1/*	$NetBSD: event.h,v 1.55 2023/07/28 18:19:01 christos Exp $	*/
2
3/*-
4 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 *	$FreeBSD: src/sys/sys/event.h,v 1.12 2001/02/24 01:44:03 jlemon Exp $
29 */
30
31#ifndef _SYS_EVENT_H_
32#define	_SYS_EVENT_H_
33
34#include <sys/featuretest.h>
35#include <sys/types.h>			/* for size_t */
36#include <sys/inttypes.h>		/* for uintptr_t */
37#include <sys/null.h>			/* for NULL */
38
39#define	EVFILT_READ		0U
40#define	EVFILT_WRITE		1U
41#define	EVFILT_AIO		2U	/* attached to aio requests */
42#define	EVFILT_VNODE		3U	/* attached to vnodes */
43#define	EVFILT_PROC		4U	/* attached to struct proc */
44#define	EVFILT_SIGNAL		5U	/* attached to struct proc */
45#define	EVFILT_TIMER		6U	/* arbitrary timer (in ms) */
46#define	EVFILT_FS		7U	/* filesystem events */
47#define	EVFILT_USER		8U	/* user events */
48#define	EVFILT_EMPTY		9U
49#define	EVFILT_SYSCOUNT		10U	/* number of filters */
50
51#ifdef EVFILT_NAMES
52static const char *evfiltnames[] = {
53	"EVFILT_READ",
54	"EVFILT_WRITE",
55	"EVFILT_AIO",
56	"EVFILT_VNODE",
57	"EVFILT_PROC",
58	"EVFILT_SIGNAL",
59	"EVFILT_TIMER",
60	"EVFILT_FS",
61	"EVFILT_USER",
62	"EVFILT_EMPTY",
63};
64#endif
65
66struct kevent {
67	uintptr_t	ident;		/* identifier for this event */
68	uint32_t	filter;		/* filter for event */
69	uint32_t	flags;		/* action flags for kqueue */
70	uint32_t	fflags;		/* filter flag value */
71	int64_t		data;		/* filter data value */
72	void		*udata;		/* opaque user data identifier */
73	uint64_t	ext[4];		/* extensions */
74};
75
76static __inline void
77_EV_SET(struct kevent *_kevp, uintptr_t _ident, uint32_t _filter,
78    uint32_t _flags, uint32_t _fflags, int64_t _data, void *_udata)
79{
80	_kevp->ident = _ident;
81	_kevp->filter = _filter;
82	_kevp->flags = _flags;
83	_kevp->fflags = _fflags;
84	_kevp->data = _data;
85	_kevp->udata = _udata;
86}
87
88#define EV_SET(kevp, ident, filter, flags, fflags, data, udata)	\
89    _EV_SET((kevp), __CAST(uintptr_t, (ident)), (filter), (flags), \
90    (fflags), (data), __CAST(void *, (udata)))
91
92/* actions */
93#define	EV_ADD		0x0001U		/* add event to kq (implies ENABLE) */
94#define	EV_DELETE	0x0002U		/* delete event from kq */
95#define	EV_ENABLE	0x0004U		/* enable event */
96#define	EV_DISABLE	0x0008U		/* disable event (not reported) */
97
98/* flags */
99#define	EV_ONESHOT	0x0010U		/* only report one occurrence */
100#define	EV_CLEAR	0x0020U		/* clear event state after reporting */
101#define EV_RECEIPT	0x0040U		/* force EV_ERROR on success, data=0 */
102#define EV_DISPATCH	0x0080U		/* disable event after reporting */
103
104#define	EV_SYSFLAGS	0xF000U		/* reserved by system */
105#define	EV_FLAG1	0x2000U		/* filter-specific flag */
106
107/* returned values */
108#define	EV_EOF		0x8000U		/* EOF detected */
109#define	EV_ERROR	0x4000U		/* error, data contains errno */
110
111/*
112 * data/hint flags/masks for EVFILT_USER, shared with userspace
113 *
114 * On input, the top two bits of fflags specifies how the lower twenty four
115 * bits should be applied to the stored value of fflags.
116 *
117 * On output, the top two bits will always be set to NOTE_FFNOP and the
118 * remaining twenty four bits will contain the stored fflags value.
