xref: /netbsd-src/sys/fs/ptyfs/ptyfs_vnops.c (revision ce2c90c7c172d95d2402a5b3d96d8f8e6d138a21)
1 /*	$NetBSD: ptyfs_vnops.c,v 1.17 2006/10/12 01:32:14 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 1.17 2006/10/12 01:32:14 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 #include <sys/kauth.h>
100 
101 #include <uvm/uvm_extern.h>	/* for PAGE_SIZE */
102 
103 #include <machine/reg.h>
104 
105 #include <fs/ptyfs/ptyfs.h>
106 #include <miscfs/genfs/genfs.h>
107 #include <miscfs/specfs/specdev.h>
108 
109 /*
110  * Vnode Operations.
111  *
112  */
113 
114 int	ptyfs_lookup	(void *);
115 #define	ptyfs_create	genfs_eopnotsupp
116 #define	ptyfs_mknod	genfs_eopnotsupp
117 int	ptyfs_open	(void *);
118 int	ptyfs_close	(void *);
119 int	ptyfs_access	(void *);
120 int	ptyfs_getattr	(void *);
121 int	ptyfs_setattr	(void *);
122 int	ptyfs_read	(void *);
123 int	ptyfs_write	(void *);
124 #define	ptyfs_fcntl	genfs_fcntl
125 int	ptyfs_ioctl	(void *);
126 int	ptyfs_poll	(void *);
127 int	ptyfs_kqfilter	(void *);
128 #define ptyfs_revoke	genfs_revoke
129 #define	ptyfs_mmap	genfs_eopnotsupp
130 #define	ptyfs_fsync	genfs_nullop
131 #define	ptyfs_seek	genfs_nullop
132 #define	ptyfs_remove	genfs_eopnotsupp
133 #define	ptyfs_link	genfs_abortop
134 #define	ptyfs_rename	genfs_eopnotsupp
135 #define	ptyfs_mkdir	genfs_eopnotsupp
136 #define	ptyfs_rmdir	genfs_eopnotsupp
137 #define	ptyfs_symlink	genfs_abortop
138 int	ptyfs_readdir	(void *);
139 #define	ptyfs_readlink	genfs_eopnotsupp
140 #define	ptyfs_abortop	genfs_abortop
141 int	ptyfs_reclaim	(void *);
142 #define	ptyfs_lock	genfs_lock
143 #define	ptyfs_unlock	genfs_unlock
144 #define	ptyfs_bmap	genfs_badop
145 #define	ptyfs_strategy	genfs_badop
146 int	ptyfs_print	(void *);
147 int	ptyfs_pathconf	(void *);
148 #define	ptyfs_islocked	genfs_islocked
149 #define	ptyfs_advlock	genfs_einval
150 #define	ptyfs_bwrite	genfs_eopnotsupp
151 #define ptyfs_putpages	genfs_null_putpages
152 
153 static int ptyfs_update(struct vnode *, const struct timespec *,
154     const struct timespec *, int);
155 static int ptyfs_chown(struct vnode *, uid_t, gid_t, kauth_cred_t,
156     struct lwp *);
157 static int ptyfs_chmod(struct vnode *, mode_t, kauth_cred_t, struct lwp *);
158 static int atoi(const char *, size_t);
159 
160 extern const struct cdevsw pts_cdevsw, ptc_cdevsw;
161 
162 /*
163  * ptyfs vnode operations.
