xref: /netbsd-src/sys/fs/ptyfs/ptyfs_vnops.c (revision 1c9b56c830954ccf3b57004ac65562e3d6afacf6)
1 /*	$NetBSD: ptyfs_vnops.c,v 1.6 2004/12/18 05:26:41 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1993, 1995
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed 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  *	@(#)procfs_vnops.c	8.18 (Berkeley) 5/21/95
35  */
36 
37 /*
38  * Copyright (c) 1993 Jan-Simon Pendry
39  *
40  * This code is derived from software contributed to Berkeley by
41  * Jan-Simon Pendry.
42  *
43  * Redistribution and use in source and binary forms, with or without
44  * modification, are permitted provided that the following conditions
45  * are met:
46  * 1. Redistributions of source code must retain the above copyright
47  *    notice, this list of conditions and the following disclaimer.
48  * 2. Redistributions in binary form must reproduce the above copyright
49  *    notice, this list of conditions and the following disclaimer in the
50  *    documentation and/or other materials provided with the distribution.
51  * 3. All advertising materials mentioning features or use of this software
52  *    must display the following acknowledgement:
53  *	This product includes software developed by the University of
54  *	California, Berkeley and its contributors.
55  * 4. Neither the name of the University nor the names of its contributors
56  *    may be used to endorse or promote products derived from this software
57  *    without specific prior written permission.
58  *
59  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
69  * SUCH DAMAGE.
70  *
71  *	@(#)procfs_vnops.c	8.18 (Berkeley) 5/21/95
72  */
73 
74 /*
75  * ptyfs vnode interface
76  */
77 
78 #include <sys/cdefs.h>
79 __KERNEL_RCSID(0, "$NetBSD: ptyfs_vnops.c,v 1.6 2004/12/18 05:26:41 christos Exp $");
80 
81 #include <sys/param.h>
82 #include <sys/systm.h>
83 #include <sys/time.h>
84 #include <sys/kernel.h>
85 #include <sys/file.h>
86 #include <sys/filedesc.h>
87 #include <sys/proc.h>
88 #include <sys/vnode.h>
89 #include <sys/namei.h>
90 #include <sys/malloc.h>
91 #include <sys/mount.h>
92 #include <sys/select.h>
93 #include <sys/dirent.h>
94 #include <sys/resourcevar.h>
95 #include <sys/stat.h>
96 #include <sys/conf.h>
97 #include <sys/tty.h>
98 #include <sys/pty.h>
99 
100 #include <uvm/uvm_extern.h>	/* for PAGE_SIZE */
101 
102 #include <machine/reg.h>
103 
104 #include <fs/ptyfs/ptyfs.h>
105 #include <miscfs/genfs/genfs.h>
106 #include <miscfs/specfs/specdev.h>
107 
108 /*
109  * Vnode Operations.
110  *
111  */
112 
113 int	ptyfs_lookup	(void *);
114 #define	ptyfs_create	genfs_eopnotsupp
115 #define	ptyfs_mknod	genfs_eopnotsupp
116 int	ptyfs_open	(void *);
117 int	ptyfs_close	(void *);
118 int	ptyfs_access	(void *);
119 int	ptyfs_getattr	(void *);
120 int	ptyfs_setattr	(void *);
121 int	ptyfs_read	(void *);
122 int	ptyfs_write	(void *);
123 #define	ptyfs_fcntl	genfs_fcntl
124 int	ptyfs_ioctl	(void *);
125 int	ptyfs_poll	(void *);
126 int	ptyfs_kqfilter	(void *);
127 #define ptyfs_revoke	genfs_revoke
128 #define	ptyfs_mmap	genfs_eopnotsupp
129 #define	ptyfs_fsync	genfs_nullop
130 #define	ptyfs_seek	genfs_nullop
131 #define	ptyfs_remove	genfs_eopnotsupp
132 #define	ptyfs_link	genfs_abortop
133 #define	ptyfs_rename	genfs_eopnotsupp
134 #define	ptyfs_mkdir	genfs_eopnotsupp
135 #define	ptyfs_rmdir	genfs_eopnotsupp
136 #define	ptyfs_symlink	genfs_abortop
137 int	ptyfs_readdir	(void *);
138 #define	ptyfs_readlink	genfs_eopnotsupp
139 #define	ptyfs_abortop	genfs_abortop
140 int	ptyfs_reclaim	(void *);
141 #define	ptyfs_lock	genfs_lock
142 #define	ptyfs_unlock	genfs_unlock
143 #define	ptyfs_bmap	genfs_badop
144 #define	ptyfs_strategy	genfs_badop
145 int	ptyfs_print	(void *);
146 int	ptyfs_pathconf	(void *);
147 #define	ptyfs_islocked	genfs_islocked
148 #define	ptyfs_advlock	genfs_einval
149 #define	ptyfs_blkatoff	genfs_eopnotsupp
150 #define	ptyfs_valloc	genfs_eopnotsupp
151 #define	ptyfs_vfree	genfs_nullop
152 #define	ptyfs_truncate	genfs_eopnotsupp
153 int	ptyfs_update	(void *);
154 #define	ptyfs_bwrite	genfs_eopnotsupp
155 #define ptyfs_putpages	genfs_null_putpages
156 
157 static int ptyfs_chown(struct vnode *, uid_t, gid_t, struct ucred *,
158     struct proc *);
159 static int ptyfs_chmod(struct vnode *, mode_t, struct ucred *, struct proc *);
160 static void ptyfs_time(struct ptyfsnode *, struct timespec *,
161     struct timespec *);
162 static int atoi(const char *, size_t);
163 
164 extern const struct cdevsw pts_cdevsw, ptc_cdevsw;
165 
166 /*
167  * ptyfs vnode operations.
