From d1f1b9cbf34c667d06adc44136e448cade8e28d9 Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Tue, 6 Mar 2018 22:16:27 +0100 Subject: [PATCH] selftests: net: Introduce first PMTU test One single test implemented so far: test_pmtu_vti6_exception checks that the PMTU of a route exception, caused by a tunnel exceeding the link layer MTU, is affected by administrative changes of the tunnel MTU. Creation of the route exception is checked too. Requested-by: David Ahern Signed-off-by: Stefano Brivio Acked-by: David Ahern Signed-off-by: David S. Miller --- tools/testing/selftests/net/Makefile | 2 +- tools/testing/selftests/net/pmtu.sh | 163 +++++++++++++++++++++++++++++++++++ 2 files changed, 164 insertions(+), 1 deletion(-) create mode 100755 tools/testing/selftests/net/pmtu.sh diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index 229a038..785fc18 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -5,7 +5,7 @@ CFLAGS = -Wall -Wl,--no-as-needed -O2 -g CFLAGS += -I../../../../usr/include/ TEST_PROGS := run_netsocktests run_afpackettests test_bpf.sh netdevice.sh rtnetlink.sh -TEST_PROGS += fib_tests.sh fib-onlink-tests.sh +TEST_PROGS += fib_tests.sh fib-onlink-tests.sh pmtu.sh TEST_GEN_FILES = socket TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy TEST_GEN_PROGS = reuseport_bpf reuseport_bpf_cpu reuseport_bpf_numa diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh new file mode 100755 index 0000000..6c19c14 --- /dev/null +++ b/tools/testing/selftests/net/pmtu.sh @@ -0,0 +1,163 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# +# Check that route PMTU values match expectations +# +# Tests currently implemented: +# +# - test_pmtu_vti6_exception +# Set up vti6 tunnel on top of veth, with xfrm states and policies, in two +# namespaces with matching endpoints. Check that route exception is +# created by exceeding link layer MTU with ping to other endpoint. Then +# decrease and increase MTU of tunnel, checking that route exception PMTU +# changes accordingly + +NS_A="ns-$(mktemp -u XXXXXX)" +NS_B="ns-$(mktemp -u XXXXXX)" +ns_a="ip netns exec ${NS_A}" +ns_b="ip netns exec ${NS_B}" + +veth6_a_addr="fd00:1::a" +veth6_b_addr="fd00:1::b" +veth6_mask="64" + +vti6_a_addr="fd00:2::a" +vti6_b_addr="fd00:2::b" +vti6_mask="64" + +setup_namespaces() { + ip netns add ${NS_A} || return 0 + ip netns add ${NS_B} + + return 1 +} + +setup_veth() { + ${ns_a} ip link add veth_a type veth peer name veth_b || return 0 + ${ns_a} ip link set veth_b netns ${NS_B} + + ${ns_a} ip addr add ${veth6_a_addr}/${veth6_mask} dev veth_a + ${ns_b} ip addr add ${veth6_b_addr}/${veth6_mask} dev veth_b + + ${ns_a} ip link set veth_a up + ${ns_b} ip link set veth_b up + + return 1 +} + +setup_vti6() { + ${ns_a} ip link add vti_a type vti6 local ${veth6_a_addr} remote ${veth6_b_addr} key 10 || return 0 + ${ns_b} ip link add vti_b type vti6 local ${veth6_b_addr} remote ${veth6_a_addr} key 10 + + ${ns_a} ip addr add ${vti6_a_addr}/${vti6_mask} dev vti_a + ${ns_b} ip addr add ${vti6_b_addr}/${vti6_mask} dev vti_b + + ${ns_a} ip link set vti_a up + ${ns_b} ip link set vti_b up + + sleep 1 + + return 1 +} + +setup_xfrm() { + ${ns_a} ip -6 xfrm state add src ${veth6_a_addr} dst ${veth6_b_addr} spi 0x1000 proto esp aead "rfc4106(gcm(aes))" 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode tunnel || return 0 + ${ns_a} ip -6 xfrm state add src ${veth6_b_addr} dst ${veth6_a_addr} spi 0x1001 proto esp aead "rfc4106(gcm(aes))" 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode tunnel + ${ns_a} ip -6 xfrm policy add dir out mark 10 tmpl src ${veth6_a_addr} dst ${veth6_b_addr} proto esp mode tunnel + ${ns_a} ip -6 xfrm policy add dir in mark 10 tmpl src ${veth6_b_addr} dst ${veth6_a_addr} proto esp mode tunnel + + ${ns_b} ip -6 xfrm state add src ${veth6_a_addr} dst ${veth6_b_addr} spi 0x1000 proto esp aead "rfc4106(gcm(aes))" 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode tunnel + ${ns_b} ip -6 xfrm state add src ${veth6_b_addr} dst ${veth6_a_addr} spi 0x1001 proto esp aead "rfc4106(gcm(aes))" 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode tunnel + ${ns_b} ip -6 xfrm policy add dir out mark 10 tmpl src ${veth6_b_addr} dst ${veth6_a_addr} proto esp mode tunnel + ${ns_b} ip -6 xfrm policy add dir in mark 10 tmpl src ${veth6_a_addr} dst ${veth6_b_addr} proto esp mode tunnel + + return 1 +} + +setup() { + tunnel_type="$1" + + [ "$(id -u)" -ne 0 ] && echo "SKIP: need to run as root" && exit 0 + + setup_namespaces && echo "SKIP: namespaces not supported" && exit 0 + setup_veth && echo "SKIP: veth not supported" && exit 0 + + case ${tunnel_type} in + "vti6") + setup_vti6 && echo "SKIP: vti6 not supported" && exit 0 + setup_xfrm && echo "SKIP: xfrm not supported" && exit 0 + ;; + *) + ;; + esac +} + +cleanup() { + ip netns del ${NS_A} 2 > /dev/null + ip netns del ${NS_B} 2 > /dev/null +} + +mtu() { + ns_cmd="${1}" + dev="${2}" + mtu="${3}" + + ${ns_cmd} ip link set dev ${dev} mtu ${mtu} +} + +route_get_dst_exception() { + dst="${1}" + + ${ns_a} ip route get "${dst}" +} + +route_get_dst_pmtu_from_exception() { + dst="${1}" + + exception="$(route_get_dst_exception ${dst})" + next=0 + for i in ${exception}; do + [ ${next} -eq 1 ] && echo "${i}" && return + [ "${i}" = "mtu" ] && next=1 + done +} + +test_pmtu_vti6_exception() { + setup vti6 + + # Create route exception by exceeding link layer MTU + mtu "${ns_a}" veth_a 4000 + mtu "${ns_b}" veth_b 4000 + mtu "${ns_a}" vti_a 5000 + mtu "${ns_b}" vti_b 5000 + ${ns_a} ping6 -q -i 0.1 -w 2 -s 60000 ${vti6_b_addr} > /dev/null + + # Check that exception was created + if [ "$(route_get_dst_pmtu_from_exception ${vti6_b_addr})" = "" ]; then + echo "FAIL: Tunnel exceeding link layer MTU didn't create route exception" + exit 1 + fi + + # Decrease tunnel MTU, check for PMTU decrease in route exception + mtu "${ns_a}" vti_a 3000 + + if [ "$(route_get_dst_pmtu_from_exception ${vti6_b_addr})" -ne 3000 ]; then + echo "FAIL: Decreasing tunnel MTU didn't decrease route exception PMTU" + exit 1 + fi + + # Increase tunnel MTU, check for PMTU increase in route exception + mtu "${ns_a}" vti_a 9000 + if [ "$(route_get_dst_pmtu_from_exception ${vti6_b_addr})" -ne 9000 ]; then + echo "FAIL: Increasing tunnel MTU didn't increase route exception PMTU" + exit 1 + fi + + echo "PASS" +} + +trap cleanup EXIT + +test_pmtu_vti6_exception + +exit 0 -- 2.7.4