xref: /freebsd/sys/sys/event.h (revision d8bdcb08d0ebe8cdc7f589cf05283882bff94d3a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
29 #ifndef _SYS_EVENT_H_
30 #define _SYS_EVENT_H_
31 
32 #include <sys/_types.h>
33 #include <sys/queue.h>
34 
35 #define EVFILT_READ		(-1)
36 #define EVFILT_WRITE		(-2)
37 #define EVFILT_AIO		(-3)	/* attached to aio requests */
38 #define EVFILT_VNODE		(-4)	/* attached to vnodes */
39 #define EVFILT_PROC		(-5)	/* attached to struct proc */
40 #define EVFILT_SIGNAL		(-6)	/* attached to struct proc */
41 #define EVFILT_TIMER		(-7)	/* timers */
42 #define EVFILT_PROCDESC		(-8)	/* attached to process descriptors */
43 #define EVFILT_FS		(-9)	/* filesystem events */
44 #define EVFILT_LIO		(-10)	/* attached to lio requests */
45 #define EVFILT_USER		(-11)	/* User events */
46 #define EVFILT_SENDFILE		(-12)	/* attached to sendfile requests */
47 #define EVFILT_EMPTY		(-13)	/* empty send socket buf */
48 #define EVFILT_JAIL		(-14)	/* attached to struct prison */
49 #define EVFILT_JAILDESC		(-15)	/* attached to jail descriptors */
50 #define EVFILT_SYSCOUNT		15
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 /*
66  * The definition of the local variable kevp could possibly conflict
67  * with a user-defined value passed in parameters a-f.
68  */
69 #define EV_SET(kevp_, a, b, c, d, e, f) do {	\
70 	struct kevent *kevp = (kevp_);		\
71 	(kevp)->ident = (a);			\
72 	(kevp)->filter = (b);			\
73 	(kevp)->flags = (c);			\
74 	(kevp)->fflags = (d);			\
75 	(kevp)->data = (e);			\
76 	(kevp)->udata = (f);			\
77 	(kevp)->ext[0] = 0;			\
78 	(kevp)->ext[1] = 0;			\
79 	(kevp)->ext[2] = 0;			\
80 	(kevp)->ext[3] = 0;			\
81 } while (0)
82 #endif
83 
84 struct kevent {
85 	__uintptr_t	ident;		/* identifier for this event */
86 	short		filter;		/* filter for event */
87 	unsigned short	flags;		/* action flags for kqueue */
88 	unsigned int	fflags;		/* filter flag value */
89 	__int64_t	data;		/* filter data value */
90 	void		*udata;		/* opaque user data identifier */
91 	__uint64_t	ext[4];		/* extensions */
92 };
93 
94 #if defined(_WANT_FREEBSD11_KEVENT)
95 /* Older structure used in FreeBSD 11.x and older. */
96 struct freebsd11_kevent {
97 	__uintptr_t	ident;		/* identifier for this event */
98 	short		filter;		/* filter for event */
99 	unsigned short	flags;
100 	unsigned int	fflags;
101 	__intptr_t	data;
102 	void		*udata;		/* opaque user data identifier */
103 };
104 #endif
105 
106 #if defined(_WANT_KEVENT32) || defined(_KERNEL)
107 #include <sys/abi_types.h>
108 
109 struct kevent32 {
110 	__uint32_t	ident;		/* identifier for this event */
111 	short		filter;		/* filter for event */
112 	unsigned short	flags;
113 	unsigned int	fflags;
114 #ifndef __amd64__
115 	__uint32_t	pad0;
116 #endif
117 	freebsd32_uint64_t data;
118 	__uint32_t	udata;		/* opaque user data identifier */
119 #ifndef __amd64__
120 	__uint32_t	pad1;
121 #endif
122 	freebsd32_uint64_t ext[4];
123 };
124 
125 #ifdef _WANT_FREEBSD11_KEVENT
126 struct freebsd11_kevent32 {
127 	__uint32_t	ident;		/* identifier for this event */
128 	short		filter;		/* filter for event */
129 	unsigned short	flags;
130 	unsigned int	fflags;
131 	__int32_t	data;
132 	__uint32_t	udata;		/* opaque user data identifier */
133 };
134 #endif
135 #endif
136 
137 /* actions */
138 #define EV_ADD		0x0001		/* add event to kq (implies enable) */
139 #define EV_DELETE	0x0002		/* delete event from kq */
