This file is indexed.

/usr/sbin/samba_kcc is in samba-common-bin 2:4.1.6+dfsg-1ubuntu2.

This file is owned by root:root, with mode 0o755.

The actual contents of the file can be viewed below.

   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
#! /usr/bin/python2.7
#
# Compute our KCC topology
#
# Copyright (C) Dave Craft 2011
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os
import sys
import random

# ensure we get messages out immediately, so they get in the samba logs,
# and don't get swallowed by a timeout
os.environ['PYTHONUNBUFFERED'] = '1'

# forcing GMT avoids a problem in some timezones with kerberos. Both MIT
# heimdal can get mutual authentication errors due to the 24 second difference
# between UTC and GMT when using some zone files (eg. the PDT zone from
# the US)
os.environ["TZ"] = "GMT"

# Find right directory when running from source tree


import optparse
import logging

from samba import (
    getopt as options,
    Ldb,
    ldb,
    dsdb,
    read_and_sub_file)
from samba.auth import system_session
from samba.samdb import SamDB
from samba.dcerpc import drsuapi
from samba.kcc_utils import *

class KCC(object):
    """The Knowledge Consistency Checker class.

    A container for objects and methods allowing a run of the KCC.  Produces a
    set of connections in the samdb for which the Distributed Replication
    Service can then utilize to replicate naming contexts
    """
    def __init__(self):
        """Initializes the partitions class which can hold
        our local DCs partitions or all the partitions in
        the forest
        """
        self.part_table = {}    # partition objects
        self.site_table = {}
        self.transport_table = {}
        self.sitelink_table = {}

        # Used in inter-site topology computation.  A list
        # of connections (by NTDSConnection object) that are
        # to be kept when pruning un-needed NTDS Connections
        self.keep_connection_list = []

        self.my_dsa_dnstr = None  # My dsa DN
        self.my_dsa = None  # My dsa object

        self.my_site_dnstr = None
        self.my_site = None

        self.samdb = None

    def load_all_transports(self):
        """Loads the inter-site transport objects for Sites

        ::returns: Raises an Exception on error
        """
        try:
            res = self.samdb.search("CN=Inter-Site Transports,CN=Sites,%s" %
                                    self.samdb.get_config_basedn(),
                                    scope=ldb.SCOPE_SUBTREE,
                                    expression="(objectClass=interSiteTransport)")
        except ldb.LdbError, (enum, estr):
            raise Exception("Unable to find inter-site transports - (%s)" %
                    estr)

        for msg in res:
            dnstr = str(msg.dn)

            # already loaded
            if dnstr in self.transport_table.keys():
                continue

            transport = Transport(dnstr)

            transport.load_transport(self.samdb)

            # Assign this transport to table
            # and index by dn
            self.transport_table[dnstr] = transport

    def load_all_sitelinks(self):
        """Loads the inter-site siteLink objects

        ::returns: Raises an Exception on error
        """
        try:
            res = self.samdb.search("CN=Inter-Site Transports,CN=Sites,%s" %
                                    self.samdb.get_config_basedn(),
                                    scope=ldb.SCOPE_SUBTREE,
                                    expression="(objectClass=siteLink)")
        except ldb.LdbError, (enum, estr):
            raise Exception("Unable to find inter-site siteLinks - (%s)" % estr)

        for msg in res:
            dnstr = str(msg.dn)

            # already loaded
            if dnstr in self.sitelink_table.keys():
                continue

            sitelink = SiteLink(dnstr)

            sitelink.load_sitelink(self.samdb)

            # Assign this siteLink to table
            # and index by dn
            self.sitelink_table[dnstr] = sitelink

    def get_sitelink(self, site1_dnstr, site2_dnstr):
        """Return the siteLink (if it exists) that connects the
        two input site DNs
        """
        for sitelink in self.sitelink_table.values():
            if sitelink.is_sitelink(site1_dnstr, site2_dnstr):
                return sitelink
        return None

    def load_my_site(self):
        """Loads the Site class for the local DSA

        ::returns: Raises an Exception on error
        """
        self.my_site_dnstr = "CN=%s,CN=Sites,%s" % (
                              self.samdb.server_site_name(),
                              self.samdb.get_config_basedn())
        site = Site(self.my_site_dnstr)
        site.load_site(self.samdb)

        self.site_table[self.my_site_dnstr] = site
        self.my_site = site

    def load_all_sites(self):
        """Discover all sites and instantiate and load each
        NTDS Site settings.

        ::returns: Raises an Exception on error
        """
        try:
            res = self.samdb.search("CN=Sites,%s" %
                                    self.samdb.get_config_basedn(),
                                    scope=ldb.SCOPE_SUBTREE,
                                    expression="(objectClass=site)")
        except ldb.LdbError, (enum, estr):
            raise Exception("Unable to find sites - (%s)" % estr)

        for msg in res:
            sitestr = str(msg.dn)

            # already loaded
            if sitestr in self.site_table.keys():
                continue

            site = Site(sitestr)
            site.load_site(self.samdb)

            self.site_table[sitestr] = site

    def load_my_dsa(self):
        """Discover my nTDSDSA dn thru the rootDSE entry

        ::returns: Raises an Exception on error.
        """
        dn = ldb.Dn(self.samdb, "")
        try:
            res = self.samdb.search(base=dn, scope=ldb.SCOPE_BASE,
                                    attrs=["dsServiceName"])
        except ldb.LdbError, (enum, estr):
            raise Exception("Unable to find my nTDSDSA - (%s)" % estr)

        self.my_dsa_dnstr = res[0]["dsServiceName"][0]
        self.my_dsa = self.my_site.get_dsa(self.my_dsa_dnstr)

    def load_all_partitions(self):
        """Discover all NCs thru the Partitions dn and
        instantiate and load the NCs.

        Each NC is inserted into the part_table by partition
        dn string (not the nCName dn string)

        ::returns: Raises an Exception on error
        """
        try:
            res = self.samdb.search("CN=Partitions,%s" %
                                    self.samdb.get_config_basedn(),
                                    scope=ldb.SCOPE_SUBTREE,
                                    expression="(objectClass=crossRef)")
        except ldb.LdbError, (enum, estr):
            raise Exception("Unable to find partitions - (%s)" % estr)

        for msg in res:
            partstr = str(msg.dn)

            # already loaded
            if partstr in self.part_table.keys():
                continue

            part = Partition(partstr)

            part.load_partition(self.samdb)
            self.part_table[partstr] = part

    def should_be_present_test(self):
        """Enumerate all loaded partitions and DSAs in local
        site and test if NC should be present as replica
        """
        for partdn, part in self.part_table.items():
            for dsadn, dsa in self.my_site.dsa_table.items():
               needed, ro, partial = part.should_be_present(dsa)
               logger.info("dsadn:%s\nncdn:%s\nneeded=%s:ro=%s:partial=%s\n" %
                           (dsadn, part.nc_dnstr, needed, ro, partial))

    def refresh_failed_links_connections(self):
        # XXX - not implemented yet
        pass

    def is_stale_link_connection(self, target_dsa):
        """Returns False if no tuple z exists in the kCCFailedLinks or
        kCCFailedConnections variables such that z.UUIDDsa is the
        objectGUID of the target dsa, z.FailureCount > 0, and
        the current time - z.TimeFirstFailure > 2 hours.
        """
        # XXX - not implemented yet
        return False

    def remove_unneeded_failed_links_connections(self):
        # XXX - not implemented yet
        pass

    def remove_unneeded_ntdsconn(self, all_connected):
        """Removes unneeded NTDS Connections after computation
        of KCC intra and inter-site topology has finished.
        """
        mydsa = self.my_dsa

        # Loop thru connections
        for cn_dnstr, cn_conn in mydsa.connect_table.items():

            s_dnstr = cn_conn.get_from_dnstr()
            if s_dnstr is None:
                cn_conn.to_be_deleted = True
                continue

            # Get the source DSA no matter what site
            s_dsa = self.get_dsa(s_dnstr)

            # Check if the DSA is in our site
            if self.my_site.same_site(s_dsa):
                same_site = True
            else:
                same_site = False

            # Given an nTDSConnection object cn, if the DC with the
            # nTDSDSA object dc that is the parent object of cn and
            # the DC with the nTDSDA object referenced by cn!fromServer
            # are in the same site, the KCC on dc deletes cn if all of
            # the following are true:
            #
            # Bit NTDSCONN_OPT_IS_GENERATED is clear in cn!options.
            #
            # No site settings object s exists for the local DC's site, or
            # bit NTDSSETTINGS_OPT_IS_TOPL_CLEANUP_DISABLED is clear in
            # s!options.
            #
            # Another nTDSConnection object cn2 exists such that cn and
            # cn2 have the same parent object, cn!fromServer = cn2!fromServer,
            # and either
            #
            #     cn!whenCreated < cn2!whenCreated
            #
            #     cn!whenCreated = cn2!whenCreated and
            #     cn!objectGUID < cn2!objectGUID
            #
            # Bit NTDSCONN_OPT_RODC_TOPOLOGY is clear in cn!options
            if same_site:
                if not cn_conn.is_generated():
                    continue

                if self.my_site.is_cleanup_ntdsconn_disabled():
                    continue

                # Loop thru connections looking for a duplicate that
                # fulfills the previous criteria
                lesser = False

                for cn2_dnstr, cn2_conn in mydsa.connect_table.items():
                    if cn2_conn is cn_conn:
                        continue

                    s2_dnstr = cn2_conn.get_from_dnstr()
                    if s2_dnstr is None:
                        continue

                    # If the NTDS Connections has a different
                    # fromServer field then no match
                    if s2_dnstr != s_dnstr:
                        continue

                    lesser = (cn_conn.whenCreated < cn2_conn.whenCreated or
                              (cn_conn.whenCreated == cn2_conn.whenCreated and
                               cmp(cn_conn.guid, cn2_conn.guid) < 0))

                    if lesser:
                        break

                if lesser and not cn_conn.is_rodc_topology():
                    cn_conn.to_be_deleted = True