164  */
165 int (**ptyfs_vnodeop_p)(void *);
166 const struct vnodeopv_entry_desc ptyfs_vnodeop_entries[] = {
167 	{ &vop_default_desc, vn_default_error },
168 	{ &vop_lookup_desc, ptyfs_lookup },		/* lookup */
169 	{ &vop_create_desc, ptyfs_create },		/* create */
170 	{ &vop_mknod_desc, ptyfs_mknod },		/* mknod */
171 	{ &vop_open_desc, ptyfs_open },			/* open */
172 	{ &vop_close_desc, ptyfs_close },		/* close */
173 	{ &vop_access_desc, ptyfs_access },		/* access */
174 	{ &vop_getattr_desc, ptyfs_getattr },		/* getattr */
175 	{ &vop_setattr_desc, ptyfs_setattr },		/* setattr */
176 	{ &vop_read_desc, ptyfs_read },			/* read */
177 	{ &vop_write_desc, ptyfs_write },		/* write */
178 	{ &vop_ioctl_desc, ptyfs_ioctl },		/* ioctl */
179 	{ &vop_fcntl_desc, ptyfs_fcntl },		/* fcntl */
180 	{ &vop_poll_desc, ptyfs_poll },			/* poll */
181 	{ &vop_kqfilter_desc, ptyfs_kqfilter },		/* kqfilter */
182 	{ &vop_revoke_desc, ptyfs_revoke },		/* revoke */
183 	{ &vop_mmap_desc, ptyfs_mmap },			/* mmap */
184 	{ &vop_fsync_desc, ptyfs_fsync },		/* fsync */
185 	{ &vop_seek_desc, ptyfs_seek },			/* seek */
186 	{ &vop_remove_desc, ptyfs_remove },		/* remove */
187 	{ &vop_link_desc, ptyfs_link },			/* link */
188 	{ &vop_rename_desc, ptyfs_rename },		/* rename */
189 	{ &vop_mkdir_desc, ptyfs_mkdir },		/* mkdir */
190 	{ &vop_rmdir_desc, ptyfs_rmdir },		/* rmdir */
191 	{ &vop_symlink_desc, ptyfs_symlink },		/* symlink */
192 	{ &vop_readdir_desc, ptyfs_readdir },		/* readdir */
193 	{ &vop_readlink_desc, ptyfs_readlink },		/* readlink */
194 	{ &vop_abortop_desc, ptyfs_abortop },		/* abortop */
195 	{ &vop_inactive_desc, spec_inactive },		/* inactive */
196 	{ &vop_reclaim_desc, ptyfs_reclaim },		/* reclaim */
197 	{ &vop_lock_desc, ptyfs_lock },			/* lock */
198 	{ &vop_unlock_desc, ptyfs_unlock },		/* unlock */
199 	{ &vop_bmap_desc, ptyfs_bmap },			/* bmap */
200 	{ &vop_strategy_desc, ptyfs_strategy },		/* strategy */
201 	{ &vop_print_desc, ptyfs_print },		/* print */
202 	{ &vop_islocked_desc, ptyfs_islocked },		/* islocked */
203 	{ &vop_pathconf_desc, ptyfs_pathconf },		/* pathconf */
204 	{ &vop_advlock_desc, ptyfs_advlock },		/* advlock */
205 	{ &vop_bwrite_desc, ptyfs_bwrite },		/* bwrite */
206 	{ &vop_putpages_desc, ptyfs_putpages },		/* putpages */
207 	{ NULL, NULL }
208 };
209 const struct vnodeopv_desc ptyfs_vnodeop_opv_desc =
210 	{ &ptyfs_vnodeop_p, ptyfs_vnodeop_entries };
211 
212 /*
213  * _reclaim is called when getnewvnode()
214  * wants to make use of an entry on the vnode
215  * free list.  at this time the filesystem needs
216  * to free any private data and remove the node
217  * from any private lists.
218  */
219 int
220 ptyfs_reclaim(void *v)
221 {
222 	struct vop_reclaim_args /* {
223 		struct vnode *a_vp;
224 	} */ *ap = v;
225 	return ptyfs_freevp(ap->a_vp);
226 }
227 
228 /*
229  * Return POSIX pathconf information applicable to special devices.
