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 <dsahern@gmail.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Stefano Brivio 2018-03-06 22:16:27 +01:00 committed by David S. Miller
parent d8c13f2271
commit d1f1b9cbf3
2 changed files with 164 additions and 1 deletions

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@ -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

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@ -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