Problem with httptunnel

[Rene Tschirley]

Hello all!


I'm using the httptunnel occasionally if a firewall blocks normal
communication (e.g. IRC). How I got the problem that I can't properly
connect to my hts. To keep analysing of the problem simple, I was trying
let my server redirect incoming connections to an existing webserver
that is up and running.

My server didn't run an own webserver. After first trouble, I thought
that the firewall is maybe blocking all outbound access if not on port
http (or ssh, ftp, etc) so I am trying to get it working with port 80:

hts verision 3.3 (Debian/GNU Linux package from debian.org) was started
on my.server.org with:

    hts -F www.ABC.DE:80 80

htc version 3.3 (same package) was started on my notebook with:

    htc -F 7887 -U "Mozilla/5.0" my.server.org:80

then i started a 'telnet localhost 7887'. I connected to localhost
and the tunnel client tried to reach the server. Server output is:

    connection from my.client.ip:42843

and that's it. I send via my telnet session a get message and type:

    GET /index.html HTTP/1.1

but nothing happens. For a very long time, there is nothing. The client
doesn't tell that it's connected to the server and I get no index.html
file back. If I omit the -U, I would not even get the server notification
of an incoming connection. It seems to be blocked by the firewall. So I
guess that now the firewall blocks the server's response, but I have no
idea why. I know that the firewall analyses the traffic and checks 
incoming downloads for visuses and such. Sadly, I can't tell the name
of the firewall.

After about 5 minutes, the connection seems to be established. The client
tells:

    connected to my.server.org:80
    disconnected from my.server.org80

where the server notes:

    disconnected from FIXME:hostname:port
    connection from my.client.ip:50030

and 10 seconds after that, the server tells:

    tunnel_accept: poll timed out
    tunnel_accept: in_fd = 5, out_fd = -1
    couldn't accept connection: Protocol not available

I tried to play with some other parameters too (-c 64k -k 30 -S) but got
no better result.

Any suggestions?


Rene