chiark / gitweb /
[PATCH] big libsysfs diet (pre 2.0 version)
[elogind.git] / libsysfs / sysfs_dir.c
index e983d0eff4e88af4ab82516e038d393c96f1585c..c86617934bb47c37a5955e0546f9551fe009c9d1 100644 (file)
@@ -1,9 +1,9 @@
 /*
- * syfs_dir.c
+ * sysfs_dir.c
  *
  * Directory utility functions for libsysfs
  *
- * Copyright (C) IBM Corp. 2003
+ * 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
 #include "libsysfs.h"
 #include "sysfs.h"
 
-/**
- * sysfs_del_attribute: routine for dlist integration
- */
-static void sysfs_del_attribute(void *attr)
+static int sort_char(void *new, void *old)
 {
-        sysfs_close_attribute((struct sysfs_attribute *)attr);
+       return ((strncmp((char *)new, (char *)old, 
+                       strlen((char *)new))) < 0 ? 1 : 0);
 }
 
 /**
- * sysfs_del_link: routine for dlist integration
+ * sysfs_del_name: free function for sysfs_open_subsystem_list
+ * @name: memory area to be freed
  */
-static void sysfs_del_link(void *ln)
+static void sysfs_del_name(void *name)
 {
-        sysfs_close_link((struct sysfs_link *)ln);
+       free(name);
 }
 
 /**
- * sysfs_del_dir: routine for dlist integration
+ * sysfs_del_attribute: routine for dlist integration
  */
-static void sysfs_del_directory(void *dir)
+static void sysfs_del_attribute(void *attr)
 {
-        sysfs_close_directory((struct sysfs_directory *)dir);
+       sysfs_close_attribute((struct sysfs_attribute *)attr);
 }
 
 /**
- * dir_attribute_name_equal: compares dir attributes by name
+ * attr_name_equal: compares attributes by name
  * @a: attribute name for comparison
  * @b: sysfs_attribute to be compared.
  * returns 1 if a==b->name or 0 if not equal
  */
-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)
-               return 1;
-       return 0;
-}
-
-/**
- * dir_link_name_equal: compares dir links by name
- * @a: link name for comparison
- * @b: sysfs_link to be compared.
- * returns 1 if a==b->name or 0 if not equal
- */
-static int dir_link_name_equal(void *a, void *b)
+static int attr_name_equal(void *a, void *b)
 {
-       if (a == NULL || b == NULL)
+       if (!a || !b)
                return 0;
 
-       if (strcmp(((unsigned char *)a), ((struct sysfs_link *)b)->name) 
-           == 0)
+       if (strcmp(((char *)a), ((struct sysfs_attribute *)b)->name) == 0)
                return 1;
-       return 0;
-}
-
-/**
- * dir_subdir_name_equal: compares subdirs by name
- * @a: name of subdirectory to compare
- * @b: sysfs_directory subdirectory to be compared
- * returns 1 if a==b->name or 0 if not equal
- */
-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)
-               return 1;
        return 0;
 }
 
@@ -104,8 +69,8 @@ static int dir_subdir_name_equal(void *a, void *b)
  */
 void sysfs_close_attribute(struct sysfs_attribute *sysattr)
 {
-       if (sysattr != NULL) {
-               if (sysattr->value != NULL)
+       if (sysattr) {
+               if (sysattr->value)
                        free(sysattr->value);
                free(sysattr);
        }
@@ -126,28 +91,27 @@ 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;
-       
-       if (path == NULL) {
+
+       if (!path) {
                errno = EINVAL;
                return NULL;
        }
        sysattr = alloc_attribute();
-       if (sysattr == NULL) {
+       if (!sysattr) {
                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, sizeof(sysattr->path));
+       safestrcpy(sysattr->path, path);
        if ((stat(sysattr->path, &fileinfo)) != 0) {
                dprintf("Stat failed: No such attribute?\n");
                sysattr->method = 0;
@@ -163,6 +127,69 @@ struct sysfs_attribute *sysfs_open_attribute(const unsigned char *path)
        return sysattr;
 }
 
