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mirror of https://github.com/systemd/systemd-stable.git synced 2024-10-30 23:21:08 +03:00
systemd-stable/libsysfs/sysfs_dir.c
ananth@in.ibm.com f4f3939a6c [PATCH] change pgsize
In udev-009 and previous releases, for klibc compatibility, the pgsize var
in sysfs_read_attribute() (file sysfs_dir.c under libsysfs) is handcoded
to 0x4000.

Should it not be 4096 bytes (0x1000 in hex) instead of 0x4000 (16k bytes)?
2005-04-26 21:13:10 -07:00

943 lines
23 KiB
C

/*
* sysfs_dir.c
*
* Directory utility functions for libsysfs
*
* Copyright (C) IBM Corp. 2003
*
* 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"
/**
* sysfs_del_attribute: routine for dlist integration
*/
static void sysfs_del_attribute(void *attr)
{
sysfs_close_attribute((struct sysfs_attribute *)attr);
}
/**
* sysfs_del_link: routine for dlist integration
*/
static void sysfs_del_link(void *ln)
{
sysfs_close_link((struct sysfs_link *)ln);
}
/**
* sysfs_del_dir: routine for dlist integration
*/
static void sysfs_del_directory(void *dir)
{
sysfs_close_directory((struct sysfs_directory *)dir);
}
/**
* dir_attribute_name_equal: compares dir 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)
{
if (a == NULL || b == NULL)
return 0;
if (strcmp(((unsigned char *)a), ((struct sysfs_link *)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;
}
/**
* sysfs_close_attribute: closes and cleans up attribute
* @sysattr: attribute to close.
*/
void sysfs_close_attribute(struct sysfs_attribute *sysattr)
{
if (sysattr != NULL) {
if (sysattr->value != NULL)
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 unsigned char *path)
{
struct sysfs_attribute *sysattr = NULL;
struct stat fileinfo;
if (path == NULL) {
errno = EINVAL;
return NULL;
}
sysattr = alloc_attribute();
if (sysattr == NULL) {
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);
sysfs_close_attribute(sysattr);
return NULL;
}
strncpy(sysattr->path, path, SYSFS_PATH_MAX);
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_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 unsigned char *new_value, size_t len)
{
int fd;
int length;
if (sysattr == NULL || new_value == NULL || len == 0) {
errno = EINVAL;
return -1;
}
if (!(sysattr->method & SYSFS_METHOD_STORE)) {
dprintf ("Store method not supported for attribute %s\n",
sysattr->path);
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)) != 0) {
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",
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 (length != len) {
dprintf("Could not write %d 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;
strncpy(sysattr->value, new_value, length);
} else {
/*"length" of the new value is same as old one */
strncpy(sysattr->value, new_value, length);
}
}
close(fd);
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;
ssize_t length = 0;
long 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 = 0x1000;
#else
pgsize = sysconf(_SC_PAGESIZE);
#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;
}
if (sysattr->len > 0) {
if ((sysattr->len == length) &&
(!(strncmp(sysattr->value, fbuf, length)))) {
close(fd);
return 0;
}
free(sysattr->value);
}
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.
*/
int sysfs_read_attribute_value(const unsigned char *attrpath,
unsigned char *value, size_t vsize)
{
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;
}
/**
* 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;
return NULL;
}
dlist_for_each_data(attr, cur, struct sysfs_attribute) {
if (strcmp(cur->name, name) == 0)
return cur->value;
}
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);
sysdir = NULL;
}
}
/**
* 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));
}
/**
* 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)
if ((sysfs_read_dir_subdirs(sysdir)) != 0)
return 0;
if (sysdir->subdirs != NULL) {
dlist_for_each_data(sysdir->subdirs, cursub,
struct sysfs_directory) {
if ((sysfs_read_dir_subdirs(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.
*/
struct sysfs_directory *sysfs_open_directory(const unsigned char *path)
{
struct sysfs_directory *sdir = NULL;
if (path == NULL) {
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, SYSFS_PATH_MAX);
return sdir;
}
/**
* 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.
