config/5896: multipart-messages and squid-proxy-server

[Andreas Achtzehn <ac...@linux-society.de>]

>Number:         5896
>Category:       config
>Synopsis:       multipart-messages and squid-proxy-server
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    apache
>State:          open
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Fri Mar 17 08:10:00 PST 2000
>Closed-Date:
>Last-Modified:
>Originator:     achtzehn@linux-society.de
>Release:        1.3.9
>Organization:
apache
>Environment:
SuSE Linux 6.3
>Description:
If apache sends a multipart-content (multipart/x-mixed-replace) in an endless loop generated by a cgi-script it doesn't stop sending it even if the user hits "stop" in his browser. This problem doesn't occure if the user has a direct connection to the web-server. It only occurs when a squid-server is used for connection. 
Unfortunately the stream is sent to the proxy-server as fast as possible and if both servers are sharing one subnet (or are connected by a very fast line) it causes the proxy-server to lockup. 
>How-To-Repeat:
This is the script I used:
#!/usr/bin/perl
print "Content-Type: multipart/x-mixed-replace;boundary=myboundary\n\n";
print "--myboundary";
while (true) {
      print "\nContent-Type: image/gif\n\n";
      open(PIC,"webcamimage.gif") || die "Could not open file : $!\n";
      while (<PIC>) {
        print $_;
      }
      close(PIC);
      print "\n--myboundary";
   }
}
print "--\n";
>Fix:
Apache has to recognize the squid-proxy and validate that the user is still "wanting" that file. If not, it has to terminate the script.
>Release-Note:
>Audit-Trail:
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