golden hour

/usr/lib/python3.9/site-packages/dns

File/Folder	Size	Actions
__init__.py	1.62 KB
__pycache__	-
_asyncbackend.py	2.3 KB
_asyncio_backend.py	8.76 KB
_ddr.py	5.12 KB
_features.py	2.33 KB
_immutable_ctx.py	2.4 KB
asyncbackend.py	2.73 KB
asyncquery.py	26.22 KB
asyncresolver.py	17.43 KB
dnssec.py	39.74 KB
dnssecalgs	-
dnssectypes.py	1.76 KB
e164.py	3.88 KB
edns.py	14.91 KB
entropy.py	4.14 KB
enum.py	3.6 KB
exception.py	5.82 KB
flags.py	2.69 KB
grange.py	2.1 KB
immutable.py	1.97 KB
inet.py	5.64 KB
ipv4.py	2.49 KB
ipv6.py	6.45 KB
message.py	64.45 KB
name.py	41.67 KB
namedict.py	3.91 KB
nameserver.py	9.68 KB
node.py	12.37 KB
opcode.py	2.67 KB
query.py	53.55 KB
quic	-
rcode.py	4.06 KB
rdata.py	28.77 KB
rdataclass.py	2.91 KB
rdataset.py	16.36 KB
rdatatype.py	7.17 KB
rdtypes	-
renderer.py	10.99 KB
resolver.py	71.83 KB
reversename.py	3.74 KB
rrset.py	8.96 KB
serial.py	3.52 KB
set.py	8.88 KB
tokenizer.py	23.03 KB
transaction.py	22.11 KB
tsig.py	11.15 KB
tsigkeyring.py	2.57 KB
ttl.py	2.91 KB
update.py	11.96 KB
version.py	1.88 KB
versioned.py	11.49 KB
win32util.py	8.89 KB
wire.py	2.76 KB
xfr.py	12.96 KB
zone.py	50.87 KB
zonefile.py	27.27 KB
zonetypes.py	690 B

Edit: ipv6.py

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

# Copyright (C) 2003-2017 Nominum, Inc.
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose with or without fee is hereby granted,
# provided that the above copyright notice and this permission notice
# appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

"""IPv6 helper functions."""

import binascii
import re
from typing import List, Union

import dns.exception
import dns.ipv4

_leading_zero = re.compile(r"0+([0-9a-f]+)")

def inet_ntoa(address: bytes) -> str:
    """Convert an IPv6 address in binary form to text form.

*address*, a ``bytes``, the IPv6 address in binary form.

Raises ``ValueError`` if the address isn't 16 bytes long.
    Returns a ``str``.
    """

if len(address) != 16:
        raise ValueError("IPv6 addresses are 16 bytes long")
    hex = binascii.hexlify(address)
    chunks = []
    i = 0
    l = len(hex)
    while i < l:
        chunk = hex[i : i + 4].decode()
        # strip leading zeros.  we do this with an re instead of
        # with lstrip() because lstrip() didn't support chars until
        # python 2.2.2
        m = _leading_zero.match(chunk)
        if m is not None:
            chunk = m.group(1)
        chunks.append(chunk)
        i += 4
    #
    # Compress the longest subsequence of 0-value chunks to ::
    #
    best_start = 0
    best_len = 0
    start = -1
    last_was_zero = False
    for i in range(8):
        if chunks[i] != "0":
            if last_was_zero:
                end = i
                current_len = end - start
                if current_len > best_len:
                    best_start = start
                    best_len = current_len
                last_was_zero = False
        elif not last_was_zero:
            start = i
            last_was_zero = True
    if last_was_zero:
        end = 8
        current_len = end - start
        if current_len > best_len:
            best_start = start
            best_len = current_len
    if best_len > 1:
        if best_start == 0 and (best_len == 6 or best_len == 5 and chunks[5] == "ffff"):
            # We have an embedded IPv4 address
            if best_len == 6:
                prefix = "::"
            else:
                prefix = "::ffff:"
            thex = prefix + dns.ipv4.inet_ntoa(address[12:])
        else:
            thex = (
                ":".join(chunks[:best_start])
                + "::"
                + ":".join(chunks[best_start + best_len :])
            )
    else:
        thex = ":".join(chunks)
    return thex

