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