[PATCH v3 6/7] selftests/tc-testing: Add mirred test cases exercising loops

From: Stephen Hemminger

Date: Thu Mar 26 2026 - 14:32:18 EST


From: Victor Nogueira <victor@xxxxxxxxxxxx>

Add mirred loop test cases to validate that those will be caught and other
test cases that were previously misinterpreted as loops by mirred.

This commit adds 12 test cases:

- Redirect multiport: dummy egress -> dev1 ingress -> dummy egress (Loop)
- Redirect singleport: dev1 ingress -> dev1 egress -> dev1 ingress (Loop)
- Redirect multiport: dev1 ingress -> dummy ingress -> dev1 egress (No Loop)
- Redirect multiport: dev1 ingress -> dummy ingress -> dev1 ingress (Loop)
- Redirect multiport: dev1 ingress -> dummy egress -> dev1 ingress (Loop)
- Redirect multiport: dummy egress -> dev1 ingress -> dummy egress, different prios (Loop)
- Redirect multiport: dev1 ingress -> dummy ingress -> dummy egress -> dev1 egress (No Loop)
- Redirect multiport: dev1 ingress -> dummy egress -> dev1 egress (No Loop)
- Redirect multiport: dev1 ingress -> dummy egress -> dummy ingress (No Loop)
- Redirect singleport: dev1 ingress -> dev1 ingress (Loop)
- Redirect singleport: dummy egress -> dummy ingress (No Loop)
- Redirect multiport: dev1 ingress -> dummy ingress -> dummy egress (No Loop)

Acked-by: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>
Acked-by: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Victor Nogueira <victor@xxxxxxxxxxxx>
---
.../tc-testing/tc-tests/actions/mirred.json | 616 +++++++++++++++++-
1 file changed, 615 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/tc-testing/tc-tests/actions/mirred.json b/tools/testing/selftests/tc-testing/tc-tests/actions/mirred.json
index b056eb966871..d0cad6571691 100644
--- a/tools/testing/selftests/tc-testing/tc-tests/actions/mirred.json
+++ b/tools/testing/selftests/tc-testing/tc-tests/actions/mirred.json
@@ -1144,6 +1144,620 @@
"teardown": [
"$TC qdisc del dev $DUMMY clsact"
]
+ },
+ {
+ "id": "531c",
+ "name": "Redirect multiport: dummy egress -> dev1 ingress -> dummy egress (Loop)",
+ "category": [
+ "filter",
+ "mirred"
+ ],
+ "plugins": {
+ "requires": [
+ "nsPlugin"
+ ]
+ },
+ "setup": [
+ "$IP link set dev $DUMMY up || true",
+ "$IP addr add 10.10.10.10/24 dev $DUMMY || true",
+ "$TC qdisc add dev $DUMMY clsact",
+ "$TC filter add dev $DUMMY egress protocol ip prio 10 matchall action mirred ingress redirect dev $DEV1 index 1",
+ "$TC qdisc add dev $DEV1 clsact",
+ "$TC filter add dev $DEV1 ingress protocol ip prio 10 matchall action mirred egress redirect dev $DUMMY index 2"
+ ],
+ "cmdUnderTest": "ping -c1 -W0.01 -I $DUMMY 10.10.10.1",
+ "expExitCode": "1",
+ "verifyCmd": "$TC -j -s actions get action mirred index 1",
+ "matchJSON": [
+ {
+ "total acts": 0
+ },
+ {
+ "actions": [
+ {
+ "order": 1,
+ "kind": "mirred",
+ "mirred_action": "redirect",
+ "direction": "ingress",
+ "index": 1,
+ "stats": {
+ "packets": 3
+ },
+ "not_in_hw": true
+ }
+ ]
+ }
+ ],
+ "teardown": [
