ptyfs_vfsops.c revision 1.23 
1/*	$NetBSD: ptyfs_vfsops.c,v 1.23 2007/01/19 14:49:09 hannken 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 1.23 2007/01/19 14:49:09 hannken 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/filedesc.h>
57#include <sys/tty.h>
58#include <sys/pty.h>
59#include <sys/kauth.h>
60
61#include <fs/ptyfs/ptyfs.h>
62#include <miscfs/specfs/specdev.h>
63
64MALLOC_DEFINE(M_PTYFSMNT, "ptyfs mount", "ptyfs mount structures");
65
66void	ptyfs_init(void);
67void	ptyfs_reinit(void);
68void	ptyfs_done(void);
69int	ptyfs_mount(struct mount *, const char *, void *, struct nameidata *,
70    struct lwp *);
71int	ptyfs_start(struct mount *, int, struct lwp *);
72int	ptyfs_unmount(struct mount *, int, struct lwp *);
73int	ptyfs_statvfs(struct mount *, struct statvfs *, struct lwp *);
74int	ptyfs_quotactl(struct mount *, int, uid_t, void *, struct lwp *);
75int	ptyfs_sync(struct mount *, int, kauth_cred_t, struct lwp *);
76int	ptyfs_vget(struct mount *, ino_t, struct vnode **);
77
78static int ptyfs__allocvp(struct ptm_pty *, struct lwp *, struct vnode **,
79    dev_t, char);
80static int ptyfs__makename(struct ptm_pty *, struct lwp *, char *, size_t,
81    dev_t, char);
82static void ptyfs__getvattr(struct ptm_pty *, struct lwp *, struct vattr *);
83
84/*
85 * ptm glue: When we mount, we make ptm point to us.
86 */
87struct ptm_pty *ptyfs_save_ptm;
88static int ptyfs_count;
89
90struct ptm_pty ptm_ptyfspty = {
91	ptyfs__allocvp,
92	ptyfs__makename,
93	ptyfs__getvattr,
94	NULL
95};
96
97static const char *
98ptyfs__getpath(struct lwp *l, const struct mount *mp)
99{
100#define MAXBUF (sizeof(mp->mnt_stat.f_mntonname) + 32)
101	struct cwdinfo *cwdi = l->l_proc->p_cwdi;
102	char *buf;
103	const char *rv;
104	size_t len;
105	char *bp;
106	int error;
107
108	rv = mp->mnt_stat.f_mntonname;
109	if (cwdi->cwdi_rdir == NULL)
110		return rv;
111
112	buf = malloc(MAXBUF, M_TEMP, M_WAITOK);
113	bp = buf + MAXBUF;
114	*--bp = '\0';
115	error = getcwd_common(cwdi->cwdi_rdir, rootvnode, &bp,
116	    buf, MAXBUF / 2, 0, l);
117	if (error)	/* XXX */
118		goto out;
119
120	len = strlen(bp);
121	if (len < sizeof(mp->mnt_stat.f_mntonname))	/* XXX */
122		rv += len;
123out:
124	free(buf, M_TEMP);
125	return rv;
126}
127
128static int
129ptyfs__makename(struct ptm_pty *pt, struct lwp *l, char *tbuf, size_t bufsiz,
130    dev_t dev, char ms)
131{
132	struct mount *mp = pt->arg;
133	size_t len;
134
135	switch (ms) {
136	case 'p':
137		/* We don't provide access to the master, should we? */
138		len = snprintf(tbuf, bufsiz, "/dev/null");
139		break;
140	case 't':
141		len = snprintf(tbuf, bufsiz, "%s/%d", ptyfs__getpath(l, mp),
142		    minor(dev));
143		break;
144	default:
145		return EINVAL;
146	}
147
148	return len >= bufsiz ? ENOSPC : 0;
149}
150
151
152static int
153/*ARGSUSED*/
154ptyfs__allocvp(struct ptm_pty *pt, struct lwp *l, struct vnode **vpp,
155    dev_t dev, char ms)
156{
157	struct mount *mp = pt->arg;