168  */
169 int (**ptyfs_vnodeop_p)(void *);
170 const struct vnodeopv_entry_desc ptyfs_vnodeop_entries[] = {
171 	{ &vop_default_desc, vn_default_error },
172 	{ &vop_lookup_desc, ptyfs_lookup },		/* lookup */
173 	{ &vop_create_desc, ptyfs_create },		/* create */
174 	{ &vop_mknod_desc, ptyfs_mknod },		/* mknod */
175 	{ &vop_open_desc, ptyfs_open },			/* open */
176 	{ &vop_close_desc, ptyfs_close },		/* close */
177 	{ &vop_access_desc, ptyfs_access },		/* access */
178 	{ &vop_getattr_desc, ptyfs_getattr },		/* getattr */
179 	{ &vop_setattr_desc, ptyfs_setattr },		/* setattr */
180 	{ &vop_read_desc, ptyfs_read },			/* read */
181 	{ &vop_write_desc, ptyfs_write },		/* write */
182 	{ &vop_ioctl_desc, ptyfs_ioctl },		/* ioctl */
183 	{ &vop_fcntl_desc, ptyfs_fcntl },		/* fcntl */
184 	{ &vop_poll_desc, ptyfs_poll },			/* poll */
185 	{ &vop_kqfilter_desc, ptyfs_kqfilter },		/* kqfilter */
186 	{ &vop_revoke_desc, ptyfs_revoke },		/* revoke */
187 	{ &vop_mmap_desc, ptyfs_mmap },			/* mmap */
188 	{ &vop_fsync_desc, ptyfs_fsync },		/* fsync */
189 	{ &vop_seek_desc, ptyfs_seek },			/* seek */
190 	{ &vop_remove_desc, ptyfs_remove },		/* remove */
191 	{ &vop_link_desc, ptyfs_link },			/* link */
192 	{ &vop_rename_desc, ptyfs_rename },		/* rename */
193 	{ &vop_mkdir_desc, ptyfs_mkdir },		/* mkdir */
194 	{ &vop_rmdir_desc, ptyfs_rmdir },		/* rmdir */
195 	{ &vop_symlink_desc, ptyfs_symlink },		/* symlink */
196 	{ &vop_readdir_desc, ptyfs_readdir },		/* readdir */
197 	{ &vop_readlink_desc, ptyfs_readlink },		/* readlink */
198 	{ &vop_abortop_desc, ptyfs_abortop },		/* abortop */
199 	{ &vop_inactive_desc, spec_inactive },		/* inactive */
200 	{ &vop_reclaim_desc, ptyfs_reclaim },		/* reclaim */
201 	{ &vop_lock_desc, ptyfs_lock },			/* lock */
202 	{ &vop_unlock_desc, ptyfs_unlock },		/* unlock */
203 	{ &vop_bmap_desc, ptyfs_bmap },			/* bmap */
204 	{ &vop_strategy_desc, ptyfs_strategy },		/* strategy */
205 	{ &vop_print_desc, ptyfs_print },		/* print */
206 	{ &vop_islocked_desc, ptyfs_islocked },		/* islocked */
207 	{ &vop_pathconf_desc, ptyfs_pathconf },		/* pathconf */
208 	{ &vop_advlock_desc, ptyfs_advlock },		/* advlock */
209 	{ &vop_blkatoff_desc, ptyfs_blkatoff },		/* blkatoff */
210 	{ &vop_valloc_desc, ptyfs_valloc },		/* valloc */
211 	{ &vop_vfree_desc, ptyfs_vfree },		/* vfree */
212 	{ &vop_truncate_desc, ptyfs_truncate },		/* truncate */
213 	{ &vop_update_desc, ptyfs_update },		/* update */
214 	{ &vop_bwrite_desc, ptyfs_bwrite },		/* bwrite */
215 	{ &vop_putpages_desc, ptyfs_putpages },		/* putpages */
216 	{ NULL, NULL }
217 };
218 const struct vnodeopv_desc ptyfs_vnodeop_opv_desc =
219 	{ &ptyfs_vnodeop_p, ptyfs_vnodeop_entries };
220 
221 /*
222  * _reclaim is called when getnewvnode()
223  * wants to make use of an entry on the vnode
224  * free list.  at this time the filesystem needs
225  * to free any private data and remove the node
226  * from any private lists.
