e='generator' content='cgit 1.2.3-korg'/>
summaryrefslogtreecommitdiffstats
path: root/test/test_bfd.py
blob: 8fb00cf348a4205a557eee9016ba2f0fe9e743cc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
#!/usr/bin/env python
""" BFD tests """

from __future__ import division
import unittest
import hashlib
import binascii
import time
from struct import pack, unpack
from random import randint, shuffle, getrandbits
from socket import AF_INET, AF_INET6, inet_ntop
from scapy.packet import Raw
from scapy.layers.l2 import Ether
from scapy.layers.inet import UDP, IP
from scapy.layers.inet6 import IPv6
from bfd import VppBFDAuthKey, BFD, BFDAuthType, VppBFDUDPSession, \
    BFDDiagCode, BFDState, BFD_vpp_echo
from framework import VppTestCase, VppTestRunner, running_extended_tests
from vpp_pg_interface import CaptureTimeoutError, is_ipv6_misc
from vpp_lo_interface import VppLoInterface
from util import ppp
from vpp_papi_provider import UnexpectedApiReturnValueError
from vpp_ip_route import VppIpRoute, VppRoutePath, DpoProto

USEC_IN_SEC = 1000000


class AuthKeyFactory(object):
    """Factory class for creating auth keys with unique conf key ID"""

    def __init__(self):
        self._conf_key_ids = {}

    def create_random_key(self, test, auth_type=BFDAuthType.keyed_sha1):
        """ create a random key with unique conf key id """
        conf_key_id = randint(0, 0xFFFFFFFF)
        while conf_key_id in self._conf_key_ids:
            conf_key_id = randint(0, 0xFFFFFFFF)
        self._conf_key_ids[conf_key_id] = 1
        key = str(bytearray([randint(0, 255) for _ in range(randint(1, 20))]))
        return VppBFDAuthKey(test=test, auth_type=auth_type,
                             conf_key_id=conf_key_id, key=key)


@unittest.skipUnless(running_extended_tests(), "part of extended tests")
class BFDAPITestCase(VppTestCase):
    """Bidirectional Forwarding Detection (BFD) - API"""

    pg0 = None
    pg1 = None

    @classmethod
    def setUpClass(cls):
        super(BFDAPITestCase, cls).setUpClass()

        try:
            cls.create_pg_interfaces(range(2))
            for i in cls.pg_interfaces:
                i.config_ip4()
                i.config_ip6()
                i.resolve_arp()

        except Exception:
            super(BFDAPITestCase, cls).tearDownClass()
            raise

    def setUp(self):
        super(BFDAPITestCase, self).setUp()
        self.factory = AuthKeyFactory()

    def test_add_bfd(self):
        """ create a BFD session """
        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4)
        session.add_vpp_config()
        self.logger.debug("Session state is %s", session.state)
        session.remove_vpp_config()
        session.add_vpp_config()
        self.logger.debug("Session state is %s", session.state)
        session.remove_vpp_config()

    def test_double_add(self):
        """ create the same BFD session twice (negative case) """
        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4)
        session.add_vpp_config()

        with self.vapi.expect_negative_api_retval():
            session.add_vpp_config()

        session.remove_vpp_config()

    def test_add_bfd6(self):
        """ create IPv6 BFD session """
        session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip6, af=AF_INET6)
        session.add_vpp_config()
        self.logger.debug("Session state is %s", session.state)
        session.remove_vpp_config()
        session.add_vpp_config()
        self.logger.debug("Session state is %s", session.state)
        session.remove_vpp_config()

    def test_mod_bfd(self):
        """ modify BFD session parameters """
        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4,
                                   desired_min_tx=50000,
                                   required_min_rx=10000,
                                   detect_mult=1)
        session.add_vpp_config()
        s = session.get_bfd_udp_session_dump_entry()
        self.assert_equal(session.desired_min_tx,
                          s.desired_min_tx,
                          "desired min transmit interval")
        self.assert_equal(session.required_min_rx,
                          s.required_min_rx,
                          "required min receive interval")
        self.assert_equal(session.detect_mult, s.detect_mult, "detect mult")
        session.modify_parameters(desired_min_tx=session.desired_min_tx * 2,
                                  required_min_rx=session.required_min_rx * 2,
                                  detect_mult=session.detect_mult * 2)
        s = session.get_bfd_udp_session_dump_entry()
        self.assert_equal(session.desired_min_tx,
                          s.desired_min_tx,
                          "desired min transmit interval")
        self.assert_equal(session.required_min_rx,
                          s.required_min_rx,
                          "required min receive interval")
        self.assert_equal(session.detect_mult, s.detect_mult, "detect mult")

    def test_add_sha1_keys(self):
        """ add SHA1 keys """
        key_count = 10
        keys = [self.factory.create_random_key(
            self) for i in range(0, key_count)]
        for key in keys:
            self.assertFalse(key.query_vpp_config())
        for key in keys:
            key.add_vpp_config()
        for key in keys:
            self.assertTrue(key.query_vpp_config())
        # remove randomly
        indexes = range(key_count)
        shuffle(indexes)
        removed = []
        for i in indexes:
            key = keys[i]
            key.remove_vpp_config()
            removed.append(i)
            for j in range(key_count):
                key = keys[j]
                if j in removed:
                    self.assertFalse(key.query_vpp_config())
                else:
                    self.assertTrue(key.query_vpp_config())
        # should be removed now
        for key in keys:
            self.assertFalse(key.query_vpp_config())
        # add back and remove again
        for key in keys:
            key.add_vpp_config()
        for key in keys:
            self.assertTrue(key.query_vpp_config())
        for key in keys:
            key.remove_vpp_config()
        for key in keys:
            self.assertFalse(key.query_vpp_config())

    def test_add_bfd_sha1(self):
        """ create a BFD session (SHA1) """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4,
                                   sha1_key=key)
        session.add_vpp_config()
        self.logger.debug("Session state is %s", session.state)
        session.remove_vpp_config()
        session.add_vpp_config()
        self.logger.debug("Session state is %s", session.state)
        session.remove_vpp_config()

    def test_double_add_sha1(self):
        """ create the same BFD session twice (negative case) (SHA1) """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4,
                                   sha1_key=key)
        session.add_vpp_config()
        with self.assertRaises(Exception):
            session.add_vpp_config()

    def test_add_auth_nonexistent_key(self):
        """ create BFD session using non-existent SHA1 (negative case) """
        session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip4,
            sha1_key=self.factory.create_random_key(self))
        with self.assertRaises(Exception):
            session.add_vpp_config()

    def test_shared_sha1_key(self):
        """ share single SHA1 key between multiple BFD sessions """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        sessions = [
            VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4,
                             sha1_key=key),
            VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip6,
                             sha1_key=key, af=AF_INET6),
            VppBFDUDPSession(self, self.pg1, self.pg1.remote_ip4,
                             sha1_key=key),
            VppBFDUDPSession(self, self.pg1, self.pg1.remote_ip6,
                             sha1_key=key, af=AF_INET6)]
        for s in sessions:
            s.add_vpp_config()
        removed = 0
        for s in sessions:
            e = key.get_bfd_auth_keys_dump_entry()
            self.assert_equal(e.use_count, len(sessions) - removed,
                              "Use count for shared key")
            s.remove_vpp_config()
            removed += 1
        e = key.get_bfd_auth_keys_dump_entry()
        self.assert_equal(e.use_count, len(sessions) - removed,
                          "Use count for shared key")

    def test_activate_auth(self):
        """ activate SHA1 authentication """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4)
        session.add_vpp_config()
        session.activate_auth(key)

    def test_deactivate_auth(self):
        """ deactivate SHA1 authentication """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4)
        session.add_vpp_config()
        session.activate_auth(key)
        session.deactivate_auth()

    def test_change_key(self):
        """ change SHA1 key """
        key1 = self.factory.create_random_key(self)
        key2 = self.factory.create_random_key(self)
        while key2.conf_key_id == key1.conf_key_id:
            key2 = self.factory.create_random_key(self)
        key1.add_vpp_config()
        key2.add_vpp_config()
        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4,
                                   sha1_key=key1)
        session.add_vpp_config()
        session.activate_auth(key2)


@unittest.skipUnless(running_extended_tests(), "part of extended tests")
class BFDTestSession(object):
    """ BFD session as seen from test framework side """

    def __init__(self, test, interface, af, detect_mult=3, sha1_key=None,
                 bfd_key_id=None, our_seq_number=None):
        self.test = test
        self.af = af
        self.sha1_key = sha1_key
        self.bfd_key_id = bfd_key_id
        self.interface = interface
        self.udp_sport = randint(49152, 65535)
        if our_seq_number is None:
            self.our_seq_number = randint(0, 40000000)
        else:
            self.our_seq_number = our_seq_number
        self.vpp_seq_number = None
        self.my_discriminator = 0
        self.desired_min_tx = 300000
        self.required_min_rx = 300000
        self.required_min_echo_rx = None
        self.detect_mult = detect_mult
        self.diag = BFDDiagCode.no_diagnostic
        self.your_discriminator = None
        self.state = BFDState.down
        self.auth_type = BFDAuthType.no_auth

    def inc_seq_num(self):
        """ increment sequence number, wrapping if needed """
        if self.our_seq_number == 0xFFFFFFFF:
            self.our_seq_number = 0
        else:
            self.our_seq_number += 1

    def update(self, my_discriminator=None, your_discriminator=None,
               desired_min_tx=None, required_min_rx=None,
               required_min_echo_rx=None, detect_mult=None,
               diag=None, state=None, auth_type=None):
        """ update BFD parameters associated with session """
        if my_discriminator is not None:
            self.my_discriminator = my_discriminator
        if your_discriminator is not None:
            self.your_discriminator = your_discriminator
        if required_min_rx is not None:
            self.required_min_rx = required_min_rx
        if required_min_echo_rx is not None:
            self.required_min_echo_rx = required_min_echo_rx
        if desired_min_tx is not None:
            self.desired_min_tx = desired_min_tx
        if detect_mult is not None:
            self.detect_mult = detect_mult
        if diag is not None:
            self.diag = diag
        if state is not None:
            self.state = state
        if auth_type is not None:
            self.auth_type = auth_type

    def fill_packet_fields(self, packet):
        """ set packet fields with known values in packet """
        bfd = packet[BFD]
        if self.my_discriminator:
            self.test.logger.debug("BFD: setting packet.my_discriminator=%s",
                                   self.my_discriminator)
            bfd.my_discriminator = self.my_discriminator
        if self.your_discriminator:
            self.test.logger.debug("BFD: setting packet.your_discriminator=%s",
                                   self.your_discriminator)
            bfd.your_discriminator = self.your_discriminator
        if self.required_min_rx:
            self.test.logger.debug(
                "BFD: setting packet.required_min_rx_interval=%s",
                self.required_min_rx)
            bfd.required_min_rx_interval = self.required_min_rx
        if self.required_min_echo_rx:
            self.test.logger.debug(
                "BFD: setting packet.required_min_echo_rx=%s",
                self.required_min_echo_rx)
            bfd.required_min_echo_rx_interval = self.required_min_echo_rx
        if self.desired_min_tx:
            self.test.logger.debug(
                "BFD: setting packet.desired_min_tx_interval=%s",
                self.desired_min_tx)
            bfd.desired_min_tx_interval = self.desired_min_tx
        if self.detect_mult:
            self.test.logger.debug(
                "BFD: setting packet.detect_mult=%s", self.detect_mult)
            bfd.detect_mult = self.detect_mult
        if self.diag:
            self.test.logger.debug("BFD: setting packet.diag=%s", self.diag)
            bfd.diag = self.diag
        if self.state:
            self.test.logger.debug("BFD: setting packet.state=%s", self.state)
            bfd.state = self.state
        if self.auth_type:
            # this is used by a negative test-case
            self.test.logger.debug("BFD: setting packet.auth_type=%s",
                                   self.auth_type)
            bfd.auth_type = self.auth_type

