test/test_mtu.py

   1 #!/usr/bin/env python3
   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, FibPathProto
  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     @classmethod
  37     def tearDownClass(cls):
  38         super(TestMTU, cls).tearDownClass()
  39
  40     def setUp(self):
  41         super(TestMTU, self).setUp()
  42         for i in self.interfaces:
  43             i.admin_up()
  44             i.config_ip4()
  45             i.config_ip6()
  46             i.disable_ipv6_ra()
  47             i.resolve_arp()
  48             i.resolve_ndp()
  49
  50     def tearDown(self):
  51         super(TestMTU, self).tearDown()
  52         if not self.vpp_dead:
  53             for i in self.pg_interfaces:
  54                 i.unconfig_ip4()
  55                 i.unconfig_ip6()
  56                 i.admin_down()
  57
  58     def validate(self, rx, expected):
  59         self.assertEqual(rx, expected.__class__(expected))
  60
  61     def validate_bytes(self, rx, expected):
  62         self.assertEqual(rx, expected)
  63
  64     def payload(self, len):
  65         return 'x' * len
  66
  67     def get_mtu(self, sw_if_index):
  68         rv = self.vapi.sw_interface_dump(sw_if_index=sw_if_index)
  69         for i in rv:
  70             if i.sw_if_index == sw_if_index:
  71                 return i.mtu[0]
  72         return 0
  73
  74     def test_ip4_mtu(self):
  75         """ IP4 MTU test """
  76
  77         p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
  78         p_ip4 = IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4,
  79                    flags='DF')
  80
  81         current_mtu = self.get_mtu(self.pg1.sw_if_index)
  82
  83         p_payload = UDP(sport=1234, dport=1234) / self.payload(
  84             current_mtu - 20 - 8)
  85
  86         p4 = p_ether / p_ip4 / p_payload
  87         p4_reply = p_ip4 / p_payload
  88         p4_reply.ttl -= 1
  89         rx = self.send_and_expect(self.pg0, p4*11, self.pg1)
  90         for p in rx:
  91             self.validate(p[1], p4_reply)
  92
  93         # MTU
  94         self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [576, 0, 0, 0])
  95         self.assertEqual(576, self.get_mtu(self.pg1.sw_if_index))
  96
  97         # Should fail. Too large MTU
  98         p_icmp4 = ICMP(type='dest-unreach', code='fragmentation-needed',
  99                        nexthopmtu=576, chksum=0x2dbb)
 100         icmp4_reply = (IP(src=self.pg0.local_ip4,
 101                           dst=self.pg0.remote_ip4,
 102                           ttl=254, len=576, id=0) /
 103                        p_icmp4 / p_ip4 / p_payload)
 104         n = icmp4_reply.__class__(icmp4_reply)
 105         s = bytes(icmp4_reply)
 106         icmp4_reply = s[0:576]
 107         rx = self.send_and_expect(self.pg0, p4*11, self.pg0)
 108         for p in rx:
 109             # p.show2()
 110             # n.show2()
 111             self.validate_bytes(bytes(p[1]), icmp4_reply)
 112
 113         # Now with DF off. Expect fragments.
 114         # First go with 1500 byte packets.
 115         p_payload = UDP(sport=1234, dport=1234) / self.payload(
 116             1500 - 20 - 8)
 117         p4 = p_ether / p_ip4 / p_payload
 118         p4.flags = 0
 119         p4_reply = p_ip4 / p_payload
 120         p4_reply.ttl = p_ip4.ttl - 1
 121         p4_reply.flags = 0
 122         p4_reply.id = 256
 123         self.pg_enable_capture()
 124         self.pg0.add_stream(p4*1)
 125         self.pg_start()
 126         rx = self.pg1.get_capture(3)
 127         reass_pkt = reassemble4(rx)
 128         self.validate(reass_pkt, p4_reply)
 129
 130         '''
 131         # Now what happens with a 9K frame
 132         p_payload = UDP(sport=1234, dport=1234) / self.payload(
 133             current_mtu - 20 - 8)
 134         p4 = p_ether / p_ip4 / p_payload
 135         p4.flags = 0
 136         p4_reply = p_ip4 / p_payload
 137         p4_reply.ttl = 62 # check this
 138         p4_reply.flags = 0
 139         p4_reply.id = 512
 140
 141         self.pg_enable_capture()
 142         self.pg0.add_stream(p4*1)
 143         self.pg_start()
 144         rx = self.pg1.get_capture(16)
 145         reass_pkt = reassemble4(rx)
 146         reass_pkt.show2()
 147         p4_reply.show2()
 148         self.validate(reass_pkt, p4_reply)
 149         '''
 150
 151         # Reset MTU
 152         self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
 153                                        [current_mtu, 0, 0, 0])
 154
 155     def test_ip6_mtu(self):
 156         """ IP6 MTU test """
 157
 158         current_mtu = self.get_mtu(self.pg1.sw_if_index)
 159
 160         p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
 161         p_ip6 = IPv6(src=self.pg0.remote_ip6, dst=self.pg1.remote_ip6)
 162
 163         p_payload = UDP(sport=1234, dport=1234) / self.payload(
 164             current_mtu - 40 - 8)
 165
 166         p6 = p_ether / p_ip6 / p_payload
 167         p6_reply = p_ip6 / p_payload
 168         p6_reply.hlim -= 1
 169         rx = self.send_and_expect(self.pg0, p6*9, self.pg1)
 170         for p in rx:
 171             self.validate(p[1], p6_reply)
 172
 173         # MTU (only checked on encap)
 174         self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [1280, 0, 0, 0])
 175         self.assertEqual(1280, self.get_mtu(self.pg1.sw_if_index))
 176
 177         # Should fail. Too large MTU
 178         p_icmp6 = ICMPv6PacketTooBig(mtu=1280, cksum=0x4c7a)
 179         icmp6_reply = (IPv6(src=self.pg0.local_ip6,
 180                             dst=self.pg0.remote_ip6,
 181                             hlim=255, plen=1240) /
 182                        p_icmp6 / p_ip6 / p_payload)
 183         icmp6_reply[2].hlim -= 1
 184         n = icmp6_reply.__class__(icmp6_reply)
 185         s = bytes(icmp6_reply)
 186         icmp6_reply_str = s[0:1280]
 187
 188         rx = self.send_and_expect(self.pg0, p6*9, self.pg0)
 189         for p in rx:
 190             self.validate_bytes(bytes(p[1]), icmp6_reply_str)
 191
 192         # Reset MTU
 193         self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
 194                                        [current_mtu, 0, 0, 0])
 195
 196
 197 if __name__ == '__main__':
 198     unittest.main(testRunner=VppTestRunner)