aboutsummaryrefslogtreecommitdiffstats
path: root/src/vnet/ip/ip_frag.h
blob: 348f5a2fbc65ab101876a41243f98d4a4c1e7bd3 (plain) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96

/*---------------------------------------------------------------------------
 * Copyright (c) 2009-2014 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *---------------------------------------------------------------------------
 */
/*
 * IPv4 and IPv6 Fragmentation Nodes
 *
 * A packet sent to those nodes require the following
 * buffer attributes to be set:
 * ip_frag.header_offset :
 *     Where to find the IPv4 (or IPv6) header in the packet. Previous
 *     bytes are left untouched and copied in every fragment. The fragments
 *     are then appended. This option is used for fragmented packets
 *     that are encapsulated.
 * ip_frag.mtu :
 *     Maximum size of IP packets, header included, but ignoring
 *     the 'ip_frag.header_offset' copied bytes.
 * ip_frag.next_index :
 *     One of ip_frag_next_t, indicating to which exit node the fragments
 *     should be sent to.
 *
 */

#ifndef IP_FRAG_H
#define IP_FRAG_H

#include <vnet/vnet.h>

#define IP_FRAG_FLAG_IP4_HEADER 0x01	//Encapsulating IPv4 header
#define IP_FRAG_FLAG_IP6_HEADER 0x02	//Encapsulating IPv6 header

#define IP4_FRAG_NODE_NAME "ip4-frag"
#define IP6_FRAG_NODE_NAME "ip6-frag"

extern vlib_node_registration_t ip4_frag_node;
extern vlib_node_registration_t ip6_frag_node;

typedef enum
{
  IP4_FRAG_NEXT_IP4_LOOKUP,
  IP4_FRAG_NEXT_IP6_LOOKUP,
  IP4_FRAG_NEXT_ICMP_ERROR,
  IP4_FRAG_NEXT_DROP,
  IP4_FRAG_N_NEXT
} ip4_frag_next_t;

typedef enum
{
  IP6_FRAG_NEXT_IP4_LOOKUP,
  IP6_FRAG_NEXT_IP6_LOOKUP,
  IP6_FRAG_NEXT_DROP,
  IP6_FRAG_N_NEXT
} ip6_frag_next_t;

#define foreach_ip_frag_error				\
  /* Must be first. */					\
 _(NONE, "packet fragmented")				\
 _(SMALL_PACKET, "packet smaller than MTU")             \
 _(FRAGMENT_SENT, "number of sent fragments")           \
 _(CANT_FRAGMENT_HEADER, "can't fragment header")	\
 _(DONT_FRAGMENT_SET, "can't fragment this packet")	\
 _(MALFORMED, "malformed packet")                       \
 _(MEMORY, "could not allocate buffer")                 \
 _(UNKNOWN, "unknown error")

typedef enum
{
#define _(sym,str) IP_FRAG_ERROR_##sym,
  foreach_ip_frag_error
#undef _
    IP_FRAG_N_ERROR,
} ip_frag_error_t;

void ip_frag_set_vnet_buffer (vlib_buffer_t * b, u16 offset, u16 mtu,
			      u8 next_index, u8 flags);

#endif /* ifndef IP_FRAG_H */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */
575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 
#!/usr/bin/env python

import six
import unittest
from random import shuffle

from framework import VppTestCase, VppTestRunner

from scapy.packet import Raw
from scapy.layers.l2 import Ether, GRE
from scapy.layers.inet import IP, UDP, ICMP
from util import ppp, fragment_rfc791, fragment_rfc8200
from scapy.layers.inet6 import IPv6, IPv6ExtHdrFragment, ICMPv6ParamProblem,\
    ICMPv6TimeExceeded
from vpp_gre_interface import VppGreInterface, VppGre6Interface
from vpp_ip import DpoProto
from vpp_ip_route import VppIpRoute, VppRoutePath

test_packet_count = 257


class TestIPv4Reassembly(VppTestCase):
    """ IPv4 Reassembly """

    @classmethod
    def setUpClass(cls):
        super(TestIPv4Reassembly, cls).setUpClass()

        cls.create_pg_interfaces([0, 1])
        cls.src_if = cls.pg0
        cls.dst_if = cls.pg1

        # setup all interfaces
        for i in cls.pg_interfaces:
            i.admin_up()
            i.config_ip4()
            i.resolve_arp()

        # packet sizes
        cls.packet_sizes = [64, 512, 1518, 9018]
        cls.padding = " abcdefghijklmn"
        cls.create_stream(cls.packet_sizes)
        cls.create_fragments()

    def setUp(self):
        """ Test setup - force timeout on existing reassemblies """
        super(TestIPv4Reassembly, self).setUp()
        self.vapi.ip_reassembly_enable_disable(
            sw_if_index=self.src_if.sw_if_index, enable_ip4=True)
        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
                                    expire_walk_interval_ms=10)
        self.sleep(.25)
        self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
                                    expire_walk_interval_ms=10000)

    def tearDown(self):
        super(TestIPv4Reassembly, self).tearDown()
        self.logger.debug(self.vapi.ppcli("show ip4-reassembly details"))

    @classmethod
    def create_stream(cls, packet_sizes, packet_count=test_packet_count):
        """Create input packet stream for defined interface.

