![Anders Broman](/assets/img/avatar_default.png)
When offset parameter is 0 replace tvb_bytes_exist() with the faster tvb_length(). non heuristic dissectors svn path=/trunk/; revision=23405
181 lines
4.9 KiB
C
181 lines
4.9 KiB
C
/* packet-xot.c
|
|
* Routines for X.25 over TCP dissection (RFC 1613)
|
|
*
|
|
* Copyright 2000, Paul Ionescu <paul@acorp.ro>
|
|
*
|
|
* $Id$
|
|
*
|
|
* Wireshark - Network traffic analyzer
|
|
* By Gerald Combs <gerald@wireshark.org>
|
|
* Copyright 1998 Gerald Combs
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include "config.h"
|
|
#endif
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <ctype.h>
|
|
|
|
#include <string.h>
|
|
#include <glib.h>
|
|
#include <epan/packet.h>
|
|
#include <epan/emem.h>
|
|
#include "packet-tcp.h"
|
|
#include <epan/prefs.h>
|
|
|
|
#define TCP_PORT_XOT 1998
|
|
|
|
static gint proto_xot = -1;
|
|
static gint hf_xot_version = -1;
|
|
static gint hf_xot_length = -1;
|
|
|
|
static gint ett_xot = -1;
|
|
|
|
/* desegmentation of X.25 over TCP */
|
|
static gboolean xot_desegment = TRUE;
|
|
|
|
static dissector_handle_t x25_handle;
|
|
|
|
static guint get_xot_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset)
|
|
{
|
|
guint16 plen;
|
|
|
|
/*
|
|
* Get the length of the X.25-over-TCP packet.
|
|
*/
|
|
plen = tvb_get_ntohs(tvb, offset + 2);
|
|
|
|
/*
|
|
* That length doesn't include the header; add that in.
|
|
*/
|
|
return plen + 4;
|
|
}
|
|
|
|
static void dissect_xot_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
int offset = 0;
|
|
guint16 version;
|
|
guint16 plen;
|
|
int length;
|
|
proto_item *ti;
|
|
proto_tree *xot_tree;
|
|
tvbuff_t *next_tvb;
|
|
|
|
/*
|
|
* Dissect the X.25-over-TCP packet.
|
|
*/
|
|
version = tvb_get_ntohs(tvb, offset + 0);
|
|
plen = tvb_get_ntohs(tvb, offset + 2);
|
|
if (check_col(pinfo->cinfo, COL_PROTOCOL))
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "XOT");
|
|
if (check_col(pinfo->cinfo, COL_INFO))
|
|
col_add_fstr(pinfo->cinfo, COL_INFO, "XOT Version = %u, size = %u",
|
|
version, plen);
|
|
|
|
if (tree) {
|
|
ti = proto_tree_add_protocol_format(tree, proto_xot, tvb, offset, 4,
|
|
"X.25 over TCP");
|
|
xot_tree = proto_item_add_subtree(ti, ett_xot);
|
|
|
|
proto_tree_add_uint(xot_tree, hf_xot_version, tvb, offset, 2, version);
|
|
proto_tree_add_uint(xot_tree, hf_xot_length, tvb, offset + 2, 2, plen);
|
|
}
|
|
|
|
/*
|
|
* Construct a tvbuff containing the amount of the payload we have
|
|
* available. Make its reported length the amount of data in the
|
|
* X.25-over-TCP packet.
|
|
*/
|
|
length = tvb_length_remaining(tvb, offset + 4);
|
|
if (length > plen)
|
|
length = plen;
|
|
if (plen > 0)
|
|
{
|
|
next_tvb = tvb_new_subset(tvb, offset + 4, length, plen);
|
|
call_dissector(x25_handle, next_tvb, pinfo, tree);
|
|
}
|
|
}
|
|
|
|
static int dissect_xot(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
/*
|
|
* Do we have the full version number and, if so, is it zero?
|
|
* If we have it but it's not zero, reject this segment.
|
|
*/
|
|
if (tvb_length(tvb) >= 2) {
|
|
if (tvb_get_ntohs(tvb, 0) != 0)
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* The version number's OK, so dissect this segment.
|
|
*/
|
|
tcp_dissect_pdus(tvb, pinfo, tree, xot_desegment, 4, get_xot_pdu_len,
|
|
dissect_xot_pdu);
|
|
|
|
return tvb_length(tvb);
|
|
}
|
|
|
|
/* Register the protocol with Wireshark */
|
|
void
|
|
proto_register_xot(void)
|
|
{
|
|
static hf_register_info hf[] = {
|
|
{ &hf_xot_version,
|
|
{ "Version", "xot.version", FT_UINT16, BASE_DEC,
|
|
NULL, 0, "Version of X.25 over TCP protocol", HFILL }},
|
|
|
|
{ &hf_xot_length,
|
|
{ "Length", "xot.length", FT_UINT16, BASE_DEC,
|
|
NULL, 0, "Length of X.25 over TCP packet", HFILL }}
|
|
|
|
};
|
|
|
|
static gint *ett[] = {
|
|
&ett_xot,
|
|
};
|
|
module_t *xot_module;
|
|
|
|
proto_xot = proto_register_protocol("X.25 over TCP", "XOT", "xot");
|
|
proto_register_field_array(proto_xot, hf, array_length(hf));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
new_register_dissector("xot", dissect_xot, proto_xot);
|
|
|
|
xot_module = prefs_register_protocol(proto_xot, NULL);
|
|
prefs_register_bool_preference(xot_module, "desegment",
|
|
"Reassemble X.25-over-TCP messages spanning multiple TCP segments",
|
|
"Whether the X.25-over-TCP dissector should reassemble messages spanning multiple TCP segments. "
|
|
"To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
|
|
&xot_desegment);
|
|
}
|
|
|
|
void
|
|
proto_reg_handoff_xot(void)
|
|
{
|
|
dissector_handle_t xot_handle;
|
|
|
|
/*
|
|
* Get a handle for the X.25 dissector.
|
|
*/
|
|
x25_handle = find_dissector("x.25");
|
|
|
|
xot_handle = new_create_dissector_handle(dissect_xot, proto_xot);
|
|
dissector_add("tcp.port", TCP_PORT_XOT, xot_handle);
|
|
}
|