[PATCH nf v2] selftests: netfilter: nft_flowtable.sh: fix offload counter verification for tunnel tests

The IPIP and IP6IP6 tunnel tests call check_counters() to verify
flowtable offloading occurred, but the flow-add rule only matches
meta oif "veth1". When traffic is routed through a tunnel device,
oif is the tunnel interface (tun0, tun6, etc.), not veth1, so
the flow-add rule never fires, no flowtable entry is created,
and counters stay at zero — producing a silent false pass.
Fix by adding tunnel-specific flow-add rules for each tunnel
interface. These match TCP dport 12345 traffic before the bare
accept rule, set ct mark, add the flow to the flowtable, and
increment routed_orig. The existing routed_repl rule on veth0
already handles the reply direction since decapsulated reply
packets exit through the physical interface.
Also add check_counters() for the IP6IP6 non-VLAN and
IP6IP6-over-VLAN tests which previously used a bare PASS message.

Fixes: fe8313316eaf ("selftests: netfilter: nft_flowtable.sh: Add IPIP flowtable selftest")
Fixes: 5e5180352193 ("selftests: netfilter: nft_flowtable.sh: Add IP6IP6 flowtable selftest")
Signed-off-by: Lorenzo Bianconi <[email protected]>
---
Changes in v2:
- Add missing tunnel-specific flow-add rules for each tunnel interface.
- Link to v1: https://lore.kernel.org/r/20260711-flowtable-selftest-ip6ip6-fix-v1-1-60e9e7384df7@kernel.org
---
 tools/testing/selftests/net/netfilter/nft_flowtable.sh | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/net/netfilter/nft_flowtable.sh b/tools/testing/selftests/net/netfilter/nft_flowtable.sh
index 08ad07500e8a..d9a21ca8ed2c 100755
--- a/tools/testing/selftests/net/netfilter/nft_flowtable.sh
+++ b/tools/testing/selftests/net/netfilter/nft_flowtable.sh
@@ -617,7 +617,11 @@ ip -6 -net "$nsr2" route add default via fee1:3::1
 ip -net "$ns2" route add default via 10.0.2.1
 ip -6 -net "$ns2" route add default via dead:2::1
 
+ip netns exec "$nsr1" nft -a insert rule inet filter forward \
+	'meta oif tun0 tcp dport 12345 ct mark set 1 flow add @f1 counter name routed_orig accept'
 ip netns exec "$nsr1" nft -a insert rule inet filter forward 'meta oif tun0 accept'
+ip netns exec "$nsr1" nft -a insert rule inet filter forward \
+	'meta oif tun6 tcp dport 12345 ct mark set 1 flow add @f1 counter name routed_orig accept'
 ip netns exec "$nsr1" nft -a insert rule inet filter forward 'meta oif tun6 accept'
 ip netns exec "$nsr1" nft -a insert rule inet filter forward \
 	'meta oif "veth0" tcp sport 12345 ct mark set 1 flow add @f1 counter name routed_repl accept'
@@ -629,7 +633,7 @@ if ! test_tcp_forwarding_nat "$ns1" "$ns2" 1 "IPIP tunnel"; then
 fi
 
 if test_tcp_forwarding "$ns1" "$ns2" 1 6 "[dead:2::99]" 12345; then
-	echo "PASS: flow offload for ns1/ns2 IP6IP6 tunnel"
+	check_counters "flow offload for ns1/ns2 IP6IP6 tunnel"
 else
 	echo "FAIL: flow offload for ns1/ns2 with IP6IP6 tunnel" 1>&2
 	ip netns exec "$nsr1" nft list ruleset
@@ -642,6 +646,8 @@ ip -net "$nsr1" link set veth1.10 up
 ip -net "$nsr1" addr add 192.168.20.1/24 dev veth1.10
 ip -net "$nsr1" addr add fee1:4::1/64 dev veth1.10 nodad
 ip netns exec "$nsr1" sysctl net.ipv4.conf.veth1/10.forwarding=1 > /dev/null
+ip netns exec "$nsr1" nft -a insert rule inet filter forward \
+	'meta oif veth1.10 tcp dport 12345 ct mark set 1 flow add @f1 counter name routed_orig accept'
 ip netns exec "$nsr1" nft -a insert rule inet filter forward 'meta oif veth1.10 accept'
 
 ip -net "$nsr1" link add name tun0.10 type ipip local 192.168.20.1 remote 192.168.20.2
@@ -649,6 +655,8 @@ ip -net "$nsr1" link set tun0.10 up
 ip -net "$nsr1" addr add 192.168.200.1/24 dev tun0.10
 ip -net "$nsr1" route change default via 192.168.200.2
 ip netns exec "$nsr1" sysctl net.ipv4.conf.tun0/10.forwarding=1 > /dev/null
+ip netns exec "$nsr1" nft -a insert rule inet filter forward \
+	'meta oif tun0.10 tcp dport 12345 ct mark set 1 flow add @f1 counter name routed_orig accept'
 ip netns exec "$nsr1" nft -a insert rule inet filter forward 'meta oif tun0.10 accept'
 
 ip -net "$nsr1" link add name tun6.10 type ip6tnl local fee1:4::1 remote fee1:4::2 encaplimit none
@@ -656,6 +664,8 @@ ip -net "$nsr1" link set tun6.10 up
 ip -net "$nsr1" addr add fee1:5::1/64 dev tun6.10 nodad
 ip -6 -net "$nsr1" route delete default
 ip -6 -net "$nsr1" route add default via fee1:5::2
+ip netns exec "$nsr1" nft -a insert rule inet filter forward \
+	'meta oif tun6.10 tcp dport 12345 ct mark set 1 flow add @f1 counter name routed_orig accept'
 ip netns exec "$nsr1" nft -a insert rule inet filter forward 'meta oif tun6.10 accept'
 
 ip -net "$nsr2" link add link veth0 name veth0.10 type vlan id 10
@@ -683,7 +693,7 @@ if ! test_tcp_forwarding_nat "$ns1" "$ns2" 1 "IPIP tunnel over vlan"; then
 fi
 
 if test_tcp_forwarding "$ns1" "$ns2" 1 6 "[dead:2::99]" 12345; then
-	echo "PASS: flow offload for ns1/ns2 IP6IP6 tunnel over vlan"
+	check_counters "flow offload for ns1/ns2 IP6IP6 tunnel over vlan"
 else
 	echo "FAIL: flow offload for ns1/ns2 with IP6IP6 tunnel over vlan" 1>&2
 	ip netns exec "$nsr1" nft list ruleset

---
base-commit: 3f1f755366687d051174739fb99f7d560202f60b
change-id: 20260711-flowtable-selftest-ip6ip6-fix-4d8a623247a3

Best regards,
-- 
Lorenzo Bianconi <[email protected]>