--- /dev/null
+# -*- encoding: utf-8 -*-
+"""
+ $Id: Lib.py,v 1.11.2.8 2011/03/16 20:06:39 customdesigned Exp $
+
+ This file is part of the pydns project.
+ Homepage: http://pydns.sourceforge.net
+
+ This code is covered by the standard Python License. See LICENSE for details.
+
+ Library code. Largely this is packers and unpackers for various types.
+"""
+
+#
+#
+# See RFC 1035:
+# ------------------------------------------------------------------------
+# Network Working Group P. Mockapetris
+# Request for Comments: 1035 ISI
+# November 1987
+# Obsoletes: RFCs 882, 883, 973
+#
+# DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION
+# ------------------------------------------------------------------------
+
+
+import string, types
+
+import Type
+import Class
+import Opcode
+import Status
+import DNS
+
+from Base import DNSError
+
+LABEL_UTF8 = False
+LABEL_ENCODING = 'idna'
+
+class UnpackError(DNSError): pass
+class PackError(DNSError): pass
+
+# Low-level 16 and 32 bit integer packing and unpacking
+
+from struct import pack as struct_pack
+from struct import unpack as struct_unpack
+from socket import inet_ntoa, inet_aton
+
+def pack16bit(n):
+ return struct_pack('!H', n)
+
+def pack32bit(n):
+ return struct_pack('!L', n)
+
+def unpack16bit(s):
+ return struct_unpack('!H', s)[0]
+
+def unpack32bit(s):
+ return struct_unpack('!L', s)[0]
+
+def addr2bin(addr):
+ return struct_unpack('!l', inet_aton(addr))[0]
+
+def bin2addr(n):
+ return inet_ntoa(struct_pack('!L', n))
+
+# Packing class
+
+class Packer:
+ " packer base class. supports basic byte/16bit/32bit/addr/string/name "
+ def __init__(self):
+ self.buf = ''
+ self.index = {}
+ def getbuf(self):
+ return self.buf
+ def addbyte(self, c):
+ if len(c) != 1: raise TypeError, 'one character expected'
+ self.buf = self.buf + c
+ def addbytes(self, bytes):
+ self.buf = self.buf + bytes
+ def add16bit(self, n):
+ self.buf = self.buf + pack16bit(n)
+ def add32bit(self, n):
+ self.buf = self.buf + pack32bit(n)
+ def addaddr(self, addr):
+ n = addr2bin(addr)
+ self.buf = self.buf + pack32bit(n)
+ def addstring(self, s):
+ if len(s) > 255:
+ raise ValueError, "Can't encode string of length "+ \
+ "%s (> 255)"%(len(s))
+ self.addbyte(chr(len(s)))
+ self.addbytes(s)
+ def addname(self, name):
+ # Domain name packing (section 4.1.4)
+ # Add a domain name to the buffer, possibly using pointers.
+ # The case of the first occurrence of a name is preserved.
+ # Redundant dots are ignored.
+ list = []
+ for label in string.splitfields(name, '.'):
+ if not label:
+ raise PackError, 'empty label'
+ list.append(label)
+ keys = []
+ for i in range(len(list)):
+ key = string.upper(string.joinfields(list[i:], '.'))
