[Patch net v6 5/8] selftests/tc-testing: Add a nested netem duplicate test

Cong Wang
2025-12-27T19:41:52Z

Integrate the reproducer from William into tc-testing and use scapy
to generate packets for testing:

# ./tdc.py -e 1676
-- ns/SubPlugin.__init__
-- scapy/SubPlugin.__init__
Test 1676: NETEM nested duplicate 100%
[ 1154.071135] v0p0id1676: entered promiscuous mode
[ 1154.101066] virtio_net virtio0 enp1s0: entered promiscuous mode
[ 1154.146301] virtio_net virtio0 enp1s0: left promiscuous mode
.
Sent 1 packets.
[ 1154.173695] v0p0id1676: left promiscuous mode
[ 1154.216159] v0p0id1676: entered promiscuous mode
.
Sent 1 packets.
[ 1154.238398] v0p0id1676: left promiscuous mode
[ 1154.260909] v0p0id1676: entered promiscuous mode
.
Sent 1 packets.
[ 1154.282708] v0p0id1676: left promiscuous mode
[ 1154.309399] v0p0id1676: entered promiscuous mode
.
Sent 1 packets.
[ 1154.337949] v0p0id1676: left promiscuous mode
[ 1154.360924] v0p0id1676: entered promiscuous mode
.
Sent 1 packets.
[ 1154.383522] v0p0id1676: left promiscuous mode

All test results:

1..1
ok 1 1676 - NETEM nested duplicate 100%

Reported-by: William Liu <will@willsroot.io>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
.../tc-testing/tc-tests/qdiscs/netem.json | 25 +++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/netem.json b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/netem.json
index 3c4444961488..03c4ceb22990 100644
--- a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/netem.json
+++ b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/netem.json
@@ -336,5 +336,30 @@
"teardown": [
"$TC qdisc del dev $DUMMY handle 1: root"
]
+ },
+ {
+ "id": "1676",
+ "name": "NETEM nested duplicate 100%",
+ "category": ["qdisc", "netem"],
+ "setup": [
+ "$TC qdisc add dev $DEV1 root handle 1: netem limit 1000 duplicate 100%",
+ "$TC qdisc add dev $DEV1 parent 1: handle 2: netem limit 1000 duplicate 100%"
+ ],
+ "teardown": [
+ "$TC qdisc del dev $DEV1 root"
+ ],
+ "plugins": {
+ "requires": ["nsPlugin", "scapyPlugin"]
+ },
+ "scapy": {
+ "iface": "$DEV0",
+ "count": 5,
+ "packet": "Ether()/IP(dst='10.10.10.1', src='10.10.10.10')/TCP(sport=12345, dport=80)"
+ },
+ "cmdUnderTest": "$TC -s qdisc show dev $DEV1",
+ "expExitCode": "0",
+ "verifyCmd": "$TC -s qdisc show dev $DEV1",
+ "matchPattern": "Sent [0-9]+ bytes [0-9]+ pkt",
+ "matchCount": "2"
}
]
--
2.34.1