            # Given an nTDSConnection object cn, if the DC with the nTDSDSA
            # object dc that is the parent object of cn and the DC with
            # the nTDSDSA object referenced by cn!fromServer are in
            # different sites, a KCC acting as an ISTG in dc's site
            # deletes cn if all of the following are true:
            #
            #     Bit NTDSCONN_OPT_IS_GENERATED is clear in cn!options.
            #
            #     cn!fromServer references an nTDSDSA object for a DC
            #     in a site other than the local DC's site.
            #
            #     The keepConnections sequence returned by
            #     CreateIntersiteConnections() does not contain
            #     cn!objectGUID, or cn is "superseded by" (see below)
            #     another nTDSConnection cn2 and keepConnections
            #     contains cn2!objectGUID.
            #
            #     The return value of CreateIntersiteConnections()
            #     was true.
            #
            #     Bit NTDSCONN_OPT_RODC_TOPOLOGY is clear in
            #     cn!options
            #
            else: # different site

                if not mydsa.is_istg():
                    continue

                if not cn_conn.is_generated():
                    continue

                if self.keep_connection(cn_conn):
                    continue

                # XXX - To be implemented

                if not all_connected:
                    continue

                if not cn_conn.is_rodc_topology():
                    cn_conn.to_be_deleted = True


        if opts.readonly:
            for dnstr, connect in mydsa.connect_table.items():
                if connect.to_be_deleted:
                    logger.info("TO BE DELETED:\n%s" % connect)
                if connect.to_be_added:
                    logger.info("TO BE ADDED:\n%s" % connect)

            # Peform deletion from our tables but perform
            # no database modification
            mydsa.commit_connections(self.samdb, ro=True)
        else:
            # Commit any modified connections
            mydsa.commit_connections(self.samdb)

    def get_dsa_by_guidstr(self, guidstr):
        """Given a DSA guid string, consule all sites looking
        for the corresponding DSA and return it.
        """
        for site in self.site_table.values():
            dsa = site.get_dsa_by_guidstr(guidstr)
            if dsa is not None:
                return dsa
        return None

    def get_dsa(self, dnstr):
        """Given a DSA dn string, consule all sites looking
        for the corresponding DSA and return it.
        """
        for site in self.site_table.values():
            dsa = site.get_dsa(dnstr)
            if dsa is not None:
                return dsa
        return None

    def modify_repsFrom(self, n_rep, t_repsFrom, s_rep, s_dsa, cn_conn):
        """Update t_repsFrom if necessary to satisfy requirements. Such
        updates are typically required when the IDL_DRSGetNCChanges
        server has moved from one site to another--for example, to
        enable compression when the server is moved from the
        client's site to another site.

        :param n_rep: NC replica we need
        :param t_repsFrom: repsFrom tuple to modify
        :param s_rep: NC replica at source DSA
        :param s_dsa: source DSA
        :param cn_conn: Local DSA NTDSConnection child

        ::returns: (update) bit field containing which portion of the
           repsFrom was modified.  This bit field is suitable as input
           to IDL_DRSReplicaModify ulModifyFields element, as it consists
           of these bits:
               drsuapi.DRSUAPI_DRS_UPDATE_SCHEDULE
               drsuapi.DRSUAPI_DRS_UPDATE_FLAGS
               drsuapi.DRSUAPI_DRS_UPDATE_ADDRESS
        """
        s_dnstr = s_dsa.dsa_dnstr
        update = 0x0

        if self.my_site.same_site(s_dsa):
            same_site = True
        else:
            same_site = False

        times = cn_conn.convert_schedule_to_repltimes()

        # if schedule doesn't match then update and modify
        if times != t_repsFrom.schedule:
            t_repsFrom.schedule = times

        # Bit DRS_PER_SYNC is set in replicaFlags if and only
        # if nTDSConnection schedule has a value v that specifies
        # scheduled replication is to be performed at least once
        # per week.
        if cn_conn.is_schedule_minimum_once_per_week():

            if (t_repsFrom.replica_flags &
                drsuapi.DRSUAPI_DRS_PER_SYNC) == 0x0:
                t_repsFrom.replica_flags |= drsuapi.DRSUAPI_DRS_PER_SYNC

        # Bit DRS_INIT_SYNC is set in t.replicaFlags if and only
        # if the source DSA and the local DC's nTDSDSA object are
        # in the same site or source dsa is the FSMO role owner
        # of one or more FSMO roles in the NC replica.
        if same_site or n_rep.is_fsmo_role_owner(s_dnstr):

            if (t_repsFrom.replica_flags &
                drsuapi.DRSUAPI_DRS_INIT_SYNC) == 0x0:
                t_repsFrom.replica_flags |= drsuapi.DRSUAPI_DRS_INIT_SYNC

        # If bit NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT is set in
        # cn!options, bit DRS_NEVER_NOTIFY is set in t.replicaFlags
        # if and only if bit NTDSCONN_OPT_USE_NOTIFY is clear in
        # cn!options. Otherwise, bit DRS_NEVER_NOTIFY is set in
        # t.replicaFlags if and only if s and the local DC's
        # nTDSDSA object are in different sites.
        if (cn_conn.options & dsdb.NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT) != 0x0:

            if (cn_conn.option & dsdb.NTDSCONN_OPT_USE_NOTIFY) == 0x0:

                if (t_repsFrom.replica_flags &
                    drsuapi.DRSUAPI_DRS_NEVER_NOTIFY) == 0x0:
                    t_repsFrom.replica_flags |= drsuapi.DRSUAPI_DRS_NEVER_NOTIFY

        elif not same_site:

            if (t_repsFrom.replica_flags &
                drsuapi.DRSUAPI_DRS_NEVER_NOTIFY) == 0x0:
                t_repsFrom.replica_flags |= drsuapi.DRSUAPI_DRS_NEVER_NOTIFY

        # Bit DRS_USE_COMPRESSION is set in t.replicaFlags if
        # and only if s and the local DC's nTDSDSA object are
        # not in the same site and the
        # NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION bit is
        # clear in cn!options
        if (not same_site and
           (cn_conn.options &
            dsdb.NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION) == 0x0):

            if (t_repsFrom.replica_flags &
                drsuapi.DRSUAPI_DRS_USE_COMPRESSION) == 0x0:
                t_repsFrom.replica_flags |= drsuapi.DRSUAPI_DRS_USE_COMPRESSION

        # Bit DRS_TWOWAY_SYNC is set in t.replicaFlags if and only
        # if bit NTDSCONN_OPT_TWOWAY_SYNC is set in cn!options.
        if (cn_conn.options & dsdb.NTDSCONN_OPT_TWOWAY_SYNC) != 0x0:

            if (t_repsFrom.replica_flags &
                drsuapi.DRSUAPI_DRS_TWOWAY_SYNC) == 0x0:
                t_repsFrom.replica_flags |= drsuapi.DRSUAPI_DRS_TWOWAY_SYNC

        # Bits DRS_DISABLE_AUTO_SYNC and DRS_DISABLE_PERIODIC_SYNC are
        # set in t.replicaFlags if and only if cn!enabledConnection = false.
        if not cn_conn.is_enabled():

            if (t_repsFrom.replica_flags &
                drsuapi.DRSUAPI_DRS_DISABLE_AUTO_SYNC) == 0x0:
                t_repsFrom.replica_flags |= \
                    drsuapi.DRSUAPI_DRS_DISABLE_AUTO_SYNC

            if (t_repsFrom.replica_flags &
                drsuapi.DRSUAPI_DRS_DISABLE_PERIODIC_SYNC) == 0x0:
                t_repsFrom.replica_flags |= \
                    drsuapi.DRSUAPI_DRS_DISABLE_PERIODIC_SYNC

        # If s and the local DC's nTDSDSA object are in the same site,
        # cn!transportType has no value, or the RDN of cn!transportType
        # is CN=IP:
        #
        #     Bit DRS_MAIL_REP in t.replicaFlags is clear.
        #
        #     t.uuidTransport = NULL GUID.
        #
        #     t.uuidDsa = The GUID-based DNS name of s.
        #
        # Otherwise:
        #
        #     Bit DRS_MAIL_REP in t.replicaFlags is set.
        #
        #     If x is the object with dsname cn!transportType,
        #     t.uuidTransport = x!objectGUID.
        #
        #     Let a be the attribute identified by
        #     x!transportAddressAttribute. If a is
        #     the dNSHostName attribute, t.uuidDsa = the GUID-based
        #      DNS name of s. Otherwise, t.uuidDsa = (s!parent)!a.
        #
        # It appears that the first statement i.e.
        #
        #     "If s and the local DC's nTDSDSA object are in the same
        #      site, cn!transportType has no value, or the RDN of
        #      cn!transportType is CN=IP:"
        #
        # could be a slightly tighter statement if it had an "or"
        # between each condition.  I believe this should
        # be interpreted as:
        #
        #     IF (same-site) OR (no-value) OR (type-ip)
        #
        # because IP should be the primary transport mechanism
        # (even in inter-site) and the absense of the transportType
        # attribute should always imply IP no matter if its multi-site
        #
        # NOTE MS-TECH INCORRECT:
        #
        #     All indications point to these statements above being
        #     incorrectly stated:
        #
        #         t.uuidDsa = The GUID-based DNS name of s.
        #
        #         Let a be the attribute identified by
        #         x!transportAddressAttribute. If a is
        #         the dNSHostName attribute, t.uuidDsa = the GUID-based
        #         DNS name of s. Otherwise, t.uuidDsa = (s!parent)!a.
        #
        #     because the uuidDSA is a GUID and not a GUID-base DNS
        #     name.  Nor can uuidDsa hold (s!parent)!a if not
        #     dNSHostName.  What should have been said is:
        #
        #         t.naDsa = The GUID-based DNS name of s
        #
        #     That would also be correct if transportAddressAttribute
        #     were "mailAddress" because (naDsa) can also correctly
        #     hold the SMTP ISM service address.
        #
        nastr = "%s._msdcs.%s" % (s_dsa.dsa_guid, self.samdb.forest_dns_name())

        # We're not currently supporting SMTP replication
        # so is_smtp_replication_available() is currently
        # always returning False
        if (same_site or
            cn_conn.transport_dnstr is None or
            cn_conn.transport_dnstr.find("CN=IP") == 0 or
            not is_smtp_replication_available()):

            if (t_repsFrom.replica_flags &
                drsuapi.DRSUAPI_DRS_MAIL_REP) != 0x0:
                t_repsFrom.replica_flags &= ~drsuapi.DRSUAPI_DRS_MAIL_REP

            null_guid = misc.GUID()
            if (t_repsFrom.transport_guid is None or
                t_repsFrom.transport_guid != null_guid):
                t_repsFrom.transport_guid = null_guid

