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source: trunk/dns/nameserver.py @ 131

Last change on this file since 131 was 131, checked in by ecprice, 17 years ago
DNS (*.servers.csail.mit.edu from database)
Property svn:executable set to ``*
File size: 118.6 KB

Line
1	#!/usr/bin/python
2	# Python Domain Name Server
3	# Copyright (C) 2002 Digital Lumber, Inc.
4
5	# This library is free software; you can redistribute it and/or
6	# modify it under the terms of the GNU Lesser General Public
7	# License as published by the Free Software Foundation; either
8	# version 2.1 of the License, or (at your option) any later version.
9
10	# This library is distributed in the hope that it will be useful,
11	# but WITHOUT ANY WARRANTY; without even the implied warranty of
12	# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13	# Lesser General Public License for more details.
14
15	# You should have received a copy of the GNU Lesser General Public
16	# License along with this library; if not, write to the Free Software
17	# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18
19	import socket
20	import asyncore
21	import asynchat
22	import select
23	import types
24	import random
25	import time
26	import signal
27	import string
28	import sys
29	import sipb_xen_database
30	from errno import EALREADY, EINPROGRESS, EWOULDBLOCK, ECONNRESET, \
31	ENOTCONN, ESHUTDOWN, EINTR, EISCONN, ETIMEDOUT
32
33	# EXAMPLE ZONE FILE DATA STRUCTURE
34
35	# NOTE:
36	# There are no trailing dots in the internal data
37	# structure. Although it's hard to tell by reading
38	# the RFC's, the dots on the end of names are just
39	# used internally by the resolvers and servers to
40	# see if they need to append a domain name onto
41	# the end of names. There are no trailing dots
42	# on names in queries on the network.
43
44	examplenet = {'example.net':{'SOA':[{'class':'IN',
45	'ttl':10,
46	'mname':'ns1.example.net',
47	'rname':'hostmaster.example.net',
48	'serial':1,
49	'refresh':10800,
50	'retry':3600,
51	'expire':604800,
52	'minimum':3600}],
53	'NS':[{'class':'IN',
54	'ttl':10,
55	'nsdname':'ns1.example.net'},
56	{'ttl':10,
57	'nsdname':'ns2.example.net'}],
58	'MX':[{'class':'IN',
59	'ttl':10,
60	'preference':10,
61	'exchange':'mail.example.net'}]},
62	'server1.example.net':{'A':[{'class':'IN',
63	'ttl':10,
64	'address':'10.1.2.3'}]},
65	'www.example.net':{'CNAME':[{'class':'IN',
66	'ttl':10,
67	'cname':'server1.example.net'}]},
68	'router.example.net':{'A':[{'class':'IN',
69	'ttl':10,
70	'address':'10.1.2.1'},
71	{'class':'IN',
72	'ttl':10,
73	'address':'10.2.1.1'}]}
74
75	}
76
77	# setup logging defaults
78	loglevel = 0
79	logfile = sys.stdout
80
81	try:
82	file
83	except NameError:
84	def file(name, mode='r', buffer=0):
85	return open(name, mode, buffer)
86
87	def log(level,msg):
88	if level <= loglevel:
89	logfile.write(msg+'\n')
90
91	def timestamp():
92	return time.strftime('%m/%d/%y %H:%M:%S')+ '-'
93
94	def inttoasc(number):
95	try:
96	hs = hex(number)[2:]
97	except:
98	log(0,'inttoasc cannot convert ' + repr(number))
99	if hs[-1:].upper() == 'L':
100	hs = hs[:-1]
101	result = ''
102	while len(hs) > 2:
103	result = chr(int(hs[-2:],16)) + result
104	hs = hs[:-2]
105	result = chr(int(hs,16)) + result
106
107	return result
108
109	def asctoint(ascnum):
110	rascnum = ''
111	for i in range(len(ascnum)-1,-1,-1):
112	rascnum = rascnum + ascnum[i]
113	result = 0
114	count = 0
115	for c in rascnum:
116	x = ord(c) << (8*count)
117	result = result + x
118	count = count + 1
119
120	return result
121
122	def ipv6net_aton(ip_string):
123	packed_ip = ''
124	# first account for shorthand syntax
125	pieces = ip_string.split(':')
126	pcount = 0
127	for part in pieces:
128	if part != '':
129	pcount = pcount + 1
130	if pcount < 8:
131	rs = '0:'*(8-pcount)
132	ip_string = ip_string.replace('::',':'+rs)
133	if ip_string[0] == ':':
134	ip_string = ip_string[1:]
135	pieces = ip_string.split(':')
136	for part in pieces:
137	# pad with the zeros
138	i = 4-len(part)
139	part = i*'0'+part
140	packed_ip = packed_ip + chr(int(part[:2],16))+ chr(int(part[2:],16))
141	return packed_ip
142
143	def ipv6net_ntoa(packed_ip):
144	ip_string = ''
145	count = 0
146	for c in packed_ip:
147	ip_string = ip_string + hex(ord(c))[2:]
148	count = count + 1
149	if count == 2:
150	ip_string = ip_string + ':'
151	count = 0
152	return ip_string[:-1]
153
154	def getversion(qname, id, rd, ra, versionstr):
155	msg = message()
156	msg.header.id = id
157	msg.header.qr = 1
158	msg.header.aa = 1
159	msg.header.rd = rd
160	msg.header.ra = ra
161	msg.header.rcode = 0
162	msg.question.qname = qname
163	msg.question.qtype = 'TXT'
164	msg.question.qclass = 'CH'
165	if qname == 'version.bind':
166	msg.header.ancount = 2
167	msg.answerlist.append({qname:{'CNAME':[{'cname':'version.oak',
168	'ttl':360000,
169	'class':'CH'}]}})
170	msg.answerlist.append({'version.oak':{'TXT':[{'txtdata':versionstr,
171	'ttl':360000,
172	'class':'CH'}]}})
173	else:
174	msg.header.ancount = 1
175	msg.answerlist.append({qname:{'TXT':[{'txtdata':versionstr,
176	'ttl':360000,
177	'class':'CH'}]}})
178	return msg
179
180	def getrcode(rcode):
181	if rcode == 0:
182	rcodestr = 'NOERROR(No error condition)'
183	elif rcode == 1:
184	rcodestr = 'FORMERR(Format Error)'
185	elif rcode == 2:
186	rcodestr = 'SERVFAIL(Internal failure)'
187	elif rcode == 3:
188	rcodestr = 'NXDOMAIN(Name does not exist)'
189	elif rcode == 4:
190	rcodestr = 'NOTIMP(Not Implemented)'
191	elif rcode == 5:
192	rcodestr = 'REFUSED(Security violation)'
193	elif rcode == 6:
194	rcodestr = 'YXDOMAIN(Name exists)'
195	elif rcode == 7:
196	rcodestr = 'YXRRSET(RR exists)'
197	elif rcode == 8:
198	rcodestr = 'NXRRSET(RR does not exist)'
199	elif rcode == 9:
200	rcodestr = 'NOTAUTH(Server not Authoritative)'
201	elif rcode == 10:
202	rcodestr = 'NOTZONE(Name not in zone)'
203	else:
204	rcodestr = 'Unknown RCODE(' + str(rcode) + ')'
205	return rcodestr
206
207	def printrdata(dnstype, rdata):
208	if dnstype == 'A':
209	return rdata['address']
210	elif dnstype == 'MX':
211	return str(rdata['preference'])+'\t'+rdata['exchange']+'.'
212	elif dnstype == 'NS':
213	return rdata['nsdname']+'.'
214	elif dnstype == 'PTR':
215	return rdata['ptrdname']+'.'
216	elif dnstype == 'CNAME':
217	return rdata['cname']+'.'
218	elif dnstype == 'SOA':
219	return (rdata['mname']+'.\t'+rdata['rname']+'. (\n'+35*' '+str(rdata['serial'])+'\n'+
220	35' '+str(rdata['refresh'])+'\n'+35' '+str(rdata['retry'])+'\n'+35*' '+
221	str(rdata['expire'])+'\n'+35*' '+str(rdata['minimum'])+' )')
222
223	def makezonedatalist(zonedata, origin):
224	# unravel structure into list
225	zonedatalist = []
226	# get soa first
227	soanode = zonedata[origin]
228	zonedatalist.append([origin+'.','SOA',soanode['SOA'][0]])
229	for item in soanode.keys():
230	if item != 'SOA':
231	for listitem in soanode[item]:
232	zonedatalist.append([origin+'.', item, listitem])
233	for nodename in zonedata.keys():
234	if nodename != origin:
235	for item in zonedata[nodename].keys():
236	for listitem in zonedata[nodename][item]:
237	zonedatalist.append([nodename+'.', item, listitem])
238	return zonedatalist
239
240	def writezonefile(zonedata, origin, file):
241	zonedatalist = makezonedatalist(zonedata, origin)
242	for rr in zonedatalist:
243	owner = rr[0]
244	dnstype = rr[1]
245	line = (owner + (35-len(owner))*' ' + str(rr[2]['ttl']) + '\t\tIN\t' +
246	dnstype + '\t' + printrdata(dnstype, rr[2]))
247	file.write(line + '\n')
248
249	def readzonefiles(zonedict):
250	for k in zonedict.keys():
251	filepath = zonedict[k]['filename']
252	try:
253	pr = zonefileparser()
254	pr.parse(zonedict[k]['origin'],filepath)
255	zonedict[k]['zonedata'] = pr.getzdict()
256	except ZonefileError, lineno:
257	log(0,'Error reading zone file ' + filepath + ' at line ' +
258	str(lineno) + '\n')
259	del zonedict[k]
260
261	def slowloop(tofunc='',timeout=5.0):
262	if not tofunc:
263	def tofunc(): return
264	map = asyncore.socket_map
265	while map:
266	r = []; w=[]; e=[]
267	for fd, obj in map.items():
268	if obj.readable():
269	r.append(fd)
270	if obj.writable():
271	w.append(fd)
272	try:
273	starttime = time.time()
274	r,w,e = select.select(r,w,e,timeout)
275	endtime = time.time()
276	if endtime-starttime >= timeout:
277	tofunc()
278	except select.error, err:
279	if err[0] != EINTR:
280	raise
281	r=[]; w=[]; e=[]
282	log(0,'ERROR in select')
283
284	for fd in r:
285	try:
286	obj=map[fd]
287	except KeyError:
288	log(0,'KeyError in socket map')
289	continue
290	try:
291	obj.handle_read_event()
292	except:
293	log(0,'calling HANDLE ERROR from loop')
294	log(0,repr(obj))
295	obj.handle_error()
296	for fd in w:
297	try:
298	obj=map[fd]
299	except KeyError:
300	log(0,'KeyError in socket map')
301	continue
302	try:
303	obj.handle_read_event()
304	except:
305	log(0,'calling HANDLE ERROR from loop')
306	log(0,repr(obj))
307	obj.handle_error()
308
309	def fastloop(tofunc='',timeout=5.0):
310	if not tofunc:
311	def tofunc(): return
312	polltimeout = timeout*1000
313	map = asyncore.socket_map
314	while map:
315	regfds = 0
316	pollobj = select.poll()
317	for fd, obj in map.items():
318	flags = 0
319	if obj.readable():
320	flags = select.POLLIN
321	if obj.writable():
322	flags = flags \| select.POLLOUT
323	if flags:
324	pollobj.register(fd, flags)
325	regfds = regfds + 1
326	try:
327	starttime = time.time()
328	r = pollobj.poll(polltimeout)
329	endtime = time.time()
330	if endtime-starttime >= timeout:
331	tofunc()
332	except select.error, err:
333	if err[0] != EINTR:
334	raise
335	r = []
336	log(0,'ERROR in select')
337	for fd, flags in r:
338	try:
339	obj = map[fd]
340	badvals = (select.POLLPRI + select.POLLERR +
341	select.POLLHUP + select.POLLNVAL)
342	if (flags & badvals):
343	if (flags & select.POLLPRI):
344	log(0,'POLLPRI')
345	if (flags & select.POLLERR):
346	log(0,'POLLERR')
347	if (flags & select.POLLHUP):
348	log(0,'POLLHUP')
349	if (flags & select.POLLNVAL):
350	log(0,'POLLNVAL')
351	obj.handle_error()
352	else:
353	if (flags & select.POLLIN):
354	obj.handle_read_event()
355	if (flags & select.POLLOUT):
356	obj.handle_write_event()
357	except KeyError:
358	log(0,'KeyError in socket map')
359	continue
360	except:
361	# print traceback
362	sf = StringIO.StringIO()
363	traceback.print_exc(file=sf)
364	log(0,'ERROR IN LOOP:')
365	log(0,sf.getvalue())
366	sf.close()
367	log(0,repr(obj))
368	obj.handle_error()
369
370	if hasattr(select,'poll'):
371	loop = fastloop
372	else:
373	loop = slowloop
374
375	class ZonefileError(Exception):
376	def __init__(self, linenum, errordesc=''):
377	self.linenum = linenum
