FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/FreeRTOS_UDP_IP.c - third_party/github/FreeRTOS/FreeRTOS-Kernel - Git at Google

 /*
  * FreeRTOS+TCP V2.2.0
  * Copyright (C) 2017 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
  * the Software without restriction, including without limitation the rights to
  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
  * the Software, and to permit persons to whom the Software is furnished to do so,
  * subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in all
  * copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
  * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
  * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
  * http://aws.amazon.com/freertos
  * http://www.FreeRTOS.org
  */

 /* Standard includes. */
 #include <stdint.h>
 #include <stdio.h>

 /* FreeRTOS includes. */
 #include "FreeRTOS.h"
 #include "task.h"
 #include "queue.h"
 #include "semphr.h"

 /* FreeRTOS+TCP includes. */
 #include "FreeRTOS_IP.h"
 #include "FreeRTOS_Sockets.h"
 #include "FreeRTOS_IP_Private.h"
 #include "FreeRTOS_UDP_IP.h"
 #include "FreeRTOS_ARP.h"
 #include "FreeRTOS_DHCP.h"
 #include "NetworkInterface.h"
 #include "NetworkBufferManagement.h"

 #if( ipconfigUSE_DNS == 1 )
 	#include "FreeRTOS_DNS.h"
 #endif

 /* The expected IP version and header length coded into the IP header itself. */
 #define ipIP_VERSION_AND_HEADER_LENGTH_BYTE ( ( uint8_t ) 0x45 )

 /* Part of the Ethernet and IP headers are always constant when sending an IPv4
 UDP packet.  This array defines the constant parts, allowing this part of the
 packet to be filled in using a simple memcpy() instead of individual writes. */
 UDPPacketHeader_t xDefaultPartUDPPacketHeader =
 {
 	/* .ucBytes : */
 	{
 		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 	/* Ethernet source MAC address. */
 		0x08, 0x00, 							/* Ethernet frame type. */
 		ipIP_VERSION_AND_HEADER_LENGTH_BYTE, 	/* ucVersionHeaderLength. */
 		0x00, 									/* ucDifferentiatedServicesCode. */
 		0x00, 0x00, 							/* usLength. */
 		0x00, 0x00, 							/* usIdentification. */
 		0x00, 0x00, 							/* usFragmentOffset. */
 		ipconfigUDP_TIME_TO_LIVE, 				/* ucTimeToLive */
 		ipPROTOCOL_UDP, 						/* ucProtocol. */
 		0x00, 0x00, 							/* usHeaderChecksum. */
 		0x00, 0x00, 0x00, 0x00 					/* Source IP address. */
 	}
 };
 /*-----------------------------------------------------------*/

 void vProcessGeneratedUDPPacket( NetworkBufferDescriptor_t * const pxNetworkBuffer )
 {
 UDPPacket_t *pxUDPPacket;
 IPHeader_t *pxIPHeader;
 eARPLookupResult_t eReturned;
 uint32_t ulIPAddress = pxNetworkBuffer->ulIPAddress;
 size_t uxPayloadSize;

 	/* Map the UDP packet onto the start of the frame. */
 	pxUDPPacket = ( UDPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer;

 #if ipconfigSUPPORT_OUTGOING_PINGS == 1
 	if( pxNetworkBuffer->usPort == ipPACKET_CONTAINS_ICMP_DATA )
 	{
 		uxPayloadSize = pxNetworkBuffer->xDataLength - sizeof( ICMPPacket_t );
 	}
 	else
 #endif
 	{
 		uxPayloadSize = pxNetworkBuffer->xDataLength - sizeof( UDPPacket_t );
 	}

 	/* Determine the ARP cache status for the requested IP address. */
 	eReturned = eARPGetCacheEntry( &( ulIPAddress ), &( pxUDPPacket->xEthernetHeader.xDestinationAddress ) );

 	if( eReturned != eCantSendPacket )
 	{
 		if( eReturned == eARPCacheHit )
 		{
 			#if( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
 				uint8_t ucSocketOptions;
 			#endif
 			iptraceSENDING_UDP_PACKET( pxNetworkBuffer->ulIPAddress );

 			/* Create short cuts to the data within the packet. */
 			pxIPHeader = &( pxUDPPacket->xIPHeader );

