Develop Reference

TcpListener AcceptSocket() accepts two connections for each single GET request

I have this web server program up and running, using TcpListener. The problem is that for each get request made through web browser (or chrome Postman extension), it captures two requests.
namespace Server
{
class WebServer2
{
private TcpListener listener;
private int port = 8080;
public WebServer2()
{
try
{
listener = new TcpListener(IPAddress.Parse("127.0.0.1"), port);
listener.Start();
Console.WriteLine("Listening...");
//start the thread which calls the method 'StartListen'
Thread th = new Thread(new ThreadStart(StartListen));
th.Start();
}
catch (Exception e)
{
Console.WriteLine("An Exception Occurred While Listening: " + e.ToString());
}
}
//Recieve Request
public void StartListen()
{
int iStartPos = 0;
String sRequest;
String sRequestedFile;
String sResponse = "";
while (true)
{
//Accept a new connection
Socket socket = listener.AcceptSocket();
if (socket.Connected)
{
Console.WriteLine("\nClient Connected");
Console.WriteLine("----------------");
//Receive data from the client
Byte[] bReceive = new Byte[1024];
int i = socket.Receive(bReceive, bReceive.Length, 0);
//Convert Byte to String
string sBuffer = Encoding.ASCII.GetString(bReceive);
//Only GET Request is accepted
if (sBuffer.Substring(0, 3) != "GET")
{
Console.WriteLine("Not a Get Request.");
socket.Close();
continue;
}
// Look for HTTP request
iStartPos = sBuffer.IndexOf("HTTP", 1);
// Get the HTTP text and version e.g. it will return "HTTP/1.1"
string sHttpVersion = sBuffer.Substring(iStartPos, 8);
// Extract the Requested Type and Requested file/directory
sRequest = sBuffer.Substring(0, iStartPos - 1);
//If file name not provided
if (sRequest.IndexOf(".") < 1)
{
Console.WriteLine("File name not Provided!");
socket.Close();
continue;
}
//Extract the requested file name
iStartPos = sRequest.LastIndexOf("/") + 1;
sRequestedFile = sRequest.Substring(iStartPos);
Console.WriteLine("Requested File: " + sRequestedFile);
int iTotBytes = 0;
sResponse = "";
FileStream fs = new FileStream(sRequestedFile, FileMode.Open, FileAccess.Read, FileShare.Read);
BinaryReader reader = new BinaryReader(fs);
byte[] bytes = new byte[fs.Length];
int read;
while ((read = reader.Read(bytes, 0, bytes.Length)) != 0)
{
// Read from the file and write the data to the network
sResponse = sResponse + Encoding.ASCII.GetString(bytes, 0, read);
iTotBytes = iTotBytes + read;
}
reader.Close();
fs.Close();
SendHeader(sHttpVersion, "text/html", iTotBytes, " 200 OK", ref socket);
SendToBrowser(bytes, ref socket);
socket.Send(bytes, bytes.Length, 0);
socket.Close();
}
}
}
// Overloaded Function, takes string, convert to bytes and calls
// overloaded sendToBrowserFunction.
public void SendToBrowser(String sData, ref Socket socket)
{
SendToBrowser(Encoding.ASCII.GetBytes(sData), ref socket);
}
/// Sends data to the browser (client)
public void SendToBrowser(Byte[] bSendData, ref Socket socket)
{
int numBytes = 0;
try
{
if (socket.Connected)
{
if ((numBytes = socket.Send(bSendData, bSendData.Length, 0)) == -1)
Console.WriteLine("Socket Error");
}
else
Console.WriteLine("Connection Dropped!");
}
catch (Exception e)
{
Console.WriteLine("Error: {0} ", e);
}
}
// This function send the Header Information to the client (Browser)
public void SendHeader(string sHttpVersion, string sMIMEHeader, int iTotBytes, string sStatusCode, ref Socket socket)
{
String sBuffer = "";
Byte[] bSendData;
if (sStatusCode.Equals("404") || sStatusCode.Equals("400"))
{
sBuffer = sBuffer + sHttpVersion + sStatusCode + "\r\n";
sBuffer = sBuffer + "Server: MyServer\r\n";
sBuffer = sBuffer + "Content-Length: " + 0 + "\r\n\r\n";
bSendData = Encoding.ASCII.GetBytes(sBuffer);
SendToBrowser(bSendData, ref socket);
}
else
{
sBuffer = sBuffer + sHttpVersion + sStatusCode + "\r\n";
sBuffer = sBuffer + "Server: MyServer\r\n";
sBuffer = sBuffer + "Content-Type: " + sMIMEHeader + "\r\n";
sBuffer = sBuffer + "Accept-Ranges: bytes\r\n";
sBuffer = sBuffer + "Content-Length: " + iTotBytes + "\r\n\r\n";
bSendData = Encoding.ASCII.GetBytes(sBuffer);
SendToBrowser(bSendData, ref socket);
}
}
}
}
Single request made by chrome against http://localhost:8080/page1.html
Request made by Postman Extension
The funny thing is, everything works find when I send request through my client program (using TcpClient).