378	self.errordesc = errordesc
379	def __str__(self):
380	return str(self.linenum) + ' (' + self.errordesc + ')'
381
382	class zonefileparser:
383	def __init__(self):
384	self.zonedata = {}
385	self.dnstypes = ['A','AAAA','CNAME','HINFO','LOC','MX',
386	'NS','PTR','RP','SOA','SRV','TXT']
387
388	def stripcomments(self, line):
389	i = line.find(';')
390	if i >= 0:
391	line = line[:i]
392	return line
393
394	def strip(self, line):
395	# strip trailing linefeeds
396	if line[-1:] == '\n':
397	line = line[:-1]
398	return line
399
400	def getzdict(self):
401	return self.zonedata
402
403	def addorigin(self, origin, name):
404	if name[-1:] != '.':
405	return name + '.' + origin
406	else:
407	return name[:-1]
408
409	def getstrings(self, s):
410	if s.find('"') == -1:
411	return s.split()
412	else:
413	x = s.split('"')
414	rlist = []
415	for i in x:
416	if i != '' and i != ' ':
417	rlist.append(i)
418	return rlist
419
420	def getlocsize(self, s):
421	if s[-1:] == 'm':
422	size = float(s[:-1])*100
423	else:
424	size = float(s)*100
425	i = 0
426	while size > 9:
427	size = size/10
428	i = i + 1
429	return (int(size),i)
430
431	def getloclat(self, l,c):
432	deg = float(l[0])
433	min = 0
434	secs = 0
435	if len(l) == 3:
436	min = float(l[1])
437	secs = float(l[2])
438	elif len(l) == 2:
439	min = float(l[1])
440	rval = ((((deg 60) + min) 60) + secs) * 1000
441	if c in ['N','E']:
442	rval = rval + (2**31)
443	elif c in ['S','W']:
444	rval = (2**31) - rval
445	else:
446	log(0,'ERROR: unsupported latitude/longitude direction')
447	return long(rval)
448
449	def getgname(self, name, iter):
450	if name == '0' or name == 'O':
451	return ''
452	start = 0
453	offset = 0
454	width = 0
455	base = 'd'
456	for x in range(name.count('$')):
457	i = name.find('$',start)
458	j = i
459	start = i+1
460	if i>0:
461	if name[i-1] == '\\':
462	continue
463	if len(name)>i+1:
464	if name[i+1] == '$':
465	continue
466	if name[i+1] == '{':
467	j = name.find('}',i+1)
468	owb = name[i+2:j].split(',')
469	if len(owb) == 1:
470	offset = int(owb[0])
471	elif len(owb) == 2:
472	offset = int(owb[0])
473	width = int(owb[1])
474	elif len(owb) == 3:
475	offset = int(owb[0])
476	width = int(owb[1])
477	base = owb[2]
478	val = iter - offset
479	if base == 'd':
480	rs = str(val)
481	elif base == 'o':
482	rs = oct(val)
483	elif base == 'x':
484	rs = hex(val)[2:].lower()
485	elif base == 'X':
486	rs = hex(val)[2:].upper()
487	else:
488	rs = ''
489	if len(rs) > width:
490	rs = (width-len(rs))*'0'+rs
491	name = name[:i]+rs+name[j+1:]
492	start = i+len(rs)+1
493
494	return name
495
496	def getrrdata(self, origin, dnstype, dnsclass, ttl, tokens):
497	rdata = {}
498	rdata['class'] = dnsclass
499	rdata['ttl'] = ttl
500	if dnstype == 'A':
501	rdata['address'] = tokens[0]
502	elif dnstype == 'AAAA':
503	rdata['address'] = tokens[0]
504	elif dnstype == 'CNAME':
505	rdata['cname'] = self.addorigin(origin,tokens[0].lower())
506	elif dnstype == 'HINFO':
507	sl = self.getstrings(' '.join(tokens))
508	rdata['cpu'] = sl[0]
509	rdata['os'] = sl[1]
510	elif dnstype == 'LOC':
511	if 'N' in tokens:
512	i = tokens.index('N')
513	else:
514	i = tokens.index('S')
515	lat = self.getloclat(tokens[0:i],tokens[i])
516	if 'E' in tokens:
517	j = tokens.index('E')
518	else:
519	j = tokens.index('W')
520	lng = self.getloclat(tokens[i+1:j],tokens[j])
521	size = self.getlocsize('1m')
522	horiz_pre = self.getlocsize('1000m')
523	vert_pre = self.getlocsize('10m')
524	if len(tokens[j+1:]) == 2:
525	size = self.getlocsize(tokens[-1:][0])
526	elif len(tokens[j+1:]) == 3:
527	size = self.getlocsize(tokens[-2:-1][0])
528	horiz_pre = self.getlocsize(tokens[-1:][0])
529	elif len(tokens[j+1:]) == 4:
530	size = self.getlocsize(tokens[-3:-2][0])
531	horiz_pre = self.getlocsize(tokens[-2:-1][0])
532	vert_pre = self.getlocsize(tokens[-1:][0])
533	if tokens[j+1][-1:] == 'm':
534	alt = int((float(tokens[j+1][:-1])*100)+10000000)
535	else:
536	size = int((float(tokens[j+1])*100)+10000000)
537	rdata['version'] = 0
538	rdata['size'] = size
539	rdata['horiz_pre'] = horiz_pre
540	rdata['vert_pre'] = vert_pre
541	rdata['latitude'] = lat
542	rdata['longitude'] = lng
543	rdata['altitude'] = 0
544	elif dnstype == 'MX':
545	rdata['preference'] = int(tokens[0])
546	rdata['exchange'] = self.addorigin(origin,tokens[1].lower())
547	elif dnstype == 'NS':
548	rdata['nsdname'] = self.addorigin(origin,tokens[0].lower())
549	elif dnstype == 'PTR':
550	rdata['ptrdname'] = self.addorigin(origin,tokens[0].lower())
551	elif dnstype == 'RP':
552	rdata['mboxdname'] = self.addorigin(origin,tokens[0].lower())
553	rdata['txtdname'] = self.addorigin(origin,tokens[1].lower())
554	elif dnstype == 'SOA':
555	rdata['mname'] = self.addorigin(origin,tokens[0].lower())
556	rdata['rname'] = self.addorigin(origin,tokens[1].lower())
557	rdata['serial'] = int(tokens[2])
558	rdata['refresh'] = int(tokens[3])
559	rdata['retry'] = int(tokens[4])
560	rdata['expire'] = int(tokens[5])
561	rdata['minimum'] = int(tokens[6])
562	elif dnstype == 'SRV':
563	rdata['priority'] = int(tokens[0])
564	rdata['weight'] = int(tokens[1])
565	rdata['port'] = int(tokens[2])
566	rdata['target'] = self.addorigin(origin,tokens[3].lower())
567	elif dnstype == 'TXT':
568	rdata['txtdata'] = self.getstrings(' '.join(tokens))[0]
569	else:
570	raise ZonefileError(lineno,'bad DNS type')
571	return rdata
572
573	def addrec(self, owner, dnstype, rrdata):
574	if self.zonedata.has_key(owner):
575	if not self.zonedata[owner].has_key(dnstype):
576	self.zonedata[owner][dnstype] = []
577	else:
578	self.zonedata[owner] = {}
579	self.zonedata[owner][dnstype] = []
580	self.zonedata[owner][dnstype].append(rrdata)
581
582	def parse(self, origin, f):
583	closefile = 0
584	if type(f) != types.FileType:
585	# must be a path
586	try:
587	f = file(f)
588	closefile = 1
589	except:
590	log(0,'Invalid path to zonefile')
591	return
592	lastowner = ''
593	lastdnsclass = ''
594	lastttl = 3600
595	lineno = 0
596	while 1:
597	line = f.readline()
598	if not line:
599	break
600	lineno = lineno + 1
601	line = self.stripcomments(line)
602	line = self.strip(line)
603	if not line:
604	continue
605	if line.find('(') >= 0:
606	# grab lines until end paren
607	if line.find(')') == -1:
608	line2 = self.stripcomments(f.readline())
609	lineno = lineno + 1
610	line2 = self.strip(line2)
611	line = line + line2
612	while line2.find(')') == -1:
613	line2 = self.strip(self.stripcomments(f.readline()))
614	lineno = lineno + 1
615	line = line + line2
616	# now strip the parenthesis
617	line = line.replace(')','')
618	line = line.replace('(','')
619	# now line equals the entire RR entry
620	tokens = line.split()
621	if tokens[0].upper() == '$ORIGIN':
622	try:
623	origin = tokens[1].lower()
624	except:
625	raise ZonefileError(lineno, 'bad origin')
626	elif tokens[0].upper() == '$INCLUDE':
627	try:
628	f2 = file(tokens[1].lower())
629	if len(tokens) > 2:
630	self.parse(tokens[2].lower(), f2)
631	else:
632	self.parse(origin, f2)
633	f2.close()
634	except:
635	raise ZonefileError(lineno, 'bad INCLUDE directive')
636	elif tokens[0].upper() == '$TTL':
637	try:
638	lastttl = int(tokens[1])
639	except:
640	raise ZonefileError(lineno, 'bad TTL directive')
641	elif tokens[0].upper() == '$GENERATE':
642	try:
643	lhs = tokens[2].lower()
644	dnstype = tokens[3].upper()
645	rhs = tokens[4].lower()
646	rng = tokens[1].split('-')
647	start = int(rng[0])
648	i = rng[1].find('/')
649	if i != -1:
650	stop = int(rng[1][:i])+1
651	step = int(rng[1][i+1:])
652	else:
653	stop = int(rng[1])+1
654	step = 1
655	for i in range(start,stop,step):
656	grhs = self.getgname(rhs,i)
657	if dnstype in ['NS','CNAME','PTR']:
658	grhs = self.addorigin(origin,grhs)
659	rrdata = self.getrrdata(origin, dnstype, 'IN', lastttl,
660	[grhs])
661	glhs = self.addorigin(origin,self.getgname(lhs,i))
662	self.addrec(glhs,dnstype, rrdata)
663	except KeyError:
664	raise ZonefileError(lineno, 'bad GENERATE directive')
665	else:
666	try:
667	# if line begins with blank then owner is last owner
668	if line[0] in string.whitespace:
669	owner = lastowner
670	else:
671	owner = tokens[0].lower()
672	tokens = tokens[1:]
673	if owner == '@':
674	owner = origin
675	elif owner[-1:] != '.':
676	owner = owner + '.' + origin
677	else:
678	owner = owner[:-1] # strip off trailing dot
679	# line format is either: [class] [ttl] type RDATA
680	# or [ttl] [class] type RDATA
681	# - items in brackets are optional
682	#
683	# need to figure out which token is type
684	# and backfill the missing data
685	count = 0
686	for token in tokens:
687	if token.upper() in self.dnstypes:
688	break
689	count = count + 1
690	# the following strips off the ttl and class if they exist
691	if count == 0:
692	ttl = lastttl
693	dnsclass = lastdnsclass
694	elif count == 1:
695	if tokens[0].isdigit():
696	ttl = int(tokens[0])
697	dnsclass = lastdnsclass
698	else:
699	ttl = lastttl
700	dnsclass = tokens[0].upper()
701	tokens = tokens[1:]
702	elif count == 2:
703	if tokens[0].isdigit():
704	ttl = int(tokens[0])
705	dnsclass = tokens[1].upper()
706	else:
707	ttl = int(tokens[1])
708	dnsclass = tokens[0].upper()
709	tokens = tokens[2:]
710	else:
711	raise ZonefileError(lineno,'bad ttl or class')
712	dnstype = tokens[0]
713	# make sure all of the structure is there
714	rrdata = self.getrrdata(origin, dnstype, dnsclass,
715	ttl, tokens[1:])
716	self.addrec(owner, dnstype, rrdata)
717	lastowner = owner
718	lastttl = ttl
719	lastdnsclass = dnsclass
720	except:
721	raise ZonefileError(lineno,'unable to parse line')
722	if closefile:
723	f.close()
724
725	class dnsconfig:
726	def __init__(self):
727	# self.zonedb = zonedb({})
728	self.cached = {}
729	self.loglevel = 0
730
731	def getview(self, msg, address, port):
732	# return:
733	# 1. a list of zone keys
734	# 2. whether or not to use the resolver
735	# (i.e. answer recursive queries)
736	# 3. a list of forwarder addresses
737	return ['servers.csail.mit.edu'], 1, []
738
739	def allowupdate(self, msg, address, port):
740	# return 1 if updates are allowed
741	# NOTE: can only update the zones
742	# returned by the getview func
743	return 1
744
745	def outpackets(self, packetlist):
746	# modify outgoing packets
747	return packetlist
748
749	class dnsheader:
750	def __init__(self, id=1):
751	self.id = id # 16bit identifier generated by queryer
752	self.qr = 0 # one bit field specifying query(0) or response(1)
753	self.opcode = 0 # 4bit field specifying type of query
754	self.aa = 0 # authoritative answer
755	self.tc = 0 # message is not truncated
756	self.rd = 1 # recursion desired
757	self.ra = 0 # recursion available?
