Source

python-clinic / Lib / ipaddress.py

Full commit
   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
# Copyright 2007 Google Inc.
#  Licensed to PSF under a Contributor Agreement.

"""A fast, lightweight IPv4/IPv6 manipulation library in Python.

This library is used to create/poke/manipulate IPv4 and IPv6 addresses
and networks.

"""

__version__ = '1.0'


import functools

IPV4LENGTH = 32
IPV6LENGTH = 128

class AddressValueError(ValueError):
    """A Value Error related to the address."""


class NetmaskValueError(ValueError):
    """A Value Error related to the netmask."""


def ip_address(address):
    """Take an IP string/int and return an object of the correct type.

    Args:
        address: A string or integer, the IP address.  Either IPv4 or
          IPv6 addresses may be supplied; integers less than 2**32 will
          be considered to be IPv4 by default.

    Returns:
        An IPv4Address or IPv6Address object.

    Raises:
        ValueError: if the *address* passed isn't either a v4 or a v6
          address

    """
    try:
        return IPv4Address(address)
    except (AddressValueError, NetmaskValueError):
        pass

    try:
        return IPv6Address(address)
    except (AddressValueError, NetmaskValueError):
        pass

    raise ValueError('%r does not appear to be an IPv4 or IPv6 address' %
                     address)


def ip_network(address, strict=True):
    """Take an IP string/int and return an object of the correct type.

    Args:
        address: A string or integer, the IP network.  Either IPv4 or
          IPv6 networks may be supplied; integers less than 2**32 will
          be considered to be IPv4 by default.

    Returns:
        An IPv4Network or IPv6Network object.

    Raises:
        ValueError: if the string passed isn't either a v4 or a v6
          address. Or if the network has host bits set.

    """
    try:
        return IPv4Network(address, strict)
    except (AddressValueError, NetmaskValueError):
        pass

    try:
        return IPv6Network(address, strict)
    except (AddressValueError, NetmaskValueError):
        pass

    raise ValueError('%r does not appear to be an IPv4 or IPv6 network' %
                     address)


def ip_interface(address):
    """Take an IP string/int and return an object of the correct type.

    Args:
        address: A string or integer, the IP address.  Either IPv4 or
          IPv6 addresses may be supplied; integers less than 2**32 will
          be considered to be IPv4 by default.

    Returns:
        An IPv4Interface or IPv6Interface object.

    Raises:
        ValueError: if the string passed isn't either a v4 or a v6
          address.

    Notes:
        The IPv?Interface classes describe an Address on a particular
        Network, so they're basically a combination of both the Address
        and Network classes.

    """
    try:
        return IPv4Interface(address)
    except (AddressValueError, NetmaskValueError):
        pass

    try:
        return IPv6Interface(address)
    except (AddressValueError, NetmaskValueError):
        pass

    raise ValueError('%r does not appear to be an IPv4 or IPv6 interface' %
                     address)


def v4_int_to_packed(address):
    """Represent an address as 4 packed bytes in network (big-endian) order.

    Args:
        address: An integer representation of an IPv4 IP address.

    Returns:
        The integer address packed as 4 bytes in network (big-endian) order.

    Raises:
        ValueError: If the integer is negative or too large to be an
          IPv4 IP address.

    """
    try:
        return address.to_bytes(4, 'big')
    except:
        raise ValueError("Address negative or too large for IPv4")


def v6_int_to_packed(address):
    """Represent an address as 16 packed bytes in network (big-endian) order.

    Args:
        address: An integer representation of an IPv6 IP address.

    Returns:
        The integer address packed as 16 bytes in network (big-endian) order.

    """
    try:
        return address.to_bytes(16, 'big')
    except:
        raise ValueError("Address negative or too large for IPv6")


def _split_optional_netmask(address):
    """Helper to split the netmask and raise AddressValueError if needed"""
    addr = str(address).split('/')
    if len(addr) > 2:
        raise AddressValueError("Only one '/' permitted in %r" % address)
    return addr


def _find_address_range(addresses):
    """Find a sequence of IPv#Address.

    Args:
        addresses: a list of IPv#Address objects.

    Returns:
        A tuple containing the first and last IP addresses in the sequence.

    """
    first = last = addresses[0]
    for ip in addresses[1:]:
        if ip._ip == last._ip + 1:
            last = ip
        else:
            break
    return (first, last)


def _count_righthand_zero_bits(number, bits):
    """Count the number of zero bits on the right hand side.

    Args:
        number: an integer.
        bits: maximum number of bits to count.

    Returns:
        The number of zero bits on the right hand side of the number.

    """
    if number == 0:
        return bits
    for i in range(bits):
        if (number >> i) & 1:
            return i
    # All bits of interest were zero, even if there are more in the number
    return bits


def summarize_address_range(first, last):
    """Summarize a network range given the first and last IP addresses.

    Example:
        >>> list(summarize_address_range(IPv4Address('192.0.2.0'),
        ...                              IPv4Address('192.0.2.130')))
        ...                                #doctest: +NORMALIZE_WHITESPACE
        [IPv4Network('192.0.2.0/25'), IPv4Network('192.0.2.128/31'),
         IPv4Network('192.0.2.130/32')]

    Args:
        first: the first IPv4Address or IPv6Address in the range.
        last: the last IPv4Address or IPv6Address in the range.

    Returns:
        An iterator of the summarized IPv(4|6) network objects.

    Raise:
        TypeError:
            If the first and last objects are not IP addresses.
            If the first and last objects are not the same version.
        ValueError:
            If the last object is not greater than the first.
            If the version of the first address is not 4 or 6.

    """
    if (not (isinstance(first, _BaseAddress) and
             isinstance(last, _BaseAddress))):
        raise TypeError('first and last must be IP addresses, not networks')
    if first.version != last.version:
        raise TypeError("%s and %s are not of the same version" % (
                         first, last))
    if first > last:
        raise ValueError('last IP address must be greater than first')

    if first.version == 4:
        ip = IPv4Network
    elif first.version == 6:
        ip = IPv6Network
    else:
        raise ValueError('unknown IP version')

    ip_bits = first._max_prefixlen
    first_int = first._ip
    last_int = last._ip
    while first_int <= last_int:
        nbits = min(_count_righthand_zero_bits(first_int, ip_bits),
                    (last_int - first_int + 1).bit_length() - 1)
        net = ip('%s/%d' % (first, ip_bits - nbits))
        yield net
        first_int += 1 << nbits
        if first_int - 1 == ip._ALL_ONES:
            break
        first = first.__class__(first_int)


def _collapse_addresses_recursive(addresses):
    """Loops through the addresses, collapsing concurrent netblocks.

    Example:

        ip1 = IPv4Network('192.0.2.0/26')
        ip2 = IPv4Network('192.0.2.64/26')
        ip3 = IPv4Network('192.0.2.128/26')
        ip4 = IPv4Network('192.0.2.192/26')

        _collapse_addresses_recursive([ip1, ip2, ip3, ip4]) ->
          [IPv4Network('192.0.2.0/24')]

        This shouldn't be called directly; it is called via
          collapse_addresses([]).

    Args:
        addresses: A list of IPv4Network's or IPv6Network's

    Returns:
        A list of IPv4Network's or IPv6Network's depending on what we were
        passed.