+ keys.append(key)
+ if self.index.has_key(key):
+ pointer = self.index[key]
+ break
+ else:
+ i = len(list)
+ pointer = None
+ # Do it into temporaries first so exceptions don't
+ # mess up self.index and self.buf
+ buf = ''
+ offset = len(self.buf)
+ index = []
+ if DNS.LABEL_UTF8:
+ enc = 'utf8'
+ else:
+ enc = DNS.LABEL_ENCODING
+ for j in range(i):
+ label = list[j]
+ try:
+ label = label.encode(enc)
+ except UnicodeEncodeError:
+ if not DNS.LABEL_UTF8: raise
+ if not label.startswith('\ufeff'):
+ label = '\ufeff'+label
+ label = label.encode(enc)
+ n = len(label)
+ if n > 63:
+ raise PackError, 'label too long'
+ if offset + len(buf) < 0x3FFF:
+ index.append((keys[j], offset + len(buf)))
+ else:
+ print 'DNS.Lib.Packer.addname:',
+ print 'warning: pointer too big'
+ buf = buf + (chr(n) + label)
+ if pointer:
+ buf = buf + pack16bit(pointer | 0xC000)
+ else:
+ buf = buf + '\0'
+ self.buf = self.buf + buf
+ for key, value in index:
+ self.index[key] = value
+ def dump(self):
+ keys = self.index.keys()
+ keys.sort()
+ print '-'*40
+ for key in keys:
+ print '%20s %3d' % (key, self.index[key])
+ print '-'*40
+ space = 1
+ for i in range(0, len(self.buf)+1, 2):
+ if self.buf[i:i+2] == '**':
+ if not space: print
+ space = 1
+ continue
+ space = 0
+ print '%4d' % i,
+ for c in self.buf[i:i+2]:
+ if ' ' < c < '\177':
+ print ' %c' % c,
+ else:
+ print '%2d' % ord(c),
+ print
+ print '-'*40
+
+
+# Unpacking class
+
+
+class Unpacker:
+ def __init__(self, buf):
+ self.buf = buf
+ self.offset = 0
+ def getbyte(self):
+ if self.offset >= len(self.buf):
+ raise UnpackError, "Ran off end of data"
+ c = self.buf[self.offset]
+ self.offset = self.offset + 1
+ return c
+ def getbytes(self, n):
+ s = self.buf[self.offset : self.offset + n]
+ if len(s) != n: raise UnpackError, 'not enough data left'
+ self.offset = self.offset + n
+ return s
+ def get16bit(self):
+ return unpack16bit(self.getbytes(2))
+ def get32bit(self):
+ return unpack32bit(self.getbytes(4))
+ def getaddr(self):
+ return bin2addr(self.get32bit())
+ def getstring(self):
+ return self.getbytes(ord(self.getbyte()))
+ def getname(self):
+ # Domain name unpacking (section 4.1.4)
+ c = self.getbyte()
+ i = ord(c)
+ if i & 0xC0 == 0xC0:
+ d = self.getbyte()
+ j = ord(d)
+ pointer = ((i<<8) | j) & ~0xC000
+ save_offset = self.offset
+ try:
+ self.offset = pointer
+ domain = self.getname()
+ finally:
+ self.offset = save_offset
+ return domain
+ if i == 0:
+ return ''
+ domain = self.getbytes(i)
+ remains = self.getname()
+ if not remains:
+ return domain
+ else:
+ return domain + '.' + remains
+
+
+# Test program for packin/unpacking (section 4.1.4)
+
+def testpacker():
+ N = 2500
+ R = range(N)
+ import timing
+ # See section 4.1.4 of RFC 1035
+ timing.start()
+ for i in R:
+ p = Packer()
+ p.addaddr('192.168.0.1')
+ p.addbytes('*' * 20)
+ p.addname('f.ISI.ARPA')
+ p.addbytes('*' * 8)
+ p.addname('Foo.F.isi.arpa')
+ p.addbytes('*' * 18)
+ p.addname('arpa')
+ p.addbytes('*' * 26)
+ p.addname('')
+ timing.finish()
+ print timing.milli(), "ms total for packing"
+ print round(timing.milli() / i, 4), 'ms per packing'
+ #p.dump()
+ u = Unpacker(p.buf)
+ u.getaddr()
+ u.getbytes(20)
+ u.getname()
+ u.getbytes(8)
+ u.getname()
+ u.getbytes(18)
+ u.getname()
+ u.getbytes(26)
+ u.getname()
+ timing.start()
+ for i in R:
+ u = Unpacker(p.buf)
+
+ res = (u.getaddr(),
+ u.getbytes(20),
+ u.getname(),
+ u.getbytes(8),
+ u.getname(),
+ u.getbytes(18),
+ u.getname(),
+ u.getbytes(26),
+ u.getname())
+ timing.finish()
+ print timing.milli(), "ms total for unpacking"
+ print round(timing.milli() / i, 4), 'ms per unpacking'
+ #for item in res: print item
+
+
+# Pack/unpack RR toplevel format (section 3.2.1)
+
+class RRpacker(Packer):
+ def __init__(self):
+ Packer.__init__(self)
+ self.rdstart = None
+ def addRRheader(self, name, type, klass, ttl, *rest):
+ self.addname(name)
+ self.add16bit(type)
+ self.add16bit(klass)
+ self.add32bit(ttl)
+ if rest:
+ if rest[1:]: raise TypeError, 'too many args'
+ rdlength = rest[0]
+ else:
+ rdlength = 0
+ self.add16bit(rdlength)
+ self.rdstart = len(self.buf)
+ def patchrdlength(self):
+ rdlength = unpack16bit(self.buf[self.rdstart-2:self.rdstart])
+ if rdlength == len(self.buf) - self.rdstart:
+ return
+ rdata = self.buf[self.rdstart:]
+ save_buf = self.buf
+ ok = 0
+ try:
+ self.buf = self.buf[:self.rdstart-2]
+ self.add16bit(len(rdata))
+ self.buf = self.buf + rdata
+ ok = 1
+ finally:
+ if not ok: self.buf = save_buf
+ def endRR(self):
+ if self.rdstart is not None:
+ self.patchrdlength()
+ self.rdstart = None
+ def getbuf(self):
+ if self.rdstart is not None: self.patchrdlength()
+ return Packer.getbuf(self)
+ # Standard RRs (section 3.3)
+ def addCNAME(self, name, klass, ttl, cname):
+ self.addRRheader(name, Type.CNAME, klass, ttl)
+ self.addname(cname)
+ self.endRR()
+ def addHINFO(self, name, klass, ttl, cpu, os):
+ self.addRRheader(name, Type.HINFO, klass, ttl)
+ self.addstring(cpu)
+ self.addstring(os)
+ self.endRR()
+ def addMX(self, name, klass, ttl, preference, exchange):
+ self.addRRheader(name, Type.MX, klass, ttl)
+ self.add16bit(preference)
+ self.addname(exchange)
+ self.endRR()
+ def addNS(self, name, klass, ttl, nsdname):
+ self.addRRheader(name, Type.NS, klass, ttl)
+ self.addname(nsdname)
+ self.endRR()
+ def addPTR(self, name, klass, ttl, ptrdname):
+ self.addRRheader(name, Type.PTR, klass, ttl)
+ self.addname(ptrdname)
+ self.endRR()
+ def addSOA(self, name, klass, ttl,
+ mname, rname, serial, refresh, retry, expire, minimum):
+ self.addRRheader(name, Type.SOA, klass, ttl)
+ self.addname(mname)
+ self.addname(rname)
+ self.add32bit(serial)
+ self.add32bit(refresh)
+ self.add32bit(retry)
+ self.add32bit(expire)
+ self.add32bit(minimum)
+ self.endRR()
+ def addTXT(self, name, klass, ttl, list):
+ self.addRRheader(name, Type.TXT, klass, ttl)
+ if type(list) is types.StringType:
+ list = [list]
+ for txtdata in list:
+ self.addstring(txtdata)
+ self.endRR()
+ # Internet specific RRs (section 3.4) -- class = IN
+ def addA(self, name, klass, ttl, address):
+ self.addRRheader(name, Type.A, klass, ttl)
+ self.addaddr(address)
+ self.endRR()
+ def addWKS(self, name, ttl, address, protocol, bitmap):
+ self.addRRheader(name, Type.WKS, Class.IN, ttl)
+ self.addaddr(address)
+ self.addbyte(chr(protocol))
+ self.addbytes(bitmap)
+ self.endRR()
+ def addSRV(self):
+ raise NotImplementedError
+
+def prettyTime(seconds):
+ if seconds<60:
+ return seconds,"%d seconds"%(seconds)
+ if seconds<3600:
+ return seconds,"%d minutes"%(seconds/60)
+ if seconds<86400:
+ return seconds,"%d hours"%(seconds/3600)
+ if seconds<604800:
+ return seconds,"%d days"%(seconds/86400)
+ else:
+ return seconds,"%d weeks"%(seconds/604800)
+
+
+class RRunpacker(Unpacker):
+ def __init__(self, buf):
+ Unpacker.__init__(self, buf)
+ self.rdend = None
+ def getRRheader(self):
+ name = self.getname()
+ rrtype = self.get16bit()
+ klass = self.get16bit()
+ ttl = self.get32bit()
+ rdlength = self.get16bit()
+ self.rdend = self.offset + rdlength
+ return (name, rrtype, klass, ttl, rdlength)
+ def endRR(self):
+ if self.offset != self.rdend:
+ raise UnpackError, 'end of RR not reached'
+ def getCNAMEdata(self):
+ return self.getname()
+ def getHINFOdata(self):
+ return self.getstring(), self.getstring()
+ def getMXdata(self):
+ return self.get16bit(), self.getname()
+ def getNSdata(self):
+ return self.getname()
+ def getPTRdata(self):
+ return self.getname()
+ def getSOAdata(self):
+ return self.getname(), \
+ self.getname(), \
+ ('serial',)+(self.get32bit(),), \
+ ('refresh ',)+prettyTime(self.get32bit()), \
+ ('retry',)+prettyTime(self.get32bit()), \
+ ('expire',)+prettyTime(self.get32bit()), \
+ ('minimum',)+prettyTime(self.get32bit())
+ def getTXTdata(self):
+ list = []
+ while self.offset != self.rdend:
+ list.append(self.getstring())
+ return list
+ getSPFdata = getTXTdata
+ def getAdata(self):
+ return self.getaddr()
+ def getWKSdata(self):
+ address = self.getaddr()
+ protocol = ord(self.getbyte())
+ bitmap = self.getbytes(self.rdend - self.offset)
+ return address, protocol, bitmap
+ def getSRVdata(self):
+ """
+ _Service._Proto.Name TTL Class SRV Priority Weight Port Target
+ """
+ priority = self.get16bit()
+ weight = self.get16bit()
+ port = self.get16bit()
+ target = self.getname()
+ #print '***priority, weight, port, target', priority, weight, port, target
+ return priority, weight, port, target
+
+
+# Pack/unpack Message Header (section 4.1)
+
+class Hpacker(Packer):
+ def addHeader(self, id, qr, opcode, aa, tc, rd, ra, z, rcode,
+ qdcount, ancount, nscount, arcount):
+ self.add16bit(id)
+ self.add16bit((qr&1)<<15 | (opcode&0xF)<<11 | (aa&1)<<10
+ | (tc&1)<<9 | (rd&1)<<8 | (ra&1)<<7
+ | (z&7)<<4 | (rcode&0xF))
+ self.add16bit(qdcount)
+ self.add16bit(ancount)
+ self.add16bit(nscount)
+ self.add16bit(arcount)
+
+class Hunpacker(Unpacker):
+ def getHeader(self):
+ id = self.get16bit()
+ flags = self.get16bit()
+ qr, opcode, aa, tc, rd, ra, z, rcode = (
+ (flags>>15)&1,
+ (flags>>11)&0xF,
+ (flags>>10)&1,
+ (flags>>9)&1,
+ (flags>>8)&1,
+ (flags>>7)&1,
+ (flags>>4)&7,
+ (flags>>0)&0xF)
+ qdcount = self.get16bit()
+ ancount = self.get16bit()
+ nscount = self.get16bit()
+ arcount = self.get16bit()
+ return (id, qr, opcode, aa, tc, rd, ra, z, rcode,
+ qdcount, ancount, nscount, arcount)
+
+
+# Pack/unpack Question (section 4.1.2)
+
+class Qpacker(Packer):
+ def addQuestion(self, qname, qtype, qclass):
+ self.addname(qname)
+ self.add16bit(qtype)
+ self.add16bit(qclass)
+
+class Qunpacker(Unpacker):
+ def getQuestion(self):
+ return self.getname(), self.get16bit(), self.get16bit()
+
+
+# Pack/unpack Message(section 4)
+# NB the order of the base classes is important for __init__()!
+
+class Mpacker(RRpacker, Qpacker, Hpacker):
+ pass
+
+class Munpacker(RRunpacker, Qunpacker, Hunpacker):
+ pass
+
+
+# Routines to print an unpacker to stdout, for debugging.
+# These affect the unpacker's current position!
