1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 #ifndef _UAPI_LINUX_WATCH_QUEUE_H
3 #define _UAPI_LINUX_WATCH_QUEUE_H
4 
5 #include <linux/types.h>
6 #include <linux/fcntl.h>
7 #include <linux/ioctl.h>
8 
9 #define O_NOTIFICATION_PIPE	O_EXCL	/* Parameter to pipe2() selecting notification pipe */
10 
11 #define IOC_WATCH_QUEUE_SET_SIZE	_IO('W', 0x60)	/* Set the size in pages */
12 #define IOC_WATCH_QUEUE_SET_FILTER	_IO('W', 0x61)	/* Set the filter */
13 
14 enum watch_notification_type {
15 	WATCH_TYPE_META		= 0,	/* Special record */
16 	WATCH_TYPE_KEY_NOTIFY	= 1,	/* Key change event notification */
17 	WATCH_TYPE__NR		= 2
18 };
19 
20 enum watch_meta_notification_subtype {
21 	WATCH_META_REMOVAL_NOTIFICATION	= 0,	/* Watched object was removed */
22 	WATCH_META_LOSS_NOTIFICATION	= 1,	/* Data loss occurred */
23 };
24 
25 /*
26  * Notification record header.  This is aligned to 64-bits so that subclasses
27  * can contain __u64 fields.
28  */
29 struct watch_notification {
30 	__u32			type:24;	/* enum watch_notification_type */
31 	__u32			subtype:8;	/* Type-specific subtype (filterable) */
32 	__u32			info;
33 #define WATCH_INFO_LENGTH	0x0000007f	/* Length of record */
34 #define WATCH_INFO_LENGTH__SHIFT 0
35 #define WATCH_INFO_ID		0x0000ff00	/* ID of watchpoint */
36 #define WATCH_INFO_ID__SHIFT	8
37 #define WATCH_INFO_TYPE_INFO	0xffff0000	/* Type-specific info */
38 #define WATCH_INFO_TYPE_INFO__SHIFT 16
39 #define WATCH_INFO_FLAG_0	0x00010000	/* Type-specific info, flag bit 0 */
40 #define WATCH_INFO_FLAG_1	0x00020000	/* ... */
41 #define WATCH_INFO_FLAG_2	0x00040000
42 #define WATCH_INFO_FLAG_3	0x00080000
43 #define WATCH_INFO_FLAG_4	0x00100000
44 #define WATCH_INFO_FLAG_5	0x00200000
45 #define WATCH_INFO_FLAG_6	0x00400000
46 #define WATCH_INFO_FLAG_7	0x00800000
47 };
48 
49 /*
50  * Notification filtering rules (IOC_WATCH_QUEUE_SET_FILTER).
51  */
52 struct watch_notification_type_filter {
53 	__u32	type;			/* Type to apply filter to */
54 	__u32	info_filter;		/* Filter on watch_notification::info */
55 	__u32	info_mask;		/* Mask of relevant bits in info_filter */
56 	__u32	subtype_filter[8];	/* Bitmask of subtypes to filter on */
57 };
58 
59 struct watch_notification_filter {
60 	__u32	nr_filters;		/* Number of filters */
61 	__u32	__reserved;		/* Must be 0 */
62 	struct watch_notification_type_filter filters[];
63 };
64 
65 
66 /*
67  * Extended watch removal notification.  This is used optionally if the type
68  * wants to indicate an identifier for the object being watched, if there is
69  * such.  This can be distinguished by the length.
70  *
71  * type -> WATCH_TYPE_META
72  * subtype -> WATCH_META_REMOVAL_NOTIFICATION
73  */
74 struct watch_notification_removal {
75 	struct watch_notification watch;
76 	__u64	id;		/* Type-dependent identifier */
77 };
78 
79 /*
80  * Type of key/keyring change notification.
81  */
82 enum key_notification_subtype {
83 	NOTIFY_KEY_INSTANTIATED	= 0, /* Key was instantiated (aux is error code) */
84 	NOTIFY_KEY_UPDATED	= 1, /* Key was updated */
85 	NOTIFY_KEY_LINKED	= 2, /* Key (aux) was added to watched keyring */
86 	NOTIFY_KEY_UNLINKED	= 3, /* Key (aux) was removed from watched keyring */
87 	NOTIFY_KEY_CLEARED	= 4, /* Keyring was cleared */
88 	NOTIFY_KEY_REVOKED	= 5, /* Key was revoked */
89 	NOTIFY_KEY_INVALIDATED	= 6, /* Key was invalidated */
90 	NOTIFY_KEY_SETATTR	= 7, /* Key's attributes got changed */
91 };
92 
93 /*
94  * Key/keyring notification record.
95  * - watch.type = WATCH_TYPE_KEY_NOTIFY
96  * - watch.subtype = enum key_notification_type
97  */
98 struct key_notification {
99 	struct watch_notification watch;
100 	__u32	key_id;		/* The key/keyring affected */
101 	__u32	aux;		/* Per-type auxiliary data */
102 };
103 
104 #endif /* _UAPI_LINUX_WATCH_QUEUE_H */
105