![Guy Harris](/assets/img/avatar_default.png)
making pointers to byte data be "guint8 *" rather than "char *", and making buffers holding byte data arrays of "guint8" rather than arrays of "char"; making pointers to text strings "char *" rather than "guchar *"; appropriately casting pointers (cast to "guint8 *" when passing to routines expecting "guint8 *" or when assigning to "guint8 *"); making port-number preferences "guint"; making enum preferences "gint"; making hf_ variables "int". Clean up white space. svn path=/trunk/; revision=14884
481 lines
13 KiB
C
481 lines
13 KiB
C
/* packet-bssap.c
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* Routines for Base Station Subsystem Application Part (BSSAP/BSAP) dissection
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* Specifications from 3GPP2 (www.3gpp2.org) and 3GPP (www.3gpp.org)
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* IOS 4.0.1 (BSAP)
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* GSM 08.06 (BSSAP)
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*
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* Copyright 2003, Michael Lum <mlum [AT] telostech.com>
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* In association with Telos Technology Inc.
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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 <gmodule.h>
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#ifdef HAVE_SYS_TYPES_H
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# include <sys/types.h>
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#endif
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#ifdef HAVE_NETINET_IN_H
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# include <netinet/in.h>
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#endif
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#include <string.h>
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#include "epan/packet.h"
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#include <epan/prefs.h>
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#include "packet-bssap.h"
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#define BSSAP 0
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#define BSAP 1
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#define BSSAP_OR_BSAP_DEFAULT BSSAP
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#define PDU_TYPE_OFFSET 0
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#define PDU_TYPE_LENGTH 1
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/* Same as below but with names typed out */
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static const value_string bssap_pdu_type_values[] = {
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{ BSSAP_PDU_TYPE_BSSMAP, "BSS Management" },
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{ BSSAP_PDU_TYPE_DTAP, "Direct Transfer" },
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{ 0, NULL } };
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static const value_string bsap_pdu_type_values[] = {
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{ BSSAP_PDU_TYPE_BSSMAP, "BS Management" },
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{ BSSAP_PDU_TYPE_DTAP, "Direct Transfer" },
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{ 0, NULL } };
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/* Same as above but in acronym for (for the Info column) */
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static const value_string bssap_pdu_type_acro_values[] = {
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{ BSSAP_PDU_TYPE_BSSMAP, "BSSMAP" },
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{ BSSAP_PDU_TYPE_DTAP, "DTAP" },
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{ 0, NULL } };
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/* Same as above but in acronym for (for the Info column) */
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static const value_string bsap_pdu_type_acro_values[] = {
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{ BSSAP_PDU_TYPE_BSSMAP, "BSMAP" },
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{ BSSAP_PDU_TYPE_DTAP, "DTAP" },
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{ 0, NULL } };
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#define PARAMETER_DLCI 0x00
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#define PARAMETER_LENGTH 0x01
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#define PARAMETER_DATA 0x02
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#define DLCI_LENGTH 1
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#define LENGTH_LENGTH 1
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#define DATA_LENGTH 1
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#define CC_MASK 0xc0
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#define SPARE_MASK 0x38
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#define SAPI_MASK 0x07
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static const value_string bssap_cc_values[] = {
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{ 0x00, "not further specified" },
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{ 0x80, "FACCH or SDCCH" },
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{ 0xc0, "SACCH" },
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{ 0, NULL } };
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static const value_string bsap_cc_values[] = {
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{ 0x00, "default for TIA/EIA/IS-2000" },
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{ 0, NULL } };
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static const value_string bssap_sapi_values[] = {
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{ 0x00, "RR/MM/CC" },
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{ 0x03, "SMS" },
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{ 0, NULL } };
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static const value_string bsap_sapi_values[] = {
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{ 0x00, "Not used" },
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{ 0, NULL } };
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/* Initialize the protocol and registered fields */
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static int proto_bssap = -1;
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static int hf_bssap_pdu_type = -1;
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static int hf_bsap_pdu_type = -1;
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static int hf_bssap_dlci_cc = -1;
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static int hf_bsap_dlci_cc = -1;
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static int hf_bssap_dlci_spare = -1;
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static int hf_bsap_dlci_rsvd = -1;
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static int hf_bssap_dlci_sapi = -1;