 		#if ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )
 			/* Is it possible that the packet is not actually a UDP packet
 			after all, but an ICMP packet. */
 			if( pxNetworkBuffer->usPort != ipPACKET_CONTAINS_ICMP_DATA )
 		#endif /* ipconfigSUPPORT_OUTGOING_PINGS */
 			{
 			UDPHeader_t *pxUDPHeader;

 				pxUDPHeader = &( pxUDPPacket->xUDPHeader );

 				pxUDPHeader->usDestinationPort = pxNetworkBuffer->usPort;
 				pxUDPHeader->usSourcePort = pxNetworkBuffer->usBoundPort;
 				pxUDPHeader->usLength = ( uint16_t ) ( uxPayloadSize + sizeof( UDPHeader_t ) );
 				pxUDPHeader->usLength = FreeRTOS_htons( pxUDPHeader->usLength );
 				pxUDPHeader->usChecksum = 0u;
 			}

 			/* memcpy() the constant parts of the header information into
 			the	correct location within the packet.  This fills in:
 				xEthernetHeader.xSourceAddress
 				xEthernetHeader.usFrameType
 				xIPHeader.ucVersionHeaderLength
 				xIPHeader.ucDifferentiatedServicesCode
 				xIPHeader.usLength
 				xIPHeader.usIdentification
 				xIPHeader.usFragmentOffset
 				xIPHeader.ucTimeToLive
 				xIPHeader.ucProtocol
 			and
 				xIPHeader.usHeaderChecksum
 			*/
 			/* Save options now, as they will be overwritten by memcpy */
 			#if( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
 				ucSocketOptions = pxNetworkBuffer->pucEthernetBuffer[ ipSOCKET_OPTIONS_OFFSET ];
 			#endif
 			/*
 			 * Offset the memcpy by the size of a MAC address to start at the packet's
 			 * Ethernet header 'source' MAC address; the preceding 'destination' should not be altered.
 			 */
 			char *pxUdpSrcAddrOffset = ( char *) pxUDPPacket + sizeof( MACAddress_t );
 			memcpy( pxUdpSrcAddrOffset, xDefaultPartUDPPacketHeader.ucBytes, sizeof( xDefaultPartUDPPacketHeader ) );

 		#if ipconfigSUPPORT_OUTGOING_PINGS == 1
 			if( pxNetworkBuffer->usPort == ipPACKET_CONTAINS_ICMP_DATA )
 			{
 				pxIPHeader->ucProtocol = ipPROTOCOL_ICMP;
 				pxIPHeader->usLength = ( uint16_t ) ( uxPayloadSize + sizeof( IPHeader_t ) + sizeof( ICMPHeader_t ) );
 			}
 			else
 		#endif /* ipconfigSUPPORT_OUTGOING_PINGS */
 			{
 				pxIPHeader->usLength = ( uint16_t ) ( uxPayloadSize + sizeof( IPHeader_t ) + sizeof( UDPHeader_t ) );
 			}

 			pxIPHeader->usLength = FreeRTOS_htons( pxIPHeader->usLength );
 			/* HT:endian: changed back to network endian */
 			pxIPHeader->ulDestinationIPAddress = pxNetworkBuffer->ulIPAddress;

 			#if( ipconfigUSE_LLMNR == 1 )
 			{
 				/* LLMNR messages are typically used on a LAN and they're
 				 * not supposed to cross routers */
 				if( pxNetworkBuffer->ulIPAddress == ipLLMNR_IP_ADDR )
 				{
 					pxIPHeader->ucTimeToLive = 0x01;
 				}
 			}
 			#endif

 			#if( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
 			{
 				pxIPHeader->usHeaderChecksum = 0u;
 				pxIPHeader->usHeaderChecksum = usGenerateChecksum( 0UL, ( uint8_t * ) &( pxIPHeader->ucVersionHeaderLength ), ipSIZE_OF_IPv4_HEADER );
 				pxIPHeader->usHeaderChecksum = ~FreeRTOS_htons( pxIPHeader->usHeaderChecksum );

 				if( ( ucSocketOptions & ( uint8_t ) FREERTOS_SO_UDPCKSUM_OUT ) != 0u )
 				{
 					usGenerateProtocolChecksum( (uint8_t*)pxUDPPacket, pxNetworkBuffer->xDataLength, pdTRUE );
 				}
 				else
 				{
 					pxUDPPacket->xUDPHeader.usChecksum = 0u;
 				}
 			}
 			#endif
 		}
 		else if( eReturned == eARPCacheMiss )
 		{
 			/* Add an entry to the ARP table with a null hardware address.
 			This allows the ARP timer to know that an ARP reply is
 			outstanding, and perform retransmissions if necessary. */
 			vARPRefreshCacheEntry( NULL, ulIPAddress );

