vlib: add virtual time support
[vpp.git] / test / test_reassembly.py
index ee7830e..b99930f 100644 (file)
@@ -1,6 +1,5 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
-import six
 import unittest
 from random import shuffle, choice, randrange
 
@@ -22,9 +21,6 @@ from vpp_papi import VppEnum
 # 35 is enough to have >257 400-byte fragments
 test_packet_count = 35
 
-# number of workers used for multi-worker test cases
-worker_count = 3
-
 
 class TestIPv4Reassembly(VppTestCase):
     """ IPv4 Reassembly """
@@ -61,7 +57,7 @@ class TestIPv4Reassembly(VppTestCase):
         self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
                                     max_reassembly_length=1000,
                                     expire_walk_interval_ms=10)
-        self.sleep(.25)
+        self.virtual_sleep(.25)
         self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
                                     max_reassembly_length=1000,
                                     expire_walk_interval_ms=10000)
@@ -95,7 +91,7 @@ class TestIPv4Reassembly(VppTestCase):
     def create_fragments(cls):
         infos = cls._packet_infos
         cls.pkt_infos = []
-        for index, info in six.iteritems(infos):
+        for index, info in infos.items():
             p = info.data
             # cls.logger.debug(ppp("Packet:",
             #                      p.__class__(scapy.compat.raw(p))))
@@ -171,6 +167,21 @@ class TestIPv4Reassembly(VppTestCase):
         self.verify_capture(packets)
         self.src_if.assert_nothing_captured()
 
+    def test_verify_clear_trace_mid_reassembly(self):
+        """ verify clear trace works mid-reassembly """
+
+        self.pg_enable_capture()
+        self.src_if.add_stream(self.fragments_200[0:-1])
+        self.pg_start()
+
+        self.logger.debug(self.vapi.cli("show trace"))
+        self.vapi.cli("clear trace")
+
+        self.src_if.add_stream(self.fragments_200[-1])
+        self.pg_start()
+        packets = self.dst_if.get_capture(len(self.pkt_infos))
+        self.verify_capture(packets)
+
     def test_reversed(self):
         """ reverse order reassembly """
 
@@ -210,12 +221,12 @@ class TestIPv4Reassembly(VppTestCase):
               IP(id=1000, src=self.src_if.remote_ip4,
                  dst=self.dst_if.remote_ip4) /
               UDP(sport=1234, dport=5678) /
-              Raw("X" * 1000))
+              Raw(b"X" * 1000))
         p2 = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
               IP(id=1001, src=self.src_if.remote_ip4,
                  dst=self.dst_if.remote_ip4) /
               UDP(sport=1234, dport=5678) /
-              Raw("X" * 1000))
+              Raw(b"X" * 1000))
         frags = fragment_rfc791(p1, 200) + fragment_rfc791(p2, 500)
 
         self.pg_enable_capture()
@@ -228,11 +239,9 @@ class TestIPv4Reassembly(VppTestCase):
     def test_5737(self):
         """ fragment length + ip header size > 65535 """
         self.vapi.cli("clear errors")
-        raw = ('E\x00\x00\x88,\xf8\x1f\xfe@\x01\x98\x00\xc0\xa8\n-\xc0\xa8\n'
-               '\x01\x08\x00\xf0J\xed\xcb\xf1\xf5Test-group: IPv4.IPv4.ipv4-'
-               'message.Ethernet-Payload.IPv4-Packet.IPv4-Header.Fragment-Of'
-               'fset; Test-case: 5737')
-
+        raw = b'''E\x00\x00\x88,\xf8\x1f\xfe@\x01\x98\x00\xc0\xa8\n-\xc0\xa8\n\
+\x01\x08\x00\xf0J\xed\xcb\xf1\xf5Test-group: IPv4.IPv4.ipv4-message.\
+Ethernet-Payload.IPv4-Packet.IPv4-Header.Fragment-Offset; Test-case: 5737'''
         malformed_packet = (Ether(dst=self.src_if.local_mac,
                                   src=self.src_if.remote_mac) /
                             IP(raw))
@@ -240,20 +249,19 @@ class TestIPv4Reassembly(VppTestCase):
              IP(id=1000, src=self.src_if.remote_ip4,
                 dst=self.dst_if.remote_ip4) /
              UDP(sport=1234, dport=5678) /
-             Raw("X" * 1000))
+             Raw(b"X" * 1000))
         valid_fragments = fragment_rfc791(p, 400)
 
