+++ /dev/null
-# Copyright (C) 2001-2007, 2009-2011 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 Names.
-
-@var root: The DNS root name.
-@type root: dns.name.Name object
-@var empty: The empty DNS name.
-@type empty: dns.name.Name object
-"""
-
-import cStringIO
-import struct
-import sys
-
-if sys.hexversion >= 0x02030000:
- import encodings.idna
-
-import dns.exception
-import dns.wiredata
-
-NAMERELN_NONE = 0
-NAMERELN_SUPERDOMAIN = 1
-NAMERELN_SUBDOMAIN = 2
-NAMERELN_EQUAL = 3
-NAMERELN_COMMONANCESTOR = 4
-
-class EmptyLabel(dns.exception.SyntaxError):
- """Raised if a label is empty."""
- pass
-
-class BadEscape(dns.exception.SyntaxError):
- """Raised if an escaped code in a text format name is invalid."""
- pass
-
-class BadPointer(dns.exception.FormError):
- """Raised if a compression pointer points forward instead of backward."""
- pass
-
-class BadLabelType(dns.exception.FormError):
- """Raised if the label type of a wire format name is unknown."""
- pass
-
-class NeedAbsoluteNameOrOrigin(dns.exception.DNSException):
- """Raised if an attempt is made to convert a non-absolute name to
- wire when there is also a non-absolute (or missing) origin."""
- pass
-
-class NameTooLong(dns.exception.FormError):
- """Raised if a name is > 255 octets long."""
- pass
-
-class LabelTooLong(dns.exception.SyntaxError):
- """Raised if a label is > 63 octets long."""
- pass
-
-class AbsoluteConcatenation(dns.exception.DNSException):
- """Raised if an attempt is made to append anything other than the
- empty name to an absolute name."""
- pass
-
-class NoParent(dns.exception.DNSException):
- """Raised if an attempt is made to get the parent of the root name
- or the empty name."""
- pass
-
-_escaped = {
- '"' : True,
- '(' : True,
- ')' : True,
- '.' : True,
- ';' : True,
- '\\' : True,
- '@' : True,
- '$' : True
- }
-
-def _escapify(label):
- """Escape the characters in label which need it.
- @returns: the escaped string
- @rtype: string"""
- text = ''
- for c in label:
- if c in _escaped:
- text += '\\' + c
- elif ord(c) > 0x20 and ord(c) < 0x7F:
- text += c
- else:
- text += '\\%03d' % ord(c)
- return text
-
-def _validate_labels(labels):
- """Check for empty labels in the middle of a label sequence,
- labels that are too long, and for too many labels.
- @raises NameTooLong: the name as a whole is too long
- @raises LabelTooLong: an individual label is too long
- @raises EmptyLabel: a label is empty (i.e. the root label) and appears
- in a position other than the end of the label sequence"""
-
- l = len(labels)
- total = 0
- i = -1
- j = 0
- for label in labels:
- ll = len(label)
- total += ll + 1
- if ll > 63:
- raise LabelTooLong
- if i < 0 and label == '':
- i = j
- j += 1
- if total > 255:
- raise NameTooLong
- if i >= 0 and i != l - 1:
- raise EmptyLabel
-
-class Name(object):
- """A DNS name.
-
- The dns.name.Name class represents a DNS name as a tuple of labels.
- Instances of the class are immutable.
-
- @ivar labels: The tuple of labels in the name. Each label is a string of
- up to 63 octets."""
-
- __slots__ = ['labels']
-
- def __init__(self, labels):
- """Initialize a domain name from a list of labels.
- @param labels: the labels
- @type labels: any iterable whose values are strings
- """
-
- super(Name, self).__setattr__('labels', tuple(labels))
- _validate_labels(self.labels)
-
- def __setattr__(self, name, value):
- raise TypeError("object doesn't support attribute assignment")
-
- def is_absolute(self):
- """Is the most significant label of this name the root label?
- @rtype: bool
- """
-
- return len(self.labels) > 0 and self.labels[-1] == ''
-
- def is_wild(self):
- """Is this name wild? (I.e. Is the least significant label '*'?)
- @rtype: bool
- """
-
- return len(self.labels) > 0 and self.labels[0] == '*'
-
- def __hash__(self):
- """Return a case-insensitive hash of the name.
- @rtype: int
- """
-
- h = 0L
- for label in self.labels:
- for c in label:
- h += ( h << 3 ) + ord(c.lower())
- return int(h % sys.maxint)
-
- def fullcompare(self, other):
- """Compare two names, returning a 3-tuple (relation, order, nlabels).
