osmocom-net-gprs September 2025

osmocom-net-gprs@lists.osmocom.org

2 participants
2 discussions

RFC: unit tests for kernel GTP module
by Harald Welte 31 Dec '25

31 Dec '25

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

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Move vlr code from osmo-msc into a own library
by Alexander 'lynxis' Couzens 10 Sep '25

10 Sep '25

Hi, a couple month ago I proposed to make the VLR code of the osmo-msc independent of the osmo-msc and create a new library called libosmo-vlr. Later use the libosmo-vlr code to integrate it into osmo-sgsn. But after take more time of this approach, I'm not sure if it is a very good idea to guarantee high stability of libosmo-vlr as we do for other osmocom libraries. Because the code is heavily integrated with both daemon and some code path are quite complex and partly not fully understood. I would rather guarantee runtime stability within a library version, but not at build time. The strategy would be increasing the library major version more often. Any thoughts? Best, lynxis PS. The current concept (because of time pressure) is to keep 2 copies of libosmo-vlr in the code base of osmo-msc and osmo-sgsn and to move it later out of it into an own library.

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osmocom-net-gprs September 2025