selftests: forwarding: router: Add test case for source IP equals destination IP

Add test case to check that packets are not dropped when they need to be
routed and their source IP equals to their destination IP.
Signed-off-by: NAmit Cohen <amitc@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

@@ -6,6 +6,8 @@ ALL_TESTS="
 	ping_ipv6
 	sip_in_class_e
 	mc_mac_mismatch
+	ipv4_sip_equal_dip
+	ipv6_sip_equal_dip
 "
 
 NUM_NETIFS=4
@@ -243,6 +245,48 @@ mc_mac_mismatch()
 	__mc_mac_mismatch "IPv6" "ipv6" 2001:db8:1::2 ff0e::3 "-6"
 }
 
+ipv4_sip_equal_dip()
+{
+	RET=0
+
+	# Disable rpfilter to prevent packets to be dropped because of it.
+	sysctl_set net.ipv4.conf.all.rp_filter 0
+	sysctl_set net.ipv4.conf.$rp1.rp_filter 0
+
+	tc filter add dev $rp2 egress protocol ip pref 1 handle 101 \
+		flower src_ip 198.51.100.2  action pass
+
+	$MZ $h1 -t udp "sp=54321,dp=12345" -c 5 -d 1msec \
+		-A 198.51.100.2 -b $rp1mac -B 198.51.100.2 -q
+
+	tc_check_packets "dev $rp2 egress" 101 5
+	check_err $? "Packets were dropped"
+
+	log_test "Source IP is equal to destination IP: IPv4"
+
+	tc filter del dev $rp2 egress protocol ip pref 1 handle 101 flower
+	sysctl_restore net.ipv4.conf.$rp1.rp_filter
+	sysctl_restore net.ipv4.conf.all.rp_filter
+}
+
+ipv6_sip_equal_dip()
+{
+	RET=0
+
+	tc filter add dev $rp2 egress protocol ipv6 pref 1 handle 101 \
+		flower src_ip 2001:db8:2::2 action pass
+
+	$MZ -6 $h1 -t udp "sp=54321,dp=12345" -c 5 -d 1msec \
+		-A 2001:db8:2::2 -b $rp1mac -B 2001:db8:2::2 -q
+
+	tc_check_packets "dev $rp2 egress" 101 5
+	check_err $? "Packets were dropped"
+
+	log_test "Source IP is equal to destination IP: IPv6"
+
+	tc filter del dev $rp2 egress protocol ipv6 pref 1 handle 101 flower
+}
+
 trap cleanup EXIT
 
 setup_prepare