git: b27d3f71c2ad - main - pf tests: improved test for CVE-2019-5598

From: Kristof Provost <kp_at_FreeBSD.org>
Date: Wed, 11 Sep 2024 11:18:28 UTC
The branch main has been updated by kp:

URL: https://cgit.FreeBSD.org/src/commit/?id=b27d3f71c2ad05e1b18e8bdce75194330e0925e4

commit b27d3f71c2ad05e1b18e8bdce75194330e0925e4
Author:     Kristof Provost <kp@FreeBSD.org>
AuthorDate: 2024-08-28 08:03:42 +0000
Commit:     Kristof Provost <kp@FreeBSD.org>
CommitDate: 2024-09-11 11:17:49 +0000

    pf tests: improved test for CVE-2019-5598
    
    Ensure that we verify that the inner and outer IP address matches for ICMP error
    messages. This is a more detailed test for CVE-2019-5598, which was fixed back
    in 2019.
    
    Sponsored by:   Rubicon Communications, LLC ("Netgate")
    Differential Revision:  https://reviews.freebsd.org/D46573
---
 tests/sys/netpfil/pf/Makefile |   1 +
 tests/sys/netpfil/pf/icmp.py  | 126 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 127 insertions(+)

diff --git a/tests/sys/netpfil/pf/Makefile b/tests/sys/netpfil/pf/Makefile
index 2b3cb9fbd858..8444c92fb8d5 100644
--- a/tests/sys/netpfil/pf/Makefile
+++ b/tests/sys/netpfil/pf/Makefile
@@ -53,6 +53,7 @@ ATF_TESTS_SH+=	altq \
 		tos
 
 ATF_TESTS_PYTEST+=	frag6.py
+ATF_TESTS_PYTEST+=	icmp.py
 ATF_TESTS_PYTEST+=	nat66.py
 ATF_TESTS_PYTEST+=	sctp.py
 
diff --git a/tests/sys/netpfil/pf/icmp.py b/tests/sys/netpfil/pf/icmp.py
new file mode 100644
index 000000000000..cb9de2bf0f36
--- /dev/null
+++ b/tests/sys/netpfil/pf/icmp.py
@@ -0,0 +1,126 @@
+#
+# 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 pytest
+import subprocess
+import re
+from atf_python.sys.net.tools import ToolsHelper
+from atf_python.sys.net.vnet import VnetTestTemplate
+
+def check(cmd):
+    ps = subprocess.Popen(cmd, shell=True)
+    ret = ps.wait()
+    if ret != 0:
+        raise Exception("Command %s returned %d" % (cmd, ret))
+
+class TestICMP(VnetTestTemplate):
+    REQUIRED_MODULES = [ "pf" ]
+    TOPOLOGY = {
+        "vnet1": {"ifaces": ["if1"]},
+        "vnet2": {"ifaces": ["if1", "if2"]},
+        "vnet3": {"ifaces": ["if2"]},
+        "if1": {"prefixes4": [("192.0.2.2/24", "192.0.2.1/24")]},
+        "if2": {"prefixes4": [("198.51.100.1/24", "198.51.100.2/24")]},
+    }
+
+    def vnet2_handler(self, vnet):
+        ifname = vnet.iface_alias_map["if1"].name
+
+        ToolsHelper.print_output("/sbin/pfctl -e")
+        ToolsHelper.pf_rules([
+            "set reassemble yes",
+            "block",
+            "pass inet proto icmp icmp-type echoreq",
+            ])
+
+        ToolsHelper.print_output("/sbin/sysctl net.inet.ip.forwarding=1")
+        ToolsHelper.print_output("/sbin/pfctl -x loud")
+
+    def vnet3_handler(self, vnet):
+        # Import in the correct vnet, so at to not confuse Scapy
+        import scapy.all as sp
+
+        ifname = vnet.iface_alias_map["if2"].name
+        ToolsHelper.print_output("/sbin/route add default 198.51.100.1")
+        ToolsHelper.print_output("/sbin/ifconfig %s inet alias 198.51.100.3/24" % ifname)
+
+        def checkfn(packet):
+            icmp = packet.getlayer(sp.ICMP)
+            if not icmp:
+                return False
+
+            if icmp.type != 3:
+                return False
+
+            packet.show()
+            return True
+
+        sp.sniff(iface=ifname, stop_filter=checkfn)
+        vnet.pipe.send("Got ICMP destination unreachable packet")
+
+    @pytest.mark.require_user("root")
+    def test_inner_match(self):
+        vnet = self.vnet_map["vnet1"]
+        dst_vnet = self.vnet_map["vnet3"]
+        sendif = vnet.iface_alias_map["if1"].name
+
+        our_mac = ToolsHelper.get_output("/sbin/ifconfig %s ether | awk '/ether/ { print $2; }'" % sendif)
+        dst_mac = re.sub("0a$", "0b", our_mac)
+
+        # Import in the correct vnet, so at to not confuse Scapy
+        import scapy.all as sp
+
+        ToolsHelper.print_output("/sbin/route add default 192.0.2.1")
+
+        # Sanity check
+        check("/sbin/ping -c 1 192.0.2.1")
+        check("/sbin/ping -c 1 198.51.100.1")
+        check("/sbin/ping -c 2 198.51.100.3")
+
+        # Establish a state
+        pkt = sp.Ether(src=our_mac, dst=dst_mac) \
+            / sp.IP(src="192.0.2.2", dst="198.51.100.2") \
+            / sp.ICMP(type='echo-request') \
+            / "PAYLOAD"
+        sp.sendp(pkt, sendif, verbose=False)
+
+        # Now try to pass an ICMP error message piggy-backing on that state, but
+        # use a different source address
+        pkt = sp.Ether(src=our_mac, dst=dst_mac) \
+            / sp.IP(src="192.0.2.2", dst="198.51.100.3") \
+            / sp.ICMP(type='dest-unreach') \
+            / sp.IP(src="198.51.100.2", dst="192.0.2.2") \
+            / sp.ICMP(type='echo-reply')
+        sp.sendp(pkt, sendif, verbose=False)
+
+        try:
+            rcvd = self.wait_object(dst_vnet.pipe, timeout=1)
+            if rcvd:
+                raise Exception(rcvd)
+        except TimeoutError as e:
+            # We expect the timeout here. It means we didn't get the destination
+            # unreachable packet in vnet3
+            pass