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-rw-r--r--libsysfs/sysfs_utils.c156
1 files changed, 156 insertions, 0 deletions
diff --git a/libsysfs/sysfs_utils.c b/libsysfs/sysfs_utils.c
new file mode 100644
index 0000000000..a2410abe69
--- /dev/null
+++ b/libsysfs/sysfs_utils.c
@@ -0,0 +1,156 @@
+/*
+ * syfs_utils.c
+ *
+ * System 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_get_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)
+{
+ FILE *mnt;
+ struct mntent *mntent;
+ int ret = 0;
+ size_t dirlen = 0;
+
+ /* check arg */
+ if (fs_type == NULL || mnt_path == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ if ((mnt = setmntent(SYSFS_PROC_MNTS, "r")) == NULL) {
+ dprintf(stderr, "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);
+ } else {
+ dprintf(stderr,
+ "Error - mount path too long\n");
+ ret = -1;
+ }
+ }
+ }
+ endmntent(mnt);
+ if (dirlen == 0 && ret == 0) {
+ dprintf(stderr, "Filesystem %s not found!\n", fs_type);
+ errno = EINVAL;
+ ret = -1;
+ }
+ return ret;
+}
+
+/*
+ * sysfs_get_mnt_path: Gets the sysfs mount point.
+ * @mnt_path: place to put "sysfs" mount point
+ * @len: size of mnt_path
+ * returns 0 with success and -1 with error.
+ */
+int sysfs_get_mnt_path(char *mnt_path, size_t len)
+{
+ int ret = -1;
+
+ if (mnt_path != NULL)
+ ret = sysfs_get_fs_mnt_path(SYSFS_FSTYPE_NAME, mnt_path, len);
+ else
+ errno = EINVAL;
+
+ return ret;
+}
+
+/**
+ * sysfs_get_name_from_path: returns last name from a "/" delimited path
+ * @path: path to get name from
+ * @name: where to put name
+ * @len: size of name
+ */
+int sysfs_get_name_from_path(const char *path, char *name, size_t len)
+{
+ char *n = NULL;
+
+ if (path == NULL || name == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+ n = strrchr(path, '/');
+ if (n == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+ n++;
+ strncpy(name, n, len);
+
+ return 0;
+}
+
+/**
+ * sysfs_get_link: returns link source
+ * @path: symbolic link's path
+ * @target: where to put name
+ * @len: size of name
+ */
+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;
+
+ if (path == NULL || target == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ memset(devdir, 0, SYSFS_PATH_MAX);
+ memset(linkpath, 0, SYSFS_PATH_MAX);
+
+ 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;
+
+ /* getting rid of leading "../.." */
+ while (*d == '/' || *d == '.')
+ d++;
+
+ d--;
+
+ strcat(devdir, d);
+ strncpy(target, devdir, len);
+
+ return 0;
+}