[PATCH net-next v2 12/12] selftests: net: Add a test for BIG TCP in UDP tunnels

[Alice Mikityanska <alice.kernel@fastmail.im>]

From: Alice Mikityanska <alice@isovalent.com>

The test sets up VXLAN and GENEVE tunnels over IPv4 and IPv6 and runs
IPv4 and IPv6 traffic through them with BIG TCP enabled. It checks that
a non-negligible amount of big aggregated packets are seen in tcpdump.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
---
 tools/testing/selftests/net/Makefile          |   1 +
 .../testing/selftests/net/big_tcp_tunnels.sh  | 145 ++++++++++++++++++
 2 files changed, 146 insertions(+)
 create mode 100755 tools/testing/selftests/net/big_tcp_tunnels.sh

diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index e97c90886f34..0134fa84fc2c 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -13,6 +13,7 @@ TEST_PROGS := \
 	arp_ndisc_untracked_subnets.sh \
 	bareudp.sh \
 	big_tcp.sh \
+	big_tcp_tunnels.sh \
 	bind_bhash.sh \
 	bpf_offload.py \
 	broadcast_ether_dst.sh \
diff --git a/tools/testing/selftests/net/big_tcp_tunnels.sh b/tools/testing/selftests/net/big_tcp_tunnels.sh
new file mode 100755
index 000000000000..6896bf36ee00
--- /dev/null
+++ b/tools/testing/selftests/net/big_tcp_tunnels.sh
@@ -0,0 +1,145 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Testing for IPv4 and IPv6 BIG TCP over VXLAN and GENEVE tunnels.
+
+SERVER_NS=$(mktemp -u server-XXXXXXXX)
+SERVER_IP4="192.168.1.1"
+SERVER_IP6="2001:db8::1:1"
+SERVER_IP4_TUN="192.168.2.1"
+SERVER_IP6_TUN="2001:db8::2:1"
+
+CLIENT_NS=$(mktemp -u client-XXXXXXXX)
+CLIENT_IP4="192.168.1.2"
+CLIENT_IP6="2001:db8::1:2"
+CLIENT_IP4_TUN="192.168.2.2"
+CLIENT_IP6_TUN="2001:db8::2:2"
+
+PACKETS_THRESHOLD=10000
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+setup() {
+	ip netns add "$SERVER_NS"
+	ip netns add "$CLIENT_NS"
+	ip -netns "$SERVER_NS" link add link1 type veth peer name link0 netns "$CLIENT_NS"
+
+	ip -netns "$CLIENT_NS" link set link0 up
+	ip -netns "$CLIENT_NS" addr replace "$CLIENT_IP4/24" dev link0
+	ip -netns "$CLIENT_NS" addr replace "$CLIENT_IP6/112" dev link0 nodad
+	ip -netns "$CLIENT_NS" link set link0 \
+		gso_max_size 196608 gso_ipv4_max_size 196608 \
+		gro_max_size 196608 gro_ipv4_max_size 196608
+	ip -netns "$SERVER_NS" link set link1 up
+	ip -netns "$SERVER_NS" addr replace "$SERVER_IP4/24" dev link1
+	ip -netns "$SERVER_NS" addr replace "$SERVER_IP6/112" dev link1 nodad
+	ip -netns "$SERVER_NS" link set link1 \
+		gso_max_size 196608 gso_ipv4_max_size 196608 \
+		gro_max_size 196608 gro_ipv4_max_size 196608
+
+	ip netns exec "$SERVER_NS" netserver 2>&1 >/dev/null
+}
+
+setup_tunnel() {
+	if [ "$2" = 4 ]; then
+		SERVER_IP="$SERVER_IP4"
+		CLIENT_IP="$CLIENT_IP4"
+		echo "Setting up ${1^^} over IPv4"
+	else
+		SERVER_IP="$SERVER_IP6"
+		CLIENT_IP="$CLIENT_IP6"
+		echo "Setting up ${1^^} over IPv6"
+	fi
+
+	if [ "$1" = vxlan ]; then
+		ip -netns "$CLIENT_NS" link add tun0 type vxlan \