        :param list packet_sizes: Required packet sizes.
        """
        for i in range(0, packet_count):
            info = cls.create_packet_info(cls.src_if, cls.src_if)
            payload = cls.info_to_payload(info)
            p = (Ether(dst=cls.src_if.local_mac, src=cls.src_if.remote_mac) /
                 IP(id=info.index, src=cls.src_if.remote_ip4,
                    dst=cls.dst_if.remote_ip4) /
                 UDP(sport=1234, dport=5678) /
                 Raw(payload))
            size = packet_sizes[(i // 2) % len(packet_sizes)]
            cls.extend_packet(p, size, cls.padding)
            info.data = p

    @classmethod
    def create_fragments(cls):
        infos = cls._packet_infos
        cls.pkt_infos = []
        for index, info in six.iteritems(infos):
            p = info.data
            # cls.logger.debug(ppp("Packet:", p.__class__(str(p))))
            fragments_400 = fragment_rfc791(p, 400)
            fragments_300 = fragment_rfc791(p, 300)
            fragments_200 = [
                x for f in fragments_400 for x in fragment_rfc791(f, 200)]
            cls.pkt_infos.append(
                (index, fragments_400, fragments_300, fragments_200))
        cls.fragments_400 = [
            x for (_, frags, _, _) in cls.pkt_infos for x in frags]
        cls.fragments_300 = [
            x for (_, _, frags, _) in cls.pkt_infos for x in frags]
        cls.fragments_200 = [
            x for (_, _, _, frags) in cls.pkt_infos for x in frags]
        cls.logger.debug("Fragmented %s packets into %s 400-byte fragments, "
                         "%s 300-byte fragments and %s 200-byte fragments" %
                         (len(infos), len(cls.fragments_400),
                             len(cls.fragments_300), len(cls.fragments_200)))

    def verify_capture(self, capture, dropped_packet_indexes=[]):
        """Verify captured packet stream.

        :param list capture: Captured packet stream.
        """
        info = None
        seen = set()
        for packet in capture:
            try:
                self.logger.debug(ppp("Got packet:", packet))
                ip = packet[IP]
                udp = packet[UDP]
                payload_info = self.payload_to_info(str(packet[Raw]))
                packet_index = payload_info.index
                self.assertTrue(
                    packet_index not in dropped_packet_indexes,
                    ppp("Packet received, but should be dropped:", packet))
                if packet_index in seen:
                    raise Exception(ppp("Duplicate packet received", packet))
                seen.add(packet_index)
                self.assertEqual(payload_info.dst, self.src_if.sw_if_index)
                info = self._packet_infos[packet_index]
                self.assertTrue(info is not None)
                self.assertEqual(packet_index, info.index)
                saved_packet = info.data
                self.assertEqual(ip.src, saved_packet[IP].src)
                self.assertEqual(ip.dst, saved_packet[IP].dst)
                self.assertEqual(udp.payload, saved_packet[UDP].payload)
            except Exception:
                self.logger.error(ppp("Unexpected or invalid packet:", packet))
                raise
        for index in self._packet_infos:
            self.assertTrue(index in seen or index in dropped_packet_indexes,
                            "Packet with packet_index %d not received" % index)

    def test_reassembly(self):
        """ basic reassembly """

        self.pg_enable_capture()
        self.src_if.add_stream(self.fragments_200)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

        # run it all again to verify correctness
        self.pg_enable_capture()
        self.src_if.add_stream(self.fragments_200)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

    def test_reversed(self):
        """ reverse order reassembly """

        fragments = list(self.fragments_200)
        fragments.reverse()

        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.packet_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

        # run it all again to verify correctness
        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.packet_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

    def test_random(self):
        """ random order reassembly """

        fragments = list(self.fragments_200)
        shuffle(fragments)

        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.packet_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

        # run it all again to verify correctness
        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.packet_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

    def test_duplicates(self):
        """ duplicate fragments """

        fragments = [
            x for (_, frags, _, _) in self.pkt_infos
            for x in frags
            for _ in range(0, min(2, len(frags)))
        ]

