From c12e0d5f267d7eb45a2f8eaa9fd44eaa2871a95e Mon Sep 17 00:00:00 2001
From: Paolo Abeni <pabeni@redhat.com>
Date: Tue, 7 Feb 2023 19:44:58 +0100
Subject: [PATCH] self-tests: introduce self-tests for RPS default mask

Ensure that RPS default mask changes take place on
all newly created netns/devices and don't affect
existing ones.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 tools/testing/selftests/net/Makefile            |  1 +
 tools/testing/selftests/net/config              |  3 ++
 tools/testing/selftests/net/rps_default_mask.sh | 57 +++++++++++++++++++++++++
 3 files changed, 61 insertions(+)
 create mode 100755 tools/testing/selftests/net/rps_default_mask.sh

diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index 951bd53..3364c54 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -46,6 +46,7 @@ TEST_PROGS += stress_reuseport_listen.sh
 TEST_PROGS += l2_tos_ttl_inherit.sh
 TEST_PROGS += bind_bhash.sh
 TEST_PROGS += ip_local_port_range.sh
+TEST_PROGS += rps_default_mask.sh
 TEST_PROGS_EXTENDED := in_netns.sh setup_loopback.sh setup_veth.sh
 TEST_PROGS_EXTENDED += toeplitz_client.sh toeplitz.sh
 TEST_GEN_FILES =  socket nettest
diff --git a/tools/testing/selftests/net/config b/tools/testing/selftests/net/config
index bd89198..cc9fd55 100644
--- a/tools/testing/selftests/net/config
+++ b/tools/testing/selftests/net/config
@@ -3,6 +3,9 @@ CONFIG_NET_NS=y
 CONFIG_BPF_SYSCALL=y
 CONFIG_TEST_BPF=m
 CONFIG_NUMA=y
+CONFIG_RPS=y
+CONFIG_SYSFS=y
+CONFIG_PROC_SYSCTL=y
 CONFIG_NET_VRF=y
 CONFIG_NET_L3_MASTER_DEV=y
 CONFIG_IPV6=y
diff --git a/tools/testing/selftests/net/rps_default_mask.sh b/tools/testing/selftests/net/rps_default_mask.sh
new file mode 100755
index 0000000..c81c0ac
--- /dev/null
+++ b/tools/testing/selftests/net/rps_default_mask.sh
@@ -0,0 +1,57 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+readonly ksft_skip=4
+readonly cpus=$(nproc)
+ret=0
+
+[ $cpus -gt 2 ] || exit $ksft_skip
+
+readonly INITIAL_RPS_DEFAULT_MASK=$(cat /proc/sys/net/core/rps_default_mask)
+readonly NETNS="ns-$(mktemp -u XXXXXX)"
+
+setup() {
+	ip netns add "${NETNS}"
+	ip -netns "${NETNS}" link set lo up
+}
+
+cleanup() {
+	echo $INITIAL_RPS_DEFAULT_MASK > /proc/sys/net/core/rps_default_mask
+	ip netns del $NETNS
+}
+
+chk_rps() {
+	local rps_mask expected_rps_mask=$3
+	local dev_name=$2
+	local msg=$1
+
+	rps_mask=$(ip netns exec $NETNS cat /sys/class/net/$dev_name/queues/rx-0/rps_cpus)
+	printf "%-60s" "$msg"
+	if [ $rps_mask -eq $expected_rps_mask ]; then
+		echo "[ ok ]"
+	else
+		echo "[fail] expected $expected_rps_mask found $rps_mask"
+		ret=1
+	fi
+}
+
+trap cleanup EXIT
+
+echo 0 > /proc/sys/net/core/rps_default_mask
+setup
+chk_rps "empty rps_default_mask" lo 0
+cleanup
+
+echo 1 > /proc/sys/net/core/rps_default_mask
+setup
+chk_rps "non zero rps_default_mask" lo 1
+
+echo 3 > /proc/sys/net/core/rps_default_mask
+chk_rps "changing rps_default_mask dont affect existing netns" lo 1
+
+ip -n $NETNS link add type veth
+ip -n $NETNS link set dev veth0 up
+ip -n $NETNS link set dev veth1 up
+chk_rps "changing rps_default_mask affect newly created devices" veth0 3
+chk_rps "changing rps_default_mask affect newly created devices[II]" veth1 3
+exit $ret
-- 
2.7.4