Add test case for multicast packet confirm race.
Without preceding patch, this should result in:
WARNING: CPU: 0 PID: 38 at net/netfilter/nf_conntrack_core.c:1198 __nf_conntrack_confirm+0x3ed/0x5f0
Workqueue: events_unbound macvlan_process_broadcast
RIP: 0010:__nf_conntrack_confirm+0x3ed/0x5f0
? __nf_conntrack_confirm+0x3ed/0x5f0
nf_confirm+0x2ad/0x2d0
nf_hook_slow+0x36/0xd0
ip_local_deliver+0xce/0x110
__netif_receive_skb_one_core+0x4f/0x70
process_backlog+0x8c/0x130
[..]
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
tools/testing/selftests/netfilter/Makefile | 3 +-
.../selftests/netfilter/bridge_netfilter.sh | 188 ++++++++++++++++++
2 files changed, 190 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/netfilter/bridge_netfilter.sh
diff --git a/tools/testing/selftests/netfilter/Makefile b/tools/testing/selftests/netfilter/Makefile
index db27153eb4a0..936c3085bb83 100644
--- a/tools/testing/selftests/netfilter/Makefile
+++ b/tools/testing/selftests/netfilter/Makefile
@@ -7,7 +7,8 @@ TEST_PROGS := nft_trans_stress.sh nft_fib.sh nft_nat.sh bridge_brouter.sh \
nft_queue.sh nft_meta.sh nf_nat_edemux.sh \
ipip-conntrack-mtu.sh conntrack_tcp_unreplied.sh \
conntrack_vrf.sh nft_synproxy.sh rpath.sh nft_audit.sh \
- conntrack_sctp_collision.sh xt_string.sh
+ conntrack_sctp_collision.sh xt_string.sh \
+ bridge_netfilter.sh
HOSTPKG_CONFIG := pkg-config
diff --git a/tools/testing/selftests/netfilter/bridge_netfilter.sh b/tools/testing/selftests/netfilter/bridge_netfilter.sh
new file mode 100644
index 000000000000..659b3ab02c8b
--- /dev/null
+++ b/tools/testing/selftests/netfilter/bridge_netfilter.sh
@@ -0,0 +1,188 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Test bridge netfilter + conntrack, a combination that doesn't really work,
+# with multicast/broadcast packets racing for hash table insertion.
+
+# eth0 br0 eth0
+# setup is: ns1 <->,ns0 <-> ns3
+# ns2 <-' `'-> ns4
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+ret=0
+
+sfx=$(mktemp -u "XXXXXXXX")
+ns0="ns0-$sfx"
+ns1="ns1-$sfx"
+ns2="ns2-$sfx"
+ns3="ns3-$sfx"
+ns4="ns4-$sfx"
+
+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
+
+for i in $(seq 0 4); do
+ eval ip netns add \$ns$i
+done
+
+cleanup() {
+ for i in $(seq 0 4); do eval ip netns del \$ns$i;done
+}
+
+trap cleanup EXIT
+
+do_ping()
+{
+ fromns="$1"
+ dstip="$2"
+
+ ip netns exec $fromns ping -c 1 -q $dstip > /dev/null
+ if [ $? -ne 0 ]; then
+ echo "ERROR: ping from $fromns to $dstip"
+ ip netns exec ${ns0} nft list ruleset
+ ret=1
+ fi
+}
+
+bcast_ping()
+{
+ fromns="$1"
+ dstip="$2"
+
+ for i in $(seq 1 1000); do
+ ip netns exec $fromns ping -q -f -b -c 1 -q $dstip > /dev/null 2>&1
+ if [ $? -ne 0 ]; then
+ echo "ERROR: ping -b from $fromns to $dstip"
+ ip netns exec ${ns0} nft list ruleset
+ fi
+ done
+}
+
+ip link add veth1 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 veth2 netns ${ns0} type veth peer name eth0 netns $ns2
+ip link add veth3 netns ${ns0} type veth peer name eth0 netns $ns3
+ip link add veth4 netns ${ns0} type veth peer name eth0 netns $ns4
+
+ip -net ${ns0} link set lo up
+
+for i in $(seq 1 4); do
+ ip -net ${ns0} link set veth$i up
+done
+
+ip -net ${ns0} link add br0 type bridge stp_state 0 forward_delay 0 nf_call_iptables 1 nf_call_ip6tables 1 nf_call_arptables 1
+if [ $? -ne 0 ]; then
+ echo "SKIP: Can't create bridge br0"
+ exit $ksft_skip
+fi
+
+# make veth0,1,2 part of bridge.