758	self.z = 0 # reserved for future use
759	self.rcode = 0 # response code (set in response)
760	self.qdcount = 1 # number of questions, only 1 is supported
761	self.ancount = 0 # number of rrs in the answer section
762	self.nscount = 0 # number of name server rrs in authority section
763	self.arcount = 0 # number or rrs in the additional section
764
765	class dnsquestion:
766	def __init__(self):
767	self.qname = 'localhost'
768	self.qtype = 'A'
769	self.qclass = 'IN'
770
771	class dnsupdatezone:
772	pass
773
774	class message:
775	def __init__(self, msgdata=''):
776	if msgdata:
777	self.header = dnsheader()
778	else:
779	self.header = dnsheader(id=random.randrange(1,32768))
780	self.question = dnsquestion()
781	self.answerlist = []
782	self.authlist = []
783	self.addlist = []
784	self.u = ''
785	self.qtypes = {1:'A',2:'NS',3:'MD',4:'MF',5:'CNAME',6:'SOA',
786	7:'MB',8:'MG',9:'MR',10:'NULL',11:'WKS',
787	12:'PTR',13:'HINFO',14:'MINFO',15:'MX',
788	16:'TXT',17:'RP',28:'AAAA',29:'LOC',33:'SRV',
789	38:'A6',39:'DNAME',251:'IXFR',252:'AXFR',
790	253:'MAILB',254:'MAILA',255:'ANY'}
791	self.rqtypes = {}
792	for key in self.qtypes.keys():
793	self.rqtypes[self.qtypes[key]] = key
794	self.qclasses = {1:'IN',2:'CS',3:'CH',4:'HS',254:'NONE',255:'ANY'}
795	self.rqclasses = {}
796	for key in self.qclasses.keys():
797	self.rqclasses[self.qclasses[key]] = key
798
799	if msgdata:
800	self.processpkt(msgdata)
801
802	def getdomainname(self, data, i):
803	log(4,'IN GETDOMAINNAME')
804	domainname = ''
805	gotpointer = 0
806	labellength= ord(data[i])
807	log(4,'labellength:' + str(labellength))
808	i = i + 1
809	while labellength != 0:
810	while labellength >= 192:
811	# pointer
812	if not gotpointer:
813	rindex = i + 1
814	gotpointer = 1
815	log(4,'got pointer')
816	i = asctoint(chr(ord(data[i-1]) & 63)+data[i])
817	log(4,'new index:'+str(i))
818	labellength = ord(data[i])
819	log(4,'labellength:' + str(labellength))
820	i = i + 1
821	if domainname:
822	domainname = domainname + '.' + data[i:i+labellength]
823	else:
824	domainname = data[i:i+labellength]
825	log(4,'domainname:'+domainname)
826	i = i + labellength
827	labellength = ord(data[i])
828	log(4,'labellength:' + str(labellength))
829	i = i + 1
830	if not gotpointer:
831	rindex = i
832
833	return domainname.lower(), rindex
834
835	def getrrdata(self, type, msgdata, rdlength, i):
836	log(4,'unpacking RR data')
837	rdata = msgdata[i:i+rdlength]
838	if type == 'A':
839	return {'address':socket.inet_ntoa(rdata)}
840	elif type == 'AAAA':
841	return {'address':ipv6net_ntoa(rdata)}
842	elif type == 'CNAME':
843	cname, i = self.getdomainname(msgdata,i)
844	return {'cname':cname}
845	elif type == 'HINFO':
846	cpulen = ord(rdata[0])
847	cpu = rdata[1:cpulen+1]
848	return {'cpu':cpu,
849	'os':rdata[cpulen+2:]}
850	elif type == 'LOC':
851	return {'version':ord(rdata[0]),
852	'size':self.locsize(rdata[1]),
853	'horiz_pre':self.locsize(rdata[2]),
854	'vert_pre':self.locsize(rdata[3]),
855	'latitude':asctoint(rdata[4:8]),
856	'longitude':asctoint(rdata[8:12]),
857	'altitude':asctoint(rdata[12:16])}
858	elif type == 'MX':
859	exchange, i = self.getdomainname(msgdata,i+2)
860	return {'preference':asctoint(rdata[:2]),
861	'exchange':exchange}
862	elif type == 'NS':
863	nsdname, i = self.getdomainname(msgdata,i)
864	return {'nsdname':nsdname}
865	elif type == 'PTR':
866	ptrdname, i = self.getdomainname(msgdata,i)
867	return {'ptrdname':ptrdname}
868	elif type == 'RP':
869	mboxdname, i = self.getdomainname(msgdata,i)
870	txtdname, i = self.getdomainname(msgdata,i)
871	return {'mboxdname':mboxdname,
872	'txtdname':txtdname}
873	elif type == 'SOA':
874	mname, i = self.getdomainname(msgdata,i)
875	rname, i = self.getdomainname(msgdata,i)
876	return {'mname':mname,
877	'rname':rname,
878	'serial':asctoint(msgdata[i:i+4]),
879	'refresh':asctoint(msgdata[i+4:i+8]),
880	'retry':asctoint(msgdata[i+8:i+12]),
881	'expire':asctoint(msgdata[i+12:i+16]),
882	'minimum':asctoint(msgdata[i+16:i+20])}
883	elif type == 'SRV':
884	target, i = self.getdomainname(msgdata,i+6)
885	return {'priority':asctoint(rdata[0:2]),
886	'weight':asctoint(rdata[2:4]),
887	'port':asctoint(rdata[4:6]),
888	'target':target}
889	elif type == 'TXT':
890	return {'txtdata':rdata[1:]}
891	else:
892	return {'rdata':rdata}
893
894	def getrr(self, data, i):
895	log(4,'unpacking RR name')
896	name, i = self.getdomainname(data, i)
897	type = asctoint(data[i:i+2])
898	type = self.qtypes.get(type,chr(type))
899	klass = asctoint(data[i+2:i+4])
900	klass = self.qclasses.get(klass,chr(klass))
901	ttl = asctoint(data[i+4:i+8])
902	rdlength = asctoint(data[i+8:i+10])
903	rrdata = self.getrrdata(type,data,rdlength,i+10)
904	rrdata['ttl'] = ttl
905	rrdata['class'] = klass
906	rr = {name:{type:[rrdata]}}
907	return rr, i+10+rdlength
908
909	def processpkt(self, msgdata):
910	self.header.id = asctoint(msgdata[:2])
911	self.header.qr = ord(msgdata[2]) >> 7
912	self.header.opcode = (ord(msgdata[2]) & 127) >> 3
913	if self.header.opcode == 5:
914	# UPDATE packet
915	log(4,'processing UPDATE packet')
916	del self.header.aa
917	del self.header.tc
918	del self.header.rd
919	del self.header.ra
920	del self.header.qdcount
921	del self.header.ancount
922	del self.header.nscount
923	del self.header.arcount
924	del self.question
925	self.zone = dnsupdatezone()
926	del self.answerlist
927	del self.authlist
928	del self.addlist
929	self.header.z = 0
930	self.header.rcode = ord(msgdata[3]) & 15
931	self.header.zocount = asctoint(msgdata[4:6])
932	self.header.prcount = asctoint(msgdata[6:8])
933	self.header.upcount = asctoint(msgdata[8:10])
934	self.header.arcount = asctoint(msgdata[10:12])
935	self.zolist = []
936	self.prlist = []
937	self.uplist = []
938	self.addlist = []
939	i = 12
940	for x in range(self.header.zocount):
941	(dn, i) = self.getdomainname(msgdata,i)
942	self.zone.zname = dn
943	type = asctoint(msgdata[i:i+2])
944	self.zone.ztype = self.qtypes.get(type,chr(type))
945	klass = asctoint(msgdata[i+2:i+4])
946	self.zone.zclass = self.qclasses.get(klass,chr(klass))
947	i = i + 4
948	for x in range(self.header.prcount):
949	rr, i = self.getrr(msgdata,i)
950	self.prlist.append(rr)
951	for x in range(self.header.upcount):
952	rr, i = self.getrr(msgdata,i)
953	self.uplist.append(rr)
954	for x in range(self.header.arcount):
955	rr, i = self.getrr(msgdata,i)
956	self.adlist.append(rr)
957	else:
958	self.header.aa = (ord(msgdata[2]) & 4) >> 2
959	self.header.tc = (ord(msgdata[2]) & 2) >> 1
960	self.header.rd = ord(msgdata[2]) & 1
961	self.header.ra = ord(msgdata[3]) >> 7
962	self.header.z = (ord(msgdata[3]) & 112) >> 4
963	self.header.rcode = ord(msgdata[3]) & 15
964	self.header.qdcount = asctoint(msgdata[4:6])
965	self.header.ancount = asctoint(msgdata[6:8])
966	self.header.nscount = asctoint(msgdata[8:10])
967	self.header.arcount = asctoint(msgdata[10:12])
968	i = 12
969	for x in range(self.header.qdcount):
970	log(4,'unpacking question')
971	(dn, i) = self.getdomainname(msgdata,i)
972	self.question.qname = dn
973	rrtype = asctoint(msgdata[i:i+2])
974	self.question.qtype = self.qtypes.get(rrtype,chr(rrtype))
975	klass = asctoint(msgdata[i+2:i+4])
976	self.question.qclass = self.qclasses.get(klass,chr(klass))
977	i = i + 4
978	for x in range(self.header.ancount):
979	log(4,'unpacking answer RR')
980	rr, i = self.getrr(msgdata,i)
981	self.answerlist.append(rr)
982	for x in range(self.header.nscount):
983	log(4,'unpacking auth RR')
984	rr, i = self.getrr(msgdata,i)
985	self.authlist.append(rr)
986	for x in range(self.header.arcount):
987	log(4,'unpacking additional RR')
988	rr, i = self.getrr(msgdata,i)
989	self.addlist.append(rr)
990	return
991
992	def pds(self, s, l):
993	# pad string with chr(0)'s so that
994	# return string length is l
995	x = l - len(s)
996	return x*chr(0) + s
997
998	def locsize(self, s):
999	x1 = ord(s) >> 4
1000	x2 = ord(s) & 15
1001	return (x1, x2)
1002
1003	def packlocsize(self, x):
1004	return chr((x[0] << 4) + x[1])
1005
1006	def packdomainname(self, name, i, msgcomp):
1007	log(4,'packing domainname: ' + name)
1008	if name == '':
1009	return chr(0)
1010	if name in msgcomp.keys():
1011	log(4,'using pointer for: ' + name)
1012	return msgcomp[name]
1013	packedname = ''
1014	tokens = name.split('.')
1015	for j in range(len(tokens)):
1016	packedname = packedname + chr(len(tokens[j])) + tokens[j]
1017	nameleft = '.'.join(tokens[j+1:])
1018	if nameleft in msgcomp.keys():
1019	log(4,'using pointer for: ' + nameleft)
1020	return packedname+msgcomp[nameleft]
1021	# haven't used a pointer so put this in the dictionary
1022	pointer = inttoasc(i)
1023	if len(pointer) == 1:
1024	msgcomp[name] = chr(192)+pointer
1025	else:
1026	msgcomp[name] = chr(192\|ord(pointer[0])) + pointer[1]
1027	log(4,'added pointer for ' + name + '(' + str(i) + ')')
1028	return packedname + chr(0)
1029
1030	def packrr(self, rr, i, msgcomp):
1031	rrname = rr.keys()[0]
1032	rrtype = rr[rrname].keys()[0]
1033	if self.rqtypes.has_key(rrtype):
1034	typeval = self.rqtypes[rrtype]
1035	else:
1036	typeval = ord(rrtype)
1037	dbrec = rr[rrname][rrtype][0]
1038	ttl = dbrec['ttl']
1039	rclass = self.rqclasses[dbrec['class']]
1040	packedrr = (self.packdomainname(rrname, i, msgcomp) +
1041	self.pds(inttoasc(typeval),2) +
1042	self.pds(inttoasc(rclass),2) +
1043	self.pds(inttoasc(ttl),4))
1044	i = i + len(packedrr) + 2
1045	if rrtype == 'A':
1046	rdata = socket.inet_aton(dbrec['address'])
1047	elif rrtype == 'AAAA':
1048	rdata = ipv6net_aton(dbrec['address'])
1049	elif rrtype == 'CNAME':
1050	rdata = self.packdomainname(dbrec['cname'], i, msgcomp)
1051	elif rrtype == 'HINFO':
1052	rdata = (chr(len(dbrec['cpu'])) + dbrec['cpu'] +
1053	chr(len(dbrec['os'])) + dbrec['os'])
1054	elif rrtype == 'LOC':
1055	rdata = (chr(dbrec['version']) +
1056	self.packlocsize(dbrec['size']) +
1057	self.packlocsize(dbrec['horiz_pre']) +
1058	self.packlocsize(dbrec['vert_pre']) +
1059	self.pds(inttoasc(dbrec['latitude']),4) +
1060	self.pds(inttoasc(dbrec['longitude']),4) +
1061	self.pds(inttoasc(dbrec['altitude']),4))
1062	elif rrtype == 'MX':
1063	rdata = (self.pds(inttoasc(dbrec['preference']),2) +
1064	self.packdomainname(dbrec['exchange'], i+2, msgcomp))
1065	elif rrtype == 'NS':
1066	rdata = self.packdomainname(dbrec['nsdname'], i, msgcomp)
1067	elif rrtype == 'PTR':
1068	rdata = self.packdomainname(dbrec['ptrdname'], i, msgcomp)
1069	elif rrtype == 'RP':
1070	rdata1 = self.packdomainname(dbrec['mboxdname'], i , msgcomp)
1071	i = i + len(rdata1)
1072	rdata2 = self.packdomainname(dbrec['mboxdname'], i , msgcomp)
1073	rdata = rdata1 + rdata2
1074	elif rrtype == 'SOA':
1075	rdata1 = self.packdomainname(dbrec['mname'], i, msgcomp)
1076	i = i + len(rdata1)
1077	rdata2 = self.packdomainname(dbrec['rname'], i, msgcomp)
1078	rdata = (rdata1 +
1079	rdata2 +
1080	self.pds(inttoasc(dbrec['serial']),4) +
1081	self.pds(inttoasc(dbrec['refresh']),4) +
1082	self.pds(inttoasc(dbrec['retry']),4) +
1083	self.pds(inttoasc(dbrec['expire']),4) +
1084	self.pds(inttoasc(dbrec['minimum']),4))
1085	elif rrtype == 'SRV':
1086	rdata = (self.pds(inttoasc(dbrec['priority']),2) +
1087	self.pds(inttoasc(dbrec['weight']),2) +
1088	self.pds(inttoasc(dbrec['port']),2) +
1089	self.packdomainname(dbrec['target'], i+6, msgcomp))
1090	elif rrtype == 'TXT':
1091	rdata = chr(len(dbrec['txtdata'])) + dbrec['txtdata']
1092	else:
1093	rdata = dbrec['rdata']
1094
1095	return packedrr+self.pds(inttoasc(len(rdata)),2)+rdata
1096
1097	def buildpkt(self):
1098	# keep dictionary of names packed (so we can use pointers)
1099	msgcomp = {}
1100	# header
1101	if self.header.id > 65535:
1102	log(0,'building packet with bad ID field')
1103	self.header.id = 1
1104	msgdata = inttoasc(self.header.id)
1105	if len(msgdata) == 1:
1106	msgdata = chr(0) + msgdata
1107	h1 = ((self.header.qr << 7) +
1108	(self.header.opcode << 3) +
1109	(self.header.aa << 2) +
1110	(self.header.tc << 1) +
1111	(self.header.rd))
1112	h2 = ((self.header.ra << 7) +
1113	(self.header.z << 4) +
1114	(self.header.rcode))
1115	msgdata = msgdata + chr(h1) + chr(h2)
1116	msgdata = msgdata + self.pds(inttoasc(self.header.qdcount),2)
1117	msgdata = msgdata + self.pds(inttoasc(self.header.ancount),2)
1118	msgdata = msgdata + self.pds(inttoasc(self.header.nscount),2)
1119	msgdata = msgdata + self.pds(inttoasc(self.header.arcount),2)
1120	# question
1121	msgdata = msgdata + self.packdomainname(self.question.qname, len(msgdata), msgcomp)
1122	if self.rqtypes.has_key(self.question.qtype):
1123	typeval = self.rqtypes[self.question.qtype]
1124	else:
1125	typeval = ord(self.question.qtype)
1126	msgdata = msgdata + self.pds(inttoasc(typeval),2)
1127	if self.rqclasses.has_key(self.question.qclass):
1128	classval = self.rqclasses[self.question.qclass]
1129	else:
1130	classval = ord(self.question.qclass)
