1 /*
2 * Copyright (c) 1990, 1993, 1995
3 * The Regents of the University of California. 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 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)fifo_vnops.c 8.10 (Berkeley) 5/27/95
34 * $FreeBSD: releng/5.1/sys/fs/fifofs/fifo_vnops.c 112529 2003-03-24 11:03:42Z bde $
35 */
36
37 #include <sys/param.h>
38 #include <sys/event.h>
39 #include <sys/filio.h>
40 #include <sys/fcntl.h>
41 #include <sys/file.h>
42 #include <sys/kernel.h>
43 #include <sys/lock.h>
44 #include <sys/mutex.h>
45 #include <sys/malloc.h>
46 #include <sys/poll.h>
47 #include <sys/proc.h> /* XXXKSE */
48 #include <sys/signalvar.h>
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/sx.h>
52 #include <sys/systm.h>
53 #include <sys/un.h>
54 #include <sys/unistd.h>
55 #include <sys/vnode.h>
56 #include <fs/fifofs/fifo.h>
57
58 /*
59 * This structure is associated with the FIFO vnode and stores
60 * the state associated with the FIFO.
61 */
62 struct fifoinfo {
63 struct socket *fi_readsock;
64 struct socket *fi_writesock;
65 long fi_readers;
66 long fi_writers;
67 };
68
69 static int fifo_print(struct vop_print_args *);
70 static int fifo_lookup(struct vop_lookup_args *);
71 static int fifo_open(struct vop_open_args *);
72 static int fifo_close(struct vop_close_args *);
73 static int fifo_read(struct vop_read_args *);
74 static int fifo_write(struct vop_write_args *);
75 static int fifo_ioctl(struct vop_ioctl_args *);
76 static int fifo_poll(struct vop_poll_args *);
77 static int fifo_kqfilter(struct vop_kqfilter_args *);
78 static int fifo_pathconf(struct vop_pathconf_args *);
79 static int fifo_advlock(struct vop_advlock_args *);
80
81 static void filt_fifordetach(struct knote *kn);
82 static int filt_fiforead(struct knote *kn, long hint);
83 static void filt_fifowdetach(struct knote *kn);
84 static int filt_fifowrite(struct knote *kn, long hint);
85
86 static struct filterops fiforead_filtops =
87 { 1, NULL, filt_fifordetach, filt_fiforead };
88 static struct filterops fifowrite_filtops =
89 { 1, NULL, filt_fifowdetach, filt_fifowrite };
90
91 vop_t **fifo_vnodeop_p;
92 static struct vnodeopv_entry_desc fifo_vnodeop_entries[] = {
93 { &vop_default_desc, (vop_t *) vop_defaultop },
94 { &vop_access_desc, (vop_t *) vop_ebadf },
95 { &vop_advlock_desc, (vop_t *) fifo_advlock },
96 { &vop_close_desc, (vop_t *) fifo_close },
97 { &vop_create_desc, (vop_t *) vop_panic },
98 { &vop_getattr_desc, (vop_t *) vop_ebadf },
99 { &vop_getwritemount_desc, (vop_t *) vop_stdgetwritemount },
100 { &vop_ioctl_desc, (vop_t *) fifo_ioctl },
101 { &vop_kqfilter_desc, (vop_t *) fifo_kqfilter },
102 { &vop_lease_desc, (vop_t *) vop_null },
103 { &vop_link_desc, (vop_t *) vop_panic },
104 { &vop_lookup_desc, (vop_t *) fifo_lookup },
105 { &vop_mkdir_desc, (vop_t *) vop_panic },
106 { &vop_mknod_desc, (vop_t *) vop_panic },
107 { &vop_open_desc, (vop_t *) fifo_open },
108 { &vop_pathconf_desc, (vop_t *) fifo_pathconf },
109 { &vop_poll_desc, (vop_t *) fifo_poll },
110 { &vop_print_desc, (vop_t *) fifo_print },
111 { &vop_read_desc, (vop_t *) fifo_read },
112 { &vop_readdir_desc, (vop_t *) vop_panic },
113 { &vop_readlink_desc, (vop_t *) vop_panic },
114 { &vop_reallocblks_desc, (vop_t *) vop_panic },
115 { &vop_reclaim_desc, (vop_t *) vop_null },
116 { &vop_remove_desc, (vop_t *) vop_panic },
117 { &vop_rename_desc, (vop_t *) vop_panic },
118 { &vop_rmdir_desc, (vop_t *) vop_panic },
119 { &vop_setattr_desc, (vop_t *) vop_ebadf },
120 { &vop_symlink_desc, (vop_t *) vop_panic },
121 { &vop_write_desc, (vop_t *) fifo_write },
122 { NULL, NULL }
123 };
124 static struct vnodeopv_desc fifo_vnodeop_opv_desc =
125 { &fifo_vnodeop_p, fifo_vnodeop_entries };
126
127 VNODEOP_SET(fifo_vnodeop_opv_desc);
128
129 int
130 fifo_vnoperate(ap)
131 struct vop_generic_args /* {
132 struct vnodeop_desc *a_desc;
133 <other random data follows, presumably>
134 } */ *ap;
135 {
136 return (VOCALL(fifo_vnodeop_p, ap->a_desc->vdesc_offset, ap));
137 }
138
139 /*
140 * Trivial lookup routine that always fails.