    """
    while True:
        last_addr = None
        ret_array = []
        optimized = False

        for cur_addr in addresses:
            if not ret_array:
                last_addr = cur_addr
                ret_array.append(cur_addr)
            elif (cur_addr.network_address >= last_addr.network_address and
                cur_addr.broadcast_address <= last_addr.broadcast_address):
                optimized = True
            elif cur_addr == list(last_addr.supernet().subnets())[1]:
                ret_array[-1] = last_addr = last_addr.supernet()
                optimized = True
            else:
                last_addr = cur_addr
                ret_array.append(cur_addr)

        addresses = ret_array
        if not optimized:
            return addresses


def collapse_addresses(addresses):
    """Collapse a list of IP objects.

    Example:
        collapse_addresses([IPv4Network('192.0.2.0/25'),
                            IPv4Network('192.0.2.128/25')]) ->
                           [IPv4Network('192.0.2.0/24')]

    Args:
        addresses: An iterator of IPv4Network or IPv6Network objects.

    Returns:
        An iterator of the collapsed IPv(4|6)Network objects.

    Raises:
        TypeError: If passed a list of mixed version objects.

    """
    i = 0
    addrs = []
    ips = []
    nets = []

    # split IP addresses and networks
    for ip in addresses:
        if isinstance(ip, _BaseAddress):
            if ips and ips[-1]._version != ip._version:
                raise TypeError("%s and %s are not of the same version" % (
                                 ip, ips[-1]))
            ips.append(ip)
        elif ip._prefixlen == ip._max_prefixlen:
            if ips and ips[-1]._version != ip._version:
                raise TypeError("%s and %s are not of the same version" % (
                                 ip, ips[-1]))
            try:
                ips.append(ip.ip)
            except AttributeError:
                ips.append(ip.network_address)
        else:
            if nets and nets[-1]._version != ip._version:
                raise TypeError("%s and %s are not of the same version" % (
                                 ip, nets[-1]))
            nets.append(ip)

    # sort and dedup
    ips = sorted(set(ips))
    nets = sorted(set(nets))

    while i < len(ips):
        (first, last) = _find_address_range(ips[i:])
        i = ips.index(last) + 1
        addrs.extend(summarize_address_range(first, last))

    return iter(_collapse_addresses_recursive(sorted(
        addrs + nets, key=_BaseNetwork._get_networks_key)))


def get_mixed_type_key(obj):
    """Return a key suitable for sorting between networks and addresses.

    Address and Network objects are not sortable by default; they're
    fundamentally different so the expression

        IPv4Address('192.0.2.0') <= IPv4Network('192.0.2.0/24')

    doesn't make any sense.  There are some times however, where you may wish
    to have ipaddress sort these for you anyway. If you need to do this, you
    can use this function as the key= argument to sorted().

    Args:
      obj: either a Network or Address object.
    Returns:
      appropriate key.

    """
    if isinstance(obj, _BaseNetwork):
        return obj._get_networks_key()
    elif isinstance(obj, _BaseAddress):
        return obj._get_address_key()
    return NotImplemented


class _TotalOrderingMixin:
    # Helper that derives the other comparison operations from
    # __lt__ and __eq__
    # We avoid functools.total_ordering because it doesn't handle
    # NotImplemented correctly yet (http://bugs.python.org/issue10042)
    def __eq__(self, other):
        raise NotImplementedError
    def __ne__(self, other):
        equal = self.__eq__(other)
        if equal is NotImplemented:
            return NotImplemented
        return not equal
    def __lt__(self, other):
        raise NotImplementedError
    def __le__(self, other):
        less = self.__lt__(other)
        if less is NotImplemented or not less:
            return self.__eq__(other)
        return less
    def __gt__(self, other):
        less = self.__lt__(other)
        if less is NotImplemented:
            return NotImplemented
        equal = self.__eq__(other)
        if equal is NotImplemented:
            return NotImplemented
        return not (less or equal)
    def __ge__(self, other):
        less = self.__lt__(other)
        if less is NotImplemented:
            return NotImplemented
        return not less

class _IPAddressBase(_TotalOrderingMixin):

    """The mother class."""

    @property
    def exploded(self):
        """Return the longhand version of the IP address as a string."""
        return self._explode_shorthand_ip_string()

    @property
    def compressed(self):
        """Return the shorthand version of the IP address as a string."""
        return str(self)

    @property
    def version(self):
        msg = '%200s has no version specified' % (type(self),)
        raise NotImplementedError(msg)

    def _check_int_address(self, address):
        if address < 0:
            msg = "%d (< 0) is not permitted as an IPv%d address"
            raise AddressValueError(msg % (address, self._version))
        if address > self._ALL_ONES:
            msg = "%d (>= 2**%d) is not permitted as an IPv%d address"
            raise AddressValueError(msg % (address, self._max_prefixlen,
                                           self._version))

    def _check_packed_address(self, address, expected_len):
        address_len = len(address)
        if address_len != expected_len:
            msg = "%r (len %d != %d) is not permitted as an IPv%d address"
            raise AddressValueError(msg % (address, address_len,
                                           expected_len, self._version))

    def _ip_int_from_prefix(self, prefixlen=None):
        """Turn the prefix length netmask into a int for comparison.

        Args:
            prefixlen: An integer, the prefix length.

        Returns:
            An integer.

        """
        if prefixlen is None:
            prefixlen = self._prefixlen
        return self._ALL_ONES ^ (self._ALL_ONES >> prefixlen)

    def _prefix_from_ip_int(self, ip_int, mask=32):
        """Return prefix length from the decimal netmask.

        Args:
            ip_int: An integer, the IP address.
            mask: The netmask.  Defaults to 32.

        Returns:
            An integer, the prefix length.

        """
        return mask - _count_righthand_zero_bits(ip_int, mask)

    def _ip_string_from_prefix(self, prefixlen=None):
        """Turn a prefix length into a dotted decimal string.

        Args:
            prefixlen: An integer, the netmask prefix length.

        Returns:
            A string, the dotted decimal netmask string.

        """
        if not prefixlen:
            prefixlen = self._prefixlen
        return self._string_from_ip_int(self._ip_int_from_prefix(prefixlen))


class _BaseAddress(_IPAddressBase):

    """A generic IP object.

    This IP class contains the version independent methods which are
    used by single IP addresses.

    """

    def __init__(self, address):
        if (not isinstance(address, bytes)
            and '/' in str(address)):
            raise AddressValueError("Unexpected '/' in %r" % address)

    def __int__(self):
        return self._ip

    def __eq__(self, other):
        try:
            return (self._ip == other._ip
                    and self._version == other._version)
        except AttributeError:
            return NotImplemented

    def __lt__(self, other):
        if self._version != other._version:
            raise TypeError('%s and %s are not of the same version' % (
                             self, other))
        if not isinstance(other, _BaseAddress):
            raise TypeError('%s and %s are not of the same type' % (
                             self, other))
        if self._ip != other._ip:
            return self._ip < other._ip
        return False

    # Shorthand for Integer addition and subtraction. This is not
    # meant to ever support addition/subtraction of addresses.
    def __add__(self, other):
        if not isinstance(other, int):
            return NotImplemented
        return self.__class__(int(self) + other)

    def __sub__(self, other):
        if not isinstance(other, int):
            return NotImplemented
        return self.__class__(int(self) - other)

    def __repr__(self):
        return '%s(%r)' % (self.__class__.__name__, str(self))

    def __str__(self):
        return str(self._string_from_ip_int(self._ip))

    def __hash__(self):
        return hash(hex(int(self._ip)))

    def _get_address_key(self):
        return (self._version, self)


class _BaseNetwork(_IPAddressBase):

    """A generic IP network object.

    This IP class contains the version independent methods which are
    used by networks.

