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—sdk:scripts:serial-udp-server [2015/05/05 15:04] (current) – created - external edit 127.0.0.1
Line 1: Line 1:
 +====== SDK Script serial-udp-server.are ======
 +<code c serial-udp-server.are>
 +/* DESC: This script reads messages coming from the serial port and forwards them via UDP to a remote host (and vice versa).
 + * Copyright (C) 2013 NetModule AG, Switzerland
 + */
 +
 +DEV = "SERIAL1";
 +
 +REMOTE_HOST = argv[1];
 +REMOTE_PORT = (int) argv[2];
 +LOCAL_PORT = (int) argv[3];
 +MAX_PACKET_SIZE = (int) argv[4];        /* bytes */
 +POLL_TIMEOUT = (int) argv[5];           /* seconds */
 +LATENCY = (int) argv[6];                /* seconds */
 +
 +void usage()
 +{
 +    printf("usage: serial-udp-server.are <remote-host> <remote-port> <local-port> <max-packet-size> <poll-timeout> <latency>\n");
 +    exit(1);
 +}
 +
 +int jiffy()
 +{
 +    sys = sysinfo();
 +    u = struct_get(sys, "uptime");
 +
 +    if (is_void(u) || u < 1) {
 +        return 0;
 +    } else {
 +        return u;
 +    }
 +}
 +
 +/* check arguments */
 +if (strlen(argv[1]) == 0) {
 +    nb_syslog("ERROR: no remote host specified");
 +    usage();
 +}
 +if (strlen(argv[2]) == 0) {
 +    nb_syslog("ERROR: no remote port specified");
 +    usage();
 +}
 +if (strlen(argv[3]) == 0) {
 +    nb_syslog("ERROR: no local port specified");
 +    usage();
 +}
 +if (strlen(argv[4]) == 0) {
 +    MAX_PACKET_SIZE = 1380;
 +}
 +if (strlen(argv[5]) == 0 || POLL_TIMEOUT < 1) {
 +    POLL_TIMEOUT = 1;
 +}
 +if (strlen(argv[6]) == 0 || LATENCY < 1) {
 +    LATENCY = 2;
 +}
 +
 +/* check serial port config */
 +status = nb_config_get("serial.0.status");
 +if (status != "2") {
 +    nb_syslog("serial port is not enabled for us");
 +    exit(1);
 +}
 +
 +/* set attributes */
 +rc = nb_serial_setattr(DEV, 115200, 8, 1, 0, 0);
 +if (rc != 0) {
 +    nb_syslog("ERROR: unable to set serial attributes (rc %d)", rc);
 +    exit(1);
 +}
 +
 +/* open serial port */
 +fd = nb_serial_open(DEV);
 +if (fd < 0) {
 +    nb_syslog("Unable to open serial device (%s)", DEV);
 +    exit(1);
 +}
 +
 +/* open UDP socket */
 +sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 +if (sock < 0) {
 +    nb_syslog("ERROR: unable to open socket");
 +    exit(1);
 +}
 +
 +/* bind socket to 1st LAN interface */
 +addr = nb_ifc_address("LAN1");
 +rc = bind(sock, REMOTE_PORT, addr);
 +if (rc == -1) {
 +    nb_syslog("ERROR: unable to bind to port %d\n", REMOTE_PORT);
 +    exit(1);
 +}
 +
 +nb_syslog("Listening for messages (local %d, remote %s:%d)", LOCAL_PORT, REMOTE_HOST, REMOTE_PORT);
 +
 +fds = mkarray(sock, fd);
 +last = jiffy();
 +buffer = "";
 +
 +while (1) {
 +    rc = select(fds, POLL_TIMEOUT);
 +    if (rc == -1) {
 +        nb_syslog("ERROR: select failed");
 +        close(fd);
 +        exit(1);
 +    } 
 +
 +    if (rc == fd) {
 +        /* received something from serial device */
 +        data = read(fd, 4096);
 +        if (data) {
 +            buffer = strcat(buffer, data);
 +        }
 +    } else if (rc == sock) {
 +        /* received something from UDP */
 +        data = recvfrom(sock);
 +        if (data) {
 +            len = strlen(data);
 +            if (len > 0) {
 +                /* write to serial device */
 +                if (len > MAX_PACKET_SIZE) len = MAX_PACKET_SIZE;
 +                write(fd, data, len);
 +            }
 +        }
 +    }
 +
 +    /* check serial buffer and send message */
 +    len = strlen(buffer);
 +    if (len == 0) continue;
 +
 +    now = jiffy();
 +    elapsed = now - last;
 +
 +    if (len < MAX_PACKET_SIZE && elapsed < LATENCY) continue;
 +
 +    if (len <= MAX_PACKET_SIZE) {
 +        msg = buffer;
 +        msglen = len;
 +        buffer = "";
 +    } else {
 +        msg = substr(buffer, 0, MAX_PACKET_SIZE);
 +        msglen = MAX_PACKET_SIZE;
 +        buffer = substr(buffer, MAX_PACKET_SIZE);
 +    }
 +
 +    /* send UDP packet */
 +    sendbufto(sock, msg, msglen, REMOTE_HOST, REMOTE_PORT);
 +    last = now;
 +}
 +
 +close(sock);
 +close(fd);
 +
 +exit(0);
 +
 +</code>
  

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sdk/scripts/serial-udp-server.txt · Last modified: 2015/05/05 15:04 by 127.0.0.1