141 */
142 /* ARGSUSED */
143 static int
144 fifo_lookup(ap)
145 struct vop_lookup_args /* {
146 struct vnode * a_dvp;
147 struct vnode ** a_vpp;
148 struct componentname * a_cnp;
149 } */ *ap;
150 {
151
152 *ap->a_vpp = NULL;
153 return (ENOTDIR);
154 }
155
156 /*
157 * Open called to set up a new instance of a fifo or
158 * to find an active instance of a fifo.
159 */
160 /* ARGSUSED */
161 static int
162 fifo_open(ap)
163 struct vop_open_args /* {
164 struct vnode *a_vp;
165 int a_mode;
166 struct ucred *a_cred;
167 struct thread *a_td;
168 } */ *ap;
169 {
170 struct vnode *vp = ap->a_vp;
171 struct fifoinfo *fip;
172 struct thread *td = ap->a_td;
173 struct socket *rso, *wso;
174 int error;
175
176 if ((fip = vp->v_fifoinfo) == NULL) {
177 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK);
178 vp->v_fifoinfo = fip;
179 error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0,
180 ap->a_td->td_ucred, ap->a_td);
181 if (error) {
182 free(fip, M_VNODE);
183 vp->v_fifoinfo = NULL;
184 return (error);
185 }
186 fip->fi_readsock = rso;
187 error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0,
188 ap->a_td->td_ucred, ap->a_td);
189 if (error) {
190 (void)soclose(rso);
191 free(fip, M_VNODE);
192 vp->v_fifoinfo = NULL;
193 return (error);
194 }
195 fip->fi_writesock = wso;
196 error = unp_connect2(wso, rso);
197 if (error) {
198 (void)soclose(wso);
199 (void)soclose(rso);
200 free(fip, M_VNODE);
201 vp->v_fifoinfo = NULL;
202 return (error);
203 }
204 fip->fi_readers = fip->fi_writers = 0;
205 wso->so_snd.sb_lowat = PIPE_BUF;
206 rso->so_state |= SS_CANTRCVMORE;
207 }
208 if (ap->a_mode & FREAD) {
209 fip->fi_readers++;
210 if (fip->fi_readers == 1) {
211 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE;
212 if (fip->fi_writers > 0) {
213 wakeup(&fip->fi_writers);
214 sowwakeup(fip->fi_writesock);
215 }
216 }
217 }
218 if (ap->a_mode & FWRITE) {
219 fip->fi_writers++;
220 if (fip->fi_writers == 1) {
221 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE;
222 if (fip->fi_readers > 0) {
223 wakeup(&fip->fi_readers);
224 sorwakeup(fip->fi_writesock);
225 }
226 }
227 }
228 if ((ap->a_mode & FREAD) && (ap->a_mode & O_NONBLOCK) == 0) {
229 if (fip->fi_writers == 0) {
230 VOP_UNLOCK(vp, 0, td);
231 error = tsleep(&fip->fi_readers,
232 PCATCH | PSOCK, "fifoor", 0);
233 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
234 if (error)
235 goto bad;
236 /*
237 * We must have got woken up because we had a writer.
