diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh index 5d9af22b360a..ba11433d17d8 100755 --- a/tools/testing/selftests/net/pmtu.sh +++ b/tools/testing/selftests/net/pmtu.sh @@ -6,6 +6,14 @@ # # Tests currently implemented: # +# - pmtu_vti4_exception +# Set up vti tunnel on top of veth, with xfrm states and policies, in two +# namespaces with matching endpoints. Check that route exception is not +# created if link layer MTU is not exceeded, then exceed it and check that +# exception is created with the expected PMTU. The approach described +# below for IPv6 doesn't apply here, because, on IPv4, administrative MTU +# changes alone won't affect PMTU +# # - 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 @@ -24,6 +32,7 @@ tests=" pmtu_vti6_exception vti6: PMTU exceptions + pmtu_vti4_exception vti4: PMTU exceptions pmtu_vti4_default_mtu vti4: default MTU assignment pmtu_vti6_default_mtu vti6: default MTU assignment" @@ -109,15 +118,27 @@ setup_vti6() { } 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 1 - ${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 ${veth6_a_addr} proto esp mode tunnel + proto=${1} + veth_a_addr="${2}" + veth_b_addr="${3}" - ${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 + ${ns_a} ip -${proto} xfrm state add src ${veth_a_addr} dst ${veth_b_addr} spi 0x1000 proto esp aead "rfc4106(gcm(aes))" 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode tunnel || return 1 + ${ns_a} ip -${proto} xfrm state add src ${veth_b_addr} dst ${veth_a_addr} spi 0x1001 proto esp aead "rfc4106(gcm(aes))" 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode tunnel + ${ns_a} ip -${proto} xfrm policy add dir out mark 10 tmpl src ${veth_a_addr} dst ${veth_b_addr} proto esp mode tunnel + ${ns_a} ip -${proto} xfrm policy add dir in mark 10 tmpl src ${veth_b_addr} dst ${veth_a_addr} proto esp mode tunnel + + ${ns_b} ip -${proto} xfrm state add src ${veth_a_addr} dst ${veth_b_addr} spi 0x1000 proto esp aead "rfc4106(gcm(aes))" 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode tunnel + ${ns_b} ip -${proto} xfrm state add src ${veth_b_addr} dst ${veth_a_addr} spi 0x1001 proto esp aead "rfc4106(gcm(aes))" 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode tunnel + ${ns_b} ip -${proto} xfrm policy add dir out mark 10 tmpl src ${veth_b_addr} dst ${veth_a_addr} proto esp mode tunnel + ${ns_b} ip -${proto} xfrm policy add dir in mark 10 tmpl src ${veth_a_addr} dst ${veth_b_addr} proto esp mode tunnel +} + +setup_xfrm4() { + setup_xfrm 4 ${veth4_a_addr} ${veth4_b_addr} +} + +setup_xfrm6() { + setup_xfrm 6 ${veth6_a_addr} ${veth6_b_addr} } setup() { @@ -182,8 +203,47 @@ route_get_dst_pmtu_from_exception() { mtu_parse "$(route_get_dst_exception "${ns_cmd}" ${dst})" } +test_pmtu_vti4_exception() { + setup namespaces veth vti4 xfrm4 || return 2 + + veth_mtu=1500 + vti_mtu=$((veth_mtu - 20)) + + # SPI SN IV ICV pad length next header + esp_payload_rfc4106=$((vti_mtu - 4 - 4 - 8 - 16 - 1 - 1)) + ping_payload=$((esp_payload_rfc4106 - 28)) + + mtu "${ns_a}" veth_a ${veth_mtu} + mtu "${ns_b}" veth_b ${veth_mtu} + mtu "${ns_a}" vti4_a ${vti_mtu} + mtu "${ns_b}" vti4_b ${vti_mtu} + + # Send DF packet without exceeding link layer MTU, check that no + # exception is created + ${ns_a} ping -q -M want -i 0.1 -w 2 -s ${ping_payload} ${vti4_b_addr} > /dev/null + pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti4_b_addr})" + if [ "${pmtu}" != "" ]; then + err " unexpected exception created with PMTU ${pmtu} for IP payload length ${esp_payload_rfc4106}" + return 1 + fi + + # Now exceed link layer MTU by one byte, check that exception is created + ${ns_a} ping -q -M want -i 0.1 -w 2 -s $((ping_payload + 1)) ${vti4_b_addr} > /dev/null + pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti4_b_addr})" + if [ "${pmtu}" = "" ]; then + err " exception not created for IP payload length $((esp_payload_rfc4106 + 1))" + return 1 + fi + + # ...with the right PMTU value + if [ ${pmtu} -ne ${esp_payload_rfc4106} ]; then + err " wrong PMTU ${pmtu} in exception, expected: ${esp_payload_rfc4106}" + return 1 + fi +} + test_pmtu_vti6_exception() { - setup namespaces veth vti6 xfrm || return 2 + setup namespaces veth vti6 xfrm6 || return 2 fail=0 # Create route exception by exceeding link layer MTU