path: root/epan/dissectors/packet-pdc.c

/* packet-pdc.c
 * Routines for PDC dissection
 * Copyright 2014, Antony Bridle <antony.bridle@nats.co.uk>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */


#include <glib.h>
#include <config.h>
#include <epan/prefs.h>
#include <epan/packet.h>
#include <epan/dissectors/packet-tcp.h>
#include <epan/reassemble.h>


void proto_register_pdc(void);
void proto_reg_handoff_pdc(void);

/*PDC Protocol*/
#define PDC_PROCOTOL "PDC"

/* PDC version */
#define PDC_VERSION 2

#define SIMPDU	1
#define RSMPDU	2
#define DRMPDU	3
#define DTMPDU	4
#define ADMPDU	5
#define EDMPDU	6
#define AKMPDU	8

/*Variable length Parameter Codes*/
#define PARAM_CODE_VERSION		2
#define PARAM_CODE_REFERENCES	3
#define PARAM_CODE_TRANSPORT	4

/* required for the TCP split packet combining */
#define PDC_MSG_SIZE_FIELD_LENGTH 2 /* minimum amount of data to find out how big the split packet should be when recombined */
#define FRAME_HEADER_LEN 8

/* global handle for calling asterix decoder if required */
static 			dissector_handle_t asterix_handle;
static int 		proto_pdc = -1;
static guint	gPREF_PORT_NUM_TCP = 0;

/*HF Declarations*/
static gint hf_pdc_len = -1;
static gint hf_pdc_mpdu_code = -1;
static gint hf_pdc_credit = -1;
static gint hf_pdc_simpdu_state = -1;
static gint hf_pdc_yr_admu_nr =-1;
static gint hf_pdc_akmpdu_mns = -1;
static gint hf_pdc_akmpdu_cdt = -1;
static gint hf_pdc_simpdu_var = -1;
static gint hf_pdc_simpdu_var_len = -1;
static gint hf_pdc_simpdu_param = -1;
static gint hf_pdc_simpdu_var_version = -1;
static gint hf_pdc_simpdu_var_REFSRC = -1;
static gint hf_pdc_simpdu_var_REFDEST = -1;
static gint hf_pdc_simpdu_var_TSEL = -1;
static gint hf_pdc_drmpdu_abort = -1;
static gint hf_pdc_drmpdu_reason = -1;
static gint hf_pdc_drmpdu_mode = -1;
static gint hf_pdc_drmpdu_init = -1;
static gint hf_pdc_dtmpdu_user_size =-1;
static gint hf_pdc_admpdu_admpdunr = -1;
static gint hf_pdc_admpdu_size = -1;

/*Tree Declarations*/
static gint ett_pdc = -1;
static gint ett_pdc_simpdu_var = -1;


/*Value String Declarations*/
static const value_string valstr_simpdu_state[] = {
		{ 1, "Operational" },
		{ 2, "Standby" },
		{ 3, "Master" },
		{ 4, "Slave" },
		{ 5, "Single" },
		{ 0, NULL }
};

static const value_string valstr_simpdu_param[] = {
		{ 2, "Version Number" },
		{ 3, "References" },
		{ 4, "Transport Selector" },
		{ 0, NULL }
};

static const value_string valstr_mpdus[] = {
		{ 1, "State Information" },
		{ 2, "Request State" },
		{ 3, "Disconnect Request" },
		{ 4, "Data" },
		{ 5, "Acknowledged Data" },
		{ 6, "Expedited Data" },
		{ 8, "Data Acknowledgement" },
		{ 0, NULL }
};

static const value_string valstr_drmpdu_abort[] = {
		{ 0, "Orderly Release" },
		{ 1, "Abortive Release" },
		{ 0, NULL }
};

static const value_string valstr_drmpdu_mode[] = {
		{ 0, "Node Shutdown" },
		{ 7, "PDC Release"},
		{ 0, NULL }
};

static const value_string valstr_drmpdu_initatior[] = {
		{ 0, "Server" },
		{ 15, "Client"},
		{ 0, NULL }
};

static const value_string valstr_drmpdu_reason[] = {
		{ 0, "Reason Not Specified" },
		{ 1, "Normal Disconnect Initiated by the MS-User" },
		{ 2, "Protocol Error" },
		{ 3, "Connection Request Refused" },
		{ 4, "The Remote Operational MS Entity Does Not Respond" },
		{ 5, "The Protocol Version Is Not Supported" },
		{ 6, "Mismatched References" },
		{ 0, NULL }
};

