xref: /freebsd/sys/fs/fifofs/fifo_vnops.c (revision 4a0f765fbf09711e612e86fce8bb09ec43f482d9)
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  * $Id$
35  */
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/proc.h>
40 #include <sys/time.h>
41 #include <sys/namei.h>
42 #include <sys/unistd.h>
43 #include <sys/kernel.h>
44 #include <sys/vnode.h>
45 #include <sys/socket.h>
46 #include <sys/socketvar.h>
47 #include <sys/stat.h>
48 #include <sys/ioctl.h>
49 #include <sys/file.h>
50 #include <sys/errno.h>
51 #include <sys/malloc.h>
52 #include <sys/un.h>
53 #include <miscfs/fifofs/fifo.h>
54 
55 /*
56  * This structure is associated with the FIFO vnode and stores
57  * the state associated with the FIFO.
58  */
59 struct fifoinfo {
60 	struct socket	*fi_readsock;
61 	struct socket	*fi_writesock;
62 	long		fi_readers;
63 	long		fi_writers;
64 };
65 
66 static int	fifo_ebadf __P((void));
67 static int	fifo_print __P((struct vop_print_args *));
68 
69 vop_t **fifo_vnodeop_p;
70 static struct vnodeopv_entry_desc fifo_vnodeop_entries[] = {
71 	{ &vop_default_desc, (vop_t *)vn_default_error },
72 	{ &vop_lookup_desc, (vop_t *)fifo_lookup },	/* lookup */
73 	{ &vop_create_desc, (vop_t *)fifo_create },	/* create */
74 	{ &vop_mknod_desc, (vop_t *)fifo_mknod },	/* mknod */
75 	{ &vop_open_desc, (vop_t *)fifo_open },		/* open */
76 	{ &vop_close_desc, (vop_t *)fifo_close },	/* close */
77 	{ &vop_access_desc, (vop_t *)fifo_access },	/* access */
78 	{ &vop_getattr_desc, (vop_t *)fifo_getattr },	/* getattr */
79 	{ &vop_setattr_desc, (vop_t *)fifo_setattr },	/* setattr */
80 	{ &vop_read_desc, (vop_t *)fifo_read },		/* read */
81 	{ &vop_write_desc, (vop_t *)fifo_write },	/* write */
82 	{ &vop_lease_desc, (vop_t *)fifo_lease_check },	/* lease */
83 	{ &vop_ioctl_desc, (vop_t *)fifo_ioctl },	/* ioctl */
84 	{ &vop_select_desc, (vop_t *)fifo_select },	/* select */
85 	{ &vop_revoke_desc, (vop_t *)fifo_revoke },	/* revoke */
86 	{ &vop_mmap_desc, (vop_t *)fifo_mmap },		/* mmap */
87 	{ &vop_fsync_desc, (vop_t *)fifo_fsync },	/* fsync */
88 	{ &vop_seek_desc, (vop_t *)fifo_seek },		/* seek */
89 	{ &vop_remove_desc, (vop_t *)fifo_remove },	/* remove */
90 	{ &vop_link_desc, (vop_t *)fifo_link },		/* link */
91 	{ &vop_rename_desc, (vop_t *)fifo_rename },	/* rename */
92 	{ &vop_mkdir_desc, (vop_t *)fifo_mkdir },	/* mkdir */
93 	{ &vop_rmdir_desc, (vop_t *)fifo_rmdir },	/* rmdir */
94 	{ &vop_symlink_desc, (vop_t *)fifo_symlink },	/* symlink */
95 	{ &vop_readdir_desc, (vop_t *)fifo_readdir },	/* readdir */
96 	{ &vop_readlink_desc, (vop_t *)fifo_readlink },	/* readlink */
97 	{ &vop_abortop_desc, (vop_t *)fifo_abortop },	/* abortop */
98 	{ &vop_inactive_desc, (vop_t *)fifo_inactive },	/* inactive */
99 	{ &vop_reclaim_desc, (vop_t *)fifo_reclaim },	/* reclaim */
100 	{ &vop_lock_desc, (vop_t *)fifo_lock },		/* lock */
101 	{ &vop_unlock_desc, (vop_t *)fifo_unlock },	/* unlock */
102 	{ &vop_bmap_desc, (vop_t *)fifo_bmap },		/* bmap */
103 	{ &vop_strategy_desc, (vop_t *)fifo_strategy },	/* strategy */
104 	{ &vop_print_desc, (vop_t *)fifo_print },	/* print */
105 	{ &vop_islocked_desc, (vop_t *)fifo_islocked },	/* islocked */
106 	{ &vop_pathconf_desc, (vop_t *)fifo_pathconf },	/* pathconf */
107 	{ &vop_advlock_desc, (vop_t *)fifo_advlock },	/* advlock */
108 	{ &vop_blkatoff_desc, (vop_t *)fifo_blkatoff },	/* blkatoff */
109 	{ &vop_valloc_desc, (vop_t *)fifo_valloc },	/* valloc */
110 	{ &vop_vfree_desc, (vop_t *)fifo_vfree },	/* vfree */
111 	{ &vop_truncate_desc, (vop_t *)fifo_truncate },	/* truncate */
112 	{ &vop_update_desc, (vop_t *)fifo_update },	/* update */
113 	{ &vop_bwrite_desc, (vop_t *)fifo_bwrite },	/* bwrite */
114 	{ NULL, NULL }
115 };
116 static struct vnodeopv_desc fifo_vnodeop_opv_desc =
117 	{ &fifo_vnodeop_p, fifo_vnodeop_entries };
118 
119 VNODEOP_SET(fifo_vnodeop_opv_desc);
120 
121 /*
122  * Trivial lookup routine that always fails.