I tested your server and got similar results:
Chrome automatically asks for a favicon.ico file for every request. This generates the extra GET request to your server.
Firefox doesn't do this and simply generates one request per refresh.
Then there is a second problem I experienced, which is the one in your Postman screenshot.
Chrome (including the Postman Extension running inside it) reconnects
without sending anything, so the server "hangs" until you get a
response filled with \0 (nul-characters).
This is part of Chrome's prediction service to load subsequent requests faster. You could disable this behavior under Settings (advanced) > Privacy:
In your server implementation, this results in the "Not a Get Request" output if no subsequent GET request follows (instead, Chrome sends \0 to signal its not sending anything anyway).
Note: I didn't experience any of this in the actual Postman application.
While the server waits for chrome to send a request, it cannot service any other requests. To prevent this from happening, consider using an asynchronous approach.

Download binary file over HTTP

I need to download a binary file , uploaded via http post. I can not able to download file.
I can see the content of data but I'm not able to save into my local disk.
this is what i see in string
--fUYxo2BFe6N Content-Disposition: form-data; name="data"; filename="EVLD_1.4.36_16_0993_0_000AAE0E0109_2D8A145A040000CC_0E0B1B0F3B29_0008.akt" Content-Type: application/x-gzip
‹ òÖwTcÈ”cdäã–æ7´fàZÇÇÈÉÀÀüA Èåp’Y9,Lp%ì#1& ‹…Äg¬ ‚
,
"8€dÐDÁ
"x#/ˆàü B D‚!!Ä ƒ³e¹!ê™è›è˜™ƒ‘e+R9*ÌG[+‚´möÛÊ€äò0²ª2¬B† --fUYxo2BFe6N Content-Disposition: form-data; name="SehirID"
16 --fUYxo2BFe6N Content-Disposition: form-data; name="CihazTipiID"
64 --fUYxo2BFe6N Content-Disposition: form-data; name="CihazAltTipiID"
1 --fUYxo2BFe6N Content-Disposition: form-data; name="md5"
1FAFE4C67252889C75C526EA4313BE27 --fUYxo2BFe6N Content-Disposition: form-data; name="mac"
000AAE0E0109 --fUYxo2BFe6N--
This is my source code for listenint requests. I can handle de requests but I'm not able to save content into a file..
public class HttpProcessor
{
public TcpClient socket;
public HttpServer srv;
private Stream inputStream;
public StreamWriter outputStream;
public String http_method;
public String http_url;
public String http_protocol_versionstring;
public Hashtable httpHeaders = new Hashtable();
private static int MAX_POST_SIZE = 10 * 1024 * 1024; // 10MB
public HttpProcessor(TcpClient s, HttpServer srv)
{
this.socket = s;
this.srv = srv;
}
private string streamReadLine(Stream inputStream)
{
int next_char;
string data = "";
while (true)
{
next_char = inputStream.ReadByte();
if (next_char == '\n') { break; }
if (next_char == '\r') { continue; }
if (next_char == -1) { Thread.Sleep(1); continue; };
data += Convert.ToChar(next_char);
}
return data;
}
public void process()
{
// we can't use a StreamReader for input, because it buffers up extra data on us inside it's
// "processed" view of the world, and we want the data raw after the headers
inputStream = new BufferedStream(socket.GetStream());
// we probably shouldn't be using a streamwriter for all output from handlers either
outputStream = new StreamWriter(new BufferedStream(socket.GetStream()));
try
{
parseRequest();
readHeaders();
if (http_method.Equals("GET"))
{
handleGETRequest();
}
else if (http_method.Equals("POST"))
{
handlePOSTRequest();
}
}
catch (Exception e)
{
Console.WriteLine("Exception: " + e.ToString());
writeFailure();
}
outputStream.Flush();
