]> git.sur5r.net Git - freertos/blobdiff - FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/portable/BufferManagement/BufferAllocation_2.c
Update version number in readiness for V10.3.0 release. Sync SVN with reviewed releas...
[freertos] / FreeRTOS-Plus / Source / FreeRTOS-Plus-TCP / portable / BufferManagement / BufferAllocation_2.c
index e008da07a5fc7790073f7d0c245ea4c2e6a048f1..51f5410a40592fb9b093c0c13a03f90b20bea903 100644 (file)
-/*\r
- * FreeRTOS+TCP V2.0.11\r
- * Copyright (C) 2017 Amazon.com, Inc. or its affiliates.  All Rights Reserved.\r
- *\r
- * Permission is hereby granted, free of charge, to any person obtaining a copy of\r
- * this software and associated documentation files (the "Software"), to deal in\r
- * the Software without restriction, including without limitation the rights to\r
- * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of\r
- * the Software, and to permit persons to whom the Software is furnished to do so,\r
- * subject to the following conditions:\r
- *\r
- * The above copyright notice and this permission notice shall be included in all\r
- * copies or substantial portions of the Software.\r
- *\r
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\r
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS\r
- * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR\r
- * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER\r
- * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN\r
- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
- *\r
- * http://www.FreeRTOS.org\r
- * http://aws.amazon.com/freertos\r
- *\r
- * 1 tab == 4 spaces!\r
- */\r
-\r
-/******************************************************************************\r
- *\r
- * See the following web page for essential buffer allocation scheme usage and\r
- * configuration details:\r
- * http://www.FreeRTOS.org/FreeRTOS-Plus/FreeRTOS_Plus_TCP/Embedded_Ethernet_Buffer_Management.html\r
- *\r
- ******************************************************************************/\r
-\r
-/* THIS FILE SHOULD NOT BE USED IF THE PROJECT INCLUDES A MEMORY ALLOCATOR\r
-THAT WILL FRAGMENT THE HEAP MEMORY.  For example, heap_2 must not be used,\r
-heap_4 can be used. */\r
-\r
-\r
-/* Standard includes. */\r
-#include <stdint.h>\r
-\r
-/* FreeRTOS includes. */\r
-#include "FreeRTOS.h"\r
-#include "task.h"\r
-#include "semphr.h"\r
-\r
-/* FreeRTOS+TCP includes. */\r
-#include "FreeRTOS_IP.h"\r
-#include "FreeRTOS_UDP_IP.h"\r
-#include "FreeRTOS_IP_Private.h"\r
-#include "NetworkInterface.h"\r
-#include "NetworkBufferManagement.h"\r
-\r
-/* The obtained network buffer must be large enough to hold a packet that might\r
-replace the packet that was requested to be sent. */\r
-#if ipconfigUSE_TCP == 1\r
-       #define baMINIMAL_BUFFER_SIZE           sizeof( TCPPacket_t )\r
-#else\r
-       #define baMINIMAL_BUFFER_SIZE           sizeof( ARPPacket_t )\r
-#endif /* ipconfigUSE_TCP == 1 */\r
-\r
-/*_RB_ This is too complex not to have an explanation. */\r
-#if defined( ipconfigETHERNET_MINIMUM_PACKET_BYTES )\r
-       #define ASSERT_CONCAT_(a, b) a##b\r
-       #define ASSERT_CONCAT(a, b) ASSERT_CONCAT_(a, b)\r
-       #define STATIC_ASSERT(e) \\r
-               ;enum { ASSERT_CONCAT(assert_line_, __LINE__) = 1/(!!(e)) }\r
-\r
-       STATIC_ASSERT( ipconfigETHERNET_MINIMUM_PACKET_BYTES <= baMINIMAL_BUFFER_SIZE );\r
-#endif\r
-\r
-/* A list of free (available) NetworkBufferDescriptor_t structures. */\r
-static List_t xFreeBuffersList;\r
-\r
-/* Some statistics about the use of buffers. */\r
-static size_t uxMinimumFreeNetworkBuffers;\r
-\r
-/* Declares the pool of NetworkBufferDescriptor_t structures that are available\r
-to the system.  All the network buffers referenced from xFreeBuffersList exist\r
-in this array.  The array is not accessed directly except during initialisation,\r
-when the xFreeBuffersList is filled (as all the buffers are free when the system\r
-is booted). */\r
-static NetworkBufferDescriptor_t xNetworkBufferDescriptors[ ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS ];\r
-\r
-/* This constant is defined as false to let FreeRTOS_TCP_IP.c know that the\r
