xref: /openbmc/linux/fs/notify/fanotify/fanotify.h (revision e3d786a3)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #include <linux/fsnotify_backend.h>
3 #include <linux/path.h>
4 #include <linux/slab.h>
5 
6 extern struct kmem_cache *fanotify_mark_cache;
7 extern struct kmem_cache *fanotify_event_cachep;
8 extern struct kmem_cache *fanotify_perm_event_cachep;
9 
10 /*
11  * Structure for normal fanotify events. It gets allocated in
12  * fanotify_handle_event() and freed when the information is retrieved by
13  * userspace
14  */
15 struct fanotify_event_info {
16 	struct fsnotify_event fse;
17 	/*
18 	 * We hold ref to this path so it may be dereferenced at any point
19 	 * during this object's lifetime
20 	 */
21 	struct path path;
22 	struct pid *pid;
23 };
24 
25 /*
26  * Structure for permission fanotify events. It gets allocated and freed in
27  * fanotify_handle_event() since we wait there for user response. When the
28  * information is retrieved by userspace the structure is moved from
29  * group->notification_list to group->fanotify_data.access_list to wait for
30  * user response.
31  */
32 struct fanotify_perm_event_info {
33 	struct fanotify_event_info fae;
34 	int response;	/* userspace answer to question */
35 	int fd;		/* fd we passed to userspace for this event */
36 };
37 
38 static inline struct fanotify_perm_event_info *
39 FANOTIFY_PE(struct fsnotify_event *fse)
40 {
41 	return container_of(fse, struct fanotify_perm_event_info, fae.fse);
42 }
43 
44 static inline bool fanotify_is_perm_event(u32 mask)
45 {
46 	return IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS) &&
47 		mask & FANOTIFY_PERM_EVENTS;
48 }
49 
50 static inline struct fanotify_event_info *FANOTIFY_E(struct fsnotify_event *fse)
51 {
52 	return container_of(fse, struct fanotify_event_info, fse);
53 }
54 
55 struct fanotify_event_info *fanotify_alloc_event(struct fsnotify_group *group,
56 						 struct inode *inode, u32 mask,
57 						 const struct path *path);
58