DNS/実装/python/dnslib/lame_check/TLD.pyについて、ここに記述してください。

{{{#!python
class TLD:
  #  get delegation ns for top domain-list input  
  def __init__(self):
      self.tld = {}     # tld ns list dictionary
      self.mroot = '202.12.27.33'   #m.root-servers.net
      for line in open('/home/tmaeno/dnslib/TLDs', 'r'):
          domain = line.strip()
          nslist = self.delegation(self.mroot,domain)
          self.tld[domain]= nslist
  #    for x in tld:
  #       print (x, tld[x])
 
  def delegation(self,address,domain):
    from dnslib.dns import DNSRecord,DNSHeader,DNSQuestion,DNSError,QTYPE,EDNS0
    ns = { }   # nslist   (+ ipaddress list) 

    try:
        q0 = DNSQuestion(domain, QTYPE.NS)
        q = DNSRecord(q=q0)
        # print('question ok', q)
        a_pkt = q.send(address, 53, tcp=False)
        a = DNSRecord.parse(a_pkt)
        if a.header.tc :        # Truncated - retry in TCP mode
           a_pkt = q.send(address, 53,tcp=True)
           a = DNSRecord.parse(a_pkt)
        # NXDOMAIN  rcode
        if a.header.rcode != 0 : # ['NOERROR', 'NXDOMAIN', 'SERVFAIL', 'REFUSED']:
           print ('ZONEX', domain, a.header.rcode)
        else:
          for r in a.auth:
              if r.rtype == QTYPE.NS:
                 ns[str(r.rdata)] = []  # address list
          for t in a.ar:
              if t.rtype == QTYPE.A :
                 tt = str(t.rname) 
                 if tt in ns :
                     ns[tt].append(str(t.rdata))
        return ns
    except DNSError as e:
                p.error(e)

  def getaddress(self,d):
      top = d.split('.')[-1]   # e.g. com
      address = ' '
      if top in self.tld:
         ns = self.tld[top]   # ns list
         for x in ns:
           address = ns[x][0]
           break
      else:  # tld unmatch
          pass
      return address
#if __name__ == '__main__':
#    print (TLD.getaddress('com'))

}}}