227  */
228 int
229 ptyfs_reclaim(void *v)
230 {
231 	struct vop_reclaim_args /* {
232 		struct vnode *a_vp;
233 	} */ *ap = v;
234 	return ptyfs_freevp(ap->a_vp);
235 }
236 
237 /*
238  * Return POSIX pathconf information applicable to special devices.
239  */
240 int
241 ptyfs_pathconf(void *v)
242 {
243 	struct vop_pathconf_args /* {
244 		struct vnode *a_vp;
245 		int a_name;
246 		register_t *a_retval;
247 	} */ *ap = v;
248 
249 	switch (ap->a_name) {
250 	case _PC_LINK_MAX:
251 		*ap->a_retval = LINK_MAX;
252 		return 0;
253 	case _PC_MAX_CANON:
254 		*ap->a_retval = MAX_CANON;
255 		return 0;
256 	case _PC_MAX_INPUT:
257 		*ap->a_retval = MAX_INPUT;
258 		return 0;
259 	case _PC_PIPE_BUF:
260 		*ap->a_retval = PIPE_BUF;
261 		return 0;
262 	case _PC_CHOWN_RESTRICTED:
263 		*ap->a_retval = 1;
264 		return 0;
265 	case _PC_VDISABLE:
266 		*ap->a_retval = _POSIX_VDISABLE;
267 		return 0;
268 	case _PC_SYNC_IO:
269 		*ap->a_retval = 1;
270 		return 0;
271 	default:
272 		return EINVAL;
273 	}
274 }
275 
276 /*
277  * _print is used for debugging.
278  * just print a readable description
279  * of (vp).
280  */
281 int
282 ptyfs_print(void *v)
283 {
284 	struct vop_print_args /* {
285 		struct vnode *a_vp;
286 	} */ *ap = v;
287 	struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
288 
289 	printf("tag VT_PTYFS, type %d, pty %d\n",
290 	    ptyfs->ptyfs_type, ptyfs->ptyfs_pty);
291 	return 0;
292 }
293 
294 /*
295  * Invent attributes for ptyfsnode (vp) and store
296  * them in (vap).
297  * Directories lengths are returned as zero since
298  * any real length would require the genuine size
299  * to be computed, and nothing cares anyway.
300  *
301  * this is relatively minimal for ptyfs.
302  */
303 int
304 ptyfs_getattr(void *v)
305 {
306 	struct vop_getattr_args /* {
307 		struct vnode *a_vp;
308 		struct vattr *a_vap;
309 		struct ucred *a_cred;
310 		struct proc *a_p;
311 	} */ *ap = v;
312 	struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
313 	struct vattr *vap = ap->a_vap;
314         struct timespec ts;
315 
316 	TIMEVAL_TO_TIMESPEC(&time, &ts);
317 	ptyfs_time(ptyfs, &ts, &ts);
318 
319 	/* start by zeroing out the attributes */
320 	VATTR_NULL(vap);
321 
322 	/* next do all the common fields */
323 	vap->va_type = ap->a_vp->v_type;
324 	vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0];
325 	vap->va_fileid = ptyfs->ptyfs_fileno;
326 	vap->va_gen = 0;
327 	vap->va_flags = 0;
328 	vap->va_nlink = 1;
329 	vap->va_blocksize = PAGE_SIZE;
330 
331 	vap->va_atime = ptyfs->ptyfs_atime;
332 	vap->va_mtime = ptyfs->ptyfs_mtime;
333 	vap->va_ctime = ptyfs->ptyfs_ctime;
334 	vap->va_birthtime = ptyfs->ptyfs_birthtime;
335 	vap->va_mode = ptyfs->ptyfs_mode;
336 	vap->va_flags = ptyfs->ptyfs_flags;
337 	vap->va_uid = ptyfs->ptyfs_uid;
338 	vap->va_gid = ptyfs->ptyfs_gid;
339 
340 	switch (ptyfs->ptyfs_type) {
341 	case PTYFSpts:
342 	case PTYFSptc:
343 		if (pty_isfree(ptyfs->ptyfs_pty, 1))
344 			return ENOENT;
345 		vap->va_bytes = vap->va_size = 0;
346 		vap->va_rdev = ap->a_vp->v_rdev;
347 		break;
348 	case PTYFSroot:
349 		vap->va_rdev = 0;
350 		vap->va_bytes = vap->va_size = DEV_BSIZE;
351 		break;
352 
353 	default:
354 		return EOPNOTSUPP;
355 	}
356 
357 	return 0;
358 }
359 
360 /*ARGSUSED*/
361 int
362 ptyfs_setattr(void *v)
363 {
364 	struct vop_setattr_args /* {
365 		struct vnodeop_desc *a_desc;
366 		struct vnode *a_vp;
367 		struct vattr *a_vap;
368 		struct ucred *a_cred;
369 		struct proc *a_p;
370 	} */ *ap = v;
