xref: /netbsd-src/sys/miscfs/fdesc/fdesc_vnops.c (revision fdecd6a253f999ae92b139670d9e15cc9df4497c)
1 /*	$NetBSD: fdesc_vnops.c,v 1.41 1997/05/05 07:13:59 mycroft 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	8.12 (Berkeley) 8/20/94
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/param.h>
48 #include <sys/systm.h>
49 #include <sys/types.h>
50 #include <sys/time.h>
51 #include <sys/proc.h>
52 #include <sys/kernel.h>	/* boottime */
53 #include <sys/resourcevar.h>
54 #include <sys/socketvar.h>
55 #include <sys/filedesc.h>
56 #include <sys/vnode.h>
57 #include <sys/malloc.h>
58 #include <sys/conf.h>
59 #include <sys/file.h>
60 #include <sys/stat.h>
61 #include <sys/mount.h>
62 #include <sys/namei.h>
63 #include <sys/buf.h>
64 #include <sys/dirent.h>
65 #include <sys/tty.h>
66 
67 #include <miscfs/fdesc/fdesc.h>
68 #include <miscfs/genfs/genfs.h>
69 
70 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
71 
72 #define FDL_WANT	0x01
73 #define FDL_LOCKED	0x02
74 static int fdcache_lock;
75 
76 dev_t devctty;
77 
78 #if (FD_STDIN != FD_STDOUT-1) || (FD_STDOUT != FD_STDERR-1)
79 FD_STDIN, FD_STDOUT, FD_STDERR must be a sequence n, n+1, n+2
80 #endif
81 
82 #define	NFDCACHE 4
83 
84 #define FD_NHASH(ix) \
85 	(&fdhashtbl[(ix) & fdhash])
86 LIST_HEAD(fdhashhead, fdescnode) *fdhashtbl;
87 u_long fdhash;
88 
89 int	fdesc_lookup	__P((void *));
90 #define	fdesc_create	genfs_eopnotsupp
91 #define	fdesc_mknod	genfs_eopnotsupp
92 int	fdesc_open	__P((void *));
93 #define	fdesc_close	genfs_nullop
94 #define	fdesc_access	genfs_nullop
95 int	fdesc_getattr	__P((void *));
96 int	fdesc_setattr	__P((void *));
97 int	fdesc_read	__P((void *));
98 int	fdesc_write	__P((void *));
99 int	fdesc_ioctl	__P((void *));
100 int	fdesc_poll	__P((void *));
101 #define	fdesc_mmap	genfs_eopnotsupp
102 #define	fdesc_fsync	genfs_nullop
103 #define	fdesc_seek	genfs_seek
104 #define	fdesc_remove	genfs_eopnotsupp
105 int	fdesc_link	__P((void *));
106 #define	fdesc_rename	genfs_eopnotsupp
107 #define	fdesc_mkdir	genfs_eopnotsupp
108 #define	fdesc_rmdir	genfs_eopnotsupp
109 int	fdesc_symlink	__P((void *));
110 int	fdesc_readdir	__P((void *));
111 int	fdesc_readlink	__P((void *));
112 #define	fdesc_abortop	genfs_abortop
113 int	fdesc_inactive	__P((void *));
114 int	fdesc_reclaim	__P((void *));
115 #define	fdesc_lock	genfs_nullop
116 #define	fdesc_unlock	genfs_nullop
117 #define	fdesc_bmap	genfs_badop
118 #define	fdesc_strategy	genfs_badop
119 int	fdesc_print	__P((void *));
120 int	fdesc_pathconf	__P((void *));
121 #define	fdesc_islocked	genfs_nullop
122 #define	fdesc_advlock	genfs_eopnotsupp
123 #define	fdesc_blkatoff	genfs_eopnotsupp
124 #define	fdesc_valloc	genfs_eopnotsupp
125 #define	fdesc_vfree	genfs_nullop
126 #define	fdesc_truncate	genfs_eopnotsupp
127 #define	fdesc_update	genfs_nullop
128 #define	fdesc_bwrite	genfs_eopnotsupp
129 
130 static int fdesc_attr __P((int, struct vattr *, struct ucred *, struct proc *));
131 
132 int (**fdesc_vnodeop_p) __P((void *));
133 struct vnodeopv_entry_desc fdesc_vnodeop_entries[] = {