+        counter = "/err/ip4-full-reassembly-feature/malformed packets"
+        error_counter = self.statistics.get_err_counter(counter)
         self.pg_enable_capture()
         self.src_if.add_stream([malformed_packet] + valid_fragments)
         self.pg_start()
 
         self.dst_if.get_capture(1)
         self.logger.debug(self.vapi.ppcli("show error"))
-        self.assert_packet_counter_equal("ip4-full-reassembly-feature", 1)
-        # TODO remove above, uncomment below once clearing of counters
-        # is supported
-        # self.assert_packet_counter_equal(
-        #     "/err/ip4-full-reassembly-feature/malformed packets", 1)
+        self.assertEqual(self.statistics.get_err_counter(counter),
+                         error_counter + 1)
 
     def test_44924(self):
         """ compress tiny fragments """
@@ -300,14 +308,14 @@ class TestIPv4Reassembly(VppTestCase):
                               IP(id=7, len=21, frag=1, ttl=64,
                                  src=self.src_if.remote_ip4,
                                  dst=self.dst_if.remote_ip4) /
-                              Raw(load='\x08')),
+                              Raw(load=b'\x08')),
                              ]
 
         p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
              IP(id=1000, src=self.src_if.remote_ip4,
                 dst=self.dst_if.remote_ip4) /
              UDP(sport=1234, dport=5678) /
-             Raw("X" * 1000))
+             Raw(b"X" * 1000))
         valid_fragments = fragment_rfc791(p, 400)
 
         self.pg_enable_capture()
@@ -472,7 +480,7 @@ class TestIPv4Reassembly(VppTestCase):
         self.src_if.add_stream(fragments)
         self.pg_start()
 
-        self.sleep(.25, "wait before sending rest of fragments")
+        self.virtual_sleep(.25, "wait before sending rest of fragments")
 
         self.src_if.add_stream(fragments2)
         self.pg_start()
@@ -531,7 +539,7 @@ class TestIPv4SVReassembly(VppTestCase):
             max_reassembly_length=1000,
             type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL,
             expire_walk_interval_ms=10)
-        self.sleep(.25)
+        self.virtual_sleep(.25)
         self.vapi.ip_reassembly_set(
             timeout_ms=1000000, max_reassemblies=1000,
             max_reassembly_length=1000,
@@ -592,6 +600,42 @@ class TestIPv4SVReassembly(VppTestCase):
             self.assertEqual(sent[IP].dst, recvd[IP].dst)
             self.assertEqual(sent[Raw].payload, recvd[Raw].payload)
 
+    def test_verify_clear_trace_mid_reassembly(self):
+        """ verify clear trace works mid-reassembly """
+        payload_len = 1000
+        payload = ""
+        counter = 0
+        while len(payload) < payload_len:
+            payload += "%u " % counter
+            counter += 1
+
+        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
+             IP(id=1, src=self.src_if.remote_ip4,
+                dst=self.dst_if.remote_ip4) /
+             UDP(sport=1234, dport=5678) /
+             Raw(payload))
+        fragments = fragment_rfc791(p, payload_len/4)
+
+        self.pg_enable_capture()
+        self.src_if.add_stream(fragments[1])
+        self.pg_start()
+
+        self.logger.debug(self.vapi.cli("show trace"))
+        self.vapi.cli("clear trace")
+
+        self.pg_enable_capture()
+        self.src_if.add_stream(fragments[0])
+        self.pg_start()
+        self.dst_if.get_capture(2)
+
+        self.logger.debug(self.vapi.cli("show trace"))
+        self.vapi.cli("clear trace")
+
+        self.pg_enable_capture()
+        self.src_if.add_stream(fragments[2:])
+        self.pg_start()
+        self.dst_if.get_capture(len(fragments[2:]))
+
     def test_timeout(self):
         """ reassembly timeout """
         payload_len = 1000
@@ -628,7 +672,7 @@ class TestIPv4SVReassembly(VppTestCase):
             self.assertEqual(sent[Raw].payload, recvd[Raw].payload)
 
         # wait for cleanup
-        self.sleep(.25, "wait before sending rest of fragments")
+        self.virtual_sleep(.25, "wait before sending rest of fragments")
 
         # send rest of fragments - shouldn't be forwarded
         self.pg_enable_capture()
@@ -673,16 +717,82 @@ class TestIPv4SVReassembly(VppTestCase):
             self.assertEqual(sent[IP].dst, recvd[IP].dst)
             self.assertEqual(sent[Raw].payload, recvd[Raw].payload)
 