+/**
+ * sysfs_read_attribute: reads value from attribute
+ * @sysattr: attribute to read
+ * returns 0 with success and -1 with error.
+ */
+int sysfs_read_attribute(struct sysfs_attribute *sysattr)
+{
+       char *fbuf = NULL;
+       char *vbuf = NULL;
+       ssize_t length = 0;
+       long pgsize = 0;
+       int fd;
+
+       if (!sysattr) {
+               errno = EINVAL;
+               return -1;
+       }
+       if (!(sysattr->method & SYSFS_METHOD_SHOW)) {
+               dprintf("Show method not supported for attribute %s\n",
+                       sysattr->path);
+               errno = EACCES;
+               return -1;
+       }
+       pgsize = sysconf(_SC_PAGESIZE);
+       fbuf = (char *)calloc(1, pgsize+1);
+       if (!fbuf) {
+               dprintf("calloc failed\n");
+               return -1;
+       }
+       if ((fd = open(sysattr->path, O_RDONLY)) < 0) {
+               dprintf("Error reading attribute %s\n", sysattr->path);
+               free(fbuf);
+               return -1;
+       }
+       length = read(fd, fbuf, pgsize);
+       if (length < 0) {
+               dprintf("Error reading from attribute %s\n", sysattr->path);
+               close(fd);
+               free(fbuf);
+               return -1;
+       }
+       if (sysattr->len > 0) {
+               if ((sysattr->len == length) && 
+                               (!(strncmp(sysattr->value, fbuf, length)))) {
+                       close(fd);
+                       free(fbuf);
+                       return 0;
+               }
+               free(sysattr->value);
+       }
+       sysattr->len = length;
+       close(fd);
+       vbuf = (char *)realloc(fbuf, length+1);
+       if (!vbuf) {
+               dprintf("realloc failed\n");
+               free(fbuf);
+               return -1;
+       }
+       sysattr->value = vbuf;
+
+       return 0;
+}
+
 /**
  * sysfs_write_attribute: write value to the attribute
  * @sysattr: attribute to write
@@ -171,32 +198,40 @@ 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;
-       
-       if (sysattr == NULL || new_value == NULL || len == 0) {
+
+       if (!sysattr || !new_value || len == 0) {
                errno = EINVAL;
                return -1;
        }
-       
+
        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) {
+               /*
+                * read attribute again to see if we can get an updated value 
+                */
+               if ((sysfs_read_attribute(sysattr))) {
+                       dprintf("Error reading attribute\n");
+                       return -1;
+               }
                if ((strncmp(sysattr->value, new_value, sysattr->len)) == 0) {
-                       dprintf("Attribute %s already has the requested value %s\n",
+                       dprintf("Attr %s already has the requested value %s\n",
                                        sysattr->name, new_value);
                        return 0;       
                }
        }
-       /* 
+       /*
         * open O_WRONLY since some attributes have no "read" but only
         * "write" permission 
-        */ 
+        */
        if ((fd = open(sysattr->path, O_WRONLY)) < 0) {
                dprintf("Error reading attribute %s\n", sysattr->path);
                return -1;
@@ -208,7 +243,7 @@ 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);
                /* 
@@ -221,7 +256,7 @@ int sysfs_write_attribute(struct sysfs_attribute *sysattr,
                        return -1;
                }
        }
-       
+
        /*
         * Validate length that has been copied. Alloc appropriate area
         * in sysfs_attribute. Verify first if the attribute supports reading
@@ -229,13 +264,13 @@ 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);
+                       safestrcpymax(sysattr->value, new_value, length);
                } else {
                        /*"length" of the new value is same as old one */ 
-                       strncpy(sysattr->value, new_value, length);
+                       safestrcpymax(sysattr->value, new_value, length);
                }
        }
                        
@@ -243,466 +278,214 @@ int sysfs_write_attribute(struct sysfs_attribute *sysattr,
        return 0;
 }
 