134 	{ &vop_default_desc, vn_default_error },
135 	{ &vop_lookup_desc, fdesc_lookup },		/* lookup */
136 	{ &vop_create_desc, fdesc_create },		/* create */
137 	{ &vop_mknod_desc, fdesc_mknod },		/* mknod */
138 	{ &vop_open_desc, fdesc_open },			/* open */
139 	{ &vop_close_desc, fdesc_close },		/* close */
140 	{ &vop_access_desc, fdesc_access },		/* access */
141 	{ &vop_getattr_desc, fdesc_getattr },		/* getattr */
142 	{ &vop_setattr_desc, fdesc_setattr },		/* setattr */
143 	{ &vop_read_desc, fdesc_read },			/* read */
144 	{ &vop_write_desc, fdesc_write },		/* write */
145 	{ &vop_ioctl_desc, fdesc_ioctl },		/* ioctl */
146 	{ &vop_poll_desc, fdesc_poll },			/* poll */
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_blkatoff_desc, fdesc_blkatoff },		/* blkatoff */
170 	{ &vop_valloc_desc, fdesc_valloc },		/* valloc */
171 	{ &vop_vfree_desc, fdesc_vfree },		/* vfree */
172 	{ &vop_truncate_desc, fdesc_truncate },		/* truncate */
173 	{ &vop_update_desc, fdesc_update },		/* update */
174 	{ &vop_bwrite_desc, fdesc_bwrite },		/* bwrite */
175 	{ (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL }
176 };
177 
178 struct vnodeopv_desc fdesc_vnodeop_opv_desc =
179 	{ &fdesc_vnodeop_p, fdesc_vnodeop_entries };
180 
181 /*
182  * Initialise cache headers
183  */
184 void
185 fdesc_init()
186 {
187 	int cttymajor;
188 
189 	/* locate the major number */
190 	for (cttymajor = 0; cttymajor < nchrdev; cttymajor++)
191 		if (cdevsw[cttymajor].d_open == cttyopen)
192 			break;
193 	devctty = makedev(cttymajor, 0);
194 	fdhashtbl = hashinit(NFDCACHE, M_CACHE, &fdhash);
195 }
196 
197 int
198 fdesc_allocvp(ftype, ix, mp, vpp)
199 	fdntype ftype;
200 	int ix;
201 	struct mount *mp;
202 	struct vnode **vpp;
203 {
204 	struct fdhashhead *fc;
205 	struct fdescnode *fd;
206 	int error = 0;
207 
208 	fc = FD_NHASH(ix);
209 loop:
210 	for (fd = fc->lh_first; fd != 0; fd = fd->fd_hash.le_next) {
211 		if (fd->fd_ix == ix && fd->fd_vnode->v_mount == mp) {
212 			if (vget(fd->fd_vnode, 0))
213 				goto loop;
214 			*vpp = fd->fd_vnode;
215 			return (error);
216 		}
217 	}
218 
219 	/*
220 	 * otherwise lock the array while we call getnewvnode
221 	 * since that can block.
222 	 */
223 	if (fdcache_lock & FDL_LOCKED) {
224 		fdcache_lock |= FDL_WANT;
225 		sleep((caddr_t) &fdcache_lock, PINOD);
226 		goto loop;
227 	}
228 	fdcache_lock |= FDL_LOCKED;
229 
230 	error = getnewvnode(VT_FDESC, mp, fdesc_vnodeop_p, vpp);
231 	if (error)
232 		goto out;
233 	MALLOC(fd, void *, sizeof(struct fdescnode), M_TEMP, M_WAITOK);
234 	(*vpp)->v_data = fd;
235 	fd->fd_vnode = *vpp;
236 	fd->fd_type = ftype;
237 	fd->fd_fd = -1;
238 	fd->fd_link = 0;
239 	fd->fd_ix = ix;
240 	LIST_INSERT_HEAD(fc, fd, fd_hash);
241 
242 out:;
243 	fdcache_lock &= ~FDL_LOCKED;
244 
245 	if (fdcache_lock & FDL_WANT) {
246 		fdcache_lock &= ~FDL_WANT;
247 		wakeup((caddr_t) &fdcache_lock);
248 	}
249 
250 	return (error);
251 }
252 
253 /*
254  * vp is the current namei directory
255  * ndp is the name to locate in that directory...