1131	msgdata = msgdata + self.pds(inttoasc(classval),2)
1132	# rr's
1133	# RR record format:
1134	# {'name' : {'type' : [rdata, rdata, ...]}
1135	# example: {'test.blah.net': {'A': [{'address': '10.1.1.2',
1136	# 'ttl': 3600L}]}}
1137	for rr in self.answerlist:
1138	log(4,'packing answer RR')
1139	msgdata = msgdata + self.packrr(rr, len(msgdata), msgcomp)
1140	for rr in self.authlist:
1141	log(4,'packing auth RR')
1142	msgdata = msgdata + self.packrr(rr, len(msgdata), msgcomp)
1143	for rr in self.addlist:
1144	log(4,'packing additional RR')
1145	msgdata = msgdata + self.packrr(rr, len(msgdata), msgcomp)
1146
1147	return msgdata
1148
1149	def printpkt(self):
1150	print 'ID: ' +str(self.header.id)
1151	if self.header.qr:
1152	print 'QR: RESPONSE'
1153	else:
1154	print 'QR: QUERY'
1155	if self.header.opcode == 0:
1156	print 'OPCODE: STANDARD QUERY'
1157	elif self.header.opcode == 1:
1158	print 'OPCODE: INVERSE QUERY'
1159	elif self.header.opcode == 2:
1160	print 'OPCODE: SERVER STATUS REQUEST'
1161	elif self.header.opcode == 5:
1162	print 'UPDATE REQUEST'
1163	else:
1164	print 'OPCODE: UNKNOWN QUERY TYPE'
1165	if self.header.opcode != 5:
1166	if self.header.aa:
1167	print 'AA: AUTHORITATIVE ANSWER'
1168	else:
1169	print 'AA: NON-AUTHORITATIVE ANSWER'
1170	if self.header.tc:
1171	print 'TC: MESSAGE IS TRUNCATED'
1172	else:
1173	print 'TC: MESSAGE IS NOT TRUNCATED'
1174	if self.header.rd:
1175	print 'RD: RECURSION DESIRED'
1176	else:
1177	print 'RD: RECURSION NOT DESIRED'
1178	if self.header.ra:
1179	print 'RA: RECURSION AVAILABLE'
1180	else:
1181	print 'RA: RECURSION IS NOT AVAILABLE'
1182	if self.header.rcode == 1:
1183	printrcode = 'FORMERR'
1184	elif self.header.rcode == 2:
1185	printrcode = 'SERVFAIL'
1186	elif self.header.rcode == 3:
1187	printrcode = 'NXDOMAIN'
1188	elif self.header.rcode == 4:
1189	printrcode = 'NOTIMP'
1190	elif self.header.rcode == 5:
1191	printrcode = 'REFUSED'
1192	elif self.header.rcode == 6:
1193	printrcode = 'YXDOMAIN'
1194	elif self.header.rcode == 7:
1195	printrcode = 'YXRRSET'
1196	elif self.header.rcode == 8:
1197	printrcode = 'NXRRSET'
1198	elif self.header.rcode == 9:
1199	printrcode = 'NOTAUTH'
1200	elif self.header.rcode == 10:
1201	printrcode = 'NOTZONE'
1202	else:
1203	printrcode = 'NOERROR'
1204	print 'RCODE: ' + printrcode
1205	if self.header.opcode == 5:
1206	print 'NUMBER OF RRs in the Zone Section: ' + str(self.header.zocount)
1207	print 'NUMBER OF RRs in the Prerequisite Section: ' + str(self.header.prcount)
1208	print 'NUMBER OF RRs in the Update Section: ' + str(self.header.upcount)
1209	print 'NUMBER OF RRs in the Additional Data Section: ' + str(self.header.arcount)
1210	print 'ZONE SECTION:'
1211	print 'zname: ' + self.zone.zname
1212	print 'zonetype: ' + self.zone.ztype
1213	print 'zoneclass: ' + self.zone.zclass
1214	print 'PREREQUISITE RRs:'
1215	for rr in self.prlist:
1216	print rr
1217	print 'UPDATE RRs:'
1218	for rr in self.uplist:
1219	print rr
1220	print 'ADDITIONAL RRs:'
1221	for rr in self.addlist:
1222	print rr
1223
1224
1225	else:
1226	print 'NUMBER OF QUESTION RRs: ' + str(self.header.qdcount)
1227	print 'NUMBER OF ANSWER RRs: ' + str(self.header.ancount)
1228	print 'NUMBER OF NAME SERVER RRs: ' + str(self.header.nscount)
1229	print 'NUMBER OF ADDITIONAL RRs: ' + str(self.header.arcount)
1230	print 'QUESTION SECTION:'
1231	print 'qname: ' + self.question.qname
1232	print 'querytype: ' + self.question.qtype
1233	print 'queryclass: ' + self.question.qclass
1234	print 'ANSWER RRs:'
1235	for rr in self.answerlist:
1236	print rr
1237	print 'AUTHORITY RRs:'
1238	for rr in self.authlist:
1239	print rr
1240	print 'ADDITIONAL RRs:'
1241	for rr in self.addlist:
1242	print rr
1243
1244	class zonedb:
1245	def __init__(self, zdict):
1246	self.zdict = zdict
1247	self.updates = {}
1248	for k in self.zdict.keys():
1249	if self.zdict[k]['type'] == 'slave':
1250	self.zdict[k]['lastupdatetime'] = 0
1251
1252	def error(self, id, qname, querytype, queryclass, rcode):
1253	error = message()
1254	error.header.id = id
1255	error.header.rcode = rcode
1256	error.header.qr = 1
1257	error.question.qname = qname
1258	error.question.qtype = querytype
1259	error.question.qclass = queryclass
1260	return error
1261
1262	def getorigin(self, zkey):
1263	origin = ''
1264	if self.zdict.has_key(zkey):
1265	origin = self.zdict[zkey]['origin']
1266	return origin
1267
1268	def getmasterip(self, zkey):
1269	masterip = ''
1270	if self.zdict.has_key(zkey):
1271	if self.zdict[zkey].has_key('masterip'):
1272	masterip = self.zdict[zkey]['masterip']
1273	return masterip
1274
1275	def zonetrans(self, query):
1276	# build a list of messages
1277	# each message contains one rr of the zone
1278	# the first and last message are the
1279	# SOA records
1280	origin = query.question.qname
1281	querytype = query.question.qtype
1282	zkey = ''
1283	for zonekey in self.zdict.keys():
1284	if self.zdict[zonekey]['origin'] == query.question.qname:
1285	zkey = zonekey
1286	if not zkey:
1287	return []
1288	zonedata = self.zdict[zkey]['zonedata']
1289	queryid = query.header.id
1290	soarec = zonedata[origin]['SOA'][0]
1291	soa = {origin:{'SOA':[soarec]}}
1292	curserial = soarec['serial']
1293	rrlist = []
1294	if querytype == 'IXFR':
1295	clientserial = query.authlist[0][origin]['SOA'][0]['serial']
1296	if clientserial < curserial:
1297	for i in range(clientserial,curserial+1):
1298	if self.updates[zkey].has_key(i):
1299	for rr in self.updates[zkey][i]['added']:
1300	rrlist.append(rr)
1301	for rr in self.updates[zkey][i]['removed']:
1302	rrlist.append(rr)
1303	if len(rrlist) > 0:
1304	rrlist.insert(0,soa)
1305	rrlist.append(soa)
1306	else:
1307	rrlist.append(soa)
1308	else:
1309	for nodename in zonedata.keys():
1310	for rrtype in zonedata[nodename].keys():
1311	if not (rrtype == 'SOA' and nodename == origin):
1312	for rr in zonedata[nodename][rrtype]:
1313	rrlist.append({nodename:{rrtype:[rr]}})
1314	rrlist.insert(0,soa)
1315	rrlist.append(soa)
1316	msglist = []
1317	for rr in rrlist:
1318	msg = message()
1319	msg.header.id = queryid
1320	msg.header.qr = 1
1321	msg.header.aa = 1
1322	msg.header.rd = 0
1323	msg.header.qdcount = 1
1324	msg.question.qname = origin
1325	msg.question.qtype = querytype
1326	msg.question.qclass = 'IN'
1327	msg.header.ancount = 1
1328	msg.answerlist.append(rr)
1329	msglist.append(msg)
1330	return msglist
1331
1332	def update_zone(self, rrlist, params):
1333	zonekey = params[0]
1334	zonedata = {}
1335	soa = rrlist.pop()
1336	origin = soa.keys()[0]
1337	for rr in rrlist:
1338	rrname = rr.keys()[0]
1339	rrtype = rr[rrname].keys()[0]
1340	dbrec = rr[rrname][rrtype][0]
1341	if zonedata.has_key(rrname):
1342	if not zonedata[rrname].has_key(rrtype):
1343	zonedata[rrname][rrtype] = []
1344	else:
1345	zonedata[rrname] = {}
1346	zonedata[rrname][rrtype] = []
1347	zonedata[rrname][rrtype].append(dbrec)
1348	self.zdict[zonekey]['zonedata'] = zonedata
1349	curtime = time.time()
1350	self.zdict[zonekey]['lastupdatetime'] = curtime
1351	try:
1352	f = file(self.zdict[zonekey]['filename'],'w')
1353	writezonefile(zonedata, self.zdict[zonekey]['origin'], f)
1354	f.close()
1355	except:
1356	log(0,'unable to write zone ' + zonekey + 'to disk')
1357	log(1,'finished zone transfer for: ' + zonekey + ' (' + str(curtime) + ')')
1358
1359	def remove_zone(self, zonekey):
1360	if self.zdict.has_key(zonekey):
1361	del self.zdict[zonekey]
1362
1363	def getslaves(self, curtime):
1364	rlist = []
1365	for k in self.zdict.keys():
1366	if self.zdict[k]['type'] == 'slave':
1367	origin = self.zdict[k]['origin']
1368	refresh = self.zdict[k]['zonedata'][origin]['SOA'][0]['refresh']
1369	if self.zdict[k]['lastupdatetime'] + refresh < curtime:
1370	rlist.append((k, origin, self.zdict[k]['masterip']))
1371	return rlist
1372
1373	def zmatch(self, qname, zkeys):
1374	for zkey in zkeys:
1375	if self.zdict.has_key(zkey):
1376	origin = self.zdict[zkey]['origin']
1377	if qname.rfind(origin) != -1:
1378	return zkey
1379	return ''
1380
1381	def getzlist(self, name, zone):
1382	if name == zone:
1383	return
1384	zlist = []
1385	i = name.rfind(zone)
1386	if i == -1:
1387	return
1388	firstpart = name[:i-1]
1389	partlist = firstpart.split('.')
1390	partlist.reverse()
1391	lastpart = zone
1392	for x in range(len(partlist)):
1393	lastpart = partlist[x] + '.' + lastpart
1394	zlist.append(lastpart)
1395	return zlist
1396
1397	def lookup(self, zkeys, query, addr, server, dorecursion, flist, cbfunc):
1398	# handle zone transfers seperately
1399	qname = query.question.qname
1400	querytype = query.question.qtype
1401	queryclass = query.question.qclass
1402	if querytype in ['AXFR','IXFR']:
1403	for zkey in self.zdict.keys():
1404	if zkey in zkeys:
1405	if qname == self.zdict[zkey]['origin']:
1406	answerlist = self.zonetrans(query)
1407	break
1408	else:
1409	answerlist = []
1410	cbfunc(query, addr, server, dorecursion, flist, answerlist)
1411	else:
1412	zonekey = self.zmatch(qname, zkeys)
1413	if zonekey:
1414	origin = self.zdict[zonekey]['origin']
1415	zonedict = self.zdict[zonekey]['zonedata']
1416	referral = 0
1417	rranswerlist = []
1418	rrnslist = []
1419	rraddlist = []
1420	answer = message()
1421	answer.header.aa = 1
1422	answer.header.id = query.header.id
1423	answer.header.qr = 1
1424	answer.header.opcode = query.header.opcode
1425	answer.header.rcode = 4
1426	answer.header.ra = dorecursion
1427	answer.question.qname = query.question.qname
1428	answer.question.qtype = query.question.qtype
1429	answer.question.qclass = query.question.qclass
1430	answer.header.ra = dorecursion
1431	s = '.servers.csail.mit.edu'
1432	if qname.endswith(s):
1433	host = qname[:-len(s)]
1434	value = sipb_xen_database.NIC.get_by(hostname=host)
1435	if value is None:
1436	pass
1437	else:
1438	ip = value.ip
1439	rranswerlist.append({qname: {'A': [{'address': ip,
1440	'class': 'IN',
1441	'ttl': 10}]}})
1442	if zonedict.has_key(qname):
1443	# found the node, now take care of CNAMEs
1444	if zonedict[qname].has_key('CNAME'):
1445	if querytype != 'CNAME':
1446	nodetype = 'CNAME'
1447	while nodetype == 'CNAME':
1448	rranswerlist.append({qname:{'CNAME':[zonedict[qname]['CNAME'][0]]}})
1449	qname = zonedict[qname]['CNAME'][0]['cname']
1450	if zonedict.has_key(qname):
1451	nodetype = zonedict[qname].keys()[0]
1452	else:
1453	# error, shouldn't have a CNAME that points to nothing
1454	return
1455	# if we get this far, then the record has matched and we should return
1456	# a reply that has no error (even if there is no info macthing the qtype)
1457	answer.header.rcode = 0
1458	answernode = zonedict[qname]
1459	if querytype == 'ANY':
1460	for type in answernode.keys():
1461	for rec in answernode[type]:
1462	rranswerlist.append({qname:{type:[rec]}})
1463	elif answernode.has_key(querytype):
1464	for rec in answernode[querytype]:
1465	rranswerlist.append({qname:{querytype:[rec]}})
1466	# do rrset ordering (cyclic)
1467	if len(answernode[querytype]) > 1:
1468	rec = answernode[querytype].pop(0)
1469	answernode[querytype].append(rec)
1470	else:
1471	# remove all cname rrs from answerlist
1472	rranswerlist = []
1473	else:
1474	# would check for wildcards here (but aren't because they seem bad)
1475	# see if we need to give a referral
1476	zlist = self.getzlist(qname,origin)
1477	for zonename in zlist:
1478	if zonedict.has_key(zonename):
1479	if zonedict[zonename].has_key('NS'):
1480	answer.header.rcode = 0
1481	referral = 1
1482	for rec in zonedict[zonename]['NS']:
1483	rrnslist.append({zonename:{'NS':[rec]}})
1484	nsdname = rec['nsdname']
1485	# add glue records if they exist
1486	if zonedict.has_key(nsdname):
1487	if zonedict[nsdname].has_key('A'):
1488	for gluerec in zonedict[nsdname]['A']:
1489	rraddlist.append({nsdname:{'A':[gluerec]}})
1490	# negative caching stuff
1491	if not referral:
1492	if not rranswerlist:
1493	# NOTE: RFC1034 section 4.3.4 says we should add the SOA record
1494	# to the additional section of the response. BIND adds
1495	# it to the ns section though
1496	answer.header.rcode = 3
1497	rrnslist.append({origin:{'SOA':[zonedict[origin]['SOA'][0]]}})
1498	else:
1499	for rec in zonedict[origin]['NS']:
1500	rrnslist.append({origin:{'NS':[rec]}})
1501	answer.header.ancount = len(rranswerlist)
1502	answer.header.nscount = len(rrnslist)
1503	answer.header.arcount = len(rraddlist)
1504	answer.answerlist = rranswerlist
1505	answer.authlist = rrnslist
1506	answer.addlist = rraddlist
1507	cbfunc(query, addr, server, dorecursion, flist, [answer])
1508	else:
1509	cbfunc(query, addr, server, dorecursion, flist, [])
1510
1511	def handle_update(self, msg, addr, ns):
1512	zkey = ''
1513	slaves = []
1514	for zonekey in self.zdict.keys():
1515	if (self.zdict[zonekey]['type'] == 'master' and
1516	self.zdict[zonekey]['origin'] == msg.zone.zname):
