1/*	$NetBSD: ptyfs_vnops.c,v 1.69 2022/08/05 10:36:02 riastradh 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 1.69 2022/08/05 10:36:02 riastradh 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
109MALLOC_DECLARE(M_PTYFSTMP);
110
111/*
112 * Vnode Operations.
113 *
114 */
115
116int	ptyfs_lookup	(void *);
117int	ptyfs_open	(void *);
118int	ptyfs_close	(void *);
119int	ptyfs_access	(void *);
120int	ptyfs_getattr	(void *);
121int	ptyfs_setattr	(void *);
122int	ptyfs_read	(void *);
123int	ptyfs_write	(void *);
124int	ptyfs_ioctl	(void *);
125int	ptyfs_poll	(void *);
126int	ptyfs_kqfilter	(void *);
127int	ptyfs_readdir	(void *);
128int	ptyfs_reclaim	(void *);
129int	ptyfs_inactive	(void *);
130int	ptyfs_print	(void *);
131int	ptyfs_pathconf	(void *);
132int	ptyfs_advlock	(void *);
133
134static int ptyfs_update(struct vnode *, const struct timespec *,
135    const struct timespec *, int);
136static int ptyfs_chown(struct vnode *, uid_t, gid_t, kauth_cred_t,
137    struct lwp *);
138static int ptyfs_chmod(struct vnode *, mode_t, kauth_cred_t, struct lwp *);
139static int atoi(const char *, size_t);
140
141/*
142 * ptyfs vnode operations.
143 */
144int (**ptyfs_vnodeop_p)(void *);
145const struct vnodeopv_entry_desc ptyfs_vnodeop_entries[] = {
146	{ &vop_default_desc, vn_default_error },
147	{ &vop_parsepath_desc, genfs_parsepath },	/* parsepath */
148	{ &vop_lookup_desc, ptyfs_lookup },		/* lookup */
149	{ &vop_create_desc, genfs_eopnotsupp },		/* create */
150	{ &vop_mknod_desc, genfs_eopnotsupp },		/* mknod */
151	{ &vop_open_desc, ptyfs_open },			/* open */
152	{ &vop_close_desc, ptyfs_close },		/* close */
153	{ &vop_access_desc, ptyfs_access },		/* access */
154	{ &vop_accessx_desc, genfs_accessx },		/* accessx */
155	{ &vop_getattr_desc, ptyfs_getattr },		/* getattr */
156	{ &vop_setattr_desc, ptyfs_setattr },		/* setattr */
157	{ &vop_read_desc, ptyfs_read },			/* read */
158	{ &vop_write_desc, ptyfs_write },		/* write */
159	{ &vop_fallocate_desc, genfs_eopnotsupp },	/* fallocate */
160	{ &vop_fdiscard_desc, genfs_eopnotsupp },	/* fdiscard */
161	{ &vop_ioctl_desc, ptyfs_ioctl },		/* ioctl */
162	{ &vop_fcntl_desc, genfs_fcntl },		/* fcntl */
163	{ &vop_poll_desc, ptyfs_poll },			/* poll */
164	{ &vop_kqfilter_desc, ptyfs_kqfilter },		/* kqfilter */
165	{ &vop_revoke_desc, genfs_revoke },		/* revoke */
166	{ &vop_mmap_desc, genfs_eopnotsupp },		/* mmap */
167	{ &vop_fsync_desc, genfs_nullop },		/* fsync */
168	{ &vop_seek_desc, genfs_nullop },		/* seek */
169	{ &vop_remove_desc, genfs_eopnotsupp },		/* remove */
170	{ &vop_link_desc, genfs_eopnotsupp },		/* link */
171	{ &vop_rename_desc, genfs_eopnotsupp },		/* rename */
172	{ &vop_mkdir_desc, genfs_eopnotsupp },		/* mkdir */
173	{ &vop_rmdir_desc, genfs_eopnotsupp },		/* rmdir */
174	{ &vop_symlink_desc, genfs_eopnotsupp },	/* symlink */
175	{ &vop_readdir_desc, ptyfs_readdir },		/* readdir */
176	{ &vop_readlink_desc, genfs_eopnotsupp },	/* readlink */
177	{ &vop_abortop_desc, genfs_abortop },		/* abortop */
178	{ &vop_inactive_desc, ptyfs_inactive },		/* inactive */
179	{ &vop_reclaim_desc, ptyfs_reclaim },		/* reclaim */
180	{ &vop_lock_desc, genfs_lock },			/* lock */
181	{ &vop_unlock_desc, genfs_unlock },		/* unlock */
182	{ &vop_bmap_desc, genfs_eopnotsupp },		/* bmap */
183	{ &vop_strategy_desc, genfs_badop },		/* strategy */
184	{ &vop_print_desc, ptyfs_print },		/* print */
185	{ &vop_islocked_desc, genfs_islocked },		/* islocked */
186	{ &vop_pathconf_desc, ptyfs_pathconf },		/* pathconf */
187	{ &vop_advlock_desc, ptyfs_advlock },		/* advlock */
188	{ &vop_bwrite_desc, genfs_eopnotsupp },		/* bwrite */
189	{ &vop_putpages_desc, genfs_null_putpages },	/* putpages */
190	{ NULL, NULL }
191};
192const struct vnodeopv_desc ptyfs_vnodeop_opv_desc =
193	{ &ptyfs_vnodeop_p, ptyfs_vnodeop_entries };
194
195/*
196 * free any private data and remove the node
197 * from any private lists.
