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: releng/8.0/sys/fs/fifofs/fifo_vnops.c 196741 2009-09-01 20:58:41Z jilles $
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 /* Close the direction we do not use, so we can get POLLHUP. */
197 if (error == 0)
198 error = soshutdown(rso, SHUT_WR);
199 if (error) {
200 (void)soclose(wso);
201 fail2:
202 (void)soclose(rso);
203 fail1:
204 free(fip, M_VNODE);
205 return (error);
206 }
207 fip->fi_readers = fip->fi_writers = 0;
208 wso->so_snd.sb_lowat = PIPE_BUF;
209 SOCKBUF_LOCK(&rso->so_rcv);
210 rso->so_rcv.sb_state |= SBS_CANTRCVMORE;
211 SOCKBUF_UNLOCK(&rso->so_rcv);
212 KASSERT(vp->v_fifoinfo == NULL,
213 ("fifo_open: v_fifoinfo race"));
214 vp->v_fifoinfo = fip;
215 }
216
217 /*
218 * General access to fi_readers and fi_writers is protected using
219 * the vnode lock.
220 *
221 * Protect the increment of fi_readers and fi_writers and the
222 * associated calls to wakeup() with the fifo mutex in addition
223 * to the vnode lock. This allows the vnode lock to be dropped
224 * for the msleep() calls below, and using the fifo mutex with
225 * msleep() prevents the wakeup from being missed.
226 */
227 mtx_lock(&fifo_mtx);
228 if (ap->a_mode & FREAD) {
229 fip->fi_readers++;
230 if (fip->fi_readers == 1) {
231 SOCKBUF_LOCK(&fip->fi_writesock->so_snd);
232 fip->fi_writesock->so_snd.sb_state &= ~SBS_CANTSENDMORE;
233 SOCKBUF_UNLOCK(&fip->fi_writesock->so_snd);
234 if (fip->fi_writers > 0) {
235 wakeup(&fip->fi_writers);
236 sowwakeup(fip->fi_writesock);
237 }
238 }
239 fp->f_seqcount = fip->fi_wgen - fip->fi_writers;
240 }
241 if (ap->a_mode & FWRITE) {
242 if ((ap->a_mode & O_NONBLOCK) && fip->fi_readers == 0) {
243 mtx_unlock(&fifo_mtx);
244 return (ENXIO);
245 }
246 fip->fi_writers++;
247 if (fip->fi_writers == 1) {
248 SOCKBUF_LOCK(&fip->fi_readsock->so_rcv);
249 fip->fi_readsock->so_rcv.sb_state &= ~SBS_CANTRCVMORE;
250 SOCKBUF_UNLOCK(&fip->fi_readsock->so_rcv);
251 if (fip->fi_readers > 0) {
252 wakeup(&fip->fi_readers);
253 sorwakeup(fip->fi_readsock);
254 }
255 }
256 }
257 if ((ap->a_mode & O_NONBLOCK) == 0) {
258 if ((ap->a_mode & FREAD) && fip->fi_writers == 0) {
259 VOP_UNLOCK(vp, 0);
260 error = msleep(&fip->fi_readers, &fifo_mtx,
261 PDROP | PCATCH | PSOCK, "fifoor", 0);
262 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
263 if (error) {
264 fip->fi_readers--;
265 if (fip->fi_readers == 0) {
266 socantsendmore(fip->fi_writesock);
267 fifo_cleanup(vp);
268 }
269 return (error);
270 }
271 mtx_lock(&fifo_mtx);
272 /*
273 * We must have got woken up because we had a writer.
274 * That (and not still having one) is the condition
275 * that we must wait for.
276 */
277 }
278 if ((ap->a_mode & FWRITE) && fip->fi_readers == 0) {
279 VOP_UNLOCK(vp, 0);
280 error = msleep(&fip->fi_writers, &fifo_mtx,
281 PDROP | PCATCH | PSOCK, "fifoow", 0);
282 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
283 if (error) {
284 fip->fi_writers--;
285 if (fip->fi_writers == 0) {
286 socantrcvmore(fip->fi_readsock);
287 mtx_lock(&fifo_mtx);
288 fip->fi_wgen++;
289 mtx_unlock(&fifo_mtx);
290 fifo_cleanup(vp);
291 }
292 return (error);
293 }
294 /*
295 * We must have got woken up because we had
296 * a reader. That (and not still having one)
297 * is the condition that we must wait for.
