVAL;
@@ -443,12 +443,16 @@ int sysfs_read_all_subdirs(struct sysfs_directory *sysdir)
 	if (sysdir->subdirs != NULL) {
 		dlist_for_each_data(sysdir->subdirs, cursub, 
 						struct sysfs_directory) {
-			if ((sysfs_read_dir_subdirs(cursub)) != 0) 
+			if ((sysfs_read_dir_subdirs(cursub)) != 0) {
 				dprintf ("Error reading subdirectory %s\n",
 						cursub->name);
+				retval = -1;
+			}
 		}
 	}
-	return 0;
+	if (!retval)
+		errno = 0;
+	return retval;
 }
 
 /**
@@ -457,7 +461,7 @@ int sysfs_read_all_subdirs(struct sysfs_directory *sysdir)
  * @path: path of directory to open.
  * returns: struct sysfs_directory * with success and NULL on error.
  */
-struct sysfs_directory *sysfs_open_directory(const unsigned char *path)
+struct sysfs_directory *sysfs_open_directory(const char *path)
 {
 	struct sysfs_directory *sdir = NULL;
 
@@ -467,7 +471,7 @@ struct sysfs_directory *sysfs_open_directory(const unsigned char *path)
 	}
 
 	if (sysfs_path_is_dir(path) != 0) {
-		dprintf("Invalid path directory %s\n", path);
+		dprintf("Invalid path to directory %s\n", path);
 		errno = EINVAL;
 		return NULL;
 	}
@@ -482,7 +486,7 @@ struct sysfs_directory *sysfs_open_directory(const unsigned char *path)
 		sysfs_close_directory(sdir);
 		return NULL;
 	}
-	strncpy(sdir->path, path, SYSFS_PATH_MAX);
+	safestrcpy(sdir->path, path);
 
 	return sdir;
 }
@@ -492,7 +496,7 @@ struct sysfs_directory *sysfs_open_directory(const unsigned char *path)
  * @path: path of link to open.
  * returns: struct sysfs_link * with success and NULL on error.
  */
-struct sysfs_link *sysfs_open_link(const unsigned char *linkpath)
+struct sysfs_link *sysfs_open_link(const char *linkpath)
 {
 	struct sysfs_link *ln = NULL;
 
@@ -506,7 +510,7 @@ struct sysfs_link *sysfs_open_link(const unsigned char *linkpath)
 		dprintf("Error allocating link %s\n", linkpath);
 		return NULL;
 	}
-	strcpy(ln->path, linkpath);
+	safestrcpy(ln->path, linkpath);
 	if ((sysfs_get_name_from_path(linkpath, ln->name, SYSFS_NAME_LEN)) != 0
 	    || (sysfs_get_link(linkpath, ln->target, SYSFS_PATH_MAX)) != 0) {
 		errno = EINVAL;
@@ -523,8 +527,7 @@ struct sysfs_link *sysfs_open_link(const unsigned char *linkpath)
  * @path: path to attribute
  * returns 0 with success and -1 with error.
  */
-static int add_attribute(struct sysfs_directory *sysdir, 
-					const unsigned char *path)
+static int add_attribute(struct sysfs_directory *sysdir, const char *path)
 {
 	struct sysfs_attribute *attr = NULL;
 
@@ -545,7 +548,7 @@ static int add_attribute(struct sysfs_directory *sysdir,
 		sysdir->attributes = dlist_new_with_delete
 			(sizeof(struct sysfs_attribute), sysfs_del_attribute);
 	}
-	dlist_unshift(sysdir->attributes, attr);
+	dlist_unshift_sorted(sysdir->attributes, attr, sort_list);
 
 	return 0;
 }
@@ -556,8 +559,7 @@ static int add_attribute(struct sysfs_directory *sysdir,
  * @path: path to subdirectory
  * returns 0 with success and -1 with error.
  */
-static int add_subdirectory(struct sysfs_directory *sysdir, 
-					const unsigned char *path)
+static int add_subdirectory(struct sysfs_directory *sysdir, const char *path)
 {
 	struct sysfs_directory *subdir = NULL;
 
@@ -569,7 +571,7 @@ static int add_subdirectory(struct sysfs_directory *sysdir,
 	if (sysdir->subdirs == NULL)
 		sysdir->subdirs = dlist_new_with_delete
 			(sizeof(struct sysfs_directory), sysfs_del_directory);
-	dlist_unshift(sysdir->subdirs, subdir);
+	dlist_unshift_sorted(sysdir->subdirs, subdir, sort_list);
 	return 0;
 }
 
