bsd/kern/tty_conf.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /* Copyright (c) 1997 Apple Computer, Inc. All Rights Reserved */
  26 /*-
  27  * Copyright (c) 1982, 1986, 1991, 1993
  28  *      The Regents of the University of California.  All rights reserved.
  29  * (c) UNIX System Laboratories, Inc.
  30  * All or some portions of this file are derived from material licensed
  31  * to the University of California by American Telephone and Telegraph
  32  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  33  * the permission of UNIX System Laboratories, Inc.
  34  *
  35  * Redistribution and use in source and binary forms, with or without
  36  * modification, are permitted provided that the following conditions
  37  * are met:
  38  * 1. Redistributions of source code must retain the above copyright
  39  *    notice, this list of conditions and the following disclaimer.
  40  * 2. Redistributions in binary form must reproduce the above copyright
  41  *    notice, this list of conditions and the following disclaimer in the
  42  *    documentation and/or other materials provided with the distribution.
  43  * 3. All advertising materials mentioning features or use of this software
  44  *    must display the following acknowledgement:
  45  *      This product includes software developed by the University of
  46  *      California, Berkeley and its contributors.
  47  * 4. Neither the name of the University nor the names of its contributors
  48  *    may be used to endorse or promote products derived from this software
  49  *    without specific prior written permission.
  50  *
  51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  61  * SUCH DAMAGE.
  62  *
  63  *      @(#)tty_conf.c  8.4 (Berkeley) 1/21/94
  64  */
  65
  66 #include <sys/param.h>
  67 #include <sys/systm.h>
  68 #include <sys/tty.h>
  69 #include <sys/conf.h>
  70
  71 #ifndef MAXLDISC
  72 #define MAXLDISC 8
  73 #endif
  74
  75 #ifndef NeXT
  76 static l_open_t         l_noopen;
  77 static l_close_t        l_noclose;
  78 static l_ioctl_t        l_nullioctl;
  79 static l_rint_t         l_norint;
  80 static l_start_t        l_nostart;
  81 #else /* NeXT */
  82 #define l_noopen        ((int (*) __P((dev_t, struct tty *)))enodev)
  83 #define l_noclose       ((int (*) __P((struct tty *, int flags)))enodev)
  84 #define l_noread        ((int (*) __P((struct tty *, struct uio *, int)))enodev)
  85 #define l_nowrite       l_noread
  86 #define l_norint        ((int (*) __P((int c, struct tty *)))enodev)
  87 #define l_nostart       ((int (*) __P((struct tty *)))enodev)
  88 static  int
  89 l_nullioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct proc *p);
  90 #endif /* !NeXT */
  91
  92 /*
  93  * XXX it probably doesn't matter what the entries other than the l_open
  94  * entry are here.  The l_nullioctl and ttymodem entries still look fishy.
  95  * Reconsider the removal of nullmodem anyway.  It was too much like
  96  * ttymodem, but a completely null version might be useful.
  97  */
  98 #define NODISC(n) \
  99         { l_noopen,     l_noclose,      l_noread,       l_nowrite, \
 100           l_nullioctl,  l_norint,       l_nostart,      ttymodem }
 101
 102 struct  linesw linesw[MAXLDISC] =
 103 {
 104                                 /* 0- termios */
 105         { ttyopen,      ttylclose,      ttread,         ttwrite,
 106           l_nullioctl,  ttyinput,       ttstart,        ttymodem },
 107         NODISC(1),              /* 1- defunct */
 108                                 /* 2- NTTYDISC */
 109 #ifdef COMPAT_43
 110         { ttyopen,      ttylclose,      ttread,         ttwrite,
 111           l_nullioctl,  ttyinput,       ttstart,        ttymodem },
 112 #else
 113         NODISC(2),
 114 #endif
 115         NODISC(3),              /* TABLDISC */
 116         NODISC(4),              /* SLIPDISC */
 117         NODISC(5),              /* PPPDISC */
 118         NODISC(6),              /* loadable */
 119         NODISC(7),              /* loadable */
 120 };
 121
 122 int     nlinesw = sizeof (linesw) / sizeof (linesw[0]);
 123
 124 static struct linesw nodisc = NODISC(0);
 125
 126 #define LOADABLE_LDISC 6
 127 /*
 128  * ldisc_register: Register a line discipline.
 129  *
 130  * discipline: Index for discipline to load, or LDISC_LOAD for us to choose.
 131  * linesw_p:   Pointer to linesw_p.
 132  *
 133  * Returns: Index used or -1 on failure.
 134  */
 135 int
 136 ldisc_register(discipline, linesw_p)
 137         int discipline;
 138         struct linesw *linesw_p;
 139 {
 140         int slot = -1;
 141
 142         if (discipline == LDISC_LOAD) {
 143                 int i;
 144                 for (i = LOADABLE_LDISC; i < MAXLDISC; i++)
 145                         if (bcmp(linesw + i, &nodisc, sizeof(nodisc)) == 0) {
 146                                 slot = i;
 147                         }
 148         }
 149         else if (discipline >= 0 && discipline < MAXLDISC) {
 150                 slot = discipline;
 151         }
 152
 153         if (slot != -1 && linesw_p)
 154                 linesw[slot] = *linesw_p;
 155
 156         return slot;
 157 }
 158
 159 /*
 160  * ldisc_deregister: Deregister a line discipline obtained with
 161  * ldisc_register.  Can only deregister "loadable" ones now.
 162  *
 163  * discipline: Index for discipline to unload.
 164  */
 165 void
 166 ldisc_deregister(discipline)
 167         int discipline;
 168 {
 169         if (discipline >= LOADABLE_LDISC && discipline < MAXLDISC) {
 170                 linesw[discipline] = nodisc;
 171         }
 172 }
 173
 174 #ifndef NeXT
 175 static int
 176 l_noopen(dev, tp)
 177         dev_t dev;
 178         struct tty *tp;
 179 {
 180
 181         return (ENODEV);
 182 }
 183
 184 static int
 185 l_noclose(tp, flag)
 186         struct tty *tp;
 187         int flag;
 188 {
 189
 190         return (ENODEV);
 191 }
 192
 193 int
 194 l_noread(tp, uio, flag)
 195         struct tty *tp;
 196         struct uio *uio;
 197         int flag;
 198 {
 199
 200         return (ENODEV);
 201 }
 202
 203 int
 204 l_nowrite(tp, uio, flag)
 205         struct tty *tp;
 206         struct uio *uio;
 207         int flag;
 208 {
 209
 210         return (ENODEV);
 211 }
 212
 213 static int
 214 l_norint(c, tp)
 215         int c;
 216         struct tty *tp;
 217 {
 218
 219         return (ENODEV);
 220 }
 221
 222 static int
 223 l_nostart(tp)
 224         struct tty *tp;
 225 {
 226
 227         return (ENODEV);
 228 }
 229 #endif /* !NeXT */
 230
 231 /*
 232  * Do nothing specific version of line
 233  * discipline specific ioctl command.
 234  */
 235 static int
 236 l_nullioctl(tp, cmd, data, flags, p)
 237         struct tty *tp;
 238         u_long cmd;
 239         caddr_t data;
 240         int flags;
 241         struct proc *p;
 242 {
 243
 244         return (-1);
 245 }