Modify incoming cookie / connection input filter

[Daniel Eckstein <de...@it-eckstein.de>]

Dear listmember,

as I am new to the list, so please let me disclaim, that I already 
searched the archives, read at perl.apache.org and other documentation, 
I am insane and sensible. :)

I am trying to modify incoming http cookie on the fly. The setup is like

user->webserver->bea connector->bea appserver

Iam using Apache 2.0.52, mod_perl 1.99, perl 5.8.5, Redhat AS Server 4.

Primary goal is to modify incoming cookies before they reach the 
connector module for bea. It would be even possible to put a additional
reverse proxy before the webserver to accomplish this. Like

user->reverse proxy -> webserver-> bea connector -> bea appserver

The first idea was to modify the cookie using simple a Perlhandler. But
this perlhandler seem to write to the response stream, which is going 
back to the client, so the modified cookie never reached the 
connector/appserver (which I can see out of its logfile).

Second idea was to use connection input filter to modify the cookie
information right in the incoming apache chain. I managed to setup the
example connection input filter from

http://perl.apache.org/docs/2.0/user/handlers/filters.html#Connection_Input_Filters

It is working, but from my opinion not as expected. I cant see any
header information written to the log, nor do I know, how I should
modify header and write them back into the input chain.

Example output:
------------
data: HTTP/1.1 304 Not Modified

data: Date: Fri, 01 Jun 2007 08:33:55 GMT

data: S
data: S
data: erver: Apache/2.0.58 (Red Hat)

data: C
data: C
data: onnection: close

data:
data:
data:
---------------

Would you please shed some light on this?

Thanks alot in advance!

Rgds,
Daniel

Re: Modify incoming cookie / connection input filter

[Torsten Foertsch <to...@gmx.net>]

On Friday 01 June 2007 12:15, Daniel Eckstein wrote:
> I am trying to modify incoming http cookie on the fly. The setup is like
>
> user->webserver->bea connector->bea appserver

You can certainly do that using a connection input filter. But I'd say that is 
much too complicated.

Apache processes requests in several phases, see
http://perl.apache.org/docs/2.0/user/handlers/http.html#HTTP_Request_Cycle_Phases

mod_proxy acts in the response phase. So you can use any of the preceeding 
phases to modify the cookie, which is a HTTP header. So you have to modify 
$r->headers_in->{Cookie}. I think a PerlFixupHandler would be best for you.

Another way to accomplish the same may be a combination of mod_headers + 
mod_rewrite. With mod_rewrite you can set environment variables. With 
mod_headers you can modify input and output headers and incorporate the 
content of environment variables.

But if you plan to use mod_perl anyway then use it here too.

> Iam using Apache 2.0.52, mod_perl 1.99, perl 5.8.5, Redhat AS Server 4.

Don't do that! This version of mod_perl is beta and is quite old, I think ~3 
years. Further, the API has changed in the late beta phase of mp2, see 
http://perl.apache.org/docs/2.0/rename.html. So when you'll update your 
server later you'll have to rewrite you programs.

Torsten

Re: Modify incoming cookie / connection input filter

[Srebrenko Sehic <ss...@gmail.com>]

On 6/1/07, Daniel Eckstein <de...@it-eckstein.de> wrote:

> Primary goal is to modify incoming cookies before they reach the
> connector module for bea. It would be even possible to put a additional
> reverse proxy before the webserver to accomplish this. Like
>
> user->reverse proxy -> webserver-> bea connector -> bea appserver

You should simply use a PerlPostReadRequestHandler and modify
$r->headers_in directly.
That should do the trick.