bsd/kern/tty_conf.c

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