This test checks that the MTU assigned by default to a vti
(IPv4) interface created on top of veth is simply veth's MTU
minus the length of the encapsulated IPv4 header.
Signed-off-by: Stefano Brivio <sbri...@redhat.com>
---
tools/testing/selftests/net/pmtu.sh | 89 +++++++++++++++++++++++++++++++------
1 file changed, 76 insertions(+), 13 deletions(-)
diff --git a/tools/testing/selftests/net/pmtu.sh
b/tools/testing/selftests/net/pmtu.sh
index feebb6fcff21..440d2defe592 100755
--- a/tools/testing/selftests/net/pmtu.sh
+++ b/tools/testing/selftests/net/pmtu.sh
@@ -1,7 +1,8 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
#
-# Check that route PMTU values match expectations
+# Check that route PMTU values match expectations, and that initial device MTU
+# values are assigned correctly
#
# Tests currently implemented:
#
@@ -11,18 +12,30 @@
# 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
+#
+# - pmtu_vti4_default_mtu
+# Set up vti4 tunnel on top of veth, in two namespaces with matching
+# endpoints. Check that MTU assigned to vti interface is the MTU of the
+# lower layer (veth) minus additional lower layer headers (zero, for veth)
+# minus IPv4 header length
-tests="pmtu_vti6_exception"
+tests="pmtu_vti6_exception pmtu_vti4_default_mtu"
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}"
+veth4_a_addr="192.168.1.1"
+veth4_b_addr="192.168.1.2"
+veth4_mask="24"
veth6_a_addr="fd00:1::a"
veth6_b_addr="fd00:1::b"
veth6_mask="64"
+vti4_a_addr="192.168.2.1"
+vti4_b_addr="192.168.2.2"
+vti4_mask="24"
vti6_a_addr="fd00:2::a"
vti6_b_addr="fd00:2::b"
vti6_mask="64"
@@ -40,6 +53,9 @@ 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 ${veth4_a_addr}/${veth4_mask} dev veth_a
+ ${ns_b} ip addr add ${veth4_b_addr}/${veth4_mask} dev veth_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
@@ -49,21 +65,40 @@ setup_veth() {
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
${veth6_a_addr} key 10
+setup_vti() {
+ proto=${1}
+ veth_a_addr="${2}"
+ veth_b_addr="${3}"
+ vti_a_addr="${4}"
+ vti_b_addr="${5}"
+ vti_mask=${6}
+
+ [ ${proto} -eq 6 ] && vti_type="vti6" || vti_type="vti"
- ${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
+ ${ns_a} ip link add vti${proto}_a type ${vti_type} local ${veth_a_addr}
remote ${veth_b_addr} key 10 || return 0
+ ${ns_b} ip link add vti${proto}_b type ${vti_type} local ${veth_b_addr}
remote ${veth_a_addr} key 10
- ${ns_a} ip link set vti_a up
- ${ns_b} ip link set vti_b up
+ ${ns_a} ip addr add ${vti_a_addr}/${vti_mask} dev vti${proto}_a
+ ${ns_b} ip addr add ${vti_b_addr}/${vti_mask} dev vti${proto}_b
+
+ ${ns_a} ip link set vti${proto}_a up
+ ${ns_b} ip link set vti${proto}_b up
sleep 1
return 1
}
+setup_vti4() {
+ setup_vti 4 ${veth4_a_addr} ${veth4_b_addr} ${vti4_a_addr}
${vti4_b_addr} ${vti4_mask}
+ return $?
+}
+
+setup_vti6() {
+ setup_vti 6 ${veth6_a_addr} ${veth6_b_addr} ${vti6_a_addr}
${vti6_b_addr} ${vti6_mask}
+ return $?
+}
+
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 ${veth6_a_addr}
spi 0x1001 proto esp aead "rfc4106(gcm(aes))"
0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode tunnel
@@ -114,6 +149,20 @@ mtu_parse() {
done
}
+link_get() {
+ ns_cmd="${1}"
+ name="${2}"
+
+ ${ns_cmd} ip link show dev "${name}"
+}
+
+link_get_mtu() {
+ ns_cmd="${1}"
+ name="${2}"
+
+ mtu_parse "$(link_get "${ns_cmd}" ${name})"
+}
+
route_get_dst_exception() {
ns_cmd="${1}"
dst="${2}"
@@ -134,8 +183,8 @@ test_pmtu_vti6_exception() {
# Create route exception by exceeding link layer MTU
mtu "${ns_a}" veth_a 4000
mtu "${ns_b}" veth_b 4000
- mtu "${ns_a}" vti_a 5000
- mtu "${ns_b}" vti_b 5000
+ mtu "${ns_a}" vti6_a 5000
+ mtu "${ns_b}" vti6_b 5000
${ns_a} ping6 -q -i 0.1 -w 2 -s 60000 ${vti6_b_addr} > /dev/null
# Check that exception was created
@@ -145,7 +194,7 @@ test_pmtu_vti6_exception() {
fi
# Decrease tunnel MTU, check for PMTU decrease in route exception
- mtu "${ns_a}" vti_a 3000
+ mtu "${ns_a}" vti6_a 3000
if [ "$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti6_b_addr})"
-ne 3000 ]; then
echo " decreasing tunnel MTU didn't decrease route exception
PMTU"
@@ -153,7 +202,7 @@ test_pmtu_vti6_exception() {
fi
# Increase tunnel MTU, check for PMTU increase in route exception
- mtu "${ns_a}" vti_a 9000
+ mtu "${ns_a}" vti6_a 9000
if [ "$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti6_b_addr})"
-ne 9000 ]; then
echo " increasing tunnel MTU didn't increase route exception
PMTU"
return 0
@@ -162,6 +211,20 @@ test_pmtu_vti6_exception() {
return 1
}
+test_pmtu_vti4_default_mtu() {
+ setup namespaces veth vti4 && return 2
+
+ # Check that MTU of vti device is MTU of veth minus IPv4 header length
+ veth_mtu="$(link_get_mtu "${ns_a}" veth_a)"
+ vti4_mtu="$(link_get_mtu "${ns_a}" vti4_a)"
+ if [ $((veth_mtu - vti4_mtu)) -ne 20 ]; then
+ echo " vti MTU ${vti4_mtu} is not veth MTU ${veth_mtu} minus
IPv4 header length"
+ return 0
+ fi
+
+ return 1
+}
+
trap cleanup EXIT
exitcode=0
--
2.15.1
