+ Guillaume: please see comment below about route_get_dst_pmtu_from_exception()) Original patch: https://lore.kernel.org/netdev/20241104072753.77042-1-deliran@verdict.gg/
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() {