[PATCH 5.12 047/178] selftests: mptcp: enable syncookie only in absence of reorders

Greg Kroah-Hartman
2021-06-21T16:39:37Z

From: Paolo Abeni <pabeni@redhat.com>

[ Upstream commit 2395da0e17935ce9158cdfae433962bdb6cbfa67 ]

Syncookie validation may fail for OoO packets, causing spurious
resets and self-tests failures, so let's force syncookie only
for tests iteration with no OoO.

Fixes: fed61c4b584c ("selftests: mptcp: make 2nd net namespace use tcp syn cookies unconditionally")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/198
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/testing/selftests/net/mptcp/mptcp_connect.sh | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.sh b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
index 65b3b983efc2..8763706b0d04 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
@@ -197,9 +197,6 @@ ip -net "$ns4" link set ns4eth3 up
ip -net "$ns4" route add default via 10.0.3.2
ip -net "$ns4" route add default via dead:beef:3::2

-# use TCP syn cookies, even if no flooding was detected.
-ip netns exec "$ns2" sysctl -q net.ipv4.tcp_syncookies=2
-
set_ethtool_flags() {
local ns="$1"
local dev="$2"
@@ -711,6 +708,14 @@ for sender in $ns1 $ns2 $ns3 $ns4;do
exit $ret
fi

+ # ns1<->ns2 is not subject to reordering/tc delays. Use it to test
+ # mptcp syncookie support.
+ if [ $sender = $ns1 ]; then
+ ip netns exec "$ns2" sysctl -q net.ipv4.tcp_syncookies=2
+ else
+ ip netns exec "$ns2" sysctl -q net.ipv4.tcp_syncookies=1
+ fi
+
run_tests "$ns2" $sender 10.0.1.2
run_tests "$ns2" $sender dead:beef:1::2
run_tests "$ns2" $sender 10.0.2.1
--
2.30.2