xref: /netbsd-src/sys/miscfs/fdesc/fdesc_vnops.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /*	$NetBSD: fdesc_vnops.c,v 1.74 2003/04/10 21:53:32 jdolecek Exp $	*/
2 
3 /*
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software donated to Berkeley by
8  * Jan-Simon Pendry.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)fdesc_vnops.c	8.17 (Berkeley) 5/22/95
39  *
40  * #Id: fdesc_vnops.c,v 1.12 1993/04/06 16:17:17 jsp Exp #
41  */
42 
43 /*
44  * /dev/fd Filesystem
45  */
46 
47 #include <sys/cdefs.h>
48 __KERNEL_RCSID(0, "$NetBSD: fdesc_vnops.c,v 1.74 2003/04/10 21:53:32 jdolecek Exp $");
49 
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/time.h>
53 #include <sys/proc.h>
54 #include <sys/kernel.h>	/* boottime */
55 #include <sys/resourcevar.h>
56 #include <sys/socketvar.h>
57 #include <sys/filedesc.h>
58 #include <sys/vnode.h>
59 #include <sys/malloc.h>
60 #include <sys/conf.h>
61 #include <sys/file.h>
62 #include <sys/stat.h>
63 #include <sys/mount.h>
64 #include <sys/namei.h>
65 #include <sys/buf.h>
66 #include <sys/dirent.h>
67 #include <sys/tty.h>
68 
69 #include <miscfs/fdesc/fdesc.h>
70 #include <miscfs/genfs/genfs.h>
71 
72 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
73 
74 #define FDL_WANT	0x01
75 #define FDL_LOCKED	0x02
76 static int fdcache_lock;
77 
78 dev_t devctty;
79 
80 #if (FD_STDIN != FD_STDOUT-1) || (FD_STDOUT != FD_STDERR-1)
81 FD_STDIN, FD_STDOUT, FD_STDERR must be a sequence n, n+1, n+2
82 #endif
83 
84 #define	NFDCACHE 4
85 
86 #define FD_NHASH(ix) \
87 	(&fdhashtbl[(ix) & fdhash])
88 LIST_HEAD(fdhashhead, fdescnode) *fdhashtbl;
89 u_long fdhash;
90 
91 int	fdesc_lookup	__P((void *));
92 #define	fdesc_create	genfs_eopnotsupp
93 #define	fdesc_mknod	genfs_eopnotsupp
94 int	fdesc_open	__P((void *));
95 #define	fdesc_close	genfs_nullop
96 #define	fdesc_access	genfs_nullop
97 int	fdesc_getattr	__P((void *));
98 int	fdesc_setattr	__P((void *));
99 int	fdesc_read	__P((void *));
100 int	fdesc_write	__P((void *));
101 int	fdesc_ioctl	__P((void *));
102 int	fdesc_poll	__P((void *));
103 int	fdesc_kqfilter	__P((void *));
104 #define	fdesc_mmap	genfs_eopnotsupp
105 #define	fdesc_fcntl	genfs_fcntl
106 #define	fdesc_fsync	genfs_nullop
107 #define	fdesc_seek	genfs_seek
108 #define	fdesc_remove	genfs_eopnotsupp
109 int	fdesc_link	__P((void *));
110 #define	fdesc_rename	genfs_eopnotsupp
111 #define	fdesc_mkdir	genfs_eopnotsupp
112 #define	fdesc_rmdir	genfs_eopnotsupp
113 int	fdesc_symlink	__P((void *));
114 int	fdesc_readdir	__P((void *));
115 int	fdesc_readlink	__P((void *));
116 #define	fdesc_abortop	genfs_abortop
117 int	fdesc_inactive	__P((void *));
118 int	fdesc_reclaim	__P((void *));
119 #define	fdesc_lock	genfs_lock
120 #define	fdesc_unlock	genfs_unlock
121 #define	fdesc_bmap	genfs_badop
122 #define	fdesc_strategy	genfs_badop
123 int	fdesc_print	__P((void *));
124 int	fdesc_pathconf	__P((void *));
125 #define	fdesc_islocked	genfs_islocked
126 #define	fdesc_advlock	genfs_einval
127 #define	fdesc_blkatoff	genfs_eopnotsupp
128 #define	fdesc_valloc	genfs_eopnotsupp
129 #define	fdesc_vfree	genfs_nullop
130 #define	fdesc_truncate	genfs_eopnotsupp
131 #define	fdesc_update	genfs_nullop
132 #define	fdesc_bwrite	genfs_eopnotsupp
133 #define fdesc_revoke	genfs_revoke
134 #define fdesc_putpages	genfs_null_putpages
135 
