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 int fi_wgen; 88 }; 89 90 static vop_print_t fifo_print; 91 static vop_open_t fifo_open; 92 static vop_close_t fifo_close; 93 static vop_pathconf_t fifo_pathconf; 94 static vop_advlock_t fifo_advlock; 95 96 static void filt_fifordetach(struct knote *kn); 97 static int filt_fiforead(struct knote *kn, long hint); 98 static void filt_fifowdetach(struct knote *kn); 99 static int filt_fifowrite(struct knote *kn, long hint); 100 static void filt_fifodetach_notsup(struct knote *kn); 101 static int filt_fifo_notsup(struct knote *kn, long hint); 102 103 static struct filterops fiforead_filtops = 104 { 1, NULL, filt_fifordetach, filt_fiforead }; 105 static struct filterops fifowrite_filtops = 106 { 1, NULL, filt_fifowdetach, filt_fifowrite }; 107 static struct filterops fifo_notsup_filtops = 108 { 1, NULL, filt_fifodetach_notsup, filt_fifo_notsup }; 109 110 struct vop_vector fifo_specops = { 111 .vop_default = &default_vnodeops, 112 113 .vop_access = VOP_EBADF, 114 .vop_advlock = fifo_advlock, 115 .vop_close = fifo_close, 116 .vop_create = VOP_PANIC, 117 .vop_getattr = VOP_EBADF, 118 .vop_ioctl = VOP_PANIC, 119 .vop_kqfilter = VOP_PANIC, 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_ELOCKED(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 struct file *a_fp; 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 fip = malloc(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 fp->f_seqcount = fip->fi_wgen - fip->fi_writers; 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 mtx_lock(&fifo_mtx); 285 fip->fi_wgen++; 286 mtx_unlock(&fifo_mtx); 287 fifo_cleanup(vp); 288 } 289 return (error); 290 } 291 /* 292 * We must have got woken up because we had 293 * a reader. That (and not still having one) 294 * is the condition that we must wait for. 295 */ 296 mtx_lock(&fifo_mtx); 297 } 298 } 299 mtx_unlock(&fifo_mtx); 300 KASSERT(fp != NULL, ("can't fifo/vnode bypass")); 301 KASSERT(fp->f_ops == &badfileops, ("not badfileops in fifo_open")); 302 finit(fp, fp->f_flag, DTYPE_FIFO, fip, &fifo_ops_f); 303 return (0); 304 } 305 306 static void 307 filt_fifordetach(struct knote *kn) 308 { 309 struct socket *so = (struct socket *)kn->kn_hook; 310 311 SOCKBUF_LOCK(&so->so_rcv); 312 knlist_remove(&so->so_rcv.sb_sel.si_note, kn, 1); 313 if (knlist_empty(&so->so_rcv.sb_sel.si_note)) 314 so->so_rcv.sb_flags &= ~SB_KNOTE; 315 SOCKBUF_UNLOCK(&so->so_rcv); 316 } 317 318 static int 319 filt_fiforead(struct knote *kn, long hint) 320 { 321 struct socket *so = (struct socket *)kn->kn_hook; 322 323 SOCKBUF_LOCK_ASSERT(&so->so_rcv); 324 kn->kn_data = so->so_rcv.sb_cc; 325 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { 326 kn->kn_flags |= EV_EOF; 327 return (1); 328 } else { 329 kn->kn_flags &= ~EV_EOF; 330 return (kn->kn_data > 0); 331 } 332 } 333 334 static void 335 filt_fifowdetach(struct knote *kn) 336 { 337 struct socket *so = (struct socket *)kn->kn_hook; 338 339 SOCKBUF_LOCK(&so->so_snd); 340 knlist_remove(&so->so_snd.sb_sel.si_note, kn, 1); 341 if (knlist_empty(&so->so_snd.sb_sel.si_note)) 342 so->so_snd.sb_flags &= ~SB_KNOTE; 343 SOCKBUF_UNLOCK(&so->so_snd); 344 } 345 346 static int 347 filt_fifowrite(struct knote *kn, long hint) 348 { 349 struct socket *so = (struct socket *)kn->kn_hook; 350 351 SOCKBUF_LOCK_ASSERT(&so->so_snd); 352 kn->kn_data = sbspace(&so->so_snd); 353 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 354 kn->kn_flags |= EV_EOF; 355 return (1); 356 } else { 357 kn->kn_flags &= ~EV_EOF; 358 return (kn->kn_data >= so->so_snd.sb_lowat); 359 } 360 } 361 362 static void 363 filt_fifodetach_notsup(struct knote *kn) 364 { 365 366 } 367 368 static int 369 filt_fifo_notsup(struct knote *kn, long hint) 370 { 371 372 return (0); 373 } 374 375 /* 376 * Device close routine 377 */ 378 /* ARGSUSED */ 379 static int 380 fifo_close(ap) 381 struct vop_close_args /* { 382 struct vnode *a_vp; 383 int a_fflag; 384 struct ucred *a_cred; 385 struct thread *a_td; 386 } */ *ap; 387 { 388 struct vnode *vp = ap->a_vp; 389 struct fifoinfo *fip = vp->v_fifoinfo; 390 391 ASSERT_VOP_ELOCKED(vp, "fifo_close"); 392 if (fip == NULL) { 393 printf("fifo_close: no v_fifoinfo %p\n", vp); 394 return (0); 395 } 396 if (ap->a_fflag & FREAD) { 397 fip->fi_readers--; 398 if (fip->fi_readers == 0) 399 socantsendmore(fip->fi_writesock); 400 } 401 if (ap->a_fflag & FWRITE) { 402 fip->fi_writers--; 403 if (fip->fi_writers == 0) { 404 socantrcvmore(fip->fi_readsock); 405 mtx_lock(&fifo_mtx); 406 fip->fi_wgen++; 407 mtx_unlock(&fifo_mtx); 408 } 409 } 410 fifo_cleanup(vp); 411 return (0); 412 } 413 414 /* 415 * Print out internal contents of a fifo vnode. 416 */ 417 int 418 fifo_printinfo(vp) 419 struct vnode *vp; 420 { 421 register struct fifoinfo *fip = vp->v_fifoinfo; 422 423 if (fip == NULL){ 424 printf(", NULL v_fifoinfo"); 425 return (0); 426 } 427 printf(", fifo with %ld readers and %ld writers", 428 fip->fi_readers, fip->fi_writers); 429 return (0); 430 } 431 432 /* 433 * Print out the contents of a fifo vnode. 434 */ 435 static int 436 fifo_print(ap) 437 struct vop_print_args /* { 438 struct vnode *a_vp; 439 } */ *ap; 440 { 441 printf(" "); 442 fifo_printinfo(ap->a_vp); 443 printf("\n"); 444 return (0); 445 } 446 447 /* 448 * Return POSIX pathconf information applicable to fifo's. 449 */ 450 static int 451 fifo_pathconf(ap) 452 struct vop_pathconf_args /* { 453 struct vnode *a_vp; 454 int a_name; 455 int *a_retval; 456 } */ *ap; 457 { 458 459 switch (ap->a_name) { 460 case _PC_LINK_MAX: 461 *ap->a_retval = LINK_MAX; 462 return (0); 463 case _PC_PIPE_BUF: 464 *ap->a_retval = PIPE_BUF; 465 return (0); 466 case _PC_CHOWN_RESTRICTED: 467 *ap->a_retval = 1; 468 return (0); 469 default: 470 return (EINVAL); 471 } 472 /* NOTREACHED */ 473 } 474 475 /* 476 * Fifo advisory byte-level locks. 