    """
    def __init__(self, address):
        self._cache = {}

    def __repr__(self):
        return '%s(%r)' % (self.__class__.__name__, str(self))

    def __str__(self):
        return '%s/%d' % (self.network_address, self.prefixlen)

    def hosts(self):
        """Generate Iterator over usable hosts in a network.

        This is like __iter__ except it doesn't return the network
        or broadcast addresses.

        """
        network = int(self.network_address)
        broadcast = int(self.broadcast_address)
        for x in range(network + 1, broadcast):
            yield self._address_class(x)

    def __iter__(self):
        network = int(self.network_address)
        broadcast = int(self.broadcast_address)
        for x in range(network, broadcast + 1):
            yield self._address_class(x)

    def __getitem__(self, n):
        network = int(self.network_address)
        broadcast = int(self.broadcast_address)
        if n >= 0:
            if network + n > broadcast:
                raise IndexError
            return self._address_class(network + n)
        else:
            n += 1
            if broadcast + n < network:
                raise IndexError
            return self._address_class(broadcast + n)

    def __lt__(self, other):
        if self._version != other._version:
            raise TypeError('%s and %s are not of the same version' % (
                             self, other))
        if not isinstance(other, _BaseNetwork):
            raise TypeError('%s and %s are not of the same type' % (
                             self, other))
        if self.network_address != other.network_address:
            return self.network_address < other.network_address
        if self.netmask != other.netmask:
            return self.netmask < other.netmask
        return False

    def __eq__(self, other):
        try:
            return (self._version == other._version and
                    self.network_address == other.network_address and
                    int(self.netmask) == int(other.netmask))
        except AttributeError:
            return NotImplemented

    def __hash__(self):
        return hash(int(self.network_address) ^ int(self.netmask))

    def __contains__(self, other):
        # always false if one is v4 and the other is v6.
        if self._version != other._version:
            return False
        # dealing with another network.
        if isinstance(other, _BaseNetwork):
            return False
        # dealing with another address
        else:
            # address
            return (int(self.network_address) <= int(other._ip) <=
                    int(self.broadcast_address))

    def overlaps(self, other):
        """Tell if self is partly contained in other."""
        return self.network_address in other or (
            self.broadcast_address in other or (
                other.network_address in self or (
                    other.broadcast_address in self)))

    @property
    def broadcast_address(self):
        x = self._cache.get('broadcast_address')
        if x is None:
            x = self._address_class(int(self.network_address) |
                                    int(self.hostmask))
            self._cache['broadcast_address'] = x
        return x

    @property
    def hostmask(self):
        x = self._cache.get('hostmask')
        if x is None:
            x = self._address_class(int(self.netmask) ^ self._ALL_ONES)
            self._cache['hostmask'] = x
        return x

    @property
    def with_prefixlen(self):
        return '%s/%d' % (self.network_address, self._prefixlen)

    @property
    def with_netmask(self):
        return '%s/%s' % (self.network_address, self.netmask)

    @property
    def with_hostmask(self):
        return '%s/%s' % (self.network_address, self.hostmask)

    @property
    def num_addresses(self):
        """Number of hosts in the current subnet."""
        return int(self.broadcast_address) - int(self.network_address) + 1

    @property
    def _address_class(self):
        # Returning bare address objects (rather than interfaces) allows for
        # more consistent behaviour across the network address, broadcast
        # address and individual host addresses.
        msg = '%200s has no associated address class' % (type(self),)
        raise NotImplementedError(msg)

    @property
    def prefixlen(self):
        return self._prefixlen

    def address_exclude(self, other):
        """Remove an address from a larger block.

        For example:

            addr1 = ip_network('192.0.2.0/28')
            addr2 = ip_network('192.0.2.1/32')
            addr1.address_exclude(addr2) =
                [IPv4Network('192.0.2.0/32'), IPv4Network('192.0.2.2/31'),
                IPv4Network('192.0.2.4/30'), IPv4Network('192.0.2.8/29')]

        or IPv6:

            addr1 = ip_network('2001:db8::1/32')
            addr2 = ip_network('2001:db8::1/128')
            addr1.address_exclude(addr2) =
                [ip_network('2001:db8::1/128'),
                ip_network('2001:db8::2/127'),
                ip_network('2001:db8::4/126'),
                ip_network('2001:db8::8/125'),
                ...
                ip_network('2001:db8:8000::/33')]

        Args:
            other: An IPv4Network or IPv6Network object of the same type.

        Returns:
            An iterator of the IPv(4|6)Network objects which is self
            minus other.

        Raises:
            TypeError: If self and other are of difffering address
              versions, or if other is not a network object.
            ValueError: If other is not completely contained by self.

        """
        if not self._version == other._version:
            raise TypeError("%s and %s are not of the same version" % (
                             self, other))

        if not isinstance(other, _BaseNetwork):
            raise TypeError("%s is not a network object" % other)

        if not (other.network_address >= self.network_address and
                other.broadcast_address <= self.broadcast_address):
            raise ValueError('%s not contained in %s' % (other, self))
        if other == self:
            raise StopIteration

        # Make sure we're comparing the network of other.
        other = other.__class__('%s/%s' % (other.network_address,
                                           other.prefixlen))

        s1, s2 = self.subnets()
        while s1 != other and s2 != other:
            if (other.network_address >= s1.network_address and
                other.broadcast_address <= s1.broadcast_address):
                yield s2
                s1, s2 = s1.subnets()
            elif (other.network_address >= s2.network_address and
                  other.broadcast_address <= s2.broadcast_address):
                yield s1
                s1, s2 = s2.subnets()
            else:
                # If we got here, there's a bug somewhere.
                raise AssertionError('Error performing exclusion: '
                                     's1: %s s2: %s other: %s' %
                                     (s1, s2, other))
        if s1 == other:
            yield s2
        elif s2 == other:
            yield s1
        else:
            # If we got here, there's a bug somewhere.
            raise AssertionError('Error performing exclusion: '
                                 's1: %s s2: %s other: %s' %
                                 (s1, s2, other))

    def compare_networks(self, other):
        """Compare two IP objects.

        This is only concerned about the comparison of the integer
        representation of the network addresses.  This means that the
        host bits aren't considered at all in this method.  If you want
        to compare host bits, you can easily enough do a
        'HostA._ip < HostB._ip'

        Args:
            other: An IP object.

        Returns:
            If the IP versions of self and other are the same, returns:

            -1 if self < other:
              eg: IPv4Network('192.0.2.0/25') < IPv4Network('192.0.2.128/25')
              IPv6Network('2001:db8::1000/124') <
                  IPv6Network('2001:db8::2000/124')
            0 if self == other
              eg: IPv4Network('192.0.2.0/24') == IPv4Network('192.0.2.0/24')
              IPv6Network('2001:db8::1000/124') ==
                  IPv6Network('2001:db8::1000/124')
            1 if self > other
              eg: IPv4Network('192.0.2.128/25') > IPv4Network('192.0.2.0/25')
                  IPv6Network('2001:db8::2000/124') >
                      IPv6Network('2001:db8::1000/124')

          Raises:
              TypeError if the IP versions are different.

        """
        # does this need to raise a ValueError?
        if self._version != other._version:
            raise TypeError('%s and %s are not of the same type' % (
                             self, other))
        # self._version == other._version below here:
        if self.network_address < other.network_address:
            return -1
        if self.network_address > other.network_address:
            return 1
        # self.network_address == other.network_address below here:
        if self.netmask < other.netmask:
            return -1
        if self.netmask > other.netmask:
            return 1
        return 0

    def _get_networks_key(self):
        """Network-only key function.

