1 /*- 2 * Copyright (c) 1990, 1993, 1995 3 * The Regents of the University of California. 4 * Copyright (c) 2005 Robert N. M. Watson 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 * 4. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)fifo_vnops.c 8.10 (Berkeley) 5/27/95 32 * $FreeBSD$ 33 */ 34 35 #include <sys/param.h> 36 #include <sys/event.h> 37 #include <sys/file.h> 38 #include <sys/filedesc.h> 39 #include <sys/filio.h> 40 #include <sys/fcntl.h> 41 #include <sys/kernel.h> 42 #include <sys/lock.h> 43 #include <sys/mutex.h> 44 #include <sys/malloc.h> 45 #include <sys/poll.h> 46 #include <sys/proc.h> 47 #include <sys/signalvar.h> 48 #include <sys/socket.h> 49 #include <sys/socketvar.h> 50 #include <sys/sx.h> 51 #include <sys/systm.h> 52 #include <sys/un.h> 53 #include <sys/unistd.h> 54 #include <sys/vnode.h> 55 #include <fs/fifofs/fifo.h> 56 57 static fo_rdwr_t fifo_read_f; 58 static fo_rdwr_t fifo_write_f; 59 static fo_ioctl_t fifo_ioctl_f; 60 static fo_poll_t fifo_poll_f; 61 static fo_kqfilter_t fifo_kqfilter_f; 62 static fo_stat_t fifo_stat_f; 63 static fo_close_t fifo_close_f; 64 static fo_truncate_t fifo_truncate_f; 65 66 struct fileops fifo_ops_f = { 67 .fo_read = fifo_read_f, 68 .fo_write = fifo_write_f, 69 .fo_truncate = fifo_truncate_f, 70 .fo_ioctl = fifo_ioctl_f, 71 .fo_poll = fifo_poll_f, 72 .fo_kqfilter = fifo_kqfilter_f, 73 .fo_stat = fifo_stat_f, 74 .fo_close = fifo_close_f, 75 .fo_flags = DFLAG_PASSABLE 76 }; 77 78 /* 79 * This structure is associated with the FIFO vnode and stores 80 * the state associated with the FIFO. 81 */ 82 struct fifoinfo { 83 struct socket *fi_readsock; 84 struct socket *fi_writesock; 85 long fi_readers; 86 long fi_writers; 87 }; 88 89 static vop_print_t fifo_print; 90 static vop_open_t fifo_open; 91 static vop_close_t fifo_close; 92 static vop_ioctl_t fifo_ioctl; 93 static vop_kqfilter_t fifo_kqfilter; 94 static vop_pathconf_t fifo_pathconf; 95 static vop_advlock_t fifo_advlock; 96 97 static void filt_fifordetach(struct knote *kn); 98 static int filt_fiforead(struct knote *kn, long hint); 99 static void filt_fifowdetach(struct knote *kn); 100 static int filt_fifowrite(struct knote *kn, long hint); 101 static void filt_fifodetach_notsup(struct knote *kn); 102 static int filt_fifo_notsup(struct knote *kn, long hint); 103 104 static struct filterops fiforead_filtops = 105 { 1, NULL, filt_fifordetach, filt_fiforead }; 106 static struct filterops fifowrite_filtops = 107 { 1, NULL, filt_fifowdetach, filt_fifowrite }; 108 static struct filterops fifo_notsup_filtops = 109 { 1, NULL, filt_fifodetach_notsup, filt_fifo_notsup }; 110 111 struct vop_vector fifo_specops = { 112 .vop_default = &default_vnodeops, 113 114 .vop_access = VOP_EBADF, 115 .vop_advlock = fifo_advlock, 116 .vop_close = fifo_close, 117 .vop_create = VOP_PANIC, 118 .vop_getattr = VOP_EBADF, 119 .vop_ioctl = fifo_ioctl, 120 .vop_kqfilter = fifo_kqfilter, 121 .vop_link = VOP_PANIC, 122 .vop_mkdir = VOP_PANIC, 123 .vop_mknod = VOP_PANIC, 124 .vop_open = fifo_open, 125 .vop_pathconf = fifo_pathconf, 126 .vop_print = fifo_print, 127 .vop_read = VOP_PANIC, 128 .vop_readdir = VOP_PANIC, 129 .vop_readlink = VOP_PANIC, 130 .vop_reallocblks = VOP_PANIC, 131 .vop_reclaim = VOP_NULL, 132 .vop_remove = VOP_PANIC, 133 .vop_rename = VOP_PANIC, 134 .vop_rmdir = VOP_PANIC, 135 .vop_setattr = VOP_EBADF, 136 .vop_symlink = VOP_PANIC, 137 .vop_write = VOP_PANIC, 138 }; 139 140 struct mtx fifo_mtx; 141 MTX_SYSINIT(fifo, &fifo_mtx, "fifo mutex", MTX_DEF); 142 143 /* 144 * Dispose of fifo resources. 