1 /*- 2 * Copyright (c) 1982, 1986, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)tty_conf.c 8.4 (Berkeley) 1/21/94 39 * $FreeBSD: src/sys/kern/tty_conf.c,v 1.16.2.1 2002/03/11 01:14:55 dd Exp $ 40 * $DragonFly: src/sys/kern/tty_conf.c,v 1.6 2006/12/23 23:47:54 swildner Exp $ 41 */ 42 43 #include "opt_compat.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/tty.h> 48 #include <sys/conf.h> 49 50 #ifndef MAXLDISC 51 #define MAXLDISC 9 52 #endif 53 54 static l_open_t l_noopen; 55 static l_close_t l_noclose; 56 static l_rint_t l_norint; 57 static l_start_t l_nostart; 58 59 /* 60 * XXX it probably doesn't matter what the entries other than the l_open 61 * entry are here. The l_nullioctl and ttymodem entries still look fishy. 62 * Reconsider the removal of nullmodem anyway. It was too much like 63 * ttymodem, but a completely null version might be useful. 64 */ 65 #define NODISC(n) \ 66 { l_noopen, l_noclose, l_noread, l_nowrite, \ 67 l_nullioctl, l_norint, l_nostart, ttymodem } 68 69 struct linesw linesw[MAXLDISC] = 70 { 71 /* 0- termios */ 72 { ttyopen, ttylclose, ttread, ttwrite, 73 l_nullioctl, ttyinput, ttstart, ttymodem }, 74 NODISC(1), /* 1- defunct */ 75 /* 2- NTTYDISC */ 76 #ifdef COMPAT_43 77 { ttyopen, ttylclose, ttread, ttwrite, 78 l_nullioctl, ttyinput, ttstart, ttymodem }, 79 #else 80 NODISC(2), 81 #endif 82 NODISC(3), /* loadable */ 83 NODISC(4), /* SLIPDISC */ 84 NODISC(5), /* PPPDISC */ 85 NODISC(6), /* NETGRAPHDISC */ 86 NODISC(7), /* loadable */ 87 NODISC(8), /* loadable */ 88 }; 89 90 int nlinesw = sizeof (linesw) / sizeof (linesw[0]); 91 92 static struct linesw nodisc = NODISC(0); 93 94 #define LOADABLE_LDISC 7 95 /* 96 * ldisc_register: Register a line discipline. 97 * 98 * discipline: Index for discipline to load, or LDISC_LOAD for us to choose. 99 * linesw_p: Pointer to linesw_p. 100 * 101 * Returns: Index used or -1 on failure. 102 */ 103 int 104 ldisc_register(int discipline, struct linesw *linesw_p) 105 { 106 int slot = -1; 107 108 if (discipline == LDISC_LOAD) { 109 int i; 110 for (i = LOADABLE_LDISC; i < MAXLDISC; i++) 111 if (bcmp(linesw + i, &nodisc, sizeof(nodisc)) == 0) { 112 slot = i; 113 } 114 } 115 else if (discipline >= 0 && discipline < MAXLDISC) { 116 slot = discipline; 117 } 118 119 if (slot != -1 && linesw_p) 120 linesw[slot] = *linesw_p; 121 122 return slot; 123 } 124 125 /* 126 * ldisc_deregister: Deregister a line discipline obtained with 127 * ldisc_register. 128 * 129 * discipline: Index for discipline to unload. 130 */ 131 void 132 ldisc_deregister(int discipline) 133 { 134 if (discipline < MAXLDISC) { 135 linesw[discipline] = nodisc; 136 } 137 } 138 139 static int 140 l_noopen(cdev_t dev, struct tty *tp) 141 { 142 143 return (ENODEV); 144 } 145 146 static int 147 l_noclose(struct tty *tp, int flag) 148 { 149 150 return (ENODEV); 151 } 152 153 int 154 l_noread(struct tty *tp, struct uio *uio, int flag) 155 { 156 157 return (ENODEV); 158 } 159 160 int 161 l_nowrite(struct tty *tp, struct uio *uio, int flag) 162 { 163 164 return (ENODEV); 165 } 166 167 static int 168 l_norint(int c, struct tty *tp) 169 { 170 171 return (ENODEV); 172 } 173 174 static int 175 l_nostart(struct tty *tp) 176 { 177 178 return (ENODEV); 179 } 180 181 /* 182 * Do nothing specific version of line 183 * discipline specific ioctl command. 184 */ 185 int 186 l_nullioctl(struct tty *tp, u_long cmd, char *data, int flags, 187 struct ucred *cred) 188 { 189 190 return (ENOIOCTL); 191 } 192