xref: /openbsd-src/sys/kern/tty_tty.c (revision bb5dd46a8458ce3e04e7bbee8bfe3ad51905912d)
1 /*	$OpenBSD: tty_tty.c,v 1.19 2016/09/02 18:11:28 tedu Exp $	*/
2 /*	$NetBSD: tty_tty.c,v 1.13 1996/03/30 22:24:46 christos Exp $	*/
3 
4 /*-
5  * Copyright (c) 1982, 1986, 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)tty_tty.c	8.2 (Berkeley) 9/23/93
33  */
34 
35 /*
36  * Indirect driver for controlling tty.
37  */
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/ioctl.h>
41 #include <sys/proc.h>
42 #include <sys/tty.h>
43 #include <sys/vnode.h>
44 #include <sys/lock.h>
45 #include <sys/file.h>
46 
47 
48 #define cttyvp(p) \
49 	((p)->p_p->ps_flags & PS_CONTROLT ? \
50 	    (p)->p_p->ps_session->s_ttyvp : NULL)
51 
52 int
53 cttyopen(dev_t dev, int flag, int mode, struct proc *p)
54 {
55 	struct vnode *ttyvp = cttyvp(p);
56 	int error;
57 
58 	if (ttyvp == NULL)
59 		return (ENXIO);
60 	vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
61 	error = VOP_OPEN(ttyvp, flag, NOCRED, p);
62 	VOP_UNLOCK(ttyvp, p);
63 	return (error);
64 }
65 
66 int
67 cttyread(dev_t dev, struct uio *uio, int flag)
68 {
69 	struct proc *p = uio->uio_procp;
70 	struct vnode *ttyvp = cttyvp(uio->uio_procp);
71 	int error;
72 
73 	if (ttyvp == NULL)
74 		return (EIO);
75 	vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
76 	error = VOP_READ(ttyvp, uio, flag, NOCRED);
77 	VOP_UNLOCK(ttyvp, p);
78 	return (error);
79 }
80 
81 int
82 cttywrite(dev_t dev, struct uio *uio, int flag)
83 {
84 	struct proc *p = uio->uio_procp;
85 	struct vnode *ttyvp = cttyvp(uio->uio_procp);
86 	int error;
87 
88 	if (ttyvp == NULL)
89 		return (EIO);
90 	vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
91 	error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
92 	VOP_UNLOCK(ttyvp, p);
93 	return (error);
94 }
95 
96 int
97 cttyioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
98 {
99 	struct vnode *ttyvp = cttyvp(p);
100 	struct session *sess;
101 	int error, secs;
102 
103 	if (ttyvp == NULL)
104 		return (EIO);
105 	if (cmd == TIOCSCTTY)		/* XXX */
106 		return (EINVAL);
107 	if (cmd == TIOCNOTTY) {
108 		if (!SESS_LEADER(p->p_p)) {
109 			atomic_clearbits_int(&p->p_p->ps_flags, PS_CONTROLT);
110 			return (0);
111 		} else
112 			return (EINVAL);
113 	}
114 	switch (cmd) {
115 	case TIOCSETVERAUTH:
116 		if ((error = suser(p, 0)))
117 			return error;
118 		secs = *(int *)addr;
119 		if (secs < 1 || secs > 3600)
120 			return EINVAL;
121 		sess = p->p_p->ps_pgrp->pg_session;
122 		sess->s_verauthuid = p->p_ucred->cr_ruid;
123 		sess->s_verauthppid = p->p_p->ps_pptr->ps_pid;
124 		timeout_add_sec(&sess->s_verauthto, secs);
125 		return 0;
126 	case TIOCCLRVERAUTH:
127 		sess = p->p_p->ps_pgrp->pg_session;
128 		timeout_del(&sess->s_verauthto);
129 		zapverauth(sess);
130 		return 0;
131 	case TIOCCHKVERAUTH:
132 		sess = p->p_p->ps_pgrp->pg_session;
133 		if (sess->s_verauthuid == p->p_ucred->cr_ruid &&
134 		    sess->s_verauthppid == p->p_p->ps_pptr->ps_pid)
135 			return 0;
136 		return EPERM;
137 	}
138 	return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
139 }
140 
141 int
142 cttypoll(dev_t dev, int events, struct proc *p)
143 {
144 	struct vnode *ttyvp = cttyvp(p);
145 
146 	if (ttyvp == NULL)	/* try operation to get EOF/failure */
147 		return (seltrue(dev, events, p));
148 	return (VOP_POLL(ttyvp, FREAD|FWRITE, events, p));
149 }
150 
151 int
152 cttykqfilter(dev_t dev, struct knote *kn)
153 {
154 	struct vnode *ttyvp = cttyvp(curproc);
155 
156 	if (ttyvp == NULL)
157 		return (ENXIO);
158 	return (VOP_KQFILTER(ttyvp, kn));
159 }
160