371 	struct vnode *vp = ap->a_vp;
372 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
373 	struct vattr *vap = ap->a_vap;
374 	struct ucred *cred = ap->a_cred;
375 	struct proc *p = ap->a_p;
376 	int error;
377 
378 	if (vap->va_size != VNOVAL) {
379  		switch (ptyfs->ptyfs_type) {
380  		case PTYFSroot:
381  			return EISDIR;
382  		case PTYFSpts:
383  		case PTYFSptc:
384 			break;
385 		default:
386 			return EINVAL;
387 		}
388 	}
389 
390 	if (vap->va_flags != VNOVAL) {
391 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
392 			return EROFS;
393 		if (cred->cr_uid != ptyfs->ptyfs_uid &&
394 		    (error = suser(cred, &p->p_acflag)) != 0)
395 			return error;
396 		if (cred->cr_uid == 0) {
397 			if ((ptyfs->ptyfs_flags & (SF_IMMUTABLE | SF_APPEND)) &&
398 			    securelevel > 0)
399 				return EPERM;
400 			/* Snapshot flag cannot be set or cleared */
401 			if ((vap->va_flags & SF_SNAPSHOT) !=
402 			    (ptyfs->ptyfs_flags & SF_SNAPSHOT))
403 				return EPERM;
404 			ptyfs->ptyfs_flags = vap->va_flags;
405 		} else {
406 			if ((ptyfs->ptyfs_flags & (SF_IMMUTABLE | SF_APPEND)) ||
407 			    (vap->va_flags & UF_SETTABLE) != vap->va_flags)
408 				return EPERM;
409 			if ((ptyfs->ptyfs_flags & SF_SETTABLE) !=
410 			    (vap->va_flags & SF_SETTABLE))
411 				return EPERM;
412 			ptyfs->ptyfs_flags &= SF_SETTABLE;
413 			ptyfs->ptyfs_flags |= (vap->va_flags & UF_SETTABLE);
414 		}
415 		ptyfs->ptyfs_flag |= PTYFS_CHANGE;
416 		if (vap->va_flags & (IMMUTABLE | APPEND))
417 			return 0;
418 	}
419 	if (ptyfs->ptyfs_flags & (IMMUTABLE | APPEND))
420 		return EPERM;
421 	/*
422 	 * Go through the fields and update iff not VNOVAL.
423 	 */
424 	if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
425 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
426 			return EROFS;
427 		if (ptyfs->ptyfs_type == PTYFSroot)
428 			return EPERM;
429 		error = ptyfs_chown(vp, vap->va_uid, vap->va_gid, cred, p);
430 		if (error)
431 			return error;
432 	}
433 
434 	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL ||
435 	    vap->va_birthtime.tv_sec != VNOVAL) {
436 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
437 			return EROFS;
438 		if ((ptyfs->ptyfs_flags & SF_SNAPSHOT) != 0)
439 			return EPERM;
440 		if (cred->cr_uid != ptyfs->ptyfs_uid &&
441 		    (error = suser(cred, &p->p_acflag)) &&
442 		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
443 		    (error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0))
444 			return (error);
445 		if (vap->va_atime.tv_sec != VNOVAL)
446 			if (!(vp->v_mount->mnt_flag & MNT_NOATIME))
447 				ptyfs->ptyfs_flag |= PTYFS_ACCESS;
448 		if (vap->va_mtime.tv_sec != VNOVAL)
449 			ptyfs->ptyfs_flag |= PTYFS_CHANGE | PTYFS_MODIFY;
450 		if (vap->va_birthtime.tv_sec != VNOVAL)
451 			ptyfs->ptyfs_birthtime = vap->va_birthtime;
452 		ptyfs->ptyfs_flag |= PTYFS_CHANGE;
453 		error = VOP_UPDATE(vp, &vap->va_atime, &vap->va_mtime, 0);
454 		if (error)
455 			return error;
456 	}
457 	if (vap->va_mode != (mode_t)VNOVAL) {
458 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
459 			return EROFS;
460 		if (ptyfs->ptyfs_type == PTYFSroot)
461 			return EPERM;
462 		if ((ptyfs->ptyfs_flags & SF_SNAPSHOT) != 0 &&
463 		    (vap->va_mode &
464 		    (S_IXUSR|S_IWUSR|S_IXGRP|S_IWGRP|S_IXOTH|S_IWOTH)))
465 			return EPERM;
466 		error = ptyfs_chmod(vp, vap->va_mode, cred, p);
467 		if (error)
468 			return error;
469 	}
470 	VN_KNOTE(vp, NOTE_ATTRIB);
471 	return 0;
472 }
473 
474 /*
475  * Change the mode on a file.