        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

    def test_overlap1(self):
        """ overlapping fragments case #1 """

        fragments = []
        for _, _, frags_300, frags_200 in self.pkt_infos:
            if len(frags_300) == 1:
                fragments.extend(frags_300)
            else:
                for i, j in zip(frags_200, frags_300):
                    fragments.extend(i)
                    fragments.extend(j)

        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

        # run it all to verify correctness
        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

    def test_overlap2(self):
        """ overlapping fragments case #2 """

        fragments = []
        for _, _, frags_300, frags_200 in self.pkt_infos:
            if len(frags_300) == 1:
                fragments.extend(frags_300)
            else:
                # care must be taken here so that there are no fragments
                # received by vpp after reassembly is finished, otherwise
                # new reassemblies will be started and packet generator will
                # freak out when it detects unfreed buffers
                zipped = zip(frags_300, frags_200)
                for i, j in zipped[:-1]:
                    fragments.extend(i)
                    fragments.extend(j)
                fragments.append(zipped[-1][0])

        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

        # run it all to verify correctness
        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

    def test_timeout_inline(self):
        """ timeout (inline) """

        dropped_packet_indexes = set(
            index for (index, frags, _, _) in self.pkt_infos if len(frags) > 1
        )

        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
                                    expire_walk_interval_ms=10000)

        self.pg_enable_capture()
        self.src_if.add_stream(self.fragments_400)
        self.pg_start()

        packets = self.dst_if.get_capture(
            len(self.pkt_infos) - len(dropped_packet_indexes))
        self.verify_capture(packets, dropped_packet_indexes)
        self.src_if.assert_nothing_captured()

    def test_timeout_cleanup(self):
        """ timeout (cleanup) """

        # whole packets + fragmented packets sans last fragment
        fragments = [
            x for (_, frags_400, _, _) in self.pkt_infos
            for x in frags_400[:-1 if len(frags_400) > 1 else None]
        ]

        # last fragments for fragmented packets
        fragments2 = [frags_400[-1]
                      for (_, frags_400, _, _) in self.pkt_infos
                      if len(frags_400) > 1]

        dropped_packet_indexes = set(
            index for (index, frags_400, _, _) in self.pkt_infos
            if len(frags_400) > 1)

        self.vapi.ip_reassembly_set(timeout_ms=100, max_reassemblies=1000,
                                    expire_walk_interval_ms=50)

        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        self.sleep(.25, "wait before sending rest of fragments")

        self.src_if.add_stream(fragments2)
        self.pg_start()

        packets = self.dst_if.get_capture(
            len(self.pkt_infos) - len(dropped_packet_indexes))
        self.verify_capture(packets, dropped_packet_indexes)
        self.src_if.assert_nothing_captured()

    def test_disabled(self):
        """ reassembly disabled """

        dropped_packet_indexes = set(
            index for (index, frags_400, _, _) in self.pkt_infos
            if len(frags_400) > 1)

        self.vapi.ip_reassembly_set(timeout_ms=1000, max_reassemblies=0,
                                    expire_walk_interval_ms=10000)

        self.pg_enable_capture()
        self.src_if.add_stream(self.fragments_400)
        self.pg_start()

        packets = self.dst_if.get_capture(
            len(self.pkt_infos) - len(dropped_packet_indexes))
        self.verify_capture(packets, dropped_packet_indexes)
        self.src_if.assert_nothing_captured()


class TestIPv6Reassembly(VppTestCase):
    """ IPv6 Reassembly """

    @classmethod
    def setUpClass(cls):
        super(TestIPv6Reassembly, cls).setUpClass()

        cls.create_pg_interfaces([0, 1])
        cls.src_if = cls.pg0
        cls.dst_if = cls.pg1

        # setup all interfaces
        for i in cls.pg_interfaces:
            i.admin_up()
            i.config_ip6()
            i.resolve_ndp()

        # packet sizes
        cls.packet_sizes = [64, 512, 1518, 9018]
        cls.padding = " abcdefghijklmn"
        cls.create_stream(cls.packet_sizes)
        cls.create_fragments()

    def setUp(self):
        """ Test setup - force timeout on existing reassemblies """
        super(TestIPv6Reassembly, self).setUp()
        self.vapi.ip_reassembly_enable_disable(
            sw_if_index=self.src_if.sw_if_index, enable_ip6=True)
        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
                                    expire_walk_interval_ms=10, is_ip6=1)
        self.sleep(.25)
        self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
                                    expire_walk_interval_ms=10000, is_ip6=1)
        self.logger.debug(self.vapi.ppcli("show ip6-reassembly details"))

    def tearDown(self):
        super(TestIPv6Reassembly, self).tearDown()
        self.logger.debug(self.vapi.ppcli("show ip6-reassembly details"))

    @classmethod
    def create_stream(cls, packet_sizes, packet_count=test_packet_count):
        """Create input packet stream for defined interface.

