selftests: forwarding: Add reverse path forwarding (RPF) test cases

In case a packet is routed using a multicast route whose specified
ingress interface does not match the interface from which the packet was
received, the packet is dropped.

Add IPv4 and IPv6 test cases for above mentioned scenario.

Signed-off-by: Ido Schimmel <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

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

···
 # +------------------+       +------------------+
 #
 
-ALL_TESTS="mcast_v4 mcast_v6"
+ALL_TESTS="mcast_v4 mcast_v6 rpf_v4 rpf_v6"
 NUM_NETIFS=6
 source lib.sh
 source tc_common.sh
···
 
 	ip route add 2001:db8:2::/64 vrf v$h1 nexthop via 2001:db8:1::1
 	ip route add 2001:db8:3::/64 vrf v$h1 nexthop via 2001:db8:1::1
+
+	tc qdisc add dev $h1 ingress
 }
 
 h1_destroy()
 {
+	tc qdisc del dev $h1 ingress
+
 	ip route del 2001:db8:3::/64 vrf v$h1
 	ip route del 2001:db8:2::/64 vrf v$h1
 
···
 	ip address add 2001:db8:1::1/64 dev $rp1
 	ip address add 2001:db8:2::1/64 dev $rp2
 	ip address add 2001:db8:3::1/64 dev $rp3
+
+	tc qdisc add dev $rp3 ingress
 }
 
 router_destroy()
 {
+	tc qdisc del dev $rp3 ingress
+
 	ip address del 2001:db8:3::1/64 dev $rp3
 	ip address del 2001:db8:2::1/64 dev $rp2
 	ip address del 2001:db8:1::1/64 dev $rp1
···
 	tc filter del dev $h2 ingress protocol ipv6 pref 1 handle 122 flower
 
 	log_test "mcast IPv6"
+}
+
+rpf_v4()
+{
+	# Add a multicast route from first router port to the other two. Send
+	# matching packets and test that both hosts receive them. Then, send
+	# the same packets via the third router port and test that they do not
+	# reach any host due to RPF check. A filter with 'skip_hw' is added to
+	# test that devices capable of multicast routing offload trap those
+	# packets. The filter is essentialy a NOP in other scenarios.
+
+	RET=0
+
+	tc filter add dev $h1 ingress protocol ip pref 1 handle 1 flower \
+		dst_ip 225.1.2.3 ip_proto udp dst_port 12345 action drop
+	tc filter add dev $h2 ingress protocol ip pref 1 handle 1 flower \
+		dst_ip 225.1.2.3 ip_proto udp dst_port 12345 action drop
+	tc filter add dev $h3 ingress protocol ip pref 1 handle 1 flower \
+		dst_ip 225.1.2.3 ip_proto udp dst_port 12345 action drop
+	tc filter add dev $rp3 ingress protocol ip pref 1 handle 1 flower \
+		skip_hw dst_ip 225.1.2.3 ip_proto udp dst_port 12345 action pass
+
+	create_mcast_sg $rp1 198.51.100.2 225.1.2.3 $rp2 $rp3
+
+	$MZ $h1 -c 5 -p 128 -t udp "ttl=10,sp=54321,dp=12345" \
+		-a 00:11:22:33:44:55 -b 01:00:5e:01:02:03 \
+		-A 198.51.100.2 -B 225.1.2.3 -q
+
+	tc_check_packets "dev $h2 ingress" 1 5
+	check_err $? "Multicast not received on first host"
+	tc_check_packets "dev $h3 ingress" 1 5
+	check_err $? "Multicast not received on second host"
+
+	$MZ $h3 -c 5 -p 128 -t udp "ttl=10,sp=54321,dp=12345" \
+		-a 00:11:22:33:44:55 -b 01:00:5e:01:02:03 \
+		-A 198.51.100.2 -B 225.1.2.3 -q
+
+	tc_check_packets "dev $h1 ingress" 1 0
+	check_err $? "Multicast received on first host when should not"
+	tc_check_packets "dev $h2 ingress" 1 5
+	check_err $? "Multicast received on second host when should not"
+	tc_check_packets "dev $rp3 ingress" 1 5
+	check_err $? "Packets not trapped due to RPF check"
+
+	delete_mcast_sg $rp1 198.51.100.2 225.1.2.3 $rp2 $rp3
+
+	tc filter del dev $rp3 ingress protocol ip pref 1 handle 1 flower
+	tc filter del dev $h3 ingress protocol ip pref 1 handle 1 flower
+	tc filter del dev $h2 ingress protocol ip pref 1 handle 1 flower
+	tc filter del dev $h1 ingress protocol ip pref 1 handle 1 flower
+
+	log_test "RPF IPv4"
+}
+
+rpf_v6()
+{
+	RET=0
+
+	tc filter add dev $h1 ingress protocol ipv6 pref 1 handle 1 flower \
+		dst_ip ff0e::3 ip_proto udp dst_port 12345 action drop
+	tc filter add dev $h2 ingress protocol ipv6 pref 1 handle 1 flower \
+		dst_ip ff0e::3 ip_proto udp dst_port 12345 action drop
+	tc filter add dev $h3 ingress protocol ipv6 pref 1 handle 1 flower \
+		dst_ip ff0e::3 ip_proto udp dst_port 12345 action drop
+	tc filter add dev $rp3 ingress protocol ipv6 pref 1 handle 1 flower \
+		skip_hw dst_ip ff0e::3 ip_proto udp dst_port 12345 action pass
+
+	create_mcast_sg $rp1 2001:db8:1::2 ff0e::3 $rp2 $rp3
+
+	$MZ $h1 -6 -c 5 -p 128 -t udp "ttl=10,sp=54321,dp=12345" \
+		-a 00:11:22:33:44:55 -b 33:33:00:00:00:03 \
+		-A 2001:db8:1::2 -B ff0e::3 -q
+
+	tc_check_packets "dev $h2 ingress" 1 5
+	check_err $? "Multicast not received on first host"
+	tc_check_packets "dev $h3 ingress" 1 5
+	check_err $? "Multicast not received on second host"
+
+	$MZ $h3 -6 -c 5 -p 128 -t udp "ttl=10,sp=54321,dp=12345" \
+		-a 00:11:22:33:44:55 -b 33:33:00:00:00:03 \
+		-A 2001:db8:1::2 -B ff0e::3 -q
+
+	tc_check_packets "dev $h1 ingress" 1 0
+	check_err $? "Multicast received on first host when should not"
+	tc_check_packets "dev $h2 ingress" 1 5
+	check_err $? "Multicast received on second host when should not"
+	tc_check_packets "dev $rp3 ingress" 1 5
+	check_err $? "Packets not trapped due to RPF check"
+
+	delete_mcast_sg $rp1 2001:db8:1::2 ff0e::3 $rp2 $rp3
+
+	tc filter del dev $rp3 ingress protocol ipv6 pref 1 handle 1 flower
+	tc filter del dev $h3 ingress protocol ipv6 pref 1 handle 1 flower
+	tc filter del dev $h2 ingress protocol ipv6 pref 1 handle 1 flower
+	tc filter del dev $h1 ingress protocol ipv6 pref 1 handle 1 flower
+
+	log_test "RPF IPv6"
 }
 
 trap cleanup EXIT