+
+def dumpM(u):
+ print 'HEADER:',
+ (id, qr, opcode, aa, tc, rd, ra, z, rcode,
+ qdcount, ancount, nscount, arcount) = u.getHeader()
+ print 'id=%d,' % id,
+ print 'qr=%d, opcode=%d, aa=%d, tc=%d, rd=%d, ra=%d, z=%d, rcode=%d,' \
+ % (qr, opcode, aa, tc, rd, ra, z, rcode)
+ if tc: print '*** response truncated! ***'
+ if rcode: print '*** nonzero error code! (%d) ***' % rcode
+ print ' qdcount=%d, ancount=%d, nscount=%d, arcount=%d' \
+ % (qdcount, ancount, nscount, arcount)
+ for i in range(qdcount):
+ print 'QUESTION %d:' % i,
+ dumpQ(u)
+ for i in range(ancount):
+ print 'ANSWER %d:' % i,
+ dumpRR(u)
+ for i in range(nscount):
+ print 'AUTHORITY RECORD %d:' % i,
+ dumpRR(u)
+ for i in range(arcount):
+ print 'ADDITIONAL RECORD %d:' % i,
+ dumpRR(u)
+
+class DnsResult:
+
+ def __init__(self,u,args):
+ self.header={}
+ self.questions=[]
+ self.answers=[]
+ self.authority=[]
+ self.additional=[]
+ self.args=args
+ self.storeM(u)
+
+ def show(self):
+ import time
+ print '; <<>> PDG.py 1.0 <<>> %s %s'%(self.args['name'],
+ self.args['qtype'])
+ opt=""
+ if self.args['rd']:
+ opt=opt+'recurs '
+ h=self.header
+ print ';; options: '+opt
+ print ';; got answer:'
+ print ';; ->>HEADER<<- opcode %s, status %s, id %d'%(
+ h['opcode'],h['status'],h['id'])
+ flags=filter(lambda x,h=h:h[x],('qr','aa','rd','ra','tc'))
+ print ';; flags: %s; Ques: %d, Ans: %d, Auth: %d, Addit: %d'%(
+ string.join(flags),h['qdcount'],h['ancount'],h['nscount'],
+ h['arcount'])
+ print ';; QUESTIONS:'
+ for q in self.questions:
+ print ';; %s, type = %s, class = %s'%(q['qname'],q['qtypestr'],
+ q['qclassstr'])
+ print
+ print ';; ANSWERS:'
+ for a in self.answers:
+ print '%-20s %-6s %-6s %s'%(a['name'],`a['ttl']`,a['typename'],
+ a['data'])
+ print
+ print ';; AUTHORITY RECORDS:'
+ for a in self.authority:
+ print '%-20s %-6s %-6s %s'%(a['name'],`a['ttl']`,a['typename'],
+ a['data'])
+ print
+ print ';; ADDITIONAL RECORDS:'
+ for a in self.additional:
+ print '%-20s %-6s %-6s %s'%(a['name'],`a['ttl']`,a['typename'],
+ a['data'])
+ print
+ if self.args.has_key('elapsed'):
+ print ';; Total query time: %d msec'%self.args['elapsed']
+ print ';; To SERVER: %s'%(self.args['server'])
+ print ';; WHEN: %s'%time.ctime(time.time())
+
+ def storeM(self,u):
+ (self.header['id'], self.header['qr'], self.header['opcode'],
+ self.header['aa'], self.header['tc'], self.header['rd'],
+ self.header['ra'], self.header['z'], self.header['rcode'],
+ self.header['qdcount'], self.header['ancount'],
+ self.header['nscount'], self.header['arcount']) = u.getHeader()
+ self.header['opcodestr']=Opcode.opcodestr(self.header['opcode'])
+ self.header['status']=Status.statusstr(self.header['rcode'])
+ for i in range(self.header['qdcount']):
+ #print 'QUESTION %d:' % i,
+ self.questions.append(self.storeQ(u))
+ for i in range(self.header['ancount']):
+ #print 'ANSWER %d:' % i,
+ self.answers.append(self.storeRR(u))
+ for i in range(self.header['nscount']):
+ #print 'AUTHORITY RECORD %d:' % i,
+ self.authority.append(self.storeRR(u))
+ for i in range(self.header['arcount']):
+ #print 'ADDITIONAL RECORD %d:' % i,
+ self.additional.append(self.storeRR(u))
+
+ def storeQ(self,u):
+ q={}
+ q['qname'], q['qtype'], q['qclass'] = u.getQuestion()
+ q['qtypestr']=Type.typestr(q['qtype'])
+ q['qclassstr']=Class.classstr(q['qclass'])
+ return q
+
+ def storeRR(self,u):
+ r={}
+ r['name'],r['type'],r['class'],r['ttl'],r['rdlength'] = u.getRRheader()
+ r['typename'] = Type.typestr(r['type'])
+ r['classstr'] = Class.classstr(r['class'])
+ #print 'name=%s, type=%d(%s), class=%d(%s), ttl=%d' \
+ # % (name,
+ # type, typename,
+ # klass, Class.classstr(class),
+ # ttl)
+ mname = 'get%sdata' % r['typename']
+ if hasattr(u, mname):
+ r['data']=getattr(u, mname)()
+ else:
+ r['data']=u.getbytes(r['rdlength'])
+ return r
+
+def dumpQ(u):
+ qname, qtype, qclass = u.getQuestion()
+ print 'qname=%s, qtype=%d(%s), qclass=%d(%s)' \
+ % (qname,
+ qtype, Type.typestr(qtype),
+ qclass, Class.classstr(qclass))
+
+def dumpRR(u):
+ name, type, klass, ttl, rdlength = u.getRRheader()
+ typename = Type.typestr(type)
+ print 'name=%s, type=%d(%s), class=%d(%s), ttl=%d' \
+ % (name,
+ type, typename,
+ klass, Class.classstr(klass),
+ ttl)
+ mname = 'get%sdata' % typename
+ if hasattr(u, mname):
+ print ' formatted rdata:', getattr(u, mname)()
+ else:
+ print ' binary rdata:', u.getbytes(rdlength)
+
+if __name__ == "__main__":
+ testpacker()
+#
+# $Log: Lib.py,v $
+# Revision 1.11.2.8 2011/03/16 20:06:39 customdesigned
+# Refer to explicit LICENSE file.
