+++ /dev/null
-# Copyright (C) 2001-2007, 2009, 2010 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 rdata.
-
-@var _rdata_modules: A dictionary mapping a (rdclass, rdtype) tuple to
-the module which implements that type.
-@type _rdata_modules: dict
-@var _module_prefix: The prefix to use when forming modules names. The
-default is 'dns.rdtypes'. Changing this value will break the library.
-@type _module_prefix: string
-@var _hex_chunk: At most this many octets that will be represented in each
-chunk of hexstring that _hexify() produces before whitespace occurs.
-@type _hex_chunk: int"""
-
-import cStringIO
-
-import dns.exception
-import dns.rdataclass
-import dns.rdatatype
-import dns.tokenizer
-
-_hex_chunksize = 32
-
-def _hexify(data, chunksize=None):
- """Convert a binary string into its hex encoding, broken up into chunks
- of I{chunksize} characters separated by a space.
-
- @param data: the binary string
- @type data: string
- @param chunksize: the chunk size. Default is L{dns.rdata._hex_chunksize}
- @rtype: string
- """
-
- if chunksize is None:
- chunksize = _hex_chunksize
- hex = data.encode('hex_codec')
- l = len(hex)
- if l > chunksize:
- chunks = []
- i = 0
- while i < l:
- chunks.append(hex[i : i + chunksize])
- i += chunksize
- hex = ' '.join(chunks)
- return hex
-
-_base64_chunksize = 32
-
-def _base64ify(data, chunksize=None):
- """Convert a binary string into its base64 encoding, broken up into chunks
- of I{chunksize} characters separated by a space.
-
- @param data: the binary string
- @type data: string
- @param chunksize: the chunk size. Default is
- L{dns.rdata._base64_chunksize}
- @rtype: string
- """
-
- if chunksize is None:
- chunksize = _base64_chunksize
- b64 = data.encode('base64_codec')
- b64 = b64.replace('\n', '')
- l = len(b64)
- if l > chunksize:
- chunks = []
- i = 0
- while i < l:
- chunks.append(b64[i : i + chunksize])
- i += chunksize
- b64 = ' '.join(chunks)
- return b64
-
-__escaped = {
- '"' : True,
- '\\' : True,
- }
-
-def _escapify(qstring):
- """Escape the characters in a quoted string which need it.
-
- @param qstring: the string
- @type qstring: string
- @returns: the escaped string
- @rtype: string
- """
-
- text = ''
- for c in qstring:
- if c in __escaped:
- text += '\\' + c
- elif ord(c) >= 0x20 and ord(c) < 0x7F:
- text += c
- else:
- text += '\\%03d' % ord(c)
- return text
-
-def _truncate_bitmap(what):
- """Determine the index of greatest byte that isn't all zeros, and
- return the bitmap that contains all the bytes less than that index.
-
- @param what: a string of octets representing a bitmap.
- @type what: string
- @rtype: string
- """
-
- for i in xrange(len(what) - 1, -1, -1):
- if what[i] != '\x00':
- break
- return ''.join(what[0 : i + 1])
-
-class Rdata(object):
- """Base class for all DNS rdata types.
- """
-
- __slots__ = ['rdclass', 'rdtype']
-
- def __init__(self, rdclass, rdtype):
- """Initialize an rdata.
- @param rdclass: The rdata class
- @type rdclass: int
- @param rdtype: The rdata type
- @type rdtype: int
- """
-
- self.rdclass = rdclass
- self.rdtype = rdtype
-
- def covers(self):
- """DNS SIG/RRSIG rdatas apply to a specific type; this type is
- returned by the covers() function. If the rdata type is not
- SIG or RRSIG, dns.rdatatype.NONE is returned. This is useful when
- creating rdatasets, allowing the rdataset to contain only RRSIGs
- of a particular type, e.g. RRSIG(NS).
- @rtype: int
- """
-
- return dns.rdatatype.NONE
-
- def extended_rdatatype(self):
- """Return a 32-bit type value, the least significant 16 bits of
- which are the ordinary DNS type, and the upper 16 bits of which are
- the "covered" type, if any.
- @rtype: int
- """
-
- return self.covers() << 16 | self.rdtype
-
- def to_text(self, origin=None, relativize=True, **kw):
- """Convert an rdata to text format.
- @rtype: string
- """
- raise NotImplementedError
-
- def to_wire(self, file, compress = None, origin = None):
- """Convert an rdata to wire format.
