index.js

/**
 * Created by creosot on 16.03.15.
 */
var net = require('net');
var moment = require('moment');
moment.locale("ru");
var crc16 = require('./libs/crc.js');

net.createServer(function(socket){
    console.log("Connected Client: " + socket.remoteAddress + ":" + socket.remotePort);
    var imei = '';
    socket.on('data', function(data){
        var buf = new Buffer(data);
        if(imei === ''){
            if(buf.length != 17 || buf.readInt16BE(0) != 15){
                myError(1);
                socket.destroy();
                return;
            }
            imei = buf.toString('ascii', 2, 17);
            socket.write('\x01');
        }
        else{
            var crc_buf = buf.slice(buf.length-2, buf.length).toString('hex');
            var crc_my = crc16(buf.slice(8, buf.length-4));
            if(crc_buf !== crc_my){
                myError(2);
                socket.destroy();
                return;
            }
            if(buf.readUInt32BE(0) != 0 || buf.readUInt8(8) != 8){
                myError(3);
                socket.destroy();
                return;
            }
            var count_record = buf.readUInt8(9);
            if(count_record !== buf.readUInt8(buf.length - 5)){
                myError(4);
                socket.destroy();
                return;
            }
            var length_data_array = buf.readUInt32BE(4);
            if(length_data_array !== (buf.length - 12)){
                myError(5);
                socket.destroy();
                return;
            }
            var length_record = length_data_array - 3;
            if((length_record/count_record)%1 !== 0){
                myError(6);
                socket.destroy();
                return;
            }
            var payload = [];
            var gl_length = 10;
            for(var i = 0; i < count_record; i++) {
                if(gl_length >= buf.length - 5){
                    myError(7);
                    socket.destroy();
                    return;
                }
                var buf_payload = buf.slice(gl_length, buf.length - 5);
                payload[i] = {};
                payload[i].IMEI = imei;
                var length = 26;   //start s numbers_one_byte_io
                if(length >= buf_payload.length){
                    myError(7);
                    socket.destroy();
                    return;
                }
                var unix_time = parseInt(buf_payload.toString('hex', 0, 8), 16);
                payload[i].Timestamp = new moment(unix_time).format('MMMM Do YYYY, H:mm:ss');
                payload[i].Gps = {};
                payload[i].Gps.Latitude = buf_payload.readUInt32BE(9)/10000000;
                payload[i].Gps.Longitude = buf_payload.readUInt32BE(13)/10000000;
                payload[i].Gps.Altitude = buf_payload.readUInt16BE(17);
                payload[i].Gps.Sputnik = buf_payload.readUInt8(21);
                payload[i].Gps.Speed = buf_payload.readUInt16BE(22);
                payload[i].Number_IO_Event = buf_payload.readUInt8(24);
                payload[i].Numbers_IO = buf_payload.readUInt8(25);

                //one_byte_io
                payload[i].One_Byte_IO = {};
                var numbers_one_byte_io = buf_payload.readUInt8(length);
                var lo_length = length + 1; //length = 26; lo_length=27
                length += numbers_one_byte_io * 2;  //1-one_byte_io= length=26+2=28
                if(++length >= buf_payload.length){ //length=29 - numbers_two_byte_io
                    myError(7);
                    socket.destroy();
                    return;
                }
                if(numbers_one_byte_io != 0) one_byte_read(buf_payload.slice(lo_length,length), payload[i].One_Byte_IO, numbers_one_byte_io);

                //two_byte_io
                payload[i].Two_Byte_IO = {};
                var numbers_two_byte_io = buf_payload.readUInt8(length); //length=29
                lo_length = length + 1;
                length += numbers_two_byte_io + numbers_two_byte_io * 2;  //1-two_byte_io= length=29+3=32
                if(++length >= buf_payload.length){ //length=33 - numbers_four_byte_io
                    myError(7);
                    socket.destroy();
                    return;
                }
                if(numbers_two_byte_io != 0) two_byte_read(buf_payload.slice(lo_length,length), payload[i].Two_Byte_IO, numbers_two_byte_io);