@@ -579,7 +581,7 @@ static int add_subdirectory(struct sysfs_directory *sysdir,
  * @path: path to link
  * returns 0 with success and -1 with error.
  */
-static int add_link(struct sysfs_directory *sysdir, const unsigned char *path)
+static int add_link(struct sysfs_directory *sysdir, const char *path)
 {
 	struct sysfs_link *ln = NULL;
 
@@ -591,7 +593,7 @@ static int add_link(struct sysfs_directory *sysdir, const unsigned char *path)
 	if (sysdir->links == NULL)
 		sysdir->links = dlist_new_with_delete
 				(sizeof(struct sysfs_link), sysfs_del_link);
-	dlist_unshift(sysdir->links, ln);
+	dlist_unshift_sorted(sysdir->links, ln, sort_list);
 	return 0;
 }
 
@@ -604,7 +606,7 @@ int sysfs_read_dir_attributes(struct sysfs_directory *sysdir)
 {
 	DIR *dir = NULL;
 	struct dirent *dirent = NULL;
-	unsigned char file_path[SYSFS_PATH_MAX];
+	char file_path[SYSFS_PATH_MAX];
 	int retval = 0;
 
 	if (sysdir == NULL) {
@@ -622,13 +624,15 @@ int sysfs_read_dir_attributes(struct sysfs_directory *sysdir)
 		if (0 == strcmp(dirent->d_name, ".."))
 			continue;
 		memset(file_path, 0, SYSFS_PATH_MAX);
-		strncpy(file_path, sysdir->path, SYSFS_PATH_MAX);
-		strcat(file_path, "/");
-		strcat(file_path, dirent->d_name);
+		safestrcpy(file_path, sysdir->path);
+		safestrcat(file_path, "/");
+		safestrcat(file_path, dirent->d_name);
 		if ((sysfs_path_is_file(file_path)) == 0)
 			retval = add_attribute(sysdir, file_path);
 	}
 	closedir(dir);
+	if (!retval)
+		errno = 0;
 	return(retval);
 }
 
@@ -641,7 +645,7 @@ int sysfs_read_dir_links(struct sysfs_directory *sysdir)
 {
 	DIR *dir = NULL;
 	struct dirent *dirent = NULL;
-	unsigned char file_path[SYSFS_PATH_MAX];
+	char file_path[SYSFS_PATH_MAX];
 	int retval = 0;
 
 	if (sysdir == NULL) {
@@ -659,9 +663,9 @@ int sysfs_read_dir_links(struct sysfs_directory *sysdir)
 		if (0 == strcmp(dirent->d_name, ".."))
 			continue;
 		memset(file_path, 0, SYSFS_PATH_MAX);
-		strncpy(file_path, sysdir->path, SYSFS_PATH_MAX);
-		strcat(file_path, "/");
-		strcat(file_path, dirent->d_name);
+		safestrcpy(file_path, sysdir->path);
+		safestrcat(file_path, "/");
+		safestrcat(file_path, dirent->d_name);
 		if ((sysfs_path_is_link(file_path)) == 0) {
 			retval = add_link(sysdir, file_path);
 			if (retval != 0)
@@ -669,6 +673,8 @@ int sysfs_read_dir_links(struct sysfs_directory *sysdir)
 		}
 	}
 	closedir(dir);
+	if (!retval)
+		errno = 0;
 	return(retval);
 }
 
@@ -681,7 +687,7 @@ int sysfs_read_dir_subdirs(struct sysfs_directory *sysdir)
 {
 	DIR *dir = NULL;
 	struct dirent *dirent = NULL;
-	unsigned char file_path[SYSFS_PATH_MAX];
+	char file_path[SYSFS_PATH_MAX];
 	int retval = 0;
 
 	if (sysdir == NULL) {
@@ -699,13 +705,15 @@ int sysfs_read_dir_subdirs(struct sysfs_directory *sysdir)
 		if (0 == strcmp(dirent->d_name, ".."))
 			continue;
 		memset(file_path, 0, SYSFS_PATH_MAX);
-		strncpy(file_path, sysdir->path, SYSFS_PATH_MAX);
-		strcat(file_path, "/");
-		strcat(file_path, dirent->d_name);
+		safestrcpy(file_path, sysdir->path);
+		safestrcat(file_path, "/");
+		safestrcat(file_path, dirent->d_name);
 		if ((sysfs_path_is_dir(file_path)) == 0)
 			retval = add_subdirectory(sysdir, file_path);
 	}
 	closedir(dir);
+	if (!retval)
+		errno = 0;
 	return(retval);
 }
 
