projects / thirdparty / pdns.git / blame
| Commit | Line | Data |
|---|---|---|
| d328c3f0 RG |
1 | import dns |
| 2 | import os | |
| 3 | import socket | |
| 4 | import struct | |
| 5 | import threading | |
| 6 | import time | |
| 7 | ||
| 8 | from recursortests import RecursorTest | |
| 9 | from twisted.internet.protocol import DatagramProtocol | |
| 10 | from twisted.internet import reactor | |
| 11 | ||
| 12 | largeReactorRunning = False | |
| 13 | ||
| 14 | class LargeAnswerTest(RecursorTest): | |
| 15 | """ | |
| 16 | This test makes sure that we correctly process an answer matching our exact | |
| 17 | udp-truncation-threshold buffer size. | |
| 18 | """ | |
| 19 | _confdir = 'LargeAnswer' | |
| 20 | _udpTruncationThreshold = 1680 | |
| 21 | ||
| 22 | _config_template = """ | |
| 23 | forward-zones=large-answer.example=%s.22 | |
| 24 | udp-truncation-threshold=%d | |
| 25 | """ % (os.environ['PREFIX'], _udpTruncationThreshold) | |
| 26 | ||
| 27 | @classmethod | |
| 28 | def startResponders(cls): | |
| 29 | global largeReactorRunning | |
| 30 | print("Launching responders..") | |
| 31 | ||
| 32 | address = cls._PREFIX + '.22' | |
| 33 | port = 53 | |
| 34 | ||
| 35 | if not largeReactorRunning: | |
| 36 | reactor.listenUDP(port, UDPLargeResponder(), interface=address) | |
| 37 | largeReactorRunning = True | |
| 38 | ||
| 39 | if not reactor.running: | |
| d023146c | 40 | cls._UDPResponder = threading.Thread(name='UDP Responder', target=reactor.run, args=(False,)) |
| d328c3f0 RG |
41 | cls._UDPResponder.setDaemon(True) |
| 42 | cls._UDPResponder.start() | |
| 43 | ||
| d328c3f0 RG |
44 | def checkResponseContent(self, rawResponse, value): |
| 45 | self.assertEquals(len(rawResponse), self._udpTruncationThreshold) | |
| 46 | response = dns.message.from_wire(rawResponse) | |
| 47 | ||
| 48 | self.assertRcodeEqual(response, dns.rcode.NOERROR) | |
| 49 | self.assertFalse(response.flags & dns.flags.TC) | |
| 50 | ||
| 51 | for record in response.answer: | |
| 52 | self.assertEquals(record.rdtype, dns.rdatatype.TXT) | |
| 53 | for part in record: | |
| 54 | for string in part.strings: | |
| 55 | self.assertTrue(len(string) == 255 or len(string) == 16) | |
| 56 | for c in string: | |
| 57 | self.assertEquals(c, value) | |
| 58 | ||
| 59 | def testLargeAnswer(self): | |
| 60 | # why the same query 10 times, do you ask? because if we are reading from | |
| 61 | # unintialized buffer memory, there is small risk that we find exactly the | |
| 62 | # value we expected by chance so let's massage our buffer a bit | |
| 63 | query = dns.message.make_query('AAAA.large-answer.example.', 'TXT', 'IN', use_edns=True, payload=4096) | |
| 64 | for _ in range(10): | |
| 65 | raw = self.sendUDPQuery(query, decode=False) | |
| 66 | self.checkResponseContent(raw, 'A') | |
| 67 | ||
| 68 | query = dns.message.make_query('ZZZZ.large-answer.example.', 'TXT', 'IN', use_edns=True, payload=4096) | |
| 69 | for _ in range(10): | |
| 70 | raw = self.sendUDPQuery(query, decode=False) | |
| 71 | self.checkResponseContent(raw, 'Z') | |
| 72 | ||
| 73 | class UDPLargeResponder(DatagramProtocol): | |
| 74 | ||
| 75 | def datagramReceived(self, datagram, address): | |
| 76 | request = dns.message.from_wire(datagram) | |
| 77 | ||
| 78 | response = dns.message.make_response(request) | |
| 79 | response.use_edns(edns=False) | |
| 80 | response.flags |= dns.flags.AA | |
| 81 | ||
| 82 | if request.question[0].name == dns.name.from_text('AAAA.large-answer.example.'): | |
| 83 | value = 'A' | |
| 84 | else: | |
| 85 | value = 'Z' | |
| 86 | ||
| 87 | answer = dns.rrset.from_text(request.question[0].name, 0, dns.rdataclass.IN, 'TXT', value*255) | |
| 88 | for _ in range(6): | |
| 89 | response.answer.append(answer) | |
| 90 | answer = dns.rrset.from_text(request.question[0].name, 0, dns.rdataclass.IN, 'TXT', value*16) | |
| 91 | response.answer.append(answer) | |
| 92 | self.transport.write(response.to_wire(max_size=65535), address) |