/// <summary>
/// Created only by HttpServer
/// </summary>
internal HttpContext(TcpClient client, HttpReader reader, HttpWriter writer, bool isSecure)
{
mTcpClient = client;
mReader = reader;
mWriter = writer;
IsSecure = isSecure;
}
async void TryProcessRequestsAsync(TcpClient client, X509Certificate certificate)
{
int concurrentRequests = Interlocked.Add(ref mConcurrentRequests, 1);
Thread.VolatileWrite(ref mMaxConcurrentRequests, Math.Max(concurrentRequests, Thread.VolatileRead(ref mMaxConcurrentRequests)));
using (client)
{
HttpContext context = null;
try
{
// Setup stream or SSL stream
client.NoDelay = true;
var tcpStream = (Stream)client.GetStream();
bool isSecure = false;
if (certificate != null)
{
// Wrap stream in an SSL stream, and authenticate
var sslStream = new SslStream(tcpStream, false);
await sslStream.AuthenticateAsServerAsync(certificate);
tcpStream = sslStream;
isSecure = true;
}
// Process requests on this possibly persistent TCP stream
var reader = new HttpReader(tcpStream, mCancellationToken, Sync);
var writer = new HttpWriter(tcpStream, mCancellationToken, Sync);
context = new HttpContext(client, reader, writer, isSecure);
await ProcessRequests(context, reader, writer).ConfigureAwait(false);
}
catch (Exception ex)
{
try
{
await ProcessExceptionAsync(context, ex);
}
catch (Exception doubleFaultEx)
{
Log.Write("DOUBLE FAULT EXCEPTION", doubleFaultEx);
}
}
}
Interlocked.Add(ref mConcurrentRequests, -1);
}
/// <summary>
/// Only called by HttpContext
/// </summary>
internal WebSocket(HttpContext context, string protocol)
{
mState = WebSocketState.Open;
mContext = context;
var request = context.Request;
var requestProtocol = request.Headers["sec-websocket-protocol"]; // TBD: Split "," separated list
if (protocol != requestProtocol)
{
throw new HttpException(400, "Invalid websocket protocol. Client requested '" + requestProtocol + "', server accepted '" + protocol + "'");
}
// RFC 6455, 4.2.1 and 4.2.2
string key = request.Headers["sec-websocket-key"];
if (key == "")
{
throw new HttpException(400, "Websocket key not sent by client");
}
string keyHash;
using (var sha = SHA1.Create())
keyHash = Convert.ToBase64String(sha.ComputeHash(Encoding.UTF8.GetBytes(key + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11")));
var response = mContext.Response;
response.StatusCode = 101;
response.StatusMessage = "Switching Protocols";
response.Connection = "Upgrade";
response.Headers["upgrade"] = "websocket";
response.Headers["Sec-WebSocket-Accept"] = keyHash;
response.Headers["Sec-WebSocket-Protocol"] = protocol;
request.ContentLength = long.MaxValue; // Stream never ends
mWriter = mContext.GetWriter(long.MaxValue);
mReader = mContext.GetReader();
}
/// <summary>
/// Process requests as long as there is not an error
/// </summary>
async Task ProcessRequests(HttpContext context, HttpReader reader, HttpWriter writer)
{
int persistentConnections = 0;
do
{
persistentConnections++;
try
{
// Read header
reader.ReadTimeout = HeaderTimeout;
var buffer = await reader.ReadHttpHeaderAsyncInternal();
reader.PositionInternal = 0;
reader.LengthInternal = HttpContext.HTTP_HEADER_MAX_SIZE;
if (buffer.Count == 0)
{
return; // Connection closed
}
// Parse header
context.ResetRequestInternal(HttpRequest.Parse(buffer), new HttpResponse());
}
catch (Exception ex)
{
Log.Write("HTTP header exception: " + ex.GetType() + " - " + ex.Message);
return; // Close connection
}
// Handle body
reader.ReadTimeout = BodyTimeout;
writer.WriteTimeout = BodyTimeout;
try
{
// Process HTTP request
var handler = HttpHandler;
if (handler == null)
{
throw new HttpException(503, "HTTP request handler not installed");
}
await handler(context).ConfigureAwait(false);
}
catch (HttpException ex) when(ex.KeepConnectionOpen && !context.Response.HeaderSent)
{
// Keep the persistent connection open only if it's OK to do so.
await ProcessExceptionAsync(context, ex);
}
await writer.FlushAsync();
// Any of these problems will terminate a persistent connection
var response = context.Response;
var request = context.Request;
var isWebsocket = request.IsWebSocketRequest;
if (!response.HeaderSent)
{
throw new HttpException(500, "Request handler did not send a response for: " + context.Request.Path);
}
if (!isWebsocket && reader.Position != request.ContentLength && request.ContentLength >= 0)
{
throw new HttpException(500, "Request handler did not read correct number of bytes: " + request.Path);
}
if (!isWebsocket && writer.Position != response.ContentLength)
{
throw new HttpException(500, "Request handler did not write correct number of bytes: " + request.Path);
}
} while (!context.Request.IsWebSocketRequest && context.Response.Connection == "keep-alive");
}