2 """IP4 and IP6 MTU functional tests"""
7 # - Verify that adjacencies inherit MTU correctly
8 # - Verify that sub-interfaces inherit MTU correctly
9 # - Different types of interfaces?
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
21 """ Test_mtu is a subclass of VPPTestCase classes.
26 class TestMTU(VppTestCase):
33 super(TestMTU, cls).setUpClass()
34 cls.create_pg_interfaces(range(2))
35 cls.interfaces = list(cls.pg_interfaces)
38 def tearDownClass(cls):
39 super(TestMTU, cls).tearDownClass()
42 super(TestMTU, self).setUp()
43 for i in self.interfaces:
52 super(TestMTU, self).tearDown()
54 for i in self.pg_interfaces:
59 def validate(self, rx, expected):
60 self.assertEqual(rx, expected.__class__(expected))
62 def validate_bytes(self, rx, expected):
63 self.assertEqual(rx, expected)
65 def payload(self, len):
68 def get_mtu(self, sw_if_index):
69 rv = self.vapi.sw_interface_dump(sw_if_index=sw_if_index)
71 if i.sw_if_index == sw_if_index:
75 def test_ip4_mtu(self):
78 p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
79 p_ip4 = IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4, flags="DF")
81 current_mtu = self.get_mtu(self.pg1.sw_if_index)
83 p_payload = UDP(sport=1234, dport=1234) / self.payload(current_mtu - 20 - 8)
85 p4 = p_ether / p_ip4 / p_payload
86 p4_reply = p_ip4 / p_payload
88 rx = self.send_and_expect(self.pg0, p4 * 11, self.pg1)
90 self.validate(p[1], p4_reply)
93 self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [576, 0, 0, 0])
94 self.assertEqual(576, self.get_mtu(self.pg1.sw_if_index))
96 # Should fail. Too large MTU
99 code="fragmentation-needed",
104 IP(src=self.pg0.local_ip4, dst=self.pg0.remote_ip4, ttl=254, len=576, id=0)
109 n = icmp4_reply.__class__(icmp4_reply)
110 s = bytes(icmp4_reply)
111 icmp4_reply = s[0:576]
112 rx = self.send_and_expect_some(self.pg0, p4 * 11, self.pg0)
116 self.validate_bytes(bytes(p[1]), icmp4_reply)
118 # Now with DF off. Expect fragments.
119 # First go with 1500 byte packets.
120 p_payload = UDP(sport=1234, dport=1234) / self.payload(1500 - 20 - 8)
121 p4 = p_ether / p_ip4 / p_payload
123 p4_reply = p_ip4 / p_payload
124 p4_reply.ttl = p_ip4.ttl - 1
127 self.pg_enable_capture()
128 self.pg0.add_stream(p4 * 1)
130 rx = self.pg1.get_capture(3)
131 reass_pkt = reassemble4(rx)
132 self.validate(reass_pkt, p4_reply)
135 # Now what happens with a 9K frame
136 p_payload = UDP(sport=1234, dport=1234) / self.payload(
137 current_mtu - 20 - 8)
138 p4 = p_ether / p_ip4 / p_payload
140 p4_reply = p_ip4 / p_payload
141 p4_reply.ttl = 62 # check this
145 self.pg_enable_capture()
146 self.pg0.add_stream(p4*1)
148 rx = self.pg1.get_capture(16)
149 reass_pkt = reassemble4(rx)
152 self.validate(reass_pkt, p4_reply)
156 self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [current_mtu, 0, 0, 0])
158 def test_ip6_mtu(self):
161 current_mtu = self.get_mtu(self.pg1.sw_if_index)
163 p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
164 p_ip6 = IPv6(src=self.pg0.remote_ip6, dst=self.pg1.remote_ip6)
166 p_payload = UDP(sport=1234, dport=1234) / self.payload(current_mtu - 40 - 8)
168 p6 = p_ether / p_ip6 / p_payload
169 p6_reply = p_ip6 / p_payload
171 rx = self.send_and_expect(self.pg0, p6 * 9, self.pg1)
173 self.validate(p[1], p6_reply)
175 # MTU (only checked on encap)
176 self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [1280, 0, 0, 0])
177 self.assertEqual(1280, self.get_mtu(self.pg1.sw_if_index))
179 # Should fail. Too large MTU
180 p_icmp6 = ICMPv6PacketTooBig(mtu=1280, cksum=0x4C7A)
182 IPv6(src=self.pg0.local_ip6, dst=self.pg0.remote_ip6, hlim=255, plen=1240)
187 icmp6_reply[2].hlim -= 1
188 n = icmp6_reply.__class__(icmp6_reply)
189 s = bytes(icmp6_reply)
190 icmp6_reply_str = s[0:1280]
192 rx = self.send_and_expect_some(self.pg0, p6 * 9, self.pg0)
194 self.validate_bytes(bytes(p[1]), icmp6_reply_str)
197 self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [current_mtu, 0, 0, 0])
200 if __name__ == "__main__":
201 unittest.main(testRunner=VppTestRunner)