The srv6_end_dt4_l3vpn_test instantiates a virtual network consisting of several routers (rt-1, rt-2) and hosts. When the IPv6 addresses of rt-{1,2} routers are configured, the Deduplicate Address Detection (DAD) kicks in when enabled in the Linux distros running the selftests. DAD is used to check whether an IPv6 address is already assigned in a network. Such a mechanism consists of sending an ICMPv6 Echo Request and waiting for a reply. As the DAD process could take too long to complete, it may cause the failing of some tests carried out by the srv6_end_dt4_l3vpn_test script.

To make the srv6_end_dt4_l3vpn_test more robust, we disable DAD on routers since we configure the virtual network manually and do not need any address deduplication mechanism at all.

Fixes: 2195444e09b4 ("selftests: add selftest for the SRv6 End.DT4 behavior") Signed-off-by: Andrea Mayer andrea.mayer@uniroma2.it --- tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh b/tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh index 1003119773e5..37f08d582d2f 100755 --- a/tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh +++ b/tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh @@ -232,10 +232,14 @@ setup_rt_networking() local nsname=rt-${rt}

ip netns add ${nsname} + + ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.accept_dad=0 + ip netns exec ${nsname} sysctl -wq net.ipv6.conf.default.accept_dad=0 + ip link set veth-rt-${rt} netns ${nsname} ip -netns ${nsname} link set veth-rt-${rt} name veth0

- ip -netns ${nsname} addr add ${IPv6_RT_NETWORK}::${rt}/64 dev veth0 + ip -netns ${nsname} addr add ${IPv6_RT_NETWORK}::${rt}/64 dev veth0 nodad ip -netns ${nsname} link set veth0 up ip -netns ${nsname} link set lo up

On some distributions, the rp_filter is automatically set (=1) by default on a netdev basis (also on VRFs). In an SRv6 End.DT4 behavior, decapsulated IPv4 packets are routed using the table associated with the VRF bound to that tunnel. During lookup operations, the rp_filter can lead to packet loss when activated on the VRF. Therefore, we chose to make this selftest more robust by explicitly disabling the rp_filter during tests (as it is automatically set by some Linux distributions).

Fixes: 2195444e09b4 ("selftests: add selftest for the SRv6 End.DT4 behavior") Reported-by: Hangbin Liu liuhangbin@gmail.com Signed-off-by: Andrea Mayer andrea.mayer@uniroma2.it Tested-by: Hangbin Liu liuhangbin@gmail.com --- .../testing/selftests/net/srv6_end_dt4_l3vpn_test.sh | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh b/tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh index 37f08d582d2f..f96282362811 100755 --- a/tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh +++ b/tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh @@ -258,6 +258,12 @@ setup_hs()

# set the networking for the host ip netns add ${hsname} + + # disable the rp_filter otherwise the kernel gets confused about how + # to route decap ipv4 packets. + ip netns exec ${rtname} sysctl -wq net.ipv4.conf.all.rp_filter=0 + ip netns exec ${rtname} sysctl -wq net.ipv4.conf.default.rp_filter=0 + ip -netns ${hsname} link add veth0 type veth peer name ${rtveth} ip -netns ${hsname} link set ${rtveth} netns ${rtname} ip -netns ${hsname} addr add ${IPv4_HS_NETWORK}.${hs}/24 dev veth0 @@ -276,11 +282,6 @@ setup_hs()

ip netns exec ${rtname} sysctl -wq net.ipv4.conf.${rtveth}.proxy_arp=1

- # disable the rp_filter otherwise the kernel gets confused about how - # to route decap ipv4 packets. - ip netns exec ${rtname} sysctl -wq net.ipv4.conf.all.rp_filter=0 - ip netns exec ${rtname} sysctl -wq net.ipv4.conf.${rtveth}.rp_filter=0 - ip netns exec ${rtname} sh -c "echo 1 > /proc/sys/net/vrf/strict_mode" }