 			/* Generate an ARP for the required IP address. */
 			iptracePACKET_DROPPED_TO_GENERATE_ARP( pxNetworkBuffer->ulIPAddress );
 			pxNetworkBuffer->ulIPAddress = ulIPAddress;
 			vARPGenerateRequestPacket( pxNetworkBuffer );
 		}
 		else
 		{
 			/* The lookup indicated that an ARP request has already been
 			sent out for the queried IP address. */
 			eReturned = eCantSendPacket;
 		}
 	}

 	if( eReturned != eCantSendPacket )
 	{
 		/* The network driver is responsible for freeing the network buffer
 		after the packet has been sent. */

 		#if defined( ipconfigETHERNET_MINIMUM_PACKET_BYTES )
 		{
 			if( pxNetworkBuffer->xDataLength < ( size_t ) ipconfigETHERNET_MINIMUM_PACKET_BYTES )
 			{
 			BaseType_t xIndex;

 				for( xIndex = ( BaseType_t ) pxNetworkBuffer->xDataLength; xIndex < ( BaseType_t ) ipconfigETHERNET_MINIMUM_PACKET_BYTES; xIndex++ )
 				{
 					pxNetworkBuffer->pucEthernetBuffer[ xIndex ] = 0u;
 				}
 				pxNetworkBuffer->xDataLength = ( size_t ) ipconfigETHERNET_MINIMUM_PACKET_BYTES;
 			}
 		}
 		#endif

 		xNetworkInterfaceOutput( pxNetworkBuffer, pdTRUE );
 	}
 	else
 	{
 		/* The packet can't be sent (DHCP not completed?).  Just drop the
 		packet. */
 		vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );
 	}
 }
 /*-----------------------------------------------------------*/

 BaseType_t xProcessReceivedUDPPacket( NetworkBufferDescriptor_t *pxNetworkBuffer, uint16_t usPort )
 {
 BaseType_t xReturn = pdPASS;
 FreeRTOS_Socket_t *pxSocket;
 configASSERT(pxNetworkBuffer);
 configASSERT(pxNetworkBuffer->pucEthernetBuffer);


 UDPPacket_t *pxUDPPacket = (UDPPacket_t *) pxNetworkBuffer->pucEthernetBuffer;

 	/* Caller must check for minimum packet size. */
 	pxSocket = pxUDPSocketLookup( usPort );

 	if( pxSocket )
 	{

 		/* When refreshing the ARP cache with received UDP packets we must be
 		careful;  hundreds of broadcast messages may pass and if we're not
 		handling them, no use to fill the ARP cache with those IP addresses. */
 		vARPRefreshCacheEntry( &( pxUDPPacket->xEthernetHeader.xSourceAddress ), pxUDPPacket->xIPHeader.ulSourceIPAddress );

 		#if( ipconfigUSE_CALLBACKS == 1 )
 		{
 			/* Did the owner of this socket register a reception handler ? */
 			if( ipconfigIS_VALID_PROG_ADDRESS( pxSocket->u.xUDP.pxHandleReceive ) )
 			{
 				struct freertos_sockaddr xSourceAddress, destinationAddress;
 				void *pcData = ( void * ) &( pxNetworkBuffer->pucEthernetBuffer[ ipUDP_PAYLOAD_OFFSET_IPv4 ] );
 				FOnUDPReceive_t xHandler = ( FOnUDPReceive_t ) pxSocket->u.xUDP.pxHandleReceive;
 				xSourceAddress.sin_port = pxNetworkBuffer->usPort;
 				xSourceAddress.sin_addr = pxNetworkBuffer->ulIPAddress;
 				destinationAddress.sin_port = usPort;
 				destinationAddress.sin_addr = pxUDPPacket->xIPHeader.ulDestinationIPAddress;

 				if( xHandler( ( Socket_t ) pxSocket, ( void* ) pcData, ( size_t ) pxNetworkBuffer->xDataLength,
 					&xSourceAddress, &destinationAddress ) )
 				{
 					xReturn = pdFAIL; /* FAIL means that we did not consume or release the buffer */
 				}
 			}
 		}
 		#endif /* ipconfigUSE_CALLBACKS */

