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-rw-r--r--lib/sysfs_utils.c393
1 files changed, 358 insertions, 35 deletions
diff --git a/lib/sysfs_utils.c b/lib/sysfs_utils.c
index a2410ab..8b1f56e 100644
--- a/lib/sysfs_utils.c
+++ b/lib/sysfs_utils.c
@@ -1,9 +1,9 @@
/*
- * syfs_utils.c
+ * sysfs_utils.c
*
* System utility functions for libsysfs
*
- * Copyright (C) 2003 International Business Machines, Inc.
+ * 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
@@ -23,15 +23,45 @@
#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_remove_trailing_slash: Removes any trailing '/' in the given path
+ * @path: Path to look for the trailing '/'
+ * Returns 0 on success 1 on error
+ */
+int sysfs_remove_trailing_slash(char *path)
+{
+ char *c = NULL;
+
+ if (path == NULL) {
+ errno = EINVAL;
+ return 1;
+ }
+ c = strrchr(path, '/');
+ if (c == NULL) {
+ dprintf("Invalid path %s\n", path);
+ errno = EINVAL;
+ return 1;
+ }
+ if (*(c+1) == '\0')
+ *c = '\0';
+ return 0;
+}
+
/**
- * sysfs_get_mnt_path: Gets the mount point for specified filesystem.
+ * sysfs_get_fs_mnt_path: Gets the mount point for specified filesystem.
* @fs_type: filesystem type to retrieve mount point
* @mnt_path: place to put the retrieved mount path
* @len: size of mnt_path
* returns 0 with success and -1 with error.
*/
-static int sysfs_get_fs_mnt_path(const char *fs_type, char *mnt_path,
- size_t len)
+static int sysfs_get_fs_mnt_path(const char *fs_type,
+ char *mnt_path, size_t len)
{
FILE *mnt;
struct mntent *mntent;
@@ -39,33 +69,35 @@ static int sysfs_get_fs_mnt_path(const char *fs_type, char *mnt_path,
size_t dirlen = 0;
/* check arg */
- if (fs_type == NULL || mnt_path == NULL) {
+ if (fs_type == NULL || mnt_path == NULL || len == 0) {
errno = EINVAL;
return -1;
}
if ((mnt = setmntent(SYSFS_PROC_MNTS, "r")) == NULL) {
- dprintf(stderr, "Error getting mount information\n");
+ dprintf("Error getting mount information\n");
return -1;
}
while (ret == 0 && dirlen == 0 && (mntent = getmntent(mnt)) != NULL) {
if (strcmp(mntent->mnt_type, fs_type) == 0) {
dirlen = strlen(mntent->mnt_dir);
if (dirlen <= (len - 1)) {
- strcpy(mnt_path, mntent->mnt_dir);
+ safestrcpymax(mnt_path, mntent->mnt_dir, len);
} else {
- dprintf(stderr,
- "Error - mount path too long\n");
+ dprintf("Error - mount path too long\n");
ret = -1;
}
}
}
endmntent(mnt);
if (dirlen == 0 && ret == 0) {
- dprintf(stderr, "Filesystem %s not found!\n", fs_type);
+ dprintf("Filesystem %s not found!\n", fs_type);
errno = EINVAL;
ret = -1;
}
+ if ((sysfs_remove_trailing_slash(mnt_path)) != 0)
+ ret = -1;
+
return ret;
}
@@ -77,12 +109,20 @@ static int sysfs_get_fs_mnt_path(const char *fs_type, char *mnt_path,
