#format python

#!/usr/bin/env python
import sys
import time
import datetime
import threading
import traceback
import SocketServer
from sets import Set

import dnslib
from dnslib import QTYPE, SOA, NS, A, AAAA, MX, CNAME
from dnslib import DNSRecord, DNSHeader, RR, RCODE

z = 'd.qmail.jp.'
IP= '192.168.10.7'
TTL = 60 * 5
PORT = 5053
#---------------- read zone -----------------------
zone ={}  #Dict;  key is a domain name
          #value: Dict for rtype
               # value: RRSet

zonetxt = open('zone.txt').read()
print(zonetxt)
print '-----'
zonerr= RR.fromZone(zonetxt)
for rr in zonerr:
  name = str(rr.rname)
  if not(name in zone) :
     zone[name] = {}   # make empty node
  if not(rr.rtype in zone[name]): 
     zone[name][rr.rtype] = Set([])  # empty query type
  zone[name][rr.rtype].add(rr)
# -----
for name in zone:
  print name, zone[name]
print '-----'
#-----
for rrs in zone:
  print (zone[rrs])

print '--------------------------------'

rrs = zone[z]  # zone apex node
if QTYPE.SOA in rrs:
   soa_record = rrs[QTYPE.SOA].pop()
print 'SOA= ', soa_record

#------
IP= '192.168.10.7'
TTL = 60 * 5
PORT = 5053
ServerIP = '192.168.10.7'

def dns_response(packet):
    query = DNSRecord.parse(packet)
    print '--- query ---' 
    print query
    print '------------'

    reply = DNSRecord(DNSHeader(id=query.header.id, qr=1, aa=1), q=query.q)
    reply  #debug print
    qname = query.q.qname
    qtype = query.q.qtype
    qt = QTYPE[qtype]
    qn = str(qname).lower()

    if qn in zone :
       print zone[qn]
       if qtype in zone[qn]:
         for rr in zone[qn][qtype]: #rrset
           print 'found RRSet', rr
           reply.add_answer(rr)
       else:
         if QTYPE.CNAME in zone[qn] :
            print 'CNAME found.'
            print zone[qn][QTYPE.CNAME]
            for rr in zone[qn][QTYPE.CNAME]:
              reply.add_answer(RR(qname, QTYPE.CNAME, ttl=TTL, rdata=rr.rdata))

       #    reply.add_answer(RR(qname, QTYPE.NS, ttl=TTL, rdata=rdata)
       #NoData response here
       #    reply.add_auth(RR(D, QTYPE.NS, ttl=TTL, rdata=rdata))
    else:  # NXDomain
       if not (qn.endswith('.' + z)): return
       reply.add_auth(soa_record)
       #NoData response here may be
       reply.header.rcode = getattr(RCODE,'NXDOMAIN')

    print "---- Reply:\n", reply
    return reply.pack()


class BaseRequestHandler(SocketServer.BaseRequestHandler):

    def get_data(self):
        raise NotImplementedError

    def send_data(self, data):
        raise NotImplementedError

    def handle(self):
        now = datetime.datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S.%f')
        print "\n\n%s request %s (%s %s):" % (self.__class__.__name__[:3], now, 
self.client_address[0],
                                               self.client_address[1])
        try:
            data = self.get_data()
            print len(data), data.encode('hex')  # repr(data).replace('\\x', '')
[1:-1]
            self.send_data(dns_response(data))
        except Exception:
            traceback.print_exc(file=sys.stderr)


class UDPRequestHandler(BaseRequestHandler):

    def get_data(self):
        return self.request[0].strip()

    def send_data(self, data):
        return self.request[1].sendto(data, self.client_address)


if __name__ == '__main__':
    print "Starting nameserver..."

    servers = [
        SocketServer.ThreadingUDPServer((ServerIP, PORT), UDPRequestHandler),
       # SocketServer.ThreadingTCPServer((ServerIP, PORT), TCPRequestHandler),
    ]
    for s in servers:
        thread = threading.Thread(target=s.serve_forever)  # that thread will st
art one more thread for each request
        thread.daemon = True  # exit the server thread when the main thread term
inates
        thread.start()
        print "%s server loop running in thread: %s" % (s.RequestHandlerClass.__
name__[:3], thread.name)

    try:
        while 1:
            time.sleep(1)
            sys.stderr.flush()
            sys.stdout.flush()

    except KeyboardInterrupt:
        pass
    finally:
        for s in servers:
            s.shutdown()