Initial import from FreeBSD RELENG_4:
[dragonfly.git] / sys / vfs / fifofs / fifo_vnops.c
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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: src/sys/miscfs/fifofs/fifo_vnops.c,v 1.45.2.4 2003/04/22 10:11:24 bde Exp $
35 */
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/unistd.h>
40#include <sys/kernel.h>
41#include <sys/lock.h>
42#include <sys/malloc.h>
43#include <sys/vnode.h>
44#include <sys/socket.h>
45#include <sys/socketvar.h>
46#include <sys/filio.h>
47#include <sys/fcntl.h>
48#include <sys/file.h>
49#include <sys/event.h>
50#include <sys/poll.h>
51#include <sys/un.h>
52#include <miscfs/fifofs/fifo.h>
53
54/*
55 * This structure is associated with the FIFO vnode and stores
56 * the state associated with the FIFO.
57 */
58struct fifoinfo {
59 struct socket *fi_readsock;
60 struct socket *fi_writesock;
61 long fi_readers;
62 long fi_writers;
63};
64
65static int fifo_badop __P((void));
66static int fifo_print __P((struct vop_print_args *));
67static int fifo_lookup __P((struct vop_lookup_args *));
68static int fifo_open __P((struct vop_open_args *));
69static int fifo_close __P((struct vop_close_args *));
70static int fifo_read __P((struct vop_read_args *));
71static int fifo_write __P((struct vop_write_args *));
72static int fifo_ioctl __P((struct vop_ioctl_args *));
73static int fifo_poll __P((struct vop_poll_args *));
74static int fifo_kqfilter __P((struct vop_kqfilter_args *));
75static int fifo_inactive __P((struct vop_inactive_args *));
76static int fifo_bmap __P((struct vop_bmap_args *));
77static int fifo_pathconf __P((struct vop_pathconf_args *));
78static int fifo_advlock __P((struct vop_advlock_args *));
79
80static void filt_fifordetach(struct knote *kn);
81static int filt_fiforead(struct knote *kn, long hint);
82static void filt_fifowdetach(struct knote *kn);
83static int filt_fifowrite(struct knote *kn, long hint);
84
85static struct filterops fiforead_filtops =
86 { 1, NULL, filt_fifordetach, filt_fiforead };
87static struct filterops fifowrite_filtops =
88 { 1, NULL, filt_fifowdetach, filt_fifowrite };
89
90vop_t **fifo_vnodeop_p;
91static struct vnodeopv_entry_desc fifo_vnodeop_entries[] = {
92 { &vop_default_desc, (vop_t *) vop_defaultop },
93 { &vop_access_desc, (vop_t *) vop_ebadf },
94 { &vop_advlock_desc, (vop_t *) fifo_advlock },
95 { &vop_bmap_desc, (vop_t *) fifo_bmap },
96 { &vop_close_desc, (vop_t *) fifo_close },
97 { &vop_create_desc, (vop_t *) fifo_badop },
98 { &vop_getattr_desc, (vop_t *) vop_ebadf },
99 { &vop_inactive_desc, (vop_t *) fifo_inactive },
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 *) fifo_badop },
104 { &vop_lookup_desc, (vop_t *) fifo_lookup },
105 { &vop_mkdir_desc, (vop_t *) fifo_badop },
106 { &vop_mknod_desc, (vop_t *) fifo_badop },
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 *) fifo_badop },
113 { &vop_readlink_desc, (vop_t *) fifo_badop },
114 { &vop_reallocblks_desc, (vop_t *) fifo_badop },
115 { &vop_reclaim_desc, (vop_t *) vop_null },
116 { &vop_remove_desc, (vop_t *) fifo_badop },
117 { &vop_rename_desc, (vop_t *) fifo_badop },
118 { &vop_rmdir_desc, (vop_t *) fifo_badop },
119 { &vop_setattr_desc, (vop_t *) vop_ebadf },
120 { &vop_symlink_desc, (vop_t *) fifo_badop },
121 { &vop_write_desc, (vop_t *) fifo_write },
122 { NULL, NULL }
123};
124static struct vnodeopv_desc fifo_vnodeop_opv_desc =
125 { &fifo_vnodeop_p, fifo_vnodeop_entries };
126
127VNODEOP_SET(fifo_vnodeop_opv_desc);
128
129int
130fifo_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 */
143static int
144fifo_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 */
161static int
162fifo_open(ap)
163 struct vop_open_args /* {
164 struct vnode *a_vp;
165 int a_mode;
166 struct ucred *a_cred;
167 struct proc *a_p;
168 } */ *ap;
169{
170 struct vnode *vp = ap->a_vp;
171 struct fifoinfo *fip;
172 struct proc *p = ap->a_p;
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, ap->a_p);
180 if (error) {
181 free(fip, M_VNODE);