476  * Inode must be locked before calling.
477  */
478 static int
479 ptyfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct proc *p)
480 {
481 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
482 	int error;
483 
484 	if (cred->cr_uid != ptyfs->ptyfs_uid &&
485 	    (error = suser(cred, &p->p_acflag)) != 0)
486 		return error;
487 	ptyfs->ptyfs_mode &= ~ALLPERMS;
488 	ptyfs->ptyfs_mode |= (mode & ALLPERMS);
489 	return 0;
490 }
491 
492 /*
493  * Perform chown operation on inode ip;
494  * inode must be locked prior to call.
495  */
496 static int
497 ptyfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred,
498     struct proc *p)
499 {
500 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
501 	int		error;
502 
503 	if (uid == (uid_t)VNOVAL)
504 		uid = ptyfs->ptyfs_uid;
505 	if (gid == (gid_t)VNOVAL)
506 		gid = ptyfs->ptyfs_gid;
507 	/*
508 	 * If we don't own the file, are trying to change the owner
509 	 * of the file, or are not a member of the target group,
510 	 * the caller's credentials must imply super-user privilege
511 	 * or the call fails.
512 	 */
513 	if ((cred->cr_uid != ptyfs->ptyfs_uid || uid != ptyfs->ptyfs_uid ||
514 	    (gid != ptyfs->ptyfs_gid &&
515 	     !(cred->cr_gid == gid || groupmember((gid_t)gid, cred)))) &&
516 	    ((error = suser(cred, &p->p_acflag)) != 0))
517 		return error;
518 
519 	ptyfs->ptyfs_gid = gid;
520 	ptyfs->ptyfs_uid = uid;
521 	return 0;
522 }
523 
524 /*
525  * implement access checking.
526  *
527  * actually, the check for super-user is slightly
528  * broken since it will allow read access to write-only
529  * objects.  this doesn't cause any particular trouble
530  * but does mean that the i/o entry points need to check
531  * that the operation really does make sense.
532  */
533 int
534 ptyfs_access(void *v)
535 {
536 	struct vop_access_args /* {
537 		struct vnode *a_vp;
538 		int a_mode;
539 		struct ucred *a_cred;
540 		struct proc *a_p;
541 	} */ *ap = v;
542 	struct vattr va;
543 	int error;
544 
545 	if ((error = VOP_GETATTR(ap->a_vp, &va, ap->a_cred, ap->a_p)) != 0)
546 		return error;
547 
548 	return vaccess(va.va_type, va.va_mode,
549 	    va.va_uid, va.va_gid, ap->a_mode, ap->a_cred);
550 }
551 
552 /*
553  * lookup.  this is incredibly complicated in the
554  * general case, however for most pseudo-filesystems
555  * very little needs to be done.
556  *
557  * Locking isn't hard here, just poorly documented.
558  *
559  * If we're looking up ".", just vref the parent & return it.
560  *
561  * If we're looking up "..", unlock the parent, and lock "..". If everything
562  * went ok, and we're on the last component and the caller requested the
563  * parent locked, try to re-lock the parent. We do this to prevent lock
564  * races.
565  *
566  * For anything else, get the needed node. Then unlock the parent if not
567  * the last component or not LOCKPARENT (i.e. if we wouldn't re-lock the
568  * parent in the .. case).
569  *
570  * We try to exit with the parent locked in error cases.