123  */
124 /* ARGSUSED */
125 int
126 fifo_lookup(ap)
127 	struct vop_lookup_args /* {
128 		struct vnode * a_dvp;
129 		struct vnode ** a_vpp;
130 		struct componentname * a_cnp;
131 	} */ *ap;
132 {
133 
134 	*ap->a_vpp = NULL;
135 	return (ENOTDIR);
136 }
137 
138 /*
139  * Open called to set up a new instance of a fifo or
140  * to find an active instance of a fifo.
141  */
142 /* ARGSUSED */
143 int
144 fifo_open(ap)
145 	struct vop_open_args /* {
146 		struct vnode *a_vp;
147 		int  a_mode;
148 		struct ucred *a_cred;
149 		struct proc *a_p;
150 	} */ *ap;
151 {
152 	struct vnode *vp = ap->a_vp;
153 	struct fifoinfo *fip;
154 	struct proc *p = ap->a_p;
155 	struct socket *rso, *wso;
156 	int error;
157 	static char openstr[] = "fifo";
158 
159 	if ((fip = vp->v_fifoinfo) == NULL) {
160 		MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK);
161 		vp->v_fifoinfo = fip;
162 		error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0, ap->a_p);
163 		if (error) {
164 			free(fip, M_VNODE);
165 			vp->v_fifoinfo = NULL;
166 			return (error);
167 		}
168 		fip->fi_readsock = rso;
169 		error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0, ap->a_p);
170 		if (error) {
171 			(void)soclose(rso);
172 			free(fip, M_VNODE);
173 			vp->v_fifoinfo = NULL;
174 			return (error);
175 		}
176 		fip->fi_writesock = wso;
177 		error = unp_connect2(wso, rso);
178 		if (error) {
179 			(void)soclose(wso);
180 			(void)soclose(rso);
181 			free(fip, M_VNODE);
182 			vp->v_fifoinfo = NULL;
183 			return (error);
184 		}
185 		fip->fi_readers = fip->fi_writers = 0;
186 		wso->so_state |= SS_CANTRCVMORE;
187 		rso->so_state |= SS_CANTSENDMORE;
188 	}
189 	if (ap->a_mode & FREAD) {
190 		fip->fi_readers++;
191 		if (fip->fi_readers == 1) {
192 			fip->fi_writesock->so_state &= ~SS_CANTSENDMORE;
193 			if (fip->fi_writers > 0)
194 				wakeup((caddr_t)&fip->fi_writers);
195 		}
196 	}
197 	if (ap->a_mode & FWRITE) {
198 		fip->fi_writers++;
199 		if (fip->fi_writers == 1) {
200 			fip->fi_readsock->so_state &= ~SS_CANTRCVMORE;
201 			if (fip->fi_readers > 0)
202 				wakeup((caddr_t)&fip->fi_readers);
203 		}
204 	}
205 	if ((ap->a_mode & FREAD) && (ap->a_mode & O_NONBLOCK) == 0) {
206 		while (fip->fi_writers == 0) {
207 			VOP_UNLOCK(vp, 0, p);
208 			error = tsleep((caddr_t)&fip->fi_readers,
209 			    PCATCH | PSOCK, openstr, 0);
210 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
211 			if (error)
212 				goto bad;
213 		}
214 	}
215 	if (ap->a_mode & FWRITE) {
216 		if (ap->a_mode & O_NONBLOCK) {
217 			if (fip->fi_readers == 0) {
218 				error = ENXIO;
219 				goto bad;
220 			}
221 		} else {
222 			while (fip->fi_readers == 0) {
223 				VOP_UNLOCK(vp, 0, p);
224 				error = tsleep((caddr_t)&fip->fi_writers,
225 				    PCATCH | PSOCK, openstr, 0);
226 				vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
227 				if (error)
228 					goto bad;
229 			}
230 		}
231 	}
232 	return (0);
233 bad:
234 	VOP_CLOSE(vp, ap->a_mode, ap->a_cred, p);
235 	return (error);
236 }
237 
238 /*
239  * Vnode op for read
240  */
241 /* ARGSUSED */
242 int
243 fifo_read(ap)
244 	struct vop_read_args /* {
245 		struct vnode *a_vp;
246 		struct uio *a_uio;
247 		int  a_ioflag;
248 		struct ucred *a_cred;
249 	} */ *ap;
250 {
251 	struct uio *uio = ap->a_uio;
252 	struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock;
253 	struct proc *p = uio->uio_procp;
