selftests: forwarding: add tunnel_key "nofrag" test case

Add a selftest that configures metadata tunnel encapsulation using the TC
"tunnel_key" action: it includes a test case for setting "nofrag" flag.

Example output:

 # selftests: net/forwarding: tc_tunnel_key.sh
 # TEST: tunnel_key nofrag (skip_hw)                                   [ OK ]
 # INFO: Could not test offloaded functionality
 ok 1 selftests: net/forwarding: tc_tunnel_key.sh

Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/forwarding/Makefile

@@ -85,6 +85,7 @@ TEST_PROGS = bridge_igmp.sh \
 	tc_mpls_l2vpn.sh \
 	tc_police.sh \
 	tc_shblocks.sh \
+	tc_tunnel_key.sh \
 	tc_vlan_modify.sh \
 	vxlan_asymmetric_ipv6.sh \
 	vxlan_asymmetric.sh \

tools/testing/selftests/net/forwarding/tc_tunnel_key.sh

@@ -0,0 +1,161 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+ALL_TESTS="tunnel_key_nofrag_test"
+
+NUM_NETIFS=4
+source tc_common.sh
+source lib.sh
+
+tcflags="skip_hw"
+
+h1_create()
+{
+	simple_if_init $h1 192.0.2.1/24
+	forwarding_enable
+	mtu_set $h1 1500
+	tunnel_create h1-et vxlan 192.0.2.1 192.0.2.2 dev $h1 dstport 0 external
+	tc qdisc add dev h1-et clsact
+	mtu_set h1-et 1230
+	mtu_restore $h1
+	mtu_set $h1 1000
+}
+
+h1_destroy()
+{
+	tc qdisc del dev h1-et clsact
+	tunnel_destroy h1-et
+	forwarding_restore
+	mtu_restore $h1
+	simple_if_fini $h1 192.0.2.1/24
+}
+
+h2_create()
+{
+	simple_if_init $h2 192.0.2.2/24
+}
+
+h2_destroy()
+{
+	simple_if_fini $h2 192.0.2.2/24
+}
+
+switch_create()
+{
+	simple_if_init $swp1 192.0.2.2/24
+	tc qdisc add dev $swp1 clsact
+	simple_if_init $swp2 192.0.2.1/24
+}
+
+switch_destroy()
+{
+	simple_if_fini $swp2 192.0.2.1/24
+	tc qdisc del dev $swp1 clsact
+	simple_if_fini $swp1 192.0.2.2/24
+}
+
+setup_prepare()
+{
+	h1=${NETIFS[p1]}
+	swp1=${NETIFS[p2]}
+
+	swp2=${NETIFS[p3]}
+	h2=${NETIFS[p4]}
+
+	h1mac=$(mac_get $h1)
+	h2mac=$(mac_get $h2)
+
+	swp1origmac=$(mac_get $swp1)
+	swp2origmac=$(mac_get $swp2)
+	ip link set $swp1 address $h2mac
+	ip link set $swp2 address $h1mac
+
+	vrf_prepare
+
+	h1_create
+	h2_create
+	switch_create
+
+	if ! tc action add action tunnel_key help 2>&1 | grep -q nofrag; then
+		log_test "SKIP: iproute doesn't support nofrag"
+		exit $ksft_skip
+	fi
+}
+
+cleanup()
+{
+	pre_cleanup
+
+	switch_destroy
+	h2_destroy
+	h1_destroy
+
+	vrf_cleanup
+
+	ip link set $swp2 address $swp2origmac
+	ip link set $swp1 address $swp1origmac
+}
+
+tunnel_key_nofrag_test()
+{
+	RET=0
+	local i
+
+	tc filter add dev $swp1 ingress protocol ip pref 100 handle 100 \
+		flower ip_flags nofrag action drop
+	tc filter add dev $swp1 ingress protocol ip pref 101 handle 101 \
+		flower ip_flags firstfrag action drop
+	tc filter add dev $swp1 ingress protocol ip pref 102 handle 102 \
+		flower ip_flags nofirstfrag action drop
+
+	# test 'nofrag' set
+	tc filter add dev h1-et egress protocol all pref 1 handle 1 matchall $tcflags \
+		action tunnel_key set src_ip 192.0.2.1 dst_ip 192.0.2.2 id 42 nofrag index 10
+	$MZ h1-et -c 1 -p 930 -a 00:aa:bb:cc:dd:ee -b 00:ee:dd:cc:bb:aa -t ip -q
+	tc_check_packets "dev $swp1 ingress" 100 1
+	check_err $? "packet smaller than MTU was not tunneled"
+
+	$MZ h1-et -c 1 -p 931 -a 00:aa:bb:cc:dd:ee -b 00:ee:dd:cc:bb:aa -t ip -q
+	tc_check_packets "dev $swp1 ingress" 100 1
+	check_err $? "packet bigger than MTU matched nofrag (nofrag was set)"
+	tc_check_packets "dev $swp1 ingress" 101 0
+	check_err $? "packet bigger than MTU matched firstfrag (nofrag was set)"
+	tc_check_packets "dev $swp1 ingress" 102 0
+	check_err $? "packet bigger than MTU matched nofirstfrag (nofrag was set)"
+
+	# test 'nofrag' cleared
+	tc actions change action tunnel_key set src_ip 192.0.2.1 dst_ip 192.0.2.2 id 42 index 10
+	$MZ h1-et -c 1 -p 931 -a 00:aa:bb:cc:dd:ee -b 00:ee:dd:cc:bb:aa -t ip -q
+	tc_check_packets "dev $swp1  ingress" 100 1
+	check_err $? "packet bigger than MTU matched nofrag (nofrag was unset)"
+	tc_check_packets "dev $swp1  ingress" 101 1
+	check_err $? "packet bigger than MTU didn't match firstfrag (nofrag was unset) "
+	tc_check_packets "dev $swp1 ingress" 102 1
+	check_err $? "packet bigger than MTU didn't match nofirstfrag (nofrag was unset) "
+
+	for i in 100 101 102; do
+		tc filter del dev $swp1 ingress protocol ip pref $i handle $i flower
+	done
+	tc filter del dev h1-et egress pref 1 handle 1 matchall
+
+	log_test "tunnel_key nofrag ($tcflags)"
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+
+tests_run
+
+tc_offload_check
+if [[ $? -ne 0 ]]; then
+	log_info "Could not test offloaded functionality"
+else
+	tcflags="skip_sw"
+	tests_run
+fi
+
+exit $EXIT_STATUS