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/* packet-vxlan.c
*
* Routines for Virtual eXtensible Local Area Network (VXLAN) packet dissection
* RFC 7348 plus draft-smith-vxlan-group-policy-01
*
* (c) Copyright 2016, Sumit Kumar Jha <sjha3@ncsu.edu>
* Support for VXLAN GPE (https://datatracker.ietf.org/doc/html/draft-ietf-nvo3-vxlan-gpe-02)
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/tfs.h>
#include "packet-vxlan.h"
#define UDP_PORT_VXLAN 4789
#define UDP_PORT_VXLAN_GPE 4790
void proto_register_vxlan(void);
void proto_reg_handoff_vxlan(void);
static int proto_vxlan = -1;
static int proto_vxlan_gpe = -1;
static int hf_vxlan_flags = -1;
static int hf_vxlan_gpe_flags = -1;
static int hf_vxlan_flags_reserved = -1;
static int hf_vxlan_reserved_8 = -1;
static int hf_vxlan_flag_a = -1;
static int hf_vxlan_flag_d = -1;
static int hf_vxlan_flag_i = -1;
static int hf_vxlan_flag_g = -1;
static int hf_vxlan_gbp = -1;
static int hf_vxlan_vni = -1;
static int hf_vxlan_gpe_flag_i = -1;
static int hf_vxlan_gpe_flag_p = -1;
static int hf_vxlan_gpe_flag_o = -1;
static int hf_vxlan_gpe_flag_ver = -1;
static int hf_vxlan_gpe_flag_reserved = -1;
static int hf_vxlan_gpe_reserved_16 = -1;
static int hf_vxlan_next_proto = -1;
static int ett_vxlan = -1;
static int ett_vxlan_flags = -1;
static int * const flags_fields[] = {
&hf_vxlan_flag_g,
&hf_vxlan_flag_i,
&hf_vxlan_flag_d,
&hf_vxlan_flag_a,
&hf_vxlan_flags_reserved,
NULL
};
static int * const gpe_flags_fields[] = {
&hf_vxlan_gpe_flag_ver,
&hf_vxlan_gpe_flag_i,
&hf_vxlan_gpe_flag_p,
&hf_vxlan_gpe_flag_o,
&hf_vxlan_gpe_flag_reserved,
NULL
};
static const value_string vxlan_next_protocols[] = {
{ VXLAN_IPV4, "IPv4" },
{ VXLAN_IPV6, "IPv6" },
{ VXLAN_ETHERNET, "Ethernet" },
{ VXLAN_NSH, "Network Service Header" },
{ VXLAN_MPLS, "MPLS"},
{ 0, NULL }
};
static dissector_handle_t eth_handle;
static dissector_table_t vxlan_dissector_table;
static int
dissect_vxlan_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int is_gpe)
{
proto_tree *vxlan_tree;
proto_item *ti;
tvbuff_t *next_tvb;
int offset = 0;
guint32 vxlan_next_proto;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "VxLAN");
col_clear(pinfo->cinfo, COL_INFO);
ti = proto_tree_add_item(tree, proto_vxlan, tvb, offset, 8, ENC_NA);
vxlan_tree = proto_item_add_subtree(ti, ett_vxlan);
if(is_gpe) {
proto_tree_add_bitmask(vxlan_tree, tvb, offset, hf_vxlan_gpe_flags, ett_vxlan_flags, gpe_flags_fields, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(vxlan_tree, hf_vxlan_gpe_reserved_16, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item_ret_uint(vxlan_tree, hf_vxlan_next_proto, tvb, offset, 1, ENC_BIG_ENDIAN, &vxlan_next_proto);
offset += 1;
} else {
proto_tree_add_bitmask(vxlan_tree, tvb, offset, hf_vxlan_flags, ett_vxlan_flags, flags_fields, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item(vxlan_tree, hf_vxlan_gbp, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
}
proto_tree_add_item(vxlan_tree, hf_vxlan_vni, tvb, offset, 3, ENC_BIG_ENDIAN);
offset += 3;
proto_tree_add_item(vxlan_tree, hf_vxlan_reserved_8, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
next_tvb = tvb_new_subset_remaining(tvb, offset);
if(is_gpe){
if(!dissector_try_uint(vxlan_dissector_table, vxlan_next_proto, next_tvb, pinfo, tree)) {
call_data_dissector(next_tvb, pinfo, tree);
}
} else {
call_dissector(eth_handle, next_tvb, pinfo, tree);
}
return tvb_captured_length(tvb);
}
static int
dissect_vxlan_gpe(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
return dissect_vxlan_common(tvb, pinfo, tree, TRUE);
}
static int
dissect_vxlan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