198 */
199int
200ptyfs_reclaim(void *v)
201{
202	struct vop_reclaim_v2_args /* {
203		struct vnode *a_vp;
204	} */ *ap = v;
205	struct vnode *vp = ap->a_vp;
206
207	VOP_UNLOCK(vp);
208
209	vp->v_data = NULL;
210	return 0;
211}
212
213int
214ptyfs_inactive(void *v)
215{
216	struct vop_inactive_v2_args /* {
217		struct vnode *a_vp;
218		bool *a_recycle;
219	} */ *ap = v;
220	struct vnode *vp = ap->a_vp;
221	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
222
223	if (ptyfs->ptyfs_type == PTYFSptc)
224		ptyfs_clr_active(vp->v_mount, ptyfs->ptyfs_pty);
225
226	return 0;
227}
228
229/*
230 * Return POSIX pathconf information applicable to special devices.
231 */
232int
233ptyfs_pathconf(void *v)
234{
235	struct vop_pathconf_args /* {
236		struct vnode *a_vp;
237		int a_name;
238		register_t *a_retval;
239	} */ *ap = v;
240
241	switch (ap->a_name) {
242	case _PC_LINK_MAX:
243		*ap->a_retval = LINK_MAX;
244		return 0;
245	case _PC_MAX_CANON:
246		*ap->a_retval = MAX_CANON;
247		return 0;
248	case _PC_MAX_INPUT:
249		*ap->a_retval = MAX_INPUT;
250		return 0;
251	case _PC_PIPE_BUF:
252		*ap->a_retval = PIPE_BUF;
253		return 0;
254	case _PC_CHOWN_RESTRICTED:
255		*ap->a_retval = 1;
256		return 0;
257	case _PC_VDISABLE:
258		*ap->a_retval = _POSIX_VDISABLE;
259		return 0;
260	case _PC_SYNC_IO:
261		*ap->a_retval = 1;
262		return 0;
263	default:
264		return genfs_pathconf(ap);
265	}
266}
267
268/*
269 * _print is used for debugging.
270 * just print a readable description
271 * of (vp).
272 */
273int
274ptyfs_print(void *v)
275{
276	struct vop_print_args /* {
277		struct vnode *a_vp;
278	} */ *ap = v;
279	struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
280
281	printf("tag VT_PTYFS, type %d, pty %d\n",
282	    ptyfs->ptyfs_type, ptyfs->ptyfs_pty);
283	return 0;
284}
285
286/*
287 * support advisory locking on pty nodes
288 */
289int
290ptyfs_advlock(void *v)
291{
292	struct vop_print_args /* {
293		struct vnode *a_vp;
294	} */ *ap = v;
295	struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
296
297	switch (ptyfs->ptyfs_type) {
298	case PTYFSpts:
299	case PTYFSptc:
300		return spec_advlock(v);
301	default:
302		return EOPNOTSUPP;
303	}
304}
305
306/*
307 * Invent attributes for ptyfsnode (vp) and store
308 * them in (vap).
309 * Directories lengths are returned as zero since
310 * any real length would require the genuine size
311 * to be computed, and nothing cares anyway.
312 *
313 * this is relatively minimal for ptyfs.