+    def send_mixed_and_verify_capture(self, traffic):
+        stream = []
+        for t in traffic:
+            for c in range(t['count']):
+                stream.append(
+                    (Ether(dst=self.src_if.local_mac,
+                           src=self.src_if.remote_mac) /
+                     IP(id=self.counter,
+                        flags=t['flags'],
+                        src=self.src_if.remote_ip4,
+                        dst=self.dst_if.remote_ip4) /
+                     UDP(sport=1234, dport=5678) /
+                     Raw("abcdef")))
+                self.counter = self.counter + 1
+
+        self.pg_enable_capture()
+        self.src_if.add_stream(stream)
+        self.pg_start()
+        self.logger.debug(self.vapi.ppcli("show ip4-sv-reassembly details"))
+        self.logger.debug(self.vapi.ppcli("show buffers"))
+        self.logger.debug(self.vapi.ppcli("show trace"))
+        self.dst_if.get_capture(len(stream))
+
+    def test_mixed(self):
+        """ mixed traffic correctly passes through SVR """
+        self.counter = 1
+
+        self.send_mixed_and_verify_capture([{'count': 1, 'flags': ''}])
+        self.send_mixed_and_verify_capture([{'count': 2, 'flags': ''}])
+        self.send_mixed_and_verify_capture([{'count': 3, 'flags': ''}])
+        self.send_mixed_and_verify_capture([{'count': 8, 'flags': ''}])
+        self.send_mixed_and_verify_capture([{'count': 257, 'flags': ''}])
+
+        self.send_mixed_and_verify_capture([{'count': 1, 'flags': 'MF'}])
+        self.send_mixed_and_verify_capture([{'count': 2, 'flags': 'MF'}])
+        self.send_mixed_and_verify_capture([{'count': 3, 'flags': 'MF'}])
+        self.send_mixed_and_verify_capture([{'count': 8, 'flags': 'MF'}])
+        self.send_mixed_and_verify_capture([{'count': 257, 'flags': 'MF'}])
+
+        self.send_mixed_and_verify_capture(
+            [{'count': 1, 'flags': ''}, {'count': 1, 'flags': 'MF'}])
+        self.send_mixed_and_verify_capture(
+            [{'count': 2, 'flags': ''}, {'count': 2, 'flags': 'MF'}])
+        self.send_mixed_and_verify_capture(
+            [{'count': 3, 'flags': ''}, {'count': 3, 'flags': 'MF'}])
+        self.send_mixed_and_verify_capture(
+            [{'count': 8, 'flags': ''}, {'count': 8, 'flags': 'MF'}])
+        self.send_mixed_and_verify_capture(
+            [{'count': 129, 'flags': ''}, {'count': 129, 'flags': 'MF'}])
+
+        self.send_mixed_and_verify_capture(
+            [{'count': 1, 'flags': ''}, {'count': 1, 'flags': 'MF'},
+             {'count': 1, 'flags': ''}, {'count': 1, 'flags': 'MF'}])
+        self.send_mixed_and_verify_capture(
+            [{'count': 2, 'flags': ''}, {'count': 2, 'flags': 'MF'},
+             {'count': 2, 'flags': ''}, {'count': 2, 'flags': 'MF'}])
+        self.send_mixed_and_verify_capture(
+            [{'count': 3, 'flags': ''}, {'count': 3, 'flags': 'MF'},
+             {'count': 3, 'flags': ''}, {'count': 3, 'flags': 'MF'}])
+        self.send_mixed_and_verify_capture(
+            [{'count': 8, 'flags': ''}, {'count': 8, 'flags': 'MF'},
+             {'count': 8, 'flags': ''}, {'count': 8, 'flags': 'MF'}])
+        self.send_mixed_and_verify_capture(
+            [{'count': 65, 'flags': ''}, {'count': 65, 'flags': 'MF'},
+             {'count': 65, 'flags': ''}, {'count': 65, 'flags': 'MF'}])
+
 
 class TestIPv4MWReassembly(VppTestCase):
     """ IPv4 Reassembly (multiple workers) """
-    worker_config = "workers %d" % worker_count
+    vpp_worker_count = 3
 
     @classmethod
     def setUpClass(cls):
         super(TestIPv4MWReassembly, cls).setUpClass()
 
