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_ioctl_t        l_nullioctl;
  76 static l_rint_t         l_norint;
  77 static l_start_t        l_nostart;
  78 #else /* NeXT */
  79 #define l_noopen        ((int (*) __P((dev_t, struct tty *)))enodev)
  80 #define l_noclose       ((int (*) __P((struct tty *, int flags)))enodev)
  81 #define l_noread        ((int (*) __P((struct tty *, struct uio *, int)))enodev)
  82 #define l_nowrite       l_noread
  83 #define l_norint        ((int (*) __P((int c, struct tty *)))enodev)
  84 #define l_nostart       ((int (*) __P((struct tty *)))enodev)
  85 static  int
  86 l_nullioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct proc *p);
  87 #endif /* !NeXT */
  88
  89 /*
  90  * XXX it probably doesn't matter what the entries other than the l_open
  91  * entry are here.  The l_nullioctl and ttymodem entries still look fishy.
  92  * Reconsider the removal of nullmodem anyway.  It was too much like
  93  * ttymodem, but a completely null version might be useful.
  94  */
  95 #define NODISC(n) \
  96         { l_noopen,     l_noclose,      l_noread,       l_nowrite, \
  97           l_nullioctl,  l_norint,       l_nostart,      ttymodem }
  98
  99 struct  linesw linesw[MAXLDISC] =
 100 {
 101                                 /* 0- termios */
 102         { ttyopen,      ttylclose,      ttread,         ttwrite,
 103           l_nullioctl,  ttyinput,       ttstart,        ttymodem },
 104         NODISC(1),              /* 1- defunct */
 105                                 /* 2- NTTYDISC */
 106 #ifdef COMPAT_43
 107         { ttyopen,      ttylclose,      ttread,         ttwrite,
 108           l_nullioctl,  ttyinput,       ttstart,        ttymodem },
 109 #else
 110         NODISC(2),
 111 #endif
 112         NODISC(3),              /* TABLDISC */
 113         NODISC(4),              /* SLIPDISC */
 114         NODISC(5),              /* PPPDISC */
 115         NODISC(6),              /* loadable */
 116         NODISC(7),              /* loadable */
 117 };
 118
 119 int     nlinesw = sizeof (linesw) / sizeof (linesw[0]);
 120
 121 static struct linesw nodisc = NODISC(0);
 122
 123 #define LOADABLE_LDISC 6
 124 /*
 125  * ldisc_register: Register a line discipline.
 126  *
 127  * discipline: Index for discipline to load, or LDISC_LOAD for us to choose.
 128  * linesw_p:   Pointer to linesw_p.
 129  *
 130  * Returns: Index used or -1 on failure.
 131  */
 132 int
 133 ldisc_register(discipline, linesw_p)
 134         int discipline;
 135         struct linesw *linesw_p;
 136 {
 137         int slot = -1;
 138
 139         if (discipline == LDISC_LOAD) {
 140                 int i;
 141                 for (i = LOADABLE_LDISC; i < MAXLDISC; i++)
 142                         if (bcmp(linesw + i, &nodisc, sizeof(nodisc)) == 0) {
 143                                 slot = i;
 144                         }
 145         }
 146         else if (discipline >= 0 && discipline < MAXLDISC) {
 147                 slot = discipline;
 148         }
 149
 150         if (slot != -1 && linesw_p)
 151                 linesw[slot] = *linesw_p;
 152
 153         return slot;
 154 }
 155
 156 /*
 157  * ldisc_deregister: Deregister a line discipline obtained with
 158  * ldisc_register.  Can only deregister "loadable" ones now.
 159  *
 160  * discipline: Index for discipline to unload.
 161  */
 162 void
 163 ldisc_deregister(discipline)
 164         int discipline;
 165 {
 166         if (discipline >= LOADABLE_LDISC && discipline < MAXLDISC) {
 167                 linesw[discipline] = nodisc;
 168         }
 169 }
 170
 171 #ifndef NeXT
 172 static int
 173 l_noopen(dev, tp)
 174         dev_t dev;
 175         struct tty *tp;
 176 {
 177
 178         return (ENODEV);
 179 }
 180
 181 static int
 182 l_noclose(tp, flag)
 183         struct tty *tp;
 184         int flag;
 185 {
 186
 187         return (ENODEV);
 188 }
 189
 190 int
 191 l_noread(tp, uio, flag)
 192         struct tty *tp;
 193         struct uio *uio;
 194         int flag;
 195 {
 196
 197         return (ENODEV);
 198 }
 199
 200 int
 201 l_nowrite(tp, uio, flag)
 202         struct tty *tp;
 203         struct uio *uio;
 204         int flag;
 205 {
 206
 207         return (ENODEV);
 208 }
 209
 210 static int
 211 l_norint(c, tp)
 212         int c;
 213         struct tty *tp;
 214 {
 215
 216         return (ENODEV);
 217 }
 218
 219 static int
 220 l_nostart(tp)
 221         struct tty *tp;
 222 {
 223
 224         return (ENODEV);
 225 }
 226 #endif /* !NeXT */
 227
 228 /*
 229  * Do nothing specific version of line
 230  * discipline specific ioctl command.
 231  */
 232 static int
 233 l_nullioctl(tp, cmd, data, flags, p)
 234         struct tty *tp;
 235         u_long cmd;
 236         caddr_t data;
 237         int flags;
 238         struct proc *p;
 239 {
 240
 241         return (-1);
 242 }