xref: /freebsd/tests/sys/netpfil/pf/icmp.py (revision 13cd0f9c1ae6a50d616aeea923bc96f8e54176cc)
1#
2# SPDX-License-Identifier: BSD-2-Clause
3#
4# Copyright (c) 2024 Rubicon Communications, LLC (Netgate)
5#
6# Redistribution and use in source and binary forms, with or without
7# modification, are permitted provided that the following conditions
8# are met:
9# 1. Redistributions of source code must retain the above copyright
10#    notice, this list of conditions and the following disclaimer.
11# 2. Redistributions in binary form must reproduce the above copyright
12#    notice, this list of conditions and the following disclaimer in the
13#    documentation and/or other materials provided with the distribution.
14#
15# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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18# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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20# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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24# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25# SUCH DAMAGE.
26
27import pytest
28import subprocess
29import re
30from atf_python.sys.net.tools import ToolsHelper
31from atf_python.sys.net.vnet import VnetTestTemplate
32
33def check(cmd):
34    ps = subprocess.Popen(cmd, shell=True)
35    ret = ps.wait()
36    if ret != 0:
37        raise Exception("Command %s returned %d" % (cmd, ret))
38
39class TestICMP(VnetTestTemplate):
40    REQUIRED_MODULES = [ "pf" ]
41    TOPOLOGY = {
42        "vnet1": {"ifaces": ["if1"]},
43        "vnet2": {"ifaces": ["if1", "if2"]},
44        "vnet3": {"ifaces": ["if2"]},
45        "if1": {"prefixes4": [("192.0.2.2/24", "192.0.2.1/24")]},
46        "if2": {"prefixes4": [("198.51.100.1/24", "198.51.100.2/24")]},
47    }
48
49    def vnet2_handler(self, vnet):
50        ifname = vnet.iface_alias_map["if1"].name
51        if2name = vnet.iface_alias_map["if2"].name
52
53        ToolsHelper.print_output("/sbin/pfctl -e")
54        ToolsHelper.pf_rules([
55            "set reassemble yes",
56            "set state-policy if-bound",
57            "block",
58            "pass inet proto icmp icmp-type echoreq",
59            ])
60
61        ToolsHelper.print_output("/sbin/sysctl net.inet.ip.forwarding=1")
62        ToolsHelper.print_output("/sbin/pfctl -x loud")
63
64        ToolsHelper.print_output("/sbin/ifconfig %s mtu 1492" % if2name)
65
66    def vnet3_handler(self, vnet):
67        # Import in the correct vnet, so at to not confuse Scapy
68        import scapy.all as sp
69
70        ifname = vnet.iface_alias_map["if2"].name
71        ToolsHelper.print_output("/sbin/route add default 198.51.100.1")
72        ToolsHelper.print_output("/sbin/ifconfig %s inet alias 198.51.100.3/24" % ifname)
73        ToolsHelper.print_output("/sbin/ifconfig %s mtu 1492" % ifname)
74
75        def checkfn(packet):
76            icmp = packet.getlayer(sp.ICMP)
77            if not icmp:
78                return False
79
80            if icmp.type != 3:
81                return False
82
83            packet.show()
84            return True
85
86        sp.sniff(iface=ifname, stop_filter=checkfn)
87        vnet.pipe.send("Got ICMP destination unreachable packet")
88
89    @pytest.mark.require_user("root")
90    @pytest.mark.require_progs(["scapy"])
91    def test_inner_match(self):
92        vnet = self.vnet_map["vnet1"]
93        dst_vnet = self.vnet_map["vnet3"]
94        sendif = vnet.iface_alias_map["if1"]
95
96        our_mac = sendif.ether
97        dst_mac = sendif.epairb.ether
98
99        # Import in the correct vnet, so at to not confuse Scapy
100        import scapy.all as sp
101
102        ToolsHelper.print_output("/sbin/route add default 192.0.2.1")
103
104        # Sanity check
105        check("/sbin/ping -c 1 192.0.2.1")
106        check("/sbin/ping -c 1 198.51.100.1")
107        check("/sbin/ping -c 2 198.51.100.3")
108
109        # Establish a state
110        pkt = sp.Ether(src=our_mac, dst=dst_mac) \
111            / sp.IP(src="192.0.2.2", dst="198.51.100.2") \
112            / sp.ICMP(type='echo-request') \
113            / "PAYLOAD"
114        sp.sendp(pkt, sendif.name, verbose=False)
115
116        # Now try to pass an ICMP error message piggy-backing on that state, but
117        # use a different source address
118        pkt = sp.Ether(src=our_mac, dst=dst_mac) \
119            / sp.IP(src="192.0.2.2", dst="198.51.100.3") \
120            / sp.ICMP(type='dest-unreach') \
121            / sp.IP(src="198.51.100.2", dst="192.0.2.2") \
122            / sp.ICMP(type='echo-reply')
123        sp.sendp(pkt, sendif.name, verbose=False)
124
125        try:
126            rcvd = self.wait_object(dst_vnet.pipe, timeout=1)
127            if rcvd:
128                raise Exception(rcvd)
129        except TimeoutError as e:
130            # We expect the timeout here. It means we didn't get the destination
131            # unreachable packet in vnet3
132            pass
133
134    def check_icmp_echo(self, sp, payload_size):
135        packet = sp.IP(dst="198.51.100.2", flags="DF") \