145 */ 146 static void 147 fifo_cleanup(struct vnode *vp) 148 { 149 struct fifoinfo *fip = vp->v_fifoinfo; 150 151 ASSERT_VOP_ELOCKED(vp, "fifo_cleanup"); 152 if (fip->fi_readers == 0 && fip->fi_writers == 0) { 153 vp->v_fifoinfo = NULL; 154 (void)soclose(fip->fi_readsock); 155 (void)soclose(fip->fi_writesock); 156 free(fip, M_VNODE); 157 } 158 } 159 160 /* 161 * Open called to set up a new instance of a fifo or 162 * to find an active instance of a fifo. 163 */ 164 /* ARGSUSED */ 165 static int 166 fifo_open(ap) 167 struct vop_open_args /* { 168 struct vnode *a_vp; 169 int a_mode; 170 struct ucred *a_cred; 171 struct thread *a_td; 172 int a_fdidx; 173 } */ *ap; 174 { 175 struct vnode *vp = ap->a_vp; 176 struct fifoinfo *fip; 177 struct thread *td = ap->a_td; 178 struct ucred *cred = ap->a_cred; 179 struct file *fp = ap->a_fp; 180 struct socket *rso, *wso; 181 int error; 182 183 ASSERT_VOP_ELOCKED(vp, "fifo_open"); 184 if (fp == NULL) 185 return (EINVAL); 186 if ((fip = vp->v_fifoinfo) == NULL) { 187 fip = malloc(sizeof(*fip), M_VNODE, M_WAITOK); 188 error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0, cred, td); 189 if (error) 190 goto fail1; 191 fip->fi_readsock = rso; 192 error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0, cred, td); 193 if (error) 194 goto fail2; 195 fip->fi_writesock = wso; 196 error = soconnect2(wso, rso); 197 if (error) { 198 (void)soclose(wso); 199 fail2: 200 (void)soclose(rso); 201 fail1: 202 free(fip, M_VNODE); 203 return (error); 204 } 205 fip->fi_readers = fip->fi_writers = 0; 206 wso->so_snd.sb_lowat = PIPE_BUF; 207 SOCKBUF_LOCK(&rso->so_rcv); 208 rso->so_rcv.sb_state |= SBS_CANTRCVMORE; 209 SOCKBUF_UNLOCK(&rso->so_rcv); 210 KASSERT(vp->v_fifoinfo == NULL, 211 ("fifo_open: v_fifoinfo race")); 212 vp->v_fifoinfo = fip; 213 } 214 215 /* 216 * General access to fi_readers and fi_writers is protected using 217 * the vnode lock. 218 * 219 * Protect the increment of fi_readers and fi_writers and the 220 * associated calls to wakeup() with the fifo mutex in addition 221 * to the vnode lock. This allows the vnode lock to be dropped 222 * for the msleep() calls below, and using the fifo mutex with 223 * msleep() prevents the wakeup from being missed. 224 */ 225 mtx_lock(&fifo_mtx); 226 if (ap->a_mode & FREAD) { 227 fip->fi_readers++; 228 if (fip->fi_readers == 1) { 229 SOCKBUF_LOCK(&fip->fi_writesock->so_snd); 230 fip->fi_writesock->so_snd.sb_state &= ~SBS_CANTSENDMORE; 231 SOCKBUF_UNLOCK(&fip->fi_writesock->so_snd); 232 if (fip->fi_writers > 0) { 233 wakeup(&fip->fi_writers); 234 sowwakeup(fip->fi_writesock); 235 } 236 } 237 } 238 if (ap->a_mode & FWRITE) { 239 if ((ap->a_mode & O_NONBLOCK) && fip->fi_readers == 0) { 240 mtx_unlock(&fifo_mtx); 241 return (ENXIO); 242 } 243 fip->fi_writers++; 244 if (fip->fi_writers == 1) { 245 SOCKBUF_LOCK(&fip->fi_readsock->so_rcv); 246 fip->fi_readsock->so_rcv.sb_state &= ~SBS_CANTRCVMORE; 247 SOCKBUF_UNLOCK(&fip->fi_readsock->so_rcv); 248 if (fip->fi_readers > 0) { 249 wakeup(&fip->fi_readers); 250 sorwakeup(fip->fi_readsock); 251 } 252 } 253 } 254 if ((ap->a_mode & O_NONBLOCK) == 0) { 255 if ((ap->a_mode & FREAD) && fip->fi_writers == 0) { 256 VOP_UNLOCK(vp, 0); 257 error = msleep(&fip->fi_readers, &fifo_mtx, 258 PDROP | PCATCH | PSOCK, "fifoor", 0); 259 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 260 if (error) { 261 fip->fi_readers--; 262 if (fip->fi_readers == 0) { 263 socantsendmore(fip->fi_writesock); 264 fifo_cleanup(vp); 265 } 266 return (error); 267 } 268 mtx_lock(&fifo_mtx); 269 /* 270 * We must have got woken up because we had a writer. 271 * That (and not still having one) is the condition 272 * that we must wait for. 273 */ 274 } 275 if ((ap->a_mode & FWRITE) && fip->fi_readers == 0) { 276 VOP_UNLOCK(vp, 0); 277 error = msleep(&fip->fi_writers, &fifo_mtx, 278 PDROP | PCATCH | PSOCK, "fifoow", 0); 279 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 280 if (error) { 281 fip->fi_writers--; 282 if (fip->fi_writers == 0) { 283 socantrcvmore(fip->fi_readsock); 284 fifo_cleanup(vp); 285 } 286 return (error); 287 } 288 /* 289 * We must have got woken up because we had 290 * a reader. That (and not still having one) 291 * is the condition that we must wait for. 292 */ 293 mtx_lock(&fifo_mtx); 294 } 295 } 296 mtx_unlock(&fifo_mtx); 297 KASSERT(fp != NULL, ("can't fifo/vnode bypass")); 298 KASSERT(fp->f_ops == &badfileops, ("not badfileops in fifo_open")); 299 finit(fp, fp->f_flag, DTYPE_FIFO, fip, &fifo_ops_f); 300 return (0); 301 } 302 303 /* 304 * Now unused vnode ioctl routine. 305 */ 306 /* ARGSUSED */ 307 static int 308 fifo_ioctl(ap) 309 struct vop_ioctl_args /* { 310 struct vnode *a_vp; 311 u_long a_command; 312 caddr_t a_data; 313 int a_fflag; 314 struct ucred *a_cred; 315 struct thread *a_td; 316 } */ *ap; 317 { 318 319 printf("WARNING: fifo_ioctl called unexpectedly\n"); 320 return (ENOTTY); 321 } 322 323 /* 324 * Now unused vnode kqfilter routine. 325 */ 326 /* ARGSUSED */ 327 static int 328 fifo_kqfilter(ap) 329 struct vop_kqfilter_args /* { 330 struct vnode *a_vp; 331 struct knote *a_kn; 332 } */ *ap; 333 { 334 335 printf("WARNING: fifo_kqfilter called unexpectedly\n"); 336 return (EINVAL); 337 } 338 339 static void 340 filt_fifordetach(struct knote *kn) 341 { 342 struct socket *so = (struct socket *)kn->kn_hook; 343 344 SOCKBUF_LOCK(&so->so_rcv); 345 knlist_remove(&so->so_rcv.sb_sel.si_note, kn, 1); 346 if (knlist_empty(&so->so_rcv.sb_sel.si_note)) 347 so->so_rcv.sb_flags &= ~SB_KNOTE; 348 SOCKBUF_UNLOCK(&so->so_rcv); 349 } 350 351 static int 352 filt_fiforead(struct knote *kn, long hint) 353 { 354 struct socket *so = (struct socket *)kn->kn_hook; 355 356 SOCKBUF_LOCK_ASSERT(&so->so_rcv); 357 kn->kn_data = so->so_rcv.sb_cc; 358 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { 359 kn->kn_flags |= EV_EOF; 360 return (1); 361 } else { 362 kn->kn_flags &= ~EV_EOF; 363 return (kn->kn_data > 0); 364 } 365 } 366 367 static void 368 filt_fifowdetach(struct knote *kn) 369 { 370 struct socket *so = (struct socket *)kn->kn_hook; 371 372 SOCKBUF_LOCK(&so->so_snd); 373 