summaryrefslogtreecommitdiff
path: root/sys/kern/tty_tty.c
blob: 0a2f5637f826552f38a78720586b61449952b554 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
/*	$OpenBSD: tty_tty.c,v 1.20 2016/09/06 08:13:23 tedu Exp $	*/
/*	$NetBSD: tty_tty.c,v 1.13 1996/03/30 22:24:46 christos Exp $	*/

/*-
 * Copyright (c) 1982, 1986, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)tty_tty.c	8.2 (Berkeley) 9/23/93
 */

/*
 * Indirect driver for controlling tty.
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/vnode.h>
#include <sys/lock.h>
#include <sys/file.h>


#define cttyvp(p) \
	((p)->p_p->ps_flags & PS_CONTROLT ? \
	    (p)->p_p->ps_session->s_ttyvp : NULL)

int
cttyopen(dev_t dev, int flag, int mode, struct proc *p)
{
	struct vnode *ttyvp = cttyvp(p);
	int error;

	if (ttyvp == NULL)
		return (ENXIO);
	vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
	error = VOP_OPEN(ttyvp, flag, NOCRED, p);
	VOP_UNLOCK(ttyvp, p);
	return (error);
}

int
cttyread(dev_t dev, struct uio *uio, int flag)
{
	struct proc *p = uio->uio_procp;
	struct vnode *ttyvp = cttyvp(uio->uio_procp);
	int error;

	if (ttyvp == NULL)
		return (EIO);
	vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
	error = VOP_READ(ttyvp, uio, flag, NOCRED);
	VOP_UNLOCK(ttyvp, p);
	return (error);
}

int
cttywrite(dev_t dev, struct uio *uio, int flag)
{
	struct proc *p = uio->uio_procp;
	struct vnode *ttyvp = cttyvp(uio->uio_procp);
	int error;

	if (ttyvp == NULL)
		return (EIO);
	vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
	error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
	VOP_UNLOCK(ttyvp, p);
	return (error);
}

int
cttyioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
{
	struct vnode *ttyvp = cttyvp(p);
	struct session *sess;
	int error, secs;

	if (ttyvp == NULL)
		return (EIO);
	if (cmd == TIOCSCTTY)		/* XXX */
		return (EINVAL);
	if (cmd == TIOCNOTTY) {
		if (!SESS_LEADER(p->p_p)) {
			atomic_clearbits_int(&p->p_p->ps_flags, PS_CONTROLT);
			return (0);
		} else
			return (EINVAL);
	}
	switch (cmd) {
	case TIOCSETVERAUTH:
		if ((error = suser(p, 0)))
			return error;
		secs = *(int *)addr;
		if (secs < 1 || secs > 3600)
			return EINVAL;
		sess = p->p_p->ps_pgrp->pg_session;
		sess->s_verauthuid = p->p_ucred->cr_ruid;
		sess->s_verauthppid = p->p_p->ps_pptr->ps_pid;
		timeout_add_sec(&sess->s_verauthto, secs);
		return 0;
	case TIOCCLRVERAUTH:
		sess = p->p_p->ps_pgrp->pg_session;
		timeout_del(&sess->s_verauthto);
		zapverauth(sess);
		return 0;
	case TIOCCHKVERAUTH:
		/*
		 * It's not clear when or what these checks are for.
		 * How can we reach this code with a differnt ruid?
		 * The ppid check is also more porous than desired.
		 * Nevertheless, the checks reflect the original intention;
		 * namely, that it be the same user using the same shell.
		 */
		sess = p->p_p->ps_pgrp->pg_session;
		if (sess->s_verauthuid == p->p_ucred->cr_ruid &&
		    sess->s_verauthppid == p->p_p->ps_pptr->ps_pid)
			return 0;
		return EPERM;
	}
	return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
}

int
cttypoll(dev_t dev, int events, struct proc *p)
{
	struct vnode *ttyvp = cttyvp(p);

	if (ttyvp == NULL)	/* try operation to get EOF/failure */
		return (seltrue(dev, events, p));
	return (VOP_POLL(ttyvp, FREAD|FWRITE, events, p));
}

int
cttykqfilter(dev_t dev, struct knote *kn)
{
	struct vnode *ttyvp = cttyvp(curproc);

	if (ttyvp == NULL)
		return (ENXIO);
	return (VOP_KQFILTER(ttyvp, kn));
}