+			id 5001 remote "$SERVER_IP" local "$CLIENT_IP" dev link0 dstport 4789
+	else
+		ip -netns "$CLIENT_NS" link add tun0 type geneve \
+			id 5001 remote "$SERVER_IP"
+	fi
+	ip -netns "$CLIENT_NS" link set tun0 up
+	ip -netns "$CLIENT_NS" addr replace "$CLIENT_IP4_TUN/24" dev tun0
+	ip -netns "$CLIENT_NS" addr replace "$CLIENT_IP6_TUN/112" dev tun0 nodad
+	ip -netns "$CLIENT_NS" link set tun0 \
+		gso_max_size 196608 gso_ipv4_max_size 196608 \
+		gro_max_size 196608 gro_ipv4_max_size 196608
+	if [ "$1" = vxlan ]; then
+		ip -netns "$SERVER_NS" link add tun1 type vxlan \
+			id 5001 remote "$CLIENT_IP" local "$SERVER_IP" dev link1 dstport 4789
+	else
+		ip -netns "$SERVER_NS" link add tun1 type geneve \
+			id 5001 remote "$CLIENT_IP"
+	fi
+	ip -netns "$SERVER_NS" link set tun1 up
+	ip -netns "$SERVER_NS" addr replace "$SERVER_IP4_TUN/24" dev tun1
+	ip -netns "$SERVER_NS" addr replace "$SERVER_IP6_TUN/112" dev tun1 nodad
+	ip -netns "$SERVER_NS" link set tun1 \
+		gso_max_size 196608 gso_ipv4_max_size 196608 \
+		gro_max_size 196608 gro_ipv4_max_size 196608
+}
+
+cleanup_tunnel() {
+	ip -netns "$CLIENT_NS" link del tun0
+	ip -netns "$SERVER_NS" link del tun1
+}
+
+cleanup() {
+	ip netns exec "$SERVER_NS" killall netserver
+	ip netns del "$SERVER_NS"
+	ip netns del "$CLIENT_NS"
+}
+
+do_test() {
+	exec 3< <(ip netns exec "$SERVER_NS" tcpdump -nn -i link1 greater 65536 2> /dev/null)
+	TCPDUMP_SERVER_PID="$!"
+	exec 4< <(wc -l <&3)
+	exec 5< <(ip netns exec "$CLIENT_NS" tcpdump -nn -i link0 greater 65536 2> /dev/null)
+	TCPDUMP_CLIENT_PID="$!"
+	exec 6< <(wc -l <&5)
+
+	if [ "$1" = 4 ]; then
+		SERVER_IP="$SERVER_IP4_TUN"
+		echo "Running IPv4 traffic in the tunnel"
+	else
+		SERVER_IP="$SERVER_IP6_TUN"
+		echo "Running IPv6 traffic in the tunnel"
+	fi
+
+	ip netns exec "$CLIENT_NS" netperf -t TCP_STREAM -l 5 -H "$SERVER_IP" -- \
+		-r 80000:80000 > /dev/null
+	kill "$TCPDUMP_SERVER_PID" "$TCPDUMP_CLIENT_PID"
+	wait "$TCPDUMP_SERVER_PID" "$TCPDUMP_CLIENT_PID"
+	PACKETS_SERVER=$(cat <&4)
+	PACKETS_CLIENT=$(cat <&6)
+	exec 3>&- 4>&- 5>&- 6>&-
+
+	# One line is empty, each packet is two lines (inner and outer).
+	echo "Captured BIG TCP GRO packets: $(((PACKETS_SERVER - 1) / 2))"
+	echo "Captured BIG TCP GSO packets: $(((PACKETS_CLIENT - 1) / 2))"
+	[ "$PACKETS_SERVER" -gt "$(( PACKETS_THRESHOLD * 2 + 1))" ] || return 1
+	[ "$PACKETS_CLIENT" -gt "$(( PACKETS_THRESHOLD * 2 + 1))" ] || return 1
+}
+
+if ! netperf -V &> /dev/null; then
+	echo "SKIP: Could not run test without netperf tool"
+	exit "$ksft_skip"
+fi
+
+if ! ip link help 2>&1 | grep gso_ipv4_max_size &> /dev/null; then
+	echo "SKIP: Could not run test without gso/gro_ipv4_max_size supported in ip-link"
+	exit "$ksft_skip"
+fi
+
+trap cleanup EXIT
+setup
+for tunnel in vxlan geneve; do
+	for tun_family in 4 6; do
+		for traffic_family in 4 6; do
+			setup_tunnel "$tunnel" "$tun_family" || exit "$?"
+			do_test "$traffic_family" || exit "$?"
+			cleanup_tunnel
+		done
+	done
+done
-- 
2.52.0