xref: /netbsd-src/sys/miscfs/fdesc/fdesc_vnops.c (revision fad4c9f71477ae11cea2ee75ec82151ac770a534)
1 /*	$NetBSD: fdesc_vnops.c,v 1.92 2006/05/14 21:31:52 elad 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 1.92 2006/05/14 21:31:52 elad 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 #include <sys/kauth.h>
65 
66 #include <miscfs/fdesc/fdesc.h>
67 #include <miscfs/genfs/genfs.h>
68 
69 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
70 
71 #define FDL_WANT	0x01
72 #define FDL_LOCKED	0x02
73 static int fdcache_lock;
74 
75 dev_t devctty;
76 
77 #if (FD_STDIN != FD_STDOUT-1) || (FD_STDOUT != FD_STDERR-1)
78 FD_STDIN, FD_STDOUT, FD_STDERR must be a sequence n, n+1, n+2
79 #endif
80 
81 #define	NFDCACHE 4
82 
83 #define FD_NHASH(ix) \
84 	(&fdhashtbl[(ix) & fdhash])
85 LIST_HEAD(fdhashhead, fdescnode) *fdhashtbl;
86 u_long fdhash;
87 
88 int	fdesc_lookup(void *);
89 #define	fdesc_create	genfs_eopnotsupp
90 #define	fdesc_mknod	genfs_eopnotsupp
91 int	fdesc_open(void *);
92 #define	fdesc_close	genfs_nullop
93 #define	fdesc_access	genfs_nullop
94 int	fdesc_getattr(void *);
95 int	fdesc_setattr(void *);
96 int	fdesc_read(void *);
97 int	fdesc_write(void *);
98 int	fdesc_ioctl(void *);
99 int	fdesc_poll(void *);
100 int	fdesc_kqfilter(void *);
101 #define	fdesc_mmap	genfs_eopnotsupp
102 #define	fdesc_fcntl	genfs_fcntl
103 #define	fdesc_fsync	genfs_nullop
104 #define	fdesc_seek	genfs_seek
105 #define	fdesc_remove	genfs_eopnotsupp
106 int	fdesc_link(void *);
107 #define	fdesc_rename	genfs_eopnotsupp
108 #define	fdesc_mkdir	genfs_eopnotsupp
109 #define	fdesc_rmdir	genfs_eopnotsupp
110 int	fdesc_symlink(void *);
111 int	fdesc_readdir(void *);
112 int	fdesc_readlink(void *);
113 #define	fdesc_abortop	genfs_abortop
114 int	fdesc_inactive(void *);
115 int	fdesc_reclaim(void *);
116 #define	fdesc_lock	genfs_lock
117 #define	fdesc_unlock	genfs_unlock
118 #define	fdesc_bmap	genfs_badop
119 #define	fdesc_strategy	genfs_badop
120 int	fdesc_print(void *);
121 int	fdesc_pathconf(void *);
122 #define	fdesc_islocked	genfs_islocked
123 #define	fdesc_advlock	genfs_einval
124 #define	fdesc_bwrite	genfs_eopnotsupp
125 #define fdesc_revoke	genfs_revoke
126 #define fdesc_putpages	genfs_null_putpages
127 
128 static int fdesc_attr(int, struct vattr *, kauth_cred_t, struct lwp *);
129 
130 int (**fdesc_vnodeop_p)(void *);
131 const struct vnodeopv_entry_desc fdesc_vnodeop_entries[] = {
132 	{ &vop_default_desc, vn_default_error },
133 	{ &vop_lookup_desc, fdesc_lookup },		/* lookup */
134 	{ &vop_create_desc, fdesc_create },		/* create */
135 	{ &vop_mknod_desc, fdesc_mknod },		/* mknod */
136 	{ &vop_open_desc, fdesc_open },			/* open */
137 	{ &vop_close_desc, fdesc_close },		/* close */
138 	{ &vop_access_desc, fdesc_access },		/* access */
139 	{ &vop_getattr_desc, fdesc_getattr },		/* getattr */
140 	{ &vop_setattr_desc, fdesc_setattr },		/* setattr */
141 	{ &vop_read_desc, fdesc_read },			/* read */
