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1# SPDX-License-Identifier: GPL-2.0-only
2# This file is part of Scapy
3# See https://scapy.net/ for more information
4# Copyright (C) Philippe Biondi <phil@secdev.org>
5
6"""
7Virtual eXtensible Local Area Network (VXLAN)
8- RFC 7348 -
9
10A Framework for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks
11http://tools.ietf.org/html/rfc7348
12https://www.ietf.org/id/draft-ietf-nvo3-vxlan-gpe-02.txt
13
14VXLAN Group Policy Option:
15http://tools.ietf.org/html/draft-smith-vxlan-group-policy-00
16"""
17
18from scapy.packet import Packet, bind_layers, bind_bottom_up, bind_top_down
19from scapy.layers.l2 import Ether
20from scapy.layers.inet import IP, UDP
21from scapy.layers.inet6 import IPv6
22from scapy.fields import FlagsField, XByteField, ThreeBytesField, \
23    ConditionalField, ShortField, ByteEnumField, X3BytesField
24
25_GP_FLAGS = ["R", "R", "R", "A", "R", "R", "D", "R"]
26
27
28class VXLAN(Packet):
29    name = "VXLAN"
30
31    fields_desc = [
32        FlagsField("flags", 0x8, 8,
33                   ['OAM', 'R', 'NextProtocol', 'Instance',
34                    'V1', 'V2', 'R', 'G']),
35        ConditionalField(
36            ShortField("reserved0", 0),
37            lambda pkt: pkt.flags.NextProtocol,
38        ),
39        ConditionalField(
40            ByteEnumField('NextProtocol', 0,
41                          {0: 'NotDefined',
42                           1: 'IPv4',
43                           2: 'IPv6',
44                           3: 'Ethernet',
45                           4: 'NSH'}),
46            lambda pkt: pkt.flags.NextProtocol,
47        ),
48        ConditionalField(
49            ThreeBytesField("reserved1", 0),
50            lambda pkt: (not pkt.flags.G) and (not pkt.flags.NextProtocol),
51        ),
52        ConditionalField(
53            FlagsField("gpflags", 0, 8, _GP_FLAGS),
54            lambda pkt: pkt.flags.G,
55        ),
56        ConditionalField(
57            ShortField("gpid", 0),
58            lambda pkt: pkt.flags.G,
59        ),
60        X3BytesField("vni", 0),
61        XByteField("reserved2", 0),
62    ]
63
64    # Use default linux implementation port
65    overload_fields = {
66        UDP: {'dport': 8472},
67    }
68
69    def mysummary(self):
70        if self.flags.G:
71            return self.sprintf("VXLAN (vni=%VXLAN.vni% gpid=%VXLAN.gpid%)")
72        else:
73            return self.sprintf("VXLAN (vni=%VXLAN.vni%)")
74
75
76bind_layers(UDP, VXLAN, dport=4789)  # RFC standard vxlan port
77bind_layers(UDP, VXLAN, dport=4790)  # RFC standard vxlan-gpe port
78bind_layers(UDP, VXLAN, dport=6633)  # New IANA assigned port for use with NSH
79bind_layers(UDP, VXLAN, dport=8472)  # Linux implementation port
80bind_layers(UDP, VXLAN, dport=48879)  # Cisco ACI
81bind_layers(UDP, VXLAN, sport=4789)
82bind_layers(UDP, VXLAN, sport=4790)
83bind_layers(UDP, VXLAN, sport=6633)
84bind_layers(UDP, VXLAN, sport=8472)
85# By default, set both ports to the RFC standard
86bind_layers(UDP, VXLAN, sport=4789, dport=4789)
87
88# Dissection
89bind_bottom_up(VXLAN, Ether, NextProtocol=0)
90bind_bottom_up(VXLAN, IP, NextProtocol=1)
91bind_bottom_up(VXLAN, IPv6, NextProtocol=2)
92bind_bottom_up(VXLAN, Ether, NextProtocol=3)
93bind_bottom_up(VXLAN, Ether, NextProtocol=None)
94# Build
95bind_top_down(VXLAN, Ether, flags=12, NextProtocol=0)
96bind_top_down(VXLAN, IP, flags=12, NextProtocol=1)
97bind_top_down(VXLAN, IPv6, flags=12, NextProtocol=2)
98bind_top_down(VXLAN, Ether, flags=12, NextProtocol=3)
99