# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
# Copyright (C) 2001-2017 Nominum, Inc.
#
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# provided that the above copyright notice and this permission notice
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# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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""" DNS Opcodes. """
import dns . enum
import dns . exception
class Opcode ( dns . enum . IntEnum ) :
#: Query
QUERY = 0
#: Inverse Query (historical)
IQUERY = 1
#: Server Status (unspecified and unimplemented anywhere)
STATUS = 2
#: Notify
NOTIFY = 4
#: Dynamic Update
UPDATE = 5
@classmethod
def _maximum ( cls ) :
return 15
@classmethod
def _unknown_exception_class ( cls ) :
return UnknownOpcode
class UnknownOpcode ( dns . exception . DNSException ) :
""" An DNS opcode is unknown. """
def from_text ( text ) :
""" Convert text into an opcode.
* text * , a ` ` str ` ` , the textual opcode
Raises ` ` dns . opcode . UnknownOpcode ` ` if the opcode is unknown .
Returns an ` ` int ` ` .
"""
return Opcode . from_text ( text )
def from_flags ( flags ) :
""" Extract an opcode from DNS message flags.
* flags * , an ` ` int ` ` , the DNS flags .
Returns an ` ` int ` ` .
"""
return ( flags & 0x7800 ) >> 11
def to_flags ( value ) :
""" Convert an opcode to a value suitable for ORing into DNS message
flags .
* value * , an ` ` int ` ` , the DNS opcode value .
Returns an ` ` int ` ` .
"""
return ( value << 11 ) & 0x7800
def to_text ( value ) :
""" Convert an opcode to text.
* value * , an ` ` int ` ` the opcode value ,
Raises ` ` dns . opcode . UnknownOpcode ` ` if the opcode is unknown .
Returns a ` ` str ` ` .
"""
return Opcode . to_text ( value )
def is_update ( flags ) :
""" Is the opcode in flags UPDATE?
* flags * , an ` ` int ` ` , the DNS message flags .
Returns a ` ` bool ` ` .
"""
return from_flags ( flags ) == Opcode . UPDATE
### BEGIN generated Opcode constants
QUERY = Opcode . QUERY
IQUERY = Opcode . IQUERY
STATUS = Opcode . STATUS
NOTIFY = Opcode . NOTIFY
UPDATE = Opcode . UPDATE
### END generated Opcode constants