xref: /netbsd-src/sys/miscfs/fdesc/fdesc_vnops.c (revision e5548b402ae4c44fb816de42c7bba9581ce23ef5)
1 /*	$NetBSD: fdesc_vnops.c,v 1.89 2005/12/11 12:24:50 christos 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. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)fdesc_vnops.c	8.17 (Berkeley) 5/22/95
35  *
36  * #Id: fdesc_vnops.c,v 1.12 1993/04/06 16:17:17 jsp Exp #
37  */
38 
39 /*
40  * /dev/fd Filesystem
41  */
42 
43 #include <sys/cdefs.h>
44 __KERNEL_RCSID(0, "$NetBSD: fdesc_vnops.c,v 1.89 2005/12/11 12:24:50 christos Exp $");
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/time.h>
49 #include <sys/proc.h>
50 #include <sys/kernel.h>	/* boottime */
51 #include <sys/resourcevar.h>
52 #include <sys/socketvar.h>
53 #include <sys/filedesc.h>
54 #include <sys/vnode.h>
55 #include <sys/malloc.h>
56 #include <sys/conf.h>
57 #include <sys/file.h>
58 #include <sys/stat.h>
59 #include <sys/mount.h>
60 #include <sys/namei.h>
61 #include <sys/buf.h>
62 #include <sys/dirent.h>
63 #include <sys/tty.h>
64 
65 #include <miscfs/fdesc/fdesc.h>
66 #include <miscfs/genfs/genfs.h>
67 
68 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
69 
70 #define FDL_WANT	0x01
71 #define FDL_LOCKED	0x02
72 static int fdcache_lock;
73 
74 dev_t devctty;
75 
76 #if (FD_STDIN != FD_STDOUT-1) || (FD_STDOUT != FD_STDERR-1)
77 FD_STDIN, FD_STDOUT, FD_STDERR must be a sequence n, n+1, n+2
78 #endif
79 
80 #define	NFDCACHE 4
81 
82 #define FD_NHASH(ix) \
83 	(&fdhashtbl[(ix) & fdhash])
84 LIST_HEAD(fdhashhead, fdescnode) *fdhashtbl;
85 u_long fdhash;
86 
87 int	fdesc_lookup(void *);
88 #define	fdesc_create	genfs_eopnotsupp
89 #define	fdesc_mknod	genfs_eopnotsupp
90 int	fdesc_open(void *);
91 #define	fdesc_close	genfs_nullop
92 #define	fdesc_access	genfs_nullop
93 int	fdesc_getattr(void *);
94 int	fdesc_setattr(void *);
95 int	fdesc_read(void *);
96 int	fdesc_write(void *);
97 int	fdesc_ioctl(void *);
98 int	fdesc_poll(void *);
99 int	fdesc_kqfilter(void *);
100 #define	fdesc_mmap	genfs_eopnotsupp
101 #define	fdesc_fcntl	genfs_fcntl
102 #define	fdesc_fsync	genfs_nullop
103 #define	fdesc_seek	genfs_seek
104 #define	fdesc_remove	genfs_eopnotsupp
105 int	fdesc_link(void *);
106 #define	fdesc_rename	genfs_eopnotsupp
107 #define	fdesc_mkdir	genfs_eopnotsupp
108 #define	fdesc_rmdir	genfs_eopnotsupp
109 int	fdesc_symlink(void *);
110 int	fdesc_readdir(void *);
111 int	fdesc_readlink(void *);
112 #define	fdesc_abortop	genfs_abortop
113 int	fdesc_inactive(void *);
114 int	fdesc_reclaim(void *);
115 #define	fdesc_lock	genfs_lock
116 #define	fdesc_unlock	genfs_unlock
117 #define	fdesc_bmap	genfs_badop
118 #define	fdesc_strategy	genfs_badop
119 int	fdesc_print(void *);
120 int	fdesc_pathconf(void *);
121 #define	fdesc_islocked	genfs_islocked
122 #define	fdesc_advlock	genfs_einval
123 #define	fdesc_bwrite	genfs_eopnotsupp
124 #define fdesc_revoke	genfs_revoke
125 #define fdesc_putpages	genfs_null_putpages
126 
127 static int fdesc_attr(int, struct vattr *, struct ucred *, struct lwp *);
