1 /* $OpenBSD: kern_event.c,v 1.33 2008/05/06 20:57:19 thib 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/kern/kern_event.c,v 1.22 2001/02/23 20:32:42 jlemon Exp $ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/kernel.h> 34 #include <sys/proc.h> 35 #include <sys/malloc.h> 36 #include <sys/unistd.h> 37 #include <sys/file.h> 38 #include <sys/filedesc.h> 39 #include <sys/fcntl.h> 40 #include <sys/selinfo.h> 41 #include <sys/queue.h> 42 #include <sys/event.h> 43 #include <sys/eventvar.h> 44 #include <sys/pool.h> 45 #include <sys/protosw.h> 46 #include <sys/socket.h> 47 #include <sys/socketvar.h> 48 #include <sys/stat.h> 49 #include <sys/uio.h> 50 #include <sys/mount.h> 51 #include <sys/poll.h> 52 #include <sys/syscallargs.h> 53 #include <sys/timeout.h> 54 55 int kqueue_scan(struct file *fp, int maxevents, 56 struct kevent *ulistp, const struct timespec *timeout, 57 struct proc *p, int *retval); 58 59 int kqueue_read(struct file *fp, off_t *poff, struct uio *uio, 60 struct ucred *cred); 61 int kqueue_write(struct file *fp, off_t *poff, struct uio *uio, 62 struct ucred *cred); 63 int kqueue_ioctl(struct file *fp, u_long com, caddr_t data, 64 struct proc *p); 65 int kqueue_poll(struct file *fp, int events, struct proc *p); 66 int kqueue_kqfilter(struct file *fp, struct knote *kn); 67 int kqueue_stat(struct file *fp, struct stat *st, struct proc *p); 68 int kqueue_close(struct file *fp, struct proc *p); 69 void kqueue_wakeup(struct kqueue *kq); 70 71 struct fileops kqueueops = { 72 kqueue_read, 73 kqueue_write, 74 kqueue_ioctl, 75 kqueue_poll, 76 kqueue_kqfilter, 77 kqueue_stat, 78 kqueue_close 79 }; 80 81 void knote_attach(struct knote *kn, struct filedesc *fdp); 82 void knote_drop(struct knote *kn, struct proc *p, struct filedesc *fdp); 83 void knote_enqueue(struct knote *kn); 84 void knote_dequeue(struct knote *kn); 85 #define knote_alloc() ((struct knote *)pool_get(&knote_pool, PR_WAITOK)) 86 #define knote_free(kn) pool_put(&knote_pool, (kn)) 87 88 void filt_kqdetach(struct knote *kn); 89 int filt_kqueue(struct knote *kn, long hint); 90 int filt_procattach(struct knote *kn); 91 void filt_procdetach(struct knote *kn); 92 int filt_proc(struct knote *kn, long hint); 93 int filt_fileattach(struct knote *kn); 94 void filt_timerexpire(void *knx); 95 int filt_timerattach(struct knote *kn); 96 void filt_timerdetach(struct knote *kn); 97 int filt_timer(struct knote *kn, long hint); 98 99 struct filterops kqread_filtops = 100 { 1, NULL, filt_kqdetach, filt_kqueue }; 101 struct filterops proc_filtops = 102 { 0, filt_procattach, filt_procdetach, filt_proc }; 103 struct filterops file_filtops = 104 { 1, filt_fileattach, NULL, NULL }; 105 struct filterops timer_filtops = 106 { 0, filt_timerattach, filt_timerdetach, filt_timer }; 107 108 struct pool knote_pool; 109 struct pool kqueue_pool; 110 int kq_ntimeouts = 0; 111 int kq_timeoutmax = (4 * 1024); 112 113 #define KNOTE_ACTIVATE(kn) do { \ 114 kn->kn_status |= KN_ACTIVE; \ 115 if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 116 knote_enqueue(kn); \ 117 } while(0) 118 119 #define KN_HASHSIZE 64 /* XXX should be tunable */ 120 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 121 122 extern struct filterops sig_filtops; 123 #ifdef notyet 124 extern struct filterops aio_filtops; 125 #endif 126 127 /* 128 * Table for for all system-defined filters. 