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/* packet-dtp.c
* Routines for the disassembly for Cisco Dynamic Trunking Protocol
*
* $Id$
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* DTP support added by Charlie Lenahan <clenahan@fortresstech.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/
#include "config.h"
#include <stdlib.h>
#include <string.h>
#include <glib.h>
#include <epan/packet.h>
/*
* It's incomplete, and it appears to be inaccurate in a number of places,
* but it's all I could find....
*/
static int proto_dtp = -1;
static int hf_dtp_version = -1;
static int hf_dtp_tlvtype = -1;
static int hf_dtp_tlvlength = -1;
static int hf_dtp_some_mac = -1;
static gint ett_dtp = -1;
static gint ett_dtp_tlv = -1;
static void dissect_dtp_tlv(tvbuff_t *tvb, int offset, int length, proto_tree *tree, proto_item *ti, guint8 type);
#define TYPE_DOMAIN 0x01
#define TYPE_STATUS 0x02
#define TYPE_DTPTYPE 0x03
#define TYPE_NEIGHBOR 0x04
static const value_string dtp_tlv_type_vals[] = {
{ TYPE_DOMAIN, "Domain" },
{ TYPE_STATUS, "Status" },
{ TYPE_DTPTYPE, "Type" },
{ TYPE_NEIGHBOR, "Neighbor" },
{ 0, NULL }
};
static void
dissect_dtp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_item *ti;
proto_tree *dtp_tree = NULL;
proto_tree *tlv_tree=NULL;
int offset = 0;
if (check_col(pinfo->cinfo, COL_PROTOCOL))
col_set_str(pinfo->cinfo, COL_PROTOCOL, "DTP");
if (check_col(pinfo->cinfo, COL_INFO))
col_set_str(pinfo->cinfo, COL_INFO, "Dynamic Trunking Protocol");
if (tree) {
ti = proto_tree_add_item(tree, proto_dtp, tvb, offset, -1, FALSE);
dtp_tree = proto_item_add_subtree(ti, ett_dtp);
}
/* We assume version */
proto_tree_add_item(dtp_tree, hf_dtp_version, tvb, offset, 1, FALSE);
offset += 1;
while (tvb_reported_length_remaining(tvb, offset) > 0) {
int type, length, valuelength;
type = tvb_get_ntohs(tvb, offset);
length = tvb_get_ntohs(tvb, offset + 2);
valuelength = (length-4);
/* make sure still in valid tlv */
if ((valuelength < 1) || ( length > tvb_length_remaining(tvb, offset) ))
break;
ti = proto_tree_add_text(dtp_tree, tvb, offset, length, "%s",
val_to_str(type, dtp_tlv_type_vals, "Unknown TLV type: 0x%02x"));
tlv_tree = proto_item_add_subtree(ti, ett_dtp_tlv);
proto_tree_add_uint(tlv_tree, hf_dtp_tlvtype, tvb, offset, 2, type);
offset+=2;
proto_tree_add_uint(tlv_tree, hf_dtp_tlvlength, tvb, offset, 2, length);
offset+=2;
if (valuelength > 0) {
dissect_dtp_tlv(tvb, offset, valuelength, tlv_tree, ti, (guint8) type);
}
offset += valuelength;
}
}
static void
dissect_dtp_tlv(tvbuff_t *tvb, int offset, int length,
proto_tree *tree, proto_item *ti, guint8 type)
{
switch (type) {
case TYPE_DOMAIN:
if (length > 0) {
proto_item_set_text(ti, "Domain: %s", tvb_format_text(tvb, offset, length - 1));
proto_tree_add_text(tree, tvb, offset, length, "Domain: %s", tvb_format_text(tvb, offset, length - 1));
} else {
proto_item_set_text(ti, "Domain: Bad length %u", length);
proto_tree_add_text(tree, tvb, offset, length, "Domain: Bad length %u", length);
}
break;
case TYPE_STATUS:
if (length > 0) {
proto_item_set_text(ti,
"Status: 0x%02x",
tvb_get_guint8(tvb, offset));
proto_tree_add_text(tree, tvb, offset, 1,
"Status: 0x%02x",
tvb_get_guint8(tvb, offset));
} else {
proto_item_set_text(ti,
"Status: Bad length %u",
length);
proto_tree_add_text(tree, tvb, offset, length,
"Status: Bad length %u",
length);
}
break;
case TYPE_DTPTYPE:
if (length > 0) {
proto_item_set_text(ti,
"Dtptype: 0x%02x",
tvb_get_guint8(tvb, offset));
proto_tree_add_text(tree, tvb, offset, 1,
"Dtptype: 0x%02x",
tvb_get_guint8(tvb, offset));
} else {
proto_item_set_text(ti,
"Dtptype: Bad length %u",
length);
proto_tree_add_text(tree, tvb, offset, length,
"Dtptype: Bad length %u",
length);
}
break;
case TYPE_NEIGHBOR:
if (length == 6) {
const guint8 *macptr=tvb_get_ptr(tvb,offset,length);
proto_item_set_text(ti, "Neighbor: %s",
ether_to_str(macptr)); /* XXX - resolve? */
proto_tree_add_ether(tree, hf_dtp_some_mac, tvb, offset,length,macptr);
} else {
proto_item_set_text(ti,
"Neighbor: Bad length %u",
length);
proto_tree_add_text(tree, tvb, offset, length,
"Neighbor: Bad length %u",
length);
}
break;
default:
proto_tree_add_text(tree, tvb, offset, length, "Data");
break;
}
}
void
proto_register_dtp(void)
{
static hf_register_info hf[] = {
{ &hf_dtp_version,
{ "Version", "dtp.version", FT_UINT8, BASE_HEX,
NULL, 0x0, "", HFILL }},
{ &hf_dtp_tlvtype,
{ "Type", "dtp.tlv_type", FT_UINT16, BASE_HEX,
VALS(dtp_tlv_type_vals), 0x0, "", HFILL }},
{ &hf_dtp_tlvlength,
{ "Length", "dtp.tlv_len", FT_UINT16, BASE_DEC,
NULL, 0x0, "", HFILL }},
{ &hf_dtp_some_mac,
{ "Neighbor", "vtp.neighbor", FT_ETHER, BASE_NONE,
NULL, 0x0, "MAC Address of neighbor", HFILL }},
};
static gint *ett[] = {
&ett_dtp,
&ett_dtp_tlv,
};
proto_dtp = proto_register_protocol("Dynamic Trunking Protocol", "DTP", "dtp");
proto_register_field_array(proto_dtp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_dtp(void)
{
dissector_handle_t dtp_handle;
dtp_handle = create_dissector_handle(dissect_dtp, proto_dtp);
dissector_add("llc.cisco_pid", 0x2004, dtp_handle);
}
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