128 
129 int (**fdesc_vnodeop_p)(void *);
130 const struct vnodeopv_entry_desc fdesc_vnodeop_entries[] = {
131 	{ &vop_default_desc, vn_default_error },
132 	{ &vop_lookup_desc, fdesc_lookup },		/* lookup */
133 	{ &vop_create_desc, fdesc_create },		/* create */
134 	{ &vop_mknod_desc, fdesc_mknod },		/* mknod */
135 	{ &vop_open_desc, fdesc_open },			/* open */
136 	{ &vop_close_desc, fdesc_close },		/* close */
137 	{ &vop_access_desc, fdesc_access },		/* access */
138 	{ &vop_getattr_desc, fdesc_getattr },		/* getattr */
139 	{ &vop_setattr_desc, fdesc_setattr },		/* setattr */
140 	{ &vop_read_desc, fdesc_read },			/* read */
141 	{ &vop_write_desc, fdesc_write },		/* write */
142 	{ &vop_ioctl_desc, fdesc_ioctl },		/* ioctl */
143 	{ &vop_fcntl_desc, fdesc_fcntl },		/* fcntl */
144 	{ &vop_poll_desc, fdesc_poll },			/* poll */
145 	{ &vop_kqfilter_desc, fdesc_kqfilter },		/* kqfilter */
146 	{ &vop_revoke_desc, fdesc_revoke },		/* revoke */
147 	{ &vop_mmap_desc, fdesc_mmap },			/* mmap */
148 	{ &vop_fsync_desc, fdesc_fsync },		/* fsync */
149 	{ &vop_seek_desc, fdesc_seek },			/* seek */
150 	{ &vop_remove_desc, fdesc_remove },		/* remove */
151 	{ &vop_link_desc, fdesc_link },			/* link */
152 	{ &vop_rename_desc, fdesc_rename },		/* rename */
153 	{ &vop_mkdir_desc, fdesc_mkdir },		/* mkdir */
154 	{ &vop_rmdir_desc, fdesc_rmdir },		/* rmdir */
155 	{ &vop_symlink_desc, fdesc_symlink },		/* symlink */
156 	{ &vop_readdir_desc, fdesc_readdir },		/* readdir */
157 	{ &vop_readlink_desc, fdesc_readlink },		/* readlink */
158 	{ &vop_abortop_desc, fdesc_abortop },		/* abortop */
159 	{ &vop_inactive_desc, fdesc_inactive },		/* inactive */
160 	{ &vop_reclaim_desc, fdesc_reclaim },		/* reclaim */
161 	{ &vop_lock_desc, fdesc_lock },			/* lock */
162 	{ &vop_unlock_desc, fdesc_unlock },		/* unlock */
163 	{ &vop_bmap_desc, fdesc_bmap },			/* bmap */
164 	{ &vop_strategy_desc, fdesc_strategy },		/* strategy */
165 	{ &vop_print_desc, fdesc_print },		/* print */
166 	{ &vop_islocked_desc, fdesc_islocked },		/* islocked */
167 	{ &vop_pathconf_desc, fdesc_pathconf },		/* pathconf */
168 	{ &vop_advlock_desc, fdesc_advlock },		/* advlock */
169 	{ &vop_bwrite_desc, fdesc_bwrite },		/* bwrite */
170 	{ &vop_putpages_desc, fdesc_putpages },		/* putpages */
171 	{ NULL, NULL }
172 };
173 
174 const struct vnodeopv_desc fdesc_vnodeop_opv_desc =
175 	{ &fdesc_vnodeop_p, fdesc_vnodeop_entries };
176 
177 extern const struct cdevsw ctty_cdevsw;
178 
179 /*
180  * Initialise cache headers
181  */
182 void
183 fdesc_init()
184 {
185 	int cttymajor;
186 
187 	/* locate the major number */
188 	cttymajor = cdevsw_lookup_major(&ctty_cdevsw);
189 	devctty = makedev(cttymajor, 0);
190 	fdhashtbl = hashinit(NFDCACHE, HASH_LIST, M_CACHE, M_NOWAIT, &fdhash);
191 }
192 
193 /*
194  * Free hash table.
195  */
196 void
197 fdesc_done()
198 {
199 	hashdone(fdhashtbl, M_CACHE);
200 }
201 
202 /*
203  * Return a locked vnode of the correct type.