// bs.Flush(); // flush any remaining output
inputStream = null; outputStream = null; // bs = null;
socket.Close();
}
public void parseRequest()
{
String request = streamReadLine(inputStream);
string[] tokens = request.Split(' ');
if (tokens.Length != 3)
{
throw new Exception("invalid http request line");
}
http_method = tokens[0].ToUpper();
http_url = tokens[1];
http_protocol_versionstring = tokens[2];
Console.WriteLine("starting: " + request);
}
public void readHeaders()
{
Console.WriteLine("readHeaders()");
String line;
while ((line = streamReadLine(inputStream)) != null)
{
if (line.Equals(""))
{
Console.WriteLine("got headers");
return;
}
int separator = line.IndexOf(':');
if (separator == -1)
{
throw new Exception("invalid http header line: " + line);
}
String name = line.Substring(0, separator);
int pos = separator + 1;
while ((pos < line.Length) && (line[pos] == ' '))
{
pos++; // strip any spaces
}
string value = line.Substring(pos, line.Length - pos);
Console.WriteLine("header: {0}:{1}", name, value);
httpHeaders[name] = value;
}
}
public void handleGETRequest()
{
srv.handleGETRequest(this);
}
private const int BUF_SIZE = 4096;
public void handlePOSTRequest()
{
// this post data processing just reads everything into a memory stream.
// this is fine for smallish things, but for large stuff we should really
// hand an input stream to the request processor. However, the input stream
// we hand him needs to let him see the "end of the stream" at this content
// length, because otherwise he won't know when he's seen it all!
Console.WriteLine("get post data start");
int content_len = 0;
MemoryStream ms = new MemoryStream();
if (this.httpHeaders.ContainsKey("Content-Length"))
{
content_len = Convert.ToInt32(this.httpHeaders["Content-Length"]);
if (content_len > MAX_POST_SIZE)
{
throw new Exception(
String.Format("POST Content-Length({0}) too big for this simple server",
content_len));
}
byte[] buf = new byte[BUF_SIZE];
int to_read = content_len;
while (to_read > 0)
{
Console.WriteLine("starting Read, to_read={0}", to_read);
int numread = this.inputStream.Read(buf, 0, Math.Min(BUF_SIZE, to_read));
Console.WriteLine("read finished, numread={0}", numread);
if (numread == 0)
{
if (to_read == 0)
{
break;
}
else
{
throw new Exception("client disconnected during post");
}
}
to_read -= numread;
ms.Write(buf, 0, numread);
}
ms.Seek(0, SeekOrigin.Begin);
// String s1 = Encoding.UTF8.GetString(ms.ToArray());
}
Console.WriteLine("get post data end");
srv.handlePOSTRequest(this, new StreamReader(ms));
}
private static Stream GetPostStream(string filePath, string boundary)
{
Stream postDataStream = new System.IO.MemoryStream();
//adding form data
string formDataHeaderTemplate = Environment.NewLine + "--" + boundary + Environment.NewLine +
"Content-Disposition: form-data; name=\"{0}\";" + Environment.NewLine + Environment.NewLine + "{1}";
//foreach (string key in formData.Keys)
//{
// byte[] formItemBytes = System.Text.Encoding.UTF8.GetBytes(string.Format(formDataHeaderTemplate,
// key, formData[key]));
// postDataStream.Write(formItemBytes, 0, formItemBytes.Length);
//}
//adding file data
FileInfo fileInfo = new FileInfo(filePath);
string fileHeaderTemplate = Environment.NewLine + "--" + boundary + Environment.NewLine +
"Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"" +
Environment.NewLine + "Content-Type: application/vnd.ms-excel" + Environment.NewLine + Environment.NewLine;
byte[] fileHeaderBytes = System.Text.Encoding.UTF8.GetBytes(string.Format(fileHeaderTemplate,