 		#if( ipconfigUDP_MAX_RX_PACKETS > 0 )
 		{
 			if( xReturn == pdPASS )
 			{
 				if ( listCURRENT_LIST_LENGTH( &( pxSocket->u.xUDP.xWaitingPacketsList ) ) >= pxSocket->u.xUDP.uxMaxPackets )
 				{
 					FreeRTOS_debug_printf( ( "xProcessReceivedUDPPacket: buffer full %ld >= %ld port %u\n",
 						listCURRENT_LIST_LENGTH( &( pxSocket->u.xUDP.xWaitingPacketsList ) ),
 						pxSocket->u.xUDP.uxMaxPackets, pxSocket->usLocalPort ) );
 					xReturn = pdFAIL; /* we did not consume or release the buffer */
 				}
 			}
 		}
 		#endif

 		if( xReturn == pdPASS )
 		{
 			vTaskSuspendAll();
 			{
 				if( xReturn == pdPASS )
 				{
 					taskENTER_CRITICAL();
 					{
 						/* Add the network packet to the list of packets to be
 						processed by the socket. */
 						vListInsertEnd( &( pxSocket->u.xUDP.xWaitingPacketsList ), &( pxNetworkBuffer->xBufferListItem ) );
 					}
 					taskEXIT_CRITICAL();
 				}
 			}
 			xTaskResumeAll();

 			/* Set the socket's receive event */
 			if( pxSocket->xEventGroup != NULL )
 			{
 				xEventGroupSetBits( pxSocket->xEventGroup, eSOCKET_RECEIVE );
 			}

 			#if( ipconfigSUPPORT_SELECT_FUNCTION == 1 )
 			{
 				if( ( pxSocket->pxSocketSet != NULL ) && ( ( pxSocket->xSelectBits & eSELECT_READ ) != 0 ) )
 				{
 					xEventGroupSetBits( pxSocket->pxSocketSet->xSelectGroup, eSELECT_READ );
 				}
 			}
 			#endif

 			#if( ipconfigSOCKET_HAS_USER_SEMAPHORE == 1 )
 			{
 				if( pxSocket->pxUserSemaphore != NULL )
 				{
 					xSemaphoreGive( pxSocket->pxUserSemaphore );
 				}
 			}
 			#endif

 			#if( ipconfigUSE_DHCP == 1 )
 			{
 				if( xIsDHCPSocket( pxSocket ) )
 				{
 					xSendEventToIPTask( eDHCPEvent );
 				}
 			}
 			#endif
 		}
 	}
 	else
 	{
 		/* There is no socket listening to the target port, but still it might
 		be for this node. */

 		#if( ipconfigUSE_DNS == 1 ) && ( ipconfigDNS_USE_CALLBACKS == 1 )
 			/* A DNS reply, check for the source port.  Although the DNS client
 			does open a UDP socket to send a messages, this socket will be
 			closed after a short timeout.  Messages that come late (after the
 			socket is closed) will be treated here. */
 			if( FreeRTOS_ntohs( pxUDPPacket->xUDPHeader.usSourcePort ) == ipDNS_PORT )
 			{
 				vARPRefreshCacheEntry( &( pxUDPPacket->xEthernetHeader.xSourceAddress ), pxUDPPacket->xIPHeader.ulSourceIPAddress );
 				xReturn = ( BaseType_t )ulDNSHandlePacket( pxNetworkBuffer );
 			}
 			else
 		#endif

 		#if( ipconfigUSE_LLMNR == 1 )
 			/* a LLMNR request, check for the destination port. */
 			if( ( usPort == FreeRTOS_ntohs( ipLLMNR_PORT ) ) ||
 				( pxUDPPacket->xUDPHeader.usSourcePort == FreeRTOS_ntohs( ipLLMNR_PORT ) ) )
 			{
 				vARPRefreshCacheEntry( &( pxUDPPacket->xEthernetHeader.xSourceAddress ), pxUDPPacket->xIPHeader.ulSourceIPAddress );
 				xReturn = ( BaseType_t )ulDNSHandlePacket( pxNetworkBuffer );
 			}
 			else
 		#endif /* ipconfigUSE_LLMNR */