204  */
205 int
206 fdesc_allocvp(ftype, ix, mp, vpp)
207 	fdntype ftype;
208 	int ix;
209 	struct mount *mp;
210 	struct vnode **vpp;
211 {
212 	struct fdhashhead *fc;
213 	struct fdescnode *fd;
214 	int error = 0;
215 
216 	fc = FD_NHASH(ix);
217 loop:
218 	for (fd = fc->lh_first; fd != 0; fd = fd->fd_hash.le_next) {
219 		if (fd->fd_ix == ix && fd->fd_vnode->v_mount == mp) {
220 			if (vget(fd->fd_vnode, LK_EXCLUSIVE))
221 				goto loop;
222 			*vpp = fd->fd_vnode;
223 			return (error);
224 		}
225 	}
226 
227 	/*
228 	 * otherwise lock the array while we call getnewvnode
229 	 * since that can block.
230 	 */
231 	if (fdcache_lock & FDL_LOCKED) {
232 		fdcache_lock |= FDL_WANT;
233 		(void) tsleep(&fdcache_lock, PINOD, "fdcache", 0);
234 		goto loop;
235 	}
236 	fdcache_lock |= FDL_LOCKED;
237 
238 	error = getnewvnode(VT_FDESC, mp, fdesc_vnodeop_p, vpp);
239 	if (error)
240 		goto out;
241 	MALLOC(fd, void *, sizeof(struct fdescnode), M_TEMP, M_WAITOK);
242 	(*vpp)->v_data = fd;
243 	fd->fd_vnode = *vpp;
244 	fd->fd_type = ftype;
245 	fd->fd_fd = -1;
246 	fd->fd_link = 0;
247 	fd->fd_ix = ix;
248 	VOP_LOCK(*vpp, LK_EXCLUSIVE);
249 	LIST_INSERT_HEAD(fc, fd, fd_hash);
250 
251 out:;
252 	fdcache_lock &= ~FDL_LOCKED;
253 
254 	if (fdcache_lock & FDL_WANT) {
255 		fdcache_lock &= ~FDL_WANT;
256 		wakeup(&fdcache_lock);
257 	}
258 
259 	return (error);
260 }
261 
262 /*
263  * vp is the current namei directory
264  * ndp is the name to locate in that directory...
265  */
266 int
267 fdesc_lookup(v)
268 	void *v;
269 {
270 	struct vop_lookup_args /* {
271 		struct vnode * a_dvp;
272 		struct vnode ** a_vpp;
273 		struct componentname * a_cnp;
274 	} */ *ap = v;
275 	struct vnode **vpp = ap->a_vpp;
276 	struct vnode *dvp = ap->a_dvp;
277 	struct componentname *cnp = ap->a_cnp;
278 	struct lwp *l = cnp->cn_lwp;
279 	const char *pname = cnp->cn_nameptr;
280 	struct proc *p = l->l_proc;
281 	int numfiles = p->p_fd->fd_nfiles;
282 	unsigned fd = 0;
283 	int error;
284 	struct vnode *fvp;
285 	const char *ln;
286 
287 	if (cnp->cn_namelen == 1 && *pname == '.') {
288 		*vpp = dvp;
289 		VREF(dvp);
290 		return (0);
291 	}
292 
293 	switch (VTOFDESC(dvp)->fd_type) {
294 	default:
295 	case Flink:
296 	case Fdesc:
297 	case Fctty:
298 		error = ENOTDIR;
299 		goto bad;
300 
301 	case Froot:
302 		if (cnp->cn_namelen == 2 && memcmp(pname, "fd", 2) == 0) {
303 			error = fdesc_allocvp(Fdevfd, FD_DEVFD, dvp->v_mount, &fvp);
304 			if (error)
305 				goto bad;
306 			*vpp = fvp;
307 			fvp->v_type = VDIR;
308 			goto good;
309 		}
310 
311 		if (cnp->cn_namelen == 3 && memcmp(pname, "tty", 3) == 0) {
312 			struct vnode *ttyvp = cttyvp(p);
313 			if (ttyvp == NULL) {
314 				error = ENXIO;
315 				goto bad;
316 			}
317 			error = fdesc_allocvp(Fctty, FD_CTTY, dvp->v_mount, &fvp);
318 			if (error)
319 				goto bad;
320 			*vpp = fvp;
321 			fvp->v_type = VCHR;
322 			goto good;
323 		}
324 
325 		ln = 0;
326 		switch (cnp->cn_namelen) {
327 		case 5:
328 			if (memcmp(pname, "stdin", 5) == 0) {
329 				ln = "fd/0";
330 				fd = FD_STDIN;
331 			}
332 			break;
333 		case 6:
334 			if (memcmp(pname, "stdout", 6) == 0) {
335 				ln = "fd/1";
336 				fd = FD_STDOUT;
337 			} else
338 			if (memcmp(pname, "stderr", 6) == 0) {
339 				ln = "fd/2";
340 				fd = FD_STDERR;
341 			}
342 			break;
343 		}
344 
345 		if (ln) {
346 			error = fdesc_allocvp(Flink, fd, dvp->v_mount, &fvp);
347 			if (error)
348 				goto bad;
349 			/* XXXUNCONST */
350 			VTOFDESC(fvp)->fd_link = __UNCONST(ln);
351 			*vpp = fvp;
352 			fvp->v_type = VLNK;
353 			goto good;
354 		} else {
355 			error = ENOENT;
356 			goto bad;
357 		}
358 
359 		/* FALL THROUGH */
360 
361 	case Fdevfd:
362 		if (cnp->cn_namelen == 2 && memcmp(pname, "..", 2) == 0) {
363 			VOP_UNLOCK(dvp, 0);
364 			cnp->cn_flags |= PDIRUNLOCK;
365 			error = fdesc_root(dvp->v_mount, vpp);
366 			if (error)
367 				goto bad;
368 			/*
369 			 * If we're at the last component and need the
370 			 * parent locked, undo the unlock above.
371 			 */
372 			if (((~cnp->cn_flags & (ISLASTCN | LOCKPARENT)) == 0) &&
373 				   ((error = vn_lock(dvp, LK_EXCLUSIVE)) == 0))
374 				cnp->cn_flags &= ~PDIRUNLOCK;
375 			return (error);
376 		}
377 
378 		fd = 0;
379 		while (*pname >= '0' && *pname <= '9') {
380 			fd = 10 * fd + *pname++ - '0';
381 			if (fd >= numfiles)
382 				break;
383 		}
384 
385 		if (*pname != '\0') {
386 			error = ENOENT;
387 			goto bad;
388 		}
389 
390 		if (fd >= numfiles || p->p_fd->fd_ofiles[fd] == NULL ||
391 		    FILE_IS_USABLE(p->p_fd->fd_ofiles[fd]) == 0) {
392 			error = EBADF;
393 			goto bad;
394 		}
395 
396 		error = fdesc_allocvp(Fdesc, FD_DESC+fd, dvp->v_mount, &fvp);
397 		if (error)
398 			goto bad;
399 		VTOFDESC(fvp)->fd_fd = fd;
400 		*vpp = fvp;
401 		goto good;
402 	}
403 
404 bad:;
405 	*vpp = NULL;
406 	return (error);
407 
408 good:;
409 	/*
410 	 * As "." was special cased above, we now unlock the parent if we're
411 	 * suppoed to. We're only supposed to not unlock if this is the
412 	 * last component, and the caller requested LOCKPARENT. So if either
413 	 * condition is false, unlock.
414 	 */
415 	if (((~cnp->cn_flags) & (ISLASTCN | LOCKPARENT)) != 0) {
416 		VOP_UNLOCK(dvp, 0);
417 		cnp->cn_flags |= PDIRUNLOCK;
418 	}
419 	return (0);
420 }
421 
422 int
423 fdesc_open(v)
424 	void *v;
425 {
426 	struct vop_open_args /* {
427 		struct vnode *a_vp;
428 		int  a_mode;
429 		struct ucred *a_cred;
430 		struct lwp *a_l;
431 	} */ *ap = v;
432 	struct vnode *vp = ap->a_vp;
433 
434 	switch (VTOFDESC(vp)->fd_type) {
435 	case Fdesc:
436 		/*
437 		 * XXX Kludge: set dupfd to contain the value of the
438 		 * the file descriptor being sought for duplication. The error
439 		 * return ensures that the vnode for this device will be
440 		 * released by vn_open. Open will detect this special error and
441 		 * take the actions in dupfdopen.  Other callers of vn_open or
442 		 * VOP_OPEN will simply report the error.