                //four_byte_io
                payload[i].Four_Byte_IO = {};
                var numbers_four_byte_io = buf_payload.readUInt8(length); //length=33
                lo_length = length + 1;
                length += numbers_four_byte_io + numbers_four_byte_io * 4;  //1-four_byte_io= length=33+5=38
                if(++length >= buf_payload.length){ //length=39 - numbers_eight_byte_io
                    myError(7);
                    socket.destroy();
                    return;
                }
//                if(numbers_four_byte_io != 0) four_byte_read(buf_payload.slice(lo_length,length), payload[i].Four_Byte_IO, numbers_four_byte_io);

                //eight_byte_io
                payload[i].Eight_Byte_IO = {};
                var numbers_eight_byte_io = buf_payload.readUInt8(length); //length=39
                lo_length = length + 1;
                length += numbers_eight_byte_io + numbers_eight_byte_io * 8;  //1-eight_byte_io= length=39+9=48
                if(length >= buf_payload.length){
                    myError(7);
                    socket.destroy();
                    return;
                }
//                if(numbers_eight_byte_io != 0) eight_byte_read(buf_payload.slice(lo_length,length + 1), payload[i].Eight_Byte_IO, numbers_eight_byte_io);
                gl_length += ++length; //length=49 - 2n record
            }
            var res = buf.slice(9,10);
            socket.write('\x00' + '\x00' + '\x00' + res);
            var str = JSON.stringify(payload,'',4);
            console.log(str);
        }
    });
}).listen(3333);

function one_byte_read(buf, payload, numbers){
    var b = new Buffer(buf);
    var l = 0;
    for(var i = 0; i < numbers; i++) {
        var val = b.readUInt8(l + 1);
        var name_val = myID(b.readUInt8(l), val);
        payload[name_val[0]] = name_val[1];
        l += 2;
    }
}

function two_byte_read(buf, payload, numbers){
    var b = new Buffer(buf);
    var l = 0;
    for(var i = 0; i < numbers; i++) {
        var val = b.readUInt16BE(l + 1);
        var name_val = myID(b.readUInt8(l), val);
        payload[name_val[0]] = name_val[1];
        l += 3;
    }
}

function myID(code, val){
    var id_name = "";
    var v = undefined;
    switch(code){
        case 1:
            id_name = "Digital_Input_1";
            if(val == 0) v="OFF"; else v="ON";
            break;
        case 2:
            id_name = "Digital_Input_2";
            if(val == 0) v="OFF"; else v="ON";
            break;
        case 3:
            id_name = "Digital_Input_3";
            if(val == 0) v="OFF"; else v="ON";
            break;
        case 4:
            id_name = "Digital_Input_4";
            if(val == 0) v="OFF"; else v="ON";
            break;
        case 9:
            id_name = "Analog_Input_1";
            v = val/1000;
            break;
        case 10:
            id_name = "Analog_Input_2";
            v = val/1000;
            break;
        case 11:
            id_name = "Analog_Input_3";
            v = val/1000;
            break;
        case 19:
            id_name = "Analog_Input_4";
            v = val/1000;
            break;
        case 66:
            id_name = "External_Power_Voltage";
            v = val/1000;
            break;
        case 67:
            id_name = "Internal_Battery_Voltage";
            v = val/1000;
            break;
        default:
            id_name = "undefined";
    }
    return [id_name, v];
}

function myError(code){
    switch(code){
        case 1:
            console.log("ERROR: bad IMEI.");
            break;
        case 2:
            console.log("ERROR: crc not valid.");
            break;
        case 3:
            console.log("ERROR: bad header AVL packet");
            break;
        case 4:
            console.log("ERROR: difference count record");
            break;
        case 5:
            console.log("ERROR: difference length data array");
            break;
        case 6:
            console.log("ERROR: difference length data array");
            break;
        case 7:
            console.log("ERROR: length > length_buf");
            break;
        default:
            console.log("ERROR");
    }
}