*/
struct sysfs_link *sysfs_open_link(const unsigned char *linkpath)
{
struct sysfs_link *ln = NULL;
if (linkpath == NULL || strlen(linkpath) > SYSFS_PATH_MAX) {
errno = EINVAL;
return NULL;
}
ln = alloc_link();
if (ln == NULL) {
dprintf("Error allocating link %s\n", linkpath);
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;
}
return ln;
}
/**
* sysfs_refresh_attributes: Refresh attributes list
* @attrlist: list of attributes to refresh
* Returns 0 on success, 1 on failure
*/
int sysfs_refresh_attributes(struct dlist *attrlist)
{
struct sysfs_attribute *attr = NULL;
if (attrlist == NULL) {
errno = EINVAL;
return 1;
}
dlist_for_each_data(attrlist, attr, struct sysfs_attribute) {
if (attr->method & SYSFS_METHOD_SHOW) {
if ((sysfs_read_attribute(attr)) != 0) {
dprintf("Error reading attribute %s\n",
attr->path);
if ((sysfs_path_is_file(attr->path)) != 0) {
dprintf("Attr %s no longer exists\n",
attr->name);
}
}
} else {
if ((sysfs_path_is_file(attr->path)) != 0) {
dprintf("Attr %s no longer exists\n",
attr->name);
}
}
}
return 0;
}
/**
* add_attribute: open and add attribute at path to given directory
* @sysdir: directory to add attribute to
* @path: path to attribute
* returns 0 with success and -1 with error.
*/
static int add_attribute(struct sysfs_directory *sysdir,
const unsigned char *path)
{
struct sysfs_attribute *attr = NULL;
attr = sysfs_open_attribute(path);
if (attr == NULL) {
dprintf("Error opening attribute %s\n", path);
return -1;
}
if (attr->method & SYSFS_METHOD_SHOW) {
if ((sysfs_read_attribute(attr)) != 0) {
dprintf("Error reading attribute %s\n", path);
sysfs_close_attribute(attr);
return 0;
}
}
if (sysdir->attributes == NULL) {
sysdir->attributes = dlist_new_with_delete
(sizeof(struct sysfs_attribute), sysfs_del_attribute);
}
dlist_unshift(sysdir->attributes, attr);
return 0;
}
/**
* add_subdirectory: open and add subdirectory at path to given directory
* @sysdir: directory to add subdir to
* @path: path to subdirectory
* returns 0 with success and -1 with error.
*/
static int add_subdirectory(struct sysfs_directory *sysdir,
const unsigned char *path)
{
struct sysfs_directory *subdir = NULL;
subdir = sysfs_open_directory(path);
if (subdir == NULL) {
dprintf("Error opening directory %s\n", path);
return -1;
}
if (sysdir->subdirs == NULL)
sysdir->subdirs = dlist_new_with_delete
(sizeof(struct sysfs_directory), sysfs_del_directory);
dlist_unshift(sysdir->subdirs, subdir);
return 0;
}
/**
* add_link: open and add link at path to given directory
* @sysdir: directory to add link to
* @path: path to link
* returns 0 with success and -1 with error.
*/
static int add_link(struct sysfs_directory *sysdir, const unsigned char *path)
{
struct sysfs_link *ln = NULL;
ln = sysfs_open_link(path);
if (ln == NULL) {
dprintf("Error opening link %s\n", path);
return -1;
}
if (sysdir->links == NULL)
sysdir->links = dlist_new_with_delete
(sizeof(struct sysfs_link), sysfs_del_link);
dlist_unshift(sysdir->links, ln);
return 0;
}
/**
* sysfs_read_dir_attributes: grabs attributes for the given directory
* @sysdir: sysfs directory to open
* returns 0 with success and -1 with error.
*/
int sysfs_read_dir_attributes(struct sysfs_directory *sysdir)
{
DIR *dir = NULL;
struct dirent *dirent = NULL;
struct stat astats;
unsigned char file_path[SYSFS_PATH_MAX];
int retval = 0;
if (sysdir == NULL) {
errno = EINVAL;
return -1;
}
dir = opendir(sysdir->path);
if (dir == NULL) {
dprintf("Error opening directory %s\n", sysdir->path);
return -1;
}
while(((dirent = readdir(dir)) != NULL) && retval == 0) {
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, SYSFS_PATH_MAX);
strcat(file_path, "/");
strcat(file_path, dirent->d_name);
if ((lstat(file_path, &astats)) != 0) {
dprintf("stat failed\n");
continue;
}
if (S_ISREG(astats.st_mode))
retval = add_attribute(sysdir, file_path);
}
closedir(dir);
return(retval);
}
/**
* sysfs_read_dir_links: grabs links in a specific directory
* @sysdir: sysfs directory to read links
* returns 0 with success and -1 with error.
