1 /*- 2 * Copyright (c) 1999,2000 Jonathan Lemon <jlemon@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/kernel.h> 32 #include <sys/proc.h> 33 #include <sys/malloc.h> 34 #include <sys/unistd.h> 35 #include <sys/file.h> 36 #include <sys/fcntl.h> 37 #include <sys/select.h> 38 #include <sys/queue.h> 39 #include <sys/event.h> 40 #include <sys/eventvar.h> 41 #include <sys/poll.h> 42 #include <sys/protosw.h> 43 #include <sys/socket.h> 44 #include <sys/socketvar.h> 45 #include <sys/stat.h> 46 #include <sys/sysproto.h> 47 #include <sys/uio.h> 48 49 #include <vm/vm_zone.h> 50 51 static int filt_nullattach(struct knote *kn); 52 static int filt_rwtypattach(struct knote *kn); 53 static int filt_kqattach(struct knote *kn); 54 static void filt_kqdetach(struct knote *kn); 55 static int filt_kqueue(struct knote *kn, long hint); 56 static int filt_procattach(struct knote *kn); 57 static void filt_procdetach(struct knote *kn); 58 static int filt_proc(struct knote *kn, long hint); 59 60 static int kqueue_scan(struct file *fp, int maxevents, 61 struct kevent *ulistp, const struct timespec *timeout, 62 struct proc *p); 63 static int kqueue_read(struct file *fp, struct uio *uio, 64 struct ucred *cred, int flags, struct proc *p); 65 static int kqueue_write(struct file *fp, struct uio *uio, 66 struct ucred *cred, int flags, struct proc *p); 67 static int kqueue_ioctl(struct file *fp, u_long com, caddr_t data, 68 struct proc *p); 69 static int kqueue_poll(struct file *fp, int events, struct ucred *cred, 70 struct proc *p); 71 static int kqueue_stat(struct file *fp, struct stat *st, struct proc *p); 72 static int kqueue_close(struct file *fp, struct proc *p); 73 static void kqueue_wakeup(struct kqueue *kq); 74 75 static void knote_attach(struct knote *kn, struct filedesc *fdp); 76 static void knote_drop(struct knote *kn, struct proc *p); 77 static void knote_enqueue(struct knote *kn); 78 static void knote_dequeue(struct knote *kn); 79 static void knote_init(void); 80 static struct knote *knote_alloc(void); 81 static void knote_free(struct knote *kn); 82 83 static vm_zone_t knote_zone; 84 85 #define KNOTE_ACTIVATE(kn) do { \ 86 kn->kn_status |= KN_ACTIVE; \ 87 if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ 88 knote_enqueue(kn); \ 89 } while(0) 90 91 #define KN_HASHSIZE 64 /* XXX should be tunable */ 92 #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) 93 94 static struct fileops kqueueops = { 95 kqueue_read, 96 kqueue_write, 97 kqueue_ioctl, 98 kqueue_poll, 99 kqueue_stat, 100 kqueue_close 101 }; 102 103 extern struct filterops so_rwfiltops[]; 104 extern struct filterops fifo_rwfiltops[]; 105 extern struct filterops pipe_rwfiltops[]; 106 extern struct filterops vn_rwfiltops[]; 107 108 static struct filterops kq_rwfiltops[] = { 109 { 1, filt_kqattach, filt_kqdetach, filt_kqueue }, 110 { 1, filt_nullattach, NULL, NULL }, 111 }; 112 113 extern struct filterops aio_filtops; 114 extern struct filterops sig_filtops; 115 extern struct filterops vn_filtops; 116 117 static struct filterops rwtype_filtops = 118 { 1, filt_rwtypattach, NULL, NULL }; 119 static struct filterops proc_filtops = 120 { 0, filt_procattach, filt_procdetach, filt_proc }; 121 122 /* 123 * XXX 124 * These must match the order of defines in <sys/file.h> 125 */ 126 static struct filterops *rwtypfilt_sw[] = { 127 NULL, /* 0 */ 128 vn_rwfiltops, /* DTYPE_VNODE */ 129 so_rwfiltops, /* DTYPE_SOCKET */ 130 pipe_rwfiltops, /* DTYPE_PIPE */ 131 fifo_rwfiltops, /* DTYPE_FIFO */ 132 kq_rwfiltops, /* DTYPE_KQUEUE */ 133 }; 134 135 /* 136 * table for for all system-defined filters. 