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-rw-r--r--libsysfs/sysfs_attr.c632
1 files changed, 632 insertions, 0 deletions
diff --git a/libsysfs/sysfs_attr.c b/libsysfs/sysfs_attr.c
new file mode 100644
index 0000000..8819926
--- /dev/null
+++ b/libsysfs/sysfs_attr.c
@@ -0,0 +1,632 @@
+/*
+ * sysfs_dir.c
+ *
+ * Directory utility functions for libsysfs
+ *
+ * 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
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+#include "libsysfs.h"
+#include "sysfs.h"
+
+static int sort_char(void *new, void *old)
+{
+ return ((strncmp((char *)new, (char *)old,
+ strlen((char *)new))) < 0 ? 1 : 0);
+}
+
+/**
+ * sysfs_del_name: free function for sysfs_open_subsystem_list
+ * @name: memory area to be freed
+ */
+static void sysfs_del_name(void *name)
+{
+ free(name);
+}
+
+/**
+ * sysfs_del_attribute: routine for dlist integration
+ */
+static void sysfs_del_attribute(void *attr)
+{
+ sysfs_close_attribute((struct sysfs_attribute *)attr);
+}
+
+/**
+ * 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 attr_name_equal(void *a, void *b)
+{
+ if (!a || !b)
+ return 0;
+
+ if (strcmp(((char *)a), ((struct sysfs_attribute *)b)->name) == 0)
+ return 1;
+
+ return 0;
+}
+
+/**
+ * sysfs_close_attribute: closes and cleans up attribute
+ * @sysattr: attribute to close.
+ */
+void sysfs_close_attribute(struct sysfs_attribute *sysattr)
+{
+ if (sysattr) {
+ if (sysattr->value)
+ free(sysattr->value);
+ free(sysattr);
+ }
+}
+
+/**
+ * alloc_attribute: allocates and initializes attribute structure
+ * returns struct sysfs_attribute with success and NULL with error.
+ */
+static struct sysfs_attribute *alloc_attribute(void)
+{
+ return (struct sysfs_attribute *)
+ calloc(1, sizeof(struct sysfs_attribute));
+}
+
+/**
+ * sysfs_open_attribute: creates sysfs_attribute structure
+ * @path: path to attribute.
+ * returns sysfs_attribute struct with success and NULL with error.
+ */
+struct sysfs_attribute *sysfs_open_attribute(const char *path)
+{
+ struct sysfs_attribute *sysattr = NULL;
+ struct stat fileinfo;
+
+ if (!path) {
+ errno = EINVAL;
+ return NULL;
+ }
+ sysattr = alloc_attribute();
+ 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 attrib name from path: %s\n", path);
+ sysfs_close_attribute(sysattr);
+ return NULL;
+ }
+ safestrcpy(sysattr->path, path);
+ if ((stat(sysattr->path, &fileinfo)) != 0) {
+ dprintf("Stat failed: No such attribute?\n");
+ sysattr->method = 0;
+ free(sysattr);
+ sysattr = NULL;
+ } else {
+ if (fileinfo.st_mode & S_IRUSR)
+ sysattr->method |= SYSFS_METHOD_SHOW;
+ if (fileinfo.st_mode & S_IWUSR)
+ sysattr->method |= SYSFS_METHOD_STORE;
+ }
+
+ 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 = getpagesize();
+ 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
+ * @new_value: value to write
+ * @len: length of "new_value"
+ * returns 0 with success and -1 with error.
+ */
+int sysfs_write_attribute(struct sysfs_attribute *sysattr,
+ const char *new_value, size_t len)
+{
+ int fd;
+ int length;
+
+ 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 &&
+ (len == sysattr->len)) {
+ 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;
+ }
+
+ length = write(fd, new_value, len);
+ if (length < 0) {
+ dprintf("Error writing to the attribute %s - invalid value?\n",
+ sysattr->name);
+ close(fd);
+ return -1;
+ } else if ((unsigned int)length != len) {
+ dprintf("Could not write %zd bytes to attribute %s\n",
+ len, sysattr->name);
+ /*
+ * since we could not write user supplied number of bytes,
+ * restore the old value if one available
+ */
+ if (sysattr->method & SYSFS_METHOD_SHOW) {
+ length = write(fd, sysattr->value, sysattr->len);
+ close(fd);
+ return -1;
+ }
+ }
+
+ /*
+ * Validate length that has been copied. Alloc appropriate area
+ * in sysfs_attribute. Verify first if the attribute supports reading
+ * (show method). If it does not, do not bother
+ */
+ if (sysattr->method & SYSFS_METHOD_SHOW) {
+ if (length != sysattr->len) {
+ sysattr->value = (char *)realloc
+ (sysattr->value, length);
+ sysattr->len = length;
+ safestrcpymax(sysattr->value, new_value, length);
+ } else {
+ /*"length" of the new value is same as old one */
+ safestrcpymax(sysattr->value, new_value, length);
+ }
+ }
+
+ close(fd);
+ return 0;
+}
+
+/**
+ * add_attribute_to_list: open and add attribute at path to given dlist
+ * @list: dlist attribute is to be added
+ * @path: path to attribute
+ * returns pointer to attr added with success and NULL with error.
