pf tests: Basic IPv6 forwarding tests

Pass/block packets in the forwarding path with pf.

Introduce the pft_set_rules() helper function, because we need to
remember to flush states between individual tests. If not we can get
packets passing despite rules blocking them because they match states
created in a previous test.

Extend pft_ping.py to be able to send IPv6 echo requests.

tests/sys/netpfil/pf/forward.sh

@@ -61,7 +61,87 @@ v4_cleanup()
 	pft_cleanup
 }
 
+atf_test_case "v6" "cleanup"
+v6_head()
+{
+	atf_set descr 'Basic IPv6 forwarding test'
+	atf_set require.user root
+	atf_set require.progs scapy
+}
+
+v6_body()
+{
+	pft_init
+
+	epair_send=$(pft_mkepair)
+	epair_recv=$(pft_mkepair)
+
+	ifconfig ${epair_send}a inet6 2001:db8:42::1/64 up no_dad -ifdisabled
+	ifconfig ${epair_recv}a up
+
+	pft_mkjail alcatraz ${epair_send}b ${epair_recv}b
+
+	jexec alcatraz ifconfig ${epair_send}b inet6 2001:db8:42::2/64 up no_dad
+	jexec alcatraz ifconfig ${epair_recv}b inet6 2001:db8:43::2/64 up no_dad
+	jexec alcatraz sysctl net.inet6.ip6.forwarding=1
+	jexec alcatraz ndp -s 2001:db8:43::3 00:01:02:03:04:05
+	route add -6 2001:db8:43::/64 2001:db8:42::2
+
+	# Sanity check, can we forward ICMP echo requests without pf?
+	atf_check -s exit:0 $(atf_get_srcdir)/pft_ping.py \
+		--ip6 \
+		--sendif ${epair_send}a \
+		--to 2001:db8:43::3 \
+		--recvif ${epair_recv}a
+
+	jexec alcatraz pfctl -e
+
+	# Block incoming echo request packets
+	pft_set_rules alcatraz \
+		"block in inet6 proto icmp6 icmp6-type echoreq"
+	atf_check -s exit:1 $(atf_get_srcdir)/pft_ping.py \
+		--ip6 \
+		--sendif ${epair_send}a \
+		--to 2001:db8:43::3 \
+		--recvif ${epair_recv}a
+
+	# Block outgoing echo request packets
+	pft_set_rules alcatraz \
+		"block out inet6 proto icmp6 icmp6-type echoreq"
+	atf_check -s exit:1 -e ignore $(atf_get_srcdir)/pft_ping.py \
+		--ip6 \
+		--sendif ${epair_send}a \
+		--to 2001:db8:43::3 \
+		--recvif ${epair_recv}a
+
+	# Allow ICMPv6 but nothing else
+	pft_set_rules alcatraz \
+		"block out" \
+		"pass out inet6 proto icmp6"
+	atf_check -s exit:0 $(atf_get_srcdir)/pft_ping.py \
+		--ip6 \
+		--sendif ${epair_send}a \
+		--to 2001:db8:43::3 \
+		--recvif ${epair_recv}a
+
+	# Allowing ICMPv4 does not allow ICMPv6
+	pft_set_rules alcatraz \
+		"block out inet6 proto icmp6 icmp6-type echoreq" \
+		"pass in proto icmp"
+	atf_check -s exit:1 $(atf_get_srcdir)/pft_ping.py \
+		--ip6 \
+		--sendif ${epair_send}a \
+		--to 2001:db8:43::3 \
+		--recvif ${epair_recv}a
+}
+
+v6_cleanup()
+{
+	pft_cleanup
+}
+
 atf_init_test_cases()
 {
 	atf_add_test_case "v4"
+	atf_add_test_case "v6"
 }

tests/sys/netpfil/pf/pft_ping.py

@@ -19,6 +19,12 @@ def run(self):
 		self.packets = sp.sniff(iface=self._recvif, timeout=3)
 
 def check_ping_request(packet, dst_ip, args):
+	if args.ip6:
+		return check_ping6_request(packet, dst_ip, args)
+	else:
+		return check_ping4_request(packet, dst_ip, args)
+
+def check_ping4_request(packet, dst_ip, args):
 	"""
 	Verify that the packet matches what we'd have sent
 	"""
@@ -51,6 +57,24 @@ def check_ping_request(packet, dst_ip, args):
 
 	return True
 
+def check_ping6_request(packet, dst_ip, args):
+	"""
+	Verify that the packet matches what we'd have sent
+	"""
+	ip = packet.getlayer(sp.IPv6)
+	if not ip:
+		return False
+	if ip.dst != dst_ip:
+		return False
+
+	icmp = packet.getlayer(sp.ICMPv6EchoRequest)
+	if not icmp:
+		return False
+	if icmp.data != str(PAYLOAD_MAGIC):
+		return False
+
+	return True
+
 def ping(send_if, dst_ip, args):
 	ether = sp.Ether()
 	ip = sp.IP(dst=dst_ip)
@@ -63,6 +87,14 @@ def ping(send_if, dst_ip, args):
 	req = ether / ip / icmp / raw
 	sp.sendp(req, iface=send_if, verbose=False)
 
+def ping6(send_if, dst_ip, args):
+	ether = sp.Ether()
+	ip6 = sp.IPv6(dst=dst_ip)
+	icmp = sp.ICMPv6EchoRequest(data=PAYLOAD_MAGIC)
+
+	req = ether / ip6 / icmp
+	sp.sendp(req, iface=send_if, verbose=False)
+
 def main():
 	parser = argparse.ArgumentParser("pft_ping.py",
 		description="Ping test tool")
@@ -71,6 +103,8 @@ def main():
 		help='The interface through which the packet(s) will be sent')
 	parser.add_argument('--recvif', nargs=1,
 		help='The interface on which to expect the ICMP echo response')
+	parser.add_argument('--ip6', action='store_true',
+		help='Use IPv6')
 	parser.add_argument('--to', nargs=1,
 		required=True,
 		help='The destination IP address for the ICMP echo request')
@@ -85,11 +119,17 @@ def main():
 
 	args = parser.parse_args()
 
+	# We may not have a default route. Tell scapy where to start looking for routes
+	sp.conf.iface6 = args.sendif[0]
+
 	sniffer = None
 	if not args.recvif is None:
 		sniffer = Sniffer(args.recvif[0])
 
-	ping(args.sendif[0], args.to[0], args)
+	if args.ip6:
+		ping6(args.sendif[0], args.to[0], args)
+	else:
+		ping(args.sendif[0], args.to[0], args)
 
 	if sniffer:
 		sniffer.join()

tests/sys/netpfil/pf/utils.subr

@@ -35,6 +35,20 @@ pft_mkjail()
 	echo $jailname >> created_jails.lst
 }
 
+pft_set_rules()
+{
+	jname=$1
+	shift
+
+	# Flush all states, rules, fragments, ...
+	jexec ${jname} pfctl -F all
+
+	while [ $# -gt 0 ]; do
+		printf "$1\n"
+		shift
+	done | jexec ${jname} pfctl -f -
+}
+
 pft_cleanup()
 {
 	if [ -f created_interfaces.lst ]; then