diff options
Diffstat (limited to 'libsysfs/sysfs_dir.c')
| -rw-r--r-- | libsysfs/sysfs_dir.c | 496 |
1 files changed, 496 insertions, 0 deletions
diff --git a/libsysfs/sysfs_dir.c b/libsysfs/sysfs_dir.c new file mode 100644 index 0000000000..a83c81f493 --- /dev/null +++ b/libsysfs/sysfs_dir.c @@ -0,0 +1,496 @@ +/* + * syfs_dir.c + * + * Directory utility functions for libsysfs + * + * Copyright (C) 2003 International Business Machines, Inc. + * + * 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_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 char *path) +{ + struct sysfs_attribute *sysattr = NULL; + struct stat fileinfo; + + if (path == NULL) { + errno = EINVAL; + return NULL; + } + sysattr = alloc_attribute(); + if (sysattr == NULL) { + dprintf(stderr, "Error allocating attribute at %s\n", path); + return NULL; + } + strncpy(sysattr->path, path, sizeof(sysattr->path)); + if ((stat(sysattr->path, &fileinfo)) != 0) { + perror("stat"); + sysattr->method = 0; + } 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; + size_t length = 0; + int pgsize = 0; + int fd; + + if (sysattr == NULL) { + errno = EINVAL; + return -1; + } + if (!(sysattr->method & SYSFS_METHOD_SHOW)) { + dprintf (stderr, "Show method not supported for attribute %s\n", + sysattr->path); + return -1; + } + pgsize = getpagesize(); + fbuf = (char *)calloc(1, pgsize+1); + if (fbuf == NULL) { + perror("calloc"); + return -1; + } + if ((fd = open(sysattr->path, O_RDONLY)) < 0) { + dprintf (stderr, "Error reading attribute %s\n", sysattr->path); + free(fbuf); + return -1; + } + length = read(fd, fbuf, pgsize); + if (length < 0) { + dprintf (stderr, "Error reading from attribute %s\n", + sysattr->path); + close(fd); + free(fbuf); + return -1; + } + sysattr->len = length; + close(fd); + vbuf = (char *)realloc(fbuf, length+1); + if (vbuf == NULL) { + perror("realloc"); + 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 char *attrpath, 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(stderr, "Invalid attribute path %s\n", attrpath); + errno = EINVAL; + return -1; + } + if((sysfs_read_attribute(attr)) != 0 || attr->value == NULL) { + dprintf(stderr, "Error reading from attribute %s\n", attrpath); + sysfs_close_attribute(attr); + return -1; + } + length = strlen(attr->value); + if (length > vsize) + dprintf(stderr, + "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 char * value - could be NULL + */ +char *sysfs_get_value_from_attributes(struct sysfs_attribute *attr, + const char *name) +{ + struct sysfs_attribute *cur = NULL; + char tmpname[SYSFS_NAME_LEN]; + + if (attr == NULL || name == NULL) { + errno = EINVAL; + return NULL; + } + cur = attr; + while (cur != NULL) { + memset(tmpname, 0, SYSFS_NAME_LEN); + if ((sysfs_get_name_from_path(cur->path, tmpname, + SYSFS_NAME_LEN)) != 0) { + cur = cur->next; + continue; + } + if (strcmp(tmpname, name) == 0) + return cur->value; + cur = cur->next; + } + return NULL; +} + +/** + * add_subdir_to_dir: adds subdirectory to directory's subdirs + * @sysdir: directory to add subdir to + * @subdir: subdirectory to add. + */ +static void add_subdir_to_dir(struct sysfs_directory *sysdir, + struct sysfs_directory *subdir) +{ + if (sysdir != NULL && subdir != NULL) { + subdir->next = sysdir->subdirs; + sysdir->subdirs = subdir; + } +} + +/** + * add_attr_to_dir: adds attribute to directory's attributes + * @sysdir: directory to add attribute to + * @sysattr: attribute to add. + */ +static void add_attr_to_dir(struct sysfs_directory *sysdir, + struct sysfs_attribute *sysattr) +{ + if (sysdir != NULL && sysattr != NULL) { + sysattr->next = sysdir->attributes; + sysdir->attributes = sysattr; + } +} + +/** + * sysfs_close_dlink: closes and cleans up directory link. + * @dlink: directory link to close. + */ +void sysfs_close_dlink(struct sysfs_dlink *dlink) +{ + if (dlink != NULL) { + dlink->next = NULL; + if (dlink->target != NULL) + sysfs_close_directory(dlink->target); + free(dlink); + } +} + +/** + * add_dlink_to_dir: adds directory link to directory's links list. + * @sysdir: directory to add it to. + * @dlink: link to add. + */ +static void add_dlink_to_dir(struct sysfs_directory *sysdir, + struct sysfs_dlink *dlink) +{ + if (sysdir != NULL && dlink != NULL) { + dlink->next = sysdir->links; + sysdir->links = dlink; + } +} + +/** + * sysfs_close_directory: closes directory, cleans up attributes and links + * @sysdir: sysfs_directory to close + */ +void sysfs_close_directory(struct sysfs_directory *sysdir) +{ + struct sysfs_directory *sdir = NULL, *dnext = NULL; + struct sysfs_dlink *dlink = NULL, *nextl = NULL; + struct