@@ -719,7 +727,7 @@ int sysfs_read_directory(struct sysfs_directory *sysdir)
 	DIR *dir = NULL;
 	struct dirent *dirent = NULL;
 	struct stat astats;
-	unsigned char file_path[SYSFS_PATH_MAX];
+	char file_path[SYSFS_PATH_MAX];
 	int retval = 0;
 
 	if (sysdir == NULL) {
@@ -737,9 +745,9 @@ int sysfs_read_directory(struct sysfs_directory *sysdir)
 		if (0 == strcmp(dirent->d_name, ".."))
 			continue;
 		memset(file_path, 0, SYSFS_PATH_MAX);
-		strncpy(file_path, sysdir->path, SYSFS_PATH_MAX);
-		strcat(file_path, "/");
-		strcat(file_path, dirent->d_name);
+		safestrcpy(file_path, sysdir->path);
+		safestrcat(file_path, "/");
+		safestrcat(file_path, dirent->d_name);
 		if ((lstat(file_path, &astats)) != 0) {
 			dprintf("stat failed\n");
 			continue;
@@ -754,6 +762,8 @@ int sysfs_read_directory(struct sysfs_directory *sysdir)
 			retval = add_attribute(sysdir, file_path);
 	}
 	closedir(dir);
+	if (!retval)
+		errno = 0;
 	return(retval);
 }
 
@@ -782,6 +792,7 @@ int sysfs_refresh_dir_attributes(struct sysfs_directory *sysdir)
 							sysdir->path);
 		return 1;
 	}
+	errno = 0;
 	return 0;
 }
 
@@ -810,6 +821,7 @@ int sysfs_refresh_dir_links(struct sysfs_directory *sysdir)
 							sysdir->path);
 		return 1;
 	}
+	errno = 0;
 	return 0;
 }
 
@@ -838,6 +850,7 @@ int sysfs_refresh_dir_subdirs(struct sysfs_directory *sysdir)
 							sysdir->path);
 		return 1;
 	}
+	errno = 0;
 	return 0;
 }
 
@@ -846,13 +859,17 @@ int sysfs_refresh_dir_subdirs(struct sysfs_directory *sysdir)
  *	directory only
  * @dir: directory to retrieve attribute from
  * @attrname: name of attribute to look for
+ *
+ * NOTE: Since we know the attribute to look for, this routine looks for the
+ * 	attribute if it was created _after_ the attrlist was read initially.
+ * 	
  * returns sysfs_attribute if found and NULL if not found
  */
 struct sysfs_attribute *sysfs_get_directory_attribute
-			(struct sysfs_directory *dir, unsigned char *attrname)
+			(struct sysfs_directory *dir, char *attrname)
 {
 	struct sysfs_attribute *attr = NULL;
-	unsigned char new_path[SYSFS_PATH_MAX];
+	char new_path[SYSFS_PATH_MAX];
 	
 	if (dir == NULL || attrname == NULL) {
 		errno = EINVAL;
@@ -873,9 +890,9 @@ struct sysfs_attribute *sysfs_get_directory_attribute
 		}
 	} else {
 		memset(new_path, 0, SYSFS_PATH_MAX);
-		strcpy(new_path, dir->path);
-		strcat(new_path, "/");
-		strcat(new_path, attrname);
+		safestrcpy(new_path, dir->path);
+		safestrcat(new_path, "/");
+		safestrcat(new_path, attrname);
 		if ((sysfs_path_is_file(new_path)) == 0) {
 			if ((add_attribute(dir, new_path)) == 0) {
 				attr = (struct sysfs_attribute *)
@@ -895,7 +912,7 @@ struct sysfs_attribute *sysfs_get_directory_attribute
  * returns reference to sysfs_link if found and NULL if not found
  */
 struct sysfs_link *sysfs_get_directory_link
-			(struct sysfs_directory *dir, unsigned char *linkname)
+			(struct sysfs_directory *dir, char *linkname)
 {
 	if (dir == NULL || linkname == NULL) {
 		errno = EINVAL;
@@ -920,7 +937,7 @@ struct sysfs_link *sysfs_get_directory_link
  * returns reference to subdirectory or NULL if not found
  */
 struct sysfs_directory *sysfs_get_subdirectory(struct sysfs_directory *dir,
-						unsigned char *subname)
+						char *subname)
 {
 	struct sysfs_directory *sub = NULL, *cursub = NULL;
 
@@ -962,7 +979,7 @@ struct sysfs_directory *sysfs_get_subdirectory(struct sysfs_directory *dir,
  * returns reference to link or NULL if not found
  */
 struct sysfs_link *sysfs_get_subdirectory_link(struct sysfs_directory *dir,
-						unsigned char *linkname)
+						char *linkname)
 {
 	struct sysfs_directory *cursub = NULL;
 	struct sysfs_link *ln = NULL;