GNU Linux-libre 6.9.2-gnu
[releases.git] / include / uapi / linux / watch_queue.h
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 */