137 */ 138 static struct filterops *sysfilt_ops[] = { 139 &rwtype_filtops, /* EVFILT_READ */ 140 &rwtype_filtops, /* EVFILT_WRITE */ 141 &aio_filtops, /* EVFILT_AIO */ 142 &vn_filtops, /* EVFILT_VNODE */ 143 &proc_filtops, /* EVFILT_PROC */ 144 &sig_filtops, /* EVFILT_SIGNAL */ 145 }; 146 147 static int 148 filt_nullattach(struct knote *kn) 149 { 150 return (ENXIO); 151 } 152 153 /* 154 * file-type specific attach routine for read/write filters 155 */ 156 static int 157 filt_rwtypattach(struct knote *kn) 158 { 159 struct filterops *fops; 160 161 fops = rwtypfilt_sw[kn->kn_fp->f_type]; 162 if (fops == NULL) 163 return (EINVAL); 164 kn->kn_fop = &fops[~kn->kn_filter]; /* convert to 0-base index */ 165 return (kn->kn_fop->f_attach(kn)); 166 } 167 168 static int 169 filt_kqattach(struct knote *kn) 170 { 171 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 172 173 SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext); 174 return (0); 175 } 176 177 static void 178 filt_kqdetach(struct knote *kn) 179 { 180 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 181 182 SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext); 183 } 184 185 /*ARGSUSED*/ 186 static int 187 filt_kqueue(struct knote *kn, long hint) 188 { 189 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; 190 191 kn->kn_data = kq->kq_count; 192 return (kn->kn_data > 0); 193 } 194 195 static int 196 filt_procattach(struct knote *kn) 197 { 198 struct proc *p; 199 200 p = pfind(kn->kn_id); 201 if (p == NULL) 202 return (ESRCH); 203 if (p_can(curproc, p, P_CAN_SEE, NULL)) 204 return (EACCES); 205 206 kn->kn_ptr.p_proc = p; 207 kn->kn_flags |= EV_CLEAR; /* automatically set */ 208 209 /* 210 * internal flag indicating registration done by kernel 211 */ 212 if (kn->kn_flags & EV_FLAG1) { 213 kn->kn_data = kn->kn_sdata; /* ppid */ 214 kn->kn_fflags = NOTE_CHILD; 215 kn->kn_flags &= ~EV_FLAG1; 216 } 217 218 /* XXX lock the proc here while adding to the list? */ 219 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); 220 221 return (0); 222 } 223 224 /* 225 * The knote may be attached to a different process, which may exit, 226 * leaving nothing for the knote to be attached to. So when the process 227 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so 228 * it will be deleted when read out. However, as part of the knote deletion, 229 * this routine is called, so a check is needed to avoid actually performing 230 * a detach, because the original process does not exist any more. 231 */ 232 static void 233 filt_procdetach(struct knote *kn) 234 { 235 struct proc *p = kn->kn_ptr.p_proc; 236 237 if (kn->kn_status & KN_DETACHED) 238 return; 239 240 /* XXX locking? this might modify another process. */ 241 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); 242 } 243 244 static int 245 filt_proc(struct knote *kn, long hint) 246 { 247 u_int event; 248 249 /* 250 * mask off extra data 251 */ 252 event = (u_int)hint & NOTE_PCTRLMASK; 253 254 /* 255 * if the user is interested in this event, record it. 256 */ 257 if (kn->kn_sfflags & event) 258 kn->kn_fflags |= event; 259 260 /* 261 * process is gone, so flag the event as finished. 