136            / sp.ICMP(type='echo-request') \
137            / sp.raw(bytes.fromhex('f0') * payload_size)
138
139        p = sp.sr1(packet, timeout=3)
140        p.show()
141
142        ip = p.getlayer(sp.IP)
143        icmp = p.getlayer(sp.ICMP)
144        assert ip
145        assert icmp
146
147        if payload_size > 1464:
148            # Expect ICMP destination unreachable, fragmentation needed
149            assert ip.src == "192.0.2.1"
150            assert ip.dst == "192.0.2.2"
151            assert icmp.type == 3 # dest-unreach
152            assert icmp.code == 4
153            assert icmp.nexthopmtu == 1492
154        else:
155            # Expect echo reply
156            assert ip.src == "198.51.100.2"
157            assert ip.dst == "192.0.2.2"
158            assert icmp.type == 0 # "echo-reply"
159            assert icmp.code == 0
160
161        return
162
163    @pytest.mark.require_user("root")
164    @pytest.mark.require_progs(["scapy"])
165    def test_fragmentation_needed(self):
166        ToolsHelper.print_output("/sbin/route add default 192.0.2.1")
167
168        ToolsHelper.print_output("/sbin/ping -c 1 198.51.100.2")
169        ToolsHelper.print_output("/sbin/ping -c 1 -D -s 1472 198.51.100.2")
170
171        # Import in the correct vnet, so at to not confuse Scapy
172        import scapy.all as sp
173
174        self.check_icmp_echo(sp, 128)
175        self.check_icmp_echo(sp, 1464)
176        self.check_icmp_echo(sp, 1468)
177
178    @pytest.mark.require_user("root")
179    @pytest.mark.require_progs(["scapy"])
180    def test_truncated_opts(self):
181        ToolsHelper.print_output("/sbin/route add default 192.0.2.1")
182
183        # Import in the correct vnet, so at to not confuse Scapy
184        import scapy.all as sp
185
186        packet = sp.IP(dst="198.51.100.2", flags="DF") \
187            / sp.ICMP(type='dest-unreach', length=108) \
188            / sp.IP(src="198.51.100.2", dst="192.0.2.2", len=1000, \
189              ihl=(120 >> 2), options=[ \
190              sp.IPOption_Security(length=100)])
191        packet.show()
192        sp.sr1(packet, timeout=3)
193
194class TestICMP_NAT(VnetTestTemplate):
195    REQUIRED_MODULES = [ "pf" ]
196    TOPOLOGY = {
197        "vnet1": {"ifaces": ["if1"]},
198        "vnet2": {"ifaces": ["if1", "if2"]},
199        "vnet3": {"ifaces": ["if2"]},
200        "if1": {"prefixes4": [("192.0.2.2/24", "192.0.2.1/24")]},
201        "if2": {"prefixes4": [("198.51.100.1/24", "198.51.100.2/24")]},
202    }
203
204    def vnet2_handler(self, vnet):
205        ifname = vnet.iface_alias_map["if1"].name
206        if2name = vnet.iface_alias_map["if2"].name
207
208        ToolsHelper.print_output("/sbin/pfctl -e")
209        ToolsHelper.pf_rules([
210            "set reassemble yes",
211            "set state-policy if-bound",
212            "nat on %s inet from 192.0.2.0/24 to any -> (%s)" % (if2name, if2name),
213            "block",
214            "pass inet proto icmp icmp-type echoreq",
215            ])
216
217        ToolsHelper.print_output("/sbin/sysctl net.inet.ip.forwarding=1")
218        ToolsHelper.print_output("/sbin/pfctl -x loud")
219
220    def vnet3_handler(self, vnet):
221        ifname = vnet.iface_alias_map["if2"].name
222        ToolsHelper.print_output("/sbin/ifconfig %s inet alias 198.51.100.3/24" % ifname)
223
224    @pytest.mark.require_user("root")
225    @pytest.mark.require_progs(["scapy"])
226    def test_id_conflict(self):
227        """
228            Test ICMP echo requests with the same ID from different clients.
229            Windows does this, and it can confuse pf.
230        """
231        ifname = self.vnet.iface_alias_map["if1"].name
232        ToolsHelper.print_output("/sbin/route add default 192.0.2.1")
233        ToolsHelper.print_output("/sbin/ifconfig %s inet alias 192.0.2.3/24" % ifname)
234
235        ToolsHelper.print_output("/sbin/ping -c 1 192.0.2.1")
236        ToolsHelper.print_output("/sbin/ping -c 1 198.51.100.1")
237        ToolsHelper.print_output("/sbin/ping -c 1 198.51.100.2")
238        ToolsHelper.print_output("/sbin/ping -c 1 198.51.100.3")
239
240        # Import in the correct vnet, so at to not confuse Scapy
241        import scapy.all as sp
242
243        # Address one
244        packet = sp.IP(src="192.0.2.2", dst="198.51.100.2", flags="DF") \
245            / sp.ICMP(type='echo-request', id=42) \
246            / sp.raw(bytes.fromhex('f0') * 16)
247
248        p = sp.sr1(packet, timeout=3)
249        p.show()
250        ip = p.getlayer(sp.IP)
251        icmp = p.getlayer(sp.ICMP)
252        assert ip
253        assert icmp
254        assert ip.dst == "192.0.2.2"
255        assert icmp.id == 42
256
257        # Address one
258        packet = sp.IP(src="192.0.2.3", dst="198.51.100.2", flags="DF") \
259            / sp.ICMP(type='echo-request', id=42) \
260            / sp.raw(bytes.fromhex('f0') * 16)
261
262        p = sp.sr1(packet, timeout=3)
263        p.show()
264        ip = p.getlayer(sp.IP)
265        icmp = p.getlayer(sp.ICMP)
266        assert ip
267        assert icmp
268        assert ip.dst == "192.0.2.3"
269        assert icmp.id == 42
270