298 */
299 mtx_lock(&fifo_mtx);
300 }
301 }
302 mtx_unlock(&fifo_mtx);
303 KASSERT(fp != NULL, ("can't fifo/vnode bypass"));
304 KASSERT(fp->f_ops == &badfileops, ("not badfileops in fifo_open"));
305 finit(fp, fp->f_flag, DTYPE_FIFO, fip, &fifo_ops_f);
306 return (0);
307 }
308
309 static void
310 filt_fifordetach(struct knote *kn)
311 {
312 struct socket *so = (struct socket *)kn->kn_hook;
313
314 SOCKBUF_LOCK(&so->so_rcv);
315 knlist_remove(&so->so_rcv.sb_sel.si_note, kn, 1);
316 if (knlist_empty(&so->so_rcv.sb_sel.si_note))
317 so->so_rcv.sb_flags &= ~SB_KNOTE;
318 SOCKBUF_UNLOCK(&so->so_rcv);
319 }
320
321 static int
322 filt_fiforead(struct knote *kn, long hint)
323 {
324 struct socket *so = (struct socket *)kn->kn_hook;
325
326 SOCKBUF_LOCK_ASSERT(&so->so_rcv);
327 kn->kn_data = so->so_rcv.sb_cc;
328 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
329 kn->kn_flags |= EV_EOF;
330 return (1);
331 } else {
332 kn->kn_flags &= ~EV_EOF;
333 return (kn->kn_data > 0);
334 }
335 }
336
337 static void
338 filt_fifowdetach(struct knote *kn)
339 {
340 struct socket *so = (struct socket *)kn->kn_hook;
341
342 SOCKBUF_LOCK(&so->so_snd);
343 knlist_remove(&so->so_snd.sb_sel.si_note, kn, 1);
344 if (knlist_empty(&so->so_snd.sb_sel.si_note))
345 so->so_snd.sb_flags &= ~SB_KNOTE;
346 SOCKBUF_UNLOCK(&so->so_snd);
347 }
348
349 static int
350 filt_fifowrite(struct knote *kn, long hint)
351 {
352 struct socket *so = (struct socket *)kn->kn_hook;
353
354 SOCKBUF_LOCK_ASSERT(&so->so_snd);
355 kn->kn_data = sbspace(&so->so_snd);
356 if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
357 kn->kn_flags |= EV_EOF;
358 return (1);
359 } else {
360 kn->kn_flags &= ~EV_EOF;
361 return (kn->kn_data >= so->so_snd.sb_lowat);
362 }
363 }
364
365 static void
366 filt_fifodetach_notsup(struct knote *kn)
367 {
368
369 }
370
371 static int
372 filt_fifo_notsup(struct knote *kn, long hint)
373 {
374
375 return (0);
376 }
377
378 /*
379 * Device close routine
380 */
381 /* ARGSUSED */
382 static int
383 fifo_close(ap)
384 struct vop_close_args /* {
385 struct vnode *a_vp;
386 int a_fflag;
387 struct ucred *a_cred;
388 struct thread *a_td;
389 } */ *ap;
390 {
391 struct vnode *vp = ap->a_vp;
392 struct fifoinfo *fip = vp->v_fifoinfo;
393
394 ASSERT_VOP_ELOCKED(vp, "fifo_close");
395 if (fip == NULL) {
396 printf("fifo_close: no v_fifoinfo %p\n", vp);
397 return (0);
398 }
399 if (ap->a_fflag & FREAD) {
400 fip->fi_readers--;
401 if (fip->fi_readers == 0)
402 socantsendmore(fip->fi_writesock);
403 }
404 if (ap->a_fflag & FWRITE) {
405 fip->fi_writers--;
406 if (fip->fi_writers == 0) {
407 socantrcvmore(fip->fi_readsock);
408 mtx_lock(&fifo_mtx);
409 fip->fi_wgen++;
410 mtx_unlock(&fifo_mtx);
411 }
412 }
413 fifo_cleanup(vp);
414 return (0);
415 }
416
417 /*
418 * Print out internal contents of a fifo vnode.
419 */
420 int
421 fifo_printinfo(vp)
422 struct vnode *vp;
423 {
424 register struct fifoinfo *fip = vp->v_fifoinfo;
425
426 if (fip == NULL){
427 printf(", NULL v_fifoinfo");
428 return (0);
429 }
430 printf(", fifo with %ld readers and %ld writers",
431 fip->fi_readers, fip->fi_writers);
432 return (0);
433 }
434
435 /*
436 * Print out the contents of a fifo vnode.