129 */ 130 struct filterops *sysfilt_ops[] = { 131 &file_filtops, /* EVFILT_READ */ 132 &file_filtops, /* EVFILT_WRITE */ 133 NULL, /*&aio_filtops,*/ /* EVFILT_AIO */ 134 &file_filtops, /* EVFILT_VNODE */ 135 &proc_filtops, /* EVFILT_PROC */ 136 &sig_filtops, /* EVFILT_SIGNAL */ 137 &timer_filtops, /* EVFILT_TIMER */ 138 }; 139 140 void kqueue_init(void); 141 142 void 143 kqueue_init(void) 144 { 145 146 pool_init(&kqueue_pool, sizeof(struct kqueue), 0, 0, 0, "kqueuepl", 147 &pool_allocator_nointr); 148 pool_init(&knote_pool, sizeof(struct knote), 0, 0, 0, "knotepl", 149 &pool_allocator_nointr); 150 } 151 152 int 153 filt_fileattach(struct knote *kn) 154 { 155 struct file *fp = kn->kn_fp; 156 157 return ((*fp->f_ops->fo_kqfilter)(fp, kn)); 158 } 159 160 int 161 kqueue_kqfilter(struct file *fp, struct knote *kn) 162 { 163 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 164 165 if (kn->kn_filter != EVFILT_READ) 166 return (1); 167 168 kn->kn_fop = &kqread_filtops; 169 SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext); 170 return (0); 171 } 172 173 void 174 filt_kqdetach(struct knote *kn) 175 { 176 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 177 178 SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext); 179 } 180 181 /*ARGSUSED*/ 182 int 183 filt_kqueue(struct knote *kn, long hint) 184 { 185 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 186 187 kn->kn_data = kq->kq_count; 188 return (kn->kn_data > 0); 189 } 190 191 int 192 filt_procattach(struct knote *kn) 193 { 194 struct proc *p; 195 196 p = pfind(kn->kn_id); 197 if (p == NULL) 198 return (ESRCH); 199 200 /* 201 * Fail if it's not owned by you, or the last exec gave us 202 * setuid/setgid privs (unless you're root). 203 */ 204 if ((p->p_cred->p_ruid != curproc->p_cred->p_ruid || 205 (p->p_flag & P_SUGID)) && suser(curproc, 0) != 0) 206 return (EACCES); 207 208 kn->kn_ptr.p_proc = p; 209 kn->kn_flags |= EV_CLEAR; /* automatically set */ 210 211 /* 212 * internal flag indicating registration done by kernel 213 */ 214 if (kn->kn_flags & EV_FLAG1) { 215 kn->kn_data = kn->kn_sdata; /* ppid */ 216 kn->kn_fflags = NOTE_CHILD; 217 kn->kn_flags &= ~EV_FLAG1; 218 } 219 220 /* XXX lock the proc here while adding to the list? */ 221 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 222 223 return (0); 224 } 225 226 /* 227 * The knote may be attached to a different process, which may exit, 228 * leaving nothing for the knote to be attached to. So when the process 229 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 230 * it will be deleted when read out. However, as part of the knote deletion, 231 * this routine is