-network buffers have a variable size: resizing may be necessary */\r
-const BaseType_t xBufferAllocFixedSize = pdFALSE;\r
-\r
-/* The semaphore used to obtain network buffers. */\r
-static SemaphoreHandle_t xNetworkBufferSemaphore = NULL;\r
-\r
-/*-----------------------------------------------------------*/\r
-\r
-BaseType_t xNetworkBuffersInitialise( void )\r
-{\r
-BaseType_t xReturn, x;\r
-\r
-       /* Only initialise the buffers and their associated kernel objects if they\r
-       have not been initialised before. */\r
-       if( xNetworkBufferSemaphore == NULL )\r
-       {\r
-               xNetworkBufferSemaphore = xSemaphoreCreateCounting( ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS, ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS );\r
-               configASSERT( xNetworkBufferSemaphore );\r
-\r
-               if( xNetworkBufferSemaphore != NULL )\r
-               {\r
-                       #if ( configQUEUE_REGISTRY_SIZE > 0 )\r
-                       {\r
-                               vQueueAddToRegistry( xNetworkBufferSemaphore, "NetBufSem" );\r
-                       }\r
-                       #endif /* configQUEUE_REGISTRY_SIZE */\r
-\r
-                       /* If the trace recorder code is included name the semaphore for viewing\r
-                       in FreeRTOS+Trace.  */\r
-                       #if( ipconfigINCLUDE_EXAMPLE_FREERTOS_PLUS_TRACE_CALLS == 1 )\r
-                       {\r
-                               extern QueueHandle_t xNetworkEventQueue;\r
-                               vTraceSetQueueName( xNetworkEventQueue, "IPStackEvent" );\r
-                               vTraceSetQueueName( xNetworkBufferSemaphore, "NetworkBufferCount" );\r
-                       }\r
-                       #endif /*  ipconfigINCLUDE_EXAMPLE_FREERTOS_PLUS_TRACE_CALLS == 1 */\r
-\r
-                       vListInitialise( &xFreeBuffersList );\r
-\r
-                       /* Initialise all the network buffers.  No storage is allocated to\r
-                       the buffers yet. */\r
-                       for( x = 0; x < ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS; x++ )\r
-                       {\r
-                               /* Initialise and set the owner of the buffer list items. */\r
-                               xNetworkBufferDescriptors[ x ].pucEthernetBuffer = NULL;\r
-                               vListInitialiseItem( &( xNetworkBufferDescriptors[ x ].xBufferListItem ) );\r
-                               listSET_LIST_ITEM_OWNER( &( xNetworkBufferDescriptors[ x ].xBufferListItem ), &xNetworkBufferDescriptors[ x ] );\r
-\r
-                               /* Currently, all buffers are available for use. */\r
-                               vListInsert( &xFreeBuffersList, &( xNetworkBufferDescriptors[ x ].xBufferListItem ) );\r
-                       }\r
-\r
-                       uxMinimumFreeNetworkBuffers = ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS;\r
-               }\r
-       }\r
-\r
-       if( xNetworkBufferSemaphore == NULL )\r
-       {\r
-               xReturn = pdFAIL;\r
-       }\r
-       else\r
-       {\r
-               xReturn = pdPASS;\r
-       }\r
-\r
-       return xReturn;\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
-uint8_t *pucGetNetworkBuffer( size_t *pxRequestedSizeBytes )\r
-{\r
-uint8_t *pucEthernetBuffer;\r
-size_t xSize = *pxRequestedSizeBytes;\r
-\r
-       if( xSize < baMINIMAL_BUFFER_SIZE )\r
-       {\r
-               /* Buffers must be at least large enough to hold a TCP-packet with\r
-               headers, or an ARP packet, in case TCP is not included. */\r
-               xSize = baMINIMAL_BUFFER_SIZE;\r
-       }\r
-\r
-       /* Round up xSize to the nearest multiple of N bytes,\r
-       where N equals 'sizeof( size_t )'. */\r
-       if( ( xSize & ( sizeof( size_t ) - 1u ) ) != 0u )\r
-       {\r
-               xSize = ( xSize | ( sizeof( size_t ) - 1u ) ) + 1u;\r
-       }\r
-       *pxRequestedSizeBytes = xSize;\r
-\r
-       /* Allocate a buffer large enough to store the requested Ethernet frame size\r
-       and a pointer to a network buffer structure (hence the addition of\r