-
-/**
- * sysfs_read_attribute: reads value from attribute
- * @sysattr: attribute to read
- * returns 0 with success and -1 with error.
- */
-int sysfs_read_attribute(struct sysfs_attribute *sysattr)
-{
-       unsigned char *fbuf = NULL;
-       unsigned char *vbuf = NULL;
-       size_t length = 0;
-       int pgsize = 0;
-       int fd;
-
-       if (sysattr == NULL) {
-               errno = EINVAL;
-               return -1;
-       }
-       if (!(sysattr->method & SYSFS_METHOD_SHOW)) {
-               dprintf("Show method not supported for attribute %s\n",
-                       sysattr->path);
-               return -1;
-       }
-#ifdef __KLIBC__
-       pgsize = 0x4000;
-#else
-       pgsize = getpagesize();
-#endif
-       fbuf = (unsigned char *)calloc(1, pgsize+1);
-       if (fbuf == NULL) {
-               dprintf("calloc failed\n");
-               return -1;
-       }
-       if ((fd = open(sysattr->path, O_RDONLY)) < 0) {
-               dprintf("Error reading attribute %s\n", sysattr->path);
-               free(fbuf);
-               return -1;
-       }
-       length = read(fd, fbuf, pgsize);
-       if (length < 0) {
-               dprintf("Error reading from attribute %s\n", sysattr->path);
-               close(fd);
-               free(fbuf);
-               return -1;
-       }
-       sysattr->len = length;
-       close(fd);
-       vbuf = (unsigned char *)realloc(fbuf, length+1);
-       if (vbuf == NULL) {
-               dprintf("realloc failed\n");
-               free(fbuf);
-               return -1;
-       }
-       sysattr->value = vbuf;
-
-       return 0;
-}
-
 /**
- * sysfs_read_attribute_value: given path to attribute, return its value.
- *     values can be up to a pagesize, if buffer is smaller the value will 
- *     be truncated. 
- * @attrpath: sysfs path to attribute
- * @value: buffer to put value
- * @vsize: size of value buffer
- * returns 0 with success and -1 with error.
+ * add_attribute: open and add attribute at path to given directory
+ * @dev: device whose attribute is to be added
+ * @path: path to attribute
+ * returns pointer to attr added with success and NULL with error.
  */
-int sysfs_read_attribute_value(const unsigned char *attrpath, 
-                                       unsigned char *value, size_t vsize)
+static struct sysfs_attribute *add_attribute(void *dev, const char *path)
 {
-       struct sysfs_attribute *attr = NULL;
-       size_t length = 0;
-
-       if (attrpath == NULL || value == NULL) {
-               errno = EINVAL;
-               return -1;
-       }
-
-       attr = sysfs_open_attribute(attrpath);
-       if (attr == NULL) {
-               dprintf("Invalid attribute path %s\n", attrpath);
-               errno = EINVAL;
-               return -1;
-       }
-       if((sysfs_read_attribute(attr)) != 0 || attr->value == NULL) {
-               dprintf("Error reading from attribute %s\n", attrpath);
-               sysfs_close_attribute(attr);
-               return -1;
-       }
-       length = strlen(attr->value);
-       if (length > vsize) 
-               dprintf("Value length %d is larger than supplied buffer %d\n",
-                       length, vsize);
-       strncpy(value, attr->value, vsize);
-       sysfs_close_attribute(attr);
-
-       return 0;
-}
+       struct sysfs_attribute *attr;
 
-/**
- * sysfs_get_value_from_attrbutes: given a linked list of attributes and an 
- *     attribute name, return its value
- * @attr: attribute to search
- * @name: name to look for
- * returns unsigned char * value - could be NULL
- */
-unsigned char *sysfs_get_value_from_attributes(struct dlist *attr, 
-                                       const unsigned char *name)
-{      
-       struct sysfs_attribute *cur = NULL;
-       
-       if (attr == NULL || name == NULL) {
-               errno = EINVAL;
+       attr = sysfs_open_attribute(path);
+       if (!attr) {
+               dprintf("Error opening attribute %s\n", path);
                return NULL;
        }
-       dlist_for_each_data(attr, cur, struct sysfs_attribute) {
-               if (strcmp(cur->name, name) == 0)
-                       return cur->value;
+       if (attr->method & SYSFS_METHOD_SHOW) {
+               if (sysfs_read_attribute(attr)) {
+                       dprintf("Error reading attribute %s\n", path);
+                       sysfs_close_attribute(attr);
+                       return NULL;
+               }
        }
-       return NULL;
-}
-
-/**
- * sysfs_close_link: closes and cleans up link.
- * @ln: link to close.
- */
-void sysfs_close_link(struct sysfs_link *ln)
-{
-       if (ln != NULL) 
-               free(ln);
-}
 
