Personal Computer World 2009 February/PCWFEB09.iso/Software/Resources/Chat & Communication/Digsby build 37/digsby_setup.exe/lib/dns/message.pyo

Python Compiled Bytecode | 2008-10-13 | 18.8 KB | 728 lines

# Source Generated with Decompyle++
# File: in.pyo (Python 2.5)

import cStringIO
import random
import struct
import sys
import time
import dns.exception as dns
import dns.flags as dns
import dns.name as dns
import dns.opcode as dns
import dns.rcode as dns
import dns.rdata as dns
import dns.rdataclass as dns
import dns.rdatatype as dns
import dns.rrset as dns
import dns.renderer as dns
import dns.tsig as dns

class ShortHeader(dns.exception.FormError):
    pass


class TrailingJunk(dns.exception.FormError):
    pass


class UnknownHeaderField(dns.exception.DNSException):
    pass


class BadEDNS(dns.exception.FormError):
    pass


class BadTSIG(dns.exception.FormError):
    pass


class UnknownTSIGKey(dns.exception.DNSException):
    pass


class Message(object):

    def __init__(self, id = None):
        if id is None:
            self.id = random.randint(0, 65535)
        else:
            self.id = id
        self.flags = 0
        self.question = []
        self.answer = []
        self.authority = []
        self.additional = []
        self.edns = -1
        self.ednsflags = 0
        self.payload = 0
        self.request_payload = 0
        self.keyring = None
        self.keyname = None
        self.request_mac = ''
        self.other_data = ''
        self.tsig_error = 0
        self.fudge = 300
        self.original_id = self.id
        self.mac = ''
        self.xfr = False
        self.origin = None
        self.tsig_ctx = None
        self.had_tsig = False
        self.multi = False
        self.first = True
        self.index = { }


    def __repr__(self):
        return '<DNS message, ID ' + `self.id` + '>'


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


    def to_text(self, origin = None, relativize = True, **kw):
        s = cStringIO.StringIO()
        print >>s, 'id %d' % self.id
        print >>s, 'opcode %s' % dns.opcode.to_text(dns.opcode.from_flags(self.flags))
        rc = dns.rcode.from_flags(self.flags, self.ednsflags)
        print >>s, 'rcode %s' % dns.rcode.to_text(rc)
        print >>s, 'flags %s' % dns.flags.to_text(self.flags)
        if self.edns >= 0:
            print >>s, 'edns %s' % self.edns
            if self.ednsflags != 0:
                print >>s, 'eflags %s' % dns.flags.edns_to_text(self.ednsflags)

            print >>s, 'payload', self.payload

        is_update = dns.opcode.is_update(self.flags)
        if is_update:
            print >>s, ';ZONE'
        else:
            print >>s, ';QUESTION'
        for rrset in self.question:
            print >>s, rrset.to_text(origin, relativize, **kw)

        if is_update:
            print >>s, ';PREREQ'
        else:
            print >>s, ';ANSWER'
        for rrset in self.answer:
            print >>s, rrset.to_text(origin, relativize, **kw)

        if is_update:
            print >>s, ';UPDATE'
        else:
            print >>s, ';AUTHORITY'
        for rrset in self.authority:
            print >>s, rrset.to_text(origin, relativize, **kw)

        print >>s, ';ADDITIONAL'
        for rrset in self.additional:
            print >>s, rrset.to_text(origin, relativize, **kw)

        return s.getvalue()[:-1]


    def __eq__(self, other):
        if not isinstance(other, Message):
            return False

        if self.id != other.id:
            return False

        if self.flags != other.flags:
            return False

        for n in self.question:
            if n not in other.question:
                return False
                continue

        for n in other.question:
            if n not in self.question:
                return False
                continue

        for n in self.answer:
            if n not in other.answer:
                return False
                continue

        for n in other.answer:
            if n not in self.answer:
                return False
                continue

        for n in self.authority:
            if n not in other.authority:
                return False
                continue

        for n in other.authority:
            if n not in self.authority:
                return False
                continue