        Returns an object that identifies this address' network and
        netmask. This function is a suitable "key" argument for sorted()
        and list.sort().

        """
        return (self._version, self.network_address, self.netmask)

    def subnets(self, prefixlen_diff=1, new_prefix=None):
        """The subnets which join to make the current subnet.

        In the case that self contains only one IP
        (self._prefixlen == 32 for IPv4 or self._prefixlen == 128
        for IPv6), yield an iterator with just ourself.

        Args:
            prefixlen_diff: An integer, the amount the prefix length
              should be increased by. This should not be set if
              new_prefix is also set.
            new_prefix: The desired new prefix length. This must be a
              larger number (smaller prefix) than the existing prefix.
              This should not be set if prefixlen_diff is also set.

        Returns:
            An iterator of IPv(4|6) objects.

        Raises:
            ValueError: The prefixlen_diff is too small or too large.
                OR
            prefixlen_diff and new_prefix are both set or new_prefix
              is a smaller number than the current prefix (smaller
              number means a larger network)

        """
        if self._prefixlen == self._max_prefixlen:
            yield self
            return

        if new_prefix is not None:
            if new_prefix < self._prefixlen:
                raise ValueError('new prefix must be longer')
            if prefixlen_diff != 1:
                raise ValueError('cannot set prefixlen_diff and new_prefix')
            prefixlen_diff = new_prefix - self._prefixlen

        if prefixlen_diff < 0:
            raise ValueError('prefix length diff must be > 0')
        new_prefixlen = self._prefixlen + prefixlen_diff

        if not self._is_valid_netmask(str(new_prefixlen)):
            raise ValueError(
                'prefix length diff %d is invalid for netblock %s' % (
                    new_prefixlen, self))

        first = self.__class__('%s/%s' %
                                 (self.network_address,
                                  self._prefixlen + prefixlen_diff))

        yield first
        current = first
        while True:
            broadcast = current.broadcast_address
            if broadcast == self.broadcast_address:
                return
            new_addr = self._address_class(int(broadcast) + 1)
            current = self.__class__('%s/%s' % (new_addr,
                                                new_prefixlen))

            yield current

    def supernet(self, prefixlen_diff=1, new_prefix=None):
        """The supernet containing the current network.

        Args:
            prefixlen_diff: An integer, the amount the prefix length of
              the network should be decreased by.  For example, given a
              /24 network and a prefixlen_diff of 3, a supernet with a
              /21 netmask is returned.

        Returns:
            An IPv4 network object.

        Raises:
            ValueError: If self.prefixlen - prefixlen_diff < 0. I.e., you have
              a negative prefix length.
                OR
            If prefixlen_diff and new_prefix are both set or new_prefix is a
              larger number than the current prefix (larger number means a
              smaller network)

        """
        if self._prefixlen == 0:
            return self

        if new_prefix is not None:
            if new_prefix > self._prefixlen:
                raise ValueError('new prefix must be shorter')
            if prefixlen_diff != 1:
                raise ValueError('cannot set prefixlen_diff and new_prefix')
            prefixlen_diff = self._prefixlen - new_prefix

        if self.prefixlen - prefixlen_diff < 0:
            raise ValueError(
                'current prefixlen is %d, cannot have a prefixlen_diff of %d' %
                (self.prefixlen, prefixlen_diff))
        # TODO (pmoody): optimize this.
        t = self.__class__('%s/%d' % (self.network_address,
                                      self.prefixlen - prefixlen_diff),
                                     strict=False)
        return t.__class__('%s/%d' % (t.network_address, t.prefixlen))

    @property
    def is_multicast(self):
        """Test if the address is reserved for multicast use.

        Returns:
            A boolean, True if the address is a multicast address.
            See RFC 2373 2.7 for details.

        """
        return (self.network_address.is_multicast and
                self.broadcast_address.is_multicast)

    @property
    def is_reserved(self):
        """Test if the address is otherwise IETF reserved.

        Returns:
            A boolean, True if the address is within one of the
            reserved IPv6 Network ranges.

        """
        return (self.network_address.is_reserved and
                self.broadcast_address.is_reserved)

    @property
    def is_link_local(self):
        """Test if the address is reserved for link-local.

        Returns:
            A boolean, True if the address is reserved per RFC 4291.

        """
        return (self.network_address.is_link_local and
                self.broadcast_address.is_link_local)

    @property
    def is_private(self):
        """Test if this address is allocated for private networks.

        Returns:
            A boolean, True if the address is reserved per RFC 4193.

        """
        return (self.network_address.is_private and
                self.broadcast_address.is_private)

    @property
    def is_unspecified(self):
        """Test if the address is unspecified.

        Returns:
            A boolean, True if this is the unspecified address as defined in
            RFC 2373 2.5.2.

        """
        return (self.network_address.is_unspecified and
                self.broadcast_address.is_unspecified)

    @property
    def is_loopback(self):
        """Test if the address is a loopback address.

        Returns:
            A boolean, True if the address is a loopback address as defined in
            RFC 2373 2.5.3.

        """
        return (self.network_address.is_loopback and
                self.broadcast_address.is_loopback)


class _BaseV4:

    """Base IPv4 object.

    The following methods are used by IPv4 objects in both single IP
    addresses and networks.

    """

    # Equivalent to 255.255.255.255 or 32 bits of 1's.
    _ALL_ONES = (2**IPV4LENGTH) - 1
    _DECIMAL_DIGITS = frozenset('0123456789')

    # the valid octets for host and netmasks. only useful for IPv4.
    _valid_mask_octets = frozenset((255, 254, 252, 248, 240, 224, 192, 128, 0))

    def __init__(self, address):
        self._version = 4
        self._max_prefixlen = IPV4LENGTH

    def _explode_shorthand_ip_string(self):
        return str(self)

    def _ip_int_from_string(self, ip_str):
        """Turn the given IP string into an integer for comparison.

        Args:
            ip_str: A string, the IP ip_str.

        Returns:
            The IP ip_str as an integer.

        Raises:
            AddressValueError: if ip_str isn't a valid IPv4 Address.

        """
        if not ip_str:
            raise AddressValueError('Address cannot be empty')

        octets = ip_str.split('.')
        if len(octets) != 4:
            raise AddressValueError("Expected 4 octets in %r" % ip_str)

        try:
            return int.from_bytes(map(self._parse_octet, octets), 'big')
        except ValueError as exc:
            raise AddressValueError("%s in %r" % (exc, ip_str)) from None

    def _parse_octet(self, octet_str):
        """Convert a decimal octet into an integer.

        Args:
            octet_str: A string, the number to parse.

        Returns:
            The octet as an integer.

        Raises:
            ValueError: if the octet isn't strictly a decimal from [0..255].

        """
        if not octet_str:
            raise ValueError("Empty octet not permitted")
        # Whitelist the characters, since int() allows a lot of bizarre stuff.
        if not self._DECIMAL_DIGITS.issuperset(octet_str):
            msg = "Only decimal digits permitted in %r"
            raise ValueError(msg % octet_str)
        # We do the length check second, since the invalid character error
        # is likely to be more informative for the user
        if len(octet_str) > 3:
            msg = "At most 3 characters permitted in %r"
            raise ValueError(msg % octet_str)
        # Convert to integer (we know digits are legal)
        octet_int = int(octet_str, 10)
        # Any octets that look like they *might* be written in octal,
        # and which don't look exactly the same in both octal and
        # decimal are rejected as ambiguous
        if octet_int > 7 and octet_str[0] == '0':
            msg = "Ambiguous (octal/decimal) value in %r not permitted"
            raise ValueError(msg % octet_str)
        if octet_int > 255:
            raise ValueError("Octet %d (> 255) not permitted" % octet_int)
        return octet_int

    def _string_from_ip_int(self, ip_int):
        """Turns a 32-bit integer into dotted decimal notation.

