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16 """Generic Internet address helper functions."""
17
18 import socket
19
20 import dns.ipv4
21 import dns.ipv6
22
23
24
25
26 AF_INET = socket.AF_INET
27
28
29
30
31
32 try:
33 AF_INET6 = socket.AF_INET6
34 except AttributeError:
35 AF_INET6 = 9999
36
38 """Convert the textual form of a network address into its binary form.
39
40 @param family: the address family
41 @type family: int
42 @param text: the textual address
43 @type text: string
44 @raises NotImplementedError: the address family specified is not
45 implemented.
46 @rtype: string
47 """
48
49 if family == AF_INET:
50 return dns.ipv4.inet_aton(text)
51 elif family == AF_INET6:
52 return dns.ipv6.inet_aton(text)
53 else:
54 raise NotImplementedError
55
57 """Convert the binary form of a network address into its textual form.
58
59 @param family: the address family
60 @type family: int
61 @param address: the binary address
62 @type address: string
63 @raises NotImplementedError: the address family specified is not
64 implemented.
65 @rtype: string
66 """
67 if family == AF_INET:
68 return dns.ipv4.inet_ntoa(address)
69 elif family == AF_INET6:
70 return dns.ipv6.inet_ntoa(address)
71 else:
72 raise NotImplementedError
73
75 """Determine the address family of a textual-form network address.
76
77 @param text: the textual address
78 @type text: string
79 @raises ValueError: the address family cannot be determined from the input.
80 @rtype: int
81 """
82 try:
83 junk = dns.ipv4.inet_aton(text)
84 return AF_INET
85 except:
86 try:
87 junk = dns.ipv6.inet_aton(text)
88 return AF_INET6
89 except:
90 raise ValueError
91
93 """Is the textual-form network address a multicast address?
94
95 @param text: the textual address
96 @raises ValueError: the address family cannot be determined from the input.
97 @rtype: bool
98 """
99 try:
100 first = ord(dns.ipv4.inet_aton(text)[0])
101 return (first >= 224 and first <= 239)
102 except:
103 try:
104 first = ord(dns.ipv6.inet_aton(text)[0])
105 return (first == 255)
106 except:
107 raise ValueError
108