int open_seriport(const char *ttypath,int uart_speed)
{
int fd = open(ttypath,O_RDWR|O_NOCTTY|O_NONBLOCK);
struct termios tios;
memset(&tios,0,sizeof(struct termios));
/* 将串口设置为原始模式 */
cfmakeraw(&tios);
/* baud rate */
cfsetospeed(&tios,look_up_uart_speed(uart_speed));
cfsetispeed(&tios,look_up_uart_speed(uart_speed));
/* 流控制选项 */
tios.c_iflag &= ~IXOFF;
tios.c_cflag &= ~CRTSCTS;
tios.c_cflag |= CS8;
//控制模式 parity check
tios.c_cflag &= ~PARENB; //no parity check
tios.c_cflag &= ~CSTOPB; //1 stop bits
/* 设置串口缓冲队列 */
tios.c_cc[VTIME] = 0;
tios.c_cc[VMIN] = 0;
/* 使串口设置生效 */
if(tcsetattr(fd,TCSADRAIN,&tios) < 0){
return fd;
}
return fd;
}
int main(int argc, char *argv[])
{
char *tty = NULL;
char const *devprefix = "/dev/";
char *name = NULL;
char buf[IFNAMSIZ+1];
struct termios tios;
speed_t old_ispeed;
speed_t old_ospeed;
int opt;
int send_open = 0;
int send_close = 0;
int send_read_status_flags = 0;
char *speed = NULL;
char *uart_speed_str = NULL;
long int uart_speed = 0;
int flow_type = FLOW_NONE;
char *btr = NULL;
int run_as_daemon = 1;
char *pch;
int ldisc = N_SLCAN;
int fd;
ttypath[0] = '\0';
while ((opt = getopt(argc, argv, "ocfs:S:t:b:?hF")) != -1) {
switch (opt) {
case 'o':
send_open = 1;
break;
case 'c':
send_close = 1;
break;
case 'f':
send_read_status_flags = 1;
break;
case 's':
speed = optarg;
if (strlen(speed) > 1)
print_usage(argv[0]);
break;
case 'S':
uart_speed_str = optarg;
errno = 0;
uart_speed = strtol(uart_speed_str, NULL, 10);
if (errno)
print_usage(argv[0]);
if (look_up_uart_speed(uart_speed) == -1) {
fprintf(stderr, "Unsupported UART speed (%lu)\n", uart_speed);
exit(EXIT_FAILURE);
}
break;
case 't':
if (!strcmp(optarg, "hw")) {
flow_type = FLOW_HW;
} else if (!strcmp(optarg, "sw")) {
flow_type = FLOW_SW;
} else {
fprintf(stderr, "Unsupported flow type (%s)\n", optarg);
exit(EXIT_FAILURE);
}
break;
case 'b':
btr = optarg;
if (strlen(btr) > 6)
print_usage(argv[0]);
break;
case 'F':
run_as_daemon = 0;
break;
case 'h':
case '?':
default:
print_usage(argv[0]);
break;
}
}
/* Initialize the logging interface */
openlog(DAEMON_NAME, LOG_PID, LOG_LOCAL5);
/* Parse serial device name and optional can interface name */
tty = argv[optind];
if (NULL == tty)
print_usage(argv[0]);
name = argv[optind + 1];
/* Prepare the tty device name string */
pch = strstr(tty, devprefix);
if (pch != tty)
snprintf(ttypath, TTYPATH_LENGTH, "%s%s", devprefix, tty);
else
snprintf(ttypath, TTYPATH_LENGTH, "%s", tty);
syslog(LOG_INFO, "starting on TTY device %s", ttypath);
/* Daemonize */
if (run_as_daemon) {
if (daemon(0, 0)) {
syslog(LOG_ERR, "failed to daemonize");
exit(EXIT_FAILURE);
}
}
else {
/* Trap signals that we expect to receive */
signal(SIGINT, child_handler);
signal(SIGTERM, child_handler);
}
/* */
slcand_running = 1;
/* Now we are a daemon -- do the work for which we were paid */