        return True


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


    def is_response(self, other):
        if other.flags & dns.flags.QR == 0 and self.id != other.id or dns.opcode.from_flags(self.flags) != dns.opcode.from_flags(other.flags):
            return False

        if dns.rcode.from_flags(other.flags, other.ednsflags) != dns.rcode.NOERROR:
            return True

        if dns.opcode.is_update(self.flags):
            return True

        for n in self.question:
            if n not in other.question:
                return False
                continue

        for n in other.question:
            if n not in self.question:
                return False
                continue

        return True


    def section_number(self, section):
        if section is self.question:
            return 0
        elif section is self.answer:
            return 1
        elif section is self.authority:
            return 2
        elif section is self.additional:
            return 3
        else:
            raise ValueError, 'unknown section'


    def find_rrset(self, section, name, rdclass, rdtype, covers = dns.rdatatype.NONE, deleting = None, create = False, force_unique = False):
        key = (self.section_number(section), name, rdclass, rdtype, covers, deleting)
        if not force_unique:
            if self.index is not None:
                rrset = self.index.get(key)
                if rrset is not None:
                    return rrset

            else:
                for rrset in section:
                    if rrset.match(name, rdclass, rdtype, covers, deleting):
                        return rrset
                        continue


        if not create:
            raise KeyError

        rrset = dns.rrset.RRset(name, rdclass, rdtype, covers, deleting)
        section.append(rrset)
        if self.index is not None:
            self.index[key] = rrset

        return rrset


    def get_rrset(self, section, name, rdclass, rdtype, covers = dns.rdatatype.NONE, deleting = None, create = False, force_unique = False):

        try:
            rrset = self.find_rrset(section, name, rdclass, rdtype, covers, deleting, create, force_unique)
        except KeyError:
            rrset = None

        return rrset


    def to_wire(self, origin = None, max_size = 0, **kw):
        if max_size == 0:
            if self.request_payload != 0:
                max_size = self.request_payload
            else:
                max_size = 65535

        if max_size < 512:
            max_size = 512
        elif max_size > 65535:
            max_size = 65535

        r = dns.renderer.Renderer(self.id, self.flags, max_size, origin)
        for rrset in self.question:
            r.add_question(rrset.name, rrset.rdtype, rrset.rdclass)

        for rrset in self.answer:
            r.add_rrset(dns.renderer.ANSWER, rrset, **kw)

        for rrset in self.authority:
            r.add_rrset(dns.renderer.AUTHORITY, rrset, **kw)

        if self.edns >= 0:
            r.add_edns(self.edns, self.ednsflags, self.payload)

        for rrset in self.additional:
            r.add_rrset(dns.renderer.ADDITIONAL, rrset, **kw)

        r.write_header()
        if self.keyname is not None:
            r.add_tsig(self.keyname, self.keyring[self.keyname], self.fudge, self.original_id, self.tsig_error, self.other_data, self.request_mac)
            self.mac = r.mac

        return r.get_wire()


    def use_tsig(self, keyring, keyname = None, fudge = 300, original_id = None, tsig_error = 0, other_data = ''):
        self.keyring = keyring
        if keyname is None:
            self.keyname = self.keyring.keys()[0]
        elif isinstance(keyname, (str, unicode)):
            keyname = dns.name.from_text(keyname)

        self.keyname = keyname
        self.fudge = fudge
        if original_id is None:
            self.original_id = self.id
        else:
            self.original_id = original_id
        self.tsig_error = tsig_error
        self.other_data = other_data


    def use_edns(self, edns = 0, ednsflags = 0, payload = 1280, request_payload = None):
        if edns is None or edns is False:
            edns = -1

        if edns is True:
            edns = 0

        if request_payload is None:
            request_payload = payload

        if edns < 0:
            ednsflags = 0
            payload = 0
            request_payload = 0
        else:
            ednsflags &= 0xFF00FFFFL
            ednsflags |= edns << 16
        self.edns = edns
        self.ednsflags = ednsflags
        self.payload = payload
        self.request_payload = request_payload