        :param list packet_sizes: Required packet sizes.
        """
        for i in range(0, packet_count):
            info = cls.create_packet_info(cls.src_if, cls.src_if)
            payload = cls.info_to_payload(info)
            p = (Ether(dst=cls.src_if.local_mac, src=cls.src_if.remote_mac) /
                 IPv6(src=cls.src_if.remote_ip6,
                      dst=cls.dst_if.remote_ip6) /
                 UDP(sport=1234, dport=5678) /
                 Raw(payload))
            size = packet_sizes[(i // 2) % len(packet_sizes)]
            cls.extend_packet(p, size, cls.padding)
            info.data = p

    @classmethod
    def create_fragments(cls):
        infos = cls._packet_infos
        cls.pkt_infos = []
        for index, info in six.iteritems(infos):
            p = info.data
            # cls.logger.debug(ppp("Packet:", p.__class__(str(p))))
            fragments_400 = fragment_rfc8200(p, info.index, 400)
            fragments_300 = fragment_rfc8200(p, info.index, 300)
            cls.pkt_infos.append((index, fragments_400, fragments_300))
        cls.fragments_400 = [
            x for _, frags, _ in cls.pkt_infos for x in frags]
        cls.fragments_300 = [
            x for _, _, frags in cls.pkt_infos for x in frags]
        cls.logger.debug("Fragmented %s packets into %s 400-byte fragments, "
                         "and %s 300-byte fragments" %
                         (len(infos), len(cls.fragments_400),
                             len(cls.fragments_300)))

    def verify_capture(self, capture, dropped_packet_indexes=[]):
        """Verify captured packet strea .

        :param list capture: Captured packet stream.
        """
        info = None
        seen = set()
        for packet in capture:
            try:
                self.logger.debug(ppp("Got packet:", packet))
                ip = packet[IPv6]
                udp = packet[UDP]
                payload_info = self.payload_to_info(str(packet[Raw]))
                packet_index = payload_info.index
                self.assertTrue(
                    packet_index not in dropped_packet_indexes,
                    ppp("Packet received, but should be dropped:", packet))
                if packet_index in seen:
                    raise Exception(ppp("Duplicate packet received", packet))
                seen.add(packet_index)
                self.assertEqual(payload_info.dst, self.src_if.sw_if_index)
                info = self._packet_infos[packet_index]
                self.assertTrue(info is not None)
                self.assertEqual(packet_index, info.index)
                saved_packet = info.data
                self.assertEqual(ip.src, saved_packet[IPv6].src)
                self.assertEqual(ip.dst, saved_packet[IPv6].dst)
                self.assertEqual(udp.payload, saved_packet[UDP].payload)
            except Exception:
                self.logger.error(ppp("Unexpected or invalid packet:", packet))
                raise
        for index in self._packet_infos:
            self.assertTrue(index in seen or index in dropped_packet_indexes,
                            "Packet with packet_index %d not received" % index)

    def test_reassembly(self):
        """ basic reassembly """

        self.pg_enable_capture()
        self.src_if.add_stream(self.fragments_400)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

        # run it all again to verify correctness
        self.pg_enable_capture()
        self.src_if.add_stream(self.fragments_400)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

    def test_reversed(self):
        """ reverse order reassembly """

        fragments = list(self.fragments_400)
        fragments.reverse()

        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

        # run it all again to verify correctness
        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

    def test_random(self):
        """ random order reassembly """

        fragments = list(self.fragments_400)
        shuffle(fragments)

        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

        # run it all again to verify correctness
        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

    def test_duplicates(self):
        """ duplicate fragments """

        fragments = [
            x for (_, frags, _) in self.pkt_infos
            for x in frags
            for _ in range(0, min(2, len(frags)))
        ]

        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)
        self.src_if.assert_nothing_captured()

    def test_overlap1(self):
        """ overlapping fragments case #1 """

        fragments = []
        for _, frags_400, frags_300 in self.pkt_infos:
            if len(frags_300) == 1:
                fragments.extend(frags_400)
            else:
                for i, j in zip(frags_300, frags_400):
                    fragments.extend(i)
                    fragments.extend(j)

        dropped_packet_indexes = set(
            index for (index, _, frags) in self.pkt_infos if len(frags) > 1
        )

        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(
            len(self.pkt_infos) - len(dropped_packet_indexes))
        self.verify_capture(packets, dropped_packet_indexes)
        self.src_if.assert_nothing_captured()

    def test_overlap2(self):
        """ overlapping fragments case #2 """

        fragments = []
        for _, frags_400, frags_300 in self.pkt_infos:
            if len(frags_400) == 1:
                fragments.extend(frags_400)
            else:
                # care must be taken here so that there are no fragments
                # received by vpp after reassembly is finished, otherwise
                # new reassemblies will be started and packet generator will
                # freak out when it detects unfreed buffers
                zipped = zip(frags_400, frags_300)
                for i, j in zipped[:-1]:
                    fragments.extend(i)
                    fragments.extend(j)
                fragments.append(zipped[-1][0])

        dropped_packet_indexes = set(
            index for (index, _, frags) in self.pkt_infos if len(frags) > 1
        )