            # See (NOTE MS-TECH INCORRECT) above
            if t_repsFrom.version == 0x1:
                if t_repsFrom.dns_name1 is None or \
                   t_repsFrom.dns_name1 != nastr:
                    t_repsFrom.dns_name1 = nastr
            else:
                if t_repsFrom.dns_name1 is None or \
                   t_repsFrom.dns_name2 is None or \
                   t_repsFrom.dns_name1 != nastr or \
                   t_repsFrom.dns_name2 != nastr:
                    t_repsFrom.dns_name1 = nastr
                    t_repsFrom.dns_name2 = nastr

        else:
            if (t_repsFrom.replica_flags &
                drsuapi.DRSUAPI_DRS_MAIL_REP) == 0x0:
                t_repsFrom.replica_flags |= drsuapi.DRSUAPI_DRS_MAIL_REP

            # We have a transport type but its not an
            # object in the database
            if cn_conn.transport_dnstr not in self.transport_table.keys():
                raise Exception("Missing inter-site transport - (%s)" %
                                cn_conn.transport_dnstr)

            x_transport = self.transport_table[cn_conn.transport_dnstr]

            if t_repsFrom.transport_guid != x_transport.guid:
                t_repsFrom.transport_guid = x_transport.guid

            # See (NOTE MS-TECH INCORRECT) above
            if x_transport.address_attr == "dNSHostName":

                if t_repsFrom.version == 0x1:
                    if t_repsFrom.dns_name1 is None or \
                       t_repsFrom.dns_name1 != nastr:
                        t_repsFrom.dns_name1 = nastr
                else:
                    if t_repsFrom.dns_name1 is None or \
                       t_repsFrom.dns_name2 is None or \
                       t_repsFrom.dns_name1 != nastr or \
                       t_repsFrom.dns_name2 != nastr:
                        t_repsFrom.dns_name1 = nastr
                        t_repsFrom.dns_name2 = nastr

            else:
                # MS tech specification says we retrieve the named
                # attribute in "transportAddressAttribute" from the parent of
                # the DSA object
                try:
                    pdnstr = s_dsa.get_parent_dnstr()
                    attrs = [ x_transport.address_attr ]

                    res = self.samdb.search(base=pdnstr, scope=ldb.SCOPE_BASE,
                                            attrs=attrs)
                except ldb.ldbError, (enum, estr):
                    raise Exception \
                        ("Unable to find attr (%s) for (%s) - (%s)" %
                         (x_transport.address_attr, pdnstr, estr))

                msg = res[0]
                nastr = str(msg[x_transport.address_attr][0])

                # See (NOTE MS-TECH INCORRECT) above
                if t_repsFrom.version == 0x1:
                    if t_repsFrom.dns_name1 is None or \
                       t_repsFrom.dns_name1 != nastr:
                        t_repsFrom.dns_name1 = nastr
                else:
                    if t_repsFrom.dns_name1 is None or \
                       t_repsFrom.dns_name2 is None or \
                       t_repsFrom.dns_name1 != nastr or \
                       t_repsFrom.dns_name2 != nastr:

                        t_repsFrom.dns_name1 = nastr
                        t_repsFrom.dns_name2 = nastr

        if t_repsFrom.is_modified():
            logger.debug("modify_repsFrom(): %s" % t_repsFrom)

    def is_repsFrom_implied(self, n_rep, cn_conn):
        """Given a NC replica and NTDS Connection, determine if the connection
        implies a repsFrom tuple should be present from the source DSA listed
        in the connection to the naming context

        :param n_rep: NC replica
        :param conn: NTDS Connection
        ::returns (True || False), source DSA:
        """
        # NTDS Connection must satisfy all the following criteria
        # to imply a repsFrom tuple is needed:
        #
        #    cn!enabledConnection = true.
        #    cn!options does not contain NTDSCONN_OPT_RODC_TOPOLOGY.
        #    cn!fromServer references an nTDSDSA object.
        s_dsa = None

        if cn_conn.is_enabled() and not cn_conn.is_rodc_topology():

            s_dnstr = cn_conn.get_from_dnstr()
            if s_dnstr is not None:
                s_dsa = self.get_dsa(s_dnstr)

            # No DSA matching this source DN string?
            if s_dsa is None:
                return False, None

        # To imply a repsFrom tuple is needed, each of these
        # must be True:
        #
        #     An NC replica of the NC "is present" on the DC to
        #     which the nTDSDSA object referenced by cn!fromServer
        #     corresponds.
        #
        #     An NC replica of the NC "should be present" on
        #     the local DC
        s_rep = s_dsa.get_current_replica(n_rep.nc_dnstr)

        if s_rep is None or not s_rep.is_present():
            return False, None

        # To imply a repsFrom tuple is needed, each of these
        # must be True:
        #
        #     The NC replica on the DC referenced by cn!fromServer is
        #     a writable replica or the NC replica that "should be
        #     present" on the local DC is a partial replica.
        #
        #     The NC is not a domain NC, the NC replica that
        #     "should be present" on the local DC is a partial
        #     replica, cn!transportType has no value, or
        #     cn!transportType has an RDN of CN=IP.
        #
        implied = (not s_rep.is_ro() or n_rep.is_partial()) and \
                  (not n_rep.is_domain() or
                   n_rep.is_partial() or
                   cn_conn.transport_dnstr is None or
                   cn_conn.transport_dnstr.find("CN=IP") == 0)

        if implied:
            return True, s_dsa
        else:
            return False, None

    def translate_ntdsconn(self):
        """This function adjusts values of repsFrom abstract attributes of NC
        replicas on the local DC to match those implied by
        nTDSConnection objects.
        """
        logger.debug("translate_ntdsconn(): enter")

        if self.my_dsa.is_translate_ntdsconn_disabled():
            return

        current_rep_table, needed_rep_table = self.my_dsa.get_rep_tables()

        # Filled in with replicas we currently have that need deleting
        delete_rep_table = {}

        # We're using the MS notation names here to allow
        # correlation back to the published algorithm.
        #
        # n_rep      - NC replica (n)
        # t_repsFrom - tuple (t) in n!repsFrom
        # s_dsa      - Source DSA of the replica. Defined as nTDSDSA
        #              object (s) such that (s!objectGUID = t.uuidDsa)
        #              In our IDL representation of repsFrom the (uuidDsa)
        #              attribute is called (source_dsa_obj_guid)
        # cn_conn    - (cn) is nTDSConnection object and child of the local DC's
        #              nTDSDSA object and (cn!fromServer = s)
        # s_rep      - source DSA replica of n
        #
        # If we have the replica and its not needed
        # then we add it to the "to be deleted" list.
        for dnstr, n_rep in current_rep_table.items():
            if dnstr not in needed_rep_table.keys():
                delete_rep_table[dnstr] = n_rep

        # Now perform the scan of replicas we'll need
        # and compare any current repsFrom against the
        # connections
        for dnstr, n_rep in needed_rep_table.items():

            # load any repsFrom and fsmo roles as we'll
            # need them during connection translation
            n_rep.load_repsFrom(self.samdb)
            n_rep.load_fsmo_roles(self.samdb)

            # Loop thru the existing repsFrom tupples (if any)
            for i, t_repsFrom in enumerate(n_rep.rep_repsFrom):

                # for each tuple t in n!repsFrom, let s be the nTDSDSA
                # object such that s!objectGUID = t.uuidDsa
                guidstr = str(t_repsFrom.source_dsa_obj_guid)
                s_dsa = self.get_dsa_by_guidstr(guidstr)

                # Source dsa is gone from config (strange)
                # so cleanup stale repsFrom for unlisted DSA
                if s_dsa is None:
                    logger.debug("repsFrom source DSA guid (%s) not found" %
                                 guidstr)
                    t_repsFrom.to_be_deleted = True
                    continue

                s_dnstr = s_dsa.dsa_dnstr

                # Retrieve my DSAs connection object (if it exists)
                # that specifies the fromServer equivalent to
                # the DSA that is specified in the repsFrom source
                cn_conn = self.my_dsa.get_connection_by_from_dnstr(s_dnstr)

                # Let (cn) be the nTDSConnection object such that (cn)
                # is a child of the local DC's nTDSDSA object and
                # (cn!fromServer = s) and (cn!options) does not contain
                # NTDSCONN_OPT_RODC_TOPOLOGY or NULL if no such (cn) exists.
                if cn_conn and cn_conn.is_rodc_topology():
                    cn_conn = None

                # KCC removes this repsFrom tuple if any of the following
                # is true:
                #     cn = NULL.
                #
                #     No NC replica of the NC "is present" on DSA that
                #     would be source of replica
                #
                #     A writable replica of the NC "should be present" on
                #     the local DC, but a partial replica "is present" on
                #     the source DSA
                s_rep = s_dsa.get_current_replica(n_rep.nc_dnstr)

                if cn_conn is None or \
                   s_rep is None or not s_rep.is_present() or \
                   (not n_rep.is_ro() and s_rep.is_partial()):

                    t_repsFrom.to_be_deleted = True
                    continue

                # If the KCC did not remove t from n!repsFrom, it updates t
                self.modify_repsFrom(n_rep, t_repsFrom, s_rep, s_dsa, cn_conn)

            # Loop thru connections and add implied repsFrom tuples
            # for each NTDSConnection under our local DSA if the
            # repsFrom is not already present
            for cn_dnstr, cn_conn in self.my_dsa.connect_table.items():

                implied, s_dsa = self.is_repsFrom_implied(n_rep, cn_conn)
                if not implied:
                    continue

                # Loop thru the existing repsFrom tupples (if any) and
                # if we already have a tuple for this connection then
                # no need to proceed to add.  It will have been changed
                # to have the correct attributes above
                for i, t_repsFrom in enumerate(n_rep.rep_repsFrom):

                     guidstr = str(t_repsFrom.source_dsa_obj_guid)
                     if s_dsa is self.get_dsa_by_guidstr(guidstr):
                         s_dsa = None
                         break

                if s_dsa is None:
                    continue

                # Create a new RepsFromTo and proceed to modify
                # it according to specification
                t_repsFrom = RepsFromTo(n_rep.nc_dnstr)

                t_repsFrom.source_dsa_obj_guid = s_dsa.dsa_guid

                self.modify_repsFrom(n_rep, t_repsFrom, s_rep, s_dsa, cn_conn)

                # Add to our NC repsFrom as this is newly computed
                if t_repsFrom.is_modified():
                    n_rep.rep_repsFrom.append(t_repsFrom)

            if opts.readonly:
                # Display any to be deleted or modified repsFrom
                text = n_rep.dumpstr_to_be_deleted()
                if text:
                    logger.info("TO BE DELETED:\n%s" % text)
                text = n_rep.dumpstr_to_be_modified()
                if text:
                    logger.info("TO BE MODIFIED:\n%s" % text)

                # Peform deletion from our tables but perform
                # no database modification
                n_rep.commit_repsFrom(self.samdb, ro=True)
            else:
                # Commit any modified repsFrom to the NC replica
                n_rep.commit_repsFrom(self.samdb)

    def keep_connection(self, cn_conn):
        """Determines if the connection is meant to be kept during the
        pruning of unneeded connections operation.