-
- I{relation} describes the relation ship beween the names,
- and is one of: dns.name.NAMERELN_NONE,
- dns.name.NAMERELN_SUPERDOMAIN, dns.name.NAMERELN_SUBDOMAIN,
- dns.name.NAMERELN_EQUAL, or dns.name.NAMERELN_COMMONANCESTOR
-
- I{order} is < 0 if self < other, > 0 if self > other, and ==
- 0 if self == other. A relative name is always less than an
- absolute name. If both names have the same relativity, then
- the DNSSEC order relation is used to order them.
-
- I{nlabels} is the number of significant labels that the two names
- have in common.
- """
-
- sabs = self.is_absolute()
- oabs = other.is_absolute()
- if sabs != oabs:
- if sabs:
- return (NAMERELN_NONE, 1, 0)
- else:
- return (NAMERELN_NONE, -1, 0)
- l1 = len(self.labels)
- l2 = len(other.labels)
- ldiff = l1 - l2
- if ldiff < 0:
- l = l1
- else:
- l = l2
-
- order = 0
- nlabels = 0
- namereln = NAMERELN_NONE
- while l > 0:
- l -= 1
- l1 -= 1
- l2 -= 1
- label1 = self.labels[l1].lower()
- label2 = other.labels[l2].lower()
- if label1 < label2:
- order = -1
- if nlabels > 0:
- namereln = NAMERELN_COMMONANCESTOR
- return (namereln, order, nlabels)
- elif label1 > label2:
- order = 1
- if nlabels > 0:
- namereln = NAMERELN_COMMONANCESTOR
- return (namereln, order, nlabels)
- nlabels += 1
- order = ldiff
- if ldiff < 0:
- namereln = NAMERELN_SUPERDOMAIN
- elif ldiff > 0:
- namereln = NAMERELN_SUBDOMAIN
- else:
- namereln = NAMERELN_EQUAL
- return (namereln, order, nlabels)
-
- def is_subdomain(self, other):
- """Is self a subdomain of other?
-
- The notion of subdomain includes equality.
- @rtype: bool
- """
-
- (nr, o, nl) = self.fullcompare(other)
- if nr == NAMERELN_SUBDOMAIN or nr == NAMERELN_EQUAL:
- return True
- return False
-
- def is_superdomain(self, other):
- """Is self a superdomain of other?
-
- The notion of subdomain includes equality.
- @rtype: bool
- """
-
- (nr, o, nl) = self.fullcompare(other)
- if nr == NAMERELN_SUPERDOMAIN or nr == NAMERELN_EQUAL:
- return True
- return False
-
- def canonicalize(self):
- """Return a name which is equal to the current name, but is in
- DNSSEC canonical form.
- @rtype: dns.name.Name object
- """
-
- return Name([x.lower() for x in self.labels])
-
- def __eq__(self, other):
- if isinstance(other, Name):
- return self.fullcompare(other)[1] == 0
- else:
- return False
-
- def __ne__(self, other):
- if isinstance(other, Name):
- return self.fullcompare(other)[1] != 0
- else:
- return True
-
- def __lt__(self, other):
- if isinstance(other, Name):
- return self.fullcompare(other)[1] < 0
- else:
- return NotImplemented
-
- def __le__(self, other):
- if isinstance(other, Name):
- return self.fullcompare(other)[1] <= 0
- else:
- return NotImplemented
-
- def __ge__(self, other):
- if isinstance(other, Name):
- return self.fullcompare(other)[1] >= 0
- else:
- return NotImplemented
-
- def __gt__(self, other):
- if isinstance(other, Name):
- return self.fullcompare(other)[1] > 0
- else:
- return NotImplemented
-
- def __repr__(self):
- return '<DNS name ' + self.__str__() + '>'
-
- def __str__(self):
- return self.to_text(False)
-
- def to_text(self, omit_final_dot = False):
- """Convert name to text format.
- @param omit_final_dot: If True, don't emit the final dot (denoting the
- root label) for absolute names. The default is False.
- @rtype: string
- """
-
- if len(self.labels) == 0:
- return '@'
- if len(self.labels) == 1 and self.labels[0] == '':
- return '.'
- if omit_final_dot and self.is_absolute():
- l = self.labels[:-1]
- else:
- l = self.labels
- s = '.'.join(map(_escapify, l))
- return s
-
- def to_unicode(self, omit_final_dot = False):
- """Convert name to Unicode text format.
-
- IDN ACE lables are converted to Unicode.
-
- @param omit_final_dot: If True, don't emit the final dot (denoting the
- root label) for absolute names. The default is False.
- @rtype: string
- """
-
- if len(self.labels) == 0:
- return u'@'
- if len(self.labels) == 1 and self.labels[0] == '':
- return u'.'
- if omit_final_dot and self.is_absolute():
- l = self.labels[:-1]
- else:
- l = self.labels
- s = u'.'.join([encodings.idna.ToUnicode(_escapify(x)) for x in l])
- return s
-
- def to_digestable(self, origin=None):
- """Convert name to a format suitable for digesting in hashes.