+ "$TC qdisc del dev $DUMMY clsact",
+ "$TC qdisc del dev $DEV1 clsact"
+ ]
+ },
+ {
+ "id": "b1d7",
+ "name": "Redirect singleport: dev1 ingress -> dev1 egress -> dev1 ingress (Loop)",
+ "category": [
+ "filter",
+ "mirred"
+ ],
+ "plugins": {
+ "requires": [
+ "nsPlugin",
+ "scapyPlugin"
+ ]
+ },
+ "setup": [
+ "$TC qdisc add dev $DEV1 clsact",
+ "$TC filter add dev $DEV1 ingress protocol ip prio 10 matchall action mirred egress redirect dev $DEV1 index 1"
+ ],
+ "cmdUnderTest": "$TC filter add dev $DEV1 egress protocol ip prio 11 matchall action mirred ingress redirect dev $DEV1 index 2",
+ "scapy": [
+ {
+ "iface": "$DEV0",
+ "count": 1,
+ "packet": "Ether()/IP(dst='10.10.10.1', src='10.10.10.10')/ICMP()"
+ }
+ ],
+ "expExitCode": "0",
+ "verifyCmd": "$TC -j -s actions get action mirred index 1",
+ "matchJSON": [
+ {
+ "total acts": 0
+ },
+ {
+ "actions": [
+ {
+ "order": 1,
+ "kind": "mirred",
+ "mirred_action": "redirect",
+ "direction": "egress",
+ "index": 1,
+ "stats": {
+ "packets": 3
+ },
+ "not_in_hw": true
+ }
+ ]
+ }
+ ],
+ "teardown": [
+ "$TC qdisc del dev $DEV1 clsact"
+ ]
+ },
+ {
+ "id": "c66d",
+ "name": "Redirect multiport: dev1 ingress -> dummy ingress -> dev1 egress (No Loop)",
+ "category": [
+ "filter",
+ "mirred"
+ ],
+ "plugins": {
+ "requires": [
+ "nsPlugin",
+ "scapyPlugin"
+ ]
+ },
+ "setup": [
+ "$TC qdisc add dev $DEV1 clsact",
+ "$TC filter add dev $DEV1 ingress protocol ip prio 10 matchall action mirred ingress redirect dev $DUMMY index 1",
+ "$TC qdisc add dev $DUMMY clsact"
+ ],
+ "cmdUnderTest": "$TC filter add dev $DUMMY ingress protocol ip prio 11 matchall action mirred egress redirect dev $DEV1 index 2",
+ "scapy": [
+ {
+ "iface": "$DEV0",
+ "count": 1,
+ "packet": "Ether()/IP(dst='10.10.10.1', src='10.10.10.10')/ICMP()"
+ }
+ ],
+ "expExitCode": "0",
+ "verifyCmd": "$TC -j -s actions get action mirred index 1",
+ "matchJSON": [
+ {
+ "total acts": 0
+ },
+ {
+ "actions": [
+ {
+ "order": 1,
+ "kind": "mirred",
+ "mirred_action": "redirect",
+ "direction": "ingress",
+ "index": 1,
+ "stats": {
+ "packets": 1
+ },
+ "not_in_hw": true
+ }
+ ]
+ }
+ ],
+ "teardown": [
+ "$TC qdisc del dev $DEV1 clsact",
+ "$TC qdisc del dev $DUMMY clsact"
+ ]
+ },
+ {
+ "id": "aa99",
+ "name": "Redirect multiport: dev1 ingress -> dummy ingress -> dev1 ingress (Loop)",
+ "category": [
+ "filter",
+ "mirred"
+ ],
+ "plugins": {
+ "requires": [
+ "nsPlugin",
+ "scapyPlugin"
+ ]
+ },
+ "setup": [
+ "$TC qdisc add dev $DEV1 clsact",
+ "$TC filter add dev $DEV1 ingress protocol ip prio 10 matchall action mirred ingress redirect dev $DUMMY index 1",
+ "$TC qdisc add dev $DUMMY clsact"
+ ],
+ "cmdUnderTest": "$TC filter add dev $DUMMY ingress protocol ip prio 11 matchall action mirred ingress redirect dev $DEV1 index 2",
+ "scapy": [
+ {
+ "iface": "$DEV0",
+ "count": 1,
+ "packet": "Ether()/IP(dst='10.10.10.1', src='10.10.10.10')/ICMP()"
+ }
+ ],
+ "expExitCode": "0",
+ "verifyCmd": "$TC -j -s actions get action mirred index 1",
