test/test_mtu.py

   1 #!/usr/bin/env python
   2 """IP4 and IP6 MTU functional tests"""
   3
   4 #
   5 # Add tests for:
   6 # - sub interfaces
   7 # - Verify that adjacencies inherit MTU correctly
   8 # - Verify that sub-interfaces inherit MTU correctly
   9 # - Different types of interfaces?
  10 #
  11 import unittest
  12 from scapy.layers.inet6 import IPv6, Ether, IP, UDP, ICMPv6PacketTooBig
  13 from scapy.layers.inet import ICMP
  14 from framework import VppTestCase, VppTestRunner
  15 from vpp_ip import DpoProto
  16 from vpp_ip_route import VppIpRoute, VppRoutePath
  17 from socket import AF_INET, AF_INET6, inet_pton
  18 from util import reassemble4
  19
  20
  21 """ Test_mtu is a subclass of VPPTestCase classes.
  22     MTU tests.
  23 """
  24
  25
  26 class TestMTU(VppTestCase):
  27     """ MTU Test Case """
  28     maxDiff = None
  29
  30     @classmethod
  31     def setUpClass(cls):
  32         super(TestMTU, cls).setUpClass()
  33         cls.create_pg_interfaces(range(2))
  34         cls.interfaces = list(cls.pg_interfaces)
  35
  36     def setUp(self):
  37         super(TestMTU, self).setUp()
  38         for i in self.interfaces:
  39             i.admin_up()
  40             i.config_ip4()
  41             i.config_ip6()
  42             i.disable_ipv6_ra()
  43             i.resolve_arp()
  44             i.resolve_ndp()
  45
  46     def tearDown(self):
  47         super(TestMTU, self).tearDown()
  48         if not self.vpp_dead:
  49             for i in self.pg_interfaces:
  50                 i.unconfig_ip4()
  51                 i.unconfig_ip6()
  52                 i.admin_down()
  53
  54     def validate(self, rx, expected):
  55         self.assertEqual(rx, expected.__class__(expected))
  56
  57     def validate_bytes(self, rx, expected):
  58         self.assertEqual(rx, expected)
  59
  60     def payload(self, len):
  61         return 'x' * len
  62
  63     def get_mtu(self, sw_if_index):
  64         rv = self.vapi.sw_interface_dump()
  65         for i in rv:
  66             if i.sw_if_index == sw_if_index:
  67                 return i.mtu[0]
  68         return 0
  69
  70     def test_ip4_mtu(self):
  71         """ IP4 MTU test """
  72
  73         p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
  74         p_ip4 = IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4,
  75                    flags='DF')
  76
  77         current_mtu = self.get_mtu(self.pg1.sw_if_index)
  78
  79         p_payload = UDP(sport=1234, dport=1234) / self.payload(
  80             current_mtu - 20 - 8)
  81
  82         p4 = p_ether / p_ip4 / p_payload
  83         p4_reply = p_ip4 / p_payload
  84         p4_reply.ttl -= 1
  85         rx = self.send_and_expect(self.pg0, p4*11, self.pg1)
  86         for p in rx:
  87             self.validate(p[1], p4_reply)
  88
  89         # MTU
  90         self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [576, 0, 0, 0])
  91         self.assertEqual(576, self.get_mtu(self.pg1.sw_if_index))
  92
  93         # Should fail. Too large MTU
  94         p_icmp4 = ICMP(type='dest-unreach', code='fragmentation-needed',
  95                        nexthopmtu=576, chksum=0x2dbb)
  96         icmp4_reply = (IP(src=self.pg0.local_ip4,
  97                           dst=self.pg0.remote_ip4,
  98                           ttl=254, len=576, id=0) /
  99                        p_icmp4 / p_ip4 / p_payload)
 100         icmp4_reply[1].ttl -= 1
 101         n = icmp4_reply.__class__(icmp4_reply)
 102         s = bytes(icmp4_reply)
 103         icmp4_reply = s[0:576]
 104         rx = self.send_and_expect(self.pg0, p4*11, self.pg0)
 105         for p in rx:
 106             # p.show2()
 107             # n.show2()
 108             self.validate_bytes(bytes(p[1]), icmp4_reply)
 109
 110         # Now with DF off. Expect fragments.