140 #define EV_ENABLE	0x0004		/* enable event */
141 #define EV_DISABLE	0x0008		/* disable event (not reported) */
142 #define EV_FORCEONESHOT	0x0100		/* enable _ONESHOT and force trigger */
143 #define EV_KEEPUDATA	0x0200		/* do not update the udata field */
144 
145 /* flags */
146 #define EV_ONESHOT	0x0010		/* only report one occurrence */
147 #define EV_CLEAR	0x0020		/* clear event state after reporting */
148 #define EV_RECEIPT	0x0040		/* force EV_ERROR on success, data=0 */
149 #define EV_DISPATCH	0x0080		/* disable event after reporting */
150 
151 #define EV_SYSFLAGS	0xF000		/* reserved by system */
152 #define	EV_DROP		0x1000		/* note should be dropped */
153 #define EV_FLAG1	0x2000		/* filter-specific flag */
154 #define EV_FLAG2	0x4000		/* filter-specific flag */
155 
156 /* returned values */
157 #define EV_EOF		0x8000		/* EOF detected */
158 #define EV_ERROR	0x4000		/* error, data contains errno */
159 
160  /*
161   * data/hint flags/masks for EVFILT_USER, shared with userspace
162   *
163   * On input, the top two bits of fflags specifies how the lower twenty four
164   * bits should be applied to the stored value of fflags.
165   *
166   * On output, the top two bits will always be set to NOTE_FFNOP and the
167   * remaining twenty four bits will contain the stored fflags value.
168   */
169 #define NOTE_FFNOP	0x00000000		/* ignore input fflags */
170 #define NOTE_FFAND	0x40000000		/* AND fflags */
171 #define NOTE_FFOR	0x80000000		/* OR fflags */
172 #define NOTE_FFCOPY	0xc0000000		/* copy fflags */
173 #define NOTE_FFCTRLMASK	0xc0000000		/* masks for operations */
174 #define NOTE_FFLAGSMASK	0x00ffffff
175 
176 #define NOTE_TRIGGER	0x01000000		/* Cause the event to be
177 						   triggered for output. */
178 
179 /*
180  * data/hint flags for EVFILT_{READ|WRITE}, shared with userspace
181  */
182 #define NOTE_LOWAT	0x0001			/* low water mark */
183 #define NOTE_FILE_POLL	0x0002			/* behave like poll() */
184 
185 /*
186  * data/hint flags for EVFILT_VNODE, shared with userspace
187  */
188 #define	NOTE_DELETE	0x0001			/* vnode was removed */
189 #define	NOTE_WRITE	0x0002			/* data contents changed */
190 #define	NOTE_EXTEND	0x0004			/* size increased */
191 #define	NOTE_ATTRIB	0x0008			/* attributes changed */
192 #define	NOTE_LINK	0x0010			/* link count changed */
193 #define	NOTE_RENAME	0x0020			/* vnode was renamed */
194 #define	NOTE_REVOKE	0x0040			/* vnode access was revoked */
195 #define	NOTE_OPEN	0x0080			/* vnode was opened */
196 #define	NOTE_CLOSE	0x0100			/* file closed, fd did not
197 						   allowed write */
198 #define	NOTE_CLOSE_WRITE 0x0200			/* file closed, fd did allowed
199 						   write */
200 #define	NOTE_READ	0x0400			/* file was read */
201 
202 /*
203  * data/hint flags for EVFILT_PROC and EVFILT_PROCDESC, shared with userspace
204  */
205 #define	NOTE_EXIT	0x80000000		/* proc/procdesc: process
206 						   exited */
207 #define	NOTE_FORK	0x40000000		/* proc/procdesc: process
208 						   forked */
209 #define	NOTE_EXEC	0x20000000		/* proc: process exec'd */
210 #define	NOTE_PDSIGCHLD	0x10000000		/* procdesc: pdwait() info
211 						   available */
212 #define	NOTE_SIGNAL	0x08000000		/* process received a signal,
213 						   shared with EVFIL_SIGNAL */
214 #define	NOTE_REAP	0x04000000		/* process reaped */
215 #define	NOTE_PCTRLMASK	0xfc000000		/* mask for hint bits */
216 #define	NOTE_PDATAMASK	0x000fffff		/* mask for pid */