158	ptyfstype type;
159
160	switch (ms) {
161	case 'p':
162		type = PTYFSptc;
163		break;
164	case 't':
165		type = PTYFSpts;
166		break;
167	default:
168		return EINVAL;
169	}
170
171	return ptyfs_allocvp(mp, vpp, type, minor(dev), l);
172}
173
174
175static void
176ptyfs__getvattr(struct ptm_pty *pt, struct lwp *l, struct vattr *vattr)
177{
178	struct mount *mp = pt->arg;
179	struct ptyfsmount *pmnt = VFSTOPTY(mp);
180	VATTR_NULL(vattr);
181	/* get real uid */
182	vattr->va_uid = kauth_cred_getuid(l->l_cred);
183	vattr->va_gid = pmnt->pmnt_gid;
184	vattr->va_mode = pmnt->pmnt_mode;
185}
186
187
188void
189ptyfs_init(void)
190{
191#ifdef _LKM
192	malloc_type_attach(M_PTYFSMNT);
193#endif
194	ptyfs_hashinit();
195}
196
197void
198ptyfs_reinit(void)
199{
200	ptyfs_hashreinit();
201}
202
203void
204ptyfs_done(void)
205{
206#ifdef _LKM
207	malloc_type_detach(M_PTYFSMNT);
208#endif
209	ptyfs_hashdone();
210}
211
212/*
213 * Mount the Pseudo tty params filesystem
214 */
215int
216ptyfs_mount(struct mount *mp, const char *path, void *data,
217    struct nameidata *ndp, struct lwp *l)
218{
219	int error = 0;
220	struct ptyfsmount *pmnt;
221	struct ptyfs_args args;
222
223	if (UIO_MX & (UIO_MX - 1)) {
224		log(LOG_ERR, "ptyfs: invalid directory entry size");
225		return EINVAL;
226	}
227
228	if (mp->mnt_flag & MNT_GETARGS) {
229		pmnt = VFSTOPTY(mp);
230		if (pmnt == NULL)
231			return EIO;
232		args.version = PTYFS_ARGSVERSION;
233		args.mode = pmnt->pmnt_mode;
234		args.gid = pmnt->pmnt_gid;
235		return copyout(&args, data, sizeof(args));
236	}
237
238	/* Don't allow more than one mount */
239	if (ptyfs_count)
240		return EBUSY;
241
242	if (mp->mnt_flag & MNT_UPDATE)
243		return EOPNOTSUPP;
244
245	if (data != NULL) {
246		error = copyin(data, &args, sizeof args);
247		if (error != 0)
248			return error;
249
250		if (args.version != PTYFS_ARGSVERSION)
251			return EINVAL;
252	} else {
253		/*
254		 * Arguments are mandatory.
255		 */
256		return EINVAL;
257	}
258
259	pmnt = malloc(sizeof(struct ptyfsmount), M_UFSMNT, M_WAITOK);
260
261	mp->mnt_data = pmnt;
262	pmnt->pmnt_gid = args.gid;
263	pmnt->pmnt_mode = args.mode;
264	mp->mnt_flag |= MNT_LOCAL;
265	vfs_getnewfsid(mp);
266
267	if ((error = set_statvfs_info(path, UIO_USERSPACE, "ptyfs",
268	    UIO_SYSSPACE, mp, l)) != 0) {
269		free(pmnt, M_UFSMNT);
270		return error;
271	}
272
273	/* Point pty access to us */
274
275	ptm_ptyfspty.arg = mp;
276	ptyfs_save_ptm = pty_sethandler(&ptm_ptyfspty);
277	ptyfs_count++;
278	return 0;
279}
280
281/*ARGSUSED*/
282int
283ptyfs_start(struct mount *mp, int flags,
284    struct lwp *p)
285{
286	return 0;
287}
288
289/*ARGSUSED*/
290int
291ptyfs_unmount(struct mount *mp, int mntflags, struct lwp *p)
292{
293	int error;
294	int flags = 0;
295
296	if (mntflags & MNT_FORCE)
297		flags |= FORCECLOSE;
298
299	if ((error = vflush(mp, 0, flags)) != 0)
300		return (error);
301
302	/* Restore where pty access was pointing */