"UploadCSVFile", fileInfo.FullName));
postDataStream.Write(fileHeaderBytes, 0, fileHeaderBytes.Length);
FileStream fileStream = fileInfo.OpenRead();
byte[] buffer = new byte[1024];
int bytesRead = 0;
while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
{
postDataStream.Write(buffer, 0, bytesRead);
}
fileStream.Close();
byte[] endBoundaryBytes = System.Text.Encoding.UTF8.GetBytes("--" + boundary + "--");
postDataStream.Write(endBoundaryBytes, 0, endBoundaryBytes.Length);
return postDataStream;
}
public void writeSuccess(string content_type = "text/html")
{
outputStream.WriteLine("HTTP/1.0 200 OK");
outputStream.WriteLine("Content-Type: " + content_type);
outputStream.WriteLine("Connection: close");
outputStream.WriteLine("");
}
public void writeFailure()
{
outputStream.WriteLine("HTTP/1.0 404 File not found");
outputStream.WriteLine("Connection: close");
outputStream.WriteLine("");
}
}
public abstract class HttpServer
{
protected int port;
TcpListener listener;
bool is_active = true;
public HttpServer(int port)
{
this.port = port;
}
public void listen()
{
listener = new TcpListener(port);
listener.Start();
while (is_active)
{
TcpClient s = listener.AcceptTcpClient();
HttpProcessor processor = new HttpProcessor(s, this);
Thread thread = new Thread(new ThreadStart(processor.process));
thread.Start();
Thread.Sleep(1);
}
}
public abstract void handleGETRequest(HttpProcessor p);
public abstract void handlePOSTRequest(HttpProcessor p, StreamReader inputData);
}
public class MyHttpServer : HttpServer
{
public MyHttpServer(int port)
: base(port)
{
}
public override void handleGETRequest(HttpProcessor p)
{
if (p.http_url.Equals("/Test.png"))
{
Stream fs = File.Open("../../Test.png", FileMode.Open);
p.writeSuccess("image/png");
fs.CopyTo(p.outputStream.BaseStream);
p.outputStream.BaseStream.Flush();
}
Console.WriteLine("request: {0}", p.http_url);
p.writeSuccess();
p.outputStream.WriteLine("<html><body><h1>test server</h1>");
p.outputStream.WriteLine("Current Time: " + DateTime.Now.ToString());
p.outputStream.WriteLine("url : {0}", p.http_url);
p.outputStream.WriteLine("<form method=post action=/form>");
p.outputStream.WriteLine("<input type=text name=foo value=foovalue>");
p.outputStream.WriteLine("<input type=submit name=bar value=barvalue>");
p.outputStream.WriteLine("</form>");
}
public override void handlePOSTRequest(HttpProcessor p, StreamReader inputData)
{
Console.WriteLine("POST request: {0}", p.http_url);
string data = inputData.ReadToEnd();
//SaveStreamToFile(inputData);
p.writeSuccess();
p.outputStream.WriteLine("<html><body><h1>test server</h1>");
p.outputStream.WriteLine("<a href=/test>return</a><p>");
p.outputStream.WriteLine("postbody: <pre>{0}</pre>", data);
}
public void SaveStreamToFile(Stream stream)
{
if (stream.Length == 0) return;
// Create a FileStream object to write a stream to a file
using (FileStream fileStream = System.IO.File.Create(#"C:/EmreDenemeHttp.txt", (int)stream.Length))
{
// Fill the bytes[] array with the stream data
byte[] bytesInStream = new byte[stream.Length];
stream.Read(bytesInStream, 0, (int)bytesInStream.Length);
// Use FileStream object to write to the specified file
fileStream.Write(bytesInStream, 0, bytesInStream.Length);
}
}
}
public class TestMain
{
public static int Main(String[] args)
{
HttpServer httpServer;
if (args.GetLength(0) > 0)
{
httpServer = new MyHttpServer(Convert.ToInt16(args[0]));
}
else
{
httpServer = new MyHttpServer(80);
}
Thread thread = new Thread(new ThreadStart(httpServer.listen));
thread.Start();
return 0;
}
}

