xref: /original-bsd/sys/miscfs/fifofs/fifo_vnops.c (revision e27dea00)
1 /*
2  * Copyright (c) 1990, 1993, 1995
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  *
7  *	@(#)fifo_vnops.c	8.10 (Berkeley) 05/27/95
8  */
9 
10 #include <sys/param.h>
11 #include <sys/systm.h>
12 #include <sys/proc.h>
13 #include <sys/time.h>
14 #include <sys/namei.h>
15 #include <sys/vnode.h>
16 #include <sys/socket.h>
17 #include <sys/socketvar.h>
18 #include <sys/stat.h>
19 #include <sys/ioctl.h>
20 #include <sys/file.h>
21 #include <sys/errno.h>
22 #include <sys/malloc.h>
23 #include <miscfs/fifofs/fifo.h>
24 
25 /*
26  * This structure is associated with the FIFO vnode and stores
27  * the state associated with the FIFO.
28  */
29 struct fifoinfo {
30 	struct socket	*fi_readsock;
31 	struct socket	*fi_writesock;
32 	long		fi_readers;
33 	long		fi_writers;
34 };
35 
36 int (**fifo_vnodeop_p)();
37 struct vnodeopv_entry_desc fifo_vnodeop_entries[] = {
38 	{ &vop_default_desc, vn_default_error },
39 	{ &vop_lookup_desc, fifo_lookup },		/* lookup */
40 	{ &vop_create_desc, fifo_create },		/* create */
41 	{ &vop_mknod_desc, fifo_mknod },		/* mknod */
42 	{ &vop_open_desc, fifo_open },			/* open */
43 	{ &vop_close_desc, fifo_close },		/* close */
44 	{ &vop_access_desc, fifo_access },		/* access */
45 	{ &vop_getattr_desc, fifo_getattr },		/* getattr */
46 	{ &vop_setattr_desc, fifo_setattr },		/* setattr */
47 	{ &vop_read_desc, fifo_read },			/* read */
48 	{ &vop_write_desc, fifo_write },		/* write */
49 	{ &vop_lease_desc, fifo_lease_check },		/* lease */
50 	{ &vop_ioctl_desc, fifo_ioctl },		/* ioctl */
51 	{ &vop_select_desc, fifo_select },		/* select */
52 	{ &vop_revoke_desc, fifo_revoke },		/* revoke */
53 	{ &vop_mmap_desc, fifo_mmap },			/* mmap */
54 	{ &vop_fsync_desc, fifo_fsync },		/* fsync */
55 	{ &vop_seek_desc, fifo_seek },			/* seek */
56 	{ &vop_remove_desc, fifo_remove },		/* remove */
57 	{ &vop_link_desc, fifo_link },			/* link */
58 	{ &vop_rename_desc, fifo_rename },		/* rename */
59 	{ &vop_mkdir_desc, fifo_mkdir },		/* mkdir */
60 	{ &vop_rmdir_desc, fifo_rmdir },		/* rmdir */
61 	{ &vop_symlink_desc, fifo_symlink },		/* symlink */
62 	{ &vop_readdir_desc, fifo_readdir },		/* readdir */
63 	{ &vop_readlink_desc, fifo_readlink },		/* readlink */
64 	{ &vop_abortop_desc, fifo_abortop },		/* abortop */
65 	{ &vop_inactive_desc, fifo_inactive },		/* inactive */
66 	{ &vop_reclaim_desc, fifo_reclaim },		/* reclaim */
67 	{ &vop_lock_desc, fifo_lock },			/* lock */
68 	{ &vop_unlock_desc, fifo_unlock },		/* unlock */
69 	{ &vop_bmap_desc, fifo_bmap },			/* bmap */
70 	{ &vop_strategy_desc, fifo_strategy },		/* strategy */
71 	{ &vop_print_desc, fifo_print },		/* print */
72 	{ &vop_islocked_desc, fifo_islocked },		/* islocked */
73 	{ &vop_pathconf_desc, fifo_pathconf },		/* pathconf */
74 	{ &vop_advlock_desc, fifo_advlock },		/* advlock */
75 	{ &vop_blkatoff_desc, fifo_blkatoff },		/* blkatoff */
76 	{ &vop_valloc_desc, fifo_valloc },		/* valloc */
77 	{ &vop_vfree_desc, fifo_vfree },		/* vfree */
78 	{ &vop_truncate_desc, fifo_truncate },		/* truncate */
79 	{ &vop_update_desc, fifo_update },		/* update */
80 	{ &vop_bwrite_desc, fifo_bwrite },		/* bwrite */
81 	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
82 };
83 struct vnodeopv_desc fifo_vnodeop_opv_desc =
84 	{ &fifo_vnodeop_p, fifo_vnodeop_entries };
85 
86 /*
87  * Trivial lookup routine that always fails.