136 static int fdesc_attr __P((int, struct vattr *, struct ucred *, struct proc *));
137 
138 int (**fdesc_vnodeop_p) __P((void *));
139 const struct vnodeopv_entry_desc fdesc_vnodeop_entries[] = {
140 	{ &vop_default_desc, vn_default_error },
141 	{ &vop_lookup_desc, fdesc_lookup },		/* lookup */
142 	{ &vop_create_desc, fdesc_create },		/* create */
143 	{ &vop_mknod_desc, fdesc_mknod },		/* mknod */
144 	{ &vop_open_desc, fdesc_open },			/* open */
145 	{ &vop_close_desc, fdesc_close },		/* close */
146 	{ &vop_access_desc, fdesc_access },		/* access */
147 	{ &vop_getattr_desc, fdesc_getattr },		/* getattr */
148 	{ &vop_setattr_desc, fdesc_setattr },		/* setattr */
149 	{ &vop_read_desc, fdesc_read },			/* read */
150 	{ &vop_write_desc, fdesc_write },		/* write */
151 	{ &vop_ioctl_desc, fdesc_ioctl },		/* ioctl */
152 	{ &vop_fcntl_desc, fdesc_fcntl },		/* fcntl */
153 	{ &vop_poll_desc, fdesc_poll },			/* poll */
154 	{ &vop_kqfilter_desc, fdesc_kqfilter },		/* kqfilter */
155 	{ &vop_revoke_desc, fdesc_revoke },		/* revoke */
156 	{ &vop_mmap_desc, fdesc_mmap },			/* mmap */
157 	{ &vop_fsync_desc, fdesc_fsync },		/* fsync */
158 	{ &vop_seek_desc, fdesc_seek },			/* seek */
159 	{ &vop_remove_desc, fdesc_remove },		/* remove */
160 	{ &vop_link_desc, fdesc_link },			/* link */
161 	{ &vop_rename_desc, fdesc_rename },		/* rename */
162 	{ &vop_mkdir_desc, fdesc_mkdir },		/* mkdir */
163 	{ &vop_rmdir_desc, fdesc_rmdir },		/* rmdir */
164 	{ &vop_symlink_desc, fdesc_symlink },		/* symlink */
165 	{ &vop_readdir_desc, fdesc_readdir },		/* readdir */
166 	{ &vop_readlink_desc, fdesc_readlink },		/* readlink */
167 	{ &vop_abortop_desc, fdesc_abortop },		/* abortop */
168 	{ &vop_inactive_desc, fdesc_inactive },		/* inactive */
169 	{ &vop_reclaim_desc, fdesc_reclaim },		/* reclaim */
170 	{ &vop_lock_desc, fdesc_lock },			/* lock */
171 	{ &vop_unlock_desc, fdesc_unlock },		/* unlock */
172 	{ &vop_bmap_desc, fdesc_bmap },			/* bmap */
173 	{ &vop_strategy_desc, fdesc_strategy },		/* strategy */
174 	{ &vop_print_desc, fdesc_print },		/* print */
175 	{ &vop_islocked_desc, fdesc_islocked },		/* islocked */
176 	{ &vop_pathconf_desc, fdesc_pathconf },		/* pathconf */
177 	{ &vop_advlock_desc, fdesc_advlock },		/* advlock */
178 	{ &vop_blkatoff_desc, fdesc_blkatoff },		/* blkatoff */
179 	{ &vop_valloc_desc, fdesc_valloc },		/* valloc */
180 	{ &vop_vfree_desc, fdesc_vfree },		/* vfree */
181 	{ &vop_truncate_desc, fdesc_truncate },		/* truncate */
182 	{ &vop_update_desc, fdesc_update },		/* update */
183 	{ &vop_bwrite_desc, fdesc_bwrite },		/* bwrite */
184 	{ &vop_putpages_desc, fdesc_putpages },		/* putpages */
185 	{ NULL, NULL }
186 };
187 
188 const struct vnodeopv_desc fdesc_vnodeop_opv_desc =
189 	{ &fdesc_vnodeop_p, fdesc_vnodeop_entries };
190 
191 extern const struct cdevsw ctty_cdevsw;
192 
193 /*
194  * Initialise cache headers
195  */
196 void
197 fdesc_init()
198 {
199 	int cttymajor;
200 
201 	/* locate the major number */
202 	cttymajor = cdevsw_lookup_major(&ctty_cdevsw);
203 	devctty = makedev(cttymajor, 0);
204 	fdhashtbl = hashinit(NFDCACHE, HASH_LIST, M_CACHE, M_NOWAIT, &fdhash);
205 }
206 
207 /*
208  * Free hash table.
209  */
210 void
211 fdesc_done()
212 {
213 	hashdone(fdhashtbl, M_CACHE);
214 }
215 
216 /*
217  * Return a locked vnode of the correct type.
