From 9566d9272600a472be3a608ea79197c57cad1dc3 Mon Sep 17 00:00:00 2001 From: Kristof Provost Date: Tue, 27 Feb 2024 14:24:25 +0100 Subject: [PATCH] pf: fix packet-to-big for route-to as well When we handle a packet via route-to (i.e. pf_route6()) we still need to verify the MTU. However, we only run that check in the forwarding case. Set the PFIL_FWD tag when running the pf_test6(PF_OUT) check from pf_route6(). We are in fact forwarding, so should call the test function as such. This will cause us to run the MTU check, and generate an ICMP6 packet-too-big error when required. See also: 54c62e3e5d8cd90c5571a1d4c8c5f062d580480e See also: f1c0030bb05cfa01bdd500e50befbb425fecc4c4 See also: https://redmine.pfsense.org/issues/14290 Sponsored by: Rubicon Communications, LLC ("Netgate") --- sys/netpfil/pf/pf.c | 4 +-- tests/sys/netpfil/pf/nat66.py | 47 +++++++++++++++++++++++++++++------ 2 files changed, 41 insertions(+), 10 deletions(-) diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c index 8bfda12b2b2e..46f01f986d05 100644 --- a/sys/netpfil/pf/pf.c +++ b/sys/netpfil/pf/pf.c @@ -7333,7 +7333,7 @@ pf_route(struct mbuf **m, struct pf_krule *r, struct ifnet *oifp, goto bad; if (pd->dir == PF_IN) { - if (pf_test(PF_OUT, 0, ifp, &m0, inp, &pd->act) != PF_PASS) + if (pf_test(PF_OUT, PFIL_FWD, ifp, &m0, inp, &pd->act) != PF_PASS) goto bad; else if (m0 == NULL) goto done; @@ -7555,7 +7555,7 @@ pf_route6(struct mbuf **m, struct pf_krule *r, struct ifnet *oifp, goto bad; if (pd->dir == PF_IN) { - if (pf_test6(PF_OUT, 0, ifp, &m0, inp, &pd->act) != PF_PASS) + if (pf_test6(PF_OUT, PFIL_FWD, ifp, &m0, inp, &pd->act) != PF_PASS) goto bad; else if (m0 == NULL) goto done; diff --git a/tests/sys/netpfil/pf/nat66.py b/tests/sys/netpfil/pf/nat66.py index 006ab5afee7f..12d3cb25af0a 100644 --- a/tests/sys/netpfil/pf/nat66.py +++ b/tests/sys/netpfil/pf/nat66.py @@ -59,21 +59,23 @@ class TestNAT66(VnetTestTemplate): def vnet2_handler(self, vnet): ifname = vnet.iface_alias_map["if1"].name ToolsHelper.print_output("/sbin/ifconfig %s mtu 9000" % ifname) + outifname = vnet.iface_alias_map["if2"].name ToolsHelper.print_output("/sbin/pfctl -e") ToolsHelper.pf_rules([ "set reassemble yes", "binat inet6 from 2001:db8::/64 to 2001:db8:1::/64 -> 2001:db8:42::/64", "binat inet6 from 2001:db8:1::/64 to 2001:db8:42::/64 -> 2001:db8::/64", - "pass inet6 proto icmp6"]) + "pass inet6 proto icmp6", + "pass in route-to ( %s 2001:db8:1::2 ) inet6 from 2001:db8::3 to 2001:db8:1::/64" % outifname]) ToolsHelper.print_output("/sbin/sysctl net.inet6.ip6.forwarding=1") def vnet3_handler(self, vnet): ToolsHelper.print_output("/sbin/route add -6 2001:db8:42::/64 2001:db8:1::1") - def check_icmp_too_big(self, sp, payload_size, frag_size=None): - packet = sp.IPv6(src="2001:db8::2", dst="2001:db8:1::2") \ + def check_icmp_too_big(self, sp, payload_size, frag_size=None, src="2001:db8::2"): + packet = sp.IPv6(src=src, dst="2001:db8:1::2") \ / sp.ICMPv6EchoRequest(data=sp.raw(bytes.fromhex('f0') * payload_size)) if frag_size is not None: @@ -97,14 +99,14 @@ def check_icmp_too_big(self, sp, payload_size, frag_size=None): # Error is from the router vnet assert ip6.src == "2001:db8::1" - assert ip6.dst == "2001:db8::2" + assert ip6.dst == src # And the relevant MTU is 1500 assert icmp6.mtu == 1500 # The icmp6 error contains our original IPv6 packet err = icmp6.getlayer(sp.IPerror6) - assert err.src == "2001:db8::2" + assert err.src == src assert err.dst == "2001:db8:1::2" assert err.nh == 58 @@ -112,8 +114,8 @@ def check_icmp_too_big(self, sp, payload_size, frag_size=None): assert found - def check_icmp_echo(self, sp, payload_size): - packet = sp.IPv6(src="2001:db8::2", dst="2001:db8:1::2") \ + def check_icmp_echo(self, sp, payload_size, src="2001:db8::2"): + packet = sp.IPv6(src=src, dst="2001:db8:1::2") \ / sp.ICMPv6EchoRequest(data=sp.raw(bytes.fromhex('f0') * payload_size)) # Delay the send so the sniffer is running when we transmit. @@ -131,7 +133,7 @@ def check_icmp_echo(self, sp, payload_size): # Error is from the router vnet assert ip6.src == "2001:db8:1::2" - assert ip6.dst == "2001:db8::2" + assert ip6.dst == src found = True @@ -164,3 +166,32 @@ def test_npt_icmp(self): # A ping that arrives fragmented self.check_icmp_too_big(sp, 12000, 5000) + + @pytest.mark.require_user("root") + def test_npt_route_to_icmp(self): + cl_vnet = self.vnet_map["vnet1"] + ifname = cl_vnet.iface_alias_map["if1"].name + ToolsHelper.print_output("/sbin/ifconfig %s mtu 9000" % ifname) + ToolsHelper.print_output("/sbin/ifconfig %s inet6 alias 2001:db8::3/64" % ifname) + + ToolsHelper.print_output("/sbin/route add -6 2001:db8:1::/64 2001:db8::1") + + # For unclear reasons vnet3 doesn't respond to the first ping. + # Just send two for now. + ToolsHelper.print_output("/sbin/ping -6 -c 1 -S 2001:db8::3 2001:db8:1::2") + ToolsHelper.print_output("/sbin/ping -6 -c 1 -S 2001:db8::3 2001:db8:1::2") + + # Import in the correct vnet, so at to not confuse Scapy + import scapy.all as sp + + # A ping that easily passes without fragmentation + self.check_icmp_echo(sp, 128, src="2001:db8::3") + + # Send a ping that just barely doesn't need to be fragmented + self.check_icmp_echo(sp, 1452, src="2001:db8::3") + + # Send a ping that just barely needs to be fragmented + self.check_icmp_too_big(sp, 1453, src="2001:db8::3") + + # A ping that arrives fragmented + self.check_icmp_too_big(sp, 12000, 5000, src="2001:db8::3")