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
14enum 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
20enum 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 */
29struct 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 */
52struct 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
59struct 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 */
74struct 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 */
82enum 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 */
98struct 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