summaryrefslogtreecommitdiffstats
path: root/serial.c
blob: 07be8ed372f6e2dbcd3471d3c5944c19493d2597 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
/******************************************************************
** File: serial.c
** Description: the serial part for microcom project
**
** Copyright (C)1999 Anca and Lucian Jurubita <ljurubita@hotmail.com>.
** All rights reserved.
****************************************************************************
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public License
** as published by the Free Software Foundation; either version 2
** of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details at www.gnu.org
****************************************************************************
** Rev. 1.0 - Feb. 2000
** Rev. 1.01 - March 2000
** Rev. 1.02 - June 2000
****************************************************************************/

#include <limits.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <arpa/telnet.h>

#include "microcom.h"

static struct termios pots;		/* old port termios settings to restore */

static void init_comm(struct termios *pts)
{
	/* some things we want to set arbitrarily */
	pts->c_lflag &= ~ICANON;
	pts->c_lflag &= ~(ECHO | ECHOCTL | ECHONL);
	pts->c_cflag |= HUPCL | CREAD | CLOCAL;
	pts->c_iflag |= IGNBRK;
	pts->c_cc[VMIN] = 1;
	pts->c_cc[VTIME] = 0;

	/* Standard CR/LF handling: this is a dumb terminal.
	 * Do no translation:
	 *  no NL -> CR/NL mapping on output, and
	 *  no CR -> NL mapping on input.
	 */
	pts->c_oflag &= ~ONLCR;
	pts->c_iflag &= ~ICRNL;
}

static ssize_t serial_write(struct ios_ops *ios, const void *buf, size_t count)
{
	return write(ios->fd, buf, count);
}

static ssize_t serial_read(struct ios_ops *ios, void *buf, size_t count)
{
	return read(ios->fd, buf, count);
}

static int serial_set_handshake_line(struct ios_ops *ios, int pin, int enable)
{
	int flag;
	int ret;

	switch (pin) {
	case PIN_DTR:
		flag = TIOCM_DTR;
		break;
	case PIN_RTS:
		flag = TIOCM_RTS;
		break;
	}

	if (enable)
		ret = ioctl(ios->fd, TIOCMBIS, &flag);
	else
		ret = ioctl(ios->fd, TIOCMBIC, &flag);

	return ret;
}

static int serial_set_speed(struct ios_ops *ios, unsigned long speed)
{
	struct termios pts;	/* termios settings on port */
	speed_t flag;
	int ret;

	tcgetattr(ios->fd, &pts);

	ret = baudrate_to_flag(speed, &flag);
	if (ret)
		return ret;

	cfsetospeed(&pts, flag);
	cfsetispeed(&pts, flag);
	tcsetattr(ios->fd, TCSANOW, &pts);

	return 0;
}

static int serial_set_flow(struct ios_ops *ios, int flow)
{
	struct termios pts;	/* termios settings on port */
	tcgetattr(ios->fd, &pts);

	switch (flow) {
	case FLOW_NONE:
		/* no flow control */
		pts.c_cflag &= ~CRTSCTS;
		pts.c_iflag &= ~(IXON | IXOFF | IXANY);
		break;
	case FLOW_HARD:
		/* hardware flow control */
		pts.c_cflag |= CRTSCTS;
		pts.c_iflag &= ~(IXON | IXOFF | IXANY);
		break;
	case FLOW_SOFT:
		/* software flow control */
		pts.c_cflag &= ~CRTSCTS;
		pts.c_iflag |= IXON | IXOFF | IXANY;
		break;
	}

	tcsetattr(ios->fd, TCSANOW, &pts);

	return 0;
}

static int serial_send_break(struct ios_ops *ios)
{
	tcsendbreak(ios->fd, 0);

	return 0;
}

/* restore original terminal settings on exit */
static void serial_exit(struct ios_ops *ios)
{
	tcsetattr(ios->fd, TCSANOW, &pots);
	close(ios->fd);
	free(ios);
}

struct ios_ops * serial_init(char *device)
{
	struct termios pts;	/* termios settings on port */
	struct ios_ops *ops;
	int fd, ret;

	ops = malloc(sizeof(*ops));
	if (!ops)
		return NULL;

	ops->write = serial_write;
	ops->read = serial_read;
	ops->set_speed = serial_set_speed;
	ops->set_flow = serial_set_flow;
	ops->set_handshake_line = serial_set_handshake_line;
	ops->send_break = serial_send_break;
	ops->exit = serial_exit;
	ops->istelnet = false;

	/* open the device */
	fd = open(device, O_RDWR | O_NONBLOCK);
	ops->fd = fd;

	if (fd < 0)
		main_usage(2, "cannot open device", device);

	/* try to lock the device */
	ret = flock(fd, LOCK_EX | LOCK_NB);
	if (ret) {
		if (!opt_force)
			main_usage(3, "could not lock port", device);
		else
			printf("could not lock port, ignoring\n");
	}

	/* modify the port configuration */
	tcgetattr(fd, &pts);
	memcpy(&pots, &pts, sizeof (pots));
	init_comm(&pts);
	tcsetattr(fd, TCSANOW, &pts);
	printf("connected to %s\n", device);

	return ops;
}