ocfs2: add security xattr API

This patch add security xattr set/get/list APIs to
support security attributes in Ocfs2.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

2 files changed, 48 insertions, 0 deletions

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 6480254fe396..db03162914cc 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -35,6 +35,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/string.h>
+#include <linux/security.h>
 
 #define MLOG_MASK_PREFIX ML_XATTR
 #include <cluster/masklog.h>
@@ -88,12 +89,14 @@ static struct ocfs2_xattr_def_value_root def_xv = {
 struct xattr_handler *ocfs2_xattr_handlers[] = {
         &ocfs2_xattr_user_handler,
         &ocfs2_xattr_trusted_handler,
+        &ocfs2_xattr_security_handler,
         NULL
 };
 
 static struct xattr_handler *ocfs2_xattr_handler_map[OCFS2_XATTR_MAX] = {
         [OCFS2_XATTR_INDEX_USER]        = &ocfs2_xattr_user_handler,
         [OCFS2_XATTR_INDEX_TRUSTED]     = &ocfs2_xattr_trusted_handler,
+        [OCFS2_XATTR_INDEX_SECURITY]    = &ocfs2_xattr_security_handler,
 };
 
 struct ocfs2_xattr_info {
@@ -4977,6 +4980,50 @@ out:
 }
 
 /*
+ * 'security' attributes support
+ */
+static size_t ocfs2_xattr_security_list(struct inode *inode, char *list,
+                                        size_t list_size, const char *name,
+                                        size_t name_len)
+{
+        const size_t prefix_len = XATTR_SECURITY_PREFIX_LEN;
+        const size_t total_len = prefix_len + name_len + 1;
+
+        if (list && total_len <= list_size) {
+                memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
+                memcpy(list + prefix_len, name, name_len);
+                list[prefix_len + name_len] = '\0';
+        }
+        return total_len;
+}
+
+static int ocfs2_xattr_security_get(struct inode *inode, const char *name,
+                                    void *buffer, size_t size)
+{
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        return ocfs2_xattr_get(inode, OCFS2_XATTR_INDEX_SECURITY, name,
+                               buffer, size);
+}
+
+static int ocfs2_xattr_security_set(struct inode *inode, const char *name,
+                                    const void *value, size_t size, int flags)
+{
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+
+        return ocfs2_xattr_set(inode, OCFS2_XATTR_INDEX_SECURITY, name, value,
+                               size, flags);
+}
+
+struct xattr_handler ocfs2_xattr_security_handler = {
+        .prefix = XATTR_SECURITY_PREFIX,
+        .list   = ocfs2_xattr_security_list,
+        .get    = ocfs2_xattr_security_get,
+        .set    = ocfs2_xattr_security_set,
+};
+
+/*
  * 'trusted' attributes support
  */
 static size_t ocfs2_xattr_trusted_list(struct inode *inode, char *list,
diff --git a/fs/ocfs2/xattr.h b/fs/ocfs2/xattr.h
index 8fbdc163c839..55c5256ff563 100644
--- a/fs/ocfs2/xattr.h
+++ b/fs/ocfs2/xattr.h
@@ -32,6 +32,7 @@ enum ocfs2_xattr_type {
 
 extern struct xattr_handler ocfs2_xattr_user_handler;
 extern struct xattr_handler ocfs2_xattr_trusted_handler;
+extern struct xattr_handler ocfs2_xattr_security_handler;
 extern struct xattr_handler *ocfs2_xattr_handlers[];
 
 ssize_t ocfs2_listxattr(struct dentry *, char *, size_t);