/* start of functions here */
static int dissect_simpdu(tvbuff_t *tvb, proto_tree *tree, guint16 offset, guint8 lenIndicator)
{
	guint16 bytesProcessed;
	guint8 paramCode;
	proto_item *simpduItem;
	proto_tree *simpduVarTree;
	proto_tree *simpduVarTree1;

	bytesProcessed = 0;

	/*Add the Credit allocation*/
	proto_tree_add_item(tree, hf_pdc_credit, tvb, offset, 1, ENC_BIG_ENDIAN);
	bytesProcessed++;

	/*Add the State*/
	proto_tree_add_item(tree, hf_pdc_simpdu_state, tvb, offset + bytesProcessed , 1, ENC_BIG_ENDIAN);
	bytesProcessed++;

	/*Add the YR-ADMU-NR*/
	proto_tree_add_item(tree, hf_pdc_yr_admu_nr, tvb, offset + bytesProcessed , 4, ENC_BIG_ENDIAN);
	bytesProcessed += 4;

	/*Determine whats in the variable part*/
	if(lenIndicator > 7)
	{
		/*Add the Variable Length Tree*/
		simpduItem = proto_tree_add_item (tree, hf_pdc_simpdu_var, tvb, offset + bytesProcessed, lenIndicator - 7, ENC_NA);
		simpduVarTree = proto_item_add_subtree (simpduItem, ett_pdc_simpdu_var);

		while((offset + bytesProcessed) < ( lenIndicator + 1 ))
		{
			/*Get the parameter code*/
			paramCode = tvb_get_guint8(tvb, offset + bytesProcessed);
			simpduItem = proto_tree_add_item (simpduVarTree, hf_pdc_simpdu_param, tvb, offset + bytesProcessed, 1, ENC_NA);
			simpduVarTree1 = proto_item_add_subtree (simpduItem, ett_pdc_simpdu_var);
			bytesProcessed++;
			switch (paramCode)
			{
			case PARAM_CODE_VERSION:
				proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_len, tvb, offset +bytesProcessed, 1, ENC_NA);
				proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_version, tvb, offset +bytesProcessed + 1, 1, ENC_NA);
				bytesProcessed += 2;
				break;
			case PARAM_CODE_REFERENCES:
				proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_len, tvb, offset +bytesProcessed, 1, ENC_NA);
				proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_REFSRC, tvb, offset +bytesProcessed + 1, 2, ENC_NA);
				proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_REFDEST, tvb, offset +bytesProcessed + 3, 2, ENC_NA);
				bytesProcessed += 5;
				break;
			case PARAM_CODE_TRANSPORT:
				proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_len, tvb, offset +bytesProcessed, 1, ENC_NA);
				proto_tree_add_item(simpduVarTree1, hf_pdc_simpdu_var_TSEL, tvb, offset +bytesProcessed + 1, 2, ENC_NA);
				bytesProcessed += 3;
				break;
			}
		} /* end of whileloop */
	}
	return (bytesProcessed);
}

static int dissect_rsmpdu(void)
{
	return (0);
}

static int dissect_drmpdu(tvbuff_t *tvb, proto_tree *tree, guint16 offset)
{
	/*DR-MPDU*/
	proto_tree_add_item(tree, hf_pdc_drmpdu_abort, tvb, offset, 1, ENC_NA);
	proto_tree_add_item(tree, hf_pdc_drmpdu_mode, tvb, offset, 1, ENC_NA);
	proto_tree_add_item(tree, hf_pdc_drmpdu_init, tvb, offset, 1, ENC_NA);
	proto_tree_add_item(tree, hf_pdc_drmpdu_reason, tvb, offset + 1, 1, ENC_NA);

	return (2);
}

static int dissect_admpdu(tvbuff_t *tvb, proto_tree *tree, guint16 offset, packet_info *pinfo)
{
	guint16		userDataLen;
	guint16		returnLen;
	tvbuff_t	*asterixTVB;

