xref: /linux/tools/testing/selftests/net/netfilter/bridge_brouter.sh (revision ab93e0dd72c37d378dd936f031ffb83ff2bd87ce)
1#!/bin/bash
2#
3# This test is for bridge 'brouting', i.e. make some packets being routed
4# rather than getting bridged even though they arrive on interface that is
5# part of a bridge.
6
7#           eth0    br0     eth0
8# setup is: ns1 <-> nsbr <-> ns2
9
10source lib.sh
11
12if ! ebtables -V > /dev/null 2>&1;then
13	echo "SKIP: Could not run test without ebtables"
14	exit $ksft_skip
15fi
16
17cleanup() {
18	cleanup_all_ns
19}
20
21trap cleanup EXIT
22
23setup_ns nsbr ns1 ns2
24
25if ! ip link add veth0 netns "$nsbr" type veth peer name eth0 netns "$ns1"; then
26	echo "SKIP: Can't create veth device"
27	exit $ksft_skip
28fi
29ip link add veth1 netns "$nsbr" type veth peer name eth0 netns "$ns2"
30
31if ! ip -net "$nsbr" link add br0 type bridge; then
32	echo "SKIP: Can't create bridge br0"
33	exit $ksft_skip
34fi
35
36ip -net "$nsbr" link set veth0 up
37ip -net "$nsbr" link set veth1 up
38
39ip -net "$nsbr" link set veth0 master br0
40ip -net "$nsbr" link set veth1 master br0
41ip -net "$nsbr" link set br0 up
42ip -net "$nsbr" addr add 10.0.0.1/24 dev br0
43
44# place both in same subnet, ${ns1} and ${ns2} connected via ${nsbr}:br0
45ip -net "$ns1" link set eth0 up
46ip -net "$ns2" link set eth0 up
47ip -net "$ns1" addr add 10.0.0.11/24 dev eth0
48ip -net "$ns2" addr add 10.0.0.12/24 dev eth0
49
50test_ebtables_broute()
51{
52	# redirect is needed so the dstmac is rewritten to the bridge itself,
53	# ip stack won't process OTHERHOST (foreign unicast mac) packets.
54	if ! ip netns exec "$nsbr" ebtables -t broute -A BROUTING -p ipv4 --ip-protocol icmp -j redirect --redirect-target=DROP; then
55		echo "SKIP: Could not add ebtables broute redirect rule"
56		return $ksft_skip
57	fi
58
59	ip netns exec "$nsbr" sysctl -q net.ipv4.conf.veth0.forwarding=0
60
61	# ping net${ns1}, expected to not work (ip forwarding is off)
62	if ip netns exec "$ns1" ping -q -c 1 10.0.0.12 -W 0.5 > /dev/null 2>&1; then
63		echo "ERROR: ping works, should have failed" 1>&2
64		return 1
65	fi
66
67	# enable forwarding on both interfaces.
68	# neither needs an ip address, but at least the bridge needs
69	# an ip address in same network segment as ${ns1} and ${ns2} (${nsbr}
70	# needs to be able to determine route for to-be-forwarded packet).
71	ip netns exec "$nsbr" sysctl -q net.ipv4.conf.veth0.forwarding=1
72	ip netns exec "$nsbr" sysctl -q net.ipv4.conf.veth1.forwarding=1
73
74	if ! ip netns exec "$ns1" ping -q -c 1 10.0.0.12 > /dev/null; then
75		echo "ERROR: ping did not work, but it should (broute+forward)" 1>&2
76		return 1
77	fi
78
79	echo "PASS: ${ns1}/${ns2} connectivity with active broute rule"
80	ip netns exec "$nsbr" ebtables -t broute -F
81
82	# ping net${ns1}, expected to work (frames are bridged)
83	if ! ip netns exec "$ns1" ping -q -c 1 10.0.0.12 > /dev/null; then
84		echo "ERROR: ping did not work, but it should (bridged)" 1>&2
85		return 1
86	fi
87
88	ip netns exec "$nsbr" ebtables -t filter -A FORWARD -p ipv4 --ip-protocol icmp -j DROP
89
90	# ping net${ns1}, expected to not work (DROP in bridge forward)
91	if ip netns exec "$ns1" ping -q -c 1 10.0.0.12 -W 0.5 > /dev/null 2>&1; then
92		echo "ERROR: ping works, should have failed (icmp forward drop)" 1>&2
93		return 1
94	fi
95
96	# re-activate brouter
97	ip netns exec "$nsbr" ebtables -t broute -A BROUTING -p ipv4 --ip-protocol icmp -j redirect --redirect-target=DROP
98
99	if ! ip netns exec "$ns2" ping -q -c 1 10.0.0.11 > /dev/null; then
100		echo "ERROR: ping did not work, but it should (broute+forward 2)" 1>&2
101		return 1
102	fi
103
104	echo "PASS: ${ns1}/${ns2} connectivity with active broute rule and bridge forward drop"
105	return 0
106}
107
108# test basic connectivity
109if ! ip netns exec "$ns1" ping -c 1 -q 10.0.0.12 > /dev/null; then
110    echo "ERROR: Could not reach ${ns2} from ${ns1}" 1>&2
111    exit 1
112fi
113
114if ! ip netns exec "$ns2" ping -c 1 -q 10.0.0.11 > /dev/null; then
115    echo "ERROR: Could not reach ${ns1} from ${ns2}" 1>&2
116    exit 1
117fi
118
119test_ebtables_broute
120exit $?
121