88  */
89 /* ARGSUSED */
90 fifo_lookup(ap)
91 	struct vop_lookup_args /* {
92 		struct vnode * a_dvp;
93 		struct vnode ** a_vpp;
94 		struct componentname * a_cnp;
95 	} */ *ap;
96 {
97 
98 	*ap->a_vpp = NULL;
99 	return (ENOTDIR);
100 }
101 
102 /*
103  * Open called to set up a new instance of a fifo or
104  * to find an active instance of a fifo.
105  */
106 /* ARGSUSED */
107 fifo_open(ap)
108 	struct vop_open_args /* {
109 		struct vnode *a_vp;
110 		int  a_mode;
111 		struct ucred *a_cred;
112 		struct proc *a_p;
113 	} */ *ap;
114 {
115 	struct vnode *vp = ap->a_vp;
116 	struct fifoinfo *fip;
117 	struct proc *p = ap->a_p;
118 	struct socket *rso, *wso;
119 	int error;
120 	static char openstr[] = "fifo";
121 
122 	if ((fip = vp->v_fifoinfo) == NULL) {
123 		MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK);
124 		vp->v_fifoinfo = fip;
125 		if (error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0)) {
126 			free(fip, M_VNODE);
127 			vp->v_fifoinfo = NULL;
128 			return (error);
129 		}
130 		fip->fi_readsock = rso;
131 		if (error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0)) {
132 			(void)soclose(rso);
133 			free(fip, M_VNODE);
134 			vp->v_fifoinfo = NULL;
135 			return (error);
136 		}
137 		fip->fi_writesock = wso;
138 		if (error = unp_connect2(wso, rso)) {
139 			(void)soclose(wso);
140 			(void)soclose(rso);
141 			free(fip, M_VNODE);
142 			vp->v_fifoinfo = NULL;
143 			return (error);
144 		}
145 		fip->fi_readers = fip->fi_writers = 0;
146 		wso->so_state |= SS_CANTRCVMORE;
147 		rso->so_state |= SS_CANTSENDMORE;
148 	}
149 	if (ap->a_mode & FREAD) {
150 		fip->fi_readers++;
151 		if (fip->fi_readers == 1) {
152 			fip->fi_writesock->so_state &= ~SS_CANTSENDMORE;
153 			if (fip->fi_writers > 0)
154 				wakeup((caddr_t)&fip->fi_writers);
155 		}
156 	}
157 	if (ap->a_mode & FWRITE) {
158 		fip->fi_writers++;
159 		if (fip->fi_writers == 1) {
160 			fip->fi_readsock->so_state &= ~SS_CANTRCVMORE;
161 			if (fip->fi_readers > 0)
162 				wakeup((caddr_t)&fip->fi_readers);
163 		}
164 	}
165 	if ((ap->a_mode & FREAD) && (ap->a_mode & O_NONBLOCK) == 0) {
166 		while (fip->fi_writers == 0) {
167 			VOP_UNLOCK(vp, 0, p);
168 			error = tsleep((caddr_t)&fip->fi_readers,
169 			    PCATCH | PSOCK, openstr, 0);
170 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
171 			if (error)
172 				goto bad;
173 		}
174 	}
175 	if (ap->a_mode & FWRITE) {
176 		if (ap->a_mode & O_NONBLOCK) {
177 			if (fip->fi_readers == 0) {
178 				error = ENXIO;
179 				goto bad;
180 			}
181 		} else {
182 			while (fip->fi_readers == 0) {
183 				VOP_UNLOCK(vp, 0, p);
184 				error = tsleep((caddr_t)&fip->fi_writers,
185 				    PCATCH | PSOCK, openstr, 0);
186 				vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
187 				if (error)
188 					goto bad;
189 			}
190 		}
191 	}
192 	return (0);
193 bad:
194 	if (error)
195 		VOP_CLOSE(vp, ap->a_mode, ap->a_cred, p);
196 	return (error);
197 }
198 
199 /*
200  * Vnode op for read
201  */
202 /* ARGSUSED */
203 fifo_read(ap)
204 	struct vop_read_args /* {
205 		struct vnode *a_vp;
206 		struct uio *a_uio;
207 		int  a_ioflag;
208 		struct ucred *a_cred;
209 	} */ *ap;
210 {
211 	struct uio *uio = ap->a_uio;
212 	struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock;
213 	struct proc *p = uio->uio_procp;
214 	int error, startresid;
215 
216 #ifdef DIAGNOSTIC
217 	if (uio->uio_rw != UIO_READ)
218 		panic("fifo_read mode");
219 #endif
220 	if (uio->uio_resid == 0)
221 		return (0);
222 	if (ap->a_ioflag & IO_NDELAY)
223 		rso->so_state |= SS_NBIO;
224 	startresid = uio->uio_resid;
225 	VOP_UNLOCK(ap->a_vp, 0, p);
226 	error = soreceive(rso, (struct mbuf **)0, uio, (struct mbuf **)0,
227 	    (struct mbuf **)0, (int *)0);
228 	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, p);
229 	/*
230 	 * Clear EOF indication after first such return.
