1/*	$NetBSD: tty_bsdpty.c,v 1.16 2010/01/08 11:35:10 pooka Exp $	*/
2
3/*-
4 * Copyright (c) 2004 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__KERNEL_RCSID(0, "$NetBSD: tty_bsdpty.c,v 1.16 2010/01/08 11:35:10 pooka Exp $");
31
32#include "opt_ptm.h"
33
34#ifdef COMPAT_BSDPTY
35/* bsd tty implementation for pty multiplexor driver /dev/ptm{,x} */
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/ioctl.h>
40#include <sys/lwp.h>
41#include <sys/tty.h>
42#include <sys/stat.h>
43#include <sys/file.h>
44#include <sys/uio.h>
45#include <sys/kernel.h>
46#include <sys/vnode.h>
47#include <sys/namei.h>
48#include <sys/signalvar.h>
49#include <sys/filedesc.h>
50#include <sys/conf.h>
51#include <sys/poll.h>
52#include <sys/pty.h>
53#include <sys/kauth.h>
54
55/*
56 * pts == /dev/tty[pqrs]?
57 * ptc == /dev/pty[pqrs]?
58 */
59
60/*
61 * All this hard-coding is really evil.
62 */
63#define TTY_GID		4
64#define TTY_PERM	(S_IRUSR|S_IWUSR|S_IWGRP)
65#define TTY_TEMPLATE	"/dev/XtyXX"
66#define TTY_NAMESIZE	sizeof(TTY_TEMPLATE)
67#define TTY_LETTERS	"pqrstuvwxyzPQRST"
68#define TTY_OLD_SUFFIX  "0123456789abcdef"
69#define TTY_NEW_SUFFIX  "ghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
70
71static int pty_makename(struct ptm_pty *, struct lwp *, char *, size_t, dev_t,
72    char);
73static int pty_allocvp(struct ptm_pty *, struct lwp *, struct vnode **,
74    dev_t, char);
75static void pty_getvattr(struct ptm_pty *, struct lwp *, struct vattr *);
76
77struct ptm_pty ptm_bsdpty = {
78	pty_allocvp,
79	pty_makename,
80	pty_getvattr,
81	NULL
82};
83
84static int
85/*ARGSUSED*/
86pty_makename(struct ptm_pty *ptm, struct lwp *l, char *bf,
87    size_t bufsiz, dev_t dev, char c)
88{
89	size_t nt;
90	dev_t minor = minor(dev);
91	const char *suffix;
92
93	if (bufsiz < TTY_NAMESIZE)
94		return EINVAL;
95
96	(void)memcpy(bf, TTY_TEMPLATE, TTY_NAMESIZE);
97
98	if (minor < 256) {
99		suffix = TTY_OLD_SUFFIX;
100		nt = sizeof(TTY_OLD_SUFFIX) - 1;
101	} else {
102		minor -= 256;
103		suffix = TTY_NEW_SUFFIX;
104		nt = sizeof(TTY_NEW_SUFFIX) - 1;
105	}
106
107	bf[5] = c;
108	bf[8] = TTY_LETTERS[minor / nt];
109	bf[9] = suffix[minor % nt];
110	return 0;
111}
112
113
114static int
115/*ARGSUSED*/
116pty_allocvp(struct ptm_pty *ptm, struct lwp *l, struct vnode **vp, dev_t dev,
117    char ms)
118{
119	int error;
120	struct pathbuf *pb;
121	struct nameidata nd;
122	char name[TTY_NAMESIZE];
123
124	error = (*ptm->makename)(ptm, l, name, sizeof(name), dev, ms);
125	if (error)
126		return error;
127
128	pb = pathbuf_create(name);
129	if (pb == NULL) {
130		return ENOMEM;
131	}
132
133	NDINIT(&nd, LOOKUP, NOFOLLOW|LOCKLEAF, pb);
134	if ((error = namei(&nd)) != 0) {
135		pathbuf_destroy(pb);
136		return error;
137	}
138	*vp = nd.ni_vp;
139	pathbuf_destroy(pb);
140	return 0;
141}
142
143
144static void
145/*ARGSUSED*/
146pty_getvattr(struct ptm_pty *ptm, struct lwp *l, struct vattr *vattr)
147{
148	vattr_null(vattr);
149	/* get real uid */
150	vattr->va_uid = kauth_cred_getuid(l->l_cred);
151	vattr->va_gid = TTY_GID;
152	vattr->va_mode = TTY_PERM;
153}
154#endif
155