MoinQ: attachment:zone.py of DNS/実装/ゾーンサーバ/zone.py

   1 #!/usr/bin/env python
   2 from sets import Set
   3 
   4 import dnslib
   5 from dnslib import QTYPE, SOA, NS, A, AAAA, MX, CNAME
   6 from dnslib import DNSRecord, DNSHeader, RR, RCODE
   7 
   8 class Zone:
   9     def __init__(self):
  10 	self.name = ''  # zone name
  11 	self.data = {}  # Dict;  key is a domain name
  12 		          #value: Dict for rtype # value: RRSet
  13 	self.cuts = {}  # delegation point; dict key: name, val: NS Set
  14         self.glue = {}
  15 	self.soa = Set([])
  16 	#self.ns = Set([])
  17 
  18     def ReadRR(self,zfile):
  19 	rrlist = RR.fromZone(zfile)
  20 	for rr in rrlist:
  21 	  name = str(rr.rname)
  22  	  if not(name in self.data) :  #new name
  23 	     self.data[name] = {}   # make empty node
  24 	     upname = '.'.join(name.split('.')[1:])
  25 	     while not (len(upname)>0 & (upname in self.data)):
  26 		self.data[upname] = {}
  27 	     	upname = '.'.join(upname.split('.')[1:])
  28 	  elif rr.rtype == QTYPE.CNAME :
  29 	     print 'CNAME error #1', self[name], rr
  30 
  31 	  if QTYPE.CNAME in self.data[name]: # CNAME exists
  32 	     print 'CNAME error #2', self.data[name], rr
  33 	  if not(rr.rtype in self.data[name]):  # new rtype -> rrset
  34 	     self.data[name][rr.rtype] = Set([])  # empty query type
  35 	  self.data[name][rr.rtype].add(rr)
  36 
  37 	  if rr.rtype == QTYPE.SOA :
  38 	    if self.name == '':
  39 	       self.name = name
  40 	       print 'SOA == ', rr
  41 	    else :
  42 	      print 'SOA duplicate ', self, name
  43 
  44     def delegation(self, nsname):
  45      	self.cuts[nsname] = self.data[nsname]
  46      	print 'cut found: ', nsname
  47 	for rrtype in self.data[nsname]:
  48 	    if rrtype == QTYPE.NS :
  49 		nsset = self.data[nsname][QTYPE.NS]
  50 		print 'Cut NS', nsset
  51 		for ns in nsset:
  52 		    self.glue[ns.rdata]= {}  # need glue
  53 		    print 'need glue for', ns.rdata
  54             else:
  55 		print 'delegation and record error', nsname
  56 
  57     def Check_cuts(self):
  58 	for ns in self.cuts:
  59            suffix = '.' + ns 
  60 	   for name in self.data.keys():
  61 	      if name.endswith(suffix):
  62 		self.cuts[ns][name] = self.data[name]
  63 		print ns, self.data[ns]
  64 		print name, self.data[name]  #glue ?
  65 		del self.data[name]
  66 
  67     def Check_zone(self):
  68 	if len(self.name)==0 :
  69 	   print 'No zone found'
  70 	   return
  71 	zsuffix = '.'+ self.name
  72 	for name in self.data:
  73   	  if name == self.name:  #zone apex
  74 	     rrs = self.data[self.name]
  75 	     if QTYPE.SOA in rrs:
  76    	        self.soa = rrs[QTYPE.SOA].copy().pop()
  77    	     #self.ns = rrs[QTYPE.NS]
  78 	  elif name.endswith(zsuffix) :  # cuts found
  79   	     if QTYPE.NS in self.data[name]:
  80 		self.delegation(name)
  81           else:  # Out of zone name
  82 	     del self.data[name]
  83 	     print 'Out of zone record',
  84 	     print name, (self.data[name])
  85 
  86         self.Check_cuts()
  87 
  88     def print_apex(self):
  89 	  print '---- zone apex record ----'
  90 	  print 'zone name ', self.name
  91 	  print self.data[self.name]
  92 	  print '-----'
  93 	  print 'SOA = ',self.soa
  94 	  #print 'NS = ', self.ns
  95 	  print 'cuts =', self.cuts.keys()
  96 	  for nn in self.cuts.keys():
  97 	      print '---', self.data[nn]	
  98 
  99     def dns_response(self, query): #query = DNSRecord.parse(packet)
 100        reply = DNSRecord(DNSHeader(id=query.header.id, qr=1, aa=1), q=query.q)
 101        qname = query.q.qname
 102        qtype = query.q.qtype
 103        qt = QTYPE[qtype]
 104        qn = str(qname).lower()
 105 
 106        if qn in self.data:
 107           print self.data[qn]
 108           if qtype in self.data[qn]:
 109             for rr in self.data[qn][qtype]: #rrset
 110 	      print 'found RRSet', rr
 111               reply.add_answer(rr) # answer RRSet
 112           elif (QTYPE.CNAME in self.data[qn]) :
 113                print 'CNAME found. ---', self.data[qn][QTYPE.CNAME]
 114 	       for rr in self.data[qn][QTYPE.CNAME]:
 115        	         reply.add_answer(RR(qname, QTYPE.CNAME, ttl=TTL, rdata=rr.rdata))
 116           #    reply.add_answer(RR(qname, QTYPE.NS, ttl=TTL, rdata=rdata)
 117           else: #NoData response here
 118             reply.add_auth(self.soa)
 119 
 120        else:  # NXDomain
 121          if not (qn.endswith('.' + self.name)): 
 122 	    print "Out of zone query"
 123 	    return
 124          # cuts test
 125 	 for nn in self.cuts:
 126 	     if qn.endswith('.' + nn):
 127 		print 'delegation found', nn, qn
 128 		print '   ', self.data[nn][QTYPE.NS]
 129 		for rr in self.data[nn][QTYPE.NS]:
 130 		   reply.add_auth(rr)
 131 		   # may need glue in additional section
 132 	        return reply
 133          # NXDOMAIN
 134          reply.add_auth(self.soa)
 135          reply.header.rcode = getattr(RCODE,'NXDOMAIN')
 136 
 137        return reply
 138 
 139 if __name__ == '__main__':
 140   print '------ start ------'
 141   zone = Zone()
 142 
 143   zone.ReadRR(open('zone.txt').read())
 144   zone.Check_zone()
 145   zone.print_apex()
 146   print  '-------- Zone processed ---------'
 147 
 148   print  '-------- query test ---------'
 149 
 150   d = DNSRecord.question("x.c.d.qMaiL.jp","A")
 151   print d
 152   print zone.dns_response(d)
 153 
 154   d = DNSRecord.question("d.c.d.qmail.jp","A")
 155   print d
 156   print zone.dns_response(d)
 157 
 158   print '---------------------------------'
 159   d = DNSRecord.question("x.d.qmail.jp","A")
 160   print d
 161   print zone.dns_response(d)