bsd/kern/tty_conf.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1997 Apple Computer, Inc. All Rights Reserved */
  23 /*-
  24  * Copyright (c) 1982, 1986, 1991, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  * (c) UNIX System Laboratories, Inc.
  27  * All or some portions of this file are derived from material licensed
  28  * to the University of California by American Telephone and Telegraph
  29  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  30  * the permission of UNIX System Laboratories, Inc.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)tty_conf.c  8.4 (Berkeley) 1/21/94
  61  */
  62
  63 #include <sys/param.h>
  64 #include <sys/systm.h>
  65 #include <sys/tty.h>
  66 #include <sys/conf.h>
  67
  68 #ifndef MAXLDISC
  69 #define MAXLDISC 8
  70 #endif
  71
  72 #ifndef NeXT
  73 static l_open_t         l_noopen;
  74 static l_close_t        l_noclose;
  75 static l_rint_t         l_norint;
  76 #else /* NeXT */
  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 #endif /* !NeXT */
  83
  84 static l_ioctl_t        l_noioctl;
  85 static l_start_t        l_nostart;
  86
  87 /*
  88  * XXX it probably doesn't matter what the entries other than the l_open
  89  * entry are here.  The l_noioctl and ttymodem entries still look fishy.
  90  * Reconsider the removal of nullmodem anyway.  It was too much like
  91  * ttymodem, but a completely null version might be useful.
  92  */
  93 #define NODISC(n) \
  94         { l_noopen,     l_noclose,      l_noread,       l_nowrite, \
  95           l_noioctl,    l_norint,       l_nostart,      ttymodem }
  96
  97 struct  linesw linesw[MAXLDISC] =
  98 {
  99                                 /* 0- termios */
 100         { ttyopen,      ttylclose,      ttread,         ttwrite,
 101           l_noioctl,    ttyinput,       ttwwakeup,      ttymodem },
 102         NODISC(1),              /* 1- defunct */
 103                                 /* 2- NTTYDISC */
 104 #if COMPAT_43_TTY
 105         { ttyopen,      ttylclose,      ttread,         ttwrite,
 106           l_noioctl,    ttyinput,       ttwwakeup,      ttymodem },
 107 #else
 108         NODISC(2),
 109 #endif
 110         NODISC(3),              /* TABLDISC */
 111         NODISC(4),              /* SLIPDISC */
 112         NODISC(5),              /* PPPDISC */
 113         NODISC(6),              /* loadable */
 114         NODISC(7),              /* loadable */
 115 };
 116
 117 int     nlinesw = sizeof (linesw) / sizeof (linesw[0]);
 118
 119 static struct linesw nodisc = NODISC(0);
 120
 121 #define LOADABLE_LDISC 6
 122 /*
 123  * ldisc_register: Register a line discipline.
 124  *
 125  * discipline: Index for discipline to load, or LDISC_LOAD for us to choose.
 126  * linesw_p:   Pointer to linesw_p.
 127  *
 128  * Returns: Index used or -1 on failure.
 129  */
 130 int
 131 ldisc_register(discipline, linesw_p)
 132         int discipline;
 133         struct linesw *linesw_p;
 134 {
 135         int slot = -1;
 136
 137         if (discipline == LDISC_LOAD) {
 138                 int i;
 139                 for (i = LOADABLE_LDISC; i < MAXLDISC; i++)
 140                         if (bcmp(linesw + i, &nodisc, sizeof(nodisc)) == 0) {
 141                                 slot = i;
 142                         }
 143         }
 144         else if (discipline >= 0 && discipline < MAXLDISC) {
 145                 slot = discipline;
 146         }
 147
 148         if (slot != -1 && linesw_p)
 149                 linesw[slot] = *linesw_p;
 150
 151         return slot;
 152 }
 153
 154 /*
 155  * ldisc_deregister: Deregister a line discipline obtained with
 156  * ldisc_register.  Can only deregister "loadable" ones now.
 157  *
 158  * discipline: Index for discipline to unload.
 159  */
 160 void
 161 ldisc_deregister(discipline)
 162         int discipline;
 163 {
 164         if (discipline >= LOADABLE_LDISC && discipline < MAXLDISC) {
 165                 linesw[discipline] = nodisc;
 166         }
 167 }
 168
 169 #ifndef NeXT
 170 static int
 171 l_noopen(dev, tp)
 172         dev_t dev;
 173         struct tty *tp;
 174 {
 175
 176         return (ENODEV);
 177 }
 178
 179 static int
 180 l_noclose(tp, flag)
 181         struct tty *tp;
 182         int flag;
 183 {
 184
 185         return (ENODEV);
 186 }
 187
 188 int
 189 l_noread(tp, uio, flag)
 190         struct tty *tp;
 191         struct uio *uio;
 192         int flag;
 193 {
 194
 195         return (ENODEV);
 196 }
 197
 198 int
 199 l_nowrite(tp, uio, flag)
 200         struct tty *tp;
 201         struct uio *uio;
 202         int flag;
 203 {
 204
 205         return (ENODEV);
 206 }
 207
 208 static int
 209 l_norint(c, tp)
 210         int c;
 211         struct tty *tp;
 212 {
 213
 214         return (ENODEV);
 215 }
 216 #endif /* !NeXT */
 217
 218 /*
 219  * Do nothing specific version of line
 220  * discipline specific ioctl command.
 221  */
 222 static int
 223 l_noioctl(__unused struct tty *tp, __unused u_long cmd, __unused caddr_t data,
 224           __unused int flags, __unused struct proc *p)
 225 {
 226
 227         return ENOTTY;
 228 }
 229
 230 static void
 231 l_nostart(__unused struct tty *tp)
 232     { }