/* wimax_harq_map_decoder.c
* WiMax HARQ Map Message decoder
*
* Copyright (c) 2007 by Intel Corporation.
*
* Author: Lu Pan <lu.pan@intel.com>
*
* $Id: wimax_harq_map_decoder.c 23661 2007-11-28 23:22:38Z gerald $
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1999 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.
*/
/* Include files */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <glib.h>
#include <epan/packet.h>
#include <epan/prefs.h>
#include "crc.h"
extern guint wimax_compact_dlmap_ie_decoder(proto_tree *tree, packet_info *pinfo, tvbuff_t *tvb, guint offset, guint nibble_offset);
extern guint wimax_compact_ulmap_ie_decoder(proto_tree *tree, packet_info *pinfo, tvbuff_t *tvb, guint offset, guint nibble_offset);
extern gint proto_wimax;
/* forward reference */
void dissector_wimax_harq_map_decoder(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
static gint proto_wimax_harq_map_decoder = -1;
static gint ett_wimax_harq_map_decoder = -1;
/* Setup protocol subtree array */
static gint *ett[] =
{
&ett_wimax_harq_map_decoder,
};
/* MASKs */
#define LSB_NIBBLE_MASK 0x0F
/* HARQ MAP masks */
#define WIMAX_HARQ_MAP_INDICATOR_MASK 0xE00000
#define WIMAX_HARQ_UL_MAP_APPENDED_MASK 0x100000
#define WIMAX_HARQ_MAP_RESERVED_MASK 0x080000
#define WIMAX_HARQ_MAP_MSG_LENGTH_MASK 0x07FC00
#define WIMAX_HARQ_MAP_DL_IE_COUNT_MASK 0x0003F0
#define WIMAX_HARQ_MAP_MSG_LENGTH_SHIFT 10
#define WIMAX_HARQ_MAP_DL_IE_COUNT_SHIFT 4
/* HARQ MAP display indexies */
static gint hf_harq_map_indicator = -1;
static gint hf_harq_ul_map_appended = -1;
static gint hf_harq_map_reserved = -1;
static gint hf_harq_map_msg_length = -1;
static gint hf_harq_dl_ie_count = -1;
static gint hf_harq_map_msg_crc = -1;
/* HARQ MAP display */
static hf_register_info hf_harq_map[] =
{
{
&hf_harq_map_indicator,
{"HARQ MAP Indicator", "wmx.harq_map.indicator", FT_UINT24, BASE_HEX, NULL, WIMAX_HARQ_MAP_INDICATOR_MASK, "", HFILL}
},
{
&hf_harq_ul_map_appended,
{"HARQ UL-MAP Appended", "wmx.harq_map.ul_map_appended", FT_UINT24, BASE_HEX, NULL, WIMAX_HARQ_UL_MAP_APPENDED_MASK, "", HFILL}
},
{
&hf_harq_map_reserved,
{"Reserved", "wmx.harq_map.reserved", FT_UINT24, BASE_HEX, NULL, WIMAX_HARQ_MAP_RESERVED_MASK, "", HFILL}
},
{
&hf_harq_map_msg_length,
{"Map Message Length", "wmx.harq_map.msg_length", FT_UINT24, BASE_DEC, NULL, WIMAX_HARQ_MAP_MSG_LENGTH_MASK, "", HFILL}
},
{
&hf_harq_dl_ie_count,
{"DL IE Count", "wmx.harq_map.dl_ie_count", FT_UINT24, BASE_DEC, NULL, WIMAX_HARQ_MAP_DL_IE_COUNT_MASK, "", HFILL}
},
{
&hf_harq_map_msg_crc,
{"HARQ MAP Message CRC", "wmx.harq_map.msg_crc", FT_UINT32, BASE_HEX, NULL, 0x0, "", HFILL}
}
};
/* Register Wimax HARQ MAP Protocol */
void proto_register_wimax_harq_map(void)
{
if (proto_wimax_harq_map_decoder == -1)
{
proto_wimax_harq_map_decoder = proto_wimax;
proto_register_subtree_array(ett, array_length(ett));
proto_register_field_array(proto_wimax_harq_map_decoder, hf_harq_map, array_length(hf_harq_map));
}
}
/* HARQ MAP message decoder */
void dissector_wimax_harq_map_decoder(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
guint i, offset = 0;
guint tvb_len, length, dl_ie_count;
guint ie_length;
proto_item *harq_map_item = NULL;
proto_tree *harq_map_tree = NULL;
guint nibble_offset;
proto_item *parent_item = NULL;
proto_item *it = NULL;
guint ulmap_appended;
guint32 harq_map_msg_crc, calculated_crc;
guint32 first_24bits;
/* check the tvb reported length */
tvb_len = tvb_reported_length(tvb);
if(!tvb_len)
{ /* do nothing if tvb is empty */
return;
}
/* Ensure the right payload type */
first_24bits = tvb_get_ntoh24(tvb, offset);
if((first_24bits & WIMAX_HARQ_MAP_INDICATOR_MASK) != WIMAX_HARQ_MAP_INDICATOR_MASK)
