[PATCH net v3 0/6] selftests: net: fix false failures due to missing features and host interference

[Aleksei Oladko]

Hi,

This series addresses several issues in the networking kselftests
that cause false-positive failures depending on the host environment,
kernel configuration, or library versions.

The main focus of these changes is to isolate tests from the host
environment (using namespaces) and to ensure proper fallback or
skipping when dependencies are missing.

Summary of changes:
1. Adds a check for cls_basic module in fib_tests. Without this
   module, the test fails when attempting to add tc rules instead
   of skipping.
2. Fixes ovs-dpctl.py to return a non-zero exit code when pyroute2
   is too old. This allows pmtu.sh to correctly fall back to ovs-vsctl
   instead of assuming the configuration was successful.
3,4,5. Move reuseport test into dedicated network namespaces. This prevents
   failures caused by port conflicts with host processes or interference
   from host firewall rules.
6. Ensures io_uring is enabled via sysctl before running io_uring_zerocopy
   test, preventing failures on systems where kernel.io_uring_disabled
   is set.

Signed-off-by: Aleksei Oladko <aleksey.oladko@xxxxxxxxxxxxx>

Changes in v2:
- Fixed a typo by adding the missing backslash in Makefile
- Added a Fixes: tag to the appropriate commit as requested
- Link to v1: https://lore.kernel.org/linux-kselftest/20260120230558.328423-1-aleksey.oladko@xxxxxxxxxxxxx

Changes in v3:
- renamed pmtu.sh to pmtu-test.sh and used pmtu.sh as the name
  of the wrapper. 
- since the test now runs in a dedicated netns, updates the ovs
  test case to correctly move network interfaces into the target
  namespace.
- Link to v2: https://lore.kernel.org/linux-kselftest/f7t1pj9v8h7.fsf@xxxxxxxxxx/T/#t

Aleksei Oladko (4):
  selftests: net: fib_tests: skip rp_filter test if cls_basic is
    unavailable
  selftests: net: make ovs-dpctl.py fail when pyroute2 is unsupported
  selftests: net: rename pmtu.sh to pmtu-test.sh
  selftests: net: io_uring_zerocopy: enable io_uring for the test

Konstantin Khorenko (2):
  selftests: net: run reuseport tests in netns to avoid port conflicts
  selftests: net: run pmtu.sh in netns to avoid host firewall
    interference

 tools/testing/selftests/net/Makefile          |   13 +-
 tools/testing/selftests/net/fib_tests.sh      |    2 +
 .../selftests/net/io_uring_zerocopy_tx.sh     |    9 +
 .../selftests/net/openvswitch/ovs-dpctl.py    |    2 +-
 tools/testing/selftests/net/pmtu-test.sh      | 2492 +++++++++++++++++
 tools/testing/selftests/net/pmtu.sh           | 2492 +----------------
 tools/testing/selftests/net/reuseport_bpf.sh  |    4 +
 .../selftests/net/reuseport_bpf_cpu.sh        |    4 +
 .../selftests/net/reuseport_bpf_numa.sh       |    4 +
 .../selftests/net/reuseport_dualstack.sh      |    4 +
 10 files changed, 2531 insertions(+), 2495 deletions(-)
 create mode 100755 tools/testing/selftests/net/pmtu-test.sh
 create mode 100755 tools/testing/selftests/net/reuseport_bpf.sh
 create mode 100755 tools/testing/selftests/net/reuseport_bpf_cpu.sh
 create mode 100755 tools/testing/selftests/net/reuseport_bpf_numa.sh
 create mode 100755 tools/testing/selftests/net/reuseport_dualstack.sh

-- 
2.43.0