        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        packets = self.dst_if.get_capture(
            len(self.pkt_infos) - len(dropped_packet_indexes))
        self.verify_capture(packets, dropped_packet_indexes)
        self.src_if.assert_nothing_captured()

    def test_timeout_inline(self):
        """ timeout (inline) """

        dropped_packet_indexes = set(
            index for (index, frags, _) in self.pkt_infos if len(frags) > 1
        )

        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
                                    expire_walk_interval_ms=10000, is_ip6=1)

        self.pg_enable_capture()
        self.src_if.add_stream(self.fragments_400)
        self.pg_start()

        packets = self.dst_if.get_capture(
            len(self.pkt_infos) - len(dropped_packet_indexes))
        self.verify_capture(packets, dropped_packet_indexes)
        pkts = self.src_if.get_capture(
            expected_count=len(dropped_packet_indexes))
        for icmp in pkts:
            self.assertIn(ICMPv6TimeExceeded, icmp)
            self.assertIn(IPv6ExtHdrFragment, icmp)
            self.assertIn(icmp[IPv6ExtHdrFragment].id, dropped_packet_indexes)
            dropped_packet_indexes.remove(icmp[IPv6ExtHdrFragment].id)

    def test_timeout_cleanup(self):
        """ timeout (cleanup) """

        # whole packets + fragmented packets sans last fragment
        fragments = [
            x for (_, frags_400, _) in self.pkt_infos
            for x in frags_400[:-1 if len(frags_400) > 1 else None]
        ]

        # last fragments for fragmented packets
        fragments2 = [frags_400[-1]
                      for (_, frags_400, _) in self.pkt_infos
                      if len(frags_400) > 1]

        dropped_packet_indexes = set(
            index for (index, frags_400, _) in self.pkt_infos
            if len(frags_400) > 1)

        self.vapi.ip_reassembly_set(timeout_ms=100, max_reassemblies=1000,
                                    expire_walk_interval_ms=50)

        self.vapi.ip_reassembly_set(timeout_ms=100, max_reassemblies=1000,
                                    expire_walk_interval_ms=50, is_ip6=1)

        self.pg_enable_capture()
        self.src_if.add_stream(fragments)
        self.pg_start()

        self.sleep(.25, "wait before sending rest of fragments")

        self.src_if.add_stream(fragments2)
        self.pg_start()

        packets = self.dst_if.get_capture(
            len(self.pkt_infos) - len(dropped_packet_indexes))
        self.verify_capture(packets, dropped_packet_indexes)
        pkts = self.src_if.get_capture(
            expected_count=len(dropped_packet_indexes))
        for icmp in pkts:
            self.assertIn(ICMPv6TimeExceeded, icmp)
            self.assertIn(IPv6ExtHdrFragment, icmp)
            self.assertIn(icmp[IPv6ExtHdrFragment].id, dropped_packet_indexes)
            dropped_packet_indexes.remove(icmp[IPv6ExtHdrFragment].id)

    def test_disabled(self):
        """ reassembly disabled """

        dropped_packet_indexes = set(
            index for (index, frags_400, _) in self.pkt_infos
            if len(frags_400) > 1)

        self.vapi.ip_reassembly_set(timeout_ms=1000, max_reassemblies=0,
                                    expire_walk_interval_ms=10000, is_ip6=1)

        self.pg_enable_capture()
        self.src_if.add_stream(self.fragments_400)
        self.pg_start()

        packets = self.dst_if.get_capture(
            len(self.pkt_infos) - len(dropped_packet_indexes))
        self.verify_capture(packets, dropped_packet_indexes)
        self.src_if.assert_nothing_captured()

    def test_missing_upper(self):
        """ missing upper layer """
        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
             IPv6(src=self.src_if.remote_ip6,
                  dst=self.src_if.local_ip6) /
             UDP(sport=1234, dport=5678) /
             Raw())
        self.extend_packet(p, 1000, self.padding)
        fragments = fragment_rfc8200(p, 1, 500)
        bad_fragment = p.__class__(str(fragments[1]))
        bad_fragment[IPv6ExtHdrFragment].nh = 59
        bad_fragment[IPv6ExtHdrFragment].offset = 0
        self.pg_enable_capture()
        self.src_if.add_stream([bad_fragment])
        self.pg_start()
        pkts = self.src_if.get_capture(expected_count=1)
        icmp = pkts[0]
        self.assertIn(ICMPv6ParamProblem, icmp)
        self.assert_equal(icmp[ICMPv6ParamProblem].code, 3, "ICMP code")

