1 #
2 # WARNING: See dnsmasq --address=/#/1.2.3.4 before!!!!!
3 #
4
5 # Fake dns multithread
6
7 from SocketServer import *
8
9 FAKEADDRESS="111.111.111.111"
10 PORT=53 #udp
11
12 class DNSQuery:
13 #da http://preachermm.blogspot.com/2006/04/servidor-fake-dns-en-python.html (single thread)
14 def __init__(self, data):
15 self.data=data
16 self.dominio=''
17 tipo = (ord(data[2]) >> 3) & 15 # Opcode bits
18 if tipo == 0: # Standard query
19 ini=12
20 lon=ord(data[ini])
21 while lon != 0:
22 self.dominio+=data[ini+1:ini+lon+1]+'.'
23 ini+=lon+1
24 lon=ord(data[ini])
25
26 def respuesta(self, ip):
27 packet=''
28 if self.dominio:
29 packet+=self.data[:2] + "\x81\x80"
30 packet+=self.data[4:6] + self.data[4:6] + '\x00\x00\x00\x00' # Questions and Answers Counts
31 packet+=self.data[12:] # Original Domain Name Question
32 packet+='\xc0\x0c' # Pointer to domain name
33 packet+='\x00\x01\x00\x01\x00\x00\x00\x3c\x00\x04' # Response type, ttl and resource data length -> 4 bytes
34 packet+=''.join(chr(int(x)) for x in ip.split('.')) # 4bytes of IP
35 return packet
36 #DNSQuery
37
38 class DNSRequestHandler (DatagramRequestHandler):
39 def handle(self):
40 DNSRequest=self.rfile.read()
41 q=DNSQuery(DNSRequest)
42 DNSDatagram=q.respuesta(FAKEADDRESS)
43 self.wfile.write(DNSDatagram)
44 #DNSRequestHandler
45
46 #crea una classe di server udp threadizzato
47 class FakeDNSServer (ThreadingMixIn, UDPServer): pass
48
49 dummyDNS=FakeDNSServer(('',PORT),DNSRequestHandler)
50
51 #per prevenire attacchi, l'unico modo x fermare il server e' killarlo (SIGTERM, SIGKILL) o premere ctrl-C
52 going=True
53 while going:
54 try:
55 dummyDNS.serve_forever()
56 except KeyboardInterrupt:
57 going=False
58 except:
59 pass
