1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 * $FreeBSD$
29 */
30
31#ifndef _SYS_EVENT_H_
32#define _SYS_EVENT_H_
33
34#include <sys/_types.h>
35#include <sys/queue.h>
36
37#define EVFILT_READ		(-1)
38#define EVFILT_WRITE		(-2)
39#define EVFILT_AIO		(-3)	/* attached to aio requests */
40#define EVFILT_VNODE		(-4)	/* attached to vnodes */
41#define EVFILT_PROC		(-5)	/* attached to struct proc */
42#define EVFILT_SIGNAL		(-6)	/* attached to struct proc */
43#define EVFILT_TIMER		(-7)	/* timers */
44#define EVFILT_PROCDESC		(-8)	/* attached to process descriptors */
45#define EVFILT_FS		(-9)	/* filesystem events */
46#define EVFILT_LIO		(-10)	/* attached to lio requests */
47#define EVFILT_USER		(-11)	/* User events */
48#define EVFILT_SENDFILE		(-12)	/* attached to sendfile requests */
49#define EVFILT_EMPTY		(-13)	/* empty send socket buf */
50#define EVFILT_SYSCOUNT		13
51
52#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
53#define	EV_SET(kevp_, a, b, c, d, e, f) do {	\
54	*(kevp_) = (struct kevent){		\
55	    .ident = (a),			\
56	    .filter = (b),			\
57	    .flags = (c),			\
58	    .fflags = (d),			\
59	    .data = (e),			\
60	    .udata = (f),			\
61	    .ext = {0},				\
62	};					\
63} while(0)
64#else /* Pre-C99 or not STDC (e.g., C++) */
65/* The definition of the local variable kevp could possibly conflict
66 * with a user-defined value passed in parameters a-f.
67 */
68#define EV_SET(kevp_, a, b, c, d, e, f) do {	\
69	struct kevent *kevp = (kevp_);		\
70	(kevp)->ident = (a);			\
71	(kevp)->filter = (b);			\
72	(kevp)->flags = (c);			\
73	(kevp)->fflags = (d);			\
74	(kevp)->data = (e);			\
75	(kevp)->udata = (f);			\
76	(kevp)->ext[0] = 0;			\
77	(kevp)->ext[1] = 0;			\
78	(kevp)->ext[2] = 0;			\
79	(kevp)->ext[3] = 0;			\
80} while(0)
81#endif
82
83struct kevent {
84	__uintptr_t	ident;		/* identifier for this event */
85	short		filter;		/* filter for event */
86	unsigned short	flags;		/* action flags for kqueue */
87	unsigned int	fflags;		/* filter flag value */
88	__int64_t	data;		/* filter data value */
89	void		*udata;		/* opaque user data identifier */
90	__uint64_t	ext[4];		/* extensions */
91};
92
93#if defined(_WANT_FREEBSD11_KEVENT)
94/* Older structure used in FreeBSD 11.x and older. */
95struct kevent_freebsd11 {
96	__uintptr_t	ident;		/* identifier for this event */
97	short		filter;		/* filter for event */
98	unsigned short	flags;
99	unsigned int	fflags;
100	__intptr_t	data;
101	void		*udata;		/* opaque user data identifier */
102};
103#endif
104
105#if defined(_WANT_KEVENT32) || (defined(_KERNEL) && defined(__LP64__))
106struct kevent32 {
107	uint32_t	ident;		/* identifier for this event */
108	short		filter;		/* filter for event */
109	u_short		flags;
110	u_int		fflags;
111#ifndef __amd64__
112	uint32_t	pad0;
113#endif
114	uint32_t	data1, data2;
115	uint32_t	udata;		/* opaque user data identifier */
116#ifndef __amd64__
117	uint32_t	pad1;
118#endif
119	uint32_t	ext64[8];
120};
121
122#ifdef _WANT_FREEBSD11_KEVENT
123struct kevent32_freebsd11 {
