Source code for pytomo.dns.inet

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"""Generic Internet address helper functions."""

from __future__ import absolute_import

import socket

from . import ipv4 as dns_ipv4
from . import ipv6 as dns_ipv6


# We assume that AF_INET is always defined.

AF_INET = socket.AF_INET

# AF_INET6 might not be defined in the socket module, but we need it.
# We'll try to use the socket module's value, and if it doesn't work,
# we'll use our own value.

try:
    AF_INET6 = socket.AF_INET6
except AttributeError:
    AF_INET6 = 9999

[docs]def inet_pton(family, text): """Convert the textual form of a network address into its binary form. @param family: the address family @type family: int @param text: the textual address @type text: string @raises NotImplementedError: the address family specified is not implemented. @rtype: string """ if family == AF_INET: return dns_ipv4.inet_aton(text) elif family == AF_INET6: return dns_ipv6.inet_aton(text) else: raise NotImplementedError
[docs]def inet_ntop(family, address): """Convert the binary form of a network address into its textual form. @param family: the address family @type family: int @param address: the binary address @type address: string @raises NotImplementedError: the address family specified is not implemented. @rtype: string """ if family == AF_INET: return dns_ipv4.inet_ntoa(address) elif family == AF_INET6: return dns_ipv6.inet_ntoa(address) else: raise NotImplementedError
[docs]def af_for_address(text): """Determine the address family of a textual-form network address. @param text: the textual address @type text: string @raises ValueError: the address family cannot be determined from the input. @rtype: int """ try: junk = dns_ipv4.inet_aton(text) return AF_INET except: try: junk = dns_ipv6.inet_aton(text) return AF_INET6 except: raise ValueError
[docs]def is_multicast(text): """Is the textual-form network address a multicast address? @param text: the textual address @raises ValueError: the address family cannot be determined from the input. @rtype: bool """ try: first = ord(dns_ipv4.inet_aton(text)[0]) return (first >= 224 and first <= 239) except: try: first = ord(dns_ipv6.inet_aton(text)[0]) return (first == 255) except: raise ValueError