443 		 */
444 		curlwp->l_dupfd = VTOFDESC(vp)->fd_fd;	/* XXX */
445 		return EDUPFD;
446 
447 	case Fctty:
448 		return ((*ctty_cdevsw.d_open)(devctty, ap->a_mode, 0, ap->a_l));
449 	case Froot:
450 	case Fdevfd:
451 	case Flink:
452 		break;
453 	}
454 
455 	return (0);
456 }
457 
458 static int
459 fdesc_attr(fd, vap, cred, l)
460 	int fd;
461 	struct vattr *vap;
462 	struct ucred *cred;
463 	struct lwp *l;
464 {
465 	struct proc *p = l->l_proc;
466 	struct filedesc *fdp = p->p_fd;
467 	struct file *fp;
468 	struct stat stb;
469 	int error;
470 
471 	if ((fp = fd_getfile(fdp, fd)) == NULL)
472 		return (EBADF);
473 
474 	switch (fp->f_type) {
475 	case DTYPE_VNODE:
476 		simple_unlock(&fp->f_slock);
477 		error = VOP_GETATTR((struct vnode *) fp->f_data, vap, cred, l);
478 		if (error == 0 && vap->va_type == VDIR) {
479 			/*
480 			 * directories can cause loops in the namespace,
481 			 * so turn off the 'x' bits to avoid trouble.
482 			 */
483 			vap->va_mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH);
484 		}
485 		break;
486 
487 	default:
488 		FILE_USE(fp);
489 		memset(&stb, 0, sizeof(stb));
490 		error = (*fp->f_ops->fo_stat)(fp, &stb, l);
491 		FILE_UNUSE(fp, l);
492 		if (error)
493 			break;
494 
495 		vattr_null(vap);
496 		switch(fp->f_type) {
497 		case DTYPE_SOCKET:
498 			vap->va_type = VSOCK;
499 			break;
500 		case DTYPE_PIPE:
501 			vap->va_type = VFIFO;
502 			break;
503 		default:
504 			/* use VNON perhaps? */
505 			vap->va_type = VBAD;
506 			break;
507 		}
508 		vap->va_mode = stb.st_mode;
509 		vap->va_nlink = stb.st_nlink;
510 		vap->va_uid = stb.st_uid;
511 		vap->va_gid = stb.st_gid;
512 		vap->va_fsid = stb.st_dev;
513 		vap->va_fileid = stb.st_ino;
514 		vap->va_size = stb.st_size;
515 		vap->va_blocksize = stb.st_blksize;
516 		vap->va_atime = stb.st_atimespec;
517 		vap->va_mtime = stb.st_mtimespec;
518 		vap->va_ctime = stb.st_ctimespec;
519 		vap->va_gen = stb.st_gen;
520 		vap->va_flags = stb.st_flags;
521 		vap->va_rdev = stb.st_rdev;
522 		vap->va_bytes = stb.st_blocks * stb.st_blksize;
523 		break;
524 	}
525 
526 	return (error);
527 }
528 
529 int
530 fdesc_getattr(v)
531 	void *v;
532 {
533 	struct vop_getattr_args /* {
534 		struct vnode *a_vp;
535 		struct vattr *a_vap;
536 		struct ucred *a_cred;
537 		struct lwp *a_l;
538 	} */ *ap = v;
539 	struct vnode *vp = ap->a_vp;
540 	struct vattr *vap = ap->a_vap;
541 	unsigned fd;
542 	int error = 0;
543 
544 	switch (VTOFDESC(vp)->fd_type) {
545 	case Froot:
546 	case Fdevfd:
547 	case Flink:
548 	case Fctty:
549 		VATTR_NULL(vap);
550 		vap->va_fileid = VTOFDESC(vp)->fd_ix;
551 
552 #define R_ALL (S_IRUSR|S_IRGRP|S_IROTH)
553 #define W_ALL (S_IWUSR|S_IWGRP|S_IWOTH)
554 #define X_ALL (S_IXUSR|S_IXGRP|S_IXOTH)
555 
556 		switch (VTOFDESC(vp)->fd_type) {
557 		case Flink:
558 			vap->va_mode = R_ALL|X_ALL;
559 			vap->va_type = VLNK;
560 			vap->va_rdev = 0;
561 			vap->va_nlink = 1;
562 			vap->va_size = strlen(VTOFDESC(vp)->fd_link);
563 			break;
564 
565 		case Fctty:
566 			vap->va_mode = R_ALL|W_ALL;
567 			vap->va_type = VCHR;
568 			vap->va_rdev = devctty;
569 			vap->va_nlink = 1;
570 			vap->va_size = 0;
571 			break;
572 
573 		default:
574 			vap->va_mode = R_ALL|X_ALL;
575 			vap->va_type = VDIR;
576 			vap->va_rdev = 0;
577 			vap->va_nlink = 2;
578 			vap->va_size = DEV_BSIZE;
579 			break;
580 		}