262 */ 263 if (event == NOTE_EXIT) { 264 kn->kn_status |= KN_DETACHED; 265 kn->kn_flags |= (EV_EOF | EV_ONESHOT); 266 return (1); 267 } 268 269 /* 270 * process forked, and user wants to track the new process, 271 * so attach a new knote to it, and immediately report an 272 * event with the parent's pid. 273 */ 274 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) { 275 struct kevent kev; 276 int error; 277 278 /* 279 * register knote with new process. 280 */ 281 kev.ident = hint & NOTE_PDATAMASK; /* pid */ 282 kev.filter = kn->kn_filter; 283 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; 284 kev.fflags = kn->kn_sfflags; 285 kev.data = kn->kn_id; /* parent */ 286 kev.udata = kn->kn_kevent.udata; /* preserve udata */ 287 error = kqueue_register(kn->kn_kq, &kev, NULL); 288 if (error) 289 kn->kn_fflags |= NOTE_TRACKERR; 290 } 291 292 return (kn->kn_fflags != 0); 293 } 294 295 int 296 kqueue(struct proc *p, struct kqueue_args *uap) 297 { 298 struct filedesc *fdp = p->p_fd; 299 struct kqueue *kq; 300 struct file *fp; 301 int fd, error; 302 303 error = falloc(p, &fp, &fd); 304 if (error) 305 return (error); 306 fp->f_flag = FREAD | FWRITE; 307 fp->f_type = DTYPE_KQUEUE; 308 fp->f_ops = &kqueueops; 309 kq = malloc(sizeof(struct kqueue), M_TEMP, M_WAITOK | M_ZERO); 310 TAILQ_INIT(&kq->kq_head); 311 fp->f_data = (caddr_t)kq; 312 p->p_retval[0] = fd; 313 if (fdp->fd_knlistsize < 0) 314 fdp->fd_knlistsize = 0; /* this process has a kq */ 315 kq->kq_fdp = fdp; 316 return (error); 317 } 318 319 #ifndef _SYS_SYSPROTO_H_ 320 struct kevent_args { 321 int fd; 322 const struct kevent *changelist; 323 int nchanges; 324 struct kevent *eventlist; 325 int nevents; 326 const struct timespec *timeout; 327 }; 328 #endif 329 int 330 kevent(struct proc *p, struct kevent_args *uap) 331 { 332 struct filedesc* fdp = p->p_fd; 333 struct kevent *kevp; 334 struct kqueue *kq; 335 struct file *fp = NULL; 336 struct timespec ts; 337 int i, n, nerrors, error; 338 339 if (((u_int)uap->fd) >= fdp->fd_nfiles || 340 (fp = fdp->fd_ofiles[uap->fd]) == NULL || 341 (fp->f_type != DTYPE_KQUEUE)) 342 return (EBADF); 343 344 fhold(fp); 345 346 if (uap->timeout != NULL) { 347 error = copyin(uap->timeout, &ts, sizeof(ts)); 348 if (error) 349 goto done; 350 uap->timeout = &ts; 351 } 352 353 kq = (struct kqueue *)fp->f_data; 354 nerrors = 0; 355 356 while (uap->nchanges > 0) { 357 n = uap->nchanges > KQ_NEVENTS ? KQ_NEVENTS : uap->nchanges; 358 error = copyin(uap->changelist, kq->kq_kev, 359 n * sizeof(struct kevent)); 360 if (error) 361 goto done; 362 for (i = 0; i < n; i++) { 363 kevp = &kq->kq_kev[i]; 364 kevp->flags &= ~EV_SYSFLAGS; 365 error = kqueue_register(kq, kevp, p); 366 if (error) { 367 if (uap->nevents != 0) { 368 kevp->flags = EV_ERROR; 369 kevp->data = error; 370 (void) copyout((caddr_t)kevp, 371 (caddr_t)uap->eventlist, 