314 */
315int
316ptyfs_getattr(void *v)
317{
318	struct vop_getattr_args /* {
319		struct vnode *a_vp;
320		struct vattr *a_vap;
321		kauth_cred_t a_cred;
322	} */ *ap = v;
323	struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
324	struct vattr *vap = ap->a_vap;
325
326	PTYFS_ITIMES(ptyfs, NULL, NULL, NULL);
327
328	/* start by zeroing out the attributes */
329	vattr_null(vap);
330
331	/* next do all the common fields */
332	vap->va_type = ap->a_vp->v_type;
333	vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0];
334	vap->va_fileid = ptyfs->ptyfs_fileno;
335	vap->va_gen = 0;
336	vap->va_flags = 0;
337	vap->va_blocksize = PAGE_SIZE;
338
339	vap->va_atime = ptyfs->ptyfs_atime;
340	vap->va_mtime = ptyfs->ptyfs_mtime;
341	vap->va_ctime = ptyfs->ptyfs_ctime;
342	vap->va_birthtime = ptyfs->ptyfs_birthtime;
343	vap->va_mode = ptyfs->ptyfs_mode;
344	vap->va_flags = ptyfs->ptyfs_flags;
345	vap->va_uid = ptyfs->ptyfs_uid;
346	vap->va_gid = ptyfs->ptyfs_gid;
347
348	switch (ptyfs->ptyfs_type) {
349	case PTYFSpts:
350	case PTYFSptc:
351		if (pty_isfree(ptyfs->ptyfs_pty, 1))
352			return ENOENT;
353		vap->va_bytes = vap->va_size = 0;
354		vap->va_rdev = ap->a_vp->v_rdev;
355		vap->va_nlink = 1;
356		break;
357	case PTYFSroot:
358		vap->va_rdev = 0;
359		vap->va_bytes = vap->va_size = DEV_BSIZE;
360		vap->va_nlink = 2;
361		break;
362	default:
363		return EOPNOTSUPP;
364	}
365
366	return 0;
367}
368
369/*ARGSUSED*/
370int
371ptyfs_setattr(void *v)
372{
373	struct vop_setattr_args /* {
374		struct vnodeop_desc *a_desc;
375		struct vnode *a_vp;
376		struct vattr *a_vap;
377		kauth_cred_t a_cred;
378	} */ *ap = v;
379	struct vnode *vp = ap->a_vp;
380	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
381	struct vattr *vap = ap->a_vap;
382	kauth_cred_t cred = ap->a_cred;
383	struct lwp *l = curlwp;
384	int error;
385	kauth_action_t action = KAUTH_VNODE_WRITE_FLAGS;
386	bool changing_sysflags = false;
387
388	if (vap->va_size != VNOVALSIZE) {
389 		switch (ptyfs->ptyfs_type) {
390 		case PTYFSroot:
391 			return EISDIR;
392 		case PTYFSpts:
393 		case PTYFSptc:
394			break;
395		default:
396			return EINVAL;
397		}
398	}
399
400	if (vap->va_flags != VNOVALFLAGS) {
401		if (vp->v_mount->mnt_flag & MNT_RDONLY)
402			return EROFS;
403
404		/* Immutable and append-only flags are not supported on ptyfs. */
405		if (vap->va_flags & (IMMUTABLE | APPEND))
406			return EINVAL;
407
408		/* Snapshot flag cannot be set or cleared */
409		if ((vap->va_flags & SF_SNAPSHOT) != (ptyfs->ptyfs_flags & SF_SNAPSHOT))
410			return EPERM;
411
412		if ((ptyfs->ptyfs_flags & SF_SETTABLE) != (vap->va_flags & SF_SETTABLE)) {
413			changing_sysflags = true;
414			action |= KAUTH_VNODE_WRITE_SYSFLAGS;
415		}
416
417		error = kauth_authorize_vnode(cred, action, vp, NULL,
418		    genfs_can_chflags(vp, cred, ptyfs->ptyfs_uid,
419		    changing_sysflags));
420		if (error)
421			return error;
422
423		if (changing_sysflags) {
424			ptyfs->ptyfs_flags = vap->va_flags;
425		} else {
426			ptyfs->ptyfs_flags &= SF_SETTABLE;
427			ptyfs->ptyfs_flags |= (vap->va_flags & UF_SETTABLE);
428		}
429		ptyfs->ptyfs_status |= PTYFS_CHANGE;
430	}
431
432	/*
433	 * Go through the fields and update iff not VNOVAL.