217 
218 /* additional flags for EVFILT_PROC */
219 #define	NOTE_TRACK	0x00000001		/* follow across fork/create */
220 #define	NOTE_TRACKERR	0x00000002		/* could not track child */
221 #define	NOTE_CHILD	0x00000004		/* am a child process */
222 
223 /* data/hint flags for EVFILT_JAIL and EVFILT_JAILDESC */
224 #define	NOTE_JAIL_CHILD		0x80000000	/* child jail was created */
225 #define	NOTE_JAIL_SET		0x40000000	/* jail was modified */
226 #define	NOTE_JAIL_ATTACH	0x20000000	/* jail was attached to */
227 #define	NOTE_JAIL_REMOVE	0x10000000	/* jail was removed */
228 #define NOTE_JAIL_MULTI		0x08000000	/* multiple child or attach */
229 #define	NOTE_JAIL_CTRLMASK	0xf0000000	/* mask for hint bits */
230 
231 /* additional flags for EVFILT_TIMER */
232 #define NOTE_SECONDS		0x00000001	/* data is seconds */
233 #define NOTE_MSECONDS		0x00000002	/* data is milliseconds */
234 #define NOTE_USECONDS		0x00000004	/* data is microseconds */
235 #define NOTE_NSECONDS		0x00000008	/* data is nanoseconds */
236 #define	NOTE_ABSTIME		0x00000010	/* timeout is absolute */
237 
238 /* Flags for kqueuex(2) */
239 #define	KQUEUE_CLOEXEC	0x00000001	/* close on exec */
240 #define	KQUEUE_CPONFORK	0x00000002	/* copy on fork */
241 
242 struct knote;
243 SLIST_HEAD(klist, knote);
244 struct kqueue;
245 TAILQ_HEAD(kqlist, kqueue);
246 struct knlist {
247 	struct	klist	kl_list;
248 	void    (*kl_lock)(void *);	/* lock function */
249 	void    (*kl_unlock)(void *);
250 	void	(*kl_assert_lock)(void *, int);
251 	void	*kl_lockarg;		/* argument passed to lock functions */
252 	int	kl_autodestroy;
253 };
254 
255 #ifdef _KERNEL
256 
257 /*
258  * Flags for knote call
259  */
260 #define	KNF_LISTLOCKED	0x0001			/* knlist is locked */
261 #define	KNF_NOKQLOCK	0x0002			/* do not keep KQ_LOCK */
262 
263 #define KNOTE(list, hint, flags)	knote(list, hint, flags)
264 #define KNOTE_LOCKED(list, hint)	knote(list, hint, KNF_LISTLOCKED)
265 #define KNOTE_UNLOCKED(list, hint)	knote(list, hint, 0)
266 
267 #define	KNLIST_EMPTY(list)		SLIST_EMPTY(&(list)->kl_list)
268 
269 /*
270  * Hint values for the optional f_touch event filter.  If f_touch is not set
271  * to NULL and f_isfd is zero the f_touch filter will be called with the type
272  * argument set to EVENT_REGISTER during a kevent() system call.  It is also
273  * called under the same conditions with the type argument set to EVENT_PROCESS
274  * when the event has been triggered.
275  */
276 #define EVENT_REGISTER	1
277 #define EVENT_PROCESS	2
278 
279 struct kinfo_knote;
280 struct proc;
281 
282 struct filterops {
283 	int	f_isfd;		/* true if ident == filedescriptor */
284 	int	(*f_attach)(struct knote *kn);
285 	void	(*f_detach)(struct knote *kn);
286 	int	(*f_event)(struct knote *kn, long hint);
287 	void	(*f_touch)(struct knote *kn, struct kevent *kev, u_long type);
288 	int	(*f_userdump)(struct proc *p, struct knote *kn,
289 		    struct kinfo_knote *kin);
290 	int	(*f_copy)(struct knote *kn, struct proc *p1);
291 };
292 
293 /*
294  * An in-flux knote cannot be dropped from its kq while the kq is
295  * unlocked.  If the KN_SCAN flag is not set, a thread can only set
296  * kn_influx when it is exclusive owner of the knote state, and can
297  * modify kn_status as if it had the KQ lock.  KN_SCAN must not be set
298  * on a knote which is already in flux.
299  *
300  * kn_sfflags, kn_sdata, and kn_kevent are protected by the knlist lock.
