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-rw-r--r--test/test_mtu.py212
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diff --git a/test/test_mtu.py b/test/test_mtu.py
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+++ b/test/test_mtu.py
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+#!/usr/bin/env python
+"""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_route import VppIpRoute, VppRoutePath, DpoProto
+from socket import AF_INET, AF_INET6, inet_pton
+import StringIO
+
+""" Test_mtu is a subclass of VPPTestCase classes.
+ MTU tests.
+"""
+
+
+def reassemble(listoffragments):
+ buffer = StringIO.StringIO()
+ first = listoffragments[0]
+ buffer.seek(20)
+ for pkt in listoffragments:
+ # pkt.show2()
+ buffer.seek(pkt[IP].frag*8)
+ buffer.write(pkt[IP].payload)
+ first.len = len(buffer.getvalue()) + 20
+ first.flags = 0
+ del(first.chksum)
+ header = str(first[IP])[:20]
+ return first[IP].__class__(header + buffer.getvalue())
+
+
+class TestMTU(VppTestCase):
+ """ MTU Test Case """
+
+ @classmethod
+ def setUpClass(cls):
+ super(TestMTU, cls).setUpClass()
+ cls.create_pg_interfaces(range(2))
+ cls.interfaces = list(cls.pg_interfaces)
+
+ def setUp(cls):
+ super(TestMTU, cls).setUp()
+ for i in cls.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__(str(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()
+ for i in rv:
+ if i.sw_if_index == sw_if_index:
+ return i.link_mtu
+ return 0
+
+ def test_ip4_mtu(self):
+ """ IP4 MTU test """
+
+ #
+ # TODO: Link MTU is 216 bytes 'off'. Fix when L3 MTU patches committed
+ #
+ mtu_offset = 216
+ 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')
+
+ # TODO: Re-enable when MTU fixes are committed
+ current_mtu = self.get_mtu(self.pg1.sw_if_index)
+ current_mtu -= mtu_offset
+
+ 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 + mtu_offset)
+ self.assertEqual(576, self.get_mtu(self.pg1.sw_if_index) - mtu_offset)
+
+ # 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)
+ icmp4_reply[1].ttl -= 1
+ n = icmp4_reply.__class__(str(icmp4_reply))
+ s = str(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(str(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 = 62 # check this
+ 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)
+ print('RX', len(rx))
+ reass_pkt = reassemble(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 = reassemble(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)
+
+ @unittest.skip("Enable when IPv6 fragmentation is added")
+ def test_ip6_mtu(self):
+ """ IP6 MTU test """
+
+ 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)
+
+ current_mtu = self.get_mtu(self.pg1.sw_if_index)
+ 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)
+ 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=254, plen=1240) /
+ p_icmp6 / p_ip6 / p_payload)
+ icmp6_reply[2].hlim -= 1
+ n = icmp6_reply.__class__(str(icmp6_reply))
+ s = str(icmp6_reply)
+ icmp6_reply = s[0:1280]
+
+ rx = self.send_and_expect(self.pg0, p6*9, self.pg0)
+ for p in rx:
+ self.validate_bytes(str(p[1]), icmp6_reply)
+
+ # Reset MTU
+ self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, current_mtu)
+
+
+if __name__ == '__main__':
+ unittest.main(testRunner=VppTestRunner)