-/**
- * sysfs_close_directory: closes directory, cleans up attributes and links
- * @sysdir: sysfs_directory to close
- */
-void sysfs_close_directory(struct sysfs_directory *sysdir)
-{
-       if (sysdir != NULL) {
-               if (sysdir->subdirs != NULL) 
-                       dlist_destroy(sysdir->subdirs);
-               if (sysdir->links != NULL)
-                       dlist_destroy(sysdir->links);
-               if (sysdir->attributes != NULL) 
-                       dlist_destroy(sysdir->attributes);
-               free(sysdir);
+       if (!((struct sysfs_device *)dev)->attrlist) {
+               ((struct sysfs_device *)dev)->attrlist = dlist_new_with_delete
+                       (sizeof(struct sysfs_attribute), sysfs_del_attribute);
        }
-}
+       dlist_unshift_sorted(((struct sysfs_device *)dev)->attrlist, 
+                       attr, sort_list);
 
-/**
- * alloc_directory: allocates and initializes directory structure
- * returns struct sysfs_directory with success or NULL with error.
- */
-static struct sysfs_directory *alloc_directory(void)
-{
-       return (struct sysfs_directory *)
-                       calloc(1, sizeof(struct sysfs_directory));
+       return attr;
 }
 
-/**
- * alloc_link: allocates and initializes link structure
- * returns struct sysfs_link with success or NULL with error.
- */
-static struct sysfs_link *alloc_link(void)
-{
-       return (struct sysfs_link *)calloc(1, sizeof(struct sysfs_link));
-}
-
-/**
- * sysfs_read_all_subdirs: calls sysfs_read_directory for all subdirs
- * @sysdir: directory whose subdirs need reading.
- * returns 0 with success and -1 with error.
- */
-int sysfs_read_all_subdirs(struct sysfs_directory *sysdir)
-{
-       struct sysfs_directory *cursub = NULL;
-
-       if (sysdir == NULL) {
-               errno = EINVAL;
-               return -1;
-       }
-       if (sysdir->subdirs == NULL)
-               return 0;
-       dlist_for_each_data(sysdir->subdirs, cursub, struct sysfs_directory) {
-               if (sysfs_read_directory(cursub) != 0) 
-                       dprintf ("Error reading subdirectory %s\n",
-                               cursub->name);
-       }
-       return 0;
-}
-
-/**
- * sysfs_open_directory: opens a sysfs directory, creates dir struct, and
- *             returns.
- * @path: path of directory to open.
- * returns: struct sysfs_directory * with success and NULL on error.
+/*
+ * get_attribute - given a sysfs_* struct and a name, return the 
+ * sysfs_attribute corresponding to "name"
+ * returns sysfs_attribute on success and NULL on error
  */
-struct sysfs_directory *sysfs_open_directory(const unsigned char *path)
+struct sysfs_attribute *get_attribute(void *dev, const char *name)
 {
-       struct sysfs_directory *sdir = NULL;
+       struct sysfs_attribute *cur = NULL;
+       char path[SYSFS_PATH_MAX];
 
-       if (path == NULL) {
+       if (!dev || !name) {
                errno = EINVAL;
                return NULL;
        }
-       sdir = alloc_directory();
-       if (sdir == NULL) {
-               dprintf("Error allocating directory %s\n", path);
-               return NULL;
-       }
-       if (sysfs_get_name_from_path(path, sdir->name, SYSFS_NAME_LEN) != 0) {
-               dprintf("Error getting directory name from path: %s\n", path);
-               sysfs_close_directory(sdir);
-               return NULL;
-       }
-       strncpy(sdir->path, path, sizeof(sdir->path));
 
-       return sdir;
+       if (((struct sysfs_device *)dev)->attrlist) {
+               /* check if attr is already in the list */
+               cur = (struct sysfs_attribute *)dlist_find_custom
+                       ((((struct sysfs_device *)dev)->attrlist), 
+                               (void *)name, attr_name_equal);
+               if (cur)
+                       return cur;
+       }
+       safestrcpymax(path, ((struct sysfs_device *)dev)->path, 
+                       SYSFS_PATH_MAX);
+       safestrcatmax(path, "/", SYSFS_PATH_MAX);
+       safestrcatmax(path, name, SYSFS_PATH_MAX);
+       if (!(sysfs_path_is_file(path)))
+               cur = add_attribute((void *)dev, path);
+       return cur;
 }
 