+ "matchJSON": [
+ {
+ "total acts": 0
+ },
+ {
+ "actions": [
+ {
+ "order": 1,
+ "kind": "mirred",
+ "mirred_action": "redirect",
+ "direction": "ingress",
+ "index": 1,
+ "stats": {
+ "packets": 2,
+ "overlimits": 1
+ },
+ "not_in_hw": true
+ }
+ ]
+ }
+ ],
+ "teardown": [
+ "$TC qdisc del dev $DEV1 clsact",
+ "$TC qdisc del dev $DUMMY clsact"
+ ]
+ },
+ {
+ "id": "37d7",
+ "name": "Redirect multiport: dev1 ingress -> dummy egress -> dev1 ingress (Loop)",
+ "category": [
+ "filter",
+ "mirred"
+ ],
+ "plugins": {
+ "requires": [
+ "nsPlugin",
+ "scapyPlugin"
+ ]
+ },
+ "setup": [
+ "$TC qdisc add dev $DEV1 clsact",
+ "$TC filter add dev $DEV1 ingress protocol ip prio 10 matchall action mirred egress redirect dev $DUMMY index 1",
+ "$TC qdisc add dev $DUMMY clsact"
+ ],
+ "cmdUnderTest": "$TC filter add dev $DUMMY egress protocol ip prio 11 matchall action mirred ingress redirect dev $DEV1 index 2",
+ "scapy": [
+ {
+ "iface": "$DEV0",
+ "count": 1,
+ "packet": "Ether()/IP(dst='10.10.10.1', src='10.10.10.10')/ICMP()"
+ }
+ ],
+ "expExitCode": "0",
+ "verifyCmd": "$TC -j -s actions get action mirred index 1",
+ "matchJSON": [
+ {
+ "total acts": 0
+ },
+ {
+ "actions": [
+ {
+ "order": 1,
+ "kind": "mirred",
+ "mirred_action": "redirect",
+ "direction": "egress",
+ "index": 1,
+ "stats": {
+ "packets": 3
+ },
+ "not_in_hw": true
+ }
+ ]
+ }
+ ],
+ "teardown": [
+ "$TC qdisc del dev $DEV1 clsact",
+ "$TC qdisc del dev $DUMMY clsact"
+ ]
+ },
+ {
+ "id": "6d02",
+ "name": "Redirect multiport: dummy egress -> dev1 ingress -> dummy egress, different prios (Loop)",
+ "category": [
+ "filter",
+ "mirred"
+ ],
+ "plugins": {
+ "requires": [
+ "nsPlugin"
+ ]
+ },
+ "setup": [
+ "$IP link set dev $DUMMY up || true",
+ "$IP addr add 10.10.10.10/24 dev $DUMMY || true",
+ "$TC qdisc add dev $DUMMY clsact",
+ "$TC filter add dev $DUMMY egress protocol ip prio 10 matchall action mirred ingress redirect dev $DEV1 index 1",
+ "$TC qdisc add dev $DEV1 clsact",
+ "$TC filter add dev $DEV1 ingress protocol ip prio 11 matchall action mirred egress redirect dev $DUMMY index 2"
+ ],
+ "cmdUnderTest": "ping -c1 -W0.01 -I $DUMMY 10.10.10.1",
+ "expExitCode": "1",
+ "verifyCmd": "$TC -j -s actions get action mirred index 1",
+ "matchJSON": [
+ {
+ "total acts": 0
+ },
+ {
+ "actions": [
+ {
+ "order": 1,
+ "kind": "mirred",
+ "mirred_action": "redirect",
+ "direction": "ingress",
+ "index": 1,
+ "stats": {
+ "packets": 3
+ },
+ "not_in_hw": true
+ }
+ ]
+ }
+ ],
+ "teardown": [
+ "$TC qdisc del dev $DUMMY clsact",
+ "$TC qdisc del dev $DEV1 clsact"
+ ]
+ },
+ {
+ "id": "8115",
+ "name": "Redirect multiport: dev1 ingress -> dummy ingress -> dummy egress -> dev1 egress (No Loop)",
+ "category": [
+ "filter",
+ "mirred"
+ ],
+ "plugins": {
+ "requires": [
+ "nsPlugin",
+ "scapyPlugin"
+ ]
+ },
+ "setup": [
+ "$TC qdisc add dev $DEV1 clsact",
+ "$TC filter add dev $DEV1 ingress protocol ip prio 10 matchall action mirred ingress redirect dev $DUMMY index 1",