477 */ 478 /* ARGSUSED */ 479 static int 480 fifo_advlock(ap) 481 struct vop_advlock_args /* { 482 struct vnode *a_vp; 483 caddr_t a_id; 484 int a_op; 485 struct flock *a_fl; 486 int a_flags; 487 } */ *ap; 488 { 489 490 return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL); 491 } 492 493 static int 494 fifo_close_f(struct file *fp, struct thread *td) 495 { 496 497 return (vnops.fo_close(fp, td)); 498 } 499 500 /* 501 * The implementation of ioctl() for named fifos is complicated by the fact 502 * that we permit O_RDWR fifo file descriptors, meaning that the actions of 503 * ioctls may have to be applied to both the underlying sockets rather than 504 * just one. The original implementation simply forward the ioctl to one 505 * or both sockets based on fp->f_flag. We now consider each ioctl 506 * separately, as the composition effect requires careful ordering. 507 * 508 * We do not blindly pass all ioctls through to the socket in order to avoid 509 * providing unnecessary ioctls that might be improperly depended on by 510 * applications (such as socket-specific, routing, and interface ioctls). 511 * 512 * Unlike sys_pipe.c, fifos do not implement the deprecated TIOCSPGRP and 513 * TIOCGPGRP ioctls. Earlier implementations of fifos did forward SIOCSPGRP 514 * and SIOCGPGRP ioctls, so we might need to re-add those here. 515 */ 516 static int 517 fifo_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, 518 struct thread *td) 519 { 520 struct fifoinfo *fi; 521 struct file filetmp; /* Local, so need not be locked. */ 522 int error; 523 524 error = ENOTTY; 525 fi = fp->f_data; 526 527 switch (com) { 528 case FIONBIO: 529 /* 530 * Non-blocking I/O is implemented at the fifo layer using 531 * MSG_NBIO, so does not need to be forwarded down the stack. 532 */ 533 return (0); 534 535 case FIOASYNC: 536 case FIOSETOWN: 537 case FIOGETOWN: 538 /* 539 * These socket ioctls don't have any ordering requirements, 540 * so are called in an arbitrary order, and only on the 541 * sockets indicated by the file descriptor rights. 542 * 543 * XXXRW: If O_RDWR and the read socket accepts an ioctl but 544 * the write socket doesn't, the socketpair is left in an 545 * inconsistent state. 546 */ 547 if (fp->f_flag & FREAD) { 548 filetmp.f_data = fi->fi_readsock; 549 filetmp.f_cred = cred; 550 error = soo_ioctl(&filetmp, com, data, cred, td); 551 if (error) 552 return (error); 553 } 554 if (fp->f_flag & FWRITE) { 555 filetmp.f_data = fi->fi_writesock; 556 filetmp.f_cred = cred; 557 error = soo_ioctl(&filetmp, com, data, cred, td); 558 } 559 return (error); 560 561 case FIONREAD: 562 /* 563 * FIONREAD will return 0 for non-readable descriptors, and 564 * the results of FIONREAD on the read socket for readable 565 * descriptors. 566 */ 567 if (!(fp->f_flag & FREAD)) { 568 *(int *)data = 0; 569 return (0); 570 } 571 filetmp.f_data = fi->fi_readsock; 572 filetmp.f_cred = cred; 573 return (soo_ioctl(&filetmp, com, data, cred, td)); 574 575 default: 576 return (ENOTTY); 577 } 578 } 579 580 /* 581 * Because fifos are now a file descriptor layer object, EVFILT_VNODE is not 582 * implemented. Likely, fifo_kqfilter() should be removed, and 583 * fifo_kqfilter_f() should know how to forward the request to the underling 584 * vnode using f_vnode in the file descriptor here. 585 */ 586 static int 587 fifo_kqfilter_f(struct file *fp, struct knote *kn) 588 { 589 struct fifoinfo *fi; 590 struct socket *so; 591 struct sockbuf *sb; 592 593 fi = fp->f_data; 594 595 /* 596 * If a filter is requested that is not supported by this file 597 * descriptor, don't return an error, but also don't ever generate an 598 * event. 