+ */
+static struct sysfs_attribute *add_attribute_to_list(struct dlist *alist,
+ const char *path)
+{
+ struct sysfs_attribute *attr;
+
+ attr = sysfs_open_attribute(path);
+ if (!attr) {
+ dprintf("Error opening attribute %s\n", path);
+ return NULL;
+ }
+ if (attr->method & SYSFS_METHOD_SHOW) {
+ if (sysfs_read_attribute(attr)) {
+ dprintf("Error reading attribute %s\n", path);
+ sysfs_close_attribute(attr);
+ return NULL;
+ }
+ }
+
+ if (!alist) {
+ alist = dlist_new_with_delete
+ (sizeof(struct sysfs_attribute), sysfs_del_attribute);
+ }
+ dlist_unshift_sorted(alist, attr, sort_list);
+ return attr;
+}
+
+/**
+ * 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.
+ */
+static struct sysfs_attribute *add_attribute(void *dev, const char *path)
+{
+ struct sysfs_attribute *attr;
+
+ attr = sysfs_open_attribute(path);
+ if (!attr) {
+ dprintf("Error opening attribute %s\n", path);
+ return NULL;
+ }
+ if (attr->method & SYSFS_METHOD_SHOW) {
+ if (sysfs_read_attribute(attr)) {
+ dprintf("Error reading attribute %s\n", path);
+ sysfs_close_attribute(attr);
+ return NULL;
+ }
+ }
+
+ 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);
+
+ return attr;
+}
+
+/*
+ * 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_attribute *get_attribute(void *dev, const char *name)
+{
+ struct sysfs_attribute *cur = NULL;
+ char path[SYSFS_PATH_MAX];
+
+ if (!dev || !name) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ 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;
+}
+
+/**
+ * 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 dlist *read_dir_links(const char *path)
+{
+ DIR *dir = NULL;
+ struct dirent *dirent = NULL;
+ char file_path[SYSFS_PATH_MAX], *linkname;
+ struct dlist *linklist = NULL;
+
+ if (!path) {
+ errno = EINVAL;
+ return NULL;
+ }
+ dir = opendir(path);
+ if (!dir) {
+ dprintf("Error opening directory %s\n", path);
+ 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)) {
+ 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);
+ }
+ }
+ closedir(dir);
+ return linklist;
+}
+
+void sysfs_close_dev_tree(void *dev);
+
+int add_subdirectory(struct sysfs_device *dev, char *path)
+{
+ struct sysfs_device *newdev;
+
+ if (!path)
+ return -1;
+
+ newdev = sysfs_open_device_path(path);
+ if (newdev == NULL)
+ return -1;
+
+ if (dev->children == NULL)
+ dev->children = dlist_new_with_delete(
+ sizeof(struct sysfs_device), sysfs_close_dev_tree);
+
+ dlist_unshift_sorted(dev->children, newdev, sort_list);
+ return 0;
+}
+
+/**
+ * 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.
+ */
+struct sysfs_device *sysfs_read_dir_subdirs(const char *path)
+{
+ DIR *dir = NULL;
+ struct dirent *dirent = NULL;
+ char file_path[SYSFS_PATH_MAX];
+ struct sysfs_device *dev = NULL;
+
+ if (!path) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ dev = sysfs_open_device_path(path);
+
+ dir = opendir(path);
+ if (!dir) {
+ dprintf("Error opening directory %s\n", path);
+ 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_dir(file_path))
+ add_subdirectory(dev, file_path);
+ }
+ closedir(dir);
+ return dev;
+}
+
+/**
+ * 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.
+ */
+struct dlist *read_dir_subdirs(const char *path)
+{
+ DIR *dir = NULL;
+ struct dirent *dirent = NULL;
+ char file_path[SYSFS_PATH_MAX], *dir_name;
+ struct dlist *dirlist = NULL;
+
+ if (!path) {
+ errno = EINVAL;
+ return NULL;
+ }
+ dir = opendir(path);
+ if (!dir) {
+ dprintf("Error opening directory %s\n", path);
+ 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_dir(file_path)) {
+ if (!dirlist) {
+ dirlist = dlist_new_with_delete
+ (SYSFS_NAME_LEN, sysfs_del_name);
+ if (!dirlist) {
+ dprintf("Error creating list\n");
+ return NULL;
+ }
+ }
+ 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 dirlist;
+}
+
+/**
+ * get_attributes_list: build a list of attributes for the given path
+ * @path: grab attributes at the given path
+ * returns dlist of attributes on success and NULL on failure
+ */
+struct dlist *get_attributes_list(struct dlist *alist, const char *path)
+{
+ DIR *dir = NULL;
+ struct dirent *dirent = NULL;
+ char file_path[SYSFS_PATH_MAX];
+
+ if (!path) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ dir = opendir(path);
+ if (!dir) {
+ dprintf("Error opening directory %s\n", path);
+ 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_file(file_path)) {
+ if (!alist) {
+ alist = dlist_new_with_delete
+ (sizeof(struct sysfs_attribute),
+ sysfs_del_attribute);
+ if (!alist) {
+ dprintf("Error creating list\n");
+ return NULL;
+ }
+ }
+ add_attribute_to_list(alist, file_path);
+ }
+ }
+ closedir(dir);
+ return alist;
+}
+
+/**
+ * get_dev_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 dlist *get_dev_attributes_list(void *dev)
+{
+ DIR *dir = NULL;
+ struct dirent *dirent = NULL;
+ struct sysfs_attribute *attr = NULL;
+ char file_path[SYSFS_PATH_MAX], path[SYSFS_PATH_MAX];
+
+ if (!dev) {
+ errno = EINVAL;
+ return NULL;
+ }
+ 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;
+ }
+ 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)) {
+ 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);
+ }
+ }
+ closedir(dir);
+ return ((struct sysfs_device *)dev)->attrlist;
+}
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