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Unable to create same TCP message with C# and C++

I want to create same message and send it with C# as I do it with C++ where all works. Note that I have C# client where I have troubles, C++ client where all works fine and C++ server that should read messages from both C# and C++ clients.
Here is how I send the message from C++:
void ConnectAuthserverCommand::SendLogin(tcp::socket &s, const flatbuffers::FlatBufferBuilder &builder) const {
ClientOpcode opc = CLIENT_LOGIN_REQUEST;
flatbuffers::FlatBufferBuilder builder2;
auto email = builder2.CreateString("test#abv.bg");
auto password = builder2.CreateString("test");
auto loginRequest = Vibranium::CreateLoginRequest(builder2, email, password);
builder2.FinishSizePrefixed(loginRequest);
size_t size2 = builder2.GetSize();
uint8_t *buf2 = builder2.GetBufferPointer();
uint8_t *actualBuffer2 = new uint8_t[size2 + 2];
actualBuffer2[1] = (opc >> 8);
actualBuffer2[0] = (opc&0xFF);
memcpy(actualBuffer2 + 2, buf2, size2);
boost::asio::write(s, boost::asio::buffer(actualBuffer2,size));
}
ClientOpcode is as follows:
enum ClientOpcode : uint16_t{
CLIENT_AUTH_CONNECTION = 0x001,
CLIENT_LOGIN_REQUEST = 0x002,
CLIENT_NUM_MSG_TYPES = 0x003,
};
What I do is the following: I get a ClientOpcode which I want to put infront of FlatBuffers message. So I create an array of uint8_t which I extend with exactly 2 bytes(Because the size of uint16_t is 2 bytes.) Than on the server I read the first 2 bytes in order to get the header and here is how I do that:
void Vibranium::Client::read_header() {
auto self(shared_from_this());
_packet.header_buffer.resize(_packet.header_size);
boost::asio::async_read(socket,
boost::asio::buffer(_packet.header_buffer.data(), _packet.header_size),
[this, self](boost::system::error_code ec,std::size_t bytes_transferred)
{
if ((boost::asio::error::eof == ec) || (boost::asio::error::connection_reset == ec))
{
Disconnect();
}
else
{
assert(_packet.header_buffer.size() >= sizeof(_packet.headerCode));
std::memcpy(&_packet.headerCode, &_packet.header_buffer[0], sizeof (_packet.headerCode));
if(_packet.headerCode)
read_size();
else
Logger::Log("UNKNOWN HEADER CODE", Logger::FatalError);
}
});
}
So far so good, however I am not able to send correctly formatted same message from the C# client. Note that I send exactly same data, take a look:
Client authClient = GameObject.Find("Client").GetComponent<AuthClient>().client; // This is how I get Client class instance.
ClientOpcode clientOpcode = ClientOpcode.CLIENT_LOGIN_REQUEST;
var builder = new FlatBuffers.FlatBufferBuilder(1);
var email = builder.CreateString("test#abv.bg");
var password = builder.CreateString("test");
var loginRequest = LoginRequest.CreateLoginRequest(builder, email, password);
builder.FinishSizePrefixed(loginRequest.Value);
authClient.Send(builder, clientOpcode);
And here is how I actually prepend the header and send the data in C#:
public static Byte[] PrependClientOpcode(FlatBufferBuilder byteBuffer, ClientOpcode code)
{
var originalArray = byteBuffer.SizedByteArray();
byte[] buffer = new byte[originalArray.Length + 2];
buffer[1] = (byte)((ushort)code / 0x0100);
buffer[0] = (byte)code;
Array.Copy(originalArray, 0, buffer, 2, originalArray.Length);
return buffer;
}
public void Send(FlatBufferBuilder builder, ClientOpcode opcode)
{
byte[] buffer = builder.SizedByteArray();
var bufferToSend = PrependClientOpcode(builder, opcode);
if (bufferToSend.Length > MaxMessageSize)
{
Logger.LogError("Client.Send: message too big: " + bufferToSend.Length + ". Limit: " + MaxMessageSize);
return;
}
if (Connected)
{
// respect max message size to avoid allocation attacks.
if (bufferToSend.Length <= MaxMessageSize)
{
// add to send queue and return immediately.
// calling Send here would be blocking (sometimes for long times
// if other side lags or wire was disconnected)
sendQueue.Enqueue(bufferToSend);
sendPending.Set(); // interrupt SendThread WaitOne()
}
}
else
{
Logger.LogWarning("Client.Send: not connected!");
}
}
ClientOpcode enum on C# is as follows:
public enum ClientOpcode : ushort
{
CLIENT_AUTH_CONNECTION = 0x001,
CLIENT_LOGIN_REQUEST = 0x002,
CLIENT_NUM_MSG_TYPES = 0x003,
}
I think I can use ushort as a replacement of uint16_t in C#. That is why ClientOpcode is ushort.
When I send the message I get error on the client saying UNKNOWN HEADER CODE. If you take a look at the C++ server code to read the header you'll see that this message is displayed when the server is unable to read the header code. So somehow I am unable to place the ClientOpcode header correctly infront of the TCP message send from the C# client.
In order to find out what are the differences I installed WireShark on the host to track both messages. Here are they:
This one is from the correctly working C++ client:
And this one is the dump of the C# client:
As you can see on the second image of the TCP dump the Length of is bigger. C++ message is with length of 58 where C# message's length is 62. Why?
The C++ client is sending data:
0200340000000c00000008000c00040008000800000014000000040000000400000074657374000000000b00000074657374406162762e626700
When the C# client is sending:
0000003a0200340000000c00000008000c00040008000800000014000000040000000400000074657374000000000b00000074657374406162762e626700
The C# client is adding to it's message in front 0000003a. If I remove that messages should be the same and all will work.
Why is my C# client adding those extra data in front and how can I fix it?

