[PATCH v2 7/7] selftests: netfilter: Torture nftables netdev hooks

[Phil Sutter <phil@nwl.cc>]

Add a ruleset which binds to various interface names via netdev-family
chains and flowtables and massage the notifiers by frequently renaming
interfaces to match these names.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 .../testing/selftests/net/netfilter/Makefile  |   1 +
 .../net/netfilter/nft_interface_stress.sh     | 106 ++++++++++++++++++
 2 files changed, 107 insertions(+)
 create mode 100755 tools/testing/selftests/net/netfilter/nft_interface_stress.sh

diff --git a/tools/testing/selftests/net/netfilter/Makefile b/tools/testing/selftests/net/netfilter/Makefile
index dd9a75a33d28..f95678882819 100644
--- a/tools/testing/selftests/net/netfilter/Makefile
+++ b/tools/testing/selftests/net/netfilter/Makefile
@@ -19,6 +19,7 @@ TEST_PROGS += nft_concat_range.sh
 TEST_PROGS += nft_conntrack_helper.sh
 TEST_PROGS += nft_fib.sh
 TEST_PROGS += nft_flowtable.sh
+TEST_PROGS += nft_interface_stress.sh
 TEST_PROGS += nft_meta.sh
 TEST_PROGS += nft_nat.sh
 TEST_PROGS += nft_nat_zones.sh
diff --git a/tools/testing/selftests/net/netfilter/nft_interface_stress.sh b/tools/testing/selftests/net/netfilter/nft_interface_stress.sh
new file mode 100755
index 000000000000..6d739f2e0ab9
--- /dev/null
+++ b/tools/testing/selftests/net/netfilter/nft_interface_stress.sh
@@ -0,0 +1,106 @@
+#!/bin/bash -e
+#
+# SPDX-License-Identifier: GPL-2.0
+#
+# Torture nftables' netdevice notifier callbacks and related code by frequent
+# renaming of interfaces which netdev-family chains and flowtables hook into.
+
+source lib.sh
+
+checktool "nft --version" "run test without nft tool"
+checktool "iperf3 --version" "run test without iperf3 tool"
+
+# how many seconds to torture the kernel, default to 80% of max run time
+TEST_RUNTIME=$((kselftest_timeout * 8 / 10))
+
+trap "cleanup_all_ns" EXIT
+
+setup_ns nsc nsr nss
+
+ip -net $nsc link add cr0 type veth peer name rc0 netns $nsr
+ip -net $nsc addr add 10.0.0.1/24 dev cr0
+ip -net $nsc link set cr0 up
+ip -net $nsc route add default via 10.0.0.2
+
+ip -net $nss link add sr0 type veth peer name rs0 netns $nsr
+ip -net $nss addr add 10.1.0.1/24 dev sr0
+ip -net $nss link set sr0 up
+ip -net $nss route add default via 10.1.0.2
+
+ip -net $nsr addr add 10.0.0.2/24 dev rc0
+ip -net $nsr link set rc0 up
+ip -net $nsr addr add 10.1.0.2/24 dev rs0
+ip -net $nsr link set rs0 up
+ip netns exec $nsr sysctl -q net.ipv4.ip_forward=1
+ip netns exec $nsr sysctl -q net.ipv4.conf.all.forwarding=1
+
+{
+	echo "table netdev t {"
+	for ((i = 0; i < 10; i++)); do
+		cat <<-EOF
+		chain chain_rc$i {
+			type filter hook ingress device rc$i priority 0
+			counter
+		}
+		chain chain_rs$i {
+			type filter hook ingress device rs$i priority 0
+			counter
+		}
+		EOF
+	done
+	echo "}"
+	echo "table ip t {"
+	for ((i = 0; i < 10; i++)); do
+		cat <<-EOF
+		flowtable ft_${i} {
+			hook ingress priority 0
+			devices = { rc$i, rs$i }
+		}
+		EOF
+	done
+	echo "chain c {"
+	echo "type filter hook forward priority 0"
+	for ((i = 0; i < 10; i++)); do
+		echo -n "iifname rc$i oifname rs$i "
+		echo    "ip protocol tcp counter flow add @ft_${i}"
+	done
+	echo "counter"
+	echo "}"
+	echo "}"
+} | ip netns exec $nsr nft -f - || {
+	echo "SKIP: Could not load nft ruleset"
+	exit $ksft_skip
+}
+
+for ((o=0, n=1; ; o=n, n++, n %= 10)); do
+	ip -net $nsr link set rc$o name rc$n
+	ip -net $nsr link set rs$o name rs$n
+done &
+rename_loop_pid=$!
+
+ip netns exec $nsr nft monitor >/dev/null &
+nft_monitor_pid=$!
+
+ip netns exec $nss iperf3 --server --daemon -1
+summary_expr='s,^\[SUM\] .* \([0-9]\+\) Mbits/sec .* receiver,\1,p'
+rate=$(ip netns exec $nsc iperf3 \
+	--format m -c 10.1.0.1 --time $TEST_RUNTIME \
+	--length 56 --parallel 10 -i 0 | sed -n "$summary_expr")
+
+kill $nft_monitor_pid
+kill $rename_loop_pid
+wait
+
+#ip netns exec $nsr nft list ruleset
+
+[[ $(</proc/sys/kernel/tainted) -eq 0 ]] || {
+	echo "FAIL: Kernel is tainted!"
+	exit $ksft_fail
+}
+
+[[ $rate -gt 0 ]] || {
+	echo "FAIL: Zero throughput in iperf3"
+	exit $ksft_fail
+}
+
+exit $ksft_pass
-- 
2.43.0