1 /*
2 * Copyright (c) 1997-2006 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28 /*-
29 * Copyright (c) 1982, 1986, 1991, 1993
30 * The Regents of the University of California. All rights reserved.
31 * (c) UNIX System Laboratories, Inc.
32 * All or some portions of this file are derived from material licensed
33 * to the University of California by American Telephone and Telegraph
34 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
35 * the permission of UNIX System Laboratories, Inc.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 3. All advertising materials mentioning features or use of this software
46 * must display the following acknowledgement:
47 * This product includes software developed by the University of
48 * California, Berkeley and its contributors.
49 * 4. Neither the name of the University nor the names of its contributors
50 * may be used to endorse or promote products derived from this software
51 * without specific prior written permission.
52 *
53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63 * SUCH DAMAGE.
64 *
65 * @(#)tty_conf.c 8.4 (Berkeley) 1/21/94
66 */
67
68 #include <sys/param.h>
69 #include <sys/systm.h>
70 #include <sys/tty.h>
71 #include <sys/conf.h>
72
73 #ifndef MAXLDISC
74 #define MAXLDISC 8
75 #endif
76
77 #define l_noopen ((l_open_t *) &enodev)
78 #define l_noclose ((l_close_t *) &enodev)
79 #define l_noread ((l_read_t *) &enodev)
80 #define l_nowrite ((l_write_t *) &enodev)
81 #define l_norint ((l_rint_t *) &enodev)
82
83 static l_ioctl_t l_noioctl;
84 static l_start_t l_nostart;
85
86 /*
87 * XXX it probably doesn't matter what the entries other than the l_open
88 * entry are here. The l_noioctl and ttymodem entries still look fishy.
89 * Reconsider the removal of nullmodem anyway. It was too much like
90 * ttymodem, but a completely null version might be useful.
91 */
92 #define NODISC(n) \
93 { l_noopen, l_noclose, l_noread, l_nowrite, \
94 l_noioctl, l_norint, l_nostart, ttymodem }
95
96 struct linesw linesw[MAXLDISC] =
97 {
98 /* 0- termios */
99 { ttyopen, ttylclose, ttread, ttwrite,
100 l_noioctl, ttyinput, ttwwakeup, ttymodem },
101 NODISC(1), /* 1- defunct */
102 /* 2- NTTYDISC */
103 { ttyopen, ttylclose, ttread, ttwrite,
104 l_noioctl, ttyinput, ttwwakeup, ttymodem },
105 NODISC(3), /* TABLDISC */
106 NODISC(4), /* SLIPDISC */
107 NODISC(5), /* PPPDISC */
108 NODISC(6), /* loadable */
109 NODISC(7), /* loadable */
110 };
111
112 const int nlinesw = sizeof(linesw) / sizeof(linesw[0]);
113
114 static struct linesw nodisc = NODISC(0);
115
116 #define LOADABLE_LDISC 6
117 /*
118 * ldisc_register: Register a line discipline.
119 *
120 * discipline: Index for discipline to load, or LDISC_LOAD for us to choose.
121 * linesw_p: Pointer to linesw_p.
122 *
123 * Returns: Index used or -1 on failure.
124 */
125 int
ldisc_register(int discipline,struct linesw * linesw_p)126 ldisc_register(int discipline, struct linesw *linesw_p)
127 {
128 int slot = -1;
129
130 if (discipline == LDISC_LOAD) {
131 int i;
132 for (i = LOADABLE_LDISC; i < MAXLDISC; i++) {
133 if (bcmp(linesw + i, &nodisc, sizeof(nodisc)) == 0) {
134 slot = i;
135 }
136 }
137 } else if (discipline >= 0 && discipline < MAXLDISC) {
138 slot = discipline;
139 }
140
141 if (slot != -1 && linesw_p) {
142 linesw[slot] = *linesw_p;
143 }
144
145 return slot;
146 }
147
148 /*
149 * ldisc_deregister: Deregister a line discipline obtained with
150 * ldisc_register. Can only deregister "loadable" ones now.
151 *
152 * discipline: Index for discipline to unload.
153 */
154 void
ldisc_deregister(int discipline)155 ldisc_deregister(int discipline)
156 {
157 if (discipline >= LOADABLE_LDISC && discipline < MAXLDISC) {
158 linesw[discipline] = nodisc;
159 }
160 }
161
162 /*
163 * Do nothing specific version of line
164 * discipline specific ioctl command.
165 */
166 static int
l_noioctl(__unused struct tty * tp,__unused u_long cmd,__unused caddr_t data,__unused int flags,__unused struct proc * p)167 l_noioctl(__unused struct tty *tp, __unused u_long cmd, __unused caddr_t data,
168 __unused int flags, __unused struct proc *p)
169 {
170 return ENOTTY;
171 }
172
173 static void
l_nostart(__unused struct tty * tp)174 l_nostart(__unused struct tty *tp)
175 {
176 }
177