-        cls.create_pg_interfaces(range(worker_count+1))
+        cls.create_pg_interfaces(range(cls.vpp_worker_count+1))
         cls.src_if = cls.pg0
         cls.send_ifs = cls.pg_interfaces[:-1]
         cls.dst_if = cls.pg_interfaces[-1]
@@ -715,7 +825,7 @@ class TestIPv4MWReassembly(VppTestCase):
         self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
                                     max_reassembly_length=1000,
                                     expire_walk_interval_ms=10)
-        self.sleep(.25)
+        self.virtual_sleep(.25)
         self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
                                     max_reassembly_length=1000,
                                     expire_walk_interval_ms=10000)
@@ -748,7 +858,7 @@ class TestIPv4MWReassembly(VppTestCase):
     def create_fragments(cls):
         infos = cls._packet_infos
         cls.pkt_infos = []
-        for index, info in six.iteritems(infos):
+        for index, info in infos.items():
             p = info.data
             # cls.logger.debug(ppp("Packet:",
             #                      p.__class__(scapy.compat.raw(p))))
@@ -795,7 +905,7 @@ class TestIPv4MWReassembly(VppTestCase):
                             "Packet with packet_index %d not received" % index)
 
     def send_packets(self, packets):
-        for counter in range(worker_count):
+        for counter in range(self.vpp_worker_count):
             if 0 == len(packets[counter]):
                 continue
             send_if = self.send_ifs[counter]
@@ -811,19 +921,19 @@ class TestIPv4MWReassembly(VppTestCase):
         # in first wave we send fragments which don't start at offset 0
         # then we send fragments with offset 0 on a different thread
         # then the rest of packets on a random thread
-        first_packets = [[] for n in range(worker_count)]
-        second_packets = [[] for n in range(worker_count)]
-        rest_of_packets = [[] for n in range(worker_count)]
+        first_packets = [[] for n in range(self.vpp_worker_count)]
+        second_packets = [[] for n in range(self.vpp_worker_count)]
+        rest_of_packets = [[] for n in range(self.vpp_worker_count)]
         for (_, p) in self.pkt_infos:
-            wi = randrange(worker_count)
+            wi = randrange(self.vpp_worker_count)
             second_packets[wi].append(p[0])
             if len(p) <= 1:
                 continue
             wi2 = wi
             while wi2 == wi:
-                wi2 = randrange(worker_count)
+                wi2 = randrange(self.vpp_worker_count)
             first_packets[wi2].append(p[1])
-            wi3 = randrange(worker_count)
+            wi3 = randrange(self.vpp_worker_count)
             rest_of_packets[wi3].extend(p[2:])
 
         self.pg_enable_capture()
@@ -836,6 +946,11 @@ class TestIPv4MWReassembly(VppTestCase):
         for send_if in self.send_ifs:
             send_if.assert_nothing_captured()
 
+        self.logger.debug(self.vapi.ppcli("show trace"))
+        self.logger.debug(self.vapi.ppcli("show ip4-full-reassembly details"))
+        self.logger.debug(self.vapi.ppcli("show buffers"))
+        self.vapi.cli("clear trace")
+
         self.pg_enable_capture()
         self.send_packets(first_packets)
         self.send_packets(second_packets)
@@ -882,7 +997,7 @@ class TestIPv6Reassembly(VppTestCase):
         self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
                                     max_reassembly_length=1000,
                                     expire_walk_interval_ms=10, is_ip6=1)
-        self.sleep(.25)
+        self.virtual_sleep(.25)
         self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
                                     max_reassembly_length=1000,
                                     expire_walk_interval_ms=10000, is_ip6=1)
@@ -918,7 +1033,7 @@ class TestIPv6Reassembly(VppTestCase):
     def create_fragments(cls):
         infos = cls._packet_infos
         cls.pkt_infos = []
-        for index, info in six.iteritems(infos):
+        for index, info in infos.items():
             p = info.data
             # cls.logger.debug(ppp("Packet:",
             #                      p.__class__(scapy.compat.raw(p))))
@@ -1006,6 +1121,21 @@ class TestIPv6Reassembly(VppTestCase):
         self.src_if.assert_nothing_captured()
         self.dst_if.assert_nothing_captured()
 
+    def test_verify_clear_trace_mid_reassembly(self):
+        """ verify clear trace works mid-reassembly """
+
+        self.pg_enable_capture()
+        self.src_if.add_stream(self.fragments_400[0:-1])
+        self.pg_start()
+
+        self.logger.debug(self.vapi.cli("show trace"))
+        self.vapi.cli("clear trace")
+
+        self.src_if.add_stream(self.fragments_400[-1])
+        self.pg_start()
+        packets = self.dst_if.get_capture(len(self.pkt_infos))
+        self.verify_capture(packets)
+
     def test_reversed(self):
         """ reverse order reassembly """
 