*/
int sysfs_get_mnt_path(char *mnt_path, size_t len)
{
- int ret = -1;
+ char *sysfs_path = NULL;
+ int ret = 0;
- if (mnt_path != NULL)
- ret = sysfs_get_fs_mnt_path(SYSFS_FSTYPE_NAME, mnt_path, len);
- else
+ if (mnt_path == NULL || len == 0) {
errno = EINVAL;
+ return -1;
+ }
+ sysfs_path = getenv(SYSFS_PATH_ENV);
+ if (sysfs_path != NULL) {
+ safestrcpymax(mnt_path, sysfs_path, len);
+ if ((sysfs_remove_trailing_slash(mnt_path)) != 0)
+ return 1;
+ } else
+ ret = sysfs_get_fs_mnt_path(SYSFS_FSTYPE_NAME, mnt_path, len);
return ret;
}
@@ -95,23 +135,33 @@ int sysfs_get_mnt_path(char *mnt_path, size_t len)
*/
int sysfs_get_name_from_path(const char *path, char *name, size_t len)
{
+ char tmp[SYSFS_PATH_MAX];
char *n = NULL;
- if (path == NULL || name == NULL) {
+ if (path == NULL || name == NULL || len == 0) {
errno = EINVAL;
return -1;
}
- n = strrchr(path, '/');
+ memset(tmp, 0, SYSFS_PATH_MAX);
+ safestrcpy(tmp, path);
+ n = strrchr(tmp, '/');
if (n == NULL) {
errno = EINVAL;
return -1;
}
+ if (*(n+1) == '\0') {
+ *n = '\0';
+ n = strrchr(tmp, '/');
+ if (n == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+ }
n++;
- strncpy(name, n, len);
-
+ safestrcpymax(name, n, len);
return 0;
}
-
+
/**
* sysfs_get_link: returns link source
* @path: symbolic link's path
@@ -122,35 +172,308 @@ int sysfs_get_link(const char *path, char *target, size_t len)
{
char devdir[SYSFS_PATH_MAX];
char linkpath[SYSFS_PATH_MAX];
- char *d = NULL;
+ char temp_path[SYSFS_PATH_MAX];
+ char *d = NULL, *s = NULL;
+ int slashes = 0, count = 0;
- if (path == NULL || target == NULL) {
+ if (path == NULL || target == NULL || len == 0) {
errno = EINVAL;
return -1;
}
memset(devdir, 0, SYSFS_PATH_MAX);
memset(linkpath, 0, SYSFS_PATH_MAX);
+ memset(temp_path, 0, SYSFS_PATH_MAX);
+ safestrcpy(devdir, path);
- if ((sysfs_get_mnt_path(devdir, SYSFS_PATH_MAX)) != 0) {
- dprintf(stderr, "Sysfs not supported on this system\n");
- return -1;
- }
-
if ((readlink(path, linkpath, SYSFS_PATH_MAX)) < 0) {
return -1;
}
-
d = linkpath;
+ /*
+ * Three cases here:
+ * 1. relative path => format ../..
+ * 2. absolute path => format /abcd/efgh
+ * 3. relative path _from_ this dir => format abcd/efgh
+ */
+ switch (*d) {
+ case '.':
+ /*
+ * handle the case where link is of type ./abcd/xxx
+ */
+ safestrcpy(temp_path, devdir);
+ if (*(d+1) == '/')
+ d += 2;
+ else if (*(d+1) == '.')
+ goto parse_path;
+ s = strrchr(temp_path, '/');
+ if (s != NULL) {
+ *(s+1) = '\0';
+ safestrcat(temp_path, d);
+ } else {
+ safestrcpy(temp_path, d);
+ }
+ safestrcpymax(target, temp_path, len);
+ break;
+ /*
+ * relative path
+ * getting rid of leading "../.."
