bsd/kern/tty_conf.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /* Copyright (c) 1997 Apple Computer, Inc. All Rights Reserved */
  31 /*-
  32  * Copyright (c) 1982, 1986, 1991, 1993
  33  *      The Regents of the University of California.  All rights reserved.
  34  * (c) UNIX System Laboratories, Inc.
  35  * All or some portions of this file are derived from material licensed
  36  * to the University of California by American Telephone and Telegraph
  37  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  38  * the permission of UNIX System Laboratories, Inc.
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  * 3. All advertising materials mentioning features or use of this software
  49  *    must display the following acknowledgement:
  50  *      This product includes software developed by the University of
  51  *      California, Berkeley and its contributors.
  52  * 4. Neither the name of the University nor the names of its contributors
  53  *    may be used to endorse or promote products derived from this software
  54  *    without specific prior written permission.
  55  *
  56  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  57  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  58  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  59  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  60  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  61  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  62  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  63  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  64  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  65  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  66  * SUCH DAMAGE.
  67  *
  68  *      @(#)tty_conf.c  8.4 (Berkeley) 1/21/94
  69  */
  70
  71 #include <sys/param.h>
  72 #include <sys/systm.h>
  73 #include <sys/tty.h>
  74 #include <sys/conf.h>
  75
  76 #ifndef MAXLDISC
  77 #define MAXLDISC 8
  78 #endif
  79
  80 #ifndef NeXT
  81 static l_open_t         l_noopen;
  82 static l_close_t        l_noclose;
  83 static l_rint_t         l_norint;
  84 #else /* NeXT */
  85 #define l_noopen        ((l_open_t *)  &enodev)
  86 #define l_noclose       ((l_close_t *) &enodev)
  87 #define l_noread        ((l_read_t *)  &enodev)
  88 #define l_nowrite       ((l_write_t *) &enodev)
  89 #define l_norint        ((l_rint_t *)  &enodev)
  90 #endif /* !NeXT */
  91
  92 static l_ioctl_t        l_noioctl;
  93 static l_start_t        l_nostart;
  94
  95 /*
  96  * XXX it probably doesn't matter what the entries other than the l_open
  97  * entry are here.  The l_noioctl and ttymodem entries still look fishy.
  98  * Reconsider the removal of nullmodem anyway.  It was too much like
  99  * ttymodem, but a completely null version might be useful.
 100  */
 101 #define NODISC(n) \
 102         { l_noopen,     l_noclose,      l_noread,       l_nowrite, \
 103           l_noioctl,    l_norint,       l_nostart,      ttymodem }
 104
 105 struct  linesw linesw[MAXLDISC] =
 106 {
 107                                 /* 0- termios */
 108         { ttyopen,      ttylclose,      ttread,         ttwrite,
 109           l_noioctl,    ttyinput,       ttwwakeup,      ttymodem },
 110         NODISC(1),              /* 1- defunct */
 111                                 /* 2- NTTYDISC */
 112 #if COMPAT_43_TTY
 113         { ttyopen,      ttylclose,      ttread,         ttwrite,
 114           l_noioctl,    ttyinput,       ttwwakeup,      ttymodem },
 115 #else
 116         NODISC(2),
 117 #endif
 118         NODISC(3),              /* TABLDISC */
 119         NODISC(4),              /* SLIPDISC */
 120         NODISC(5),              /* PPPDISC */
 121         NODISC(6),              /* loadable */
 122         NODISC(7),              /* loadable */
 123 };
 124
 125 int     nlinesw = sizeof (linesw) / sizeof (linesw[0]);
 126
 127 static struct linesw nodisc = NODISC(0);
 128
 129 #define LOADABLE_LDISC 6
 130 /*
 131  * ldisc_register: Register a line discipline.
 132  *
 133  * discipline: Index for discipline to load, or LDISC_LOAD for us to choose.
 134  * linesw_p:   Pointer to linesw_p.
 135  *
 136  * Returns: Index used or -1 on failure.
 137  */
 138 int
 139 ldisc_register(discipline, linesw_p)
 140         int discipline;
 141         struct linesw *linesw_p;
 142 {
 143         int slot = -1;
 144
 145         if (discipline == LDISC_LOAD) {
 146                 int i;
 147                 for (i = LOADABLE_LDISC; i < MAXLDISC; i++)
 148                         if (bcmp(linesw + i, &nodisc, sizeof(nodisc)) == 0) {
 149                                 slot = i;
 150                         }
 151         }
 152         else if (discipline >= 0 && discipline < MAXLDISC) {
 153                 slot = discipline;
 154         }
 155
 156         if (slot != -1 && linesw_p)
 157                 linesw[slot] = *linesw_p;
 158
 159         return slot;
 160 }
 161
 162 /*
 163  * ldisc_deregister: Deregister a line discipline obtained with
 164  * ldisc_register.  Can only deregister "loadable" ones now.
 165  *
 166  * discipline: Index for discipline to unload.
 167  */
 168 void
 169 ldisc_deregister(discipline)
 170         int discipline;
 171 {
 172         if (discipline >= LOADABLE_LDISC && discipline < MAXLDISC) {
 173                 linesw[discipline] = nodisc;
 174         }
 175 }
 176
 177 #ifndef NeXT
 178 static int
 179 l_noopen(dev, tp)
 180         dev_t dev;
 181         struct tty *tp;
 182 {
 183
 184         return (ENODEV);
 185 }
 186
 187 static int
 188 l_noclose(tp, flag)
 189         struct tty *tp;
 190         int flag;
 191 {
 192
 193         return (ENODEV);
 194 }
 195
 196 int
 197 l_noread(tp, uio, flag)
 198         struct tty *tp;
 199         struct uio *uio;
 200         int flag;
 201 {
 202
 203         return (ENODEV);
 204 }
 205
 206 int
 207 l_nowrite(tp, uio, flag)
 208         struct tty *tp;
 209         struct uio *uio;
 210         int flag;
 211 {
 212
 213         return (ENODEV);
 214 }
 215
 216 static int
 217 l_norint(c, tp)
 218         int c;
 219         struct tty *tp;
 220 {
 221
 222         return (ENODEV);
 223 }
 224 #endif /* !NeXT */
 225
 226 /*
 227  * Do nothing specific version of line
 228  * discipline specific ioctl command.
 229  */
 230 static int
 231 l_noioctl(__unused struct tty *tp, __unused u_long cmd, __unused caddr_t data,
 232           __unused int flags, __unused struct proc *p)
 233 {
 234
 235         return ENOTTY;
 236 }
 237
 238 static void
 239 l_nostart(__unused struct tty *tp)
 240     { }