-       ipBUFFER_PADDING bytes). */\r
-       pucEthernetBuffer = ( uint8_t * ) pvPortMalloc( xSize + ipBUFFER_PADDING );\r
-       configASSERT( pucEthernetBuffer );\r
-\r
-       if( pucEthernetBuffer != NULL )\r
-       {\r
-               /* Enough space is left at the start of the buffer to place a pointer to\r
-               the network buffer structure that references this Ethernet buffer.\r
-               Return a pointer to the start of the Ethernet buffer itself. */\r
-               pucEthernetBuffer += ipBUFFER_PADDING;\r
-       }\r
-\r
-       return pucEthernetBuffer;\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
-void vReleaseNetworkBuffer( uint8_t *pucEthernetBuffer )\r
-{\r
-       /* There is space before the Ethernet buffer in which a pointer to the\r
-       network buffer that references this Ethernet buffer is stored.  Remove the\r
-       space before freeing the buffer. */\r
-       if( pucEthernetBuffer != NULL )\r
-       {\r
-               pucEthernetBuffer -= ipBUFFER_PADDING;\r
-               vPortFree( ( void * ) pucEthernetBuffer );\r
-       }\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
-NetworkBufferDescriptor_t *pxGetNetworkBufferWithDescriptor( size_t xRequestedSizeBytes, TickType_t xBlockTimeTicks )\r
-{\r
-NetworkBufferDescriptor_t *pxReturn = NULL;\r
-size_t uxCount;\r
-\r
-       if( xNetworkBufferSemaphore != NULL )\r
-       {\r
-               if( ( xRequestedSizeBytes != 0u ) && ( xRequestedSizeBytes < ( size_t ) baMINIMAL_BUFFER_SIZE ) )\r
-               {\r
-                       /* ARP packets can replace application packets, so the storage must be\r
-                       at least large enough to hold an ARP. */\r
-                       xRequestedSizeBytes = baMINIMAL_BUFFER_SIZE;\r
-               }\r
-\r
-               /* Add 2 bytes to xRequestedSizeBytes and round up xRequestedSizeBytes\r
-               to the nearest multiple of N bytes, where N equals 'sizeof( size_t )'. */\r
-               xRequestedSizeBytes += 2u;\r
-               if( ( xRequestedSizeBytes & ( sizeof( size_t ) - 1u ) ) != 0u )\r
-               {\r
-                       xRequestedSizeBytes = ( xRequestedSizeBytes | ( sizeof( size_t ) - 1u ) ) + 1u;\r
-               }\r
-\r
-               /* If there is a semaphore available, there is a network buffer available. */\r
-               if( xSemaphoreTake( xNetworkBufferSemaphore, xBlockTimeTicks ) == pdPASS )\r
-               {\r
-                       /* Protect the structure as it is accessed from tasks and interrupts. */\r
-                       taskENTER_CRITICAL();\r
-                       {\r
-                               pxReturn = ( NetworkBufferDescriptor_t * ) listGET_OWNER_OF_HEAD_ENTRY( &xFreeBuffersList );\r
-                               uxListRemove( &( pxReturn->xBufferListItem ) );\r
-                       }\r
-                       taskEXIT_CRITICAL();\r
-\r
-                       /* Reading UBaseType_t, no critical section needed. */\r
-                       uxCount = listCURRENT_LIST_LENGTH( &xFreeBuffersList );\r
-\r
-                       if( uxMinimumFreeNetworkBuffers > uxCount )\r
-                       {\r
-                               uxMinimumFreeNetworkBuffers = uxCount;\r
-                       }\r
-\r
-                       /* Allocate storage of exactly the requested size to the buffer. */\r
-                       configASSERT( pxReturn->pucEthernetBuffer == NULL );\r
-                       if( xRequestedSizeBytes > 0 )\r
-                       {\r
-                               /* Extra space is obtained so a pointer to the network buffer can\r
-                               be stored at the beginning of the buffer. */\r
-                               pxReturn->pucEthernetBuffer = ( uint8_t * ) pvPortMalloc( xRequestedSizeBytes + ipBUFFER_PADDING );\r
-\r
-                               if( pxReturn->pucEthernetBuffer == NULL )\r
-                               {\r
-                                       /* The attempt to allocate storage for the buffer payload failed,\r
-                                       so the network buffer structure cannot be used and must be\r