    def test_invalid_frag_size(self):
        """ fragment size not a multiple of 8 """
        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
             IPv6(src=self.src_if.remote_ip6,
                  dst=self.src_if.local_ip6) /
             UDP(sport=1234, dport=5678) /
             Raw())
        self.extend_packet(p, 1000, self.padding)
        fragments = fragment_rfc8200(p, 1, 500)
        bad_fragment = fragments[0]
        self.extend_packet(bad_fragment, len(bad_fragment) + 5)
        self.pg_enable_capture()
        self.src_if.add_stream([bad_fragment])
        self.pg_start()
        pkts = self.src_if.get_capture(expected_count=1)
        icmp = pkts[0]
        self.assertIn(ICMPv6ParamProblem, icmp)
        self.assert_equal(icmp[ICMPv6ParamProblem].code, 0, "ICMP code")

    def test_invalid_packet_size(self):
        """ total packet size > 65535 """
        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
             IPv6(src=self.src_if.remote_ip6,
                  dst=self.src_if.local_ip6) /
             UDP(sport=1234, dport=5678) /
             Raw())
        self.extend_packet(p, 1000, self.padding)
        fragments = fragment_rfc8200(p, 1, 500)
        bad_fragment = fragments[1]
        bad_fragment[IPv6ExtHdrFragment].offset = 65500
        self.pg_enable_capture()
        self.src_if.add_stream([bad_fragment])
        self.pg_start()
        pkts = self.src_if.get_capture(expected_count=1)
        icmp = pkts[0]
        self.assertIn(ICMPv6ParamProblem, icmp)
        self.assert_equal(icmp[ICMPv6ParamProblem].code, 0, "ICMP code")


class TestIPv4ReassemblyLocalNode(VppTestCase):
    """ IPv4 Reassembly for packets coming to ip4-local node """

    @classmethod
    def setUpClass(cls):
        super(TestIPv4ReassemblyLocalNode, cls).setUpClass()

        cls.create_pg_interfaces([0])
        cls.src_dst_if = cls.pg0

        # setup all interfaces
        for i in cls.pg_interfaces:
            i.admin_up()
            i.config_ip4()
            i.resolve_arp()

        cls.padding = " abcdefghijklmn"
        cls.create_stream()
        cls.create_fragments()

    def setUp(self):
        """ Test setup - force timeout on existing reassemblies """
        super(TestIPv4ReassemblyLocalNode, self).setUp()
        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
                                    expire_walk_interval_ms=10)
        self.sleep(.25)
        self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
                                    expire_walk_interval_ms=10000)

    def tearDown(self):
        super(TestIPv4ReassemblyLocalNode, self).tearDown()
        self.logger.debug(self.vapi.ppcli("show ip4-reassembly details"))

    @classmethod
    def create_stream(cls, packet_count=test_packet_count):
        """Create input packet stream for defined interface.

        :param list packet_sizes: Required packet sizes.
        """
        for i in range(0, packet_count):
            info = cls.create_packet_info(cls.src_dst_if, cls.src_dst_if)
            payload = cls.info_to_payload(info)
            p = (Ether(dst=cls.src_dst_if.local_mac,
                       src=cls.src_dst_if.remote_mac) /
                 IP(id=info.index, src=cls.src_dst_if.remote_ip4,
                    dst=cls.src_dst_if.local_ip4) /
                 ICMP(type='echo-request', id=1234) /
                 Raw(payload))
            cls.extend_packet(p, 1518, cls.padding)
            info.data = p

    @classmethod
    def create_fragments(cls):
        infos = cls._packet_infos
        cls.pkt_infos = []
        for index, info in six.iteritems(infos):
            p = info.data
            # cls.logger.debug(ppp("Packet:", p.__class__(str(p))))
            fragments_300 = fragment_rfc791(p, 300)
            cls.pkt_infos.append((index, fragments_300))
        cls.fragments_300 = [x for (_, frags) in cls.pkt_infos for x in frags]
        cls.logger.debug("Fragmented %s packets into %s 300-byte fragments" %
                         (len(infos), len(cls.fragments_300)))

    def verify_capture(self, capture):
        """Verify captured packet stream.