        Consults the keep_connection_list[] which was built during
        intersite NC replica graph computation.

        ::returns (True or False): if (True) connection should not be pruned
        """
        if cn_conn in self.keep_connection_list:
            return True
        return False

    def merge_failed_links(self):
        """Merge of kCCFailedLinks and kCCFailedLinks from bridgeheads.
        The KCC on a writable DC attempts to merge the link and connection
        failure information from bridgehead DCs in its own site to help it
        identify failed bridgehead DCs.
        """
        # MS-TECH Ref 6.2.2.3.2 Merge of kCCFailedLinks and kCCFailedLinks
        #     from Bridgeheads

        # XXX - not implemented yet

    def setup_graph(self):
        """Set up a GRAPH, populated with a VERTEX for each site
        object, a MULTIEDGE for each siteLink object, and a
        MUTLIEDGESET for each siteLinkBridge object (or implied
        siteLinkBridge).

        ::returns: a new graph
        """
        # XXX - not implemented yet
        return None

    def get_bridgehead(self, site, part, transport, partial_ok, detect_failed):
        """Get a bridghead DC.

        :param site: site object representing for which a bridgehead
            DC is desired.
        :param part: crossRef for NC to replicate.
        :param transport: interSiteTransport object for replication
            traffic.
        :param partial_ok: True if a DC containing a partial
            replica or a full replica will suffice, False if only
            a full replica will suffice.
        :param detect_failed: True to detect failed DCs and route
            replication traffic around them, False to assume no DC
            has failed.
        ::returns: dsa object for the bridgehead DC or None
        """

        bhs = self.get_all_bridgeheads(site, part, transport,
                                       partial_ok, detect_failed)
        if len(bhs) == 0:
            logger.debug("get_bridgehead: exit\n\tsitedn=%s\n\tbhdn=None" %
                         site.site_dnstr)
            return None
        else:
            logger.debug("get_bridgehead: exit\n\tsitedn=%s\n\tbhdn=%s" %
                         (site.site_dnstr, bhs[0].dsa_dnstr))
            return bhs[0]

    def get_all_bridgeheads(self, site, part, transport,
                            partial_ok, detect_failed):
        """Get all bridghead DCs satisfying the given criteria

        :param site: site object representing the site for which
            bridgehead DCs are desired.
        :param part: partition for NC to replicate.
        :param transport: interSiteTransport object for
            replication traffic.
        :param partial_ok: True if a DC containing a partial
            replica or a full replica will suffice, False if
            only a full replica will suffice.
        :param detect_ok: True to detect failed DCs and route
            replication traffic around them, FALSE to assume
            no DC has failed.
        ::returns: list of dsa object for available bridgehead
            DCs or None
        """

        bhs = []

        logger.debug("get_all_bridgeheads: %s" % transport)

        for key, dsa in site.dsa_table.items():

            pdnstr = dsa.get_parent_dnstr()

            # IF t!bridgeheadServerListBL has one or more values and
            # t!bridgeheadServerListBL does not contain a reference
            # to the parent object of dc then skip dc
            if (len(transport.bridgehead_list) != 0 and
                pdnstr not in transport.bridgehead_list):
                continue

            # IF dc is in the same site as the local DC
            #    IF a replica of cr!nCName is not in the set of NC replicas
            #    that "should be present" on dc or a partial replica of the
            #    NC "should be present" but partialReplicasOkay = FALSE
            #        Skip dc
            if self.my_site.same_site(dsa):
                needed, ro, partial = part.should_be_present(dsa)
                if not needed or (partial and not partial_ok):
                    continue

            # ELSE
            #     IF an NC replica of cr!nCName is not in the set of NC
            #     replicas that "are present" on dc or a partial replica of
            #     the NC "is present" but partialReplicasOkay = FALSE
            #          Skip dc
            else:
                rep = dsa.get_current_replica(part.nc_dnstr)
                if rep is None or (rep.is_partial() and not partial_ok):
                    continue

            # IF AmIRODC() and cr!nCName corresponds to default NC then
            #     Let dsaobj be the nTDSDSA object of the dc
            #     IF  dsaobj.msDS-Behavior-Version < DS_BEHAVIOR_WIN2008
            #         Skip dc
            if self.my_dsa.is_ro() and part.is_default():
                if not dsa.is_minimum_behavior(DS_BEHAVIOR_WIN2008):
                    continue

            # IF t!name != "IP" and the parent object of dc has no value for
            # the attribute specified by t!transportAddressAttribute
            #     Skip dc
            if transport.name != "IP":
                # MS tech specification says we retrieve the named
                # attribute in "transportAddressAttribute" from the parent
                # of the DSA object
                try:
                    attrs = [ transport.address_attr ]

                    res = self.samdb.search(base=pdnstr, scope=ldb.SCOPE_BASE,
                                            attrs=attrs)
                except ldb.ldbError, (enum, estr):
                    continue

                msg = res[0]
                nastr = str(msg[transport.address_attr][0])

            # IF BridgeheadDCFailed(dc!objectGUID, detectFailedDCs) = TRUE
            #     Skip dc
            if self.is_bridgehead_failed(dsa, detect_failed):
                continue

            logger.debug("get_all_bridgeheads: dsadn=%s" % dsa.dsa_dnstr)
            bhs.append(dsa)

        # IF bit NTDSSETTINGS_OPT_IS_RAND_BH_SELECTION_DISABLED is set in
        # s!options
        #    SORT bhs such that all GC servers precede DCs that are not GC
        #    servers, and otherwise by ascending objectGUID
        # ELSE
        #    SORT bhs in a random order
        if site.is_random_bridgehead_disabled():
            bhs.sort(sort_dsa_by_gc_and_guid)
        else:
            random.shuffle(bhs)

        return bhs


    def is_bridgehead_failed(self, dsa, detect_failed):
        """Determine whether a given DC is known to be in a failed state
        ::returns: True if and only if the DC should be considered failed
        """
        # XXX - not implemented yet
        return False

    def create_connection(self, part, rbh, rsite, transport,
                          lbh, lsite, link_opt, link_sched,
                          partial_ok, detect_failed):
        """Create an nTDSConnection object with the given parameters
        if one does not already exist.

        :param part: crossRef object for the NC to replicate.
        :param rbh: nTDSDSA object for DC to act as the
            IDL_DRSGetNCChanges server (which is in a site other
            than the local DC's site).
        :param rsite: site of the rbh
        :param transport: interSiteTransport object for the transport
            to use for replication traffic.
        :param lbh: nTDSDSA object for DC to act as the
            IDL_DRSGetNCChanges client (which is in the local DC's site).
        :param lsite: site of the lbh
        :param link_opt: Replication parameters (aggregated siteLink options, etc.)
        :param link_sched: Schedule specifying the times at which
            to begin replicating.
        :partial_ok: True if bridgehead DCs containing partial
            replicas of the NC are acceptable.
        :param detect_failed: True to detect failed DCs and route
            replication traffic around them, FALSE to assume no DC
            has failed.
        """
        rbhs_all = self.get_all_bridgeheads(rsite, part, transport,
                                            partial_ok, False)

        # MS-TECH says to compute rbhs_avail but then doesn't use it
        # rbhs_avail = self.get_all_bridgeheads(rsite, part, transport,
        #                                        partial_ok, detect_failed)

        lbhs_all = self.get_all_bridgeheads(lsite, part, transport,
                                            partial_ok, False)

        # MS-TECH says to compute lbhs_avail but then doesn't use it
        # lbhs_avail = self.get_all_bridgeheads(lsite, part, transport,
        #                                       partial_ok, detect_failed)

        # FOR each nTDSConnection object cn such that the parent of cn is
        # a DC in lbhsAll and cn!fromServer references a DC in rbhsAll
        for ldsa in lbhs_all:
            for cn in ldsa.connect_table.values():

                rdsa = None
                for rdsa in rbhs_all:
                    if cn.from_dnstr == rdsa.dsa_dnstr:
                        break

                if rdsa is None:
                    continue

                # IF bit NTDSCONN_OPT_IS_GENERATED is set in cn!options and
                # NTDSCONN_OPT_RODC_TOPOLOGY is clear in cn!options and
                # cn!transportType references t
                if (cn.is_generated() and not cn.is_rodc_topology() and
                    cn.transport_dnstr == transport.dnstr):

                    # IF bit NTDSCONN_OPT_USER_OWNED_SCHEDULE is clear in
                    # cn!options and cn!schedule != sch
                    #     Perform an originating update to set cn!schedule to
                    #     sched
                    if (not cn.is_user_owned_schedule() and
                        not cn.is_equivalent_schedule(link_sched)):
                        cn.schedule = link_sched
                        cn.set_modified(True)

                    # IF bits NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT and
                    # NTDSCONN_OPT_USE_NOTIFY are set in cn
                    if cn.is_override_notify_default() and \
                       cn.is_use_notify():

                        # IF bit NTDSSITELINK_OPT_USE_NOTIFY is clear in
                        # ri.Options
                        #    Perform an originating update to clear bits
                        #    NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT and
                        #    NTDSCONN_OPT_USE_NOTIFY in cn!options
                        if (link_opt & dsdb.NTDSSITELINK_OPT_USE_NOTIFY) == 0:
                            cn.options &= \
                                ~(dsdb.NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT |
                                  dsdb.NTDSCONN_OPT_USE_NOTIFY)
                            cn.set_modified(True)

                    # ELSE
                    else:

                        # IF bit NTDSSITELINK_OPT_USE_NOTIFY is set in
                        # ri.Options
                        #     Perform an originating update to set bits
                        #     NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT and
                        #     NTDSCONN_OPT_USE_NOTIFY in cn!options
                        if (link_opt & dsdb.NTDSSITELINK_OPT_USE_NOTIFY) != 0:
                            cn.options |= \
                                (dsdb.NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT |
                                 dsdb.NTDSCONN_OPT_USE_NOTIFY)
                            cn.set_modified(True)


