diff options
Diffstat (limited to 'epan/dissectors/packet-mtp2.c')
| -rw-r--r-- | epan/dissectors/packet-mtp2.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/epan/dissectors/packet-mtp2.c b/epan/dissectors/packet-mtp2.c new file mode 100644 index 0000000000..9dfc559b6c --- /dev/null +++ b/epan/dissectors/packet-mtp2.c @@ -0,0 +1,219 @@ +/* packet-mtp2.c + * Routines for MTP2 dissection + * It is hopefully (needs testing) compliant to + * ITU-T Q.703 + * + * Copyright 2001, Michael Tuexen <tuexen [AT] fh-muenster.de> + * + * $Id$ + * + * Ethereal - Network traffic analyzer + * By Gerald Combs <gerald@ethereal.com> + * 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 <glib.h> +#include <epan/packet.h> + +#define LITTLE_ENDIAN_BYTE_ORDER TRUE + +/* 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 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 BSN_MASK 0x7f +#define BIB_MASK 0x80 +#define FSN_MASK 0x7f +#define FIB_MASK 0x80 +#define LI_MASK 0x3f +#define SPARE_MASK 0xc0 + +static void +dissect_mtp2_header(tvbuff_t *su_tvb, proto_item *mtp2_tree) +{ + if (mtp2_tree) { + proto_tree_add_item(mtp2_tree, hf_mtp2_bsn, su_tvb, BSN_BIB_OFFSET, BSN_BIB_LENGTH, LITTLE_ENDIAN_BYTE_ORDER); + proto_tree_add_item(mtp2_tree, hf_mtp2_bib, su_tvb, BSN_BIB_OFFSET, BSN_BIB_LENGTH, LITTLE_ENDIAN_BYTE_ORDER); + proto_tree_add_item(mtp2_tree, hf_mtp2_fsn, su_tvb, FSN_FIB_OFFSET, FSN_FIB_LENGTH, LITTLE_ENDIAN_BYTE_ORDER); + proto_tree_add_item(mtp2_tree, hf_mtp2_fib, su_tvb, FSN_FIB_OFFSET, FSN_FIB_LENGTH, LITTLE_ENDIAN_BYTE_ORDER); + proto_tree_add_item(mtp2_tree, hf_mtp2_li, su_tvb, LI_OFFSET, LI_LENGTH, LITTLE_ENDIAN_BYTE_ORDER); + proto_tree_add_item(mtp2_tree, hf_mtp2_spare, su_tvb, LI_OFFSET, LI_LENGTH, LITTLE_ENDIAN_BYTE_ORDER); + } +} + +static void +dissect_mtp2_fisu(packet_info *pinfo) +{ + if (check_col(pinfo->cinfo, COL_INFO)) + col_set_str(pinfo->cinfo, COL_INFO, "FISU "); +} + +static const value_string status_field_vals[] = { + { 0x0, "Status Indication O" }, + { 0x1, "Status Indication N" }, + { 0x2, "Status Indication E" }, + { 0x3, "Status Indication OS" }, + { 0x4, "Status Indication PO" }, + { 0x5, "Status Indication BO" }, + { 0, NULL} +}; + +#define SF_OFFSET (LI_OFFSET + LI_LENGTH) +#define SF_LENGTH 1 +#define LONG_SF_LENGTH 2 + +static void +dissect_mtp2_lssu(tvbuff_t *su_tvb, packet_info *pinfo, proto_item *mtp2_tree) +{ + guint8 li; + + if (check_col(pinfo->cinfo, COL_INFO)) + col_set_str(pinfo->cinfo, COL_INFO, "LSSU "); + + if (mtp2_tree) { + li = tvb_get_guint8(su_tvb, LI_OFFSET); + if ((li & LI_MASK) == 1) + proto_tree_add_item(mtp2_tree, hf_mtp2_sf, su_tvb, SF_OFFSET, SF_LENGTH, LITTLE_ENDIAN_BYTE_ORDER); + else + proto_tree_add_item(mtp2_tree, hf_mtp2_long_sf, su_tvb, SF_OFFSET, LONG_SF_LENGTH, LITTLE_ENDIAN_BYTE_ORDER); + } +} + +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)) + col_set_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.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) +{ + dissector_handle_t mtp2_handle; + + mtp2_handle = create_dissector_handle(dissect_mtp2, proto_mtp2); + + dissector_add("wtap_encap", WTAP_ENCAP_MTP2, mtp2_handle); + + mtp3_handle = find_dissector("mtp3"); + mtp3_proto_id = proto_get_id_by_filter_name("mtp3"); +} |