I am stuck with reading data from HttpListener. Data arrives, I verify it with request.ContentLength64 that is usually over 8000 and it increases as the server generates more and more data.
The server sends data as HTTP post and the content type is text/plain.
When I try to check whether streamreader got some data via its length attribute I get 0.
The code is a little bit messy as I was trying different ways to make it work but unfortunatelly I had no luck.
Does anyone got an idea what I'm doing wrong?
Thanks!
HttpListener listener2 = new HttpListener();
listener2.Prefixes.Clear();
listener2.Prefixes.Add("http://+:4200/");
listener2.Prefixes.Add("http://XXX.XXX.eu/");
listener2.Start();
LogWriteLine("http listener started listening to: " +listener2.Prefixes);
try
{
while (true)//change to match end check
{
LogWriteLine("http listener waiting");
HttpListenerContext context = listener2.GetContext();
LogWriteLine("http request arrived");
HttpListenerRequest request = context.Request;
// Obtain a response object.
HttpListenerResponse response = context.Response;
System.IO.Stream body = request.InputStream;
System.Text.Encoding encoding = request.ContentEncoding;
System.IO.StreamReader reader = new System.IO.StreamReader(body, encoding);
if (!request.HasEntityBody)
{
LogWriteLine("No client data was sent with the request.");
Thread.Sleep(300);
//return;
}
if (request.ContentType != null)
{
LogWriteLine("Client data content type " + request.ContentType);
}
LogWriteLine("Client data content length " + request.ContentLength64); //Works fine
LogWriteLine("Start of client data:");
// Convert the data to a string and display it on the console.
Console.WriteLine(body.CanSeek);
string s = reader.ReadToEnd();
var ahoj = new StreamReader(context.Request.InputStream).ReadToEnd();
Console.WriteLine("ahoj length " + ahoj.Length); //0
Console.WriteLine(s); //nothing
string text;
var bytes = default(byte[]);
using (var reader1 = new StreamReader(request.InputStream,
request.ContentEncoding))
{
text = reader1.ReadToEnd();
Console.WriteLine(text + text.Length); //output: 0
using (var memstream = new MemoryStream())
{
reader1.BaseStream.CopyTo(memstream);
bytes = memstream.ToArray();
}
Console.WriteLine("bytes:" + bytes.Length); //output: bytes: 0
}
LogWriteLine("End of client data:");
//write to console file
sw.Write(s);
body.Close();
reader.Close();
}
}
catch (Exception ex)
{
Console.WriteLine(ex);
}
I have a TCP server which writes data back to the client only for certain messages which the clients sends to the server.
It is basically is a command based server for which the server responds with a string only for certain commands otherwise nothing is sent back to the client.
The code given below is an approach which assumes that if any data is sent by the server it shows it as "MESSAGE FROM SERVER" appended with the data which was sent.
class TcpEchoClient
{
static void Main(string[] args)
{
Console.WriteLine("Starting echo client...");
string ipaddress = "127.0.0.1";
TcpClient client = null;
NetworkStream netstream = null;
try
{
client = new TcpClient(ipaddress,1000);
netstream = client.GetStream();
}
catch
{
Console.ReadKey();
Environment.Exit(0);
}
while(true)
{
Console.WriteLine("Message : ");
string t = Console.ReadLine();
string readdata = null;
Console.WriteLine("\n");
if (write(t,netstream))
{
Console.WriteLine("Message sent.");
if (client.Available!=0)
{
readdata = read(netstream);
Console.WriteLine("MESSAGE FROM SERVER : "+readdata);
}
}
else
{
Console.WriteLine("Unable to send message.");
}
}
}
static bool write(string dat, NetworkStream stream)
{
try
{
StreamWriter writer = new StreamWriter(stream) { AutoFlush = true };
try{writer.WriteLine(dat);}
catch (IOException){return false;}
if (SHAHash(dat, "DATA") != SHAHash(read(stream), "DATA"))
return false;
}catch (InvalidOperationException){return false;}
return true;
}
static string read(NetworkStream stream)
{
StreamReader reader = new StreamReader(stream);
string readdata = null;
try
{
readdata = reader.ReadLine();
reader.BaseStream.Flush();
}
catch(IOException)
{
return null;
}
return readdata;
}
}
The function SHAHash is not shown in this post. Its format is SHAHash(message,salt).