434	 */
435	if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
436		if (vp->v_mount->mnt_flag & MNT_RDONLY)
437			return EROFS;
438		error = ptyfs_chown(vp, vap->va_uid, vap->va_gid, cred, l);
439		if (error)
440			return error;
441	}
442
443	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL ||
444	    vap->va_birthtime.tv_sec != VNOVAL) {
445		if (vp->v_mount->mnt_flag & MNT_RDONLY)
446			return EROFS;
447		if ((ptyfs->ptyfs_flags & SF_SNAPSHOT) != 0)
448			return EPERM;
449		error = kauth_authorize_vnode(cred, KAUTH_VNODE_WRITE_TIMES, vp,
450		    NULL, genfs_can_chtimes(vp, cred, ptyfs->ptyfs_uid,
451		    vap->va_vaflags));
452		if (error)
453			return (error);
454		if (vap->va_atime.tv_sec != VNOVAL)
455			if (!(vp->v_mount->mnt_flag & MNT_NOATIME))
456				ptyfs->ptyfs_status |= PTYFS_ACCESS;
457		if (vap->va_mtime.tv_sec != VNOVAL) {
458			ptyfs->ptyfs_status |= PTYFS_CHANGE | PTYFS_MODIFY;
459			if (vp->v_mount->mnt_flag & MNT_RELATIME)
460				ptyfs->ptyfs_status |= PTYFS_ACCESS;
461		}
462		if (vap->va_birthtime.tv_sec != VNOVAL)
463			ptyfs->ptyfs_birthtime = vap->va_birthtime;
464		ptyfs->ptyfs_status |= PTYFS_CHANGE;
465		error = ptyfs_update(vp, &vap->va_atime, &vap->va_mtime, 0);
466		if (error)
467			return error;
468	}
469	if (vap->va_mode != (mode_t)VNOVAL) {
470		if (vp->v_mount->mnt_flag & MNT_RDONLY)
471			return EROFS;
472		if ((ptyfs->ptyfs_flags & SF_SNAPSHOT) != 0 &&
473		    (vap->va_mode &
474		    (S_IXUSR|S_IWUSR|S_IXGRP|S_IWGRP|S_IXOTH|S_IWOTH)))
475			return EPERM;
476		error = ptyfs_chmod(vp, vap->va_mode, cred, l);
477		if (error)
478			return error;
479	}
480	return 0;
481}
482
483/*
484 * Change the mode on a file.
485 * Inode must be locked before calling.
486 */
487static int
488ptyfs_chmod(struct vnode *vp, mode_t mode, kauth_cred_t cred, struct lwp *l)
489{
490	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
491	int error;
492
493	error = kauth_authorize_vnode(cred, KAUTH_VNODE_WRITE_SECURITY, vp,
494	    NULL, genfs_can_chmod(vp, cred, ptyfs->ptyfs_uid, ptyfs->ptyfs_gid,
495	    mode));
496	if (error)
497		return (error);
498
499	ptyfs->ptyfs_mode &= ~ALLPERMS;
500	ptyfs->ptyfs_mode |= (mode & ALLPERMS);
501	return 0;
502}
503
504/*
505 * Perform chown operation on inode ip;
506 * inode must be locked prior to call.
507 */
508static int
509ptyfs_chown(struct vnode *vp, uid_t uid, gid_t gid, kauth_cred_t cred,
510    struct lwp *l)
511{
512	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
513	int error;
514
515	if (uid == (uid_t)VNOVAL)
516		uid = ptyfs->ptyfs_uid;
517	if (gid == (gid_t)VNOVAL)
518		gid = ptyfs->ptyfs_gid;
519
520	error = kauth_authorize_vnode(cred, KAUTH_VNODE_CHANGE_OWNERSHIP, vp,
521	    NULL, genfs_can_chown(vp, cred, ptyfs->ptyfs_uid, ptyfs->ptyfs_gid,
522	    uid, gid));
523	if (error)
524		return (error);
525
526	ptyfs->ptyfs_gid = gid;
527	ptyfs->ptyfs_uid = uid;
528	return 0;
529}
530
531/*
532 * implement access checking.
533 *
534 * actually, the check for super-user is slightly
535 * broken since it will allow read access to write-only
536 * objects.  this doesn't cause any particular trouble
537 * but does mean that the i/o entry points need to check
538 * that the operation really does make sense.
