xref: /netbsd-src/sys/miscfs/fdesc/fdesc_vnops.c (revision 5e4c038a45edbc7d63b7c2daa76e29f88b64a4e3)
1 /*	$NetBSD: fdesc_vnops.c,v 1.69 2002/04/02 17:46:06 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 1.69 2002/04/02 17:46:06 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_rele
93 #define	fdesc_mknod	genfs_eopnotsupp_rele
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 #define	fdesc_mmap	genfs_eopnotsupp
104 #define	fdesc_fcntl	genfs_fcntl
105 #define	fdesc_fsync	genfs_nullop
106 #define	fdesc_seek	genfs_seek
107 #define	fdesc_remove	genfs_eopnotsupp_rele
108 int	fdesc_link	__P((void *));
109 #define	fdesc_rename	genfs_eopnotsupp_rele
110 #define	fdesc_mkdir	genfs_eopnotsupp_rele
111 #define	fdesc_rmdir	genfs_eopnotsupp_rele
112 int	fdesc_symlink	__P((void *));
113 int	fdesc_readdir	__P((void *));
114 int	fdesc_readlink	__P((void *));
115 #define	fdesc_abortop	genfs_abortop
116 int	fdesc_inactive	__P((void *));
117 int	fdesc_reclaim	__P((void *));
118 #define	fdesc_lock	genfs_lock
119 #define	fdesc_unlock	genfs_unlock
120 #define	fdesc_bmap	genfs_badop
121 #define	fdesc_strategy	genfs_badop
122 int	fdesc_print	__P((void *));
123 int	fdesc_pathconf	__P((void *));
124 #define	fdesc_islocked	genfs_islocked
125 #define	fdesc_advlock	genfs_einval
126 #define	fdesc_blkatoff	genfs_eopnotsupp
127 #define	fdesc_valloc	genfs_eopnotsupp
128 #define	fdesc_vfree	genfs_nullop
129 #define	fdesc_truncate	genfs_eopnotsupp
130 #define	fdesc_update	genfs_nullop
131 #define	fdesc_bwrite	genfs_eopnotsupp
132 #define fdesc_revoke	genfs_revoke
133 #define fdesc_putpages	genfs_null_putpages
134 
135 static int fdesc_attr __P((int, struct vattr *, struct ucred *, struct proc *));
136 
137 int (**fdesc_vnodeop_p) __P((void *));
138 const struct vnodeopv_entry_desc fdesc_vnodeop_entries[] = {
139 	{ &vop_default_desc, vn_default_error },
140 	{ &vop_lookup_desc, fdesc_lookup },		/* lookup */
141 	{ &vop_create_desc, fdesc_create },		/* create */
142 	{ &vop_mknod_desc, fdesc_mknod },		/* mknod */
143 	{ &vop_open_desc, fdesc_open },			/* open */
144 	{ &vop_close_desc, fdesc_close },		/* close */
145 	{ &vop_access_desc, fdesc_access },		/* access */
146 	{ &vop_getattr_desc, fdesc_getattr },		/* getattr */
147 	{ &vop_setattr_desc, fdesc_setattr },		/* setattr */
148 	{ &vop_read_desc, fdesc_read },			/* read */
149 	{ &vop_write_desc, fdesc_write },		/* write */
150 	{ &vop_ioctl_desc, fdesc_ioctl },		/* ioctl */
151 	{ &vop_fcntl_desc, fdesc_fcntl },		/* fcntl */
152 	{ &vop_poll_desc, fdesc_poll },			/* poll */
153 	{ &vop_revoke_desc, fdesc_revoke },		/* revoke */
154 	{ &vop_mmap_desc, fdesc_mmap },			/* mmap */
155 	{ &vop_fsync_desc, fdesc_fsync },		/* fsync */
156 	{ &vop_seek_desc, fdesc_seek },			/* seek */
157 	{ &vop_remove_desc, fdesc_remove },		/* remove */
158 	{ &vop_link_desc, fdesc_link },			/* link */
159 	{ &vop_rename_desc, fdesc_rename },		/* rename */
160 	{ &vop_mkdir_desc, fdesc_mkdir },		/* mkdir */
161 	{ &vop_rmdir_desc, fdesc_rmdir },		/* rmdir */
162 	{ &vop_symlink_desc, fdesc_symlink },		/* symlink */
163 	{ &vop_readdir_desc, fdesc_readdir },		/* readdir */
164 	{ &vop_readlink_desc, fdesc_readlink },		/* readlink */