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static int hf_bsap_dlci_sapi = -1;
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static int hf_bssap_length = -1;
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/* Initialize the subtree pointers */
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static gint ett_bssap = -1;
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static gint ett_bssap_dlci = -1;
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static dissector_handle_t data_handle;
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static dissector_table_t bssap_dissector_table;
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static dissector_table_t bsap_dissector_table;
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/*
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* Keep track of pdu_type so we can call appropriate sub-dissector
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*/
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static guint8 pdu_type = 0xFF;
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static gint bssap_or_bsap_global = BSSAP_OR_BSAP_DEFAULT;
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static void
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dissect_bssap_unknown_message(tvbuff_t *message_tvb, proto_tree *bssap_tree)
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{
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guint32 message_length;
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message_length = tvb_length(message_tvb);
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proto_tree_add_text(bssap_tree, message_tvb, 0, message_length,
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"Unknown message (%u byte%s)",
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message_length, plurality(message_length, "", "s"));
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}
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static void
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dissect_bssap_unknown_param(tvbuff_t *tvb, proto_tree *tree, guint8 type, guint16 length)
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{
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proto_tree_add_text(tree, tvb, 0, length,
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"Unknown parameter 0x%x (%u byte%s)",
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type, length, plurality(length, "", "s"));
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}
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static void
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dissect_bssap_data_param(tvbuff_t *tvb, packet_info *pinfo,
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proto_tree *bssap_tree, proto_tree *tree)
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{
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if ((pdu_type <= 0x01))
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{
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if (bssap_or_bsap_global == BSSAP)
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{
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/* BSSAP */
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if (dissector_try_port(bssap_dissector_table, pdu_type, tvb, pinfo, tree)) return;
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}
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else
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{
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/* BSAP */
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if (dissector_try_port(bsap_dissector_table, pdu_type, tvb, pinfo, tree)) return;
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}
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}
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/* No sub-dissection occured, treat it as raw data */
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call_dissector(data_handle, tvb, pinfo, bssap_tree);
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}
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static void
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dissect_bssap_dlci_param(tvbuff_t *tvb, proto_tree *tree, guint16 length)
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{
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proto_item *dlci_item = 0;
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proto_tree *dlci_tree = 0;
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guint8 oct;
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dlci_item =
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proto_tree_add_text(tree, tvb, 0, length,
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"Data Link Connection Identifier");
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dlci_tree = proto_item_add_subtree(dlci_item, ett_bssap_dlci);
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oct = tvb_get_guint8(tvb, 0);
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if (bssap_or_bsap_global == BSSAP)
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{
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proto_tree_add_uint(dlci_tree, hf_bssap_dlci_cc, tvb, 0, length, oct);
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proto_tree_add_uint(dlci_tree, hf_bssap_dlci_spare, tvb, 0, length, oct);
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proto_tree_add_uint(dlci_tree, hf_bssap_dlci_sapi, tvb, 0, length, oct);
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}
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else
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{
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proto_tree_add_uint(dlci_tree, hf_bsap_dlci_cc, tvb, 0, length, oct);
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proto_tree_add_uint(dlci_tree, hf_bsap_dlci_rsvd, tvb, 0, length, oct);
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proto_tree_add_uint(dlci_tree, hf_bsap_dlci_sapi, tvb, 0, length, oct);
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}
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}
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static void
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dissect_bssap_length_param(tvbuff_t *tvb, proto_tree *tree, guint16 length)
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{
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guint8 data_length;
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data_length = tvb_get_guint8(tvb, 0);
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proto_tree_add_uint(tree, hf_bssap_length, tvb, 0, length, data_length);
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}
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/*
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* Dissect a parameter given its type, offset into tvb, and length.
