xref: /titanic_41/usr/src/cmd/ttymon/tmautobaud.c (revision 4445fffbbb1ea25fd0e9ea68b9380dd7a6709025)
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 }
184