        Args:
            ip_int: An integer, the IP address.

        Returns:
            The IP address as a string in dotted decimal notation.

        """
        return '.'.join(map(str, ip_int.to_bytes(4, 'big')))

    def _is_valid_netmask(self, netmask):
        """Verify that the netmask is valid.

        Args:
            netmask: A string, either a prefix or dotted decimal
              netmask.

        Returns:
            A boolean, True if the prefix represents a valid IPv4
            netmask.

        """
        mask = netmask.split('.')
        if len(mask) == 4:
            try:
                for x in mask:
                    if int(x) not in self._valid_mask_octets:
                        return False
            except ValueError:
                # Found something that isn't an integer or isn't valid
                return False
            for idx, y in enumerate(mask):
                if idx > 0 and y > mask[idx - 1]:
                    return False
            return True
        try:
            netmask = int(netmask)
        except ValueError:
            return False
        return 0 <= netmask <= self._max_prefixlen

    def _is_hostmask(self, ip_str):
        """Test if the IP string is a hostmask (rather than a netmask).

        Args:
            ip_str: A string, the potential hostmask.

        Returns:
            A boolean, True if the IP string is a hostmask.

        """
        bits = ip_str.split('.')
        try:
            parts = [x for x in map(int, bits) if x in self._valid_mask_octets]
        except ValueError:
            return False
        if len(parts) != len(bits):
            return False
        if parts[0] < parts[-1]:
            return True
        return False

    @property
    def max_prefixlen(self):
        return self._max_prefixlen

    @property
    def version(self):
        return self._version


class IPv4Address(_BaseV4, _BaseAddress):

    """Represent and manipulate single IPv4 Addresses."""

    def __init__(self, address):

        """
        Args:
            address: A string or integer representing the IP

              Additionally, an integer can be passed, so
              IPv4Address('192.0.2.1') == IPv4Address(3221225985).
              or, more generally
              IPv4Address(int(IPv4Address('192.0.2.1'))) ==
                IPv4Address('192.0.2.1')

        Raises:
            AddressValueError: If ipaddress isn't a valid IPv4 address.

        """
        _BaseAddress.__init__(self, address)
        _BaseV4.__init__(self, address)

        # Efficient constructor from integer.
        if isinstance(address, int):
            self._check_int_address(address)
            self._ip = address
            return

        # Constructing from a packed address
        if isinstance(address, bytes):
            self._check_packed_address(address, 4)
            self._ip = int.from_bytes(address, 'big')
            return

        # Assume input argument to be string or any object representation
        # which converts into a formatted IP string.
        addr_str = str(address)
        self._ip = self._ip_int_from_string(addr_str)

    @property
    def packed(self):
        """The binary representation of this address."""
        return v4_int_to_packed(self._ip)

    @property
    def is_reserved(self):
        """Test if the address is otherwise IETF reserved.

         Returns:
             A boolean, True if the address is within the
             reserved IPv4 Network range.

        """
        reserved_network = IPv4Network('240.0.0.0/4')
        return self in reserved_network

    @property
    def is_private(self):
        """Test if this address is allocated for private networks.

        Returns:
            A boolean, True if the address is reserved per RFC 1918.

        """
        private_10 = IPv4Network('10.0.0.0/8')
        private_172 = IPv4Network('172.16.0.0/12')
        private_192 = IPv4Network('192.168.0.0/16')
        return (self in private_10 or
                self in private_172 or
                self in private_192)

    @property
    def is_multicast(self):
        """Test if the address is reserved for multicast use.

        Returns:
            A boolean, True if the address is multicast.
            See RFC 3171 for details.

        """
        multicast_network = IPv4Network('224.0.0.0/4')
        return self in multicast_network

    @property
    def is_unspecified(self):
        """Test if the address is unspecified.

        Returns:
            A boolean, True if this is the unspecified address as defined in
            RFC 5735 3.

        """
        unspecified_address = IPv4Address('0.0.0.0')
        return self == unspecified_address

    @property
    def is_loopback(self):
        """Test if the address is a loopback address.

        Returns:
            A boolean, True if the address is a loopback per RFC 3330.

        """
        loopback_network = IPv4Network('127.0.0.0/8')
        return self in loopback_network

    @property
    def is_link_local(self):
        """Test if the address is reserved for link-local.

        Returns:
            A boolean, True if the address is link-local per RFC 3927.

        """
        linklocal_network = IPv4Network('169.254.0.0/16')
        return self in linklocal_network


class IPv4Interface(IPv4Address):

    def __init__(self, address):
        if isinstance(address, (bytes, int)):
            IPv4Address.__init__(self, address)
            self.network = IPv4Network(self._ip)
            self._prefixlen = self._max_prefixlen
            return

        addr = _split_optional_netmask(address)
        IPv4Address.__init__(self, addr[0])

        self.network = IPv4Network(address, strict=False)
        self._prefixlen = self.network._prefixlen

        self.netmask = self.network.netmask
        self.hostmask = self.network.hostmask

    def __str__(self):
        return '%s/%d' % (self._string_from_ip_int(self._ip),
                          self.network.prefixlen)

    def __eq__(self, other):
        address_equal = IPv4Address.__eq__(self, other)
        if not address_equal or address_equal is NotImplemented:
            return address_equal
        try:
            return self.network == other.network
        except AttributeError:
            # An interface with an associated network is NOT the
            # same as an unassociated address. That's why the hash
            # takes the extra info into account.
            return False

    def __lt__(self, other):
        address_less = IPv4Address.__lt__(self, other)
        if address_less is NotImplemented:
            return NotImplemented
        try:
            return self.network < other.network
        except AttributeError:
            # We *do* allow addresses and interfaces to be sorted. The
            # unassociated address is considered less than all interfaces.
            return False

    def __hash__(self):
        return self._ip ^ self._prefixlen ^ int(self.network.network_address)

    @property
    def ip(self):
        return IPv4Address(self._ip)

    @property
    def with_prefixlen(self):
        return '%s/%s' % (self._string_from_ip_int(self._ip),
                          self._prefixlen)

    @property
    def with_netmask(self):
        return '%s/%s' % (self._string_from_ip_int(self._ip),
                          self.netmask)

    @property
    def with_hostmask(self):
        return '%s/%s' % (self._string_from_ip_int(self._ip),
                          self.hostmask)


class IPv4Network(_BaseV4, _BaseNetwork):

    """This class represents and manipulates 32-bit IPv4 network + addresses..

    Attributes: [examples for IPv4Network('192.0.2.0/27')]
        .network_address: IPv4Address('192.0.2.0')
        .hostmask: IPv4Address('0.0.0.31')
        .broadcast_address: IPv4Address('192.0.2.32')
        .netmask: IPv4Address('255.255.255.224')
        .prefixlen: 27

    """
    # Class to use when creating address objects
    _address_class = IPv4Address

    def __init__(self, address, strict=True):

        """Instantiate a new IPv4 network object.