218  */
219 int
220 fdesc_allocvp(ftype, ix, mp, vpp)
221 	fdntype ftype;
222 	int ix;
223 	struct mount *mp;
224 	struct vnode **vpp;
225 {
226 	struct fdhashhead *fc;
227 	struct fdescnode *fd;
228 	int error = 0;
229 
230 	fc = FD_NHASH(ix);
231 loop:
232 	for (fd = fc->lh_first; fd != 0; fd = fd->fd_hash.le_next) {
233 		if (fd->fd_ix == ix && fd->fd_vnode->v_mount == mp) {
234 			if (vget(fd->fd_vnode, LK_EXCLUSIVE))
235 				goto loop;
236 			*vpp = fd->fd_vnode;
237 			return (error);
238 		}
239 	}
240 
241 	/*
242 	 * otherwise lock the array while we call getnewvnode
243 	 * since that can block.
244 	 */
245 	if (fdcache_lock & FDL_LOCKED) {
246 		fdcache_lock |= FDL_WANT;
247 		(void) tsleep(&fdcache_lock, PINOD, "fdcache", 0);
248 		goto loop;
249 	}
250 	fdcache_lock |= FDL_LOCKED;
251 
252 	error = getnewvnode(VT_FDESC, mp, fdesc_vnodeop_p, vpp);
253 	if (error)
254 		goto out;
255 	MALLOC(fd, void *, sizeof(struct fdescnode), M_TEMP, M_WAITOK);
256 	(*vpp)->v_data = fd;
257 	fd->fd_vnode = *vpp;
258 	fd->fd_type = ftype;
259 	fd->fd_fd = -1;
260 	fd->fd_link = 0;
261 	fd->fd_ix = ix;
262 	VOP_LOCK(*vpp, LK_EXCLUSIVE);
263 	LIST_INSERT_HEAD(fc, fd, fd_hash);
264 
265 out:;
266 	fdcache_lock &= ~FDL_LOCKED;
267 
268 	if (fdcache_lock & FDL_WANT) {
269 		fdcache_lock &= ~FDL_WANT;
270 		wakeup((caddr_t) &fdcache_lock);
271 	}
272 
273 	return (error);
274 }
275 
276 /*
277  * vp is the current namei directory
278  * ndp is the name to locate in that directory...
279  */
280 int
281 fdesc_lookup(v)
282 	void *v;
283 {
284 	struct vop_lookup_args /* {
285 		struct vnode * a_dvp;
286 		struct vnode ** a_vpp;
287 		struct componentname * a_cnp;
288 	} */ *ap = v;
289 	struct vnode **vpp = ap->a_vpp;
290 	struct vnode *dvp = ap->a_dvp;
291 	struct componentname *cnp = ap->a_cnp;
292 	struct proc *p = cnp->cn_proc;
293 	const char *pname = cnp->cn_nameptr;
294 	int nfiles = p->p_fd->fd_nfiles;
295 	unsigned fd = 0;
296 	int error;
297 	struct vnode *fvp;
298 	char *ln;
299 
300 	if (cnp->cn_namelen == 1 && *pname == '.') {
301 		*vpp = dvp;
302 		VREF(dvp);
303 		return (0);
304 	}
305 
306 	switch (VTOFDESC(dvp)->fd_type) {
307 	default:
308 	case Flink:
309 	case Fdesc:
310 	case Fctty:
311 		error = ENOTDIR;
312 		goto bad;
313 
314 	case Froot:
315 		if (cnp->cn_namelen == 2 && memcmp(pname, "fd", 2) == 0) {
316 			error = fdesc_allocvp(Fdevfd, FD_DEVFD, dvp->v_mount, &fvp);
317 			if (error)
318 				goto bad;
319 			*vpp = fvp;
320 			fvp->v_type = VDIR;
321 			goto good;
322 		}
323 
324 		if (cnp->cn_namelen == 3 && memcmp(pname, "tty", 3) == 0) {
325 			struct vnode *ttyvp = cttyvp(p);
326 			if (ttyvp == NULL) {
327 				error = ENXIO;
328 				goto bad;
329 			}
330 			error = fdesc_allocvp(Fctty, FD_CTTY, dvp->v_mount, &fvp);
331 			if (error)
332 				goto bad;
333 			*vpp = fvp;
334 			fvp->v_type = VCHR;
335 			goto good;
336 		}
337 
338 		ln = 0;
339 		switch (cnp->cn_namelen) {
340 		case 5:
341 			if (memcmp(pname, "stdin", 5) == 0) {
342 				ln = "fd/0";
343 				fd = FD_STDIN;
344 			}
345 			break;
346 		case 6:
347 			if (memcmp(pname, "stdout", 6) == 0) {
348 				ln = "fd/1";
349 				fd = FD_STDOUT;
350 			} else
351 			if (memcmp(pname, "stderr", 6) == 0) {
352 				ln = "fd/2";
353 				fd = FD_STDERR;
354 			}
355 			break;
356 		}
357 
358 		if (ln) {
359 			error = fdesc_allocvp(Flink, fd, dvp->v_mount, &fvp);
360 			if (error)
361 				goto bad;
362 			VTOFDESC(fvp)->fd_link = ln;
363 			*vpp = fvp;
364 			fvp->v_type = VLNK;
365 			goto good;
366 		} else {
367 			error = ENOENT;
368 			goto bad;
369 		}
370 
371 		/* FALL THROUGH */
372 
373 	case Fdevfd:
374 		if (cnp->cn_namelen == 2 && memcmp(pname, "..", 2) == 0) {
375 			VOP_UNLOCK(dvp, 0);
376 			cnp->cn_flags |= PDIRUNLOCK;
377 			error = fdesc_root(dvp->v_mount, vpp);
378 			if (error)
379 				goto bad;
380 			/*
381 			 * If we're at the last component and need the
382 			 * parent locked, undo the unlock above.