+for i in $(seq 1 3); do
+ ip -net ${ns0} link set veth$i master br0
+done
+
+# add a macvlan on top of the bridge.
+MACVLAN_ADDR=ba:f3:13:37:42:23
+ip -net ${ns0} link add link br0 name macvlan0 type macvlan mode private
+ip -net ${ns0} link set macvlan0 address ${MACVLAN_ADDR}
+ip -net ${ns0} link set macvlan0 up
+ip -net ${ns0} addr add 10.23.0.1/24 dev macvlan0
+
+# add a macvlan on top of veth4.
+MACVLAN_ADDR=ba:f3:13:37:42:24
+ip -net ${ns0} link add link veth4 name macvlan4 type macvlan mode vepa
+ip -net ${ns0} link set macvlan4 address ${MACVLAN_ADDR}
+ip -net ${ns0} link set macvlan4 up
+
+# make the macvlan part of the bridge.
+# veth4 is not a bridge port, only the macvlan on top of it.
+ip -net ${ns0} link set macvlan4 master br0
+
+ip -net ${ns0} link set br0 up
+ip -net ${ns0} addr add 10.0.0.1/24 dev br0
+ip netns exec ${ns0} sysctl -q net.bridge.bridge-nf-call-iptables=1
+ret=$?
+if [ $ret -ne 0 ] ; then
+ echo "SKIP: bridge netfilter not available"
+ ret=$ksft_skip
+fi
+
+# for testing, so namespaces will reply to ping -b probes.
+ip netns exec ${ns0} sysctl -q net.ipv4.icmp_echo_ignore_broadcasts=0
+
+# enable conntrack in ns0 and drop broadcast packets in forward to
+# avoid them from getting confirmed in the postrouting hook before
+# the cloned skb is passed up the stack.
+ip netns exec ${ns0} nft -f - <<EOF
+table ip filter {
+ chain input {
+ type filter hook input priority 1; policy accept
+ iifname br0 counter
+ ct state new accept
+ }
+}
+
+table bridge filter {
+ chain forward {
+ type filter hook forward priority 0; policy accept
+ meta pkttype broadcast ip protocol icmp counter drop
+ }
+}
+EOF
+
+# place 1, 2 & 3 in same subnet, connected via ns0:br0.
+# ns4 is placed in same subnet as well, but its not
+# part of the bridge: the corresponding veth4 is not
+# part of the bridge, only its macvlan interface.
+for i in $(seq 1 4); do
+ eval ip -net \$ns$i link set lo up
+ eval ip -net \$ns$i link set eth0 up
+done
+for i in $(seq 1 2); do
+ eval ip -net \$ns$i addr add 10.0.0.1$i/24 dev eth0
+done
+
+ip -net ${ns3} addr add 10.23.0.13/24 dev eth0
+ip -net ${ns4} addr add 10.23.0.14/24 dev eth0
+
+# test basic connectivity
+do_ping ${ns1} 10.0.0.12
+do_ping ${ns3} 10.23.0.1
+do_ping ${ns4} 10.23.0.1
+
+if [ $ret -eq 0 ];then
+ echo "PASS: netns connectivity: ns1 can reach ns2, ns3 and ns4 can reach ns0"
+fi
+
+bcast_ping ${ns1} 10.0.0.255
+
+# This should deliver broadcast to macvlan0, which is on top of ns0:br0.
+bcast_ping ${ns3} 10.23.0.255
+
+# same, this time via veth4:macvlan4.
+bcast_ping ${ns4} 10.23.0.255
+
+read t < /proc/sys/kernel/tainted
+
+if [ $t -eq 0 ];then
+ echo PASS: kernel not tainted
+else
+ echo ERROR: kernel is tainted
+ ret=1
+fi
+
+exit $ret
--
2.43.0
