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
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