124	u_int32_t	ident;		/* identifier for this event */
125	short		filter;		/* filter for event */
126	u_short		flags;
127	u_int		fflags;
128	int32_t		data;
129	u_int32_t	udata;		/* opaque user data identifier */
130};
131#endif
132#endif
133
134/* actions */
135#define EV_ADD		0x0001		/* add event to kq (implies enable) */
136#define EV_DELETE	0x0002		/* delete event from kq */
137#define EV_ENABLE	0x0004		/* enable event */
138#define EV_DISABLE	0x0008		/* disable event (not reported) */
139#define EV_FORCEONESHOT	0x0100		/* enable _ONESHOT and force trigger */
140
141/* flags */
142#define EV_ONESHOT	0x0010		/* only report one occurrence */
143#define EV_CLEAR	0x0020		/* clear event state after reporting */
144#define EV_RECEIPT	0x0040		/* force EV_ERROR on success, data=0 */
145#define EV_DISPATCH	0x0080		/* disable event after reporting */
146
147#define EV_SYSFLAGS	0xF000		/* reserved by system */
148#define	EV_DROP		0x1000		/* note should be dropped */
149#define EV_FLAG1	0x2000		/* filter-specific flag */
150#define EV_FLAG2	0x4000		/* filter-specific flag */
151
152/* returned values */
153#define EV_EOF		0x8000		/* EOF detected */
154#define EV_ERROR	0x4000		/* error, data contains errno */
155
156 /*
157  * data/hint flags/masks for EVFILT_USER, shared with userspace
158  *
159  * On input, the top two bits of fflags specifies how the lower twenty four
160  * bits should be applied to the stored value of fflags.
161  *
162  * On output, the top two bits will always be set to NOTE_FFNOP and the
163  * remaining twenty four bits will contain the stored fflags value.
164  */
165#define NOTE_FFNOP	0x00000000		/* ignore input fflags */
166#define NOTE_FFAND	0x40000000		/* AND fflags */
167#define NOTE_FFOR	0x80000000		/* OR fflags */
168#define NOTE_FFCOPY	0xc0000000		/* copy fflags */
169#define NOTE_FFCTRLMASK	0xc0000000		/* masks for operations */
170#define NOTE_FFLAGSMASK	0x00ffffff
171
172#define NOTE_TRIGGER	0x01000000		/* Cause the event to be
173						   triggered for output. */
174
175/*
176 * data/hint flags for EVFILT_{READ|WRITE}, shared with userspace
177 */
178#define NOTE_LOWAT	0x0001			/* low water mark */
179#define NOTE_FILE_POLL	0x0002			/* behave like poll() */
180
181/*
182 * data/hint flags for EVFILT_VNODE, shared with userspace
183 */
184#define	NOTE_DELETE	0x0001			/* vnode was removed */
185#define	NOTE_WRITE	0x0002			/* data contents changed */
186#define	NOTE_EXTEND	0x0004			/* size increased */
187#define	NOTE_ATTRIB	0x0008			/* attributes changed */
188#define	NOTE_LINK	0x0010			/* link count changed */
189#define	NOTE_RENAME	0x0020			/* vnode was renamed */
190#define	NOTE_REVOKE	0x0040			/* vnode access was revoked */
191#define	NOTE_OPEN	0x0080			/* vnode was opened */
192#define	NOTE_CLOSE	0x0100			/* file closed, fd did not
193						   allowed write */
194#define	NOTE_CLOSE_WRITE 0x0200			/* file closed, fd did allowed
195						   write */
196#define	NOTE_READ	0x0400			/* file was read */
197
198/*
199 * data/hint flags for EVFILT_PROC and EVFILT_PROCDESC, shared with userspace
