## This file is part of Scapy
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## See http://www.secdev.org/projects/scapy for more informations
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## Copyright (C) Philippe Biondi <phil@secdev.org>
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## This program is published under a GPLv2 license
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"""
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Convert IPv6 addresses between textual representation and binary.
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These functions are missing when python is compiled
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without IPv6 support, on Windows for instance.
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"""
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from __future__ import absolute_import
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import socket
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import re
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import binascii
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from scapy.modules.six.moves import range
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from scapy.compat import *
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_IP6_ZEROS = re.compile('(?::|^)(0(?::0)+)(?::|$)')
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_INET6_PTON_EXC = socket.error("illegal IP address string passed to inet_pton")
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def _inet6_pton(addr):
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"""Convert an IPv6 address from text representation into binary form,
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used when socket.inet_pton is not available.
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"""
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joker_pos = None
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result = b""
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addr = plain_str(addr)
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if addr == '::':
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return b'\x00' * 16
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if addr.startswith('::'):
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addr = addr[1:]
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if addr.endswith('::'):
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addr = addr[:-1]
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parts = addr.split(":")
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nparts = len(parts)
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for i, part in enumerate(parts):
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if not part:
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# "::" indicates one or more groups of 2 null bytes
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if joker_pos is None:
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joker_pos = len(result)
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else:
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# Wildcard is only allowed once
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raise _INET6_PTON_EXC
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elif i + 1 == nparts and '.' in part:
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# The last part of an IPv6 address can be an IPv4 address
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if part.count('.') != 3:
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# we have to do this since socket.inet_aton('1.2') ==
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# b'\x01\x00\x00\x02'
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raise _INET6_PTON_EXC
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try:
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result += socket.inet_aton(part)
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except socket.error:
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raise _INET6_PTON_EXC
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else:
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# Each part must be 16bit. Add missing zeroes before decoding.
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try:
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result += hex_bytes(part.rjust(4, "0"))
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except (binascii.Error, TypeError):
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raise _INET6_PTON_EXC
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# If there's a wildcard, fill up with zeros to reach 128bit (16 bytes)
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if joker_pos is not None:
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if len(result) == 16:
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raise _INET6_PTON_EXC
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result = (result[:joker_pos] + b"\x00" * (16 - len(result))
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+ result[joker_pos:])
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if len(result) != 16:
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raise _INET6_PTON_EXC
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return result
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_INET_PTON = {
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socket.AF_INET: socket.inet_aton,
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socket.AF_INET6: _inet6_pton,
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}
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def inet_pton(af, addr):
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"""Convert an IP address from text representation into binary form."""
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# Will replace Net/Net6 objects
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addr = plain_str(addr)
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# Use inet_pton if available
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try:
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return socket.inet_pton(af, addr)
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except AttributeError:
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try:
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return _INET_PTON[af](addr)
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except KeyError:
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raise socket.error("Address family not supported by protocol")
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def _inet6_ntop(addr):
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"""Convert an IPv6 address from binary form into text representation,
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used when socket.inet_pton is not available.
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"""
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# IPv6 addresses have 128bits (16 bytes)
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if len(addr) != 16:
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raise ValueError("invalid length of packed IP address string")
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# Decode to hex representation
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address = ":".join(bytes_hex(addr[idx:idx + 2]).decode().lstrip('0') or '0'
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for idx in range(0, 16, 2))
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try:
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# Get the longest set of zero blocks. We need to take a look
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# at group 1 regarding the length, as 0:0:1:0:0:2:3:4 would
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# have two matches: 0:0: and :0:0: where the latter is longer,
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# though the first one should be taken. Group 1 is in both
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# cases 0:0.
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match = max(_IP6_ZEROS.finditer(address),
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key=lambda m: m.end(1) - m.start(1))
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return '{}::{}'.format(address[:match.start()], address[match.end():])
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except ValueError:
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return address
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_INET_NTOP = {
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socket.AF_INET: socket.inet_ntoa,
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socket.AF_INET6: _inet6_ntop,
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}
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def inet_ntop(af, addr):
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"""Convert an IP address from binary form into text representation."""
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# Use inet_ntop if available
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addr = raw(addr)
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try:
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return socket.inet_ntop(af, addr)
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except AttributeError:
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try:
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return _INET_NTOP[af](addr)
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except KeyError:
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raise ValueError("unknown address family %d" % af)
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