kernel/tools/testing/selftests/net/test_neigh.sh, branch linux-rolling-stable

selftests: net: Fix flaky neighbor garbage collection test

2025-08-01T20:51:41Z

The purpose of the "Periodic garbage collection" test case is to make sure that "extern_valid" neighbors are not flushed during periodic garbage collection, unlike regular neighbor entries. The test case is currently doing the following: 1. Changing the base reachable time to 10 seconds so that periodic garbage collection will run every 5 seconds. 2. Changing the garbage collection stale time to 5 seconds so that neighbors that have not been used in the last 5 seconds will be considered for removal. 3. Waiting for the base reachable time change to take effect. 4. Adding an "extern_valid" neighbor, a non-"extern_valid" neighbor and a bunch of other neighbors so that the threshold ("thresh1") will be crossed and stale neighbors will be flushed during garbage collection. 5. Waiting for 10 seconds to give garbage collection a chance to run. 6. Checking that the "extern_valid" neighbor was not flushed and that the non-"extern_valid" neighbor was flushed. The test sometimes fails in the netdev CI because the non-"extern_valid" neighbor was not flushed. I am unable to reproduce this locally, but my theory that since we do not know exactly when the periodic garbage collection runs, it is possible for it to run at a time when the non-"extern_valid" neighbor is still not considered stale. Fix by moving the addition of the two neighbors before step 3 and by reducing the garbage collection stale time to 1 second, to ensure that both neighbors are considered stale when garbage collection runs. Fixes: 171f2ee31a42 ("selftests: net: Add a selftest for externally validated neighbor entries") Reported-by: Jakub Kicinski Closes: https://lore.kernel.org/netdev/20250728093504.4ebbd73c@kernel.org/ Signed-off-by: Ido Schimmel Link: https://patch.msgid.link/20250731110914.506890-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski

selftests: net: Add a selftest for externally validated neighbor entries

2025-07-01T01:14:24Z

Add test cases for externally validated neighbor entries, testing both IPv4 and IPv6. Name the file "test_neigh.sh" so that it could be possibly extended in the future with more neighbor test cases. Example output: # ./test_neigh.sh TEST: IPv4 "extern_valid" flag: Add entry [ OK ] TEST: IPv4 "extern_valid" flag: Add with an invalid state [ OK ] TEST: IPv4 "extern_valid" flag: Add with "use" flag [ OK ] TEST: IPv4 "extern_valid" flag: Replace entry [ OK ] TEST: IPv4 "extern_valid" flag: Replace entry with "managed" flag [ OK ] TEST: IPv4 "extern_valid" flag: Replace with an invalid state [ OK ] TEST: IPv4 "extern_valid" flag: Interface down [ OK ] TEST: IPv4 "extern_valid" flag: Carrier down [ OK ] TEST: IPv4 "extern_valid" flag: Transition to "reachable" state [ OK ] TEST: IPv4 "extern_valid" flag: Transition back to "stale" state [ OK ] TEST: IPv4 "extern_valid" flag: Forced garbage collection [ OK ] TEST: IPv4 "extern_valid" flag: Periodic garbage collection [ OK ] TEST: IPv6 "extern_valid" flag: Add entry [ OK ] TEST: IPv6 "extern_valid" flag: Add with an invalid state [ OK ] TEST: IPv6 "extern_valid" flag: Add with "use" flag [ OK ] TEST: IPv6 "extern_valid" flag: Replace entry [ OK ] TEST: IPv6 "extern_valid" flag: Replace entry with "managed" flag [ OK ] TEST: IPv6 "extern_valid" flag: Replace with an invalid state [ OK ] TEST: IPv6 "extern_valid" flag: Interface down [ OK ] TEST: IPv6 "extern_valid" flag: Carrier down [ OK ] TEST: IPv6 "extern_valid" flag: Transition to "reachable" state [ OK ] TEST: IPv6 "extern_valid" flag: Transition back to "stale" state [ OK ] TEST: IPv6 "extern_valid" flag: Forced garbage collection [ OK ] TEST: IPv6 "extern_valid" flag: Periodic garbage collection [ OK ] Signed-off-by: Ido Schimmel Link: https://patch.msgid.link/20250626073111.244534-3-idosch@nvidia.com Signed-off-by: Jakub Kicinski