372 sizeof(*kevp)); 373 uap->eventlist++; 374 uap->nevents--; 375 nerrors++; 376 } else { 377 goto done; 378 } 379 } 380 } 381 uap->nchanges -= n; 382 uap->changelist += n; 383 } 384 if (nerrors) { 385 p->p_retval[0] = nerrors; 386 error = 0; 387 goto done; 388 } 389 390 error = kqueue_scan(fp, uap->nevents, uap->eventlist, uap->timeout, p); 391 done: 392 if (fp != NULL) 393 fdrop(fp, p); 394 return (error); 395 } 396 397 int 398 kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p) 399 { 400 struct filedesc *fdp = kq->kq_fdp; 401 struct filterops *fops; 402 struct file *fp = NULL; 403 struct knote *kn = NULL; 404 int s, error = 0; 405 406 if (kev->filter < 0) { 407 if (kev->filter + EVFILT_SYSCOUNT < 0) 408 return (EINVAL); 409 fops = sysfilt_ops[~kev->filter]; /* to 0-base index */ 410 } else { 411 /* 412 * XXX 413 * filter attach routine is responsible for insuring that 414 * the identifier can be attached to it. 415 */ 416 printf("unknown filter: %d\n", kev->filter); 417 return (EINVAL); 418 } 419 420 if (fops->f_isfd) { 421 /* validate descriptor */ 422 if ((u_int)kev->ident >= fdp->fd_nfiles || 423 (fp = fdp->fd_ofiles[kev->ident]) == NULL) 424 return (EBADF); 425 fhold(fp); 426 427 if (kev->ident < fdp->fd_knlistsize) { 428 SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link) 429 if (kq == kn->kn_kq && 430 kev->filter == kn->kn_filter) 431 break; 432 } 433 } else { 434 if (fdp->fd_knhashmask != 0) { 435 struct klist *list; 436 437 list = &fdp->fd_knhash[ 438 KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)]; 439 SLIST_FOREACH(kn, list, kn_link) 440 if (kev->ident == kn->kn_id && 441 kq == kn->kn_kq && 442 kev->filter == kn->kn_filter) 443 break; 444 } 445 } 446 447 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) { 448 error = ENOENT; 449 goto done; 450 } 451 452 /* 453 * kn now contains the matching knote, or NULL if no match 454 */ 455 if (kev->flags & EV_ADD) { 456 457 if (kn == NULL) { 458 kn = knote_alloc(); 459 if (kn == NULL) { 460 error = ENOMEM; 461 goto done; 462 } 463 kn->kn_fp = fp; 464 kn->kn_kq = kq; 465 kn->kn_fop = fops; 466 467 /* 468 * apply reference count to knode structure, so 469 * do not release it at the end of this routine. 470 */ 471 fp = NULL; 472 473 kn->kn_sfflags = kev->fflags; 474 kn->kn_sdata = kev->data; 475 kev->fflags = 0; 476 kev->data = 0; 477 kn->kn_kevent = *kev; 478 479 knote_attach(kn, fdp); 480 if ((error = fops->f_attach(kn)) != 0) { 481 knote_drop(kn, p); 482 goto done; 483 } 484 } else { 485 /* 486 * The user may change some filter values after the 487 * initial EV_ADD, but doing so will not reset any 488 * filter which have already been triggered. 489 */ 490 kn->kn_sfflags = kev->fflags; 491 kn->kn_sdata = kev->data; 492 kn->kn_kevent.udata = kev->udata; 493 } 494 495 s = splhigh(); 496 if (kn->kn_fop->f_event(kn, 0)) 497 KNOTE_ACTIVATE(kn); 498 splx(s); 499 500 } else if (kev->flags & EV_DELETE) { 501 kn->kn_fop->f_detach(kn); 502 knote_drop(kn, p); 503 goto done; 504 } 505 506 if ((kev->flags & EV_DISABLE) && 507 ((kn->kn_status & KN_DISABLED) == 0)) { 508 s = splhigh(); 509 kn->kn_status |= KN_DISABLED; 510 splx(s); 511 } 512 513 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { 514 s = splhigh(); 515 kn->kn_status &= ~KN_DISABLED; 516 if ((kn->kn_status & KN_ACTIVE) && 517 ((kn->kn_status & KN_QUEUED) == 0)) 518 knote_enqueue(kn); 519 splx(s); 520 } 521 522 done: 523 if (fp != NULL) 524 fdrop(fp, p); 525 return (error); 526 } 527 528 static int 529 kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp, 530 const struct timespec *tsp, struct proc *p) 531 { 532 struct kqueue *kq = (struct kqueue *)fp->f_data; 533 struct kevent *kevp; 534 struct timeval atv, rtv, ttv; 535 struct knote *kn, marker; 536 int s, count, timeout, nkev = 0, error = 0; 537 538 count = maxevents; 539 if (count == 0) 540 goto done; 541 542 if (tsp != NULL) { 543 TIMESPEC_TO_TIMEVAL(&atv, tsp); 544 if (itimerfix(&atv)) { 545 error = EINVAL; 546 goto done; 547 } 548 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) 549 timeout = -1; 550 else 551 timeout = atv.tv_sec > 24 * 60 * 60 ? 552 24 * 60 * 60 * hz : tvtohz(&atv); 553 getmicrouptime(&rtv); 554 timevaladd(&atv, &rtv); 555 } else { 556 atv.tv_sec = 0; 557 atv.tv_usec = 0; 558 timeout = 0; 559 } 560 goto start; 561 562 retry: 563 if (atv.tv_sec || atv.tv_usec) { 564 getmicrouptime(&rtv); 565 if (timevalcmp(&rtv, &atv, >=)) 566 goto done; 567 ttv = atv; 568 timevalsub(&ttv, &rtv); 569 timeout = ttv.tv_sec > 24 * 60 * 60 ? 570 24 * 60 * 60 * hz : tvtohz(&ttv); 571 } 572 573 start: 574 kevp = kq->kq_kev; 575 s = splhigh(); 576 if (kq->kq_count == 0) { 577 if (timeout < 0) { 578 error = EWOULDBLOCK; 579 } else { 580 kq->kq_state |= KQ_SLEEP; 581 error = tsleep(kq, PSOCK | PCATCH, "kqread", timeout); 582 } 583 splx(s); 584 if (error == 0) 585 goto retry; 586 /* don't restart after signals... */ 587 if (error == ERESTART) 588 error = EINTR; 589 else if (error == EWOULDBLOCK) 590 error = 0; 591 goto done; 592 } 593 594 TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe); 595 while (count) { 596 kn = TAILQ_FIRST(&kq->kq_head); 597 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 598 if (kn == &marker) { 599 splx(s); 600 if (count == maxevents) 601 goto retry; 602 goto done; 603 } 604 if (kn->kn_status & KN_DISABLED) { 605 kn->kn_status &= ~KN_QUEUED; 606 kq->kq_count--; 607 continue; 608 } 609 if ((kn->kn_flags & EV_ONESHOT) == 0 && 610 kn->kn_fop->f_event(kn, 0) == 0) { 611 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 612 kq->kq_count--; 613 continue; 614 } 615 *kevp = kn->kn_kevent; 616 kevp++; 617 nkev++; 618 if (kn->kn_flags & EV_ONESHOT) { 619 kn->kn_status &= ~KN_QUEUED; 620 kq->kq_count--; 621 splx(s); 622 kn->kn_fop->f_detach(kn); 623 knote_drop(kn, p); 624 s = splhigh(); 625 } else if (kn->kn_flags & EV_CLEAR) { 626 kn->kn_data = 0; 627 kn->kn_fflags = 0; 628 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); 629 kq->kq_count--; 630 } else { 631 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 632 } 633 count--; 634 if (nkev == KQ_NEVENTS) { 635 splx(s); 636 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, 637 sizeof(struct kevent) * nkev); 638 ulistp += nkev; 639 nkev = 0; 640 kevp = kq->kq_kev; 641 s = splhigh(); 642 if (error) 643 break; 644 } 645 } 646 TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe); 647 splx(s); 648 done: 649 if (nkev != 0) 650 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, 651 sizeof(struct kevent) * nkev); 652 p->p_retval[0] = maxevents - count; 653 return (error); 654 } 655 656 /* 657 * XXX 658 * This could be expanded to call kqueue_scan, if desired. 