Enter 2006 September/Enter 09 2006.iso/Internet/SpamExperts Home 1.1/SpamExperts Home.exe/lib/spamexperts.modules/dns/rdataset.pyc

Python Compiled Bytecode | 2006-07-14 | 10.4 KB | 317 lines

# Source Generated with Decompyle++
# File: in.pyc (Python 2.4)

'''DNS rdatasets (an rdataset is a set of rdatas of a given type and class)'''
import random
import StringIO
import struct
import dns.exception as dns
import dns.rdatatype as dns
import dns.rdataclass as dns
import dns.rdata as dns
import dns.set as dns
SimpleSet = dns.set.Set

class DifferingCovers(dns.exception.DNSException):
    '''Raised if an attempt is made to add a SIG/RRSIG whose covered type
    is not the same as that of the other rdatas in the rdataset.'''
    pass


class IncompatibleTypes(dns.exception.DNSException):
    '''Raised if an attempt is made to add rdata of an incompatible type.'''
    pass


class Rdataset(dns.set.Set):
    '''A DNS rdataset.

    @ivar rdclass: The class of the rdataset
    @type rdclass: int
    @ivar rdtype: The type of the rdataset
    @type rdtype: int
    @ivar covers: The covered type.  Usually this value is
    dns.rdatatype.NONE, but if the rdtype is dns.rdatatype.SIG or
    dns.rdatatype.RRSIG, then the covers value will be the rdata
    type the SIG/RRSIG covers.  The library treats the SIG and RRSIG
    types as if they were a family of
    types, e.g. RRSIG(A), RRSIG(NS), RRSIG(SOA).  This makes RRSIGs much
    easier to work with than if RRSIGs covering different rdata
    types were aggregated into a single RRSIG rdataset.
    @type covers: int
    @ivar ttl: The DNS TTL (Time To Live) value
    @type ttl: int
    '''
    __slots__ = [
        'rdclass',
        'rdtype',
        'covers',
        'ttl']

    def __init__(self, rdclass, rdtype, covers = dns.rdatatype.NONE):
        '''Create a new rdataset of the specified class and type.

        @see: the description of the class instance variables for the
        meaning of I{rdclass} and I{rdtype}'''
        super(Rdataset, self).__init__()
        self.rdclass = rdclass
        self.rdtype = rdtype
        self.covers = covers
        self.ttl = 0


    def _clone(self):
        obj = super(Rdataset, self)._clone()
        obj.rdclass = self.rdclass
        obj.rdtype = self.rdtype
        obj.covers = self.covers
        obj.ttl = self.ttl
        return obj


    def update_ttl(self, ttl):
        """Set the TTL of the rdataset to be the lesser of the set's current
        TTL or the specified TTL.  If the set contains no rdatas, set the TTL
        to the specified TTL.
        @param ttl: The TTL
        @type ttl: int"""
        if len(self) == 0:
            self.ttl = ttl
        elif ttl < self.ttl:
            self.ttl = ttl



    def add(self, rd, ttl = None):
        '''Add the specified rdata to the rdataset.

        If the optional I{ttl} parameter is supplied, then
        self.update_ttl(ttl) will be called prior to adding the rdata.

        @param rd: The rdata
        @type rd: dns.rdata.Rdata object
        @param ttl: The TTL
        @type ttl: int'''
        if self.rdclass != rd.rdclass or self.rdtype != rd.rdtype:
            raise IncompatibleTypes

        if ttl is not None:
            self.update_ttl(ttl)

        if self.rdtype == dns.rdatatype.RRSIG or self.rdtype == dns.rdatatype.SIG:
            covers = rd.covers()
            if len(self) == 0 and self.covers == dns.rdatatype.NONE:
                self.covers = covers
            elif self.covers != covers:
                raise DifferingCovers


        if dns.rdatatype.is_singleton(rd.rdtype) and len(self) > 0:
            self.clear()

        super(Rdataset, self).add(rd)


    def union_update(self, other):
        self.update_ttl(other.ttl)
        super(Rdataset, self).union_update(other)


    def intersection_update(self, other):
        self.update_ttl(other.ttl)
        super(Rdataset, self).intersection_update(other)


    def update(self, other):
        '''Add all rdatas in other to self.

        @param other: The rdataset from which to update
        @type other: dns.rdataset.Rdataset object'''
        self.update_ttl(other.ttl)
        super(Rdataset, self).update(other)


    def __repr__(self):
        if self.covers == 0:
            ctext = ''
        else:
            ctext = '(' + dns.rdatatype.to_text(self.covers) + ')'
        return '<DNS ' + dns.rdataclass.to_text(self.rdclass) + ' ' + dns.rdatatype.to_text(self.rdtype) + ctext + ' rdataset>'


    def __str__(self):
        return self.to_text()


    def __eq__(self, other):
        '''Two rdatasets are equal if they have the same class, type, and
        covers, and contain the same rdata.
        @rtype: bool'''
        if not isinstance(other, Rdataset):
            return False

        if self.rdclass != other.rdclass and self.rdtype != other.rdtype or self.covers != other.covers:
            return False

        return super(Rdataset, self).__eq__(other)


    def __ne__(self, other):
        return not self.__eq__(other)


    def to_text(self, name = None, origin = None, relativize = True, override_rdclass = None, **kw):
        '''Convert the rdataset into DNS master file format.