383 			 */
384 			if (((~cnp->cn_flags & (ISLASTCN | LOCKPARENT)) == 0) &&
385 				   ((error = vn_lock(dvp, LK_EXCLUSIVE)) == 0))
386 				cnp->cn_flags &= ~PDIRUNLOCK;
387 			return (error);
388 		}
389 
390 		fd = 0;
391 		while (*pname >= '0' && *pname <= '9') {
392 			fd = 10 * fd + *pname++ - '0';
393 			if (fd >= nfiles)
394 				break;
395 		}
396 
397 		if (*pname != '\0') {
398 			error = ENOENT;
399 			goto bad;
400 		}
401 
402 		if (fd >= nfiles || p->p_fd->fd_ofiles[fd] == NULL ||
403 		    FILE_IS_USABLE(p->p_fd->fd_ofiles[fd]) == 0) {
404 			error = EBADF;
405 			goto bad;
406 		}
407 
408 		error = fdesc_allocvp(Fdesc, FD_DESC+fd, dvp->v_mount, &fvp);
409 		if (error)
410 			goto bad;
411 		VTOFDESC(fvp)->fd_fd = fd;
412 		*vpp = fvp;
413 		goto good;
414 	}
415 
416 bad:;
417 	*vpp = NULL;
418 	return (error);
419 
420 good:;
421 	/*
422 	 * As "." was special cased above, we now unlock the parent if we're
423 	 * suppoed to. We're only supposed to not unlock if this is the
424 	 * last component, and the caller requested LOCKPARENT. So if either
425 	 * condition is false, unlock.
426 	 */
427 	if (((~cnp->cn_flags) & (ISLASTCN | LOCKPARENT)) != 0) {
428 		VOP_UNLOCK(dvp, 0);
429 		cnp->cn_flags |= PDIRUNLOCK;
430 	}
431 	return (0);
432 }
433 
434 int
435 fdesc_open(v)
436 	void *v;
437 {
438 	struct vop_open_args /* {
439 		struct vnode *a_vp;
440 		int  a_mode;
441 		struct ucred *a_cred;
442 		struct proc *a_p;
443 	} */ *ap = v;
444 	struct vnode *vp = ap->a_vp;
445 
446 	switch (VTOFDESC(vp)->fd_type) {
447 	case Fdesc:
448 		/*
449 		 * XXX Kludge: set p->p_dupfd to contain the value of the
450 		 * the file descriptor being sought for duplication. The error
451 		 * return ensures that the vnode for this device will be
452 		 * released by vn_open. Open will detect this special error and
453 		 * take the actions in dupfdopen.  Other callers of vn_open or
454 		 * VOP_OPEN will simply report the error.
455 		 */
456 		ap->a_p->p_dupfd = VTOFDESC(vp)->fd_fd;	/* XXX */
457 		return (ENODEV);
458 
459 	case Fctty:
460 		return ((*ctty_cdevsw.d_open)(devctty, ap->a_mode, 0, ap->a_p));
461 	case Froot:
462 	case Fdevfd:
463 	case Flink:
464 		break;
465 	}
466 
467 	return (0);
468 }
469 
470 static int
471 fdesc_attr(fd, vap, cred, p)
472 	int fd;
473 	struct vattr *vap;
474 	struct ucred *cred;
475 	struct proc *p;
476 {
477 	struct filedesc *fdp = p->p_fd;
478 	struct file *fp;
479 	struct stat stb;
480 	int error;
481 
482 	if ((fp = fd_getfile(fdp, fd)) == NULL)
483 		return (EBADF);
484 
485 	switch (fp->f_type) {
486 	case DTYPE_VNODE:
487 		simple_unlock(&fp->f_slock);
488 		error = VOP_GETATTR((struct vnode *) fp->f_data, vap, cred, p);
489 		if (error == 0 && vap->va_type == VDIR) {
490 			/*
491 			 * directories can cause loops in the namespace,
492 			 * so turn off the 'x' bits to avoid trouble.