571  */
572 int
573 ptyfs_lookup(void *v)
574 {
575 	struct vop_lookup_args /* {
576 		struct vnode * a_dvp;
577 		struct vnode ** a_vpp;
578 		struct componentname * a_cnp;
579 	} */ *ap = v;
580 	struct componentname *cnp = ap->a_cnp;
581 	struct vnode **vpp = ap->a_vpp;
582 	struct vnode *dvp = ap->a_dvp;
583 	const char *pname = cnp->cn_nameptr;
584 	struct ptyfsnode *ptyfs;
585 	int pty, error, wantpunlock;
586 
587 	*vpp = NULL;
588 	cnp->cn_flags &= ~PDIRUNLOCK;
589 
590 	if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)
591 		return EROFS;
592 
593 	if (cnp->cn_namelen == 1 && *pname == '.') {
594 		*vpp = dvp;
595 		VREF(dvp);
596 		return 0;
597 	}
598 
599 	wantpunlock = ~cnp->cn_flags & (LOCKPARENT | ISLASTCN);
600 	ptyfs = VTOPTYFS(dvp);
601 	switch (ptyfs->ptyfs_type) {
602 	case PTYFSroot:
603 		/*
604 		 * Shouldn't get here with .. in the root node.
605 		 */
606 		if (cnp->cn_flags & ISDOTDOT)
607 			return EIO;
608 
609 		pty = atoi(pname, cnp->cn_namelen);
610 
611 		if (pty < 0 || pty >= npty || pty_isfree(pty, 1))
612 			break;
613 
614 		error = ptyfs_allocvp(dvp->v_mount, vpp, PTYFSpts, pty,
615 		    curproc);
616 		if (error == 0 && wantpunlock) {
617 			VOP_UNLOCK(dvp, 0);
618 			cnp->cn_flags |= PDIRUNLOCK;
619 		}
620 		return error;
621 
622 	default:
623 		return ENOTDIR;
624 	}
625 
626 	return cnp->cn_nameiop == LOOKUP ? ENOENT : EROFS;
627 }
628 
629 /*
630  * readdir returns directory entries from ptyfsnode (vp).
631  *
632  * the strategy here with ptyfs is to generate a single
633  * directory entry at a time (struct dirent) and then
634  * copy that out to userland using uiomove.  a more efficent
635  * though more complex implementation, would try to minimize
636  * the number of calls to uiomove().  for ptyfs, this is
637  * hardly worth the added code complexity.
638  *
639  * this should just be done through read()
640  */
641 int
642 ptyfs_readdir(void *v)
643 {
644 	struct vop_readdir_args /* {
645 		struct vnode *a_vp;
646 		struct uio *a_uio;
647 		struct ucred *a_cred;
648 		int *a_eofflag;
649 		off_t **a_cookies;
650 		int *a_ncookies;
651 	} */ *ap = v;
652 	struct uio *uio = ap->a_uio;
653 	struct dirent d;
654 	struct ptyfsnode *ptyfs;
655 	off_t i;
656 	int error;
657 	off_t *cookies = NULL;
658 	int ncookies;
659 	struct vnode *vp;
660 	int nc = 0;
661 
662 	vp = ap->a_vp;
663 	ptyfs = VTOPTYFS(vp);
664 
665 	if (uio->uio_resid < UIO_MX)
666 		return EINVAL;
667 	if (uio->uio_offset < 0)
668 		return EINVAL;
669 
670 	error = 0;
671 	i = uio->uio_offset;
672 	(void)memset(&d, 0, sizeof(d));
673 	d.d_reclen = UIO_MX;
674 	ncookies = uio->uio_resid / UIO_MX;
675 
676 	switch (ptyfs->ptyfs_type) {
677 	case PTYFSroot: /* root */
678 
679 		if (i >= npty)
680 			return 0;
681 
682 		if (ap->a_ncookies) {
683 			ncookies = min(ncookies, (npty + 2 - i));
684 			cookies = malloc(ncookies * sizeof (off_t),
685 			    M_TEMP, M_WAITOK);
686 			*ap->a_cookies = cookies;
687 		}
688 
689 		for (; i < 2; i++) {
690 			switch (i) {
691 			case 0:		/* `.' */
692 			case 1:		/* `..' */
693 				d.d_fileno = PTYFS_FILENO(0, PTYFSroot);
694 				d.d_namlen = i + 1;
695 				(void)memcpy(d.d_name, "..", d.d_namlen);
696 				d.d_name[i + 1] = '\0';
697 				d.d_type = DT_DIR;
698 				break;
699 			}
700 			if ((error = uiomove(&d, UIO_MX, uio)) != 0)
701 				break;
702 			if (cookies)
703 				*cookies++ = i + 1;
704 			nc++;
705 		}
