1#!/usr/bin/env python3
2#
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29import unittest
30
31import config
32import thread_cert
33
34# Test description:
35#   This test verifies publishing infrastructure NAT64 prefix in Thread network.
36#
37#
38# Topology:
39#
40#   ----------------(eth)--------------------
41#           |
42#          BR (with DNS64 on infrastructure interface)
43#           |
44#        ROUTER
45#
46
47BR = 1
48ROUTER = 2
49
50OMR_PREFIX = "2000:0:1111:4444::/64"
51# The prefix is set smaller than the default infrastructure NAT64 prefix.
52SMALL_NAT64_PREFIX = "2000:0:0:1:0:0::/96"
53
54NAT64_PREFIX_REFRESH_DELAY = 305
55
56NAT64_STATE_DISABLED = 'disabled'
57NAT64_STATE_NOT_RUNNING = 'not_running'
58NAT64_STATE_IDLE = 'idle'
59NAT64_STATE_ACTIVE = 'active'
60
61
62class Nat64SingleBorderRouter(thread_cert.TestCase):
63    USE_MESSAGE_FACTORY = False
64
65    TOPOLOGY = {
66        BR: {
67            'name': 'BR',
68            'allowlist': [ROUTER],
69            'is_otbr': True,
70            'version': '1.2',
71        },
72        ROUTER: {
73            'name': 'Router',
74            'allowlist': [BR],
75            'version': '1.2',
76        },
77    }
78
79    def test(self):
80        br = self.nodes[BR]
81        router = self.nodes[ROUTER]
82
83        br.start()
84        # When feature flag is enabled, NAT64 might be disabled by default. So
85        # ensure NAT64 is enabled here.
86        br.nat64_set_enabled(True)
87        self.simulator.go(config.LEADER_STARTUP_DELAY)
88        self.assertEqual('leader', br.get_state())
89
90        router.start()
91        self.simulator.go(config.ROUTER_STARTUP_DELAY)
92        self.assertEqual('router', router.get_state())
93
94        # Case 1 No infra-derived OMR prefix. BR publishes its local prefix.
95        local_nat64_prefix = br.get_br_nat64_prefix()
96
97        self.assertEqual(len(br.get_netdata_nat64_routes()), 1)
98        nat64_prefix = br.get_netdata_nat64_routes()[0]
99        self.assertEqual(nat64_prefix, local_nat64_prefix)
100
101        self.assertDictIncludes(br.nat64_state, {
102            'PrefixManager': NAT64_STATE_ACTIVE,
103            'Translator': NAT64_STATE_ACTIVE
104        })
105
106        # Case 2 Add OMR prefix. BR publishes the infrastructure nat64 prefix
107        br.add_prefix(OMR_PREFIX)
108        br.register_netdata()
109        self.simulator.go(10)
110
111        favored_nat64_prefix = br.get_br_favored_nat64_prefix()
112        self.assertNotEqual(favored_nat64_prefix, local_nat64_prefix)
113        infra_nat64_prefix = favored_nat64_prefix
114
115        self.assertEqual(len(br.get_netdata_nat64_routes()), 1)
116        nat64_prefix = br.get_netdata_nat64_routes()[0]
117        self.assertEqual(nat64_prefix, infra_nat64_prefix)
118        self.assertDictIncludes(br.nat64_state, {
119            'PrefixManager': NAT64_STATE_ACTIVE,
120            'Translator': NAT64_STATE_NOT_RUNNING
121        })
122
123        # Case 3 Unpublish infrastructure prefix when a smaller prefix in medium
124        # preference is present
125        br.add_route(SMALL_NAT64_PREFIX, stable=False, nat64=True, prf='med')
126        br.register_netdata()
127        self.simulator.go(5)
128
129        self.assertEqual(len(br.get_netdata_nat64_routes()), 1)
130        self.assertNotEqual(infra_nat64_prefix, br.get_netdata_nat64_routes()[0])
131        self.assertDictIncludes(br.nat64_state, {
132            'PrefixManager': NAT64_STATE_IDLE,
133            'Translator': NAT64_STATE_NOT_RUNNING
134        })
135
136        br.remove_route(SMALL_NAT64_PREFIX)
137        br.register_netdata()
138        self.simulator.go(10)
139
140        self.assertEqual(len(br.get_netdata_nat64_routes()), 1)
141        self.assertEqual(nat64_prefix, infra_nat64_prefix)
142
143        # Case 4 No change when a smaller prefix in low preference is present
144        br.add_route(SMALL_NAT64_PREFIX, stable=False, nat64=True, prf='low')
145        br.register_netdata()
146        self.simulator.go(5)
147
148        self.assertEqual(len(br.get_netdata_nat64_routes()), 2)
149        self.assertEqual(br.get_netdata_nat64_routes(), [infra_nat64_prefix, SMALL_NAT64_PREFIX])
150        self.assertDictIncludes(br.nat64_state, {
151            'PrefixManager': NAT64_STATE_ACTIVE,
152            'Translator': NAT64_STATE_NOT_RUNNING
153        })
154
155        br.remove_route(SMALL_NAT64_PREFIX)
156        br.register_netdata()
157        self.simulator.go(5)
158
159        # Case 5 Infrastructure nat64 prefix no longer presents
160        br.bash("service bind9 stop")
161        self.simulator.go(NAT64_PREFIX_REFRESH_DELAY)
162
163        local_nat64_prefix = br.get_br_nat64_prefix()
164        self.assertNotEqual(local_nat64_prefix, infra_nat64_prefix)
165        self.assertEqual(len(br.get_netdata_nat64_routes()), 1)
166        self.assertEqual(br.get_netdata_nat64_routes()[0], local_nat64_prefix)
167        self.assertDictIncludes(br.nat64_state, {
168            'PrefixManager': NAT64_STATE_ACTIVE,
169            'Translator': NAT64_STATE_ACTIVE
170        })
171
172        # Case 6 Infrastructure nat64 prefix is recovered
173        br.bash("service bind9 start")
174        self.simulator.go(NAT64_PREFIX_REFRESH_DELAY)
175
176        self.assertEqual(br.get_br_favored_nat64_prefix(), infra_nat64_prefix)
177        self.assertEqual(len(br.get_netdata_nat64_routes()), 1)
178        self.assertEqual(br.get_netdata_nat64_routes()[0], infra_nat64_prefix)
179        self.assertDictIncludes(br.nat64_state, {
180            'PrefixManager': NAT64_STATE_ACTIVE,
181            'Translator': NAT64_STATE_NOT_RUNNING
182        })
183
184        # Case 7 Change infrastructure nat64 prefix
185        br.bash("sed -i 's/dns64 /\/\/dns64 /' /etc/bind/named.conf.options")
186        br.bash("sed -i '/\/\/dns64 /a dns64 " + SMALL_NAT64_PREFIX + " {};' /etc/bind/named.conf.options")
187        br.bash("service bind9 restart")
188        self.simulator.go(NAT64_PREFIX_REFRESH_DELAY)
189
190        self.assertEqual(br.get_br_favored_nat64_prefix(), SMALL_NAT64_PREFIX)
191        self.assertEqual(len(br.get_netdata_nat64_routes()), 1)
192        self.assertEqual(br.get_netdata_nat64_routes()[0], SMALL_NAT64_PREFIX)
193        self.assertDictIncludes(br.nat64_state, {
194            'PrefixManager': NAT64_STATE_ACTIVE,
195            'Translator': NAT64_STATE_NOT_RUNNING
196        })
197
198
199if __name__ == '__main__':
200    unittest.main()
201