The problem faced is that messages sent by the server is not always read by the client. Sometimes the data sent by the server shows up a the client console, and sometimes it does not.
What correction should I make to the above code so that I can read data from the server only when it sends it. That is I require the following code to be executed only when the server sends some data to the client otherwise it should not be executed.
readdata = read(netstream);
Console.WriteLine("MESSAGE FROM SERVER : "+readdata);
Be prudent when using flush or autoflush. Sometimes it executes before send/receive operations... but this usually happens when working with threads.
My first tip that the stream readers/writers are not destructed properly. Try packing them into a using statement.
TCP isnt synchronous so you can't write data and expect the response to be available immediately. When you do the following check
if (client.Available!=0)
there is no guarantee that the server has sent any response yet. You need to keep checking until there is data available or read the data asynchronously
I would use NetworkStream.BeginRead and callbacks to get the server response
class StreamData
{
public NetworkStream netstream;
public byte[] myReadBuffer;
}
class TcpEchoClient
{
static void Main(string[] args)
{
Console.WriteLine("Starting echo client...");
string ipaddress = "127.0.0.1";
TcpClient client = null;
NetworkStream netstream = null;
try
{
client = new TcpClient(ipaddress, 13000);
netstream = client.GetStream();
}
catch
{
Console.ReadKey();
Environment.Exit(0);
}
var streamData = new StreamData
{
netstream = netstream,
myReadBuffer = new byte[1024],
};
netstream.BeginRead(streamData.myReadBuffer, 0, streamData.myReadBuffer.Length,
new AsyncCallback(myReadCallBack),
streamData);
while (true)
{
Console.WriteLine("Message : ");
string t = Console.ReadLine();
Console.WriteLine("\n");
if (write(t, netstream))
{
Console.WriteLine("Message sent.");
}
else
{
Console.WriteLine("Unable to send message.");
}
}
}
static void myReadCallBack(IAsyncResult ar)
{
var streamData = (StreamData)ar.AsyncState;
int bytesRead = streamData.netstream.EndRead(ar);
var readdata = Encoding.ASCII.GetString(streamData.myReadBuffer, 0, bytesRead);
//Be aware that this might not be the complete message depending on the size of the message and the buffer size
Console.WriteLine("You received the following message : " + readdata);
//Start waiting for more data
streamData.netstream.BeginRead(streamData.myReadBuffer, 0, streamData.myReadBuffer.Length,
new AsyncCallback(myReadCallBack),
streamData);
}
static bool write(string dat, NetworkStream stream)
{
try
{
StreamWriter writer = new StreamWriter(stream) { AutoFlush = true };
try { writer.WriteLine(dat); }
catch (IOException) { return false; }
//if (SHAHash(dat, "DATA") != SHAHash(read(stream), "DATA"))
// return false;
}
catch (InvalidOperationException) { return false; }
return true;
}
}
Currently developing a simple message server using sockets and sometimes the TCPClient receives the correct number of bytes but each byte is 0.
Here's the sender code.
try
{
//c.clientSocket.NoDelay = true;
// Send back an OK
var clientStream = c.clientSocket.GetStream();
var Response = JsonConvert.SerializeObject(new Packet("SERVER", c.ClientName, new List<Payload>() { new Payload(MessageLibrary.Commands.OK, null) }));
var msg = System.Text.Encoding.ASCII.GetBytes(Response);
clientStream.Write(msg, 0, msg.Length);
}
catch (Exception ex)
{
if (ExceptionRaised != null)
ExceptionRaised(c.ClientName, ex);
}
Response = "{\"TimeStamp\":\"2016-03-18T08:15:15.0881326+00:00\",\"Sender\":\"SERVER\",\"Payload\":[{\"Command\":\"OK\",\"CommandValue\":\"\"}],\"Destination\":\"GBCO0101\"}"
Msg contains 139 bytes
So this seems ok, here is the receiving code.
static void OnDataRecieved(IAsyncResult result)
{
TcpClient client = result.AsyncState as TcpClient;
// Get a stream object for reading and writing
try
{
NetworkStream stream = client.GetStream();
int ReadBytes = stream.EndRead(result);
if (ReadBytes == 0)
{
// Client gone
Console.WriteLine("Server lost");
}
else
{
// Translate data bytes to a ASCII string.
var data = System.Text.Encoding.ASCII.GetString(ClientReadBuffer, 0, ReadBytes);
ClientReadBuffer = new byte[ClientReadBuffer.Length];
stream.BeginRead(ClientReadBuffer, 0, ClientReadBuffer.Length, new AsyncCallback(OnDataRecieved), client);
ProcessData(data);
}
}
catch (Exception ex)
{
Console.WriteLine("lost connection");
Console.WriteLine(ex.Message);
}
}
If I take a look at ProcessData(data); I can see that data = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
ReadBytes = 139
So the right amount of bytes seems to be correct but the data itself is wrong. What can cause this?