659 */ 660 /*ARGSUSED*/ 661 static int 662 kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred, 663 int flags, struct proc *p) 664 { 665 return (ENXIO); 666 } 667 668 /*ARGSUSED*/ 669 static int 670 kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred, 671 int flags, struct proc *p) 672 { 673 return (ENXIO); 674 } 675 676 /*ARGSUSED*/ 677 static int 678 kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p) 679 { 680 return (ENOTTY); 681 } 682 683 /*ARGSUSED*/ 684 static int 685 kqueue_poll(struct file *fp, int events, struct ucred *cred, struct proc *p) 686 { 687 struct kqueue *kq = (struct kqueue *)fp->f_data; 688 int revents = 0; 689 int s = splnet(); 690 691 if (events & (POLLIN | POLLRDNORM)) { 692 if (kq->kq_count) { 693 revents |= events & (POLLIN | POLLRDNORM); 694 } else { 695 selrecord(p, &kq->kq_sel); 696 kq->kq_state |= KQ_SEL; 697 } 698 } 699 splx(s); 700 return (revents); 701 } 702 703 /*ARGSUSED*/ 704 static int 705 kqueue_stat(struct file *fp, struct stat *st, struct proc *p) 706 { 707 struct kqueue *kq = (struct kqueue *)fp->f_data; 708 709 bzero((void *)st, sizeof(*st)); 710 st->st_size = kq->kq_count; 711 st->st_blksize = sizeof(struct kevent); 712 st->st_mode = S_IFIFO; 713 return (0); 714 } 715 716 /*ARGSUSED*/ 717 static int 718 kqueue_close(struct file *fp, struct proc *p) 719 { 720 struct kqueue *kq = (struct kqueue *)fp->f_data; 721 struct filedesc *fdp = p->p_fd; 722 struct knote **knp, *kn, *kn0; 723 int i; 724 725 for (i = 0; i < fdp->fd_knlistsize; i++) { 726 knp = &SLIST_FIRST(&fdp->fd_knlist[i]); 727 kn = *knp; 728 while (kn != NULL) { 729 kn0 = SLIST_NEXT(kn, kn_link); 730 if (kq == kn->kn_kq) { 731 kn->kn_fop->f_detach(kn); 732 fdrop(kn->kn_fp, p); 733 knote_free(kn); 734 *knp = kn0; 735 } else { 736 knp = &SLIST_NEXT(kn, kn_link); 737 } 738 kn = kn0; 739 } 740 } 741 if (fdp->fd_knhashmask != 0) { 742 for (i = 0; i < fdp->fd_knhashmask + 1; i++) { 743 knp = &SLIST_FIRST(&fdp->fd_knhash[i]); 744 kn = *knp; 745 while (kn != NULL) { 746 kn0 = SLIST_NEXT(kn, kn_link); 747 if (kq == kn->kn_kq) { 748 kn->kn_fop->f_detach(kn); 749 /* XXX non-fd release of kn->kn_ptr */ 750 knote_free(kn); 751 *knp = kn0; 752 } else { 753 knp = &SLIST_NEXT(kn, kn_link); 754 } 755 kn = kn0; 756 } 757 } 758 } 759 free(kq, M_TEMP); 760 fp->f_data = NULL; 761 762 return (0); 763 } 764 765 static void 766 kqueue_wakeup(struct kqueue *kq) 767 { 768 769 if (kq->kq_state & KQ_SLEEP) { 770 kq->kq_state &= ~KQ_SLEEP; 771 wakeup(kq); 772 } 773 if (kq->kq_state & KQ_SEL) { 774 kq->kq_state &= ~KQ_SEL; 775 selwakeup(&kq->kq_sel); 776 } 777 KNOTE(&kq->kq_sel.si_note, 0); 778 } 779 780 /* 781 * walk down a list of knotes, activating them if their event has triggered. 