581 		vap->va_uid = 0;
582 		vap->va_gid = 0;
583 		vap->va_fsid = vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0];
584 		vap->va_blocksize = DEV_BSIZE;
585 		vap->va_atime.tv_sec = boottime.tv_sec;
586 		vap->va_atime.tv_nsec = 0;
587 		vap->va_mtime = vap->va_atime;
588 		vap->va_ctime = vap->va_mtime;
589 		vap->va_gen = 0;
590 		vap->va_flags = 0;
591 		vap->va_bytes = 0;
592 		break;
593 
594 	case Fdesc:
595 		fd = VTOFDESC(vp)->fd_fd;
596 		error = fdesc_attr(fd, vap, ap->a_cred, ap->a_l);
597 		break;
598 
599 	default:
600 		panic("fdesc_getattr");
601 		break;
602 	}
603 
604 	if (error == 0)
605 		vp->v_type = vap->va_type;
606 
607 	return (error);
608 }
609 
610 int
611 fdesc_setattr(v)
612 	void *v;
613 {
614 	struct vop_setattr_args /* {
615 		struct vnode *a_vp;
616 		struct vattr *a_vap;
617 		struct ucred *a_cred;
618 		struct lwp *a_l;
619 	} */ *ap = v;
620 	struct filedesc *fdp = ap->a_l->l_proc->p_fd;
621 	struct file *fp;
622 	unsigned fd;
623 
624 	/*
625 	 * Can't mess with the root vnode
626 	 */
627 	switch (VTOFDESC(ap->a_vp)->fd_type) {
628 	case Fdesc:
629 		break;
630 
631 	case Fctty:
632 		return (0);
633 
634 	default:
635 		return (EACCES);
636 	}
637 
638 	fd = VTOFDESC(ap->a_vp)->fd_fd;
639 	if ((fp = fd_getfile(fdp, fd)) == NULL)
640 		return (EBADF);
641 
642 	/*
643 	 * XXX: Can't reasonably set the attr's on any types currently.
644 	 *      On vnode's this will cause truncation and socket/pipes make
645 	 *      no sense.
646 	 */
647 	simple_unlock(&fp->f_slock);
648 	return (0);
649 }
650 
651 
652 struct fdesc_target {
653 	ino_t ft_fileno;
654 	u_char ft_type;
655 	u_char ft_namlen;
656 	const char *ft_name;
657 } fdesc_targets[] = {
658 #define N(s) sizeof(s)-1, s
659 	{ FD_DEVFD,  DT_DIR,     N("fd")     },
660 	{ FD_STDIN,  DT_LNK,     N("stdin")  },
661 	{ FD_STDOUT, DT_LNK,     N("stdout") },
662 	{ FD_STDERR, DT_LNK,     N("stderr") },
663 	{ FD_CTTY,   DT_UNKNOWN, N("tty")    },
664 #undef N
665 #define UIO_MX _DIRENT_RECLEN((struct dirent *)NULL, sizeof("stderr") - 1)
666 };
667 static int nfdesc_targets = sizeof(fdesc_targets) / sizeof(fdesc_targets[0]);
668 
669 int
670 fdesc_readdir(v)
671 	void *v;
672 {
673 	struct vop_readdir_args /* {
674 		struct vnode *a_vp;
675 		struct uio *a_uio;
676 		struct ucred *a_cred;
677 		int *a_eofflag;
678 		off_t **a_cookies;
679 		int *a_ncookies;
680 	} */ *ap = v;
681 	struct uio *uio = ap->a_uio;
682 	struct dirent d;
683 	struct filedesc *fdp;
684 	off_t i;
685 	int j;
686 	int error;
687 	off_t *cookies = NULL;
688 	int ncookies;
689 
690 	switch (VTOFDESC(ap->a_vp)->fd_type) {
691 	case Fctty:
692 		return 0;
693 
694 	case Fdesc:
695 		return ENOTDIR;
696 
697 	default:
698 		break;
699 	}
700 
701 	fdp = uio->uio_lwp ? uio->uio_lwp->l_proc->p_fd : NULL;
702 
703 	if (uio->uio_resid < UIO_MX)
704 		return EINVAL;
705 	if (uio->uio_offset < 0)
706 		return EINVAL;
707 
708 	error = 0;
709 	i = uio->uio_offset;
710 	(void)memset(&d, 0, UIO_MX);
711 	d.d_reclen = UIO_MX;
712 	if (ap->a_ncookies)
713 		ncookies = uio->uio_resid / UIO_MX;
714 	else
715 		ncookies = 0;
716 
717 	if (VTOFDESC(ap->a_vp)->fd_type == Froot) {
718 		struct fdesc_target *ft;
719 
720 		if (i >= nfdesc_targets)
721 			return 0;
722 
723 		if (ap->a_ncookies) {
724 			ncookies = min(ncookies, (nfdesc_targets - i));
725 			cookies = malloc(ncookies * sizeof(off_t),