-                                       released. */\r
-                                       vReleaseNetworkBufferAndDescriptor( pxReturn );\r
-                                       pxReturn = NULL;\r
-                               }\r
-                               else\r
-                               {\r
-                                       /* Store a pointer to the network buffer structure in the\r
-                                       buffer storage area, then move the buffer pointer on past the\r
-                                       stored pointer so the pointer value is not overwritten by the\r
-                                       application when the buffer is used. */\r
-                                       *( ( NetworkBufferDescriptor_t ** ) ( pxReturn->pucEthernetBuffer ) ) = pxReturn;\r
-                                       pxReturn->pucEthernetBuffer += ipBUFFER_PADDING;\r
-\r
-                                       /* Store the actual size of the allocated buffer, which may be\r
-                                       greater than the original requested size. */\r
-                                       pxReturn->xDataLength = xRequestedSizeBytes;\r
-\r
-                                       #if( ipconfigUSE_LINKED_RX_MESSAGES != 0 )\r
-                                       {\r
-                                               /* make sure the buffer is not linked */\r
-                                               pxReturn->pxNextBuffer = NULL;\r
-                                       }\r
-                                       #endif /* ipconfigUSE_LINKED_RX_MESSAGES */\r
-                               }\r
-                       }\r
-                       else\r
-                       {\r
-                               /* A descriptor is being returned without an associated buffer being\r
-                               allocated. */\r
-                       }\r
-               }\r
-       }\r
-\r
-       if( pxReturn == NULL )\r
-       {\r
-               iptraceFAILED_TO_OBTAIN_NETWORK_BUFFER();\r
-       }\r
-       else\r
-       {\r
-               iptraceNETWORK_BUFFER_OBTAINED( pxReturn );\r
-       }\r
-\r
-       return pxReturn;\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
-void vReleaseNetworkBufferAndDescriptor( NetworkBufferDescriptor_t * const pxNetworkBuffer )\r
-{\r
-BaseType_t xListItemAlreadyInFreeList;\r
-\r
-       /* Ensure the buffer is returned to the list of free buffers before the\r
-       counting semaphore is 'given' to say a buffer is available.  Release the\r
-       storage allocated to the buffer payload.  THIS FILE SHOULD NOT BE USED\r
-       IF THE PROJECT INCLUDES A MEMORY ALLOCATOR THAT WILL FRAGMENT THE HEAP\r
-       MEMORY.  For example, heap_2 must not be used, heap_4 can be used. */\r
-       vReleaseNetworkBuffer( pxNetworkBuffer->pucEthernetBuffer );\r
-       pxNetworkBuffer->pucEthernetBuffer = NULL;\r
-\r
-       taskENTER_CRITICAL();\r
-       {\r
-               xListItemAlreadyInFreeList = listIS_CONTAINED_WITHIN( &xFreeBuffersList, &( pxNetworkBuffer->xBufferListItem ) );\r
-\r
-               if( xListItemAlreadyInFreeList == pdFALSE )\r
-               {\r
-                       vListInsertEnd( &xFreeBuffersList, &( pxNetworkBuffer->xBufferListItem ) );\r
-               }\r
-       }\r
-       taskEXIT_CRITICAL();\r
-\r
-       /*\r
-        * Update the network state machine, unless the program fails to release its 'xNetworkBufferSemaphore'.\r
-        * The program should only try to release its semaphore if 'xListItemAlreadyInFreeList' is false.\r
-        */\r
-       if( xListItemAlreadyInFreeList == pdFALSE )\r
-       {\r
-               if ( xSemaphoreGive( xNetworkBufferSemaphore ) == pdTRUE )\r
-               {\r
-                       iptraceNETWORK_BUFFER_RELEASED( pxNetworkBuffer );\r
-               }\r
-       }\r
-       else\r
-       {\r
-               iptraceNETWORK_BUFFER_RELEASED( pxNetworkBuffer );\r
-       }\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
-/*\r
- * Returns the number of free network buffers\r
- */\r
-UBaseType_t uxGetNumberOfFreeNetworkBuffers( void )\r