142 	{ &vop_write_desc, fdesc_write },		/* write */
143 	{ &vop_ioctl_desc, fdesc_ioctl },		/* ioctl */
144 	{ &vop_fcntl_desc, fdesc_fcntl },		/* fcntl */
145 	{ &vop_poll_desc, fdesc_poll },			/* poll */
146 	{ &vop_kqfilter_desc, fdesc_kqfilter },		/* kqfilter */
147 	{ &vop_revoke_desc, fdesc_revoke },		/* revoke */
148 	{ &vop_mmap_desc, fdesc_mmap },			/* mmap */
149 	{ &vop_fsync_desc, fdesc_fsync },		/* fsync */
150 	{ &vop_seek_desc, fdesc_seek },			/* seek */
151 	{ &vop_remove_desc, fdesc_remove },		/* remove */
152 	{ &vop_link_desc, fdesc_link },			/* link */
153 	{ &vop_rename_desc, fdesc_rename },		/* rename */
154 	{ &vop_mkdir_desc, fdesc_mkdir },		/* mkdir */
155 	{ &vop_rmdir_desc, fdesc_rmdir },		/* rmdir */
156 	{ &vop_symlink_desc, fdesc_symlink },		/* symlink */
157 	{ &vop_readdir_desc, fdesc_readdir },		/* readdir */
158 	{ &vop_readlink_desc, fdesc_readlink },		/* readlink */
159 	{ &vop_abortop_desc, fdesc_abortop },		/* abortop */
160 	{ &vop_inactive_desc, fdesc_inactive },		/* inactive */
161 	{ &vop_reclaim_desc, fdesc_reclaim },		/* reclaim */
162 	{ &vop_lock_desc, fdesc_lock },			/* lock */
163 	{ &vop_unlock_desc, fdesc_unlock },		/* unlock */
164 	{ &vop_bmap_desc, fdesc_bmap },			/* bmap */
165 	{ &vop_strategy_desc, fdesc_strategy },		/* strategy */
166 	{ &vop_print_desc, fdesc_print },		/* print */
167 	{ &vop_islocked_desc, fdesc_islocked },		/* islocked */
168 	{ &vop_pathconf_desc, fdesc_pathconf },		/* pathconf */
169 	{ &vop_advlock_desc, fdesc_advlock },		/* advlock */
170 	{ &vop_bwrite_desc, fdesc_bwrite },		/* bwrite */
171 	{ &vop_putpages_desc, fdesc_putpages },		/* putpages */
172 	{ NULL, NULL }
173 };
174 
175 const struct vnodeopv_desc fdesc_vnodeop_opv_desc =
176 	{ &fdesc_vnodeop_p, fdesc_vnodeop_entries };
177 
178 extern const struct cdevsw ctty_cdevsw;
179 
180 /*
181  * Initialise cache headers
182  */
183 void
184 fdesc_init()
185 {
186 	int cttymajor;
187 
188 	/* locate the major number */
189 	cttymajor = cdevsw_lookup_major(&ctty_cdevsw);
190 	devctty = makedev(cttymajor, 0);
191 	fdhashtbl = hashinit(NFDCACHE, HASH_LIST, M_CACHE, M_NOWAIT, &fdhash);
192 }
193 
194 /*
195  * Free hash table.
196  */
197 void
198 fdesc_done()
199 {
200 	hashdone(fdhashtbl, M_CACHE);
201 }
202 
203 /*
204  * Return a locked vnode of the correct type.
205  */
206 int
207 fdesc_allocvp(ftype, ix, mp, vpp)
208 	fdntype ftype;
209 	int ix;
210 	struct mount *mp;
211 	struct vnode **vpp;
212 {
213 	struct fdhashhead *fc;
214 	struct fdescnode *fd;
215 	int error = 0;
216 
217 	fc = FD_NHASH(ix);
218 loop:
219 	for (fd = fc->lh_first; fd != 0; fd = fd->fd_hash.le_next) {
220 		if (fd->fd_ix == ix && fd->fd_vnode->v_mount == mp) {
221 			if (vget(fd->fd_vnode, LK_EXCLUSIVE))
222 				goto loop;
223 			*vpp = fd->fd_vnode;
224 			return (error);
225 		}
226 	}
227 
228 	/*
229 	 * otherwise lock the array while we call getnewvnode
230 	 * since that can block.