If you mean you see this as string in your browser, the mime type sent by your server to your client may be wrong.
By default it is set to text/html.
It should be something like application/x-binary
or perhaps application/x-gzip
Check what mime type is fetched by your client when you display the page and act accordingly on your server.

How to Relay SSL(HTTPS) response through Proxy?

I have to trace the HTTP traffic .It work without Https. I try for the https, it successfully get the response via Sslstream through the certificate. When i forward ssl response for the relay but it doesn’t getting the response.
Please let me how to relay SSL response?
Please check the following code for the same.
Thanks
public void ThreadHandleHTTPClient(object o)
{
try{
Socket client = (Socket)o;
Stream ns = new NetworkStream(client);
//Stream outStrem = ns;
//RECEIVE CLIENT DATA
byte[] buffer = new byte[2048];
int rec = 0, sent = 0, transferred = 0, rport = 0;
string data = "";
do
{
rec = ns.Read(buffer, 0, buffer.Length);
data += Encoding.ASCII.GetString(buffer, 0, rec);
} while (rec == buffer.Length);
//PARSE DESTINATION AND SEND REQUEST
string line = data.Replace("\r\n", "\n").Split(new string[] { "\n" }, StringSplitOptions.None)[0];
string e=line.Split(new string[] { " " }, StringSplitOptions.None)[1];
Uri uri = new Uri(e);
if (uri.Scheme == "https" || line.Contains("CONNECT"))
{
rport = 443;
//Make tunnel for the HTTPS which is authentic host.
SslStream sslStream = sslTunnel(ns, uri.OriginalString, "1.0");
ns = sslStream;
string remoteUri = "https://" + uri.Scheme;
StreamReader clientStreamReader = new StreamReader(sslStream);
string httpCmd = clientStreamReader.ReadLine();
string[] splitBuffer = httpCmd.Split(_spaceSplit, 3);
remoteUri = remoteUri + splitBuffer[1];
myQuery = string.Empty;
//Read the SSL Stream save command in myQuery variable.
readRequestHeadersEx(clientStreamReader);
data = myQuery;
data = splitBuffer[0]+" ";
data += remoteUri;
data += " ";
data += splitBuffer[2];
data += "\r\n";
data += myQuery;
data += "\r\n";
line = data.Replace("\r\n", "\n").Split(new string[] { "\n" }, StringSplitOptions.None)[0];
uri = new Uri(line.Split(new string[] { " " }, StringSplitOptions.None)[1]);
}
else
{
rport = 80;
}
IPHostEntry rh = Dns.GetHostEntry(uri.Host);
Socket remoteserver = new Socket(rh.AddressList[0].AddressFamily, SocketType.Stream, ProtocolType.IP);
remoteserver.Connect(new IPEndPoint(rh.AddressList[0], rport));
byte[] databytes = Encoding.ASCII.GetBytes(data);
remoteserver.Send(databytes, databytes.Length, SocketFlags.None);
//START RELAY
buffer = new byte[2048];
rec = 0;
data = "";
do
{
transferred = 0;
do
{
rec = remoteserver.Receive(buffer, buffer.Length, SocketFlags.None);
sent = client.Send(buffer, rec, SocketFlags.None);
transferred += rec;
data += Encoding.ASCII.GetString(buffer, 0, rec);
} while (rec == buffer.Length);
if (transferred == 0)
break;
} while (transferred > 0);
client.Close();
}
catch (Exception ex)
{
}
}
public void Start(IPAddress ip, int port)
{
TcpListener listener = new TcpListener(ip, port);
listener.Start(100);
while (true)
{
Socket client = listener.AcceptSocket();
Thread th = new Thread(ThreadHandleHTTPClient);
th.Start(client);
}
listener.Stop();
}