230  */
231 int
232 ptyfs_pathconf(void *v)
233 {
234 	struct vop_pathconf_args /* {
235 		struct vnode *a_vp;
236 		int a_name;
237 		register_t *a_retval;
238 	} */ *ap = v;
239 
240 	switch (ap->a_name) {
241 	case _PC_LINK_MAX:
242 		*ap->a_retval = LINK_MAX;
243 		return 0;
244 	case _PC_MAX_CANON:
245 		*ap->a_retval = MAX_CANON;
246 		return 0;
247 	case _PC_MAX_INPUT:
248 		*ap->a_retval = MAX_INPUT;
249 		return 0;
250 	case _PC_PIPE_BUF:
251 		*ap->a_retval = PIPE_BUF;
252 		return 0;
253 	case _PC_CHOWN_RESTRICTED:
254 		*ap->a_retval = 1;
255 		return 0;
256 	case _PC_VDISABLE:
257 		*ap->a_retval = _POSIX_VDISABLE;
258 		return 0;
259 	case _PC_SYNC_IO:
260 		*ap->a_retval = 1;
261 		return 0;
262 	default:
263 		return EINVAL;
264 	}
265 }
266 
267 /*
268  * _print is used for debugging.
269  * just print a readable description
270  * of (vp).
271  */
272 int
273 ptyfs_print(void *v)
274 {
275 	struct vop_print_args /* {
276 		struct vnode *a_vp;
277 	} */ *ap = v;
278 	struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
279 
280 	printf("tag VT_PTYFS, type %d, pty %d\n",
281 	    ptyfs->ptyfs_type, ptyfs->ptyfs_pty);
282 	return 0;
283 }
284 
285 /*
286  * Invent attributes for ptyfsnode (vp) and store
287  * them in (vap).
288  * Directories lengths are returned as zero since
289  * any real length would require the genuine size
290  * to be computed, and nothing cares anyway.
291  *
292  * this is relatively minimal for ptyfs.
293  */
294 int
295 ptyfs_getattr(void *v)
296 {
297 	struct vop_getattr_args /* {
298 		struct vnode *a_vp;
299 		struct vattr *a_vap;
300 		kauth_cred_t a_cred;
301 		struct lwp *a_l;
302 	} */ *ap = v;
303 	struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
304 	struct vattr *vap = ap->a_vap;
305 
306 	PTYFS_ITIMES(ptyfs, NULL, NULL, NULL);
307 
308 	/* start by zeroing out the attributes */
309 	VATTR_NULL(vap);
310 
311 	/* next do all the common fields */
312 	vap->va_type = ap->a_vp->v_type;
313 	vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0];
314 	vap->va_fileid = ptyfs->ptyfs_fileno;
315 	vap->va_gen = 0;
316 	vap->va_flags = 0;
317 	vap->va_nlink = 1;
318 	vap->va_blocksize = PAGE_SIZE;
319 
320 	vap->va_atime = ptyfs->ptyfs_atime;
321 	vap->va_mtime = ptyfs->ptyfs_mtime;
322 	vap->va_ctime = ptyfs->ptyfs_ctime;
323 	vap->va_birthtime = ptyfs->ptyfs_birthtime;
324 	vap->va_mode = ptyfs->ptyfs_mode;
325 	vap->va_flags = ptyfs->ptyfs_flags;
326 	vap->va_uid = ptyfs->ptyfs_uid;
327 	vap->va_gid = ptyfs->ptyfs_gid;
328 
329 	switch (ptyfs->ptyfs_type) {
330 	case PTYFSpts:
331 	case PTYFSptc:
332 		if (pty_isfree(ptyfs->ptyfs_pty, 1))
333 			return ENOENT;
334 		vap->va_bytes = vap->va_size = 0;
335 		vap->va_rdev = ap->a_vp->v_rdev;
336 		break;
337 	case PTYFSroot:
338 		vap->va_rdev = 0;
339 		vap->va_bytes = vap->va_size = DEV_BSIZE;
340 		break;
341 
342 	default:
343 		return EOPNOTSUPP;
344 	}
345 
346 	return 0;
347 }
348 
349 /*ARGSUSED*/
350 int
351 ptyfs_setattr(void *v)
352 {
353 	struct vop_setattr_args /* {
354 		struct vnodeop_desc *a_desc;
355 		struct vnode *a_vp;
356 		struct vattr *a_vap;
357 		kauth_cred_t a_cred;
358 		struct lwp *a_l;
359 	} */ *ap = v;
360 	struct vnode *vp = ap->a_vp;
361 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
362 	struct vattr *vap = ap->a_vap;
363 	kauth_cred_t cred = ap->a_cred;
364 	struct lwp *l = ap->a_l;
365 	int error;
366 
367 	if (vap->va_size != VNOVAL) {