301  */
302 struct knote {
303 	SLIST_ENTRY(knote)	kn_link;	/* for kq */
304 	SLIST_ENTRY(knote)	kn_selnext;	/* for struct selinfo */
305 	struct			knlist *kn_knlist;	/* f_attach populated */
306 	TAILQ_ENTRY(knote)	kn_tqe;
307 	struct			kqueue *kn_kq;	/* which queue we are on */
308 	struct 			kevent kn_kevent;
309 	void			*kn_hook;
310 	int			kn_hookid;
311 	int			kn_status;	/* protected by kq lock */
312 #define KN_ACTIVE	0x01			/* event has been triggered */
313 #define KN_QUEUED	0x02			/* event is on queue */
314 #define KN_DISABLED	0x04			/* event is disabled */
315 #define KN_DETACHED	0x08			/* knote is detached */
316 #define KN_MARKER	0x20			/* ignore this knote */
317 #define KN_KQUEUE	0x40			/* this knote belongs to a kq */
318 #define	KN_SCAN		0x100			/* flux set in kqueue_scan() */
319 #define	KN_CPONFORK	(KN_ACTIVE | KN_DISABLED) /* state preserved by fork */
320 	int			kn_influx;
321 	unsigned int		kn_sfflags;	/* saved filter flags */
322 	int64_t			kn_sdata;	/* saved data field */
323 	union {
324 		struct		file *p_fp;	/* file data pointer */
325 		struct		proc *p_proc;	/* proc pointer */
326 		struct		kaiocb *p_aio;	/* AIO job pointer */
327 		struct		aioliojob *p_lio;	/* LIO job pointer */
328 		struct		prison *p_prison;	/* prison pointer */
329 		void		*p_v;		/* generic other pointer */
330 	} kn_ptr;
331 	const struct		filterops *kn_fop;
332 
333 #define kn_id		kn_kevent.ident
334 #define kn_filter	kn_kevent.filter
335 #define kn_flags	kn_kevent.flags
336 #define kn_fflags	kn_kevent.fflags
337 #define kn_data		kn_kevent.data
338 #define kn_fp		kn_ptr.p_fp
339 };
340 struct kevent_copyops {
341 	void	*arg;
342 	int	(*k_copyout)(void *arg, struct kevent *kevp, int count);
343 	int	(*k_copyin)(void *arg, struct kevent *kevp, int count);
344 	size_t	kevent_size;
345 };
346 
347 struct thread;
348 struct proc;
349 struct knlist;
350 struct mtx;
351 struct rwlock;
352 
353 void	knote(struct knlist *list, long hint, int lockflags);
354 void	knote_fork(struct knlist *list, int pid);
355 int	knote_triv_copy(struct knote *kn, struct proc *p1);
356 struct knlist *knlist_alloc(struct mtx *lock);
357 void	knlist_detach(struct knlist *knl);
358 void	knlist_add(struct knlist *knl, struct knote *kn, int islocked);
359 void	knlist_remove(struct knlist *knl, struct knote *kn, int islocked);
360 int	knlist_empty(struct knlist *knl);
361 void	knlist_init(struct knlist *knl, void *lock, void (*kl_lock)(void *),
362 	    void (*kl_unlock)(void *), void (*kl_assert_lock)(void *, int));
363 void	knlist_init_mtx(struct knlist *knl, struct mtx *lock);
364 void	knlist_destroy(struct knlist *knl);
365 void	knlist_cleardel(struct knlist *knl, struct thread *td,
366 	    int islocked, int killkn);
367 #define knlist_clear(knl, islocked)				\
368 	knlist_cleardel((knl), NULL, (islocked), 0)
369 #define knlist_delete(knl, td, islocked)			\
370 	knlist_cleardel((knl), (td), (islocked), 1)
371 void	knote_fdclose(struct thread *p, int fd);
372 int 	kqfd_register(int fd, struct kevent *kev, struct thread *p,
373 	    int mflag);
374 int	kqueue_add_filteropts(int filt, const struct filterops *filtops);
375 int	kqueue_del_filteropts(int filt);
376 void	kqueue_drain_schedtask(void);
377 
378 #else 	/* !_KERNEL */
379 
380 #include <sys/cdefs.h>
381 struct timespec;
382 
383 __BEGIN_DECLS
384 int     kqueue(void);
385 int     kqueuex(unsigned flags);
386 int     kqueue1(int flags);
387 int     kevent(int kq, const struct kevent *changelist, int nchanges,
388 	    struct kevent *eventlist, int nevents,
389 	    const struct timespec *timeout);
390 __END_DECLS
391 
392 #endif /* !_KERNEL */
393 
394 #endif /* !_SYS_EVENT_H_ */
395