    def create_packet(self):
        """ create a BFD packet, reflecting the current state of session """
        if self.sha1_key:
            bfd = BFD(flags="A")
            bfd.auth_type = self.sha1_key.auth_type
            bfd.auth_len = BFD.sha1_auth_len
            bfd.auth_key_id = self.bfd_key_id
            bfd.auth_seq_num = self.our_seq_number
            bfd.length = BFD.sha1_auth_len + BFD.bfd_pkt_len
        else:
            bfd = BFD()
        if self.af == AF_INET6:
            packet = (Ether(src=self.interface.remote_mac,
                            dst=self.interface.local_mac) /
                      IPv6(src=self.interface.remote_ip6,
                           dst=self.interface.local_ip6,
                           hlim=255) /
                      UDP(sport=self.udp_sport, dport=BFD.udp_dport) /
                      bfd)
        else:
            packet = (Ether(src=self.interface.remote_mac,
                            dst=self.interface.local_mac) /
                      IP(src=self.interface.remote_ip4,
                         dst=self.interface.local_ip4,
                         ttl=255) /
                      UDP(sport=self.udp_sport, dport=BFD.udp_dport) /
                      bfd)
        self.test.logger.debug("BFD: Creating packet")
        self.fill_packet_fields(packet)
        if self.sha1_key:
            hash_material = str(packet[BFD])[:32] + self.sha1_key.key + \
                "\0" * (20 - len(self.sha1_key.key))
            self.test.logger.debug("BFD: Calculated SHA1 hash: %s" %
                                   hashlib.sha1(hash_material).hexdigest())
            packet[BFD].auth_key_hash = hashlib.sha1(hash_material).digest()
        return packet

    def send_packet(self, packet=None, interface=None):
        """ send packet on interface, creating the packet if needed """
        if packet is None:
            packet = self.create_packet()
        if interface is None:
            interface = self.test.pg0
        self.test.logger.debug(ppp("Sending packet:", packet))
        interface.add_stream(packet)
        self.test.pg_start()

    def verify_sha1_auth(self, packet):
        """ Verify correctness of authentication in BFD layer. """
        bfd = packet[BFD]
        self.test.assert_equal(bfd.auth_len, 28, "Auth section length")
        self.test.assert_equal(bfd.auth_type, self.sha1_key.auth_type,
                               BFDAuthType)
        self.test.assert_equal(bfd.auth_key_id, self.bfd_key_id, "Key ID")
        self.test.assert_equal(bfd.auth_reserved, 0, "Reserved")
        if self.vpp_seq_number is None:
            self.vpp_seq_number = bfd.auth_seq_num
            self.test.logger.debug("Received initial sequence number: %s" %
                                   self.vpp_seq_number)
        else:
            recvd_seq_num = bfd.auth_seq_num
            self.test.logger.debug("Received followup sequence number: %s" %
                                   recvd_seq_num)
            if self.vpp_seq_number < 0xffffffff:
                if self.sha1_key.auth_type == \
                        BFDAuthType.meticulous_keyed_sha1:
                    self.test.assert_equal(recvd_seq_num,
                                           self.vpp_seq_number + 1,
                                           "BFD sequence number")
                else:
                    self.test.assert_in_range(recvd_seq_num,
                                              self.vpp_seq_number,
                                              self.vpp_seq_number + 1,
                                              "BFD sequence number")
            else:
                if self.sha1_key.auth_type == \
                        BFDAuthType.meticulous_keyed_sha1:
                    self.test.assert_equal(recvd_seq_num, 0,
                                           "BFD sequence number")
                else:
                    self.test.assertIn(recvd_seq_num, (self.vpp_seq_number, 0),
                                       "BFD sequence number not one of "
                                       "(%s, 0)" % self.vpp_seq_number)
            self.vpp_seq_number = recvd_seq_num
        # last 20 bytes represent the hash - so replace them with the key,
        # pad the result with zeros and hash the result
        hash_material = bfd.original[:-20] + self.sha1_key.key + \
            "\0" * (20 - len(self.sha1_key.key))
        expected_hash = hashlib.sha1(hash_material).hexdigest()
        self.test.assert_equal(binascii.hexlify(bfd.auth_key_hash),
                               expected_hash, "Auth key hash")

    def verify_bfd(self, packet):
        """ Verify correctness of BFD layer. """
        bfd = packet[BFD]
        self.test.assert_equal(bfd.version, 1, "BFD version")
        self.test.assert_equal(bfd.your_discriminator,
                               self.my_discriminator,
                               "BFD - your discriminator")
        if self.sha1_key:
            self.verify_sha1_auth(packet)


def bfd_session_up(test):
    """ Bring BFD session up """
    test.logger.info("BFD: Waiting for slow hello")
    p = wait_for_bfd_packet(test, 2)
    old_offset = None
    if hasattr(test, 'vpp_clock_offset'):
        old_offset = test.vpp_clock_offset
    test.vpp_clock_offset = time.time() - p.time
    test.logger.debug("BFD: Calculated vpp clock offset: %s",
                      test.vpp_clock_offset)
    if old_offset:
        test.assertAlmostEqual(
            old_offset, test.vpp_clock_offset, delta=0.5,
            msg="vpp clock offset not stable (new: %s, old: %s)" %
            (test.vpp_clock_offset, old_offset))
    test.logger.info("BFD: Sending Init")
    test.test_session.update(my_discriminator=randint(0, 40000000),
                             your_discriminator=p[BFD].my_discriminator,
                             state=BFDState.init)
    if test.test_session.sha1_key and test.test_session.sha1_key.auth_type == \
            BFDAuthType.meticulous_keyed_sha1:
        test.test_session.inc_seq_num()
    test.test_session.send_packet()
    test.logger.info("BFD: Waiting for event")
    e = test.vapi.wait_for_event(1, "bfd_udp_session_details")
    verify_event(test, e, expected_state=BFDState.up)
    test.logger.info("BFD: Session is Up")
    test.test_session.update(state=BFDState.up)
    if test.test_session.sha1_key and test.test_session.sha1_key.auth_type == \
            BFDAuthType.meticulous_keyed_sha1:
        test.test_session.inc_seq_num()
    test.test_session.send_packet()
    test.assert_equal(test.vpp_session.state, BFDState.up, BFDState)


def bfd_session_down(test):
    """ Bring BFD session down """
    test.assert_equal(test.vpp_session.state, BFDState.up, BFDState)
    test.test_session.update(state=BFDState.down)
    if test.test_session.sha1_key and test.test_session.sha1_key.auth_type == \
            BFDAuthType.meticulous_keyed_sha1:
        test.test_session.inc_seq_num()
    test.test_session.send_packet()
    test.logger.info("BFD: Waiting for event")
    e = test.vapi.wait_for_event(1, "bfd_udp_session_details")
    verify_event(test, e, expected_state=BFDState.down)
    test.logger.info("BFD: Session is Down")
    test.assert_equal(test.vpp_session.state, BFDState.down, BFDState)


def verify_bfd_session_config(test, session, state=None):
    dump = session.get_bfd_udp_session_dump_entry()
    test.assertIsNotNone(dump)
    # since dump is not none, we have verified that sw_if_index and addresses
    # are valid (in get_bfd_udp_session_dump_entry)
    if state:
        test.assert_equal(dump.state, state, "session state")
    test.assert_equal(dump.required_min_rx, session.required_min_rx,
                      "required min rx interval")
    test.assert_equal(dump.desired_min_tx, session.desired_min_tx,
                      "desired min tx interval")
    test.assert_equal(dump.detect_mult, session.detect_mult,
                      "detect multiplier")
    if session.sha1_key is None:
        test.assert_equal(dump.is_authenticated, 0, "is_authenticated flag")
    else:
        test.assert_equal(dump.is_authenticated, 1, "is_authenticated flag")
        test.assert_equal(dump.bfd_key_id, session.bfd_key_id,
                          "bfd key id")
        test.assert_equal(dump.conf_key_id,
                          session.sha1_key.conf_key_id,
                          "config key id")


def verify_ip(test, packet):
    """ Verify correctness of IP layer. """
    if test.vpp_session.af == AF_INET6:
        ip = packet[IPv6]
        local_ip = test.pg0.local_ip6
        remote_ip = test.pg0.remote_ip6
        test.assert_equal(ip.hlim, 255, "IPv6 hop limit")
    else:
        ip = packet[IP]
        local_ip = test.pg0.local_ip4
        remote_ip = test.pg0.remote_ip4
        test.assert_equal(ip.ttl, 255, "IPv4 TTL")
    test.assert_equal(ip.src, local_ip, "IP source address")
    test.assert_equal(ip.dst, remote_ip, "IP destination address")


def verify_udp(test, packet):
    """ Verify correctness of UDP layer. """
    udp = packet[UDP]
    test.assert_equal(udp.dport, BFD.udp_dport, "UDP destination port")
    test.assert_in_range(udp.sport, BFD.udp_sport_min, BFD.udp_sport_max,
                         "UDP source port")


def verify_event(test, event, expected_state):
    """ Verify correctness of event values. """
    e = event
    test.logger.debug("BFD: Event: %s" % repr(e))
    test.assert_equal(e.sw_if_index,
                      test.vpp_session.interface.sw_if_index,
                      "BFD interface index")
    is_ipv6 = 0
    if test.vpp_session.af == AF_INET6:
        is_ipv6 = 1
    test.assert_equal(e.is_ipv6, is_ipv6, "is_ipv6")
    if test.vpp_session.af == AF_INET:
        test.assert_equal(e.local_addr[:4], test.vpp_session.local_addr_n,
                          "Local IPv4 address")
        test.assert_equal(e.peer_addr[:4], test.vpp_session.peer_addr_n,
                          "Peer IPv4 address")
    else:
        test.assert_equal(e.local_addr, test.vpp_session.local_addr_n,
                          "Local IPv6 address")
        test.assert_equal(e.peer_addr, test.vpp_session.peer_addr_n,
                          "Peer IPv6 address")
    test.assert_equal(e.state, expected_state, BFDState)


def wait_for_bfd_packet(test, timeout=1, pcap_time_min=None):
    """ wait for BFD packet and verify its correctness

    :param timeout: how long to wait
    :param pcap_time_min: ignore packets with pcap timestamp lower than this

    :returns: tuple (packet, time spent waiting for packet)
    """
    test.logger.info("BFD: Waiting for BFD packet")
    deadline = time.time() + timeout
    counter = 0
    while True:
        counter += 1
        # sanity check
        test.assert_in_range(counter, 0, 100, "number of packets ignored")
        time_left = deadline - time.time()
        if time_left < 0:
            raise CaptureTimeoutError("Packet did not arrive within timeout")
        p = test.pg0.wait_for_packet(timeout=time_left)
        test.logger.debug(ppp("BFD: Got packet:", p))
        if pcap_time_min is not None and p.time < pcap_time_min:
            test.logger.debug(ppp("BFD: ignoring packet (pcap time %s < "
                                  "pcap time min %s):" %
                                  (p.time, pcap_time_min), p))
        else:
            break
    bfd = p[BFD]
    if bfd is None:
        raise Exception(ppp("Unexpected or invalid BFD packet:", p))
    if bfd.payload:
        raise Exception(ppp("Unexpected payload in BFD packet:", bfd))
    verify_ip(test, p)
    verify_udp(test, p)
    test.test_session.verify_bfd(p)
    return p


@unittest.skipUnless(running_extended_tests(), "part of extended tests")
class BFD4TestCase(VppTestCase):
    """Bidirectional Forwarding Detection (BFD)"""

    pg0 = None
    vpp_clock_offset = None
    vpp_session = None
    test_session = None

    @classmethod
    def setUpClass(cls):
        super(BFD4TestCase, cls).setUpClass()
        try:
            cls.create_pg_interfaces([0])
            cls.create_loopback_interfaces([0])
            cls.loopback0 = cls.lo_interfaces[0]
            cls.loopback0.config_ip4()
            cls.loopback0.admin_up()
            cls.pg0.config_ip4()
            cls.pg0.configure_ipv4_neighbors()
            cls.pg0.admin_up()
            cls.pg0.resolve_arp()

        except Exception:
            super(BFD4TestCase, cls).tearDownClass()
            raise

    def setUp(self):
        super(BFD4TestCase, self).setUp()
        self.factory = AuthKeyFactory()
        self.vapi.want_bfd_events()
        self.pg0.enable_capture()
        try:
            self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                                self.pg0.remote_ip4)
            self.vpp_session.add_vpp_config()
            self.vpp_session.admin_up()
            self.test_session = BFDTestSession(self, self.pg0, AF_INET)
        except:
            self.vapi.want_bfd_events(enable_disable=0)
            raise

    def tearDown(self):
        if not self.vpp_dead:
            self.vapi.want_bfd_events(enable_disable=0)
        self.vapi.collect_events()  # clear the event queue
        super(BFD4TestCase, self).tearDown()

    def test_session_up(self):
        """ bring BFD session up """
        bfd_session_up(self)

    def test_session_up_by_ip(self):
        """ bring BFD session up - first frame looked up by address pair """
        self.logger.info("BFD: Sending Slow control frame")
        self.test_session.update(my_discriminator=randint(0, 40000000))
        self.test_session.send_packet()
        self.pg0.enable_capture()
        p = self.pg0.wait_for_packet(1)
        self.assert_equal(p[BFD].your_discriminator,
                          self.test_session.my_discriminator,
                          "BFD - your discriminator")
        self.assert_equal(p[BFD].state, BFDState.init, BFDState)
        self.test_session.update(your_discriminator=p[BFD].my_discriminator,
                                 state=BFDState.up)
        self.logger.info("BFD: Waiting for event")
        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
        verify_event(self, e, expected_state=BFDState.init)
        self.logger.info("BFD: Sending Up")
        self.test_session.send_packet()
        self.logger.info("BFD: Waiting for event")
        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
        verify_event(self, e, expected_state=BFDState.up)
        self.logger.info("BFD: Session is Up")
        self.test_session.update(state=BFDState.up)
        self.test_session.send_packet()
        self.assert_equal(self.vpp_session.state, BFDState.up, BFDState)

    def test_session_down(self):
        """ bring BFD session down """
        bfd_session_up(self)
        bfd_session_down(self)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_hold_up(self):
        """ hold BFD session up """
        bfd_session_up(self)
        for dummy in range(self.test_session.detect_mult * 2):
            wait_for_bfd_packet(self)
            self.test_session.send_packet()
        self.assert_equal(len(self.vapi.collect_events()), 0,
                          "number of bfd events")