send complex object using socket in C# but also simple text string

my goal is to send simple text data and also complex data to client application using socket..this is some of my code
private void button1_Click(object sender, EventArgs e)
{
byte[] data;
data = Encoding.ASCII.GetBytes("Welcome!!!");
ns.Write(data, 0, data.Length);
ns.Flush();
List<Person> list = new List<Person>();
for (int a = 0; a < 5; a++)
{
Person person = new Person();
person.Name = textBox1.Text;
person.Age = int.Parse(textBox2.Text);
list.Add(person);
}
BinaryFormatter formatter = new BinaryFormatter();
for (int a = 0; a < 5; a++)
{
formatter.Serialize(ns, list[a]);
}
ns.Flush();
}
and at the client i write this code to add all data to listview
private void AddToListView()
{
while (true && ns.DataAvailable)
{
byte[] data = new byte[1024];
int recv;
recv = ns.Read(data, 0, data.Length);
textFromServer = Encoding.ASCII.GetString(data, 0, recv);
ns.Flush();
listView1.Items.Add(textFromServer);
temp = formatter.Deserialize(ns) as Person;
ns.Flush();
listView1.Items.Add(temp.Name);
listView1.Items.Add(temp.Age);
}
}
but when i debug the application,,nothing happens...if i delete the networkstream read() process,,the application run nicely..the problem is,i not only need to send the user object,,but also simple text to client..can someone help me please?
is it possible using networkstream.read() and binaryformatter.deserialize() at the same time??or,we have to choose one of it?
i mean when just to send/receive simple text,,we use networkstream.read()/write(),,and for complex object we use serialize/deserialize..is it possible??

The problem with what you are doing is that the server and client need to have an agreed upon protocol by which to send and receive data. For instance your Client code will read everything that is available in the first ns.Read call you make. There is nothing that signals the end of one type of data and the beginning of the next, and thus you don't have an agreed upon method by which you are sending/reading data.
Easiest might be for you to encapsulate the data into another object that can contain both strings and objects.
[Serializable]
public class EncapsulatedData{
public EncapsulatedData(){}
public string Message{ get; set; }
public ISerializable Object{ get; set; }
}
And you will set Object to be a ISerializable type of yours, such as Person. Then you should be able to deserialize on the client and check Message or Object.
There are cleaner ways to do this, but the above trick should work for you.

using System;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Threading;
namespace ClientServer
{
class ClientServerProgram
{
public static void SendHeader(string sMIMEHeader, int iTotBytes, string sStatusCode, ref Socket mySocket)
{
String sBuffer = "";
// if Mime type is not provided set default to text/html
if (sMIMEHeader.Length == 0)
{
sMIMEHeader = "text/html"; // Default Mime Type is text/html
}
sBuffer = sBuffer + "HTTP/1.1" + sStatusCode + "\r\n";
sBuffer = sBuffer + "Server: cx1193719-b\r\n";
sBuffer = sBuffer + "Content-Type: " + sMIMEHeader + "\r\n";
sBuffer = sBuffer + "Accept-Ranges: bytes\r\n";
sBuffer = sBuffer + "Content-Length: " + iTotBytes + "\r\n\r\n";
Byte[] bSendData = Encoding.ASCII.GetBytes(sBuffer);
mySocket.Send(Encoding.ASCII.GetBytes(sBuffer),Encoding.ASCII.GetBytes(sBuffer).Length, 0);
Console.WriteLine("Total Bytes : " + iTotBytes.ToString());
}
public static void ReceiveCallback(IAsyncResult AsyncCall)
{
System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
string messageString = "I am a little busy, come back later!";
Byte[] message = encoding.GetBytes(messageString);
Socket listener = (Socket)AsyncCall.AsyncState;
Socket client = listener.EndAccept(AsyncCall);
Console.WriteLine("Received Connection from {0}", client.RemoteEndPoint);
SendHeader("text/html", message.Length, "202 OK", ref client);
client.Send(message);
Console.WriteLine("Ending the connection");
client.Close();
listener.BeginAccept(new AsyncCallback(ReceiveCallback), listener);
}
public static void Main()
{
IPAddress localAddress = IPAddress.Parse("192.0.127.1");
Socket listenSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
IPEndPoint ipEndpoint = new IPEndPoint(localAddress, 8080);
listenSocket.Bind(ipEndpoint);
listenSocket.Listen(1);
listenSocket.BeginAccept(new AsyncCallback(ReceiveCallback), listenSocket);
while (true)
{
Console.WriteLine("Waiting....");
Thread.Sleep(1000);
}
}
}