238 * That (and not still having one) is the condition
239 * that we must wait for.
240 */
241 }
242 }
243 if (ap->a_mode & FWRITE) {
244 if (ap->a_mode & O_NONBLOCK) {
245 if (fip->fi_readers == 0) {
246 error = ENXIO;
247 goto bad;
248 }
249 } else {
250 if (fip->fi_readers == 0) {
251 VOP_UNLOCK(vp, 0, td);
252 error = tsleep(&fip->fi_writers,
253 PCATCH | PSOCK, "fifoow", 0);
254 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
255 if (error)
256 goto bad;
257 /*
258 * We must have got woken up because we had
259 * a reader. That (and not still having one)
260 * is the condition that we must wait for.
261 */
262 }
263 }
264 }
265 return (0);
266 bad:
267 VOP_CLOSE(vp, ap->a_mode, ap->a_cred, td);
268 return (error);
269 }
270
271 /*
272 * Vnode op for read
273 */
274 /* ARGSUSED */
275 static int
276 fifo_read(ap)
277 struct vop_read_args /* {
278 struct vnode *a_vp;
279 struct uio *a_uio;
280 int a_ioflag;
281 struct ucred *a_cred;
282 } */ *ap;
283 {
284 struct uio *uio = ap->a_uio;
285 struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock;
286 struct thread *td = uio->uio_td;
287 int error, startresid;
288
289 #ifdef DIAGNOSTIC
290 if (uio->uio_rw != UIO_READ)
291 panic("fifo_read mode");
292 #endif
293 if (uio->uio_resid == 0)
294 return (0);
295 if (ap->a_ioflag & IO_NDELAY)
296 rso->so_state |= SS_NBIO;
297 startresid = uio->uio_resid;
298 VOP_UNLOCK(ap->a_vp, 0, td);
299 error = soreceive(rso, (struct sockaddr **)0, uio, (struct mbuf **)0,
300 (struct mbuf **)0, (int *)0);
301 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, td);
302 if (ap->a_ioflag & IO_NDELAY)
303 rso->so_state &= ~SS_NBIO;
304 return (error);
305 }
306
307 /*
308 * Vnode op for write
309 */
310 /* ARGSUSED */
311 static int
312 fifo_write(ap)
313 struct vop_write_args /* {
314 struct vnode *a_vp;
315 struct uio *a_uio;
316 int a_ioflag;
317 struct ucred *a_cred;
318 } */ *ap;
319 {
320 struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock;
321 struct thread *td = ap->a_uio->uio_td;
322 int error;
323
324 #ifdef DIAGNOSTIC
325 if (ap->a_uio->uio_rw != UIO_WRITE)
326 panic("fifo_write mode");
327 #endif
328 if (ap->a_ioflag & IO_NDELAY)
329 wso->so_state |= SS_NBIO;
330 VOP_UNLOCK(ap->a_vp, 0, td);
331 error = sosend(wso, (struct sockaddr *)0, ap->a_uio, 0,
332 (struct mbuf *)0, 0, td);
333 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, td);
334 if (ap->a_ioflag & IO_NDELAY)
335 wso->so_state &= ~SS_NBIO;
336 return (error);
337 }
338
339 /*
340 * Device ioctl operation.