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_slow_timer(self):
        """ verify slow periodic control frames while session down """
        packet_count = 3
        self.logger.info("BFD: Waiting for %d BFD packets", packet_count)
        prev_packet = wait_for_bfd_packet(self, 2)
        for dummy in range(packet_count):
            next_packet = wait_for_bfd_packet(self, 2)
            time_diff = next_packet.time - prev_packet.time
            # spec says the range should be <0.75, 1>, allow extra 0.05 margin
            # to work around timing issues
            self.assert_in_range(
                time_diff, 0.70, 1.05, "time between slow packets")
            prev_packet = next_packet

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_zero_remote_min_rx(self):
        """ no packets when zero remote required min rx interval """
        bfd_session_up(self)
        self.test_session.update(required_min_rx=0)
        self.test_session.send_packet()
        for dummy in range(self.test_session.detect_mult):
            self.sleep(self.vpp_session.required_min_rx / USEC_IN_SEC,
                       "sleep before transmitting bfd packet")
            self.test_session.send_packet()
            try:
                p = wait_for_bfd_packet(self, timeout=0)
                self.logger.error(ppp("Received unexpected packet:", p))
            except CaptureTimeoutError:
                pass
        self.assert_equal(
            len(self.vapi.collect_events()), 0, "number of bfd events")
        self.test_session.update(required_min_rx=300000)
        for dummy in range(3):
            self.test_session.send_packet()
            wait_for_bfd_packet(
                self, timeout=self.test_session.required_min_rx / USEC_IN_SEC)
        self.assert_equal(
            len(self.vapi.collect_events()), 0, "number of bfd events")

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_conn_down(self):
        """ verify session goes down after inactivity """
        bfd_session_up(self)
        detection_time = self.test_session.detect_mult *\
            self.vpp_session.required_min_rx / USEC_IN_SEC
        self.sleep(detection_time, "waiting for BFD session time-out")
        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
        verify_event(self, e, expected_state=BFDState.down)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_large_required_min_rx(self):
        """ large remote required min rx interval """
        bfd_session_up(self)
        p = wait_for_bfd_packet(self)
        interval = 3000000
        self.test_session.update(required_min_rx=interval)
        self.test_session.send_packet()
        time_mark = time.time()
        count = 0
        # busy wait here, trying to collect a packet or event, vpp is not
        # allowed to send packets and the session will timeout first - so the
        # Up->Down event must arrive before any packets do
        while time.time() < time_mark + interval / USEC_IN_SEC:
            try:
                p = wait_for_bfd_packet(self, timeout=0)
                # if vpp managed to send a packet before we did the session
                # session update, then that's fine, ignore it
                if p.time < time_mark - self.vpp_clock_offset:
                    continue
                self.logger.error(ppp("Received unexpected packet:", p))
                count += 1
            except CaptureTimeoutError:
                pass
            events = self.vapi.collect_events()
            if len(events) > 0:
                verify_event(self, events[0], BFDState.down)
                break
        self.assert_equal(count, 0, "number of packets received")

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_immediate_remote_min_rx_reduction(self):
        """ immediately honor remote required min rx reduction """
        self.vpp_session.remove_vpp_config()
        self.vpp_session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip4, desired_min_tx=10000)
        self.pg0.enable_capture()
        self.vpp_session.add_vpp_config()
        self.test_session.update(desired_min_tx=1000000,
                                 required_min_rx=1000000)
        bfd_session_up(self)
        reference_packet = wait_for_bfd_packet(self)
        time_mark = time.time()
        interval = 300000
        self.test_session.update(required_min_rx=interval)
        self.test_session.send_packet()
        extra_time = time.time() - time_mark
        p = wait_for_bfd_packet(self)
        # first packet is allowed to be late by time we spent doing the update
        # calculated in extra_time
        self.assert_in_range(p.time - reference_packet.time,
                             .95 * 0.75 * interval / USEC_IN_SEC,
                             1.05 * interval / USEC_IN_SEC + extra_time,
                             "time between BFD packets")
        reference_packet = p
        for dummy in range(3):
            p = wait_for_bfd_packet(self)
            diff = p.time - reference_packet.time
            self.assert_in_range(diff, .95 * .75 * interval / USEC_IN_SEC,
                                 1.05 * interval / USEC_IN_SEC,
                                 "time between BFD packets")
            reference_packet = p

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_modify_req_min_rx_double(self):
        """ modify session - double required min rx """
        bfd_session_up(self)
        p = wait_for_bfd_packet(self)
        self.test_session.update(desired_min_tx=10000,
                                 required_min_rx=10000)
        self.test_session.send_packet()
        # double required min rx
        self.vpp_session.modify_parameters(
            required_min_rx=2 * self.vpp_session.required_min_rx)
        p = wait_for_bfd_packet(
            self, pcap_time_min=time.time() - self.vpp_clock_offset)
        # poll bit needs to be set
        self.assertIn("P", p.sprintf("%BFD.flags%"),
                      "Poll bit not set in BFD packet")
        # finish poll sequence with final packet
        final = self.test_session.create_packet()
        final[BFD].flags = "F"
        timeout = self.test_session.detect_mult * \
            max(self.test_session.desired_min_tx,
                self.vpp_session.required_min_rx) / USEC_IN_SEC
        self.test_session.send_packet(final)
        time_mark = time.time()
        e = self.vapi.wait_for_event(2 * timeout, "bfd_udp_session_details")
        verify_event(self, e, expected_state=BFDState.down)
        time_to_event = time.time() - time_mark
        self.assert_in_range(time_to_event, .9 * timeout,
                             1.1 * timeout, "session timeout")

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_modify_req_min_rx_halve(self):
        """ modify session - halve required min rx """
        self.vpp_session.modify_parameters(
            required_min_rx=2 * self.vpp_session.required_min_rx)
        bfd_session_up(self)
        p = wait_for_bfd_packet(self)
        self.test_session.update(desired_min_tx=10000,
                                 required_min_rx=10000)
        self.test_session.send_packet()
        p = wait_for_bfd_packet(
            self, pcap_time_min=time.time() - self.vpp_clock_offset)
        # halve required min rx
        old_required_min_rx = self.vpp_session.required_min_rx
        self.vpp_session.modify_parameters(
            required_min_rx=0.5 * self.vpp_session.required_min_rx)
        # now we wait 0.8*3*old-req-min-rx and the session should still be up
        self.sleep(0.8 * self.vpp_session.detect_mult *
                   old_required_min_rx / USEC_IN_SEC,
                   "wait before finishing poll sequence")
        self.assert_equal(len(self.vapi.collect_events()), 0,
                          "number of bfd events")
        p = wait_for_bfd_packet(self)
        # poll bit needs to be set
        self.assertIn("P", p.sprintf("%BFD.flags%"),
                      "Poll bit not set in BFD packet")
        # finish poll sequence with final packet
        final = self.test_session.create_packet()
        final[BFD].flags = "F"
        self.test_session.send_packet(final)
        # now the session should time out under new conditions
        detection_time = self.test_session.detect_mult *\
            self.vpp_session.required_min_rx / USEC_IN_SEC
        before = time.time()
        e = self.vapi.wait_for_event(
            2 * detection_time, "bfd_udp_session_details")
        after = time.time()
        self.assert_in_range(after - before,
                             0.9 * detection_time,
                             1.1 * detection_time,
                             "time before bfd session goes down")
        verify_event(self, e, expected_state=BFDState.down)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_modify_detect_mult(self):
        """ modify detect multiplier """
        bfd_session_up(self)
        p = wait_for_bfd_packet(self)
        self.vpp_session.modify_parameters(detect_mult=1)
        p = wait_for_bfd_packet(
            self, pcap_time_min=time.time() - self.vpp_clock_offset)
        self.assert_equal(self.vpp_session.detect_mult,
                          p[BFD].detect_mult,
                          "detect mult")
        # poll bit must not be set
        self.assertNotIn("P", p.sprintf("%BFD.flags%"),
                         "Poll bit not set in BFD packet")
        self.vpp_session.modify_parameters(detect_mult=10)
        p = wait_for_bfd_packet(
            self, pcap_time_min=time.time() - self.vpp_clock_offset)
        self.assert_equal(self.vpp_session.detect_mult,
                          p[BFD].detect_mult,
                          "detect mult")
        # poll bit must not be set
        self.assertNotIn("P", p.sprintf("%BFD.flags%"),
                         "Poll bit not set in BFD packet")

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_queued_poll(self):
        """ test poll sequence queueing """
        bfd_session_up(self)
        p = wait_for_bfd_packet(self)
        self.vpp_session.modify_parameters(
            required_min_rx=2 * self.vpp_session.required_min_rx)
        p = wait_for_bfd_packet(self)
        poll_sequence_start = time.time()
        poll_sequence_length_min = 0.5
        send_final_after = time.time() + poll_sequence_length_min
        # poll bit needs to be set
        self.assertIn("P", p.sprintf("%BFD.flags%"),
                      "Poll bit not set in BFD packet")
        self.assert_equal(p[BFD].required_min_rx_interval,
                          self.vpp_session.required_min_rx,
                          "BFD required min rx interval")
        self.vpp_session.modify_parameters(
            required_min_rx=2 * self.vpp_session.required_min_rx)
        # 2nd poll sequence should be queued now
        # don't send the reply back yet, wait for some time to emulate
        # longer round-trip time
        packet_count = 0
        while time.time() < send_final_after:
            self.test_session.send_packet()
            p = wait_for_bfd_packet(self)
            self.assert_equal(len(self.vapi.collect_events()), 0,
                              "number of bfd events")
            self.assert_equal(p[BFD].required_min_rx_interval,
                              self.vpp_session.required_min_rx,
                              "BFD required min rx interval")
            packet_count += 1
            # poll bit must be set
            self.assertIn("P", p.sprintf("%BFD.flags%"),
                          "Poll bit not set in BFD packet")
        final = self.test_session.create_packet()
        final[BFD].flags = "F"
        self.test_session.send_packet(final)
        # finish 1st with final
        poll_sequence_length = time.time() - poll_sequence_start
        # vpp must wait for some time before starting new poll sequence
        poll_no_2_started = False
        for dummy in range(2 * packet_count):
            p = wait_for_bfd_packet(self)
            self.assert_equal(len(self.vapi.collect_events()), 0,
                              "number of bfd events")
            if "P" in p.sprintf("%BFD.flags%"):
                poll_no_2_started = True
                if time.time() < poll_sequence_start + poll_sequence_length:
                    raise Exception("VPP started 2nd poll sequence too soon")
                final = self.test_session.create_packet()
                final[BFD].flags = "F"
                self.test_session.send_packet(final)
                break
            else:
                self.test_session.send_packet()
        self.assertTrue(poll_no_2_started, "2nd poll sequence not performed")
        # finish 2nd with final
        final = self.test_session.create_packet()
        final[BFD].flags = "F"
        self.test_session.send_packet(final)
        p = wait_for_bfd_packet(self)
        # poll bit must not be set
        self.assertNotIn("P", p.sprintf("%BFD.flags%"),
                         "Poll bit set in BFD packet")

