xref: /netbsd-src/sys/fs/ptyfs/ptyfs_vnops.c (revision 5b84b3983f71fd20a534cfa5d1556623a8aaa717)
1 /*	$NetBSD: ptyfs_vnops.c,v 1.9 2005/09/12 16:42:09 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 1.9 2005/09/12 16:42:09 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 int atoi(const char *, size_t);
161 
162 extern const struct cdevsw pts_cdevsw, ptc_cdevsw;
163 
164 /*
165  * ptyfs vnode operations.
166  */
167 int (**ptyfs_vnodeop_p)(void *);
168 const struct vnodeopv_entry_desc ptyfs_vnodeop_entries[] = {
169 	{ &vop_default_desc, vn_default_error },
170 	{ &vop_lookup_desc, ptyfs_lookup },		/* lookup */
171 	{ &vop_create_desc, ptyfs_create },		/* create */
172 	{ &vop_mknod_desc, ptyfs_mknod },		/* mknod */
173 	{ &vop_open_desc, ptyfs_open },			/* open */
174 	{ &vop_close_desc, ptyfs_close },		/* close */
175 	{ &vop_access_desc, ptyfs_access },		/* access */
176 	{ &vop_getattr_desc, ptyfs_getattr },		/* getattr */
177 	{ &vop_setattr_desc, ptyfs_setattr },		/* setattr */
178 	{ &vop_read_desc, ptyfs_read },			/* read */
179 	{ &vop_write_desc, ptyfs_write },		/* write */
180 	{ &vop_ioctl_desc, ptyfs_ioctl },		/* ioctl */
181 	{ &vop_fcntl_desc, ptyfs_fcntl },		/* fcntl */
182 	{ &vop_poll_desc, ptyfs_poll },			/* poll */
183 	{ &vop_kqfilter_desc, ptyfs_kqfilter },		/* kqfilter */
184 	{ &vop_revoke_desc, ptyfs_revoke },		/* revoke */
185 	{ &vop_mmap_desc, ptyfs_mmap },			/* mmap */
186 	{ &vop_fsync_desc, ptyfs_fsync },		/* fsync */
187 	{ &vop_seek_desc, ptyfs_seek },			/* seek */
188 	{ &vop_remove_desc, ptyfs_remove },		/* remove */
189 	{ &vop_link_desc, ptyfs_link },			/* link */
190 	{ &vop_rename_desc, ptyfs_rename },		/* rename */
191 	{ &vop_mkdir_desc, ptyfs_mkdir },		/* mkdir */
192 	{ &vop_rmdir_desc, ptyfs_rmdir },		/* rmdir */
193 	{ &vop_symlink_desc, ptyfs_symlink },		/* symlink */
194 	{ &vop_readdir_desc, ptyfs_readdir },		/* readdir */
195 	{ &vop_readlink_desc, ptyfs_readlink },		/* readlink */
196 	{ &vop_abortop_desc, ptyfs_abortop },		/* abortop */
197 	{ &vop_inactive_desc, spec_inactive },		/* inactive */
198 	{ &vop_reclaim_desc, ptyfs_reclaim },		/* reclaim */
199 	{ &vop_lock_desc, ptyfs_lock },			/* lock */
200 	{ &vop_unlock_desc, ptyfs_unlock },		/* unlock */
201 	{ &vop_bmap_desc, ptyfs_bmap },			/* bmap */
202 	{ &vop_strategy_desc, ptyfs_strategy },		/* strategy */
203 	{ &vop_print_desc, ptyfs_print },		/* print */
204 	{ &vop_islocked_desc, ptyfs_islocked },		/* islocked */
205 	{ &vop_pathconf_desc, ptyfs_pathconf },		/* pathconf */
206 	{ &vop_advlock_desc, ptyfs_advlock },		/* advlock */
207 	{ &vop_blkatoff_desc, ptyfs_blkatoff },		/* blkatoff */
208 	{ &vop_valloc_desc, ptyfs_valloc },		/* valloc */
209 	{ &vop_vfree_desc, ptyfs_vfree },		/* vfree */
210 	{ &vop_truncate_desc, ptyfs_truncate },		/* truncate */
211 	{ &vop_update_desc, ptyfs_update },		/* update */
212 	{ &vop_bwrite_desc, ptyfs_bwrite },		/* bwrite */
213 	{ &vop_putpages_desc, ptyfs_putpages },		/* putpages */
214 	{ NULL, NULL }
215 };
216 const struct vnodeopv_desc ptyfs_vnodeop_opv_desc =
217 	{ &ptyfs_vnodeop_p, ptyfs_vnodeop_entries };
218 
219 /*
220  * _reclaim is called when getnewvnode()
221  * wants to make use of an entry on the vnode
222  * free list.  at this time the filesystem needs
223  * to free any private data and remove the node
224  * from any private lists.
