security: new security_inode_init_security API adds function callback
This patch changes the security_inode_init_security API by adding a
filesystem specific callback to write security extended attributes.
This change is in preparation for supporting the initialization of
multiple LSM xattrs and the EVM xattr. Initially the callback function
walks an array of xattrs, writing each xattr separately, but could be
optimized to write multiple xattrs at once.
For existing security_inode_init_security() calls, which have not yet
been converted to use the new callback function, such as those in
reiserfs and ocfs2, this patch defines security_old_inode_init_security().
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
diff --git a/include/linux/security.h b/include/linux/security.h
index 8ce59ef..6a20c70 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -36,6 +36,7 @@
#include <linux/key.h>
#include <linux/xfrm.h>
#include <linux/slab.h>
+#include <linux/xattr.h>
#include <net/flow.h>
/* Maximum number of letters for an LSM name string */
@@ -147,6 +148,10 @@
void __user *buffer, size_t *lenp, loff_t *ppos);
#endif
+/* security_inode_init_security callback function to write xattrs */
+typedef int (*initxattrs) (struct inode *inode,
+ const struct xattr *xattr_array, void *fs_data);
+
#ifdef CONFIG_SECURITY
struct security_mnt_opts {
@@ -1704,8 +1709,11 @@
int security_inode_alloc(struct inode *inode);
void security_inode_free(struct inode *inode);
int security_inode_init_security(struct inode *inode, struct inode *dir,
- const struct qstr *qstr, char **name,
- void **value, size_t *len);
+ const struct qstr *qstr,
+ initxattrs initxattrs, void *fs_data);
+int security_old_inode_init_security(struct inode *inode, struct inode *dir,
+ const struct qstr *qstr, char **name,
+ void **value, size_t *len);
int security_inode_create(struct inode *dir, struct dentry *dentry, int mode);
int security_inode_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *new_dentry);
@@ -2035,9 +2043,8 @@
static inline int security_inode_init_security(struct inode *inode,
struct inode *dir,
const struct qstr *qstr,
- char **name,
- void **value,
- size_t *len)
+ initxattrs initxattrs,
+ void *fs_data)
{
return -EOPNOTSUPP;
}
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index aed54c5..7a37866 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -67,6 +67,12 @@
size_t size, int flags, int handler_flags);
};
+struct xattr {
+ char *name;
+ void *value;
+ size_t value_len;
+};
+
ssize_t xattr_getsecurity(struct inode *, const char *, void *, size_t);
ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t);
ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);