bpo-34788: Add support for scoped IPv6 addresses (GH-13772)

Automerge-Triggered-By: @asvetlov

Author: opavlyuk

Doc/library/ipaddress.rst

@@ -217,11 +217,20 @@ write code that handles both IP versions correctly.  Address objects are
       :RFC:`4291` for details.  For example,
       ``"0000:0000:0000:0000:0000:0abc:0007:0def"`` can be compressed to
       ``"::abc:7:def"``.
+
+      Optionally, the string may also have a scope zone ID, expressed
+      with a suffix ``%scope_id``. If present, the scope ID must be non-empty,
+      and may not contain ``%``.
+      See :RFC:`4007` for details.
+      For example, ``fe80::1234%1`` might identify address ``fe80::1234`` on the first link of the node.
    2. An integer that fits into 128 bits.
    3. An integer packed into a :class:`bytes` object of length 16, big-endian.
 
+
    >>> ipaddress.IPv6Address('2001:db8::1000')
    IPv6Address('2001:db8::1000')
+   >>> ipaddress.IPv6Address('ff02::5678%1')
+   IPv6Address('ff02::5678%1')
 
    .. attribute:: compressed
 
@@ -268,6 +277,12 @@ write code that handles both IP versions correctly.  Address objects are
       ``::FFFF/96``), this property will report the embedded IPv4 address.
       For any other address, this property will be ``None``.
 
+   .. attribute:: scope_id
+
+      For scoped addresses as defined by :RFC:`4007`, this property identifies
+      the particular zone of the address's scope that the address belongs to,
+      as a string. When no scope zone is specified, this property will be ``None``.
+
    .. attribute:: sixtofour
 
       For addresses that appear to be 6to4 addresses  (starting with
@@ -299,6 +314,8 @@ the :func:`str` and :func:`int` builtin functions::
    >>> int(ipaddress.IPv6Address('::1'))
    1
 
+Note that IPv6 scoped addresses are converted to integers without scope zone ID.
+
 
 Operators
 ^^^^^^^^^
@@ -311,15 +328,20 @@ IPv6).
 Comparison operators
 """"""""""""""""""""
 
-Address objects can be compared with the usual set of comparison operators.  Some
-examples::
+Address objects can be compared with the usual set of comparison operators.
+Same IPv6 addresses with different scope zone IDs are not equal.
+Some examples::
 
    >>> IPv4Address('127.0.0.2') > IPv4Address('127.0.0.1')
    True
    >>> IPv4Address('127.0.0.2') == IPv4Address('127.0.0.1')
    False
    >>> IPv4Address('127.0.0.2') != IPv4Address('127.0.0.1')
    True
+   >>> IPv6Address('fe80::1234') == IPv6Address('fe80::1234%1')
+   False
+   >>> IPv6Address('fe80::1234%1') != IPv6Address('fe80::1234%2')
+   True
 
 
 Arithmetic operators

Doc/library/socket.rst

@@ -78,15 +78,15 @@ created.  Socket addresses are represented as follows:
     Python programs.
 
 - For :const:`AF_INET6` address family, a four-tuple ``(host, port, flowinfo,
-  scopeid)`` is used, where *flowinfo* and *scopeid* represent the ``sin6_flowinfo``
+  scope_id)`` is used, where *flowinfo* and *scope_id* represent the ``sin6_flowinfo``
   and ``sin6_scope_id`` members in :const:`struct sockaddr_in6` in C.  For
-  :mod:`socket` module methods, *flowinfo* and *scopeid* can be omitted just for
-  backward compatibility.  Note, however, omission of *scopeid* can cause problems
+  :mod:`socket` module methods, *flowinfo* and *scope_id* can be omitted just for
+  backward compatibility.  Note, however, omission of *scope_id* can cause problems
   in manipulating scoped IPv6 addresses.
 
   .. versionchanged:: 3.7
-     For multicast addresses (with *scopeid* meaningful) *address* may not contain
-     ``%scope`` (or ``zone id``) part. This information is superfluous and may
+     For multicast addresses (with *scope_id* meaningful) *address* may not contain
+     ``%scope_id`` (or ``zone id``) part. This information is superfluous and may
      be safely omitted (recommended).
 
 - :const:`AF_NETLINK` sockets are represented as pairs ``(pid, groups)``.
@@ -738,7 +738,7 @@ The :mod:`socket` module also offers various network-related services:
    :const:`AI_CANONNAME` is part of the *flags* argument; else *canonname*
    will be empty.  *sockaddr* is a tuple describing a socket address, whose
    format depends on the returned *family* (a ``(address, port)`` 2-tuple for
-   :const:`AF_INET`, a ``(address, port, flow info, scope id)`` 4-tuple for
+   :const:`AF_INET`, a ``(address, port, flowinfo, scope_id)`` 4-tuple for
    :const:`AF_INET6`), and is meant to be passed to the :meth:`socket.connect`
    method.
 
@@ -759,7 +759,7 @@ The :mod:`socket` module also offers various network-related services:
 
    .. versionchanged:: 3.7
       for IPv6 multicast addresses, string representing an address will not
-      contain ``%scope`` part.
+      contain ``%scope_id`` part.
 
 .. function:: getfqdn([name])
 
@@ -827,8 +827,8 @@ The :mod:`socket` module also offers various network-related services:
    or numeric address representation in *host*.  Similarly, *port* can contain a
    string port name or a numeric port number.
 
