xref: /netbsd-src/sys/kern/tty_tty.c (revision cda4f8f6ee55684e8d311b86c99ea59191e6b74f)
1 /*-
2  * Copyright (c) 1982, 1986, 1991 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	from: @(#)tty_tty.c	7.15 (Berkeley) 5/28/91
34  *	$Id: tty_tty.c,v 1.5 1993/06/27 06:01:58 andrew Exp $
35  */
36 
37 /*
38  * Indirect driver for controlling tty.
39  */
40 #include "param.h"
41 #include "systm.h"
42 #include "conf.h"
43 #include "ioctl.h"
44 #include "tty.h"
45 #include "proc.h"
46 #include "vnode.h"
47 #include "file.h"
48 
49 #define cttyvp(p) ((p)->p_flag&SCTTY ? (p)->p_session->s_ttyvp : NULL)
50 
51 /*ARGSUSED*/
52 int
53 cttyopen(dev, flag, mode, p)
54 	dev_t dev;
55 	int flag, mode;
56 	struct proc *p;
57 {
58 	struct vnode *ttyvp = cttyvp(p);
59 	int error;
60 
61 	if (ttyvp == NULL)
62 		return (ENXIO);
63 	VOP_LOCK(ttyvp);
64 	error = VOP_ACCESS(ttyvp,
65 	  (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p);
66 	if (!error)
67 		error = VOP_OPEN(ttyvp, flag, NOCRED, p);
68 	VOP_UNLOCK(ttyvp);
69 	return (error);
70 }
71 
72 /*ARGSUSED*/
73 int
74 cttyread(dev, uio, flag)
75 	dev_t dev;
76 	struct uio *uio;
77 	int flag;
78 {
79 	register struct vnode *ttyvp = cttyvp(uio->uio_procp);
80 	int error;
81 
82 	if (ttyvp == NULL)
83 		return (EIO);
84 	VOP_LOCK(ttyvp);
85 	error = VOP_READ(ttyvp, uio, flag, NOCRED);
86 	VOP_UNLOCK(ttyvp);
87 	return (error);
88 }
89 
90 /*ARGSUSED*/
91 int
92 cttywrite(dev, uio, flag)
93 	dev_t dev;
94 	struct uio *uio;
95 	int flag;
96 {
97 	register struct vnode *ttyvp = cttyvp(uio->uio_procp);
98 	int error;
99 
100 	if (ttyvp == NULL)
101 		return (EIO);
102 	VOP_LOCK(ttyvp);
103 	error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
104 	VOP_UNLOCK(ttyvp);
105 	return (error);
106 }
107 
108 /*ARGSUSED*/
109 int
110 cttyioctl(dev, cmd, addr, flag, p)
111 	dev_t dev;
112 	int cmd;
113 	caddr_t addr;
114 	int flag;
115 	struct proc *p;
116 {
117 	struct vnode *ttyvp = cttyvp(p);
118 
119 	if (ttyvp == NULL)
120 		return (EIO);
121 	if (cmd == TIOCNOTTY) {
122 		if (!SESS_LEADER(p)) {
123 			p->p_flag &= ~SCTTY;
124 			return (0);
125 		} else
126 			return (EINVAL);
127 	}
128 	return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
129 }
130 
131 /*ARGSUSED*/
132 int
133 cttyselect(dev, flag, p)
134 	dev_t dev;
135 	int flag;
136 	struct proc *p;
137 {
138 	struct vnode *ttyvp = cttyvp(p);
139 
140 	if (ttyvp == NULL)
141 		return (1);	/* try operation to get EOF/failure */
142 	return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, p));
143 }
144