ptyfs_vfsops.c revision 1.7 
1/*	$NetBSD: ptyfs_vfsops.c,v 1.7 2005/05/11 17:38:54 christos Exp $	*/
2
3/*
4 * Copyright (c) 1992, 1993, 1995
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software donated to Berkeley by
8 * Jan-Simon Pendry.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. 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 */
35
36/*
37 * Pseudo-tty Filesystem
38 */
39
40#include <sys/cdefs.h>
41__KERNEL_RCSID(0, "$NetBSD: ptyfs_vfsops.c,v 1.7 2005/05/11 17:38:54 christos Exp $");
42
43#include <sys/param.h>
44#include <sys/systm.h>
45#include <sys/sysctl.h>
46#include <sys/conf.h>
47#include <sys/proc.h>
48#include <sys/vnode.h>
49#include <sys/mount.h>
50#include <sys/namei.h>
51#include <sys/stat.h>
52#include <sys/dirent.h>
53#include <sys/malloc.h>
54#include <sys/syslog.h>
55#include <sys/select.h>
56#include <sys/tty.h>
57#include <sys/pty.h>
58
59#include <fs/ptyfs/ptyfs.h>
60#include <miscfs/specfs/specdev.h>
61
62MALLOC_DEFINE(M_PTYFSMNT, "ptyfs mount", "ptyfs mount structures");
63
64void	ptyfs_init(void);
65void	ptyfs_reinit(void);
66void	ptyfs_done(void);
67int	ptyfs_mount(struct mount *, const char *, void *, struct nameidata *,
68    struct proc *);
69int	ptyfs_start(struct mount *, int, struct proc *);
70int	ptyfs_unmount(struct mount *, int, struct proc *);
71int	ptyfs_statvfs(struct mount *, struct statvfs *, struct proc *);
72int	ptyfs_quotactl(struct mount *, int, uid_t, void *, struct proc *);
73int	ptyfs_sync(struct mount *, int, struct ucred *, struct proc *);
74int	ptyfs_vget(struct mount *, ino_t, struct vnode **);
75int	ptyfs_fhtovp(struct mount *, struct fid *, struct vnode **);
76int	ptyfs_checkexp(struct mount *, struct mbuf *, int *, struct ucred **);
77int	ptyfs_vptofh(struct vnode *, struct fid *);
78
79static int ptyfs__allocvp(struct ptm_pty *, struct proc *, struct vnode **,
80    dev_t, char);
81static int ptyfs__makename(struct ptm_pty *, char *, size_t, dev_t, char);
82static void ptyfs__getvattr(struct ptm_pty *, struct proc *, struct vattr *);
83
84/*
85 * ptm glue: When we mount, we make ptm point to us.
86 */
87struct ptm_pty *ptyfs_save_ptm;
88
89struct ptm_pty ptm_ptyfspty = {
90	ptyfs__allocvp,
91	ptyfs__makename,
92	ptyfs__getvattr,
93	NULL
94};
95
96static int
97ptyfs__makename(struct ptm_pty *pt, char *buf, size_t bufsiz, dev_t dev,
98    char ms)
99{
100	struct mount *mp = pt->arg;
101	size_t len;
102
103	switch (ms) {
104	case 'p':
105		/* We don't provide access to the master, should we? */
106		len = snprintf(buf, bufsiz, "/dev/null");
107		break;
108	case 't':
109		len = snprintf(buf, bufsiz, "%s/%d", mp->mnt_stat.f_mntonname,
110		    minor(dev));
111		break;
112	default:
113		return EINVAL;
114	}
115
116	return len >= bufsiz ? ENOSPC : 0;
117}
118
119
120static int
121/*ARGSUSED*/
122ptyfs__allocvp(struct ptm_pty *pt, struct proc *p, struct vnode **vpp,
123    dev_t dev, char ms)
124{
125	struct mount *mp = pt->arg;
126	ptyfstype type;
127
128	switch (ms) {
129	case 'p':