It's unlikely.
Are you really using ClientReadBuffer on the first stream.BeginRead() (it's not included in the code above)? You probably have one somewhere that doesn't do the read in the same way.
And why do you create a new instance of it for every read? Waste of resources. Just reuse it.
Another thing is that TCP is stream based. Don't expect the bytes received to match the buffer that you sent. See this question for instance.
I'm trying to make a proxy server with C#.
Here's my code:
static void Main(string[] args)
{
TcpListener server = null;
try
{
// Set the TcpListener on port 13000.
Int32 port = 13000;
IPAddress localAddr = IPAddress.Parse("127.0.0.1");
// TcpListener server = new TcpListener(port);
server = new TcpListener(localAddr, port);
// Start listening for client requests.
server.Start();
// Buffer for reading data
Byte[] bytes = new Byte[256];
String data = null;
WebRequest request;
WebResponse response;
// Enter the listening loop.
while (true)
{
Console.Write("Waiting for a connection... ");
// Perform a blocking call to accept requests.
// You could also user server.AcceptSocket() here.
TcpClient client = server.AcceptTcpClient();
Console.WriteLine("Connected!");
data = null;
// Get a stream object for reading and writing
NetworkStream stream = client.GetStream();
int i;
String[] input;
// Loop to receive all the data sent by the client.
while (stream.DataAvailable)
{
data = null;
i = stream.Read(bytes, 0, bytes.Length);
// Translate data bytes to a ASCII string.
data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
Console.WriteLine(String.Format("Received: {0}", data));
input = data.Split();
Console.WriteLine("\n\r\n input[1]" + input[1] + "\n");
Stream dataStream;
StreamReader reader;
string responseFromServer;
try
{
request = WebRequest.Create(input[1]);
response = request.GetResponse();
// Process the data sent by the client.
data = data.ToUpper();
dataStream = response.GetResponseStream();
// Open the stream using a StreamReader for easy access.
reader = new StreamReader(dataStream);
// Read the content.
responseFromServer = reader.ReadToEnd();
// Display the content
Console.WriteLine(responseFromServer);
// Clean up the streams and the response.
byte[] msg = System.Text.Encoding.ASCII.GetBytes(responseFromServer);
// Send back a response.
stream.Write(msg, 0, msg.Length);
// Console.WriteLine("Sent: {0}", data);
//stream.Write();
reader.Close();
response.Close();
}
catch (System.UriFormatException e)
{
Console.WriteLine("Exception due to" + e.Data);
Console.WriteLine("Input[1] = " + input[1]);
}
data = null;
}
// Shutdown and end connection
client.Close();
}
}
catch (SocketException e)
{
Console.WriteLine("SocketException: {0}", e);
}
finally
{
// Stop listening for new clients.
server.Stop();
}
Console.WriteLine("\nHit enter to continue...");
Console.Read();
}
It does not work for ssl requests but seems to work for http.
However, it does not load any images.
I'm using Firefox as the browser.
Any ideas why?
Also is this the best way to make a proxy server? Are there any other methods?
After a bit of testing, I wrote my own code.
using System;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Threading;
using System.Text;
namespace SharpProxy
{
class MainClass
{
private static void StartAcceptingClient(IAsyncResult ar)
{
var tcpClient = server.EndAcceptTcpClient(ar);
server.BeginAcceptTcpClient(new AsyncCallback(StartAcceptingClient), null);
// Read the data stream from the client.