368  		switch (ptyfs->ptyfs_type) {
369  		case PTYFSroot:
370  			return EISDIR;
371  		case PTYFSpts:
372  		case PTYFSptc:
373 			break;
374 		default:
375 			return EINVAL;
376 		}
377 	}
378 
379 	if (vap->va_flags != VNOVAL) {
380 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
381 			return EROFS;
382 		if (kauth_cred_geteuid(cred) != ptyfs->ptyfs_uid &&
383 		    (error = kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER,
384 		    &l->l_acflag)) != 0)
385 			return error;
386 		if (kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER, NULL) == 0) {
387 			if ((ptyfs->ptyfs_flags & (SF_IMMUTABLE | SF_APPEND)) &&
388 			    securelevel > 0)
389 				return EPERM;
390 			/* Snapshot flag cannot be set or cleared */
391 			if ((vap->va_flags & SF_SNAPSHOT) !=
392 			    (ptyfs->ptyfs_flags & SF_SNAPSHOT))
393 				return EPERM;
394 			ptyfs->ptyfs_flags = vap->va_flags;
395 		} else {
396 			if ((ptyfs->ptyfs_flags & (SF_IMMUTABLE | SF_APPEND)) ||
397 			    (vap->va_flags & UF_SETTABLE) != vap->va_flags)
398 				return EPERM;
399 			if ((ptyfs->ptyfs_flags & SF_SETTABLE) !=
400 			    (vap->va_flags & SF_SETTABLE))
401 				return EPERM;
402 			ptyfs->ptyfs_flags &= SF_SETTABLE;
403 			ptyfs->ptyfs_flags |= (vap->va_flags & UF_SETTABLE);
404 		}
405 		ptyfs->ptyfs_flag |= PTYFS_CHANGE;
406 		if (vap->va_flags & (IMMUTABLE | APPEND))
407 			return 0;
408 	}
409 	if (ptyfs->ptyfs_flags & (IMMUTABLE | APPEND))
410 		return EPERM;
411 	/*
412 	 * Go through the fields and update iff not VNOVAL.
413 	 */
414 	if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
415 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
416 			return EROFS;
417 		if (ptyfs->ptyfs_type == PTYFSroot)
418 			return EPERM;
419 		error = ptyfs_chown(vp, vap->va_uid, vap->va_gid, cred, l);
420 		if (error)
421 			return error;
422 	}
423 
424 	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL ||
425 	    vap->va_birthtime.tv_sec != VNOVAL) {
426 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
427 			return EROFS;
428 		if ((ptyfs->ptyfs_flags & SF_SNAPSHOT) != 0)
429 			return EPERM;
430 		if (kauth_cred_geteuid(cred) != ptyfs->ptyfs_uid &&
431 		    (error = kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER,
432 		    &l->l_acflag)) &&
433 		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
434 		    (error = VOP_ACCESS(vp, VWRITE, cred, l)) != 0))
435 			return (error);
436 		if (vap->va_atime.tv_sec != VNOVAL)
437 			if (!(vp->v_mount->mnt_flag & MNT_NOATIME))
438 				ptyfs->ptyfs_flag |= PTYFS_ACCESS;
439 		if (vap->va_mtime.tv_sec != VNOVAL)
440 			ptyfs->ptyfs_flag |= PTYFS_CHANGE | PTYFS_MODIFY;
441 		if (vap->va_birthtime.tv_sec != VNOVAL)
442 			ptyfs->ptyfs_birthtime = vap->va_birthtime;
443 		ptyfs->ptyfs_flag |= PTYFS_CHANGE;
444 		error = ptyfs_update(vp, &vap->va_atime, &vap->va_mtime, 0);
445 		if (error)
446 			return error;
447 	}
448 	if (vap->va_mode != (mode_t)VNOVAL) {
449 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
450 			return EROFS;
451 		if (ptyfs->ptyfs_type == PTYFSroot)
452 			return EPERM;
453 		if ((ptyfs->ptyfs_flags & SF_SNAPSHOT) != 0 &&
454 		    (vap->va_mode &
455 		    (S_IXUSR|S_IWUSR|S_IXGRP|S_IWGRP|S_IXOTH|S_IWOTH)))
456 			return EPERM;
457 		error = ptyfs_chmod(vp, vap->va_mode, cred, l);
458 		if (error)
459 			return error;
460 	}
461 	VN_KNOTE(vp, NOTE_ATTRIB);
462 	return 0;
463 }
464 
465 /*
466  * Change the mode on a file.