437 */
438 static int
439 fifo_print(ap)
440 struct vop_print_args /* {
441 struct vnode *a_vp;
442 } */ *ap;
443 {
444 printf(" ");
445 fifo_printinfo(ap->a_vp);
446 printf("\n");
447 return (0);
448 }
449
450 /*
451 * Return POSIX pathconf information applicable to fifo's.
452 */
453 static int
454 fifo_pathconf(ap)
455 struct vop_pathconf_args /* {
456 struct vnode *a_vp;
457 int a_name;
458 int *a_retval;
459 } */ *ap;
460 {
461
462 switch (ap->a_name) {
463 case _PC_LINK_MAX:
464 *ap->a_retval = LINK_MAX;
465 return (0);
466 case _PC_PIPE_BUF:
467 *ap->a_retval = PIPE_BUF;
468 return (0);
469 case _PC_CHOWN_RESTRICTED:
470 *ap->a_retval = 1;
471 return (0);
472 default:
473 return (EINVAL);
474 }
475 /* NOTREACHED */
476 }
477
478 /*
479 * Fifo advisory byte-level locks.
480 */
481 /* ARGSUSED */
482 static int
483 fifo_advlock(ap)
484 struct vop_advlock_args /* {
485 struct vnode *a_vp;
486 caddr_t a_id;
487 int a_op;
488 struct flock *a_fl;
489 int a_flags;
490 } */ *ap;
491 {
492
493 return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL);
494 }
495
496 static int
497 fifo_close_f(struct file *fp, struct thread *td)
498 {
499
500 return (vnops.fo_close(fp, td));
501 }
502
503 /*
504 * The implementation of ioctl() for named fifos is complicated by the fact
505 * that we permit O_RDWR fifo file descriptors, meaning that the actions of
506 * ioctls may have to be applied to both the underlying sockets rather than
507 * just one. The original implementation simply forward the ioctl to one
508 * or both sockets based on fp->f_flag. We now consider each ioctl
509 * separately, as the composition effect requires careful ordering.
510 *
511 * We do not blindly pass all ioctls through to the socket in order to avoid
512 * providing unnecessary ioctls that might be improperly depended on by
513 * applications (such as socket-specific, routing, and interface ioctls).
514 *
515 * Unlike sys_pipe.c, fifos do not implement the deprecated TIOCSPGRP and
516 * TIOCGPGRP ioctls. Earlier implementations of fifos did forward SIOCSPGRP
517 * and SIOCGPGRP ioctls, so we might need to re-add those here.
518 */
519 static int
520 fifo_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred,
521 struct thread *td)
522 {
523 struct fifoinfo *fi;
524 struct file filetmp; /* Local, so need not be locked. */
525 int error;
526
527 error = ENOTTY;
528 fi = fp->f_data;
529
530 switch (com) {
531 case FIONBIO:
532 /*
533 * Non-blocking I/O is implemented at the fifo layer using
534 * MSG_NBIO, so does not need to be forwarded down the stack.
535 */
536 return (0);
537
538 case FIOASYNC:
539 case FIOSETOWN:
540 case FIOGETOWN:
541 /*
542 * These socket ioctls don't have any ordering requirements,
543 * so are called in an arbitrary order, and only on the
544 * sockets indicated by the file descriptor rights.
545 *
546 * XXXRW: If O_RDWR and the read socket accepts an ioctl but
547 * the write socket doesn't, the socketpair is left in an
548 * inconsistent state.
549 */
550 if (fp->f_flag & FREAD) {
551 filetmp.f_data = fi->fi_readsock;
552 filetmp.f_cred = cred;
553 error = soo_ioctl(&filetmp, com, data, cred, td);
554 if (error)
555 return (error);
556 }
557 if (fp->f_flag & FWRITE) {
558 filetmp.f_data = fi->fi_writesock;
559 filetmp.f_cred = cred;
560 error = soo_ioctl(&filetmp, com, data, cred, td);
561 }
562 return (error);
563
564 case FIONREAD:
565 /*
566 * FIONREAD will return 0 for non-readable descriptors, and
567 * the results of FIONREAD on the read socket for readable
568 * descriptors.
569 */
570 if (!(fp->f_flag & FREAD)) {
571 *(int *)data = 0;
572 return (0);
573 }
574 filetmp.f_data = fi->fi_readsock;
575 filetmp.f_cred = cred;
576 return (soo_ioctl(&filetmp, com, data, cred, td));
577
578 default:
579 return (ENOTTY);
580 }
581 }
582
583 /*
584 * Because fifos are now a file descriptor layer object, EVFILT_VNODE is not
585 * implemented. Likely, fifo_kqfilter() should be removed, and
586 * fifo_kqfilter_f() should know how to forward the request to the underling
587 * vnode using f_vnode in the file descriptor here.