539 */
540int
541ptyfs_access(void *v)
542{
543	struct vop_access_args /* {
544		struct vnode *a_vp;
545		accmode_t a_accmode;
546		kauth_cred_t a_cred;
547	} */ *ap = v;
548	struct vattr va;
549	int error;
550
551	if ((error = VOP_GETATTR(ap->a_vp, &va, ap->a_cred)) != 0)
552		return error;
553
554	return kauth_authorize_vnode(ap->a_cred,
555	    KAUTH_ACCESS_ACTION(ap->a_accmode, ap->a_vp->v_type, va.va_mode),
556	    ap->a_vp, NULL, genfs_can_access(ap->a_vp, ap->a_cred, va.va_uid,
557	    va.va_gid, va.va_mode, NULL, ap->a_accmode));
558}
559
560/*
561 * lookup.  this is incredibly complicated in the
562 * general case, however for most pseudo-filesystems
563 * very little needs to be done.
564 *
565 * Locking isn't hard here, just poorly documented.
566 *
567 * If we're looking up ".", just vref the parent & return it.
568 *
569 * If we're looking up "..", unlock the parent, and lock "..". If everything
570 * went ok, try to re-lock the parent. We do this to prevent lock races.
571 *
572 * For anything else, get the needed node.
573 *
574 * We try to exit with the parent locked in error cases.
575 */
576int
577ptyfs_lookup(void *v)
578{
579	struct vop_lookup_v2_args /* {
580		struct vnode * a_dvp;
581		struct vnode ** a_vpp;
582		struct componentname * a_cnp;
583	} */ *ap = v;
584	struct componentname *cnp = ap->a_cnp;
585	struct vnode **vpp = ap->a_vpp;
586	struct vnode *dvp = ap->a_dvp;
587	const char *pname = cnp->cn_nameptr;
588	struct ptyfsnode *ptyfs;
589	int pty, error;
590
591	*vpp = NULL;
592
593	if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)
594		return EROFS;
595
596	if (cnp->cn_namelen == 1 && *pname == '.') {
597		*vpp = dvp;
598		vref(dvp);
599		return 0;
600	}
601
602	ptyfs = VTOPTYFS(dvp);
603	switch (ptyfs->ptyfs_type) {
604	case PTYFSroot:
605		/*
606		 * Shouldn't get here with .. in the root node.
607		 */
608		if (cnp->cn_flags & ISDOTDOT)
609			return EIO;
610
611		pty = atoi(pname, cnp->cn_namelen);
612		if (pty < 0 || ptyfs_next_active(dvp->v_mount, pty) != pty)
613			break;
614		error = ptyfs_allocvp(dvp->v_mount, vpp, PTYFSpts, pty);
615		if (error)
616			return error;
617		if (ptyfs_next_active(dvp->v_mount, pty) != pty) {
618			vrele(*vpp);
619			*vpp = NULL;
620			return ENOENT;
621		}
622		return 0;
623
624	default:
625		return ENOTDIR;
626	}
627
628	return cnp->cn_nameiop == LOOKUP ? ENOENT : EROFS;
629}
630
631/*
632 * readdir returns directory entries from ptyfsnode (vp).
633 *
634 * the strategy here with ptyfs is to generate a single
635 * directory entry at a time (struct dirent) and then
636 * copy that out to userland using uiomove.  a more efficient
637 * though more complex implementation, would try to minimize
638 * the number of calls to uiomove().  for ptyfs, this is
639 * hardly worth the added code complexity.
