selftests: add txtimestamp kselftest

Run the transmit timestamp tests as part of kselftests.

Add a txtimestamp.sh test script that runs most variants:
ipv4/ipv6, tcp/udp/raw/raw_ipproto/pf_packet, data/nodata,
setsockopt/cmsg. The script runs tests with netem delays.

Refine txtimestamp.c to validate results. Take expected
netem delays as input and compare against real timestamps.

To run without dependencies, add a listener socket to be
able to connect in the case of TCP.

Add the timestamping directory to the kselftests Makefile.
Build all the binaries. Only run verified txtimestamp.sh.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 57 insertions, 0 deletions

diff --git a/tools/testing/selftests/networking/timestamping/txtimestamp.sh b/tools/testing/selftests/networking/timestamping/txtimestamp.sh
new file mode 100755
index 000000000000..df0d86ca72b7
--- /dev/null
+++ b/tools/testing/selftests/networking/timestamping/txtimestamp.sh
@@ -0,0 +1,57 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Send packets with transmit timestamps over loopback with netem
+# Verify that timestamps correspond to netem delay
+
+set -e
+
+setup() {
+	# set 1ms delay on lo egress
+	tc qdisc add dev lo root netem delay 1ms
+
+	# set 2ms delay on ifb0 egress
+	modprobe ifb
+	ip link add ifb_netem0 type ifb
+	ip link set dev ifb_netem0 up
+	tc qdisc add dev ifb_netem0 root netem delay 2ms
+
+	# redirect lo ingress through ifb0 egress
+	tc qdisc add dev lo handle ffff: ingress
+	tc filter add dev lo parent ffff: \
+		u32 match mark 0 0xffff \
+		action mirred egress redirect dev ifb_netem0
+}
+
+run_test_v4v6() {
+	# SND will be delayed 1000us
+	# ACK will be delayed 6000us: 1 + 2 ms round-trip
+	local -r args="$@ -v 1000 -V 6000"
+
+	./txtimestamp ${args} -4 -L 127.0.0.1
+	./txtimestamp ${args} -6 -L ::1
+}
+
+run_test_tcpudpraw() {
+	local -r args=$@
+
+	run_test_v4v6 ${args}		# tcp
+	run_test_v4v6 ${args} -u	# udp
+	run_test_v4v6 ${args} -r	# raw
+	run_test_v4v6 ${args} -R	# raw (IPPROTO_RAW)
+	run_test_v4v6 ${args} -P	# pf_packet
+}
+
+run_test_all() {
+	run_test_tcpudpraw		# setsockopt
+	run_test_tcpudpraw -C		# cmsg
+	run_test_tcpudpraw -n		# timestamp w/o data
+}
+
+if [[ "$(ip netns identify)" == "root" ]]; then
+	../../net/in_netns.sh $0 $@
+else
+	setup
+	run_test_all
+	echo "OK. All tests passed"
+fi