aboutsummaryrefslogtreecommitdiff
path: root/rpc_serial.c
blob: bae8b83f3f7047011d0a33c1816c2fbafe826a7e (plain) (blame)
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
/*
 * rpc_serial.c
 * ------------
 * Remote procedure call transport over serial line with SLIP framing.
 *
 * Copyright (c) 2016, NORDUnet A/S All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the NORDUnet nor the names of its contributors may
 *   be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <netinet/in.h>
#include <termios.h>
#include <unistd.h>
#include <fcntl.h>

#include "hal.h"
#include "hal_internal.h"
#include "slip_internal.h"

/*
 * Not thrilled about having OS-specific conditionals, but as such things
 * go, this seems relatively safe: gcc and clang both define it on Mac OS X,
 * and anything *not* on Mac OS X which defines it is begging for trouble.
 */

#ifndef HAL_RPC_SERIAL_USE_MACOSX_IOCTL
#define HAL_RPC_SERIAL_USE_MACOSX_IOCTL	(defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__))
#endif

#if HAL_RPC_SERIAL_USE_MACOSX_IOCTL
#include <IOKit/serial/ioss.h>
#include <sys/ioctl.h>
#endif

static int fd = -1;

hal_error_t hal_serial_init(const char * const device, const uint32_t speed)
{
    struct termios tty;
    speed_t termios_speed;

    /*
     * Apparently Linux is too cool to need an atomic mechanism for
     * locking an existing file, so we can't uses O_EXLOCK.  Sigh.
     */

    fd = open(device, O_RDWR | O_NOCTTY | O_SYNC);
    if (fd == -1)
	return perror(device), HAL_ERROR_RPC_TRANSPORT;

    if (flock(fd, LOCK_EX) < 0)
        return perror(device), HAL_ERROR_RPC_TRANSPORT;

    if (tcgetattr (fd, &tty) != 0)
	return perror("tcgetattr"), HAL_ERROR_RPC_TRANSPORT;

#if !HAL_RPC_SERIAL_USE_MACOSX_IOCTL

    switch (speed) {
    case 115200:
        termios_speed = B115200;
	break;
    case 921600:
        termios_speed = B921600;
	break;
    default:
        hal_log(HAL_LOG_ERROR, "invalid line speed %lu\n", (unsigned long) speed);
	return HAL_ERROR_RPC_TRANSPORT;
    }

    cfsetospeed (&tty, termios_speed);
    cfsetispeed (&tty, termios_speed);

#endif

    tty.c_cflag &= ~CSIZE;
    tty.c_cflag |= (CS8 | CLOCAL | CREAD);

    tty.c_iflag = 0;
    tty.c_oflag = 0;
    tty.c_lflag = 0;

    tty.c_cc[VMIN] = 1;
    tty.c_cc[VTIME] = 0;

    if (tcsetattr (fd, TCSANOW, &tty) != 0)
	return perror("tcsetattr"), HAL_ERROR_RPC_TRANSPORT;

#if HAL_RPC_SERIAL_USE_MACOSX_IOCTL

    termios_speed = speed;

    if (ioctl(fd, IOSSIOSPEED, &speed) < 0)
        return perror("ioctl(IOSSIOSPEED)"), HAL_ERROR_RPC_TRANSPORT;

#endif

    return HAL_OK;
}

hal_error_t hal_serial_close(void)
{
    int ret = close(fd);
    fd = -1;
    if (ret != 0)
        return perror("close"), HAL_ERROR_RPC_TRANSPORT;
    return HAL_OK;
}

hal_error_t hal_serial_send_char(const uint8_t c)
{
    if (write(fd, &c, 1) != 1)
	return perror("write"), HAL_ERROR_RPC_TRANSPORT;
    return HAL_OK;
}

hal_error_t hal_serial_recv_char(uint8_t * const c)
{
    if (read(fd, c, 1) != 1)
	return perror("read"), HAL_ERROR_RPC_TRANSPORT;
    return HAL_OK;
}

/* Access routine for the file descriptor, so daemon can poll on it.
 */
int hal_serial_get_fd(void)
{
    return fd;
}