+#
+# Revision 1.11.2.7 2009/06/09 18:39:06 customdesigned
+# Built-in SPF support
+#
+# Revision 1.11.2.6 2008/10/15 22:34:06 customdesigned
+# Default to idna encoding.
+#
+# Revision 1.11.2.5 2008/09/17 17:35:14 customdesigned
+# Use 7-bit ascii encoding, because case folding needs to be disabled
+# before utf8 is safe to use, even experimentally.
+#
+# Revision 1.11.2.4 2008/09/17 16:09:53 customdesigned
+# Encode unicode labels as UTF-8
+#
+# Revision 1.11.2.3 2007/05/22 20:27:40 customdesigned
+# Fix unpacker underflow.
+#
+# Revision 1.11.2.2 2007/05/22 20:25:53 customdesigned
+# Use socket.inetntoa,inetaton.
+#
+# Revision 1.11.2.1 2007/05/22 20:20:39 customdesigned
+# Mark utf-8 encoding
+#
+# Revision 1.11 2002/03/19 13:05:02 anthonybaxter
+# converted to class based exceptions (there goes the python1.4 compatibility :)
+#
+# removed a quite gross use of 'eval()'.
+#
+# Revision 1.10 2002/03/19 12:41:33 anthonybaxter
+# tabnannied and reindented everything. 4 space indent, no tabs.
+# yay.
+#
+# Revision 1.9 2002/03/19 10:30:33 anthonybaxter
+# first round of major bits and pieces. The major stuff here (summarised
+# from my local, off-net CVS server :/ this will cause some oddities with
+# the
+#
+# tests/testPackers.py:
+# a large slab of unit tests for the packer and unpacker code in DNS.Lib
+#
+# DNS/Lib.py:
+# placeholder for addSRV.
+# added 'klass' to addA, make it the same as the other A* records.
+# made addTXT check for being passed a string, turn it into a length 1 list.
+# explicitly check for adding a string of length > 255 (prohibited).
+# a bunch of cleanups from a first pass with pychecker
+# new code for pack/unpack. the bitwise stuff uses struct, for a smallish
+# (disappointly small, actually) improvement, while addr2bin is much
+# much faster now.
+#
+# DNS/Base.py:
+# added DiscoverNameServers. This automatically does the right thing
+# on unix/ win32. No idea how MacOS handles this. *sigh*
+# Incompatible change: Don't use ParseResolvConf on non-unix, use this
+# function, instead!
+# a bunch of cleanups from a first pass with pychecker
+#
+# Revision 1.8 2001/08/09 09:08:55 anthonybaxter
+# added identifying header to top of each file
+#
+# Revision 1.7 2001/07/19 07:50:44 anthony
+# Added SRV (RFC 2782) support. Code from Michael Ströder.
+#
+# Revision 1.6 2001/07/19 07:39:18 anthony
+# 'type' -> 'rrtype' in getRRheader(). Fix from Michael Ströder.
+#
+# Revision 1.5 2001/07/19 07:34:19 anthony
+# oops. glitch in storeRR (fixed now).
+# Reported by Bastian Kleineidam and by greg lin.
+#
+# Revision 1.4 2001/07/19 07:16:42 anthony
+# Changed (opcode&0xF)<<11 to (opcode*0xF)<<11.
+# Patch from Timothy J. Miller.
+#
+# Revision 1.3 2001/07/19 06:57:07 anthony
+# cvs keywords added
+#
+#