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: 171f2ee31a ("selftests: net: Add a selftest for externally validated neighbor entries")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Closes: https://lore.kernel.org/netdev/20250728093504.4ebbd73c@kernel.org/
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250731110914.506890-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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 <idosch@nvidia.com>
Link: https://patch.msgid.link/20250626073111.244534-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
