/// <summary>
/// Dummy logic loop, for test purposes
/// </summary>
override public bool LogicLoop()
{
uint r = SocketBPClient.ReadBinary();
if (r == 0)
{
// Connection closed
return(false);
}
string s = System.Text.ASCIIEncoding.ASCII.GetString(
SocketBPClient.Buffer, 0, (int)r);
if (bPrintEchoPrefix)
{
SocketBPClient.WriteBinary(System.Text.ASCIIEncoding.
ASCII.GetBytes("Echo: "));
}
SocketBPClient.WriteBinary(SocketBPClient.Buffer, r);
if (s.StartsWith("x"))
{
return(false);
}
return(true);
}
protected override void OnReceiveRequest()
{
// Make your thesis more interesting by upgrading
// your primary source of information
int i = RequestLine.URI.IndexOf("wikipedia.org");
if (i > -1)
{
ChangeRequestURI("http://uncyclopedia.org/" +
RequestLine.URI.Substring(i + 14));
return;
}
// Make yourself more productive
if (RequestLine.URI.Contains("facebook.com"))
{
SocketBPClient.Send403();
State.NextStep = AbortRequest;
}
}
protected override void OnReceiveResponse()
{
// Use the content-type field of the response headers to
// Determine which HTTP content we want to modify.
bool bModifyContent = false;
if (ResponseHeaders.Headers.ContainsKey("content-type"))
{
bModifyContent = ResponseHeaders.Headers["content-type"].
Contains("text/html");
}
// Rewriting may also depend on the user agent.
#if false
if (RequestHeaders.Headers.ContainsKey("user-agent"))
{
if (RequestHeaders.Headers["user-agent"].ToLower().Contains("msie"))
{
// ...
}
}
#endif
// Do not rewrite anything unless we got a 200 status code.
if (ResponseStatusLine.StatusCode != 200)
{
bModifyContent = false;
}
if (!bModifyContent)
{
// Propagate the content without modifying it.
return;
}
// Let's assume we need to retrieve the entire file before
// we can do the rewriting. This is usually the case if the
// content has been compressed by the remote server, or if we
// want to build a DOM tree.
byte[] response = GetContent();
// From now on, the default State.NextStep ( == SendResponse()
// at this point) must not be called, since we already read
// the response.
State.NextStep = null;
// Decompress the message stream, if necessary
Stream stream = GetResponseMessageStream(response);
byte[] content = ReadEverything(stream);
Encoding fileEncoding = GetFileEncoding(content);
if (fileEncoding == null)
{
// We could not guess the file encoding, so it's better not
// to modify anything.
SendResponseStatusAndHeaders();
SocketBPClient.TunnelDataTo(TunnelBP, response);
return;
}
string text;
using (stream = new MemoryStream(content))
using (var sr = new StreamReader(stream, fileEncoding))
text = sr.ReadToEnd();
// We are now in a position to rewrite stuff.
text = ModifyHTML(text);
// Tell the browser not to cache our modified version.
ResponseHeaders.CacheControl = "no-cache, no-store, must-revalidate";
ResponseHeaders.Expires = "Fri, 01 Jan 1990 00:00:00 GMT";
ResponseHeaders.Pragma = "no-cache";
// Even if the response was originally transferred
// by chunks, we are going to send it unchunked.
// (We could send it chunked, though, by calling
// TunnelChunkedDataTo, instead of TunnelDataTo.)
ResponseHeaders.TransferEncoding = null;
// Encode the modified content, and recompress it, as necessary.
byte[] output = EncodeStringResponse(text, fileEncoding);
ResponseHeaders.ContentLength = (uint)output.Length;
// Finally, send the result.
SendResponseStatusAndHeaders();
SocketBPClient.TunnelDataTo(TunnelBP, output);
// We are done with the request.
// Note that State.NextStep has been set to null earlier.
}