254 	int error, startresid;
255 
256 #ifdef DIAGNOSTIC
257 	if (uio->uio_rw != UIO_READ)
258 		panic("fifo_read mode");
259 #endif
260 	if (uio->uio_resid == 0)
261 		return (0);
262 	if (ap->a_ioflag & IO_NDELAY)
263 		rso->so_state |= SS_NBIO;
264 	startresid = uio->uio_resid;
265 	VOP_UNLOCK(ap->a_vp, 0, p);
266 	error = soreceive(rso, (struct mbuf **)0, uio, (struct mbuf **)0,
267 	    (struct mbuf **)0, (int *)0);
268 	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, p);
269 	/*
270 	 * Clear EOF indication after first such return.
271 	 */
272 	if (uio->uio_resid == startresid)
273 		rso->so_state &= ~SS_CANTRCVMORE;
274 	if (ap->a_ioflag & IO_NDELAY)
275 		rso->so_state &= ~SS_NBIO;
276 	return (error);
277 }
278 
279 /*
280  * Vnode op for write
281  */
282 /* ARGSUSED */
283 int
284 fifo_write(ap)
285 	struct vop_write_args /* {
286 		struct vnode *a_vp;
287 		struct uio *a_uio;
288 		int  a_ioflag;
289 		struct ucred *a_cred;
290 	} */ *ap;
291 {
292 	struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock;
293 	struct proc *p = ap->a_uio->uio_procp;
294 	int error;
295 
296 #ifdef DIAGNOSTIC
297 	if (ap->a_uio->uio_rw != UIO_WRITE)
298 		panic("fifo_write mode");
299 #endif
300 	if (ap->a_ioflag & IO_NDELAY)
301 		wso->so_state |= SS_NBIO;
302 	VOP_UNLOCK(ap->a_vp, 0, p);
303 	error = sosend(wso, (struct mbuf *)0, ap->a_uio, 0, (struct mbuf *)0, 0);
304 	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, p);
305 	if (ap->a_ioflag & IO_NDELAY)
306 		wso->so_state &= ~SS_NBIO;
307 	return (error);
308 }
309 
310 /*
311  * Device ioctl operation.
312  */
313 /* ARGSUSED */
314 int
315 fifo_ioctl(ap)
316 	struct vop_ioctl_args /* {
317 		struct vnode *a_vp;
318 		int  a_command;
319 		caddr_t  a_data;
320 		int  a_fflag;
321 		struct ucred *a_cred;
322 		struct proc *a_p;
323 	} */ *ap;
324 {
325 	struct file filetmp;
326 	int error;
327 
328 	if (ap->a_command == FIONBIO)
329 		return (0);
330 	if (ap->a_fflag & FREAD) {
331 		filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock;
332 		error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p);
333 		if (error)
334 			return (error);
335 	}
336 	if (ap->a_fflag & FWRITE) {
337 		filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock;
338 		error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p);
339 		if (error)
340 			return (error);
341 	}
342 	return (0);
343 }
344 
345 /* ARGSUSED */
346 int
347 fifo_select(ap)
348 	struct vop_select_args /* {
349 		struct vnode *a_vp;
350 		int  a_which;
351 		int  a_fflags;
352 		struct ucred *a_cred;
353 		struct proc *a_p;
354 	} */ *ap;
355 {
356 	struct file filetmp;
357 	int ready;
358 
359 	if (ap->a_fflags & FREAD) {
360 		filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock;
361 		ready = soo_select(&filetmp, ap->a_which, ap->a_p);
362 		if (ready)
363 			return (ready);
364 	}
365 	if (ap->a_fflags & FWRITE) {
366 		filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock;
367 		ready = soo_select(&filetmp, ap->a_which, ap->a_p);
368 		if (ready)
369 			return (ready);
370 	}
371 	return (0);
372 }
373 
374 int
375 fifo_inactive(ap)
376 	struct vop_inactive_args /* {
377 		struct vnode *a_vp;
378 		struct proc *a_p;
379 	} */ *ap;
380 {
381 
382 	VOP_UNLOCK(ap->a_vp, 0, ap->a_p);
383 	return (0);
384 }
385 
386 /*
387  * This is a noop, simply returning what one has been given.