225  */
226 int
227 ptyfs_reclaim(void *v)
228 {
229 	struct vop_reclaim_args /* {
230 		struct vnode *a_vp;
231 	} */ *ap = v;
232 	return ptyfs_freevp(ap->a_vp);
233 }
234 
235 /*
236  * Return POSIX pathconf information applicable to special devices.
237  */
238 int
239 ptyfs_pathconf(void *v)
240 {
241 	struct vop_pathconf_args /* {
242 		struct vnode *a_vp;
243 		int a_name;
244 		register_t *a_retval;
245 	} */ *ap = v;
246 
247 	switch (ap->a_name) {
248 	case _PC_LINK_MAX:
249 		*ap->a_retval = LINK_MAX;
250 		return 0;
251 	case _PC_MAX_CANON:
252 		*ap->a_retval = MAX_CANON;
253 		return 0;
254 	case _PC_MAX_INPUT:
255 		*ap->a_retval = MAX_INPUT;
256 		return 0;
257 	case _PC_PIPE_BUF:
258 		*ap->a_retval = PIPE_BUF;
259 		return 0;
260 	case _PC_CHOWN_RESTRICTED:
261 		*ap->a_retval = 1;
262 		return 0;
263 	case _PC_VDISABLE:
264 		*ap->a_retval = _POSIX_VDISABLE;
265 		return 0;
266 	case _PC_SYNC_IO:
267 		*ap->a_retval = 1;
268 		return 0;
269 	default:
270 		return EINVAL;
271 	}
272 }
273 
274 /*
275  * _print is used for debugging.
276  * just print a readable description
277  * of (vp).
278  */
279 int
280 ptyfs_print(void *v)
281 {
282 	struct vop_print_args /* {
283 		struct vnode *a_vp;
284 	} */ *ap = v;
285 	struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
286 
287 	printf("tag VT_PTYFS, type %d, pty %d\n",
288 	    ptyfs->ptyfs_type, ptyfs->ptyfs_pty);
289 	return 0;
290 }
291 
292 /*
293  * Invent attributes for ptyfsnode (vp) and store
294  * them in (vap).
295  * Directories lengths are returned as zero since
296  * any real length would require the genuine size
297  * to be computed, and nothing cares anyway.
298  *
299  * this is relatively minimal for ptyfs.