182 vp->v_fifoinfo = NULL;
183 return (error);
184 }
185 fip->fi_readsock = rso;
186 error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0, ap->a_p);
187 if (error) {
188 (void)soclose(rso);
189 free(fip, M_VNODE);
190 vp->v_fifoinfo = NULL;
191 return (error);
192 }
193 fip->fi_writesock = wso;
194 error = unp_connect2(wso, rso);
195 if (error) {
196 (void)soclose(wso);
197 (void)soclose(rso);
198 free(fip, M_VNODE);
199 vp->v_fifoinfo = NULL;
200 return (error);
201 }
202 fip->fi_readers = fip->fi_writers = 0;
203 wso->so_snd.sb_lowat = PIPE_BUF;
204 rso->so_state |= SS_CANTRCVMORE;
205 }
206 if (ap->a_mode & FREAD) {
207 fip->fi_readers++;
208 if (fip->fi_readers == 1) {
209 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE;
210 if (fip->fi_writers > 0) {
211 wakeup((caddr_t)&fip->fi_writers);
212 sowwakeup(fip->fi_writesock);
213 }
214 }
215 }
216 if (ap->a_mode & FWRITE) {
217 fip->fi_writers++;
218 if (fip->fi_writers == 1) {
219 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE;
220 if (fip->fi_readers > 0) {
221 wakeup((caddr_t)&fip->fi_readers);
222 sorwakeup(fip->fi_writesock);
223 }
224 }
225 }
226 if ((ap->a_mode & FREAD) && (ap->a_mode & O_NONBLOCK) == 0) {
227 if (fip->fi_writers == 0) {
228 VOP_UNLOCK(vp, 0, p);
229 error = tsleep((caddr_t)&fip->fi_readers,
230 PCATCH | PSOCK, "fifoor", 0);
231 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
232 if (error)
233 goto bad;
234 /*
235 * We must have got woken up because we had a writer.
236 * That (and not still having one) is the condition
237 * that we must wait for.
238 */
239 }
240 }
241 if (ap->a_mode & FWRITE) {
242 if (ap->a_mode & O_NONBLOCK) {
243 if (fip->fi_readers == 0) {
244 error = ENXIO;
245 goto bad;
246 }
247 } else {
248 if (fip->fi_readers == 0) {
249 VOP_UNLOCK(vp, 0, p);
250 error = tsleep((caddr_t)&fip->fi_writers,
251 PCATCH | PSOCK, "fifoow", 0);
252 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
253 if (error)
254 goto bad;
255 /*
256 * We must have got woken up because we had
257 * a reader. That (and not still having one)
258 * is the condition that we must wait for.
259 */
260 }
261 }
262 }
263 return (0);
264bad:
265 VOP_CLOSE(vp, ap->a_mode, ap->a_cred, p);
266 return (error);
267}
268
269/*
270 * Vnode op for read
271 */
272/* ARGSUSED */
273static int
274fifo_read(ap)
275 struct vop_read_args /* {
276 struct vnode *a_vp;
277 struct uio *a_uio;
278 int a_ioflag;
279 struct ucred *a_cred;
280 } */ *ap;
281{
282 struct uio *uio = ap->a_uio;
283 struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock;
284 struct proc *p = uio->uio_procp;
285 int error, startresid;
286
287#ifdef DIAGNOSTIC
288 if (uio->uio_rw != UIO_READ)
289 panic("fifo_read mode");
290#endif
291 if (uio->uio_resid == 0)
292 return (0);
293 if (ap->a_ioflag & IO_NDELAY)
294 rso->so_state |= SS_NBIO;
295 startresid = uio->uio_resid;
296 VOP_UNLOCK(ap->a_vp, 0, p);
297 error = soreceive(rso, (struct sockaddr **)0, uio, (struct mbuf **)0,
298 (struct mbuf **)0, (int *)0);
299 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, p);
300 if (ap->a_ioflag & IO_NDELAY)
301 rso->so_state &= ~SS_NBIO;
302 return (error);
303}
304
305/*
306 * Vnode op for write
307 */
308/* ARGSUSED */
309static int
310fifo_write(ap)
311 struct vop_write_args /* {
312 struct vnode *a_vp;
313 struct uio *a_uio;
314 int a_ioflag;
315 struct ucred *a_cred;
316 } */ *ap;
317{
318 struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock;
319 struct proc *p = ap->a_uio->uio_procp;
320 int error;
321
322#ifdef DIAGNOSTIC
323 if (ap->a_uio->uio_rw != UIO_WRITE)
324 panic("fifo_write mode");
325#endif
326 if (ap->a_ioflag & IO_NDELAY)
327 wso->so_state |= SS_NBIO;
328 VOP_UNLOCK(ap->a_vp, 0, p);
329 error = sosend(wso, (struct sockaddr *)0, ap->a_uio, 0,
330 (struct mbuf *)0, 0, p);
331 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, p);
332 if (ap->a_ioflag & IO_NDELAY)
333 wso->so_state &= ~SS_NBIO;
334 return (error);
335}
336
337/*
338 * Device ioctl operation.