231 	 */
232 	if (fdcache_lock & FDL_LOCKED) {
233 		fdcache_lock |= FDL_WANT;
234 		(void) tsleep(&fdcache_lock, PINOD, "fdcache", 0);
235 		goto loop;
236 	}
237 	fdcache_lock |= FDL_LOCKED;
238 
239 	error = getnewvnode(VT_FDESC, mp, fdesc_vnodeop_p, vpp);
240 	if (error)
241 		goto out;
242 	MALLOC(fd, void *, sizeof(struct fdescnode), M_TEMP, M_WAITOK);
243 	(*vpp)->v_data = fd;
244 	fd->fd_vnode = *vpp;
245 	fd->fd_type = ftype;
246 	fd->fd_fd = -1;
247 	fd->fd_link = 0;
248 	fd->fd_ix = ix;
249 	VOP_LOCK(*vpp, LK_EXCLUSIVE);
250 	LIST_INSERT_HEAD(fc, fd, fd_hash);
251 
252 out:;
253 	fdcache_lock &= ~FDL_LOCKED;
254 
255 	if (fdcache_lock & FDL_WANT) {
256 		fdcache_lock &= ~FDL_WANT;
257 		wakeup(&fdcache_lock);
258 	}
259 
260 	return (error);
261 }
262 
263 /*
264  * vp is the current namei directory
265  * ndp is the name to locate in that directory...
266  */
267 int
268 fdesc_lookup(v)
269 	void *v;
270 {
271 	struct vop_lookup_args /* {
272 		struct vnode * a_dvp;
273 		struct vnode ** a_vpp;
274 		struct componentname * a_cnp;
275 	} */ *ap = v;
276 	struct vnode **vpp = ap->a_vpp;
277 	struct vnode *dvp = ap->a_dvp;
278 	struct componentname *cnp = ap->a_cnp;
279 	struct lwp *l = cnp->cn_lwp;
280 	const char *pname = cnp->cn_nameptr;
281 	struct proc *p = l->l_proc;
282 	int numfiles = p->p_fd->fd_nfiles;
283 	unsigned fd = 0;
284 	int error;
285 	struct vnode *fvp;
286 	const char *ln;
287 
288 	if (cnp->cn_namelen == 1 && *pname == '.') {
289 		*vpp = dvp;
290 		VREF(dvp);
291 		return (0);
292 	}
293 
294 	switch (VTOFDESC(dvp)->fd_type) {
295 	default:
296 	case Flink:
297 	case Fdesc:
298 	case Fctty:
299 		error = ENOTDIR;
300 		goto bad;
301 
302 	case Froot:
303 		if (cnp->cn_namelen == 2 && memcmp(pname, "fd", 2) == 0) {
304 			error = fdesc_allocvp(Fdevfd, FD_DEVFD, dvp->v_mount, &fvp);
305 			if (error)
306 				goto bad;
307 			*vpp = fvp;
308 			fvp->v_type = VDIR;
309 			goto good;
310 		}
311 
312 		if (cnp->cn_namelen == 3 && memcmp(pname, "tty", 3) == 0) {
313 			struct vnode *ttyvp = cttyvp(p);
314 			if (ttyvp == NULL) {
315 				error = ENXIO;
316 				goto bad;
317 			}
318 			error = fdesc_allocvp(Fctty, FD_CTTY, dvp->v_mount, &fvp);
319 			if (error)
320 				goto bad;
321 			*vpp = fvp;
322 			fvp->v_type = VCHR;
323 			goto good;
324 		}
325 
326 		ln = 0;
327 		switch (cnp->cn_namelen) {
328 		case 5:
329 			if (memcmp(pname, "stdin", 5) == 0) {
330 				ln = "fd/0";
331 				fd = FD_STDIN;
332 			}
333 			break;
334 		case 6:
335 			if (memcmp(pname, "stdout", 6) == 0) {
336 				ln = "fd/1";
337 				fd = FD_STDOUT;
338 			} else
339 			if (memcmp(pname, "stderr", 6) == 0) {
340 				ln = "fd/2";
341 				fd = FD_STDERR;
342 			}
343 			break;
344 		}
345 
346 		if (ln) {
347 			error = fdesc_allocvp(Flink, fd, dvp->v_mount, &fvp);
348 			if (error)
349 				goto bad;
350 			/* XXXUNCONST */
351 			VTOFDESC(fvp)->fd_link = __UNCONST(ln);
352 			*vpp = fvp;
353 			fvp->v_type = VLNK;
354 			goto good;
355 		} else {
356 			error = ENOENT;
357 			goto bad;
358 		}
359 
360 		/* FALL THROUGH */
361 
362 	case Fdevfd:
363 		if (cnp->cn_namelen == 2 && memcmp(pname, "..", 2) == 0) {
364 			VOP_UNLOCK(dvp, 0);
365 			cnp->cn_flags |= PDIRUNLOCK;
366 			error = fdesc_root(dvp->v_mount, vpp);
367 			if (error)
368 				goto bad;
369 			/*
370 			 * If we're at the last component and need the
371 			 * parent locked, undo the unlock above.
