diff options
Diffstat (limited to 'epan/dissectors/packet-bssap.c')
| -rw-r--r-- | epan/dissectors/packet-bssap.c | 480 |
1 files changed, 480 insertions, 0 deletions
diff --git a/epan/dissectors/packet-bssap.c b/epan/dissectors/packet-bssap.c new file mode 100644 index 0000000000..c422677a99 --- /dev/null +++ b/epan/dissectors/packet-bssap.c @@ -0,0 +1,480 @@ +/* packet-bssap.c + * Routines for Base Station Subsystem Application Part (BSSAP/BSAP) dissection + * Specifications from 3GPP2 (www.3gpp2.org) and 3GPP (www.3gpp.org) + * IOS 4.0.1 (BSAP) + * GSM 08.06 (BSSAP) + * + * Copyright 2003, Michael Lum <mlum [AT] telostech.com> + * In association with Telos Technology Inc. + * + * $Id$ + * + * Ethereal - Network traffic analyzer + * By Gerald Combs <gerald@ethereal.com> + * 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 <gmodule.h> + +#ifdef HAVE_SYS_TYPES_H +# include <sys/types.h> +#endif + +#ifdef HAVE_NETINET_IN_H +# include <netinet/in.h> +#endif + +#include <string.h> + +#include "epan/packet.h" +#include "prefs.h" +#include "packet-bssap.h" + +#define BSSAP 0 +#define BSAP 1 + +#define BSSAP_OR_BSAP_DEFAULT BSSAP + +#define PDU_TYPE_OFFSET 0 +#define PDU_TYPE_LENGTH 1 + +/* Same as below but with names typed out */ +static const value_string bssap_pdu_type_values[] = { + { BSSAP_PDU_TYPE_BSSMAP, "BSS Management" }, + { BSSAP_PDU_TYPE_DTAP, "Direct Transfer" }, + { 0, NULL } }; + +static const value_string bsap_pdu_type_values[] = { + { BSSAP_PDU_TYPE_BSSMAP, "BS Management" }, + { BSSAP_PDU_TYPE_DTAP, "Direct Transfer" }, + { 0, NULL } }; + +/* Same as above but in acronym for (for the Info column) */ +static const value_string bssap_pdu_type_acro_values[] = { + { BSSAP_PDU_TYPE_BSSMAP, "BSSMAP" }, + { BSSAP_PDU_TYPE_DTAP, "DTAP" }, + { 0, NULL } }; + +/* Same as above but in acronym for (for the Info column) */ +static const value_string bsap_pdu_type_acro_values[] = { + { BSSAP_PDU_TYPE_BSSMAP, "BSMAP" }, + { BSSAP_PDU_TYPE_DTAP, "DTAP" }, + { 0, NULL } }; + +#define PARAMETER_DLCI 0x00 +#define PARAMETER_LENGTH 0x01 +#define PARAMETER_DATA 0x02 + +#define DLCI_LENGTH 1 +#define LENGTH_LENGTH 1 +#define DATA_LENGTH 1 + +#define CC_MASK 0xc0 +#define SPARE_MASK 0x38 +#define SAPI_MASK 0x07 + +static const value_string bssap_cc_values[] = { + { 0x00, "not further specified" }, + { 0x80, "FACCH or SDCCH" }, + { 0xc0, "SACCH" }, + { 0, NULL } }; + +static const value_string bsap_cc_values[] = { + { 0x00, "default for TIA/EIA/IS-2000" }, + { 0, NULL } }; + +static const value_string bssap_sapi_values[] = { + { 0x00, "RR/MM/CC" }, + { 0x03, "SMS" }, + { 0, NULL } }; + +static const value_string bsap_sapi_values[] = { + { 0x00, "Not used" }, + { 0, NULL } }; + + +/* Initialize the protocol and registered fields */ +static int proto_bssap = -1; +static int hf_bssap_pdu_type = -1; +static int hf_bsap_pdu_type = -1; +static int hf_bssap_dlci_cc = -1; +static int hf_bsap_dlci_cc = -1; +static int hf_bssap_dlci_spare = -1; +static int hf_bsap_dlci_rsvd = -1; +static int hf_bssap_dlci_sapi = -1; +static int hf_bsap_dlci_sapi = -1; +static int hf_bssap_length = -1; + +/* Initialize the subtree pointers */ +static gint ett_bssap = -1; +static gint ett_bssap_dlci = -1; + +static dissector_handle_t data_handle; + +static dissector_table_t bssap_dissector_table; +static dissector_table_t bsap_dissector_table; + +/* + * Keep track of pdu_type so we can call appropriate sub-dissector + */ +static guint8 pdu_type = 0xFF; + +static guint bssap_or_bsap_global = BSSAP_OR_BSAP_DEFAULT; + + +static void +dissect_bssap_unknown_message(tvbuff_t *message_tvb, proto_tree *bssap_tree) +{ + guint32 message_length; + + message_length = tvb_length(message_tvb); + + proto_tree_add_text(bssap_tree, message_tvb, 0, message_length, + "Unknown message (%u byte%s)", + message_length, plurality(message_length, "", "s")); +} + +static void +dissect_bssap_unknown_param(tvbuff_t *tvb, proto_tree *tree, guint8 type, guint16 length) +{ + proto_tree_add_text(tree, tvb, 0, length, + "Unknown parameter 0x%x (%u byte%s)", + type, length, plurality(length, "", "s")); +} + +static void +dissect_bssap_data_param(tvbuff_t *tvb, packet_info *pinfo, + proto_tree *bssap_tree, proto_tree *tree) +{ + if ((pdu_type <= 0x01)) + { + if (bssap_or_bsap_global == BSSAP) + { + /* BSSAP */ + if (dissector_try_port(bssap_dissector_table, pdu_type, tvb, pinfo, tree)) return; + } + else + { + /* BSAP */ + if (dissector_try_port(bsap_dissector_table, pdu_type, tvb, pinfo, tree)) return; + } + } + + /* No sub-dissection occured, treat it as raw data */ + call_dissector(data_handle, tvb, pinfo, bssap_tree); +} + +static void +dissect_bssap_dlci_param(tvbuff_t *tvb, proto_tree *tree, guint16 length) +{ + proto_item *dlci_item = 0; + proto_tree *dlci_tree = 0; + guint8 oct; + + dlci_item = + proto_tree_add_text(tree, tvb, 0, length, + "Data Link Connection Identifier"); + + dlci_tree = proto_item_add_subtree(dlci_item, ett_bssap_dlci); + + oct = tvb_get_guint8(tvb, 0); + + if (bssap_or_bsap_global == BSSAP) + { + proto_tree_add_uint(dlci_tree, hf_bssap_dlci_cc, tvb, 0, length, oct); + proto_tree_add_uint(dlci_tree, hf_bssap_dlci_spare, tvb, 0, length, oct); + proto_tree_add_uint(dlci_tree, hf_bssap_dlci_sapi, tvb, 0, length, oct); + } + else + { + proto_tree_add_uint(dlci_tree, hf_bsap_dlci_cc, tvb, 0, length, oct); + proto_tree_add_uint(dlci_tree, hf_bsap_dlci_rsvd, tvb, 0, length, oct); + proto_tree_add_uint(dlci_tree, hf_bsap_dlci_sapi, tvb, 0, length, oct); + } +} + +static void +dissect_bssap_length_param(tvbuff_t *tvb, proto_tree *tree, guint16 length) +{ + guint8 data_length; + + data_length = tvb_get_guint8(tvb, 0); + proto_tree_add_uint(tree, hf_bssap_length, tvb, 0, length, data_length); +} + +/* + * Dissect a parameter given its type, offset into tvb, and length. + */ +static guint16 +dissect_bssap_parameter(tvbuff_t *tvb, packet_info *pinfo, proto_tree *bssap_tree, + proto_tree *tree, guint8 parameter_type, gint offset, + guint16 parameter_length) +{ + tvbuff_t *parameter_tvb; + + parameter_tvb = tvb_new_subset(tvb, offset, parameter_length, parameter_length); + + switch (parameter_type) + { + case PARAMETER_DLCI: + dissect_bssap_dlci_param(parameter_tvb, bssap_tree, parameter_length); + break; + + case