	/*Add the ad*/
	proto_tree_add_item(tree, hf_pdc_admpdu_admpdunr, tvb, offset, 4, ENC_BIG_ENDIAN);
	offset += 4;

	if (PDC_VERSION == 2)
	{
		proto_tree_add_item(tree, hf_pdc_admpdu_size, tvb, offset, 2, ENC_BIG_ENDIAN);
		/* length of user data field */
		userDataLen = tvb_get_ntohs(tvb, offset);
		offset += 2;

		returnLen = userDataLen + 6;
		asterixTVB = tvb_new_subset(tvb, offset, userDataLen, userDataLen);

		if(asterix_handle != NULL)
			call_dissector(asterix_handle, asterixTVB, pinfo, tree);

		return (returnLen);
	}
	return (2);
}

static int dissect_dtmpdu(tvbuff_t *tvb, proto_tree *tree, guint16 offset, packet_info *pinfo)
{
	guint16		userDataLen;
	guint16		returnLen;
	tvbuff_t	*asterixTVB;

	if (PDC_VERSION == 2)
	{
		proto_tree_add_item(tree, hf_pdc_dtmpdu_user_size, tvb, offset, 2, ENC_BIG_ENDIAN);
		/* length of user data field */
		userDataLen = tvb_get_ntohs(tvb, 2);
		returnLen = userDataLen + 2;
		asterixTVB = tvb_new_subset(tvb, offset + 2, userDataLen, userDataLen);

		if(asterix_handle != NULL)
			call_dissector(asterix_handle, asterixTVB, pinfo, tree);

		return (returnLen);
	}
	return (2);
}

static int dissect_edmpdu(tvbuff_t *tvb, proto_tree *tree, guint16 offset, packet_info *pinfo)
{
	guint16		userDataLen;
	guint16		returnLen;
	tvbuff_t	*asterixTVB;

	if (PDC_VERSION == 2)
	{
		proto_tree_add_item(tree, hf_pdc_dtmpdu_user_size, tvb, offset, 2, ENC_BIG_ENDIAN);
		/* length of user data field */
		userDataLen = tvb_get_ntohs(tvb, 2);
		returnLen = userDataLen + 2;
		asterixTVB = tvb_new_subset(tvb, offset + 2, userDataLen, userDataLen);

		if(asterix_handle != NULL)
			call_dissector(asterix_handle, asterixTVB, pinfo, tree);

		return (returnLen);
	}
	return 2;
}

static int dissect_akmpdu(tvbuff_t *tvb, proto_tree *tree, guint16 offset)
{
	proto_tree_add_item(tree, hf_pdc_akmpdu_mns, tvb, offset, 2, ENC_BIG_ENDIAN);
	proto_tree_add_item(tree, hf_pdc_akmpdu_cdt, tvb, offset, 2, ENC_BIG_ENDIAN);
	proto_tree_add_item(tree, hf_pdc_yr_admu_nr, tvb, offset + 2, 4, ENC_BIG_ENDIAN);
	return (6);
}

static int dissect_pdc_packet(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo)
{
	guint i = 0;
	guint8 len_indicator;
	guint8 mpduCode;
	guint16 length;
	proto_item *pdcPacketItem;
	proto_tree *pdcPacketTree;

	length = 0;
	pdcPacketItem = NULL;
	pdcPacketTree = NULL;

	/*Get the length indictor and the MPDU Code*/
	len_indicator = tvb_get_guint8 (tvb, i);
	mpduCode = tvb_get_guint8 (tvb, i + 1);
	length += 2;

	/*Add the PDC Tree*/
	pdcPacketItem = proto_tree_add_item (tree, proto_pdc, tvb, i, len_indicator + 1, ENC_NA);
	pdcPacketTree = proto_item_add_subtree (pdcPacketItem, ett_pdc);

	/*Add the Length and packet type*/
	proto_tree_add_item(pdcPacketTree, hf_pdc_len, tvb, i, 1, ENC_BIG_ENDIAN);
	proto_tree_add_item(pdcPacketTree, hf_pdc_mpdu_code, tvb, i + 1, 1, ENC_BIG_ENDIAN);