 		#if( ipconfigUSE_NBNS == 1 )
 			/* a NetBIOS request, check for the destination port */
 			if( ( usPort == FreeRTOS_ntohs( ipNBNS_PORT ) ) ||
 				( pxUDPPacket->xUDPHeader.usSourcePort == FreeRTOS_ntohs( ipNBNS_PORT ) ) )
 			{
 				vARPRefreshCacheEntry( &( pxUDPPacket->xEthernetHeader.xSourceAddress ), pxUDPPacket->xIPHeader.ulSourceIPAddress );
 				xReturn = ( BaseType_t )ulNBNSHandlePacket( pxNetworkBuffer );
 			}
 			else
 		#endif /* ipconfigUSE_NBNS */
 		{
 			xReturn = pdFAIL;
 		}
 	}

 	return xReturn;
 }
 /*-----------------------------------------------------------*/
	/*
	* FreeRTOS+TCP V2.2.0
	* Copyright (C) 2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy of
	* this software and associated documentation files (the "Software"), to deal in
	* the Software without restriction, including without limitation the rights to
	* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
	* the Software, and to permit persons to whom the Software is furnished to do so,
	* subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in all
	* copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
	* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
	* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
	* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*
	* http://aws.amazon.com/freertos
	* http://www.FreeRTOS.org
	*/

	/* Standard includes. */
	#include <stdint.h>
	#include <stdio.h>

	/* FreeRTOS includes. */
	#include "FreeRTOS.h"
	#include "task.h"
	#include "queue.h"
	#include "semphr.h"

	/* FreeRTOS+TCP includes. */
	#include "FreeRTOS_IP.h"
	#include "FreeRTOS_Sockets.h"
	#include "FreeRTOS_IP_Private.h"
	#include "FreeRTOS_UDP_IP.h"
	#include "FreeRTOS_ARP.h"
	#include "FreeRTOS_DHCP.h"
	#include "NetworkInterface.h"
	#include "NetworkBufferManagement.h"

	#if( ipconfigUSE_DNS == 1 )
	#include "FreeRTOS_DNS.h"
	#endif

	/* The expected IP version and header length coded into the IP header itself. */
	#define ipIP_VERSION_AND_HEADER_LENGTH_BYTE ( ( uint8_t ) 0x45 )

	/* Part of the Ethernet and IP headers are always constant when sending an IPv4
	UDP packet. This array defines the constant parts, allowing this part of the
	packet to be filled in using a simple memcpy() instead of individual writes. */
	UDPPacketHeader_t xDefaultPartUDPPacketHeader =
	{
	/* .ucBytes : */
	{
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* Ethernet source MAC address. */
	0x08, 0x00, /* Ethernet frame type. */
	ipIP_VERSION_AND_HEADER_LENGTH_BYTE, /* ucVersionHeaderLength. */
	0x00, /* ucDifferentiatedServicesCode. */
	0x00, 0x00, /* usLength. */
	0x00, 0x00, /* usIdentification. */
	0x00, 0x00, /* usFragmentOffset. */
	ipconfigUDP_TIME_TO_LIVE, /* ucTimeToLive */
	ipPROTOCOL_UDP, /* ucProtocol. */
	0x00, 0x00, /* usHeaderChecksum. */
	0x00, 0x00, 0x00, 0x00 /* Source IP address. */
	}
	};
	/-----------------------------------------------------------/

	void vProcessGeneratedUDPPacket( NetworkBufferDescriptor_t * const pxNetworkBuffer )
	{
	UDPPacket_t *pxUDPPacket;
	IPHeader_t *pxIPHeader;
	eARPLookupResult_t eReturned;
	uint32_t ulIPAddress = pxNetworkBuffer->ulIPAddress;
	size_t uxPayloadSize;

	/* Map the UDP packet onto the start of the frame. */
	pxUDPPacket = ( UDPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer;

	#if ipconfigSUPPORT_OUTGOING_PINGS == 1
	if( pxNetworkBuffer->usPort == ipPACKET_CONTAINS_ICMP_DATA )
	{
	uxPayloadSize = pxNetworkBuffer->xDataLength - sizeof( ICMPPacket_t );
	}
	else
	#endif
	{
	uxPayloadSize = pxNetworkBuffer->xDataLength - sizeof( UDPPacket_t );
	}

	/* Determine the ARP cache status for the requested IP address. */
	eReturned = eARPGetCacheEntry( &( ulIPAddress ), &( pxUDPPacket->xEthernetHeader.xDestinationAddress ) );

	if( eReturned != eCantSendPacket )
	{
	if( eReturned == eARPCacheHit )
	{
	#if( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
	uint8_t ucSocketOptions;
	#endif
	iptraceSENDING_UDP_PACKET( pxNetworkBuffer->ulIPAddress );

	/* Create short cuts to the data within the packet. */
	pxIPHeader = &( pxUDPPacket->xIPHeader );