339 */
340/* ARGSUSED */
341static int
342fifo_ioctl(ap)
343 struct vop_ioctl_args /* {
344 struct vnode *a_vp;
345 int a_command;
346 caddr_t a_data;
347 int a_fflag;
348 struct ucred *a_cred;
349 struct proc *a_p;
350 } */ *ap;
351{
352 struct file filetmp;
353 int error;
354
355 if (ap->a_command == FIONBIO)
356 return (0);
357 if (ap->a_fflag & FREAD) {
358 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock;
359 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p);
360 if (error)
361 return (error);
362 }
363 if (ap->a_fflag & FWRITE) {
364 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock;
365 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p);
366 if (error)
367 return (error);
368 }
369 return (0);
370}
371
372/* ARGSUSED */
373static int
374fifo_kqfilter(ap)
375 struct vop_kqfilter_args /* {
376 struct vnode *a_vp;
377 struct knote *a_kn;
378 } */ *ap;
379{
380 struct fifoinfo *fi = ap->a_vp->v_fifoinfo;
381 struct socket *so;
382 struct sockbuf *sb;
383
384 switch (ap->a_kn->kn_filter) {
385 case EVFILT_READ:
386 ap->a_kn->kn_fop = &fiforead_filtops;
387 so = fi->fi_readsock;
388 sb = &so->so_rcv;
389 break;
390 case EVFILT_WRITE:
391 ap->a_kn->kn_fop = &fifowrite_filtops;
392 so = fi->fi_writesock;
393 sb = &so->so_snd;
394 break;
395 default:
396 return (1);
397 }
398
399 ap->a_kn->kn_hook = (caddr_t)so;
400
401 SLIST_INSERT_HEAD(&sb->sb_sel.si_note, ap->a_kn, kn_selnext);
402 sb->sb_flags |= SB_KNOTE;
403
404 return (0);
405}
406
407static void
408filt_fifordetach(struct knote *kn)
409{
410 struct socket *so = (struct socket *)kn->kn_hook;
411
412 SLIST_REMOVE(&so->so_rcv.sb_sel.si_note, kn, knote, kn_selnext);
413 if (SLIST_EMPTY(&so->so_rcv.sb_sel.si_note))
414 so->so_rcv.sb_flags &= ~SB_KNOTE;
415}
416
417static int
418filt_fiforead(struct knote *kn, long hint)
419{
420 struct socket *so = (struct socket *)kn->kn_hook;
421
422 kn->kn_data = so->so_rcv.sb_cc;
423 if (so->so_state & SS_CANTRCVMORE) {
424 kn->kn_flags |= EV_EOF;
425 return (1);
426 }
427 kn->kn_flags &= ~EV_EOF;
428 return (kn->kn_data > 0);
429}
430
431static void
432filt_fifowdetach(struct knote *kn)
433{
434 struct socket *so = (struct socket *)kn->kn_hook;
435
436 SLIST_REMOVE(&so->so_snd.sb_sel.si_note, kn, knote, kn_selnext);
437 if (SLIST_EMPTY(&so->so_snd.sb_sel.si_note))
438 so->so_snd.sb_flags &= ~SB_KNOTE;
439}
440
441static int
442filt_fifowrite(struct knote *kn, long hint)
443{
444 struct socket *so = (struct socket *)kn->kn_hook;
445
446 kn->kn_data = sbspace(&so->so_snd);
447 if (so->so_state & SS_CANTSENDMORE) {
448 kn->kn_flags |= EV_EOF;
449 return (1);
450 }
451 kn->kn_flags &= ~EV_EOF;
452 return (kn->kn_data >= so->so_snd.sb_lowat);
453}
454
455/* ARGSUSED */
456static int
457fifo_poll(ap)
458 struct vop_poll_args /* {
459 struct vnode *a_vp;
460 int a_events;
461 struct ucred *a_cred;
462 struct proc *a_p;
463 } */ *ap;
464{
465 struct file filetmp;
466 int revents = 0;
467
468 if (ap->a_events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
469 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock;
470 if (filetmp.f_data)
471 revents |= soo_poll(&filetmp, ap->a_events, ap->a_cred,
472 ap->a_p);
473 }
474 if (ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND)) {
475 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock;
476 if (filetmp.f_data)
477 revents |= soo_poll(&filetmp, ap->a_events, ap->a_cred,
478 ap->a_p);
479 }
480 return (revents);
481}
482
483static int
484fifo_inactive(ap)
485 struct vop_inactive_args /* {
486 struct vnode *a_vp;
487 struct proc *a_p;
488 } */ *ap;
489{
490
491 VOP_UNLOCK(ap->a_vp, 0, ap->a_p);
492 return (0);
493}
494
495/*
496 * This is a noop, simply returning what one has been given.