+ "$TC qdisc add dev $DUMMY clsact",
+ "$TC filter add dev $DUMMY ingress protocol ip prio 11 matchall action mirred egress redirect dev $DUMMY index 2"
+ ],
+ "cmdUnderTest": "$TC filter add dev $DUMMY egress protocol ip prio 12 matchall action mirred egress redirect dev $DEV1 index 3",
+ "scapy": [
+ {
+ "iface": "$DEV0",
+ "count": 1,
+ "packet": "Ether()/IP(dst='10.10.10.1', src='10.10.10.10')/ICMP()"
+ }
+ ],
+ "expExitCode": "0",
+ "verifyCmd": "$TC -j -s actions get action mirred index 1",
+ "matchJSON": [
+ {
+ "total acts": 0
+ },
+ {
+ "actions": [
+ {
+ "order": 1,
+ "kind": "mirred",
+ "mirred_action": "redirect",
+ "direction": "ingress",
+ "index": 1,
+ "stats": {
+ "packets": 1
+ },
+ "not_in_hw": true
+ }
+ ]
+ }
+ ],
+ "teardown": [
+ "$TC qdisc del dev $DEV1 clsact",
+ "$TC qdisc del dev $DUMMY clsact"
+ ]
+ },
+ {
+ "id": "9eb3",
+ "name": "Redirect multiport: dev1 ingress -> dummy egress -> dev1 egress (No Loop)",
+ "category": [
+ "filter",
+ "mirred"
+ ],
+ "plugins": {
+ "requires": [
+ "nsPlugin",
+ "scapyPlugin"
+ ]
+ },
+ "setup": [
+ "$TC qdisc add dev $DEV1 clsact",
+ "$TC filter add dev $DEV1 ingress protocol ip prio 10 matchall action mirred egress redirect dev $DUMMY index 1",
+ "$TC qdisc add dev $DUMMY clsact"
+ ],
+ "cmdUnderTest": "$TC filter add dev $DUMMY egress protocol ip prio 11 matchall action mirred egress redirect dev $DEV1 index 2",
+ "scapy": [
+ {
+ "iface": "$DEV0",
+ "count": 1,
+ "packet": "Ether()/IP(dst='10.10.10.1', src='10.10.10.10')/ICMP()"
+ }
+ ],
+ "expExitCode": "0",
+ "verifyCmd": "$TC -j -s actions get action mirred index 1",
+ "matchJSON": [
+ {
+ "total acts": 0
+ },
+ {
+ "actions": [
+ {
+ "order": 1,
+ "kind": "mirred",
+ "mirred_action": "redirect",
+ "direction": "egress",
+ "index": 1,
+ "stats": {
+ "packets": 1
+ },
+ "not_in_hw": true
+ }
+ ]
+ }
+ ],
+ "teardown": [
+ "$TC qdisc del dev $DEV1 clsact",
+ "$TC qdisc del dev $DUMMY clsact"
+ ]
+ },
+ {
+ "id": "d837",
+ "name": "Redirect multiport: dev1 ingress -> dummy egress -> dummy ingress (No Loop)",
+ "category": [
+ "filter",
+ "mirred"
+ ],
+ "plugins": {
+ "requires": [
+ "nsPlugin",
+ "scapyPlugin"
+ ]
+ },
+ "setup": [
+ "$TC qdisc add dev $DEV1 clsact",
+ "$TC filter add dev $DEV1 ingress protocol ip prio 10 matchall action mirred egress redirect dev $DUMMY index 1",
+ "$TC qdisc add dev $DUMMY clsact"
+ ],
+ "cmdUnderTest": "$TC filter add dev $DUMMY egress protocol ip prio 11 matchall action mirred ingress redirect dev $DUMMY index 2",
+ "scapy": [
+ {
+ "iface": "$DEV0",
+ "count": 1,
+ "packet": "Ether()/IP(dst='10.10.10.1', src='10.10.10.10')/ICMP()"
+ }
+ ],
+ "expExitCode": "0",
+ "verifyCmd": "$TC -j -s actions get action mirred index 1",
+ "matchJSON": [
+ {
+ "total acts": 0
+ },
+ {
+ "actions": [
+ {
+ "order": 1,
+ "kind": "mirred",
+ "mirred_action": "redirect",
+ "direction": "egress",
+ "index": 1,
+ "stats": {
+ "packets": 1
+ },
+ "not_in_hw": true
+ }
+ ]
+ }
+ ],
+ "teardown": [