493 			 */
494 			vap->va_mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH);
495 		}
496 		break;
497 
498 	default:
499 		FILE_USE(fp);
500 		memset(&stb, 0, sizeof(stb));
501 		error = (*fp->f_ops->fo_stat)(fp, &stb, p);
502 		FILE_UNUSE(fp, p);
503 		if (error)
504 			break;
505 
506 		vattr_null(vap);
507 		switch(fp->f_type) {
508 		case DTYPE_SOCKET:
509 			vap->va_type = VSOCK;
510 			break;
511 		case DTYPE_PIPE:
512 			vap->va_type = VFIFO;
513 			break;
514 		default:
515 			/* use VNON perhaps? */
516 			vap->va_type = VBAD;
517 			break;
518 		}
519 		vap->va_mode = stb.st_mode;
520 		vap->va_nlink = stb.st_nlink;
521 		vap->va_uid = stb.st_uid;
522 		vap->va_gid = stb.st_gid;
523 		vap->va_fsid = stb.st_dev;
524 		vap->va_fileid = stb.st_ino;
525 		vap->va_size = stb.st_size;
526 		vap->va_blocksize = stb.st_blksize;
527 		vap->va_atime = stb.st_atimespec;
528 		vap->va_mtime = stb.st_mtimespec;
529 		vap->va_ctime = stb.st_ctimespec;
530 		vap->va_gen = stb.st_gen;
531 		vap->va_flags = stb.st_flags;
532 		vap->va_rdev = stb.st_rdev;
533 		vap->va_bytes = stb.st_blocks * stb.st_blksize;
534 		break;
535 	}
536 
537 	return (error);
538 }
539 
540 int
541 fdesc_getattr(v)
542 	void *v;
543 {
544 	struct vop_getattr_args /* {
545 		struct vnode *a_vp;
546 		struct vattr *a_vap;
547 		struct ucred *a_cred;
548 		struct proc *a_p;
549 	} */ *ap = v;
550 	struct vnode *vp = ap->a_vp;
551 	struct vattr *vap = ap->a_vap;
552 	unsigned fd;
553 	int error = 0;
554 
555 	switch (VTOFDESC(vp)->fd_type) {
556 	case Froot:
557 	case Fdevfd:
558 	case Flink:
559 	case Fctty:
560 		VATTR_NULL(vap);
561 		vap->va_fileid = VTOFDESC(vp)->fd_ix;
562 
563 #define R_ALL (S_IRUSR|S_IRGRP|S_IROTH)
564 #define W_ALL (S_IWUSR|S_IWGRP|S_IWOTH)
565 #define X_ALL (S_IXUSR|S_IXGRP|S_IXOTH)
566 
567 		switch (VTOFDESC(vp)->fd_type) {
568 		case Flink:
569 			vap->va_mode = R_ALL|X_ALL;
570 			vap->va_type = VLNK;
571 			vap->va_rdev = 0;
572 			vap->va_nlink = 1;
573 			vap->va_size = strlen(VTOFDESC(vp)->fd_link);
574 			break;
575 
576 		case Fctty:
577 			vap->va_mode = R_ALL|W_ALL;
578 			vap->va_type = VCHR;
579 			vap->va_rdev = devctty;
580 			vap->va_nlink = 1;
581 			vap->va_size = 0;
582 			break;
583 
584 		default:
585 			vap->va_mode = R_ALL|X_ALL;
586 			vap->va_type = VDIR;
587 			vap->va_rdev = 0;
588 			vap->va_nlink = 2;
589 			vap->va_size = DEV_BSIZE;
590 			break;
591 		}
592 		vap->va_uid = 0;
593 		vap->va_gid = 0;
594 		vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
595 		vap->va_blocksize = DEV_BSIZE;
596 		vap->va_atime.tv_sec = boottime.tv_sec;
597 		vap->va_atime.tv_nsec = 0;
598 		vap->va_mtime = vap->va_atime;
599 		vap->va_ctime = vap->va_mtime;
600 		vap->va_gen = 0;
601 		vap->va_flags = 0;
602 		vap->va_bytes = 0;
603 		break;
604 
605 	case Fdesc:
606 		fd = VTOFDESC(vp)->fd_fd;
607 		error = fdesc_attr(fd, vap, ap->a_cred, ap->a_p);
608 		break;
609 
610 	default:
611 		panic("fdesc_getattr");
612 		break;
613 	}
614 
615 	if (error == 0)
616 		vp->v_type = vap->va_type;
617 
618 	return (error);
619 }
620 
621 int
622 fdesc_setattr(v)
623 	void *v;
624 {
625 	struct vop_setattr_args /* {
626 		struct vnode *a_vp;
627 		struct vattr *a_vap;
628 		struct ucred *a_cred;
629 		struct proc *a_p;
630 	} */ *ap = v;
631 	struct filedesc *fdp = ap->a_p->p_fd;
632 	struct file *fp;
633 	unsigned fd;
634 
635 	/*
636 	 * Can't mess with the root vnode
637 	 */
638 	switch (VTOFDESC(ap->a_vp)->fd_type) {
639 	case Fdesc:
640 		break;
641 
642 	case Fctty:
643 		return (0);
644 
645 	default:
646 		return (EACCES);
647 	}
648 
649 	fd = VTOFDESC(ap->a_vp)->fd_fd;
650 	if ((fp = fd_getfile(fdp, fd)) == NULL)
651 		return (EBADF);
652 
653 	/*
654 	 * XXX: Can't reasonably set the attr's on any types currently.
