From: "Alessandro Carminati (Red Hat)" alessandro.carminati@gmail.com

[ Upstream commit f803bcf9208a2540acb4c32bdc3616673169f490 ]

In some systems, the netcat server can incur in delay to start listening. When this happens, the test can randomly fail in various points. This is an example error message:

# ip gre none gso # encap 192.168.1.1 to 192.168.1.2, type gre, mac none len 2000 # test basic connectivity # Ncat: Connection refused.

The issue stems from a race condition between the netcat client and server. The test author had addressed this problem by implementing a sleep, which I have removed in this patch. This patch introduces a function capable of sleeping for up to two seconds. However, it can terminate the waiting period early if the port is reported to be listening.

Signed-off-by: Alessandro Carminati (Red Hat) alessandro.carminati@gmail.com Signed-off-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20240314105911.213411-1-alessandro.carminati@gma... Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/bpf/test_tc_tunnel.sh | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/test_tc_tunnel.sh b/tools/testing/selftests/bpf/test_tc_tunnel.sh index 7c76b841b17bb..21bde60c95230 100755 --- a/tools/testing/selftests/bpf/test_tc_tunnel.sh +++ b/tools/testing/selftests/bpf/test_tc_tunnel.sh @@ -71,7 +71,6 @@ cleanup() { server_listen() { ip netns exec "${ns2}" nc "${netcat_opt}" -l -p "${port}" > "${outfile}" & server_pid=$! - sleep 0.2 }

client_connect() { @@ -92,6 +91,16 @@ verify_data() { fi }

+wait_for_port() { + for i in $(seq 20); do + if ip netns exec "${ns2}" ss ${2:--4}OHntl | grep -q "$1"; then + return 0 + fi + sleep 0.1 + done + return 1 +} + set -e

# no arguments: automated test, run all @@ -183,6 +192,7 @@ setup # basic communication works echo "test basic connectivity" server_listen +wait_for_port ${port} ${netcat_opt} client_connect verify_data

@@ -194,6 +204,7 @@ ip netns exec "${ns1}" tc filter add dev veth1 egress \ section "encap_${tuntype}_${mac}" echo "test bpf encap without decap (expect failure)" server_listen +wait_for_port ${port} ${netcat_opt} ! client_connect

if [[ "$tuntype" =~ "udp" ]]; then