    def want_dnssec(self, wanted = True):
        if wanted:
            if self.edns < 0:
                self.use_edns()

            self.ednsflags |= dns.flags.DO
        elif self.edns >= 0:
            self.ednsflags &= ~(dns.flags.DO)



    def rcode(self):
        return dns.rcode.from_flags(self.flags, self.ednsflags)


    def set_rcode(self, rcode):
        (value, evalue) = dns.rcode.to_flags(rcode)
        self.flags &= 65520
        self.flags |= value
        self.ednsflags &= 0xFFFFFFL
        self.ednsflags |= evalue


    def opcode(self):
        return dns.opcode.from_flags(self.flags)


    def set_opcode(self, opcode):
        self.flags &= 34815
        self.flags |= dns.opcode.to_flags(opcode)



class _WireReader(object):

    def __init__(self, wire, message, question_only = False):
        self.wire = wire
        self.message = message
        self.current = 0
        self.updating = False
        self.zone_rdclass = dns.rdataclass.IN
        self.question_only = question_only


    def _get_question(self, qcount):
        if self.updating and qcount > 1:
            raise dns.exception.FormError

        for i in xrange(0, qcount):
            (qname, used) = dns.name.from_wire(self.wire, self.current)
            if self.message.origin is not None:
                qname = qname.relativize(self.message.origin)

            self.current = self.current + used
            (rdtype, rdclass) = struct.unpack('!HH', self.wire[self.current:self.current + 4])
            self.current = self.current + 4
            self.message.find_rrset(self.message.question, qname, rdclass, rdtype, create = True, force_unique = True)
            if self.updating:
                self.zone_rdclass = rdclass
                continue



    def _get_section(self, section, count):
        if self.updating:
            force_unique = True
        else:
            force_unique = False
        seen_opt = False
        for i in xrange(0, count):
            rr_start = self.current
            (name, used) = dns.name.from_wire(self.wire, self.current)
            if self.message.origin is not None:
                name = name.relativize(self.message.origin)

            self.current = self.current + used
            (rdtype, rdclass, ttl, rdlen) = struct.unpack('!HHIH', self.wire[self.current:self.current + 10])
            self.current = self.current + 10
            if rdtype == dns.rdatatype.OPT:
                if section is not self.message.additional or seen_opt:
                    raise BadEDNS

                self.message.payload = rdclass
                self.message.ednsflags = ttl
                self.message.edns = (ttl & 16711680) >> 16
                seen_opt = True
            elif rdtype == dns.rdatatype.TSIG:
                if not section is self.message.additional and i == count - 1:
                    raise BadTSIG

                if self.message.keyring is None:
                    raise UnknownTSIGKey, 'got signed message without keyring'

                secret = self.message.keyring.get(name)
                if secret is None:
                    raise UnknownTSIGKey, "key '%s' unknown" % name

                self.message.tsig_ctx = dns.tsig.validate(self.wire, name, secret, int(time.time()), self.message.request_mac, rr_start, self.current, rdlen, self.message.tsig_ctx, self.message.multi, self.message.first)
                self.message.had_tsig = True
            elif ttl < 0:
                ttl = 0

            if self.updating:
                if rdclass == dns.rdataclass.ANY or rdclass == dns.rdataclass.NONE:
                    deleting = rdclass
                    rdclass = self.zone_rdclass
                else:
                    deleting = None
            if deleting == dns.rdataclass.ANY:
                covers = dns.rdatatype.NONE
                rd = None
            else:
                rd = dns.rdata.from_wire(rdclass, rdtype, self.wire, self.current, rdlen, self.message.origin)
                covers = rd.covers()
            if self.message.xfr and rdtype == dns.rdatatype.SOA:
                force_unique = True

            rrset = self.message.find_rrset(section, name, rdclass, rdtype, covers, deleting, True, force_unique)
            if rd is not None:
                rrset.add(rd, ttl)

            self.current = self.current + rdlen



    def read(self):
        l = len(self.wire)
        if l < 12:
            raise ShortHeader

