1 /*- 2 * (MPSAFE) 3 * 4 * Copyright (c) 1982, 1986, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)tty_conf.c 8.4 (Berkeley) 1/21/94 41 * $FreeBSD: src/sys/kern/tty_conf.c,v 1.16.2.1 2002/03/11 01:14:55 dd Exp $ 42 */ 43 44 #include "opt_compat.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/tty.h> 49 #include <sys/conf.h> 50 51 #ifndef MAXLDISC 52 #define MAXLDISC 9 53 #endif 54 55 static l_open_t l_noopen; 56 static l_close_t l_noclose; 57 static l_rint_t l_norint; 58 static l_start_t l_nostart; 59 60 /* 61 * XXX it probably doesn't matter what the entries other than the l_open 62 * entry are here. The l_nullioctl and ttymodem entries still look fishy. 63 * Reconsider the removal of nullmodem anyway. It was too much like 64 * ttymodem, but a completely null version might be useful. 65 */ 66 #define NODISC(n) \ 67 { l_noopen, l_noclose, l_noread, l_nowrite, \ 68 l_nullioctl, l_norint, l_nostart, ttymodem } 69 70 struct linesw linesw[MAXLDISC] = 71 { 72 /* 0- termios */ 73 { ttyopen, ttylclose, ttread, ttwrite, 74 l_nullioctl, ttyinput, ttstart, ttymodem }, 75 NODISC(1), /* 1- defunct */ 76 /* 2- NTTYDISC */ 77 #ifdef COMPAT_43 78 { ttyopen, ttylclose, ttread, ttwrite, 79 l_nullioctl, ttyinput, ttstart, ttymodem }, 80 #else 81 NODISC(2), 82 #endif 83 NODISC(3), /* loadable */ 84 NODISC(4), /* SLIPDISC */ 85 NODISC(5), /* PPPDISC */ 86 NODISC(6), /* NETGRAPHDISC */ 87 NODISC(7), /* loadable */ 88 NODISC(8), /* loadable */ 89 }; 90 91 int nlinesw = NELEM(linesw); 92 93 static struct linesw nodisc = NODISC(0); 94 95 #define LOADABLE_LDISC 7 96 /* 97 * ldisc_register: Register a line discipline. 98 * 99 * discipline: Index for discipline to load, or LDISC_LOAD for us to choose. 100 * linesw_p: Pointer to linesw_p. 101 * 102 * Returns: Index used or -1 on failure. 103 */ 104 int 105 ldisc_register(int discipline, struct linesw *linesw_p) 106 { 107 int slot = -1; 108 109 lwkt_gettoken(&tty_token); 110 if (discipline == LDISC_LOAD) { 111 int i; 112 for (i = LOADABLE_LDISC; i < MAXLDISC; i++) 113 if (bcmp(linesw + i, &nodisc, sizeof(nodisc)) == 0) { 114 slot = i; 115 } 116 } 117 else if (discipline >= 0 && discipline < MAXLDISC) { 118 slot = discipline; 119 } 120 121 if (slot != -1 && linesw_p) 122 linesw[slot] = *linesw_p; 123 124 lwkt_reltoken(&tty_token); 125 return slot; 126 } 127 128 /* 129 * ldisc_deregister: Deregister a line discipline obtained with 130 * ldisc_register. 131 * 132 * discipline: Index for discipline to unload. 133 */ 134 void 135 ldisc_deregister(int discipline) 136 { 137 lwkt_gettoken(&tty_token); 138 if (discipline < MAXLDISC) { 139 linesw[discipline] = nodisc; 140 } 141 lwkt_reltoken(&tty_token); 142 } 143 144 static int 145 l_noopen(cdev_t dev, struct tty *tp) 146 { 147 148 return (ENODEV); 149 } 150 151 static int 152 l_noclose(struct tty *tp, int flag) 153 { 154 155 return (ENODEV); 156 } 157 158 int 159 l_noread(struct tty *tp, struct uio *uio, int flag) 160 { 161 162 return (ENODEV); 163 } 164 165 int 166 l_nowrite(struct tty *tp, struct uio *uio, int flag) 167 { 168 169 return (ENODEV); 170 } 171 172 static int 173 l_norint(int c, struct tty *tp) 174 { 175 176 return (ENODEV); 177 } 178 179 static int 180 l_nostart(struct tty *tp) 181 { 182 183 return (ENODEV); 184 } 185 186 /* 187 * Do nothing specific version of line 188 * discipline specific ioctl command. 189 */ 190 int 191 l_nullioctl(struct tty *tp, u_long cmd, char *data, int flags, 192 struct ucred *cred) 193 { 194 195 return (ENOIOCTL); 196 } 197