knlist_remove(&so->so_snd.sb_sel.si_note, kn, 1); 374 if (knlist_empty(&so->so_snd.sb_sel.si_note)) 375 so->so_snd.sb_flags &= ~SB_KNOTE; 376 SOCKBUF_UNLOCK(&so->so_snd); 377 } 378 379 static int 380 filt_fifowrite(struct knote *kn, long hint) 381 { 382 struct socket *so = (struct socket *)kn->kn_hook; 383 384 SOCKBUF_LOCK_ASSERT(&so->so_snd); 385 kn->kn_data = sbspace(&so->so_snd); 386 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 387 kn->kn_flags |= EV_EOF; 388 return (1); 389 } else { 390 kn->kn_flags &= ~EV_EOF; 391 return (kn->kn_data >= so->so_snd.sb_lowat); 392 } 393 } 394 395 static void 396 filt_fifodetach_notsup(struct knote *kn) 397 { 398 399 } 400 401 static int 402 filt_fifo_notsup(struct knote *kn, long hint) 403 { 404 405 return (0); 406 } 407 408 /* 409 * Device close routine 410 */ 411 /* ARGSUSED */ 412 static int 413 fifo_close(ap) 414 struct vop_close_args /* { 415 struct vnode *a_vp; 416 int a_fflag; 417 struct ucred *a_cred; 418 struct thread *a_td; 419 } */ *ap; 420 { 421 struct vnode *vp = ap->a_vp; 422 struct fifoinfo *fip = vp->v_fifoinfo; 423 424 ASSERT_VOP_ELOCKED(vp, "fifo_close"); 425 if (fip == NULL) { 426 printf("fifo_close: no v_fifoinfo %p\n", vp); 427 return (0); 428 } 429 if (ap->a_fflag & FREAD) { 430 fip->fi_readers--; 431 if (fip->fi_readers == 0) 432 socantsendmore(fip->fi_writesock); 433 } 434 if (ap->a_fflag & FWRITE) { 435 fip->fi_writers--; 436 if (fip->fi_writers == 0) 437 socantrcvmore(fip->fi_readsock); 438 } 439 fifo_cleanup(vp); 440 return (0); 441 } 442 443 /* 444 * Print out internal contents of a fifo vnode. 445 */ 446 int 447 fifo_printinfo(vp) 448 struct vnode *vp; 449 { 450 register struct fifoinfo *fip = vp->v_fifoinfo; 451 452 if (fip == NULL){ 453 printf(", NULL v_fifoinfo"); 454 return (0); 455 } 456 printf(", fifo with %ld readers and %ld writers", 457 fip->fi_readers, fip->fi_writers); 458 return (0); 459 } 460 461 /* 462 * Print out the contents of a fifo vnode. 463 */ 464 static int 465 fifo_print(ap) 466 struct vop_print_args /* { 467 struct vnode *a_vp; 468 } */ *ap; 469 { 470 printf(" "); 471 fifo_printinfo(ap->a_vp); 472 printf("\n"); 473 return (0); 474 } 475 476 /* 477 * Return POSIX pathconf information applicable to fifo's. 478 */ 479 static int 480 fifo_pathconf(ap) 481 struct vop_pathconf_args /* { 482 struct vnode *a_vp; 483 int a_name; 484 int *a_retval; 485 } */ *ap; 486 { 487 488 switch (ap->a_name) { 489 case _PC_LINK_MAX: 490 *ap->a_retval = LINK_MAX; 491 return (0); 492 case _PC_PIPE_BUF: 493 *ap->a_retval = PIPE_BUF; 494 return (0); 495 case _PC_CHOWN_RESTRICTED: 496 *ap->a_retval = 1; 497 return (0); 498 default: 499 return (EINVAL); 500 } 501 /* NOTREACHED */ 502 } 503 504 /* 505 * Fifo advisory byte-level locks. 506 */ 507 /* ARGSUSED */ 508 static int 509 fifo_advlock(ap) 510 struct vop_advlock_args /* { 511 struct vnode *a_vp; 512 caddr_t a_id; 513 int a_op; 514 struct flock *a_fl; 515 int a_flags; 516 } */ *ap; 517 { 518 519 return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL); 520 } 521 522 static int 523 fifo_close_f(struct file *fp, struct thread *td) 524 { 525 526 return (vnops.fo_close(fp, td)); 527 } 528 529 /* 530 * The implementation of ioctl() for named fifos is complicated by the fact 531 * that we permit O_RDWR fifo file descriptors, meaning that the actions of 532 * ioctls may have to be applied to both the underlying sockets rather than 533 * just one. The original implementation simply forward the ioctl to one 534 * or both sockets based on fp->f_flag. We now consider each ioctl 535 * separately, as the composition effect requires careful ordering. 