NetworkStream stream = tcpClient.GetStream();
byte[] buffer = new byte[256];
Console.WriteLine("====== GOT A NEW TCP CLIENT ====== " + tcpClient.Client.RemoteEndPoint.ToString());
int read = stream.Read(buffer, 0, 1);
MemoryStream saved = new MemoryStream();
saved.Write(buffer, 0, read);
bool isValid = false;
while (read > 0 )
{
read = stream.Read(buffer, 0, 1);
saved.Write(buffer, 0, read);
//Check if the last four bytes were a double \r\n.
var aBytes = saved.ToArray();
int len = aBytes.Length;
if (aBytes.Length >= 4 && aBytes[len - 1] == '\n' && aBytes[len - 2] == '\r' && aBytes[len - 3] == '\n' && aBytes[len - 4] == '\r')
{
isValid = true;
break;
}
}
Console.WriteLine("End of receive.");
string originalRequest = Encoding.ASCII.GetString(saved.ToArray());
byte[] origBytes = saved.ToArray();
saved.Close();
Console.WriteLine(originalRequest);
if (!isValid)
{
Console.WriteLine("This wasn't a valid request");
return;
}
//Find the hoster and do our own request.
string host = originalRequest.Split(new char[] { '\n' }).First(line => line.StartsWith("Host:"));
host = host.Substring(5).Trim(); //Cut of rest.
Console.WriteLine("The host is: " + host);
//Do our own request.
try
{
Socket sProxy = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
sProxy.Connect(host, 80);
sProxy.Send(origBytes);
//Now route everything between the tcpclient and this socket...
//create the state object
var state = new ProxyState() { ourSocket = sProxy, incomingClient = stream };
sProxy.BeginReceive(state.ReceiveBuffer, 0, state.ReceiveBuffer.Length, SocketFlags.None, new AsyncCallback(Receiver), state);
stream.BeginRead(state.SendBuffer, 0, state.SendBuffer.Length, new AsyncCallback(SendToHTTPServer), state);
}
catch (Exception) { Console.WriteLine("Exception while doing our own request"); }
}
static TcpListener server = null;
public static void Main(string[] args)
{
try
{
// Set the TcpListener on port 13000.
Int32 port = 13000;
IPAddress localAddr = IPAddress.Parse("0.0.0.0");
// TcpListener server = new TcpListener(port);
server = new TcpListener(localAddr, port);
// Start listening for client requests.
server.Start();
Console.WriteLine("Server started on " + server.LocalEndpoint.ToString());
server.BeginAcceptTcpClient(new AsyncCallback(StartAcceptingClient), null);
while (true)
Thread.Sleep(10);
}
catch (Exception) { Console.WriteLine("Setting up the server failed"); }
}
private static void SendToHTTPServer(IAsyncResult ar)
{
try
{
ProxyState back = (ProxyState)ar.AsyncState;
int rec = back.incomingClient.EndRead(ar);
//Push this content to the server
back.ourSocket.Send(back.SendBuffer.Take(rec).ToArray());
back.incomingClient.BeginRead(back.SendBuffer, 0, back.SendBuffer.Length, new AsyncCallback(SendToHTTPServer), back);
}
catch (Exception e) { Console.WriteLine("Exc. when sending to server: " + e.ToString()); }
}
static void Receiver(IAsyncResult state)
{
try
{
ProxyState back = (ProxyState)state.AsyncState;
int rec = back.ourSocket.EndReceive(state);
//Set up the back and forth connections
back.incomingClient.Write(back.ReceiveBuffer, 0, rec);
back.ourSocket.BeginReceive(back.ReceiveBuffer, 0, back.ReceiveBuffer.Length, SocketFlags.None, new AsyncCallback(Receiver), back);
}
catch (Exception e) { Console.WriteLine("Exc. when receiving from client: " + e.ToString()); }
}
//Every proxy connection has an end an and a beginning, plus a
//Sending buffer and a receive buffer
class ProxyState
{
public NetworkStream incomingClient { get; set; }
public Socket ourSocket { get; set; }
private byte[] buffReceive = new byte[512];
private byte[] buffSend = new byte[512];
public byte[] ReceiveBuffer { get { return buffReceive; } set { buffReceive = value; } }
public byte[] SendBuffer { get { return buffSend; } set { buffSend = value; } }
}
}
}
Here's how it works: I listen on a port, and wait for a HTTP request. This is ended by a double carriage return and a linefeed, a \r\n\r\n. As soon as that happens, I try to parse the original host from the request with a Linq statement. I open my own socket to the server, and make use of the asynchronous callbacks. Basically, you need to write everything that comes from the proxy-iniator to the HTTP-Server, and everything that the HTTP-Server sends back needs to be pushed back to the original client aswell. This is why I set up my own state-object, which just saves the incomming client and the Socket, which is connected to the original HTTP server. And as such, communication can happen and I act as a proxy server.