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*/
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static guint16
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dissect_bssap_parameter(tvbuff_t *tvb, packet_info *pinfo, proto_tree *bssap_tree,
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proto_tree *tree, guint8 parameter_type, gint offset,
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guint16 parameter_length)
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{
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tvbuff_t *parameter_tvb;
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parameter_tvb = tvb_new_subset(tvb, offset, parameter_length, parameter_length);
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switch (parameter_type)
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{
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case PARAMETER_DLCI:
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dissect_bssap_dlci_param(parameter_tvb, bssap_tree, parameter_length);
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break;
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case PARAMETER_LENGTH:
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dissect_bssap_length_param(parameter_tvb, bssap_tree, parameter_length);
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break;
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case PARAMETER_DATA:
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dissect_bssap_data_param(parameter_tvb, pinfo, bssap_tree, tree);
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break;
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default:
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dissect_bssap_unknown_param(parameter_tvb, bssap_tree, parameter_type,
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parameter_length);
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break;
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}
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return(parameter_length);
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}
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static guint16
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dissect_bssap_var_parameter(tvbuff_t *tvb, packet_info *pinfo,
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proto_tree *bssap_tree, proto_tree *tree,
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guint8 parameter_type, gint offset)
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{
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guint16 parameter_length;
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guint8 length_length;
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parameter_length = tvb_get_guint8(tvb, offset);
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length_length = LENGTH_LENGTH;
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offset += length_length;
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dissect_bssap_parameter(tvb, pinfo, bssap_tree, tree, parameter_type,
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offset, parameter_length);
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return(parameter_length + length_length);
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}
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static void
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dissect_bssap_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *bssap_tree,
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proto_tree *tree)
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{
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gint offset = 0;
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/*
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* Extract the PDU type
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*/
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pdu_type = tvb_get_guint8(tvb, PDU_TYPE_OFFSET);
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offset = PDU_TYPE_LENGTH;
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if (bssap_tree)
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{
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/*
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* add the message type to the protocol tree
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*/
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proto_tree_add_uint(bssap_tree,
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(bssap_or_bsap_global == BSSAP) ? hf_bssap_pdu_type : hf_bsap_pdu_type,
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tvb, PDU_TYPE_OFFSET, PDU_TYPE_LENGTH, pdu_type);
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}
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/* Starting a new message dissection */
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switch (pdu_type)
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{
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case BSSAP_PDU_TYPE_BSSMAP:
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offset += dissect_bssap_parameter(tvb, pinfo, bssap_tree, tree,
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PARAMETER_LENGTH, offset,
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LENGTH_LENGTH);
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offset += dissect_bssap_var_parameter(tvb, pinfo, bssap_tree, tree,
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PARAMETER_DATA,
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(offset - LENGTH_LENGTH));
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break;
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case BSSAP_PDU_TYPE_DTAP:
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offset += dissect_bssap_parameter(tvb, pinfo, bssap_tree, tree,
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PARAMETER_DLCI,
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offset, DLCI_LENGTH);
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offset += dissect_bssap_parameter(tvb, pinfo, bssap_tree, tree,
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PARAMETER_LENGTH, offset,
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LENGTH_LENGTH);
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offset += dissect_bssap_var_parameter(tvb, pinfo, bssap_tree, tree,
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PARAMETER_DATA,
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(offset - LENGTH_LENGTH));
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break;
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default:
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if (check_col(pinfo->cinfo, COL_INFO))
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{
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col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
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val_to_str(pdu_type, ((bssap_or_bsap_global == BSSAP) ?
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bssap_pdu_type_acro_values : bsap_pdu_type_acro_values),
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"Unknown"));
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}
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dissect_bssap_unknown_message(tvb, bssap_tree);
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break;
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}
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}
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static void
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dissect_bssap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_item *bssap_item;
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proto_tree *bssap_tree = NULL;
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/*
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* Make entry in the Protocol column on summary display
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*/
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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{
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col_set_str(pinfo->cinfo, COL_PROTOCOL, ((bssap_or_bsap_global == BSSAP) ? "BSSAP" : "BSAP"));
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}
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/*
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* create the bssap protocol tree
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*/
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proto_tree_add_item_hidden(tree, proto_bssap, tvb, 0, -1, FALSE);
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bssap_item = proto_tree_add_text(tree, tvb, 0, -1, (bssap_or_bsap_global == BSSAP) ? "BSSAP" : "BSAP");
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bssap_tree = proto_item_add_subtree(bssap_item, ett_bssap);
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/* dissect the message */
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dissect_bssap_message(tvb, pinfo, bssap_tree, tree);
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}
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static gboolean
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dissect_bssap_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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/* Is it a BSSAP/BSAP packet?
