osmocom-net-gprs March 2021

osmocom-net-gprs@lists.osmocom.org

6 participants
6 discussions

RFC: unit tests for kernel GTP module
by Harald Welte 01 Jan '26

01 Jan '26

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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Question about establishing stable internet link between UE and HNB connected to our developed network core.
by morteza ali Ahmadi 27 Mar '21

27 Mar '21

Hi, osmocom team members. In order to have an internet connection in UE, we have run OsmoGGSN project to set up GGSN. Also, SGSN is developed in our system. At this step, UE connects to our network core and we can query to an arbitrary site in the UE browser and we see the answer of the query without any problem and everything is OK. But after about 30 or 40 seconds, UE sends "Deactivate PDP Context Request" with SM Cause "SM Cause: Protocol error, unspecified (111)" and the connection is reset and a new "Activate PDP Context Request" is required. What is the reason and how can we solve it? -- *When there is much light, The shadow is deep...*

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Automatic testing for kernel GTP tunnel driver
by Harald Welte 17 Mar '21

17 Mar '21

Hi all, in recent months - after many years of no patches at all - the kernel GTP driver has received significant interest in terms of contributions. Given the presumed few users of the GTP tunnel driver, as well as the tendency to use super ancient versions of software in the telecom world, I think that the usual "let's have the users test -rcX kernels" approach is unlikely going to work. Within Osmocom (a group of FOSS projects implementing various cellular standards, protocol stacks and network elements) we are used to rather comprehensive functional test suites that we execute automatically at least once per 24 hours. That is for the 99% of our software that is userspace code. For the kernel GTP code, it's of course not that simple, and we never had any related testing so far. In 2021, 5 years after the GTP kernel driver was merged mainline, we now finally have set up some test jobs for kernel GTP. Those jobs execute the same GGSN test suite that we run against the userspace dataplane (handling GTP-U and GTP-C in a userspace program "osmo-ggsn"). The only difference is that they configure osmo-ggsn to use the kernel GTP driver for GTP-U. Those tests are executed by jenkins, in the following jobs: * ttcn3-ggsn-test-kernel-latest-torvalds https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-ggsn-test-kernel-l… runs GGSN test suite against latest released osmo-ggsn version with kernel-gtp of torvalds/linux.git test results at https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-ggsn-test-kernel-l… (make sure to click "Expand All") * ttcn3-ggsn-test-kernel-latest-torvalds https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-ggsn-test-kernel-l… runs GGSN test suite against latest released osmo-ggsn version with kernel-gtp of net-next.git test results at https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-ggsn-test-kernel-l… (make sure to click "Expand All") * ttcn3-ggsn-test-kernel-latest https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-ggsn-test-kernel-l… runs GGSN test suite against latest released osmo-ggsn version with kernel-gtp of Debian 10 kernel package test results at https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-ggsn-test-kernel-l… (make sure to click "Expand All") * ttcn3-ggsn-test-latest https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-ggsn-test-latest/ runs GGSN test suite against latest released osmo-ggsn version with userspace GTP-U, not using any kernel GTP driver test results at https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-ggsn-test-latest/t… this serves as a base line that shows the test suite can fully pass, and any failures in the aove are either bugs or lack of features (like IPv6) Contrary to the above jenkins jobs which all run automatically once every 24 hours, there is also one jenkins job for manual execution: * ttcn3-ggsn-test-kernel-git https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-ggsn-test-kernel-g… this is the same test suite and osmo-ggsn as above, but a developer can manually trigger the job and specify * URL of the kernel git repo to build * branch of the kernel git repo to build * whether to use osmo-ggsn latest tag or master If any one is working on the kernel GTP driver and wants to get access to triggering that jenkins job in order to test your patches/branches before submission, please register an account at https://jenkins.osmocom.org/ and contact me privately. We are always happy about any contributions in terms of extending test coverage. This could be done by e.g. adding jobs using other P-GW/GGSN software than osmo-ggsn, or by extending the coverage of the test cases of the test suite. For anyone interested in more details, please see our redmine issue https://osmocom.org/issues/3208 tracks the development of the tests. The test suite source code (in TTCN-3) is at https://git.osmocom.org/osmo-ttcn3-hacks/tree/ggsn_tests with containerization + configs at https://git.osmocom.org/docker-playground/tree/ttcn3-ggsn-test I'd like to thank Oliver Smith <osmith(a)sysmocom.de> for creating the above automatic test CI integration. Development of this was funded by sysmocom (https://sysmocom.de/) If you have any questions, please feel free to reach out to Oliver and/or me. 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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[PATCH] Net: gtp: Fixed missing blank line after declaration
by Chinmayi Shetty 16 Mar '21

16 Mar '21

Signed-off-by: Chinmayi Shetty <chinmayishetty359(a)gmail.com> --- drivers/net/gtp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index efe5247d8c42..79998f4394e5 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -437,7 +437,7 @@ static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx) gtp1->length = htons(payload_len); gtp1->tid = htonl(pctx->u.v1.o_tei); - /* TODO: Suppport for extension header, sequence number and N-PDU. + /* TODO: Support for extension header, sequence number and N-PDU. * Update the length field if any of them is available. */ } -- 2.25.1

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[PATCH] Net: gtp: Fixed missing blank line after declaration
by Chinmayi Shetty 14 Mar '21

14 Mar '21

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Osmocom Mailing List re-organization
by Harald Welte 04 Mar '21

04 Mar '21

Dear Osmocom community, This topic has been past due for way too many years by now: A re-organization of our major mailing lists. I would like to propose the following changes. Pleas let me know if you have any comments or feedback. I'm aware that renaming will mean people have to update their mail filter rules, but I think we're long past the point where the names of some of our lists started to confuse users. == openbsc(a)lists.osmocom.org == * openbsc doesn't exist anymore since OsmoNITB, which is also obsolete * does already cover anything "Osmocom CNI" related * Proposed new name: osmocom-cni(a)lists.osmocom.org == osmocom-net-gprs(a)lists.osmocom.org == This date back to when GPRS was a highly experimental add-on to our GSM code base. This list should simply be merged with openbsc@ as osmocom-cni(a)lists.osmocom.org == simtrace(a)lists.osmocom.org == Historically was created to cover only the simtrace project. We should rename this to osmocom-simcard(a)lists.osmocom.org or something along those lines. I would like to suggest it covers * SIMtrace / SIMtrace2 hardware + firmware * pySim and related tools for working with SIM/USIM/UICC cards * any other information / discussion related to SIM/USIM/UICC cards, like OTA, ARA-M, ... == osmodevcon(a)lists.osmocom.org == This has been a private list for people attending OsmoDevCon I would like to open up list membership to the general public, and ensure it also covers the new OsmoDevCall. We could then have discussions regarding feedback, topics, scheduling, etc. on that list. Maybe rename it to osmocom-events(a)lists.osmocom.org instead? To differentiate: osmocom-event-orga(a)lists.osmocom.org should remain a private list related to organizational / administrative topics of those involved with organizing future events. == nextepc(a)lists.osmocom.org == Should have been renamed to open5gs(a)lists.osmocom.org quite some time ago, I simply forgot about it. My apologies. -- - Harald Welte <laforge(a)osmocom.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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osmocom-net-gprs March 2021