+ */
+parse_path:
+ while (*d == '/' || *d == '.') {
+ if (*d == '/')
+ slashes++;
+ d++;
+ }
+ d--;
+ s = &devdir[strlen(devdir)-1];
+ while (s != NULL && count != (slashes+1)) {
+ s--;
+ if (*s == '/')
+ count++;
+ }
+ safestrcpymax(s, d, (SYSFS_PATH_MAX-strlen(devdir)));
+ safestrcpymax(target, devdir, len);
+ break;
+ case '/':
+ /* absolute path - copy as is */
+ safestrcpymax(target, linkpath, len);
+ break;
+ default:
+ /* relative path from this directory */
+ safestrcpy(temp_path, devdir);
+ s = strrchr(temp_path, '/');
+ if (s != NULL) {
+ *(s+1) = '\0';
+ safestrcat(temp_path, linkpath);
+ } else {
+ safestrcpy(temp_path, linkpath);
+ }
+ safestrcpymax(target, temp_path, len);
+ }
+ return 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);
+}
- /* getting rid of leading "../.." */
- while (*d == '/' || *d == '.')
- d++;
- d--;
+/**
+ * sysfs_close_list: generic list free routine
+ * @list: dlist to free
+ * Returns nothing
+ */
+void sysfs_close_list(struct dlist *list)
+{
+ if (list != NULL)
+ dlist_destroy(list);
+}
+
+/**
+ * sysfs_open_subsystem_list: gets a list of all supported "name" subsystem
+ * details from the system
+ * @name: name of the subsystem, eg., "bus", "class", "devices"
+ * Returns a dlist of supported names or NULL if subsystem not supported
+ */
+struct dlist *sysfs_open_subsystem_list(char *name)
+{
+ char sysfs_path[SYSFS_PATH_MAX], *subsys_name = NULL;
+ char *c = NULL;
+ struct sysfs_directory *dir = NULL, *cur = NULL;
+ struct dlist *list = NULL;
- strcat(devdir, d);
- strncpy(target, devdir, len);
+ if (name == NULL)
+ return NULL;
- return 0;
+ if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) {
+ dprintf("Error getting sysfs mount point\n");
+ return NULL;
+ }
+
+ safestrcat(sysfs_path, "/");
+ safestrcat(sysfs_path, name);
+ dir = sysfs_open_directory(sysfs_path);
+ if (dir == NULL) {
+ dprintf("Error opening sysfs_directory at %s\n", sysfs_path);
+ return NULL;
+ }
+
+ if ((sysfs_read_dir_subdirs(dir)) != 0) {
+ dprintf("Error reading sysfs_directory at %s\n", sysfs_path);
+ sysfs_close_directory(dir);
+ return NULL;
+ }
+
+ if (dir->subdirs != NULL) {
+ list = dlist_new_with_delete(SYSFS_NAME_LEN,
+ sysfs_del_name);
+ if (list == NULL) {
+ dprintf("Error creating list\n");
+ sysfs_close_directory(dir);
+ return NULL;
+ }
+
+ dlist_for_each_data(dir->subdirs, cur,
+ struct sysfs_directory) {
+ subsys_name = (char *)calloc(1, SYSFS_NAME_LEN);
+ safestrcpymax(subsys_name, cur->name, SYSFS_NAME_LEN);
+ dlist_unshift_sorted(list, subsys_name, sort_char);
+ }
+ }
+ sysfs_close_directory(dir);
+ /*
+ * We are now considering "block" as a "class". Hence, if the subsys
+ * name requested here is "class", verify if "block" is supported on
+ * this system and return the same.