-   For IPv6 addresses, ``%scope`` is appended to the host part if *sockaddr*
-   contains meaningful *scopeid*. Usually this happens for multicast addresses.
+   For IPv6 addresses, ``%scope_id`` is appended to the host part if *sockaddr*
+   contains meaningful *scope_id*. Usually this happens for multicast addresses.
 
    For more information about *flags* you can consult :manpage:`getnameinfo(3)`.
 
@@ -1354,7 +1354,7 @@ to sockets.
 
    .. versionchanged:: 3.7
       For multicast IPv6 address, first item of *address* does not contain
-      ``%scope`` part anymore. In order to get full IPv6 address use
+      ``%scope_id`` part anymore. In order to get full IPv6 address use
       :func:`getnameinfo`.
 
 .. method:: socket.recvmsg(bufsize[, ancbufsize[, flags]])

Doc/tools/susp-ignored.csv

@@ -147,6 +147,8 @@ library/ipaddress,,:db8,>>> ipaddress.IPv6Address('2001:db8::1000')
 library/ipaddress,,::,>>> ipaddress.IPv6Address('2001:db8::1000')
 library/ipaddress,,:db8,IPv6Address('2001:db8::1000')
 library/ipaddress,,::,IPv6Address('2001:db8::1000')
+library/ipaddress,,::,IPv6Address('ff02::5678%1')
+library/ipaddress,,::,fe80::1234
 library/ipaddress,,:db8,">>> ipaddress.ip_address(""2001:db8::1"").reverse_pointer"
 library/ipaddress,,::,">>> ipaddress.ip_address(""2001:db8::1"").reverse_pointer"
 library/ipaddress,,::,"""::abc:7:def"""

Doc/whatsnew/3.9.rst

@@ -213,6 +213,15 @@ now raises :exc:`ImportError` instead of :exc:`ValueError` for invalid relative
 import attempts.
 (Contributed by Ngalim Siregar in :issue:`37444`.)
 
+ipaddress
+---------
+
+:mod:`ipaddress` now supports IPv6 Scoped Addresses (IPv6 address with suffix ``%<scope_id>``).
+
+Scoped IPv6 addresses can be parsed using :class:`ipaddress.IPv6Address`.
+If present, scope zone ID is available through the :attr:`~ipaddress.IPv6Address.scope_id` attribute.
+(Contributed by Oleksandr Pavliuk in :issue:`34788`.)
+
 math
 ----
 

Lib/ipaddress.py

@@ -1836,6 +1836,26 @@ def _reverse_pointer(self):
         reverse_chars = self.exploded[::-1].replace(':', '')
         return '.'.join(reverse_chars) + '.ip6.arpa'
 
+    @staticmethod
+    def _split_scope_id(ip_str):
+        """Helper function to parse IPv6 string address with scope id.
+
+        See RFC 4007 for details.
+
+        Args:
+            ip_str: A string, the IPv6 address.
+
+        Returns:
+            (addr, scope_id) tuple.
+
+        """
+        addr, sep, scope_id = ip_str.partition('%')
+        if not sep:
+            scope_id = None
+        elif not scope_id or '%' in scope_id:
+            raise AddressValueError('Invalid IPv6 address: "%r"' % ip_str)
+        return addr, scope_id
+
     @property
     def max_prefixlen(self):
         return self._max_prefixlen
@@ -1849,7 +1869,7 @@ class IPv6Address(_BaseV6, _BaseAddress):
 
     """Represent and manipulate single IPv6 Addresses."""
 
-    __slots__ = ('_ip', '__weakref__')
+    __slots__ = ('_ip', '_scope_id', '__weakref__')
 
     def __init__(self, address):
         """Instantiate a new IPv6 address object.
@@ -1872,21 +1892,52 @@ def __init__(self, address):
         if isinstance(address, int):
             self._check_int_address(address)
             self._ip = address
+            self._scope_id = None
             return
 
         # Constructing from a packed address
         if isinstance(address, bytes):
             self._check_packed_address(address, 16)
             self._ip = int.from_bytes(address, 'big')
+            self._scope_id = None
             return
 
         # Assume input argument to be string or any object representation
         # which converts into a formatted IP string.
         addr_str = str(address)
         if '/' in addr_str:
             raise AddressValueError("Unexpected '/' in %r" % address)
+        addr_str, self._scope_id = self._split_scope_id(addr_str)
+
         self._ip = self._ip_int_from_string(addr_str)
 
+    def __str__(self):
+        ip_str = super().__str__()
+        return ip_str + '%' + self._scope_id if self._scope_id else ip_str
+
+    def __hash__(self):
+        return hash((self._ip, self._scope_id))
+
+    def __eq__(self, other):
+        address_equal = super().__eq__(other)
+        if address_equal is NotImplemented:
+            return NotImplemented
+        if not address_equal:
+            return False
+        return self._scope_id == getattr(other, '_scope_id', None)
+
+    @property
+    def scope_id(self):
+        """Identifier of a particular zone of the address's scope.
+
+        See RFC 4007 for details.
+
+        Returns:
+            A string identifying the zone of the address if specified, else None.
+
+        """
+        return self._scope_id
+
     @property
     def packed(self):
         """The binary representation of this address."""
@@ -2040,7 +2091,7 @@ def hostmask(self):
         return self.network.hostmask
 
     def __str__(self):
-        return '%s/%d' % (self._string_from_ip_int(self._ip),
+        return '%s/%d' % (super().__str__(),
                           self._prefixlen)
 
     def __eq__(self, other):