PARAMETER_LENGTH: + dissect_bssap_length_param(parameter_tvb, bssap_tree, parameter_length); + break; + + case PARAMETER_DATA: + dissect_bssap_data_param(parameter_tvb, pinfo, bssap_tree, tree); + break; + + default: + dissect_bssap_unknown_param(parameter_tvb, bssap_tree, parameter_type, + parameter_length); + break; + } + + return(parameter_length); +} + +static guint16 +dissect_bssap_var_parameter(tvbuff_t *tvb, packet_info *pinfo, + proto_tree *bssap_tree, proto_tree *tree, + guint8 parameter_type, gint offset) +{ + guint16 parameter_length; + guint8 length_length; + + parameter_length = tvb_get_guint8(tvb, offset); + length_length = LENGTH_LENGTH; + + offset += length_length; + + dissect_bssap_parameter(tvb, pinfo, bssap_tree, tree, parameter_type, + offset, parameter_length); + + return(parameter_length + length_length); +} + +static void +dissect_bssap_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *bssap_tree, + proto_tree *tree) +{ + gint offset = 0; + + /* + * Extract the PDU type + */ + pdu_type = tvb_get_guint8(tvb, PDU_TYPE_OFFSET); + offset = PDU_TYPE_LENGTH; + + if (bssap_tree) + { + /* + * add the message type to the protocol tree + */ + proto_tree_add_uint(bssap_tree, + (bssap_or_bsap_global == BSSAP) ? hf_bssap_pdu_type : hf_bsap_pdu_type, + tvb, PDU_TYPE_OFFSET, PDU_TYPE_LENGTH, pdu_type); + } + + /* Starting a new message dissection */ + + switch (pdu_type) + { + case BSSAP_PDU_TYPE_BSSMAP: + offset += dissect_bssap_parameter(tvb, pinfo, bssap_tree, tree, + PARAMETER_LENGTH, offset, + LENGTH_LENGTH); + offset += dissect_bssap_var_parameter(tvb, pinfo, bssap_tree, tree, + PARAMETER_DATA, + (offset - LENGTH_LENGTH)); + break; + + case BSSAP_PDU_TYPE_DTAP: + offset += dissect_bssap_parameter(tvb, pinfo, bssap_tree, tree, + PARAMETER_DLCI, + offset, DLCI_LENGTH); + offset += dissect_bssap_parameter(tvb, pinfo, bssap_tree, tree, + PARAMETER_LENGTH, offset, + LENGTH_LENGTH); + offset += dissect_bssap_var_parameter(tvb, pinfo, bssap_tree, tree, + PARAMETER_DATA, + (offset - LENGTH_LENGTH)); + break; + + default: + if (check_col(pinfo->cinfo, COL_INFO)) + { + col_append_fstr(pinfo->cinfo, COL_INFO, "%s ", + val_to_str(pdu_type, ((bssap_or_bsap_global == BSSAP) ? + bssap_pdu_type_acro_values : bsap_pdu_type_acro_values), + "Unknown")); + + } + + dissect_bssap_unknown_message(tvb, bssap_tree); + break; + } +} + +static void +dissect_bssap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) +{ + proto_item *bssap_item; + proto_tree *bssap_tree = NULL; + + /* + * Make entry in the Protocol column on summary display + */ + if (check_col(pinfo->cinfo, COL_PROTOCOL)) + { + col_set_str(pinfo->cinfo, COL_PROTOCOL, ((bssap_or_bsap_global == BSSAP) ? "BSSAP" : "BSAP")); + } + + /* + * create the bssap protocol tree + */ + proto_tree_add_item_hidden(tree, proto_bssap, tvb, 0, -1, FALSE); + bssap_item = proto_tree_add_text(tree, tvb, 0, -1, (bssap_or_bsap_global == BSSAP) ? "BSSAP" : "BSAP"); + bssap_tree = proto_item_add_subtree(bssap_item, ett_bssap); + + /* dissect the message */ + + dissect_bssap_message(tvb, pinfo, bssap_tree, tree); +} + +static