1
# Copyright (C) 2003-2007, 2009, 2010 Nominum, Inc.
3
# Permission to use, copy, modify, and distribute this software and its
4
# documentation for any purpose with or without fee is hereby granted,
5
# provided that the above copyright notice and this permission notice
6
# appear in all copies.
8
# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
9
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
11
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
14
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16
"""Generic Internet address helper functions."""
24
# We assume that AF_INET is always defined.
26
AF_INET = socket.AF_INET
28
# AF_INET6 might not be defined in the socket module, but we need it.
29
# We'll try to use the socket module's value, and if it doesn't work,
30
# we'll use our own value.
33
AF_INET6 = socket.AF_INET6
34
except AttributeError:
37
def inet_pton(family, text):
38
"""Convert the textual form of a network address into its binary form.
40
@param family: the address family
42
@param text: the textual address
44
@raises NotImplementedError: the address family specified is not
50
return dns.ipv4.inet_aton(text)
51
elif family == AF_INET6:
52
return dns.ipv6.inet_aton(text)
54
raise NotImplementedError
56
def inet_ntop(family, address):
57
"""Convert the binary form of a network address into its textual form.
59
@param family: the address family
61
@param address: the binary address
63
@raises NotImplementedError: the address family specified is not
68
return dns.ipv4.inet_ntoa(address)
69
elif family == AF_INET6:
70
return dns.ipv6.inet_ntoa(address)
72
raise NotImplementedError
74
def af_for_address(text):
75
"""Determine the address family of a textual-form network address.
77
@param text: the textual address
79
@raises ValueError: the address family cannot be determined from the input.
83
junk = dns.ipv4.inet_aton(text)
87
junk = dns.ipv6.inet_aton(text)
92
def is_multicast(text):
93
"""Is the textual-form network address a multicast address?
95
@param text: the textual address
96
@raises ValueError: the address family cannot be determined from the input.
100
first = ord(dns.ipv4.inet_aton(text)[0])
101
return (first >= 224 and first <= 239)
104
first = ord(dns.ipv6.inet_aton(text)[0])
105
return (first == 255)