1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2#ifndef _LINUX_WATCH_QUEUE_H
3#define _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 /* _LINUX_WATCH_QUEUE_H */