256  */
257 int
258 fdesc_lookup(v)
259 	void *v;
260 {
261 	struct vop_lookup_args /* {
262 		struct vnode * a_dvp;
263 		struct vnode ** a_vpp;
264 		struct componentname * a_cnp;
265 	} */ *ap = v;
266 	struct vnode **vpp = ap->a_vpp;
267 	struct vnode *dvp = ap->a_dvp;
268 	const char *pname;
269 	struct proc *p;
270 	int nfiles;
271 	unsigned fd = 0;
272 	int error;
273 	struct vnode *fvp;
274 	char *ln;
275 
276 	pname = ap->a_cnp->cn_nameptr;
277 	if (ap->a_cnp->cn_namelen == 1 && *pname == '.') {
278 		*vpp = dvp;
279 		VREF(dvp);
280 		VOP_LOCK(dvp);
281 		return (0);
282 	}
283 
284 	p = ap->a_cnp->cn_proc;
285 	nfiles = p->p_fd->fd_nfiles;
286 
287 	switch (VTOFDESC(dvp)->fd_type) {
288 	default:
289 	case Flink:
290 	case Fdesc:
291 	case Fctty:
292 		error = ENOTDIR;
293 		goto bad;
294 
295 	case Froot:
296 		if (ap->a_cnp->cn_namelen == 2 && bcmp(pname, "fd", 2) == 0) {
297 			error = fdesc_allocvp(Fdevfd, FD_DEVFD, dvp->v_mount, &fvp);
298 			if (error)
299 				goto bad;
300 			*vpp = fvp;
301 			fvp->v_type = VDIR;
302 			VOP_LOCK(fvp);
303 			return (0);
304 		}
305 
306 		if (ap->a_cnp->cn_namelen == 3 && bcmp(pname, "tty", 3) == 0) {
307 			struct vnode *ttyvp = cttyvp(p);
308 			if (ttyvp == NULL) {
309 				error = ENXIO;
310 				goto bad;
311 			}
312 			error = fdesc_allocvp(Fctty, FD_CTTY, dvp->v_mount, &fvp);
313 			if (error)
314 				goto bad;
315 			*vpp = fvp;
316 			fvp->v_type = VCHR;
317 			VOP_LOCK(fvp);
318 			return (0);
319 		}
320 
321 		ln = 0;
322 		switch (ap->a_cnp->cn_namelen) {
323 		case 5:
324 			if (bcmp(pname, "stdin", 5) == 0) {
325 				ln = "fd/0";
326 				fd = FD_STDIN;
327 			}
328 			break;
329 		case 6:
330 			if (bcmp(pname, "stdout", 6) == 0) {
331 				ln = "fd/1";
332 				fd = FD_STDOUT;
333 			} else
334 			if (bcmp(pname, "stderr", 6) == 0) {
335 				ln = "fd/2";
336 				fd = FD_STDERR;
337 			}
338 			break;
339 		}
340 
341 		if (ln) {
342 			error = fdesc_allocvp(Flink, fd, dvp->v_mount, &fvp);
343 			if (error)
344 				goto bad;
345 			VTOFDESC(fvp)->fd_link = ln;
346 			*vpp = fvp;
347 			fvp->v_type = VLNK;
348 			VOP_LOCK(fvp);
349 			return (0);
350 		} else {
351 			error = ENOENT;
352 			goto bad;
353 		}
354 
355 		/* FALL THROUGH */
356 
357 	case Fdevfd:
358 		if (ap->a_cnp->cn_namelen == 2 && bcmp(pname, "..", 2) == 0) {
359 			error = fdesc_root(dvp->v_mount, vpp);
360 			return (error);
361 		}
362 
363 		fd = 0;
364 		while (*pname >= '0' && *pname <= '9') {
365 			fd = 10 * fd + *pname++ - '0';
366 			if (fd >= nfiles)
367 				break;
368 		}
369 
370 		if (*pname != '\0') {
371 			error = ENOENT;
372 			goto bad;
373 		}
374 
375 		if (fd >= nfiles || p->p_fd->fd_ofiles[fd] == NULL) {
376 			error = EBADF;
377 			goto bad;
378 		}
379 
380 		error = fdesc_allocvp(Fdesc, FD_DESC+fd, dvp->v_mount, &fvp);
381 		if (error)
382 			goto bad;
383 		VTOFDESC(fvp)->fd_fd = fd;
384 		*vpp = fvp;
385 		return (0);
386 	}
387 
388 bad:;
389 	*vpp = NULL;
390 	return (error);
391 }
392 
393 int
394 fdesc_open(v)
395 	void *v;
396 {
397 	struct vop_open_args /* {
398 		struct vnode *a_vp;
399 		int  a_mode;
400 		struct ucred *a_cred;
401 		struct proc *a_p;
402 	} */ *ap = v;
403 	struct vnode *vp = ap->a_vp;
404 
405 	switch (VTOFDESC(vp)->fd_type) {
406 	case Fdesc:
407 		/*
408 		 * XXX Kludge: set p->p_dupfd to contain the value of the
409 		 * the file descriptor being sought for duplication. The error
410 		 * return ensures that the vnode for this device will be
411 		 * released by vn_open. Open will detect this special error and
412 		 * take the actions in dupfdopen.  Other callers of vn_open or
413 		 * VOP_OPEN will simply report the error.
414 		 */
415 		ap->a_p->p_dupfd = VTOFDESC(vp)->fd_fd;	/* XXX */
416 		return (ENODEV);
417 
418 	case Fctty:
419 		return (cttyopen(devctty, ap->a_mode, 0, ap->a_p));
420 	case Froot:
421 	case Fdevfd:
422 	case Flink:
423 		break;
424 	}
425 
426 	return (0);
427 }
428 
429 static int
430 fdesc_attr(fd, vap, cred, p)
431 	int fd;
432 	struct vattr *vap;
433 	struct ucred *cred;
434 	struct proc *p;
435 {
436 	struct filedesc *fdp = p->p_fd;
437 	struct file *fp;
438 	struct stat stb;
439 	int error;
440 
441 	if (fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL)
442 		return (EBADF);
443 
444 	switch (fp->f_type) {
445 	case DTYPE_VNODE:
446 		error = VOP_GETATTR((struct vnode *) fp->f_data, vap, cred, p);
447 		if (error == 0 && vap->va_type == VDIR) {
448 			/*
449 			 * directories can cause loops in the namespace,
450 			 * so turn off the 'x' bits to avoid trouble.