165 	{ &vop_abortop_desc, fdesc_abortop },		/* abortop */
166 	{ &vop_inactive_desc, fdesc_inactive },		/* inactive */
167 	{ &vop_reclaim_desc, fdesc_reclaim },		/* reclaim */
168 	{ &vop_lock_desc, fdesc_lock },			/* lock */
169 	{ &vop_unlock_desc, fdesc_unlock },		/* unlock */
170 	{ &vop_bmap_desc, fdesc_bmap },			/* bmap */
171 	{ &vop_strategy_desc, fdesc_strategy },		/* strategy */
172 	{ &vop_print_desc, fdesc_print },		/* print */
173 	{ &vop_islocked_desc, fdesc_islocked },		/* islocked */
174 	{ &vop_pathconf_desc, fdesc_pathconf },		/* pathconf */
175 	{ &vop_advlock_desc, fdesc_advlock },		/* advlock */
176 	{ &vop_blkatoff_desc, fdesc_blkatoff },		/* blkatoff */
177 	{ &vop_valloc_desc, fdesc_valloc },		/* valloc */
178 	{ &vop_vfree_desc, fdesc_vfree },		/* vfree */
179 	{ &vop_truncate_desc, fdesc_truncate },		/* truncate */
180 	{ &vop_update_desc, fdesc_update },		/* update */
181 	{ &vop_bwrite_desc, fdesc_bwrite },		/* bwrite */
182 	{ &vop_putpages_desc, fdesc_putpages },		/* putpages */
183 	{ NULL, NULL }
184 };
185 
186 const struct vnodeopv_desc fdesc_vnodeop_opv_desc =
187 	{ &fdesc_vnodeop_p, fdesc_vnodeop_entries };
188 
189 /*
190  * Initialise cache headers
191  */
192 void
193 fdesc_init()
194 {
195 	int cttymajor;
196 
197 	/* locate the major number */
198 	for (cttymajor = 0; cttymajor < nchrdev; cttymajor++)
199 		if (cdevsw[cttymajor].d_open == cttyopen)
200 			break;
201 	devctty = makedev(cttymajor, 0);
202 	fdhashtbl = hashinit(NFDCACHE, HASH_LIST, M_CACHE, M_NOWAIT, &fdhash);
203 }
204 
205 /*
206  * Free hash table.
207  */
208 void
209 fdesc_done()
210 {
211 	hashdone(fdhashtbl, M_CACHE);
212 }
213 
214 /*
215  * Return a locked vnode of the correct type.
216  */
217 int
218 fdesc_allocvp(ftype, ix, mp, vpp)
219 	fdntype ftype;
220 	int ix;
221 	struct mount *mp;
222 	struct vnode **vpp;
223 {
224 	struct fdhashhead *fc;
225 	struct fdescnode *fd;
226 	int error = 0;
227 
228 	fc = FD_NHASH(ix);
229 loop:
230 	for (fd = fc->lh_first; fd != 0; fd = fd->fd_hash.le_next) {
231 		if (fd->fd_ix == ix && fd->fd_vnode->v_mount == mp) {
232 			if (vget(fd->fd_vnode, LK_EXCLUSIVE))
233 				goto loop;
234 			*vpp = fd->fd_vnode;
235 			return (error);
236 		}
237 	}
238 
239 	/*
240 	 * otherwise lock the array while we call getnewvnode
241 	 * since that can block.
242 	 */
243 	if (fdcache_lock & FDL_LOCKED) {
244 		fdcache_lock |= FDL_WANT;
245 		(void) tsleep(&fdcache_lock, PINOD, "fdcache", 0);
246 		goto loop;
247 	}
248 	fdcache_lock |= FDL_LOCKED;
249 
250 	error = getnewvnode(VT_FDESC, mp, fdesc_vnodeop_p, vpp);
251 	if (error)
252 		goto out;
253 	MALLOC(fd, void *, sizeof(struct fdescnode), M_TEMP, M_WAITOK);
254 	(*vpp)->v_data = fd;
255 	fd->fd_vnode = *vpp;
256 	fd->fd_type = ftype;
257 	fd->fd_fd = -1;
258 	fd->fd_link = 0;
259 	fd->fd_ix = ix;
260 	VOP_LOCK(*vpp, LK_EXCLUSIVE);
261 	LIST_INSERT_HEAD(fc, fd, fd_hash);
262 
263 out:;
264 	fdcache_lock &= ~FDL_LOCKED;
265 
266 	if (fdcache_lock & FDL_WANT) {
267 		fdcache_lock &= ~FDL_WANT;
268 		wakeup((caddr_t) &fdcache_lock);
269 	}
270 
271 	return (error);
272 }
273 
274 /*
275  * vp is the current namei directory
276  * ndp is the name to locate in that directory...