300  */
301 int
302 ptyfs_getattr(void *v)
303 {
304 	struct vop_getattr_args /* {
305 		struct vnode *a_vp;
306 		struct vattr *a_vap;
307 		struct ucred *a_cred;
308 		struct proc *a_p;
309 	} */ *ap = v;
310 	struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
311 	struct vattr *vap = ap->a_vap;
312 
313 	PTYFS_ITIMES(ptyfs, NULL, NULL, NULL);
314 
315 	/* start by zeroing out the attributes */
316 	VATTR_NULL(vap);
317 
318 	/* next do all the common fields */
319 	vap->va_type = ap->a_vp->v_type;
320 	vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0];
321 	vap->va_fileid = ptyfs->ptyfs_fileno;
322 	vap->va_gen = 0;
323 	vap->va_flags = 0;
324 	vap->va_nlink = 1;
325 	vap->va_blocksize = PAGE_SIZE;
326 
327 	vap->va_atime = ptyfs->ptyfs_atime;
328 	vap->va_mtime = ptyfs->ptyfs_mtime;
329 	vap->va_ctime = ptyfs->ptyfs_ctime;
330 	vap->va_birthtime = ptyfs->ptyfs_birthtime;
331 	vap->va_mode = ptyfs->ptyfs_mode;
332 	vap->va_flags = ptyfs->ptyfs_flags;
333 	vap->va_uid = ptyfs->ptyfs_uid;
334 	vap->va_gid = ptyfs->ptyfs_gid;
335 
336 	switch (ptyfs->ptyfs_type) {
337 	case PTYFSpts:
338 	case PTYFSptc:
339 		if (pty_isfree(ptyfs->ptyfs_pty, 1))
340 			return ENOENT;
341 		vap->va_bytes = vap->va_size = 0;
342 		vap->va_rdev = ap->a_vp->v_rdev;
343 		break;
344 	case PTYFSroot:
345 		vap->va_rdev = 0;
346 		vap->va_bytes = vap->va_size = DEV_BSIZE;
347 		break;
348 
349 	default:
350 		return EOPNOTSUPP;
351 	}
352 
353 	return 0;
354 }
355 
356 /*ARGSUSED*/
357 int
358 ptyfs_setattr(void *v)
359 {
360 	struct vop_setattr_args /* {
361 		struct vnodeop_desc *a_desc;
362 		struct vnode *a_vp;
363 		struct vattr *a_vap;
364 		struct ucred *a_cred;
365 		struct proc *a_p;
366 	} */ *ap = v;
367 	struct vnode *vp = ap->a_vp;
368 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
369 	struct vattr *vap = ap->a_vap;
370 	struct ucred *cred = ap->a_cred;
371 	struct proc *p = ap->a_p;
372 	int error;
373 
374 	if (vap->va_size != VNOVAL) {
375  		switch (ptyfs->ptyfs_type) {
376  		case PTYFSroot:
377  			return EISDIR;
378  		case PTYFSpts:
379  		case PTYFSptc:
380 			break;
381 		default:
382 			return EINVAL;
383 		}
384 	}
385 
386 	if (vap->va_flags != VNOVAL) {
387 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
388 			return EROFS;
389 		if (cred->cr_uid != ptyfs->ptyfs_uid &&
390 		    (error = suser(cred, &p->p_acflag)) != 0)
391 			return error;
392 		if (cred->cr_uid == 0) {
393 			if ((ptyfs->ptyfs_flags & (SF_IMMUTABLE | SF_APPEND)) &&
394 			    securelevel > 0)
395 				return EPERM;
396 			/* Snapshot flag cannot be set or cleared */
397 			if ((vap->va_flags & SF_SNAPSHOT) !=
398 			    (ptyfs->ptyfs_flags & SF_SNAPSHOT))
399 				return EPERM;
400 			ptyfs->ptyfs_flags = vap->va_flags;
401 		} else {
402 			if ((ptyfs->ptyfs_flags & (SF_IMMUTABLE | SF_APPEND)) ||
403 			    (vap->va_flags & UF_SETTABLE) != vap->va_flags)
404 				return EPERM;
405 			if ((ptyfs->ptyfs_flags & SF_SETTABLE) !=
406 			    (vap->va_flags & SF_SETTABLE))
407 				return EPERM;
408 			ptyfs->ptyfs_flags &= SF_SETTABLE;
409 			ptyfs->ptyfs_flags |= (vap->va_flags & UF_SETTABLE);
410 		}
411 		ptyfs->ptyfs_flag |= PTYFS_CHANGE;
412 		if (vap->va_flags & (IMMUTABLE | APPEND))
413 			return 0;
414 	}
415 	if (ptyfs->ptyfs_flags & (IMMUTABLE | APPEND))
416 		return EPERM;
417 	/*
418 	 * Go through the fields and update iff not VNOVAL.