return dissect_vxlan_common(tvb, pinfo, tree, FALSE);
}
/* Register VxLAN with Wireshark */
void
proto_register_vxlan(void)
{
static hf_register_info hf[] = {
{ &hf_vxlan_flags,
{ "Flags", "vxlan.flags",
FT_UINT16, BASE_HEX, NULL, 0x00,
NULL, HFILL
},
},
{ &hf_vxlan_gpe_flags,
{ "Flags", "vxlan.flags",
FT_UINT8, BASE_HEX, NULL, 0x00,
NULL, HFILL
},
},
{ &hf_vxlan_flags_reserved,
{ "Reserved(R)", "vxlan.flags_reserved",
FT_UINT16, BASE_HEX, NULL, 0x77b7,
NULL, HFILL,
},
},
{ &hf_vxlan_gpe_flag_reserved,
{ "Reserved(R)", "vxlan.flags_reserved",
FT_UINT8, BASE_DEC, NULL, 0xC2,
NULL, HFILL,
},
},
{ &hf_vxlan_flag_g,
{ "GBP Extension", "vxlan.flag_g",
FT_BOOLEAN, 16, TFS(&tfs_defined_not_defined), 0x8000,
NULL, HFILL,
},
},
{ &hf_vxlan_flag_i,
{ "VXLAN Network ID (VNI)", "vxlan.flag_i",
FT_BOOLEAN, 16, NULL, 0x0800,
NULL, HFILL,
},
},
{ &hf_vxlan_flag_d,
{ "Don't Learn", "vxlan.flag_d",
FT_BOOLEAN, 16, NULL, 0x0040,
NULL, HFILL,
},
},
{ &hf_vxlan_flag_a,
{ "Policy Applied", "vxlan.flag_a",
FT_BOOLEAN, 16, NULL, 0x0008,
NULL, HFILL,
},
},
{ &hf_vxlan_gpe_flag_ver,
{ "Version", "vxlan.ver",
FT_UINT8, BASE_DEC, NULL, 0x30,
NULL, HFILL,
},
},
{ &hf_vxlan_gpe_flag_i,
{ "Instance", "vxlan.i_bit",
FT_UINT8, BASE_DEC, NULL, 0x08,
NULL, HFILL,
},
},
{ &hf_vxlan_gpe_flag_p,
{ "Next Protocol Bit", "vxlan.p_bit",
FT_UINT8, BASE_DEC, NULL, 0x04,
NULL, HFILL,
},
},
{ &hf_vxlan_gpe_flag_o,
{ "OAM bit", "vxlan.o_bit",
FT_UINT8, BASE_DEC, NULL, 0x01,
NULL, HFILL,
},
},
{ &hf_vxlan_gbp,
{ "Group Policy ID", "vxlan.gbp",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL
},
},
{ &hf_vxlan_vni,
{ "VXLAN Network Identifier (VNI)", "vxlan.vni",
FT_UINT24, BASE_DEC, NULL, 0x0,
NULL, HFILL
},
},
{ &hf_vxlan_reserved_8,
{ "Reserved", "vxlan.reserved8",
FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL
},
},
{ &hf_vxlan_gpe_reserved_16,
{ "Reserved", "vxlan.reserved_16",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL
},
},
{ &hf_vxlan_next_proto,
{ "Next Protocol", "vxlan.next_proto",
FT_UINT8, BASE_DEC, VALS(vxlan_next_protocols), 0x0,
NULL, HFILL
},
},
};
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_vxlan,
&ett_vxlan_flags,
};
/* Register the protocol name and description */
proto_vxlan = proto_register_protocol("Virtual eXtensible Local Area Network", "VXLAN", "vxlan");
/* Protocol registered just for Decode As */
proto_vxlan_gpe = proto_register_protocol_in_name_only("Virtual eXtensible Local Area Network (GPE)", "VXLAN (GPE)", "vxlan_gpe", proto_vxlan, FT_PROTOCOL);
/* Required function calls to register the header fields and subtrees used */
proto_register_field_array(proto_vxlan, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
vxlan_dissector_table = register_dissector_table("vxlan.next_proto", "VXLAN Next Protocol", proto_vxlan, FT_UINT8, BASE_DEC);
}
void
proto_reg_handoff_vxlan(void)
{
dissector_handle_t vxlan_handle;
dissector_handle_t vxlan_gpe_handle;
/*
* RFC 7348 Figures 1 and 2, in the Payload section, say
*
* "(Note that the original Ethernet Frame's FCS is not included)"
*
* meaning that the inner Ethernet frame does *not* include an
* FCS.
*/
eth_handle = find_dissector_add_dependency("eth_withoutfcs", proto_vxlan);
vxlan_handle = create_dissector_handle(dissect_vxlan, proto_vxlan);
vxlan_gpe_handle = create_dissector_handle(dissect_vxlan_gpe, proto_vxlan_gpe);
dissector_add_uint_with_preference("udp.port", UDP_PORT_VXLAN, vxlan_handle);
dissector_add_uint_with_preference("udp.port", UDP_PORT_VXLAN_GPE, vxlan_gpe_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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