{ /* do nothing if tvb is not a HARQ MAP message */
return;
}
/* update the info column */
if (check_col(pinfo->cinfo, COL_INFO))
{
col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "HARQ-MAP Message: ");
}
if (tree)
{ /* we are being asked for details */
/* get the parent */
parent_item = proto_tree_get_parent(tree);
/* display HARQ-MAP Message and create subtree */
harq_map_item = proto_tree_add_protocol_format(tree, proto_wimax_harq_map_decoder, tvb, offset, tvb_len, "HARQ-MAP Message (%u bytes)", tvb_len);
harq_map_tree = proto_item_add_subtree(harq_map_item, ett_wimax_harq_map_decoder);
/* display the HARQ MAP Indicator */
proto_tree_add_item(harq_map_tree, hf_harq_map_indicator, tvb, offset, 3, FALSE);
/* display the HARQ MAp UL-MAP Appended */
proto_tree_add_item(harq_map_tree, hf_harq_ul_map_appended, tvb, offset, 3, FALSE);
/* display the reserved bit */
proto_tree_add_item(harq_map_tree, hf_harq_map_reserved, tvb, offset, 3, FALSE);
/* display the HARQ MAP message length */
proto_tree_add_item(harq_map_tree, hf_harq_map_msg_length, tvb, offset, 3, FALSE);
/* display the DL IE count */
proto_tree_add_item(harq_map_tree, hf_harq_dl_ie_count, tvb, offset, 3, FALSE);
/* get the message length */
length = ((first_24bits & WIMAX_HARQ_MAP_MSG_LENGTH_MASK) >> WIMAX_HARQ_MAP_MSG_LENGTH_SHIFT);
/* get the DL IE count */
dl_ie_count = ((first_24bits & WIMAX_HARQ_MAP_DL_IE_COUNT_MASK) >> WIMAX_HARQ_MAP_DL_IE_COUNT_SHIFT);
/* get the UL MAP appended */
ulmap_appended = (first_24bits & WIMAX_HARQ_UL_MAP_APPENDED_MASK);
if (parent_item == NULL || parent_item->finfo == NULL)
{
parent_item = harq_map_item; /* Prevent crash */
}
/* set the offsets to Compact DL-MAP IEs */
offset += 2;
nibble_offset = 1;
/* process the compact dl_map ies */
for(i=0; i<dl_ie_count; i++)
{ /* add the DL-MAp IEs info */
proto_item_append_text(parent_item, " - DL-MAP IEs");
/* decode Compact DL-MAP IEs */
ie_length = wimax_compact_dlmap_ie_decoder(harq_map_tree, pinfo, tvb, offset, nibble_offset);
offset += ((nibble_offset + ie_length) >> 1);
nibble_offset = ((nibble_offset + ie_length) & 1);
}
/* check if there exist the compact ul_map IEs */
if (ulmap_appended)
{ /* add the UL-MAp IEs info */
proto_item_append_text(parent_item, ",UL-MAP IEs");
/* process the compact ul_map ies */
while(offset < (length - sizeof(harq_map_msg_crc)))
{ /* decode Compact UL-MAP IEs */
ie_length = wimax_compact_ulmap_ie_decoder(harq_map_tree, pinfo, tvb, offset, nibble_offset);
/* Prevent endless loop with erroneous data. */
if (ie_length < 2)
ie_length = 2;
offset += ((nibble_offset + ie_length) >> 1);
nibble_offset = ((nibble_offset + ie_length) & 1);
}
}
/* handle the padding */
if(nibble_offset)
{
/* add the Padding info */
proto_item_append_text(parent_item, ",Padding");
proto_tree_add_protocol_format(harq_map_tree, proto_wimax_harq_map_decoder, tvb, offset, 1, "Padding Nibble: 0x%x", (tvb_get_guint8(tvb, offset) & LSB_NIBBLE_MASK));
}
/* add the CRC info */
proto_item_append_text(parent_item, ",CRC");
/* get the CRC */
harq_map_msg_crc = tvb_get_ntohl(tvb, length - sizeof(harq_map_msg_crc));
/* calculate the HARQ MAM Message CRC */
calculated_crc = wimax_mac_calc_crc32((guint8 *)tvb_get_ptr(tvb, 0, length - sizeof(harq_map_msg_crc)), length - sizeof(harq_map_msg_crc));
/* display the CRC */
it = proto_tree_add_item(harq_map_tree, hf_harq_map_msg_crc, tvb, length - sizeof(harq_map_msg_crc), sizeof(harq_map_msg_crc), FALSE);
/* verify the CRC */
if (harq_map_msg_crc != calculated_crc)
{
proto_item_append_text(it, " - incorrect! (should be: 0x%x)", calculated_crc);
}
}
}
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