/* msg_fpc.c
 * WiMax MAC Management FPC Message decoder
 *
 * Copyright (c) 2007 by Intel Corporation.
 *
 * Author: John R. Underwood <junderx@yahoo.com>
 *
 * $Id$
 *
 * 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 "moduleinfo.h"

#include <glib.h>
#include <epan/packet.h>
#include <epan/prefs.h>
#include "crc.h"
#include "wimax_tlv.h"
#include "wimax_mac.h"

extern gint man_ofdma;

/* Forward reference */
void dissect_mac_mgmt_msg_fpc_decoder(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);

static gint proto_mac_mgmt_msg_fpc_decoder = -1;

static gint ett_mac_mgmt_msg_fpc_decoder = -1;

/* Setup protocol subtree array */
static gint *ett[] =
{
	&ett_mac_mgmt_msg_fpc_decoder,
};

/* FPC fields */
static gint hf_fpc_message_type = -1;
static gint hf_fpc_number_of_stations = -1;
static gint hf_fpc_basic_cid = -1;
static gint hf_fpc_power_adjust = -1;
static gint hf_fpc_power_measurement_frame = -1;
static gint hf_fpc_invalid_tlv = -1;

/* FPC fields display */
static hf_register_info hf[] =
{
	{
		&hf_fpc_message_type,
		{
			"MAC Management Message Type", "wmx.macmgtmsgtype.fpc",
			FT_UINT8, BASE_DEC, NULL, 0x0,
			"", HFILL
		}
	},
	{
		&hf_fpc_basic_cid,
		{
			"Basic CID", "wmx.fpc.basic_cid",
			FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL
		}
	},
	{
		&hf_fpc_invalid_tlv,
		{
			"Invalid TLV", "wmx.fpc.invalid_tlv",
			FT_BYTES, BASE_HEX, NULL, 0, "", HFILL
		}
	},
	{
		&hf_fpc_number_of_stations,
		{
			"Number of stations", "wmx.fpc.number_stations",
			FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL
		}
	},
	{
		&hf_fpc_power_adjust,
		{
			"Power Adjust.  Signed change in power level (incr of 0.25dB) that the SS shall apply to its current power setting", "wmx.fpc.power_adjust",
			FT_FLOAT, BASE_DEC, NULL, 0x0, "", HFILL
		}
	},
	{
		&hf_fpc_power_measurement_frame,
		{
			"Power measurement frame.  The 8 LSB of the frame number in which the BS measured the power corrections referred to in the message", "wmx.fpc.power_measurement_frame",
			FT_INT8, BASE_DEC, NULL, 0x0, "", HFILL
		}
	}
};


/* Register Wimax Mac Payload Protocol and Dissector */
void proto_register_mac_mgmt_msg_fpc(void)
{
	if (proto_mac_mgmt_msg_fpc_decoder == -1) {
		proto_mac_mgmt_msg_fpc_decoder = proto_register_protocol (
							"WiMax FPC Message", /* name */
							"WiMax FPC (fpc)", /* short name */
							"wmx.fpc" /* abbrev */
							);

		proto_register_field_array(proto_mac_mgmt_msg_fpc_decoder, hf, array_length(hf));
		proto_register_subtree_array(ett, array_length(ett));
	}
}

/* Decode FPC messages. */
void dissect_mac_mgmt_msg_fpc_decoder(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree)
{
	guint offset = 0;
	guint i;
	guint number_stations;
	guint tvb_len, payload_type;
	proto_item *fpc_item = NULL;
	proto_tree *fpc_tree = NULL;
	gint8 value;
	gfloat power_change;

	/* Ensure the right payload type */
	payload_type = tvb_get_guint8(tvb, 0);
	if(payload_type != MAC_MGMT_MSG_FPC)
	{
		return;
	}

	if (tree)
	{	/* we are being asked for details */

		/* Get the tvb reported length */
		tvb_len =  tvb_reported_length(tvb);
		/* display MAC payload type FPC */
		fpc_item = proto_tree_add_protocol_format(tree, proto_mac_mgmt_msg_fpc_decoder, tvb, 0, tvb_len, "MAC Management Message, FPC (38)");
		/* add MAC FPC subtree */
		fpc_tree = proto_item_add_subtree(fpc_item, ett_mac_mgmt_msg_fpc_decoder);
		/* display the Message Type */
		proto_tree_add_item(fpc_tree, hf_fpc_message_type, tvb, offset, 1, FALSE);
		offset ++;
		/* display the Number of stations */
		proto_tree_add_item(fpc_tree, hf_fpc_number_of_stations, tvb, offset, 1, FALSE);

		number_stations = tvb_get_guint8(tvb, offset);
		offset++;
		for (i = 0; i < number_stations; i++ ) {
			/* display the Basic CID*/
			proto_tree_add_item(fpc_tree, hf_fpc_basic_cid, tvb, offset, 2, FALSE);
			offset += 2;

			/* display the Power adjust value */
			value = (gint8)tvb_get_guint8(tvb, offset);
			power_change = (float)0.25 * value;  /* 0.25dB incr */

			/* display the Power adjust value in dB */
			proto_tree_add_float_format_value(fpc_tree, hf_fpc_power_adjust, tvb, offset, 1, power_change, " %.2f dB", power_change);
			offset++;

			/* display the Power measurement frame */
			proto_tree_add_item(fpc_tree, hf_fpc_power_measurement_frame, tvb, offset, 1, FALSE);
			offset++;

			if ( offset >= tvb_len ) {
				break;
			}
		}
	}
}