497 */
498static int
499fifo_bmap(ap)
500 struct vop_bmap_args /* {
501 struct vnode *a_vp;
502 daddr_t a_bn;
503 struct vnode **a_vpp;
504 daddr_t *a_bnp;
505 int *a_runp;
506 int *a_runb;
507 } */ *ap;
508{
509
510 if (ap->a_vpp != NULL)
511 *ap->a_vpp = ap->a_vp;
512 if (ap->a_bnp != NULL)
513 *ap->a_bnp = ap->a_bn;
514 if (ap->a_runp != NULL)
515 *ap->a_runp = 0;
516 if (ap->a_runb != NULL)
517 *ap->a_runb = 0;
518 return (0);
519}
520
521/*
522 * Device close routine
523 */
524/* ARGSUSED */
525static int
526fifo_close(ap)
527 struct vop_close_args /* {
528 struct vnode *a_vp;
529 int a_fflag;
530 struct ucred *a_cred;
531 struct proc *a_p;
532 } */ *ap;
533{
534 register struct vnode *vp = ap->a_vp;
535 register struct fifoinfo *fip = vp->v_fifoinfo;
536 int error1, error2;
537
538 if (ap->a_fflag & FREAD) {
539 fip->fi_readers--;
540 if (fip->fi_readers == 0)
541 socantsendmore(fip->fi_writesock);
542 }
543 if (ap->a_fflag & FWRITE) {
544 fip->fi_writers--;
545 if (fip->fi_writers == 0)
546 socantrcvmore(fip->fi_readsock);
547 }
548 if (vp->v_usecount > 1)
549 return (0);
550 error1 = soclose(fip->fi_readsock);
551 error2 = soclose(fip->fi_writesock);
552 FREE(fip, M_VNODE);
553 vp->v_fifoinfo = NULL;
554 if (error1)
555 return (error1);
556 return (error2);
557}
558
559
560/*
561 * Print out internal contents of a fifo vnode.
562 */
563int
564fifo_printinfo(vp)
565 struct vnode *vp;
566{
567 register struct fifoinfo *fip = vp->v_fifoinfo;
568
569 printf(", fifo with %ld readers and %ld writers",
570 fip->fi_readers, fip->fi_writers);
571 return (0);
572}
573
574/*
575 * Print out the contents of a fifo vnode.
576 */
577static int
578fifo_print(ap)
579 struct vop_print_args /* {
580 struct vnode *a_vp;
581 } */ *ap;
582{
583
584 printf("tag VT_NON");
585 fifo_printinfo(ap->a_vp);
586 printf("\n");
587 return (0);
588}
589
590/*
591 * Return POSIX pathconf information applicable to fifo's.
592 */
593int
594fifo_pathconf(ap)
595 struct vop_pathconf_args /* {
596 struct vnode *a_vp;
597 int a_name;
598 int *a_retval;
599 } */ *ap;
600{
601
602 switch (ap->a_name) {
603 case _PC_LINK_MAX:
604 *ap->a_retval = LINK_MAX;
605 return (0);
606 case _PC_PIPE_BUF:
607 *ap->a_retval = PIPE_BUF;
608 return (0);
609 case _PC_CHOWN_RESTRICTED:
610 *ap->a_retval = 1;
611 return (0);
612 default:
613 return (EINVAL);
614 }
615 /* NOTREACHED */
616}
617
618/*
619 * Fifo advisory byte-level locks.
620 */
621/* ARGSUSED */
622static int
623fifo_advlock(ap)
624 struct vop_advlock_args /* {
625 struct vnode *a_vp;
626 caddr_t a_id;
627 int a_op;
628 struct flock *a_fl;
629 int a_flags;
630 } */ *ap;
631{
632
633 return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL);
634}
635
636/*
637 * Fifo bad operation
638 */
639static int
640fifo_badop()
641{
642
643 panic("fifo_badop called");
644 /* NOTREACHED */
645}