277  */
278 int
279 fdesc_lookup(v)
280 	void *v;
281 {
282 	struct vop_lookup_args /* {
283 		struct vnode * a_dvp;
284 		struct vnode ** a_vpp;
285 		struct componentname * a_cnp;
286 	} */ *ap = v;
287 	struct vnode **vpp = ap->a_vpp;
288 	struct vnode *dvp = ap->a_dvp;
289 	struct componentname *cnp = ap->a_cnp;
290 	struct proc *p = cnp->cn_proc;
291 	const char *pname = cnp->cn_nameptr;
292 	int nfiles = p->p_fd->fd_nfiles;
293 	unsigned fd = 0;
294 	int error;
295 	struct vnode *fvp;
296 	char *ln;
297 
298 	if (cnp->cn_namelen == 1 && *pname == '.') {
299 		*vpp = dvp;
300 		VREF(dvp);
301 		return (0);
302 	}
303 
304 	switch (VTOFDESC(dvp)->fd_type) {
305 	default:
306 	case Flink:
307 	case Fdesc:
308 	case Fctty:
309 		error = ENOTDIR;
310 		goto bad;
311 
312 	case Froot:
313 		if (cnp->cn_namelen == 2 && memcmp(pname, "fd", 2) == 0) {
314 			error = fdesc_allocvp(Fdevfd, FD_DEVFD, dvp->v_mount, &fvp);
315 			if (error)
316 				goto bad;
317 			*vpp = fvp;
318 			fvp->v_type = VDIR;
319 			goto good;
320 		}
321 
322 		if (cnp->cn_namelen == 3 && memcmp(pname, "tty", 3) == 0) {
323 			struct vnode *ttyvp = cttyvp(p);
324 			if (ttyvp == NULL) {
325 				error = ENXIO;
326 				goto bad;
327 			}
328 			error = fdesc_allocvp(Fctty, FD_CTTY, dvp->v_mount, &fvp);
329 			if (error)
330 				goto bad;
331 			*vpp = fvp;
332 			fvp->v_type = VCHR;
333 			goto good;
334 		}
335 
336 		ln = 0;
337 		switch (cnp->cn_namelen) {
338 		case 5:
339 			if (memcmp(pname, "stdin", 5) == 0) {
340 				ln = "fd/0";
341 				fd = FD_STDIN;
342 			}
343 			break;
344 		case 6:
345 			if (memcmp(pname, "stdout", 6) == 0) {
346 				ln = "fd/1";
347 				fd = FD_STDOUT;
348 			} else
349 			if (memcmp(pname, "stderr", 6) == 0) {
350 				ln = "fd/2";
351 				fd = FD_STDERR;
352 			}
353 			break;
354 		}
355 
356 		if (ln) {
357 			error = fdesc_allocvp(Flink, fd, dvp->v_mount, &fvp);
358 			if (error)
359 				goto bad;
360 			VTOFDESC(fvp)->fd_link = ln;
361 			*vpp = fvp;
362 			fvp->v_type = VLNK;
363 			goto good;
364 		} else {
365 			error = ENOENT;
366 			goto bad;
367 		}
368 
369 		/* FALL THROUGH */
370 
371 	case Fdevfd:
372 		if (cnp->cn_namelen == 2 && memcmp(pname, "..", 2) == 0) {
373 			VOP_UNLOCK(dvp, 0);
374 			cnp->cn_flags |= PDIRUNLOCK;
375 			error = fdesc_root(dvp->v_mount, vpp);
376 			if (error)
377 				goto bad;
378 			/*
379 			 * If we're at the last component and need the
380 			 * parent locked, undo the unlock above.