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_poll_response(self):
        """ test correct response to control frame with poll bit set """
        bfd_session_up(self)
        poll = self.test_session.create_packet()
        poll[BFD].flags = "P"
        self.test_session.send_packet(poll)
        final = wait_for_bfd_packet(
            self, pcap_time_min=time.time() - self.vpp_clock_offset)
        self.assertIn("F", final.sprintf("%BFD.flags%"))

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_no_periodic_if_remote_demand(self):
        """ no periodic frames outside poll sequence if remote demand set """
        bfd_session_up(self)
        demand = self.test_session.create_packet()
        demand[BFD].flags = "D"
        self.test_session.send_packet(demand)
        transmit_time = 0.9 \
            * max(self.vpp_session.required_min_rx,
                  self.test_session.desired_min_tx) \
            / USEC_IN_SEC
        count = 0
        for dummy in range(self.test_session.detect_mult * 2):
            time.sleep(transmit_time)
            self.test_session.send_packet(demand)
            try:
                p = wait_for_bfd_packet(self, timeout=0)
                self.logger.error(ppp("Received unexpected packet:", p))
                count += 1
            except CaptureTimeoutError:
                pass
        events = self.vapi.collect_events()
        for e in events:
            self.logger.error("Received unexpected event: %s", e)
        self.assert_equal(count, 0, "number of packets received")
        self.assert_equal(len(events), 0, "number of events received")

    def test_echo_looped_back(self):
        """ echo packets looped back """
        # don't need a session in this case..
        self.vpp_session.remove_vpp_config()
        self.pg0.enable_capture()
        echo_packet_count = 10
        # random source port low enough to increment a few times..
        udp_sport_tx = randint(1, 50000)
        udp_sport_rx = udp_sport_tx
        echo_packet = (Ether(src=self.pg0.remote_mac,
                             dst=self.pg0.local_mac) /
                       IP(src=self.pg0.remote_ip4,
                          dst=self.pg0.remote_ip4) /
                       UDP(dport=BFD.udp_dport_echo) /
                       Raw("this should be looped back"))
        for dummy in range(echo_packet_count):
            self.sleep(.01, "delay between echo packets")
            echo_packet[UDP].sport = udp_sport_tx
            udp_sport_tx += 1
            self.logger.debug(ppp("Sending packet:", echo_packet))
            self.pg0.add_stream(echo_packet)
            self.pg_start()
        for dummy in range(echo_packet_count):
            p = self.pg0.wait_for_packet(1)
            self.logger.debug(ppp("Got packet:", p))
            ether = p[Ether]
            self.assert_equal(self.pg0.remote_mac,
                              ether.dst, "Destination MAC")
            self.assert_equal(self.pg0.local_mac, ether.src, "Source MAC")
            ip = p[IP]
            self.assert_equal(self.pg0.remote_ip4, ip.dst, "Destination IP")
            self.assert_equal(self.pg0.remote_ip4, ip.src, "Destination IP")
            udp = p[UDP]
            self.assert_equal(udp.dport, BFD.udp_dport_echo,
                              "UDP destination port")
            self.assert_equal(udp.sport, udp_sport_rx, "UDP source port")
            udp_sport_rx += 1
            # need to compare the hex payload here, otherwise BFD_vpp_echo
            # gets in way
            self.assertEqual(str(p[UDP].payload),
                             str(echo_packet[UDP].payload),
                             "Received packet is not the echo packet sent")
        self.assert_equal(udp_sport_tx, udp_sport_rx, "UDP source port (== "
                          "ECHO packet identifier for test purposes)")

    def test_echo(self):
        """ echo function """
        bfd_session_up(self)
        self.test_session.update(required_min_echo_rx=150000)
        self.test_session.send_packet()
        detection_time = self.test_session.detect_mult *\
            self.vpp_session.required_min_rx / USEC_IN_SEC
        # echo shouldn't work without echo source set
        for dummy in range(10):
            sleep = self.vpp_session.required_min_rx / USEC_IN_SEC
            self.sleep(sleep, "delay before sending bfd packet")
            self.test_session.send_packet()
        p = wait_for_bfd_packet(
            self, pcap_time_min=time.time() - self.vpp_clock_offset)
        self.assert_equal(p[BFD].required_min_rx_interval,
                          self.vpp_session.required_min_rx,
                          "BFD required min rx interval")
        self.test_session.send_packet()
        self.vapi.bfd_udp_set_echo_source(self.loopback0.sw_if_index)
        echo_seen = False
        # should be turned on - loopback echo packets
        for dummy in range(3):
            loop_until = time.time() + 0.75 * detection_time
            while time.time() < loop_until:
                p = self.pg0.wait_for_packet(1)
                self.logger.debug(ppp("Got packet:", p))
                if p[UDP].dport == BFD.udp_dport_echo:
                    self.assert_equal(
                        p[IP].dst, self.pg0.local_ip4, "BFD ECHO dst IP")
                    self.assertNotEqual(p[IP].src, self.loopback0.local_ip4,
                                        "BFD ECHO src IP equal to loopback IP")
                    self.logger.debug(ppp("Looping back packet:", p))
                    self.assert_equal(p[Ether].dst, self.pg0.remote_mac,
                                      "ECHO packet destination MAC address")
                    p[Ether].dst = self.pg0.local_mac
                    self.pg0.add_stream(p)
                    self.pg_start()
                    echo_seen = True
                elif p.haslayer(BFD):
                    if echo_seen:
                        self.assertGreaterEqual(
                            p[BFD].required_min_rx_interval,
                            1000000)
                    if "P" in p.sprintf("%BFD.flags%"):
                        final = self.test_session.create_packet()
                        final[BFD].flags = "F"
                        self.test_session.send_packet(final)
                else:
                    raise Exception(ppp("Received unknown packet:", p))

                self.assert_equal(len(self.vapi.collect_events()), 0,
                                  "number of bfd events")
            self.test_session.send_packet()
        self.assertTrue(echo_seen, "No echo packets received")

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_echo_fail(self):
        """ session goes down if echo function fails """
        bfd_session_up(self)
        self.test_session.update(required_min_echo_rx=150000)
        self.test_session.send_packet()
        detection_time = self.test_session.detect_mult *\
            self.vpp_session.required_min_rx / USEC_IN_SEC
        self.vapi.bfd_udp_set_echo_source(self.loopback0.sw_if_index)
        # echo function should be used now, but we will drop the echo packets
        verified_diag = False
        for dummy in range(3):
            loop_until = time.time() + 0.75 * detection_time
            while time.time() < loop_until:
                p = self.pg0.wait_for_packet(1)
                self.logger.debug(ppp("Got packet:", p))
                if p[UDP].dport == BFD.udp_dport_echo:
                    # dropped
                    pass
                elif p.haslayer(BFD):
                    if "P" in p.sprintf("%BFD.flags%"):
                        self.assertGreaterEqual(
                            p[BFD].required_min_rx_interval,
                            1000000)
                        final = self.test_session.create_packet()
                        final[BFD].flags = "F"
                        self.test_session.send_packet(final)
                    if p[BFD].state == BFDState.down:
                        self.assert_equal(p[BFD].diag,
                                          BFDDiagCode.echo_function_failed,
                                          BFDDiagCode)
                        verified_diag = True
                else:
                    raise Exception(ppp("Received unknown packet:", p))
            self.test_session.send_packet()
        events = self.vapi.collect_events()
        self.assert_equal(len(events), 1, "number of bfd events")
        self.assert_equal(events[0].state, BFDState.down, BFDState)
        self.assertTrue(verified_diag, "Incorrect diagnostics code received")

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_echo_stop(self):
        """ echo function stops if peer sets required min echo rx zero """
        bfd_session_up(self)
        self.test_session.update(required_min_echo_rx=150000)
        self.test_session.send_packet()
        self.vapi.bfd_udp_set_echo_source(self.loopback0.sw_if_index)
        # wait for first echo packet
        while True:
            p = self.pg0.wait_for_packet(1)
            self.logger.debug(ppp("Got packet:", p))
            if p[UDP].dport == BFD.udp_dport_echo:
                self.logger.debug(ppp("Looping back packet:", p))
                p[Ether].dst = self.pg0.local_mac
                self.pg0.add_stream(p)
                self.pg_start()
                break
            elif p.haslayer(BFD):
                # ignore BFD
                pass
            else:
                raise Exception(ppp("Received unknown packet:", p))
        self.test_session.update(required_min_echo_rx=0)
        self.test_session.send_packet()
        # echo packets shouldn't arrive anymore
        for dummy in range(5):
            wait_for_bfd_packet(
                self, pcap_time_min=time.time() - self.vpp_clock_offset)
            self.test_session.send_packet()
            events = self.vapi.collect_events()
            self.assert_equal(len(events), 0, "number of bfd events")

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_echo_source_removed(self):
        """ echo function stops if echo source is removed """
        bfd_session_up(self)
        self.test_session.update(required_min_echo_rx=150000)
        self.test_session.send_packet()
        self.vapi.bfd_udp_set_echo_source(self.loopback0.sw_if_index)
        # wait for first echo packet
        while True:
            p = self.pg0.wait_for_packet(1)
            self.logger.debug(ppp("Got packet:", p))
            if p[UDP].dport == BFD.udp_dport_echo:
                self.logger.debug(ppp("Looping back packet:", p))
                p[Ether].dst = self.pg0.local_mac
                self.pg0.add_stream(p)
                self.pg_start()
                break
            elif p.haslayer(BFD):
                # ignore BFD
                pass
            else:
                raise Exception(ppp("Received unknown packet:", p))
        self.vapi.bfd_udp_del_echo_source()
        self.test_session.send_packet()
        # echo packets shouldn't arrive anymore
        for dummy in range(5):
            wait_for_bfd_packet(
                self, pcap_time_min=time.time() - self.vpp_clock_offset)
            self.test_session.send_packet()
            events = self.vapi.collect_events()
            self.assert_equal(len(events), 0, "number of bfd events")

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_stale_echo(self):
        """ stale echo packets don't keep a session up """
        bfd_session_up(self)
        self.test_session.update(required_min_echo_rx=150000)
        self.vapi.bfd_udp_set_echo_source(self.loopback0.sw_if_index)
        self.test_session.send_packet()
        # should be turned on - loopback echo packets
        echo_packet = None
        timeout_at = None
        timeout_ok = False
        for dummy in range(10 * self.vpp_session.detect_mult):
            p = self.pg0.wait_for_packet(1)
            if p[UDP].dport == BFD.udp_dport_echo:
                if echo_packet is None:
                    self.logger.debug(ppp("Got first echo packet:", p))
                    echo_packet = p
                    timeout_at = time.time() + self.vpp_session.detect_mult * \
                        self.test_session.required_min_echo_rx / USEC_IN_SEC
                else:
                    self.logger.debug(ppp("Got followup echo packet:", p))
                self.logger.debug(ppp("Looping back first echo packet:", p))
                echo_packet[Ether].dst = self.pg0.local_mac
                self.pg0.add_stream(echo_packet)
                self.pg_start()
            elif p.haslayer(BFD):
                self.logger.debug(ppp("Got packet:", p))
                if "P" in p.sprintf("%BFD.flags%"):
                    final = self.test_session.create_packet()
                    final[BFD].flags = "F"
                    self.test_session.send_packet(final)
                if p[BFD].state == BFDState.down:
                    self.assertIsNotNone(
                        timeout_at,
                        "Session went down before first echo packet received")
                    now = time.time()
                    self.assertGreaterEqual(
                        now, timeout_at,
                        "Session timeout at %s, but is expected at %s" %
                        (now, timeout_at))
                    self.assert_equal(p[BFD].diag,
                                      BFDDiagCode.echo_function_failed,
                                      BFDDiagCode)
                    events = self.vapi.collect_events()
                    self.assert_equal(len(events), 1, "number of bfd events")
                    self.assert_equal(events[0].state, BFDState.down, BFDState)
                    timeout_ok = True
                    break
            else:
                raise Exception(ppp("Received unknown packet:", p))
            self.test_session.send_packet()
        self.assertTrue(timeout_ok, "Expected timeout event didn't occur")