called, so a check is needed to avoid actually performing 232 * a detach, because the original process does not exist any more. 233 */ 234 void 235 filt_procdetach(struct knote *kn) 236 { 237 struct proc *p = kn->kn_ptr.p_proc; 238 239 if (kn->kn_status & KN_DETACHED) 240 return; 241 242 /* XXX locking? this might modify another process. */ 243 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 244 } 245 246 int 247 filt_proc(struct knote *kn, long hint) 248 { 249 u_int event; 250 251 /* 252 * mask off extra data 253 */ 254 event = (u_int)hint & NOTE_PCTRLMASK; 255 256 /* 257 * if the user is interested in this event, record it. 258 */ 259 if (kn->kn_sfflags & event) 260 kn->kn_fflags |= event; 261 262 /* 263 * process is gone, so flag the event as finished. 264 */ 265 if (event == NOTE_EXIT) { 266 kn->kn_status |= KN_DETACHED; 267 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 268 return (1); 269 } 270 271 /* 272 * process forked, and user wants to track the new process, 273 * so attach a new knote to it, and immediately report an 274 * event with the parent's pid. 275 */ 276 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) { 277 struct kevent kev; 278 int error; 279 280 /* 281 * register knote with new process. 282 */ 283 kev.ident = hint & NOTE_PDATAMASK; /* pid */ 284 kev.filter = kn->kn_filter; 285 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 286 kev.fflags = kn->kn_sfflags; 287 kev.data = kn->kn_id; /* parent */ 288 kev.udata = kn->kn_kevent.udata; /* preserve udata */ 289 error = kqueue_register(kn->kn_kq, &kev, NULL); 290 if (error) 291 kn->kn_fflags |= NOTE_TRACKERR; 292 } 293 294 return (kn->kn_fflags != 0); 295 } 296 297 void 298 filt_timerexpire(void *knx) 299 { 300 struct knote *kn = knx; 301 struct timeval tv; 302 int tticks; 303 304 kn->kn_data++; 305 KNOTE_ACTIVATE(kn); 306 307 if ((kn->kn_flags & EV_ONESHOT) == 0) { 308 tv.tv_sec = kn->kn_sdata / 1000; 309 tv.tv_usec = (kn->kn_sdata % 1000) * 1000; 310 tticks = tvtohz(&tv); 311 timeout_add((struct timeout *)kn->kn_hook, tticks); 312 } 313 } 314 315 316 /* 317 * data contains amount of time to sleep, in milliseconds 318 */ 319 int 320 filt_timerattach(struct knote *kn) 321 { 322 struct timeout *to; 323 struct timeval tv; 324 int tticks; 325 326 if (kq_ntimeouts > kq_timeoutmax) 327 return (ENOMEM); 328 kq_ntimeouts++; 329 330 tv.tv_sec = kn->kn_sdata / 1000; 331 tv.tv_usec = (kn->kn_sdata % 1000) * 1000; 332 tticks = tvtohz(&tv); 333 334 kn->kn_flags |= EV_CLEAR; /* automatically set */ 335 to = malloc(sizeof(*to), M_KEVENT, M_WAITOK); 336 timeout_set(to, filt_timerexpire, kn); 337 timeout_add(to, tticks); 338 kn->kn_hook = to; 339 340 return (0); 341 } 342 343 void 344 filt_timerdetach(struct knote *kn) 345 { 346 struct timeout *to; 347 348 to = (struct timeout *)kn->kn_hook; 349 timeout_del(to); 350 free(to, M_KEVENT); 351 kq_ntimeouts--; 352 } 353 354 int 355 filt_timer(struct knote *kn, long hint) 356 { 357 return (kn->kn_data != 0); 358 } 359 360 361 /* 362 * filt_seltrue: 363 * 364 * This filter "event" routine simulates seltrue(). 