/* packet-mtp2.c * Routines for MTP2 dissection * It is hopefully (needs testing) compliant to * ITU-T Q.703 * * Copyright 2001, Michael Tuexen * * $Id: packet-mtp2.c,v 1.3 2002/01/21 07:36:37 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * Copied from packet-m2pa.c * * 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 #include /* Initialize the protocol and registered fields */ static int proto_mtp2 = -1; static int hf_mtp2_bsn = -1; static int hf_mtp2_bib = -1; static int hf_mtp2_fsn = -1; static int hf_mtp2_fib = -1; static int hf_mtp2_li = -1; static int hf_mtp2_spare = -1; static int hf_mtp2_sf = -1; static int hf_mtp2_long_sf = -1; /* Initialize the subtree pointers */ static gint ett_mtp2 = -1; static dissector_handle_t mtp3_handle; static int mtp3_proto_id; #define BSN_BIB_LENGTH 1 #define FSN_FIB_LENGTH 1 #define LI_LENGTH 1 #define HEADER_LENGTH (BSN_BIB_LENGTH + FSN_FIB_LENGTH + LI_LENGTH) #define SF_LENGTH 1 #define LONG_SF_LENGTH 2 #define BSN_BIB_OFFSET 0 #define FSN_FIB_OFFSET (BSN_BIB_OFFSET + BSN_BIB_LENGTH) #define LI_OFFSET (FSN_FIB_OFFSET + FSN_FIB_LENGTH) #define SIO_OFFSET (LI_OFFSET + LI_LENGTH) #define SF_OFFSET (LI_OFFSET + LI_LENGTH) #define BSN_MASK 0x7f #define BIB_MASK 0x80 #define FSN_MASK 0x7f #define FIB_MASK 0x80 #define LI_MASK 0x3f #define SPARE_MASK 0xc0 #define STATUS_O 0x0 #define STATUS_N 0x1 #define STATUS_E 0x2 #define STATUS_OS 0x3 #define STATUS_PO 0x4 #define STATUS_B 0x5 static const value_string status_field_vals[] = { { STATUS_O, "Status Indication O" }, { STATUS_N, "Status Indication N" }, { STATUS_E, "Status Indication E" }, { STATUS_OS, "Status Indication OS" }, { STATUS_PO, "Status Indication PO" }, { STATUS_B, "Status Indication BO" }, { 0, NULL} }; static void dissect_mtp2_header(tvbuff_t *su_tvb, proto_item *mtp2_tree) { guint8 bsn_bib, fsn_fib, li; bsn_bib = tvb_get_guint8(su_tvb, BSN_BIB_OFFSET); fsn_fib = tvb_get_guint8(su_tvb, FSN_FIB_OFFSET); li = tvb_get_guint8(su_tvb, LI_OFFSET); if (mtp2_tree) { proto_tree_add_uint(mtp2_tree, hf_mtp2_bsn, su_tvb, BSN_BIB_OFFSET, BSN_BIB_LENGTH, bsn_bib); proto_tree_add_uint(mtp2_tree, hf_mtp2_bib, su_tvb, BSN_BIB_OFFSET, BSN_BIB_LENGTH, bsn_bib); proto_tree_add_uint(mtp2_tree, hf_mtp2_fsn, su_tvb, FSN_FIB_OFFSET, FSN_FIB_LENGTH, fsn_fib); proto_tree_add_uint(mtp2_tree, hf_mtp2_fib, su_tvb, FSN_FIB_OFFSET, FSN_FIB_LENGTH, fsn_fib); proto_tree_add_uint(mtp2_tree, hf_mtp2_li, su_tvb, LI_OFFSET, LI_LENGTH, li); proto_tree_add_uint(mtp2_tree, hf_mtp2_spare, su_tvb, LI_OFFSET, LI_LENGTH, li); } } static void dissect_mtp2_fisu(packet_info *pinfo) { if (check_col(pinfo->cinfo, COL_INFO)) col_append_str(pinfo->cinfo, COL_INFO, "FISU"); } static void dissect_mtp2_lssu(tvbuff_t *su_tvb, packet_info *pinfo, proto_item *mtp2_tree) { guint8 li, sf; guint16 long_sf; if (check_col(pinfo->cinfo, COL_INFO)) col_append_str(pinfo->cinfo, COL_INFO, "LSSU"); if (mtp2_tree) { li = tvb_get_guint8(su_tvb, LI_OFFSET); if ((li & LI_MASK) == 