Revert "(experimental) force to use custom dns"

This reverts commit 2a6a5e62d4.

lib/dns/flags.py

@@ -1,130 +0,0 @@
-# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
-
-# Copyright (C) 2001-2017 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.
-
-"""DNS Message Flags."""
-
-# Standard DNS flags
-
-#: Query Response
-QR = 0x8000
-#: Authoritative Answer
-AA = 0x0400
-#: Truncated Response
-TC = 0x0200
-#: Recursion Desired
-RD = 0x0100
-#: Recursion Available
-RA = 0x0080
-#: Authentic Data
-AD = 0x0020
-#: Checking Disabled
-CD = 0x0010
-
-# EDNS flags
-
-#: DNSSEC answer OK
-DO = 0x8000
-
-_by_text = {
-    'QR': QR,
-    'AA': AA,
-    'TC': TC,
-    'RD': RD,
-    'RA': RA,
-    'AD': AD,
-    'CD': CD
-}
-
-_edns_by_text = {
-    'DO': DO
-}
-
-
-# We construct the inverse mappings programmatically to ensure that we
-# cannot make any mistakes (e.g. omissions, cut-and-paste errors) that
-# would cause the mappings not to be true inverses.
-
-_by_value = {y: x for x, y in _by_text.items()}
-
-_edns_by_value = {y: x for x, y in _edns_by_text.items()}
-
-
-def _order_flags(table):
-    order = list(table.items())
-    order.sort()
-    order.reverse()
-    return order
-
-_flags_order = _order_flags(_by_value)
-
-_edns_flags_order = _order_flags(_edns_by_value)
-
-
-def _from_text(text, table):
-    flags = 0
-    tokens = text.split()
-    for t in tokens:
-        flags = flags | table[t.upper()]
-    return flags
-
-
-def _to_text(flags, table, order):
-    text_flags = []
-    for k, v in order:
-        if flags & k != 0:
-            text_flags.append(v)
-    return ' '.join(text_flags)
-
-
-def from_text(text):
-    """Convert a space-separated list of flag text values into a flags
-    value.
-
-    Returns an ``int``
-    """
-
-    return _from_text(text, _by_text)
-
-
-def to_text(flags):
-    """Convert a flags value into a space-separated list of flag text
-    values.
-
-    Returns a ``text``.
-    """
-
-    return _to_text(flags, _by_value, _flags_order)
-
-
-def edns_from_text(text):
-    """Convert a space-separated list of EDNS flag text values into a EDNS
-    flags value.
-
-    Returns an ``int``
-    """
-
-    return _from_text(text, _edns_by_text)
-
-
-def edns_to_text(flags):
-    """Convert an EDNS flags value into a space-separated list of EDNS flag
-    text values.
-
-    Returns a ``text``.
-    """
-
-    return _to_text(flags, _edns_by_value, _edns_flags_order)