[PATCH net-next 5/9] selftests: pmtu: Add pmtu_vti6_default_mtu test

[Stefano Brivio]

Same as pmtu_vti4_default_mtu, but on IPv6 with vti6.

Signed-off-by: Stefano Brivio <sbri...@redhat.com>
---
 tools/testing/selftests/net/pmtu.sh | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/pmtu.sh 
b/tools/testing/selftests/net/pmtu.sh
index 440d2defe592..67b77f9108ee 100755
--- a/tools/testing/selftests/net/pmtu.sh
+++ b/tools/testing/selftests/net/pmtu.sh
@@ -18,8 +18,11 @@
 #      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
+#
+# - pmtu_vti6_default_mtu
+#      Same as above, for IPv6
 
-tests="pmtu_vti6_exception pmtu_vti4_default_mtu"
+tests="pmtu_vti6_exception pmtu_vti4_default_mtu pmtu_vti6_default_mtu"
 
 NS_A="ns-$(mktemp -u XXXXXX)"
 NS_B="ns-$(mktemp -u XXXXXX)"
@@ -225,6 +228,20 @@ test_pmtu_vti4_default_mtu() {
        return 1
 }
 
+test_pmtu_vti6_default_mtu() {
+       setup namespaces veth vti6 && return 2
+
+       # Check that MTU of vti device is MTU of veth minus IPv6 header length
+       veth_mtu="$(link_get_mtu "${ns_a}" veth_a)"
+       vti6_mtu="$(link_get_mtu "${ns_a}" vti6_a)"
+       if [ $((veth_mtu - vti6_mtu)) -ne 40 ]; then
+               echo "  vti MTU ${vti6_mtu} is not veth MTU ${veth_mtu} minus 
IPv6 header length"
+               return 0
+       fi
+
+       return 1
+}
+
 trap cleanup EXIT
 
 exitcode=0
-- 
2.15.1