Webrick transparent proxy

I've a absolute simple proxy running.

require 'webrick' 
require 'webrick/httpproxy' 

s = WEBrick::HTTPProxyServer.new(:Port => 8080,
    :RequestCallback => Proc.new{|req,res| puts req.request_line, req.raw_header})

# Shutdown functionality
trap("INT"){s.shutdown}

# run the beast
s.start

This should in my mind not influence the communication in any way. But some sites doesn't work any more. 开发者_运维百科Specially http://lastfm.de 's embedded flash players doesn't work.

The header looks link:

- -> http://ext.last.fm/2.0/?api%5Fsig=aa3e9ac9edf46ceb9a673cb76e61fef4&flashresponse=true&y=1269686332&streaming=true&playlistURL=lastfm%3A%2F%2Fplaylist%2Ftrack%2F42620245&fod=true&sk=ee93ae4f438767bf0183d26478610732&lang=de&api%5Fkey=da6ae1e99462ee22e81ac91ed39b43a4&method=playlist%2Efetch
GET http://play.last.fm/preview/118270350.mp3 HTTP/1.1
Host: play.last.fm
User-Agent: Mozilla/5.0 (X11; U; Linux i686; de; rv:1.9.2) Gecko/20100308 Ubuntu/10.04 (lucid) Firefox/3.6
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: de,en-us;q=0.7,en;q=0.3
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Proxy-Connection: keep-alive
Cookie: AnonWSSession=ee93ae4f438767bf0183d26478610732; AnonSession=cb8096e3b0d8ec9f4ffd6497a6d052d9-12bb36d49132e492bb309324d8a4100fc422b3be9c3add15ee90eae3190db5fc
localhost - - [27/Mar/2010:11:38:52 CET] "GET http://www.lastfm.de/log/flashclient/minor/Track_Loading_Fail/Buffering_Timeout HTTP/1.1" 404 7593
- -> http://www.lastfm.de/log/flashclient/minor/Track_Loading_Fail/Buffering_Timeout
localhost - - [27/Mar/2010:11:38:52 CET] "GET http://play.last.fm/preview/118270350.mp3 HTTP/1.1" 302 0

I nead some hints why or what the communication disturb.

WEBrick is blocking I/O ... This mean it does not able to stream the response. For example if you go on a youtube page to see a video, the stream will not be forwarded to your browser until the proxy have downloaded all the video cotent. If you want the video be played in your browser during it download, you have to look for a non blocking I/O solution like EventMachine.

Perhaps it's the crossdomain.xml file on Lastfm.de?

It is set to only allow flash access from the following domains:

*.last.fm
*.audioscrobbler.com
87.117.229.54

http://lastfm.de/crossdomain.xml