-
- The name is canonicalized and converted to uncompressed wire format.
-
- @param origin: If the name is relative and origin is not None, then
- origin will be appended to it.
- @type origin: dns.name.Name object
- @raises NeedAbsoluteNameOrOrigin: All names in wire format are
- absolute. If self is a relative name, then an origin must be supplied;
- if it is missing, then this exception is raised
- @rtype: string
- """
-
- if not self.is_absolute():
- if origin is None or not origin.is_absolute():
- raise NeedAbsoluteNameOrOrigin
- labels = list(self.labels)
- labels.extend(list(origin.labels))
- else:
- labels = self.labels
- dlabels = ["%s%s" % (chr(len(x)), x.lower()) for x in labels]
- return ''.join(dlabels)
-
- def to_wire(self, file = None, compress = None, origin = None):
- """Convert name to wire format, possibly compressing it.
-
- @param file: the file where the name is emitted (typically
- a cStringIO file). If None, a string containing the wire name
- will be returned.
- @type file: file or None
- @param compress: The compression table. If None (the default) names
- will not be compressed.
- @type compress: dict
- @param origin: If the name is relative and origin is not None, then
- origin will be appended to it.
- @type origin: dns.name.Name object
- @raises NeedAbsoluteNameOrOrigin: All names in wire format are
- absolute. If self is a relative name, then an origin must be supplied;
- if it is missing, then this exception is raised
- """
-
- if file is None:
- file = cStringIO.StringIO()
- want_return = True
- else:
- want_return = False
-
- if not self.is_absolute():
- if origin is None or not origin.is_absolute():
- raise NeedAbsoluteNameOrOrigin
- labels = list(self.labels)
- labels.extend(list(origin.labels))
- else:
- labels = self.labels
- i = 0
- for label in labels:
- n = Name(labels[i:])
- i += 1
- if not compress is None:
- pos = compress.get(n)
- else:
- pos = None
- if not pos is None:
- value = 0xc000 + pos
- s = struct.pack('!H', value)
- file.write(s)
- break
- else:
- if not compress is None and len(n) > 1:
- pos = file.tell()
- if pos < 0xc000:
- compress[n] = pos
- l = len(label)
- file.write(chr(l))
- if l > 0:
- file.write(label)
- if want_return:
- return file.getvalue()
-
- def __len__(self):
- """The length of the name (in labels).
- @rtype: int
- """
-
- return len(self.labels)
-
- def __getitem__(self, index):
- return self.labels[index]
-
- def __getslice__(self, start, stop):
- return self.labels[start:stop]
-
- def __add__(self, other):
- return self.concatenate(other)
-
- def __sub__(self, other):
- return self.relativize(other)
-
- def split(self, depth):
- """Split a name into a prefix and suffix at depth.
-
- @param depth: the number of labels in the suffix
- @type depth: int
- @raises ValueError: the depth was not >= 0 and <= the length of the
- name.
- @returns: the tuple (prefix, suffix)
- @rtype: tuple
- """
-
- l = len(self.labels)
- if depth == 0:
- return (self, dns.name.empty)
- elif depth == l:
- return (dns.name.empty, self)
- elif depth < 0 or depth > l:
- raise ValueError('depth must be >= 0 and <= the length of the name')
- return (Name(self[: -depth]), Name(self[-depth :]))
-
- def concatenate(self, other):
- """Return a new name which is the concatenation of self and other.
- @rtype: dns.name.Name object
- @raises AbsoluteConcatenation: self is absolute and other is
- not the empty name
- """
-
- if self.is_absolute() and len(other) > 0:
- raise AbsoluteConcatenation
- labels = list(self.labels)
- labels.extend(list(other.labels))
- return Name(labels)
-
- def relativize(self, origin):
- """If self is a subdomain of origin, return a new name which is self
- relative to origin. Otherwise return self.
- @rtype: dns.name.Name object
- """
-
- if not origin is None and self.is_subdomain(origin):
- return Name(self[: -len(origin)])
- else:
- return self
-
- def derelativize(self, origin):
- """If self is a relative name, return a new name which is the
- concatenation of self and origin. Otherwise return self.
- @rtype: dns.name.Name object
- """
-
- if not self.is_absolute():
- return self.concatenate(origin)
- else:
- return self
-
- def choose_relativity(self, origin=None, relativize=True):
- """Return a name with the relativity desired by the caller. If
- origin is None, then self is returned. Otherwise, if
- relativize is true the name is relativized, and if relativize is
- false the name is derelativized.
- @rtype: dns.name.Name object
- """
-
- if origin:
- if relativize:
- return self.relativize(origin)
- else:
- return self.derelativize(origin)
- else:
- return self
-
- def parent(self):
- """Return the parent of the name.
