+ Guillaume: please see comment below about route_get_dst_pmtu_from_exception()) Original patch: https://lore.kernel.org/netdev/20241104072753.77042-1-deliran@xxxxxxxxxx/ On Mon, Nov 04, 2024 at 07:27:50AM +0000, Vladimir Vdovin wrote: > diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh > index 569bce8b6383..f24c84184c61 100755 > --- a/tools/testing/selftests/net/pmtu.sh > +++ b/tools/testing/selftests/net/pmtu.sh > @@ -197,6 +197,12 @@ > # > # - pmtu_ipv6_route_change > # Same as above but with IPv6 > +# > +# - pmtu_ipv4_mp_exceptions > +# Use the same topology as in pmtu_ipv4, but add routeable "dummy" No need for "dummy" as these are regular addresses on the loopback device > +# addresses on host A and B on lo0 reachable via both routers. There is no "lo0" device. Only "lo". Run with "-v" and you will see a lot of errors > +# Host A and B "dummy" addresses have multipath routes to each other. > +# Check that PMTU exceptions are created for both paths. > > source lib.sh > source net_helper.sh > @@ -266,7 +272,8 @@ tests=" > list_flush_ipv4_exception ipv4: list and flush cached exceptions 1 > list_flush_ipv6_exception ipv6: list and flush cached exceptions 1 > pmtu_ipv4_route_change ipv4: PMTU exception w/route replace 1 > - pmtu_ipv6_route_change ipv6: PMTU exception w/route replace 1" > + pmtu_ipv6_route_change ipv6: PMTU exception w/route replace 1 > + pmtu_ipv4_mp_exceptions ipv4: PMTU multipath nh exceptions 1" > > # Addressing and routing for tests with routers: four network segments, with > # index SEGMENT between 1 and 4, a common prefix (PREFIX4 or PREFIX6) and an > @@ -343,6 +350,9 @@ tunnel6_a_addr="fd00:2::a" > tunnel6_b_addr="fd00:2::b" > tunnel6_mask="64" > > +dummy4_a_addr="192.168.99.99" > +dummy4_b_addr="192.168.88.88" Let's change to "host4_a_addr" and "host4_b_addr" (or similar) as we are no longer using a dummy device > + > dummy6_0_prefix="fc00:1000::" > dummy6_1_prefix="fc00:1001::" > dummy6_mask="64" > @@ -984,6 +994,50 @@ setup_ovs_bridge() { > run_cmd ip route add ${prefix6}:${b_r1}::1 via ${prefix6}:${a_r1}::2 > } > > +setup_multipath() { > + if [ "$USE_NH" = "yes" ]; then > + setup_multipath_new > + else > + setup_multipath_old > + fi Please move setup_multipath_{new,old}() before setup_multipath() like setup_routing() and related functions > + > + # Set up routers with routes to dummies > + run_cmd ${ns_r1} ip route add ${dummy4_a_addr} via ${prefix4}.${a_r1}.1 > + run_cmd ${ns_r2} ip route add ${dummy4_a_addr} via ${prefix4}.${a_r2}.1 > + run_cmd ${ns_r1} ip route add ${dummy4_b_addr} via ${prefix4}.${b_r1}.1 > + run_cmd ${ns_r2} ip route add ${dummy4_b_addr} via ${prefix4}.${b_r2}.1 > +} > + > +setup_multipath_new() { > + # Set up host A with multipath routes to host B dummy4_b_addr > + run_cmd ${ns_a} ip addr add ${dummy4_a_addr} dev lo0 s/lo0/lo/ same in other places > + run_cmd ${ns_a} ip nexthop add id 201 via ${prefix4}.${a_r1}.2 dev veth_A-R1 > + run_cmd ${ns_a} ip nexthop add id 202 via ${prefix4}.${a_r2}.2 dev veth_A-R2 > + run_cmd ${ns_a} ip nexthop add id 203 group 201/202 > + run_cmd ${ns_a} ip route add ${dummy4_b_addr} nhid 203 Maybe number the nexthops 401..403 so that we can later use 601..603 for IPv6 like $routes_nh is doing > + > + # Set up host B with multipath routes to host A dummy4_a_addr > + run_cmd ${ns_b} ip addr add ${dummy4_b_addr} dev lo0 > + run_cmd ${ns_b} ip nexthop add id 201 via ${prefix4}.