200 */
201#define	NOTE_EXIT	0x80000000		/* process exited */
202#define	NOTE_FORK	0x40000000		/* process forked */
203#define	NOTE_EXEC	0x20000000		/* process exec'd */
204#define	NOTE_PCTRLMASK	0xf0000000		/* mask for hint bits */
205#define	NOTE_PDATAMASK	0x000fffff		/* mask for pid */
206
207/* additional flags for EVFILT_PROC */
208#define	NOTE_TRACK	0x00000001		/* follow across forks */
209#define	NOTE_TRACKERR	0x00000002		/* could not track child */
210#define	NOTE_CHILD	0x00000004		/* am a child process */
211
212/* additional flags for EVFILT_TIMER */
213#define NOTE_SECONDS		0x00000001	/* data is seconds */
214#define NOTE_MSECONDS		0x00000002	/* data is milliseconds */
215#define NOTE_USECONDS		0x00000004	/* data is microseconds */
216#define NOTE_NSECONDS		0x00000008	/* data is nanoseconds */
217#define	NOTE_ABSTIME		0x00000010	/* timeout is absolute */
218
219struct knote;
220SLIST_HEAD(klist, knote);
221struct kqueue;
222TAILQ_HEAD(kqlist, kqueue);
223struct knlist {
224	struct	klist	kl_list;
225	void    (*kl_lock)(void *);	/* lock function */
226	void    (*kl_unlock)(void *);
227	void	(*kl_assert_locked)(void *);
228	void	(*kl_assert_unlocked)(void *);
229	void	*kl_lockarg;		/* argument passed to lock functions */
230	int	kl_autodestroy;
231};
232
233
234#ifdef _KERNEL
235
236/*
237 * Flags for knote call
238 */
239#define	KNF_LISTLOCKED	0x0001			/* knlist is locked */
240#define	KNF_NOKQLOCK	0x0002			/* do not keep KQ_LOCK */
241
242#define KNOTE(list, hint, flags)	knote(list, hint, flags)
243#define KNOTE_LOCKED(list, hint)	knote(list, hint, KNF_LISTLOCKED)
244#define KNOTE_UNLOCKED(list, hint)	knote(list, hint, 0)
245
246#define	KNLIST_EMPTY(list)		SLIST_EMPTY(&(list)->kl_list)
247
248/*
249 * Flag indicating hint is a signal.  Used by EVFILT_SIGNAL, and also
250 * shared by EVFILT_PROC  (all knotes attached to p->p_klist)
251 */
252#define NOTE_SIGNAL	0x08000000
253
254/*
255 * Hint values for the optional f_touch event filter.  If f_touch is not set
256 * to NULL and f_isfd is zero the f_touch filter will be called with the type
257 * argument set to EVENT_REGISTER during a kevent() system call.  It is also
258 * called under the same conditions with the type argument set to EVENT_PROCESS
259 * when the event has been triggered.
260 */
261#define EVENT_REGISTER	1
262#define EVENT_PROCESS	2
263
264struct filterops {
265	int	f_isfd;		/* true if ident == filedescriptor */
266	int	(*f_attach)(struct knote *kn);
267	void	(*f_detach)(struct knote *kn);
268	int	(*f_event)(struct knote *kn, long hint);
269	void	(*f_touch)(struct knote *kn, struct kevent *kev, u_long type);
270};
271
272/*
273 * An in-flux knote cannot be dropped from its kq while the kq is
274 * unlocked.  If the KN_SCAN flag is not set, a thread can only set
275 * kn_influx when it is exclusive owner of the knote state, and can
276 * modify kn_status as if it had the KQ lock.  KN_SCAN must not be set
277 * on a knote which is already in flux.
278 *
279 * kn_sfflags, kn_sdata, and kn_kevent are protected by the knlist lock.