467  * Inode must be locked before calling.
468  */
469 static int
470 ptyfs_chmod(struct vnode *vp, mode_t mode, kauth_cred_t cred, struct lwp *l)
471 {
472 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
473 	int error;
474 
475 	if (kauth_cred_geteuid(cred) != ptyfs->ptyfs_uid &&
476 	    (error = kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER,
477 	    &l->l_acflag)) != 0)
478 		return error;
479 	ptyfs->ptyfs_mode &= ~ALLPERMS;
480 	ptyfs->ptyfs_mode |= (mode & ALLPERMS);
481 	return 0;
482 }
483 
484 /*
485  * Perform chown operation on inode ip;
486  * inode must be locked prior to call.
487  */
488 static int
489 ptyfs_chown(struct vnode *vp, uid_t uid, gid_t gid, kauth_cred_t cred,
490     struct lwp *l)
491 {
492 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
493 	int		error, ismember = 0;
494 
495 	if (uid == (uid_t)VNOVAL)
496 		uid = ptyfs->ptyfs_uid;
497 	if (gid == (gid_t)VNOVAL)
498 		gid = ptyfs->ptyfs_gid;
499 	/*
500 	 * If we don't own the file, are trying to change the owner
501 	 * of the file, or are not a member of the target group,
502 	 * the caller's credentials must imply super-user privilege
503 	 * or the call fails.
504 	 */
505 	if ((kauth_cred_geteuid(cred) != ptyfs->ptyfs_uid || uid != ptyfs->ptyfs_uid ||
506 	    (gid != ptyfs->ptyfs_gid &&
507 	    !(kauth_cred_getegid(cred) == gid ||
508 	    (kauth_cred_ismember_gid(cred, gid, &ismember) == 0 && ismember)))) &&
509 	    ((error = kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER,
510 	    &l->l_acflag)) != 0))
511 		return error;
512 
513 	ptyfs->ptyfs_gid = gid;
514 	ptyfs->ptyfs_uid = uid;
515 	return 0;
516 }
517 
518 /*
519  * implement access checking.
520  *
521  * actually, the check for super-user is slightly
522  * broken since it will allow read access to write-only
523  * objects.  this doesn't cause any particular trouble
524  * but does mean that the i/o entry points need to check
525  * that the operation really does make sense.
526  */
527 int
528 ptyfs_access(void *v)
529 {
530 	struct vop_access_args /* {
531 		struct vnode *a_vp;
532 		int a_mode;
533 		kauth_cred_t a_cred;
534 		struct lwp *a_l;
535 	} */ *ap = v;
536 	struct vattr va;
537 	int error;
538 
539 	if ((error = VOP_GETATTR(ap->a_vp, &va, ap->a_cred, ap->a_l)) != 0)
540 		return error;
541 
542 	return vaccess(va.va_type, va.va_mode,
543 	    va.va_uid, va.va_gid, ap->a_mode, ap->a_cred);
544 }
545 
546 /*
547  * lookup.  this is incredibly complicated in the
548  * general case, however for most pseudo-filesystems
549  * very little needs to be done.
550  *
551  * Locking isn't hard here, just poorly documented.
552  *
553  * If we're looking up ".", just vref the parent & return it.
554  *
555  * If we're looking up "..", unlock the parent, and lock "..". If everything
556  * went ok, and we're on the last component and the caller requested the
557  * parent locked, try to re-lock the parent. We do this to prevent lock
558  * races.
