/*====================================================================*
*
*   Copyright (c) 2013 Qualcomm Atheros, Inc.
*
*   All rights reserved.
*
*====================================================================*/

/*====================================================================*
 *
 *   bool UnwantedMessage (void const * memory, size_t extent, uint8_t MMV, uint16_t MMTYPE);
 *
 *   mme.h
 *
 *   return true (-1) if memory does not contains a Qualcomm Atheros 
 *   vendor specific message having the requested version and type; 
 *   otherwise, return 0;
 *
 *   the message version determines the location of the OUI field; 
 *   messages with MMV = 1 have an FMI used to track multi-part 
 *   confirmation counts; out of order counts are treated as an 
 *   error;
 *
 *   constant __WHYNOT__ displays reason for message rejection;
 *
 *   this implementation conditionally compiles code that enforces
 *   proper frame fragmentation but that code may be disabled due
 *
 *   some problems with legacy homeplug software;
 *
 *   batch is the fragment group identifier taken from the fragment
 *   frame;
 *
 *   total is the number of fragements in the group taken from the
 *   fragment frame;
 *
 *   index is the fragment identifier from the fragment frame;
 *
 *   count is the number of fragments received so far;
 *
 *   Contributor(s):
 *      Charles Maier <cmaier@qca.qualcomm.com>
 *      Matthieu Poullet <m.poullet@avm.de>
 *
 *--------------------------------------------------------------------*/

#ifndef UNWANTEDMESSAGE_SOURCE
#define UNWANTEDMESSAGE_SOURCE

#include <stdint.h>
#include <memory.h>

#include "../tools/endian.h"
#include "../tools/error.h"
#include "../mme/mme.h"

signed UnwantedMessage (void const * memory, size_t extent, uint8_t MMV, uint16_t MMTYPE) 

{ 
	extern const byte localcast [ETHER_ADDR_LEN]; 
	struct homeplug1 * homeplug = (struct homeplug1 *) (memory); 
	if (! extent) 
	{ 
		return (- 1); 
	} 
	if (extent < (ETHER_MIN_LEN - ETHER_CRC_LEN)) 
	{ 

#if defined (__WHYNOT__)

		error (0, 0, "Wrong Ethernet Frame Size: Received " SIZE_T_SPEC " bytes but need at least %d", extent, ETHER_MIN_LEN - ETHER_CRC_LEN); 

#endif

		return (- 1); 
	} 
	if (extent > (ETHER_MAX_LEN)) 
	{ 

#if defined (__WHYNOT__)

		error (0, 0, "Wrong Ethernet Frame Size: Received " SIZE_T_SPEC " bytes but need at most %d", extent, ETHER_MAX_LEN); 

#endif

		return (- 1); 
	} 
	if (ntohs (homeplug->ethernet.MTYPE) != ETH_P_HPAV) 
	{ 

#if defined (__WHYNOT__)

		error (0, 0, "Wrong Ethernet Frame Type: Received %04X while waiting for %04X", ntohs (homeplug->ethernet.MTYPE), ETH_P_HPAV); 

#endif

		return (- 1); 
	} 
	if (homeplug->homeplug.MMV != MMV) 
	{ 

#if defined (__WHYNOT__)

		error (0, 0, "Wrong Message Version: Received %02X but expected %02X", homeplug->homeplug.MMV, MMV); 

#endif

		return (- 1); 
	} 
	if (homeplug->homeplug.MMV == 0) 
	{ 
		struct qualcomm_hdr * qualcomm = (struct qualcomm_hdr *) (& homeplug->homeplug); 
		if (LE16TOH (qualcomm->MMTYPE) != MMTYPE) 
		{ 

#if defined (__WHYNOT__)

			error (0, 0, "Wrong Message Type: Received %04X while waiting for %04X", LE16TOH (qualcomm->MMTYPE), MMTYPE); 

#endif

			return (- 1); 
		} 
		if ((MMTYPE < VS_MMTYPE_MIN) || (MMTYPE > VS_MMTYPE_MAX)) 
		{ 
		} 
		else if (memcmp (localcast, qualcomm->OUI, sizeof (qualcomm->OUI))) 
		{ 

#if defined (__WHYNOT__)

			error (0, 0, "Wrong Message Vendor"); 

#endif

			return (- 1); 
		} 
	} 
	if (homeplug->homeplug.MMV == 1) 
	{ 
		struct qualcomm_fmi * qualcomm = (struct qualcomm_fmi *) (& homeplug->homeplug); 

#if FMI

		static unsigned total = 0; 
		static unsigned index = 0; 
		static unsigned count = 0; 

#endif

		if (LE16TOH (qualcomm->MMTYPE) != MMTYPE) 
		{ 

#if defined (__WHYNOT__)

			error (0, 0, "Wrong Message Type: Received %04X while waiting for %04X", LE16TOH (qualcomm->MMTYPE), MMTYPE); 

#endif

			return (- 1); 
		} 

#if FMI

		index = qualcomm->FMID >> 0 & 0x0F; 
		if (! index) 
		{ 
			total = qualcomm->FMID >> 4 & 0x0F; 
			count = qualcomm->FMID >> 0 & 0x0F; 
			if (memcmp (localcast, qualcomm->OUI, sizeof (qualcomm->OUI))) 
			{ 

#if defined (__WHYNOT__)

				error (0, 0, "Wrong Message Vendor"); 

#endif

				return (- 1); 
			} 
		} 
		if (index != count) 
		{ 

#if defined (__WHYNOT__)

			error (0, 0, "Message Fragment Out-of-order"); 

#endif

			return (- 1); 
		} 
		if (count > total) 
		{ 

#if defined (__WHYNOT__)

			error (0, 0, "Fragment Count Exceeds Total"); 

#endif

			return (- 1); 
		} 
		count++; 

#endif

	} 
	return (0); 
} 

#endif