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_invalid_echo_checksum(self):
        """ echo packets with invalid checksum don't keep a session up """
        bfd_session_up(self)
        self.test_session.update(required_min_echo_rx=150000)
        self.vapi.bfd_udp_set_echo_source(self.loopback0.sw_if_index)
        self.test_session.send_packet()
        # should be turned on - loopback echo packets
        timeout_at = None
        timeout_ok = False
        for dummy in range(10 * self.vpp_session.detect_mult):
            p = self.pg0.wait_for_packet(1)
            if p[UDP].dport == BFD.udp_dport_echo:
                self.logger.debug(ppp("Got echo packet:", p))
                if timeout_at is None:
                    timeout_at = time.time() + self.vpp_session.detect_mult * \
                        self.test_session.required_min_echo_rx / USEC_IN_SEC
                p[BFD_vpp_echo].checksum = getrandbits(64)
                p[Ether].dst = self.pg0.local_mac
                self.logger.debug(ppp("Looping back modified echo packet:", p))
                self.pg0.add_stream(p)
                self.pg_start()
            elif p.haslayer(BFD):
                self.logger.debug(ppp("Got packet:", p))
                if "P" in p.sprintf("%BFD.flags%"):
                    final = self.test_session.create_packet()
                    final[BFD].flags = "F"
                    self.test_session.send_packet(final)
                if p[BFD].state == BFDState.down:
                    self.assertIsNotNone(
                        timeout_at,
                        "Session went down before first echo packet received")
                    now = time.time()
                    self.assertGreaterEqual(
                        now, timeout_at,
                        "Session timeout at %s, but is expected at %s" %
                        (now, timeout_at))
                    self.assert_equal(p[BFD].diag,
                                      BFDDiagCode.echo_function_failed,
                                      BFDDiagCode)
                    events = self.vapi.collect_events()
                    self.assert_equal(len(events), 1, "number of bfd events")
                    self.assert_equal(events[0].state, BFDState.down, BFDState)
                    timeout_ok = True
                    break
            else:
                raise Exception(ppp("Received unknown packet:", p))
            self.test_session.send_packet()
        self.assertTrue(timeout_ok, "Expected timeout event didn't occur")

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_admin_up_down(self):
        """ put session admin-up and admin-down """
        bfd_session_up(self)
        self.vpp_session.admin_down()
        self.pg0.enable_capture()
        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
        verify_event(self, e, expected_state=BFDState.admin_down)
        for dummy in range(2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.admin_down, BFDState)
        # try to bring session up - shouldn't be possible
        self.test_session.update(state=BFDState.init)
        self.test_session.send_packet()
        for dummy in range(2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.admin_down, BFDState)
        self.vpp_session.admin_up()
        self.test_session.update(state=BFDState.down)
        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
        verify_event(self, e, expected_state=BFDState.down)
        p = wait_for_bfd_packet(
            self, pcap_time_min=time.time() - self.vpp_clock_offset)
        self.assert_equal(p[BFD].state, BFDState.down, BFDState)
        self.test_session.send_packet()
        p = wait_for_bfd_packet(
            self, pcap_time_min=time.time() - self.vpp_clock_offset)
        self.assert_equal(p[BFD].state, BFDState.init, BFDState)
        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
        verify_event(self, e, expected_state=BFDState.init)
        self.test_session.update(state=BFDState.up)
        self.test_session.send_packet()
        p = wait_for_bfd_packet(
            self, pcap_time_min=time.time() - self.vpp_clock_offset)
        self.assert_equal(p[BFD].state, BFDState.up, BFDState)
        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
        verify_event(self, e, expected_state=BFDState.up)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_config_change_remote_demand(self):
        """ configuration change while peer in demand mode """
        bfd_session_up(self)
        demand = self.test_session.create_packet()
        demand[BFD].flags = "D"
        self.test_session.send_packet(demand)
        self.vpp_session.modify_parameters(
            required_min_rx=2 * self.vpp_session.required_min_rx)
        p = wait_for_bfd_packet(
            self, pcap_time_min=time.time() - self.vpp_clock_offset)
        # poll bit must be set
        self.assertIn("P", p.sprintf("%BFD.flags%"), "Poll bit not set")
        # terminate poll sequence
        final = self.test_session.create_packet()
        final[BFD].flags = "D+F"
        self.test_session.send_packet(final)
        # vpp should be quiet now again
        transmit_time = 0.9 \
            * max(self.vpp_session.required_min_rx,
                  self.test_session.desired_min_tx) \
            / USEC_IN_SEC
        count = 0
        for dummy in range(self.test_session.detect_mult * 2):
            time.sleep(transmit_time)
            self.test_session.send_packet(demand)
            try:
                p = wait_for_bfd_packet(self, timeout=0)
                self.logger.error(ppp("Received unexpected packet:", p))
                count += 1
            except CaptureTimeoutError:
                pass
        events = self.vapi.collect_events()
        for e in events:
            self.logger.error("Received unexpected event: %s", e)
        self.assert_equal(count, 0, "number of packets received")
        self.assert_equal(len(events), 0, "number of events received")

    def test_intf_deleted(self):
        """ interface with bfd session deleted """
        intf = VppLoInterface(self, 0)
        intf.config_ip4()
        intf.admin_up()
        sw_if_index = intf.sw_if_index
        vpp_session = VppBFDUDPSession(self, intf, intf.remote_ip4)
        vpp_session.add_vpp_config()
        vpp_session.admin_up()
        intf.remove_vpp_config()
        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
        self.assert_equal(e.sw_if_index, sw_if_index, "sw_if_index")
        self.assertFalse(vpp_session.query_vpp_config())


@unittest.skipUnless(running_extended_tests(), "part of extended tests")
class BFD6TestCase(VppTestCase):
    """Bidirectional Forwarding Detection (BFD) (IPv6) """

    pg0 = None
    vpp_clock_offset = None
    vpp_session = None
    test_session = None

    @classmethod
    def setUpClass(cls):
        super(BFD6TestCase, cls).setUpClass()
        try:
            cls.create_pg_interfaces([0])
            cls.pg0.config_ip6()
            cls.pg0.configure_ipv6_neighbors()
            cls.pg0.admin_up()
            cls.pg0.resolve_ndp()
            cls.create_loopback_interfaces([0])
            cls.loopback0 = cls.lo_interfaces[0]
            cls.loopback0.config_ip6()
            cls.loopback0.admin_up()

        except Exception:
            super(BFD6TestCase, cls).tearDownClass()
            raise

    def setUp(self):
        super(BFD6TestCase, self).setUp()
        self.factory = AuthKeyFactory()
        self.vapi.want_bfd_events()
        self.pg0.enable_capture()
        try:
            self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                                self.pg0.remote_ip6,
                                                af=AF_INET6)
            self.vpp_session.add_vpp_config()
            self.vpp_session.admin_up()
            self.test_session = BFDTestSession(self, self.pg0, AF_INET6)
            self.logger.debug(self.vapi.cli("show adj nbr"))
        except:
            self.vapi.want_bfd_events(enable_disable=0)
            raise

    def tearDown(self):
        if not self.vpp_dead:
            self.vapi.want_bfd_events(enable_disable=0)
        self.vapi.collect_events()  # clear the event queue
        super(BFD6TestCase, self).tearDown()

    def test_session_up(self):
        """ bring BFD session up """
        bfd_session_up(self)

    def test_session_up_by_ip(self):
        """ bring BFD session up - first frame looked up by address pair """
        self.logger.info("BFD: Sending Slow control frame")
        self.test_session.update(my_discriminator=randint(0, 40000000))
        self.test_session.send_packet()
        self.pg0.enable_capture()
        p = self.pg0.wait_for_packet(1)
        self.assert_equal(p[BFD].your_discriminator,
                          self.test_session.my_discriminator,
                          "BFD - your discriminator")
        self.assert_equal(p[BFD].state, BFDState.init, BFDState)
        self.test_session.update(your_discriminator=p[BFD].my_discriminator,
                                 state=BFDState.up)
        self.logger.info("BFD: Waiting for event")
        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
        verify_event(self, e, expected_state=BFDState.init)
        self.logger.info("BFD: Sending Up")
        self.test_session.send_packet()
        self.logger.info("BFD: Waiting for event")
        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
        verify_event(self, e, expected_state=BFDState.up)
        self.logger.info("BFD: Session is Up")
        self.test_session.update(state=BFDState.up)
        self.test_session.send_packet()
        self.assert_equal(self.vpp_session.state, BFDState.up, BFDState)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_hold_up(self):
        """ hold BFD session up """
        bfd_session_up(self)
        for dummy in range(self.test_session.detect_mult * 2):
            wait_for_bfd_packet(self)
            self.test_session.send_packet()
        self.assert_equal(len(self.vapi.collect_events()), 0,
                          "number of bfd events")
        self.assert_equal(self.vpp_session.state, BFDState.up, BFDState)

    def test_echo_looped_back(self):
        """ echo packets looped back """
        # don't need a session in this case..
        self.vpp_session.remove_vpp_config()
        self.pg0.enable_capture()
        echo_packet_count = 10
        # random source port low enough to increment a few times..
        udp_sport_tx = randint(1, 50000)
        udp_sport_rx = udp_sport_tx
        echo_packet = (Ether(src=self.pg0.remote_mac,
                             dst=self.pg0.local_mac) /
                       IPv6(src=self.pg0.remote_ip6,
                            dst=self.pg0.remote_ip6) /
                       UDP(dport=BFD.udp_dport_echo) /
                       Raw("this should be looped back"))
        for dummy in range(echo_packet_count):
            self.sleep(.01, "delay between echo packets")
            echo_packet[UDP].sport = udp_sport_tx
            udp_sport_tx += 1
            self.logger.debug(ppp("Sending packet:", echo_packet))
            self.pg0.add_stream(echo_packet)
            self.pg_start()
        for dummy in range(echo_packet_count):
            p = self.pg0.wait_for_packet(1)
            self.logger.debug(ppp("Got packet:", p))
            ether = p[Ether]
            self.assert_equal(self.pg0.remote_mac,
                              ether.dst, "Destination MAC")
            self.assert_equal(self.pg0.local_mac, ether.src, "Source MAC")
            ip = p[IPv6]
            self.assert_equal(self.pg0.remote_ip6, ip.dst, "Destination IP")
            self.assert_equal(self.pg0.remote_ip6, ip.src, "Destination IP")
            udp = p[UDP]
            self.assert_equal(udp.dport, BFD.udp_dport_echo,
                              "UDP destination port")
            self.assert_equal(udp.sport, udp_sport_rx, "UDP source port")
            udp_sport_rx += 1
            # need to compare the hex payload here, otherwise BFD_vpp_echo
            # gets in way
            self.assertEqual(str(p[UDP].payload),
                             str(echo_packet[UDP].payload),
                             "Received packet is not the echo packet sent")
        self.assert_equal(udp_sport_tx, udp_sport_rx, "UDP source port (== "
                          "ECHO packet identifier for test purposes)")
        self.assert_equal(udp_sport_tx, udp_sport_rx, "UDP source port (== "
                          "ECHO packet identifier for test purposes)")

    def test_echo(self):
        """ echo function """
        bfd_session_up(self)
        self.test_session.update(required_min_echo_rx=150000)
        self.test_session.send_packet()
        detection_time = self.test_session.detect_mult *\
            self.vpp_session.required_min_rx / USEC_IN_SEC
        # echo shouldn't work without echo source set
        for dummy in range(10):
            sleep = self.vpp_session.required_min_rx / USEC_IN_SEC
            self.sleep(sleep, "delay before sending bfd packet")
            self.test_session.send_packet()
        p = wait_for_bfd_packet(
            self, pcap_time_min=time.time() - self.vpp_clock_offset)
        self.assert_equal(p[BFD].required_min_rx_interval,
                          self.vpp_session.required_min_rx,
                          "BFD required min rx interval")
        self.test_session.send_packet()
        self.vapi.bfd_udp_set_echo_source(self.loopback0.sw_if_index)
        echo_seen = False
        # should be turned on - loopback echo packets
        for dummy in range(3):
            loop_until = time.time() + 0.75 * detection_time
            while time.time() < loop_until:
                p = self.pg0.wait_for_packet(1)
                self.logger.debug(ppp("Got packet:", p))
                if p[UDP].dport == BFD.udp_dport_echo:
                    self.assert_equal(
                        p[IPv6].dst, self.pg0.local_ip6, "BFD ECHO dst IP")
                    self.assertNotEqual(p[IPv6].src, self.loopback0.local_ip6,
                                        "BFD ECHO src IP equal to loopback IP")
                    self.logger.debug(ppp("Looping back packet:", p))
                    self.assert_equal(p[Ether].dst, self.pg0.remote_mac,
                                      "ECHO packet destination MAC address")
                    p[Ether].dst = self.pg0.local_mac
                    self.pg0.add_stream(p)
                    self.pg_start()
                    echo_seen = True
                elif p.haslayer(BFD):
                    if echo_seen:
                        self.assertGreaterEqual(
                            p[BFD].required_min_rx_interval,
                            1000000)
                    if "P" in p.sprintf("%BFD.flags%"):
                        final = self.test_session.create_packet()
                        final[BFD].flags = "F"
                        self.test_session.send_packet(final)
                else:
                    raise Exception(ppp("Received unknown packet:", p))

                self.assert_equal(len(self.vapi.collect_events()), 0,
                                  "number of bfd events")
            self.test_session.send_packet()
        self.assertTrue(echo_seen, "No echo packets received")

    def test_intf_deleted(self):
        """ interface with bfd session deleted """
        intf = VppLoInterface(self, 0)
        intf.config_ip6()
        intf.admin_up()
        sw_if_index = intf.sw_if_index
        vpp_session = VppBFDUDPSession(
            self, intf, intf.remote_ip6, af=AF_INET6)
        vpp_session.add_vpp_config()
        vpp_session.admin_up()
        intf.remove_vpp_config()
        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
        self.assert_equal(e.sw_if_index, sw_if_index, "sw_if_index")
        self.assertFalse(vpp_session.query_vpp_config())