C# send image over HTTP

I have a small HTTP-Server here written in C# and until now I only needed to send raw text back to the sender. But now I have to send a JPG-Image and I dont unterstand how.
this is what I have now:
// Read the HTTP Request
Byte[] bReceive = new Byte[MAXBUFFERSIZE];
int i = socket.Receive(bReceive, bReceive.Length, 0);
//Convert Byte to String
string sBuffer = Encoding.ASCII.GetString(bReceive);
// Look for HTTP request
iStartPos = sBuffer.IndexOf("HTTP", 1);
// Extract the Command without GET_/ at the beginning and _HTTP at the end
sRequest = sBuffer.Substring(5, iStartPos - 1 - 5);
String answer = handleRequest(sRequest);
// Send the response
socket.Send(Encoding.UTF8.GetBytes(answer));
I think I have to do some kind of filestream instead of a string but I really have no glue..

Do you want to send from file or Bitmap object?
MemoryStream myMemoryStream = new MemoryStream();
myImage.Save(myMemoryStream);
myMemoryStream.Position = 0;
EDIT
// Send the response
SendVarData(socket,memoryStream.ToArray());
for sending MemoryStream by socket you can use this method given here
private static int SendVarData(Socket s, byte[] data)
{
int total = 0;
int size = data.Length;
int dataleft = size;
int sent;
byte[] datasize = new byte[4];
datasize = BitConverter.GetBytes(size);
sent = s.Send(datasize);
while (total < size)
{
sent = s.Send(data, total, dataleft, SocketFlags.None);
total += sent;
dataleft -= sent;
}
return total;
}

Why did you create a httpserver by yourself? Why not use a open source one? For instance mine: http://webserver.codeplex.com
public class Example
{
private HttpListener _listener;
public void StartTutorial()
{
_listener = HttpListener.Create(IPAddress.Any, 8081);
_listener.RequestReceived += OnRequest;
_listener.Start(5);
}
private void OnRequest(object source, RequestEventArgs args)
{
IHttpClientContext context = (IHttpClientContext)source;
IHttpRequest request = args.Request;
IHttpResponse response = request.CreateResponse(context);
response.Body = new FileStream("Path\\to\\file.jpg");
response.ContentType = "image\jpeg";
response.Send();
}
}
Edit
If you really want do do it by yourself:
string responseHeaders = "HTTP/1.1 200 The file is coming right up!\r\n" +
"Server: MyOwnServer\r\n" +
"Content-Length: " + new FileInfo("C:\\image.jpg").Length + "\r\n" +
"Content-Type: image/jpeg\r\n" +
"Content-Disposition: inline;filename=\"image.jpg;\"\r\n" +
"\r\n";
//headers should ALWAYS be ascii. Never UTF8
var headers = Encoding.ASCII.GetBytes(responseHeaders);
socket.Send(headers, 0, headers.Length);
socket.SendFile("C:\\image.jpg");