451 			 */
452 			vap->va_mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH);
453 		}
454 		break;
455 
456 	case DTYPE_SOCKET:
457 		error = soo_stat((struct socket *)fp->f_data, &stb);
458 		if (error == 0) {
459 			vattr_null(vap);
460 			vap->va_type = VSOCK;
461 			vap->va_mode = stb.st_mode;
462 			vap->va_nlink = stb.st_nlink;
463 			vap->va_uid = stb.st_uid;
464 			vap->va_gid = stb.st_gid;
465 			vap->va_fsid = stb.st_dev;
466 			vap->va_fileid = stb.st_ino;
467 			vap->va_size = stb.st_size;
468 			vap->va_blocksize = stb.st_blksize;
469 			vap->va_atime = stb.st_atimespec;
470 			vap->va_mtime = stb.st_mtimespec;
471 			vap->va_ctime = stb.st_ctimespec;
472 			vap->va_gen = stb.st_gen;
473 			vap->va_flags = stb.st_flags;
474 			vap->va_rdev = stb.st_rdev;
475 			vap->va_bytes = stb.st_blocks * stb.st_blksize;
476 		}
477 		break;
478 
479 	default:
480 		panic("fdesc attr");
481 		break;
482 	}
483 
484 	return (error);
485 }
486 
487 int
488 fdesc_getattr(v)
489 	void *v;
490 {
491 	struct vop_getattr_args /* {
492 		struct vnode *a_vp;
493 		struct vattr *a_vap;
494 		struct ucred *a_cred;
495 		struct proc *a_p;
496 	} */ *ap = v;
497 	struct vnode *vp = ap->a_vp;
498 	struct vattr *vap = ap->a_vap;
499 	unsigned fd;
500 	int error = 0;
501 
502 	switch (VTOFDESC(vp)->fd_type) {
503 	case Froot:
504 	case Fdevfd:
505 	case Flink:
506 	case Fctty:
507 		VATTR_NULL(vap);
508 		vap->va_fileid = VTOFDESC(vp)->fd_ix;
509 
510 #define R_ALL (S_IRUSR|S_IRGRP|S_IROTH)
511 #define W_ALL (S_IWUSR|S_IWGRP|S_IWOTH)
512 #define X_ALL (S_IXUSR|S_IXGRP|S_IXOTH)
513 
514 		switch (VTOFDESC(vp)->fd_type) {
515 		case Flink:
516 			vap->va_mode = R_ALL|X_ALL;
517 			vap->va_type = VLNK;
518 			vap->va_rdev = 0;
519 			vap->va_nlink = 1;
520 			vap->va_size = strlen(VTOFDESC(vp)->fd_link);
521 			break;
522 
523 		case Fctty:
524 			vap->va_mode = R_ALL|W_ALL;
525 			vap->va_type = VCHR;
526 			vap->va_rdev = devctty;
527 			vap->va_nlink = 1;
528 			vap->va_size = 0;
529 			break;
530 
531 		default:
532 			vap->va_mode = R_ALL|X_ALL;
533 			vap->va_type = VDIR;
534 			vap->va_rdev = 0;
535 			vap->va_nlink = 2;
536 			vap->va_size = DEV_BSIZE;
537 			break;
538 		}
539 		vap->va_uid = 0;
540 		vap->va_gid = 0;
541 		vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
542 		vap->va_blocksize = DEV_BSIZE;
543 		vap->va_atime.tv_sec = boottime.tv_sec;
544 		vap->va_atime.tv_nsec = 0;
545 		vap->va_mtime = vap->va_atime;
546 		vap->va_ctime = vap->va_mtime;
547 		vap->va_gen = 0;
548 		vap->va_flags = 0;
549 		vap->va_bytes = 0;
550 		break;
551 
552 	case Fdesc:
553 		fd = VTOFDESC(vp)->fd_fd;
554 		error = fdesc_attr(fd, vap, ap->a_cred, ap->a_p);
555 		break;
556 
557 	default:
558 		panic("fdesc_getattr");
559 		break;
560 	}
561 
562 	if (error == 0)
563 		vp->v_type = vap->va_type;
564 
565 	return (error);
566 }
567 
568 int
569 fdesc_setattr(v)
570 	void *v;
571 {
572 	struct vop_setattr_args /* {
573 		struct vnode *a_vp;
574 		struct vattr *a_vap;
575 		struct ucred *a_cred;
576 		struct proc *a_p;
577 	} */ *ap = v;
578 	struct filedesc *fdp = ap->a_p->p_fd;
579 	struct file *fp;
580 	unsigned fd;
581 	int error;
582 
583 	/*
584 	 * Can't mess with the root vnode
585 	 */
586 	switch (VTOFDESC(ap->a_vp)->fd_type) {
587 	case Fdesc:
588 		break;
589 
590 	case Fctty:
591 		return (0);
592 
593 	default:
594 		return (EACCES);
595 	}
596 
597 	fd = VTOFDESC(ap->a_vp)->fd_fd;
598 	if (fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL) {
599 		return (EBADF);
600 	}
601 
602 	/*
603 	 * Can setattr the underlying vnode, but not sockets!