 111         # First go with 1500 byte packets.
 112         p_payload = UDP(sport=1234, dport=1234) / self.payload(
 113             1500 - 20 - 8)
 114         p4 = p_ether / p_ip4 / p_payload
 115         p4.flags = 0
 116         p4_reply = p_ip4 / p_payload
 117         p4_reply.ttl = 62  # check this
 118         p4_reply.flags = 0
 119         p4_reply.id = 256
 120         self.pg_enable_capture()
 121         self.pg0.add_stream(p4*1)
 122         self.pg_start()
 123         rx = self.pg1.get_capture(3)
 124         reass_pkt = reassemble4(rx)
 125         self.validate(reass_pkt, p4_reply)
 126
 127         '''
 128         # Now what happens with a 9K frame
 129         p_payload = UDP(sport=1234, dport=1234) / self.payload(
 130             current_mtu - 20 - 8)
 131         p4 = p_ether / p_ip4 / p_payload
 132         p4.flags = 0
 133         p4_reply = p_ip4 / p_payload
 134         p4_reply.ttl = 62 # check this
 135         p4_reply.flags = 0
 136         p4_reply.id = 512
 137
 138         self.pg_enable_capture()
 139         self.pg0.add_stream(p4*1)
 140         self.pg_start()
 141         rx = self.pg1.get_capture(16)
 142         reass_pkt = reassemble4(rx)
 143         reass_pkt.show2()
 144         p4_reply.show2()
 145         self.validate(reass_pkt, p4_reply)
 146         '''
 147
 148         # Reset MTU
 149         self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
 150                                        [current_mtu, 0, 0, 0])
 151
 152     def test_ip6_mtu(self):
 153         """ IP6 MTU test """
 154
 155         current_mtu = self.get_mtu(self.pg1.sw_if_index)
 156
 157         p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
 158         p_ip6 = IPv6(src=self.pg0.remote_ip6, dst=self.pg1.remote_ip6)
 159
 160         p_payload = UDP(sport=1234, dport=1234) / self.payload(
 161             current_mtu - 40 - 8)
 162
 163         p6 = p_ether / p_ip6 / p_payload
 164         p6_reply = p_ip6 / p_payload
 165         p6_reply.hlim -= 1
 166         rx = self.send_and_expect(self.pg0, p6*9, self.pg1)
 167         for p in rx:
 168             self.validate(p[1], p6_reply)
 169
 170         # MTU (only checked on encap)
 171         self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [1280, 0, 0, 0])
 172         self.assertEqual(1280, self.get_mtu(self.pg1.sw_if_index))
 173
 174         # Should fail. Too large MTU
 175         p_icmp6 = ICMPv6PacketTooBig(mtu=1280, cksum=0x4c7a)
 176         icmp6_reply = (IPv6(src=self.pg0.local_ip6,
 177                             dst=self.pg0.remote_ip6,
 178                             hlim=255, plen=1240) /
 179                        p_icmp6 / p_ip6 / p_payload)
 180         icmp6_reply[2].hlim -= 1
 181         n = icmp6_reply.__class__(icmp6_reply)
 182         s = bytes(icmp6_reply)
 183         icmp6_reply_str = s[0:1280]
 184
 185         rx = self.send_and_expect(self.pg0, p6*9, self.pg0)
 186         for p in rx:
 187             self.validate_bytes(bytes(p[1]), icmp6_reply_str)
 188
 189         # Reset MTU
 190         self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
 191                                        [current_mtu, 0, 0, 0])
 192
 193
 194 if __name__ == '__main__':
 195     unittest.main(testRunner=VppTestRunner)