341 */
342 /* ARGSUSED */
343 static int
344 fifo_ioctl(ap)
345 struct vop_ioctl_args /* {
346 struct vnode *a_vp;
347 u_long a_command;
348 caddr_t a_data;
349 int a_fflag;
350 struct ucred *a_cred;
351 struct thread *a_td;
352 } */ *ap;
353 {
354 struct file filetmp; /* Local, so need not be locked. */
355 int error;
356
357 if (ap->a_command == FIONBIO)
358 return (0);
359 if (ap->a_fflag & FREAD) {
360 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock;
361 filetmp.f_cred = ap->a_cred;
362 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data,
363 ap->a_td->td_ucred, ap->a_td);
364 if (error)
365 return (error);
366 }
367 if (ap->a_fflag & FWRITE) {
368 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock;
369 filetmp.f_cred = ap->a_cred;
370 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data,
371 ap->a_td->td_ucred, ap->a_td);
372 if (error)
373 return (error);
374 }
375 return (0);
376 }
377
378 /* ARGSUSED */
379 static int
380 fifo_kqfilter(ap)
381 struct vop_kqfilter_args /* {
382 struct vnode *a_vp;
383 struct knote *a_kn;
384 } */ *ap;
385 {
386 struct fifoinfo *fi = ap->a_vp->v_fifoinfo;
387 struct socket *so;
388 struct sockbuf *sb;
389
390 switch (ap->a_kn->kn_filter) {
391 case EVFILT_READ:
392 ap->a_kn->kn_fop = &fiforead_filtops;
393 so = fi->fi_readsock;
394 sb = &so->so_rcv;
395 break;
396 case EVFILT_WRITE:
397 ap->a_kn->kn_fop = &fifowrite_filtops;
398 so = fi->fi_writesock;
399 sb = &so->so_snd;
400 break;
401 default:
402 return (1);
403 }
404
405 ap->a_kn->kn_hook = (caddr_t)so;
406
407 SLIST_INSERT_HEAD(&sb->sb_sel.si_note, ap->a_kn, kn_selnext);
408 sb->sb_flags |= SB_KNOTE;
409
410 return (0);
411 }
412
413 static void
414 filt_fifordetach(struct knote *kn)
415 {
416 struct socket *so = (struct socket *)kn->kn_hook;
417
418 SLIST_REMOVE(&so->so_rcv.sb_sel.si_note, kn, knote, kn_selnext);
419 if (SLIST_EMPTY(&so->so_rcv.sb_sel.si_note))
420 so->so_rcv.sb_flags &= ~SB_KNOTE;
421 }
422
423 static int
424 filt_fiforead(struct knote *kn, long hint)
425 {
426 struct socket *so = (struct socket *)kn->kn_hook;
427
428 kn->kn_data = so->so_rcv.sb_cc;
429 if (so->so_state & SS_CANTRCVMORE) {
430 kn->kn_flags |= EV_EOF;
431 return (1);
432 }
433 kn->kn_flags &= ~EV_EOF;
434 return (kn->kn_data > 0);
435 }
436
437 static void
438 filt_fifowdetach(struct knote *kn)
439 {
440 struct socket *so = (struct socket *)kn->kn_hook;
441
442 SLIST_REMOVE(&so->so_snd.sb_sel.si_note, kn, knote, kn_selnext);
443 if (SLIST_EMPTY(&so->so_snd.sb_sel.si_note))
444 so->so_snd.sb_flags &= ~SB_KNOTE;
445 }
446
447 static int
448 filt_fifowrite(struct knote *kn, long hint)
449 {
450 struct socket *so = (struct socket *)kn->kn_hook;
451
452 kn->kn_data = sbspace(&so->so_snd);
453 if (so->so_state & SS_CANTSENDMORE) {
454 kn->kn_flags |= EV_EOF;
455 return (1);
456 }
457 kn->kn_flags &= ~EV_EOF;
458 return (kn->kn_data >= so->so_snd.sb_lowat);
459 }
460
461 /* ARGSUSED */
462 static int
463 fifo_poll(ap)
464 struct vop_poll_args /* {
465 struct vnode *a_vp;
466 int a_events;
467 struct ucred *a_cred;
468 struct thread *a_td;
469 } */ *ap;
470 {
471 struct file filetmp;
472 int events, revents = 0;
473
474 events = ap->a_events &
475 (POLLIN | POLLINIGNEOF | POLLPRI | POLLRDNORM | POLLRDBAND);
476 if (events) {
477 /*
478 * If POLLIN or POLLRDNORM is requested and POLLINIGNEOF is
479 * not, then convert the first two to the last one. This
480 * tells the socket poll function to ignore EOF so that we
481 * block if there is no writer (and no data). Callers can
482 * set POLLINIGNEOF to get non-blocking behavior.