706 		if (error) {
707 			ncookies = nc;
708 			break;
709 		}
710 		for (; uio->uio_resid >= UIO_MX && i < npty; i++) {
711 			/* check for used ptys */
712 			if (pty_isfree(i - 2, 1))
713 				continue;
714 
715 			d.d_fileno = PTYFS_FILENO(i - 2, PTYFSpts);
716 			d.d_namlen = snprintf(d.d_name, sizeof(d.d_name),
717 			    "%lld", (long long)(i - 2));
718 			d.d_type = DT_CHR;
719 			if ((error = uiomove(&d, UIO_MX, uio)) != 0)
720 				break;
721 			if (cookies)
722 				*cookies++ = i + 1;
723 			nc++;
724 		}
725 		ncookies = nc;
726 		break;
727 
728 	default:
729 		error = ENOTDIR;
730 		break;
731 	}
732 
733 	if (ap->a_ncookies) {
734 		if (error) {
735 			if (cookies)
736 				free(*ap->a_cookies, M_TEMP);
737 			*ap->a_ncookies = 0;
738 			*ap->a_cookies = NULL;
739 		} else
740 			*ap->a_ncookies = ncookies;
741 	}
742 	uio->uio_offset = i;
743 	return error;
744 }
745 
746 int
747 ptyfs_open(void *v)
748 {
749 	struct vop_open_args /* {
750 		struct vnode *a_vp;
751 		int  a_mode;
752 		struct ucred *a_cred;
753 		struct proc *a_p;
754 	} */ *ap = v;
755 	struct vnode *vp = ap->a_vp;
756 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
757 
758 	ptyfs->ptyfs_flag |= PTYFS_CHANGE|PTYFS_ACCESS;
759 	switch (ptyfs->ptyfs_type) {
760 	case PTYFSpts:
761 	case PTYFSptc:
762 		return spec_open(v);
763 	case PTYFSroot:
764 		return 0;
765 	default:
766 		return EINVAL;
767 	}
768 }
769 
770 int
771 ptyfs_close(void *v)
772 {
773 	struct vop_close_args /* {
774 		struct vnode *a_vp;
775 		int  a_fflag;
776 		struct ucred *a_cred;
777 		struct proc *a_p;
778 	} */ *ap = v;
779 	struct vnode *vp = ap->a_vp;
780 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
781         struct timespec ts;
782 
783         simple_lock(&vp->v_interlock);
784         if (vp->v_usecount > 1) {
785 		TIMEVAL_TO_TIMESPEC(&time, &ts);
786 		ptyfs_time(ptyfs, &ts, &ts);
787         }
788         simple_unlock(&vp->v_interlock);
789 
790 	switch (ptyfs->ptyfs_type) {
791 	case PTYFSpts:
792 	case PTYFSptc:
793 		return spec_close(v);
794 	case PTYFSroot:
795 		return 0;
796 	default:
797 		return EINVAL;
798 	}
799 }
800 
801 int
802 ptyfs_read(void *v)
803 {
804 	struct vop_read_args /* {
805 		struct vnode *a_vp;
806 		struct uio *a_uio;
807 		int  a_ioflag;
808 		struct ucred *a_cred;
809 	} */ *ap = v;
810 	struct vnode *vp = ap->a_vp;
811 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
812 	int error;
813 
814 	ptyfs->ptyfs_flag |= PTYFS_ACCESS;
815 	switch (ptyfs->ptyfs_type) {
816 	case PTYFSpts:
817 		VOP_UNLOCK(vp, 0);
818 		error = (*pts_cdevsw.d_read)(vp->v_rdev, ap->a_uio,
819 		    ap->a_ioflag);
820 		vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
821 		return error;
822 	case PTYFSptc:
823 		VOP_UNLOCK(vp, 0);
824 		error = (*ptc_cdevsw.d_read)(vp->v_rdev, ap->a_uio,
825 		    ap->a_ioflag);
826 		vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
827 		return error;
828 	default:
829 		return EOPNOTSUPP;
830 	}
831 }
832 
833 int
834 ptyfs_write(void *v)
835 {
836 	struct vop_write_args /* {
837 		struct vnode *a_vp;
838 		struct uio *a_uio;
839 		int  a_ioflag;
840 		struct ucred *a_cred;
841 	} */ *ap = v;
842 	int error;
843 	struct vnode *vp = ap->a_vp;
844 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
845 
846 	ptyfs->ptyfs_flag |= PTYFS_MODIFY;
847 	switch (ptyfs->ptyfs_type) {
848 	case PTYFSpts:
849 		VOP_UNLOCK(vp, 0);
850 		error = (*pts_cdevsw.d_write)(vp->v_rdev, ap->a_uio,