388  */
389 int
390 fifo_bmap(ap)
391 	struct vop_bmap_args /* {
392 		struct vnode *a_vp;
393 		daddr_t  a_bn;
394 		struct vnode **a_vpp;
395 		daddr_t *a_bnp;
396 		int *a_runp;
397 		int *a_runb;
398 	} */ *ap;
399 {
400 
401 	if (ap->a_vpp != NULL)
402 		*ap->a_vpp = ap->a_vp;
403 	if (ap->a_bnp != NULL)
404 		*ap->a_bnp = ap->a_bn;
405 	if (ap->a_runp != NULL)
406 		*ap->a_runp = 0;
407 	if (ap->a_runb != NULL)
408 		*ap->a_runb = 0;
409 	return (0);
410 }
411 
412 /*
413  * Device close routine
414  */
415 /* ARGSUSED */
416 int
417 fifo_close(ap)
418 	struct vop_close_args /* {
419 		struct vnode *a_vp;
420 		int  a_fflag;
421 		struct ucred *a_cred;
422 		struct proc *a_p;
423 	} */ *ap;
424 {
425 	register struct vnode *vp = ap->a_vp;
426 	register struct fifoinfo *fip = vp->v_fifoinfo;
427 	int error1, error2;
428 
429 	if (ap->a_fflag & FREAD) {
430 		fip->fi_readers--;
431 		if (fip->fi_readers == 0)
432 			socantsendmore(fip->fi_writesock);
433 	}
434 	if (ap->a_fflag & FWRITE) {
435 		fip->fi_writers--;
436 		if (fip->fi_writers == 0)
437 			socantrcvmore(fip->fi_readsock);
438 	}
439 	if (vp->v_usecount > 1)
440 		return (0);
441 	error1 = soclose(fip->fi_readsock);
442 	error2 = soclose(fip->fi_writesock);
443 	FREE(fip, M_VNODE);
444 	vp->v_fifoinfo = NULL;
445 	if (error1)
446 		return (error1);
447 	return (error2);
448 }
449 
450 
451 /*
452  * Print out internal contents of a fifo vnode.
453  */
454 int
455 fifo_printinfo(vp)
456 	struct vnode *vp;
457 {
458 	register struct fifoinfo *fip = vp->v_fifoinfo;
459 
460 	printf(", fifo with %ld readers and %ld writers",
461 		fip->fi_readers, fip->fi_writers);
462 	return (0);
463 }
464 
465 /*
466  * Print out the contents of a fifo vnode.
467  */
468 static int
469 fifo_print(ap)
470 	struct vop_print_args /* {
471 		struct vnode *a_vp;
472 	} */ *ap;
473 {
474 
475 	printf("tag VT_NON");
476 	fifo_printinfo(ap->a_vp);
477 	printf("\n");
478 	return (0);
479 }
480 
481 /*
482  * Return POSIX pathconf information applicable to fifo's.
483  */
484 int
485 fifo_pathconf(ap)
486 	struct vop_pathconf_args /* {
487 		struct vnode *a_vp;
488 		int a_name;
489 		int *a_retval;
490 	} */ *ap;
491 {
492 
493 	switch (ap->a_name) {
494 	case _PC_LINK_MAX:
495 		*ap->a_retval = LINK_MAX;
496 		return (0);
497 	case _PC_PIPE_BUF:
498 		*ap->a_retval = PIPE_BUF;
499 		return (0);
500 	case _PC_CHOWN_RESTRICTED:
501 		*ap->a_retval = 1;
502 		return (0);
503 	default:
504 		return (EINVAL);
505 	}
506 	/* NOTREACHED */
507 }
508 
509 /*
510  * Fifo failed operation
511  */
512 static int
513 fifo_ebadf()
514 {
515 
516 	return (EBADF);
517 }
518 
519 /*
520  * Fifo advisory byte-level locks.
521  */
522 /* ARGSUSED */
523 int
524 fifo_advlock(ap)
525 	struct vop_advlock_args /* {
526 		struct vnode *a_vp;
527 		caddr_t  a_id;
528 		int  a_op;
529 		struct flock *a_fl;
530 		int  a_flags;
531 	} */ *ap;
532 {
533 
534 	return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL);
535 }
536 
537 /*
538  * Fifo bad operation
539  */
540 int
541 fifo_badop()
542 {
543 
544 	panic("fifo_badop called");
545 	/* NOTREACHED */
546 }
547