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* If octet_1 == 0x00 and octet_2 == length(tvb) - 2
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* or if octet_1 == 0x01 and octet_3 == length(tvb) - 3
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* then we'll assume it is a bssap packet
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*/
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switch (tvb_get_guint8(tvb, 0))
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{
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case 0x00:
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if (tvb_get_guint8(tvb, 1) != (tvb_length(tvb) - 2)) { return(FALSE); }
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break;
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case 0x01:
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if (tvb_get_guint8(tvb, 2) != (tvb_length(tvb) - 3)) { return(FALSE); }
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break;
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default:
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return(FALSE);
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}
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dissect_bssap(tvb, pinfo, tree);
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return(TRUE);
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}
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/* Register the protocol with Ethereal */
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void
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proto_register_bssap(void)
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{
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module_t *bssap_module;
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/* Setup list of header fields */
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static hf_register_info hf[] = {
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{ &hf_bssap_pdu_type,
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{ "Message Type", "bssap.pdu_type",
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FT_UINT8, BASE_HEX, VALS(bssap_pdu_type_values), 0x0,
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"", HFILL}},
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{ &hf_bsap_pdu_type,
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{ "Message Type", "bsap.pdu_type",
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FT_UINT8, BASE_HEX, VALS(bsap_pdu_type_values), 0x0,
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"", HFILL}},
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{ &hf_bssap_dlci_cc,
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{ "Control Channel", "bssap.dlci.cc",
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FT_UINT8, BASE_HEX, VALS(bssap_cc_values), CC_MASK,
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"", HFILL}},
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{ &hf_bsap_dlci_cc,
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{ "Control Channel", "bsap.dlci.cc",
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FT_UINT8, BASE_HEX, VALS(bsap_cc_values), CC_MASK,
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"", HFILL}},
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{ &hf_bssap_dlci_spare,
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{ "Spare", "bssap.dlci.spare",
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FT_UINT8, BASE_HEX, NULL, SPARE_MASK,
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"", HFILL}},
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{ &hf_bsap_dlci_rsvd,
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{ "Reserved", "bsap.dlci.rsvd",
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FT_UINT8, BASE_HEX, NULL, SPARE_MASK,
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"", HFILL}},
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{ &hf_bssap_dlci_sapi,
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{ "SAPI", "bssap.dlci.sapi",
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FT_UINT8, BASE_HEX, VALS(bssap_sapi_values), SAPI_MASK,
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"", HFILL}},
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{ &hf_bsap_dlci_sapi,
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{ "SAPI", "bsap.dlci.sapi",
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FT_UINT8, BASE_HEX, VALS(bsap_sapi_values), SAPI_MASK,
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"", HFILL}},
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{ &hf_bssap_length,
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{ "Length", "bssap.length",
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FT_UINT8, BASE_DEC, NULL, 0x0,
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"", HFILL}},
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};
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/* Setup protocol subtree array */
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static gint *ett[] = {
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&ett_bssap,
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&ett_bssap_dlci,
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};
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static enum_val_t bssap_or_bsap_options[] = {
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{ "bssap", "BSSAP", BSSAP },
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{ "bsap", "BSAP", BSAP },
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{ NULL, NULL, 0 }
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};
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/* Register the protocol name and description */
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proto_bssap = proto_register_protocol("BSSAP/BSAP", "BSSAP", "bssap");
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/* Required function calls to register the header fields and subtrees used */
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proto_register_field_array(proto_bssap, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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bssap_module = prefs_register_protocol(proto_bssap, NULL);
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prefs_register_enum_preference(bssap_module,
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"bsap_or_bssap",
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"Identify to sub-dissector as",
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"For the sake of sub-dissectors registering to accept data from the BSSAP/BSAP dissector, this defines whether it is identified as BSSAP or BSAP.",
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&bssap_or_bsap_global,
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bssap_or_bsap_options,
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|
FALSE);
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|
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bssap_dissector_table = register_dissector_table("bssap.pdu_type", "BSSAP Message Type", FT_UINT8, BASE_DEC);
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bsap_dissector_table = register_dissector_table("bsap.pdu_type", "BSAP Message Type", FT_UINT8, BASE_DEC);
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}
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|
|
|
void
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proto_reg_handoff_bssap(void)
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|
{
|
|
heur_dissector_add("sccp", dissect_bssap_heur, proto_bssap);
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|
|
|
data_handle = find_dissector("data");
|
|
}
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