559  *
560  * For anything else, get the needed node. Then unlock the parent if not
561  * the last component or not LOCKPARENT (i.e. if we wouldn't re-lock the
562  * parent in the .. case).
563  *
564  * We try to exit with the parent locked in error cases.
565  */
566 int
567 ptyfs_lookup(void *v)
568 {
569 	struct vop_lookup_args /* {
570 		struct vnode * a_dvp;
571 		struct vnode ** a_vpp;
572 		struct componentname * a_cnp;
573 	} */ *ap = v;
574 	struct componentname *cnp = ap->a_cnp;
575 	struct vnode **vpp = ap->a_vpp;
576 	struct vnode *dvp = ap->a_dvp;
577 	const char *pname = cnp->cn_nameptr;
578 	struct ptyfsnode *ptyfs;
579 	int pty, error, wantpunlock;
580 
581 	*vpp = NULL;
582 	cnp->cn_flags &= ~PDIRUNLOCK;
583 
584 	if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)
585 		return EROFS;
586 
587 	if (cnp->cn_namelen == 1 && *pname == '.') {
588 		*vpp = dvp;
589 		VREF(dvp);
590 		return 0;
591 	}
592 
593 	wantpunlock = ~cnp->cn_flags & (LOCKPARENT | ISLASTCN);
594 	ptyfs = VTOPTYFS(dvp);
595 	switch (ptyfs->ptyfs_type) {
596 	case PTYFSroot:
597 		/*
598 		 * Shouldn't get here with .. in the root node.
599 		 */
600 		if (cnp->cn_flags & ISDOTDOT)
601 			return EIO;
602 
603 		pty = atoi(pname, cnp->cn_namelen);
604 
605 		if (pty < 0 || pty >= npty || pty_isfree(pty, 1))
606 			break;
607 
608 		error = ptyfs_allocvp(dvp->v_mount, vpp, PTYFSpts, pty,
609 		    curlwp);
610 		if (error == 0 && wantpunlock) {
611 			VOP_UNLOCK(dvp, 0);
612 			cnp->cn_flags |= PDIRUNLOCK;
613 		}
614 		return error;
615 
616 	default:
617 		return ENOTDIR;
618 	}
619 
620 	return cnp->cn_nameiop == LOOKUP ? ENOENT : EROFS;
621 }
622 
623 /*
624  * readdir returns directory entries from ptyfsnode (vp).
625  *
626  * the strategy here with ptyfs is to generate a single
627  * directory entry at a time (struct dirent) and then
628  * copy that out to userland using uiomove.  a more efficent
629  * though more complex implementation, would try to minimize
630  * the number of calls to uiomove().  for ptyfs, this is
631  * hardly worth the added code complexity.
632  *
633  * this should just be done through read()
634  */
635 int
636 ptyfs_readdir(void *v)
637 {
638 	struct vop_readdir_args /* {
639 		struct vnode *a_vp;
640 		struct uio *a_uio;
641 		kauth_cred_t a_cred;
642 		int *a_eofflag;
643 		off_t **a_cookies;
644 		int *a_ncookies;
645 	} */ *ap = v;
646 	struct uio *uio = ap->a_uio;
647 	struct dirent d;
648 	struct ptyfsnode *ptyfs;
649 	off_t i;
650 	int error;
651 	off_t *cookies = NULL;
652 	int ncookies;
653 	struct vnode *vp;
654 	int nc = 0;
655 
656 	vp = ap->a_vp;
657 	ptyfs = VTOPTYFS(vp);
658 
659 	if (uio->uio_resid < UIO_MX)
660 		return EINVAL;
661 	if (uio->uio_offset < 0)
662 		return EINVAL;
663 
664 	error = 0;
665 	i = uio->uio_offset;
666 	(void)memset(&d, 0, sizeof(d));
667 	d.d_reclen = UIO_MX;
668 	ncookies = uio->uio_resid / UIO_MX;
669 
670 	switch (ptyfs->ptyfs_type) {
671 	case PTYFSroot: /* root */
672 
673 		if (i >= npty)
674 			return 0;
675 
