D7net
Home
Console
Upload
information
Create File
Create Folder
About
Tools
:
/
proc
/
thread-self
/
root
/
proc
/
self
/
root
/
lib
/
python3.6
/
site-packages
/
dns
/
Filename :
wiredata.py
back
Copy
# Copyright (C) 2011 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 Wire Data Helper""" import sys import dns.exception from ._compat import binary_type, string_types # Figure out what constant python passes for an unspecified slice bound. # It's supposed to be sys.maxint, yet on 64-bit windows sys.maxint is 2^31 - 1 # but Python uses 2^63 - 1 as the constant. Rather than making pointless # extra comparisons, duplicating code, or weakening WireData, we just figure # out what constant Python will use. class _SliceUnspecifiedBound(binary_type): def __getitem__(self, key): return key.stop if sys.version_info < (3,): def __getslice__(self, i, j): # pylint: disable=getslice-method return self.__getitem__(slice(i, j)) _unspecified_bound = _SliceUnspecifiedBound()[1:] class WireData(binary_type): # WireData is a string with stricter slicing def __getitem__(self, key): try: if isinstance(key, slice): # make sure we are not going outside of valid ranges, # do stricter control of boundaries than python does # by default start = key.start stop = key.stop if sys.version_info < (3,): if stop == _unspecified_bound: # handle the case where the right bound is unspecified stop = len(self) if start < 0 or stop < 0: raise dns.exception.FormError # If it's not an empty slice, access left and right bounds # to make sure they're valid if start != stop: super(WireData, self).__getitem__(start) super(WireData, self).__getitem__(stop - 1) else: for index in (start, stop): if index is None: continue elif abs(index) > len(self): raise dns.exception.FormError return WireData(super(WireData, self).__getitem__( slice(start, stop))) return bytearray(self.unwrap())[key] except IndexError: raise dns.exception.FormError if sys.version_info < (3,): def __getslice__(self, i, j): # pylint: disable=getslice-method return self.__getitem__(slice(i, j)) def __iter__(self): i = 0 while 1: try: yield self[i] i += 1 except dns.exception.FormError: raise StopIteration def unwrap(self): return binary_type(self) def maybe_wrap(wire): if isinstance(wire, WireData): return wire elif isinstance(wire, binary_type): return WireData(wire) elif isinstance(wire, string_types): return WireData(wire.encode()) raise ValueError("unhandled type %s" % type(wire))