	#if ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )
	/* Is it possible that the packet is not actually a UDP packet
	after all, but an ICMP packet. */
	if( pxNetworkBuffer->usPort != ipPACKET_CONTAINS_ICMP_DATA )
	#endif /* ipconfigSUPPORT_OUTGOING_PINGS */
	{
	UDPHeader_t *pxUDPHeader;

	pxUDPHeader = &( pxUDPPacket->xUDPHeader );

	pxUDPHeader->usDestinationPort = pxNetworkBuffer->usPort;
	pxUDPHeader->usSourcePort = pxNetworkBuffer->usBoundPort;
	pxUDPHeader->usLength = ( uint16_t ) ( uxPayloadSize + sizeof( UDPHeader_t ) );
	pxUDPHeader->usLength = FreeRTOS_htons( pxUDPHeader->usLength );
	pxUDPHeader->usChecksum = 0u;
	}

	/* memcpy() the constant parts of the header information into
	the correct location within the packet. This fills in:
	xEthernetHeader.xSourceAddress
	xEthernetHeader.usFrameType
	xIPHeader.ucVersionHeaderLength
	xIPHeader.ucDifferentiatedServicesCode
	xIPHeader.usLength
	xIPHeader.usIdentification
	xIPHeader.usFragmentOffset
	xIPHeader.ucTimeToLive
	xIPHeader.ucProtocol
	and
	xIPHeader.usHeaderChecksum
	*/
	/* Save options now, as they will be overwritten by memcpy */
	#if( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
	ucSocketOptions = pxNetworkBuffer->pucEthernetBuffer[ ipSOCKET_OPTIONS_OFFSET ];
	#endif
	/*
	* Offset the memcpy by the size of a MAC address to start at the packet's
	* Ethernet header 'source' MAC address; the preceding 'destination' should not be altered.
	*/
	char pxUdpSrcAddrOffset = ( char ) pxUDPPacket + sizeof( MACAddress_t );
	memcpy( pxUdpSrcAddrOffset, xDefaultPartUDPPacketHeader.ucBytes, sizeof( xDefaultPartUDPPacketHeader ) );

	#if ipconfigSUPPORT_OUTGOING_PINGS == 1
	if( pxNetworkBuffer->usPort == ipPACKET_CONTAINS_ICMP_DATA )
	{
	pxIPHeader->ucProtocol = ipPROTOCOL_ICMP;
	pxIPHeader->usLength = ( uint16_t ) ( uxPayloadSize + sizeof( IPHeader_t ) + sizeof( ICMPHeader_t ) );
	}
	else
	#endif /* ipconfigSUPPORT_OUTGOING_PINGS */
	{
	pxIPHeader->usLength = ( uint16_t ) ( uxPayloadSize + sizeof( IPHeader_t ) + sizeof( UDPHeader_t ) );
	}

	pxIPHeader->usLength = FreeRTOS_htons( pxIPHeader->usLength );
	/* HT:endian: changed back to network endian */
	pxIPHeader->ulDestinationIPAddress = pxNetworkBuffer->ulIPAddress;

	#if( ipconfigUSE_LLMNR == 1 )
	{
	/* LLMNR messages are typically used on a LAN and they're
	* not supposed to cross routers */
	if( pxNetworkBuffer->ulIPAddress == ipLLMNR_IP_ADDR )
	{
	pxIPHeader->ucTimeToLive = 0x01;
	}
	}
	#endif

	#if( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
	{
	pxIPHeader->usHeaderChecksum = 0u;
	pxIPHeader->usHeaderChecksum = usGenerateChecksum( 0UL, ( uint8_t * ) &( pxIPHeader->ucVersionHeaderLength ), ipSIZE_OF_IPv4_HEADER );
	pxIPHeader->usHeaderChecksum = ~FreeRTOS_htons( pxIPHeader->usHeaderChecksum );

	if( ( ucSocketOptions & ( uint8_t ) FREERTOS_SO_UDPCKSUM_OUT ) != 0u )
	{
	usGenerateProtocolChecksum( (uint8_t*)pxUDPPacket, pxNetworkBuffer->xDataLength, pdTRUE );
	}
	else
	{
	pxUDPPacket->xUDPHeader.usChecksum = 0u;
	}
	}
	#endif
	}
	else if( eReturned == eARPCacheMiss )
	{
	/* Add an entry to the ARP table with a null hardware address.
	This allows the ARP timer to know that an ARP reply is
	outstanding, and perform retransmissions if necessary. */
	vARPRefreshCacheEntry( NULL, ulIPAddress );