1517	zkey = zonekey
1518	if not zkey:
1519	log(2,'SENDING NOTAUTH UPDATE ERROR')
1520	errormsg = self.error(msg.header.id, msg.zone.zname,
1521	msg.zone.ztype, msg.zone.zclass, 9)
1522	return errormsg, '', slaves
1523	# find the slaves for the zone
1524	if self.zdict[zkey].has_key('slaves'):
1525	slaves = self.zdict[zkey]['slaves']
1526	origin = self.zdict[zkey]['origin']
1527	zd = self.zdict[zkey]['zonedata']
1528	# check the permissions
1529	if not ns.config.allowupdate(msg, addr[0], addr[1]):
1530	log(2,'SENDING REFUSED UPDATE ERROR')
1531	errormsg = self.error(msg.header.id, msg.zone.zname,
1532	msg.zone.ztype, msg.zone.zclass, 5)
1533	return errormsg, origin, slaves
1534	# now check the prereqs
1535	temprrset = {}
1536	for rr in msg.prlist:
1537	rrname = rr.keys()[0]
1538	rrtype = rr[rrname].keys()[0]
1539	dbrec = rr[rrname][rrtype][0]
1540	if dbrec['ttl'] != 0:
1541	log(2,'FORMERROR(1)')
1542	errormsg = self.error(msg.header.id, msg.zone.zname,
1543	msg.zone.ztype, msg.zone.zclass, 1)
1544	return errormsg, origin, slaves
1545	if rrname.rfind(msg.zone.zname) == -1:
1546	log(2,'NOTZONE(10)')
1547	errormsg = self.error(msg.header.id, msg.zone.zname,
1548	msg.zone.ztype, msg.zone.zclass, 10)
1549	return errormsg, origin, slaves
1550	if dbrec['class'] == 'ANY':
1551	if dbrec['rdata']:
1552	log(2,'FORMERROR(1)')
1553	errormsg = self.error(msg.header.id, msg.zone.zname,
1554	msg.zone.ztype, msg.zone.zclass, 1)
1555	return errormsg, origin, slaves
1556	if rrtype == 'ANY':
1557	if not zd.has_key(rrname):
1558	log(2,'NXDOMAIN(3)')
1559	errormsg = self.error(msg.header.id, msg.zone.zname,
1560	msg.zone.ztype, msg.zone.zclass, 3)
1561	return errormsg, origin, slaves
1562	else:
1563	rrsettest = 0
1564	if zd.has_key(rrname):
1565	if zd[rrname].has_key(rrtype):
1566	rrsettest = 1
1567	if not rrsettest:
1568	log(2,'NXRRSET(8)')
1569	errormsg = self.error(msg.header.id, msg.zone.zname,
1570	msg.zone.ztype, msg.zone.zclass, 8)
1571	return errormsg, origin, slaves
1572	if dbrec['class'] == 'NONE':
1573	if dbrec['rdata']:
1574	log(2,'FORMERROR(1)')
1575	errormsg = self.error(msg.header.id, msg.zone.zname,
1576	msg.zone.ztype, msg.zone.zclass, 1)
1577	return errormsg, origin, slaves
1578	if rrtype == 'ANY':
1579	if zd.has_key(rrname):
1580	log(2,'YXDOMAIN(6)')
1581	errormsg = self.error(msg.header.id, msg.zone.zname,
1582	msg.zone.ztype, msg.zone.zclass, 6)
1583	return errormsg, origin, slaves
1584	else:
1585	if zd.has_key(rrname):
1586	if zd[rrname].has_key(rrtype):
1587	log(2,'YXRRSET(7)')
1588	errormsg = self.error(msg.header.id, msg.zone.zname,
1589	msg.zone.ztype, msg.zone.zclass, 7)
1590	return errormsg, origin, slaves
1591	if dbrec['class'] == msg.zone.zclass:
1592	if temprrset.has_key(rrname):
1593	if not temprrset[rrname].has_key(rrtype):
1594	temprrset[rrname][rrtype] = []
1595	else:
1596	temprrset[rrname] = {}
1597	temprrset[rrname][rrtype] = []
1598	temprrset[rrname][rrtype].append(dbrec)
1599	else:
1600	log(2,'FORMERROR(1)')
1601	errormsg = self.error(msg.header.id, msg.zone.zname,
1602	msg.zone.ztype, msg.zone.zclass, 1)
1603	return errormsg, origin, slaves
1604	for nodename in temprrset.keys():
1605	if not self.rrmatch(temprrset[nodename],zd[nodename]):
1606	log(2,'NXRRSET(8)')
1607	errormsg = self.error(msg.header.id, msg.zone.zname,
1608	msg.zone.ztype, msg.zone.zclass, 8)
1609	return errormsg, origin, slaves
1610
1611	# update section prescan
1612	for rr in msg.uplist:
1613	rrname = rr.keys()[0]
1614	rrtype = rr[rrname].keys()[0]
1615	dbrec = rr[rrname][rrtype][0]
1616	if rrname.rfind(msg.zone.zname) == -1:
1617	log(2,'NOTZONE(10)')
1618	errormsg = self.error(msg.header.id, msg.zone.zname,
1619	msg.zone.ztype, msg.zone.zclass, 10)
1620	return errormsg, origin, slaves
1621	if dbrec['class'] == msg.zone.zclass:
1622	if rrtype in ['ANY','MAILA','MAILB','AXFR']:
1623	log(2,'FORMERROR(1)')
1624	errormsg = self.error(msg.header.id, msg.zone.zname,
1625	msg.zone.ztype, msg.zone.zclass, 1)
1626	return errormsg, origin, slaves
1627	elif dbrec['class'] == 'ANY':
1628	if dbrec['ttl'] != 0 or dbrec['rdata'] or rrtype in ['MAILA','MAILB','AXFR']:
1629	log(2,'FORMERROR(1)')
1630	errormsg = self.error(msg.header.id, msg.zone.zname,
1631	msg.zone.ztype, msg.zone.zclass, 1)
1632	return errormsg, origin, slaves
1633	elif dbrec['class'] == 'NONE':
1634	if dbrec['ttl'] != 0 or rrtype in ['ANY','MAILA','MAILB','AXFR']:
1635	log(2,'FORMERROR(1)')
1636	errormsg = self.error(msg.header.id, msg.zone.zname,
1637	msg.zone.ztype, msg.zone.zclass, 1)
1638	return errormsg, origin, slaves
1639	else:
1640	log(2,'FORMERROR(1)')
1641	errormsg = self.error(msg.header.id, msg.zone.zname,
1642	msg.zone.ztype, msg.zone.zclass, 1)
1643	return errormsg, origin, slaves
1644
1645	# now handle actual update
1646	curserial = zd[msg.zone.zname]['SOA'][0]['serial']
1647	# update the soa serial here
1648	clearupdatehist = 0
1649	if len(msg.uplist) > 0:
1650	# initialize history structure
1651	if not self.updates.has_key(zkey):
1652	self.updates[zkey] = {}
1653	self.updates[zkey][curserial] = {'removed':[],
1654	'added':[]}
1655	if curserial == 2**32:
1656	newserial = 2
1657	clearupdatehist = 1
1658	else:
1659	newserial = curserial + 1
1660	self.updates[zkey][newserial] = {'removed':[],
1661	'added':[]}
1662	zd[msg.zone.zname]['SOA'][0]['serial'] = newserial
1663	for rr in msg.uplist:
1664	rrname = rr.keys()[0]
1665	rrtype = rr[rrname].keys()[0]
1666	dbrec = rr[rrname][rrtype][0]
1667	if dbrec['class'] == msg.zone.zclass:
1668	if rrtype == 'SOA':
1669	if zd.has_key(rrname):
1670	if zd[rrname].has_key('SOA'):
1671	if dbrec['serial'] > zd[rrname]['SOA'][0]['serial']:
1672	del zd[rrname]['SOA'][0]
1673	zd[rrname]['SOA'].append(dbrec)
1674	clearupdatehist = 1
1675	elif rrtype == 'WKS':
1676	if zd.has_key(rrname):
1677	if zd[rrname].has_key('WKS'):
1678	rdata = zd[rrname]['WKS'][0]
1679	oldrr = {rrname:{'WKS':[rdata]}}
1680	self.updates[zkey][curserial]['removed'].append(oldrr)
1681	del zd[rrname]['WKS'][0]
1682	zd[rrname]['WKS'].append(dbrec)
1683	newrr = {rrname:{'WKS':[dbrec]}}
1684	self.updates[zkey][newserial]['added'].append(newrr)
1685	else:
1686	if zd.has_key(rrname):
1687	if not zd[rrname].has_key(rrtype):
1688	zd[rrname][rrtype] = []
1689	else:
1690	zd[rrname] = {}
1691	zd[rrname][rrtype] = []
1692	zd[rrname][rrtype].append(dbrec)
1693	newrr = {rrname:{rrtype:[dbrec]}}
1694	self.updates[zkey][newserial]['added'].append(newrr)
1695	elif dbrec['class'] == 'ANY':
1696	if rrtype == 'ANY':
1697	if rrname == msg.zone.zname:
1698	if zd.has_key(rrname):
1699	for dnstype in zd[rrname].keys():
1700	if dnstype not in ['SOA','NS']:
1701	for rdata in zd[rrname][dnstype]:
1702	oldrr = {rrname:{dnstype:[rdata]}}
1703	self.updates[zkey][curserial]['removed'].append(oldrr)
1704	del zd[rrname][dnstype]
1705	else:
1706	if zd.has_key(rrname):
1707	for dnstype in zd[rrname].keys():
1708	for rdata in zd[rrname][dnstype]:
1709	oldrr = {rrname:{dnstype:[rdata]}}
1710	self.updates[zkey][curserial]['removed'].append(oldrr)
1711	del zd[rrname]
1712	else:
1713	if zd.has_key(rrname):
1714	if zd[rrname].has_key(rrtype):
1715	if rrname == msg.zone.zname:
1716	if rrtype not in ['SOA','NS']:
1717	for rdata in zd[rrname][dnstype]:
1718	oldrr = {rrname:{dnstype:[rdata]}}
1719	self.updates[zkey][curserial]['removed'].append(oldrr)
1720	del zd[rrname][rrtype]
1721	else:
1722	for rdata in zd[rrname][dnstype]:
1723	oldrr = {rrname:{dnstype:[rdata]}}
1724	self.updates[zkey][curserial]['removed'].append(oldrr)
1725	del zd[rrname][rrtype]
1726	elif dbrec['class'] == 'NONE':
1727	if not (rrname == msg.zone.zname and rrtype in ['SOA','NS']):
1728	if zd.had_key(rrname):
1729	if zd[rrname].has_key(rrtype):
1730	for i in range(len(zd[rrname][rrtype])):
1731	if dbrec == zd[rrname][rrtype][i]:
1732	rdata = zd[rrname][dnstype][i]
1733	oldrr = {rrname:{dnstype:[rdata]}}
1734	self.updates[zkey][curserial]['removed'].append(oldrr)
1735	del zd[rrname][rrtype][i]
1736	if len(zd[rrname][rrtype]) == 0:
1737	del zd[rrname][rrtype]
1738	if clearupdatehist:
1739	self.updates[zkey] = {}
1740	log(2,'SENDING UPDATE NOERROR MSG')
1741	noerrormsg = self.error(msg.header.id, msg.zone.zname,
1742	msg.zone.ztype, msg.zone.zclass, 0)
1743	return noerrormsg, origin, slaves
1744
1745	class dnscache:
1746	def __init__(self,cachezone):
1747	self.cachedb = cachezone
1748	# go through and set all of the root ttls to zero
1749	for node in self.cachedb.keys():
1750	for rtype in self.cachedb[node].keys():
1751	for rr in self.cachedb[node][rtype]:
1752	rr['ttl'] = 0
1753	if rtype == 'NS':
1754	rr['rtt'] = 0
1755	# add special entries for localhost
1756	self.cachedb['localhost'] = {'A':[{'address':'127.0.0.1', 'ttl':0, 'class':'IN'}]}
1757	self.cachedb['1.0.0.127.in-addr.arpa'] = {'PTR':[{'ptrdname':'localhost', 'ttl':0,'class':'IN'}]}
1758	self.cachedb['']['SOA'] = []
1759	self.cachedb['']['SOA'].append({'class':'IN','ttl':0,'mname':'cachedb',
1760	'rname':'cachedb@localhost','serial':1,'refresh':10800,
1761	'retry':3600,'expire':604800,'minimum':3600})
1762
1763	def hasrdata(self, irrdata, rrdatalist):
1764	# compare everything but ttls
1765	test = 0
1766	testrrdata = irrdata.copy()
1767	del testrrdata['ttl']
1768	for rrdata in rrdatalist:
1769	temprrdata = rrdata.copy()
1770	del temprrdata['ttl']
1771	if temprrdata == testrrdata:
1772	test = 1
1773	return test
1774
1775	def add(self, rr, qzone, nsdname):
1776	# NOTE: can't cache records from sites
1777	# that don't own those records (i.e. example.com
1778	# can't give us A records for www.example.net)
1779	name = rr.keys()[0]
1780	if (qzone != '') and (name[-len(qzone):] != qzone):
1781	log(2,'cache GOT possible POISON: ' + name + ' for zone ' + qzone)
1782	return
1783	rtype = rr[name].keys()[0]
1784	rdata = rr[name][rtype][0]
1785	if rdata['ttl'] < 3600:
1786	log(2,'low ttl: ' + str(rdata['ttl']))
1787	rdata['ttl'] = 3600
1788	rdata['ttl'] = int(time.time() + rdata['ttl'])
1789	if rtype == 'NS':
1790	rdata['rtt'] = 0
1791	name = name.lower()
1792	rtype = rtype.upper()
1793	if self.cachedb.has_key(name):
1794	if self.cachedb[name].has_key(rtype):
1795	if not self.hasrdata(rdata, self.cachedb[name][rtype]):
1796	self.cachedb[name][rtype].append(rdata)
1797	log(3,'appended rdata to ' +
1798	name + '(' + rtype + ') in cache')
1799	else:
1800	log(3,'same rdata for ' + name + '(' +
1801	rtype + ') is already in cache')
1802	else:
1803	self.cachedb[name][rtype] = [rdata]
1804	log(3,'appended ' + rtype + ' and rdata to node ' +
1805	name + ' in cache')
1806	else:
1807	self.cachedb[name] = {rtype:[rdata]}
1808	log(3,'added node ' + name + '(' + rtype + ') to cache')
1809	self.reap()
1810
1811	def addneg(self, qname, querytype, queryclass):
1812	if not self.cachedb.has_key(qname):
1813	self.cachedb['qname'] = {querytype: [{'ttl':time.time()+3600}]}
1814	else:
1815	if not self.cachedb[qname].has_key(querytype):
1816	self.cachedb[qname][querytype] = [{'ttl':time.time()+3600}]
1817
1818	def haskey(self, qname, querytype, msg=''):
1819	log(3,'looking for ' + qname + '(' + querytype + ') in cache')
1820	if self.cachedb.has_key(qname):
1821	rranswerlist = []
1822	rrnslist = []
1823	rraddlist = []
1824	if self.cachedb[qname].has_key('CNAME'):
1825	if querytype != 'CNAME':
1826	nodetype = 'CNAME'
1827	while nodetype == 'CNAME':
1828	if len(self.cachedb[qname]['CNAME'][0].keys()) > 1:
1829	log(3,'Adding CNAME to cache answer')
1830	rranswerlist.append({qname:{'CNAME':[self.cachedb[qname]['CNAME'][0]]}})
1831	qname = self.cachedb[qname]['CNAME'][0]['cname']
1832	if self.cachedb.has_key(qname):
1833	nodetype = self.cachedb[qname].keys()[0]
1834	else:
1835	# shouldn't have a CNAME that points to nothing
1836	return
1837	if querytype == 'ANY':
1838	for type in self.cache[qname].keys():
1839	for rec in self.cachedb[qname][type]:
1840	# can't append negative entries
1841	if len(rec.keys()) > 1:
1842	rranswerlist.append({qname:{type:[rec]}})
1843	elif self.cachedb[qname].has_key(querytype):
1844	for rec in self.cachedb[qname][querytype]:
1845	if len(rec.keys()) > 1:
1846	rranswerlist.append({qname:{querytype:[rec]}})
1847	if rranswerlist:
1848	if msg:
1849	answer = message()
1850	answer.header.id = msg.header.id
1851	answer.header.qr = 1
1852	answer.header.opcode = msg.header.opcode
1853	answer.header.ra = 1
1854	answer.question.qname = msg.question.qname
1855	answer.question.qtype = msg.question.qtype
1856	answer.question.qclass = msg.question.qclass
1857	answer.header.rcode = 0
1858	answer.header.ancount = len(rranswerlist)
1859	answer.answerlist = rranswerlist
1860	return answer
1861	else:
1862	return 1
1863	else:
1864	log(3,'Cache has no node for ' + qname)
1865
1866	def getnslist(self, qname):
1867	# find the best nameserver to ask from the cache
1868	tokens = qname.split('.')