381 			 */
382 			if (((~cnp->cn_flags & (ISLASTCN | LOCKPARENT)) == 0) &&
383 				   ((error = vn_lock(dvp, LK_EXCLUSIVE)) == 0))
384 				cnp->cn_flags &= ~PDIRUNLOCK;
385 			return (error);
386 		}
387 
388 		fd = 0;
389 		while (*pname >= '0' && *pname <= '9') {
390 			fd = 10 * fd + *pname++ - '0';
391 			if (fd >= nfiles)
392 				break;
393 		}
394 
395 		if (*pname != '\0') {
396 			error = ENOENT;
397 			goto bad;
398 		}
399 
400 		if (fd >= nfiles || p->p_fd->fd_ofiles[fd] == NULL ||
401 		    FILE_IS_USABLE(p->p_fd->fd_ofiles[fd]) == 0) {
402 			error = EBADF;
403 			goto bad;
404 		}
405 
406 		error = fdesc_allocvp(Fdesc, FD_DESC+fd, dvp->v_mount, &fvp);
407 		if (error)
408 			goto bad;
409 		VTOFDESC(fvp)->fd_fd = fd;
410 		*vpp = fvp;
411 		goto good;
412 	}
413 
414 bad:;
415 	*vpp = NULL;
416 	return (error);
417 
418 good:;
419 	/*
420 	 * As "." was special cased above, we now unlock the parent if we're
421 	 * suppoed to. We're only supposed to not unlock if this is the
422 	 * last component, and the caller requested LOCKPARENT. So if either
423 	 * condition is false, unlock.
424 	 */
425 	if (((~cnp->cn_flags) & (ISLASTCN | LOCKPARENT)) != 0) {
426 		VOP_UNLOCK(dvp, 0);
427 		cnp->cn_flags |= PDIRUNLOCK;
428 	}
429 	return (0);
430 }
431 
432 int
433 fdesc_open(v)
434 	void *v;
435 {
436 	struct vop_open_args /* {
437 		struct vnode *a_vp;
438 		int  a_mode;
439 		struct ucred *a_cred;
440 		struct proc *a_p;
441 	} */ *ap = v;
442 	struct vnode *vp = ap->a_vp;
443 
444 	switch (VTOFDESC(vp)->fd_type) {
445 	case Fdesc:
446 		/*
447 		 * XXX Kludge: set p->p_dupfd to contain the value of the
448 		 * the file descriptor being sought for duplication. The error
449 		 * return ensures that the vnode for this device will be
450 		 * released by vn_open. Open will detect this special error and
451 		 * take the actions in dupfdopen.  Other callers of vn_open or
452 		 * VOP_OPEN will simply report the error.
453 		 */
454 		ap->a_p->p_dupfd = VTOFDESC(vp)->fd_fd;	/* XXX */
455 		return (ENODEV);
456 
457 	case Fctty:
458 		return (cttyopen(devctty, ap->a_mode, 0, ap->a_p));
459 	case Froot:
460 	case Fdevfd:
461 	case Flink:
462 		break;
463 	}
464 
465 	return (0);
466 }
467 
468 static int
469 fdesc_attr(fd, vap, cred, p)
470 	int fd;
471 	struct vattr *vap;
472 	struct ucred *cred;
473 	struct proc *p;
474 {
475 	struct filedesc *fdp = p->p_fd;
476 	struct file *fp;
477 	struct stat stb;
478 	int error;
479 
480 	if ((fp = fd_getfile(fdp, fd)) == NULL)
481 		return (EBADF);
482 
483 	switch (fp->f_type) {
484 	case DTYPE_VNODE:
485 		error = VOP_GETATTR((struct vnode *) fp->f_data, vap, cred, p);
486 		if (error == 0 && vap->va_type == VDIR) {
487 			/*
488 			 * directories can cause loops in the namespace,
489 			 * so turn off the 'x' bits to avoid trouble.
