/*
*FUNCTION : ListenAndRespond
*PARAMETERS : ref TcpListener server: server that listen client
*RETURNS : no return
*DESCRIPTION : This method accept client and create a stream, through the stream it communicate with client
* It enters infinite loop to get clients message in try block, if the stream has problem with connection
* it throws exception.
*/
public void ListenAndRespond(ref TcpListener server)
{
// Buffer for reading data
Byte[] bytes = new Byte[10240];
String request = null;
try
{
// 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!");
request = null;
// Get a stream object for reading and writing
NetworkStream stream = client.GetStream();
int i;
// Loop to receive all the data sent by the client.
while ((i = stream.Read(bytes, 0, bytes.Length)) != 0)
{
// Translate data bytes to a ASCII string.
request = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
//Console.WriteLine("Received: {0}", request);
// parse the request and return the full response
byte[] respondMsg = ParseRequest(request);
//log request header
Logging.WriteLog(HTTPRequestHeader);
// string respondMsg = request.ToUpper();
//serialize the response
//byte[] msg = System.Text.Encoding.Default.GetBytes(respondMsg);
// Send back a response.
stream.Write(respondMsg, 0, respondMsg.Length);
//Console.WriteLine("Response Sent...");
//log response header
Logging.WriteLog(HTTPResponseHeader);
//clear the messages
HTTPRequestHeader = "";
HTTPResponseBody = "";
HTTPResponseHeader = "";
}
// Shutdown and end connection
client.Close();
}
}
catch (SocketException e)
{
//Console.WriteLine("SocketException: {0}", e.Message);
Logging.WriteLog($"SocketException: {e.Message}");
}
catch (Exception e)
{
Logging.WriteLog($"Exception: {e.Message}");
}
}
/*
*FUNCTION : ParseRequest
*PARAMETERS : string request : The request string from the client
*RETURNS : byte[] : A byte array that contains response
*DESCRIPTION : This method first,parse header of the request. second, find the file that client request,
* third, generate header and body of response, forth, combine header and body in byte array form
* It fill the header with error code and error message if errors accur
*/
public byte[] ParseRequest(string request)
{
try
{
string requestFirstLine = request.Substring(0, request.IndexOf('\r'));
string requestTheRest = request.Substring(request.IndexOf('\n') + 1);
//In the parsed first line the [0] is method, the [1] is file path, the [2] is HTML Version
string[] parsedRequestFirstLine = requestFirstLine.Split(' ');
string method = parsedRequestFirstLine[0];
string filePath = WebRoot + parsedRequestFirstLine[1];
string requestSecondLine = requestTheRest.Substring(0, requestTheRest.IndexOf('\r'));
//creat the request header
HTTPRequestHeader = requestFirstLine + Environment.NewLine + requestSecondLine;
//method is not GET
if (method != "GET")
{
StatusCode = "405 Method Not Allowed";
}
//file does not exist
else if(!File.Exists(filePath))
{
StatusCode = "404 Not Found";
}
else
{
//check suffix if not found in dictionary 406
FileSuffix = Path.GetExtension(filePath);
if(!MIMETypes.ContainsKey(FileSuffix))
{
StatusCode = "406 Not Acceptable";
}
else
{
byte[] content = File.ReadAllBytes(filePath);
byteBody = content;
ContentLength = content.Length;
// all OK 200
StatusCode = "200 OK";
}
}
//after parsing build the response
BuildResponse();
}
catch (Exception e)
{
// File I/O exceptions 500
if( e is ArgumentException ||
e is ArgumentNullException ||
e is PathTooLongException ||
e is IOException ||
e is UnauthorizedAccessException)
{
StatusCode = "500 Internal Server Error";
}
//parse exception 400
else
{
StatusCode = "400 Bad Request";
}
//Console.WriteLine($"Exception:{e.Message}");
Logging.WriteLog($"Exception:{e.Message}");
BuildResponse();
}
if(StatusCode!="200 OK")
{
byteBody = System.Text.Encoding.UTF8.GetBytes(HTTPResponseBody);
}
byte[] byteHeader = System.Text.Encoding.UTF8.GetBytes(HTTPResponseHeader + Environment.NewLine + Environment.NewLine);
return Combine(byteHeader, byteBody);
}