372 			 */
373 			if (((~cnp->cn_flags & (ISLASTCN | LOCKPARENT)) == 0) &&
374 				   ((error = vn_lock(dvp, LK_EXCLUSIVE)) == 0))
375 				cnp->cn_flags &= ~PDIRUNLOCK;
376 			return (error);
377 		}
378 
379 		fd = 0;
380 		while (*pname >= '0' && *pname <= '9') {
381 			fd = 10 * fd + *pname++ - '0';
382 			if (fd >= numfiles)
383 				break;
384 		}
385 
386 		if (*pname != '\0') {
387 			error = ENOENT;
388 			goto bad;
389 		}
390 
391 		if (fd >= numfiles || p->p_fd->fd_ofiles[fd] == NULL ||
392 		    FILE_IS_USABLE(p->p_fd->fd_ofiles[fd]) == 0) {
393 			error = EBADF;
394 			goto bad;
395 		}
396 
397 		error = fdesc_allocvp(Fdesc, FD_DESC+fd, dvp->v_mount, &fvp);
398 		if (error)
399 			goto bad;
400 		VTOFDESC(fvp)->fd_fd = fd;
401 		*vpp = fvp;
402 		goto good;
403 	}
404 
405 bad:;
406 	*vpp = NULL;
407 	return (error);
408 
409 good:;
410 	/*
411 	 * As "." was special cased above, we now unlock the parent if we're
412 	 * suppoed to. We're only supposed to not unlock if this is the
413 	 * last component, and the caller requested LOCKPARENT. So if either
414 	 * condition is false, unlock.
415 	 */
416 	if (((~cnp->cn_flags) & (ISLASTCN | LOCKPARENT)) != 0) {
417 		VOP_UNLOCK(dvp, 0);
418 		cnp->cn_flags |= PDIRUNLOCK;
419 	}
420 	return (0);
421 }
422 
423 int
424 fdesc_open(v)
425 	void *v;
426 {
427 	struct vop_open_args /* {
428 		struct vnode *a_vp;
429 		int  a_mode;
430 		kauth_cred_t a_cred;
431 		struct lwp *a_l;
432 	} */ *ap = v;
433 	struct vnode *vp = ap->a_vp;
434 
435 	switch (VTOFDESC(vp)->fd_type) {
436 	case Fdesc:
437 		/*
438 		 * XXX Kludge: set dupfd to contain the value of the
439 		 * the file descriptor being sought for duplication. The error
440 		 * return ensures that the vnode for this device will be
441 		 * released by vn_open. Open will detect this special error and
442 		 * take the actions in dupfdopen.  Other callers of vn_open or
443 		 * VOP_OPEN will simply report the error.
444 		 */
445 		curlwp->l_dupfd = VTOFDESC(vp)->fd_fd;	/* XXX */
446 		return EDUPFD;
447 
448 	case Fctty:
449 		return ((*ctty_cdevsw.d_open)(devctty, ap->a_mode, 0, ap->a_l));
450 	case Froot:
451 	case Fdevfd:
452 	case Flink:
453 		break;
454 	}
455 
456 	return (0);
457 }
458 
459 static int
460 fdesc_attr(fd, vap, cred, l)
461 	int fd;
462 	struct vattr *vap;
463 	kauth_cred_t cred;
464 	struct lwp *l;
465 {
466 	struct proc *p = l->l_proc;
467 	struct filedesc *fdp = p->p_fd;
468 	struct file *fp;
469 	struct stat stb;
470 	int error;
471 
472 	if ((fp = fd_getfile(fdp, fd)) == NULL)
473 		return (EBADF);
474 
475 	switch (fp->f_type) {
476 	case DTYPE_VNODE:
477 		simple_unlock(&fp->f_slock);
478 		error = VOP_GETATTR((struct vnode *) fp->f_data, vap, cred, l);
479 		if (error == 0 && vap->va_type == VDIR) {
480 			/*
481 			 * directories can cause loops in the namespace,
482 			 * so turn off the 'x' bits to avoid trouble.