676 		if (ap->a_ncookies) {
677 			ncookies = min(ncookies, (npty + 2 - i));
678 			cookies = malloc(ncookies * sizeof (off_t),
679 			    M_TEMP, M_WAITOK);
680 			*ap->a_cookies = cookies;
681 		}
682 
683 		for (; i < 2; i++) {
684 			switch (i) {
685 			case 0:		/* `.' */
686 			case 1:		/* `..' */
687 				d.d_fileno = PTYFS_FILENO(0, PTYFSroot);
688 				d.d_namlen = i + 1;
689 				(void)memcpy(d.d_name, "..", d.d_namlen);
690 				d.d_name[i + 1] = '\0';
691 				d.d_type = DT_DIR;
692 				break;
693 			}
694 			if ((error = uiomove(&d, UIO_MX, uio)) != 0)
695 				break;
696 			if (cookies)
697 				*cookies++ = i + 1;
698 			nc++;
699 		}
700 		if (error) {
701 			ncookies = nc;
702 			break;
703 		}
704 		for (; uio->uio_resid >= UIO_MX && i < npty; i++) {
705 			/* check for used ptys */
706 			if (pty_isfree(i - 2, 1))
707 				continue;
708 
709 			d.d_fileno = PTYFS_FILENO(i - 2, PTYFSpts);
710 			d.d_namlen = snprintf(d.d_name, sizeof(d.d_name),
711 			    "%lld", (long long)(i - 2));
712 			d.d_type = DT_CHR;
713 			if ((error = uiomove(&d, UIO_MX, uio)) != 0)
714 				break;
715 			if (cookies)
716 				*cookies++ = i + 1;
717 			nc++;
718 		}
719 		ncookies = nc;
720 		break;
721 
722 	default:
723 		error = ENOTDIR;
724 		break;
725 	}
726 
727 	if (ap->a_ncookies) {
728 		if (error) {
729 			if (cookies)
730 				free(*ap->a_cookies, M_TEMP);
731 			*ap->a_ncookies = 0;
732 			*ap->a_cookies = NULL;
733 		} else
734 			*ap->a_ncookies = ncookies;
735 	}
736 	uio->uio_offset = i;
737 	return error;
738 }
739 
740 int
741 ptyfs_open(void *v)
742 {
743 	struct vop_open_args /* {
744 		struct vnode *a_vp;
745 		int  a_mode;
746 		kauth_cred_t a_cred;
747 		struct lwp *a_l;
748 	} */ *ap = v;
749 	struct vnode *vp = ap->a_vp;
750 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
751 
752 	ptyfs->ptyfs_flag |= PTYFS_CHANGE|PTYFS_ACCESS;
753 	switch (ptyfs->ptyfs_type) {
754 	case PTYFSpts:
755 	case PTYFSptc:
756 		return spec_open(v);
757 	case PTYFSroot:
758 		return 0;
759 	default:
760 		return EINVAL;
761 	}
762 }
763 
764 int
765 ptyfs_close(void *v)
766 {
767 	struct vop_close_args /* {
768 		struct vnode *a_vp;
769 		int  a_fflag;
770 		kauth_cred_t a_cred;
771 		struct lwp *a_l;
772 	} */ *ap = v;
773 	struct vnode *vp = ap->a_vp;
774 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
775 
776 	simple_lock(&vp->v_interlock);
777 	if (vp->v_usecount > 1)
778 		PTYFS_ITIMES(ptyfs, NULL, NULL, NULL);
779 	simple_unlock(&vp->v_interlock);
780 
781 	switch (ptyfs->ptyfs_type) {
782 	case PTYFSpts:
783 	case PTYFSptc:
784 		return spec_close(v);
785 	case PTYFSroot:
786 		return 0;
787 	default:
788 		return EINVAL;
789 	}
790 }
791 
792 int
793 ptyfs_read(void *v)
794 {
795 	struct vop_read_args /* {
796 		struct vnode *a_vp;
797 		struct uio *a_uio;
798 		int  a_ioflag;
799 		kauth_cred_t a_cred;
800 	} */ *ap = v;
801 	struct timespec ts;
802 	struct vnode *vp = ap->a_vp;
803 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
804 	int error;
805 