130		type = PTYFSptc;
131		break;
132	case 't':
133		type = PTYFSpts;
134		break;
135	default:
136		return EINVAL;
137	}
138
139	return ptyfs_allocvp(mp, vpp, type, minor(dev), p);
140}
141
142
143static void
144ptyfs__getvattr(struct ptm_pty *pt, struct proc *p, struct vattr *vattr)
145{
146	struct mount *mp = pt->arg;
147	struct ptyfsmount *pmnt = VFSTOPTY(mp);
148	VATTR_NULL(vattr);
149	/* get real uid */
150	vattr->va_uid = p->p_cred->p_ruid;
151	vattr->va_gid = pmnt->pmnt_gid;
152	vattr->va_mode = pmnt->pmnt_mode;
153}
154
155
156void
157ptyfs_init(void)
158{
159#ifdef _LKM
160	malloc_type_attach(M_PTYFSMNT);
161#endif
162	ptyfs_hashinit();
163}
164
165void
166ptyfs_reinit(void)
167{
168	ptyfs_hashreinit();
169}
170
171void
172ptyfs_done(void)
173{
174#ifdef _LKM
175	malloc_type_detach(M_PTYFSMNT);
176#endif
177	ptyfs_hashdone();
178}
179
180/*
181 * Mount the Pseudo tty params filesystem
182 */
183int
184ptyfs_mount(struct mount *mp, const char *path, void *data,
185    struct nameidata *ndp, struct proc *p)
186{
187	int error = 0;
188	struct ptyfsmount *pmnt;
189	struct ptyfs_args args;
190
191	if (UIO_MX & (UIO_MX - 1)) {
192		log(LOG_ERR, "ptyfs: invalid directory entry size");
193		return EINVAL;
194	}
195
196	if (mp->mnt_flag & MNT_GETARGS) {
197		pmnt = VFSTOPTY(mp);
198		if (pmnt == NULL)
199			return EIO;
200		args.version = PTYFS_ARGSVERSION;
201		args.mode = pmnt->pmnt_mode;
202		args.gid = pmnt->pmnt_gid;
203		return copyout(&args, data, sizeof(args));
204	}
205
206	if (mp->mnt_flag & MNT_UPDATE)
207		return EOPNOTSUPP;
208
209	if (data != NULL) {
210		error = copyin(data, &args, sizeof args);
211		if (error != 0)
212			return error;
213
214		if (args.version != PTYFS_ARGSVERSION)
215			return EINVAL;
216	} else {
217		/*
218		 * Arguments are mandatory.
219		 */
220		return EINVAL;
221	}
222
223	pmnt = malloc(sizeof(struct ptyfsmount), M_UFSMNT, M_WAITOK);
224
225	mp->mnt_data = pmnt;
226	pmnt->pmnt_gid = args.gid;
227	pmnt->pmnt_mode = args.mode;
228	mp->mnt_flag |= MNT_LOCAL;
229	vfs_getnewfsid(mp);
230
231	if ((error = set_statvfs_info(path, UIO_USERSPACE, "ptyfs",
232	    UIO_SYSSPACE, mp, p)) != 0) {
233		return error;
234	}
235
236	/* Point pty access to us */
237	if (ptyfs_save_ptm != NULL)
238		return EBUSY;
239
240	ptm_ptyfspty.arg = mp;
241	ptyfs_save_ptm = pty_sethandler(&ptm_ptyfspty);
242	return 0;
243}
244
245/*ARGSUSED*/
246int
247ptyfs_start(struct mount *mp, int flags, struct proc *p)
248{
249	return 0;
250}
251
252/*ARGSUSED*/
253int
254ptyfs_unmount(struct mount *mp, int mntflags, struct proc *p)
255{
256	int error;
257	int flags = 0;
258
259	if (mntflags & MNT_FORCE)
260		flags |= FORCECLOSE;
261
262	if ((error = vflush(mp, 0, flags)) != 0)
263		return (error);
264
265	/* Restore where pty access was pointing */
266	ptm_ptyfspty.arg = NULL;
267	(void)pty_sethandler(ptyfs_save_ptm);
268	ptyfs_save_ptm = NULL;
269
270	/*
271	 * Finally, throw away the ptyfsmount structure
272	 */
273	free(mp->mnt_data, M_UFSMNT);