	/* Generate an ARP for the required IP address. */
	iptracePACKET_DROPPED_TO_GENERATE_ARP( pxNetworkBuffer->ulIPAddress );
	pxNetworkBuffer->ulIPAddress = ulIPAddress;
	vARPGenerateRequestPacket( pxNetworkBuffer );
	}
	else
	{
	/* The lookup indicated that an ARP request has already been
	sent out for the queried IP address. */
	eReturned = eCantSendPacket;
	}
	}

	if( eReturned != eCantSendPacket )
	{
	/* The network driver is responsible for freeing the network buffer
	after the packet has been sent. */

	#if defined( ipconfigETHERNET_MINIMUM_PACKET_BYTES )
	{
	if( pxNetworkBuffer->xDataLength < ( size_t ) ipconfigETHERNET_MINIMUM_PACKET_BYTES )
	{
	BaseType_t xIndex;

	for( xIndex = ( BaseType_t ) pxNetworkBuffer->xDataLength; xIndex < ( BaseType_t ) ipconfigETHERNET_MINIMUM_PACKET_BYTES; xIndex++ )
	{
	pxNetworkBuffer->pucEthernetBuffer[ xIndex ] = 0u;
	}
	pxNetworkBuffer->xDataLength = ( size_t ) ipconfigETHERNET_MINIMUM_PACKET_BYTES;
	}
	}
	#endif

	xNetworkInterfaceOutput( pxNetworkBuffer, pdTRUE );
	}
	else
	{
	/* The packet can't be sent (DHCP not completed?). Just drop the
	packet. */
	vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );
	}
	}
	/-----------------------------------------------------------/

	BaseType_t xProcessReceivedUDPPacket( NetworkBufferDescriptor_t *pxNetworkBuffer, uint16_t usPort )
	{
	BaseType_t xReturn = pdPASS;
	FreeRTOS_Socket_t *pxSocket;
	configASSERT(pxNetworkBuffer);
	configASSERT(pxNetworkBuffer->pucEthernetBuffer);


	UDPPacket_t pxUDPPacket = (UDPPacket_t ) pxNetworkBuffer->pucEthernetBuffer;

	/* Caller must check for minimum packet size. */
	pxSocket = pxUDPSocketLookup( usPort );

	if( pxSocket )
	{

	/* When refreshing the ARP cache with received UDP packets we must be
	careful; hundreds of broadcast messages may pass and if we're not
	handling them, no use to fill the ARP cache with those IP addresses. */
	vARPRefreshCacheEntry( &( pxUDPPacket->xEthernetHeader.xSourceAddress ), pxUDPPacket->xIPHeader.ulSourceIPAddress );

	#if( ipconfigUSE_CALLBACKS == 1 )
	{
	/* Did the owner of this socket register a reception handler ? */
	if( ipconfigIS_VALID_PROG_ADDRESS( pxSocket->u.xUDP.pxHandleReceive ) )
	{
	struct freertos_sockaddr xSourceAddress, destinationAddress;
	void pcData = ( void ) &( pxNetworkBuffer->pucEthernetBuffer[ ipUDP_PAYLOAD_OFFSET_IPv4 ] );
	FOnUDPReceive_t xHandler = ( FOnUDPReceive_t ) pxSocket->u.xUDP.pxHandleReceive;
	xSourceAddress.sin_port = pxNetworkBuffer->usPort;
	xSourceAddress.sin_addr = pxNetworkBuffer->ulIPAddress;
	destinationAddress.sin_port = usPort;
	destinationAddress.sin_addr = pxUDPPacket->xIPHeader.ulDestinationIPAddress;

	if( xHandler( ( Socket_t ) pxSocket, ( void* ) pcData, ( size_t ) pxNetworkBuffer->xDataLength,
	&xSourceAddress, &destinationAddress ) )
	{
	xReturn = pdFAIL; /* FAIL means that we did not consume or release the buffer */
	}
	}
	}
	#endif /* ipconfigUSE_CALLBACKS */

