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117 lines
2.7 KiB
117 lines
2.7 KiB
# 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 Opcodes.""" |
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import dns.enum |
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import dns.exception |
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class Opcode(dns.enum.IntEnum): |
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#: Query |
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QUERY = 0 |
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#: Inverse Query (historical) |
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IQUERY = 1 |
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#: Server Status (unspecified and unimplemented anywhere) |
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STATUS = 2 |
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#: Notify |
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NOTIFY = 4 |
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#: Dynamic Update |
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UPDATE = 5 |
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@classmethod |
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def _maximum(cls): |
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return 15 |
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@classmethod |
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def _unknown_exception_class(cls): |
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return UnknownOpcode |
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class UnknownOpcode(dns.exception.DNSException): |
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"""An DNS opcode is unknown.""" |
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def from_text(text: str) -> Opcode: |
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"""Convert text into an opcode. |
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*text*, a ``str``, the textual opcode |
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Raises ``dns.opcode.UnknownOpcode`` if the opcode is unknown. |
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Returns an ``int``. |
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""" |
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return Opcode.from_text(text) |
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def from_flags(flags: int) -> Opcode: |
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"""Extract an opcode from DNS message flags. |
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*flags*, an ``int``, the DNS flags. |
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Returns an ``int``. |
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""" |
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return Opcode((flags & 0x7800) >> 11) |
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def to_flags(value: Opcode) -> int: |
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"""Convert an opcode to a value suitable for ORing into DNS message |
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flags. |
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*value*, an ``int``, the DNS opcode value. |
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Returns an ``int``. |
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""" |
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return (value << 11) & 0x7800 |
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def to_text(value: Opcode) -> str: |
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"""Convert an opcode to text. |
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*value*, an ``int`` the opcode value, |
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Raises ``dns.opcode.UnknownOpcode`` if the opcode is unknown. |
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Returns a ``str``. |
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""" |
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return Opcode.to_text(value) |
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def is_update(flags: int) -> bool: |
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"""Is the opcode in flags UPDATE? |
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*flags*, an ``int``, the DNS message flags. |
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Returns a ``bool``. |
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""" |
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return from_flags(flags) == Opcode.UPDATE |
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### BEGIN generated Opcode constants |
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QUERY = Opcode.QUERY |
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IQUERY = Opcode.IQUERY |
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STATUS = Opcode.STATUS |
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NOTIFY = Opcode.NOTIFY |
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UPDATE = Opcode.UPDATE |
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### END generated Opcode constants
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