C# Serialport not receiving all the bytes in a single transmission

I'm using the following code to receive hex data over the serial port, it seems that some of these transmissions are broken up into 2 lines when they are parts of the same transmission. How do I make sure that each transmission is received properly?
public void Receiver(object sender, SerialDataReceivedEventArgs e)
{
string data;
do
{
data = COMPort.ReadExisting();
} while (COMPort.BytesToRead != 0);
RxARR = data.ToCharArray().ToList();
Dispatcher.Invoke(new MethodInvoker(Display)); // Start "Display" on the UI thread
}

You should never assume that data from a serial port is provided to you in one go (the same is true for network communication by the way). You need to make sure that your code accepts a message only if you have received everything.
Everything is hard to define. This can either be all characters until a defined termination sequence (for example \r\n or EOL byte) or until a fixed number of bytes is read. Generally one can say, as every message can be fragmented, reliable communcation is not possible without a defined end of message signal.
What we do is:
Create a StringBuilder
Read everything into that StringBuilder
Search for termination sequence
Remove everything from the StringBuilder up to and including the termination sequence
Process that chunk of data
Repeat from 3 until termination sequence is not found
Keep the remaining characters in StringBuilder, as this is the start of a new message
Pseudo code:
private StringBuilder serialBuffer = new StringBuilder();
private string terminationSequence = "\r\n"; // Anything that can't be part of a message
public void Receiver(object sender, SerialDataReceivedEventArgs e)
{
string data = COMPort.ReadExisting();
serialBuffer.Append(data);
string bufferString = serialBuffer.ToString();
int index = -1;
do
{
index = bufferString.IndexOf(terminationSequence);
if (index > -1)
{
string message = bufferString.Substring(0, index);
bufferString = bufferString.Remove(0, index + terminationSequence.Length);
HandleMessage(message);
}
}
while (index > -1)
serialBuffer = new StringBuilder(bufferString);
}
By the way: Looping within your DataReceived event is not desired, as this event is called by the SerialPort whenever something new is ready to be read. Reading in a loop may interfere with what SerialPort is doing by default. So: Don't read in a loop within that event! The "loop" is the event being fired in sequence by SerialPort.

I Had almost the same situation.
Like Thorsten said the data sometimes does not come at once..
Maybe because of Hardware or BaundRate..
What really works for me was:
var end = '\r';
int dataLength = _serialPort.BytesToRead;
byte[] data = new byte[dataLength];
int nbrDataRead = _serialPort.Read(data, 0, dataLength);
RxString = Encoding.ASCII.GetString(data);
txtCod.AppendText(RxString);
if (RxString.IndexOf((char)end) > -1)
{
this.Invoke(new EventHandler(Final));
}

C# Tcp is losing packets?