@@ -1085,7 +1215,7 @@ class TestIPv6Reassembly(VppTestCase):
              IPv6(src=self.src_if.remote_ip6,
                   dst=self.dst_if.remote_ip6) /
              UDP(sport=1234, dport=5678) /
-             Raw("X" * 1000))
+             Raw(b"X" * 1000))
         frags = fragment_rfc8200(p, 1, 300) + fragment_rfc8200(p, 2, 500)
 
         self.pg_enable_capture()
@@ -1207,7 +1337,7 @@ class TestIPv6Reassembly(VppTestCase):
         self.src_if.add_stream(fragments)
         self.pg_start()
 
-        self.sleep(.25, "wait before sending rest of fragments")
+        self.virtual_sleep(.25, "wait before sending rest of fragments")
 
         self.src_if.add_stream(fragments2)
         self.pg_start()
@@ -1304,13 +1434,13 @@ class TestIPv6Reassembly(VppTestCase):
 
 class TestIPv6MWReassembly(VppTestCase):
     """ IPv6 Reassembly (multiple workers) """
-    worker_config = "workers %d" % worker_count
+    vpp_worker_count = 3
 
     @classmethod
     def setUpClass(cls):
         super(TestIPv6MWReassembly, cls).setUpClass()
 
-        cls.create_pg_interfaces(range(worker_count+1))
+        cls.create_pg_interfaces(range(cls.vpp_worker_count+1))
         cls.src_if = cls.pg0
         cls.send_ifs = cls.pg_interfaces[:-1]
         cls.dst_if = cls.pg_interfaces[-1]
@@ -1343,7 +1473,7 @@ class TestIPv6MWReassembly(VppTestCase):
         self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
                                     max_reassembly_length=1000,
                                     expire_walk_interval_ms=10, is_ip6=1)
-        self.sleep(.25)
+        self.virtual_sleep(.25)
         self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
                                     max_reassembly_length=1000,
                                     expire_walk_interval_ms=1000, is_ip6=1)
@@ -1376,7 +1506,7 @@ class TestIPv6MWReassembly(VppTestCase):
     def create_fragments(cls):
         infos = cls._packet_infos
         cls.pkt_infos = []
-        for index, info in six.iteritems(infos):
+        for index, info in infos.items():
             p = info.data
             # cls.logger.debug(ppp("Packet:",
             #                      p.__class__(scapy.compat.raw(p))))
@@ -1423,7 +1553,7 @@ class TestIPv6MWReassembly(VppTestCase):
                             "Packet with packet_index %d not received" % index)
 
     def send_packets(self, packets):
-        for counter in range(worker_count):
+        for counter in range(self.vpp_worker_count):
             if 0 == len(packets[counter]):
                 continue
             send_if = self.send_ifs[counter]
@@ -1439,19 +1569,19 @@ class TestIPv6MWReassembly(VppTestCase):
         # in first wave we send fragments which don't start at offset 0
         # then we send fragments with offset 0 on a different thread
         # then the rest of packets on a random thread
-        first_packets = [[] for n in range(worker_count)]
-        second_packets = [[] for n in range(worker_count)]
-        rest_of_packets = [[] for n in range(worker_count)]
+        first_packets = [[] for n in range(self.vpp_worker_count)]
+        second_packets = [[] for n in range(self.vpp_worker_count)]
+        rest_of_packets = [[] for n in range(self.vpp_worker_count)]
         for (_, p) in self.pkt_infos:
-            wi = randrange(worker_count)
+            wi = randrange(self.vpp_worker_count)
             second_packets[wi].append(p[0])
             if len(p) <= 1:
                 continue
             wi2 = wi
             while wi2 == wi:
-                wi2 = randrange(worker_count)
+                wi2 = randrange(self.vpp_worker_count)
             first_packets[wi2].append(p[1])
-            wi3 = randrange(worker_count)
+            wi3 = randrange(self.vpp_worker_count)
             rest_of_packets[wi3].extend(p[2:])
 
         self.pg_enable_capture()
@@ -1464,6 +1594,11 @@ class TestIPv6MWReassembly(VppTestCase):
         for send_if in self.send_ifs:
             send_if.assert_nothing_captured()
 