fd = open(ttypath, O_RDWR | O_NONBLOCK | O_NOCTTY);
if (fd < 0) {
syslog(LOG_NOTICE, "failed to open TTY device %s\n", ttypath);
perror(ttypath);
exit(EXIT_FAILURE);
}
/* Configure baud rate */
memset(&tios, 0, sizeof(struct termios));
if (tcgetattr(fd, &tios) < 0) {
syslog(LOG_NOTICE, "failed to get attributes for TTY device %s: %s\n", ttypath, strerror(errno));
exit(EXIT_FAILURE);
}
/* Get old values for later restore */
old_ispeed = cfgetispeed(&tios);
old_ospeed = cfgetospeed(&tios);
/* Reset UART settings */
cfmakeraw(&tios);
tios.c_iflag &= ~IXOFF;
tios.c_cflag &= ~CRTSCTS;
/* Baud Rate */
cfsetispeed(&tios, look_up_uart_speed(uart_speed));
cfsetospeed(&tios, look_up_uart_speed(uart_speed));
/* Flow control */
if (flow_type == FLOW_HW)
tios.c_cflag |= CRTSCTS;
else if (flow_type == FLOW_SW)
tios.c_iflag |= (IXON | IXOFF);
/* apply changes */
if (tcsetattr(fd, TCSADRAIN, &tios) < 0)
syslog(LOG_NOTICE, "Cannot set attributes for device \"%s\": %s!\n", ttypath, strerror(errno));
if (speed) {
sprintf(buf, "C\rS%s\r", speed);
write(fd, buf, strlen(buf));
}
if (btr) {
sprintf(buf, "C\rs%s\r", btr);
write(fd, buf, strlen(buf));
}
if (send_read_status_flags) {
sprintf(buf, "F\r");
write(fd, buf, strlen(buf));
}
if (send_open) {
sprintf(buf, "O\r");
write(fd, buf, strlen(buf));
}
/* set slcan like discipline on given tty */
if (ioctl(fd, TIOCSETD, &ldisc) < 0) {
perror("ioctl TIOCSETD");
exit(EXIT_FAILURE);
}
/* retrieve the name of the created CAN netdevice */
if (ioctl(fd, SIOCGIFNAME, buf) < 0) {
perror("ioctl SIOCGIFNAME");
exit(EXIT_FAILURE);
}
syslog(LOG_NOTICE, "attached TTY %s to netdevice %s\n", ttypath, buf);
/* try to rename the created netdevice */
if (name) {
struct ifreq ifr;
int s = socket(PF_INET, SOCK_DGRAM, 0);
if (s < 0)
perror("socket for interface rename");
else {
strncpy(ifr.ifr_name, buf, IFNAMSIZ);
strncpy(ifr.ifr_newname, name, IFNAMSIZ);
if (ioctl(s, SIOCSIFNAME, &ifr) < 0) {
syslog(LOG_NOTICE, "netdevice %s rename to %s failed\n", buf, name);
perror("ioctl SIOCSIFNAME rename");
exit(EXIT_FAILURE);
} else
syslog(LOG_NOTICE, "netdevice %s renamed to %s\n", buf, name);
close(s);
}
}
/* The Big Loop */
while (slcand_running)
sleep(1); /* wait 1 second */
/* Reset line discipline */
syslog(LOG_INFO, "stopping on TTY device %s", ttypath);
ldisc = N_TTY;
if (ioctl(fd, TIOCSETD, &ldisc) < 0) {
perror("ioctl TIOCSETD");
exit(EXIT_FAILURE);
}
if (send_close) {
sprintf(buf, "C\r");
write(fd, buf, strlen(buf));
}
/* Reset old rates */
cfsetispeed(&tios, old_ispeed);
cfsetospeed(&tios, old_ospeed);
/* apply changes */
if (tcsetattr(fd, TCSADRAIN, &tios) < 0)
syslog(LOG_NOTICE, "Cannot set attributes for device \"%s\": %s!\n", ttypath, strerror(errno));
/* Finish up */
syslog(LOG_NOTICE, "terminated on %s", ttypath);
closelog();
return exit_code;
}