599 */ 600 if ((kn->kn_filter == EVFILT_READ) && !(fp->f_flag & FREAD)) { 601 kn->kn_fop = &fifo_notsup_filtops; 602 return (0); 603 } 604 605 if ((kn->kn_filter == EVFILT_WRITE) && !(fp->f_flag & FWRITE)) { 606 kn->kn_fop = &fifo_notsup_filtops; 607 return (0); 608 } 609 610 switch (kn->kn_filter) { 611 case EVFILT_READ: 612 kn->kn_fop = &fiforead_filtops; 613 so = fi->fi_readsock; 614 sb = &so->so_rcv; 615 break; 616 case EVFILT_WRITE: 617 kn->kn_fop = &fifowrite_filtops; 618 so = fi->fi_writesock; 619 sb = &so->so_snd; 620 break; 621 default: 622 return (EINVAL); 623 } 624 625 kn->kn_hook = (caddr_t)so; 626 627 SOCKBUF_LOCK(sb); 628 knlist_add(&sb->sb_sel.si_note, kn, 1); 629 sb->sb_flags |= SB_KNOTE; 630 SOCKBUF_UNLOCK(sb); 631 632 return (0); 633 } 634 635 static int 636 fifo_poll_f(struct file *fp, int events, struct ucred *cred, struct thread *td) 637 { 638 struct fifoinfo *fip; 639 struct file filetmp; 640 int levents, revents = 0; 641 642 fip = fp->f_data; 643 levents = events & 644 (POLLIN | POLLINIGNEOF | POLLPRI | POLLRDNORM | POLLRDBAND); 645 if ((fp->f_flag & FREAD) && levents) { 646 filetmp.f_data = fip->fi_readsock; 647 filetmp.f_cred = cred; 648 mtx_lock(&fifo_mtx); 649 if (fp->f_seqcount == fip->fi_wgen) 650 levents |= POLLINIGNEOF; 651 mtx_unlock(&fifo_mtx); 652 revents |= soo_poll(&filetmp, levents, cred, td); 653 } 654 levents = events & (POLLOUT | POLLWRNORM | POLLWRBAND); 655 if ((fp->f_flag & FWRITE) && levents) { 656 filetmp.f_data = fip->fi_writesock; 657 filetmp.f_cred = cred; 658 revents |= soo_poll(&filetmp, levents, cred, td); 659 } 660 return (revents); 661 } 662 663 static int 664 fifo_read_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td) 665 { 666 struct fifoinfo *fip; 667 int sflags; 668 669 fip = fp->f_data; 670 KASSERT(uio->uio_rw == UIO_READ,("fifo_read mode")); 671 if (uio->uio_resid == 0) 672 return (0); 673 sflags = (fp->f_flag & FNONBLOCK) ? MSG_NBIO : 0; 674 return (soreceive(fip->fi_readsock, NULL, uio, NULL, NULL, &sflags)); 675 } 676 677 static int 678 fifo_stat_f(struct file *fp, struct stat *sb, struct ucred *cred, struct thread *td) 679 { 680 681 return (vnops.fo_stat(fp, sb, cred, td)); 682 } 683 684 static int 685 fifo_truncate_f(struct file *fp, off_t length, struct ucred *cred, struct thread *td) 686 { 687 688 return (vnops.fo_truncate(fp, length, cred, td)); 689 } 690 691 static int 692 fifo_write_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td) 693 { 694 struct fifoinfo *fip; 695 int sflags; 696 697 fip = fp->f_data; 698 KASSERT(uio->uio_rw == UIO_WRITE,("fifo_write mode")); 699 sflags = (fp->f_flag & FNONBLOCK) ? MSG_NBIO : 0; 700 return (sosend(fip->fi_writesock, NULL, uio, 0, NULL, sflags, td)); 701 } 702