1 files changed, 77 insertions, 0 deletions

diff --git a/fs/ext4/xattr_security.c b/fs/ext4/xattr_security.c
new file mode 100644
index 000000000000..b6a6861951f9
--- /dev/null
+++ b/fs/ext4/xattr_security.c
@@ -0,0 +1,77 @@
+/*
+ * linux/fs/ext4/xattr_security.c
+ * Handler for storing security labels as extended attributes.
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/smp_lock.h>
+#include <linux/ext4_jbd2.h>
+#include <linux/ext4_fs.h>
+#include <linux/security.h>
+#include "xattr.h"
+
+static size_t
+ext4_xattr_security_list(struct inode *inode, char *list, size_t list_size,
+                         const char *name, size_t name_len)
+{
+        const size_t prefix_len = sizeof(XATTR_SECURITY_PREFIX)-1;
+        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
+ext4_xattr_security_get(struct inode *inode, const char *name,
+                       void *buffer, size_t size)
+{
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        return ext4_xattr_get(inode, EXT4_XATTR_INDEX_SECURITY, name,
+                              buffer, size);
+}
+
+static int
+ext4_xattr_security_set(struct inode *inode, const char *name,
+                       const void *value, size_t size, int flags)
+{
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        return ext4_xattr_set(inode, EXT4_XATTR_INDEX_SECURITY, name,
+                              value, size, flags);
+}
+
+int
+ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir)
+{
+        int err;
+        size_t len;
+        void *value;
+        char *name;
+
+        err = security_inode_init_security(inode, dir, &name, &value, &len);
+        if (err) {
+                if (err == -EOPNOTSUPP)
+                        return 0;
+                return err;
+        }
+        err = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_SECURITY,
+                                    name, value, len, 0);
+        kfree(name);
+        kfree(value);
+        return err;
+}
+
+struct xattr_handler ext4_xattr_security_handler = {
+        .prefix = XATTR_SECURITY_PREFIX,
+        .list   = ext4_xattr_security_list,
+        .get    = ext4_xattr_security_get,
+        .set    = ext4_xattr_security_set,
+};