[PATCH net v2 2/2 RESEND] selftests: tc-testing: add u32 node ID pool exhaustion test
From: Jamal Hadi Salim <jhs@mojatatu.com>
Date: 2026-08-22 22:21:06
Subsystem:
kernel selftest framework, the rest · Maintainers:
Shuah Khan, Shuah Khan, Linus Torvalds
Add a tdc test case that fills the u32 node ID space with 4095 auto-generated handles, then attempts to add a 4096th. On the fixed kernel the 4096th filter is rejected with ENOSPC (exit 2). On the unfixed kernel it silently succeeds with a duplicate handle. Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> --- .../tc-testing/tc-tests/filters/u32.json | 24 +++++++++++++++++++ 1 file changed, 24 insertions(+)
diff --git a/tools/testing/selftests/tc-testing/tc-tests/filters/u32.json b/tools/testing/selftests/tc-testing/tc-tests/filters/u32.json
index b2ca9d4e991b..039bb8278a60 100644
--- a/tools/testing/selftests/tc-testing/tc-tests/filters/u32.json
+++ b/tools/testing/selftests/tc-testing/tc-tests/filters/u32.json@@ -353,5 +353,29 @@ "teardown": [ "$TC qdisc del dev $DEV1 parent root drr" ] + }, + { + "id": "934a", + "name": "Add u32 filter when node ID pool is exhausted (4096th filter rejected)", + "category": [ + "filter", + "u32" + ], + "plugins": { + "requires": "nsPlugin" + }, + "setup": [ + "$TC qdisc add dev $DUMMY clsact", + "bash -c 'yes \"filter add dev $DUMMY ingress prio 1 protocol ip u32 match u8 0 0 at 0\" | head -n 4095 > /tmp/u32_batch.txt'", + "bash -c '$TC -b /tmp/u32_batch.txt'" + ], + "cmdUnderTest": "$TC filter add dev $DUMMY ingress prio 1 protocol ip u32 match u8 0 0 at 0", + "expExitCode": "2", + "verifyCmd": "$TC -d filter show dev $DUMMY ingress", + "matchPattern": "fh 800::", + "matchCount": "4095", + "teardown": [ + "$TC qdisc del dev $DUMMY clsact" + ] } ]
--
2.43.0