You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
128 lines
4.8 KiB
128 lines
4.8 KiB
# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
|
|
|
|
# Copyright (C) 2003-2017 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.
|
|
|
|
"""Common DNS Exceptions.
|
|
|
|
Dnspython modules may also define their own exceptions, which will
|
|
always be subclasses of ``DNSException``.
|
|
"""
|
|
|
|
class DNSException(Exception):
|
|
"""Abstract base class shared by all dnspython exceptions.
|
|
|
|
It supports two basic modes of operation:
|
|
|
|
a) Old/compatible mode is used if ``__init__`` was called with
|
|
empty *kwargs*. In compatible mode all *args* are passed
|
|
to the standard Python Exception class as before and all *args* are
|
|
printed by the standard ``__str__`` implementation. Class variable
|
|
``msg`` (or doc string if ``msg`` is ``None``) is returned from ``str()``
|
|
if *args* is empty.
|
|
|
|
b) New/parametrized mode is used if ``__init__`` was called with
|
|
non-empty *kwargs*.
|
|
In the new mode *args* must be empty and all kwargs must match
|
|
those set in class variable ``supp_kwargs``. All kwargs are stored inside
|
|
``self.kwargs`` and used in a new ``__str__`` implementation to construct
|
|
a formatted message based on the ``fmt`` class variable, a ``string``.
|
|
|
|
In the simplest case it is enough to override the ``supp_kwargs``
|
|
and ``fmt`` class variables to get nice parametrized messages.
|
|
"""
|
|
|
|
msg = None # non-parametrized message
|
|
supp_kwargs = set() # accepted parameters for _fmt_kwargs (sanity check)
|
|
fmt = None # message parametrized with results from _fmt_kwargs
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
self._check_params(*args, **kwargs)
|
|
if kwargs:
|
|
self.kwargs = self._check_kwargs(**kwargs)
|
|
self.msg = str(self)
|
|
else:
|
|
self.kwargs = dict() # defined but empty for old mode exceptions
|
|
if self.msg is None:
|
|
# doc string is better implicit message than empty string
|
|
self.msg = self.__doc__
|
|
if args:
|
|
super(DNSException, self).__init__(*args)
|
|
else:
|
|
super(DNSException, self).__init__(self.msg)
|
|
|
|
def _check_params(self, *args, **kwargs):
|
|
"""Old exceptions supported only args and not kwargs.
|
|
|
|
For sanity we do not allow to mix old and new behavior."""
|
|
if args or kwargs:
|
|
assert bool(args) != bool(kwargs), \
|
|
'keyword arguments are mutually exclusive with positional args'
|
|
|
|
def _check_kwargs(self, **kwargs):
|
|
if kwargs:
|
|
assert set(kwargs.keys()) == self.supp_kwargs, \
|
|
'following set of keyword args is required: %s' % (
|
|
self.supp_kwargs)
|
|
return kwargs
|
|
|
|
def _fmt_kwargs(self, **kwargs):
|
|
"""Format kwargs before printing them.
|
|
|
|
Resulting dictionary has to have keys necessary for str.format call
|
|
on fmt class variable.
|
|
"""
|
|
fmtargs = {}
|
|
for kw, data in kwargs.items():
|
|
if isinstance(data, (list, set)):
|
|
# convert list of <someobj> to list of str(<someobj>)
|
|
fmtargs[kw] = list(map(str, data))
|
|
if len(fmtargs[kw]) == 1:
|
|
# remove list brackets [] from single-item lists
|
|
fmtargs[kw] = fmtargs[kw].pop()
|
|
else:
|
|
fmtargs[kw] = data
|
|
return fmtargs
|
|
|
|
def __str__(self):
|
|
if self.kwargs and self.fmt:
|
|
# provide custom message constructed from keyword arguments
|
|
fmtargs = self._fmt_kwargs(**self.kwargs)
|
|
return self.fmt.format(**fmtargs)
|
|
else:
|
|
# print *args directly in the same way as old DNSException
|
|
return super(DNSException, self).__str__()
|
|
|
|
|
|
class FormError(DNSException):
|
|
"""DNS message is malformed."""
|
|
|
|
|
|
class SyntaxError(DNSException):
|
|
"""Text input is malformed."""
|
|
|
|
|
|
class UnexpectedEnd(SyntaxError):
|
|
"""Text input ended unexpectedly."""
|
|
|
|
|
|
class TooBig(DNSException):
|
|
"""The DNS message is too big."""
|
|
|
|
|
|
class Timeout(DNSException):
|
|
"""The DNS operation timed out."""
|
|
supp_kwargs = {'timeout'}
|
|
fmt = "The DNS operation timed out after {timeout} seconds"
|