${b_r1}.2 dev veth_A-R1 s/veth_A-R1/veth_B-R1/ > + run_cmd ${ns_b} ip nexthop add id 202 via ${prefix4}.${b_r2}.2 dev veth_A-R2 s/veth_A-R2/veth_B-R2/ > + run_cmd ${ns_b} ip nexthop add id 203 group 201/202 > + run_cmd ${ns_b} ip route add ${dummy4_a_addr} nhid 203 > +} > + > +setup_multipath_old() { > + # Set up host A with multipath routes to host B dummy4_b_addr > + run_cmd ${ns_a} ip addr add ${dummy4_a_addr} dev lo0 > + run_cmd ${ns_a} ip route add ${dummy4_b_addr} \ > + nexthop via ${prefix4}.${a_r1}.2 weight 1 \ > + nexthop via ${prefix4}.${a_r2}.2 weight 1 > + > + # Set up host B with multipath routes to host A dummy4_a_addr > + run_cmd ${ns_b} ip addr add ${dummy4_b_addr} dev lo0 > + run_cmd ${ns_a} ip route add ${dummy4_a_addr} \ s/ns_a/ns_b/ > + nexthop via ${prefix4}.${a_b1}.2 weight 1 \ s/a_b1/b_r1/ > + nexthop via ${prefix4}.${a_b2}.2 weight 1 s/a_b2/b_r2/ > +} > + > setup() { > [ "$(id -u)" -ne 0 ] && echo " need to run as root" && return $ksft_skip > > @@ -2329,6 +2383,45 @@ test_pmtu_ipv6_route_change() { > test_pmtu_ipvX_route_change 6 > } > > +test_pmtu_ipv4_mp_exceptions() { > + setup namespaces routing multipath || return $ksft_skip > + > + trace "${ns_a}" veth_A-R1 "${ns_r1}" veth_R1-A \ > + "${ns_r1}" veth_R1-B "${ns_b}" veth_B-R1 \ > + "${ns_a}" veth_A-R2 "${ns_r2}" veth_R2-A \ > + "${ns_r2}" veth_R2-B "${ns_b}" veth_B-R2 > + > + # Set up initial MTU values > + mtu "${ns_a}" veth_A-R1 2000 > + mtu "${ns_r1}" veth_R1-A 2000 > + mtu "${ns_r1}" veth_R1-B 1400 > + mtu "${ns_b}" veth_B-R1 1400 > + > + mtu "${ns_a}" veth_A-R2 2000 > + mtu "${ns_r2}" veth_R2-A 2000 > + mtu "${ns_r2}" veth_R2-B 1500 > + mtu "${ns_b}" veth_B-R2 1500 > + > + fail=0 > + > + # Ping and expect two nexthop exceptions for two routes in nh group > + run_cmd ${ns_a} ping -q -M want -i 0.1 -c 1 -s 1800 "${dummy4_b_addr}" > + I looked more into pmtu.sh and this hunk from here ... > + # Do route lookup before checking cached exceptions. > + # The following commands are needed for dst entries to be cached > + # in both paths exceptions and therefore dumped to user space > + run_cmd ${ns_a} ip route get ${dummy4_b_addr} oif veth_A-R1 > + run_cmd ${ns_a} ip route get ${dummy4_b_addr} oif veth_A-R2 > + > + # Check cached exceptions > + if [ "$(${ns_a} ip -oneline route list cache | grep mtu | wc -l)" -ne 2 ]; then > + err " there are not enough cached exceptions" > + fail=1 > + fi ... until here can be replaced by route_get_dst_pmtu_from_exception() and check_pmtu_value() like in other test cases. There are two prerequisites: 1. We should set the same MTU in both paths as otherwise we don't know which MTU will be cached and what to pass to check_pmtu_value() as the expected value. I did see that check_pmtu_value() accepts "any", but I think it's better to check for a specific value. 