365 */ 366 int 367 filt_seltrue(struct knote *kn, long hint) 368 { 369 370 /* 371 * We don't know how much data can be read/written, 372 * but we know that it *can* be. This is about as 373 * good as select/poll does as well. 374 */ 375 kn->kn_data = 0; 376 return (1); 377 } 378 379 int 380 sys_kqueue(struct proc *p, void *v, register_t *retval) 381 { 382 struct filedesc *fdp = p->p_fd; 383 struct kqueue *kq; 384 struct file *fp; 385 int fd, error; 386 387 error = falloc(p, &fp, &fd); 388 if (error) 389 return (error); 390 fp->f_flag = FREAD | FWRITE; 391 fp->f_type = DTYPE_KQUEUE; 392 fp->f_ops = &kqueueops; 393 kq = pool_get(&kqueue_pool, PR_WAITOK|PR_ZERO); 394 TAILQ_INIT(&kq->kq_head); 395 fp->f_data = (caddr_t)kq; 396 *retval = fd; 397 if (fdp->fd_knlistsize < 0) 398 fdp->fd_knlistsize = 0; /* this process has a kq */ 399 kq->kq_fdp = fdp; 400 FILE_SET_MATURE(fp); 401 return (0); 402 } 403 404 int 405 sys_kevent(struct proc *p, void *v, register_t *retval) 406 { 407 struct filedesc* fdp = p->p_fd; 408 struct sys_kevent_args /* { 409 syscallarg(int) fd; 410 syscallarg(const struct kevent *) changelist; 411 syscallarg(int) nchanges; 412 syscallarg(struct kevent *) eventlist; 413 syscallarg(int) nevents; 414 syscallarg(const struct timespec *) timeout; 415 } */ *uap = v; 416 struct kevent *kevp; 417 struct kqueue *kq; 418 struct file *fp; 419 struct timespec ts; 420 int i, n, nerrors, error; 421 422 if ((fp = fd_getfile(fdp, SCARG(uap, fd))) == NULL || 423 (fp->f_type != DTYPE_KQUEUE)) 424 return (EBADF); 425 426 FREF(fp); 427 428 if (SCARG(uap, timeout) != NULL) { 429 error = copyin(SCARG(uap, timeout), &ts, sizeof(ts)); 430 if (error) 431 goto done; 432 SCARG(uap, timeout) = &ts; 433 } 434 435 kq = (struct kqueue *)fp->f_data; 436 nerrors = 0; 437 438 while (SCARG(uap, nchanges) > 0) { 439 n = SCARG(uap, nchanges) > KQ_NEVENTS 440 ? KQ_NEVENTS : SCARG(uap, nchanges); 441 error = copyin(SCARG(uap, changelist), kq->kq_kev, 442 n * sizeof(struct kevent)); 443 if (error) 444 goto done; 445 for (i = 0; i < n; i++) { 446 kevp = &kq->kq_kev[i]; 447 kevp->flags &= ~EV_SYSFLAGS; 448 error = kqueue_register(kq, kevp, p); 449 if (error) { 450 if (SCARG(uap, nevents) != 0) { 451 kevp->flags = EV_ERROR; 452 kevp->data = error; 453 (void) copyout((caddr_t)kevp, 454 (caddr_t)SCARG(uap, eventlist), 455 sizeof(*kevp)); 456 SCARG(uap, eventlist)++; 457 SCARG(uap, nevents)--; 458 nerrors++; 459 } else { 460 goto done; 461 } 462 } 463 } 464 SCARG(uap, nchanges) -= n; 465 SCARG(uap, changelist) += n; 466 } 467 if (nerrors) { 468 *retval = nerrors; 469 error = 0; 470 goto done; 471 } 472 473 error = kqueue_scan(fp, SCARG(uap, nevents), SCARG(uap, eventlist), 474 SCARG(uap, timeout), p, &n); 475 *retval = n; 476 done: 477 FRELE(fp); 478 return (error); 479 } 480 481 int 482 kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p) 483 { 484 struct filedesc *fdp = kq->kq_fdp; 485 struct filterops *fops = NULL; 486 struct file *fp = NULL; 487 struct knote *kn = NULL; 488 int s, error = 0; 489 490 if (kev->filter < 0) { 491 if (kev->filter + EVFILT_SYSCOUNT < 0) 492 return (EINVAL); 493 fops = sysfilt_ops[~kev->filter]; /* to 0-base index */ 494 } 495 496 if (fops == NULL) { 497 /* 498 * XXX 499 * filter attach routine is responsible for ensuring that 500 * the identifier can be attached to it. 501 */ 502 return (EINVAL); 503 } 504 505 if (fops->f_isfd) { 506 /* validate descriptor */ 507 if ((fp = fd_getfile(fdp, kev->ident)) == NULL) 508 return (EBADF); 509 FREF(fp); 510 fp->f_count++; 511 512 if (kev->ident < fdp->fd_knlistsize) { 513 SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link) 514 if (kq == kn->kn_kq && 515 kev->filter == kn->kn_filter) 516 break; 517 } 518 } else { 519 if (fdp->fd_knhashmask != 0) { 520 struct klist *list; 521 522 list = &fdp->fd_knhash[ 523 KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)]; 524 SLIST_FOREACH(kn, list, kn_link) 525 if (kev->ident == kn->kn_id && 526 kq == kn->kn_kq && 527 kev->filter == kn->kn_filter) 528 break; 529 } 530 } 531 532 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) { 533 error = ENOENT; 534 goto done; 535 } 536 537 /* 538 * kn now contains the matching knote, or NULL if no match 539 */ 540 if (kev->flags & EV_ADD) { 541 542 if (kn == NULL) { 543 kn = knote_alloc(); 544 if (kn == NULL) { 545 error = ENOMEM; 546 goto done; 547 } 548 kn->kn_fp = fp; 549 kn->kn_kq = kq; 550 kn->kn_fop = fops; 551 552 /* 553 * apply reference count to knote structure, and 554 * do not release it at the end of this routine. 555 */ 556 if (fp != NULL) 557 FRELE(fp); 558 fp = NULL; 559 560 kn->kn_sfflags = kev->fflags; 561 kn->kn_sdata = kev->data; 562 kev->fflags = 0; 563 kev->data = 0; 564 kn->kn_kevent = *kev; 565 566 knote_attach(kn, fdp); 567 if ((error = fops->f_attach(kn)) != 0) { 568 knote_drop(kn, p, fdp); 569 goto done; 570 } 571 } else { 572 /* 573 * The user may change some filter values after the 574 * initial EV_ADD, but doing so will not reset any 575 * filters which have already been triggered. 576 */ 577 kn->kn_sfflags = kev->fflags; 578 kn->kn_sdata = kev->data; 579 kn->kn_kevent.udata = kev->udata; 580 } 581 582 s = splhigh(); 583 if (kn->kn_fop->f_event(kn, 0)) 584 KNOTE_ACTIVATE(kn); 585 splx(s); 586 587 } else if (kev->flags & EV_DELETE) { 588 kn->kn_fop->f_detach(kn); 589 knote_drop(kn, p, p->p_fd); 590 goto done; 591 } 592 593 if ((kev->flags & EV_DISABLE) && 594 ((kn->kn_status & KN_DISABLED) == 0)) { 595 s = splhigh(); 596 kn->kn_status |= KN_DISABLED; 597 splx(s); 598 } 599 600 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 601 s = splhigh(); 602 kn->kn_status &= ~KN_DISABLED; 603 if ((kn->kn_status & KN_ACTIVE) && 604 ((kn->kn_status & KN_QUEUED) == 0)) 605 knote_enqueue(kn); 606 splx(s); 607 } 608 609 done: 610 if (fp != NULL) 611 closef(fp, p); 612 return (error); 613 } 614 615 int 616 kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp, 617 const struct