726 			    M_TEMP, M_WAITOK);
727 			*ap->a_cookies = cookies;
728 			*ap->a_ncookies = ncookies;
729 		}
730 
731 		for (ft = &fdesc_targets[i]; uio->uio_resid >= UIO_MX &&
732 		    i < nfdesc_targets; ft++, i++) {
733 			switch (ft->ft_fileno) {
734 			case FD_CTTY:
735 				if (uio->uio_lwp == NULL ||
736 				    cttyvp(uio->uio_lwp->l_proc) == NULL)
737 					continue;
738 				break;
739 
740 			case FD_STDIN:
741 			case FD_STDOUT:
742 			case FD_STDERR:
743 				if (fdp == NULL)
744 					continue;
745 				if ((ft->ft_fileno - FD_STDIN) >=
746 				    fdp->fd_nfiles)
747 					continue;
748 				if (fdp->fd_ofiles[ft->ft_fileno - FD_STDIN]
749 				    == NULL
750 				    || FILE_IS_USABLE(
751 				    fdp->fd_ofiles[ft->ft_fileno - FD_STDIN])
752 				    == 0)
753 					continue;
754 				break;
755 			}
756 
757 			d.d_fileno = ft->ft_fileno;
758 			d.d_namlen = ft->ft_namlen;
759 			(void)memcpy(d.d_name, ft->ft_name, ft->ft_namlen + 1);
760 			d.d_type = ft->ft_type;
761 
762 			if ((error = uiomove(&d, UIO_MX, uio)) != 0)
763 				break;
764 			if (cookies)
765 				*cookies++ = i + 1;
766 		}
767 	} else {
768 		int nfdp = fdp ? fdp->fd_nfiles : 0;
769 		if (ap->a_ncookies) {
770 			ncookies = min(ncookies, nfdp + 2);
771 			cookies = malloc(ncookies * sizeof(off_t),
772 			    M_TEMP, M_WAITOK);
773 			*ap->a_cookies = cookies;
774 			*ap->a_ncookies = ncookies;
775 		}
776 		for (; i - 2 < nfdp && uio->uio_resid >= UIO_MX; i++) {
777 			switch (i) {
778 			case 0:
779 			case 1:
780 				d.d_fileno = FD_ROOT;		/* XXX */
781 				d.d_namlen = i + 1;
782 				(void)memcpy(d.d_name, "..", d.d_namlen);
783 				d.d_name[i + 1] = '\0';
784 				d.d_type = DT_DIR;
785 				break;
786 
787 			default:
788 				KASSERT(fdp != NULL);
789 				j = (int)i - 2;
790 				if (fdp->fd_ofiles[j] == NULL ||
791 				    FILE_IS_USABLE(fdp->fd_ofiles[j]) == 0)
792 					continue;
793 				d.d_fileno = j + FD_STDIN;
794 				d.d_namlen = sprintf(d.d_name, "%d", j);
795 				d.d_type = DT_UNKNOWN;
796 				break;
797 			}
798 
799 			if ((error = uiomove(&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 		void *a_data;
906 		int  a_fflag;
907 		struct ucred *a_cred;
908 		struct lwp *a_l;
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_l);
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 lwp *a_l;
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_l);
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 lwp *l;
962 	struct file *fp;
963 
964 	switch (VTOFDESC(ap->a_vp)->fd_type) {
965 	case Fctty:
966 		error = (*ctty_cdevsw.d_kqfilter)(devctty, ap->a_kn);
967 		break;
968 
969 	case Fdesc:
970 		/* just invoke kqfilter for the underlying descriptor */
971 		l = curlwp;	/* XXX hopefully ok to use curproc here */
972 		p = l->l_proc;
973 		if ((fp = fd_getfile(p->p_fd, VTOFDESC(ap->a_vp)->fd_fd)) == NULL)
974 			return (1);
975 
976 		FILE_USE(fp);
977 		error = (*fp->f_ops->fo_kqfilter)(fp, ap->a_kn);
978 		FILE_UNUSE(fp, l);
979 		break;
980 
981 	default:
982 		return (genfs_kqfilter(v));
983 	}
984 
985 	return (error);
986 }
987 
988 int
989 fdesc_inactive(v)
990 	void *v;
991 {
992 	struct vop_inactive_args /* {
993 		struct vnode *a_vp;
994 		struct lwp *a_l;
995 	} */ *ap = v;
996 	struct vnode *vp = ap->a_vp;
997 
998 	/*
999 	 * Clear out the v_type field to avoid
1000 	 * nasty things happening in vgone().