                    # IF bit NTDSCONN_OPT_TWOWAY_SYNC is set in cn!options
                    if cn.is_twoway_sync():

                        # IF bit NTDSSITELINK_OPT_TWOWAY_SYNC is clear in
                        # ri.Options
                        #     Perform an originating update to clear bit
                        #     NTDSCONN_OPT_TWOWAY_SYNC in cn!options
                        if (link_opt & dsdb.NTDSSITELINK_OPT_TWOWAY_SYNC) == 0:
                            cn.options &= ~dsdb.NTDSCONN_OPT_TWOWAY_SYNC
                            cn.set_modified(True)

                    # ELSE
                    else:

                        # IF bit NTDSSITELINK_OPT_TWOWAY_SYNC is set in
                        # ri.Options
                        #     Perform an originating update to set bit
                        #     NTDSCONN_OPT_TWOWAY_SYNC in cn!options
                        if (link_opt & dsdb.NTDSSITELINK_OPT_TWOWAY_SYNC) != 0:
                            cn.options |= dsdb.NTDSCONN_OPT_TWOWAY_SYNC
                            cn.set_modified(True)


                    # IF bit NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION is set
                    # in cn!options
                    if cn.is_intersite_compression_disabled():

                        # IF bit NTDSSITELINK_OPT_DISABLE_COMPRESSION is clear
                        # in ri.Options
                        #     Perform an originating update to clear bit
                        #     NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION in
                        #     cn!options
                        if (link_opt &
                            dsdb.NTDSSITELINK_OPT_DISABLE_COMPRESSION) == 0:
                            cn.options &= \
                                ~dsdb.NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION
                            cn.set_modified(True)

                    # ELSE
                    else:
                        # IF bit NTDSSITELINK_OPT_DISABLE_COMPRESSION is set in
                        # ri.Options
                        #     Perform an originating update to set bit
                        #     NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION in
                        #     cn!options
                        if (link_opt &
                            dsdb.NTDSSITELINK_OPT_DISABLE_COMPRESSION) != 0:
                            cn.options |= \
                                dsdb.NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION
                            cn.set_modified(True)

                    # Display any modified connection
                    if opts.readonly:
                        if cn.to_be_modified:
                            logger.info("TO BE MODIFIED:\n%s" % cn)

                        ldsa.commit_connections(self.samdb, ro=True)
                    else:
                        ldsa.commit_connections(self.samdb)
        # ENDFOR

        valid_connections = 0

        # FOR each nTDSConnection object cn such that cn!parent is
        # a DC in lbhsAll and cn!fromServer references a DC in rbhsAll
        for ldsa in lbhs_all:
            for cn in ldsa.connect_table.values():

                rdsa = None
                for rdsa in rbhs_all:
                    if cn.from_dnstr == rdsa.dsa_dnstr:
                        break

                if rdsa is None:
                    continue

                # IF (bit NTDSCONN_OPT_IS_GENERATED is clear in cn!options or
                # cn!transportType references t) and
                # NTDSCONN_OPT_RODC_TOPOLOGY is clear in cn!options
                if ((not cn.is_generated() or
                     cn.transport_dnstr == transport.dnstr) and
                     not cn.is_rodc_topology()):

                    # LET rguid be the objectGUID of the nTDSDSA object
                    # referenced by cn!fromServer
                    # LET lguid be (cn!parent)!objectGUID

                    # IF BridgeheadDCFailed(rguid, detectFailedDCs) = FALSE and
                    # BridgeheadDCFailed(lguid, detectFailedDCs) = FALSE
                    #     Increment cValidConnections by 1
                    if (not self.is_bridgehead_failed(rdsa, detect_failed) and
                        not self.is_bridgehead_failed(ldsa, detect_failed)):
                        valid_connections += 1

                    # IF keepConnections does not contain cn!objectGUID
                    #     APPEND cn!objectGUID to keepConnections
                    if not self.keep_connection(cn):
                        self.keep_connection_list.append(cn)

        # ENDFOR

        # IF cValidConnections = 0
        if valid_connections == 0:

            # LET opt be NTDSCONN_OPT_IS_GENERATED
            opt = dsdb.NTDSCONN_OPT_IS_GENERATED

            # IF bit NTDSSITELINK_OPT_USE_NOTIFY is set in ri.Options
            #     SET bits NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT and
            #     NTDSCONN_OPT_USE_NOTIFY in opt
            if (link_opt & dsdb.NTDSSITELINK_OPT_USE_NOTIFY) != 0:
                opt |= (dsdb.NTDSCONN_OPT_OVERRIDE_NOTIFY_DEFAULT |
                        dsdb.NTDSCONN_USE_NOTIFY)

            # IF bit NTDSSITELINK_OPT_TWOWAY_SYNC is set in ri.Options
            #     SET bit NTDSCONN_OPT_TWOWAY_SYNC opt
            if (link_opt & dsdb.NTDSSITELINK_OPT_TWOWAY_SYNC) != 0:
                opt |= dsdb.NTDSCONN_OPT_TWOWAY_SYNC

            # IF bit NTDSSITELINK_OPT_DISABLE_COMPRESSION is set in
            # ri.Options
            #     SET bit NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION in opt
            if (link_opt &
                dsdb.NTDSSITELINK_OPT_DISABLE_COMPRESSION) != 0:
                opt |= dsdb.NTDSCONN_OPT_DISABLE_INTERSITE_COMPRESSION

            # Perform an originating update to create a new nTDSConnection
            # object cn that is a child of lbh, cn!enabledConnection = TRUE,
            # cn!options = opt, cn!transportType is a reference to t,
            # cn!fromServer is a reference to rbh, and cn!schedule = sch
            cn = lbh.new_connection(opt, 0, transport, lbh.dsa_dnstr, link_sched)

            # Display any added connection
            if opts.readonly:
                if cn.to_be_added:
                    logger.info("TO BE ADDED:\n%s" % cn)

                    lbh.commit_connections(self.samdb, ro=True)
            else:
                lbh.commit_connections(self.samdb)

            # APPEND cn!objectGUID to keepConnections
            if not self.keep_connection(cn):
                self.keep_connection_list.append(cn)

    def create_connections(self, graph, part, detect_failed):
        """Construct an NC replica graph for the NC identified by
        the given crossRef, then create any additional nTDSConnection
        objects required.

        :param graph: site graph.
        :param part: crossRef object for NC.
        :param detect_failed:  True to detect failed DCs and route
            replication traffic around them, False to assume no DC
            has failed.

        Modifies self.keep_connection_list by adding any connections
        deemed to be "in use".

        ::returns: (all_connected, found_failed_dc)
        (all_connected) True if the resulting NC replica graph
            connects all sites that need to be connected.
        (found_failed_dc) True if one or more failed DCs were
            detected.
        """
        all_connected = True
        found_failed = False

        logger.debug("create_connections(): enter\n\tpartdn=%s\n\tdetect_failed=%s" %
                     (part.nc_dnstr, detect_failed))

        # XXX - This is a highly abbreviated function from the MS-TECH
        #       ref.  It creates connections between bridgeheads to all
        #       sites that have appropriate replicas.  Thus we are not
        #       creating a minimum cost spanning tree but instead
        #       producing a fully connected tree.  This should produce
        #       a full (albeit not optimal cost) replication topology.
        my_vertex = Vertex(self.my_site, part)
        my_vertex.color_vertex()

        # No NC replicas for this NC in the site of the local DC,
        # so no nTDSConnection objects need be created
        if my_vertex.is_white():
            return all_connected, found_failed

        # LET partialReplicaOkay be TRUE if and only if
        # localSiteVertex.Color = COLOR.BLACK
        if my_vertex.is_black():
            partial_ok = True
        else:
            partial_ok = False

        # Utilize the IP transport only for now
        transport = None
        for transport in self.transport_table.values():
            if transport.name == "IP":
               break

        if transport is None:
            raise Exception("Unable to find inter-site transport for IP")

        for rsite in self.site_table.values():

            # We don't make connections to our own site as that
            # is intrasite topology generator's job
            if rsite is self.my_site:
                continue

            # Determine bridgehead server in remote site
            rbh = self.get_bridgehead(rsite, part, transport,
                                      partial_ok, detect_failed)

            # RODC acts as an BH for itself
            # IF AmIRODC() then
            #     LET lbh be the nTDSDSA object of the local DC
            # ELSE
            #     LET lbh be the result of GetBridgeheadDC(localSiteVertex.ID,
            #     cr, t, partialReplicaOkay, detectFailedDCs)
            if self.my_dsa.is_ro():
               lsite = self.my_site
               lbh = self.my_dsa
            else:
               lsite = self.my_site
               lbh = self.get_bridgehead(lsite, part, transport,
                                           partial_ok, detect_failed)

            # Find the siteLink object that enumerates the connection
            # between the two sites if it is present
            sitelink = self.get_sitelink(lsite.site_dnstr, rsite.site_dnstr)
            if sitelink is None:
                link_opt = 0x0
                link_sched = None
            else:
                link_opt = sitelink.options
                link_sched = sitelink.schedule

            self.create_connection(part, rbh, rsite, transport,
                                   lbh, lsite, link_opt, link_sched,
                                   partial_ok, detect_failed)

        return all_connected, found_failed

    def create_intersite_connections(self):
        """Computes an NC replica graph for each NC replica that "should be
        present" on the local DC or "is present" on any DC in the same site
        as the local DC. For each edge directed to an NC replica on such a
        DC from an NC replica on a DC in another site, the KCC creates an
        nTDSConnection object to imply that edge if one does not already
        exist.

        Modifies self.keep_connection_list - A list of nTDSConnection
        objects for edges that are directed
        to the local DC's site in one or more NC replica graphs.

        returns: True if spanning trees were created for all NC replica
            graphs, otherwise False.
        """
        all_connected = True
        self.keep_connection_list = []

        # LET crossRefList be the set containing each object o of class
        # crossRef such that o is a child of the CN=Partitions child of the
        # config NC

        # FOR each crossRef object cr in crossRefList
        #    IF cr!enabled has a value and is false, or if FLAG_CR_NTDS_NC
        #        is clear in cr!systemFlags, skip cr.
        #    LET g be the GRAPH return of SetupGraph()

        for part in self.part_table.values():

            if not part.is_enabled():
                continue

            if part.is_foreign():
                continue

            graph = self.setup_graph()

            # Create nTDSConnection objects, routing replication traffic
            # around "failed" DCs.
            found_failed = False

            connected, found_failed = self.create_connections(graph, part, True)

            if not connected:
                all_connected = False

                if found_failed:
                    # One or more failed DCs preclude use of the ideal NC
                    # replica graph. Add connections for the ideal graph.
                    self.create_connections(graph, part, False)

        return all_connected

    def intersite(self):
        """The head method for generating the inter-site KCC replica
        connection graph and attendant nTDSConnection objects
        in the samdb.