- @rtype: string
- """
-
- raise NotImplementedError
-
- def to_digestable(self, origin = None):
- """Convert rdata to a format suitable for digesting in hashes. This
- is also the DNSSEC canonical form."""
- f = cStringIO.StringIO()
- self.to_wire(f, None, origin)
- return f.getvalue()
-
- def validate(self):
- """Check that the current contents of the rdata's fields are
- valid. If you change an rdata by assigning to its fields,
- it is a good idea to call validate() when you are done making
- changes.
- """
- dns.rdata.from_text(self.rdclass, self.rdtype, self.to_text())
-
- def __repr__(self):
- covers = self.covers()
- if covers == dns.rdatatype.NONE:
- ctext = ''
- else:
- ctext = '(' + dns.rdatatype.to_text(covers) + ')'
- return '<DNS ' + dns.rdataclass.to_text(self.rdclass) + ' ' + \
- dns.rdatatype.to_text(self.rdtype) + ctext + ' rdata: ' + \
- str(self) + '>'
-
- def __str__(self):
- return self.to_text()
-
- def _cmp(self, other):
- """Compare an rdata with another rdata of the same rdtype and
- rdclass. Return < 0 if self < other in the DNSSEC ordering,
- 0 if self == other, and > 0 if self > other.
- """
-
- raise NotImplementedError
-
- def __eq__(self, other):
- if not isinstance(other, Rdata):
- return False
- if self.rdclass != other.rdclass or \
- self.rdtype != other.rdtype:
- return False
- return self._cmp(other) == 0
-
- def __ne__(self, other):
- if not isinstance(other, Rdata):
- return True
- if self.rdclass != other.rdclass or \
- self.rdtype != other.rdtype:
- return True
- return self._cmp(other) != 0
-
- def __lt__(self, other):
- if not isinstance(other, Rdata) or \
- self.rdclass != other.rdclass or \
- self.rdtype != other.rdtype:
- return NotImplemented
- return self._cmp(other) < 0
-
- def __le__(self, other):
- if not isinstance(other, Rdata) or \
- self.rdclass != other.rdclass or \
- self.rdtype != other.rdtype:
- return NotImplemented
- return self._cmp(other) <= 0
-
- def __ge__(self, other):
- if not isinstance(other, Rdata) or \
- self.rdclass != other.rdclass or \
- self.rdtype != other.rdtype:
- return NotImplemented
- return self._cmp(other) >= 0
-
- def __gt__(self, other):
- if not isinstance(other, Rdata) or \
- self.rdclass != other.rdclass or \
- self.rdtype != other.rdtype:
- return NotImplemented
- return self._cmp(other) > 0
-
- def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
- """Build an rdata object from text format.
-
- @param rdclass: The rdata class
- @type rdclass: int
- @param rdtype: The rdata type
- @type rdtype: int
- @param tok: The tokenizer
- @type tok: dns.tokenizer.Tokenizer
- @param origin: The origin to use for relative names
- @type origin: dns.name.Name
- @param relativize: should names be relativized?
- @type relativize: bool
- @rtype: dns.rdata.Rdata instance
- """
-
- raise NotImplementedError
-
- from_text = classmethod(from_text)
-
- def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
- """Build an rdata object from wire format
-
- @param rdclass: The rdata class
- @type rdclass: int
- @param rdtype: The rdata type
- @type rdtype: int
- @param wire: The wire-format message
- @type wire: string
- @param current: The offet in wire of the beginning of the rdata.
- @type current: int
- @param rdlen: The length of the wire-format rdata
- @type rdlen: int
- @param origin: The origin to use for relative names
- @type origin: dns.name.Name
- @rtype: dns.rdata.Rdata instance
- """
-
- raise NotImplementedError
-
- from_wire = classmethod(from_wire)
-
- def choose_relativity(self, origin = None, relativize = True):
- """Convert any domain names in the rdata to the specified
- relativization.
- """
-
- pass
-
-
-class GenericRdata(Rdata):
- """Generate Rdata Class
-
- This class is used for rdata types for which we have no better
- implementation. It implements the DNS "unknown RRs" scheme.