@unittest.skipUnless(running_extended_tests(), "part of extended tests")
class BFDFIBTestCase(VppTestCase):
    """ BFD-FIB interactions (IPv6) """

    vpp_session = None
    test_session = None

    def setUp(self):
        super(BFDFIBTestCase, self).setUp()
        self.create_pg_interfaces(range(1))

        self.vapi.want_bfd_events()
        self.pg0.enable_capture()

        for i in self.pg_interfaces:
            i.admin_up()
            i.config_ip6()
            i.configure_ipv6_neighbors()

    def tearDown(self):
        if not self.vpp_dead:
            self.vapi.want_bfd_events(enable_disable=0)

        super(BFDFIBTestCase, self).tearDown()

    @staticmethod
    def pkt_is_not_data_traffic(p):
        """ not data traffic implies BFD or the usual IPv6 ND/RA"""
        if p.haslayer(BFD) or is_ipv6_misc(p):
            return True
        return False

    def test_session_with_fib(self):
        """ BFD-FIB interactions """

        # packets to match against both of the routes
        p = [(Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
              IPv6(src="3001::1", dst="2001::1") /
              UDP(sport=1234, dport=1234) /
              Raw('\xa5' * 100)),
             (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
              IPv6(src="3001::1", dst="2002::1") /
              UDP(sport=1234, dport=1234) /
              Raw('\xa5' * 100))]

        # A recursive and a non-recursive route via a next-hop that
        # will have a BFD session
        ip_2001_s_64 = VppIpRoute(self, "2001::", 64,
                                  [VppRoutePath(self.pg0.remote_ip6,
                                                self.pg0.sw_if_index,
                                                proto=DpoProto.DPO_PROTO_IP6)],
                                  is_ip6=1)
        ip_2002_s_64 = VppIpRoute(self, "2002::", 64,
                                  [VppRoutePath(self.pg0.remote_ip6,
                                                0xffffffff,
                                                proto=DpoProto.DPO_PROTO_IP6)],
                                  is_ip6=1)
        ip_2001_s_64.add_vpp_config()
        ip_2002_s_64.add_vpp_config()

        # bring the session up now the routes are present
        self.vpp_session = VppBFDUDPSession(self,
                                            self.pg0,
                                            self.pg0.remote_ip6,
                                            af=AF_INET6)
        self.vpp_session.add_vpp_config()
        self.vpp_session.admin_up()
        self.test_session = BFDTestSession(self, self.pg0, AF_INET6)

        # session is up - traffic passes
        bfd_session_up(self)

        self.pg0.add_stream(p)
        self.pg_start()
        for packet in p:
            captured = self.pg0.wait_for_packet(
                1,
                filter_out_fn=self.pkt_is_not_data_traffic)
            self.assertEqual(captured[IPv6].dst,
                             packet[IPv6].dst)

        # session is up - traffic is dropped
        bfd_session_down(self)

        self.pg0.add_stream(p)
        self.pg_start()
        with self.assertRaises(CaptureTimeoutError):
            self.pg0.wait_for_packet(1, self.pkt_is_not_data_traffic)

        # session is up - traffic passes
        bfd_session_up(self)

        self.pg0.add_stream(p)
        self.pg_start()
        for packet in p:
            captured = self.pg0.wait_for_packet(
                1,
                filter_out_fn=self.pkt_is_not_data_traffic)
            self.assertEqual(captured[IPv6].dst,
                             packet[IPv6].dst)


@unittest.skipUnless(running_extended_tests(), "part of extended tests")
class BFDSHA1TestCase(VppTestCase):
    """Bidirectional Forwarding Detection (BFD) (SHA1 auth) """

    pg0 = None
    vpp_clock_offset = None
    vpp_session = None
    test_session = None

    @classmethod
    def setUpClass(cls):
        super(BFDSHA1TestCase, cls).setUpClass()
        try:
            cls.create_pg_interfaces([0])
            cls.pg0.config_ip4()
            cls.pg0.admin_up()
            cls.pg0.resolve_arp()

        except Exception:
            super(BFDSHA1TestCase, cls).tearDownClass()
            raise

    def setUp(self):
        super(BFDSHA1TestCase, self).setUp()
        self.factory = AuthKeyFactory()
        self.vapi.want_bfd_events()
        self.pg0.enable_capture()

    def tearDown(self):
        if not self.vpp_dead:
            self.vapi.want_bfd_events(enable_disable=0)
        self.vapi.collect_events()  # clear the event queue
        super(BFDSHA1TestCase, self).tearDown()

    def test_session_up(self):
        """ bring BFD session up """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                            self.pg0.remote_ip4,
                                            sha1_key=key)
        self.vpp_session.add_vpp_config()
        self.vpp_session.admin_up()
        self.test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key,
            bfd_key_id=self.vpp_session.bfd_key_id)
        bfd_session_up(self)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_hold_up(self):
        """ hold BFD session up """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                            self.pg0.remote_ip4,
                                            sha1_key=key)
        self.vpp_session.add_vpp_config()
        self.vpp_session.admin_up()
        self.test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key,
            bfd_key_id=self.vpp_session.bfd_key_id)
        bfd_session_up(self)
        for dummy in range(self.test_session.detect_mult * 2):
            wait_for_bfd_packet(self)
            self.test_session.send_packet()
        self.assert_equal(self.vpp_session.state, BFDState.up, BFDState)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_hold_up_meticulous(self):
        """ hold BFD session up - meticulous auth """
        key = self.factory.create_random_key(
            self, BFDAuthType.meticulous_keyed_sha1)
        key.add_vpp_config()
        self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                            self.pg0.remote_ip4, sha1_key=key)
        self.vpp_session.add_vpp_config()
        self.vpp_session.admin_up()
        # specify sequence number so that it wraps
        self.test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key,
            bfd_key_id=self.vpp_session.bfd_key_id,
            our_seq_number=0xFFFFFFFF - 4)
        bfd_session_up(self)
        for dummy in range(30):
            wait_for_bfd_packet(self)
            self.test_session.inc_seq_num()
            self.test_session.send_packet()
        self.assert_equal(self.vpp_session.state, BFDState.up, BFDState)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_send_bad_seq_number(self):
        """ session is not kept alive by msgs with bad sequence numbers"""
        key = self.factory.create_random_key(
            self, BFDAuthType.meticulous_keyed_sha1)
        key.add_vpp_config()
        self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                            self.pg0.remote_ip4, sha1_key=key)
        self.vpp_session.add_vpp_config()
        self.test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key,
            bfd_key_id=self.vpp_session.bfd_key_id)
        bfd_session_up(self)
        detection_time = self.test_session.detect_mult *\
            self.vpp_session.required_min_rx / USEC_IN_SEC
        send_until = time.time() + 2 * detection_time
        while time.time() < send_until:
            self.test_session.send_packet()
            self.sleep(0.7 * self.vpp_session.required_min_rx / USEC_IN_SEC,
                       "time between bfd packets")
        e = self.vapi.collect_events()
        # session should be down now, because the sequence numbers weren't
        # updated
        self.assert_equal(len(e), 1, "number of bfd events")
        verify_event(self, e[0], expected_state=BFDState.down)

    def execute_rogue_session_scenario(self, vpp_bfd_udp_session,
                                       legitimate_test_session,
                                       rogue_test_session,
                                       rogue_bfd_values=None):
        """ execute a rogue session interaction scenario

        1. create vpp session, add config
        2. bring the legitimate session up
        3. copy the bfd values from legitimate session to rogue session
        4. apply rogue_bfd_values to rogue session
        5. set rogue session state to down
        6. send message to take the session down from the rogue session
        7. assert that the legitimate session is unaffected
        """

        self.vpp_session = vpp_bfd_udp_session
        self.vpp_session.add_vpp_config()
        self.test_session = legitimate_test_session
        # bring vpp session up
        bfd_session_up(self)
        # send packet from rogue session
        rogue_test_session.update(
            my_discriminator=self.test_session.my_discriminator,
            your_discriminator=self.test_session.your_discriminator,
            desired_min_tx=self.test_session.desired_min_tx,
            required_min_rx=self.test_session.required_min_rx,
            detect_mult=self.test_session.detect_mult,
            diag=self.test_session.diag,
            state=self.test_session.state,
            auth_type=self.test_session.auth_type)
        if rogue_bfd_values:
            rogue_test_session.update(**rogue_bfd_values)
        rogue_test_session.update(state=BFDState.down)
        rogue_test_session.send_packet()
        wait_for_bfd_packet(self)
        self.assert_equal(self.vpp_session.state, BFDState.up, BFDState)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_mismatch_auth(self):
        """ session is not brought down by unauthenticated msg """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        vpp_session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip4, sha1_key=key)
        legitimate_test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key,
            bfd_key_id=vpp_session.bfd_key_id)
        rogue_test_session = BFDTestSession(self, self.pg0, AF_INET)
        self.execute_rogue_session_scenario(vpp_session,
                                            legitimate_test_session,
                                            rogue_test_session)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_mismatch_bfd_key_id(self):
        """ session is not brought down by msg with non-existent key-id """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        vpp_session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip4, sha1_key=key)
        # pick a different random bfd key id
        x = randint(0, 255)
        while x == vpp_session.bfd_key_id:
            x = randint(0, 255)
        legitimate_test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key,
            bfd_key_id=vpp_session.bfd_key_id)
        rogue_test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key, bfd_key_id=x)
        self.execute_rogue_session_scenario(vpp_session,
                                            legitimate_test_session,
                                            rogue_test_session)

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_mismatched_auth_type(self):
        """ session is not brought down by msg with wrong auth type """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        vpp_session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip4, sha1_key=key)
        legitimate_test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key,
            bfd_key_id=vpp_session.bfd_key_id)
        rogue_test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key,
            bfd_key_id=vpp_session.bfd_key_id)
        self.execute_rogue_session_scenario(
            vpp_session, legitimate_test_session, rogue_test_session,
            {'auth_type': BFDAuthType.keyed_md5})

    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
    def test_restart(self):
        """ simulate remote peer restart and resynchronization """
        key = self.factory.create_random_key(
            self, BFDAuthType.meticulous_keyed_sha1)
        key.add_vpp_config()
        self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                            self.pg0.remote_ip4, sha1_key=key)
        self.vpp_session.add_vpp_config()
        self.test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key,
            bfd_key_id=self.vpp_session.bfd_key_id, our_seq_number=0)
        bfd_session_up(self)
        # don't send any packets for 2*detection_time
        detection_time = self.test_session.detect_mult *\
            self.vpp_session.required_min_rx / USEC_IN_SEC
        self.sleep(2 * detection_time, "simulating peer restart")
        events = self.vapi.collect_events()
        self.assert_equal(len(events), 1, "number of bfd events")
        verify_event(self, events[0], expected_state=BFDState.down)
        self.test_session.update(state=BFDState.down)
        # reset sequence number
        self.test_session.our_seq_number = 0
        self.test_session.vpp_seq_number = None
        # now throw away any pending packets
        self.pg0.enable_capture()
        bfd_session_up(self)