483 			 */
484 			vap->va_mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH);
485 		}
486 		break;
487 
488 	default:
489 		FILE_USE(fp);
490 		memset(&stb, 0, sizeof(stb));
491 		error = (*fp->f_ops->fo_stat)(fp, &stb, l);
492 		FILE_UNUSE(fp, l);
493 		if (error)
494 			break;
495 
496 		vattr_null(vap);
497 		switch(fp->f_type) {
498 		case DTYPE_SOCKET:
499 			vap->va_type = VSOCK;
500 			break;
501 		case DTYPE_PIPE:
502 			vap->va_type = VFIFO;
503 			break;
504 		default:
505 			/* use VNON perhaps? */
506 			vap->va_type = VBAD;
507 			break;
508 		}
509 		vap->va_mode = stb.st_mode;
510 		vap->va_nlink = stb.st_nlink;
511 		vap->va_uid = stb.st_uid;
512 		vap->va_gid = stb.st_gid;
513 		vap->va_fsid = stb.st_dev;
514 		vap->va_fileid = stb.st_ino;
515 		vap->va_size = stb.st_size;
516 		vap->va_blocksize = stb.st_blksize;
517 		vap->va_atime = stb.st_atimespec;
518 		vap->va_mtime = stb.st_mtimespec;
519 		vap->va_ctime = stb.st_ctimespec;
520 		vap->va_gen = stb.st_gen;
521 		vap->va_flags = stb.st_flags;
522 		vap->va_rdev = stb.st_rdev;
523 		vap->va_bytes = stb.st_blocks * stb.st_blksize;
524 		break;
525 	}
526 
527 	return (error);
528 }
529 
530 int
531 fdesc_getattr(v)
532 	void *v;
533 {
534 	struct vop_getattr_args /* {
535 		struct vnode *a_vp;
536 		struct vattr *a_vap;
537 		kauth_cred_t a_cred;
538 		struct lwp *a_l;
539 	} */ *ap = v;
540 	struct vnode *vp = ap->a_vp;
541 	struct vattr *vap = ap->a_vap;
542 	unsigned fd;
543 	int error = 0;
544 
545 	switch (VTOFDESC(vp)->fd_type) {
546 	case Froot:
547 	case Fdevfd:
548 	case Flink:
549 	case Fctty:
550 		VATTR_NULL(vap);
551 		vap->va_fileid = VTOFDESC(vp)->fd_ix;
552 
553 #define R_ALL (S_IRUSR|S_IRGRP|S_IROTH)
554 #define W_ALL (S_IWUSR|S_IWGRP|S_IWOTH)
555 #define X_ALL (S_IXUSR|S_IXGRP|S_IXOTH)
556 
557 		switch (VTOFDESC(vp)->fd_type) {
558 		case Flink:
559 			vap->va_mode = R_ALL|X_ALL;
560 			vap->va_type = VLNK;
561 			vap->va_rdev = 0;
562 			vap->va_nlink = 1;
563 			vap->va_size = strlen(VTOFDESC(vp)->fd_link);
564 			break;
565 
566 		case Fctty:
567 			vap->va_mode = R_ALL|W_ALL;
568 			vap->va_type = VCHR;
569 			vap->va_rdev = devctty;
570 			vap->va_nlink = 1;
571 			vap->va_size = 0;
572 			break;
573 
574 		default:
575 			vap->va_mode = R_ALL|X_ALL;
576 			vap->va_type = VDIR;
577 			vap->va_rdev = 0;
578 			vap->va_nlink = 2;
579 			vap->va_size = DEV_BSIZE;
580 			break;
581 		}
582 		vap->va_uid = 0;
583 		vap->va_gid = 0;
584 		vap->va_fsid = vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0];
585 		vap->va_blocksize = DEV_BSIZE;
586 		vap->va_atime.tv_sec = boottime.tv_sec;
587 		vap->va_atime.tv_nsec = 0;
588 		vap->va_mtime = vap->va_atime;
589 		vap->va_ctime = vap->va_mtime;
590 		vap->va_gen = 0;
591 		vap->va_flags = 0;
592 		vap->va_bytes = 0;
593 		break;
594 
595 	case Fdesc:
596 		fd = VTOFDESC(vp)->fd_fd;
597 		error = fdesc_attr(fd, vap, ap->a_cred, ap->a_l);
598 		break;
599 
600 	default:
601 		panic("fdesc_getattr");
602 		break;
603 	}
604 
605 	if (error == 0)
606 		vp->v_type = vap->va_type;
607 
608 	return (error);
609 }
610 
611 int
612 fdesc_setattr(v)
613 	void *v;
614 {
615 	struct vop_setattr_args /* {
616 		struct vnode *a_vp;
617 		struct vattr *a_vap;
618 		kauth_cred_t a_cred;
619 		struct lwp *a_l;
620 	} */ *ap = v;
621 	struct filedesc *fdp = ap->a_l->l_proc->p_fd;
622 	struct file *fp;
623 	unsigned fd;
624 
625 	/*
626 	 * Can't mess with the root vnode
627 	 */
628 	switch (VTOFDESC(ap->a_vp)->fd_type) {
629 	case Fdesc:
630 		break;
631 
632 	case Fctty:
633 		return (0);
634 
635 	default:
636 		return (EACCES);
637 	}
638 
639 	fd = VTOFDESC(ap->a_vp)->fd_fd;
640 	if ((fp = fd_getfile(fdp, fd)) == NULL)
641 		return (EBADF);
642 
643 	/*
644 	 * XXX: Can't reasonably set the attr's on any types currently.
