selftests: pmtu: Introduce FoU and GUE PMTU exceptions tests

Introduce eight tests, for FoU and GUE, with IPv4 and IPv6 payload,
on IPv4 and IPv6 transport, that check that PMTU exceptions are created
with the right value when exceeding the MTU on a link of the path.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh
index 14d20782ccb764e29ab0437f0c8029f4113406a7..e2c94e47707cb3e3af50b539db2cc66d9fc88890 100755 (executable)
--- a/tools/testing/selftests/net/pmtu.sh
+++ b/tools/testing/selftests/net/pmtu.sh
@@ -59,6 +59,14 @@
 #      Same as pmtu_ipv6_vxlan6_exception, but using a GENEVE tunnel instead of
 #      VXLAN
 #
+# - pmtu_ipv{4,6}_fou{4,6}_exception
+#      Same as pmtu_ipv4_vxlan4, but using a direct IPv4/IPv6 encapsulation
+#      (FoU) over IPv4/IPv6, instead of VXLAN
+#
+# - pmtu_ipv{4,6}_fou{4,6}_exception
+#      Same as pmtu_ipv4_vxlan4, but using a generic UDP IPv4/IPv6
+#      encapsulation (GUE) over IPv4/IPv6, instead of VXLAN
+#
 # - 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
@@ -113,6 +121,14 @@ tests="
        pmtu_ipv6_geneve4_exception     IPv6 over geneve4: PMTU exceptions
        pmtu_ipv4_geneve6_exception     IPv4 over geneve6: PMTU exceptions
        pmtu_ipv6_geneve6_exception     IPv6 over geneve6: PMTU exceptions
+       pmtu_ipv4_fou4_exception        IPv4 over fou4: PMTU exceptions
+       pmtu_ipv6_fou4_exception        IPv6 over fou4: PMTU exceptions
+       pmtu_ipv4_fou6_exception        IPv4 over fou6: PMTU exceptions
+       pmtu_ipv6_fou6_exception        IPv6 over fou6: PMTU exceptions
+       pmtu_ipv4_gue4_exception        IPv4 over gue4: PMTU exceptions
+       pmtu_ipv6_gue4_exception        IPv6 over gue4: PMTU exceptions
+       pmtu_ipv4_gue6_exception        IPv4 over gue6: PMTU exceptions
+       pmtu_ipv6_gue6_exception        IPv6 over gue6: PMTU exceptions
        pmtu_vti6_exception             vti6: PMTU exceptions
        pmtu_vti4_exception             vti4: PMTU exceptions
        pmtu_vti4_default_mtu           vti4: default MTU assignment
@@ -200,6 +216,89 @@ nsname() {
        eval echo \$NS_$1
 }
 
+setup_fou_or_gue() {
+       outer="${1}"
+       inner="${2}"
+       encap="${3}"
+
+       if [ "${outer}" = "4" ]; then
+               modprobe fou || return 2
+               a_addr="${prefix4}.${a_r1}.1"
+               b_addr="${prefix4}.${b_r1}.1"
+               if [ "${inner}" = "4" ]; then
+                       type="ipip"
+                       ipproto="4"
+               else
+                       type="sit"
+                       ipproto="41"
+               fi
+       else
+               modprobe fou6 || return 2
+               a_addr="${prefix6}:${a_r1}::1"
+               b_addr="${prefix6}:${b_r1}::1"
+               if [ "${inner}" = "4" ]; then
+                       type="ip6tnl"
+                       mode="mode ipip6"
+                       ipproto="4 -6"
+               else
+                       type="ip6tnl"
+                       mode="mode ip6ip6"
+                       ipproto="41 -6"
+               fi
+       fi
+
+       ${ns_a} ip fou add port 5555 ipproto ${ipproto} || return 2
+       ${ns_a} ip link add ${encap}_a type ${type} ${mode} local ${a_addr} remote ${b_addr} encap ${encap} encap-sport auto encap-dport 5556 || return 2
+
+       ${ns_b} ip fou add port 5556 ipproto ${ipproto}
+       ${ns_b} ip link add ${encap}_b type ${type} ${mode} local ${b_addr} remote ${a_addr} encap ${encap} encap-sport auto encap-dport 5555
+
+       if [ "${inner}" = "4" ]; then
+               ${ns_a} ip addr add ${tunnel4_a_addr}/${tunnel4_mask} dev ${encap}_a
+               ${ns_b} ip addr add ${tunnel4_b_addr}/${tunnel4_mask} dev ${encap}_b
+       else
+               ${ns_a} ip addr add ${tunnel6_a_addr}/${tunnel6_mask} dev ${encap}_a
+               ${ns_b} ip addr add ${tunnel6_b_addr}/${tunnel6_mask} dev ${encap}_b
+       fi
+
+       ${ns_a} ip link set ${encap}_a up
+       ${ns_b} ip link set ${encap}_b up
+
+       sleep 1
+}
+
+setup_fou44() {
+       setup_fou_or_gue 4 4 fou
+}
+
+setup_fou46() {
+       setup_fou_or_gue 4 6 fou
+}
+
+setup_fou64() {
+       setup_fou_or_gue 6 4 fou
+}
+
+setup_fou66() {
+       setup_fou_or_gue 6 6 fou
+}
+
+setup_gue44() {
+       setup_fou_or_gue 4 4 gue
+}
+
+setup_gue46() {
+       setup_fou_or_gue 4 6 gue
+}
+
+setup_gue64() {
+       setup_fou_or_gue 6 4 gue
+}
+
+setup_gue66() {
+       setup_fou_or_gue 6 6 gue
+}
+
 setup_namespaces() {
        for n in ${NS_A} ${NS_B} ${NS_R1} ${NS_R2}; do
                ip netns add ${n} || return 1
@@ -627,6 +726,86 @@ test_pmtu_ipv6_geneve6_exception() {
        test_pmtu_ipvX_over_vxlanY_or_geneveY_exception geneve 6 6
 }
 