+ "$TC qdisc del dev $DEV1 clsact",
+ "$TC qdisc del dev $DUMMY clsact"
+ ]
+ },
+ {
+ "id": "2071",
+ "name": "Redirect singleport: dev1 ingress -> dev1 ingress (Loop)",
+ "category": [
+ "filter",
+ "mirred"
+ ],
+ "plugins": {
+ "requires": [
+ "nsPlugin",
+ "scapyPlugin"
+ ]
+ },
+ "setup": [
+ "$TC qdisc add dev $DEV1 clsact"
+ ],
+ "cmdUnderTest": "$TC filter add dev $DEV1 ingress protocol ip prio 10 matchall action mirred ingress redirect dev $DEV1 index 1",
+ "scapy": [
+ {
+ "iface": "$DEV0",
+ "count": 1,
+ "packet": "Ether()/IP(dst='10.10.10.1', src='10.10.10.10')/ICMP()"
+ }
+ ],
+ "expExitCode": "0",
+ "verifyCmd": "$TC -j -s actions get action mirred index 1",
+ "matchJSON": [
+ {
+ "total acts": 0
+ },
+ {
+ "actions": [
+ {
+ "order": 1,
+ "kind": "mirred",
+ "mirred_action": "redirect",
+ "direction": "ingress",
+ "index": 1,
+ "stats": {
+ "packets": 1,
+ "overlimits": 1
+ },
+ "not_in_hw": true
+ }
+ ]
+ }
+ ],
+ "teardown": [
+ "$TC qdisc del dev $DEV1 clsact"
+ ]
+ },
+ {
+ "id": "0101",
+ "name": "Redirect singleport: dummy egress -> dummy ingress (No Loop)",
+ "category": [
+ "filter",
+ "mirred"
+ ],
+ "plugins": {
+ "requires": [
+ "nsPlugin"
+ ]
+ },
+ "setup": [
+ "$IP addr add 10.10.10.10/24 dev $DUMMY || true",
+ "$TC qdisc add dev $DUMMY clsact",
+ "$TC filter add dev $DUMMY egress protocol ip prio 11 matchall action mirred ingress redirect dev $DUMMY index 1"
+ ],
+ "cmdUnderTest": "ping -c1 -W0.01 -I $DUMMY 10.10.10.1",
+ "expExitCode": "1",
+ "verifyCmd": "$TC -j -s actions get action mirred index 1",
+ "matchJSON": [
+ {
+ "total acts": 0
+ },
+ {
+ "actions": [
+ {
+ "order": 1,
+ "kind": "mirred",
+ "mirred_action": "redirect",
+ "direction": "ingress",
+ "index": 1,
+ "stats": {
+ "packets": 1
+ },
+ "not_in_hw": true
+ }
+ ]
+ }
+ ],
+ "teardown": [
+ "$TC qdisc del dev $DUMMY clsact"
+ ]
+ },
+ {
+ "id": "cf97",
+ "name": "Redirect multiport: dev1 ingress -> dummy ingress -> dummy egress (No Loop)",
+ "category": [
+ "filter",
+ "mirred"
+ ],
+ "plugins": {
+ "requires": [
+ "nsPlugin",
+ "scapyPlugin"
+ ]
+ },
+ "setup": [
+ "$TC qdisc add dev $DEV1 clsact",
+ "$TC filter add dev $DEV1 ingress protocol ip prio 10 matchall action mirred ingress redirect dev $DUMMY index 1",
+ "$TC qdisc add dev $DUMMY clsact"
+ ],
+ "cmdUnderTest": "$TC filter add dev $DUMMY ingress protocol ip prio 11 matchall action mirred egress redirect dev $DUMMY index 2",
+ "scapy": [
+ {
+ "iface": "$DEV0",
+ "count": 1,
+ "packet": "Ether()/IP(dst='10.10.10.1', src='10.10.10.10')/ICMP()"
+ }
+ ],
+ "expExitCode": "0",
+ "verifyCmd": "$TC -j -s actions get action mirred index 1",
+ "matchJSON": [
+ {
+ "total acts": 0
+ },
+ {
+ "actions": [
+ {
+ "order": 1,
+ "kind": "mirred",
+ "mirred_action": "redirect",
+ "direction": "ingress",
+ "index": 1,
+ "stats": {
+ "packets": 1
+ },
+ "not_in_hw": true
+ }
+ ]
+ }
+ ],
+ "teardown": [
+ "$TC qdisc del dev $DEV1 clsact",
+ "$TC qdisc del dev $DUMMY clsact"
+ ]
}
-
]
--
2.53.0