Date: Fri, 4 Aug 2023 13:59:15 GMT From: Kristof Provost <kp@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: b23dbabb7f3e - main - pf: test rules evaluation in the face of multiple IPv6 fragment headers Message-ID: <202308041359.374DxFGx070046@gitrepo.freebsd.org>
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The branch main has been updated by kp: URL: https://cgit.FreeBSD.org/src/commit/?id=b23dbabb7f3edb3f323a64f03e37be2c9a8b2a45 commit b23dbabb7f3edb3f323a64f03e37be2c9a8b2a45 Author: Kristof Provost <kp@FreeBSD.org> AuthorDate: 2023-07-13 06:34:54 +0000 Commit: Kristof Provost <kp@FreeBSD.org> CommitDate: 2023-08-04 13:24:16 +0000 pf: test rules evaluation in the face of multiple IPv6 fragment headers Send an ICMPv6 echo request packet with multiple IPv6 fragment headers. Set rules to pass all packets, except for ICMPv6 echo requests. pf ought to drop the echo request, but doesn't because it reassembles the packet, and then doesn't handle the second fragment header. In other words: it fails to detect the ICMPv6 echo header. Reported by: Enrico Bassetti bassetti@di.uniroma1.it (NetSecurityLab @ Sapienza University of Rome) MFC after: instant Sponsored by: Rubicon Communications, LLC ("Netgate") --- tests/atf_python/sys/net/tools.py | 21 ++++++++++++++ tests/sys/netpfil/pf/Makefile | 2 ++ tests/sys/netpfil/pf/frag6.py | 60 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 83 insertions(+) diff --git a/tests/atf_python/sys/net/tools.py b/tests/atf_python/sys/net/tools.py index 567d9d4b21ac..44bd74d8578f 100644 --- a/tests/atf_python/sys/net/tools.py +++ b/tests/atf_python/sys/net/tools.py @@ -1,6 +1,7 @@ #!/usr/local/bin/python3 import json import os +import subprocess class ToolsHelper(object): @@ -13,6 +14,26 @@ class ToolsHelper(object): print("run: '{}'".format(cmd)) return os.popen(cmd).read() + @classmethod + def pf_rules(cls, rules, verbose=True): + pf_conf = "" + for r in rules: + pf_conf = pf_conf + r + "\n" + + if verbose: + print("Set rules:") + print(pf_conf) + + ps = subprocess.Popen("/sbin/pfctl -g -f -", shell=True, + stdin=subprocess.PIPE) + ps.communicate(bytes(pf_conf, 'utf-8')) + ret = ps.wait() + if ret != 0: + raise Exception("Failed to set pf rules %d" % ret) + + if verbose: + cls.print_output("/sbin/pfctl -sr") + @classmethod def print_output(cls, cmd: str, verbose=True): if verbose: diff --git a/tests/sys/netpfil/pf/Makefile b/tests/sys/netpfil/pf/Makefile index 19c87486d8bb..5c59584d2ec9 100644 --- a/tests/sys/netpfil/pf/Makefile +++ b/tests/sys/netpfil/pf/Makefile @@ -40,6 +40,8 @@ ATF_TESTS_SH+= altq \ table \ tos +ATF_TESTS_PYTEST+= frag6.py + # Tests reuse jail names and so cannot run in parallel. TEST_METADATA+= is_exclusive=true diff --git a/tests/sys/netpfil/pf/frag6.py b/tests/sys/netpfil/pf/frag6.py new file mode 100644 index 000000000000..28b1829d418c --- /dev/null +++ b/tests/sys/netpfil/pf/frag6.py @@ -0,0 +1,60 @@ +import pytest +import logging +import threading +import time +logging.getLogger("scapy").setLevel(logging.CRITICAL) +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 TestFrag6(VnetTestTemplate): + REQUIRED_MODULES = ["pf"] + TOPOLOGY = { + "vnet1": {"ifaces": ["if1"]}, + "vnet2": {"ifaces": ["if1"]}, + "if1": {"prefixes6": [("2001:db8::1/64", "2001:db8::2/64")]}, + } + + def vnet2_handler(self, vnet): + ToolsHelper.print_output("/sbin/pfctl -e") + ToolsHelper.pf_rules([ + "scrub fragment reassemble", + "pass", + "block in inet6 proto icmp6 icmp6-type echoreq", + ]) + + def check_ping_reply(self, packet): + print(packet) + return False + + @pytest.mark.require_user("root") + def test_dup_frag_hdr(self): + "Test packets with duplicate fragment headers" + srv_vnet = self.vnet_map["vnet2"] + + # Import in the correct vnet, so at to not confuse Scapy + import scapy.all as sp + + packet = sp.IPv6(src="2001:db8::1", dst="2001:db8::2") \ + / sp.IPv6ExtHdrFragment(offset = 0, m = 0) \ + / sp.IPv6ExtHdrFragment(offset = 0, m = 0) \ + / sp.ICMPv6EchoRequest(data=sp.raw(bytes.fromhex('f00f') * 128)) + + # 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) + for p in packets: + assert not p.getlayer(sp.ICMPv6EchoReply)
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