There is a bug report on netfilter.org bugzilla pointing to fib
expression dropping ipv6 DAD packets.
Add a test case that demonstrates this problem.
Next patch excludes icmpv6 packets coming from any to linklocal.
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
tools/testing/selftests/netfilter/Makefile | 2 +-
tools/testing/selftests/netfilter/nft_fib.sh | 221 +++++++++++++++++++
2 files changed, 222 insertions(+), 1 deletion(-)
create mode 100755 tools/testing/selftests/netfilter/nft_fib.sh
diff --git a/tools/testing/selftests/netfilter/Makefile b/tools/testing/selftests/netfilter/Makefile
index 3171069a6b46..cd6430b39982 100644
--- a/tools/testing/selftests/netfilter/Makefile
+++ b/tools/testing/selftests/netfilter/Makefile
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
# Makefile for netfilter selftests
-TEST_PROGS := nft_trans_stress.sh nft_nat.sh bridge_brouter.sh \
+TEST_PROGS := nft_trans_stress.sh nft_fib.sh nft_nat.sh bridge_brouter.sh \
conntrack_icmp_related.sh nft_flowtable.sh ipvs.sh \
nft_concat_range.sh nft_conntrack_helper.sh \
nft_queue.sh nft_meta.sh nf_nat_edemux.sh \
diff --git a/tools/testing/selftests/netfilter/nft_fib.sh b/tools/testing/selftests/netfilter/nft_fib.sh
new file mode 100755
index 000000000000..6caf6ac8c285
--- /dev/null
+++ b/tools/testing/selftests/netfilter/nft_fib.sh
@@ -0,0 +1,221 @@
+#!/bin/bash
+#
+# This tests the fib expression.
+#
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+ret=0
+
+sfx=$(mktemp -u "XXXXXXXX")
+ns1="ns1-$sfx"
+ns2="ns2-$sfx"
+nsrouter="nsrouter-$sfx"
+timeout=4
+
+log_netns=$(sysctl -n net.netfilter.nf_log_all_netns)
+
+cleanup()
+{
+ ip netns del ${ns1}
+ ip netns del ${ns2}
+ ip netns del ${nsrouter}
+
+ [ $log_netns -eq 0 ] && sysctl -q net.netfilter.nf_log_all_netns=$log_netns
+}
+
+nft --version > /dev/null 2>&1
+if [ $? -ne 0 ];then
+ echo "SKIP: Could not run test without nft tool"
+ 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 ${nsrouter}
+if [ $? -ne 0 ];then
+ echo "SKIP: Could not create net namespace"
+ exit $ksft_skip
+fi
+
+trap cleanup EXIT
+
+dmesg | grep -q ' nft_rpfilter: '
+if [ $? -eq 0 ]; then
+ dmesg -c | grep ' nft_rpfilter: '
+ echo "WARN: a previous test run has failed" 1>&2
+fi
+
+sysctl -q net.netfilter.nf_log_all_netns=1
+ip netns add ${ns1}
+ip netns add ${ns2}
+
+load_ruleset() {
+ local netns=$1
+
+ip netns exec ${netns} nft -f /dev/stdin <<EOF
+table inet filter {
+ chain prerouting {
+ type filter hook prerouting priority 0; policy accept;
+ fib saddr . iif oif missing counter log prefix "$netns nft_rpfilter: " drop
+ }
+}
+EOF
+}
+
+load_ruleset_count() {
+ local netns=$1
+
+ip netns exec ${netns} nft -f /dev/stdin <<EOF
+table inet filter {
+ chain prerouting {
+ type filter hook prerouting priority 0; policy accept;
+ ip daddr 1.1.1.1 fib saddr . iif oif missing counter drop
+ ip6 daddr 1c3::c01d fib saddr . iif oif missing counter drop
+ }
+}
+EOF
+}
+
+check_drops() {
+ dmesg | grep -q ' nft_rpfilter: '
+ if [ $? -eq 0 ]; then
+ dmesg | grep ' nft_rpfilter: '
+ echo "FAIL: rpfilter did drop packets"
+ return 1
+ fi
+
+ return 0
+}
+
+check_fib_counter() {
+ local want=$1
+ local ns=$2
+ local address=$3
+
+ line=$(ip netns exec ${ns} nft list table inet filter | grep 'fib saddr . iif' | grep $address | grep "packets $want" )
+ ret=$?
