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