655 	 *      On vnode's this will cause truncation and socket/pipes make
656 	 *      no sense.
657 	 */
658 	simple_unlock(&fp->f_slock);
659 	return (0);
660 }
661 
662 #define UIO_MX 32
663 
664 struct fdesc_target {
665 	ino_t ft_fileno;
666 	u_char ft_type;
667 	u_char ft_namlen;
668 	char *ft_name;
669 } fdesc_targets[] = {
670 /* NOTE: The name must be less than UIO_MX-16 chars in length */
671 #define N(s) sizeof(s)-1, s
672 	{ FD_DEVFD,  DT_DIR,     N("fd")     },
673 	{ FD_STDIN,  DT_LNK,     N("stdin")  },
674 	{ FD_STDOUT, DT_LNK,     N("stdout") },
675 	{ FD_STDERR, DT_LNK,     N("stderr") },
676 	{ FD_CTTY,   DT_UNKNOWN, N("tty")    },
677 #undef N
678 };
679 static int nfdesc_targets = sizeof(fdesc_targets) / sizeof(fdesc_targets[0]);
680 
681 int
682 fdesc_readdir(v)
683 	void *v;
684 {
685 	struct vop_readdir_args /* {
686 		struct vnode *a_vp;
687 		struct uio *a_uio;
688 		struct ucred *a_cred;
689 		int *a_eofflag;
690 		off_t **a_cookies;
691 		int *a_ncookies;
692 	} */ *ap = v;
693 	struct uio *uio = ap->a_uio;
694 	struct dirent d;
695 	struct filedesc *fdp;
696 	off_t i;
697 	int error;
698 	off_t *cookies = NULL;
699 	int ncookies = 0;
700 
701 	switch (VTOFDESC(ap->a_vp)->fd_type) {
702 	case Fctty:
703 		return (0);
704 
705 	case Fdesc:
706 		return (ENOTDIR);
707 
708 	default:
709 		break;
710 	}
711 
712 	fdp = uio->uio_procp->p_fd;
713 
714 	if (uio->uio_resid < UIO_MX)
715 		return (EINVAL);
716 	if (uio->uio_offset < 0)
717 		return (EINVAL);
718 
719 	error = 0;
720 	i = uio->uio_offset;
721 	memset((caddr_t)&d, 0, UIO_MX);
722 	d.d_reclen = UIO_MX;
723 	if (ap->a_ncookies)
724 		ncookies = (uio->uio_resid / UIO_MX);
725 
726 	if (VTOFDESC(ap->a_vp)->fd_type == Froot) {
727 		struct fdesc_target *ft;
728 
729 		if (i >= nfdesc_targets)
730 			return 0;
731 
732 		if (ap->a_ncookies) {
733 			ncookies = min(ncookies, (nfdesc_targets - i));
734 			cookies = malloc(ncookies * sizeof(off_t),
735 			    M_TEMP, M_WAITOK);
736 			*ap->a_cookies = cookies;
737 			*ap->a_ncookies = ncookies;
738 		}
739 
740 		for (ft = &fdesc_targets[i];
741 		     uio->uio_resid >= UIO_MX && i < nfdesc_targets; ft++, i++) {
742 			switch (ft->ft_fileno) {
743 			case FD_CTTY:
744 				if (cttyvp(uio->uio_procp) == NULL)
745 					continue;
746 				break;
747 
748 			case FD_STDIN:
749 			case FD_STDOUT:
750 			case FD_STDERR:
751 				if ((ft->ft_fileno - FD_STDIN) >= fdp->fd_nfiles)
752 					continue;
753 				if (fdp->fd_ofiles[ft->ft_fileno - FD_STDIN] == NULL
754 				    || FILE_IS_USABLE(fdp->fd_ofiles[ft->ft_fileno - FD_STDIN]) == 0)
755 					continue;
756 				break;
757 			}
758 
759 			d.d_fileno = ft->ft_fileno;
760 			d.d_namlen = ft->ft_namlen;
761 			memcpy(d.d_name, ft->ft_name, ft->ft_namlen + 1);
762 			d.d_type = ft->ft_type;
763 
764 			if ((error = uiomove((caddr_t)&d, UIO_MX, uio)) != 0)
765 				break;
766 			if (cookies)
767 				*cookies++ = i + 1;
768 		}
769 	} else {
770 		if (ap->a_ncookies) {
771 			ncookies = min(ncookies, (fdp->fd_nfiles + 2));
772 			cookies = malloc(ncookies * sizeof(off_t),
773 			    M_TEMP, M_WAITOK);
774 			*ap->a_cookies = cookies;
775 			*ap->a_ncookies = ncookies;
776 		}
777 		for (; i - 2 < fdp->fd_nfiles && uio->uio_resid >= UIO_MX;
778 		     i++) {
779 			switch (i) {
780 			case 0:
781 			case 1:
782 				d.d_fileno = FD_ROOT;		/* XXX */
783 				d.d_namlen = i + 1;
784 				memcpy(d.d_name, "..", d.d_namlen);