        :param list capture: Captured packet stream.
        """
        info = None
        seen = set()
        for packet in capture:
            try:
                self.logger.debug(ppp("Got packet:", packet))
                ip = packet[IP]
                icmp = packet[ICMP]
                payload_info = self.payload_to_info(str(packet[Raw]))
                packet_index = payload_info.index
                if packet_index in seen:
                    raise Exception(ppp("Duplicate packet received", packet))
                seen.add(packet_index)
                self.assertEqual(payload_info.dst, self.src_dst_if.sw_if_index)
                info = self._packet_infos[packet_index]
                self.assertTrue(info is not None)
                self.assertEqual(packet_index, info.index)
                saved_packet = info.data
                self.assertEqual(ip.src, saved_packet[IP].dst)
                self.assertEqual(ip.dst, saved_packet[IP].src)
                self.assertEqual(icmp.type, 0)  # echo reply
                self.assertEqual(icmp.id, saved_packet[ICMP].id)
                self.assertEqual(icmp.payload, saved_packet[ICMP].payload)
            except Exception:
                self.logger.error(ppp("Unexpected or invalid packet:", packet))
                raise
        for index in self._packet_infos:
            self.assertTrue(index in seen or index in dropped_packet_indexes,
                            "Packet with packet_index %d not received" % index)

    def test_reassembly(self):
        """ basic reassembly """

        self.pg_enable_capture()
        self.src_dst_if.add_stream(self.fragments_300)
        self.pg_start()

        packets = self.src_dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)

        # run it all again to verify correctness
        self.pg_enable_capture()
        self.src_dst_if.add_stream(self.fragments_300)
        self.pg_start()

        packets = self.src_dst_if.get_capture(len(self.pkt_infos))
        self.verify_capture(packets)


class TestFIFReassembly(VppTestCase):
    """ Fragments in fragments reassembly """

    @classmethod
    def setUpClass(cls):
        super(TestFIFReassembly, cls).setUpClass()

        cls.create_pg_interfaces([0, 1])
        cls.src_if = cls.pg0
        cls.dst_if = cls.pg1
        for i in cls.pg_interfaces:
            i.admin_up()
            i.config_ip4()
            i.resolve_arp()
            i.config_ip6()
            i.resolve_ndp()

        cls.packet_sizes = [64, 512, 1518, 9018]
        cls.padding = " abcdefghijklmn"

    def setUp(self):
        """ Test setup - force timeout on existing reassemblies """
        super(TestFIFReassembly, self).setUp()
        self.vapi.ip_reassembly_enable_disable(
            sw_if_index=self.src_if.sw_if_index, enable_ip4=True,
            enable_ip6=True)
        self.vapi.ip_reassembly_enable_disable(
            sw_if_index=self.dst_if.sw_if_index, enable_ip4=True,
            enable_ip6=True)
        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
                                    expire_walk_interval_ms=10)
        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
                                    expire_walk_interval_ms=10, is_ip6=1)
        self.sleep(.25)
        self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
                                    expire_walk_interval_ms=10000)
        self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
                                    expire_walk_interval_ms=10000, is_ip6=1)

    def tearDown(self):
        self.logger.debug(self.vapi.ppcli("show ip4-reassembly details"))
        self.logger.debug(self.vapi.ppcli("show ip6-reassembly details"))
        super(TestFIFReassembly, self).tearDown()

    def verify_capture(self, capture, ip_class, dropped_packet_indexes=[]):
        """Verify captured packet stream.

        :param list capture: Captured packet stream.
        """
        info = None
        seen = set()
        for packet in capture:
            try:
                self.logger.debug(ppp("Got packet:", packet))
                ip = packet[ip_class]
                udp = packet[UDP]
                payload_info = self.payload_to_info(str(packet[Raw]))
                packet_index = payload_info.index
                self.assertTrue(
                    packet_index not in dropped_packet_indexes,
                    ppp("Packet received, but should be dropped:", packet))
                if packet_index in seen:
                    raise Exception(ppp("Duplicate packet received", packet))
                seen.add(packet_index)
                self.assertEqual(payload_info.dst, self.dst_if.sw_if_index)
                info = self._packet_infos[packet_index]
                self.assertTrue(info is not None)
                self.assertEqual(packet_index, info.index)
                saved_packet = info.data
                self.assertEqual(ip.src, saved_packet[ip_class].src)
                self.assertEqual(ip.dst, saved_packet[ip_class].dst)
                self.assertEqual(udp.payload, saved_packet[UDP].payload)
            except Exception:
                self.logger.error(ppp("Unexpected or invalid packet:", packet))
                raise
        for index in self._packet_infos:
            self.assertTrue(index in seen or index in dropped_packet_indexes,
                            "Packet with packet_index %d not received" % index)

    def test_fif4(self):
        """ Fragments in fragments (4o4) """