231 	 */
232 	if (uio->uio_resid == startresid)
233 		rso->so_state &= ~SS_CANTRCVMORE;
234 	if (ap->a_ioflag & IO_NDELAY)
235 		rso->so_state &= ~SS_NBIO;
236 	return (error);
237 }
238 
239 /*
240  * Vnode op for write
241  */
242 /* ARGSUSED */
243 fifo_write(ap)
244 	struct vop_write_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 socket *wso = ap->a_vp->v_fifoinfo->fi_writesock;
252 	struct proc *p = ap->a_uio->uio_procp;
253 	int error;
254 
255 #ifdef DIAGNOSTIC
256 	if (ap->a_uio->uio_rw != UIO_WRITE)
257 		panic("fifo_write mode");
258 #endif
259 	if (ap->a_ioflag & IO_NDELAY)
260 		wso->so_state |= SS_NBIO;
261 	VOP_UNLOCK(ap->a_vp, 0, p);
262 	error = sosend(wso, (struct mbuf *)0, ap->a_uio, 0, (struct mbuf *)0, 0);
263 	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, p);
264 	if (ap->a_ioflag & IO_NDELAY)
265 		wso->so_state &= ~SS_NBIO;
266 	return (error);
267 }
268 
269 /*
270  * Device ioctl operation.
271  */
272 /* ARGSUSED */
273 fifo_ioctl(ap)
274 	struct vop_ioctl_args /* {
275 		struct vnode *a_vp;
276 		int  a_command;
277 		caddr_t  a_data;
278 		int  a_fflag;
279 		struct ucred *a_cred;
280 		struct proc *a_p;
281 	} */ *ap;
282 {
283 	struct file filetmp;
284 	int error;
285 
286 	if (ap->a_command == FIONBIO)
287 		return (0);
288 	if (ap->a_fflag & FREAD) {
289 		filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock;
290 		error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p);
291 		if (error)
292 			return (error);
293 	}
294 	if (ap->a_fflag & FWRITE) {
295 		filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock;
296 		error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p);
297 		if (error)
298 			return (error);
299 	}
300 	return (0);
301 }
302 
303 /* ARGSUSED */
304 fifo_select(ap)
305 	struct vop_select_args /* {
306 		struct vnode *a_vp;
307 		int  a_which;
308 		int  a_fflags;
309 		struct ucred *a_cred;
310 		struct proc *a_p;
311 	} */ *ap;
312 {
313 	struct file filetmp;
314 	int ready;
315 
316 	if (ap->a_fflags & FREAD) {
317 		filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock;
318 		ready = soo_select(&filetmp, ap->a_which, ap->a_p);
319 		if (ready)
320 			return (ready);
321 	}
322 	if (ap->a_fflags & FWRITE) {
323 		filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock;
324 		ready = soo_select(&filetmp, ap->a_which, ap->a_p);
325 		if (ready)
326 			return (ready);
327 	}
328 	return (0);
329 }
330 
331 int
fifo_inactive(ap)332 fifo_inactive(ap)
333 	struct vop_inactive_args /* {
334 		struct vnode *a_vp;
335 		struct proc *a_p;
336 	} */ *ap;
337 {
338 
339 	VOP_UNLOCK(ap->a_vp, 0, ap->a_p);
340 	return (0);
341 }
342 
343 /*
344  * This is a noop, simply returning what one has been given.