I wrote a C# chat software that uses a new (at least for me) system that I called request system. I don't know if that has been created before, but for now I think of it as my creation :P
Anyhow, this system works like this:
soc receives a signal
checks the signal
if the data it just received is the number 2, the client software knows that the server is about to send a chat message. if the number is 3, so the client knows that the server is about to send the member list, and so on.
The problem is this: when I do step-by-step in VS2012 it works fine, the chat is working properly. When I use it on debug mode or just run it on my desktop, there seems to be missing data, and it shouldn't be because the code is working just fine...
Example of code for the sending&receiving message on client:
public void RecieveSystem()
{
while (true)
{
byte[] req = new byte[1];
soc.Receive(req);
int requestID = int.Parse(Encoding.UTF8.GetString(req));
if (requestID == 3)
{
byte[] textSize = new byte[5];
soc.Receive(textSize);
byte[] text = new byte[int.Parse(Encoding.UTF8.GetString(textSize))];
soc.Receive(text);
Dispatcher.Invoke(() => { ChatBox.Text += Encoding.UTF8.GetString(text) + "\r\n"; });
}
}
}
public void OutSystem(string inputText)
{
byte[] req = Encoding.UTF8.GetBytes("3");
soc.Send(req);
byte[] textSize = Encoding.UTF8.GetBytes(Encoding.UTF8.GetByteCount(inputText).ToString());
soc.Send(textSize);
byte[] text = Encoding.UTF8.GetBytes(inputText);
soc.Send(text);
Thread.CurrentThread.Abort();
}
and on the server:
public void UpdateChat(string text)
{
byte[] req = Encoding.UTF8.GetBytes("3");
foreach (User user in onlineUsers)
user.UserSocket.Send(req);
byte[] textSize = Encoding.UTF8.GetBytes(Encoding.UTF8.GetByteCount(text).ToString());
foreach (User user in onlineUsers)
user.UserSocket.Send(textSize);
byte[] data = Encoding.UTF8.GetBytes(text);
foreach (User user in onlineUsers)
user.UserSocket.Send(data);
}
public void RequestSystem(Socket soc)
{
~~~
}
else if (request == 3)
{
byte[] dataSize = new byte[5];
soc.Receive(dataSize);
byte[] data = new byte[int.Parse(Encoding.UTF8.GetString(dataSize))];
soc.Receive(data);
UpdateChat(Encoding.UTF8.GetString(data));
}
}
catch
{
if (!soc.Connected)
{
Dispatcher.Invoke(() => { OnlineMembers.Items.Remove(decodedName + " - " + soc.RemoteEndPoint); Status.Text += soc.RemoteEndPoint + " Has disconnected"; });
onlineUsers.Remove(user);
Thread.CurrentThread.Abort();
}
}
}
}
What could be the problem?

You're assuming that you'll have one packet for each Send call. That's not stream-oriented - that's packet-oriented. You're sending multiple pieces of data which I suspect are coalesced into a single packet, and then you'll get them all in a single Receive call. (Even if there are multiple packets involved, a single Receive call could still receive all the data.)
If you're using TCP/IP, you should be thinking in a more stream-oriented fashion. I'd also encourage you to change the design of your protocol, which is odd to say the least. It's fine to use a length prefix before each message, but why would you want to encode it as text when you've got a perfectly good binary connection between the two computers?
I suggest you look at BinaryReader and BinaryWriter: use TcpClient and TcpListener rather than Socket (or at least use NetworkStream), and use the reader/writer pair to make it easier to read and write pieces of data (either payloads or primitives such as the length of messages). (BinaryWriter.Write(string) even performs the length-prefixing for you, which makes things a lot easier.)

Incomplete data received across network from C# to Arduino

I am trying to send a word over to an Arduino running as a server, from a WPF C# application. Every now and again the complete work is not sent.
C# Code
public void send(String message)
{
TcpClient tcpclnt = new TcpClient();
ConState.Content = "Connecting.....";
try
{
tcpclnt.Connect("192.168.0.177", 23);
ConState.Content = "Connected";
String str = message;
Stream stm = tcpclnt.GetStream();
ASCIIEncoding asen = new ASCIIEncoding();
byte[] ba = asen.GetBytes(str);
stm.Write(ba, 0, ba.Length);
tcpclnt.Close();
}
catch (Exception)
{
ConState.Content = "Not Connected";
return;
}
}
How it is sent to the method:
String mes = "back;";
send(mes);
Arduino code:
if (client.available() > 0) {
// Read the bytes incoming from the client:
char thisChar = client.read();
if (thisChar == ';')
{
//Add a space
Serial.println("");
}
else {
//Print because it's not a space
Serial.write(thisChar);
}
}
The Arduino is using the chat server example. I am sending "back;" and "forward;" across. The results on the serial monitor:
back
forwaback
forward
back
forwaforwar

The problem seems to be with this code:
if (client.available() > 0) {
// read the bytes incoming from the client:
char thisChar = client.read();
...
}
What it does is:
Check if we have received data from the client
Read a single byte from the client buffer
Exit, and go on to do other things
As the OP pointed out, this comes direct from Arduino chat server example. In that example, this working correctly in loop() depends on the alreadyConnected flag being set right after a new connection is made: if it isn't, then the buffer is flushed before any data is read. That's one possible landmine.
Nonetheless, there is no reason to change the if block to be a while loop in the OP's case so, in other words instead of
if (client.available() > 0) {
have
while (client.available() > 0) {
The only reason to have an if statement there is to make sure that you frequently do other processing in loop() if you have clients that send a lot of data: If the reading of client data is done from inside a while this loop will not exit until the there is no more data from the client. Since this doesn't seem to be an issue in the asked-about case, the if to while change makes sense.

block ip by hwid from a text file

I'm working o a project that monitors the IP and HWID on a specific port by TCPListen sent from a client that kills a specific process.
Monitor works perfect, I receive ip and hwid and manage to save to .txt files but what I want to do is to implement a method in server how to block the ip by reading the hwid from a text file.
If some one can help me please I will appreciate it really.
Here is a part from code of client(send) , server (receive):
Server:
textFromClient = ("From: " + tcpClient.Client.RemoteEndPoint + " HWID:" + encoder.GetString(message, 0, bytesRead));
Client:
byte[] outStream = System.Text.Encoding.ASCII.GetBytes(getUniqueID("C"));
serverStream.Write(outStream, 0, outStream.Length);
serverStream.Flush();
I think I understand but maybe that I didn't explain right. Well, my server listen on any ip on port 8000 . Clients connects automaticly to server ip and port: exemple : 127.0.0.1:8000. Well clients works like this: When client is connected to server it runs a application".exe". Client is made to kill the process of some application by name. I made a timer for kill the process all the time client is running. When a process is killed client sends to server the IP from pc where process was killed and HWID code: byte[] outStream = System.Text.Encoding.ASCII.GetBytes(getUniqueID("C"));
serverStream.Write(outStream, 0, outStream.Length);
serverStream.Flush(); and server recive on a listbox the ip and hwid. Well i'm thinking to do so . Example: On this recive message code where i get the HWID from client encoder.GetString(message, 0, bytesRead) to do something like:
if (encoder.GetString(message, 0, bytesRead) = LoadBlockHWID(new FileInfo(#"c:\testfileHWID.txt")));
{
//Code to block connection from specified IP on hwid.
}
I whant that server should not let the client connect to server by HWID. I think I must edit server to see ip and hwid connected and client to send hwid when connected.

Load your HWID into a List/Dictionary by reading your file before you start accepting connections.
in your code where you get tcpClient.Client.RemoteEndPoint, extract just the IPAddress out of that.
Then compare the IPAddress to the block list and if it matches, then see if the HWID matches if that matches then don't perform the task otherwise just do it.
mBlockCheck = new SO15147104();
Here is an example for you. Just instantiate the class and in your line where you Might want to block a request, just
if (!mBlockCheck.BlockRequest(ip, hwid))
{
//Do the operation
}
This is the class code you should be able to figure out from this.
using System.Collections.Generic;
using System.IO;
using System.Net;
public class SO15147104
{
private List<string> HWIDLookup;
private List<IPAddress> IPAddressLookup;
public SO15147104()
{
HWIDLookup = LoadBlockHWID(new FileInfo(#"c:\testfileHWID.txt"));
IPAddressLookup = LoadBlockIPAddresses(new FileInfo(
#"c:\testfileIPAddresses.txt"));
}
public bool BlockRequest(IPAddress ip, string HWIDtoCheck)
{
if (IPAddressLookup.Contains(ip) &&
HWIDLookup.Contains(HWIDtoCheck.ToUpperInvariant().Trim()))
{
return true;
}
return false;
}
private List<IPAddress> LoadBlockIPAddresses(FileInfo fi)
{
List<IPAddress> result = new List<IPAddress>();
using (StreamReader sr = fi.OpenText())
{
while (!sr.EndOfStream)
{
IPAddress theIP = IPAddress.Any;
string thisLine = sr.ReadLine().Trim();
//This should allow IPv6 and IPv4 to be listed 1IP per Line
if (IPAddress.TryParse(thisLine, out theIP))
{
result.Add(theIP);
}
}
}
return result;
}
private List<string> LoadBlockHWID(FileInfo fi)
{
List<string> result = new List<string>();
using (StreamReader sr = fi.OpenText())
{
while (!sr.EndOfStream)
{
result.Add(sr.ReadLine().Trim().ToUpperInvariant());
}
}
return result;
}