RFC: unit tests for kernel GTP module

[Harald Welte <laforge@gnumonks.org>]

Dear GTP-interested folks,

I would love to somehow get towards some degree of unit testing (or even
"continuous integration") for teh kernel GTP code.

We currently have the original code in the kernel, we had some recent
small fixes and now are getting more patches into place.  With
relatively few active users out there (and probably none of them in
production yet), it's particularly easy to introduce regressions while
working on the code.  Also, having tested new code even against a
test set with limited covrage could help to get more confidence in new
patches and thus get them merged sooner.

Using tools like sgsnemu of OpenGGSN and the command line tools included
in libgtpnl, it should be possibel to cook up some scripts for testing.
Even the most basic set of tests would be an improvement over what we
have now.  One could also think about pcap replay to test with
hand-crafted or real-world packets from other GTP implementations.

As much as I'd like to put something like this into place myself, I
don't think I will be able to work much on this in the near future. The
GTP module at this point is a pure hobby and contrary to some years ago
while I started it, I don't have any contract work in the GTP area at
this point, so other projects currently unfortunately get more
attention.

So in case somebody among the GTP-interested parties (Travelping, OAI,
...) would want to do something in terms of testing, I'd be more than
happy if somebody would step ahead.  Otherwise it's all just vapourware
going to end up on my ever-growing TODO list :/

Also, if netdev folks have some ideas/pointers about possible
frameworks/tools for this kind of testing [it must exist for at least
some other kernel networking code?]: Please let me know.  I'd be
interested to have a look if there's something that can be used as a
basis (starting network namespaces, sending/transmitting packets, test
case startup/teardown, ...)

My "old school" approach would have been to start one or multiple
user-mode-linux kernels (those that are to be tested), and then have
scripts that set up a gtp socket and gtp tunnels via the libgtp command
line tools, and throw packets at that.   But I'm sure there must be
quite powerful frameworks for that kind of testing in the 21st century?
How do other tunneling implementations handle this?

Regards,
	Harald
-- 
- Harald Welte <laforge@gnumonks.org>           http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
                                                  (ETSI EN 300 175-7 Ch. A6)