490 			 */
491 			vap->va_mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH);
492 		}
493 		break;
494 
495 	default:
496 		FILE_USE(fp);
497 		memset(&stb, 0, sizeof(stb));
498 		error = (*fp->f_ops->fo_stat)(fp, &stb, p);
499 		FILE_UNUSE(fp, p);
500 		if (error)
501 			break;
502 
503 		vattr_null(vap);
504 		switch(fp->f_type) {
505 		case DTYPE_SOCKET:
506 			vap->va_type = VSOCK;
507 			break;
508 		case DTYPE_PIPE:
509 			vap->va_type = VFIFO;
510 			break;
511 		default:
512 			/* use VNON perhaps? */
513 			vap->va_type = VBAD;
514 			break;
515 		}
516 		vap->va_mode = stb.st_mode;
517 		vap->va_nlink = stb.st_nlink;
518 		vap->va_uid = stb.st_uid;
519 		vap->va_gid = stb.st_gid;
520 		vap->va_fsid = stb.st_dev;
521 		vap->va_fileid = stb.st_ino;
522 		vap->va_size = stb.st_size;
523 		vap->va_blocksize = stb.st_blksize;
524 		vap->va_atime = stb.st_atimespec;
525 		vap->va_mtime = stb.st_mtimespec;
526 		vap->va_ctime = stb.st_ctimespec;
527 		vap->va_gen = stb.st_gen;
528 		vap->va_flags = stb.st_flags;
529 		vap->va_rdev = stb.st_rdev;
530 		vap->va_bytes = stb.st_blocks * stb.st_blksize;
531 		break;
532 	}
533 
534 	return (error);
535 }
536 
537 int
538 fdesc_getattr(v)
539 	void *v;
540 {
541 	struct vop_getattr_args /* {
542 		struct vnode *a_vp;
543 		struct vattr *a_vap;
544 		struct ucred *a_cred;
545 		struct proc *a_p;
546 	} */ *ap = v;
547 	struct vnode *vp = ap->a_vp;
548 	struct vattr *vap = ap->a_vap;
549 	unsigned fd;
550 	int error = 0;
551 
552 	switch (VTOFDESC(vp)->fd_type) {
553 	case Froot:
554 	case Fdevfd:
555 	case Flink:
556 	case Fctty:
557 		VATTR_NULL(vap);
558 		vap->va_fileid = VTOFDESC(vp)->fd_ix;
559 
560 #define R_ALL (S_IRUSR|S_IRGRP|S_IROTH)
561 #define W_ALL (S_IWUSR|S_IWGRP|S_IWOTH)
562 #define X_ALL (S_IXUSR|S_IXGRP|S_IXOTH)
563 
564 		switch (VTOFDESC(vp)->fd_type) {
565 		case Flink:
566 			vap->va_mode = R_ALL|X_ALL;
567 			vap->va_type = VLNK;
568 			vap->va_rdev = 0;
569 			vap->va_nlink = 1;
570 			vap->va_size = strlen(VTOFDESC(vp)->fd_link);
571 			break;
572 
573 		case Fctty:
574 			vap->va_mode = R_ALL|W_ALL;
575 			vap->va_type = VCHR;
576 			vap->va_rdev = devctty;
577 			vap->va_nlink = 1;
578 			vap->va_size = 0;
579 			break;
580 
581 		default:
582 			vap->va_mode = R_ALL|X_ALL;
583 			vap->va_type = VDIR;
584 			vap->va_rdev = 0;
585 			vap->va_nlink = 2;
586 			vap->va_size = DEV_BSIZE;
587 			break;
588 		}
589 		vap->va_uid = 0;
590 		vap->va_gid = 0;
591 		vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
592 		vap->va_blocksize = DEV_BSIZE;
593 		vap->va_atime.tv_sec = boottime.tv_sec;
594 		vap->va_atime.tv_nsec = 0;
595 		vap->va_mtime = vap->va_atime;
596 		vap->va_ctime = vap->va_mtime;
597 		vap->va_gen = 0;
598 		vap->va_flags = 0;
599 		vap->va_bytes = 0;
600 		break;
601 
602 	case Fdesc:
603 		fd = VTOFDESC(vp)->fd_fd;
604 		error = fdesc_attr(fd, vap, ap->a_cred, ap->a_p);
605 		break;
606 
607 	default:
608 		panic("fdesc_getattr");
609 		break;
610 	}
611 
612 	if (error == 0)
613 		vp->v_type = vap->va_type;
614 
615 	return (error);
616 }
617 
618 int
619 fdesc_setattr(v)
620 	void *v;
621 {
622 	struct vop_setattr_args /* {
623 		struct vnode *a_vp;
624 		struct vattr *a_vap;
625 		struct ucred *a_cred;
626 		struct proc *a_p;
627 	} */ *ap = v;
628 	struct filedesc *fdp = ap->a_p->p_fd;
629 	struct file *fp;
630 	unsigned fd;
631 
632 	/*
633 	 * Can't mess with the root vnode
634 	 */
635 	switch (VTOFDESC(ap->a_vp)->fd_type) {
636 	case Fdesc:
637 		break;
638 
639 	case Fctty:
640 		return (0);
641 
642 	default:
643 		return (EACCES);
644 	}
645 
646 	fd = VTOFDESC(ap->a_vp)->fd_fd;
647 	if ((fp = fd_getfile(fdp, fd)) == NULL)
648 		return (EBADF);
649 
650 	/*
651 	 * XXX: Can't reasonably set the attr's on any types currently.