 /**
- * sysfs_open_link: opens a sysfs link, creates struct, and returns
- * @path: path of link to open.
- * returns: struct sysfs_link * with success and NULL on error.
+ * read_dir_links: grabs links in a specific directory
+ * @sysdir: sysfs directory to read
+ * returns list of link names with success and NULL with error.
  */
-struct sysfs_link *sysfs_open_link(const unsigned char *linkpath)
+struct dlist *read_dir_links(const char *path)
 {
-       struct sysfs_link *ln = NULL;
+       DIR *dir = NULL;
+       struct dirent *dirent = NULL;
+       char file_path[SYSFS_PATH_MAX], *linkname;
+       struct dlist *linklist = NULL;
 
-       if (linkpath == NULL || strlen(linkpath) > SYSFS_PATH_MAX) {
+       if (!path) {
                errno = EINVAL;
                return NULL;
        }
-
-       ln = alloc_link();
-       if (ln == NULL) {
-               dprintf("Error allocating link %s\n", linkpath);
+       dir = opendir(path);
+       if (!dir) {
+               dprintf("Error opening directory %s\n", path);
                return NULL;
        }
-       strcpy(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;
-               dprintf("Invalid link path %s\n", linkpath);
-               return NULL;
+       while ((dirent = readdir(dir)) != NULL) {
+               if (0 == strcmp(dirent->d_name, "."))
+                        continue;
+               if (0 == strcmp(dirent->d_name, ".."))
+                       continue;
+               memset(file_path, 0, SYSFS_PATH_MAX);
+               safestrcpy(file_path, path);
+               safestrcat(file_path, "/");
+               safestrcat(file_path, dirent->d_name);
+               if ((sysfs_path_is_link(file_path)) == 0) {
+                       if (!linklist) {
+                               linklist = dlist_new_with_delete
+                                       (SYSFS_NAME_LEN, sysfs_del_name);
+                               if (!linklist) {
+                                       dprintf("Error creating list\n");
+                                       return NULL;
+                               }
+                       }
+                       linkname = (char *)calloc(1, SYSFS_NAME_LEN);
+                       safestrcpymax(linkname, dirent->d_name, SYSFS_NAME_LEN);
+                       dlist_unshift_sorted(linklist, linkname, sort_char);
+               }
        }
-
-       return ln;
+       closedir(dir);
+       return linklist;
 }
 
 /**
- * sysfs_read_directory: grabs attributes, links, and subdirectories
- * @sysdir: sysfs directory to open
- * returns 0 with success and -1 with error.
+ * read_dir_subdirs: grabs subdirs in a specific directory
+ * @sysdir: sysfs directory to read
+ * returns list of directory names with success and NULL with error.
  */
-int sysfs_read_directory(struct sysfs_directory *sysdir)
+struct dlist *read_dir_subdirs(const char *path)
 {
        DIR *dir = NULL;
        struct dirent *dirent = NULL;
-       struct stat astats;
-       struct sysfs_attribute *attr = NULL;
-       struct sysfs_directory *subdir = NULL;
-       struct sysfs_link *ln = NULL;
-       unsigned char file_path[SYSFS_PATH_MAX];
-       int retval = 0;
+       char file_path[SYSFS_PATH_MAX], *dir_name;
+       struct dlist *dirlist = NULL;
 