782 */ 783 void 784 knote(struct klist *list, long hint) 785 { 786 struct knote *kn; 787 788 SLIST_FOREACH(kn, list, kn_selnext) 789 if (kn->kn_fop->f_event(kn, hint)) 790 KNOTE_ACTIVATE(kn); 791 } 792 793 /* 794 * remove all knotes from a specified klist 795 */ 796 void 797 knote_remove(struct proc *p, struct klist *list) 798 { 799 struct knote *kn; 800 801 while ((kn = SLIST_FIRST(list)) != NULL) { 802 kn->kn_fop->f_detach(kn); 803 knote_drop(kn, p); 804 } 805 } 806 807 /* 808 * remove all knotes referencing a specified fd 809 */ 810 void 811 knote_fdclose(struct proc *p, int fd) 812 { 813 struct filedesc *fdp = p->p_fd; 814 struct klist *list = &fdp->fd_knlist[fd]; 815 816 knote_remove(p, list); 817 } 818 819 static void 820 knote_attach(struct knote *kn, struct filedesc *fdp) 821 { 822 struct klist *list; 823 int size; 824 825 if (! kn->kn_fop->f_isfd) { 826 if (fdp->fd_knhashmask == 0) 827 fdp->fd_knhash = hashinit(KN_HASHSIZE, M_TEMP, 828 &fdp->fd_knhashmask); 829 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 830 goto done; 831 } 832 833 if (fdp->fd_knlistsize <= kn->kn_id) { 834 size = fdp->fd_knlistsize; 835 while (size <= kn->kn_id) 836 size += KQEXTENT; 837 MALLOC(list, struct klist *, 838 size * sizeof(struct klist *), M_TEMP, M_WAITOK); 839 bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list, 840 fdp->fd_knlistsize * sizeof(struct klist *)); 841 bzero((caddr_t)list + 842 fdp->fd_knlistsize * sizeof(struct klist *), 843 (size - fdp->fd_knlistsize) * sizeof(struct klist *)); 844 if (fdp->fd_knlist != NULL) 845 FREE(fdp->fd_knlist, M_TEMP); 846 fdp->fd_knlistsize = size; 847 fdp->fd_knlist = list; 848 } 849 list = &fdp->fd_knlist[kn->kn_id]; 850 done: 851 SLIST_INSERT_HEAD(list, kn, kn_link); 852 kn->kn_status = 0; 853 } 854 855 /* 856 * should be called at spl == 0, since we don't want to hold spl 857 * while calling fdrop and free. 858 */ 859 static void 860 knote_drop(struct knote *kn, struct proc *p) 861 { 862 struct filedesc *fdp = p->p_fd; 863 struct klist *list; 864 865 if (kn->kn_fop->f_isfd) 866 list = &fdp->fd_knlist[kn->kn_id]; 867 else 868 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; 869 870 SLIST_REMOVE(list, kn, knote, kn_link); 871 if (kn->kn_status & KN_QUEUED) 872 knote_dequeue(kn); 873 if (kn->kn_fop->f_isfd) 874 fdrop(kn->kn_fp, p); 875 knote_free(kn); 876 } 877 878 879 static void 880 knote_enqueue(struct knote *kn) 881 { 882 struct kqueue *kq = kn->kn_kq; 883 int s = splhigh(); 884 885 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); 886 887 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); 888 kn->kn_status |= KN_QUEUED; 889 kq->kq_count++; 890 splx(s); 891 kqueue_wakeup(kq); 892 } 893 894 static void 895 knote_dequeue(struct knote *kn) 896 { 897 struct kqueue *kq = kn->kn_kq; 898 int s = splhigh(); 899 900 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); 901 902 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); 903 kn->kn_status &= ~KN_QUEUED; 904 kq->kq_count--; 905 splx(s); 906 } 907 908 static void 909 knote_init(void) 910 { 911 knote_zone = zinit("KNOTE", sizeof(struct knote), 0, 0, 1); 912 } 913 SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL) 914 915 static struct knote * 916 knote_alloc(void) 917 { 918 return ((struct knote *)zalloc(knote_zone)); 919 } 920 921 static void 922 knote_free(struct knote *kn) 923 { 924 zfree(knote_zone, kn); 925 } 926