#!/usr/bin/env python3 """IP4 and IP6 MTU functional tests""" # # Add tests for: # - sub interfaces # - Verify that adjacencies inherit MTU correctly # - Verify that sub-interfaces inherit MTU correctly # - Different types of interfaces? # import unittest from scapy.layers.inet6 import IPv6, Ether, IP, UDP, ICMPv6PacketTooBig from scapy.layers.inet import ICMP from framework import VppTestCase, VppTestRunner from vpp_ip import DpoProto from vpp_ip_route import VppIpRoute, VppRoutePath, FibPathProto from socket import AF_INET, AF_INET6, inet_pton from util import reassemble4 """ Test_mtu is a subclass of VPPTestCase classes. MTU tests. """ class TestMTU(VppTestCase): """ MTU Test Case """ maxDiff = None @classmethod def setUpClass(cls): super(TestMTU, cls).setUpClass() cls.create_pg_interfaces(range(2)) cls.interfaces = list(cls.pg_interfaces) @classmethod def tearDownClass(cls): super(TestMTU, cls).tearDownClass() def setUp(self): super(TestMTU, self).setUp() for i in self.interfaces: i.admin_up() i.config_ip4() i.config_ip6() i.disable_ipv6_ra() i.resolve_arp() i.resolve_ndp() def tearDown(self): super(TestMTU, self).tearDown() if not self.vpp_dead: for i in self.pg_interfaces: i.unconfig_ip4() i.unconfig_ip6() i.admin_down() def validate(self, rx, expected): self.assertEqual(rx, expected.__class__(expected)) def validate_bytes(self, rx, expected): self.assertEqual(rx, expected) def payload(self, len): return 'x' * len def get_mtu(self, sw_if_index): rv = self.vapi.sw_interface_dump(sw_if_index=sw_if_index) for i in rv: if i.sw_if_index == sw_if_index: return i.mtu[0] return 0 def test_ip4_mtu(self): """ IP4 MTU test """ p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) p_ip4 = IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4, flags='DF') current_mtu = self.get_mtu(self.pg1.sw_if_index) p_payload = UDP(sport=1234, dport=1234) / self.payload( current_mtu - 20 - 8) p4 = p_ether / p_ip4 / p_payload p4_reply = p_ip4 / p_payload p4_reply.ttl -= 1 rx = self.send_and_expect(self.pg0, p4*11, self.pg1) for p in rx: self.validate(p[1], p4_reply) # MTU self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [576, 0, 0, 0]) self.assertEqual(576, self.get_mtu(self.pg1.sw_if_index)) # Should fail. Too large MTU p_icmp4 = ICMP(type='dest-unreach', code='fragmentation-needed', nexthopmtu=576, chksum=0x2dbb) icmp4_reply = (IP(src=self.pg0.local_ip4, dst=self.pg0.remote_ip4, ttl=254, len=576, id=0) / p_icmp4 / p_ip4 / p_payload) n = icmp4_reply.__class__(icmp4_reply) s = bytes(icmp4_reply) icmp4_reply = s[0:576] rx = self.send_and_expect(self.pg0, p4*11, self.pg0) for p in rx: # p.show2() # n.show2() self.validate_bytes(bytes(p[1]), icmp4_reply) # Now with DF off. Expect fragments. # First go with 1500 byte packets. p_payload = UDP(sport=1234, dport=1234) / self.payload( 1500 - 20 - 8) p4 = p_ether / p_ip4 / p_payload p4.flags = 0 p4_reply = p_ip4 / p_payload p4_reply.ttl = p_ip4.ttl - 1 p4_reply.flags = 0 p4_reply.id = 256 self.pg_enable_capture() self.pg0.add_stream(p4*1) self.pg_start() rx = self.pg1.get_capture(3) reass_pkt = reassemble4(rx) self.validate(reass_pkt, p4_reply) ''' # Now what happens with a 9K frame p_payload = UDP(sport=1234, dport=1234) / self.payload( current_mtu - 20 - 8) p4 = p_ether / p_ip4 / p_payload p4.flags = 0 p4_reply = p_ip4 / p_payload p4_reply.ttl = 62 # check this p4_reply.flags = 0 p4_reply.id = 512 self.pg_enable_capture() self.pg0.add_stream(p4*1) self.pg_start() rx = self.pg1.get_capture(16) reass_pkt = reassemble4(rx) reass_pkt.show2() p4_reply.show2() self.validate(reass_pkt, p4_reply) ''' # Reset MTU self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [current_mtu, 0, 0, 0]) def test_ip6_mtu(self): """ IP6 MTU test """ current_mtu = self.get_mtu(self.pg1.sw_if_index) p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) p_ip6 = IPv6(src=self.pg0.remote_ip6, dst=self.pg1.remote_ip6) p_payload = UDP(sport=1234, dport=1234) / self.payload( current_mtu - 40 - 8) p6 = p_ether / p_ip6 / p_payload p6_reply = p_ip6 / p_payload p6_reply.hlim -= 1 rx = self.send_and_expect(self.pg0, p6*9, self.pg1) for p in rx: self.validate(p[1], p6_reply) # MTU (only checked on encap) self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [1280, 0, 0, 0]) self.assertEqual(1280, self.get_mtu(self.pg1.sw_if_index)) # Should fail. Too large MTU p_icmp6 = ICMPv6PacketTooBig(mtu=1280, cksum=0x4c7a) icmp6_reply = (IPv6(src=self.pg0.local_ip6, dst=self.pg0.remote_ip6, hlim=255, plen=1240) / p_icmp6 / p_ip6 / p_payload) icmp6_reply[2].hlim -= 1 n = icmp6_reply.__class__(icmp6_reply) s = bytes(icmp6_reply) icmp6_reply_str = s[0:1280] rx = self.send_and_expect(self.pg0, p6*9, self.pg0) for p in rx: self.validate_bytes(bytes(p[1]), icmp6_reply_str) # Reset MTU self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [current_mtu, 0, 0, 0]) if __name__ == '__main__': unittest.main(testRunner=VppTestRunner)