sysfs_attribute *attr = NULL, *anext = NULL; + + if (sysdir != NULL) { + if (sysdir->subdirs != NULL) { + for (sdir = sysdir->subdirs; sdir != NULL; + sdir = dnext) { + dnext = sdir->next; + sysfs_close_directory(sdir); + } + } + if (sysdir->links != NULL) { + for (dlink = sysdir->links; dlink != NULL; + dlink = nextl) { + nextl = dlink->next; + sysfs_close_dlink(dlink); + } + } + if (sysdir->attributes != NULL) { + for (attr = sysdir->attributes; attr != NULL; + attr = anext) { + anext = attr->next; + /* sysfs_close_attribute(attr); */ + if (attr->value != NULL) + free(attr->value); + free(attr); + } + } + free(sysdir); + } +} + +/** + * 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_dlink: allocates and initializes directory link structure + * returns struct sysfs_dlink with success or NULL with error. + */ +static struct sysfs_dlink *alloc_dlink(void) +{ + return (struct sysfs_dlink *)calloc(1, sizeof(struct sysfs_dlink)); +} + +/** + * 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 char *path) +{ + struct sysfs_directory *sdir = NULL; + + if (path == NULL) { + errno = EINVAL; + return NULL; + } + sdir = alloc_directory(); + if (sdir == NULL) { + dprintf(stderr, "Error allocating directory %s\n", path); + return NULL; + } + strncpy(sdir->path, path, sizeof(sdir->path)); + + return sdir; +} + +/** + * sysfs_open_dlink: opens a sysfs directory link, creates struct, and returns + * @path: path of link to open. + * returns: struct sysfs_dlink * with success and NULL on error. + */ +struct sysfs_dlink *sysfs_open_dlink(const char *linkpath) +{ + struct sysfs_dlink *dlink = NULL; + struct sysfs_directory *tdir = NULL; + char name[SYSFS_NAME_LEN]; + char target[SYSFS_PATH_MAX]; + + if (linkpath == NULL) { + errno = EINVAL; + return NULL; + } + + memset(name, 0, SYSFS_NAME_LEN); + memset(target, 0, SYSFS_PATH_MAX); + if ((sysfs_get_name_from_path(linkpath, name, SYSFS_NAME_LEN)) != 0 + || (sysfs_get_link(linkpath, target, SYSFS_PATH_MAX)) != 0) { + errno = EINVAL; + dprintf(stderr, "Invalid link path %s\n", linkpath); + return NULL; + } + dlink = alloc_dlink(); + if (dlink == NULL) { + dprintf(stderr, + "Error allocating directory link %s\n", linkpath); + return NULL; + } + strcpy(dlink->name, name); + tdir = sysfs_open_directory(target); + if (tdir == NULL) { + dprintf(stderr, "Invalid directory link target %s\n", target); + sysfs_close_dlink(dlink); + return NULL; + } + dlink->target = tdir; + + return dlink; +} + +/** + * 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; + struct sysfs_attribute *attr = NULL; + struct sysfs_directory *subdir = NULL; + struct sysfs_dlink *dlink = NULL; + char file_path[SYSFS_PATH_MAX]; + int retval = 0; + + if (sysdir == NULL) { + errno = EINVAL; + return -1; + } + dir = opendir(sysdir->path); + if (dir == NULL) { + perror("opendir"); + 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, sizeof(file_path)); + strncat(file_path, "/", sizeof(file_path)); + strncat(file_path, dirent->d_name, sizeof(file_path)); + if ((lstat(file_path, &astats)) != 0) { + perror("stat"); + continue; + } + if (S_ISREG(astats.st_mode)) { + attr = sysfs_open_attribute(file_path); + if (attr == NULL) { + dprintf (stderr, "Error opening attribute %s\n", + file_path); + retval = -1; + break; + } + if (attr->method & SYSFS_METHOD_SHOW) { + if ((sysfs_read_attribute(attr)) != 0) { + dprintf (stderr, + "Error reading attribute %s\n", + file_path); + sysfs_close_attribute(attr); + continue; + } + } + add_attr_to_dir(sysdir, attr); + } else if (S_ISDIR(astats.st_mode)) { + subdir = sysfs_open_directory(file_path); + if (subdir == NULL) { + dprintf (stderr, "Error opening directory %s\n", + file_path); + retval = -1; + break; + } + add_subdir_to_dir(sysdir, subdir); + } else if (S_ISLNK(astats.st_mode)) { + dlink = sysfs_open_dlink(file_path); + if (dlink == NULL) { + dprintf(stderr, "Error opening link %s\n", + file_path); + retval = -1; + break; + } + add_dlink_to_dir(sysdir, dlink); + } + } + closedir(dir); + return(retval); +} + +/** + * sysfs_read_dlinks: reads a directory link's target directory. Can + * supply a linked list of links. + * @dlink: directory link to read. + * returns 0 with success or -1 with error. + */ +int sysfs_read_dlinks(struct sysfs_dlink *dlink) +{ + struct sysfs_dlink *cur = NULL; + + if (dlink == NULL || dlink->target == NULL) { + errno = EINVAL; + return -1; + } + cur = dlink; + while (cur != NULL) { + if ((sysfs_read_directory(cur->target)) != 0) { + dprintf(stderr, + "Error reading directory link target %s\n", + dlink->name); + return -1; + } + cur = cur->next; + } + + return 0; +} |