536 * 537 * We do not blindly pass all ioctls through to the socket in order to avoid 538 * providing unnecessary ioctls that might be improperly depended on by 539 * applications (such as socket-specific, routing, and interface ioctls). 540 * 541 * Unlike sys_pipe.c, fifos do not implement the deprecated TIOCSPGRP and 542 * TIOCGPGRP ioctls. Earlier implementations of fifos did forward SIOCSPGRP 543 * and SIOCGPGRP ioctls, so we might need to re-add those here. 544 */ 545 static int 546 fifo_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, 547 struct thread *td) 548 { 549 struct fifoinfo *fi; 550 struct file filetmp; /* Local, so need not be locked. */ 551 int error; 552 553 error = ENOTTY; 554 fi = fp->f_data; 555 556 switch (com) { 557 case FIONBIO: 558 /* 559 * Non-blocking I/O is implemented at the fifo layer using 560 * MSG_NBIO, so does not need to be forwarded down the stack. 561 */ 562 return (0); 563 564 case FIOASYNC: 565 case FIOSETOWN: 566 case FIOGETOWN: 567 /* 568 * These socket ioctls don't have any ordering requirements, 569 * so are called in an arbitrary order, and only on the 570 * sockets indicated by the file descriptor rights. 571 * 572 * XXXRW: If O_RDWR and the read socket accepts an ioctl but 573 * the write socket doesn't, the socketpair is left in an 574 * inconsistent state. 575 */ 576 if (fp->f_flag & FREAD) { 577 filetmp.f_data = fi->fi_readsock; 578 filetmp.f_cred = cred; 579 error = soo_ioctl(&filetmp, com, data, cred, td); 580 if (error) 581 return (error); 582 } 583 if (fp->f_flag & FWRITE) { 584 filetmp.f_data = fi->fi_writesock; 585 filetmp.f_cred = cred; 586 error = soo_ioctl(&filetmp, com, data, cred, td); 587 } 588 return (error); 589 590 case FIONREAD: 591 /* 592 * FIONREAD will return 0 for non-readable descriptors, and 593 * the results of FIONREAD on the read socket for readable 594 * descriptors. 595 */ 596 if (!(fp->f_flag & FREAD)) { 597 *(int *)data = 0; 598 return (0); 599 } 600 filetmp.f_data = fi->fi_readsock; 601 filetmp.f_cred = cred; 602 return (soo_ioctl(&filetmp, com, data, cred, td)); 603 604 default: 605 return (ENOTTY); 606 } 607 } 608 609 /* 610 * Because fifos are now a file descriptor layer object, EVFILT_VNODE is not 611 * implemented. Likely, fifo_kqfilter() should be removed, and 612 * fifo_kqfilter_f() should know how to forward the request to the underling 613 * vnode using f_vnode in the file descriptor here. 614 */ 615 static int 616 fifo_kqfilter_f(struct file *fp, struct knote *kn) 617 { 618 struct fifoinfo *fi; 619 struct socket *so; 620 struct sockbuf *sb; 621 622 fi = fp->f_data; 623 624 /* 625 * If a filter is requested that is not supported by this file 626 * descriptor, don't return an error, but also don't ever generate an 627 * event. 628 */ 629 if ((kn->kn_filter == EVFILT_READ) && !