*/
int sysfs_read_dir_links(struct sysfs_directory *sysdir)
{
DIR *dir = NULL;
struct dirent *dirent = NULL;
struct stat astats;
unsigned char file_path[SYSFS_PATH_MAX];
int retval = 0;
if (sysdir == NULL) {
errno = EINVAL;
return -1;
}
dir = opendir(sysdir->path);
if (dir == NULL) {
dprintf("Error opening directory %s\n", sysdir->path);
return -1;
}
while(((dirent = readdir(dir)) != NULL) && retval == 0) {
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, SYSFS_PATH_MAX);
strcat(file_path, "/");
strcat(file_path, dirent->d_name);
if ((lstat(file_path, &astats)) != 0) {
dprintf("stat failed\n");
continue;
}
if (S_ISLNK(astats.st_mode)) {
retval = add_link(sysdir, file_path);
if (retval != 0)
break;
}
}
closedir(dir);
return(retval);
}
/**
* sysfs_read_dir_subdirs: grabs subdirs in a specific directory
* @sysdir: sysfs directory to read links
* returns 0 with success and -1 with error.
*/
int sysfs_read_dir_subdirs(struct sysfs_directory *sysdir)
{
DIR *dir = NULL;
struct dirent *dirent = NULL;
struct stat astats;
unsigned char file_path[SYSFS_PATH_MAX];
int retval = 0;
if (sysdir == NULL) {
errno = EINVAL;
return -1;
}
dir = opendir(sysdir->path);
if (dir == NULL) {
dprintf("Error opening directory %s\n", sysdir->path);
return -1;
}
while(((dirent = readdir(dir)) != NULL) && retval == 0) {
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, SYSFS_PATH_MAX);
strcat(file_path, "/");
strcat(file_path, dirent->d_name);
if ((lstat(file_path, &astats)) != 0) {
dprintf("stat failed\n");
continue;
}
if (S_ISDIR(astats.st_mode))
retval = add_subdirectory(sysdir, file_path);
}
closedir(dir);
return(retval);
}
/**
* sysfs_read_directory: grabs attributes, links, and subdirectories
* @sysdir: sysfs directory to open
* returns 0 with success and -1 with error.
*/
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];
int retval = 0;
if (sysdir == NULL) {
errno = EINVAL;
return -1;
}
dir = opendir(sysdir->path);
if (dir == NULL) {
dprintf("Error opening directory %s\n", sysdir->path);
return -1;
}
while(((dirent = readdir(dir)) != NULL) && retval == 0) {
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, SYSFS_PATH_MAX);
strcat(file_path, "/");
strcat(file_path, dirent->d_name);
if ((lstat(file_path, &astats)) != 0) {
dprintf("stat failed\n");
continue;
}
if (S_ISDIR(astats.st_mode))
retval = add_subdirectory(sysdir, file_path);
else if (S_ISLNK(astats.st_mode))
retval = add_link(sysdir, file_path);
else if (S_ISREG(astats.st_mode))
retval = add_attribute(sysdir, file_path);
}
closedir(dir);
return(retval);
}
/**
* sysfs_get_directory_attribute: retrieves attribute attrname from current
* directory only
* @dir: directory to retrieve attribute from
* @attrname: name of attribute to look for
* 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_attribute *attr = NULL;
unsigned char new_path[SYSFS_PATH_MAX];
if (dir == NULL || attrname == NULL) {
errno = EINVAL;
return NULL;
}
if (dir->attributes == NULL)
if ((sysfs_read_dir_attributes(dir) != 0)
|| (dir->attributes == NULL))
return NULL;
attr = (struct sysfs_attribute *)dlist_find_custom
(dir->attributes, attrname, dir_attribute_name_equal);
if (attr == NULL) {
memset(new_path, 0, SYSFS_PATH_MAX);
strcpy(new_path, dir->path);
strcat(new_path, "/");
strcat(new_path, attrname);
if ((sysfs_path_is_file(new_path)) == 0) {
if ((add_attribute(dir, new_path)) == 0) {
attr = (struct sysfs_attribute *)
dlist_find_custom(dir->attributes,
attrname, dir_attribute_name_equal);
}
}
}
return attr;
}
/**
* 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;
}
if (dir->links == NULL)
if ((sysfs_read_dir_links(dir) != 0) || (dir->links == NULL))
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;
if (dir == NULL || subname == NULL) {
errno = EINVAL;
return NULL;
}
if (dir->subdirs == NULL)
if (sysfs_read_dir_subdirs(dir) != 0)
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) {
if (sysfs_read_dir_subdirs(cursub) != 0)
continue;
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 || linkname == NULL) {
errno = EINVAL;
return NULL;
}
ln = sysfs_get_directory_link(dir, linkname);
if (ln != NULL)
return ln;
if (dir->subdirs == NULL)
if (sysfs_read_dir_subdirs(dir) != 0)
return NULL;
if (dir->subdirs != NULL) {
dlist_for_each_data(dir->subdirs, cursub,
struct sysfs_directory) {
ln = sysfs_get_subdirectory_link(cursub, linkname);
if (ln != NULL)
return ln;
}
}
return NULL;
}