- @rtype: dns.name.Name object
- @raises NoParent: the name is either the root name or the empty name,
- and thus has no parent.
- """
- if self == root or self == empty:
- raise NoParent
- return Name(self.labels[1:])
-
-root = Name([''])
-empty = Name([])
-
-def from_unicode(text, origin = root):
- """Convert unicode text into a Name object.
-
- Lables are encoded in IDN ACE form.
-
- @rtype: dns.name.Name object
- """
-
- if not isinstance(text, unicode):
- raise ValueError("input to from_unicode() must be a unicode string")
- if not (origin is None or isinstance(origin, Name)):
- raise ValueError("origin must be a Name or None")
- labels = []
- label = u''
- escaping = False
- edigits = 0
- total = 0
- if text == u'@':
- text = u''
- if text:
- if text == u'.':
- return Name(['']) # no Unicode "u" on this constant!
- for c in text:
- if escaping:
- if edigits == 0:
- if c.isdigit():
- total = int(c)
- edigits += 1
- else:
- label += c
- escaping = False
- else:
- if not c.isdigit():
- raise BadEscape
- total *= 10
- total += int(c)
- edigits += 1
- if edigits == 3:
- escaping = False
- label += chr(total)
- elif c == u'.' or c == u'\u3002' or \
- c == u'\uff0e' or c == u'\uff61':
- if len(label) == 0:
- raise EmptyLabel
- labels.append(encodings.idna.ToASCII(label))
- label = u''
- elif c == u'\\':
- escaping = True
- edigits = 0
- total = 0
- else:
- label += c
- if escaping:
- raise BadEscape
- if len(label) > 0:
- labels.append(encodings.idna.ToASCII(label))
- else:
- labels.append('')
- if (len(labels) == 0 or labels[-1] != '') and not origin is None:
- labels.extend(list(origin.labels))
- return Name(labels)
-
-def from_text(text, origin = root):
- """Convert text into a Name object.
- @rtype: dns.name.Name object
- """
-
- if not isinstance(text, str):
- if isinstance(text, unicode) and sys.hexversion >= 0x02030000:
- return from_unicode(text, origin)
- else:
- raise ValueError("input to from_text() must be a string")
- if not (origin is None or isinstance(origin, Name)):
- raise ValueError("origin must be a Name or None")
- labels = []
- label = ''
- escaping = False
- edigits = 0
- total = 0
- if text == '@':
- text = ''
- if text:
- if text == '.':
- return Name([''])
- for c in text:
- if escaping:
- if edigits == 0:
- if c.isdigit():
- total = int(c)
- edigits += 1
- else:
- label += c
- escaping = False
- else:
- if not c.isdigit():
- raise BadEscape
- total *= 10
- total += int(c)
- edigits += 1
- if edigits == 3:
- escaping = False
- label += chr(total)
- elif c == '.':
- if len(label) == 0:
- raise EmptyLabel
- labels.append(label)
- label = ''
- elif c == '\\':
- escaping = True
- edigits = 0
- total = 0
- else:
- label += c
- if escaping:
- raise BadEscape
- if len(label) > 0:
- labels.append(label)
- else:
- labels.append('')
- if (len(labels) == 0 or labels[-1] != '') and not origin is None:
- labels.extend(list(origin.labels))
- return Name(labels)
-
-def from_wire(message, current):
- """Convert possibly compressed wire format into a Name.
- @param message: the entire DNS message
- @type message: string
- @param current: the offset of the beginning of the name from the start
- of the message
- @type current: int
- @raises dns.name.BadPointer: a compression pointer did not point backwards
- in the message
- @raises dns.name.BadLabelType: an invalid label type was encountered.
- @returns: a tuple consisting of the name that was read and the number
- of bytes of the wire format message which were consumed reading it
- @rtype: (dns.name.Name object, int) tuple
- """
-
- if not isinstance(message, str):
- raise ValueError("input to from_wire() must be a byte string")
- message = dns.wiredata.maybe_wrap(message)
- labels = []
- biggest_pointer = current
- hops = 0
- count = ord(message[current])
- current += 1
- cused = 1
- while count != 0:
- if count < 64:
- labels.append(message[current : current + count].unwrap())
- current += count
- if hops == 0:
- cused += count
- elif count >= 192:
- current = (count & 0x3f) * 256 + ord(message[current])
- if hops == 0:
- cused += 1
- if current >= biggest_pointer:
- raise BadPointer
- biggest_pointer = current
- hops += 1
- else:
- raise BadLabelType
- count = ord(message[current])
- current += 1
- if hops == 0:
- cused += 1
- labels.append('')
- return (Name(labels), cused)
git.samba.org / samba.git / blobdiff