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