1 /* $OpenBSD: tty_tty.c,v 1.10 2007/03/15 10:22:30 art 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/file.h>
45 #include <sys/conf.h>
46
47
48 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
49
50 /*ARGSUSED*/
51 int
52 cttyopen(dev_t dev, int flag, int mode, struct proc *p)
53 {
54 struct vnode *ttyvp = cttyvp(p);
55 int error;
56
57 if (ttyvp == NULL)
58 return (ENXIO);
59 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
60 #ifdef PARANOID
61 /*
62 * Since group is tty and mode is 620 on most terminal lines
63 * and since sessions protect terminals from processes outside
64 * your session, this check is probably no longer necessary.
65 * Since it inhibits setuid root programs that later switch
66 * to another user from accessing /dev/tty, we have decided
67 * to delete this test. (mckusick 5/93)
68 */
69 error = VOP_ACCESS(ttyvp,
70 (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p);
71 if (!error)
72 #endif /* PARANOID */
73 error = VOP_OPEN(ttyvp, flag, NOCRED, p);
74 VOP_UNLOCK(ttyvp, 0, p);
75 return (error);
76 }
77
78 /*ARGSUSED*/
79 int
80 cttyread(dev_t dev, struct uio *uio, int flag)
81 {
82 struct proc *p = uio->uio_procp;
83 struct vnode *ttyvp = cttyvp(uio->uio_procp);
84 int error;
85
86 if (ttyvp == NULL)
87 return (EIO);
88 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
89 error = VOP_READ(ttyvp, uio, flag, NOCRED);
90 VOP_UNLOCK(ttyvp, 0, p);
91 return (error);
92 }
93
94 /*ARGSUSED*/
95 int
96 cttywrite(dev_t dev, struct uio *uio, int flag)
97 {
98 struct proc *p = uio->uio_procp;
99 struct vnode *ttyvp = cttyvp(uio->uio_procp);
100 int error;
101
102 if (ttyvp == NULL)
103 return (EIO);
104 vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
105 error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
106 VOP_UNLOCK(ttyvp, 0, p);
107 return (error);
108 }
109
110 /*ARGSUSED*/
111 int
112 cttyioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
113 {
114 struct vnode *ttyvp = cttyvp(p);
115
116 if (ttyvp == NULL)
117 return (EIO);
118 if (cmd == TIOCSCTTY) /* XXX */
119 return (EINVAL);
120 if (cmd == TIOCNOTTY) {
121 if (!SESS_LEADER(p)) {
122 atomic_clearbits_int(&p->p_flag, P_CONTROLT);
123 return (0);
124 } else
125 return (EINVAL);
126 }
127 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
128 }
129
130 /*ARGSUSED*/
131 int
132 cttypoll(dev_t dev, int events, struct proc *p)
133 {
134 struct vnode *ttyvp = cttyvp(p);
135
136 if (ttyvp == NULL) /* try operation to get EOF/failure */
137 return (seltrue(dev, events, p));
138 return (VOP_POLL(ttyvp, events, p));
139 }