	/*Call the correct dissecting function*/
	switch(mpduCode)
	{
	case SIMPDU:
		length += dissect_simpdu(tvb, pdcPacketTree, length, len_indicator);
		col_set_str(pinfo->cinfo, COL_INFO, "SIMPDU");
		break;
	case RSMPDU:
		length += dissect_rsmpdu();
		col_set_str(pinfo->cinfo, COL_INFO, "RSMPDU");
		break;
	case DRMPDU:
		length += dissect_drmpdu(tvb, pdcPacketTree, length);
		col_set_str(pinfo->cinfo, COL_INFO, "DRMPDU");
		break;
	case DTMPDU:
		length += dissect_dtmpdu(tvb, pdcPacketTree, length, pinfo);
		col_set_str(pinfo->cinfo, COL_INFO, "DTMPDU");
		break;
	case ADMPDU:
		length += dissect_admpdu(tvb, pdcPacketTree, length, pinfo);
		col_set_str(pinfo->cinfo, COL_INFO, "ADMPDU");
		break;
	case EDMPDU:
		length += dissect_edmpdu(tvb, pdcPacketTree, length, pinfo);
		col_set_str(pinfo->cinfo, COL_INFO, "EDMPDU");
		break;
	case AKMPDU:
		length += dissect_akmpdu(tvb, pdcPacketTree, length);
		col_set_str(pinfo->cinfo, COL_INFO, "AKMPDU");
		break;
	default:
		break;
	};
	return (length);
}

/* Actual dissector bits and bytes done here */
static int dissect_pdc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{

	/*Set the Column*/
	col_set_str (pinfo->cinfo, COL_PROTOCOL, PDC_PROCOTOL );
	col_clear (pinfo->cinfo, COL_INFO);

	if (tree)
	{ /* we are being asked for details */
		dissect_pdc_packet(tvb, tree, pinfo);
	}

	return tvb_length(tvb);
}

/* function to provide TCP split packet combiner with size of packet */
static guint get_pdc_message_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset)
{
	guint16 size;
	guint8 extra=0;
	guint8 mpdu_type=0;
	mpdu_type=tvb_get_guint8(tvb,offset+1);
	switch (mpdu_type)
	{
	case SIMPDU:
		size=tvb_get_guint8(tvb,offset);
		extra=1;
		break;
	case RSMPDU:
		size=tvb_get_guint8(tvb,offset);
		extra=1;
		break;
	case DRMPDU:
		size=tvb_get_guint8(tvb,offset);
		extra=1;
		break;
	case DTMPDU:
		size=tvb_get_ntohs(tvb, offset+2);
		extra=4;
		break;
	case ADMPDU:
		size=tvb_get_ntohs(tvb,offset+6);
		extra=8;
		break;
	case EDMPDU:
		size=tvb_get_guint8(tvb,offset);
		extra=1;
		break;
	case AKMPDU:
		size=tvb_get_guint8(tvb,offset)+1;
		extra=0;
		break;
	default:
		size=0;
		extra=0;
	}
	return (guint)(size+extra);
}

/* top level call to recombine split tcp packets */

static void tcp_dissect_pdc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
	guint8 mpdu_type=0;
	guint8 minimum_bytes=2;
	mpdu_type=tvb_get_guint8(tvb,1);
	switch (mpdu_type)
	{
	case SIMPDU:
		minimum_bytes=2;
		break;
	case RSMPDU:
		minimum_bytes=2;
		break;
	case DRMPDU:
		minimum_bytes=2;
		break;
	case DTMPDU:
		minimum_bytes=4;
		break;
	case ADMPDU:
		minimum_bytes=8;
		break;
	case EDMPDU:
		minimum_bytes=2;
		break;
	case AKMPDU:
		minimum_bytes=2;
		break;
	default:
		minimum_bytes=2;
		break;
	}
	tcp_dissect_pdus(tvb, pinfo, tree, TRUE, minimum_bytes, get_pdc_message_len, dissect_pdc, NULL);
}

/* function to register pdc dissector and get handle for asterix dissector */
void proto_reg_handoff_pdc(void)
{
	dissector_handle_t pdc_handle;

	asterix_handle = find_dissector("asterix");
	pdc_handle = create_dissector_handle(tcp_dissect_pdc, proto_pdc);
	dissector_add_uint("tcp.port", gPREF_PORT_NUM_TCP, pdc_handle);
}

void proto_register_pdc(void)
{
	module_t *pdc_pref_module;