851 		    ap->a_ioflag);
852 		vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
853 		return error;
854 	case PTYFSptc:
855 		VOP_UNLOCK(vp, 0);
856 		error = (*ptc_cdevsw.d_write)(vp->v_rdev, ap->a_uio,
857 		    ap->a_ioflag);
858 		vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
859 		return error;
860 	default:
861 		return EOPNOTSUPP;
862 	}
863 }
864 
865 int
866 ptyfs_ioctl(void *v)
867 {
868 	struct vop_ioctl_args /* {
869 		struct vnode *a_vp;
870 		u_long a_command;
871 		void *a_data;
872 		int  a_fflag;
873 		struct ucred *a_cred;
874 		struct proc *a_p;
875 	} */ *ap = v;
876 	struct vnode *vp = ap->a_vp;
877 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
878 
879 	switch (ptyfs->ptyfs_type) {
880 	case PTYFSpts:
881 		return (*pts_cdevsw.d_ioctl)(vp->v_rdev, ap->a_command,
882 		    ap->a_data, ap->a_fflag, ap->a_p);
883 	case PTYFSptc:
884 		return (*ptc_cdevsw.d_ioctl)(vp->v_rdev, ap->a_command,
885 		    ap->a_data, ap->a_fflag, ap->a_p);
886 	default:
887 		return EOPNOTSUPP;
888 	}
889 }
890 
891 int
892 ptyfs_poll(void *v)
893 {
894 	struct vop_poll_args /* {
895 		struct vnode *a_vp;
896 		int a_events;
897 		struct proc *a_p;
898 	} */ *ap = v;
899 	struct vnode *vp = ap->a_vp;
900 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
901 
902 	switch (ptyfs->ptyfs_type) {
903 	case PTYFSpts:
904 		return (*pts_cdevsw.d_poll)(vp->v_rdev, ap->a_events, ap->a_p);
905 	case PTYFSptc:
906 		return (*ptc_cdevsw.d_poll)(vp->v_rdev, ap->a_events, ap->a_p);
907 	default:
908 		return genfs_poll(v);
909 	}
910 }
911 
912 int
913 ptyfs_kqfilter(void *v)
914 {
915 	struct vop_kqfilter_args /* {
916 		struct vnode *a_vp;
917 		struct knote *a_kn;
918 	} */ *ap = v;
919 	struct vnode *vp = ap->a_vp;
920 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
921 
922 	switch (ptyfs->ptyfs_type) {
923 	case PTYFSpts:
924 		return (*pts_cdevsw.d_kqfilter)(vp->v_rdev, ap->a_kn);
925 	case PTYFSptc:
926 		return (*ptc_cdevsw.d_kqfilter)(vp->v_rdev, ap->a_kn);
927 	default:
928 		return genfs_kqfilter(v);
929 	}
930 }
931 
932 int
933 ptyfs_update(v)
934 	void *v;
935 {
936 	struct vop_update_args /* {
937 		struct vnode *a_vp;
938 		struct timespec *a_access;
939 		struct timespec *a_modify;
940 		int a_flags;
941 	} */ *ap = v;
942 	struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
943 	struct timespec ts;
944 
945 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
946 		return 0;
947 
948 	TIMEVAL_TO_TIMESPEC(&time, &ts);
949 	if (ap->a_access == NULL)
950 		ap->a_access = &ts;
951 	if (ap->a_modify == NULL)
952 		ap->a_modify = &ts;
953 	ptyfs_time(ptyfs, ap->a_access, ap->a_modify);
954 	return 0;
955 }
956 
957 static void
958 ptyfs_time(struct ptyfsnode *ptyfs, struct timespec *atime,
959     struct timespec *mtime)
960 {
961 	if (ptyfs->ptyfs_flag & PTYFS_MODIFY) {
962 		ptyfs->ptyfs_mtime = *mtime;
963 		ptyfs->ptyfs_atime = *atime;
964 	} else if (ptyfs->ptyfs_flag & PTYFS_ACCESS)
965 		ptyfs->ptyfs_atime = *atime;
966 	if (ptyfs->ptyfs_flag & PTYFS_CHANGE)
967 		ptyfs->ptyfs_ctime = *atime;
968 	ptyfs->ptyfs_flag = 0;
969 }
970 
971 /*
972  * convert decimal ascii to int
973  */
974 static int
975 atoi(const char *b, size_t len)
976 {
977 	int p = 0;
978 
979 	while (len--) {
980 		char c = *b++;
981 		if (c < '0' || c > '9')
982 			return -1;
983 		p = 10 * p + (c - '0');
984 	}
985 
986 	return p;
987 }
988