640 *
641 * this should just be done through read()
642 */
643int
644ptyfs_readdir(void *v)
645{
646	struct vop_readdir_args /* {
647		struct vnode *a_vp;
648		struct uio *a_uio;
649		kauth_cred_t a_cred;
650		int *a_eofflag;
651		off_t **a_cookies;
652		int *a_ncookies;
653	} */ *ap = v;
654	struct uio *uio = ap->a_uio;
655	struct dirent *dp;
656	struct ptyfsnode *ptyfs;
657	off_t i;
658	int error;
659	off_t *cookies = NULL;
660	int ncookies;
661	struct vnode *vp;
662	int n, nc = 0;
663
664	vp = ap->a_vp;
665	ptyfs = VTOPTYFS(vp);
666
667	if (uio->uio_resid < UIO_MX)
668		return EINVAL;
669	if (uio->uio_offset < 0)
670		return EINVAL;
671
672	dp = malloc(sizeof(struct dirent), M_PTYFSTMP, M_WAITOK | M_ZERO);
673
674	error = 0;
675	i = uio->uio_offset;
676	dp->d_reclen = UIO_MX;
677	ncookies = uio->uio_resid / UIO_MX;
678
679	if (ptyfs->ptyfs_type != PTYFSroot) {
680		error = ENOTDIR;
681		goto out;
682	}
683
684	if (i >= npty)
685		goto out;
686
687	if (ap->a_ncookies) {
688		ncookies = uimin(ncookies, (npty + 2 - i));
689		cookies = malloc(ncookies * sizeof (off_t),
690		    M_TEMP, M_WAITOK);
691		*ap->a_cookies = cookies;
692	}
693
694	for (; i < 2 && uio->uio_resid >= UIO_MX; i++) {
695		/* `.' and/or `..' */
696		dp->d_fileno = PTYFS_FILENO(PTYFSroot, 0);
697		dp->d_namlen = i + 1;
698		(void)memcpy(dp->d_name, "..", dp->d_namlen);
699		dp->d_name[i + 1] = '\0';
700		dp->d_type = DT_DIR;
701		if ((error = uiomove(dp, UIO_MX, uio)) != 0)
702			goto out;
703		if (cookies)
704			*cookies++ = i + 1;
705		nc++;
706	}
707	while (uio->uio_resid >= UIO_MX) {
708		/* check for used ptys */
709		n = ptyfs_next_active(vp->v_mount, i - 2);
710		if (n < 0)
711			break;
712		dp->d_fileno = PTYFS_FILENO(PTYFSpts, n);
713		dp->d_namlen = snprintf(dp->d_name, sizeof(dp->d_name),
714		    "%lld", (long long)(n));
715		dp->d_type = DT_CHR;
716		if ((error = uiomove(dp, UIO_MX, uio)) != 0)
717			goto out;
718		i = n + 3;
719		if (cookies)
720			*cookies++ = i;
721		nc++;
722	}
723
724out:
725	/* not pertinent in error cases */
726	ncookies = nc;
727
728	if (ap->a_ncookies) {
729		if (error) {
730			if (cookies)
731				free(*ap->a_cookies, M_TEMP);
732			*ap->a_ncookies = 0;
733			*ap->a_cookies = NULL;
734		} else
735			*ap->a_ncookies = ncookies;
736	}
737	uio->uio_offset = i;
738	free(dp, M_PTYFSTMP);
739	return error;
740}
741
742int
743ptyfs_open(void *v)
744{
745	struct vop_open_args /* {
746		struct vnode *a_vp;
747		int  a_mode;
748		kauth_cred_t a_cred;
749	} */ *ap = v;
750	struct vnode *vp = ap->a_vp;
751	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
752
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
764int
765ptyfs_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	} */ *ap = v;
772	struct vnode *vp = ap->a_vp;
773	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
774
775	mutex_enter(vp->v_interlock);
776	if (vrefcnt(vp) > 1)
777		PTYFS_ITIMES(ptyfs, NULL, NULL, NULL);
778	mutex_exit(vp->v_interlock);
779
780	switch (ptyfs->ptyfs_type) {
781	case PTYFSpts:
782	case PTYFSptc:
783		return spec_close(v);
784	case PTYFSroot:
785		return 0;
786	default:
787		return EINVAL;
788	}
789}
790
791int
792ptyfs_read(void *v)
793{
794	struct vop_read_args /* {
795		struct vnode *a_vp;
796		struct uio *a_uio;
797		int  a_ioflag;
798		kauth_cred_t a_cred;
799	} */ *ap = v;
800	struct timespec ts;
801	struct vnode *vp = ap->a_vp;
802	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
803	int error;
804
805	if (vp->v_type == VDIR)
806		return EISDIR;
807
808	ptyfs->ptyfs_status |= PTYFS_ACCESS;
809	/* hardclock() resolution is good enough for ptyfs */
810	getnanotime(&ts);