-       if (sysdir == NULL) {
+       if (!path) {
                errno = EINVAL;
-               return -1;
+               return NULL;
        }
-       dir = opendir(sysdir->path);
-       if (dir == NULL) {
-               dprintf("Error opening directory %s\n", sysdir->path);
-               return -1;
+       dir = opendir(path);
+       if (!dir) {
+               dprintf("Error opening directory %s\n", path);
+               return NULL;
        }
-       while(((dirent = readdir(dir)) != NULL) && retval == 0) {
+       while ((dirent = readdir(dir)) != NULL) {
                if (0 == strcmp(dirent->d_name, "."))
                         continue;
                if (0 == strcmp(dirent->d_name, ".."))
                        continue;
                memset(file_path, 0, SYSFS_PATH_MAX);
-               strncpy(file_path, sysdir->path, sizeof(file_path));
-               strncat(file_path, "/", sizeof(file_path));
-               strncat(file_path, dirent->d_name, sizeof(file_path));
-               if ((lstat(file_path, &astats)) != 0) {
-                       dprintf("stat failed\n");
-                       continue;
-               }
-               if (S_ISREG(astats.st_mode)) {  
-                       attr = sysfs_open_attribute(file_path);
-                       if (attr == NULL) {
-                               dprintf("Error opening attribute %s\n",
-                                       file_path);
-                               retval = -1;
-                               break;
-                       }
-                       if (attr->method & SYSFS_METHOD_SHOW) {
-                               if ((sysfs_read_attribute(attr)) != 0) {
-                                       dprintf("Error reading attribute %s\n",
-                                               file_path);
-                                       sysfs_close_attribute(attr);
-                                       continue;
+               safestrcpy(file_path, path);
+               safestrcat(file_path, "/");
+               safestrcat(file_path, dirent->d_name);
+               if ((sysfs_path_is_dir(file_path)) == 0) {
+                       if (!dirlist) {
+                               dirlist = dlist_new_with_delete
+                                       (SYSFS_NAME_LEN, sysfs_del_name);
+                               if (!dirlist) {
+                                       dprintf("Error creating list\n");
+                                       return NULL;
                                }
                        }
-                                               
-                       if (sysdir->attributes == NULL) {
-                               sysdir->attributes = dlist_new_with_delete
-                                       (sizeof(struct sysfs_attribute),
-                                                       sysfs_del_attribute);
-                       }
-                       dlist_unshift(sysdir->attributes, attr);
-               } else if (S_ISDIR(astats.st_mode)) {
-                       subdir = sysfs_open_directory(file_path);
-                       if (subdir == NULL) {
-                               dprintf("Error opening directory %s\n",
-                                       file_path);
-                               retval = -1;
-                               break;
-                       }
-                       if (sysdir->subdirs == NULL)
-                               sysdir->subdirs = dlist_new_with_delete
-                                       (sizeof(struct sysfs_directory),
-                                                       sysfs_del_directory);
-                       dlist_unshift(sysdir->subdirs, subdir);
-               } else if (S_ISLNK(astats.st_mode)) {
-                       ln = sysfs_open_link(file_path);
-                       if (ln == NULL) {
-                               dprintf("Error opening link %s\n", file_path);
-                               retval = -1;
-                               break;
-                       }
-                       if (sysdir->links == NULL)
-                               sysdir->links = dlist_new_with_delete
-                                               (sizeof(struct sysfs_link),
-                                                               sysfs_del_link);
-                       dlist_unshift(sysdir->links, ln);
+                       dir_name = (char *)calloc(1, SYSFS_NAME_LEN);
+                       safestrcpymax(dir_name, dirent->d_name, SYSFS_NAME_LEN);
+                       dlist_unshift_sorted(dirlist, dir_name, sort_char);
                }
        }
        closedir(dir);
-       return(retval);
+       return dirlist;
 }
 
 /**
- * sysfs_get_directory_attribute: retrieves attribute attrname
- * @dir: directory to retrieve attribute from
- * @attrname: name of attribute to look for
- * returns sysfs_attribute if found and NULL if not found
+ * get_attributes_list: build a list of attributes for the given device
+ * @dev: devices whose attributes list is required
+ * returns dlist of attributes on success and NULL on failure
  */
-struct sysfs_attribute *sysfs_get_directory_attribute
-                       (struct sysfs_directory *dir, unsigned char *attrname)
+struct dlist *get_attributes_list(void *dev)
 {
-       struct sysfs_directory *sdir = NULL;
+       DIR *dir = NULL;
+       struct dirent *dirent = NULL;
        struct sysfs_attribute *attr = NULL;
-       
-       if (dir == NULL || attrname == NULL) {
-               errno = EINVAL;
-               return NULL;
-       }
-       
-       attr = (struct sysfs_attribute *)dlist_find_custom(dir->attributes,
-               attrname, dir_attribute_name_equal);
-       if (attr != NULL)
-               return attr;
-       
-       if (dir->subdirs != NULL) {
-               dlist_for_each_data(dir->subdirs, sdir, 
-                                       struct sysfs_directory) {
-                       if (sdir->attributes == NULL)
-                               continue;
-                       attr = sysfs_get_directory_attribute(sdir, attrname);
-                       if (attr != NULL)
-                               return attr;
-               }
-       }
-       return NULL;
-}
-
-/**
- * sysfs_get_directory_link: retrieves link from one directory list
- * @dir: directory to retrieve link from
- * @linkname: name of link to look for
- * 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)
-{
-       if (dir == NULL || linkname == NULL) {
-               errno = EINVAL;
-               return NULL;
-       }
-       return (struct sysfs_link *)dlist_find_custom(dir->links,
-               linkname, dir_link_name_equal);
-}
-
-/**
- * sysfs_get_subdirectory: retrieves subdirectory by name.
- * @dir: directory to search for subdirectory.
- * @subname: subdirectory name to get.
- * returns reference to subdirectory or NULL if not found
- */
-struct sysfs_directory *sysfs_get_subdirectory(struct sysfs_directory *dir,
-                                               unsigned char *subname)
-{
-       struct sysfs_directory *sub = NULL, *cursub = NULL;
+       char file_path[SYSFS_PATH_MAX], path[SYSFS_PATH_MAX];
 