280 */
281struct knote {
282	SLIST_ENTRY(knote)	kn_link;	/* for kq */
283	SLIST_ENTRY(knote)	kn_selnext;	/* for struct selinfo */
284	struct			knlist *kn_knlist;	/* f_attach populated */
285	TAILQ_ENTRY(knote)	kn_tqe;
286	struct			kqueue *kn_kq;	/* which queue we are on */
287	struct 			kevent kn_kevent;
288	void			*kn_hook;
289	int			kn_hookid;
290	int			kn_status;	/* protected by kq lock */
291#define KN_ACTIVE	0x01			/* event has been triggered */
292#define KN_QUEUED	0x02			/* event is on queue */
293#define KN_DISABLED	0x04			/* event is disabled */
294#define KN_DETACHED	0x08			/* knote is detached */
295#define KN_MARKER	0x20			/* ignore this knote */
296#define KN_KQUEUE	0x40			/* this knote belongs to a kq */
297#define	KN_SCAN		0x100			/* flux set in kqueue_scan() */
298	int			kn_influx;
299	int			kn_sfflags;	/* saved filter flags */
300	int64_t			kn_sdata;	/* saved data field */
301	union {
302		struct		file *p_fp;	/* file data pointer */
303		struct		proc *p_proc;	/* proc pointer */
304		struct		kaiocb *p_aio;	/* AIO job pointer */
305		struct		aioliojob *p_lio;	/* LIO job pointer */
306		void		*p_v;		/* generic other pointer */
307	} kn_ptr;
308	struct			filterops *kn_fop;
309
310#define kn_id		kn_kevent.ident
311#define kn_filter	kn_kevent.filter
312#define kn_flags	kn_kevent.flags
313#define kn_fflags	kn_kevent.fflags
314#define kn_data		kn_kevent.data
315#define kn_fp		kn_ptr.p_fp
316};
317struct kevent_copyops {
318	void	*arg;
319	int	(*k_copyout)(void *arg, struct kevent *kevp, int count);
320	int	(*k_copyin)(void *arg, struct kevent *kevp, int count);
321	size_t	kevent_size;
322};
323
324struct thread;
325struct proc;
326struct knlist;
327struct mtx;
328struct rwlock;
329
330void	knote(struct knlist *list, long hint, int lockflags);
331void	knote_fork(struct knlist *list, int pid);
332struct knlist *knlist_alloc(struct mtx *lock);
333void	knlist_detach(struct knlist *knl);
334void	knlist_add(struct knlist *knl, struct knote *kn, int islocked);
335void	knlist_remove(struct knlist *knl, struct knote *kn, int islocked);
336int	knlist_empty(struct knlist *knl);
337void	knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *),
338	    void (*kl_unlock)(void *), void (*kl_assert_locked)(void *),
339	    void (*kl_assert_unlocked)(void *));
340void	knlist_init_mtx(struct knlist *knl, struct mtx *lock);
341void	knlist_init_rw_reader(struct knlist *knl, struct rwlock *lock);
342void	knlist_destroy(struct knlist *knl);
343void	knlist_cleardel(struct knlist *knl, struct thread *td,
344	    int islocked, int killkn);
345#define knlist_clear(knl, islocked)				\
346	knlist_cleardel((knl), NULL, (islocked), 0)
347#define knlist_delete(knl, td, islocked)			\
348	knlist_cleardel((knl), (td), (islocked), 1)
349void	knote_fdclose(struct thread *p, int fd);
350int 	kqfd_register(int fd, struct kevent *kev, struct thread *p,
351	    int mflag);
352int	kqueue_add_filteropts(int filt, struct filterops *filtops);
353int	kqueue_del_filteropts(int filt);
354
355#else 	/* !_KERNEL */
356
357#include <sys/cdefs.h>
358struct timespec;
359
360__BEGIN_DECLS
361int     kqueue(void);
362int     kevent(int kq, const struct kevent *changelist, int nchanges,
363	    struct kevent *eventlist, int nevents,
364	    const struct timespec *timeout);
365__END_DECLS
366
367#endif /* !_KERNEL */
368
369#endif /* !_SYS_EVENT_H_ */
370