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