        @see: L{dns.name.Name.choose_relativity} for more information
        on how I{origin} and I{relativize} determine the way names
        are emitted.

        Any additional keyword arguments are passed on to the rdata
        to_text() method.

        @param name: If name is not None, emit a RRs with I{name} as
        the owner name.
        @type name: dns.name.Name object
        @param origin: The origin for relative names, or None.
        @type origin: dns.name.Name object
        @param relativize: True if names should names be relativized
        @type relativize: bool'''
        if name is not None:
            name = name.choose_relativity(origin, relativize)
            ntext = str(name)
            pad = ' '
        else:
            ntext = ''
            pad = ''
        s = StringIO.StringIO()
        if override_rdclass is not None:
            rdclass = override_rdclass
        else:
            rdclass = self.rdclass
        if len(self) == 0:
            print >>s, '%s%s%s %s' % (ntext, pad, dns.rdataclass.to_text(rdclass), dns.rdatatype.to_text(self.rdtype))
        else:
            for rd in self:
                print >>s, '%s%s%d %s %s %s' % (ntext, pad, self.ttl, dns.rdataclass.to_text(rdclass), dns.rdatatype.to_text(self.rdtype), rd.to_text(origin = origin, relativize = relativize, **kw))

        return s.getvalue()[:-1]


    def to_wire(self, name, file, compress = None, origin = None, override_rdclass = None, want_shuffle = True):
        '''Convert the rdataset to wire format.

        @param name: The owner name of the RRset that will be emitted
        @type name: dns.name.Name object
        @param file: The file to which the wire format data will be appended
        @type file: file
        @param compress: The compression table to use; the default is None.
        @type compress: dict
        @param origin: The origin to be appended to any relative names when
        they are emitted.  The default is None.
        @returns: the number of records emitted
        @rtype: int
        '''
        if override_rdclass is not None:
            rdclass = override_rdclass
            want_shuffle = False
        else:
            rdclass = self.rdclass
        file.seek(0, 2)
        if len(self) == 0:
            name.to_wire(file, compress, origin)
            stuff = struct.pack('!HHIH', self.rdtype, rdclass, 0, 0)
            file.write(stuff)
            return 1
        elif want_shuffle:
            l = list(self)
            random.shuffle(l)
        else:
            l = self
        for rd in l:
            name.to_wire(file, compress, origin)
            stuff = struct.pack('!HHIH', self.rdtype, rdclass, self.ttl, 0)
            file.write(stuff)
            start = file.tell()
            rd.to_wire(file, compress, origin)
            end = file.tell()
            if not end - start < 65536:
                raise AssertionError
            file.seek(start - 2)
            stuff = struct.pack('!H', end - start)
            file.write(stuff)
            file.seek(0, 2)

        return len(self)


    def match(self, rdclass, rdtype, covers):
        '''Returns True if this rdataset matches the specified class, type,
        and covers'''
        if self.rdclass == rdclass and self.rdtype == rdtype and self.covers == covers:
            return True

        return False



def from_text_list(rdclass, rdtype, ttl, text_rdatas):
    '''Create an rdataset with the specified class, type, and TTL, and with
    the specified list of rdatas in text format.

    @rtype: dns.rdataset.Rdataset object
    '''
    if isinstance(rdclass, str):
        rdclass = dns.rdataclass.from_text(rdclass)

    if isinstance(rdtype, str):
        rdtype = dns.rdatatype.from_text(rdtype)

    r = Rdataset(rdclass, rdtype)
    r.update_ttl(ttl)
    for t in text_rdatas:
        rd = dns.rdata.from_text(r.rdclass, r.rdtype, t)
        r.add(rd)

    return r


def from_text(rdclass, rdtype, ttl, *text_rdatas):
    '''Create an rdataset with the specified class, type, and TTL, and with
    the specified rdatas in text format.

    @rtype: dns.rdataset.Rdataset object
    '''
    return from_text_list(rdclass, rdtype, ttl, text_rdatas)


def from_rdata_list(ttl, rdatas):
    '''Create an rdataset with the specified TTL, and with
    the specified list of rdata objects.

    @rtype: dns.rdataset.Rdataset object
    '''
    if len(rdatas) == 0:
        raise ValueError, 'rdata list must not be empty'

    r = None
    for rd in rdatas:
        if r is None:
            r = Rdataset(rd.rdclass, rd.rdtype)
            r.update_ttl(ttl)
            first_time = False

        r.add(rd)

    return r


def from_rdata(ttl, *rdatas):
    '''Create an rdataset with the specified TTL, and with
    the specified rdata objects.

    @rtype: dns.rdataset.Rdataset object
    '''
    return from_rdata_list(ttl, rdatas)