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
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):
32 super(TestMTU, cls).setUpClass()
33 cls.create_pg_interfaces(range(2))
34 cls.interfaces = list(cls.pg_interfaces)
37 super(TestMTU, self).setUp()
38 for i in self.interfaces:
47 super(TestMTU, self).tearDown()
49 for i in self.pg_interfaces:
54 def validate(self, rx, expected):
55 self.assertEqual(rx, expected.__class__(expected))
57 def validate_bytes(self, rx, expected):
58 self.assertEqual(rx, expected)
60 def payload(self, len):
63 def get_mtu(self, sw_if_index):
64 rv = self.vapi.sw_interface_dump()
66 if i.sw_if_index == sw_if_index:
70 def test_ip4_mtu(self):
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,
77 current_mtu = self.get_mtu(self.pg1.sw_if_index)
79 p_payload = UDP(sport=1234, dport=1234) / self.payload(
82 p4 = p_ether / p_ip4 / p_payload
83 p4_reply = p_ip4 / p_payload
85 rx = self.send_and_expect(self.pg0, p4*11, self.pg1)
87 self.validate(p[1], p4_reply)
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))
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)
108 self.validate_bytes(bytes(p[1]), icmp4_reply)
110 # Now with DF off. Expect fragments.
111 # First go with 1500 byte packets.
112 p_payload = UDP(sport=1234, dport=1234) / self.payload(
114 p4 = p_ether / p_ip4 / p_payload
116 p4_reply = p_ip4 / p_payload
117 p4_reply.ttl = 62 # check this
120 self.pg_enable_capture()
121 self.pg0.add_stream(p4*1)
123 rx = self.pg1.get_capture(3)
124 reass_pkt = reassemble4(rx)
125 self.validate(reass_pkt, p4_reply)
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
133 p4_reply = p_ip4 / p_payload
134 p4_reply.ttl = 62 # check this
138 self.pg_enable_capture()
139 self.pg0.add_stream(p4*1)
141 rx = self.pg1.get_capture(16)
142 reass_pkt = reassemble4(rx)
145 self.validate(reass_pkt, p4_reply)
149 self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
150 [current_mtu, 0, 0, 0])
152 def test_ip6_mtu(self):
155 current_mtu = self.get_mtu(self.pg1.sw_if_index)
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)
160 p_payload = UDP(sport=1234, dport=1234) / self.payload(
161 current_mtu - 40 - 8)
163 p6 = p_ether / p_ip6 / p_payload
164 p6_reply = p_ip6 / p_payload
166 rx = self.send_and_expect(self.pg0, p6*9, self.pg1)
168 self.validate(p[1], p6_reply)
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))
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]
185 rx = self.send_and_expect(self.pg0, p6*9, self.pg0)
187 self.validate_bytes(bytes(p[1]), icmp6_reply_str)
190 self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
191 [current_mtu, 0, 0, 0])
194 if __name__ == '__main__':
195 unittest.main(testRunner=VppTestRunner)