1869	nsdict = {}
1870	curtime = time.time()
1871	for i in range(len(tokens)):
1872	domainname = '.'.join(tokens[i:])
1873	if self.cachedb.has_key(domainname):
1874	if self.cachedb[domainname].has_key('NS'):
1875	for nsrec in self.cachedb[domainname]['NS']:
1876	badserver = 0
1877	if nsrec.has_key('badtill'):
1878	if nsrec['badtill'] < curtime:
1879	del nsrec['badtill']
1880	else:
1881	badserver = 1
1882	if badserver:
1883	log(2,'BAD SERVER, not using ' + nsrec['nsdname'])
1884	if self.cachedb.has_key(nsrec['nsdname']) and not badserver:
1885	if self.cachedb[nsrec['nsdname']].has_key('A'):
1886	for arec in self.cachedb[nsrec['nsdname']]['A']:
1887	nsdict[nsrec['rtt']] = {'name':nsrec['nsdname'],
1888	'ip':arec['address']}
1889	if nsdict:
1890	break
1891	if not nsdict:
1892	domainname = ''
1893	# nothing in the cache matches so give back the root servers
1894	for nsrec in self.cachedb['']['NS']:
1895	badserver = 0
1896	if nsrec.has_key('badtill'):
1897	if curtime > nsrec['badtill']:
1898	del nsrec['badtill']
1899	else:
1900	badserver = 1
1901	if not badserver:
1902	for arec in self.cachedb[nsrec['nsdname']]['A']:
1903	nsdict[(nsrec['rtt'])] = {'name':nsrec['nsdname'],'ip':arec['address']}
1904
1905	return (domainname, nsdict)
1906
1907	def badns(self, zonename, nsdname):
1908	if self.cachedb.has_key(zonename):
1909	if self.cachedb[zonename].has_key('NS'):
1910	for nsrec in self.cachedb[zonename]['NS']:
1911	if nsrec['nsdname'] == nsdname:
1912	log(2,'Setting ' + nsdname + ' as bad nameserver')
1913	nsrec['badtill'] = time.time() + 3600
1914
1915
1916	def updatertt(self, qname, zone, rtt):
1917	if self.cachedb.has_key(zone):
1918	if self.cachedb[zone].has_key('NS'):
1919	for rr in self.cachedb[zone]['NS']:
1920	if rr['nsdname'] == qname:
1921	log(2,'updating rtt for ' + qname + ' to ' + str(rtt))
1922	rr['rtt'] = rtt
1923
1924	def reap(self):
1925	# expire all old records
1926	ntime = time.time()
1927	for nodename in self.cachedb.keys():
1928	for rrtype in self.cachedb[nodename].keys():
1929	for rdata in self.cachedb[nodename][rrtype]:
1930	ttl = rdata['ttl']
1931	if ttl != 0:
1932	if ttl < ntime:
1933	self.cachedb[nodename][rrtype].remove(rdata)
1934	if len(self.cachedb[nodename][rrtype]) == 0:
1935	del self.cachedb[nodename][rrtype]
1936	if len(self.cachedb[nodename]) == 0:
1937	del self.cachedb[nodename]
1938
1939	return
1940
1941	def zonetrans(self, queryid):
1942	# build a list of messages
1943	# each message contains one rr of the zone
1944	# the first and last message are the
1945	# SOA records
1946	zonedata = self.cachedb
1947	rrlist = []
1948	soa = {'':{'SOA':[zonedata['']['SOA'][0]]}}
1949	for nodename in zonedata.keys():
1950	for rrtype in zonedata[nodename].keys():
1951	if not (rrtype == 'SOA' and nodename == ''):
1952	for rr in zonedata[nodename][rrtype]:
1953	rrlist.append({nodename:{rrtype:[rr]}})
1954	rrlist.insert(0,soa)
1955	rrlist.append(soa)
1956	msglist = []
1957	for rr in rrlist:
1958	msg = message()
1959	msg.header.id = queryid
1960	msg.header.qr = 1
1961	msg.header.aa = 1
1962	msg.header.rd = 0
1963	msg.header.qdcount = 1
1964	msg.question.qname = 'cache'
1965	msg.question.qtype = 'AXFR'
1966	msg.question.qclass = 'IN'
1967	msg.header.ancount = 1
1968	msg.answerlist.append(rr)
1969	msglist.append(msg)
1970	return msglist
1971
1972	class gethostaddr(asyncore.dispatcher):
1973	def __init__(self, hostname, cbfunc, serveraddr='127.0.0.1'):
1974	asyncore.dispatcher.__init__(self)
1975	self.msg = message()
1976	self.msg.question.qname = hostname
1977	self.msg.question.qtype = 'A'
1978	self.cbfunc = cbfunc
1979	self.create_socket(socket.AF_INET, socket.SOCK_DGRAM)
1980	self.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 200 * 1024)
1981	self.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 200 * 1024)
1982	self.socket.sendto(self.msg.buildpkt(), (serveraddr,53))
1983
1984	def handle_read(self):
1985	replydata, addr = self.socket.recvfrom(1500)
1986	self.close()
1987	try:
1988	replymsg = message(replydata)
1989	except:
1990	log(0,'unable to process packet')
1991	return
1992	answername = replymsg.question.qname
1993	cname = ''
1994	# go through twice to catch cnames after A recs
1995	for rr in replymsg.answerlist:
1996	rrname = rr.keys()[0]
1997	rrtype = rr[rrname].keys()[0]
1998	dbrec = rr[rrname][rrtype][0]
1999	if rrname == answername and rrtype == 'CNAME':
2000	answername = dbrec['cname']
2001	cname = answername
2002	for rr in replymsg.answerlist:
2003	rrname = rr.keys()[0]
2004	rrtype = rr[rrname].keys()[0]
2005	dbrec = rr[rrname][rrtype][0]
2006	if rrname == answername and rrtype == 'A':
2007	self.cbfunc(dbrec['address'])
2008	return
2009	# if we got a cname and no A send query for cname
2010	if cname:
2011	self.msg = message()
2012	self.msg.question.qname = cname
2013	self.msg.question.qtype = 'A'
2014	self.socket.sendto(self.msg.buildpkt(), (serveraddr,53))
2015	else:
2016	self.cbfunc('')
2017
2018	def writable(self):
2019	return 0
2020
2021	def handle_write(self):
2022	pass
2023
2024	def handle_connect(self):
2025	pass
2026
2027	def handle_close(self):
2028	self.close()
2029
2030	def log_info (self, message, type='info'):
2031	if __debug__ or type != 'info':
2032	log(0,'%s: %s' % (type, message))
2033
2034	class simpleudprequest(asyncore.dispatcher):
2035	def __init__(self, msg, cbfunc, serveraddr='127.0.0.1', outqkey=''):
2036	asyncore.dispatcher.__init__(self)
2037	self.gotanswer = 0
2038	self.msg = msg
2039	self.cbfunc = cbfunc
2040	self.create_socket(socket.AF_INET, socket.SOCK_DGRAM)
2041	self.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 200 * 1024)
2042	self.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 200 * 1024)
2043	self.outqkey = outqkey
2044	self.socket.sendto(self.msg.buildpkt(), (serveraddr,53))
2045
2046	def handle_read(self):
2047	replydata, addr = self.socket.recvfrom(1500)
2048	self.close()
2049	try:
2050	replymsg = message(replydata)
2051	except:
2052	log(0,'unable to process packet')
2053	return
2054	self.cbfunc(replymsg, self.outqkey)
2055
2056	def writable(self):
2057	return 0
2058
2059	def handle_write(self):
2060	pass
2061
2062	def handle_connect(self):
2063	pass
2064
2065	def handle_close(self):
2066	self.close()
2067
2068	def log_info (self, message, type='info'):
2069	if __debug__ or type != 'info':
2070	log(0,'%s: %s' % (type, message))
2071
2072	class simpletcprequest(asyncore.dispatcher):
2073	def __init__(self, msg, cbfunc, cbparams=[], serveraddr='127.0.0.1', errorfunc=''):
2074	asyncore.dispatcher.__init__(self)
2075	self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
2076	self.query = msg
2077	self.cbfunc = cbfunc
2078	self.cbparams = cbparams
2079	self.errorfunc = errorfunc
2080	msgdata = msg.buildpkt()
2081	ml = inttoasc(len(msgdata))
2082	if len(ml) == 1:
2083	ml = chr(0) + ml
2084	self.buffer = ml+msgdata
2085	self.rbuffer = ''
2086	self.rmsgleft = 0
2087	self.rrlist = []
2088	log(2,'sending tcp request to ' + serveraddr)
2089	self.connect((serveraddr,53))
2090
2091	def recv (self, buffer_size):
2092	try:
2093	data = self.socket.recv (buffer_size)
2094	if not data:
2095	# a closed connection is indicated by signaling
2096	# a read condition, and having recv() return 0.
2097	self.handle_close()
2098	return ''
2099	else:
2100	return data
2101	except socket.error, why:
2102	# winsock sometimes throws ENOTCONN
2103	if why[0] in [ECONNRESET, ENOTCONN, ESHUTDOWN, ETIMEDOUT]:
2104	self.handle_close()
2105	return ''
2106	else:
2107	raise socket.error, why
2108
2109	def handle_connect(self):
2110	pass
2111
2112	def handle_msg(self, msg):
2113	if self.query.question.qtype == 'AXFR':
2114	if len(self.rrlist) == 0:
2115	if len(msg.answerlist) == 0:
2116	if self.errorfunc:
2117	self.errorfunc(self.cbparams[0])
2118	self.close()
2119	return
2120	rr = msg.answerlist[0]
2121	rrname = rr.keys()[0]
2122	rrtype = rr[rrname].keys()[0]
2123	self.rrlist.append(rr)
2124	if rrtype == 'SOA' and len(self.rrlist) > 1:
2125	self.close()
2126	if self.cbparams:
2127	self.cbfunc(self.rrlist, self.cbparams)
2128	else:
2129	self.cbfunc(self.rrlist)
2130	else:
2131	self.close()
2132	if self.cbparams:
2133	self.cbfunc(msg, self.cbparams)
2134	else:
2135	self.cbfunc(msg)
2136
2137	def handle_read(self):
2138	data = self.recv(8192)
2139	if len(self.rbuffer) == 0:
2140	self.rmsglength = asctoint(data[:2])
2141	data = data[2:]
2142	self.rbuffer = self.rbuffer + data
2143	while len(self.rbuffer) >= self.rmsglength and self.rmsglength != 0:
2144	msgdata = self.rbuffer[:self.rmsglength]
2145	self.rbuffer = self.rbuffer[self.rmsglength:]
2146	if len(self.rbuffer) == 0:
2147	self.rmsglength = 0
2148	else:
2149	self.rmsglength = asctoint(self.rbuffer[:2])
2150	self.rbuffer = self.rbuffer[2:]
2151	try:
2152	self.handle_msg(message(msgdata))
2153	except:
2154	return
2155
2156	def writable(self):
2157	return (len(self.buffer) > 0)
2158
2159	def handle_write(self):
2160	sent = self.send(self.buffer)
2161	self.buffer = self.buffer[sent:]
2162
2163	def handle_close(self):
2164	if self.errorfunc:
2165	self.errorfunc(self.query.question.qname)
2166	self.close()
2167
2168	def log_info (self, message, type='info'):
2169	if __debug__ or type != 'info':
2170	log(0,'%s: %s' % (type, message))
2171
2172	class udpdnsserver(asyncore.dispatcher):
2173	def __init__(self, port, dnsserver):
2174	asyncore.dispatcher.__init__(self)
2175	self.create_socket(socket.AF_INET, socket.SOCK_DGRAM)
2176	self.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 200 * 1024)
2177	self.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 200 * 1024)
2178	self.bind(('',port))
2179	self.dnsserver = dnsserver
2180	self.maxmsgsize = 500
2181
2182	def handle_read(self):
2183	try:
2184	while 1:
2185	msgdata, addr = self.socket.recvfrom(1500)
2186	self.dnsserver.handle_packet(msgdata, addr, self)
2187	except socket.error, why:
2188	if why[0] != asyncore.EWOULDBLOCK:
2189	raise socket.error, why
2190
2191	def sendpackets(self, msglist, addr):
2192	for msg in msglist:
2193	msgdata = msg.buildpkt()
2194	if len(msgdata) > self.maxmsgsize:
2195	msg.header.tc = 1
2196	# take off all the answers to ensure
2197	# the packet size is small enough
2198	msg.header.ancount = 0
2199	msg.header.nscount = 0
2200	msg.header.arcount = 0
2201	msg.answerlist = []
2202	msg.authlist = []
2203	msg.addlist = []
2204	msgdata = msg.buildpkt()
2205	self.sendto(msgdata, addr)
2206
2207	def writable(self):
2208	return 0
2209
2210	def handle_write(self):
2211	pass
2212
2213	def handle_connect(self):
2214	pass
2215
2216	def handle_close(self):
2217	# print '1:In handle close'
2218	return
2219
2220	def log_info (self, message, type='info'):
2221	if __debug__ or type != 'info':
2222	log(0,'%s: %s' % (type, message))
2223
2224	class tcpdnschannel(asynchat.async_chat):
2225	def __init__(self, server, s, addr):
2226	asynchat.async_chat.__init__(self, s)
2227	self.server = server
2228	self.addr = addr
2229	self.set_terminator(None)
2230	self.databuffer = ''
2231	self.msglength = 0
2232	log(3,'Created new tcp channel')
2233
2234	def collect_incoming_data(self, data):
2235	if self.msglength == 0:
2236	self.msglength = asctoint(data[:2])
2237	data = data[2:]
2238	self.databuffer = self.databuffer + data
2239	if len(self.databuffer) == self.msglength:
2240	# got entire message
2241	self.server.dnsserver.handle_packet(self.databuffer, self.addr, self)
2242	self.databuffer = ''
2243
2244	def sendpackets(self, msglist, addr):
2245	for msg in msglist:
2246	x = msg.buildpkt()
2247	ml = inttoasc(len(x))
2248	if len(ml) == 1:
2249	ml = chr(0) + ml
2250	self.push(ml+x)
2251	self.close()
2252
2253	def log_info (self, message, type='info'):
2254	if __debug__ or type != 'info':
2255	log(0,'%s: %s' % (type, message))
2256
2257	class tcpdnsserver(asyncore.dispatcher):
2258	def __init__(self, port, dnsserver):
2259	asyncore.dispatcher.__init__(self)
2260	self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
2261	self.set_reuse_addr()
2262	self.bind(('',port))
2263	self.listen(5)
2264	self.dnsserver = dnsserver
2265
2266	def handle_accept(self):
2267	conn, addr = self.accept()
2268	tcpdnschannel(self, conn, addr)
2269
2270	def handle_close(self):
2271	self.close()
2272
2273	def log_info (self, message, type='info'):
2274	if __debug__ or type != 'info':
2275	log(0,'%s: %s' % (type, message))
2276
2277	class nameserver:
2278	def __init__(self, resolver, localconfig):