-       if (dir == NULL || dir->subdirs == NULL || subname == NULL) {
+       if (!dev) {
                errno = EINVAL;
                return NULL;
        }
-       sub = (struct sysfs_directory *)dlist_find_custom(dir->subdirs,
-               subname, dir_subdir_name_equal);
-       if (sub != NULL) 
-               return sub;
-
-       if (dir->subdirs != NULL) {
-               dlist_for_each_data(dir->subdirs, cursub, 
-                                       struct sysfs_directory) {
-                       if (cursub->subdirs == NULL)
-                               continue;
-                       sub = sysfs_get_subdirectory(cursub, subname);
-                       if (sub != NULL)
-                               return sub;
-               }
-       }
-       return NULL;
-}
-
-/**
- * sysfs_get_subdirectory_link: looks through all subdirs for specific link.
- * @dir: directory and subdirectories to search for link.
- * @linkname: link name to get.
- * returns reference to link or NULL if not found
- */
-struct sysfs_link *sysfs_get_subdirectory_link(struct sysfs_directory *dir,
-                                               unsigned char *linkname)
-{
-       struct sysfs_directory *cursub = NULL;
-       struct sysfs_link *ln = NULL;
-
-       if (dir == NULL || dir->links == NULL || linkname == NULL) {
-               errno = EINVAL;
+       memset(path, 0, SYSFS_PATH_MAX);
+       safestrcpy(path, ((struct sysfs_device *)dev)->path);
+       dir = opendir(path);
+       if (!dir) {
+               dprintf("Error opening directory %s\n", path);
                return NULL;
        }
-
-       ln = sysfs_get_directory_link(dir, linkname);
-       if (ln != NULL)
-               return ln;
-
-       if (dir->subdirs == NULL)
-               return NULL;
-
-       if (dir->subdirs != NULL) {
-               dlist_for_each_data(dir->subdirs, cursub, 
-                                               struct sysfs_directory) {
-                       if (cursub->subdirs == NULL)
-                               continue;
-                       ln = sysfs_get_subdirectory_link(cursub, linkname);
-                       if (ln != NULL)
-                               return ln;
+       while ((dirent = readdir(dir)) != NULL) {
+               if (0 == strcmp(dirent->d_name, "."))
+                        continue;
+               if (0 == strcmp(dirent->d_name, ".."))
+                       continue;
+               memset(file_path, 0, SYSFS_PATH_MAX);
+               safestrcpy(file_path, path);
+               safestrcat(file_path, "/");
+               safestrcat(file_path, dirent->d_name);
+               if ((sysfs_path_is_file(file_path)) == 0) {
+                       if (((struct sysfs_device *)dev)->attrlist) {
+                               /* check if attr is already in the list */
+                               attr = (struct sysfs_attribute *)
+                               dlist_find_custom
+                               ((((struct sysfs_device *)dev)->attrlist), 
+                               (void *)dirent->d_name, attr_name_equal);
+                               if (attr) 
+                                       continue;
+                               else 
+                                       add_attribute(dev, file_path);
+                       } else 
+                               attr = add_attribute(dev, file_path);
                }
        }
-       return NULL;
+       closedir(dir);
+       return ((struct sysfs_device *)dev)->attrlist;
 }