+ */
+ if (strcmp(name, SYSFS_CLASS_NAME) == 0) {
+ c = strstr(sysfs_path, SYSFS_CLASS_NAME);
+ if (c == NULL)
+ goto out;
+ *c = '\0';
+ safestrcpymax(c, SYSFS_BLOCK_NAME,
+ sizeof(sysfs_path) - strlen(sysfs_path));
+ if ((sysfs_path_is_dir(sysfs_path)) == 0) {
+ subsys_name = (char *)calloc(1, SYSFS_NAME_LEN);
+ safestrcpymax(subsys_name, SYSFS_BLOCK_NAME,
+ SYSFS_NAME_LEN);
+ dlist_unshift_sorted(list, subsys_name, sort_char);
+ }
+ }
+out:
+ return list;
+}
+
+
+/**
+ * sysfs_open_bus_devices_list: gets a list of all devices on "name" bus
+ * @name: name of the subsystem, eg., "pci", "scsi", "usb"
+ * Returns a dlist of supported names or NULL if subsystem not supported
+ */
+struct dlist *sysfs_open_bus_devices_list(char *name)
+{
+ char sysfs_path[SYSFS_PATH_MAX], *device_name = NULL;
+ struct sysfs_directory *dir = NULL;
+ struct sysfs_link *cur = NULL;
+ struct dlist *list = NULL;
+
+ if (name == NULL)
+ return NULL;
+
+ if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) {
+ dprintf("Error getting sysfs mount point\n");
+ return NULL;
+ }
+
+ safestrcat(sysfs_path, "/");
+ safestrcat(sysfs_path, SYSFS_BUS_NAME);
+ safestrcat(sysfs_path, "/");
+ safestrcat(sysfs_path, name);
+ safestrcat(sysfs_path, "/");
+ safestrcat(sysfs_path, SYSFS_DEVICES_NAME);
+ dir = sysfs_open_directory(sysfs_path);
+ if (dir == NULL) {
+ dprintf("Error opening sysfs_directory at %s\n", sysfs_path);
+ return NULL;
+ }
+
+ if ((sysfs_read_dir_links(dir)) != 0) {
+ dprintf("Error reading sysfs_directory at %s\n", sysfs_path);
+ sysfs_close_directory(dir);
+ return NULL;
+ }
+
+ if (dir->links != NULL) {
+ list = dlist_new_with_delete(SYSFS_NAME_LEN,
+ sysfs_del_name);
+ if (list == NULL) {
+ dprintf("Error creating list\n");
+ sysfs_close_directory(dir);
+ return NULL;
+ }
+
+ dlist_for_each_data(dir->links, cur,
+ struct sysfs_link) {
+ device_name = (char *)calloc(1, SYSFS_NAME_LEN);
+ safestrcpymax(device_name, cur->name, SYSFS_NAME_LEN);
+ dlist_unshift_sorted(list, device_name, sort_char);
+ }
+ }
+ sysfs_close_directory(dir);
+ return list;
+}
+
+/**
+ * sysfs_path_is_dir: Check if the path supplied points to a directory
+ * @path: path to validate
+ * Returns 0 if path points to dir, 1 otherwise
+ */
+int sysfs_path_is_dir(const char *path)
+{
+ struct stat astats;
+
+ if (path == NULL) {
+ errno = EINVAL;
+ return 1;
+ }
+ if ((lstat(path, &astats)) != 0) {
+ dprintf("stat() failed\n");
+ return 1;
+ }
+ if (S_ISDIR(astats.st_mode))
+ return 0;
+
+ return 1;
+}
+
+/**
+ * sysfs_path_is_link: Check if the path supplied points to a link
+ * @path: path to validate
+ * Returns 0 if path points to link, 1 otherwise
+ */
+int sysfs_path_is_link(const char *path)
+{
+ struct stat astats;
+
+ if (path == NULL) {
+ errno = EINVAL;
+ return 1;
+ }
+ if ((lstat(path, &astats)) != 0) {
+ dprintf("stat() failed\n");
+ return 1;
+ }
+ if (S_ISLNK(astats.st_mode))
+ return 0;
+
+ return 1;
+}
+
+/**
+ * sysfs_path_is_file: Check if the path supplied points to a file
+ * @path: path to validate
+ * Returns 0 if path points to file, 1 otherwise
+ */
+int sysfs_path_is_file(const char *path)
+{
+ struct stat astats;
+
+ if (path == NULL) {
+ errno = EINVAL;
+ return 1;
+ }
+ if ((lstat(path, &astats)) != 0) {
+ dprintf("stat() failed\n");
+ return 1;
+ }
+ if (S_ISREG(astats.st_mode))
+ return 0;
+
+ return 1;
}
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