selftests/tc-testing: add hhf hh_limit cap tests

Cover the new TCA_HHF_HH_FLOWS_LIMIT bound: values above 2*HH_FLOWS_CNT
(4294967295, 65536, 2049) are rejected with the configured limit left
untouched on both the change and the add path, the boundary value 2048 is
accepted (installed at 100 first so the boundary change is load-bearing),
and an add-time hh_limit 500 is preserved instead of being clobbered by
the default.

Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Tested-by: hybris <hybris@mojatatu.ai>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/QDISC-B855.v1.20260911153152@mojatatu.com.2
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 128 insertions, 0 deletions

diff --git a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/hhf_flows_limit.json b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/hhf_flows_limit.json
new file mode 100644
index 000000000000..44538b9266b6
--- /dev/null
+++ b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/hhf_flows_limit.json
@@ -0,0 +1,128 @@
+[
+    {
+        "id": "e3cc",
+        "name": "HHF hh_limit rejects value above 2*HH_FLOWS_CNT cap (4294967295)",
+        "category": [
+            "qdisc",
+            "hhf"
+        ],
+        "plugins": {
+            "requires": "nsPlugin"
+        },
+        "setup": [
+            "$TC qdisc add dev $DUMMY handle 1: root hhf"
+        ],
+        "cmdUnderTest": "$TC qdisc change dev $DUMMY handle 1: root hhf hh_limit 4294967295",
+        "expExitCode": "2",
+        "verifyCmd": "$TC qdisc show dev $DUMMY",
+        "matchPattern": "qdisc hhf 1: root refcnt [0-9]+.*hh_limit 2048",
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DUMMY handle 1: root"
+        ]
+    },
+    {
+        "id": "f681",
+        "name": "HHF hh_limit rejects 65536 (above 2*HH_FLOWS_CNT cap)",
+        "category": [
+            "qdisc",
+            "hhf"
+        ],
+        "plugins": {
+            "requires": "nsPlugin"
+        },
+        "setup": [
+            "$TC qdisc add dev $DUMMY handle 1: root hhf"
+        ],
+        "cmdUnderTest": "$TC qdisc change dev $DUMMY handle 1: root hhf hh_limit 65536",
+        "expExitCode": "2",
+        "verifyCmd": "$TC qdisc show dev $DUMMY",
+        "matchPattern": "qdisc hhf 1: root refcnt [0-9]+.*hh_limit 2048",
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DUMMY handle 1: root"
+        ]
+    },
+    {
+        "id": "223d",
+        "name": "HHF hh_limit accepts boundary value 2048 (2*HH_FLOWS_CNT)",
+        "category": [
+            "qdisc",
+            "hhf"
+        ],
+        "plugins": {
+            "requires": "nsPlugin"
+        },
+        "setup": [
+            "$TC qdisc add dev $DUMMY handle 1: root hhf hh_limit 100"
+        ],
+        "cmdUnderTest": "$TC qdisc change dev $DUMMY handle 1: root hhf hh_limit 2048",
+        "expExitCode": "0",
+        "verifyCmd": "$TC qdisc show dev $DUMMY",
+        "matchPattern": "qdisc hhf 1: root refcnt [0-9]+.*hh_limit 2048",
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DUMMY handle 1: root"
+        ]
+    },
+    {
+        "id": "147f",
+        "name": "HHF hh_limit rejects first value above cap (2049)",
+        "category": [
+            "qdisc",
+            "hhf"
+        ],
+        "plugins": {
+            "requires": "nsPlugin"
+        },
+        "setup": [
+            "$TC qdisc add dev $DUMMY handle 1: root hhf"
+        ],
+        "cmdUnderTest": "$TC qdisc change dev $DUMMY handle 1: root hhf hh_limit 2049",
+        "expExitCode": "2",
+        "verifyCmd": "$TC qdisc show dev $DUMMY",
+        "matchPattern": "qdisc hhf 1: root refcnt [0-9]+.*hh_limit 2048",
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DUMMY handle 1: root"
+        ]
+    },
+    {
+        "id": "4d4f",
+        "name": "HHF add-time hh_limit 500 is preserved (init does not clobber user value)",
+        "category": [
+            "qdisc",
+            "hhf"
+        ],
+        "plugins": {
+            "requires": "nsPlugin"
+        },
+        "setup": [],
+        "cmdUnderTest": "$TC qdisc add dev $DUMMY handle 1: root hhf hh_limit 500",
+        "expExitCode": "0",
+        "verifyCmd": "$TC qdisc show dev $DUMMY",
+        "matchPattern": "qdisc hhf 1: root refcnt [0-9]+.*hh_limit 500",
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DUMMY handle 1: root"
+        ]
+    },
+    {
+        "id": "ca99",
+        "name": "HHF add-time hh_limit 4294967295 is rejected (no qdisc installed)",
+        "category": [
+            "qdisc",
+            "hhf"
+        ],
+        "plugins": {
+            "requires": "nsPlugin"
+        },
+        "setup": [],
+        "cmdUnderTest": "$TC qdisc add dev $DUMMY handle 1: root hhf hh_limit 4294967295",
+        "expExitCode": "2",
+        "verifyCmd": "$TC qdisc show dev $DUMMY",
+        "matchPattern": "qdisc hhf 1: root",
+        "matchCount": "0",
+        "teardown": []
+    }
+]