806 	ptyfs->ptyfs_flag |= PTYFS_ACCESS;
807 	/* hardclock() resolution is good enough for ptyfs */
808 	getnanotime(&ts);
809 	(void)ptyfs_update(vp, &ts, &ts, 0);
810 
811 	switch (ptyfs->ptyfs_type) {
812 	case PTYFSpts:
813 		VOP_UNLOCK(vp, 0);
814 		error = (*pts_cdevsw.d_read)(vp->v_rdev, ap->a_uio,
815 		    ap->a_ioflag);
816 		vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
817 		return error;
818 	case PTYFSptc:
819 		VOP_UNLOCK(vp, 0);
820 		error = (*ptc_cdevsw.d_read)(vp->v_rdev, ap->a_uio,
821 		    ap->a_ioflag);
822 		vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
823 		return error;
824 	default:
825 		return EOPNOTSUPP;
826 	}
827 }
828 
829 int
830 ptyfs_write(void *v)
831 {
832 	struct vop_write_args /* {
833 		struct vnode *a_vp;
834 		struct uio *a_uio;
835 		int  a_ioflag;
836 		kauth_cred_t a_cred;
837 	} */ *ap = v;
838 	struct timespec ts;
839 	struct vnode *vp = ap->a_vp;
840 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
841 	int error;
842 
843 	ptyfs->ptyfs_flag |= PTYFS_MODIFY;
844 	getnanotime(&ts);
845 	(void)ptyfs_update(vp, &ts, &ts, 0);
846 
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 		kauth_cred_t a_cred;
874 		struct lwp *a_l;
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_l);
883 	case PTYFSptc:
884 		return (*ptc_cdevsw.d_ioctl)(vp->v_rdev, ap->a_command,
885 		    ap->a_data, ap->a_fflag, ap->a_l);
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 lwp *a_l;
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_l);
905 	case PTYFSptc:
906 		return (*ptc_cdevsw.d_poll)(vp->v_rdev, ap->a_events, ap->a_l);
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 static int
933 ptyfs_update(struct vnode *vp, const struct timespec *acc,
934     const struct timespec *mod, int flags __unused)
935 {
936 	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
937 
938 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
939 		return 0;
940 
941 	PTYFS_ITIMES(ptyfs, acc, mod, NULL);
942 	return 0;
943 }
944 
945 void
946 ptyfs_itimes(struct ptyfsnode *ptyfs, const struct timespec *acc,
947     const struct timespec *mod, const struct timespec *cre)
948 {
949 	struct timespec now;
950 
951 	KASSERT(ptyfs->ptyfs_flag & (PTYFS_ACCESS|PTYFS_CHANGE|PTYFS_MODIFY));
952 
953 	getnanotime(&now);
954 	if (ptyfs->ptyfs_flag & (PTYFS_ACCESS|PTYFS_MODIFY)) {
955 		if (acc == NULL)
956 			acc = &now;
957 		ptyfs->ptyfs_atime = *acc;
958 	}
959 	if (ptyfs->ptyfs_flag & PTYFS_MODIFY) {
960 		if (mod == NULL)
961 			mod = &now;
962 		ptyfs->ptyfs_mtime = *mod;
963 	}
964 	if (ptyfs->ptyfs_flag & PTYFS_CHANGE) {
965 		if (cre == NULL)
966 			cre = &now;
967 		ptyfs->ptyfs_ctime = *cre;
968 	}
969 	ptyfs->ptyfs_flag &= ~(PTYFS_ACCESS|PTYFS_CHANGE|PTYFS_MODIFY);
970 }
971 
972 /*
973  * convert decimal ascii to int
974  */
975 static int
976 atoi(const char *b, size_t len)
977 {
978 	int p = 0;
979 
980 	while (len--) {
981 		char c = *b++;
982 		if (c < '0' || c > '9')
983 			return -1;
984 		p = 10 * p + (c - '0');
985 	}
986 
987 	return p;
988 }
989