timespec *tsp, struct proc *p, int *retval) 618 { 619 struct kqueue *kq = (struct kqueue *)fp->f_data; 620 struct kevent *kevp; 621 struct timeval atv, rtv, ttv; 622 struct knote *kn, marker; 623 int s, count, timeout, nkev = 0, error = 0; 624 625 count = maxevents; 626 if (count == 0) 627 goto done; 628 629 if (tsp != NULL) { 630 TIMESPEC_TO_TIMEVAL(&atv, tsp); 631 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) { 632 /* No timeout, just poll */ 633 timeout = -1; 634 goto start; 635 } 636 if (itimerfix(&atv)) { 637 error = EINVAL; 638 goto done; 639 } 640 641 timeout = atv.tv_sec > 24 * 60 * 60 ? 642 24 * 60 * 60 * hz : tvtohz(&atv); 643 644 getmicrouptime(&rtv); 645 timeradd(&atv, &rtv, &atv); 646 } else { 647 atv.tv_sec = 0; 648 atv.tv_usec = 0; 649 timeout = 0; 650 } 651 goto start; 652 653 retry: 654 if (atv.tv_sec || atv.tv_usec) { 655 getmicrouptime(&rtv); 656 if (timercmp(&rtv, &atv, >=)) 657 goto done; 658 ttv = atv; 659 timersub(&ttv, &rtv, &ttv); 660 timeout = ttv.tv_sec > 24 * 60 * 60 ? 661 24 * 60 * 60 * hz : tvtohz(&ttv); 662 } 663 664 start: 665 kevp = kq->kq_kev; 666 s = splhigh(); 667 if (kq->kq_count == 0) { 668 if (timeout < 0) { 669 error = EWOULDBLOCK; 670 } else { 671 kq->kq_state |= KQ_SLEEP; 672 error = tsleep(kq, PSOCK | PCATCH, "kqread", timeout); 673 } 674 splx(s); 675 if (error == 0) 676 goto retry; 677 /* don't restart after signals... */ 678 if (error == ERESTART) 679 error = EINTR; 680 else if (error == EWOULDBLOCK) 681 error = 0; 682 goto done; 683 } 684 685 TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe); 686 while (count) { 687 kn = TAILQ_FIRST(&kq->kq_head); 688 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 689 if (kn == &marker) { 690 splx(s); 691 if (count == maxevents) 692 goto retry; 693 goto done; 694 } 695 if (kn->kn_status & KN_DISABLED) { 696 kn->kn_status &= ~KN_QUEUED; 697 kq->kq_count--; 698 continue; 699 } 700 if ((kn->kn_flags & EV_ONESHOT) == 0 && 701 kn->kn_fop->f_event(kn, 0) == 0) { 702 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 703 kq->kq_count--; 704 continue; 705 } 706 *kevp = kn->kn_kevent; 707 kevp++; 708 nkev++; 709 if (kn->kn_flags & EV_ONESHOT) { 710 kn->kn_status &= ~KN_QUEUED; 711 kq->kq_count--; 712 splx(s); 713 kn->kn_fop->f_detach(kn); 714 knote_drop(kn, p, p->p_fd); 715 s = splhigh(); 716 } else if (kn->kn_flags & EV_CLEAR) { 717 kn->kn_data = 0; 718 kn->kn_fflags = 0; 719 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 720 kq->kq_count--; 721 } else { 722 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 723 } 724 count--; 725 if (nkev == KQ_NEVENTS) { 726 splx(s); 727 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, 728 sizeof(struct kevent) * nkev); 729 ulistp += nkev; 730 nkev = 0; 731 kevp = kq->kq_kev; 732 s = splhigh(); 733 if (error) 734 break; 735 } 736 } 737 TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe); 738 splx(s); 739 done: 740 if (nkev != 0) 741 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, 742 sizeof(struct kevent) * nkev); 743 *retval = maxevents - count; 744 return (error); 745 } 746 747 /* 748 * XXX 749 * This could be expanded to call kqueue_scan, if desired. 