604 	 */
605 	switch (fp->f_type) {
606 	case DTYPE_VNODE:
607 		error = VOP_SETATTR((struct vnode *) fp->f_data, ap->a_vap, ap->a_cred, ap->a_p);
608 		break;
609 
610 	case DTYPE_SOCKET:
611 		error = 0;
612 		break;
613 
614 	default:
615 		panic("fdesc setattr");
616 		break;
617 	}
618 
619 	return (error);
620 }
621 
622 #define UIO_MX 32
623 
624 struct fdesc_target {
625 	ino_t ft_fileno;
626 	u_char ft_type;
627 	u_char ft_namlen;
628 	char *ft_name;
629 } fdesc_targets[] = {
630 /* NOTE: The name must be less than UIO_MX-16 chars in length */
631 #define N(s) sizeof(s)-1, s
632 	{ FD_DEVFD,  DT_DIR,     N("fd")     },
633 	{ FD_STDIN,  DT_LNK,     N("stdin")  },
634 	{ FD_STDOUT, DT_LNK,     N("stdout") },
635 	{ FD_STDERR, DT_LNK,     N("stderr") },
636 	{ FD_CTTY,   DT_UNKNOWN, N("tty")    },
637 #undef N
638 };
639 static int nfdesc_targets = sizeof(fdesc_targets) / sizeof(fdesc_targets[0]);
640 
641 int
642 fdesc_readdir(v)
643 	void *v;
644 {
645 	struct vop_readdir_args /* {
646 		struct vnode *a_vp;
647 		struct uio *a_uio;
648 		struct ucred *a_cred;
649 		int *a_eofflag;
650 		u_long *a_cookies;
651 		int a_ncookies;
652 	} */ *ap = v;
653 	struct uio *uio = ap->a_uio;
654 	struct dirent d;
655 	struct filedesc *fdp;
656 	int i;
657 	int error;
658 	u_long *cookies = ap->a_cookies;
659 	int ncookies = ap->a_ncookies;
660 
661 	switch (VTOFDESC(ap->a_vp)->fd_type) {
662 	case Fctty:
663 		return (0);
664 
665 	case Fdesc:
666 		return (ENOTDIR);
667 
668 	default:
669 		break;
670 	}
671 
672 	fdp = uio->uio_procp->p_fd;
673 
674 	if (uio->uio_resid < UIO_MX)
675 		return (EINVAL);
676 	if (uio->uio_offset < 0)
677 		return (EINVAL);
678 
679 	error = 0;
680 	i = uio->uio_offset;
681 	bzero((caddr_t)&d, UIO_MX);
682 	d.d_reclen = UIO_MX;
683 
684 	if (VTOFDESC(ap->a_vp)->fd_type == Froot) {
685 		struct fdesc_target *ft;
686 
687 		for (ft = &fdesc_targets[i];
688 		     uio->uio_resid >= UIO_MX && i < nfdesc_targets; ft++, i++) {
689 			switch (ft->ft_fileno) {
690 			case FD_CTTY:
691 				if (cttyvp(uio->uio_procp) == NULL)
692 					continue;
693 				break;
694 
695 			case FD_STDIN:
696 			case FD_STDOUT:
697 			case FD_STDERR:
698 				if ((ft->ft_fileno - FD_STDIN) >= fdp->fd_nfiles)
699 					continue;
700 				if (fdp->fd_ofiles[ft->ft_fileno - FD_STDIN] == NULL)
701 					continue;
702 				break;
703 			}
704 
705 			d.d_fileno = ft->ft_fileno;
706 			d.d_namlen = ft->ft_namlen;
707 			bcopy(ft->ft_name, d.d_name, ft->ft_namlen + 1);
708 			d.d_type = ft->ft_type;
709 
710 			if ((error = uiomove((caddr_t)&d, UIO_MX, uio)) != 0)
711 				break;
712 			if (ncookies-- > 0)
713 				*cookies++ = i + 1;
714 		}
715 	} else {
716 		for (; i - 2 < fdp->fd_nfiles && uio->uio_resid >= UIO_MX;
717 		     i++) {
718 			switch (i) {
719 			case 0:
720 			case 1:
721 				d.d_fileno = FD_ROOT;		/* XXX */
722 				d.d_namlen = i + 1;
723 				bcopy("..", d.d_name, d.d_namlen);
724 				d.d_name[i + 1] = '\0';
725 				d.d_type = DT_DIR;
726 				break;
727 
728 			default:
729 				if (fdp->fd_ofiles[i - 2] == NULL)
