forked from kk7ds/dantracker
/
serial.c
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serial.c
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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8; c-brace-offset: -8; c-argdecl-indent: 8 -*- */
/* Copyright 2012 Dan Smith <dsmith@danplanet.com> */
#include <stdio.h>
#include <unistd.h>
#include <termios.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <signal.h>
#include <fap.h>
#define FEND 0xC0
static int ALARM_INSTALLED = 0;
void alarm_handler(int signal)
{
printf("IO Timeout\n");
}
int get_packet(int fd, char *buf, unsigned int *len)
{
unsigned char byte = 0x00;
char packet[512] = "";
int ret;
int pos = 0;
unsigned int tnc_id;
if (!ALARM_INSTALLED) {
struct sigaction action;
action.sa_handler = alarm_handler;
action.sa_flags = 0;
sigemptyset(&action.sa_mask);
sigaction(SIGALRM, &action, NULL);
ALARM_INSTALLED = 1;
}
alarm(5); /* Five second timeout */
while (byte != FEND) {
ret = read(fd, &byte, 1);
if (ret < 0) {
printf("TNC read failed: %m\n");
return 0;
}
}
packet[pos++] = byte;
while (1 && (pos < sizeof(packet))) {
ret = read(fd, &byte, 1);
if (ret != 1)
continue;
packet[pos++] = byte;
if (byte == FEND)
break;
}
alarm(0);
packet[sizeof(packet)-1] = '\0';
ret = fap_kiss_to_tnc2(packet, pos, buf, len, &tnc_id);
if (!ret)
printf("Failed to convert packet: %s\n", packet);
return ret;
}
int get_rate_const(int baudrate)
{
switch (baudrate) {
case 1200: return B1200;
case 4800: return B4800;
case 9600: return B9600;
case 19200: return B19200;
case 38400: return B38400;
case 115200: return B115200;
};
printf("Unsupported baudrate %i\n", baudrate);
return B9600;
}
int serial_set_rate(int fd, int baudrate, int hwflow)
{
struct termios term;
int ret;
ret = tcgetattr(fd, &term);
if (ret < 0)
goto err;
cfmakeraw(&term);
cfsetspeed(&term, get_rate_const(baudrate));
if (hwflow)
term.c_cflag |= CRTSCTS;
else
term.c_cflag &= ~CRTSCTS;
ret = tcsetattr(fd, TCSAFLUSH, &term);
if (ret < 0)
goto err;
return 0;
err:
perror("unable to configure serial port");
return ret;
}
int serial_open(const char *device, int baudrate, int hwflow)
{
int fd;
int ret;
struct stat s;
printf("Opening serial device %s, hang check ... ", device);
fd = open(device, O_RDWR);
printf("return 0x%02x\n", fd);
if (fd < 0)
return fd;
fstat(fd, &s);
if (S_ISCHR(s.st_mode)) {
ret = serial_set_rate(fd, baudrate, hwflow);
if (ret) {
close(fd);
fd = ret;
}
}
return fd;
}