750 */ 751 /*ARGSUSED*/ 752 int 753 kqueue_read(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred) 754 { 755 return (ENXIO); 756 } 757 758 /*ARGSUSED*/ 759 int 760 kqueue_write(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred) 761 762 { 763 return (ENXIO); 764 } 765 766 /*ARGSUSED*/ 767 int 768 kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p) 769 { 770 return (ENOTTY); 771 } 772 773 /*ARGSUSED*/ 774 int 775 kqueue_poll(struct file *fp, int events, struct proc *p) 776 { 777 struct kqueue *kq = (struct kqueue *)fp->f_data; 778 int revents = 0; 779 int s = splhigh(); 780 781 if (events & (POLLIN | POLLRDNORM)) { 782 if (kq->kq_count) { 783 revents |= events & (POLLIN | POLLRDNORM); 784 } else { 785 selrecord(p, &kq->kq_sel); 786 kq->kq_state |= KQ_SEL; 787 } 788 } 789 splx(s); 790 return (revents); 791 } 792 793 /*ARGSUSED*/ 794 int 795 kqueue_stat(struct file *fp, struct stat *st, struct proc *p) 796 { 797 struct kqueue *kq = (struct kqueue *)fp->f_data; 798 799 bzero((void *)st, sizeof(*st)); 800 st->st_size = kq->kq_count; 801 st->st_blksize = sizeof(struct kevent); 802 st->st_mode = S_IFIFO; 803 return (0); 804 } 805 806 /*ARGSUSED*/ 807 int 808 kqueue_close(struct file *fp, struct proc *p) 809 { 810 struct kqueue *kq = (struct kqueue *)fp->f_data; 811 struct filedesc *fdp = p->p_fd; 812 struct knote **knp, *kn, *kn0; 813 int i; 814 815 for (i = 0; i < fdp->fd_knlistsize; i++) { 816 knp = &SLIST_FIRST(&fdp->fd_knlist[i]); 817 kn = *knp; 818 while (kn != NULL) { 819 kn0 = SLIST_NEXT(kn, kn_link); 820 if (kq == kn->kn_kq) { 821 FREF(kn->kn_fp); 822 kn->kn_fop->f_detach(kn); 823 closef(kn->kn_fp, p); 824 knote_free(kn); 825 *knp = kn0; 826 } else { 827 knp = &SLIST_NEXT(kn, kn_link); 828 } 829 kn = kn0; 830 } 831 } 832 if (fdp->fd_knhashmask != 0) { 833 for (i = 0; i < fdp->fd_knhashmask + 1; i++) { 834 knp = &SLIST_FIRST(&fdp->fd_knhash[i]); 835 kn = *knp; 836 while (kn != NULL) { 837 kn0 = SLIST_NEXT(kn, kn_link); 838 if (kq == kn->kn_kq) { 839 kn->kn_fop->f_detach(kn); 840 /* XXX non-fd release of kn->kn_ptr */ 841 knote_free(kn); 842 *knp = kn0; 843 } else { 844 knp = &SLIST_NEXT(kn, kn_link); 845 } 846 kn = kn0; 847 } 848 } 849 } 850 pool_put(&kqueue_pool, kq); 851 fp->f_data = NULL; 852 853 return (0); 854 } 855 856 void 857 kqueue_wakeup(struct kqueue *kq) 858 { 859 860 if (kq->kq_state & KQ_SLEEP) { 861 kq->kq_state &= ~KQ_SLEEP; 862 wakeup(kq); 863 } 864 if (kq->kq_state & KQ_SEL) { 865 kq->kq_state &= ~KQ_SEL; 866 selwakeup(&kq->kq_sel); 867 } 868 KNOTE(&kq->kq_sel.si_note, 0); 869 } 870 871 /* 872 * walk down a list of knotes, activating them if their event has triggered. 