Multi tool use

Reading a tcp packet on Node js server

I am trying to read a tcp packet on node js sent from c++ tcp client. Below is the struct sent by tcp client

struct LoginPacket
{
uint16_t packetLength; // value:24
uint8_t cmd; // value: 96
uint8_t version; // value: 1
uint8_t checkSum; // value: 1
uint8_t type1; // value: 1
uint8_t type2; // value: 1
uint8_t random; // value: 8
uint8_t lengthOfText; // value: 7
char *textField; // value: "abcd"
};


Below is my nodejs server application to read this struct.

var tcpSock = require('net');

var server = tcpSock.createServer(function(socket) {
socket.write('Echo serverrn');
socket.pipe(socket);

//var buffer = new Buffer(4096, 'hex');
// listen for incoming data
socket.on("data", function(data){

buf = new Buffer(256);
len = buf.write(data.toString());

var Struct = require('struct').Struct;

function getPacketHeader(buffer){
var packetHeader = new Struct()
.word16Ule('packetLength')
.word8Ube('cmd')
.word8Ube('version')
.word8Ube('checkSum')
.word8Ube('type1')
.word8Ube('type2')
.word8Ube('random')
.word8Ube('lengthOfText')
.charsnt('textField', 4)

packetHeader._setBuff(buffer);
return packetHeader;

};

// pack incoming data into the buffer
var incomingPacket = getPacketHeader(buf);
var packetLength = incomingPacket.get('packetLength');
var command = incomingPacket.get('cmd');
var version = incomingPacket.get('version');
var checkSum = incomingPacket.get('checkSum');
var type1 = incomingPacket.get('type1');
var type2 = incomingPacket.get('type2');
var random = incomingPacket.get('random');
var lengthOfTextField = incomingPacket.get('lengthOfTextField');
var textField = incomingPacket.get('textField');

console.log(packetLength);
console.log(command);
console.log(version);
console.log(checkSum);
console.log(token);
console.log(random);
console.log(magicNumber);
console.log(lengthOfTextField);
console.log(textField);
})

});

server.listen(8000, '127.0.0.1');


When i allocate textField size to 5 bytes and send string "abcd" from client, the server is printing blank for text field.

Output

24
96
1
1
1
1
8
7


Can you please help me in reading string properly ?

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