| Message ID | 20230608-upstream-net-20230608-mptcp-selftests-support-old-kernels-part-2-v1-0-20997a6fd841@tessares.net |
|---|---|
| Headers | show |
| Series | selftests: mptcp: skip tests not supported by old kernels (part 2) | expand |
Hello: This series was applied to netdev/net.git (main) by Jakub Kicinski <kuba@kernel.org>: On Thu, 08 Jun 2023 18:38:42 +0200 you wrote: > After a few years of increasing test coverage in the MPTCP selftests, we > realised [1] the last version of the selftests is supposed to run on old > kernels without issues. > > Supporting older versions is not that easy for this MPTCP case: these > selftests are often validating the internals by checking packets that > are exchanged, when some MIB counters are incremented after some > actions, how connections are getting opened and closed in some cases, > etc. In other words, it is not limited to the socket interface between > the userspace and the kernelspace. > > [...] Here is the summary with links: - [net,01/14] selftests: mptcp: lib: skip if missing symbol https://git.kernel.org/netdev/net/c/673004821ab9 - [net,02/14] selftests: mptcp: connect: skip transp tests if not supported https://git.kernel.org/netdev/net/c/07bf49401909 - [net,03/14] selftests: mptcp: connect: skip disconnect tests if not supported https://git.kernel.org/netdev/net/c/4ad39a42da2e - [net,04/14] selftests: mptcp: connect: skip TFO tests if not supported https://git.kernel.org/netdev/net/c/06b03083158e - [net,05/14] selftests: mptcp: diag: skip listen tests if not supported https://git.kernel.org/netdev/net/c/dc97251bf0b7 - [net,06/14] selftests: mptcp: diag: skip inuse tests if not supported https://git.kernel.org/netdev/net/c/dc93086aff04 - [net,07/14] selftests: mptcp: pm nl: remove hardcoded default limits https://git.kernel.org/netdev/net/c/2177d0b08e42 - [net,08/14] selftests: mptcp: pm nl: skip fullmesh flag checks if not supported https://git.kernel.org/netdev/net/c/f3761b50b8e4 - [net,09/14] selftests: mptcp: sockopt: relax expected returned size https://git.kernel.org/netdev/net/c/8dee6ca2ac1e - [net,10/14] selftests: mptcp: sockopt: skip getsockopt checks if not supported https://git.kernel.org/netdev/net/c/c6f7eccc5198 - [net,11/14] selftests: mptcp: sockopt: skip TCP_INQ checks if not supported https://git.kernel.org/netdev/net/c/b631e3a4e94c - [net,12/14] selftests: mptcp: userspace pm: skip if 'ip' tool is unavailable https://git.kernel.org/netdev/net/c/723d6b9b1233 - [net,13/14] selftests: mptcp: userspace pm: skip if not supported https://git.kernel.org/netdev/net/c/f90adb033891 - [net,14/14] selftests: mptcp: userspace pm: skip PM listener events tests if unavailable https://git.kernel.org/netdev/net/c/626cb7a5f6b8 You are awesome, thank you!
