Source code for dns.inet

# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license

# Copyright (C) 2003-2017 Nominum, Inc.
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"""Generic Internet address helper functions."""

import socket
from typing import Any, Optional, Tuple

import dns.ipv4
import dns.ipv6

# We assume that AF_INET and AF_INET6 are always defined.  We keep
# these here for the benefit of any old code (unlikely though that
# is!).
AF_INET = socket.AF_INET
AF_INET6 = socket.AF_INET6


[docs] def inet_pton(family: int, text: str) -> bytes: """Convert the textual form of a network address into its binary form. *family* is an ``int``, the address family. *text* is a ``str``, the textual address. Raises ``NotImplementedError`` if the address family specified is not implemented. Returns a ``bytes``. """ if family == AF_INET: return dns.ipv4.inet_aton(text) elif family == AF_INET6: return dns.ipv6.inet_aton(text, True) else: raise NotImplementedError
[docs] def inet_ntop(family: int, address: bytes) -> str: """Convert the binary form of a network address into its textual form. *family* is an ``int``, the address family. *address* is a ``bytes``, the network address in binary form. Raises ``NotImplementedError`` if the address family specified is not implemented. Returns a ``str``. """ 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: str) -> int: """Determine the address family of a textual-form network address. *text*, a ``str``, the textual address. Raises ``ValueError`` if the address family cannot be determined from the input. Returns an ``int``. """ try: dns.ipv4.inet_aton(text) return AF_INET except Exception: try: dns.ipv6.inet_aton(text, True) return AF_INET6 except Exception: raise ValueError
[docs] def is_multicast(text: str) -> bool: """Is the textual-form network address a multicast address? *text*, a ``str``, the textual address. Raises ``ValueError`` if the address family cannot be determined from the input. Returns a ``bool``. """ try: first = dns.ipv4.inet_aton(text)[0] return first >= 224 and first <= 239 except Exception: try: first = dns.ipv6.inet_aton(text, True)[0] return first == 255 except Exception: raise ValueError
[docs] def is_address(text: str) -> bool: """Is the specified string an IPv4 or IPv6 address? *text*, a ``str``, the textual address. Returns a ``bool``. """ try: dns.ipv4.inet_aton(text) return True except Exception: try: dns.ipv6.inet_aton(text, True) return True except Exception: return False
[docs] def low_level_address_tuple( high_tuple: Tuple[str, int], af: Optional[int] = None ) -> Any: """Given a "high-level" address tuple, i.e. an (address, port) return the appropriate "low-level" address tuple suitable for use in socket calls. If an *af* other than ``None`` is provided, it is assumed the address in the high-level tuple is valid and has that af. If af is ``None``, then af_for_address will be called. """ address, port = high_tuple if af is None: af = af_for_address(address) if af == AF_INET: return (address, port) elif af == AF_INET6: i = address.find("%") if i < 0: # no scope, shortcut! return (address, port, 0, 0) # try to avoid getaddrinfo() addrpart = address[:i] scope = address[i + 1 :] if scope.isdigit(): return (addrpart, port, 0, int(scope)) try: return (addrpart, port, 0, socket.if_nametoindex(scope)) except AttributeError: # pragma: no cover (we can't really test this) ai_flags = socket.AI_NUMERICHOST ((*_, tup), *_) = socket.getaddrinfo(address, port, flags=ai_flags) return tup else: raise NotImplementedError(f"unknown address family {af}")
[docs] def any_for_af(af): """Return the 'any' address for the specified address family.""" if af == socket.AF_INET: return "0.0.0.0" elif af == socket.AF_INET6: return "::" raise NotImplementedError(f"unknown address family {af}")
[docs] def canonicalize(text: str) -> str: """Verify that *address* is a valid text form IPv4 or IPv6 address and return its canonical text form. IPv6 addresses with scopes are rejected. *text*, a ``str``, the address in textual form. Raises ``ValueError`` if the text is not valid. """ try: return dns.ipv6.canonicalize(text) except Exception: try: return dns.ipv4.canonicalize(text) except Exception: raise ValueError