        Args:
            address: A string or integer representing the IP [& network].
              '192.0.2.0/24'
              '192.0.2.0/255.255.255.0'
              '192.0.0.2/0.0.0.255'
              are all functionally the same in IPv4. Similarly,
              '192.0.2.1'
              '192.0.2.1/255.255.255.255'
              '192.0.2.1/32'
              are also functionaly equivalent. That is to say, failing to
              provide a subnetmask will create an object with a mask of /32.

              If the mask (portion after the / in the argument) is given in
              dotted quad form, it is treated as a netmask if it starts with a
              non-zero field (e.g. /255.0.0.0 == /8) and as a hostmask if it
              starts with a zero field (e.g. 0.255.255.255 == /8), with the
              single exception of an all-zero mask which is treated as a
              netmask == /0. If no mask is given, a default of /32 is used.

              Additionally, an integer can be passed, so
              IPv4Network('192.0.2.1') == IPv4Network(3221225985)
              or, more generally
              IPv4Interface(int(IPv4Interface('192.0.2.1'))) ==
                IPv4Interface('192.0.2.1')

        Raises:
            AddressValueError: If ipaddress isn't a valid IPv4 address.
            NetmaskValueError: If the netmask isn't valid for
              an IPv4 address.
            ValueError: If strict is True and a network address is not
              supplied.

        """

        _BaseV4.__init__(self, address)
        _BaseNetwork.__init__(self, address)

        # Constructing from a packed address
        if isinstance(address, bytes):
            self.network_address = IPv4Address(address)
            self._prefixlen = self._max_prefixlen
            self.netmask = IPv4Address(self._ALL_ONES)
            #fixme: address/network test here
            return

        # Efficient constructor from integer.
        if isinstance(address, int):
            self.network_address = IPv4Address(address)
            self._prefixlen = self._max_prefixlen
            self.netmask = IPv4Address(self._ALL_ONES)
            #fixme: address/network test here.
            return

        # Assume input argument to be string or any object representation
        # which converts into a formatted IP prefix string.
        addr = _split_optional_netmask(address)
        self.network_address = IPv4Address(self._ip_int_from_string(addr[0]))

        if len(addr) == 2:
            mask = addr[1].split('.')

            if len(mask) == 4:
                # We have dotted decimal netmask.
                if self._is_valid_netmask(addr[1]):
                    self.netmask = IPv4Address(self._ip_int_from_string(
                            addr[1]))
                elif self._is_hostmask(addr[1]):
                    self.netmask = IPv4Address(
                        self._ip_int_from_string(addr[1]) ^ self._ALL_ONES)
                else:
                    raise NetmaskValueError('%r is not a valid netmask'
                                                     % addr[1])

                self._prefixlen = self._prefix_from_ip_int(int(self.netmask))
            else:
                # We have a netmask in prefix length form.
                if not self._is_valid_netmask(addr[1]):
                    raise NetmaskValueError('%r is not a valid netmask'
                                                     % addr[1])
                self._prefixlen = int(addr[1])
                self.netmask = IPv4Address(self._ip_int_from_prefix(
                    self._prefixlen))
        else:
            self._prefixlen = self._max_prefixlen
            self.netmask = IPv4Address(self._ip_int_from_prefix(
                self._prefixlen))

        if strict:
            if (IPv4Address(int(self.network_address) & int(self.netmask)) !=
                self.network_address):
                raise ValueError('%s has host bits set' % self)
        self.network_address = IPv4Address(int(self.network_address) &
                                           int(self.netmask))

        if self._prefixlen == (self._max_prefixlen - 1):
            self.hosts = self.__iter__


class _BaseV6:

    """Base IPv6 object.

    The following methods are used by IPv6 objects in both single IP
    addresses and networks.

    """

    _ALL_ONES = (2**IPV6LENGTH) - 1
    _HEXTET_COUNT = 8
    _HEX_DIGITS = frozenset('0123456789ABCDEFabcdef')

    def __init__(self, address):
        self._version = 6
        self._max_prefixlen = IPV6LENGTH

    def _ip_int_from_string(self, ip_str):
        """Turn an IPv6 ip_str into an integer.

        Args:
            ip_str: A string, the IPv6 ip_str.

        Returns:
            An int, the IPv6 address

        Raises:
            AddressValueError: if ip_str isn't a valid IPv6 Address.

        """
        if not ip_str:
            raise AddressValueError('Address cannot be empty')

        parts = ip_str.split(':')

        # An IPv6 address needs at least 2 colons (3 parts).
        _min_parts = 3
        if len(parts) < _min_parts:
            msg = "At least %d parts expected in %r" % (_min_parts, ip_str)
            raise AddressValueError(msg)

        # If the address has an IPv4-style suffix, convert it to hexadecimal.
        if '.' in parts[-1]:
            try:
                ipv4_int = IPv4Address(parts.pop())._ip
            except AddressValueError as exc:
                raise AddressValueError("%s in %r" % (exc, ip_str)) from None
            parts.append('%x' % ((ipv4_int >> 16) & 0xFFFF))
            parts.append('%x' % (ipv4_int & 0xFFFF))

        # An IPv6 address can't have more than 8 colons (9 parts).
        # The extra colon comes from using the "::" notation for a single
        # leading or trailing zero part.
        _max_parts = self._HEXTET_COUNT + 1
        if len(parts) > _max_parts:
            msg = "At most %d colons permitted in %r" % (_max_parts-1, ip_str)
            raise AddressValueError(msg)

        # Disregarding the endpoints, find '::' with nothing in between.
        # This indicates that a run of zeroes has been skipped.
        skip_index = None
        for i in range(1, len(parts) - 1):
            if not parts[i]:
                if skip_index is not None:
                    # Can't have more than one '::'
                    msg = "At most one '::' permitted in %r" % ip_str
                    raise AddressValueError(msg)
                skip_index = i

        # parts_hi is the number of parts to copy from above/before the '::'
        # parts_lo is the number of parts to copy from below/after the '::'
        if skip_index is not None:
            # If we found a '::', then check if it also covers the endpoints.
            parts_hi = skip_index
            parts_lo = len(parts) - skip_index - 1
            if not parts[0]:
                parts_hi -= 1
                if parts_hi:
                    msg = "Leading ':' only permitted as part of '::' in %r"
                    raise AddressValueError(msg % ip_str)  # ^: requires ^::
            if not parts[-1]:
                parts_lo -= 1
                if parts_lo:
                    msg = "Trailing ':' only permitted as part of '::' in %r"
                    raise AddressValueError(msg % ip_str)  # :$ requires ::$
            parts_skipped = self._HEXTET_COUNT - (parts_hi + parts_lo)
            if parts_skipped < 1:
                msg = "Expected at most %d other parts with '::' in %r"
                raise AddressValueError(msg % (self._HEXTET_COUNT-1, ip_str))
        else:
            # Otherwise, allocate the entire address to parts_hi.  The
            # endpoints could still be empty, but _parse_hextet() will check
            # for that.
            if len(parts) != self._HEXTET_COUNT:
                msg = "Exactly %d parts expected without '::' in %r"
                raise AddressValueError(msg % (self._HEXTET_COUNT, ip_str))
            if not parts[0]:
                msg = "Leading ':' only permitted as part of '::' in %r"
                raise AddressValueError(msg % ip_str)  # ^: requires ^::
            if not parts[-1]:
                msg = "Trailing ':' only permitted as part of '::' in %r"
                raise AddressValueError(msg % ip_str)  # :$ requires ::$
            parts_hi = len(parts)
            parts_lo = 0
            parts_skipped = 0

        try:
            # Now, parse the hextets into a 128-bit integer.
            ip_int = 0
            for i in range(parts_hi):
                ip_int <<= 16
                ip_int |= self._parse_hextet(parts[i])
            ip_int <<= 16 * parts_skipped
            for i in range(-parts_lo, 0):
                ip_int <<= 16
                ip_int |= self._parse_hextet(parts[i])
            return ip_int
        except ValueError as exc:
            raise AddressValueError("%s in %r" % (exc, ip_str)) from None

    def _parse_hextet(self, hextet_str):
        """Convert an IPv6 hextet string into an integer.