        (self.message.id, self.message.flags, qcount, ancount, aucount, adcount) = struct.unpack('!HHHHHH', self.wire[:12])
        self.current = 12
        if dns.opcode.is_update(self.message.flags):
            self.updating = True

        self._get_question(qcount)
        if self.question_only:
            return None

        self._get_section(self.message.answer, ancount)
        self._get_section(self.message.authority, aucount)
        self._get_section(self.message.additional, adcount)
        if self.current != l:
            raise TrailingJunk

        if self.message.multi and self.message.tsig_ctx and not (self.message.had_tsig):
            self.message.tsig_ctx.update(self.wire)




def from_wire(wire, keyring = None, request_mac = '', xfr = False, origin = None, tsig_ctx = None, multi = False, first = True, question_only = False):
    m = Message(id = 0)
    m.keyring = keyring
    m.request_mac = request_mac
    m.xfr = xfr
    m.origin = origin
    m.tsig_ctx = tsig_ctx
    m.multi = multi
    m.first = first
    reader = _WireReader(wire, m, question_only)
    reader.read()
    return m


class _TextReader(object):

    def __init__(self, text, message):
        self.message = message
        self.tok = dns.tokenizer.Tokenizer(text)
        self.last_name = None
        self.zone_rdclass = dns.rdataclass.IN
        self.updating = False


    def _header_line(self, section):
        (ttype, what) = self.tok.get()
        if what == 'id':
            self.message.id = self.tok.get_int()
        elif what == 'flags':
            while True:
                token = self.tok.get()
                if token[0] != dns.tokenizer.IDENTIFIER:
                    self.tok.unget(token)
                    break

                self.message.flags = self.message.flags | dns.flags.from_text(token[1])
            if dns.opcode.is_update(self.message.flags):
                self.updating = True

        elif what == 'edns':
            self.message.edns = self.tok.get_int()
            self.message.ednsflags = self.message.ednsflags | self.message.edns << 16
        elif what == 'eflags':
            if self.message.edns < 0:
                self.message.edns = 0

            while True:
                token = self.tok.get()
                if token[0] != dns.tokenizer.IDENTIFIER:
                    self.tok.unget(token)
                    break

                self.message.ednsflags = self.message.ednsflags | dns.flags.edns_from_text(token[1])
        elif what == 'payload':
            self.message.payload = self.tok.get_int()
            if self.message.edns < 0:
                self.message.edns = 0

        elif what == 'opcode':
            text = self.tok.get_string()
            self.message.flags = self.message.flags | dns.opcode.to_flags(dns.opcode.from_text(text))
        elif what == 'rcode':
            text = self.tok.get_string()
            self.message.set_rcode(dns.rcode.from_text(text))
        else:
            raise UnknownHeaderField
        self.tok.get_eol()


    def _question_line(self, section):
        token = self.tok.get(want_leading = True)
        if token[0] != dns.tokenizer.WHITESPACE:
            self.last_name = dns.name.from_text(token[1], None)

        name = self.last_name
        token = self.tok.get()
        if token[0] != dns.tokenizer.IDENTIFIER:
            raise dns.exception.SyntaxError


        try:
            rdclass = dns.rdataclass.from_text(token[1])
            token = self.tok.get()
            if token[0] != dns.tokenizer.IDENTIFIER:
                raise dns.exception.SyntaxError
        except dns.exception.SyntaxError:
            raise dns.exception.SyntaxError
        except:
            rdclass = dns.rdataclass.IN

        rdtype = dns.rdatatype.from_text(token[1])
        self.message.find_rrset(self.message.question, name, rdclass, rdtype, create = True, force_unique = True)
        if self.updating:
            self.zone_rdclass = rdclass

        self.tok.get_eol()


    def _rr_line(self, section):
        deleting = None
        token = self.tok.get(want_leading = True)
        if token[0] != dns.tokenizer.WHITESPACE:
            self.last_name = dns.name.from_text(token[1], None)

        name = self.last_name
        token = self.tok.get()
        if token[0] != dns.tokenizer.IDENTIFIER:
            raise dns.exception.SyntaxError