483 */
484 if (events & (POLLIN | POLLRDNORM) &&
485 !(events & POLLINIGNEOF)) {
486 events &= ~(POLLIN | POLLRDNORM);
487 events |= POLLINIGNEOF;
488 }
489
490 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock;
491 filetmp.f_cred = ap->a_cred;
492 if (filetmp.f_data)
493 revents |= soo_poll(&filetmp, events,
494 ap->a_td->td_ucred, ap->a_td);
495
496 /* Reverse the above conversion. */
497 if ((revents & POLLINIGNEOF) &&
498 !(ap->a_events & POLLINIGNEOF)) {
499 revents |= (ap->a_events & (POLLIN | POLLRDNORM));
500 revents &= ~POLLINIGNEOF;
501 }
502 }
503 events = ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND);
504 if (events) {
505 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock;
506 filetmp.f_cred = ap->a_cred;
507 if (filetmp.f_data) {
508 revents |= soo_poll(&filetmp, events,
509 ap->a_td->td_ucred, ap->a_td);
510 }
511 }
512 return (revents);
513 }
514
515 /*
516 * Device close routine
517 */
518 /* ARGSUSED */
519 static int
520 fifo_close(ap)
521 struct vop_close_args /* {
522 struct vnode *a_vp;
523 int a_fflag;
524 struct ucred *a_cred;
525 struct thread *a_td;
526 } */ *ap;
527 {
528 register struct vnode *vp = ap->a_vp;
529 register struct fifoinfo *fip = vp->v_fifoinfo;
530 int error1, error2;
531
532 if (ap->a_fflag & FREAD) {
533 fip->fi_readers--;
534 if (fip->fi_readers == 0)
535 socantsendmore(fip->fi_writesock);
536 }
537 if (ap->a_fflag & FWRITE) {
538 fip->fi_writers--;
539 if (fip->fi_writers == 0)
540 socantrcvmore(fip->fi_readsock);
541 }
542 if (vrefcnt(vp) > 1)
543 return (0);
544 error1 = soclose(fip->fi_readsock);
545 error2 = soclose(fip->fi_writesock);
546 FREE(fip, M_VNODE);
547 vp->v_fifoinfo = NULL;
548 if (error1)
549 return (error1);
550 return (error2);
551 }
552
553
554 /*
555 * Print out internal contents of a fifo vnode.
556 */
557 int
558 fifo_printinfo(vp)
559 struct vnode *vp;
560 {
561 register struct fifoinfo *fip = vp->v_fifoinfo;
562
563 printf(", fifo with %ld readers and %ld writers",
564 fip->fi_readers, fip->fi_writers);
565 return (0);
566 }
567
568 /*
569 * Print out the contents of a fifo vnode.
570 */
571 static int
572 fifo_print(ap)
573 struct vop_print_args /* {
574 struct vnode *a_vp;
575 } */ *ap;
576 {
577 fifo_printinfo(ap->a_vp);
578 printf("\n");
579 return (0);
580 }
581
582 /*
583 * Return POSIX pathconf information applicable to fifo's.
584 */
585 static int
586 fifo_pathconf(ap)
587 struct vop_pathconf_args /* {
588 struct vnode *a_vp;
589 int a_name;
590 int *a_retval;
591 } */ *ap;
592 {
593
594 switch (ap->a_name) {
595 case _PC_LINK_MAX:
596 *ap->a_retval = LINK_MAX;
597 return (0);
598 case _PC_PIPE_BUF:
599 *ap->a_retval = PIPE_BUF;
600 return (0);
601 case _PC_CHOWN_RESTRICTED:
602 *ap->a_retval = 1;
603 return (0);
604 default:
605 return (EINVAL);
606 }
607 /* NOTREACHED */
608 }
609
610 /*
611 * Fifo advisory byte-level locks.
612 */
613 /* ARGSUSED */
614 static int
615 fifo_advlock(ap)
616 struct vop_advlock_args /* {
617 struct vnode *a_vp;
618 caddr_t a_id;
619 int a_op;
620 struct flock *a_fl;
621 int a_flags;
622 } */ *ap;
623 {
624
625 return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL);
626 }
Cache object: fc13f06e603e4ad198f7537908a9977f
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