        Args:
            hextet_str: A string, the number to parse.

        Returns:
            The hextet as an integer.

        Raises:
            ValueError: if the input isn't strictly a hex number from
              [0..FFFF].

        """
        # Whitelist the characters, since int() allows a lot of bizarre stuff.
        if not self._HEX_DIGITS.issuperset(hextet_str):
            raise ValueError("Only hex digits permitted in %r" % hextet_str)
        # We do the length check second, since the invalid character error
        # is likely to be more informative for the user
        if len(hextet_str) > 4:
            msg = "At most 4 characters permitted in %r"
            raise ValueError(msg % hextet_str)
        # Length check means we can skip checking the integer value
        return int(hextet_str, 16)

    def _compress_hextets(self, hextets):
        """Compresses a list of hextets.

        Compresses a list of strings, replacing the longest continuous
        sequence of "0" in the list with "" and adding empty strings at
        the beginning or at the end of the string such that subsequently
        calling ":".join(hextets) will produce the compressed version of
        the IPv6 address.

        Args:
            hextets: A list of strings, the hextets to compress.

        Returns:
            A list of strings.

        """
        best_doublecolon_start = -1
        best_doublecolon_len = 0
        doublecolon_start = -1
        doublecolon_len = 0
        for index, hextet in enumerate(hextets):
            if hextet == '0':
                doublecolon_len += 1
                if doublecolon_start == -1:
                    # Start of a sequence of zeros.
                    doublecolon_start = index
                if doublecolon_len > best_doublecolon_len:
                    # This is the longest sequence of zeros so far.
                    best_doublecolon_len = doublecolon_len
                    best_doublecolon_start = doublecolon_start
            else:
                doublecolon_len = 0
                doublecolon_start = -1

        if best_doublecolon_len > 1:
            best_doublecolon_end = (best_doublecolon_start +
                                    best_doublecolon_len)
            # For zeros at the end of the address.
            if best_doublecolon_end == len(hextets):
                hextets += ['']
            hextets[best_doublecolon_start:best_doublecolon_end] = ['']
            # For zeros at the beginning of the address.
            if best_doublecolon_start == 0:
                hextets = [''] + hextets

        return hextets

    def _string_from_ip_int(self, ip_int=None):
        """Turns a 128-bit integer into hexadecimal notation.

        Args:
            ip_int: An integer, the IP address.

        Returns:
            A string, the hexadecimal representation of the address.

        Raises:
            ValueError: The address is bigger than 128 bits of all ones.

        """
        if ip_int is None:
            ip_int = int(self._ip)

        if ip_int > self._ALL_ONES:
            raise ValueError('IPv6 address is too large')

        hex_str = '%032x' % ip_int
        hextets = ['%x' % int(hex_str[x:x+4], 16) for x in range(0, 32, 4)]

        hextets = self._compress_hextets(hextets)
        return ':'.join(hextets)

    def _explode_shorthand_ip_string(self):
        """Expand a shortened IPv6 address.

        Args:
            ip_str: A string, the IPv6 address.

        Returns:
            A string, the expanded IPv6 address.

        """
        if isinstance(self, IPv6Network):
            ip_str = str(self.network_address)
        elif isinstance(self, IPv6Interface):
            ip_str = str(self.ip)
        else:
            ip_str = str(self)

        ip_int = self._ip_int_from_string(ip_str)
        hex_str = '%032x' % ip_int
        parts = [hex_str[x:x+4] for x in range(0, 32, 4)]
        if isinstance(self, (_BaseNetwork, IPv6Interface)):
            return '%s/%d' % (':'.join(parts), self._prefixlen)
        return ':'.join(parts)

    @property
    def max_prefixlen(self):
        return self._max_prefixlen

    @property
    def version(self):
        return self._version


class IPv6Address(_BaseV6, _BaseAddress):

    """Represent and manipulate single IPv6 Addresses."""

    def __init__(self, address):
        """Instantiate a new IPv6 address object.

        Args:
            address: A string or integer representing the IP

              Additionally, an integer can be passed, so
              IPv6Address('2001:db8::') ==
                IPv6Address(42540766411282592856903984951653826560)
              or, more generally
              IPv6Address(int(IPv6Address('2001:db8::'))) ==
                IPv6Address('2001:db8::')

        Raises:
            AddressValueError: If address isn't a valid IPv6 address.

        """
        _BaseAddress.__init__(self, address)
        _BaseV6.__init__(self, address)

        # Efficient constructor from integer.
        if isinstance(address, int):
            self._check_int_address(address)
            self._ip = address
            return

        # Constructing from a packed address
        if isinstance(address, bytes):
            self._check_packed_address(address, 16)
            self._ip = int.from_bytes(address, 'big')
            return

        # Assume input argument to be string or any object representation
        # which converts into a formatted IP string.
        addr_str = str(address)
        self._ip = self._ip_int_from_string(addr_str)

    @property
    def packed(self):
        """The binary representation of this address."""
        return v6_int_to_packed(self._ip)

    @property
    def is_multicast(self):
        """Test if the address is reserved for multicast use.

        Returns:
            A boolean, True if the address is a multicast address.
            See RFC 2373 2.7 for details.

        """
        multicast_network = IPv6Network('ff00::/8')
        return self in multicast_network

    @property
    def is_reserved(self):
        """Test if the address is otherwise IETF reserved.

        Returns:
            A boolean, True if the address is within one of the
            reserved IPv6 Network ranges.

        """
        reserved_networks = [IPv6Network('::/8'), IPv6Network('100::/8'),
                             IPv6Network('200::/7'), IPv6Network('400::/6'),
                             IPv6Network('800::/5'), IPv6Network('1000::/4'),
                             IPv6Network('4000::/3'), IPv6Network('6000::/3'),
                             IPv6Network('8000::/3'), IPv6Network('A000::/3'),
                             IPv6Network('C000::/3'), IPv6Network('E000::/4'),
                             IPv6Network('F000::/5'), IPv6Network('F800::/6'),
                             IPv6Network('FE00::/9')]

        return any(self in x for x in reserved_networks)

    @property
    def is_link_local(self):
        """Test if the address is reserved for link-local.

        Returns:
            A boolean, True if the address is reserved per RFC 4291.

        """
        linklocal_network = IPv6Network('fe80::/10')
        return self in linklocal_network

    @property
    def is_site_local(self):
        """Test if the address is reserved for site-local.

        Note that the site-local address space has been deprecated by RFC 3879.
        Use is_private to test if this address is in the space of unique local
        addresses as defined by RFC 4193.

        Returns:
            A boolean, True if the address is reserved per RFC 3513 2.5.6.

        """
        sitelocal_network = IPv6Network('fec0::/10')
        return self in sitelocal_network

    @property
    def is_private(self):
        """Test if this address is allocated for private networks.

        Returns:
            A boolean, True if the address is reserved per RFC 4193.

        """
        private_network = IPv6Network('fc00::/7')
        return self in private_network

    @property
    def is_unspecified(self):
        """Test if the address is unspecified.