        try:
            ttl = int(token[1], 0)
            token = self.tok.get()
            if token[0] != dns.tokenizer.IDENTIFIER:
                raise dns.exception.SyntaxError
        except dns.exception.SyntaxError:
            raise dns.exception.SyntaxError
        except:
            ttl = 0


        try:
            rdclass = dns.rdataclass.from_text(token[1])
            token = self.tok.get()
            if token[0] != dns.tokenizer.IDENTIFIER:
                raise dns.exception.SyntaxError

            if rdclass == dns.rdataclass.ANY or rdclass == dns.rdataclass.NONE:
                deleting = rdclass
                rdclass = self.zone_rdclass
        except dns.exception.SyntaxError:
            raise dns.exception.SyntaxError
        except:
            rdclass = dns.rdataclass.IN

        rdtype = dns.rdatatype.from_text(token[1])
        token = self.tok.get()
        if token[0] != dns.tokenizer.EOL and token[0] != dns.tokenizer.EOF:
            self.tok.unget(token)
            rd = dns.rdata.from_text(rdclass, rdtype, self.tok, None)
            covers = rd.covers()
        else:
            rd = None
            covers = dns.rdatatype.NONE
        rrset = self.message.find_rrset(section, name, rdclass, rdtype, covers, deleting, True, self.updating)
        if rd is not None:
            rrset.add(rd, ttl)



    def read(self):
        line_method = self._header_line
        section = None
        while None:
            token = self.tok.get(True, True)
            if token[0] == dns.tokenizer.EOL or token[0] == dns.tokenizer.EOF:
                break

            if token[0] == dns.tokenizer.COMMENT:
                u = token[1].upper()
                if u == 'HEADER':
                    line_method = self._header_line
                elif u == 'QUESTION' or u == 'ZONE':
                    line_method = self._question_line
                    section = self.message.question
                elif u == 'ANSWER' or u == 'PREREQ':
                    line_method = self._rr_line
                    section = self.message.answer
                elif u == 'AUTHORITY' or u == 'UPDATE':
                    line_method = self._rr_line
                    section = self.message.authority
                elif u == 'ADDITIONAL':
                    line_method = self._rr_line
                    section = self.message.additional

                self.tok.get_eol()
                continue

            line_method(section)
            continue
            return None



def from_text(text):
    m = Message()
    reader = _TextReader(text, m)
    reader.read()
    return m


def from_file(f):
    if sys.hexversion >= 33751040:
        str_type = basestring
        opts = 'rU'
    else:
        str_type = str
        opts = 'r'
    if isinstance(f, str_type):
        f = file(f, opts)
        want_close = True
    else:
        want_close = False

    try:
        m = from_text(f)
    finally:
        if want_close:
            f.close()


    return m


def make_query(qname, rdtype, rdclass = dns.rdataclass.IN, use_edns = None, want_dnssec = False):
    if isinstance(qname, (str, unicode)):
        qname = dns.name.from_text(qname)

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

    if isinstance(rdclass, str):
        rdclass = dns.rdataclass.from_text(rdclass)

    m = Message()
    m.flags |= dns.flags.RD
    m.find_rrset(m.question, qname, rdclass, rdtype, create = True, force_unique = True)
    m.use_edns(use_edns)
    m.want_dnssec(want_dnssec)
    return m


def make_response(query, recursion_available = False, our_payload = 8192):
    if query.flags & dns.flags.QR:
        raise dns.exception.FormError, 'specified query message is not a query'

    response = dns.message.Message(query.id)
    response.flags = dns.flags.QR | query.flags & dns.flags.RD
    if recursion_available:
        response.flags |= dns.flags.RA

    response.set_opcode(query.opcode())
    response.question = list(query.question)
    if query.edns >= 0:
        response.use_edns(0, 0, our_payload, query.payload)

    if query.keyname is not None:
        response.keyname = query.keyname
        response.keyring = query.keyring
        response.request_mac = query.mac

    return response