        Produces self.keep_connection_list[] of NTDS Connections
        that should be kept during subsequent pruning process.

        ::return (True or False):  (True) if the produced NC replica
            graph connects all sites that need to be connected
        """

        # Retrieve my DSA
        mydsa = self.my_dsa
        mysite = self.my_site
        all_connected = True

        logger.debug("intersite(): enter")

        # Determine who is the ISTG
        if opts.readonly:
            mysite.select_istg(self.samdb, mydsa, ro=True)
        else:
            mysite.select_istg(self.samdb, mydsa, ro=False)

        # Test whether local site has topology disabled
        if mysite.is_intersite_topology_disabled():
            logger.debug("intersite(): exit disabled all_connected=%d" %
                         all_connected)
            return all_connected

        if not mydsa.is_istg():
            logger.debug("intersite(): exit not istg all_connected=%d" %
                         all_connected)
            return all_connected

        self.merge_failed_links()

        # For each NC with an NC replica that "should be present" on the
        # local DC or "is present" on any DC in the same site as the
        # local DC, the KCC constructs a site graph--a precursor to an NC
        # replica graph. The site connectivity for a site graph is defined
        # by objects of class interSiteTransport, siteLink, and
        # siteLinkBridge in the config NC.

        all_connected = self.create_intersite_connections()

        logger.debug("intersite(): exit all_connected=%d" % all_connected)
        return all_connected

    def update_rodc_connection(self):
        """Runs when the local DC is an RODC and updates the RODC NTFRS
        connection object.
        """
        # Given an nTDSConnection object cn1, such that cn1.options contains
        # NTDSCONN_OPT_RODC_TOPOLOGY, and another nTDSConnection object cn2,
        # does not contain NTDSCONN_OPT_RODC_TOPOLOGY, modify cn1 to ensure
        # that the following is true:
        #
        #     cn1.fromServer = cn2.fromServer
        #     cn1.schedule = cn2.schedule
        #
        # If no such cn2 can be found, cn1 is not modified.
        # If no such cn1 can be found, nothing is modified by this task.

        # XXX - not implemented yet

    def intrasite_max_node_edges(self, node_count):
        """Returns the maximum number of edges directed to a node in
        the intrasite replica graph.

        The KCC does not create more
        than 50 edges directed to a single DC. To optimize replication,
        we compute that each node should have n+2 total edges directed
        to it such that (n) is the smallest non-negative integer
        satisfying (node_count <= 2*(n*n) + 6*n + 7)

        :param node_count: total number of nodes in the replica graph
        """
        n = 0
        while True:
            if node_count <= (2 * (n * n) + (6 * n) + 7):
                break
            n = n + 1
        n = n + 2
        if n < 50:
            return n
        return 50

    def construct_intrasite_graph(self, site_local, dc_local,
                                  nc_x, gc_only, detect_stale):

        # We're using the MS notation names here to allow
        # correlation back to the published algorithm.
        #
        # nc_x     - naming context (x) that we are testing if it
        #            "should be present" on the local DC
        # f_of_x   - replica (f) found on a DC (s) for NC (x)
        # dc_s     - DC where f_of_x replica was found
        # dc_local - local DC that potentially needs a replica
        #            (f_of_x)
        # r_list   - replica list R
        # p_of_x   - replica (p) is partial and found on a DC (s)
        #            for NC (x)
        # l_of_x   - replica (l) is the local replica for NC (x)
        #            that should appear on the local DC
        # r_len = is length of replica list |R|
        #
        # If the DSA doesn't need a replica for this
        # partition (NC x) then continue
        needed, ro, partial = nc_x.should_be_present(dc_local)

        logger.debug("construct_intrasite_graph(): enter" +
                     "\n\tgc_only=%d" % gc_only +
                     "\n\tdetect_stale=%d" % detect_stale +
                     "\n\tneeded=%s" % needed +
                     "\n\tro=%s" % ro +
                     "\n\tpartial=%s" % partial +
                     "\n%s" % nc_x)

        if not needed:
            return

        # Create a NCReplica that matches what the local replica
        # should say.  We'll use this below in our r_list
        l_of_x = NCReplica(dc_local.dsa_dnstr, dc_local.dsa_guid,
                           nc_x.nc_dnstr)

        l_of_x.identify_by_basedn(self.samdb)

        l_of_x.rep_partial = partial
        l_of_x.rep_ro = ro

        # Add this replica that "should be present" to the
        # needed replica table for this DSA
        dc_local.add_needed_replica(l_of_x)

        # Empty replica sequence list
        r_list = []

        # We'll loop thru all the DSAs looking for
        # writeable NC replicas that match the naming
        # context dn for (nc_x)
        #
        for dc_s_dn, dc_s in self.my_site.dsa_table.items():

            # If this partition (nc_x) doesn't appear as a
            # replica (f_of_x) on (dc_s) then continue
            if not nc_x.nc_dnstr in dc_s.current_rep_table.keys():
                continue

            # Pull out the NCReplica (f) of (x) with the dn
            # that matches NC (x) we are examining.
            f_of_x = dc_s.current_rep_table[nc_x.nc_dnstr]

            # Replica (f) of NC (x) must be writable
            if f_of_x.is_ro():
                continue

            # Replica (f) of NC (x) must satisfy the
            # "is present" criteria for DC (s) that
            # it was found on
            if not f_of_x.is_present():
                continue

            # DC (s) must be a writable DSA other than
            # my local DC.  In other words we'd only replicate
            # from other writable DC
            if dc_s.is_ro() or dc_s is dc_local:
                continue

            # Certain replica graphs are produced only
            # for global catalogs, so test against
            # method input parameter
            if gc_only and not dc_s.is_gc():
                continue

            # DC (s) must be in the same site as the local DC
            # as this is the intra-site algorithm. This is
            # handled by virtue of placing DSAs in per
            # site objects (see enclosing for() loop)

            # If NC (x) is intended to be read-only full replica
            # for a domain NC on the target DC then the source
            # DC should have functional level at minimum WIN2008
            #
            # Effectively we're saying that in order to replicate
            # to a targeted RODC (which was introduced in Windows 2008)
            # then we have to replicate from a DC that is also minimally
            # at that level.
            #
            # You can also see this requirement in the MS special
            # considerations for RODC which state that to deploy
            # an RODC, at least one writable domain controller in
            # the domain must be running Windows Server 2008
            if ro and not partial and nc_x.nc_type == NCType.domain:
                if not dc_s.is_minimum_behavior(DS_BEHAVIOR_WIN2008):
                    continue

            # If we haven't been told to turn off stale connection
            # detection and this dsa has a stale connection then
            # continue
            if detect_stale and self.is_stale_link_connection(dc_s):
               continue

            # Replica meets criteria.  Add it to table indexed
            # by the GUID of the DC that it appears on
            r_list.append(f_of_x)

        # If a partial (not full) replica of NC (x) "should be present"
        # on the local DC, append to R each partial replica (p of x)
        # such that p "is present" on a DC satisfying the same
        # criteria defined above for full replica DCs.
        if partial:

            # Now we loop thru all the DSAs looking for
            # partial NC replicas that match the naming
            # context dn for (NC x)
            for dc_s_dn, dc_s in self.my_site.dsa_table.items():

                # If this partition NC (x) doesn't appear as a
                # replica (p) of NC (x) on the dsa DC (s) then
                # continue
                if not nc_x.nc_dnstr in dc_s.current_rep_table.keys():
                    continue

                # Pull out the NCReplica with the dn that
                # matches NC (x) we are examining.
                p_of_x = dsa.current_rep_table[nc_x.nc_dnstr]

                # Replica (p) of NC (x) must be partial
                if not p_of_x.is_partial():
                    continue

                # Replica (p) of NC (x) must satisfy the
                # "is present" criteria for DC (s) that
                # it was found on
                if not p_of_x.is_present():
                    continue

                # DC (s) must be a writable DSA other than
                # my DSA.  In other words we'd only replicate
                # from other writable DSA
                if dc_s.is_ro() or dc_s is dc_local:
                    continue

                # Certain replica graphs are produced only
                # for global catalogs, so test against
                # method input parameter
                if gc_only and not dc_s.is_gc():
                    continue

                # DC (s) must be in the same site as the local DC
                # as this is the intra-site algorithm. This is
                # handled by virtue of placing DSAs in per
                # site objects (see enclosing for() loop)

                # This criteria is moot (a no-op) for this case
                # because we are scanning for (partial = True).  The
                # MS algorithm statement says partial replica scans
                # should adhere to the "same" criteria as full replica
                # scans so the criteria doesn't change here...its just
                # rendered pointless.
                #
                # The case that is occurring would be a partial domain
                # replica is needed on a local DC global catalog.  There
                # is no minimum windows behavior for those since GCs
                # have always been present.
                if ro and not partial and nc_x.nc_type == NCType.domain:
                    if not dc_s.is_minimum_behavior(DS_BEHAVIOR_WIN2008):
                        continue

                # If we haven't been told to turn off stale connection
                # detection and this dsa has a stale connection then
                # continue
                if detect_stale and self.is_stale_link_connection(dc_s):
                    continue

                # Replica meets criteria.  Add it to table indexed
                # by the GUID of the DSA that it appears on
                r_list.append(p_of_x)

        # Append to R the NC replica that "should be present"
        # on the local DC
        r_list.append(l_of_x)

        r_list.sort(sort_replica_by_dsa_guid)

        r_len = len(r_list)

        max_node_edges = self.intrasite_max_node_edges(r_len)

        # Add a node for each r_list element to the replica graph
        graph_list = []
        for rep in r_list:
            node = GraphNode(rep.rep_dsa_dnstr, max_node_edges)
            graph_list.append(node)

        # For each r(i) from (0 <= i < |R|-1)
        i = 0
        while i < (r_len-1):
            # Add an edge from r(i) to r(i+1) if r(i) is a full
            # replica or r(i+1) is a partial replica
            if not r_list[i].is_partial() or r_list[i+1].is_partial():
                graph_list[i+1].add_edge_from(r_list[i].rep_dsa_dnstr)

            # Add an edge from r(i+1) to r(i) if r(i+1) is a full
            # replica or ri is a partial replica.
            if not r_list[i+1].is_partial() or r_list[i].is_partial():
                graph_list[i].add_edge_from(r_list[i+1].rep_dsa_dnstr)
            i = i + 1