2279	self.resolver = resolver
2280	self.config = localconfig
2281	self.zdb = self.config.zonedatabase
2282	self.last_reap_time = time.time()
2283	self.maint_int = 10
2284	self.slavesupdating = []
2285	self.notifys = []
2286	self.sentnotify = []
2287	self.notify_retry_time = 30
2288	self.notify_retries = 4
2289	self.askedsoa = {}
2290	self.soatimeout = 10
2291
2292	def error(self, id, qname, querytype, queryclass, rcode):
2293	error = message()
2294	error.header.id = id
2295	error.header.rcode = rcode
2296	error.header.qr = 1
2297	error.question.qname = qname
2298	error.question.qtype = querytype
2299	error.question.qclass = queryclass
2300	return error
2301
2302	def need_zonetransfer(self, zkey, origin, masterip, trynum=0):
2303	self.askedsoa[zkey] = {'masterip':masterip,
2304	'senttime':time.time(),
2305	'origin':origin,
2306	'trynum':trynum+1}
2307	query = message()
2308	query.header.id = random.randrange(1,32768)
2309	query.header.rd = 0
2310	query.question.qname = origin
2311	query.question.qtype = 'SOA'
2312	query.question.qclass = 'IN'
2313	log(3,'slave checking for new data in ' + origin)
2314	simpleudprequest(query, self.handle_soaquery,
2315	masterip, zkey)
2316
2317	def handle_soaquery(self, msg, zkey):
2318	origin = msg.question.qname
2319	masterip = self.askedsoa[zkey]['masterip']
2320	del self.askedsoa[zkey]
2321	if zkey not in self.slavesupdating:
2322	self.slavesupdating.append(zkey)
2323	query = message()
2324	query.header.id = random.randrange(1,32768)
2325	query.header.rd = 0
2326	query.question.qname = origin
2327	query.question.qtype = 'AXFR'
2328	query.question.qclass = 'IN'
2329	log(3,'Updating slave zone: ' + zkey)
2330	simpletcprequest(query, self.handle_zonetrans,
2331	[zkey],masterip,self.handle_zterror)
2332
2333	def handle_zonetrans(self, rrlist, params):
2334	log(1,'handling zone transfer')
2335	zonekey = params[0]
2336	self.zdb.update_zone(rrlist, params)
2337	self.slavesupdating.remove(zonekey)
2338
2339	def handle_zterror(self, zonekey):
2340	self.slavesupdating.remove(zonekey)
2341	self.zdb.remove_zone(zonekey)
2342
2343	def rrmatch(self, rrset1, rrset2):
2344	for rrtype in rrset1.keys():
2345	if rrtype not in rrset2.keys():
2346	return
2347	else:
2348	if len(rrset1[rrtype]) != len(rrset2[rrtype]):
2349	return
2350	return 1
2351
2352	def process_notify(self, msg, ipaddr, port):
2353	(zkeys, dorecursion, flist) = self.config.getview(msg, ipaddr, port)
2354	goodzkey = ''
2355	for zkey in zkeys:
2356	origin = self.zdb.getorigin(zkey)
2357	if origin == msg.question.qname:
2358	masterip = self.zdb.getmasterip(zkey)
2359	if masterip:
2360	goodzkey = zkey
2361	if goodzkey:
2362	log(3,'got NOTIFY from ' + masterip)
2363	self.need_zonetransfer(goodzkey, origin, masterip, 0)
2364	return
2365
2366	def notify(self):
2367	curtime = time.time()
2368	for origin, ipaddr, trynum, senttime in self.sentnotify:
2369	if senttime + self.notify_retry_time > curtime:
2370	self.notifys.append((origin, ipaddr, trynum))
2371	self.sentnotify.remove((origin, ipaddr, trynum, senttime))
2372	for origin, ipaddr, trynum in self.notifys:
2373	msg = message()
2374	msg.question.qname = origin
2375	msg.question.qtype = 'SOA'
2376	msg.question.qclass = 'IN'
2377	msg.header.opcode = 4
2378	# there probably is a better way to do this
2379	if self.resolver:
2380	self.resolver.send_to([msg],(ipaddr,53))
2381	if trynum+1 <= self.notify_retries:
2382	self.sentnotify.append((origin,ipaddr,trynum+1,curtime))
2383	self.notifys = []
2384
2385	def handle_packet(self, msgdata, addr, server):
2386	# self.reap()
2387	try:
2388	msg = message(msgdata)
2389	except:
2390	return
2391	# find a matching view
2392	(zkeys, dorecursion, flist) = self.config.getview(msg, addr[0], addr[1])
2393	if not msg.header.qr and msg.header.opcode == 5:
2394	log(2,'GOT UPDATE PACKET')
2395	# check the zone section
2396	if (msg.header.zocount != 1 or
2397	msg.zone.ztype != 'SOA' or
2398	msg.zone.zclass != 'IN'):
2399	log(2,'SENDING FORMERR UPDATE ERROR')
2400	errormsg = self.error(msg.header.id, msg.zone.zname,
2401	msg.zone.ztype, msg.zone.zclass, 1)
2402	server.sendpackets([errormsg],addr)
2403	else:
2404	(answer, origin, slaves) = self.zdb.handle_update(msg, addr, self)
2405	if answer.header.rcode == 0:
2406	# schedule NOTIFYs to slaves
2407	for ipaddr in slaves:
2408	self.notifys.append((origin, ipaddr, 0))
2409	server.sendpackets([answer],addr)
2410	elif msg.header.opcode == 4:
2411	if msg.header.qr:
2412	log(0,'got NOTIFY response')
2413	for origin, ipaddr, trynum, senttime in self.sentnotify:
2414	if ipaddr == addr[0] and msg.question.qname == origin:
2415	self.sentnotify.remove((origin, ipaddr, trynum, senttime))
2416	else:
2417	log(0,'got NOTIFY')
2418	self.process_notify(msg, addr[0], addr[1])
2419	elif not msg.header.qr and msg.header.opcode == 0:
2420	# it's a question
2421	qname = msg.question.qname.lower()
2422	log(2,'GOT QUERY for ' + qname + '(' + msg.question.qtype +
2423	') from ' + addr[0])
2424	# handle special version packet
2425	if (msg.question.qtype == 'TXT' and
2426	msg.question.qclass == 'CH'):
2427	if qname == 'version.bind':
2428	server.sendpackets([getversion(qname,
2429	msg.header.id,
2430	msg.header.rd,
2431	dorecursion, '1.0')],addr)
2432	elif qname == 'version.oak':
2433	server.sendpackets([getversion(qname,
2434	msg.header.id,
2435	msg.header.rd,
2436	dorecursion, '1.0')],addr)
2437	return
2438	self.zdb.lookup(zkeys, msg, addr, server, dorecursion,
2439	flist, self.lookup_callback)
2440
2441	def lookup_callback(self, msg, addr, server, dorecursion, flist, answerlist):
2442	if answerlist:
2443	server.sendpackets(self.config.outpackets(answerlist), addr)
2444	elif dorecursion:
2445	if msg.question.qtype in ['AXFR','IXFR']:
2446	if msg.question.qname == 'cache' and msg.question.qtype == 'AXFR':
2447	if self.resolver:
2448	server.sendpackets(self.resolver.cache.zonetrans(msg.header.id),addr)
2449	else:
2450	# won't forward zone transfers and
2451	# don't handle recursive zone transfers
2452	server.sendpackets([self.error(msg.header.id, msg.question.qname,
2453	msg.question.qtype,
2454	msg.question.qclass,2)],addr)
2455	else:
2456	self.resolver.handle_query(msg, addr, flist, server.sendpackets)
2457
2458	def reap(self):
2459	log(4,'in nameserver reap')
2460	# do all maintenence (interval) stuff here
2461	if self.resolver:
2462	self.resolver.reap()
2463	self.notify()
2464	curtime = time.time()
2465	if curtime > (self.last_reap_time + self.maint_int):
2466	self.last_reap_time = curtime
2467	# do zone transfers here if slave server and haven't asked for soa
2468	for (zkey, origin, masterip) in self.zdb.getslaves(curtime):
2469	if not self.askedsoa.has_key(zkey):
2470	self.need_zonetransfer(zkey, origin, masterip)
2471	for zkey in self.askedsoa.keys():
2472	if curtime > self.askedsoa[zkey]['senttime'] + self.soatimeout:
2473	if self.askedsoa[zkey]['trynum'] > 3:
2474	self.zdb.remove_zone(zkey)
2475	del self.askedsoa[zkey]
2476	else:
2477	masterip = self.askedsoa[zkey]['masterip']
2478	origin = self.askedsoa[zkey]['origin']
2479	trynum = self.askedsoa[zkey]['trynum']
2480	del self.askedsoa[zkey]
2481	self.need_zonetransfer(zkey, origin, masterip, trynum)
2482
2483	def log_info (self, message, type='info'):
2484	if __debug__ or type != 'info':
2485	log(0,'%s: %s' % (type, message))
2486
2487	class resolver(asyncore.dispatcher):
2488	def __init__(self, cache, port=0):
2489	asyncore.dispatcher.__init__(self)
2490	self.create_socket(socket.AF_INET, socket.SOCK_DGRAM)
2491	self.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 200 * 1024)
2492	self.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 200 * 1024)
2493	self.bind(('',port))
2494	self.cache = cache
2495	self.outqnum = 0
2496	self.outq = {}
2497	self.holdq = {}
2498	self.holdtime = 10
2499	self.holdqlength = 100
2500	self.last_reap_time = time.time()
2501	self.maint_int = 10
2502	self.timeout = 3
2503
2504	def getoutqkey(self):
2505	self.outqnum = self.outqnum + 1
2506	if self.outqnum == 99999:
2507	self.outqnum = 1
2508	return str(self.outqnum)
2509
2510	def error(self, id, qname, querytype, queryclass, rcode):
2511	error = message()
2512	error.header.id = id
2513	error.header.rcode = rcode
2514	error.header.qr = 1
2515	error.question.qname = qname
2516	error.question.qtype = querytype
2517	error.question.qclass = queryclass
2518	return error
2519
2520	def qpacket(self, id, qname, querytype, queryclass):
2521	# create a question
2522	query = message()
2523	query.header.id = id
2524	query.header.rd = 0
2525	query.question.qname = qname
2526	query.question.qtype = querytype
2527	query.question.qclass = queryclass
2528	return query
2529
2530	def send_to(self, msglist, addr):
2531	for msg in msglist:
2532	data = msg.buildpkt()
2533	if len(data) > 512:
2534	# packet to big
2535	msg.header.tc = 1
2536	msg.header.ancount = 0
2537	msg.answerlist = []
2538	msg.header.nscount = 0
2539	msg.authlist = []
2540	msg.header.arcount = 0
2541	msg.addlist = []
2542	self.socket.sendto(msg.buildpkt(), addr)
2543	else:
2544	self.socket.sendto(data, addr)
2545
2546	def handle_read(self):
2547	try:
2548	while 1:
2549	msgdata, addr = self.socket.recvfrom(1500)
2550	# should put 'try' here in production server
2551	self.handle_packet(msgdata, addr)
2552	except socket.error, why:
2553	if why[0] != asyncore.EWOULDBLOCK:
2554	raise socket.error, why
2555
2556	def handle_packet(self, msgdata, addr):
2557	try:
2558	msg = message(msgdata)
2559	except:
2560	return
2561	if not msg.header.qr:
2562	self.handle_query(msg, addr, [], self.send_to)
2563	else:
2564	log(2,'received unsolicited reply')
2565
2566
2567	def handle_query(self, msg, addr, flist, cbfunc):
2568	qname = msg.question.qname
2569	querytype = msg.question.qtype
2570	queryclass = msg.question.qclass
2571	# check the cache first
2572	answer = self.cache.haskey(qname,querytype,msg)
2573	if answer:
2574	cbfunc([answer], addr)
2575	log(2,'sent answer for ' + qname + '(' + querytype +
2576	') from cache')
2577	else:
2578	# check if query is already in progess
2579	for oqkey in self.outq.keys():
2580	if (self.outq[oqkey]['qname'] == qname and
2581	self.outq[oqkey]['querytype'] == querytype):
2582	log(2,'query already in progress for '+qname+'('+querytype+')')
2583	# put entry in hold queue to try later
2584	hqrec = {'processtime':time.time()+self.holdtime,
2585	'query':msg,'addr':addr,
2586	'qname':qname,'querytype':querytype,
2587	'queryclass':queryclass,
2588	'cbfunc':cbfunc}
2589	self.putonhold(hqrec)
2590	return
2591
2592	outqkey = self.getoutqkey()+str(msg.header.id)
2593	self.outq[outqkey] = {'query':msg,
2594	'addr':addr,
2595	'qname':qname,
2596	'querytype':querytype,
2597	'queryclass':queryclass,
2598	'cbfunc':cbfunc,
2599	'answerlist':[],
2600	'addlist':[],
2601	'qsent':0}
2602	if flist:
2603	self.outq[outqkey]['flist'] = flist
2604	self.askfns(outqkey)
2605	else:
2606	self.askns(outqkey)
2607
2608	def putonhold(self,hqrec):
2609	hqid = hqrec['qname']+hqrec['querytype']
2610	if self.holdq.has_key(hqid):
2611	if len(self.holdq[hqid]) < self.holdqlength:
2612	hqrec['processtime']=time.time()+self.holdtime
2613	self.holdq[hqid].append(hqrec)
2614
2615
2616	def askns(self, outqkey):
2617	qname = self.outq[outqkey]['qname']
2618	querytype = self.outq[outqkey]['querytype']
2619	queryclass = self.outq[outqkey]['queryclass']
2620	# don't try more than 10 times to avoid loops
2621	if self.outq[outqkey]['qsent'] == 10:
2622	del self.outq[outqkey]
2623	log(2,'Dropping query for ' + qname + '(' + querytype + ')' +
2624	' POSSIBLE LOOP')
2625	return
2626	# find the best nameservers to ask from the cache
2627	(qzone, nsdict) = self.cache.getnslist(qname)
2628	if not nsdict:
2629	# there are no good servers
2630	if self.outq[outqkey]['addr'] != 'IQ':
2631	qid = self.outq[outqkey]['query'].header.id
2632	self.outq[outqkey]['cbfunc'](self.error(qid,qname,querytype,queryclass,2),
2633	self.outq[outqkey]['addr'])
2634	del self.outq[outqkey]
2635	log(2,'Dropping query for ' + qname + '(' + querytype + ')' +
2636	'no good name servers to ask')
2637	return
2638	# pick the best nameserver
2639	rtts = nsdict.keys()
2640	rtts.sort()
2641	bestnsip = nsdict[rtts[0]]['ip']
2642	bestnsname = nsdict[rtts[0]]['name']
2643	# fill in the callback data structure
2644	id=random.randrange(1,32768)
2645	self.outq[outqkey]['nsqueriedlastip'] = bestnsip
2646	self.outq[outqkey]['nsqueriedlastname'] = bestnsname