gboolean +dissect_bssap_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) +{ + /* Is it a BSSAP/BSAP packet? + * If octet_1 == 0x00 and octet_2 == length(tvb) - 2 + * or if octet_1 == 0x01 and octet_3 == length(tvb) - 3 + * then we'll assume it is a bssap packet + */ + switch (tvb_get_guint8(tvb, 0)) + { + case 0x00: + if (tvb_get_guint8(tvb, 1) != (tvb_length(tvb) - 2)) { return(FALSE); } + break; + + case 0x01: + if (tvb_get_guint8(tvb, 2) != (tvb_length(tvb) - 3)) { return(FALSE); } + break; + + default: + return(FALSE); + } + + dissect_bssap(tvb, pinfo, tree); + + return(TRUE); +} + +/* Register the protocol with Ethereal */ +void +proto_register_bssap(void) +{ + module_t *bssap_module; + + /* Setup list of header fields */ + static hf_register_info hf[] = { + { &hf_bssap_pdu_type, + { "Message Type", "bssap.pdu_type", + FT_UINT8, BASE_HEX, VALS(bssap_pdu_type_values), 0x0, + "", HFILL}}, + { &hf_bsap_pdu_type, + { "Message Type", "bsap.pdu_type", + FT_UINT8, BASE_HEX, VALS(bsap_pdu_type_values), 0x0, + "", HFILL}}, + { &hf_bssap_dlci_cc, + { "Control Channel", "bssap.dlci.cc", + FT_UINT8, BASE_HEX, VALS(bssap_cc_values), CC_MASK, + "", HFILL}}, + { &hf_bsap_dlci_cc, + { "Control Channel", "bsap.dlci.cc", + FT_UINT8, BASE_HEX, VALS(bsap_cc_values), CC_MASK, + "", HFILL}}, + { &hf_bssap_dlci_spare, + { "Spare", "bssap.dlci.spare", + FT_UINT8, BASE_HEX, NULL, SPARE_MASK, + "", HFILL}}, + { &hf_bsap_dlci_rsvd, + { "Reserved", "bsap.dlci.rsvd", + FT_UINT8, BASE_HEX, NULL, SPARE_MASK, + "", HFILL}}, + { &hf_bssap_dlci_sapi, + { "SAPI", "bssap.dlci.sapi", + FT_UINT8, BASE_HEX, VALS(bssap_sapi_values), SAPI_MASK, + "", HFILL}}, + { &hf_bsap_dlci_sapi, + { "SAPI", "bsap.dlci.sapi", + FT_UINT8, BASE_HEX, VALS(bsap_sapi_values), SAPI_MASK, + "", HFILL}}, + { &hf_bssap_length, + { "Length", "bssap.length", + FT_UINT8, BASE_DEC, NULL, 0x0, + "", HFILL}}, + }; + + /* Setup protocol subtree array */ + static gint *ett[] = { + &ett_bssap, + &ett_bssap_dlci, + }; + + static enum_val_t bssap_or_bsap_options[] = { + { "bssap", "BSSAP", BSSAP }, + { "bsap", "BSAP", BSAP }, + { NULL, NULL, 0 } + }; + + + /* Register the protocol name and description */ + proto_bssap = proto_register_protocol("BSSAP/BSAP", "BSSAP", "bssap"); + + /* Required function calls to register the header fields and subtrees used */ + proto_register_field_array(proto_bssap, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); + + bssap_module = prefs_register_protocol(proto_bssap, NULL); + + prefs_register_enum_preference(bssap_module, + "bsap_or_bssap", + "Identify to sub-dissector as", + "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.", + &bssap_or_bsap_global, + bssap_or_bsap_options, + FALSE); + + bssap_dissector_table = register_dissector_table("bssap.pdu_type", "BSSAP Message Type", FT_UINT8, BASE_DEC); + bsap_dissector_table = register_dissector_table("bsap.pdu_type", "BSAP Message Type", FT_UINT8, BASE_DEC); +} + +void +proto_reg_handoff_bssap(void) +{ + heur_dissector_add("sccp", dissect_bssap_heur, proto_bssap); + + data_handle = find_dissector("data"); +} |