419 	 */
420 	if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
421 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
422 			return EROFS;
423 		if (ptyfs->ptyfs_type == PTYFSroot)
424 			return EPERM;
425 		error = ptyfs_chown(vp, vap->va_uid, vap->va_gid, cred, p);
426 		if (error)
427 			return error;
428 	}
429 
430 	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL ||
431 	    vap->va_birthtime.tv_sec != VNOVAL) {
432 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
433 			return EROFS;
434 		if ((ptyfs->ptyfs_flags & SF_SNAPSHOT) != 0)
435 			return EPERM;
436 		if (cred->cr_uid != ptyfs->ptyfs_uid &&
437 		    (error = suser(cred, &p->p_acflag)) &&
438 		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
439 		    (error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0))
440 			return (error);
441 		if (vap->va_atime.tv_sec != VNOVAL)
442 			if (!(vp->v_mount->mnt_flag & MNT_NOATIME))
443 				ptyfs->ptyfs_flag |= PTYFS_ACCESS;
444 		if (vap->va_mtime.tv_sec != VNOVAL)
445 			ptyfs->ptyfs_flag |= PTYFS_CHANGE | PTYFS_MODIFY;
446 		if (vap->va_birthtime.tv_sec != VNOVAL)
447 			ptyfs->ptyfs_birthtime = vap->va_birthtime;
448 		ptyfs->ptyfs_flag |= PTYFS_CHANGE;
449 		error = VOP_UPDATE(vp, &vap->va_atime, &vap->va_mtime, 0);
450 		if (error)
451 			return error;
452 	}
453 	if (vap->va_mode != (mode_t)VNOVAL) {
454 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
455 			return EROFS;
456 		if (ptyfs->ptyfs_type == PTYFSroot)
457 			return EPERM;
458 		if ((ptyfs->ptyfs_flags & SF_SNAPSHOT) != 0 &&
459 		    (vap->va_mode &
460 		    (S_IXUSR|S_IWUSR|S_IXGRP|S_IWGRP|S_IXOTH|S_IWOTH)))
461 			return EPERM;
462 		error = ptyfs_chmod(vp, vap->va_mode, cred, p);
463 		if (error)
464 			return error;
465 	}
466 	VN_KNOTE(vp, NOTE_ATTRIB);
467 	return 0;
468 }
469 
470 /*
471  * Change the mode on a file.
472  * Inode must be locked before calling.
473  */
474 static int
475 ptyfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct proc *p)
476 {
477 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
478 	int error;
479 
480 	if (cred->cr_uid != ptyfs->ptyfs_uid &&
481 	    (error = suser(cred, &p->p_acflag)) != 0)
482 		return error;
483 	ptyfs->ptyfs_mode &= ~ALLPERMS;
484 	ptyfs->ptyfs_mode |= (mode & ALLPERMS);
485 	return 0;
486 }
487 
488 /*
489  * Perform chown operation on inode ip;
490  * inode must be locked prior to call.
491  */
492 static int
493 ptyfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred,
494     struct proc *p)
495 {
496 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
497 	int		error;
498 
499 	if (uid == (uid_t)VNOVAL)
500 		uid = ptyfs->ptyfs_uid;
501 	if (gid == (gid_t)VNOVAL)
502 		gid = ptyfs->ptyfs_gid;
503 	/*
504 	 * If we don't own the file, are trying to change the owner
505 	 * of the file, or are not a member of the target group,
506 	 * the caller's credentials must imply super-user privilege
507 	 * or the call fails.
508 	 */
509 	if ((cred->cr_uid != ptyfs->ptyfs_uid || uid != ptyfs->ptyfs_uid ||
510 	    (gid != ptyfs->ptyfs_gid &&
511 	     !(cred->cr_gid == gid || groupmember((gid_t)gid, cred)))) &&
512 	    ((error = suser(cred, &p->p_acflag)) != 0))
513 		return error;
514 
515 	ptyfs->ptyfs_gid = gid;
516 	ptyfs->ptyfs_uid = uid;
517 	return 0;
518 }
519 
520 /*
521  * implement access checking.
