# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
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# Copyright (C) 2001-2017 Nominum, Inc.
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#
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# Permission to use, copy, modify, and distribute this software and its
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# documentation for any purpose with or without fee is hereby granted,
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# provided that the above copyright notice and this permission notice
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# appear in all copies.
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#
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# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
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# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
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# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
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# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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"""DNS Result Codes."""
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import dns.exception
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from ._compat import long
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#: No error
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NOERROR = 0
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#: Form error
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FORMERR = 1
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#: Server failure
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SERVFAIL = 2
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#: Name does not exist ("Name Error" in RFC 1025 terminology).
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NXDOMAIN = 3
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#: Not implemented
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NOTIMP = 4
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#: Refused
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REFUSED = 5
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#: Name exists.
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YXDOMAIN = 6
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#: RRset exists.
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YXRRSET = 7
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#: RRset does not exist.
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NXRRSET = 8
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#: Not authoritative.
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NOTAUTH = 9
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#: Name not in zone.
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NOTZONE = 10
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#: Bad EDNS version.
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BADVERS = 16
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_by_text = {
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'NOERROR': NOERROR,
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'FORMERR': FORMERR,
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'SERVFAIL': SERVFAIL,
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'NXDOMAIN': NXDOMAIN,
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'NOTIMP': NOTIMP,
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'REFUSED': REFUSED,
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'YXDOMAIN': YXDOMAIN,
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'YXRRSET': YXRRSET,
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'NXRRSET': NXRRSET,
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'NOTAUTH': NOTAUTH,
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'NOTZONE': NOTZONE,
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'BADVERS': BADVERS
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}
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# We construct the inverse mapping programmatically to ensure that we
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# cannot make any mistakes (e.g. omissions, cut-and-paste errors) that
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# would cause the mapping not to be a true inverse.
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_by_value = {y: x for x, y in _by_text.items()}
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class UnknownRcode(dns.exception.DNSException):
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"""A DNS rcode is unknown."""
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def from_text(text):
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"""Convert text into an rcode.
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*text*, a ``text``, the textual rcode or an integer in textual form.
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Raises ``dns.rcode.UnknownRcode`` if the rcode mnemonic is unknown.
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Returns an ``int``.
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"""
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if text.isdigit():
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v = int(text)
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if v >= 0 and v <= 4095:
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return v
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v = _by_text.get(text.upper())
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if v is None:
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raise UnknownRcode
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return v
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def from_flags(flags, ednsflags):
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"""Return the rcode value encoded by flags and ednsflags.
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*flags*, an ``int``, the DNS flags field.
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*ednsflags*, an ``int``, the EDNS flags field.
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Raises ``ValueError`` if rcode is < 0 or > 4095
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Returns an ``int``.
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"""
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value = (flags & 0x000f) | ((ednsflags >> 20) & 0xff0)
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if value < 0 or value > 4095:
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raise ValueError('rcode must be >= 0 and <= 4095')
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return value
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def to_flags(value):
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"""Return a (flags, ednsflags) tuple which encodes the rcode.
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*value*, an ``int``, the rcode.
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Raises ``ValueError`` if rcode is < 0 or > 4095.
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Returns an ``(int, int)`` tuple.
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"""
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if value < 0 or value > 4095:
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raise ValueError('rcode must be >= 0 and <= 4095')
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v = value & 0xf
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ev = long(value & 0xff0) << 20
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return (v, ev)
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def to_text(value):
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"""Convert rcode into text.
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*value*, and ``int``, the rcode.
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Raises ``ValueError`` if rcode is < 0 or > 4095.
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Returns a ``text``.
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"""
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if value < 0 or value > 4095:
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raise ValueError('rcode must be >= 0 and <= 4095')
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text = _by_value.get(value)
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if text is None:
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text = str(value)
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return text
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