119 */
120#define	NOTE_FFNOP	0x00000000U		/* ignore input fflags */
121#define	NOTE_FFAND	0x40000000U		/* AND fflags */
122#define	NOTE_FFOR	0x80000000U		/* OR fflags */
123#define	NOTE_FFCOPY	0xc0000000U		/* copy fflags */
124
125#define	NOTE_FFCTRLMASK	0xc0000000U		/* masks for operations */
126#define	NOTE_FFLAGSMASK	0x00ffffffU
127
128#define	NOTE_TRIGGER	0x01000000U		/* Cause the event to be
129						   triggered for output. */
130/*
131 * hint flag for in-kernel use - must not equal any existing note
132 */
133#ifdef _KERNEL
134#define NOTE_SUBMIT	0x01000000U		/* initial knote submission */
135#endif
136/*
137 * data/hint flags for EVFILT_{READ|WRITE}, shared with userspace
138 */
139#define	NOTE_LOWAT	0x0001U			/* low water mark */
140
141/*
142 * data/hint flags for EVFILT_VNODE, shared with userspace
143 */
144#define	NOTE_DELETE	0x0001U			/* vnode was removed */
145#define	NOTE_WRITE	0x0002U			/* data contents changed */
146#define	NOTE_EXTEND	0x0004U			/* size increased */
147#define	NOTE_ATTRIB	0x0008U			/* attributes changed */
148#define	NOTE_LINK	0x0010U			/* link count changed */
149#define	NOTE_RENAME	0x0020U			/* vnode was renamed */
150#define	NOTE_REVOKE	0x0040U			/* vnode access was revoked */
151#define	NOTE_OPEN	0x0080U			/* vnode was opened */
152#define	NOTE_CLOSE	0x0100U			/* file closed (no FWRITE) */
153#define	NOTE_CLOSE_WRITE 0x0200U		/* file closed (FWRITE) */
154#define	NOTE_READ	0x0400U			/* file was read */
155
156/*
157 * data/hint flags for EVFILT_PROC, shared with userspace
158 */
159#define	NOTE_EXIT	0x80000000U		/* process exited */
160#define	NOTE_FORK	0x40000000U		/* process forked */
161#define	NOTE_EXEC	0x20000000U		/* process exec'd */
162#define	NOTE_PCTRLMASK	0xf0000000U		/* mask for hint bits */
163#define	NOTE_PDATAMASK	0x000fffffU		/* mask for pid */
164
165/* additional flags for EVFILT_PROC */
166#define	NOTE_TRACK	0x00000001U		/* follow across forks */
167#define	NOTE_TRACKERR	0x00000002U		/* could not track child */
168#define	NOTE_CHILD	0x00000004U		/* am a child process */
169
170/* additional flags for EVFILT_TIMER */
171#define	NOTE_MSECONDS	0x00000000U		/* data is milliseconds */
172#define	NOTE_SECONDS	0x00000001U		/* data is seconds */
173#define	NOTE_USECONDS	0x00000002U		/* data is microseconds */
174#define	NOTE_NSECONDS	0x00000003U		/* data is nanoseconds */
175#define	NOTE_ABSTIME	0x00000010U		/* timeout is absolute */
176#ifdef _KERNEL
177#define	NOTE_TIMER_UNITMASK 0x0003U
178#endif /* _KERNEL */
179
180/*
181 * This is currently visible to userland to work around broken
182 * programs which pull in <sys/proc.h> or <sys/select.h>.
183 */
184#include <sys/queue.h>
185struct knote;
186SLIST_HEAD(klist, knote);
187
188
189/*
190 * ioctl(2)s supported on kqueue descriptors.
191 */
192#include <sys/ioctl.h>
193
194struct kfilter_mapping {
195	char		*name;		/* name to lookup or return */
196	size_t		len;		/* length of name */
197	uint32_t	filter;		/* filter to lookup or return */
198};
199
200/* map filter to name (max size len) */
201#define KFILTER_BYFILTER	_IOWR('k', 0, struct kfilter_mapping)
202/* map name to filter (len ignored) */
203#define KFILTER_BYNAME		_IOWR('k', 1, struct kfilter_mapping)
204
205#ifdef _KERNEL
206
207#define	KNOTE(list, hint)	if (!SLIST_EMPTY(list)) knote(list, hint)
208
209/*
210 * Flag indicating hint is a signal.  Used by EVFILT_SIGNAL, and also
211 * shared by EVFILT_PROC  (all knotes attached to p->p_klist)
212 */
213#define	NOTE_SIGNAL	0x08000000U
214
215/*
216 * Hint values for the optional f_touch event filter.  If f_touch is not set
217 * to NULL and f_isfd is zero the f_touch filter will be called with the type
218 * argument set to EVENT_REGISTER during a kevent() system call.  It is also
219 * called under the same conditions with the type argument set to EVENT_PROCESS
220 * when the event has been triggered.
221 */
222#define	EVENT_REGISTER	1
223#define	EVENT_PROCESS	2
224
225/*
226 * Callback methods for each filter type.