- """
-
- __slots__ = ['data']
-
- def __init__(self, rdclass, rdtype, data):
- super(GenericRdata, self).__init__(rdclass, rdtype)
- self.data = data
-
- def to_text(self, origin=None, relativize=True, **kw):
- return r'\# %d ' % len(self.data) + _hexify(self.data)
-
- def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
- token = tok.get()
- if not token.is_identifier() or token.value != '\#':
- raise dns.exception.SyntaxError(r'generic rdata does not start with \#')
- length = tok.get_int()
- chunks = []
- while 1:
- token = tok.get()
- if token.is_eol_or_eof():
- break
- chunks.append(token.value)
- hex = ''.join(chunks)
- data = hex.decode('hex_codec')
- if len(data) != length:
- raise dns.exception.SyntaxError('generic rdata hex data has wrong length')
- return cls(rdclass, rdtype, data)
-
- from_text = classmethod(from_text)
-
- def to_wire(self, file, compress = None, origin = None):
- file.write(self.data)
-
- def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
- return cls(rdclass, rdtype, wire[current : current + rdlen])
-
- from_wire = classmethod(from_wire)
-
- def _cmp(self, other):
- return cmp(self.data, other.data)
-
-_rdata_modules = {}
-_module_prefix = 'dns.rdtypes'
-
-def get_rdata_class(rdclass, rdtype):
-
- def import_module(name):
- mod = __import__(name)
- components = name.split('.')
- for comp in components[1:]:
- mod = getattr(mod, comp)
- return mod
-
- mod = _rdata_modules.get((rdclass, rdtype))
- rdclass_text = dns.rdataclass.to_text(rdclass)
- rdtype_text = dns.rdatatype.to_text(rdtype)
- rdtype_text = rdtype_text.replace('-', '_')
- if not mod:
- mod = _rdata_modules.get((dns.rdatatype.ANY, rdtype))
- if not mod:
- try:
- mod = import_module('.'.join([_module_prefix,
- rdclass_text, rdtype_text]))
- _rdata_modules[(rdclass, rdtype)] = mod
- except ImportError:
- try:
- mod = import_module('.'.join([_module_prefix,
- 'ANY', rdtype_text]))
- _rdata_modules[(dns.rdataclass.ANY, rdtype)] = mod
- except ImportError:
- mod = None
- if mod:
- cls = getattr(mod, rdtype_text)
- else:
- cls = GenericRdata
- return cls
-
-def from_text(rdclass, rdtype, tok, origin = None, relativize = True):
- """Build an rdata object from text format.
-
- This function attempts to dynamically load a class which
- implements the specified rdata class and type. If there is no
- class-and-type-specific implementation, the GenericRdata class
- is used.
-
- Once a class is chosen, its from_text() class method is called
- with the parameters to this function.
-
- @param rdclass: The rdata class
- @type rdclass: int
- @param rdtype: The rdata type
- @type rdtype: int
- @param tok: The tokenizer
- @type tok: dns.tokenizer.Tokenizer
- @param origin: The origin to use for relative names
- @type origin: dns.name.Name
- @param relativize: Should names be relativized?
- @type relativize: bool
- @rtype: dns.rdata.Rdata instance"""
-
- if isinstance(tok, str):
- tok = dns.tokenizer.Tokenizer(tok)
- cls = get_rdata_class(rdclass, rdtype)
- if cls != GenericRdata:
- # peek at first token
- token = tok.get()
- tok.unget(token)
- if token.is_identifier() and \
- token.value == r'\#':
- #
- # Known type using the generic syntax. Extract the
- # wire form from the generic syntax, and then run
- # from_wire on it.
- #
- rdata = GenericRdata.from_text(rdclass, rdtype, tok, origin,
- relativize)
- return from_wire(rdclass, rdtype, rdata.data, 0, len(rdata.data),
- origin)
- return cls.from_text(rdclass, rdtype, tok, origin, relativize)
-
-def from_wire(rdclass, rdtype, wire, current, rdlen, origin = None):
- """Build an rdata object from wire format
-
- This function attempts to dynamically load a class which
- implements the specified rdata class and type. If there is no
- class-and-type-specific implementation, the GenericRdata class
- is used.
-
- Once a class is chosen, its from_wire() class method is called
- with the parameters to this function.
-
- @param rdclass: The rdata class
- @type rdclass: int
- @param rdtype: The rdata type
- @type rdtype: int
- @param wire: The wire-format message
- @type wire: string
- @param current: The offet in wire of the beginning of the rdata.
- @type current: int
- @param rdlen: The length of the wire-format rdata
- @type rdlen: int
- @param origin: The origin to use for relative names
- @type origin: dns.name.Name
- @rtype: dns.rdata.Rdata instance"""
-
- cls = get_rdata_class(rdclass, rdtype)
- return cls.from_wire(rdclass, rdtype, wire, current, rdlen, origin)
git.samba.org / idra / samba.git / blobdiff