645 	 *      On vnode's this will cause truncation and socket/pipes make
646 	 *      no sense.
647 	 */
648 	simple_unlock(&fp->f_slock);
649 	return (0);
650 }
651 
652 
653 struct fdesc_target {
654 	ino_t ft_fileno;
655 	u_char ft_type;
656 	u_char ft_namlen;
657 	const char *ft_name;
658 } fdesc_targets[] = {
659 #define N(s) sizeof(s)-1, s
660 	{ FD_DEVFD,  DT_DIR,     N("fd")     },
661 	{ FD_STDIN,  DT_LNK,     N("stdin")  },
662 	{ FD_STDOUT, DT_LNK,     N("stdout") },
663 	{ FD_STDERR, DT_LNK,     N("stderr") },
664 	{ FD_CTTY,   DT_UNKNOWN, N("tty")    },
665 #undef N
666 #define UIO_MX _DIRENT_RECLEN((struct dirent *)NULL, sizeof("stderr") - 1)
667 };
668 static int nfdesc_targets = sizeof(fdesc_targets) / sizeof(fdesc_targets[0]);
669 
670 int
671 fdesc_readdir(v)
672 	void *v;
673 {
674 	struct vop_readdir_args /* {
675 		struct vnode *a_vp;
676 		struct uio *a_uio;
677 		kauth_cred_t a_cred;
678 		int *a_eofflag;
679 		off_t **a_cookies;
680 		int *a_ncookies;
681 	} */ *ap = v;
682 	struct uio *uio = ap->a_uio;
683 	struct dirent d;
684 	struct filedesc *fdp;
685 	off_t i;
686 	int j;
687 	int error;
688 	off_t *cookies = NULL;
689 	int ncookies;
690 
691 	switch (VTOFDESC(ap->a_vp)->fd_type) {
692 	case Fctty:
693 		return 0;
694 
695 	case Fdesc:
696 		return ENOTDIR;
697 
698 	default:
699 		break;
700 	}
701 
702 	fdp = curproc->p_fd;
703 
704 	if (uio->uio_resid < UIO_MX)
705 		return EINVAL;
706 	if (uio->uio_offset < 0)
707 		return EINVAL;
708 
709 	error = 0;
710 	i = uio->uio_offset;
711 	(void)memset(&d, 0, UIO_MX);
712 	d.d_reclen = UIO_MX;
713 	if (ap->a_ncookies)
714 		ncookies = uio->uio_resid / UIO_MX;
715 	else
716 		ncookies = 0;
717 
718 	if (VTOFDESC(ap->a_vp)->fd_type == Froot) {
719 		struct fdesc_target *ft;
720 
721 		if (i >= nfdesc_targets)
722 			return 0;
723 
724 		if (ap->a_ncookies) {
725 			ncookies = min(ncookies, (nfdesc_targets - i));
726 			cookies = malloc(ncookies * sizeof(off_t),
727 			    M_TEMP, M_WAITOK);
728 			*ap->a_cookies = cookies;
729 			*ap->a_ncookies = ncookies;
730 		}
731 
732 		for (ft = &fdesc_targets[i]; uio->uio_resid >= UIO_MX &&
733 		    i < nfdesc_targets; ft++, i++) {
734 			switch (ft->ft_fileno) {
735 			case FD_CTTY:
736 				if (cttyvp(curproc) == 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 == NULL || 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 		kauth_cred_t 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 		kauth_cred_t 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 		kauth_cred_t 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 		kauth_cred_t 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