[Patch net v2 2/2] selftests: add a test case for rp filter

[Cong Wang <xiyou.wangcong@gmail.com>]

Add a test case to simulate the loopback packet case fixed
in the previous patch.

This test gets passed after the fix:

IPv4 rp_filter tests
    TEST: rp_filter passes local packets                                [ OK ]
    TEST: rp_filter passes loopback packets                             [ OK ]

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
 tools/testing/selftests/net/fib_tests.sh | 30 +++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/fib_tests.sh b/tools/testing/selftests/net/fib_tests.sh
index 9457aaeae092..a9e45471edfe 100755
--- a/tools/testing/selftests/net/fib_tests.sh
+++ b/tools/testing/selftests/net/fib_tests.sh
@@ -9,12 +9,13 @@ ret=0
 ksft_skip=4
 
 # all tests in this script. Can be overridden with -t option
-TESTS="unregister down carrier nexthop ipv6_rt ipv4_rt ipv6_addr_metric ipv4_addr_metric ipv6_route_metrics ipv4_route_metrics ipv4_route_v6_gw"
+TESTS="unregister down carrier nexthop ipv6_rt ipv4_rt ipv6_addr_metric ipv4_addr_metric ipv6_route_metrics ipv4_route_metrics ipv4_route_v6_gw rp_filter"
 
 VERBOSE=0
 PAUSE_ON_FAIL=no
 PAUSE=no
 IP="ip -netns ns1"
+NETNS="ip netns exec ns1"
 
 log_test()
 {
@@ -433,6 +434,32 @@ fib_carrier_test()
 	fib_carrier_unicast_test
 }
 
+fib_rp_filter_test()
+{
+	echo
+	echo "IPv4 rp_filter tests"
+
+	setup
+
+	$IP link set dev lo address 52:54:00:6a:c7:5e
+	$IP link set dev dummy0 address 52:54:00:6a:c7:5e
+	echo 1 | $NETNS tee /proc/sys/net/ipv4/conf/all/rp_filter > /dev/null
+	echo 1 | $NETNS tee /proc/sys/net/ipv4/conf/all/accept_local > /dev/null
+	echo 1 | $NETNS tee /proc/sys/net/ipv4/conf/all/route_localnet > /dev/null
+
+	$NETNS tc qd add dev dummy0 parent root handle 1: fq_codel
+	$NETNS tc filter add dev dummy0 parent 1: protocol arp basic action mirred egress redirect dev lo
+	$NETNS tc filter add dev dummy0 parent 1: protocol ip basic action mirred egress redirect dev lo
+
+	run_cmd "ip netns exec ns1 ping -I dummy0 -w1 -c1 198.51.100.1"
+	log_test $? 0 "rp_filter passes local packets"
+
+	run_cmd "ip netns exec ns1 ping -I dummy0 -w1 -c1 127.0.0.1"
+	log_test $? 0 "rp_filter passes loopback packets"
+
+	cleanup
+}
+
 ################################################################################
 # Tests on nexthop spec
 
@@ -1557,6 +1584,7 @@ do
 	fib_unreg_test|unregister)	fib_unreg_test;;
 	fib_down_test|down)		fib_down_test;;
 	fib_carrier_test|carrier)	fib_carrier_test;;
+	fib_rp_filter_test|rp_filter)	fib_rp_filter_test;;
 	fib_nexthop_test|nexthop)	fib_nexthop_test;;
 	ipv6_route_test|ipv6_rt)	ipv6_route_test;;
 	ipv4_route_test|ipv4_rt)	ipv4_route_test;;
-- 
2.21.0