        # Add an edge from r|R|-1 to r0 if r|R|-1 is a full replica
        # or r0 is a partial replica.
        if not r_list[r_len-1].is_partial() or r_list[0].is_partial():
            graph_list[0].add_edge_from(r_list[r_len-1].rep_dsa_dnstr)

        # Add an edge from r0 to r|R|-1 if r0 is a full replica or
        # r|R|-1 is a partial replica.
        if not r_list[0].is_partial() or r_list[r_len-1].is_partial():
            graph_list[r_len-1].add_edge_from(r_list[0].rep_dsa_dnstr)

        # For each existing nTDSConnection object implying an edge
        # from rj of R to ri such that j != i, an edge from rj to ri
        # is not already in the graph, and the total edges directed
        # to ri is less than n+2, the KCC adds that edge to the graph.
        i = 0
        while i < r_len:
            dsa = self.my_site.dsa_table[graph_list[i].dsa_dnstr]
            graph_list[i].add_edges_from_connections(dsa)
            i = i + 1

        i = 0
        while i < r_len:
            tnode = graph_list[i]

            # To optimize replication latency in sites with many NC replicas, the
            # KCC adds new edges directed to ri to bring the total edges to n+2,
            # where the NC replica rk of R from which the edge is directed
            # is chosen at random such that k != i and an edge from rk to ri
            # is not already in the graph.
            #
            # Note that the KCC tech ref does not give a number for the definition
            # of "sites with many NC replicas".   At a bare minimum to satisfy
            # n+2 edges directed at a node we have to have at least three replicas
            # in |R| (i.e. if n is zero then at least replicas from two other graph
            # nodes may direct edges to us).
            if r_len >= 3:
                # pick a random index
                findex = rindex = random.randint(0, r_len-1)

                # while this node doesn't have sufficient edges
                while not tnode.has_sufficient_edges():
                    # If this edge can be successfully added (i.e. not
                    # the same node and edge doesn't already exist) then
                    # select a new random index for the next round
                    if tnode.add_edge_from(graph_list[rindex].dsa_dnstr):
                        findex = rindex = random.randint(0, r_len-1)
                    else:
                        # Otherwise continue looking against each node
                        # after the random selection
                        rindex = rindex + 1
                        if rindex >= r_len:
                            rindex = 0

                        if rindex == findex:
                            logger.error("Unable to satisfy max edge criteria!")
                            break

            # Print the graph node in debug mode
            logger.debug("%s" % tnode)

            # For each edge directed to the local DC, ensure a nTDSConnection
            # points to us that satisfies the KCC criteria
            if graph_list[i].dsa_dnstr == dc_local.dsa_dnstr:
                graph_list[i].add_connections_from_edges(dc_local)

            i = i + 1

    def intrasite(self):
        """The head method for generating the intra-site KCC replica
        connection graph and attendant nTDSConnection objects
        in the samdb
        """
        # Retrieve my DSA
        mydsa = self.my_dsa

        logger.debug("intrasite(): enter")

        # Test whether local site has topology disabled
        mysite = self.site_table[self.my_site_dnstr]
        if mysite.is_intrasite_topology_disabled():
            return

        detect_stale = (not mysite.is_detect_stale_disabled())

        # Loop thru all the partitions.
        for partdn, part in self.part_table.items():
            self.construct_intrasite_graph(mysite, mydsa, part, False,
                                           detect_stale)

        # If the DC is a GC server, the KCC constructs an additional NC
        # replica graph (and creates nTDSConnection objects) for the
        # config NC as above, except that only NC replicas that "are present"
        # on GC servers are added to R.
        for partdn, part in self.part_table.items():
            if part.is_config():
                self.construct_intrasite_graph(mysite, mydsa, part, True,
                                               detect_stale)

        # The DC repeats the NC replica graph computation and nTDSConnection
        # creation for each of the NC replica graphs, this time assuming
        # that no DC has failed. It does so by re-executing the steps as
        # if the bit NTDSSETTINGS_OPT_IS_TOPL_DETECT_STALE_DISABLED were
        # set in the options attribute of the site settings object for
        # the local DC's site.  (ie. we set "detec_stale" flag to False)

        # Loop thru all the partitions.
        for partdn, part in self.part_table.items():
            self.construct_intrasite_graph(mysite, mydsa, part, False,
                                           False) # don't detect stale

        # If the DC is a GC server, the KCC constructs an additional NC
        # replica graph (and creates nTDSConnection objects) for the
        # config NC as above, except that only NC replicas that "are present"
        # on GC servers are added to R.
        for partdn, part in self.part_table.items():
            if part.is_config():
                self.construct_intrasite_graph(mysite, mydsa, part, True,
                                               False)  # don't detect stale

        if opts.readonly:
            # Display any to be added or modified repsFrom
            for dnstr, connect in mydsa.connect_table.items():
                if connect.to_be_deleted:
                    logger.info("TO BE DELETED:\n%s" % connect)
                if connect.to_be_modified:
                    logger.info("TO BE MODIFIED:\n%s" % connect)
                if connect.to_be_added:
                    logger.info("TO BE ADDED:\n%s" % connect)

            mydsa.commit_connections(self.samdb, ro=True)
        else:
            # Commit any newly created connections to the samdb
            mydsa.commit_connections(self.samdb)

    def run(self, dburl, lp, creds):
        """Method to perform a complete run of the KCC and
        produce an updated topology for subsequent NC replica
        syncronization between domain controllers
        """
        # We may already have a samdb setup if we are
        # currently importing an ldif for a test run
        if self.samdb is None:
            try:
                self.samdb = SamDB(url=lp.samdb_url(),
                                   session_info=system_session(),
                                   credentials=creds, lp=lp)

            except ldb.LdbError, (num, msg):
                logger.error("Unable to open sam database %s : %s" %
                             (lp.samdb_url(), msg))
                return 1

        try:
            # Setup
            self.load_my_site()
            self.load_my_dsa()

            self.load_all_sites()
            self.load_all_partitions()
            self.load_all_transports()
            self.load_all_sitelinks()

            # These are the published steps (in order) for the
            # MS-TECH description of the KCC algorithm

            # Step 1
            self.refresh_failed_links_connections()

            # Step 2
            self.intrasite()

            # Step 3
            all_connected = self.intersite()

            # Step 4
            self.remove_unneeded_ntdsconn(all_connected)

            # Step 5
            self.translate_ntdsconn()

            # Step 6
            self.remove_unneeded_failed_links_connections()

            # Step 7
            self.update_rodc_connection()

        except Exception, estr:
            logger.error("%s" % estr)
            return 1

        return 0

    def import_ldif(self, dburl, lp, creds, ldif_file):
        """Routine to import all objects and attributes that are relevent
        to the KCC algorithms from a previously exported LDIF file.

        The point of this function is to allow a programmer/debugger to
        import an LDIF file with non-security relevent information that
        was previously extracted from a DC database.  The LDIF file is used
        to create a temporary abbreviated database.  The KCC algorithm can
        then run against this abbreviated database for debug or test
        verification that the topology generated is computationally the
        same between different OSes and algorithms.

        :param dburl: path to the temporary abbreviated db to create
        :param ldif_file: path to the ldif file to import
        """
        if os.path.exists(dburl):
            logger.error("Specify a database (%s) that doesn't already exist." %
                         dburl)
            return 1

        # Use ["modules:"] as we are attempting to build a sam
        # database as opposed to start it here.
        self.samdb = Ldb(url=dburl, session_info=system_session(),
                         lp=lp, options=["modules:"])

        self.samdb.transaction_start()
        try:
            data = read_and_sub_file(ldif_file, None)
            self.samdb.add_ldif(data, None)

        except Exception, estr:
            logger.error("%s" % estr)
            self.samdb.transaction_cancel()
            return 1
        else:
            self.samdb.transaction_commit()

        self.samdb = None

        # We have an abbreviated list of options here because we have built
        # an abbreviated database.  We use the rootdse and extended-dn
        # modules only during this re-open
        self.samdb = SamDB(url=dburl, session_info=system_session(),
                           credentials=creds, lp=lp,
                           options=["modules:rootdse,extended_dn_out_ldb"])
        return 0

    def export_ldif(self, dburl, lp, creds, ldif_file):
        """Routine to extract all objects and attributes that are relevent
        to the KCC algorithms from a DC database.

        The point of this function is to allow a programmer/debugger to
        extract an LDIF file with non-security relevent information from
        a DC database.  The LDIF file can then be used to "import" via
        the import_ldif() function this file into a temporary abbreviated
        database.  The KCC algorithm can then run against this abbreviated
        database for debug or test verification that the topology generated
        is computationally the same between different OSes and algorithms.

        :param dburl: LDAP database URL to extract info from
        :param ldif_file: output LDIF file name to create
        """
        try:
            self.samdb = SamDB(url=dburl,
                               session_info=system_session(),
                               credentials=creds, lp=lp)
        except ldb.LdbError, (enum, estr):
            logger.error("Unable to open sam database (%s) : %s" %
                         (lp.samdb_url(), estr))
            return 1

        if os.path.exists(ldif_file):
            logger.error("Specify a file (%s) that doesn't already exist." %
                         ldif_file)
            return 1

        try:
            f = open(ldif_file, "w")
        except (enum, estr):
            logger.error("Unable to open (%s) : %s" % (ldif_file, estr))
            return 1

        try:
            # Query Partitions
            attrs = [ "objectClass",
                      "objectGUID",
                      "cn",
                      "whenChanged",
                      "objectSid",
                      "Enabled",
                      "systemFlags",
                      "dnsRoot",
                      "nCName",
                      "msDS-NC-Replica-Locations",
                      "msDS-NC-RO-Replica-Locations" ]

            sstr = "CN=Partitions,%s" % self.samdb.get_config_basedn()
            res = self.samdb.search(base=sstr, scope=ldb.SCOPE_SUBTREE,
                                     attrs=attrs,
                                     expression="(objectClass=crossRef)")

            # Write partitions output
            write_search_result(self.samdb, f, res)

            # Query cross reference container
            attrs = [ "objectClass",
                      "objectGUID",
                      "cn",
                      "whenChanged",
                      "fSMORoleOwner",
                      "systemFlags",
                      "msDS-Behavior-Version",
                      "msDS-EnabledFeature" ]

            sstr = "CN=Partitions,%s" % self.samdb.get_config_basedn()
            res = self.samdb.search(base=sstr, scope=ldb.SCOPE_SUBTREE,
                                     attrs=attrs,
                                     expression="(objectClass=crossRefContainer)")

