forked from osmocom/wireshark
![Ronnie Sahlberg](/assets/img/avatar_default.png)
while this should improve performance by unmeasurably little it does have the sideeffect that once we finish the rewrite tcp analysis might actually work and work well even for tcp over tcp tunnelling. this also means that if you include packet-tcp.h you also need to include emem.h . svn path=/trunk/; revision=17681
177 lines
4.8 KiB
C
177 lines
4.8 KiB
C
/* packet-xot.c
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* Routines for X.25 over TCP dissection (RFC 1613)
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*
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* Copyright 2000, Paul Ionescu <paul@acorp.ro>
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*
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* $Id$
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@ethereal.com>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <ctype.h>
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#include <string.h>
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#include <glib.h>
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#include <epan/packet.h>
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#include <epan/emem.h>
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#include "packet-tcp.h"
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#include <epan/prefs.h>
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#define TCP_PORT_XOT 1998
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static gint proto_xot = -1;
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static gint hf_xot_version = -1;
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static gint hf_xot_length = -1;
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static gint ett_xot = -1;
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/* desegmentation of X.25 over TCP */
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static gboolean xot_desegment = TRUE;
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static dissector_handle_t x25_handle;
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static guint get_xot_pdu_len(tvbuff_t *tvb, int offset)
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{
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guint16 plen;
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/*
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* Get the length of the X.25-over-TCP packet.
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*/
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plen = tvb_get_ntohs(tvb, offset + 2);
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/*
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* That length doesn't include the header; add that in.
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*/
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return plen + 4;
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}
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static void dissect_xot_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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int offset = 0;
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guint16 version;
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guint16 plen;
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int length;
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proto_item *ti;
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proto_tree *xot_tree;
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tvbuff_t *next_tvb;
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/*
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* Dissect the X.25-over-TCP packet.
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*/
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version = tvb_get_ntohs(tvb, offset + 0);
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plen = tvb_get_ntohs(tvb, offset + 2);
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "XOT");
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if (check_col(pinfo->cinfo, COL_INFO))
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col_add_fstr(pinfo->cinfo, COL_INFO, "XOT Version = %u, size = %u",
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version, plen);
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if (tree) {
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ti = proto_tree_add_protocol_format(tree, proto_xot, tvb, offset, 4,
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"X.25 over TCP");
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xot_tree = proto_item_add_subtree(ti, ett_xot);
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proto_tree_add_uint(xot_tree, hf_xot_version, tvb, offset, 2, version);
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proto_tree_add_uint(xot_tree, hf_xot_length, tvb, offset + 2, 2, plen);
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}
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/*
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* Construct a tvbuff containing the amount of the payload we have
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* available. Make its reported length the amount of data in the
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* X.25-over-TCP packet.
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*/
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length = tvb_length_remaining(tvb, offset + 4);
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if (length > plen)
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length = plen;
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next_tvb = tvb_new_subset(tvb, offset + 4, length, plen);
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call_dissector(x25_handle, next_tvb, pinfo, tree);
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}
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static int dissect_xot(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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/*
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* Do we have the full version number and, if so, is it zero?
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* If we have it but it's not zero, reject this segment.
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*/
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if (tvb_bytes_exist(tvb, 0, 2)) {
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if (tvb_get_ntohs(tvb, 0) != 0)
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return 0;
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}
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/*
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* The version number's OK, so dissect this segment.
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*/
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tcp_dissect_pdus(tvb, pinfo, tree, xot_desegment, 4, get_xot_pdu_len,
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dissect_xot_pdu);
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return tvb_length(tvb);
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}
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/* Register the protocol with Ethereal */
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void
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proto_register_xot(void)
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{
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static hf_register_info hf[] = {
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{ &hf_xot_version,
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{ "Version", "xot.version", FT_UINT16, BASE_DEC,
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NULL, 0, "Version of X.25 over TCP protocol", HFILL }},
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{ &hf_xot_length,
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{ "Length", "xot.length", FT_UINT16, BASE_DEC,
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NULL, 0, "Length of X.25 over TCP packet", HFILL }}
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};
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static gint *ett[] = {
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&ett_xot,
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};
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module_t *xot_module;
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proto_xot = proto_register_protocol("X.25 over TCP", "XOT", "xot");
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proto_register_field_array(proto_xot, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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xot_module = prefs_register_protocol(proto_xot, NULL);
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prefs_register_bool_preference(xot_module, "desegment",
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"Reassemble X.25-over-TCP messages spanning multiple TCP segments",
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"Whether the X.25-over-TCP dissector should reassemble messages spanning multiple TCP segments. "
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"To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
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&xot_desegment);
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}
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void
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proto_reg_handoff_xot(void)
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{
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dissector_handle_t xot_handle;
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/*
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* Get a handle for the X.25 dissector.
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*/
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x25_handle = find_dissector("x.25");
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xot_handle = new_create_dissector_handle(dissect_xot, proto_xot);
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dissector_add("tcp.port", TCP_PORT_XOT, xot_handle);
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}
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