2647	self.outq[outqkey]['nsdict'] = nsdict
2648	self.outq[outqkey]['qzone'] = qzone
2649	self.outq[outqkey]['qsenttime'] = time.time()
2650	self.outq[outqkey]['qsent'] = self.outq[outqkey]['qsent'] + 1
2651	# self.socket.sendto(self.qpacket(id,qname,querytype,queryclass), (bestnsip,53))
2652	self.outq[outqkey]['request'] = simpleudprequest(self.qpacket(id,qname,querytype,queryclass),
2653	self.handle_response, bestnsip, outqkey)
2654	# update rtt so that we ask a different server next time
2655	self.cache.updatertt(bestnsname,qzone,1)
2656	log(2,outqkey+'\|sent query to ' + bestnsip + '(' + bestnsname +
2657	') for ' + qname + '(' + querytype + ')')
2658
2659	def askfns(self, outqkey):
2660	flist = self.outq[outqkey]['flist']
2661	qname = self.outq[outqkey]['qname']
2662	querytype = self.outq[outqkey]['querytype']
2663	queryclass = self.outq[outqkey]['queryclass']
2664	self.outq[outqkey]['qsenttime'] = time.time()
2665	id=random.randrange(1,32768)
2666	# self.socket.sendto(self.qpacket(id,qname,querytype,queryclass), (flist[0],53))
2667	self.outq[outqkey]['request'] = simpleudprequest(self.qpacket(id,qname,querytype,queryclass),
2668	self.handle_fresponse, flist[0], outqkey)
2669	log(2,''+outqkey+'\|sent query to forwarder')
2670
2671	def handle_response(self, msg, outqkey):
2672	# either reponse:
2673	# 1. contains a name error
2674	# 2. answers the question
2675	# (cache data and return it)
2676	# 3. is (contains) a CNAME and qtype isn't
2677	# (cache cname and change qname to it)
2678	# (check if qname and qtype are in any other rrs in the response)
2679	# (must check cache again here)
2680	# 4. contains a better delegation
2681	# (cache the delegation and start again)
2682	# 5. is aserver failure
2683	# (delete server from list and try again)
2684
2685	# make sure that original question is still outstanding
2686	if not self.outq.has_key(outqkey):
2687	# should never get here
2688	# if we do we aren't doing housekeeping of callbacks very well
2689	log(2,''+outqkey+'\|got response for a question already answered for ' + msg.question.qname)
2690	return
2691
2692	querytype = self.outq[outqkey]['querytype']
2693	if msg.header.rcode not in [1,2,4,5]:
2694	# update rtt time
2695	rtt = time.time() - self.outq[outqkey]['qsenttime']
2696	nsname = self.outq[outqkey]['nsqueriedlastname']
2697	zone = self.outq[outqkey]['qzone']
2698	self.cache.updatertt(nsname,zone,rtt)
2699
2700	if msg.header.rcode == 3:
2701	log(2,outqkey+'\|GOT Name Error for ' + msg.question.qname +
2702	'(' + msg.question.qtype + ')')
2703	# name error
2704	# cache negative answer
2705	self.cache.addneg(self.outq[outqkey]['qname'],
2706	self.outq[outqkey]['querytype'],
2707	self.outq[outqkey]['queryclass'])
2708	if self.outq[outqkey]['addr'] != 'IQ':
2709	answer = message()
2710	answer.question.qname = self.outq[outqkey]['query'].question.qname
2711	answer.question.qtype = self.outq[outqkey]['query'].question.qtype
2712	answer.question.qclass = self.outq[outqkey]['query'].question.qclass
2713	answer.header.id = self.outq[outqkey]['query'].header.id
2714	answer.header.qr = 1
2715	answer.header.opcode = self.outq[outqkey]['query'].header.opcode
2716	answer.header.ra = 1
2717	self.outq[outqkey]['cbfunc']([answer], self.outq[outqkey]['addr'])
2718	del self.outq[outqkey]
2719
2720	elif msg.header.ancount > 0:
2721	# answer (may be CNAME)
2722	haveanswer = 0
2723	cname = ''
2724	log(2,'CACHING ANSWERLIST ENTRIES')
2725	for rr in msg.answerlist:
2726	rrname = rr.keys()[0]
2727	rrtype = rr[rrname].keys()[0]
2728	if ((rrname == msg.question.qname or rrname == cname ) and
2729	rrtype == msg.question.qtype):
2730	haveanswer = 1
2731	if rrname == msg.question.qname and rrtype == 'CNAME':
2732	cname = rr[rrname][rrtype][0]['cname']
2733	self.cache.add(rr, self.outq[outqkey]['qzone'],
2734	self.outq[outqkey]['nsqueriedlastname'])
2735	if haveanswer:
2736	if self.outq[outqkey]['addr'] != 'IQ':
2737	log(2,''+outqkey+'\|GOT Answer for ' + msg.question.qname +
2738	'(' + msg.question.qtype + ')' )
2739	answer = message()
2740	answer.answerlist = msg.answerlist + self.outq[outqkey]['answerlist']
2741	answer.header.ancount = len(answer.answerlist)
2742	answer.question.qname = self.outq[outqkey]['query'].question.qname
2743	answer.question.qtype = self.outq[outqkey]['query'].question.qtype
2744	answer.question.qclass = self.outq[outqkey]['query'].question.qclass
2745	answer.header.id = self.outq[outqkey]['query'].header.id
2746	answer.header.qr = 1
2747	answer.header.opcode = self.outq[outqkey]['query'].header.opcode
2748	answer.header.ra = 1
2749	self.outq[outqkey]['cbfunc']([answer], self.outq[outqkey]['addr'])
2750	log(2,outqkey+'\|sent answer retrieved from remote server for ' +
2751	self.outq[outqkey]['query'].question.qname)
2752	else:
2753	log(2,outqkey+'\|GOT Answer(IQ) for ' + msg.question.qname + '(' +
2754	msg.question.qtype + ')')
2755	del self.outq[outqkey]
2756	elif cname:
2757	log(2,outqkey+'\|GOT CNAME for ' + msg.question.qname + '(' + msg.question.qtype + ')')
2758	self.outq[outqkey]['answerlist'] = self.outq[outqkey]['answerlist'] + msg.answerlist
2759	self.outq[outqkey]['qname'] = cname
2760	self.askns(outqkey)
2761	else:
2762	log(2,outqkey+'\|GOT BOGUS answer for ' + msg.question.qname + '(' +
2763	msg.question.qtype + ')')
2764	del self.outq[outqkey]
2765
2766	elif msg.header.nscount > 0 and msg.header.ancount == 0:
2767	log(2,outqkey+'\|GOT DELEGATION for ' + msg.question.qname + '(' + msg.question.qtype + ')')
2768	# delegation
2769	# cache the nameserver rrs and start over
2770	# if there are no glue records for nameservers must fetch them first
2771	log(2,'CACHING AUTHLIST ENTRIES')
2772	for rr in msg.authlist:
2773	self.cache.add(rr,self.outq[outqkey]['qzone'],self.outq[outqkey]['nsqueriedlastname'])
2774	log(2,'CACHING ADDLIST ENTRIES')
2775	for rr in msg.addlist:
2776	self.cache.add(rr,self.outq[outqkey]['qzone'],self.outq[outqkey]['nsqueriedlastname'])
2777	rrlist = msg.authlist+msg.addlist
2778	fetchglue = 0
2779	nscount = 0
2780	for rr in msg.authlist:
2781	nodename = rr.keys()[0]
2782	if rr[nodename].keys()[0] == 'NS':
2783	nscount = nscount + 1
2784	nsdname = rr[nodename]['NS'][0]['nsdname']
2785	if not self.cache.haskey(nsdname,'A'):
2786	log(2,outqkey+'\|Glue record not in cache for ' + nsdname + '(A)')
2787	fetchglue = fetchglue + 1
2788	# need to fetch A rec
2789	noutqkey = self.getoutqkey()+str(random.randrange(1,32768))
2790	self.outq[noutqkey] = {'query':'',
2791	'addr':'IQ',
2792	'qname':nsdname,
2793	'querytype':'A',
2794	'queryclass':'IN',
2795	'qsent':0}
2796	log(2,outqkey+'\|sending a query to fetch glue records for ' + nsdname + '(A)')
2797	self.askns(noutqkey)
2798	if not nscount:
2799	log(2,outqkey+'\|Dropping query (no ns recs) for ' +
2800	msg.question.qname + '(' + msg.question.qtype + ')' )
2801	del self.outq[outqkey]
2802	elif fetchglue == nscount:
2803	log(2,outqkey+'\|Stalling query (no glue recs) for ' +
2804	msg.question.qname + '(' + msg.question.qtype + ')')
2805	self.putonhold(self.outq[outqkey])
2806	del self.outq[outqkey]
2807	else:
2808	log(2,outqkey+'\|got (some) glue with delegation')
2809	self.askns(outqkey)
2810
2811	elif msg.header.rcode in [1,2,4,5]:
2812	log(2,outqkey+'\|GOT ' + getrcode(msg.header.rcode))
2813	log(2,'SERVER ' + self.outq[outqkey]['nsqueriedlastname'] + '(' +
2814	self.outq[outqkey]['nsqueriedlastip'] + ') FAILURE for ' + msg.question.qname)
2815	# don't ask this server for a while
2816	self.cache.badns(self.outq[outqkey]['qzone'],self.outq[outqkey]['nsqueriedlastname'])
2817	self.askns(outqkey)
2818	else:
2819	log(2,outqkey+'\|GOT UNPARSEABLE REPLY')
2820	msg.printpkt()
2821
2822	def handle_fresponse(self, msg, outqkey):
2823	if msg.header.rcode in [1,2,4,5]:
2824	self.outq[outqkey]['flist'].pop(0)
2825	if len(self.outq[outqkey]['flist']) == 0:
2826	qid = self.outq[outqkey]['query'].header.id
2827	qname = self.outq[outqkey]['qname']
2828	querytype = self.outq[outqkey]['querytype']
2829	queryclass = self.outq[outqkey]['queryclass']
2830	self.outq[outqkey]['cbfunc'](self.error(qid,qname,querytype,queryclass,2),
2831	self.outq[outqkey]['addr'])
2832	del self.outq[outqkey]
2833	else:
2834	self.askfns(outqkey)
2835	else:
2836	answer = message()
2837	answer.header.id = self.outq[outqkey]['query'].header.id
2838	answer.header.qr = 1
2839	answer.header.opcode = self.outq[outqkey]['query'].header.opcode
2840	answer.header.ra = 1
2841	answer.question.qname = self.outq[outqkey]['query'].question.qname
2842	answer.question.qtype = self.outq[outqkey]['query'].question.qtype
2843	answer.question.qclass = self.outq[outqkey]['query'].question.qclass
2844	answer.header.ancount = msg.header.ancount
2845	answer.header.nscount = msg.header.nscount
2846	answer.header.arcount = msg.header.arcount
2847	answer.answerlist = msg.answerlist
2848	answer.authlist = msg.authlist
2849	answer.addlist = msg.addlist
2850	if msg.header.rcode == 3:
2851	# name error
2852	# cache negative answer
2853	self.cache.addneg(self.outq[outqkey]['qname'],
2854	self.outq[outqkey]['querytype'],
2855	self.outq[outqkey]['queryclass'])
2856	else:
2857	# cache all rrs
2858	for rr in msg.answerlist:
2859	self.cache.add(rr,'','forwarder')
2860	for rr in msg.authlist:
2861	self.cache.add(rr,'','forwarder')
2862	for rr in msg.addlist:
2863	self.cache.add(rr,'','forwarder')
2864	self.outq[outqkey]['cbfunc']([answer], self.outq[outqkey]['addr'])
2865	del self.outq[outqkey]
2866
2867	def writable(self):
2868	return 0
2869
2870	def handle_write(self):
2871	pass
2872
2873	def handle_connect(self):
2874	pass
2875
2876	def handle_close(self):
2877	# print '1:In handle close'
2878	return
2879
2880	def process_holdq(self):
2881	curtime = time.time()
2882	for hqkey in self.holdq.keys():
2883	for hqrec in self.holdq[hqkey]:
2884	if curtime >= hqrec['processtime']:
2885	log(2,'processing held query')
2886	answer = self.cache.haskey(hqrec['qname'],
2887	hqrec['querytype'],
2888	hqrec['query'])
2889	if answer:
2890	hqrec['cbfunc']([answer], hqrec['addr'])
2891	log(2,'sent answer for ' + hqrec['qname'] +
2892	'(' + hqrec['querytype'] + ') from cache')
2893	self.holdq[hqkey].remove(hqrec)
2894	if len(self.holdq[hqkey]) == 0:
2895	del self.holdq[hqkey]
2896
2897	def reap(self):
2898	self.process_holdq()
2899	curtime = time.time()
2900	log(3,timestamp() + 'processed HOLDQ (sockets: ' +
2901	str(len(asyncore.socket_map.keys()))+')')
2902	if curtime > (self.last_reap_time + self.maint_int):
2903	self.last_reap_time = curtime
2904	for outqkey in self.outq.keys():
2905	if curtime > self.outq[outqkey]['qsenttime'] + self.timeout:
2906	log(2,'query for '+self.outq[outqkey]['qname']+'('+
2907	self.outq[outqkey]['querytype']+') expired')
2908	# don't set forwarders as bad
2909	if not self.outq[outqkey].has_key('flist'):
2910	self.cache.badns(self.outq[outqkey]['qzone'],
2911	self.outq[outqkey]['nsqueriedlastname'])
2912	if self.outq[outqkey].has_key('request'):
2913	log(3,'closing socket for expired query')
2914	self.outq[outqkey]['request'].close()
2915	del self.outq[outqkey]
2916	return
2917
2918	def log_info (self, message, type='info'):
2919	if __debug__ or type != 'info':
2920	log(0,'%s: %s' % (type, message))
2921
2922
2923	def run(configobj):
2924	global loglevel
2925	r = resolver(dnscache(configobj.cached))
2926	ns = nameserver(r, configobj)
2927	udpds = udpdnsserver(53, ns)
2928	tcpds = tcpdnsserver(53, ns)
2929	loglevel = configobj.loglevel
2930	try:
2931	loop(ns.reap)
2932	except KeyboardInterrupt:
2933	print 'server done'
2934
2935	if __name__ == '__main__':
2936	sipb_xen_database.connect('postgres://sipb-xen@sipb-xen-dev/sipb_xen')
2937	zonedict = {'example.net':{'origin':'example.net',
2938	'filename':'db.example.net',
2939	'type':'master',
2940	'slaves':[]}}
2941
2942
2943	zonedict = {'servers.csail.mit.edu':{'origin':'servers.csail.mit.edu',
2944	'filename':'db.servers.csail.mit.edu',
2945	'type':'master',
2946	'slaves':[]}}
2947
2948	zonedict2 = {'example.net':{'origin':'example.net',
2949	'filename':'db.example.net',
2950	'type':'slave',
2951	'masterip':'127.0.0.1'}}
2952	readzonefiles(zonedict)
2953	lconfig = dnsconfig()
2954	lconfig.zonedatabase = zonedb(zonedict)
2955	pr = zonefileparser()
2956	pr.parse('','db.ca')
2957	lconfig.cached = pr.getzdict()
2958	lconfig.loglevel = 3
2959
2960	run(lconfig)

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