811	(void)ptyfs_update(vp, &ts, &ts, 0);
812
813	switch (ptyfs->ptyfs_type) {
814	case PTYFSpts:
815	case PTYFSptc:
816		VOP_UNLOCK(vp);
817		error = cdev_read(vp->v_rdev, ap->a_uio, ap->a_ioflag);
818		vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
819		return error;
820	default:
821		return EOPNOTSUPP;
822	}
823}
824
825int
826ptyfs_write(void *v)
827{
828	struct vop_write_args /* {
829		struct vnode *a_vp;
830		struct uio *a_uio;
831		int  a_ioflag;
832		kauth_cred_t a_cred;
833	} */ *ap = v;
834	struct timespec ts;
835	struct vnode *vp = ap->a_vp;
836	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
837	int error;
838
839	ptyfs->ptyfs_status |= PTYFS_MODIFY;
840	getnanotime(&ts);
841	(void)ptyfs_update(vp, &ts, &ts, 0);
842
843	switch (ptyfs->ptyfs_type) {
844	case PTYFSpts:
845	case PTYFSptc:
846		VOP_UNLOCK(vp);
847		error = cdev_write(vp->v_rdev, ap->a_uio, ap->a_ioflag);
848		vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
849		return error;
850	default:
851		return EOPNOTSUPP;
852	}
853}
854
855int
856ptyfs_ioctl(void *v)
857{
858	struct vop_ioctl_args /* {
859		struct vnode *a_vp;
860		u_long a_command;
861		void *a_data;
862		int  a_fflag;
863		kauth_cred_t a_cred;
864	} */ *ap = v;
865	struct vnode *vp = ap->a_vp;
866	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
867
868	switch (ptyfs->ptyfs_type) {
869	case PTYFSpts:
870	case PTYFSptc:
871		return cdev_ioctl(vp->v_rdev, ap->a_command,
872		    ap->a_data, ap->a_fflag, curlwp);
873	default:
874		return EOPNOTSUPP;
875	}
876}
877
878int
879ptyfs_poll(void *v)
880{
881	struct vop_poll_args /* {
882		struct vnode *a_vp;
883		int a_events;
884	} */ *ap = v;
885	struct vnode *vp = ap->a_vp;
886	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
887
888	switch (ptyfs->ptyfs_type) {
889	case PTYFSpts:
890	case PTYFSptc:
891		return cdev_poll(vp->v_rdev, ap->a_events, curlwp);
892	default:
893		return genfs_poll(v);
894	}
895}
896
897int
898ptyfs_kqfilter(void *v)
899{
900	struct vop_kqfilter_args /* {
901		struct vnode *a_vp;
902		struct knote *a_kn;
903	} */ *ap = v;
904	struct vnode *vp = ap->a_vp;
905	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
906
907	switch (ptyfs->ptyfs_type) {
908	case PTYFSpts:
909	case PTYFSptc:
910		return cdev_kqfilter(vp->v_rdev, ap->a_kn);
911	default:
912		return genfs_kqfilter(v);
913	}
914}
915
916static int
917ptyfs_update(struct vnode *vp, const struct timespec *acc,
918    const struct timespec *mod, int flags)
919{
920	struct ptyfsnode *ptyfs = VTOPTYFS(vp);
921
922	if (vp->v_mount->mnt_flag & MNT_RDONLY)
923		return 0;
924
925	PTYFS_ITIMES(ptyfs, acc, mod, NULL);
926	return 0;
927}
928
929void
930ptyfs_itimes(struct ptyfsnode *ptyfs, const struct timespec *acc,
931    const struct timespec *mod, const struct timespec *cre)
932{
933	struct timespec now;
934
935	KASSERT(ptyfs->ptyfs_status & (PTYFS_ACCESS|PTYFS_CHANGE|PTYFS_MODIFY));
936
937	getnanotime(&now);
938	if (ptyfs->ptyfs_status & PTYFS_ACCESS) {
939		if (acc == NULL)
940			acc = &now;
941		ptyfs->ptyfs_atime = *acc;
942	}
943	if (ptyfs->ptyfs_status & PTYFS_MODIFY) {
944		if (mod == NULL)
945			mod = &now;
946		ptyfs->ptyfs_mtime = *mod;
947	}
948	if (ptyfs->ptyfs_status & PTYFS_CHANGE) {
949		if (cre == NULL)
950			cre = &now;
951		ptyfs->ptyfs_ctime = *cre;
952	}
953	ptyfs->ptyfs_status &= ~(PTYFS_ACCESS|PTYFS_CHANGE|PTYFS_MODIFY);
954}
955
956/*
957 * convert decimal ascii to int
958 */
959static int
960atoi(const char *b, size_t len)
961{
962	int p = 0;
963
964	while (len--) {
965		char c = *b++;
966		if (c < '0' || c > '9')
967			return -1;
968		p = 10 * p + (c - '0');
969	}
970
971	return p;
972}
973