785 				d.d_name[i + 1] = '\0';
786 				d.d_type = DT_DIR;
787 				break;
788 
789 			default:
790 				if (fdp->fd_ofiles[i - 2] == NULL ||
791 				    FILE_IS_USABLE(fdp->fd_ofiles[i - 2]) == 0)
792 					continue;
793 				d.d_fileno = i - 2 + FD_STDIN;
794 				d.d_namlen = sprintf(d.d_name, "%d", (int) i - 2);
795 				d.d_type = DT_UNKNOWN;
796 				break;
797 			}
798 
799 			if ((error = uiomove((caddr_t)&d, UIO_MX, uio)) != 0)
800 				break;
801 			if (cookies)
802 				*cookies++ = i + 1;
803 		}
804 	}
805 
806 	if (ap->a_ncookies && error) {
807 		free(*ap->a_cookies, M_TEMP);
808 		*ap->a_ncookies = 0;
809 		*ap->a_cookies = NULL;
810 	}
811 
812 	uio->uio_offset = i;
813 	return (error);
814 }
815 
816 int
817 fdesc_readlink(v)
818 	void *v;
819 {
820 	struct vop_readlink_args /* {
821 		struct vnode *a_vp;
822 		struct uio *a_uio;
823 		struct ucred *a_cred;
824 	} */ *ap = v;
825 	struct vnode *vp = ap->a_vp;
826 	int error;
827 
828 	if (vp->v_type != VLNK)
829 		return (EPERM);
830 
831 	if (VTOFDESC(vp)->fd_type == Flink) {
832 		char *ln = VTOFDESC(vp)->fd_link;
833 		error = uiomove(ln, strlen(ln), ap->a_uio);
834 	} else {
835 		error = EOPNOTSUPP;
836 	}
837 
838 	return (error);
839 }
840 
841 int
842 fdesc_read(v)
843 	void *v;
844 {
845 	struct vop_read_args /* {
846 		struct vnode *a_vp;
847 		struct uio *a_uio;
848 		int  a_ioflag;
849 		struct ucred *a_cred;
850 	} */ *ap = v;
851 	int error = EOPNOTSUPP;
852 	struct vnode *vp = ap->a_vp;
853 
854 	switch (VTOFDESC(vp)->fd_type) {
855 	case Fctty:
856 		VOP_UNLOCK(vp, 0);
857 		error = (*ctty_cdevsw.d_read)(devctty, ap->a_uio, ap->a_ioflag);
858 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
859 		break;
860 
861 	default:
862 		error = EOPNOTSUPP;
863 		break;
864 	}
865 
866 	return (error);
867 }
868 
869 int
870 fdesc_write(v)
871 	void *v;
872 {
873 	struct vop_write_args /* {
874 		struct vnode *a_vp;
875 		struct uio *a_uio;
876 		int  a_ioflag;
877 		struct ucred *a_cred;
878 	} */ *ap = v;
879 	int error = EOPNOTSUPP;
880 	struct vnode *vp = ap->a_vp;
881 
882 	switch (VTOFDESC(vp)->fd_type) {
883 	case Fctty:
884 		VOP_UNLOCK(vp, 0);
885 		error = (*ctty_cdevsw.d_write)(devctty, ap->a_uio,
886 					       ap->a_ioflag);
887 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
888 		break;
889 
890 	default:
891 		error = EOPNOTSUPP;
892 		break;
893 	}
894 
895 	return (error);
896 }
897 
898 int
899 fdesc_ioctl(v)
900 	void *v;
901 {
902 	struct vop_ioctl_args /* {
903 		struct vnode *a_vp;
904 		u_long a_command;
905 		caddr_t  a_data;
906 		int  a_fflag;
907 		struct ucred *a_cred;
908 		struct proc *a_p;
909 	} */ *ap = v;
910 	int error = EOPNOTSUPP;
911 
912 	switch (VTOFDESC(ap->a_vp)->fd_type) {
913 	case Fctty:
914 		error = (*ctty_cdevsw.d_ioctl)(devctty, ap->a_command,
915 					       ap->a_data, ap->a_fflag,
916 					       ap->a_p);
917 		break;
918 
919 	default:
920 		error = EOPNOTSUPP;
921 		break;
922 	}
923 
924 	return (error);
925 }
926 
927 int
928 fdesc_poll(v)
929 	void *v;
930 {
931 	struct vop_poll_args /* {
932 		struct vnode *a_vp;
933 		int a_events;
934 		struct proc *a_p;
935 	} */ *ap = v;
936 	int revents;
937 
938 	switch (VTOFDESC(ap->a_vp)->fd_type) {
939 	case Fctty:
940 		revents = (*ctty_cdevsw.d_poll)(devctty, ap->a_events, ap->a_p);
941 		break;
942 
943 	default:
944 		revents = genfs_poll(v);
945 		break;