        Returns:
            A boolean, True if this is the unspecified address as defined in
            RFC 2373 2.5.2.

        """
        return self._ip == 0

    @property
    def is_loopback(self):
        """Test if the address is a loopback address.

        Returns:
            A boolean, True if the address is a loopback address as defined in
            RFC 2373 2.5.3.

        """
        return self._ip == 1

    @property
    def ipv4_mapped(self):
        """Return the IPv4 mapped address.

        Returns:
            If the IPv6 address is a v4 mapped address, return the
            IPv4 mapped address. Return None otherwise.

        """
        if (self._ip >> 32) != 0xFFFF:
            return None
        return IPv4Address(self._ip & 0xFFFFFFFF)

    @property
    def teredo(self):
        """Tuple of embedded teredo IPs.

        Returns:
            Tuple of the (server, client) IPs or None if the address
            doesn't appear to be a teredo address (doesn't start with
            2001::/32)

        """
        if (self._ip >> 96) != 0x20010000:
            return None
        return (IPv4Address((self._ip >> 64) & 0xFFFFFFFF),
                IPv4Address(~self._ip & 0xFFFFFFFF))

    @property
    def sixtofour(self):
        """Return the IPv4 6to4 embedded address.

        Returns:
            The IPv4 6to4-embedded address if present or None if the
            address doesn't appear to contain a 6to4 embedded address.

        """
        if (self._ip >> 112) != 0x2002:
            return None
        return IPv4Address((self._ip >> 80) & 0xFFFFFFFF)


class IPv6Interface(IPv6Address):

    def __init__(self, address):
        if isinstance(address, (bytes, int)):
            IPv6Address.__init__(self, address)
            self.network = IPv6Network(self._ip)
            self._prefixlen = self._max_prefixlen
            return

        addr = _split_optional_netmask(address)
        IPv6Address.__init__(self, addr[0])
        self.network = IPv6Network(address, strict=False)
        self.netmask = self.network.netmask
        self._prefixlen = self.network._prefixlen
        self.hostmask = self.network.hostmask

    def __str__(self):
        return '%s/%d' % (self._string_from_ip_int(self._ip),
                          self.network.prefixlen)

    def __eq__(self, other):
        address_equal = IPv6Address.__eq__(self, other)
        if not address_equal or address_equal is NotImplemented:
            return address_equal
        try:
            return self.network == other.network
        except AttributeError:
            # An interface with an associated network is NOT the
            # same as an unassociated address. That's why the hash
            # takes the extra info into account.
            return False

    def __lt__(self, other):
        address_less = IPv6Address.__lt__(self, other)
        if address_less is NotImplemented:
            return NotImplemented
        try:
            return self.network < other.network
        except AttributeError:
            # We *do* allow addresses and interfaces to be sorted. The
            # unassociated address is considered less than all interfaces.
            return False

    def __hash__(self):
        return self._ip ^ self._prefixlen ^ int(self.network.network_address)

    @property
    def ip(self):
        return IPv6Address(self._ip)

    @property
    def with_prefixlen(self):
        return '%s/%s' % (self._string_from_ip_int(self._ip),
                          self._prefixlen)

    @property
    def with_netmask(self):
        return '%s/%s' % (self._string_from_ip_int(self._ip),
                          self.netmask)

    @property
    def with_hostmask(self):
        return '%s/%s' % (self._string_from_ip_int(self._ip),
                          self.hostmask)

    @property
    def is_unspecified(self):
        return self._ip == 0 and self.network.is_unspecified

    @property
    def is_loopback(self):
        return self._ip == 1 and self.network.is_loopback


class IPv6Network(_BaseV6, _BaseNetwork):

    """This class represents and manipulates 128-bit IPv6 networks.

    Attributes: [examples for IPv6('2001:db8::1000/124')]
        .network_address: IPv6Address('2001:db8::1000')
        .hostmask: IPv6Address('::f')
        .broadcast_address: IPv6Address('2001:db8::100f')
        .netmask: IPv6Address('ffff:ffff:ffff:ffff:ffff:ffff:ffff:fff0')
        .prefixlen: 124

    """

    # Class to use when creating address objects
    _address_class = IPv6Address

    def __init__(self, address, strict=True):
        """Instantiate a new IPv6 Network object.

        Args:
            address: A string or integer representing the IPv6 network or the
              IP and prefix/netmask.
              '2001:db8::/128'
              '2001:db8:0000:0000:0000:0000:0000:0000/128'
              '2001:db8::'
              are all functionally the same in IPv6.  That is to say,
              failing to provide a subnetmask will create an object with
              a mask of /128.

              Additionally, an integer can be passed, so
              IPv6Network('2001:db8::') ==
                IPv6Network(42540766411282592856903984951653826560)
              or, more generally
              IPv6Network(int(IPv6Network('2001:db8::'))) ==
                IPv6Network('2001:db8::')

            strict: A boolean. If true, ensure that we have been passed
              A true network address, eg, 2001:db8::1000/124 and not an
              IP address on a network, eg, 2001:db8::1/124.

        Raises:
            AddressValueError: If address isn't a valid IPv6 address.
            NetmaskValueError: If the netmask isn't valid for
              an IPv6 address.
            ValueError: If strict was True and a network address was not
              supplied.

        """
        _BaseV6.__init__(self, address)
        _BaseNetwork.__init__(self, address)

        # Efficient constructor from integer.
        if isinstance(address, int):
            self.network_address = IPv6Address(address)
            self._prefixlen = self._max_prefixlen
            self.netmask = IPv6Address(self._ALL_ONES)
            return

        # Constructing from a packed address
        if isinstance(address, bytes):
            self.network_address = IPv6Address(address)
            self._prefixlen = self._max_prefixlen
            self.netmask = IPv6Address(self._ALL_ONES)
            return

        # Assume input argument to be string or any object representation
        # which converts into a formatted IP prefix string.
        addr = _split_optional_netmask(address)

        self.network_address = IPv6Address(self._ip_int_from_string(addr[0]))

        if len(addr) == 2:
            if self._is_valid_netmask(addr[1]):
                self._prefixlen = int(addr[1])
            else:
                raise NetmaskValueError('%r is not a valid netmask'
                                                     % addr[1])
        else:
            self._prefixlen = self._max_prefixlen

        self.netmask = IPv6Address(self._ip_int_from_prefix(self._prefixlen))
        if strict:
            if (IPv6Address(int(self.network_address) & int(self.netmask)) !=
                self.network_address):
                raise ValueError('%s has host bits set' % self)
        self.network_address = IPv6Address(int(self.network_address) &
                                           int(self.netmask))

        if self._prefixlen == (self._max_prefixlen - 1):
            self.hosts = self.__iter__

    def _is_valid_netmask(self, prefixlen):
        """Verify that the netmask/prefixlen is valid.

        Args:
            prefixlen: A string, the netmask in prefix length format.

        Returns:
            A boolean, True if the prefix represents a valid IPv6
            netmask.

        """
        try:
            prefixlen = int(prefixlen)
        except ValueError:
            return False
        return 0 <= prefixlen <= self._max_prefixlen

    @property
    def is_site_local(self):
        """Test if the address is reserved for site-local.

        Note that the site-local address space has been deprecated by RFC 3879.
        Use is_private to test if this address is in the space of unique local
        addresses as defined by RFC 4193.

        Returns:
            A boolean, True if the address is reserved per RFC 3513 2.5.6.

        """
        return (self.network_address.is_site_local and
                self.broadcast_address.is_site_local)