bridge_brouter.sh

  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 $?