2. route_get_dst_pmtu_from_exception() is not very flexible in the keywords it accepts for "ip route get" and we need to pass "oif". It can be solved by [1] (please test), but Guillaume might have a better idea. Then, the above hunk can be replaced by [2]. [1] diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh index 569bce8b6383..6e790d38e5d9 100755 --- a/tools/testing/selftests/net/pmtu.sh +++ b/tools/testing/selftests/net/pmtu.sh @@ -1076,23 +1076,15 @@ link_get_mtu() { } route_get_dst_exception() { - ns_cmd="${1}" - dst="${2}" - dsfield="${3}" - - if [ -z "${dsfield}" ]; then - dsfield=0 - fi + ns_cmd="${1}"; shift - ${ns_cmd} ip route get "${dst}" dsfield "${dsfield}" + ${ns_cmd} ip route get "$@" } route_get_dst_pmtu_from_exception() { - ns_cmd="${1}" - dst="${2}" - dsfield="${3}" + ns_cmd="${1}"; shift - mtu_parse "$(route_get_dst_exception "${ns_cmd}" "${dst}" "${dsfield}")" + mtu_parse "$(route_get_dst_exception "${ns_cmd}" "$@")" } check_pmtu_value() { @@ -1235,10 +1227,10 @@ test_pmtu_ipv4_dscp_icmp_exception() { run_cmd "${ns_a}" ping -q -M want -Q "${dsfield}" -c 1 -w 1 -s "${len}" "${dst2}" # Check that exceptions have been created with the correct PMTU - pmtu_1="$(route_get_dst_pmtu_from_exception "${ns_a}" "${dst1}" "${policy_mark}")" + pmtu_1="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst1} dsfield ${policy_mark})" check_pmtu_value "1400" "${pmtu_1}" "exceeding MTU" || return 1 - pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" "${dst2}" "${policy_mark}")" + pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst2} dsfield ${policy_mark})" check_pmtu_value "1500" "${pmtu_2}" "exceeding MTU" || return 1 } @@ -1285,9 +1277,9 @@ test_pmtu_ipv4_dscp_udp_exception() { UDP:"${dst2}":50000,tos="${dsfield}" # Check that exceptions have been created with the correct PMTU - pmtu_1="$(route_get_dst_pmtu_from_exception "${ns_a}" "${dst1}" "${policy_mark}")" + pmtu_1="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst1} dsfield ${policy_mark})" check_pmtu_value "1400" "${pmtu_1}" "exceeding MTU" || return 1 - pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" "${dst2}" "${policy_mark}")" + pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst2} dsfield ${policy_mark})" check_pmtu_value "1500" "${pmtu_2}" "exceeding MTU" || return 1 } [2] diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh index a3c3f7f99e5b..10b8ac2d7f47 100755 --- a/tools/testing/selftests/net/pmtu.sh +++ b/tools/testing/selftests/net/pmtu.sh @@ -2399,19 +2399,11 @@ test_pmtu_ipv4_mp_exceptions() { # Ping and expect two nexthop exceptions for two routes in nh group run_cmd ${ns_a} ping -q -M want -i 0.1 -c 1 -s 1800 "${dummy4_b_addr}" - # Do route lookup before checking cached exceptions. - # The following commands are needed for dst entries to be cached - # in both paths exceptions and therefore dumped to user space - run_cmd ${ns_a} ip route get ${dummy4_b_addr} oif veth_A-R1 - run_cmd ${ns_a} ip route get ${dummy4_b_addr} oif veth_A-R2 - - # Check cached exceptions - if [ "$(${ns_a} ip -oneline route list cache | grep mtu | wc -l)" -ne 2 ]; then - err " there are not enough cached exceptions" - fail=1 - fi - - return ${fail} + # Check that exceptions have been created with the correct PMTU + pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dummy4_b_addr} oif veth_A-R1)" + check_pmtu_value "1500" "${pmtu}" "exceeding MTU (veth_A-R1)" || return 1 + pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dummy4_b_addr} oif veth_A-R2)" + check_pmtu_value "1500" "${pmtu}" "exceeding MTU (veth_A-R2)" || return 1 } usage() {