+
+ if [ $ret -ne 0 ];then
+ echo "Netns $ns fib counter doesn't match expected packet count of $want for $address" 1>&2
+ ip netns exec ${ns} nft list table inet filter
+ return 1
+ fi
+
+ if [ $want -gt 0 ]; then
+ echo "PASS: fib expression did drop packets for $address"
+ fi
+
+ return 0
+}
+
+load_ruleset ${nsrouter}
+load_ruleset ${ns1}
+load_ruleset ${ns2}
+
+ip link add veth0 netns ${nsrouter} type veth peer name eth0 netns ${ns1} > /dev/null 2>&1
+if [ $? -ne 0 ];then
+ echo "SKIP: No virtual ethernet pair device support in kernel"
+ exit $ksft_skip
+fi
+ip link add veth1 netns ${nsrouter} type veth peer name eth0 netns ${ns2}
+
+ip -net ${nsrouter} link set lo up
+ip -net ${nsrouter} link set veth0 up
+ip -net ${nsrouter} addr add 10.0.1.1/24 dev veth0
+ip -net ${nsrouter} addr add dead:1::1/64 dev veth0
+
+ip -net ${nsrouter} link set veth1 up
+ip -net ${nsrouter} addr add 10.0.2.1/24 dev veth1
+ip -net ${nsrouter} addr add dead:2::1/64 dev veth1
+
+ip -net ${ns1} link set lo up
+ip -net ${ns1} link set eth0 up
+
+ip -net ${ns2} link set lo up
+ip -net ${ns2} link set eth0 up
+
+ip -net ${ns1} addr add 10.0.1.99/24 dev eth0
+ip -net ${ns1} addr add dead:1::99/64 dev eth0
+ip -net ${ns1} route add default via 10.0.1.1
+ip -net ${ns1} route add default via dead:1::1
+
+ip -net ${ns2} addr add 10.0.2.99/24 dev eth0
+ip -net ${ns2} addr add dead:2::99/64 dev eth0
+ip -net ${ns2} route add default via 10.0.2.1
+ip -net ${ns2} route add default via dead:2::1
+
+test_ping() {
+ local daddr4=$1
+ local daddr6=$2
+
+ ip netns exec ${ns1} ping -c 1 -q $daddr4 > /dev/null
+ ret=$?
+ if [ $ret -ne 0 ];then
+ check_drops
+ echo "FAIL: ${ns1} cannot reach $daddr4, ret $ret" 1>&2
+ return 1
+ fi
+
+ ip netns exec ${ns1} ping -c 3 -q $daddr6 > /dev/null
+ ret=$?
+ if [ $ret -ne 0 ];then
+ check_drops
+ echo "FAIL: ${ns1} cannot reach $daddr6, ret $ret" 1>&2
+ return 1
+ fi
+
+ return 0
+}
+
+ip netns exec ${nsrouter} sysctl net.ipv6.conf.all.forwarding=1 > /dev/null
+ip netns exec ${nsrouter} sysctl net.ipv4.conf.veth0.forwarding=1 > /dev/null
+ip netns exec ${nsrouter} sysctl net.ipv4.conf.veth1.forwarding=1 > /dev/null
+
+sleep 3
+
+test_ping 10.0.2.1 dead:2::1 || exit 1
+check_drops || exit 1
+
+test_ping 10.0.2.99 dead:2::99 || exit 1
+check_drops || exit 1
+
+echo "PASS: fib expression did not cause unwanted packet drops"
+
+ip netns exec ${nsrouter} nft flush table inet filter
+
+ip -net ${ns1} route del default
+ip -net ${ns1} -6 route del default
+
+ip -net ${ns1} addr del 10.0.1.99/24 dev eth0
+ip -net ${ns1} addr del dead:1::99/64 dev eth0
+
+ip -net ${ns1} addr add 10.0.2.99/24 dev eth0
+ip -net ${ns1} addr add dead:2::99/64 dev eth0
+
+ip -net ${ns1} route add default via 10.0.2.1
+ip -net ${ns1} -6 route add default via dead:2::1
+
+ip -net ${nsrouter} addr add dead:2::1/64 dev veth0
+
+# switch to ruleset that doesn't log, this time
+# its expected that this does drop the packets.
+load_ruleset_count ${nsrouter}
+
+# ns1 has a default route, but nsrouter does not.
+# must not check return value, ping to 1.1.1.1 will
+# fail.
+check_fib_counter 0 ${nsrouter} 1.1.1.1 || exit 1
+check_fib_counter 0 ${nsrouter} 1c3::c01d || exit 1
+
+ip netns exec ${ns1} ping -c 1 -W 1 -q 1.1.1.1 > /dev/null
+check_fib_counter 1 ${nsrouter} 1.1.1.1 || exit 1
+
+sleep 2
+ip netns exec ${ns1} ping -c 3 -q 1c3::c01d > /dev/null
+check_fib_counter 3 ${nsrouter} 1c3::c01d || exit 1
+
+exit 0
--
2.31.1