After a few years of increasing test coverage in the MPTCP selftests, we realised [1] the last version of the selftests is supposed to run on old kernels without issues. Supporting older versions is not that easy for this MPTCP case: these selftests are often validating the internals by checking packets that are exchanged, when some MIB counters are incremented after some actions, how connections are getting opened and closed in some cases, etc. In other words, it is not limited to the socket interface between the userspace and the kernelspace. In addition to that, the current MPTCP selftests run a lot of different sub-tests but the TAP13 protocol used in the selftests don't support sub-tests: one failure in sub-tests implies that the whole selftest is seen as failed at the end because sub-tests are not tracked. It is then important to skip sub-tests not supported by old kernels. To minimise the modifications and reduce the complexity to support old versions, the idea is to look at external signs and skip the whole selftests or just some sub-tests before starting them. This cannot be applied in all cases. This second part focuses on marking different sub-tests as skipped if some MPTCP features are not supported. A few techniques are used here: - Before starting some tests: - Check if a file (sysctl knob) is present: that's what patch 13/14 is doing for the userspace PM feature. - Check if a symbol is present in /proc/kallsyms: patch 1/14 adds some helpers in mptcp_lib.sh to ease its use. Then these helpers are used in patches 2, 3, 4, 10, 11 and 14/14. - Set a flag and get the status to check if a feature is supported: patch 8/14 is doing that with the 'fullmesh' flag. - After having launched the tests: - Retrieve the counters after a test and check if they are different than 0. Similar to the check with the flag, that's not ideal but in this case, the counters were already present before the introduction of MPTCP but they have been supported by MPTCP sockets only later. Patches 5 and 6/14 are using this technique. Before skipping tests, SELFTESTS_MPTCP_LIB_EXPECT_ALL_FEATURES env var value is checked: if it is set to 1, the test is marked as "failed" instead of "skipped". MPTCP public CI expects to have all features supported and it sets this env var to 1 to catch regressions in these new checks. Patches 7/14 and 9/14 are a bit different because they don't skip tests: - Patch 7/14 retrieves the default values instead of using hardcoded ones because these default values have been modified at some points. Then the comparisons are done with the default values. - patch 9/14 relaxes the expected returned size from MPTCP's getsockopt because the different structures gathering various info can get new fields and get bigger over time. We cannot expect that the userspace is using the same structure as the kernel. Patch 12/14 marks the test as "skipped" instead of "failed" if the "ip" tool is not available. In this second part, the "mptcp_join" selftest is not modified yet. This will come soon after in the third part with quite a few patches. Link: https://lore.kernel.org/stable/CA+G9fYtDGpgT4dckXD-y-N92nqUxuvue_7AtDdBcHrbOMsDZLg@mail.gmail.com/ [1] Link: https://github.com/multipath-tcp/mptcp_net-next/issues/368 Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> --- Matthieu Baerts (14): selftests: mptcp: lib: skip if missing symbol selftests: mptcp: connect: skip transp tests if not supported selftests: mptcp: connect: skip disconnect tests if not supported selftests: mptcp: connect: skip TFO tests if not supported selftests: mptcp: diag: skip listen tests if not supported selftests: mptcp: diag: skip inuse tests if not supported selftests: mptcp: pm nl: remove hardcoded default limits selftests: mptcp: pm nl: skip fullmesh flag checks if not supported selftests: mptcp: sockopt: relax expected returned size selftests: mptcp: sockopt: skip getsockopt checks if not supported selftests: mptcp: sockopt: skip TCP_INQ checks if not supported selftests: mptcp: userspace pm: skip if 'ip' tool is unavailable selftests: mptcp: userspace pm: skip if not supported selftests: mptcp: userspace pm: skip PM listener events tests if unavailable tools/testing/selftests/net/mptcp/config | 1 + tools/testing/selftests/net/mptcp/diag.sh | 42 +++++++++------------- tools/testing/selftests/net/mptcp/mptcp_connect.sh | 20 +++++++++++ tools/testing/selftests/net/mptcp/mptcp_lib.sh | 38 ++++++++++++++++++++ tools/testing/selftests/net/mptcp/mptcp_sockopt.c | 18 ++++++---- tools/testing/selftests/net/mptcp/mptcp_sockopt.sh | 20 +++++++++-- tools/testing/selftests/net/mptcp/pm_netlink.sh | 27 ++++++++------ tools/testing/selftests/net/mptcp/userspace_pm.sh | 13 ++++++- 8 files changed, 135 insertions(+), 44 deletions(-) --- base-commit: 6c0ec7ab5aaff3706657dd4946798aed483b9471 change-id: 20230608-upstream-net-20230608-mptcp-selftests-support-old-kernels-part-2-6e337e1f047d Best regards,