xref: /linux-6.15/include/linux/fanotify.h (revision 71ccc212)
1 #ifndef _LINUX_FANOTIFY_H
2 #define _LINUX_FANOTIFY_H
3 
4 #include <linux/types.h>
5 
6 /* the following events that user-space can register for */
7 #define FAN_ACCESS		0x00000001	/* File was accessed */
8 #define FAN_MODIFY		0x00000002	/* File was modified */
9 #define FAN_CLOSE_WRITE		0x00000008	/* Unwrittable file closed */
10 #define FAN_CLOSE_NOWRITE	0x00000010	/* Writtable file closed */
11 #define FAN_OPEN		0x00000020	/* File was opened */
12 
13 #define FAN_EVENT_ON_CHILD	0x08000000	/* interested in child events */
14 
15 /* FIXME currently Q's have no limit.... */
16 #define FAN_Q_OVERFLOW		0x00004000	/* Event queued overflowed */
17 
18 #define FAN_OPEN_PERM		0x00010000	/* File open in perm check */
19 #define FAN_ACCESS_PERM		0x00020000	/* File accessed in perm check */
20 
21 /* helper events */
22 #define FAN_CLOSE		(FAN_CLOSE_WRITE | FAN_CLOSE_NOWRITE) /* close */
23 
24 /* flags used for fanotify_init() */
25 #define FAN_CLOEXEC		0x00000001
26 #define FAN_NONBLOCK		0x00000002
27 
28 #define FAN_ALL_INIT_FLAGS	(FAN_CLOEXEC | FAN_NONBLOCK)
29 
30 /* flags used for fanotify_modify_mark() */
31 #define FAN_MARK_ADD		0x00000001
32 #define FAN_MARK_REMOVE		0x00000002
33 #define FAN_MARK_DONT_FOLLOW	0x00000004
34 #define FAN_MARK_ONLYDIR	0x00000008
35 #define FAN_MARK_MOUNT		0x00000010
36 #define FAN_MARK_IGNORED_MASK	0x00000020
37 #define FAN_MARK_IGNORED_SURV_MODIFY	0x00000040
38 #define FAN_MARK_FLUSH		0x00000080
39 
40 #define FAN_ALL_MARK_FLAGS	(FAN_MARK_ADD |\
41 				 FAN_MARK_REMOVE |\
42 				 FAN_MARK_DONT_FOLLOW |\
43 				 FAN_MARK_ONLYDIR |\
44 				 FAN_MARK_MOUNT |\
45 				 FAN_MARK_IGNORED_MASK |\
46 				 FAN_MARK_IGNORED_SURV_MODIFY)
47 
48 /*
49  * All of the events - we build the list by hand so that we can add flags in
50  * the future and not break backward compatibility.  Apps will get only the
51  * events that they originally wanted.  Be sure to add new events here!
52  */
53 #define FAN_ALL_EVENTS (FAN_ACCESS |\
54 			FAN_MODIFY |\
55 			FAN_CLOSE |\
56 			FAN_OPEN)
57 
58 /*
59  * All events which require a permission response from userspace
60  */
61 #define FAN_ALL_PERM_EVENTS (FAN_OPEN_PERM |\
62 			     FAN_ACCESS_PERM)
63 
64 #define FAN_ALL_OUTGOING_EVENTS	(FAN_ALL_EVENTS |\
65 				 FAN_ALL_PERM_EVENTS |\
66 				 FAN_Q_OVERFLOW)
67 
68 #define FANOTIFY_METADATA_VERSION	2
69 
70 struct fanotify_event_metadata {
71 	__u32 event_len;
72 	__u32 vers;
73 	__u64 mask;
74 	__s32 fd;
75 	__s32 pid;
76 } __attribute__ ((packed));
77 
78 struct fanotify_response {
79 	__s32 fd;
80 	__u32 response;
81 } __attribute__ ((packed));
82 
83 /* Legit userspace responses to a _PERM event */
84 #define FAN_ALLOW	0x01
85 #define FAN_DENY	0x02
86 
87 /* Helper functions to deal with fanotify_event_metadata buffers */
88 #define FAN_EVENT_METADATA_LEN (sizeof(struct fanotify_event_metadata))
89 
90 #define FAN_EVENT_NEXT(meta, len) ((len) -= (meta)->event_len, \
91 				   (struct fanotify_event_metadata*)(((char *)(meta)) + \
92 				   (meta)->event_len))
93 
94 #define FAN_EVENT_OK(meta, len)	((long)(len) >= (long)FAN_EVENT_METADATA_LEN && \
95 				(long)(meta)->event_len >= (long)FAN_EVENT_METADATA_LEN && \
96 				(long)(meta)->event_len <= (long)(len))
97 
98 #endif /* _LINUX_FANOTIFY_H */
99