usr/src/cmd/ttymon/tmautobaud.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  28 /*        All Rights Reserved   */
  29
  30
  31 #pragma ident   "%Z%%M% %I%     %E% SMI"
  32
  33 #include <stdio.h>
  34 #include <errno.h>
  35 #include <fcntl.h>
  36 #include <string.h>
  37 #include <termio.h>
  38 #include <unistd.h>
  39 #include <signal.h>
  40 #include <stdlib.h>
  41 #include <sys/types.h>
  42 #include <sys/stropts.h>
  43
  44 #include "tmextern.h"
  45
  46 #define NTRY    5
  47
  48 /*
  49  * At this time, we only recognize certain speeds.
  50  * This table can be expanded if new patterns are found
  51  */
  52 static struct   autobaud {
  53         char    *a_speed;
  54         char    *a_pattern;     /* first byte is length */
  55 } autob2400[] = {
  56 #ifdef i386
  57         /*
  58          * These are the bit patterns returned on x86 boxes
  59          */
  60         "110",          "\1\000",
  61 #else
  62         "110",          "\3\000\000\000",
  63 #endif
  64         "1200",         "\2\346\200",
  65         "2400",         "\1\15",
  66         "4800",         "\1\371",
  67         "4800",         "\1\362",
  68         "9600",         "\1\377",
  69         0,              0
  70 };
  71
  72 extern  struct  strbuf *peek_ptr;
  73
  74 /*
  75  *      auto_termio - set termio to allow autobaud
  76  *                  - the line is set to raw mode, with VMIN = 5, VTIME = 1
  77  *                  - baud rate is set to 2400
  78  */
  79 int
  80 auto_termio(int fd)
  81 {
  82         struct termio termio;
  83         struct termios termios;
  84
  85         if (ioctl(fd, TCGETS, &termios) == -1) {
  86                 if (ioctl(fd, TCGETA, &termio) == -1) {
  87                         log("auto_termio: ioctl TCGETA failed, fd = %d: %s", fd,
  88                             strerror(errno));
  89                         return(-1);
  90                 }
  91                 termio.c_iflag = 0;
  92                 termio.c_cflag &= ~(CBAUD|CSIZE|PARENB);
  93                 termio.c_cflag |= CREAD|HUPCL|(CS8&CSIZE)|(B2400&CBAUD);
  94                 termio.c_lflag &= ~(ISIG|ICANON|ECHO|ECHOE|ECHOK);
  95                 termio.c_oflag = 0;
  96
  97                 termio.c_cc[VMIN] = 5;
  98                 termio.c_cc[VTIME] = 1;
  99
 100                 if (ioctl(fd, TCSETAF, &termio) == -1) {
 101                         log("auto_termio: ioctl TCSETAF failed, fd = %d: %s",
 102                             fd, strerror(errno));
 103                         return(-1);
 104                 }
 105         } else {
 106                 termios.c_iflag &= 0xffff0000;
 107                 termios.c_cflag &= ~(CSIZE|PARENB);
 108                 termios.c_cflag |= CREAD|HUPCL|(CS8&CSIZE);
 109                 termios.c_lflag &= ~(ISIG|ICANON|ECHO|ECHOE|ECHOK);
 110                 termios.c_oflag &= 0xffff0000;
 111
 112                 termios.c_cc[VMIN] = 5;
 113                 termios.c_cc[VTIME] = 1;
 114                 cfsetospeed(&termios, B2400);
 115
 116                 if (ioctl(fd, TCSETSF, &termios) == -1) {
 117                         log("auto_termio: ioctl TCSETSF failed, fd = %d: %s",
 118                               fd, strerror(errno));
 119                         return(-1);
 120                 }
 121         }
 122         return(0);
 123 }
 124
 125 /*
 126  *      autobaud - determine the baudrate by reading data at 2400 baud rate
 127  *               - the program is anticipating <CR>
 128  *               - the bit pattern is matched again an autobaud table
 129  *               - if a match is found, the matched speed is returned
 130  *               - otherwise, NULL is returned
 131  */
 132
 133 char *
 134 autobaud(int fd, int timeout)
 135 {
 136         int i, k, count;
 137         static char     buf[5];
 138         register char *cp = buf;
 139         struct  autobaud *tp;
 140         struct  sigaction sigact;
 141         extern  void    timedout();
 142         extern  void    flush_input();
 143
 144 #ifdef  DEBUG
 145         debug("in autobaud");
 146 #endif
 147         auto_termio(fd);
 148         sigact.sa_flags = 0;
 149         sigact.sa_handler = SIG_IGN;
 150         (void)sigemptyset(&sigact.sa_mask);
 151         (void)sigaction(SIGINT, &sigact, NULL);
 152         count = NTRY;
 153         while (count--) {
 154                 if (timeout) {
 155                         sigact.sa_flags = 0;
 156                         sigact.sa_handler = timedout;
 157                         (void)sigemptyset(&sigact.sa_mask);
 158                         (void)sigaction(SIGALRM, &sigact, NULL);
 159                         (void)alarm((unsigned)timeout);
 160                 }
 161                 cp = &buf[1];
 162                 if ( peek_ptr ) {
 163                         strncpy(cp, peek_ptr->buf, k=peek_ptr->len);
 164                         peek_ptr = NULL;
 165                 } else if ((k=read(fd, cp, 5)) < 0) {
 166                         fatal("autobaud: read failed: %s", strerror(errno));
 167                 }
 168                 if (timeout)
 169                         (void)alarm((unsigned)0);
 170                 buf[0] = (char)k;
 171                 for (tp = autob2400; tp->a_speed; tp++) {
 172                         for (i = 0;; i++) {
 173                                 if (buf[i] != tp->a_pattern[i])
 174                                         break;
 175                                 if (i == buf[0]) {
 176                                         return(tp->a_speed);
 177                                 }
 178                         }
 179                 }
 180                 flush_input(fd);
 181         } /* end while */
 182         return(NULL);           /* autobaud failed */
 183 }