873 */ 874 void 875 knote(struct klist *list, long hint) 876 { 877 struct knote *kn; 878 879 SLIST_FOREACH(kn, list, kn_selnext) 880 if (kn->kn_fop->f_event(kn, hint)) 881 KNOTE_ACTIVATE(kn); 882 } 883 884 /* 885 * remove all knotes from a specified klist 886 */ 887 void 888 knote_remove(struct proc *p, struct klist *list) 889 { 890 struct knote *kn; 891 892 while ((kn = SLIST_FIRST(list)) != NULL) { 893 kn->kn_fop->f_detach(kn); 894 knote_drop(kn, p, p->p_fd); 895 } 896 } 897 898 /* 899 * remove all knotes referencing a specified fd 900 */ 901 void 902 knote_fdclose(struct proc *p, int fd) 903 { 904 struct filedesc *fdp = p->p_fd; 905 struct klist *list = &fdp->fd_knlist[fd]; 906 907 knote_remove(p, list); 908 } 909 910 void 911 knote_attach(struct knote *kn, struct filedesc *fdp) 912 { 913 struct klist *list; 914 int size; 915 916 if (! kn->kn_fop->f_isfd) { 917 if (fdp->fd_knhashmask == 0) 918 fdp->fd_knhash = hashinit(KN_HASHSIZE, M_TEMP, 919 M_WAITOK, &fdp->fd_knhashmask); 920 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 921 goto done; 922 } 923 924 if (fdp->fd_knlistsize <= kn->kn_id) { 925 size = fdp->fd_knlistsize; 926 while (size <= kn->kn_id) 927 size += KQEXTENT; 928 list = malloc(size * sizeof(struct klist *), M_TEMP, M_WAITOK); 929 bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list, 930 fdp->fd_knlistsize * sizeof(struct klist *)); 931 bzero((caddr_t)list + 932 fdp->fd_knlistsize * sizeof(struct klist *), 933 (size - fdp->fd_knlistsize) * sizeof(struct klist *)); 934 if (fdp->fd_knlist != NULL) 935 free(fdp->fd_knlist, M_TEMP); 936 fdp->fd_knlistsize = size; 937 fdp->fd_knlist = list; 938 } 939 list = &fdp->fd_knlist[kn->kn_id]; 940 done: 941 SLIST_INSERT_HEAD(list, kn, kn_link); 942 kn->kn_status = 0; 943 } 944 945 /* 946 * should be called at spl == 0, since we don't want to hold spl 947 * while calling closef and free. 948 */ 949 void 950 knote_drop(struct knote *kn, struct proc *p, struct filedesc *fdp) 951 { 952 struct klist *list; 953 954 if (kn->kn_fop->f_isfd) 955 list = &fdp->fd_knlist[kn->kn_id]; 956 else 957 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 958 959 SLIST_REMOVE(list, kn, knote, kn_link); 960 if (kn->kn_status & KN_QUEUED) 961 knote_dequeue(kn); 962 if (kn->kn_fop->f_isfd) { 963 FREF(kn->kn_fp); 964 closef(kn->kn_fp, p); 965 } 966 knote_free(kn); 967 } 968 969 970 void 971 knote_enqueue(struct knote *kn) 972 { 973 struct kqueue *kq = kn->kn_kq; 974 int s = splhigh(); 975 976 KASSERT((kn->kn_status & KN_QUEUED) == 0); 977 978 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 979 kn->kn_status |= KN_QUEUED; 980 kq->kq_count++; 981 splx(s); 982 kqueue_wakeup(kq); 983 } 984 985 void 986 knote_dequeue(struct knote *kn) 987 { 988 struct kqueue *kq = kn->kn_kq; 989 int s = splhigh(); 990 991 KASSERT(kn->kn_status & KN_QUEUED); 992 993 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 994 kn->kn_status &= ~KN_QUEUED; 995 kq->kq_count--; 996 splx(s); 997 } 998 999 void 1000 klist_invalidate(struct klist *list) 1001 { 1002 struct knote *kn; 1003 1004 SLIST_FOREACH(kn, list, kn_selnext) { 1005 kn->kn_status |= KN_DETACHED; 1006 kn->kn_flags |= EV_EOF | EV_ONESHOT; 1007 } 1008 } 1009