# Copyright (C) 2003-2007, 2009, 2010 Nominum, Inc.
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# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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"""NS-like base classes."""
from __future__ import absolute_import
import cStringIO
from .. import exception as dns_exception
from .. import rdata as dns_rdata
from .. import name as dns_name
[docs]class NSBase(dns_rdata.Rdata):
"""Base class for rdata that is like an NS record.
@ivar target: the target name of the rdata
@type target: dns_name.Name object"""
__slots__ = ['target']
def __init__(self, rdclass, rdtype, target):
super(NSBase, self).__init__(rdclass, rdtype)
self.target = target
[docs] def to_text(self, origin=None, relativize=True, **kw):
target = self.target.choose_relativity(origin, relativize)
return str(target)
[docs] def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
target = tok.get_name()
target = target.choose_relativity(origin, relativize)
tok.get_eol()
return cls(rdclass, rdtype, target)
from_text = classmethod(from_text)
[docs] def to_wire(self, file, compress = None, origin = None):
self.target.to_wire(file, compress, origin)
[docs] def to_digestable(self, origin = None):
return self.target.to_digestable(origin)
[docs] def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
(target, cused) = dns_name.from_wire(wire[: current + rdlen],
current)
if cused != rdlen:
raise dns_exception.FormError
if not origin is None:
target = target.relativize(origin)
return cls(rdclass, rdtype, target)
from_wire = classmethod(from_wire)
[docs] def choose_relativity(self, origin = None, relativize = True):
self.target = self.target.choose_relativity(origin, relativize)
def _cmp(self, other):
return cmp(self.target, other.target)
[docs]class UncompressedNS(NSBase):
"""Base class for rdata that is like an NS record, but whose name
is not compressed when convert to DNS wire format, and whose
digestable form is not downcased."""
[docs] def to_wire(self, file, compress = None, origin = None):
super(UncompressedNS, self).to_wire(file, None, origin)
[docs] def to_digestable(self, origin = None):
f = cStringIO.StringIO()
self.to_wire(f, None, origin)
return f.getvalue()