730 					continue;
731 				d.d_fileno = i - 2 + FD_STDIN;
732 				d.d_namlen = sprintf(d.d_name, "%d", i - 2);
733 				d.d_type = DT_UNKNOWN;
734 				break;
735 			}
736 
737 			if ((error = uiomove((caddr_t)&d, UIO_MX, uio)) != 0)
738 				break;
739 			if (ncookies-- > 0)
740 				*cookies++ = i + 1;
741 		}
742 	}
743 
744 	uio->uio_offset = i;
745 	return (error);
746 }
747 
748 int
749 fdesc_readlink(v)
750 	void *v;
751 {
752 	struct vop_readlink_args /* {
753 		struct vnode *a_vp;
754 		struct uio *a_uio;
755 		struct ucred *a_cred;
756 	} */ *ap = v;
757 	struct vnode *vp = ap->a_vp;
758 	int error;
759 
760 	if (vp->v_type != VLNK)
761 		return (EPERM);
762 
763 	if (VTOFDESC(vp)->fd_type == Flink) {
764 		char *ln = VTOFDESC(vp)->fd_link;
765 		error = uiomove(ln, strlen(ln), ap->a_uio);
766 	} else {
767 		error = EOPNOTSUPP;
768 	}
769 
770 	return (error);
771 }
772 
773 int
774 fdesc_read(v)
775 	void *v;
776 {
777 	struct vop_read_args /* {
778 		struct vnode *a_vp;
779 		struct uio *a_uio;
780 		int  a_ioflag;
781 		struct ucred *a_cred;
782 	} */ *ap = v;
783 	int error = EOPNOTSUPP;
784 
785 	switch (VTOFDESC(ap->a_vp)->fd_type) {
786 	case Fctty:
787 		error = cttyread(devctty, ap->a_uio, ap->a_ioflag);
788 		break;
789 
790 	default:
791 		error = EOPNOTSUPP;
792 		break;
793 	}
794 
795 	return (error);
796 }
797 
798 int
799 fdesc_write(v)
800 	void *v;
801 {
802 	struct vop_write_args /* {
803 		struct vnode *a_vp;
804 		struct uio *a_uio;
805 		int  a_ioflag;
806 		struct ucred *a_cred;
807 	} */ *ap = v;
808 	int error = EOPNOTSUPP;
809 
810 	switch (VTOFDESC(ap->a_vp)->fd_type) {
811 	case Fctty:
812 		error = cttywrite(devctty, ap->a_uio, ap->a_ioflag);
813 		break;
814 
815 	default:
816 		error = EOPNOTSUPP;
817 		break;
818 	}
819 
820 	return (error);
821 }
822 
823 int
824 fdesc_ioctl(v)
825 	void *v;
826 {
827 	struct vop_ioctl_args /* {
828 		struct vnode *a_vp;
829 		u_long a_command;
830 		caddr_t  a_data;
831 		int  a_fflag;
832 		struct ucred *a_cred;
833 		struct proc *a_p;
834 	} */ *ap = v;
835 	int error = EOPNOTSUPP;
836 
837 	switch (VTOFDESC(ap->a_vp)->fd_type) {
838 	case Fctty:
839 		error = cttyioctl(devctty, ap->a_command, ap->a_data,
840 				  ap->a_fflag, ap->a_p);
841 		break;
842 
843 	default:
844 		error = EOPNOTSUPP;
845 		break;
846 	}
847 
848 	return (error);
849 }
850 
851 int
852 fdesc_poll(v)
853 	void *v;
854 {
855 	struct vop_poll_args /* {
856 		struct vnode *a_vp;
857 		int a_events;
858 		struct proc *a_p;
859 	} */ *ap = v;
860 	int revents;
861 
862 	switch (VTOFDESC(ap->a_vp)->fd_type) {
863 	case Fctty:
864 		revents = cttypoll(devctty, ap->a_events, ap->a_p);
865 		break;
866 
867 	default:
868 		revents = genfs_poll(v);
869 		break;
870 	}
871 
872 	return (revents);
873 }
874 
875 int
876 fdesc_inactive(v)
877 	void *v;
878 {
879 	struct vop_inactive_args /* {
880 		struct vnode *a_vp;
881 	} */ *ap = v;
882 	struct vnode *vp = ap->a_vp;
883 
884 	/*
885 	 * Clear out the v_type field to avoid
886 	 * nasty things happening in vgone().