@unittest.skipUnless(running_extended_tests(), "part of extended tests")
class BFDAuthOnOffTestCase(VppTestCase):
    """Bidirectional Forwarding Detection (BFD) (changing auth) """

    pg0 = None
    vpp_session = None
    test_session = None

    @classmethod
    def setUpClass(cls):
        super(BFDAuthOnOffTestCase, cls).setUpClass()
        try:
            cls.create_pg_interfaces([0])
            cls.pg0.config_ip4()
            cls.pg0.admin_up()
            cls.pg0.resolve_arp()

        except Exception:
            super(BFDAuthOnOffTestCase, cls).tearDownClass()
            raise

    def setUp(self):
        super(BFDAuthOnOffTestCase, self).setUp()
        self.factory = AuthKeyFactory()
        self.vapi.want_bfd_events()
        self.pg0.enable_capture()

    def tearDown(self):
        if not self.vpp_dead:
            self.vapi.want_bfd_events(enable_disable=0)
        self.vapi.collect_events()  # clear the event queue
        super(BFDAuthOnOffTestCase, self).tearDown()

    def test_auth_on_immediate(self):
        """ turn auth on without disturbing session state (immediate) """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                            self.pg0.remote_ip4)
        self.vpp_session.add_vpp_config()
        self.test_session = BFDTestSession(self, self.pg0, AF_INET)
        bfd_session_up(self)
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.send_packet()
        self.vpp_session.activate_auth(key)
        self.test_session.bfd_key_id = self.vpp_session.bfd_key_id
        self.test_session.sha1_key = key
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.send_packet()
        self.assert_equal(self.vpp_session.state, BFDState.up, BFDState)
        self.assert_equal(len(self.vapi.collect_events()), 0,
                          "number of bfd events")

    def test_auth_off_immediate(self):
        """ turn auth off without disturbing session state (immediate) """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                            self.pg0.remote_ip4, sha1_key=key)
        self.vpp_session.add_vpp_config()
        self.test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key,
            bfd_key_id=self.vpp_session.bfd_key_id)
        bfd_session_up(self)
        # self.vapi.want_bfd_events(enable_disable=0)
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.inc_seq_num()
            self.test_session.send_packet()
        self.vpp_session.deactivate_auth()
        self.test_session.bfd_key_id = None
        self.test_session.sha1_key = None
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.inc_seq_num()
            self.test_session.send_packet()
        self.assert_equal(self.vpp_session.state, BFDState.up, BFDState)
        self.assert_equal(len(self.vapi.collect_events()), 0,
                          "number of bfd events")

    def test_auth_change_key_immediate(self):
        """ change auth key without disturbing session state (immediate) """
        key1 = self.factory.create_random_key(self)
        key1.add_vpp_config()
        key2 = self.factory.create_random_key(self)
        key2.add_vpp_config()
        self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                            self.pg0.remote_ip4, sha1_key=key1)
        self.vpp_session.add_vpp_config()
        self.test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key1,
            bfd_key_id=self.vpp_session.bfd_key_id)
        bfd_session_up(self)
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.send_packet()
        self.vpp_session.activate_auth(key2)
        self.test_session.bfd_key_id = self.vpp_session.bfd_key_id
        self.test_session.sha1_key = key2
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.send_packet()
        self.assert_equal(self.vpp_session.state, BFDState.up, BFDState)
        self.assert_equal(len(self.vapi.collect_events()), 0,
                          "number of bfd events")

    def test_auth_on_delayed(self):
        """ turn auth on without disturbing session state (delayed) """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                            self.pg0.remote_ip4)
        self.vpp_session.add_vpp_config()
        self.test_session = BFDTestSession(self, self.pg0, AF_INET)
        bfd_session_up(self)
        for dummy in range(self.test_session.detect_mult * 2):
            wait_for_bfd_packet(self)
            self.test_session.send_packet()
        self.vpp_session.activate_auth(key, delayed=True)
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.send_packet()
        self.test_session.bfd_key_id = self.vpp_session.bfd_key_id
        self.test_session.sha1_key = key
        self.test_session.send_packet()
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.send_packet()
        self.assert_equal(self.vpp_session.state, BFDState.up, BFDState)
        self.assert_equal(len(self.vapi.collect_events()), 0,
                          "number of bfd events")

    def test_auth_off_delayed(self):
        """ turn auth off without disturbing session state (delayed) """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                            self.pg0.remote_ip4, sha1_key=key)
        self.vpp_session.add_vpp_config()
        self.test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key,
            bfd_key_id=self.vpp_session.bfd_key_id)
        bfd_session_up(self)
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.send_packet()
        self.vpp_session.deactivate_auth(delayed=True)
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.send_packet()
        self.test_session.bfd_key_id = None
        self.test_session.sha1_key = None
        self.test_session.send_packet()
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.send_packet()
        self.assert_equal(self.vpp_session.state, BFDState.up, BFDState)
        self.assert_equal(len(self.vapi.collect_events()), 0,
                          "number of bfd events")

    def test_auth_change_key_delayed(self):
        """ change auth key without disturbing session state (delayed) """
        key1 = self.factory.create_random_key(self)
        key1.add_vpp_config()
        key2 = self.factory.create_random_key(self)
        key2.add_vpp_config()
        self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                            self.pg0.remote_ip4, sha1_key=key1)
        self.vpp_session.add_vpp_config()
        self.vpp_session.admin_up()
        self.test_session = BFDTestSession(
            self, self.pg0, AF_INET, sha1_key=key1,
            bfd_key_id=self.vpp_session.bfd_key_id)
        bfd_session_up(self)
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.send_packet()
        self.vpp_session.activate_auth(key2, delayed=True)
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.send_packet()
        self.test_session.bfd_key_id = self.vpp_session.bfd_key_id
        self.test_session.sha1_key = key2
        self.test_session.send_packet()
        for dummy in range(self.test_session.detect_mult * 2):
            p = wait_for_bfd_packet(self)
            self.assert_equal(p[BFD].state, BFDState.up, BFDState)
            self.test_session.send_packet()
        self.assert_equal(self.vpp_session.state, BFDState.up, BFDState)
        self.assert_equal(len(self.vapi.collect_events()), 0,
                          "number of bfd events")


@unittest.skipUnless(running_extended_tests(), "part of extended tests")
class BFDCLITestCase(VppTestCase):
    """Bidirectional Forwarding Detection (BFD) (CLI) """
    pg0 = None

    @classmethod
    def setUpClass(cls):
        super(BFDCLITestCase, cls).setUpClass()

        try:
            cls.create_pg_interfaces((0,))
            cls.pg0.config_ip4()
            cls.pg0.config_ip6()
            cls.pg0.resolve_arp()
            cls.pg0.resolve_ndp()

        except Exception:
            super(BFDCLITestCase, cls).tearDownClass()
            raise

    def setUp(self):
        super(BFDCLITestCase, self).setUp()
        self.factory = AuthKeyFactory()
        self.pg0.enable_capture()

    def tearDown(self):
        try:
            self.vapi.want_bfd_events(enable_disable=0)
        except UnexpectedApiReturnValueError:
            # some tests aren't subscribed, so this is not an issue
            pass
        self.vapi.collect_events()  # clear the event queue
        super(BFDCLITestCase, self).tearDown()

    def cli_verify_no_response(self, cli):
        """ execute a CLI, asserting that the response is empty """
        self.assert_equal(self.vapi.cli(cli),
                          "",
                          "CLI command response")

    def cli_verify_response(self, cli, expected):
        """ execute a CLI, asserting that the response matches expectation """
        self.assert_equal(self.vapi.cli(cli).strip(),
                          expected,
                          "CLI command response")

    def test_show(self):
        """ show commands """
        k1 = self.factory.create_random_key(self)
        k1.add_vpp_config()
        k2 = self.factory.create_random_key(
            self, auth_type=BFDAuthType.meticulous_keyed_sha1)
        k2.add_vpp_config()
        s1 = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4)
        s1.add_vpp_config()
        s2 = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip6, af=AF_INET6,
                              sha1_key=k2)
        s2.add_vpp_config()
        self.logger.info(self.vapi.ppcli("show bfd keys"))
        self.logger.info(self.vapi.ppcli("show bfd sessions"))
        self.logger.info(self.vapi.ppcli("show bfd"))

    def test_set_del_sha1_key(self):
        """ set/delete SHA1 auth key """
        k = self.factory.create_random_key(self)
        self.registry.register(k, self.logger)
        self.cli_verify_no_response(
            "bfd key set conf-key-id %s type keyed-sha1 secret %s" %
            (k.conf_key_id,
                "".join("{:02x}".format(ord(c)) for c in k.key)))
        self.assertTrue(k.query_vpp_config())
        self.vpp_session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip4, sha1_key=k)
        self.vpp_session.add_vpp_config()
        self.test_session = \
            BFDTestSession(self, self.pg0, AF_INET, sha1_key=k,
                           bfd_key_id=self.vpp_session.bfd_key_id)
        self.vapi.want_bfd_events()
        bfd_session_up(self)
        bfd_session_down(self)
        # try to replace the secret for the key - should fail because the key
        # is in-use
        k2 = self.factory.create_random_key(self)
        self.cli_verify_response(
            "bfd key set conf-key-id %s type keyed-sha1 secret %s" %
            (k.conf_key_id,
                "".join("{:02x}".format(ord(c)) for c in k2.key)),
            "bfd key set: `bfd_auth_set_key' API call failed, "
            "rv=-103:BFD object in use")
        # manipulating the session using old secret should still work
        bfd_session_up(self)
        bfd_session_down(self)
        self.vpp_session.remove_vpp_config()
        self.cli_verify_no_response(
            "bfd key del conf-key-id %s" % k.conf_key_id)
        self.assertFalse(k.query_vpp_config())

    def test_set_del_meticulous_sha1_key(self):
        """ set/delete meticulous SHA1 auth key """
        k = self.factory.create_random_key(
            self, auth_type=BFDAuthType.meticulous_keyed_sha1)
        self.registry.register(k, self.logger)
        self.cli_verify_no_response(
            "bfd key set conf-key-id %s type meticulous-keyed-sha1 secret %s" %
            (k.conf_key_id,
                "".join("{:02x}".format(ord(c)) for c in k.key)))
        self.assertTrue(k.query_vpp_config())
        self.vpp_session = VppBFDUDPSession(self, self.pg0,
                                            self.pg0.remote_ip6, af=AF_INET6,
                                            sha1_key=k)
        self.vpp_session.add_vpp_config()
        self.vpp_session.admin_up()
        self.test_session = \
            BFDTestSession(self, self.pg0, AF_INET6, sha1_key=k,
                           bfd_key_id=self.vpp_session.bfd_key_id)
        self.vapi.want_bfd_events()
        bfd_session_up(self)
        bfd_session_down(self)
        # try to replace the secret for the key - should fail because the key
        # is in-use
        k2 = self.factory.create_random_key(self)
        self.cli_verify_response(
            "bfd key set conf-key-id %s type keyed-sha1 secret %s" %
            (k.conf_key_id,
                "".join("{:02x}".format(ord(c)) for c in k2.key)),
            "bfd key set: `bfd_auth_set_key' API call failed, "
            "rv=-103:BFD object in use")
        # manipulating the session using old secret should still work
        bfd_session_up(self)
        bfd_session_down(self)
        self.vpp_session.remove_vpp_config()
        self.cli_verify_no_response(
            "bfd key del conf-key-id %s" % k.conf_key_id)
        self.assertFalse(k.query_vpp_config())

    def test_add_mod_del_bfd_udp(self):
        """ create/modify/delete IPv4 BFD UDP session """
        vpp_session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip4)
        self.registry.register(vpp_session, self.logger)
        cli_add_cmd = "bfd udp session add interface %s local-addr %s " \
            "peer-addr %s desired-min-tx %s required-min-rx %s "\
            "detect-mult %s" % (self.pg0.name, self.pg0.local_ip4,
                                self.pg0.remote_ip4,
                                vpp_session.desired_min_tx,
                                vpp_session.required_min_rx,
                                vpp_session.detect_mult)
        self.cli_verify_no_response(cli_add_cmd)
        # 2nd add should fail
        self.cli_verify_response(
            cli_add_cmd,
            "bfd udp session add: `bfd_add_add_session' API call"
            " failed, rv=-101:Duplicate BFD object")
        verify_bfd_session_config(self, vpp_session)
        mod_session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip4,
            required_min_rx=2 * vpp_session.required_min_rx,
            desired_min_tx=3 * vpp_session.desired_min_tx,
            detect_mult=4 * vpp_session.detect_mult)
        self.cli_verify_no_response(
            "bfd udp session mod interface %s local-addr %s peer-addr %s "
            "desired-min-tx %s required-min-rx %s detect-mult %s" %
            (self.pg0.name, self.pg0.local_ip4, self.pg0.remote_ip4,
             mod_session.desired_min_tx, mod_session.required_min_rx,
             mod_session.detect_mult))
        verify_bfd_session_config(self, mod_session)
        cli_del_cmd = "bfd udp session del interface %s local-addr %s "\
            "peer-addr %s" % (self.pg0.name,
                              self.pg0.local_ip4, self.pg0.remote_ip4)
        self.cli_verify_no_response(cli_del_cmd)
        # 2nd del is expected to fail
        self.cli_verify_response(
            cli_del_cmd, "bfd udp session del: `bfd_udp_del_session' API call"
            " failed, rv=-102:No such BFD object")
        self.assertFalse(vpp_session.query_vpp_config())

