Need a testing tool to change messages on the fly

[SeekerOfKnowledge]

Hi all.
I was asked to suggest a way to test the system I am
working on by intercepting data being sent to it
and then changing it in various ways, such as
blocking the packets, multiplying them several times,
and changing it's contents, all in regard to the
packet internal identification (a certain field in the
message body).
What I need to know is, do any of you guys know of an
off-the-shelf tool that can supply me with these abilities ?
I can do the interception myself, I just need the nice MMI
and communication engine to do the dirty work for me.
I need to be able to define the message structure, and
then define a kind of a scenario to be run, e.g. in times
10.0-20.0 from Start, block all messages with Id=10300,
in times 15.5.15.7 change third field in messages with Id=20400
to 5 .

Thanx in advance. ======
SeekerOfKnowledge
======

 

[pansophic]

I wouldn't exactly call it off-the-shelf, but I did some work like this with Net::RawIP in Perl. You had to change the routing between the two systems, to force them through a third, but it was a simple route command on both boxes under test.

The code would copy from one port to the other, unless a certain set of conditions were met, then it would modify the packet prior to forwarding.

It is well above my ability to code, but I had it written for me. Leave your email address if you are interested in the source. It shouldn't be difficult to modify.
pansophic

 

[SeekerOfKnowledge]

Hi Panasophic

I would be grateful if you send the code to
Baturlan@hotmail.com

Thanx ======
SeekerOfKnowledge
======

 

[giwiwuz5]

Yes, Fluke Networks has a product called a Link Analyzer that is uses a Protocol Analysis Application to drive the hardware. Once you collect data in-line of it occurring you can manipulate the packets in any way you see fit and re-play them later. Hope this helps?