	static hf_register_info hf[] =
	{
			{ &hf_pdc_len,{ "Length Indicator", "pdc.li",FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
			{ &hf_pdc_mpdu_code,{ "MPDU code", "pdc.mpducode", FT_UINT8, BASE_DEC, VALS(valstr_mpdus), 0x0, NULL, HFILL }},
			{ &hf_pdc_credit,{ "Credit", "pdc.cdt", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
			{ &hf_pdc_yr_admu_nr,{ "YR-ADMU-NR", "pdc.yradmunr", FT_UINT32, BASE_DEC, NULL, 0x0, NULL , HFILL }},
			{ &hf_pdc_simpdu_state,{ "State", "pdc.state", FT_UINT8, BASE_DEC, VALS(valstr_simpdu_state), 0x0, NULL, HFILL }},
			{ &hf_pdc_akmpdu_mns,{ "MNS", "pdc.akmpdu.mns", FT_UINT16, BASE_DEC, NULL, 0x8000, NULL, HFILL }},
			{ &hf_pdc_akmpdu_cdt,{ "CDT", "pdc.akmpdu.cdt", FT_UINT16, BASE_DEC, NULL, 0x07FF, NULL, HFILL }},
			{ &hf_pdc_simpdu_var,{ "Variable Part", "pdc.simpdu.variable", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL }},
			{ &hf_pdc_simpdu_param,{ "Parameter", "pdc.simpdu.param", FT_UINT8, BASE_DEC, VALS(valstr_simpdu_param), 0x0, NULL, HFILL }},
			{ &hf_pdc_simpdu_var_len, { "Length", "pdc.simpdu.variable.length", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
			{ &hf_pdc_simpdu_var_version, { "PDC Version Number", "pdc.simpdu.variable.version", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
			{ &hf_pdc_simpdu_var_REFSRC,{ "Reference Source", "pdc.simpdu.variable.refsrc", FT_UINT32, BASE_DEC, NULL, 0x0,NULL, HFILL }},
			{ &hf_pdc_simpdu_var_REFDEST,{ "Reference Destination", "pdc.simpdu.variable.refdst",FT_UINT32, BASE_DEC, NULL, 0x0,NULL, HFILL }},
			{ &hf_pdc_simpdu_var_TSEL,{ "Transport Selector", "pdc.simpdu.tsel", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
			{ &hf_pdc_drmpdu_abort,{ "Abort", "pdc.drmpdu.abort", FT_UINT8, BASE_DEC, VALS(valstr_drmpdu_abort), 0x80, NULL, HFILL }},
			{ &hf_pdc_drmpdu_reason,{ "Reason", "pdc.drmpdu.reason", FT_UINT8, BASE_DEC, VALS(valstr_drmpdu_reason), 0x0, NULL, HFILL }},
			{ &hf_pdc_drmpdu_mode,{ "Mode", "pdc.drmpdu.mode", FT_UINT8, BASE_DEC, VALS(valstr_drmpdu_mode), 0x70, NULL, HFILL }},
			{ &hf_pdc_drmpdu_init,{ "Reason", "pdc.drmpdu.init", FT_UINT8, BASE_DEC, VALS(valstr_drmpdu_initatior), 0x0F, NULL, HFILL }},
			{ &hf_pdc_dtmpdu_user_size,{ "User Data Length", "pdc.dtmpdu.usersize", FT_UINT16, BASE_DEC, NULL, 0x0, NULL , HFILL }},
			{ &hf_pdc_admpdu_admpdunr,{ "AD-MPDU-NR", "pdc.admpdu.admpdunr",FT_UINT32, BASE_DEC, NULL, 0x0, NULL , HFILL }},
			{ &hf_pdc_admpdu_size,{ "User Data Size", "pdc.admpdu.usersize",FT_UINT16, BASE_DEC, NULL, 0x0, NULL , HFILL }},
	};

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

	proto_pdc = proto_register_protocol (
			"PDC Protocol",	/* name       */
			"PDC",			/* short name */
			"pdc"			/* abbrev     */
	);

	/*Required Function Calls to register the header fields and subtrees used*/
	proto_register_field_array(proto_pdc, hf, array_length(hf));
	proto_register_subtree_array(ett, array_length(ett));
	new_register_dissector("pdc", dissect_pdc, proto_pdc);

	/*Register Preferences Module*/
	pdc_pref_module = prefs_register_protocol(proto_pdc, proto_reg_handoff_pdc);

	/*Register Preferences*/
	prefs_register_uint_preference(pdc_pref_module, "tcp.port", "PDC Port", "PDC Port if other then the default", 10, &gPREF_PORT_NUM_TCP);
}

/*
 * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 8
 * tab-width: 8
 * indent-tabs-mode: t
 * End:
 *
 * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 * :indentSize=8:tabSize=8:noTabs=false:
 */