    def test_add_mod_del_bfd_udp6(self):
        """ create/modify/delete IPv6 BFD UDP session """
        vpp_session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip6, af=AF_INET6)
        self.registry.register(vpp_session, self.logger)
        cli_add_cmd = "bfd udp session add interface %s local-addr %s " \
            "peer-addr %s desired-min-tx %s required-min-rx %s "\
            "detect-mult %s" % (self.pg0.name, self.pg0.local_ip6,
                                self.pg0.remote_ip6,
                                vpp_session.desired_min_tx,
                                vpp_session.required_min_rx,
                                vpp_session.detect_mult)
        self.cli_verify_no_response(cli_add_cmd)
        # 2nd add should fail
        self.cli_verify_response(
            cli_add_cmd,
            "bfd udp session add: `bfd_add_add_session' API call"
            " failed, rv=-101:Duplicate BFD object")
        verify_bfd_session_config(self, vpp_session)
        mod_session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip6, af=AF_INET6,
            required_min_rx=2 * vpp_session.required_min_rx,
            desired_min_tx=3 * vpp_session.desired_min_tx,
            detect_mult=4 * vpp_session.detect_mult)
        self.cli_verify_no_response(
            "bfd udp session mod interface %s local-addr %s peer-addr %s "
            "desired-min-tx %s required-min-rx %s detect-mult %s" %
            (self.pg0.name, self.pg0.local_ip6, self.pg0.remote_ip6,
             mod_session.desired_min_tx,
             mod_session.required_min_rx, mod_session.detect_mult))
        verify_bfd_session_config(self, mod_session)
        cli_del_cmd = "bfd udp session del interface %s local-addr %s "\
            "peer-addr %s" % (self.pg0.name,
                              self.pg0.local_ip6, self.pg0.remote_ip6)
        self.cli_verify_no_response(cli_del_cmd)
        # 2nd del is expected to fail
        self.cli_verify_response(
            cli_del_cmd,
            "bfd udp session del: `bfd_udp_del_session' API call"
            " failed, rv=-102:No such BFD object")
        self.assertFalse(vpp_session.query_vpp_config())

    def test_add_mod_del_bfd_udp_auth(self):
        """ create/modify/delete IPv4 BFD UDP session (authenticated) """
        key = self.factory.create_random_key(self)
        key.add_vpp_config()
        vpp_session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip4, sha1_key=key)
        self.registry.register(vpp_session, self.logger)
        cli_add_cmd = "bfd udp session add interface %s local-addr %s " \
            "peer-addr %s desired-min-tx %s required-min-rx %s "\
            "detect-mult %s conf-key-id %s bfd-key-id %s"\
            % (self.pg0.name, self.pg0.local_ip4, self.pg0.remote_ip4,
               vpp_session.desired_min_tx, vpp_session.required_min_rx,
               vpp_session.detect_mult, key.conf_key_id,
               vpp_session.bfd_key_id)
        self.cli_verify_no_response(cli_add_cmd)
        # 2nd add should fail
        self.cli_verify_response(
            cli_add_cmd,
            "bfd udp session add: `bfd_add_add_session' API call"
            " failed, rv=-101:Duplicate BFD object")
        verify_bfd_session_config(self, vpp_session)
        mod_session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip4, sha1_key=key,
            bfd_key_id=vpp_session.bfd_key_id,
            required_min_rx=2 * vpp_session.required_min_rx,
            desired_min_tx=3 * vpp_session.desired_min_tx,
            detect_mult=4 * vpp_session.detect_mult)
        self.cli_verify_no_response(
            "bfd udp session mod interface %s local-addr %s peer-addr %s "
            "desired-min-tx %s required-min-rx %s detect-mult %s" %
            (self.pg0.name, self.pg0.local_ip4, self.pg0.remote_ip4,
             mod_session.desired_min_tx,
             mod_session.required_min_rx, mod_session.detect_mult))
        verify_bfd_session_config(self, mod_session)
        cli_del_cmd = "bfd udp session del interface %s local-addr %s "\
            "peer-addr %s" % (self.pg0.name,
                              self.pg0.local_ip4, self.pg0.remote_ip4)
        self.cli_verify_no_response(cli_del_cmd)
        # 2nd del is expected to fail
        self.cli_verify_response(
            cli_del_cmd,
            "bfd udp session del: `bfd_udp_del_session' API call"
            " failed, rv=-102:No such BFD object")
        self.assertFalse(vpp_session.query_vpp_config())

    def test_add_mod_del_bfd_udp6_auth(self):
        """ create/modify/delete IPv6 BFD UDP session (authenticated) """
        key = self.factory.create_random_key(
            self, auth_type=BFDAuthType.meticulous_keyed_sha1)
        key.add_vpp_config()
        vpp_session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip6, af=AF_INET6, sha1_key=key)
        self.registry.register(vpp_session, self.logger)
        cli_add_cmd = "bfd udp session add interface %s local-addr %s " \
            "peer-addr %s desired-min-tx %s required-min-rx %s "\
            "detect-mult %s conf-key-id %s bfd-key-id %s" \
            % (self.pg0.name, self.pg0.local_ip6, self.pg0.remote_ip6,
               vpp_session.desired_min_tx, vpp_session.required_min_rx,
               vpp_session.detect_mult, key.conf_key_id,
               vpp_session.bfd_key_id)
        self.cli_verify_no_response(cli_add_cmd)
        # 2nd add should fail
        self.cli_verify_response(
            cli_add_cmd,
            "bfd udp session add: `bfd_add_add_session' API call"
            " failed, rv=-101:Duplicate BFD object")
        verify_bfd_session_config(self, vpp_session)
        mod_session = VppBFDUDPSession(
            self, self.pg0, self.pg0.remote_ip6, af=AF_INET6, sha1_key=key,
            bfd_key_id=vpp_session.bfd_key_id,
            required_min_rx=2 * vpp_session.required_min_rx,
            desired_min_tx=3 * vpp_session.desired_min_tx,
            detect_mult=4 * vpp_session.detect_mult)
        self.cli_verify_no_response(
            "bfd udp session mod interface %s local-addr %s peer-addr %s "
            "desired-min-tx %s required-min-rx %s detect-mult %s" %
            (self.pg0.name, self.pg0.local_ip6, self.pg0.remote_ip6,
             mod_session.desired_min_tx,
             mod_session.required_min_rx, mod_session.detect_mult))
        verify_bfd_session_config(self, mod_session)
        cli_del_cmd = "bfd udp session del interface %s local-addr %s "\
            "peer-addr %s" % (self.pg0.name,
                              self.pg0.local_ip6, self.pg0.remote_ip6)
        self.cli_verify_no_response(cli_del_cmd)
        # 2nd del is expected to fail
        self.cli_verify_response(
            cli_del_cmd,
            "bfd udp session del: `bfd_udp_del_session' API call"
            " failed, rv=-102:No such BFD object")
        self.assertFalse(vpp_session.query_vpp_config())

    def test_auth_on_off(self):
        """ turn authentication on and off """
        key = self.factory.create_random_key(
            self, auth_type=BFDAuthType.meticulous_keyed_sha1)
        key.add_vpp_config()
        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4)
        auth_session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4,
                                        sha1_key=key)
        session.add_vpp_config()
        cli_activate = \
            "bfd udp session auth activate interface %s local-addr %s "\
            "peer-addr %s conf-key-id %s bfd-key-id %s"\
            % (self.pg0.name, self.pg0.local_ip4, self.pg0.remote_ip4,
               key.conf_key_id, auth_session.bfd_key_id)
        self.cli_verify_no_response(cli_activate)
        verify_bfd_session_config(self, auth_session)
        self.cli_verify_no_response(cli_activate)
        verify_bfd_session_config(self, auth_session)
        cli_deactivate = \
            "bfd udp session auth deactivate interface %s local-addr %s "\
            "peer-addr %s "\
            % (self.pg0.name, self.pg0.local_ip4, self.pg0.remote_ip4)
        self.cli_verify_no_response(cli_deactivate)
        verify_bfd_session_config(self, session)
        self.cli_verify_no_response(cli_deactivate)
        verify_bfd_session_config(self, session)

    def test_auth_on_off_delayed(self):
        """ turn authentication on and off (delayed) """
        key = self.factory.create_random_key(
            self, auth_type=BFDAuthType.meticulous_keyed_sha1)
        key.add_vpp_config()
        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4)
        auth_session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4,
                                        sha1_key=key)
        session.add_vpp_config()
        cli_activate = \
            "bfd udp session auth activate interface %s local-addr %s "\
            "peer-addr %s conf-key-id %s bfd-key-id %s delayed yes"\
            % (self.pg0.name, self.pg0.local_ip4, self.pg0.remote_ip4,
               key.conf_key_id, auth_session.bfd_key_id)
        self.cli_verify_no_response(cli_activate)
        verify_bfd_session_config(self, auth_session)
        self.cli_verify_no_response(cli_activate)
        verify_bfd_session_config(self, auth_session)
        cli_deactivate = \
            "bfd udp session auth deactivate interface %s local-addr %s "\
            "peer-addr %s delayed yes"\
            % (self.pg0.name, self.pg0.local_ip4, self.pg0.remote_ip4)
        self.cli_verify_no_response(cli_deactivate)
        verify_bfd_session_config(self, session)
        self.cli_verify_no_response(cli_deactivate)
        verify_bfd_session_config(self, session)

    def test_admin_up_down(self):
        """ put session admin-up and admin-down """
        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4)
        session.add_vpp_config()
        cli_down = \
            "bfd udp session set-flags admin down interface %s local-addr %s "\
            "peer-addr %s "\
            % (self.pg0.name, self.pg0.local_ip4, self.pg0.remote_ip4)
        cli_up = \
            "bfd udp session set-flags admin up interface %s local-addr %s "\
            "peer-addr %s "\
            % (self.pg0.name, self.pg0.local_ip4, self.pg0.remote_ip4)
        self.cli_verify_no_response(cli_down)
        verify_bfd_session_config(self, session, state=BFDState.admin_down)
        self.cli_verify_no_response(cli_up)
        verify_bfd_session_config(self, session, state=BFDState.down)

    def test_set_del_udp_echo_source(self):
        """ set/del udp echo source """
        self.create_loopback_interfaces([0])
        self.loopback0 = self.lo_interfaces[0]
        self.loopback0.admin_up()
        self.cli_verify_response("show bfd echo-source",
                                 "UDP echo source is not set.")
        cli_set = "bfd udp echo-source set interface %s" % self.loopback0.name
        self.cli_verify_no_response(cli_set)
        self.cli_verify_response("show bfd echo-source",
                                 "UDP echo source is: %s\n"
                                 "IPv4 address usable as echo source: none\n"
                                 "IPv6 address usable as echo source: none" %
                                 self.loopback0.name)
        self.loopback0.config_ip4()
        unpacked = unpack("!L", self.loopback0.local_ip4n)
        echo_ip4 = inet_ntop(AF_INET, pack("!L", unpacked[0] ^ 1))
        self.cli_verify_response("show bfd echo-source",
                                 "UDP echo source is: %s\n"
                                 "IPv4 address usable as echo source: %s\n"
                                 "IPv6 address usable as echo source: none" %
                                 (self.loopback0.name, echo_ip4))
        unpacked = unpack("!LLLL", self.loopback0.local_ip6n)
        echo_ip6 = inet_ntop(AF_INET6, pack("!LLLL", unpacked[0], unpacked[1],
                                            unpacked[2], unpacked[3] ^ 1))
        self.loopback0.config_ip6()
        self.cli_verify_response("show bfd echo-source",
                                 "UDP echo source is: %s\n"
                                 "IPv4 address usable as echo source: %s\n"
                                 "IPv6 address usable as echo source: %s" %
                                 (self.loopback0.name, echo_ip4, echo_ip6))
        cli_del = "bfd udp echo-source del"
        self.cli_verify_no_response(cli_del)
        self.cli_verify_response("show bfd echo-source",
                                 "UDP echo source is not set.")

if __name__ == '__main__':
    unittest.main(testRunner=VppTestRunner)