_v4_ending = re.compile(rb"(.*):(\d+\.\d+\.\d+\.\d+)$")
_colon_colon_start = re.compile(rb"::.*")
_colon_colon_end = re.compile(rb".*::$")

def inet_aton(text: Union[str, bytes], ignore_scope: bool = False) -> bytes:
    """Convert an IPv6 address in text form to binary form.

*text*, a ``str`` or ``bytes``, the IPv6 address in textual form.

*ignore_scope*, a ``bool``.  If ``True``, a scope will be ignored.
    If ``False``, the default, it is an error for a scope to be present.

Returns a ``bytes``.
    """

#
    # Our aim here is not something fast; we just want something that works.
    #
    if not isinstance(text, bytes):
        btext = text.encode()
    else:
        btext = text

if ignore_scope:
        parts = btext.split(b"%")
        l = len(parts)
        if l == 2:
            btext = parts[0]
        elif l > 2:
            raise dns.exception.SyntaxError

if btext == b"":
        raise dns.exception.SyntaxError
    elif btext.endswith(b":") and not btext.endswith(b"::"):
        raise dns.exception.SyntaxError
    elif btext.startswith(b":") and not btext.startswith(b"::"):
        raise dns.exception.SyntaxError
    elif btext == b"::":
        btext = b"0::"
    #
    # Get rid of the icky dot-quad syntax if we have it.
    #
    m = _v4_ending.match(btext)
    if m is not None:
        b = dns.ipv4.inet_aton(m.group(2))
        btext = (
            "{}:{:02x}{:02x}:{:02x}{:02x}".format(
                m.group(1).decode(), b[0], b[1], b[2], b[3]
            )
        ).encode()
    #
    # Try to turn '::<whatever>' into ':<whatever>'; if no match try to
    # turn '<whatever>::' into '<whatever>:'
    #
    m = _colon_colon_start.match(btext)
    if m is not None:
        btext = btext[1:]
    else:
        m = _colon_colon_end.match(btext)
        if m is not None:
            btext = btext[:-1]
    #
    # Now canonicalize into 8 chunks of 4 hex digits each
    #
    chunks = btext.split(b":")
    l = len(chunks)
    if l > 8:
        raise dns.exception.SyntaxError
    seen_empty = False
    canonical: List[bytes] = []
    for c in chunks:
        if c == b"":
            if seen_empty:
                raise dns.exception.SyntaxError
            seen_empty = True
            for _ in range(0, 8 - l + 1):
                canonical.append(b"0000")
        else:
            lc = len(c)
            if lc > 4:
                raise dns.exception.SyntaxError
            if lc != 4:
                c = (b"0" * (4 - lc)) + c
            canonical.append(c)
    if l < 8 and not seen_empty:
        raise dns.exception.SyntaxError
    btext = b"".join(canonical)

#
    # Finally we can go to binary.
    #
    try:
        return binascii.unhexlify(btext)
    except (binascii.Error, TypeError):
        raise dns.exception.SyntaxError

_mapped_prefix = b"\x00" * 10 + b"\xff\xff"

def is_mapped(address: bytes) -> bool:
    """Is the specified address a mapped IPv4 address?

*address*, a ``bytes`` is an IPv6 address in binary form.

Returns a ``bool``.
    """

return address.startswith(_mapped_prefix)

def canonicalize(text: Union[str, bytes]) -> str:
    """Verify that *address* is a valid text form IPv6 address and return its
    canonical text form.  Addresses with scopes are rejected.

*text*, a ``str`` or ``bytes``, the IPv6 address in textual form.

Raises ``dns.exception.SyntaxError`` if the text is not valid.
    """
    return dns.ipv6.inet_ntoa(dns.ipv6.inet_aton(text))