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 * $DragonFly: src/sys/kern/tty_conf.c,v 1.6 2006/12/23 23:47:54 swildner Exp $ 43 */ 44 45 #include "opt_compat.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/tty.h> 50 #include <sys/conf.h> 51 52 #ifndef MAXLDISC 53 #define MAXLDISC 9 54 #endif 55 56 static l_open_t l_noopen; 57 static l_close_t l_noclose; 58 static l_rint_t l_norint; 59 static l_start_t l_nostart; 60 61 /* 62 * XXX it probably doesn't matter what the entries other than the l_open 63 * entry are here. The l_nullioctl and ttymodem entries still look fishy. 64 * Reconsider the removal of nullmodem anyway. It was too much like 65 * ttymodem, but a completely null version might be useful. 66 */ 67 #define NODISC(n) \ 68 { l_noopen, l_noclose, l_noread, l_nowrite, \ 69 l_nullioctl, l_norint, l_nostart, ttymodem } 70 71 struct linesw linesw[MAXLDISC] = 72 { 73 /* 0- termios */ 74 { ttyopen, ttylclose, ttread, ttwrite, 75 l_nullioctl, ttyinput, ttstart, ttymodem }, 76 NODISC(1), /* 1- defunct */ 77 /* 2- NTTYDISC */ 78 #ifdef COMPAT_43 79 { ttyopen, ttylclose, ttread, ttwrite, 80 l_nullioctl, ttyinput, ttstart, ttymodem }, 81 #else 82 NODISC(2), 83 #endif 84 NODISC(3), /* loadable */ 85 NODISC(4), /* SLIPDISC */ 86 NODISC(5), /* PPPDISC */ 87 NODISC(6), /* NETGRAPHDISC */ 88 NODISC(7), /* loadable */ 89 NODISC(8), /* loadable */ 90 }; 91 92 int nlinesw = sizeof (linesw) / sizeof (linesw[0]); 93 94 static struct linesw nodisc = NODISC(0); 95 96 #define LOADABLE_LDISC 7 97 /* 98 * ldisc_register: Register a line discipline. 99 * 100 * discipline: Index for discipline to load, or LDISC_LOAD for us to choose. 101 * linesw_p: Pointer to linesw_p. 102 * 103 * Returns: Index used or -1 on failure. 104 */ 105 int 106 ldisc_register(int discipline, struct linesw *linesw_p) 107 { 108 int slot = -1; 109 110 lwkt_gettoken(&tty_token); 111 if (discipline == LDISC_LOAD) { 112 int i; 113 for (i = LOADABLE_LDISC; i < MAXLDISC; i++) 114 if (bcmp(linesw + i, &nodisc, sizeof(nodisc)) == 0) { 115 slot = i; 116 } 117 } 118 else if (discipline >= 0 && discipline < MAXLDISC) { 119 slot = discipline; 120 } 121 122 if (slot != -1 && linesw_p) 123 linesw[slot] = *linesw_p; 124 125 lwkt_reltoken(&tty_token); 126 return slot; 127 } 128 129 /* 130 * ldisc_deregister: Deregister a line discipline obtained with 131 * ldisc_register. 132 * 133 * discipline: Index for discipline to unload. 134 */ 135 void 136 ldisc_deregister(int discipline) 137 { 138 lwkt_gettoken(&tty_token); 139 if (discipline < MAXLDISC) { 140 linesw[discipline] = nodisc; 141 } 142 lwkt_reltoken(&tty_token); 143 } 144 145 static int 146 l_noopen(cdev_t dev, struct tty *tp) 147 { 148 149 return (ENODEV); 150 } 151 152 static int 153 l_noclose(struct tty *tp, int flag) 154 { 155 156 return (ENODEV); 157 } 158 159 int 160 l_noread(struct tty *tp, struct uio *uio, int flag) 161 { 162 163 return (ENODEV); 164 } 165 166 int 167 l_nowrite(struct tty *tp, struct uio *uio, int flag) 168 { 169 170 return (ENODEV); 171 } 172 173 static int 174 l_norint(int c, struct tty *tp) 175 { 176 177 return (ENODEV); 178 } 179 180 static int 181 l_nostart(struct tty *tp) 182 { 183 184 return (ENODEV); 185 } 186 187 /* 188 * Do nothing specific version of line 189 * discipline specific ioctl command. 190 */ 191 int 192 l_nullioctl(struct tty *tp, u_long cmd, char *data, int flags, 193 struct ucred *cred) 194 { 195 196 return (ENOIOCTL); 197 } 198