345  */
346 fifo_bmap(ap)
347 	struct vop_bmap_args /* {
348 		struct vnode *a_vp;
349 		daddr_t  a_bn;
350 		struct vnode **a_vpp;
351 		daddr_t *a_bnp;
352 		int *a_runp;
353 	} */ *ap;
354 {
355 
356 	if (ap->a_vpp != NULL)
357 		*ap->a_vpp = ap->a_vp;
358 	if (ap->a_bnp != NULL)
359 		*ap->a_bnp = ap->a_bn;
360 	if (ap->a_runp != NULL)
361 		*ap->a_runp = 0;
362 	return (0);
363 }
364 
365 /*
366  * Device close routine
367  */
368 /* ARGSUSED */
369 fifo_close(ap)
370 	struct vop_close_args /* {
371 		struct vnode *a_vp;
372 		int  a_fflag;
373 		struct ucred *a_cred;
374 		struct proc *a_p;
375 	} */ *ap;
376 {
377 	register struct vnode *vp = ap->a_vp;
378 	register struct fifoinfo *fip = vp->v_fifoinfo;
379 	int error1, error2;
380 
381 	if (ap->a_fflag & FREAD) {
382 		fip->fi_readers--;
383 		if (fip->fi_readers == 0)
384 			socantsendmore(fip->fi_writesock);
385 	}
386 	if (ap->a_fflag & FWRITE) {
387 		fip->fi_writers--;
388 		if (fip->fi_writers == 0)
389 			socantrcvmore(fip->fi_readsock);
390 	}
391 	if (vp->v_usecount > 1)
392 		return (0);
393 	error1 = soclose(fip->fi_readsock);
394 	error2 = soclose(fip->fi_writesock);
395 	FREE(fip, M_VNODE);
396 	vp->v_fifoinfo = NULL;
397 	if (error1)
398 		return (error1);
399 	return (error2);
400 }
401 
402 /*
403  * Print out the contents of a fifo vnode.
404  */
405 fifo_print(ap)
406 	struct vop_print_args /* {
407 		struct vnode *a_vp;
408 	} */ *ap;
409 {
410 
411 	printf("tag VT_NON");
412 	fifo_printinfo(ap->a_vp);
413 	printf("\n");
414 }
415 
416 /*
417  * Print out internal contents of a fifo vnode.
418  */
419 fifo_printinfo(vp)
420 	struct vnode *vp;
421 {
422 	register struct fifoinfo *fip = vp->v_fifoinfo;
423 
424 	printf(", fifo with %d readers and %d writers",
425 		fip->fi_readers, fip->fi_writers);
426 }
427 
428 /*
429  * Return POSIX pathconf information applicable to fifo's.
430  */
431 fifo_pathconf(ap)
432 	struct vop_pathconf_args /* {
433 		struct vnode *a_vp;
434 		int a_name;
435 		int *a_retval;
436 	} */ *ap;
437 {
438 
439 	switch (ap->a_name) {
440 	case _PC_LINK_MAX:
441 		*ap->a_retval = LINK_MAX;
442 		return (0);
443 	case _PC_PIPE_BUF:
444 		*ap->a_retval = PIPE_BUF;
445 		return (0);
446 	case _PC_CHOWN_RESTRICTED:
447 		*ap->a_retval = 1;
448 		return (0);
449 	default:
450 		return (EINVAL);
451 	}
452 	/* NOTREACHED */
453 }
454 
455 /*
456  * Fifo failed operation
457  */
fifo_ebadf()458 fifo_ebadf()
459 {
460 
461 	return (EBADF);
462 }
463 
464 /*
465  * Fifo advisory byte-level locks.
466  */
467 /* ARGSUSED */
468 fifo_advlock(ap)
469 	struct vop_advlock_args /* {
470 		struct vnode *a_vp;
471 		caddr_t  a_id;
472 		int  a_op;
473 		struct flock *a_fl;
474 		int  a_flags;
475 	} */ *ap;
476 {
477 
478 	return (EOPNOTSUPP);
479 }
480 
481 /*
482  * Fifo bad operation
483  */
fifo_badop()484 fifo_badop()
485 {
486 
487 	panic("fifo_badop called");
488 	/* NOTREACHED */
489 }
490