652 	 *      On vnode's this will cause truncation and socket/pipes make
653 	 *      no sense.
654 	 */
655 	return (0);
656 }
657 
658 #define UIO_MX 32
659 
660 struct fdesc_target {
661 	ino_t ft_fileno;
662 	u_char ft_type;
663 	u_char ft_namlen;
664 	char *ft_name;
665 } fdesc_targets[] = {
666 /* NOTE: The name must be less than UIO_MX-16 chars in length */
667 #define N(s) sizeof(s)-1, s
668 	{ FD_DEVFD,  DT_DIR,     N("fd")     },
669 	{ FD_STDIN,  DT_LNK,     N("stdin")  },
670 	{ FD_STDOUT, DT_LNK,     N("stdout") },
671 	{ FD_STDERR, DT_LNK,     N("stderr") },
672 	{ FD_CTTY,   DT_UNKNOWN, N("tty")    },
673 #undef N
674 };
675 static int nfdesc_targets = sizeof(fdesc_targets) / sizeof(fdesc_targets[0]);
676 
677 int
678 fdesc_readdir(v)
679 	void *v;
680 {
681 	struct vop_readdir_args /* {
682 		struct vnode *a_vp;
683 		struct uio *a_uio;
684 		struct ucred *a_cred;
685 		int *a_eofflag;
686 		off_t **a_cookies;
687 		int *a_ncookies;
688 	} */ *ap = v;
689 	struct uio *uio = ap->a_uio;
690 	struct dirent d;
691 	struct filedesc *fdp;
692 	off_t i;
693 	int error;
694 	off_t *cookies = NULL;
695 	int ncookies = 0;
696 
697 	switch (VTOFDESC(ap->a_vp)->fd_type) {
698 	case Fctty:
699 		return (0);
700 
701 	case Fdesc:
702 		return (ENOTDIR);
703 
704 	default:
705 		break;
706 	}
707 
708 	fdp = uio->uio_procp->p_fd;
709 
710 	if (uio->uio_resid < UIO_MX)
711 		return (EINVAL);
712 	if (uio->uio_offset < 0)
713 		return (EINVAL);
714 
715 	error = 0;
716 	i = uio->uio_offset;
717 	memset((caddr_t)&d, 0, UIO_MX);
718 	d.d_reclen = UIO_MX;
719 	if (ap->a_ncookies)
720 		ncookies = (uio->uio_resid / UIO_MX);
721 
722 	if (VTOFDESC(ap->a_vp)->fd_type == Froot) {
723 		struct fdesc_target *ft;
724 
725 		if (i >= nfdesc_targets)
726 			return 0;
727 
728 		if (ap->a_ncookies) {
729 			ncookies = min(ncookies, (nfdesc_targets - i));
730 			cookies = malloc(ncookies * sizeof(off_t),
731 			    M_TEMP, M_WAITOK);
732 			*ap->a_cookies = cookies;
733 			*ap->a_ncookies = ncookies;
734 		}
735 
736 		for (ft = &fdesc_targets[i];
737 		     uio->uio_resid >= UIO_MX && i < nfdesc_targets; ft++, i++) {
738 			switch (ft->ft_fileno) {
739 			case FD_CTTY:
740 				if (cttyvp(uio->uio_procp) == NULL)
741 					continue;
742 				break;
743 
744 			case FD_STDIN:
745 			case FD_STDOUT:
746 			case FD_STDERR:
747 				if ((ft->ft_fileno - FD_STDIN) >= fdp->fd_nfiles)
748 					continue;
749 				if (fdp->fd_ofiles[ft->ft_fileno - FD_STDIN] == NULL
750 				    || FILE_IS_USABLE(fdp->fd_ofiles[ft->ft_fileno - FD_STDIN]) == 0)
751 					continue;
752 				break;
753 			}
754 
755 			d.d_fileno = ft->ft_fileno;
756 			d.d_namlen = ft->ft_namlen;
757 			memcpy(d.d_name, ft->ft_name, ft->ft_namlen + 1);
758 			d.d_type = ft->ft_type;
759 
760 			if ((error = uiomove((caddr_t)&d, UIO_MX, uio)) != 0)
761 				break;
762 			if (cookies)
763 				*cookies++ = i + 1;
764 		}
765 	} else {
766 		if (ap->a_ncookies) {
767 			ncookies = min(ncookies, (fdp->fd_nfiles + 2));
768 			cookies = malloc(ncookies * sizeof(off_t),
769 			    M_TEMP, M_WAITOK);
770 			*ap->a_cookies = cookies;
771 			*ap->a_ncookies = ncookies;
772 		}
773 		for (; i - 2 < fdp->fd_nfiles && uio->uio_resid >= UIO_MX;
774 		     i++) {
775 			switch (i) {
776 			case 0:
777 			case 1:
778 				d.d_fileno = FD_ROOT;		/* XXX */
779 				d.d_namlen = i + 1;
780 				memcpy(d.d_name, "..", d.d_namlen);
781 				d.d_name[i + 1] = '\0';
782 				d.d_type = DT_DIR;
783 				break;
784 
785 			default:
786 				if (fdp->fd_ofiles[i - 2] == NULL ||