522  *
523  * actually, the check for super-user is slightly
524  * broken since it will allow read access to write-only
525  * objects.  this doesn't cause any particular trouble
526  * but does mean that the i/o entry points need to check
527  * that the operation really does make sense.
528  */
529 int
530 ptyfs_access(void *v)
531 {
532 	struct vop_access_args /* {
533 		struct vnode *a_vp;
534 		int a_mode;
535 		struct ucred *a_cred;
536 		struct proc *a_p;
537 	} */ *ap = v;
538 	struct vattr va;
539 	int error;
540 
541 	if ((error = VOP_GETATTR(ap->a_vp, &va, ap->a_cred, ap->a_p)) != 0)
542 		return error;
543 
544 	return vaccess(va.va_type, va.va_mode,
545 	    va.va_uid, va.va_gid, ap->a_mode, ap->a_cred);
546 }
547 
548 /*
549  * lookup.  this is incredibly complicated in the
550  * general case, however for most pseudo-filesystems
551  * very little needs to be done.
552  *
553  * Locking isn't hard here, just poorly documented.
554  *
555  * If we're looking up ".", just vref the parent & return it.
556  *
557  * If we're looking up "..", unlock the parent, and lock "..". If everything
558  * went ok, and we're on the last component and the caller requested the
559  * parent locked, try to re-lock the parent. We do this to prevent lock
560  * races.
561  *
562  * For anything else, get the needed node. Then unlock the parent if not
563  * the last component or not LOCKPARENT (i.e. if we wouldn't re-lock the
564  * parent in the .. case).
565  *
566  * We try to exit with the parent locked in error cases.
567  */
568 int
569 ptyfs_lookup(void *v)
570 {
571 	struct vop_lookup_args /* {
572 		struct vnode * a_dvp;
573 		struct vnode ** a_vpp;
574 		struct componentname * a_cnp;
575 	} */ *ap = v;
576 	struct componentname *cnp = ap->a_cnp;
577 	struct vnode **vpp = ap->a_vpp;
578 	struct vnode *dvp = ap->a_dvp;
579 	const char *pname = cnp->cn_nameptr;
580 	struct ptyfsnode *ptyfs;
581 	int pty, error, wantpunlock;
582 
583 	*vpp = NULL;
584 	cnp->cn_flags &= ~PDIRUNLOCK;
585 
586 	if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)
587 		return EROFS;
588 
589 	if (cnp->cn_namelen == 1 && *pname == '.') {
590 		*vpp = dvp;
591 		VREF(dvp);
592 		return 0;
593 	}
594 
595 	wantpunlock = ~cnp->cn_flags & (LOCKPARENT | ISLASTCN);
596 	ptyfs = VTOPTYFS(dvp);
597 	switch (ptyfs->ptyfs_type) {
598 	case PTYFSroot:
599 		/*
600 		 * Shouldn't get here with .. in the root node.
601 		 */
602 		if (cnp->cn_flags & ISDOTDOT)
603 			return EIO;
604 
605 		pty = atoi(pname, cnp->cn_namelen);
606 
607 		if (pty < 0 || pty >= npty || pty_isfree(pty, 1))
608 			break;
609 
610 		error = ptyfs_allocvp(dvp->v_mount, vpp, PTYFSpts, pty,
611 		    curproc);
612 		if (error == 0 && wantpunlock) {
613 			VOP_UNLOCK(dvp, 0);
614 			cnp->cn_flags |= PDIRUNLOCK;
615 		}
616 		return error;
617 
618 	default:
619 		return ENOTDIR;
620 	}
621 
622 	return cnp->cn_nameiop == LOOKUP ? ENOENT : EROFS;
623 }
624 
625 /*
626  * readdir returns directory entries from ptyfsnode (vp).
627  *
628  * the strategy here with ptyfs is to generate a single
629  * directory entry at a time (struct dirent) and then
630  * copy that out to userland using uiomove.  a more efficent
631  * though more complex implementation, would try to minimize
632  * the number of calls to uiomove().  for ptyfs, this is
633  * hardly worth the added code complexity.