887 	 */
888 	vp->v_type = VNON;
889 	return (0);
890 }
891 
892 int
893 fdesc_reclaim(v)
894 	void *v;
895 {
896 	struct vop_reclaim_args /* {
897 		struct vnode *a_vp;
898 	} */ *ap = v;
899 	struct vnode *vp = ap->a_vp;
900 	struct fdescnode *fd = VTOFDESC(vp);
901 
902 	LIST_REMOVE(fd, fd_hash);
903 	FREE(vp->v_data, M_TEMP);
904 	vp->v_data = 0;
905 
906 	return (0);
907 }
908 
909 /*
910  * Return POSIX pathconf information applicable to special devices.
911  */
912 int
913 fdesc_pathconf(v)
914 	void *v;
915 {
916 	struct vop_pathconf_args /* {
917 		struct vnode *a_vp;
918 		int a_name;
919 		register_t *a_retval;
920 	} */ *ap = v;
921 
922 	switch (ap->a_name) {
923 	case _PC_LINK_MAX:
924 		*ap->a_retval = LINK_MAX;
925 		return (0);
926 	case _PC_MAX_CANON:
927 		*ap->a_retval = MAX_CANON;
928 		return (0);
929 	case _PC_MAX_INPUT:
930 		*ap->a_retval = MAX_INPUT;
931 		return (0);
932 	case _PC_PIPE_BUF:
933 		*ap->a_retval = PIPE_BUF;
934 		return (0);
935 	case _PC_CHOWN_RESTRICTED:
936 		*ap->a_retval = 1;
937 		return (0);
938 	case _PC_VDISABLE:
939 		*ap->a_retval = _POSIX_VDISABLE;
940 		return (0);
941 	default:
942 		return (EINVAL);
943 	}
944 	/* NOTREACHED */
945 }
946 
947 /*
948  * Print out the contents of a /dev/fd vnode.
949  */
950 /* ARGSUSED */
951 int
952 fdesc_print(v)
953 	void *v;
954 {
955 	printf("tag VT_NON, fdesc vnode\n");
956 	return (0);
957 }
958 
959 int
960 fdesc_link(v)
961 	void *v;
962 {
963 	struct vop_link_args /* {
964 		struct vnode *a_dvp;
965 		struct vnode *a_vp;
966 		struct componentname *a_cnp;
967 	} */ *ap = v;
968 
969 	VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
970 	vput(ap->a_dvp);
971 	return (EROFS);
972 }
973 
974 int
975 fdesc_symlink(v)
976 	void *v;
977 {
978 	struct vop_symlink_args /* {
979 		struct vnode *a_dvp;
980 		struct vnode **a_vpp;
981 		struct componentname *a_cnp;
982 		struct vattr *a_vap;
983 		char *a_target;
984 	} */ *ap = v;
985 
986 	VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
987 	vput(ap->a_dvp);
988 	return (EROFS);
989 }
990