summaryrefslogtreecommitdiffstats
path: root/security/landlock/fs.h
diff options
context:
space:
mode:
Diffstat (limited to 'security/landlock/fs.h')
-rw-r--r--security/landlock/fs.h71
1 files changed, 71 insertions, 0 deletions
diff --git a/security/landlock/fs.h b/security/landlock/fs.h
new file mode 100644
index 000000000..8db7acf91
--- /dev/null
+++ b/security/landlock/fs.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Landlock LSM - Filesystem management and hooks
+ *
+ * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
+ * Copyright © 2018-2020 ANSSI
+ */
+
+#ifndef _SECURITY_LANDLOCK_FS_H
+#define _SECURITY_LANDLOCK_FS_H
+
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/rcupdate.h>
+
+#include "ruleset.h"
+#include "setup.h"
+
+/**
+ * struct landlock_inode_security - Inode security blob
+ *
+ * Enable to reference a &struct landlock_object tied to an inode (i.e.
+ * underlying object).
+ */
+struct landlock_inode_security {
+ /**
+ * @object: Weak pointer to an allocated object. All assignments of a
+ * new object are protected by the underlying inode->i_lock. However,
+ * atomically disassociating @object from the inode is only protected
+ * by @object->lock, from the time @object's usage refcount drops to
+ * zero to the time this pointer is nulled out (cf. release_inode() and
+ * hook_sb_delete()). Indeed, such disassociation doesn't require
+ * inode->i_lock thanks to the careful rcu_access_pointer() check
+ * performed by get_inode_object().
+ */
+ struct landlock_object __rcu *object;
+};
+
+/**
+ * struct landlock_superblock_security - Superblock security blob
+ *
+ * Enable hook_sb_delete() to wait for concurrent calls to release_inode().
+ */
+struct landlock_superblock_security {
+ /**
+ * @inode_refs: Number of pending inodes (from this superblock) that
+ * are being released by release_inode().
+ * Cf. struct super_block->s_fsnotify_inode_refs .
+ */
+ atomic_long_t inode_refs;
+};
+
+static inline struct landlock_inode_security *
+landlock_inode(const struct inode *const inode)
+{
+ return inode->i_security + landlock_blob_sizes.lbs_inode;
+}
+
+static inline struct landlock_superblock_security *
+landlock_superblock(const struct super_block *const superblock)
+{
+ return superblock->s_security + landlock_blob_sizes.lbs_superblock;
+}
+
+__init void landlock_add_fs_hooks(void);
+
+int landlock_append_fs_rule(struct landlock_ruleset *const ruleset,
+ const struct path *const path,
+ access_mask_t access_hierarchy);
+
+#endif /* _SECURITY_LANDLOCK_FS_H */