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
97
98
99
100
101
102
103
104
105
106
107
108
|
/*
* Copyright (c) 2003 Markus Friedl. All rights reserved.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "config.h"
#include <epan/packet.h>
void proto_register_udpencap(void);
void proto_reg_handoff_udpencap(void);
#define UDPENCAP_PORT 4500
static int proto_udpencap = -1;
static int hf_nat_keepalive = -1;
static int hf_non_esp_marker = -1;
static gint ett_udpencap = -1;
static dissector_handle_t esp_handle;
static dissector_handle_t isakmp_handle;
/*
* UDP Encapsulation of IPsec Packets
* draft-ietf-ipsec-udp-encaps-06.txt
*/
static int
dissect_udpencap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
tvbuff_t *next_tvb;
proto_tree *udpencap_tree;
proto_item *ti;
guint32 spi;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "UDPENCAP");
col_clear(pinfo->cinfo, COL_INFO);
ti = proto_tree_add_item(tree, proto_udpencap, tvb, 0, -1, ENC_NA);
udpencap_tree = proto_item_add_subtree(ti, ett_udpencap);
/* 1 byte of 0xFF indicates NAT-keepalive */
if ((tvb_captured_length(tvb) == 1) && (tvb_get_guint8(tvb, 0) == 0xff)) {
col_set_str(pinfo->cinfo, COL_INFO, "NAT-keepalive");
proto_tree_add_item(udpencap_tree, hf_nat_keepalive, tvb, 0, 1, ENC_NA);
} else {
/* SPI of zero indicates IKE traffic, otherwise it's ESP */
spi = tvb_get_ntohl(tvb, 0);
if (spi == 0) {
col_set_str(pinfo->cinfo, COL_INFO, "ISAKMP");
proto_tree_add_item(udpencap_tree, hf_non_esp_marker, tvb, 0, 4, ENC_NA);
proto_item_set_len(ti, 4);
next_tvb = tvb_new_subset_remaining(tvb, 4);
call_dissector(isakmp_handle, next_tvb, pinfo, tree);
} else {
col_set_str(pinfo->cinfo, COL_INFO, "ESP");
proto_item_set_len(ti, 0);
call_dissector(esp_handle, tvb, pinfo, tree);
}
}
return tvb_captured_length(tvb);
}
void
proto_register_udpencap(void)
{
static hf_register_info hf[] = {
{ &hf_nat_keepalive, { "NAT-keepalive packet", "udpencap.nat_keepalive",
FT_NONE, BASE_NONE, NULL, 0, NULL, HFILL }},
{ &hf_non_esp_marker, { "Non-ESP Marker", "udpencap.non_esp_marker",
FT_NONE, BASE_NONE, NULL, 0, NULL, HFILL }},
};
static gint *ett[] = {
&ett_udpencap,
};
proto_udpencap = proto_register_protocol("UDP Encapsulation of IPsec Packets", "UDPENCAP", "udpencap");
proto_register_field_array(proto_udpencap, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_udpencap(void)
{
dissector_handle_t udpencap_handle;
esp_handle = find_dissector_add_dependency("esp", proto_udpencap);
isakmp_handle = find_dissector_add_dependency("isakmp", proto_udpencap);
udpencap_handle = create_dissector_handle(dissect_udpencap, proto_udpencap);
dissector_add_uint_with_preference("udp.port", UDPENCAP_PORT, udpencap_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local Variables:
* c-basic-offset: 2
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* ex: set shiftwidth=2 tabstop=8 expandtab:
* :indentSize=2:tabSize=8:noTabs=true:
*/
|