1) { sf = tvb_get_guint8(su_tvb, SF_OFFSET); proto_tree_add_uint(mtp2_tree, hf_mtp2_sf, su_tvb, SF_OFFSET, SF_LENGTH, sf); } else { long_sf = tvb_get_letohs(su_tvb, SF_OFFSET); proto_tree_add_uint(mtp2_tree, hf_mtp2_long_sf, su_tvb, SF_OFFSET, LONG_SF_LENGTH, long_sf); } } } static void dissect_mtp2_msu(tvbuff_t *su_tvb, packet_info *pinfo, proto_item *mtp2_item, proto_item *tree) { gint sif_sio_length; tvbuff_t *sif_sio_tvb; if ((check_col(pinfo->cinfo, COL_INFO)) && (!proto_is_protocol_enabled(mtp3_proto_id))) col_append_str(pinfo->cinfo, COL_INFO, "MSU"); sif_sio_length = tvb_length(su_tvb) - HEADER_LENGTH; sif_sio_tvb = tvb_new_subset(su_tvb, SIO_OFFSET, sif_sio_length, sif_sio_length); call_dissector(mtp3_handle, sif_sio_tvb, pinfo, tree); if (tree) proto_item_set_len(mtp2_item, HEADER_LENGTH); } static void dissect_mtp2_su(tvbuff_t *su_tvb, packet_info *pinfo, proto_item *mtp2_item, proto_item *mtp2_tree, proto_tree *tree) { guint8 li; dissect_mtp2_header(su_tvb, mtp2_tree); li = tvb_get_guint8(su_tvb, LI_OFFSET); switch(li & LI_MASK) { case 0: dissect_mtp2_fisu(pinfo); break; case 1: case 2: dissect_mtp2_lssu(su_tvb, pinfo, mtp2_tree); break; default: dissect_mtp2_msu(su_tvb, pinfo, mtp2_item, tree); break; } } static void dissect_mtp2(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { proto_item *mtp2_item = NULL; proto_tree *mtp2_tree = NULL; if (check_col(pinfo->cinfo, COL_PROTOCOL)) col_set_str(pinfo->cinfo, COL_PROTOCOL, "MTP2"); if (tree) { mtp2_item = proto_tree_add_item(tree, proto_mtp2, tvb, 0, -1, FALSE); mtp2_tree = proto_item_add_subtree(mtp2_item, ett_mtp2); }; dissect_mtp2_su(tvb, pinfo, mtp2_item, mtp2_tree, tree); } void proto_register_mtp2(void) { static hf_register_info hf[] = { { &hf_mtp2_bsn, { "Backward sequence number", "mtp2.bsn", FT_UINT8, BASE_DEC, NULL, BSN_MASK, "", HFILL } }, { &hf_mtp2_bib, { "Backward indicator bit", "mtp2.bib", FT_UINT8, BASE_DEC, NULL, BIB_MASK, "", HFILL } }, { &hf_mtp2_fsn, { "Forward sequence number", "mtp2.fsn", FT_UINT8, BASE_DEC, NULL, FSN_MASK, "", HFILL } }, { &hf_mtp2_fib, { "Forward indicator bit", "mtp2.fib", FT_UINT8, BASE_DEC, NULL, FIB_MASK, "", HFILL } }, { &hf_mtp2_li, { "Length Indicator", "mtp2.li", FT_UINT8, BASE_DEC, NULL, LI_MASK, "", HFILL } }, { &hf_mtp2_spare, { "Spare", "mtp2.spare", FT_UINT8, BASE_DEC, NULL, SPARE_MASK, "", HFILL } }, { &hf_mtp2_sf, { "Status field", "mtp2.sf", FT_UINT8, BASE_DEC, VALS(status_field_vals), 0x0, "", HFILL } }, { &hf_mtp2_long_sf, { "Status field", "mtp2.long_sf", FT_UINT16, BASE_HEX, NULL, 0x0, "", HFILL } } }; static gint *ett[] = { &ett_mtp2 }; proto_mtp2 = proto_register_protocol("Message Transfer Part Level 2", "MTP2", "mtp2"); register_dissector("mtp2", dissect_mtp2, proto_mtp2); proto_register_field_array(proto_mtp2, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); }; void proto_reg_handoff_mtp2(void) { mtp3_handle = find_dissector("mtp3"); mtp3_proto_id = proto_get_id_by_filter_name("mtp3"); }