[PATCH net-next v5 2/2] selftests: openvswitch: add pop_vlan test
From: Minxi Hou <hidden>
Date: 2026-05-05 12:50:27
Also in:
linux-kselftest, lkml
Subsystem:
kernel selftest framework, networking [general], openvswitch, the rest · Maintainers:
Shuah Khan, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Aaron Conole, Eelco Chaudron, Ilya Maximets, Linus Torvalds
Add test_pop_vlan() to verify OVS kernel datapath pop_vlan action correctly strips 802.1Q VLAN tags from frames. Test structure: - Baseline: untagged forwarding validates basic connectivity. - Negative: forward without pop_vlan, tagged frame is invisible to ns2 (no VLAN sub-interface), ping fails. - Positive: pop_vlan strips tag on forward path, push_vlan restores tag on return path, ping succeeds. Use static ARP entries to avoid VLAN-tagged ARP complexity. Rely on ping success/failure for verification — no tcpdump or pcap files needed. Signed-off-by: Minxi Hou <redacted> --- .../selftests/net/openvswitch/openvswitch.sh | 77 +++++++++++++++++++ 1 file changed, 77 insertions(+)
diff --git a/tools/testing/selftests/net/openvswitch/openvswitch.sh b/tools/testing/selftests/net/openvswitch/openvswitch.sh
index b327d3061ed5..a64f4d515e83 100755
--- a/tools/testing/selftests/net/openvswitch/openvswitch.sh
+++ b/tools/testing/selftests/net/openvswitch/openvswitch.sh@@ -27,6 +27,7 @@ tests=" upcall_interfaces ovs: test the upcall interfaces tunnel_metadata ovs: test extraction of tunnel metadata drop_reason drop: test drop reasons are emitted + pop_vlan vlan: POP_VLAN action strips tag psample psample: Sampling packets with psample" info() {
@@ -830,6 +831,82 @@ test_tunnel_metadata() { return 0 } +test_pop_vlan() { + modprobe -q 8021q 2>/dev/null || true + [ -d /sys/module/8021q ] || \ + { info "CONFIG_VLAN_8021Q missing"; return $ksft_skip; } + + local sbx="test_pop_vlan" + sbx_add "$sbx" || return $? + ovs_add_dp "$sbx" vlandp || return 1 + + ovs_add_netns_and_veths "$sbx" vlandp \ + ns1 veth1 ns1veth 192.0.2.1/24 || return 1 + ovs_add_netns_and_veths "$sbx" vlandp \ + ns2 veth2 ns2veth 192.0.2.2/24 || return 1 + + # Baseline: untagged bidirectional forwarding + ovs_add_flow "$sbx" vlandp \ + 'in_port(1),eth(),eth_type(0x0806),arp()' '2' || return 1 + ovs_add_flow "$sbx" vlandp \ + 'in_port(2),eth(),eth_type(0x0806),arp()' '1' || return 1 + ovs_add_flow "$sbx" vlandp \ + 'in_port(1),eth(),eth_type(0x0800),ipv4()' '2' || return 1 + ovs_add_flow "$sbx" vlandp \ + 'in_port(2),eth(),eth_type(0x0800),ipv4()' '1' || return 1 + ovs_sbx "$sbx" ip netns exec ns1 ping -c 3 -W 2 \ + 192.0.2.2 || return 1 + + # VLAN topology: ns1 uses VLAN sub-interface, ns2 is plain + ip -n ns1 link add link ns1veth name ns1veth.10 \ + type vlan id 10 || return 1 + on_exit "ip -n ns1 link del ns1veth.10 2>/dev/null" + ip -n ns1 addr add 198.51.100.1/24 dev ns1veth.10 || return 1 + ip -n ns1 link set ns1veth.10 up || return 1 + ip -n ns2 addr add 198.51.100.2/24 dev ns2veth || return 1 + + ovs_del_flows "$sbx" vlandp + + # Static ARP: avoids VLAN-tagged ARP complexity + local ns1veth10mac ns2mac + ns1veth10mac=$(ip -n ns1 link show ns1veth.10 \ + | awk '/link\/ether/ {print $2}') + ns2mac=$(ip -n ns2 link show ns2veth \ + | awk '/link\/ether/ {print $2}') + ip -n ns1 neigh replace 198.51.100.2 lladdr "$ns2mac" \ + dev ns1veth.10 nud permanent || return 1 + ip -n ns2 neigh replace 198.51.100.1 \ + lladdr "$ns1veth10mac" \ + dev ns2veth nud permanent || return 1 + + local vlan_match='in_port(1),eth(),eth_type(0x8100),' + vlan_match+='vlan(vid=10),' + vlan_match+='encap(eth_type(0x0800),' + vlan_match+='ipv4(src=198.51.100.1,proto=1),icmp())' + + # Negative: forward without pop_vlan — tagged frame + # is invisible to ns2 (no VLAN sub-interface), ping fails + ovs_add_flow "$sbx" vlandp "$vlan_match" '2' || return 1 + ovs_sbx "$sbx" ip netns exec ns1 ping -I ns1veth.10 \ + -c 3 -W 1 198.51.100.2 >/dev/null 2>&1 \ + && { info "FAIL: ping should fail without pop_vlan" + return 1; } + + ovs_del_flows "$sbx" vlandp + + # Positive: pop_vlan strips tag on forward path, + # push_vlan restores tag on return path — ping succeeds + ovs_add_flow "$sbx" vlandp \ + "$vlan_match" 'pop_vlan,2' || return 1 + ovs_add_flow "$sbx" vlandp \ + 'in_port(2),eth(),eth_type(0x0800),ipv4()' \ + 'push_vlan(vid=10,pcp=0,tpid=0x8100),1' || return 1 + ovs_sbx "$sbx" ip netns exec ns1 ping -I ns1veth.10 \ + -c 3 -W 2 198.51.100.2 || return 1 + + return 0 +} + run_test() { ( tname="$1"
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2.53.0