+test_pmtu_ipvX_over_fouY_or_gueY() {
+       inner_family=${1}
+       outer_family=${2}
+       encap=${3}
+       ll_mtu=4000
+
+       setup namespaces routing ${encap}${outer_family}${inner_family} || return 2
+       trace "${ns_a}" ${encap}_a   "${ns_b}"  ${encap}_b \
+             "${ns_a}" veth_A-R1    "${ns_r1}" veth_R1-A \
+             "${ns_b}" veth_B-R1    "${ns_r1}" veth_R1-B
+
+       if [ ${inner_family} -eq 4 ]; then
+               ping=ping
+               dst=${tunnel4_b_addr}
+       else
+               ping=${ping6}
+               dst=${tunnel6_b_addr}
+       fi
+
+       if [ "${encap}" = "gue" ]; then
+               encap_overhead=4
+       else
+               encap_overhead=0
+       fi
+
+       if [ ${outer_family} -eq 4 ]; then
+               #                      IPv4 header   UDP header
+               exp_mtu=$((${ll_mtu} - 20          - 8         - ${encap_overhead}))
+       else
+               #                      IPv6 header   Option 4   UDP header
+               exp_mtu=$((${ll_mtu} - 40          - 8        - 8       - ${encap_overhead}))
+       fi
+
+       # Create route exception by exceeding link layer MTU
+       mtu "${ns_a}"  veth_A-R1 $((${ll_mtu} + 1000))
+       mtu "${ns_r1}" veth_R1-A $((${ll_mtu} + 1000))
+       mtu "${ns_b}"  veth_B-R1 ${ll_mtu}
+       mtu "${ns_r1}" veth_R1-B ${ll_mtu}
+
+       mtu "${ns_a}" ${encap}_a $((${ll_mtu} + 1000))
+       mtu "${ns_b}" ${encap}_b $((${ll_mtu} + 1000))
+       ${ns_a} ${ping} -q -M want -i 0.1 -w 2 -s $((${ll_mtu} + 500)) ${dst} > /dev/null
+
+       # Check that exception was created
+       pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst})"
+       check_pmtu_value ${exp_mtu} "${pmtu}" "exceeding link layer MTU on ${encap} interface"
+}
+
+test_pmtu_ipv4_fou4_exception() {
+       test_pmtu_ipvX_over_fouY_or_gueY 4 4 fou
+}
+
+test_pmtu_ipv6_fou4_exception() {
+       test_pmtu_ipvX_over_fouY_or_gueY 6 4 fou
+}
+
+test_pmtu_ipv4_fou6_exception() {
+       test_pmtu_ipvX_over_fouY_or_gueY 4 6 fou
+}
+
+test_pmtu_ipv6_fou6_exception() {
+       test_pmtu_ipvX_over_fouY_or_gueY 6 6 fou
+}
+
+test_pmtu_ipv4_gue4_exception() {
+       test_pmtu_ipvX_over_fouY_or_gueY 4 4 gue
+}
+
+test_pmtu_ipv6_gue4_exception() {
+       test_pmtu_ipvX_over_fouY_or_gueY 6 4 gue
+}
+
+test_pmtu_ipv4_gue6_exception() {
+       test_pmtu_ipvX_over_fouY_or_gueY 4 6 gue
+}
+
+test_pmtu_ipv6_gue6_exception() {
+       test_pmtu_ipvX_over_fouY_or_gueY 6 6 gue
+}
+
 test_pmtu_vti4_exception() {
        setup namespaces veth vti4 xfrm4 || return 2
        trace "${ns_a}" veth_a    "${ns_b}" veth_b \