git: 57c50d6b3673 - main - pf tests: test ICMP6 packet too big with binat

From: Kristof Provost <kp_at_FreeBSD.org>
Date: Mon, 22 Jan 2024 12:52:52 UTC
The branch main has been updated by kp:

URL: https://cgit.FreeBSD.org/src/commit/?id=57c50d6b3673225064d9c38cd06a41ec1730d3d1

commit 57c50d6b3673225064d9c38cd06a41ec1730d3d1
Author:     Kristof Provost <kp@FreeBSD.org>
AuthorDate: 2024-01-17 17:03:56 +0000
Commit:     Kristof Provost <kp@FreeBSD.org>
CommitDate: 2024-01-22 12:49:56 +0000

    pf tests: test ICMP6 packet too big with binat
    
    Sponsored by:   Rubicon Communications, LLC ("Netgate")
    Differential Revision:  https://reviews.freebsd.org/D43500
---
 tests/sys/netpfil/pf/Makefile |   1 +
 tests/sys/netpfil/pf/nat66.py | 166 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 167 insertions(+)

diff --git a/tests/sys/netpfil/pf/Makefile b/tests/sys/netpfil/pf/Makefile
index f1a2fff5a45d..30099fdc4c17 100644
--- a/tests/sys/netpfil/pf/Makefile
+++ b/tests/sys/netpfil/pf/Makefile
@@ -46,6 +46,7 @@ ATF_TESTS_SH+=	altq \
 		tos
 
 ATF_TESTS_PYTEST+=	frag6.py
+ATF_TESTS_PYTEST+=	nat66.py
 ATF_TESTS_PYTEST+=	sctp.py
 
 # Tests reuse jail names and so cannot run in parallel.
diff --git a/tests/sys/netpfil/pf/nat66.py b/tests/sys/netpfil/pf/nat66.py
new file mode 100644
index 000000000000..006ab5afee7f
--- /dev/null
+++ b/tests/sys/netpfil/pf/nat66.py
@@ -0,0 +1,166 @@
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright (c) 2024 Rubicon Communications, LLC (Netgate)
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+
+import ctypes
+import ipaddress
+import pytest
+import re
+import socket
+import threading
+import time
+from atf_python.sys.net.tools import ToolsHelper
+from atf_python.sys.net.vnet import VnetTestTemplate
+
+class DelayedSend(threading.Thread):
+    def __init__(self, packet):
+        threading.Thread.__init__(self)
+        self._packet = packet
+
+        self.start()
+
+    def run(self):
+        import scapy.all as sp
+        time.sleep(1)
+        sp.send(self._packet)
+
+class TestNAT66(VnetTestTemplate):
+    REQUIRED_MODUES = [ "pf" ]
+    TOPOLOGY = {
+        "vnet1": {"ifaces": ["if1"]},
+        "vnet2": {"ifaces": ["if1", "if2"]},
+        "vnet3": {"ifaces": ["if2"]},
+        "if1": {"prefixes6": [("2001:db8::2/64", "2001:db8::1/64")]},
+        "if2": {"prefixes6": [("2001:db8:1::1/64", "2001:db8:1::2/64")]},
+    }
+
+    def vnet2_handler(self, vnet):
+        ifname = vnet.iface_alias_map["if1"].name
+        ToolsHelper.print_output("/sbin/ifconfig %s mtu 9000" % ifname)
+
+        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"])
+
+        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") \
+            / sp.ICMPv6EchoRequest(data=sp.raw(bytes.fromhex('f0') * payload_size))
+
+        if frag_size is not None:
+            packet = sp.fragment6(packet, frag_size)
+
+        # Delay the send so the sniffer is running when we transmit.
+        s = DelayedSend(packet)
+
+        packets = sp.sniff(iface=self.vnet.iface_alias_map["if1"].name,
+            timeout=3)
+        found=False
+        for p in packets:
+            # We can't get a reply to this
+            assert not p.getlayer(sp.ICMPv6EchoReply)
+
+            if not p.getlayer(sp.ICMPv6PacketTooBig):
+                continue
+
+            ip6 = p.getlayer(sp.IPv6)
+            icmp6 = p.getlayer(sp.ICMPv6PacketTooBig)
+
+            # Error is from the router vnet
+            assert ip6.src == "2001:db8::1"
+            assert ip6.dst == "2001:db8::2"
+
+            # 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.dst == "2001:db8:1::2"
+            assert err.nh == 58
+
+            found = True
+
+        assert found
+
+    def check_icmp_echo(self, sp, payload_size):
+        packet = sp.IPv6(src="2001:db8::2", 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.
+        s = DelayedSend(packet)
+
+        packets = sp.sniff(iface=self.vnet.iface_alias_map["if1"].name,
+            timeout=3)
+        found=False
+        for p in packets:
+            if not p.getlayer(sp.ICMPv6EchoReply):
+                continue
+
+            ip6 = p.getlayer(sp.IPv6)
+            icmp6 = p.getlayer(sp.ICMPv6EchoReply)
+
+            # Error is from the router vnet
+            assert ip6.src == "2001:db8:1::2"
+            assert ip6.dst == "2001:db8::2"
+
+            found = True
+
+        assert found
+
+    @pytest.mark.require_user("root")
+    def test_npt_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/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 2001:db8:1::2")
+        ToolsHelper.print_output("/sbin/ping -6 -c 1 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)
+
+        # Send a ping that just barely doesn't need to be fragmented
+        self.check_icmp_echo(sp, 1452)
+
+        # Send a ping that just barely needs to be fragmented
+        self.check_icmp_too_big(sp, 1453)
+
+        # A ping that arrives fragmented
+        self.check_icmp_too_big(sp, 12000, 5000)