	#if( ipconfigUDP_MAX_RX_PACKETS > 0 )
	{
	if( xReturn == pdPASS )
	{
	if ( listCURRENT_LIST_LENGTH( &( pxSocket->u.xUDP.xWaitingPacketsList ) ) >= pxSocket->u.xUDP.uxMaxPackets )
	{
	FreeRTOS_debug_printf( ( "xProcessReceivedUDPPacket: buffer full %ld >= %ld port %u\n",
	listCURRENT_LIST_LENGTH( &( pxSocket->u.xUDP.xWaitingPacketsList ) ),
	pxSocket->u.xUDP.uxMaxPackets, pxSocket->usLocalPort ) );
	xReturn = pdFAIL; /* we did not consume or release the buffer */
	}
	}
	}
	#endif

	if( xReturn == pdPASS )
	{
	vTaskSuspendAll();
	{
	if( xReturn == pdPASS )
	{
	taskENTER_CRITICAL();
	{
	/* Add the network packet to the list of packets to be
	processed by the socket. */
	vListInsertEnd( &( pxSocket->u.xUDP.xWaitingPacketsList ), &( pxNetworkBuffer->xBufferListItem ) );
	}
	taskEXIT_CRITICAL();
	}
	}
	xTaskResumeAll();

	/* Set the socket's receive event */
	if( pxSocket->xEventGroup != NULL )
	{
	xEventGroupSetBits( pxSocket->xEventGroup, eSOCKET_RECEIVE );
	}

	#if( ipconfigSUPPORT_SELECT_FUNCTION == 1 )
	{
	if( ( pxSocket->pxSocketSet != NULL ) && ( ( pxSocket->xSelectBits & eSELECT_READ ) != 0 ) )
	{
	xEventGroupSetBits( pxSocket->pxSocketSet->xSelectGroup, eSELECT_READ );
	}
	}
	#endif

	#if( ipconfigSOCKET_HAS_USER_SEMAPHORE == 1 )
	{
	if( pxSocket->pxUserSemaphore != NULL )
	{
	xSemaphoreGive( pxSocket->pxUserSemaphore );
	}
	}
	#endif

	#if( ipconfigUSE_DHCP == 1 )
	{
	if( xIsDHCPSocket( pxSocket ) )
	{
	xSendEventToIPTask( eDHCPEvent );
	}
	}
	#endif
	}
	}
	else
	{
	/* There is no socket listening to the target port, but still it might
	be for this node. */

	#if( ipconfigUSE_DNS == 1 ) && ( ipconfigDNS_USE_CALLBACKS == 1 )
	/* A DNS reply, check for the source port. Although the DNS client
	does open a UDP socket to send a messages, this socket will be
	closed after a short timeout. Messages that come late (after the
	socket is closed) will be treated here. */
	if( FreeRTOS_ntohs( pxUDPPacket->xUDPHeader.usSourcePort ) == ipDNS_PORT )
	{
	vARPRefreshCacheEntry( &( pxUDPPacket->xEthernetHeader.xSourceAddress ), pxUDPPacket->xIPHeader.ulSourceIPAddress );
	xReturn = ( BaseType_t )ulDNSHandlePacket( pxNetworkBuffer );
	}
	else
	#endif

	#if( ipconfigUSE_LLMNR == 1 )
	/* a LLMNR request, check for the destination port. */
	if( ( usPort == FreeRTOS_ntohs( ipLLMNR_PORT ) ) \|\|
	( pxUDPPacket->xUDPHeader.usSourcePort == FreeRTOS_ntohs( ipLLMNR_PORT ) ) )
	{
	vARPRefreshCacheEntry( &( pxUDPPacket->xEthernetHeader.xSourceAddress ), pxUDPPacket->xIPHeader.ulSourceIPAddress );
	xReturn = ( BaseType_t )ulDNSHandlePacket( pxNetworkBuffer );
	}
	else
	#endif /* ipconfigUSE_LLMNR */

	#if( ipconfigUSE_NBNS == 1 )
	/* a NetBIOS request, check for the destination port */
	if( ( usPort == FreeRTOS_ntohs( ipNBNS_PORT ) ) \|\|
	( pxUDPPacket->xUDPHeader.usSourcePort == FreeRTOS_ntohs( ipNBNS_PORT ) ) )
	{
	vARPRefreshCacheEntry( &( pxUDPPacket->xEthernetHeader.xSourceAddress ), pxUDPPacket->xIPHeader.ulSourceIPAddress );
	xReturn = ( BaseType_t )ulNBNSHandlePacket( pxNetworkBuffer );
	}
	else
	#endif /* ipconfigUSE_NBNS */
	{
	xReturn = pdFAIL;
	}
	}

	return xReturn;
	}
	/-----------------------------------------------------------/