            # Write cross reference container output
            write_search_result(self.samdb, f, res)

            # Query Sites
            attrs = [ "objectClass",
                      "objectGUID",
                      "cn",
                      "whenChanged",
                      "systemFlags" ]

            sstr = "CN=Sites,%s" % self.samdb.get_config_basedn()
            sites = self.samdb.search(base=sstr, scope=ldb.SCOPE_SUBTREE,
                                      attrs=attrs,
                                      expression="(objectClass=site)")

            # Write sites output
            write_search_result(self.samdb, f, sites)

            # Query NTDS Site Settings
            for msg in sites:
                sitestr = str(msg.dn)

                attrs = [ "objectClass",
                          "objectGUID",
                          "cn",
                          "whenChanged",
                          "interSiteTopologyGenerator",
                          "interSiteTopologyFailover",
                          "schedule",
                          "options" ]

                sstr = "CN=NTDS Site Settings,%s" % sitestr
                res = self.samdb.search(base=sstr, scope=ldb.SCOPE_BASE,
                                         attrs=attrs)

                # Write Site Settings output
                write_search_result(self.samdb, f, res)

            # Naming context list
            nclist = []

            # Query Directory Service Agents
            for msg in sites:
                sstr = str(msg.dn)

                ncattrs = [ "hasMasterNCs",
                            "msDS-hasMasterNCs",
                            "hasPartialReplicaNCs",
                            "msDS-HasDomainNCs",
                            "msDS-hasFullReplicaNCs",
                            "msDS-HasInstantiatedNCs" ]
                attrs = [ "objectClass",
                            "objectGUID",
                            "cn",
                            "whenChanged",
                            "invocationID",
                            "options",
                            "msDS-isRODC",
                            "msDS-Behavior-Version" ]

                res = self.samdb.search(base=sstr, scope=ldb.SCOPE_SUBTREE,
                                        attrs=attrs + ncattrs,
                                        expression="(objectClass=nTDSDSA)")

                # Spin thru all the DSAs looking for NC replicas
                # and build a list of all possible Naming Contexts
                # for subsequent retrieval below
                for msg in res:
                    for k in msg.keys():
                        if k in ncattrs:
                            for value in msg[k]:
                                # Some of these have binary DNs so
                                # use dsdb_Dn to split out relevent parts
                                dsdn = dsdb_Dn(self.samdb, value)
                                dnstr = str(dsdn.dn)
                                if dnstr not in nclist:
                                    nclist.append(dnstr)

                # Write DSA output
                write_search_result(self.samdb, f, res)

            # Query NTDS Connections
            for msg in sites:
                sstr = str(msg.dn)

                attrs = [ "objectClass",
                          "objectGUID",
                          "cn",
                          "whenChanged",
                          "options",
                          "whenCreated",
                          "enabledConnection",
                          "schedule",
                          "transportType",
                          "fromServer",
                          "systemFlags" ]

                res = self.samdb.search(base=sstr, scope=ldb.SCOPE_SUBTREE,
                                        attrs=attrs,
                                        expression="(objectClass=nTDSConnection)")
                # Write NTDS Connection output
                write_search_result(self.samdb, f, res)


            # Query Intersite transports
            attrs = [ "objectClass",
                      "objectGUID",
                      "cn",
                      "whenChanged",
                      "options",
                      "name",
                      "bridgeheadServerListBL",
                      "transportAddressAttribute" ]

            sstr = "CN=Inter-Site Transports,CN=Sites,%s" % \
                   self.samdb.get_config_basedn()
            res = self.samdb.search(sstr, scope=ldb.SCOPE_SUBTREE,
                                     attrs=attrs,
                                     expression="(objectClass=interSiteTransport)")

            # Write inter-site transport output
            write_search_result(self.samdb, f, res)

            # Query siteLink
            attrs = [ "objectClass",
                      "objectGUID",
                      "cn",
                      "whenChanged",
                      "systemFlags",
                      "options",
                      "schedule",
                      "replInterval",
                      "siteList",
                      "cost" ]

            sstr = "CN=Sites,%s" % \
                   self.samdb.get_config_basedn()
            res = self.samdb.search(sstr, scope=ldb.SCOPE_SUBTREE,
                                     attrs=attrs,
                                     expression="(objectClass=siteLink)")

            # Write siteLink output
            write_search_result(self.samdb, f, res)

            # Query siteLinkBridge
            attrs = [ "objectClass",
                      "objectGUID",
                      "cn",
                      "whenChanged",
                      "siteLinkList" ]

            sstr = "CN=Sites,%s" % self.samdb.get_config_basedn()
            res = self.samdb.search(sstr, scope=ldb.SCOPE_SUBTREE,
                                     attrs=attrs,
                                     expression="(objectClass=siteLinkBridge)")

            # Write siteLinkBridge output
            write_search_result(self.samdb, f, res)

            # Query servers containers
            # Needed for samdb.server_site_name()
            attrs = [ "objectClass",
                      "objectGUID",
                      "cn",
                      "whenChanged",
                      "systemFlags" ]

            sstr = "CN=Sites,%s" % self.samdb.get_config_basedn()
            res = self.samdb.search(sstr, scope=ldb.SCOPE_SUBTREE,
                                     attrs=attrs,
                                     expression="(objectClass=serversContainer)")

            # Write servers container output
            write_search_result(self.samdb, f, res)

            # Query servers
            # Needed because some transport interfaces refer back to
            # attributes found in the server object.   Also needed
            # so extended-dn will be happy with dsServiceName in rootDSE
            attrs = [ "objectClass",
                      "objectGUID",
                      "cn",
                      "whenChanged",
                      "systemFlags",
                      "dNSHostName",
                      "mailAddress" ]

            sstr = "CN=Sites,%s" % self.samdb.get_config_basedn()
            res = self.samdb.search(sstr, scope=ldb.SCOPE_SUBTREE,
                                     attrs=attrs,
                                     expression="(objectClass=server)")

            # Write server output
            write_search_result(self.samdb, f, res)

            # Query Naming Context replicas
            attrs = [ "objectClass",
                      "objectGUID",
                      "cn",
                      "whenChanged",
                      "objectSid",
                      "fSMORoleOwner",
                      "msDS-Behavior-Version",
                      "repsFrom",
                      "repsTo" ]

            for sstr in nclist:
                res = self.samdb.search(sstr, scope=ldb.SCOPE_BASE,
                                        attrs=attrs)

                # Write naming context output
                write_search_result(self.samdb, f, res)

            # Query rootDSE replicas
            attrs=[ "objectClass",
                    "objectGUID",
                    "cn",
                    "whenChanged",
                    "rootDomainNamingContext",
                    "configurationNamingContext",
                    "schemaNamingContext",
                    "defaultNamingContext",
                    "dsServiceName" ]

            sstr = ""
            res = self.samdb.search(sstr, scope=ldb.SCOPE_BASE,
                                     attrs=attrs)

            # Record the rootDSE object as a dn as it
            # would appear in the base ldb file.  We have
            # to save it this way because we are going to
            # be importing as an abbreviated database.
            res[0].dn = ldb.Dn(self.samdb, "@ROOTDSE")

            # Write rootdse output
            write_search_result(self.samdb, f, res)

        except ldb.LdbError, (enum, estr):
            logger.error("Error processing (%s) : %s" % (sstr, estr))
            return 1

        f.close()
        return 0

##################################################
# Global Functions
##################################################
def sort_replica_by_dsa_guid(rep1, rep2):
    return cmp(rep1.rep_dsa_guid, rep2.rep_dsa_guid)

def sort_dsa_by_gc_and_guid(dsa1, dsa2):
    if dsa1.is_gc() and not dsa2.is_gc():
        return -1
    if not dsa1.is_gc() and dsa2.is_gc():
        return +1
    return cmp(dsa1.dsa_guid, dsa2.dsa_guid)

def is_smtp_replication_available():
    """Currently always returns false because Samba
    doesn't implement SMTP transfer for NC changes
    between DCs
    """
    return False

def write_search_result(samdb, f, res):
    for msg in res:
        lstr = samdb.write_ldif(msg, ldb.CHANGETYPE_NONE)
        f.write("%s" % lstr)

##################################################
# samba_kcc entry point
##################################################

parser = optparse.OptionParser("samba_kcc [options]")
sambaopts = options.SambaOptions(parser)
credopts = options.CredentialsOptions(parser)

parser.add_option_group(sambaopts)
parser.add_option_group(credopts)
parser.add_option_group(options.VersionOptions(parser))

parser.add_option("--readonly",
                  help="compute topology but do not update database",
                  action="store_true")

parser.add_option("--debug",
                  help="debug output",
                  action="store_true")

parser.add_option("--seed",
                  help="random number seed",
                  type=str, metavar="<number>")

parser.add_option("--importldif",
                  help="import topology ldif file",
                  type=str, metavar="<file>")

parser.add_option("--exportldif",
                  help="export topology ldif file",
                  type=str, metavar="<file>")

parser.add_option("-H", "--URL" ,
                  help="LDB URL for database or target server",
                  type=str, metavar="<URL>", dest="dburl")

parser.add_option("--tmpdb",
                  help="schemaless database file to create for ldif import",
                  type=str, metavar="<file>")

logger = logging.getLogger("samba_kcc")
logger.addHandler(logging.StreamHandler(sys.stdout))

lp = sambaopts.get_loadparm()
creds = credopts.get_credentials(lp, fallback_machine=True)

opts, args = parser.parse_args()

if opts.readonly is None:
    opts.readonly = False

if opts.debug:
    logger.setLevel(logging.DEBUG)
elif opts.readonly:
    logger.setLevel(logging.INFO)
else:
    logger.setLevel(logging.WARNING)

# initialize seed from optional input parameter
if opts.seed:
    random.seed(int(opts.seed))
else:
    random.seed(0xACE5CA11)

if opts.dburl is None:
    opts.dburl = lp.samdb_url()

# Instantiate Knowledge Consistency Checker and perform run
kcc = KCC()

if opts.exportldif:
    rc = kcc.export_ldif(opts.dburl, lp, creds, opts.exportldif)
    sys.exit(rc)

if opts.importldif:
    if opts.tmpdb is None or opts.tmpdb.startswith('ldap'):
        logger.error("Specify a target temp database file with --tmpdb option.")
        sys.exit(1)

    rc = kcc.import_ldif(opts.tmpdb, lp, creds, opts.importldif)
    if rc != 0:
        sys.exit(rc)

rc = kcc.run(opts.dburl, lp, creds)
sys.exit(rc)