274	mp->mnt_data = 0;
275
276	return 0;
277}
278
279int
280ptyfs_root(struct mount *mp, struct vnode **vpp)
281{
282	/* setup "." */
283	return ptyfs_allocvp(mp, vpp, PTYFSroot, 0, NULL);
284}
285
286/*ARGSUSED*/
287int
288ptyfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg, struct proc *p)
289{
290	return EOPNOTSUPP;
291}
292
293/*ARGSUSED*/
294int
295ptyfs_statvfs(struct mount *mp, struct statvfs *sbp, struct proc *p)
296{
297	sbp->f_bsize = DEV_BSIZE;
298	sbp->f_frsize = DEV_BSIZE;
299	sbp->f_iosize = DEV_BSIZE;
300	sbp->f_blocks = 2;		/* 1K to keep df happy */
301	sbp->f_bfree = 0;
302	sbp->f_bavail = 0;
303	sbp->f_bresvd = 0;
304	sbp->f_files = 1024;	/* XXX lie */
305	sbp->f_ffree = 128;	/* XXX lie */
306	sbp->f_favail = 128;	/* XXX lie */
307	sbp->f_fresvd = 0;
308	sbp->f_namemax = MAXNAMLEN;
309	copy_statvfs_info(sbp, mp);
310	return 0;
311}
312
313/*ARGSUSED*/
314int
315ptyfs_sync(struct mount *mp, int waitfor, struct ucred *uc, struct proc *p)
316{
317	return 0;
318}
319
320/*
321 * Kernfs flat namespace lookup.
322 * Currently unsupported.
323 */
324/*ARGSUSED*/
325int
326ptyfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
327{
328	return EOPNOTSUPP;
329}
330
331/*ARGSUSED*/
332int
333ptyfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
334{
335	return EOPNOTSUPP;
336}
337
338/*ARGSUSED*/
339int
340ptyfs_checkexp(struct mount *mp, struct mbuf *mb, int *wh, struct ucred **anon)
341{
342	return EOPNOTSUPP;
343}
344
345SYSCTL_SETUP(sysctl_vfs_ptyfs_setup, "sysctl vfs.ptyfs subtree setup")
346{
347
348	sysctl_createv(clog, 0, NULL, NULL,
349		       CTLFLAG_PERMANENT,
350		       CTLTYPE_NODE, "vfs", NULL,
351		       NULL, 0, NULL, 0,
352		       CTL_VFS, CTL_EOL);
353	sysctl_createv(clog, 0, NULL, NULL,
354		       CTLFLAG_PERMANENT,
355		       CTLTYPE_NODE, "ptyfs",
356		       SYSCTL_DESCR("Pty file system"),
357		       NULL, 0, NULL, 0,
358		       CTL_VFS, 23, CTL_EOL);
359	/*
360	 * XXX the "23" above could be dynamic, thereby eliminating
361	 * one more instance of the "number to vfs" mapping problem,
362	 * but "23" is the order as taken from sys/mount.h
363	 */
364}
365
366
367/*ARGSUSED*/
368int
369ptyfs_vptofh(struct vnode *vp, struct fid *fhp)
370{
371	return EOPNOTSUPP;
372}
373
374extern const struct vnodeopv_desc ptyfs_vnodeop_opv_desc;
375
376const struct vnodeopv_desc * const ptyfs_vnodeopv_descs[] = {
377	&ptyfs_vnodeop_opv_desc,
378	NULL,
379};
380
381struct vfsops ptyfs_vfsops = {
382	MOUNT_PTYFS,
383	ptyfs_mount,
384	ptyfs_start,
385	ptyfs_unmount,
386	ptyfs_root,
387	ptyfs_quotactl,
388	ptyfs_statvfs,
389	ptyfs_sync,
390	ptyfs_vget,
391	ptyfs_fhtovp,
392	ptyfs_vptofh,
393	ptyfs_init,
394	ptyfs_reinit,
395	ptyfs_done,
396	NULL,
397	NULL,				/* vfs_mountroot */
398	ptyfs_checkexp,
399	(int (*)(struct mount *, struct vnode *, struct timespec *))eopnotsupp,
400	(int (*)(struct mount *, int, struct vnode *, int, const char *,
401	    struct proc *))eopnotsupp,
402	ptyfs_vnodeopv_descs,
403};
404VFS_ATTACH(ptyfs_vfsops);
405