946 	}
947 
948 	return (revents);
949 }
950 
951 int
952 fdesc_kqfilter(v)
953 	void *v;
954 {
955 	struct vop_kqfilter_args /* {
956 		struct vnode *a_vp;
957 		struct knote *a_kn;
958 	} */ *ap = v;
959 	int error;
960 	struct proc *p;
961 	struct file *fp;
962 
963 	switch (VTOFDESC(ap->a_vp)->fd_type) {
964 	case Fctty:
965 		error = (*ctty_cdevsw.d_kqfilter)(devctty, ap->a_kn);
966 		break;
967 
968 	case Fdesc:
969 		/* just invoke kqfilter for the underlying descriptor */
970 		p = curproc;	/* XXX hopefully ok to use curproc here */
971 		if ((fp = fd_getfile(p->p_fd, VTOFDESC(ap->a_vp)->fd_fd)) == NULL)
972 			return (1);
973 
974 		FILE_USE(fp);
975 		error = (*fp->f_ops->fo_kqfilter)(fp, ap->a_kn);
976 		FILE_UNUSE(fp, p);
977 		break;
978 
979 	default:
980 		return (genfs_kqfilter(v));
981 	}
982 
983 	return (error);
984 }
985 
986 int
987 fdesc_inactive(v)
988 	void *v;
989 {
990 	struct vop_inactive_args /* {
991 		struct vnode *a_vp;
992 		struct proc *a_p;
993 	} */ *ap = v;
994 	struct vnode *vp = ap->a_vp;
995 
996 	/*
997 	 * Clear out the v_type field to avoid
998 	 * nasty things happening in vgone().
999 	 */
1000 	VOP_UNLOCK(vp, 0);
1001 	vp->v_type = VNON;
1002 	return (0);
1003 }
1004 
1005 int
1006 fdesc_reclaim(v)
1007 	void *v;
1008 {
1009 	struct vop_reclaim_args /* {
1010 		struct vnode *a_vp;
1011 	} */ *ap = v;
1012 	struct vnode *vp = ap->a_vp;
1013 	struct fdescnode *fd = VTOFDESC(vp);
1014 
1015 	LIST_REMOVE(fd, fd_hash);
1016 	FREE(vp->v_data, M_TEMP);
1017 	vp->v_data = 0;
1018 
1019 	return (0);
1020 }
1021 
1022 /*
1023  * Return POSIX pathconf information applicable to special devices.
1024  */
1025 int
1026 fdesc_pathconf(v)
1027 	void *v;
1028 {
1029 	struct vop_pathconf_args /* {
1030 		struct vnode *a_vp;
1031 		int a_name;
1032 		register_t *a_retval;
1033 	} */ *ap = v;
1034 
1035 	switch (ap->a_name) {
1036 	case _PC_LINK_MAX:
1037 		*ap->a_retval = LINK_MAX;
1038 		return (0);
1039 	case _PC_MAX_CANON:
1040 		*ap->a_retval = MAX_CANON;
1041 		return (0);
1042 	case _PC_MAX_INPUT:
1043 		*ap->a_retval = MAX_INPUT;
1044 		return (0);
1045 	case _PC_PIPE_BUF:
1046 		*ap->a_retval = PIPE_BUF;
1047 		return (0);
1048 	case _PC_CHOWN_RESTRICTED:
1049 		*ap->a_retval = 1;
1050 		return (0);
1051 	case _PC_VDISABLE:
1052 		*ap->a_retval = _POSIX_VDISABLE;
1053 		return (0);
1054 	case _PC_SYNC_IO:
1055 		*ap->a_retval = 1;
1056 		return (0);
1057 	default:
1058 		return (EINVAL);
1059 	}
1060 	/* NOTREACHED */
1061 }
1062 
1063 /*
1064  * Print out the contents of a /dev/fd vnode.
1065  */
1066 /* ARGSUSED */
1067 int
1068 fdesc_print(v)
1069 	void *v;
1070 {
1071 	printf("tag VT_NON, fdesc vnode\n");
1072 	return (0);
1073 }
1074 
1075 int
1076 fdesc_link(v)
1077 	void *v;
1078 {
1079 	struct vop_link_args /* {
1080 		struct vnode *a_dvp;
1081 		struct vnode *a_vp;
1082 		struct componentname *a_cnp;
1083 	} */ *ap = v;
1084 
1085 	VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
1086 	vput(ap->a_dvp);
1087 	return (EROFS);
1088 }
1089 
1090 int
1091 fdesc_symlink(v)
1092 	void *v;
1093 {
1094 	struct vop_symlink_args /* {
1095 		struct vnode *a_dvp;
1096 		struct vnode **a_vpp;
1097 		struct componentname *a_cnp;
1098 		struct vattr *a_vap;
1099 		char *a_target;
1100 	} */ *ap = v;
1101 
1102 	VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
1103 	vput(ap->a_dvp);
1104 	return (EROFS);
1105 }
1106