        # TODO this should be ideally in setUpClass, but then we hit a bug
        # with VppIpRoute incorrectly reporting it's present when it's not
        # so we need to manually remove the vpp config, thus we cannot have
        # it shared for multiple test cases
        self.tun_ip4 = "1.1.1.2"

        self.gre4 = VppGreInterface(self, self.src_if.local_ip4, self.tun_ip4)
        self.gre4.add_vpp_config()
        self.gre4.admin_up()
        self.gre4.config_ip4()

        self.vapi.ip_reassembly_enable_disable(
            sw_if_index=self.gre4.sw_if_index, enable_ip4=True)

        self.route4 = VppIpRoute(self, self.tun_ip4, 32,
                                 [VppRoutePath(self.src_if.remote_ip4,
                                               self.src_if.sw_if_index)])
        self.route4.add_vpp_config()

        self.reset_packet_infos()
        for i in range(test_packet_count):
            info = self.create_packet_info(self.src_if, self.dst_if)
            payload = self.info_to_payload(info)
            # Ethernet header here is only for size calculation, thus it
            # doesn't matter how it's initialized. This is to ensure that
            # reassembled packet is not > 9000 bytes, so that it's not dropped
            p = (Ether() /
                 IP(id=i, src=self.src_if.remote_ip4,
                    dst=self.dst_if.remote_ip4) /
                 UDP(sport=1234, dport=5678) /
                 Raw(payload))
            size = self.packet_sizes[(i // 2) % len(self.packet_sizes)]
            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)
                     for x in fragment_rfc791(p.data, 400)]

        encapped_fragments = \
            [Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
             IP(src=self.tun_ip4, dst=self.src_if.local_ip4) /
                GRE() /
                p
                for p in fragments]

        fragmented_encapped_fragments = \
            [x for p in encapped_fragments
             for x in fragment_rfc791(p, 200)]

        self.src_if.add_stream(fragmented_encapped_fragments)

        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()

        self.src_if.assert_nothing_captured()
        packets = self.dst_if.get_capture(len(self._packet_infos))
        self.verify_capture(packets, IP)

        # TODO remove gre vpp config by hand until VppIpRoute gets fixed
        # so that it's query_vpp_config() works as it should
        self.gre4.remove_vpp_config()
        self.logger.debug(self.vapi.ppcli("show interface"))

    def test_fif6(self):
        """ Fragments in fragments (6o6) """
        # TODO this should be ideally in setUpClass, but then we hit a bug
        # with VppIpRoute incorrectly reporting it's present when it's not
        # so we need to manually remove the vpp config, thus we cannot have
        # it shared for multiple test cases
        self.tun_ip6 = "1002::1"

        self.gre6 = VppGre6Interface(self, self.src_if.local_ip6, self.tun_ip6)
        self.gre6.add_vpp_config()
        self.gre6.admin_up()
        self.gre6.config_ip6()

        self.vapi.ip_reassembly_enable_disable(
            sw_if_index=self.gre6.sw_if_index, enable_ip6=True)

        self.route6 = VppIpRoute(self, self.tun_ip6, 128,
                                 [VppRoutePath(self.src_if.remote_ip6,
                                               self.src_if.sw_if_index,
                                               proto=DpoProto.DPO_PROTO_IP6)],
                                 is_ip6=1)
        self.route6.add_vpp_config()

        self.reset_packet_infos()
        for i in range(test_packet_count):
            info = self.create_packet_info(self.src_if, self.dst_if)
            payload = self.info_to_payload(info)
            # Ethernet header here is only for size calculation, thus it
            # doesn't matter how it's initialized. This is to ensure that
            # reassembled packet is not > 9000 bytes, so that it's not dropped
            p = (Ether() /
                 IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6) /
                 UDP(sport=1234, dport=5678) /
                 Raw(payload))
            size = self.packet_sizes[(i // 2) % len(self.packet_sizes)]
            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)
                     for x in fragment_rfc8200(
                         i.data, i.index, 400)]

        encapped_fragments = \
            [Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
             IPv6(src=self.tun_ip6, dst=self.src_if.local_ip6) /
                GRE() /
                p
                for p in fragments]

        fragmented_encapped_fragments = \
            [x for p in encapped_fragments for x in (
                fragment_rfc8200(
                    p,
                    2 * len(self._packet_infos) + p[IPv6ExtHdrFragment].id,
                    200)
                if IPv6ExtHdrFragment in p else [p]
            )
            ]

        self.src_if.add_stream(fragmented_encapped_fragments)

        self.pg_enable_capture(self.pg_interfaces)
        self.pg_start()

        self.src_if.assert_nothing_captured()
        packets = self.dst_if.get_capture(len(self._packet_infos))
        self.verify_capture(packets, IPv6)

        # TODO remove gre vpp config by hand until VppIpRoute gets fixed
        # so that it's query_vpp_config() works as it should
        self.gre6.remove_vpp_config()


if __name__ == '__main__':
    unittest.main(testRunner=VppTestRunner)