(fp->f_flag & FREAD)) { 630 kn->kn_fop = &fifo_notsup_filtops; 631 return (0); 632 } 633 634 if ((kn->kn_filter == EVFILT_WRITE) && !(fp->f_flag & FWRITE)) { 635 kn->kn_fop = &fifo_notsup_filtops; 636 return (0); 637 } 638 639 switch (kn->kn_filter) { 640 case EVFILT_READ: 641 kn->kn_fop = &fiforead_filtops; 642 so = fi->fi_readsock; 643 sb = &so->so_rcv; 644 break; 645 case EVFILT_WRITE: 646 kn->kn_fop = &fifowrite_filtops; 647 so = fi->fi_writesock; 648 sb = &so->so_snd; 649 break; 650 default: 651 return (EINVAL); 652 } 653 654 kn->kn_hook = (caddr_t)so; 655 656 SOCKBUF_LOCK(sb); 657 knlist_add(&sb->sb_sel.si_note, kn, 1); 658 sb->sb_flags |= SB_KNOTE; 659 SOCKBUF_UNLOCK(sb); 660 661 return (0); 662 } 663 664 static int 665 fifo_poll_f(struct file *fp, int events, struct ucred *cred, struct thread *td) 666 { 667 struct fifoinfo *fip; 668 struct file filetmp; 669 int levents, revents = 0; 670 671 fip = fp->f_data; 672 levents = events & 673 (POLLIN | POLLINIGNEOF | POLLPRI | POLLRDNORM | POLLRDBAND); 674 if ((fp->f_flag & FREAD) && levents) { 675 /* 676 * If POLLIN or POLLRDNORM is requested and POLLINIGNEOF is 677 * not, then convert the first two to the last one. This 678 * tells the socket poll function to ignore EOF so that we 679 * block if there is no writer (and no data). Callers can 680 * set POLLINIGNEOF to get non-blocking behavior. 681 */ 682 if (levents & (POLLIN | POLLRDNORM) && 683 !(levents & POLLINIGNEOF)) { 684 levents &= ~(POLLIN | POLLRDNORM); 685 levents |= POLLINIGNEOF; 686 } 687 688 filetmp.f_data = fip->fi_readsock; 689 filetmp.f_cred = cred; 690 revents |= soo_poll(&filetmp, levents, cred, td); 691 692 /* Reverse the above conversion. */ 693 if ((revents & POLLINIGNEOF) && !(events & POLLINIGNEOF)) { 694 revents |= (events & (POLLIN | POLLRDNORM)); 695 revents &= ~POLLINIGNEOF; 696 } 697 } 698 levents = events & (POLLOUT | POLLWRNORM | POLLWRBAND); 699 if ((fp->f_flag & FWRITE) && levents) { 700 filetmp.f_data = fip->fi_writesock; 701 filetmp.f_cred = cred; 702 revents |= soo_poll(&filetmp, levents, cred, td); 703 } 704 return (revents); 705 } 706 707 static int 708 fifo_read_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td) 709 { 710 struct fifoinfo *fip; 711 int sflags; 712 713 fip = fp->f_data; 714 KASSERT(uio->uio_rw == UIO_READ,("fifo_read mode")); 715 if (uio->uio_resid == 0) 716 return (0); 717 sflags = (fp->f_flag & FNONBLOCK) ? MSG_NBIO : 0; 718 return (soreceive(fip->fi_readsock, NULL, uio, NULL, NULL, &sflags)); 719 } 720 721 static int 722 fifo_stat_f(struct file *fp, struct stat *sb, struct ucred *cred, struct thread *td) 723 { 724 725 return (vnops.fo_stat(fp, sb, cred, td)); 726 } 727 728 static int 729 fifo_truncate_f(struct file *fp, off_t length, struct ucred *cred, struct thread *td) 730 { 731 732 return (vnops.fo_truncate(fp, length, cred, td)); 733 } 734 735 static int 736 fifo_write_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td) 737 { 738 struct fifoinfo *fip; 739 int sflags; 740 741 fip = fp->f_data; 742 KASSERT(uio->uio_rw == UIO_WRITE,("fifo_write mode")); 743 sflags = (fp->f_flag & FNONBLOCK) ? MSG_NBIO : 0; 744 return (sosend(fip->fi_writesock, NULL, uio, 0, NULL, sflags, td)); 745 } 746