diff --git a/fake_dns.py b/fake_dns.py index 83f3e6e..62a02a0 100644 --- a/fake_dns.py +++ b/fake_dns.py @@ -1,48 +1,31 @@ +import dns.message +import dns.rdata import dns.resolver import socketserver import os -class DNSQuery: - def __init__(self, data): - self.data = data - self.domain = '' - t = (data[2] >> 3) & 15 - if t == 0: - i = 12 - l = data[i] - while l != 0: - self.domain += data[i + 1:i + l + 1].decode('utf-8') + '.' - i += l + 1 - l = data[i] - - def response(self): - packet = b'' - if self.domain: - name = self.domain - namemap = DNSServer.namemap - if namemap.__contains__(name): - ip = namemap[name] - else: - answer = DNSServer.resolver.cache.data.get((name, 1, 1)) - if not answer: - answer = DNSServer.resolver.resolve(name) - DNSServer.resolver.cache.put((name, 1, 1), answer) - ip = answer[0].to_text() - packet += self.data[:2] + b'\x81\x80' - packet += self.data[4:6] + self.data[4:6] + b'\x00\x00\x00\x00' - packet += self.data[12:] - packet += b'\xc0\x0c' - packet += b'\x00\x01\x00\x01\x00\x00\x00\x3c\x00\x04' - packet += bytes(map(int, ip.split('.'))) - return packet - class DNSUDPHandler(socketserver.BaseRequestHandler): def handle(self): data = self.request[0] socket = self.request[1] try: - query = DNSQuery(data) - socket.sendto(query.response(), self.client_address) + query = dns.message.from_wire(data) + response = dns.message.make_response(query) + for question in query.question: + name = question.name.to_text() + if name in DNSServer.namemap and question.rdtype == 1: + ip = DNSServer.namemap[name] + else: + answer = DNSServer.resolver.cache.data.get((name, 1, 1)) + if not answer: + answer = DNSServer.resolver.resolve(name) + DNSServer.resolver.cache.put((name, 1, 1), answer) + ip = answer[0].to_text() + rdata = dns.rdata.from_text(1, 1, ip) + rrset = dns.rrset.RRset(question.name, 1, 1) + rrset.add(rdata) + response.answer.append(rrset) + socket.sendto(response.to_wire(), self.client_address) except Exception as e: print('fake_dns: %s' % repr(e))