227 */
228struct filterops {
229	int	f_flags;		/* flags; see below */
230	int	(*f_attach)	(struct knote *);
231					/* called when knote is ADDed */
232	void	(*f_detach)	(struct knote *);
233					/* called when knote is DELETEd */
234	int	(*f_event)	(struct knote *, long);
235					/* called when event is triggered */
236	int	(*f_touch)	(struct knote *, struct kevent *, long);
237};
238
239/* filterops flags */
240#define	FILTEROP_ISFD	__BIT(0)	/* ident == file descriptor */
241#define	FILTEROP_MPSAFE	__BIT(1)	/* does not require KERNEL_LOCK */
242
243/*
244 * Field locking:
245 *
246 * f	kn_kq->kq_fdp->fd_lock
247 * q	kn_kq->kq_lock
248 * o	object mutex (e.g. device driver or vnode interlock)
249 */
250struct kfilter;
251
252struct knote {
253	SLIST_ENTRY(knote)	kn_link;	/* f: for fd */
254	SLIST_ENTRY(knote)	kn_selnext;	/* o: for struct selinfo */
255	TAILQ_ENTRY(knote)	kn_tqe;		/* q: for struct kqueue */
256	struct kqueue		*kn_kq;		/* q: which queue we are on */
257	struct kevent		kn_kevent;	/* (see below for locking) */
258	uint32_t		kn_status;	/* q: flags below */
259	uint32_t		kn_sfflags;	/*    saved filter flags */
260	uintptr_t		kn_sdata;	/*    saved data field */
261	void			*kn_obj;	/*    monitored obj */
262	const struct filterops	*kn_fop;
263	struct kfilter		*kn_kfilter;
264	void 			*kn_hook;
265	int			kn_hookid;
266
267#define	KN_ACTIVE	0x01U			/* event has been triggered */
268#define	KN_QUEUED	0x02U			/* event is on queue */
269#define	KN_DISABLED	0x04U			/* event is disabled */
270#define	KN_DETACHED	0x08U			/* knote is detached */
271#define	KN_MARKER	0x10U			/* is a marker */
272#define	KN_BUSY		0x20U			/* is being scanned */
273#define	KN_WILLDETACH	0x40U			/* being detached imminently */
274/* Toggling KN_BUSY also requires kn_kq->kq_fdp->fd_lock. */
275#define __KN_FLAG_BITS \
276    "\20" \
277    "\1ACTIVE" \
278    "\2QUEUED" \
279    "\3DISABLED" \
280    "\4DETACHED" \
281    "\5MARKER" \
282    "\6BUSY" \
283    "\7WILLDETACH"
284
285
286/*
287 * The only time knote::kn_flags can be modified without synchronization
288 * is during filter attach, because the knote has not yet been published.
289 * This is usually to set EV_CLEAR or EV_ONESHOT as mandatory flags for
290 * that filter.
291 */
292#define	kn_id		kn_kevent.ident
293#define	kn_filter	kn_kevent.filter
294#define	kn_flags	kn_kevent.flags		/* q */
295#define	kn_fflags	kn_kevent.fflags	/* o */
296#define	kn_data		kn_kevent.data		/* o */
297};
298
299#include <sys/systm.h>	/* for copyin_t */
300
301struct lwp;
302struct timespec;
303
304void	kqueue_init(void);
305void	knote(struct klist *, long);
306void	knote_fdclose(int);
307void	knote_set_eof(struct knote *, uint32_t);
308void	knote_clear_eof(struct knote *);
309
310typedef	int (*kevent_fetch_changes_t)(void *, const struct kevent *,
311    struct kevent *, size_t, int);
312typedef	int (*kevent_put_events_t)(void *, struct kevent *, struct kevent *,
313    size_t, int);
314
315struct kevent_ops {
316	void *keo_private;
317	copyin_t keo_fetch_timeout;
318	kevent_fetch_changes_t keo_fetch_changes;
319	kevent_put_events_t keo_put_events;
320};
321
322
323int	kevent_fetch_changes(void *, const struct kevent *, struct kevent *,
324    size_t, int);
325int 	kevent_put_events(void *, struct kevent *, struct kevent *, size_t,
326    int);
327int	kevent1(register_t *, int, const struct kevent *,
328    size_t, struct kevent *, size_t, const struct timespec *,
329    const struct kevent_ops *);
330
331int	kfilter_register(const char *, const struct filterops *, int *);
332int	kfilter_unregister(const char *);
333
334int	filt_seltrue(struct knote *, long);
335extern const struct filterops seltrue_filtops;
336
337void	klist_init(struct klist *);
338void	klist_fini(struct klist *);
339void	klist_insert(struct klist *, struct knote *);
340bool	klist_remove(struct klist *, struct knote *);
341
342#else 	/* !_KERNEL */
343
344#include <sys/cdefs.h>
345struct timespec;
346
347__BEGIN_DECLS
348#if defined(_NETBSD_SOURCE)
349int	kqueue(void);
350int	kqueue1(int);
351#ifndef __LIBC12_SOURCE__
352int	kevent(int, const struct kevent *, size_t, struct kevent *, size_t,
353		    const struct timespec *) __RENAME(__kevent100);
354#endif
355#endif /* !_POSIX_C_SOURCE */
356__END_DECLS
357
358#endif /* !_KERNEL */
359
360#endif /* !_SYS_EVENT_H_ */
361