588 */
589 static int
590 fifo_kqfilter_f(struct file *fp, struct knote *kn)
591 {
592 struct fifoinfo *fi;
593 struct socket *so;
594 struct sockbuf *sb;
595
596 fi = fp->f_data;
597
598 /*
599 * If a filter is requested that is not supported by this file
600 * descriptor, don't return an error, but also don't ever generate an
601 * event.
602 */
603 if ((kn->kn_filter == EVFILT_READ) && !(fp->f_flag & FREAD)) {
604 kn->kn_fop = &fifo_notsup_filtops;
605 return (0);
606 }
607
608 if ((kn->kn_filter == EVFILT_WRITE) && !(fp->f_flag & FWRITE)) {
609 kn->kn_fop = &fifo_notsup_filtops;
610 return (0);
611 }
612
613 switch (kn->kn_filter) {
614 case EVFILT_READ:
615 kn->kn_fop = &fiforead_filtops;
616 so = fi->fi_readsock;
617 sb = &so->so_rcv;
618 break;
619 case EVFILT_WRITE:
620 kn->kn_fop = &fifowrite_filtops;
621 so = fi->fi_writesock;
622 sb = &so->so_snd;
623 break;
624 default:
625 return (EINVAL);
626 }
627
628 kn->kn_hook = (caddr_t)so;
629
630 SOCKBUF_LOCK(sb);
631 knlist_add(&sb->sb_sel.si_note, kn, 1);
632 sb->sb_flags |= SB_KNOTE;
633 SOCKBUF_UNLOCK(sb);
634
635 return (0);
636 }
637
638 static int
639 fifo_poll_f(struct file *fp, int events, struct ucred *cred, struct thread *td)
640 {
641 struct fifoinfo *fip;
642 struct file filetmp;
643 int levents, revents = 0;
644
645 fip = fp->f_data;
646 levents = events &
647 (POLLIN | POLLINIGNEOF | POLLPRI | POLLRDNORM | POLLRDBAND);
648 if ((fp->f_flag & FREAD) && levents) {
649 filetmp.f_data = fip->fi_readsock;
650 filetmp.f_cred = cred;
651 mtx_lock(&fifo_mtx);
652 if (fp->f_seqcount == fip->fi_wgen)
653 levents |= POLLINIGNEOF;
654 mtx_unlock(&fifo_mtx);
655 revents |= soo_poll(&filetmp, levents, cred, td);
656 }
657 levents = events & (POLLOUT | POLLWRNORM | POLLWRBAND);
658 if ((fp->f_flag & FWRITE) && levents) {
659 filetmp.f_data = fip->fi_writesock;
660 filetmp.f_cred = cred;
661 revents |= soo_poll(&filetmp, levents, cred, td);
662 }
663 return (revents);
664 }
665
666 static int
667 fifo_read_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td)
668 {
669 struct fifoinfo *fip;
670 int sflags;
671
672 fip = fp->f_data;
673 KASSERT(uio->uio_rw == UIO_READ,("fifo_read mode"));
674 if (uio->uio_resid == 0)
675 return (0);
676 sflags = (fp->f_flag & FNONBLOCK) ? MSG_NBIO : 0;
677 return (soreceive(fip->fi_readsock, NULL, uio, NULL, NULL, &sflags));
678 }
679
680 static int
681 fifo_stat_f(struct file *fp, struct stat *sb, struct ucred *cred, struct thread *td)
682 {
683
684 return (vnops.fo_stat(fp, sb, cred, td));
685 }
686
687 static int
688 fifo_truncate_f(struct file *fp, off_t length, struct ucred *cred, struct thread *td)
689 {
690
691 return (vnops.fo_truncate(fp, length, cred, td));
692 }
693
694 static int
695 fifo_write_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td)
696 {
697 struct fifoinfo *fip;
698 int sflags;
699
700 fip = fp->f_data;
701 KASSERT(uio->uio_rw == UIO_WRITE,("fifo_write mode"));
702 sflags = (fp->f_flag & FNONBLOCK) ? MSG_NBIO : 0;
703 return (sosend(fip->fi_writesock, NULL, uio, 0, NULL, sflags, td));
704 }
Cache object: 91a5960089ca2f58589f2413333c8890
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