634  *
635  * this should just be done through read()
636  */
637 int
638 ptyfs_readdir(void *v)
639 {
640 	struct vop_readdir_args /* {
641 		struct vnode *a_vp;
642 		struct uio *a_uio;
643 		struct ucred *a_cred;
644 		int *a_eofflag;
645 		off_t **a_cookies;
646 		int *a_ncookies;
647 	} */ *ap = v;
648 	struct uio *uio = ap->a_uio;
649 	struct dirent d;
650 	struct ptyfsnode *ptyfs;
651 	off_t i;
652 	int error;
653 	off_t *cookies = NULL;
654 	int ncookies;
655 	struct vnode *vp;
656 	int nc = 0;
657 
658 	vp = ap->a_vp;
659 	ptyfs = VTOPTYFS(vp);
660 
661 	if (uio->uio_resid < UIO_MX)
662 		return EINVAL;
663 	if (uio->uio_offset < 0)
664 		return EINVAL;
665 
666 	error = 0;
667 	i = uio->uio_offset;
668 	(void)memset(&d, 0, sizeof(d));
669 	d.d_reclen = UIO_MX;
670 	ncookies = uio->uio_resid / UIO_MX;
671 
672 	switch (ptyfs->ptyfs_type) {
673 	case PTYFSroot: /* root */
674 
675 		if (i >= npty)
676 			return 0;
677 
678 		if (ap->a_ncookies) {
679 			ncookies = min(ncookies, (npty + 2 - i));
680 			cookies = malloc(ncookies * sizeof (off_t),
681 			    M_TEMP, M_WAITOK);
682 			*ap->a_cookies = cookies;
683 		}
684 
685 		for (; i < 2; i++) {
686 			switch (i) {
687 			case 0:		/* `.' */
688 			case 1:		/* `..' */
689 				d.d_fileno = PTYFS_FILENO(0, PTYFSroot);
690 				d.d_namlen = i + 1;
691 				(void)memcpy(d.d_name, "..", d.d_namlen);
692 				d.d_name[i + 1] = '\0';
693 				d.d_type = DT_DIR;
694 				break;
695 			}
696 			if ((error = uiomove(&d, UIO_MX, uio)) != 0)
697 				break;
698 			if (cookies)
699 				*cookies++ = i + 1;
700 			nc++;
701 		}
702 		if (error) {
703 			ncookies = nc;
704 			break;
705 		}
706 		for (; uio->uio_resid >= UIO_MX && i < npty; i++) {
707 			/* check for used ptys */
708 			if (pty_isfree(i - 2, 1))
709 				continue;
710 
711 			d.d_fileno = PTYFS_FILENO(i - 2, PTYFSpts);
712 			d.d_namlen = snprintf(d.d_name, sizeof(d.d_name),
713 			    "%lld", (long long)(i - 2));
714 			d.d_type = DT_CHR;
715 			if ((error = uiomove(&d, UIO_MX, uio)) != 0)
716 				break;
717 			if (cookies)
718 				*cookies++ = i + 1;
719 			nc++;
720 		}
721 		ncookies = nc;
722 		break;
723 
724 	default:
725 		error = ENOTDIR;
726 		break;
727 	}
728 
729 	if (ap->a_ncookies) {
730 		if (error) {
731 			if (cookies)
732 				free(*ap->a_cookies, M_TEMP);
733 			*ap->a_ncookies = 0;
734 			*ap->a_cookies = NULL;
735 		} else
736 			*ap->a_ncookies = ncookies;
737 	}
738 	uio->uio_offset = i;
739 	return error;
740 }
741 
742 int
743 ptyfs_open(void *v)
744 {
745 	struct vop_open_args /* {
746 		struct vnode *a_vp;
747 		int  a_mode;
748 		struct ucred *a_cred;
749 		struct proc *a_p;
750 	} */ *ap = v;
751 	struct vnode *vp = ap->a_vp;
752 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
753 
754 	ptyfs->ptyfs_flag |= PTYFS_CHANGE|PTYFS_ACCESS;
755 	switch (ptyfs->ptyfs_type) {
756 	case PTYFSpts:
757 	case PTYFSptc:
758 		return spec_open(v);
759 	case PTYFSroot:
760 		return 0;
761 	default:
762 		return EINVAL;
763 	}
764 }
765 
766 int
767 ptyfs_close(void *v)
768 {
769 	struct vop_close_args /* {
770 		struct vnode *a_vp;
771 		int  a_fflag;
772 		struct ucred *a_cred;
773 		struct proc *a_p;
774 	} */ *ap = v;
775 	struct vnode *vp = ap->a_vp;
776 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
777 
778         simple_lock(&vp->v_interlock);
779         if (vp->v_usecount > 1)
780 		PTYFS_ITIMES(ptyfs, NULL, NULL, NULL);
781         simple_unlock(&vp->v_interlock);
782 
783 	switch (ptyfs->ptyfs_type) {
784 	case PTYFSpts:
785 	case PTYFSptc:
786 		return spec_close(v);
787 	case PTYFSroot:
788 		return 0;
789 	default:
790 		return EINVAL;
791 	}
792 }
793 
794 int
795 ptyfs_read(void *v)
796 {
797 	struct vop_read_args /* {
798 		struct vnode *a_vp;
799 		struct uio *a_uio;
800 		int  a_ioflag;
801 		struct ucred *a_cred;
802 	} */ *ap = v;
803 	struct vnode *vp = ap->a_vp;
804 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
805 	int error;
806 
807 	ptyfs->ptyfs_flag |= PTYFS_ACCESS;
808 	switch (ptyfs->ptyfs_type) {
809 	case PTYFSpts:
810 		VOP_UNLOCK(vp, 0);
811 		error = (*pts_cdevsw.d_read)(vp->v_rdev, ap->a_uio,
812 		    ap->a_ioflag);
813 		vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
814 		return error;
815 	case PTYFSptc:
816 		VOP_UNLOCK(vp, 0);
817 		error = (*ptc_cdevsw.d_read)(vp->v_rdev, ap->a_uio,
818 		    ap->a_ioflag);
819 		vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
820 		return error;
821 	default:
822 		return EOPNOTSUPP;
823 	}
824 }
825 
826 int
827 ptyfs_write(void *v)
828 {
829 	struct vop_write_args /* {
830 		struct vnode *a_vp;
831 		struct uio *a_uio;
832 		int  a_ioflag;
833 		struct ucred *a_cred;
834 	} */ *ap = v;
835 	int error;
836 	struct vnode *vp = ap->a_vp;
837 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
838 
839 	ptyfs->ptyfs_flag |= PTYFS_MODIFY;
840 	switch (ptyfs->ptyfs_type) {
841 	case PTYFSpts:
842 		VOP_UNLOCK(vp, 0);
843 		error = (*pts_cdevsw.d_write)(vp->v_rdev, ap->a_uio,
844 		    ap->a_ioflag);
845 		vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
846 		return error;
847 	case PTYFSptc:
848 		VOP_UNLOCK(vp, 0);
849 		error = (*ptc_cdevsw.d_write)(vp->v_rdev, ap->a_uio,
850 		    ap->a_ioflag);
851 		vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
852 		return error;
853 	default:
854 		return EOPNOTSUPP;
855 	}
856 }
857 
858 int
859 ptyfs_ioctl(void *v)
860 {
861 	struct vop_ioctl_args /* {
862 		struct vnode *a_vp;
863 		u_long a_command;
864 		void *a_data;
865 		int  a_fflag;
866 		struct ucred *a_cred;
867 		struct proc *a_p;
868 	} */ *ap = v;
869 	struct vnode *vp = ap->a_vp;
870 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
871 
872 	switch (ptyfs->ptyfs_type) {
873 	case PTYFSpts:
874 		return (*pts_cdevsw.d_ioctl)(vp->v_rdev, ap->a_command,
875 		    ap->a_data, ap->a_fflag, ap->a_p);
876 	case PTYFSptc:
877 		return (*ptc_cdevsw.d_ioctl)(vp->v_rdev, ap->a_command,
878 		    ap->a_data, ap->a_fflag, ap->a_p);
879 	default:
880 		return EOPNOTSUPP;
881 	}
882 }
883 
884 int
885 ptyfs_poll(void *v)
886 {
887 	struct vop_poll_args /* {
888 		struct vnode *a_vp;
889 		int a_events;
890 		struct proc *a_p;
891 	} */ *ap = v;
892 	struct vnode *vp = ap->a_vp;
893 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
894 
895 	switch (ptyfs->ptyfs_type) {
896 	case PTYFSpts:
897 		return (*pts_cdevsw.d_poll)(vp->v_rdev, ap->a_events, ap->a_p);
898 	case PTYFSptc:
899 		return (*ptc_cdevsw.d_poll)(vp->v_rdev, ap->a_events, ap->a_p);
900 	default:
901 		return genfs_poll(v);
902 	}
903 }
904 
905 int
906 ptyfs_kqfilter(void *v)
907 {
908 	struct vop_kqfilter_args /* {
909 		struct vnode *a_vp;
910 		struct knote *a_kn;
911 	} */ *ap = v;
912 	struct vnode *vp = ap->a_vp;
913 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
914 
915 	switch (ptyfs->ptyfs_type) {
916 	case PTYFSpts:
917 		return (*pts_cdevsw.d_kqfilter)(vp->v_rdev, ap->a_kn);
918 	case PTYFSptc:
919 		return (*ptc_cdevsw.d_kqfilter)(vp->v_rdev, ap->a_kn);
920 	default:
921 		return genfs_kqfilter(v);
922 	}
923 }
924 
925 int
926 ptyfs_update(v)
927 	void *v;
928 {
929 	struct vop_update_args /* {
930 		struct vnode *a_vp;
931 		struct timespec *a_access;
932 		struct timespec *a_modify;
933 		int a_flags;
934 	} */ *ap = v;
935 	struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
936 
937 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
938 		return 0;
939 
940 	PTYFS_ITIMES(ptyfs, ap->a_access, ap->a_modify, NULL);
941 	return 0;
942 }
943 
944 void
945 ptyfs_itimes(struct ptyfsnode *ptyfs, const struct timespec *acc,
946     const struct timespec *mod, const struct timespec *cre)
947 {
948 	struct timespec *ts = NULL, tsb;
949 
950 	KASSERT(ptyfs->ptyfs_flag & (PTYFS_ACCESS|PTYFS_CHANGE|PTYFS_MODIFY));
951 	if (ptyfs->ptyfs_flag & (PTYFS_ACCESS|PTYFS_MODIFY)) {
952 		if (acc == NULL)
953 			acc = ts == NULL ? (ts = nanotime(&tsb)) : ts;
954 		ptyfs->ptyfs_atime = *acc;
955 	}
956 	if (ptyfs->ptyfs_flag & PTYFS_MODIFY) {
957 		if (mod == NULL)
958 			mod = ts == NULL ? (ts = nanotime(&tsb)) : ts;
959 		ptyfs->ptyfs_mtime = *mod;
960 	}
961 	if (ptyfs->ptyfs_flag & PTYFS_CHANGE) {
962 		if (cre == NULL)
963 			cre = ts == NULL ? (ts = nanotime(&tsb)) : ts;
964 		ptyfs->ptyfs_ctime = *cre;
965 	}
966 	ptyfs->ptyfs_flag &= ~(PTYFS_ACCESS|PTYFS_CHANGE|PTYFS_MODIFY);
967 }
968 
969 /*
970  * convert decimal ascii to int
971  */
972 static int
973 atoi(const char *b, size_t len)
974 {
975 	int p = 0;
976 
977 	while (len--) {
978 		char c = *b++;
979 		if (c < '0' || c > '9')
980 			return -1;
981 		p = 10 * p + (c - '0');
982 	}
983 
984 	return p;
985 }
986