787 				    FILE_IS_USABLE(fdp->fd_ofiles[i - 2]) == 0)
788 					continue;
789 				d.d_fileno = i - 2 + FD_STDIN;
790 				d.d_namlen = sprintf(d.d_name, "%d", (int) i - 2);
791 				d.d_type = DT_UNKNOWN;
792 				break;
793 			}
794 
795 			if ((error = uiomove((caddr_t)&d, UIO_MX, uio)) != 0)
796 				break;
797 			if (cookies)
798 				*cookies++ = i + 1;
799 		}
800 	}
801 
802 	if (ap->a_ncookies && error) {
803 		free(*ap->a_cookies, M_TEMP);
804 		*ap->a_ncookies = 0;
805 		*ap->a_cookies = NULL;
806 	}
807 
808 	uio->uio_offset = i;
809 	return (error);
810 }
811 
812 int
813 fdesc_readlink(v)
814 	void *v;
815 {
816 	struct vop_readlink_args /* {
817 		struct vnode *a_vp;
818 		struct uio *a_uio;
819 		struct ucred *a_cred;
820 	} */ *ap = v;
821 	struct vnode *vp = ap->a_vp;
822 	int error;
823 
824 	if (vp->v_type != VLNK)
825 		return (EPERM);
826 
827 	if (VTOFDESC(vp)->fd_type == Flink) {
828 		char *ln = VTOFDESC(vp)->fd_link;
829 		error = uiomove(ln, strlen(ln), ap->a_uio);
830 	} else {
831 		error = EOPNOTSUPP;
832 	}
833 
834 	return (error);
835 }
836 
837 int
838 fdesc_read(v)
839 	void *v;
840 {
841 	struct vop_read_args /* {
842 		struct vnode *a_vp;
843 		struct uio *a_uio;
844 		int  a_ioflag;
845 		struct ucred *a_cred;
846 	} */ *ap = v;
847 	int error = EOPNOTSUPP;
848 	struct vnode *vp = ap->a_vp;
849 
850 	switch (VTOFDESC(vp)->fd_type) {
851 	case Fctty:
852 		VOP_UNLOCK(vp, 0);
853 		error = cttyread(devctty, ap->a_uio, ap->a_ioflag);
854 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
855 		break;
856 
857 	default:
858 		error = EOPNOTSUPP;
859 		break;
860 	}
861 
862 	return (error);
863 }
864 
865 int
866 fdesc_write(v)
867 	void *v;
868 {
869 	struct vop_write_args /* {
870 		struct vnode *a_vp;
871 		struct uio *a_uio;
872 		int  a_ioflag;
873 		struct ucred *a_cred;
874 	} */ *ap = v;
875 	int error = EOPNOTSUPP;
876 	struct vnode *vp = ap->a_vp;
877 
878 	switch (VTOFDESC(vp)->fd_type) {
879 	case Fctty:
880 		VOP_UNLOCK(vp, 0);
881 		error = cttywrite(devctty, ap->a_uio, ap->a_ioflag);
882 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
883 		break;
884 
885 	default:
886 		error = EOPNOTSUPP;
887 		break;
888 	}
889 
890 	return (error);
891 }
892 
893 int
894 fdesc_ioctl(v)
895 	void *v;
896 {
897 	struct vop_ioctl_args /* {
898 		struct vnode *a_vp;
899 		u_long a_command;
900 		caddr_t  a_data;
901 		int  a_fflag;
902 		struct ucred *a_cred;
903 		struct proc *a_p;
904 	} */ *ap = v;
905 	int error = EOPNOTSUPP;
906 
907 	switch (VTOFDESC(ap->a_vp)->fd_type) {
908 	case Fctty:
909 		error = cttyioctl(devctty, ap->a_command, ap->a_data,
910 				  ap->a_fflag, ap->a_p);
911 		break;
912 
913 	default:
914 		error = EOPNOTSUPP;
915 		break;
916 	}
917 
918 	return (error);
919 }
920 
921 int
922 fdesc_poll(v)
923 	void *v;
924 {
925 	struct vop_poll_args /* {
926 		struct vnode *a_vp;
927 		int a_events;
928 		struct proc *a_p;
929 	} */ *ap = v;
930 	int revents;
931 
932 	switch (VTOFDESC(ap->a_vp)->fd_type) {
933 	case Fctty:
934 		revents = cttypoll(devctty, ap->a_events, ap->a_p);
935 		break;
936 
937 	default:
938 		revents = genfs_poll(v);
939 		break;
940 	}
941 
942 	return (revents);
943 }
944 
945 int
946 fdesc_inactive(v)
947 	void *v;
948 {
949 	struct vop_inactive_args /* {
950 		struct vnode *a_vp;
951 		struct proc *a_p;
952 	} */ *ap = v;
953 	struct vnode *vp = ap->a_vp;
954 
955 	/*
956 	 * Clear out the v_type field to avoid
957 	 * nasty things happening in vgone().
