[PATCH net 04/14] selftests: mptcp: connect: skip TFO tests if not supported

[Matthieu Baerts]

Selftests are supposed to run on any kernels, including the old ones not
supporting all MPTCP features.

One of them is the support of TCP_FASTOPEN socket option with MPTCP
connections introduced by commit 4ffb0a02346c ("mptcp: add TCP_FASTOPEN
sock option").

It is possible to look for "mptcp_fastopen_" in kallsyms to know if the
feature is supported or not.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/368
Fixes: ca7ae8916043 ("selftests: mptcp: mptfo Initiator/Listener")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
---
 tools/testing/selftests/net/mptcp/mptcp_connect.sh | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.sh b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
index 895114fb6832..773dd770a567 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
@@ -777,6 +777,11 @@ run_tests_peekmode()
 
 run_tests_mptfo()
 {
+	if ! mptcp_lib_kallsyms_has "mptcp_fastopen_"; then
+		echo "INFO: TFO not supported by the kernel: SKIP"
+		return
+	fi
+
 	echo "INFO: with MPTFO start"
 	ip netns exec "$ns1" sysctl -q net.ipv4.tcp_fastopen=2
 	ip netns exec "$ns2" sysctl -q net.ipv4.tcp_fastopen=1

-- 
2.40.1