Here's a screenshot with all the connections done right:
This proxy server is far from perfect, but the basic concept should be clear. This gave me some inspiration.
You use a streamreader on binary image data, that is not going to work. Not every binary is a valid ASCII encoded string. You should read the response as binary, and write it to the other stream as binary as well. You can try to convert it to ascii to print it to the console, but do not use the converted text to respond, because all the non-valid ascii characters will be converted to ?-s. I did modify your code to first read the response in a MemoryStream, and write that back. The data written to the console is still converted, but not user anywhere else.
static void Main(string[] args)
{
TcpListener server = null;
try
{
// Set the TcpListener on port 13000.
Int32 port = 13000;
IPAddress localAddr = IPAddress.Parse("127.0.0.1");
// TcpListener server = new TcpListener(port);
server = new TcpListener(localAddr, port);
// Start listening for client requests.
server.Start();
// Buffer for reading data
Byte[] bytes = new Byte[256];
String data = null;
WebRequest request;
WebResponse response;
// Enter the listening loop.
while (true)
{
Console.Write("Waiting for a connection... ");
// Perform a blocking call to accept requests.
// You could also user server.AcceptSocket() here.
TcpClient client = server.AcceptTcpClient();
Console.WriteLine("Connected!");
data = null;
// Get a stream object for reading and writing
NetworkStream stream = client.GetStream();
int i;
String[] input;
// Loop to receive all the data sent by the client.
while (stream.DataAvailable)
{
data = null;
i = stream.Read(bytes, 0, bytes.Length);
// Translate data bytes to a ASCII string.
data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
Console.WriteLine(String.Format("Received: {0}", data));
input = data.Split();
Console.WriteLine("\n\r\n input[1]" + input[1] + "\n");
Stream dataStream;
StreamReader reader;
string responseFromServer;
try
{
request = WebRequest.Create(input[1]);
response = request.GetResponse();
// Process the data sent by the client.
data = data.ToUpper();
dataStream = response.GetResponseStream();
MemoryStream ms = new MemoryStream();
dataStream.CopyTo(ms);
ms.Position = 0;
// Open the stream using a StreamReader for easy access.
reader = new StreamReader(ms);
// Read the content.
responseFromServer = reader.ReadToEnd();
// Display the content
Console.WriteLine(responseFromServer);
// Clean up the streams and the response.
byte[] msg = ms.ToArray();
// Send back a response.
stream.Write(msg, 0, msg.Length);
// Console.WriteLine("Sent: {0}", data);
//stream.Write();
reader.Close();
response.Close();
}
catch (System.UriFormatException e)
{
Console.WriteLine("Exception due to" + e.Data);
Console.WriteLine("Input[1] = " + input[1]);
}
data = null;
}
// Shutdown and end connection
client.Close();
}
}
catch (SocketException e)
{
Console.WriteLine("SocketException: {0}", e);
}
finally
{
// Stop listening for new clients.
server.Stop();
}
Console.WriteLine("\nHit enter to continue...");
Console.Read();
}
Can i recevied a int on StreamReader Sockets C#?
I am developed a app client in java data send a int by sockets to app server in C# but i don't know how can i recevied a int. Because if i put a int mensagem = sr.ReadLine() not work !
The code of server app in C#:
//Some code not include.
public void Server()
{
Socket soc = listener.AcceptSocket();
//Informa uma conecção
//MessageBox.Show("Conectado: " + soc.RemoteEndPoint);
try
{
Stream s = new NetworkStream(soc);
StreamReader sr = new StreamReader(s);
StreamWriter sw = new StreamWriter(s);
sw.AutoFlush = true; // enable automatic flushing
while (true)
{
string mensagem = sr.ReadLine(); //if i put int message not work why?
comando(mensagem);
}
//s.Close();
}
catch (Exception e)
{
MessageBox.Show("Erro!" + e.Message);
}
//MessageBox.Show("Disconectado: " + soc.RemoteEndPoint);
//soc.Close();
} //Fim Função Server
ReadLine returns a string. You can use TryParse to get your integer:
int fromClient;
if (!int.TryParse(mensagem, out fromClient))
{
// error parsing as integer
}
// fromClient is either the parsed value or 0 if TryParse was false