1001 	 */
1002 	VOP_UNLOCK(vp, 0);
1003 	vp->v_type = VNON;
1004 	return (0);
1005 }
1006 
1007 int
1008 fdesc_reclaim(v)
1009 	void *v;
1010 {
1011 	struct vop_reclaim_args /* {
1012 		struct vnode *a_vp;
1013 	} */ *ap = v;
1014 	struct vnode *vp = ap->a_vp;
1015 	struct fdescnode *fd = VTOFDESC(vp);
1016 
1017 	LIST_REMOVE(fd, fd_hash);
1018 	FREE(vp->v_data, M_TEMP);
1019 	vp->v_data = 0;
1020 
1021 	return (0);
1022 }
1023 
1024 /*
1025  * Return POSIX pathconf information applicable to special devices.
1026  */
1027 int
1028 fdesc_pathconf(v)
1029 	void *v;
1030 {
1031 	struct vop_pathconf_args /* {
1032 		struct vnode *a_vp;
1033 		int a_name;
1034 		register_t *a_retval;
1035 	} */ *ap = v;
1036 
1037 	switch (ap->a_name) {
1038 	case _PC_LINK_MAX:
1039 		*ap->a_retval = LINK_MAX;
1040 		return (0);
1041 	case _PC_MAX_CANON:
1042 		*ap->a_retval = MAX_CANON;
1043 		return (0);
1044 	case _PC_MAX_INPUT:
1045 		*ap->a_retval = MAX_INPUT;
1046 		return (0);
1047 	case _PC_PIPE_BUF:
1048 		*ap->a_retval = PIPE_BUF;
1049 		return (0);
1050 	case _PC_CHOWN_RESTRICTED:
1051 		*ap->a_retval = 1;
1052 		return (0);
1053 	case _PC_VDISABLE:
1054 		*ap->a_retval = _POSIX_VDISABLE;
1055 		return (0);
1056 	case _PC_SYNC_IO:
1057 		*ap->a_retval = 1;
1058 		return (0);
1059 	default:
1060 		return (EINVAL);
1061 	}
1062 	/* NOTREACHED */
1063 }
1064 
1065 /*
1066  * Print out the contents of a /dev/fd vnode.
1067  */
1068 /* ARGSUSED */
1069 int
1070 fdesc_print(v)
1071 	void *v;
1072 {
1073 	printf("tag VT_NON, fdesc vnode\n");
1074 	return (0);
1075 }
1076 
1077 int
1078 fdesc_link(v)
1079 	void *v;
1080 {
1081 	struct vop_link_args /* {
1082 		struct vnode *a_dvp;
1083 		struct vnode *a_vp;
1084 		struct componentname *a_cnp;
1085 	} */ *ap = v;
1086 
1087 	VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
1088 	vput(ap->a_dvp);
1089 	return (EROFS);
1090 }
1091 
1092 int
1093 fdesc_symlink(v)
1094 	void *v;
1095 {
1096 	struct vop_symlink_args /* {
1097 		struct vnode *a_dvp;
1098 		struct vnode **a_vpp;
1099 		struct componentname *a_cnp;
1100 		struct vattr *a_vap;
1101 		char *a_target;
1102 	} */ *ap = v;
1103 
1104 	VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
1105 	vput(ap->a_dvp);
1106 	return (EROFS);
1107 }
1108