958 	 */
959 	VOP_UNLOCK(vp, 0);
960 	vp->v_type = VNON;
961 	return (0);
962 }
963 
964 int
965 fdesc_reclaim(v)
966 	void *v;
967 {
968 	struct vop_reclaim_args /* {
969 		struct vnode *a_vp;
970 	} */ *ap = v;
971 	struct vnode *vp = ap->a_vp;
972 	struct fdescnode *fd = VTOFDESC(vp);
973 
974 	LIST_REMOVE(fd, fd_hash);
975 	FREE(vp->v_data, M_TEMP);
976 	vp->v_data = 0;
977 
978 	return (0);
979 }
980 
981 /*
982  * Return POSIX pathconf information applicable to special devices.
983  */
984 int
985 fdesc_pathconf(v)
986 	void *v;
987 {
988 	struct vop_pathconf_args /* {
989 		struct vnode *a_vp;
990 		int a_name;
991 		register_t *a_retval;
992 	} */ *ap = v;
993 
994 	switch (ap->a_name) {
995 	case _PC_LINK_MAX:
996 		*ap->a_retval = LINK_MAX;
997 		return (0);
998 	case _PC_MAX_CANON:
999 		*ap->a_retval = MAX_CANON;
1000 		return (0);
1001 	case _PC_MAX_INPUT:
1002 		*ap->a_retval = MAX_INPUT;
1003 		return (0);
1004 	case _PC_PIPE_BUF:
1005 		*ap->a_retval = PIPE_BUF;
1006 		return (0);
1007 	case _PC_CHOWN_RESTRICTED:
1008 		*ap->a_retval = 1;
1009 		return (0);
1010 	case _PC_VDISABLE:
1011 		*ap->a_retval = _POSIX_VDISABLE;
1012 		return (0);
1013 	case _PC_SYNC_IO:
1014 		*ap->a_retval = 1;
1015 		return (0);
1016 	default:
1017 		return (EINVAL);
1018 	}
1019 	/* NOTREACHED */
1020 }
1021 
1022 /*
1023  * Print out the contents of a /dev/fd vnode.
1024  */
1025 /* ARGSUSED */
1026 int
1027 fdesc_print(v)
1028 	void *v;
1029 {
1030 	printf("tag VT_NON, fdesc vnode\n");
1031 	return (0);
1032 }
1033 
1034 int
1035 fdesc_link(v)
1036 	void *v;
1037 {
1038 	struct vop_link_args /* {
1039 		struct vnode *a_dvp;
1040 		struct vnode *a_vp;
1041 		struct componentname *a_cnp;
1042 	} */ *ap = v;
1043 
1044 	VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
1045 	vput(ap->a_dvp);
1046 	return (EROFS);
1047 }
1048 
1049 int
1050 fdesc_symlink(v)
1051 	void *v;
1052 {
1053 	struct vop_symlink_args /* {
1054 		struct vnode *a_dvp;
1055 		struct vnode **a_vpp;
1056 		struct componentname *a_cnp;
1057 		struct vattr *a_vap;
1058 		char *a_target;
1059 	} */ *ap = v;
1060 
1061 	VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
1062 	vput(ap->a_dvp);
1063 	return (EROFS);
1064 }
1065