test/test_dns.py

   1 #!/usr/bin/env python3
   2
   3 import unittest
   4
   5 from framework import VppTestCase
   6 from asfframework import VppTestRunner
   7 from ipaddress import *
   8 from config import config
   9
  10 from scapy.layers.inet import IP, UDP
  11 from scapy.layers.l2 import Ether
  12 from scapy.layers.dns import DNS, DNSQR
  13
  14
  15 @unittest.skipIf("dns" in config.excluded_plugins, "Exclude DNS plugin tests")
  16 class TestDns(VppTestCase):
  17     """Dns Test Cases"""
  18
  19     @classmethod
  20     def setUpClass(cls):
  21         super(TestDns, cls).setUpClass()
  22
  23     @classmethod
  24     def tearDownClass(cls):
  25         super(TestDns, cls).tearDownClass()
  26
  27     def setUp(self):
  28         super(TestDns, self).setUp()
  29
  30         self.create_pg_interfaces(range(1))
  31
  32         for i in self.pg_interfaces:
  33             i.admin_up()
  34             i.config_ip4()
  35             i.resolve_arp()
  36
  37     def tearDown(self):
  38         super(TestDns, self).tearDown()
  39
  40     def create_stream(self, src_if):
  41         """Create input packet stream for defined interface.
  42
  43         :param VppInterface src_if: Interface to create packet stream for.
  44         """
  45         good_request = (
  46             Ether(dst=src_if.local_mac, src=src_if.remote_mac)
  47             / IP(src=src_if.remote_ip4)
  48             / UDP(sport=1234, dport=53)
  49             / DNS(rd=1, qd=DNSQR(qname="bozo.clown.org"))
  50         )
  51
  52         bad_request = (
  53             Ether(dst=src_if.local_mac, src=src_if.remote_mac)
  54             / IP(src=src_if.remote_ip4)
  55             / UDP(sport=1234, dport=53)
  56             / DNS(rd=1, qd=DNSQR(qname="no.clown.org"))
  57         )
  58         pkts = [good_request, bad_request]
  59         return pkts
  60
  61     def verify_capture(self, dst_if, capture):
  62         """Verify captured input packet stream for defined interface.
  63
  64         :param VppInterface dst_if: Interface to verify captured packet stream
  65             for.
  66         :param list capture: Captured packet stream.
  67         """
  68         self.logger.info("Verifying capture on interface %s" % dst_if.name)
  69         for packet in capture:
  70             dns = packet[DNS]
  71             self.assertEqual(dns.an[0].rdata, "1.2.3.4")
  72
  73     def test_dns_unittest(self):
  74         """DNS Name Resolver Basic Functional Test"""
  75
  76         # Set up an upstream name resolver. We won't actually go there
  77         self.vapi.dns_name_server_add_del(
  78             is_ip6=0, is_add=1, server_address=IPv4Address("8.8.8.8").packed
  79         )
  80
  81         # Enable name resolution
  82         self.vapi.dns_enable_disable(enable=1)
  83
  84         # Manually add a static dns cache entry
  85         self.logger.info(self.vapi.cli("dns cache add bozo.clown.org 1.2.3.4"))
  86
  87         # Test the binary API
  88         rv = self.vapi.dns_resolve_name(name=b"bozo.clown.org")
  89         self.assertEqual(rv.ip4_address, IPv4Address("1.2.3.4").packed)
  90
  91         # Configure 127.0.0.1/8 on the pg interface
  92         self.vapi.sw_interface_add_del_address(
  93             sw_if_index=self.pg0.sw_if_index, prefix="127.0.0.1/8"
  94         )
  95
  96         # Send a couple of DNS request packets, one for bozo.clown.org
  97         # and one for no.clown.org which won't resolve
  98
  99         pkts = self.create_stream(self.pg0)
 100         self.pg0.add_stream(pkts)
 101         self.pg_enable_capture(self.pg_interfaces)
 102
 103         self.pg_start()
 104         pkts = self.pg0.get_capture(1)
 105         self.verify_capture(self.pg0, pkts)
 106
 107         # Make sure that the cache contents are correct
 108         str = self.vapi.cli("show dns cache verbose")
 109         self.assertIn("1.2.3.4", str)
 110         self.assertIn("[P] no.clown.org:", str)
 111
 112
 113 if __name__ == "__main__":
 114     unittest.main(testRunner=VppTestRunner)