303	(void)pty_sethandler(ptyfs_save_ptm);
304	ptyfs_save_ptm = NULL;
305	ptm_ptyfspty.arg = NULL;
306
307	/*
308	 * Finally, throw away the ptyfsmount structure
309	 */
310	free(mp->mnt_data, M_UFSMNT);
311	mp->mnt_data = 0;
312	ptyfs_count--;
313
314	return 0;
315}
316
317int
318ptyfs_root(struct mount *mp, struct vnode **vpp)
319{
320	/* setup "." */
321	return ptyfs_allocvp(mp, vpp, PTYFSroot, 0, NULL);
322}
323
324/*ARGSUSED*/
325int
326ptyfs_quotactl(struct mount *mp, int cmd, uid_t uid,
327    void *arg, struct lwp *p)
328{
329	return EOPNOTSUPP;
330}
331
332/*ARGSUSED*/
333int
334ptyfs_statvfs(struct mount *mp, struct statvfs *sbp, struct lwp *p)
335{
336	sbp->f_bsize = DEV_BSIZE;
337	sbp->f_frsize = DEV_BSIZE;
338	sbp->f_iosize = DEV_BSIZE;
339	sbp->f_blocks = 2;		/* 1K to keep df happy */
340	sbp->f_bfree = 0;
341	sbp->f_bavail = 0;
342	sbp->f_bresvd = 0;
343	sbp->f_files = 1024;	/* XXX lie */
344	sbp->f_ffree = 128;	/* XXX lie */
345	sbp->f_favail = 128;	/* XXX lie */
346	sbp->f_fresvd = 0;
347	sbp->f_namemax = MAXNAMLEN;
348	copy_statvfs_info(sbp, mp);
349	return 0;
350}
351
352/*ARGSUSED*/
353int
354ptyfs_sync(struct mount *mp, int waitfor,
355    kauth_cred_t uc, struct lwp *p)
356{
357	return 0;
358}
359
360/*
361 * Kernfs flat namespace lookup.
362 * Currently unsupported.
363 */
364/*ARGSUSED*/
365int
366ptyfs_vget(struct mount *mp, ino_t ino,
367    struct vnode **vpp)
368{
369	return EOPNOTSUPP;
370}
371
372SYSCTL_SETUP(sysctl_vfs_ptyfs_setup, "sysctl vfs.ptyfs subtree setup")
373{
374
375	sysctl_createv(clog, 0, NULL, NULL,
376		       CTLFLAG_PERMANENT,
377		       CTLTYPE_NODE, "vfs", NULL,
378		       NULL, 0, NULL, 0,
379		       CTL_VFS, CTL_EOL);
380	sysctl_createv(clog, 0, NULL, NULL,
381		       CTLFLAG_PERMANENT,
382		       CTLTYPE_NODE, "ptyfs",
383		       SYSCTL_DESCR("Pty file system"),
384		       NULL, 0, NULL, 0,
385		       CTL_VFS, 23, CTL_EOL);
386	/*
387	 * XXX the "23" above could be dynamic, thereby eliminating
388	 * one more instance of the "number to vfs" mapping problem,
389	 * but "23" is the order as taken from sys/mount.h
390	 */
391}
392
393
394extern const struct vnodeopv_desc ptyfs_vnodeop_opv_desc;
395
396const struct vnodeopv_desc * const ptyfs_vnodeopv_descs[] = {
397	&ptyfs_vnodeop_opv_desc,
398	NULL,
399};
400
401struct vfsops ptyfs_vfsops = {
402	MOUNT_PTYFS,
403	ptyfs_mount,
404	ptyfs_start,
405	ptyfs_unmount,
406	ptyfs_root,
407	ptyfs_quotactl,
408	ptyfs_statvfs,
409	ptyfs_sync,
410	ptyfs_vget,
411	(void *)eopnotsupp,		/* vfs_fhtovp */
412	(void *)eopnotsupp,		/* vfs_vptofp */
413	ptyfs_init,
414	ptyfs_reinit,
415	ptyfs_done,
416	NULL,				/* vfs_mountroot */
417	(int (*)(struct mount *, struct vnode *, struct timespec *))eopnotsupp,
418	(int (*)(struct mount *, int, struct vnode *, int, const char *,
419	    struct lwp *))eopnotsupp,
420	vfs_stdsuspendctl,
421	ptyfs_vnodeopv_descs,
422	0,
423	{ NULL, NULL },
424};
425VFS_ATTACH(ptyfs_vfsops);
426