selftests: netfilter: add ebtables broute test case

# SPDX-License-Identifier: GPL-2.0

# Makefile for netfilter selftests

TEST_PROGS := nft_trans_stress.sh nft_nat.sh

TEST_PROGS := nft_trans_stress.sh nft_nat.sh bridge_brouter.sh

include ../lib.mk

#!/bin/bash

#

# This test is for bridge 'brouting', i.e. make some packets being routed

# rather than getting bridged even though they arrive on interface that is

# part of a bridge.

#           eth0    br0     eth0

# setup is: ns1 <-> ns0 <-> ns2

# Kselftest framework requirement - SKIP code is 4.

ksft_skip=4

ret=0

ebtables -V > /dev/null 2>&1

if [ $? -ne 0 ];then

	echo "SKIP: Could not run test without ebtables"

	exit $ksft_skip

fi

ip -Version > /dev/null 2>&1

if [ $? -ne 0 ];then

	echo "SKIP: Could not run test without ip tool"

	exit $ksft_skip

fi

ip netns add ns0

ip netns add ns1

ip netns add ns2

ip link add veth0 netns ns0 type veth peer name eth0 netns ns1

if [ $? -ne 0 ]; then

	echo "SKIP: Can't create veth device"

	exit $ksft_skip

fi

ip link add veth1 netns ns0 type veth peer name eth0 netns ns2

ip -net ns0 link set lo up

ip -net ns0 link set veth0 up

ip -net ns0 link set veth1 up

ip -net ns0 link add br0 type bridge

if [ $? -ne 0 ]; then

	echo "SKIP: Can't create bridge br0"

	exit $ksft_skip

fi

ip -net ns0 link set veth0 master br0

ip -net ns0 link set veth1 master br0

ip -net ns0 link set br0 up

ip -net ns0 addr add 10.0.0.1/24 dev br0

# place both in same subnet, ns1 and ns2 connected via ns0:br0

for i in 1 2; do

  ip -net ns$i link set lo up

  ip -net ns$i link set eth0 up

  ip -net ns$i addr add 10.0.0.1$i/24 dev eth0

done

test_ebtables_broute()

{

	local cipt

	# redirect is needed so the dstmac is rewritten to the bridge itself,

	# ip stack won't process OTHERHOST (foreign unicast mac) packets.

	ip netns exec ns0 ebtables -t broute -A BROUTING -p ipv4 --ip-protocol icmp -j redirect --redirect-target=DROP

	if [ $? -ne 0 ]; then

		echo "SKIP: Could not add ebtables broute redirect rule"

		return $ksft_skip

	fi

	# ping netns1, expected to not work (ip forwarding is off)

	ip netns exec ns1 ping -q -c 1 10.0.0.12 > /dev/null 2>&1

	if [ $? -eq 0 ]; then

		echo "ERROR: ping works, should have failed" 1>&2

		return 1

	fi

	# enable forwarding on both interfaces.

	# neither needs an ip address, but at least the bridge needs

	# an ip address in same network segment as ns1 and ns2 (ns0

	# needs to be able to determine route for to-be-forwarded packet).

	ip netns exec ns0 sysctl -q net.ipv4.conf.veth0.forwarding=1

	ip netns exec ns0 sysctl -q net.ipv4.conf.veth1.forwarding=1

	sleep 1

	ip netns exec ns1 ping -q -c 1 10.0.0.12 > /dev/null

	if [ $? -ne 0 ]; then

		echo "ERROR: ping did not work, but it should (broute+forward)" 1>&2

		return 1

	fi

	echo "PASS: ns1/ns2 connectivity with active broute rule"

	ip netns exec ns0 ebtables -t broute -F

	# ping netns1, expected to work (frames are bridged)

	ip netns exec ns1 ping -q -c 1 10.0.0.12 > /dev/null

	if [ $? -ne 0 ]; then

		echo "ERROR: ping did not work, but it should (bridged)" 1>&2

		return 1

	fi

	ip netns exec ns0 ebtables -t filter -A FORWARD -p ipv4 --ip-protocol icmp -j DROP

	# ping netns1, expected to not work (DROP in bridge forward)

	ip netns exec ns1 ping -q -c 1 10.0.0.12 > /dev/null 2>&1

	if [ $? -eq 0 ]; then

		echo "ERROR: ping works, should have failed (icmp forward drop)" 1>&2

		return 1

	fi

	# re-activate brouter

	ip netns exec ns0 ebtables -t broute -A BROUTING -p ipv4 --ip-protocol icmp -j redirect --redirect-target=DROP

	ip netns exec ns2 ping -q -c 1 10.0.0.11 > /dev/null

	if [ $? -ne 0 ]; then

		echo "ERROR: ping did not work, but it should (broute+forward 2)" 1>&2

		return 1

	fi

	echo "PASS: ns1/ns2 connectivity with active broute rule and bridge forward drop"

	return 0

}

# test basic connectivity

ip netns exec ns1 ping -c 1 -q 10.0.0.12 > /dev/null

if [ $? -ne 0 ]; then

    echo "ERROR: Could not reach ns2 from ns1" 1>&2

    ret=1

fi

ip netns exec ns2 ping -c 1 -q 10.0.0.11 > /dev/null

if [ $? -ne 0 ]; then

    echo "ERROR: Could not reach ns1 from ns2" 1>&2

    ret=1

fi

if [ $ret -eq 0 ];then

    echo "PASS: netns connectivity: ns1 and ns2 can reach each other"

fi

test_ebtables_broute

ret=$?

for i in 0 1 2; do ip netns del ns$i;done

exit $ret