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 */