+        self.logger.debug(self.vapi.ppcli("show trace"))
+        self.logger.debug(self.vapi.ppcli("show ip6-full-reassembly details"))
+        self.logger.debug(self.vapi.ppcli("show buffers"))
+        self.vapi.cli("clear trace")
+
         self.pg_enable_capture()
         self.send_packets(first_packets)
         self.send_packets(second_packets)
@@ -1503,7 +1638,7 @@ class TestIPv6SVReassembly(VppTestCase):
             max_reassembly_length=1000,
             type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL,
             expire_walk_interval_ms=10, is_ip6=1)
-        self.sleep(.25)
+        self.virtual_sleep(.25)
         self.vapi.ip_reassembly_set(
             timeout_ms=1000000, max_reassemblies=1000,
             max_reassembly_length=1000,
@@ -1563,6 +1698,41 @@ class TestIPv6SVReassembly(VppTestCase):
             self.assertEqual(sent[IPv6].dst, recvd[IPv6].dst)
             self.assertEqual(sent[Raw].payload, recvd[Raw].payload)
 
+    def test_verify_clear_trace_mid_reassembly(self):
+        """ verify clear trace works mid-reassembly """
+        payload_len = 1000
+        payload = ""
+        counter = 0
+        while len(payload) < payload_len:
+            payload += "%u " % counter
+            counter += 1
+
+        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
+             IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6) /
+             UDP(sport=1234, dport=5678) /
+             Raw(payload))
+        fragments = fragment_rfc8200(p, 1, payload_len/4)
+
+        self.pg_enable_capture()
+        self.src_if.add_stream(fragments[1])
+        self.pg_start()
+
+        self.logger.debug(self.vapi.cli("show trace"))
+        self.vapi.cli("clear trace")
+
+        self.pg_enable_capture()
+        self.src_if.add_stream(fragments[0])
+        self.pg_start()
+        self.dst_if.get_capture(2)
+
+        self.logger.debug(self.vapi.cli("show trace"))
+        self.vapi.cli("clear trace")
+
+        self.pg_enable_capture()
+        self.src_if.add_stream(fragments[2:])
+        self.pg_start()
+        self.dst_if.get_capture(len(fragments[2:]))
+
     def test_timeout(self):
         """ reassembly timeout """
         payload_len = 1000
@@ -1599,7 +1769,7 @@ class TestIPv6SVReassembly(VppTestCase):
             self.assertEqual(sent[Raw].payload, recvd[Raw].payload)
 
         # wait for cleanup
-        self.sleep(.25, "wait before sending rest of fragments")
+        self.virtual_sleep(.25, "wait before sending rest of fragments")
 
         # send rest of fragments - shouldn't be forwarded
         self.pg_enable_capture()
@@ -1675,7 +1845,7 @@ class TestIPv4ReassemblyLocalNode(VppTestCase):
         self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
                                     max_reassembly_length=1000,
                                     expire_walk_interval_ms=10)
-        self.sleep(.25)
+        self.virtual_sleep(.25)
         self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
                                     max_reassembly_length=1000,
                                     expire_walk_interval_ms=10000)
@@ -1709,7 +1879,7 @@ class TestIPv4ReassemblyLocalNode(VppTestCase):
     def create_fragments(cls):
         infos = cls._packet_infos
         cls.pkt_infos = []
-        for index, info in six.iteritems(infos):
+        for index, info in infos.items():
             p = info.data
             # cls.logger.debug(ppp("Packet:",
             #                      p.__class__(scapy.compat.raw(p))))
@@ -1811,7 +1981,7 @@ class TestFIFReassembly(VppTestCase):
         self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
                                     max_reassembly_length=1000,
                                     expire_walk_interval_ms=10, is_ip6=1)
-        self.sleep(.25)
+        self.virtual_sleep(.25)
         self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
                                     max_reassembly_length=1000,
                                     expire_walk_interval_ms=10000)
@@ -1900,7 +2070,7 @@ class TestFIFReassembly(VppTestCase):
             self.extend_packet(p, size, self.padding)
             info.data = p[IP]  # use only IP part, without ethernet header
 
-        fragments = [x for _, p in six.iteritems(self._packet_infos)
+        fragments = [x for _, p in self._packet_infos.items()
                      for x in fragment_rfc791(p.data, 400)]
 
         encapped_fragments = \
@@ -1965,7 +2135,7 @@ class TestFIFReassembly(VppTestCase):
             self.extend_packet(p, size, self.padding)
             info.data = p[IPv6]  # use only IPv6 part, without ethernet header
 
-        fragments = [x for _, i in six.iteritems(self._packet_infos)
+        fragments = [x for _, i in self._packet_infos.items()
                      for x in fragment_rfc8200(
                          i.data, i.index, 400)]