-{\r
-       return listCURRENT_LIST_LENGTH( &xFreeBuffersList );\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
-UBaseType_t uxGetMinimumFreeNetworkBuffers( void )\r
-{\r
-       return uxMinimumFreeNetworkBuffers;\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
-NetworkBufferDescriptor_t *pxResizeNetworkBufferWithDescriptor( NetworkBufferDescriptor_t * pxNetworkBuffer, size_t xNewSizeBytes )\r
-{\r
-size_t xOriginalLength;\r
-uint8_t *pucBuffer;\r
-\r
-       xOriginalLength = pxNetworkBuffer->xDataLength + ipBUFFER_PADDING;\r
-       xNewSizeBytes = xNewSizeBytes + ipBUFFER_PADDING;\r
-\r
-       pucBuffer = pucGetNetworkBuffer( &( xNewSizeBytes ) );\r
-\r
-       if( pucBuffer == NULL )\r
-       {\r
-               /* In case the allocation fails, return NULL. */\r
-               pxNetworkBuffer = NULL;\r
-       }\r
-       else\r
-       {\r
-               pxNetworkBuffer->xDataLength = xNewSizeBytes;\r
-               if( xNewSizeBytes > xOriginalLength )\r
-               {\r
-                       xNewSizeBytes = xOriginalLength;\r
-               }\r
-\r
-               memcpy( pucBuffer - ipBUFFER_PADDING, pxNetworkBuffer->pucEthernetBuffer - ipBUFFER_PADDING, xNewSizeBytes );\r
-               vReleaseNetworkBuffer( pxNetworkBuffer->pucEthernetBuffer );\r
-               pxNetworkBuffer->pucEthernetBuffer = pucBuffer;\r
-       }\r
-\r
-       return pxNetworkBuffer;\r
-}\r
-\r
+/*
+ * FreeRTOS+TCP V2.0.11
+ * 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://www.FreeRTOS.org
+ * http://aws.amazon.com/freertos
+ *
+ * 1 tab == 4 spaces!
+ */
+
+/******************************************************************************
+ *
+ * See the following web page for essential buffer allocation scheme usage and
+ * configuration details:
+ * http://www.FreeRTOS.org/FreeRTOS-Plus/FreeRTOS_Plus_TCP/Embedded_Ethernet_Buffer_Management.html
+ *
+ ******************************************************************************/
+
+/* THIS FILE SHOULD NOT BE USED IF THE PROJECT INCLUDES A MEMORY ALLOCATOR
+THAT WILL FRAGMENT THE HEAP MEMORY.  For example, heap_2 must not be used,
+heap_4 can be used. */
+
+
+/* Standard includes. */
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+#include "semphr.h"
+
+/* FreeRTOS+TCP includes. */
+#include "FreeRTOS_IP.h"
+#include "FreeRTOS_UDP_IP.h"
+#include "FreeRTOS_IP_Private.h"
+#include "NetworkInterface.h"
+#include "NetworkBufferManagement.h"
+
+/* The obtained network buffer must be large enough to hold a packet that might
+replace the packet that was requested to be sent. */
+#if ipconfigUSE_TCP == 1
+       #define baMINIMAL_BUFFER_SIZE           sizeof( TCPPacket_t )
+#else
+       #define baMINIMAL_BUFFER_SIZE           sizeof( ARPPacket_t )
+#endif /* ipconfigUSE_TCP == 1 */
+
+/*_RB_ This is too complex not to have an explanation. */
+#if defined( ipconfigETHERNET_MINIMUM_PACKET_BYTES )
+       #define ASSERT_CONCAT_(a, b) a##b
+       #define ASSERT_CONCAT(a, b) ASSERT_CONCAT_(a, b)
+       #define STATIC_ASSERT(e) \
+               ;enum { ASSERT_CONCAT(assert_line_, __LINE__) = 1/(!!(e)) }
+
+       STATIC_ASSERT( ipconfigETHERNET_MINIMUM_PACKET_BYTES <= baMINIMAL_BUFFER_SIZE );
+#endif
+
+/* A list of free (available) NetworkBufferDescriptor_t structures. */
+static List_t xFreeBuffersList;
+
+/* Some statistics about the use of buffers. */
+static size_t uxMinimumFreeNetworkBuffers;
+
+/* Declares the pool of NetworkBufferDescriptor_t structures that are available
+to the system.  All the network buffers referenced from xFreeBuffersList exist
+in this array.  The array is not accessed directly except during initialisation,
+when the xFreeBuffersList is filled (as all the buffers are free when the system
+is booted). */
+static NetworkBufferDescriptor_t xNetworkBufferDescriptors[ ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS ];
+
+/* This constant is defined as false to let FreeRTOS_TCP_IP.c know that the
+network buffers have a variable size: resizing may be necessary */
+const BaseType_t xBufferAllocFixedSize = pdFALSE;
+
+/* The semaphore used to obtain network buffers. */
+static SemaphoreHandle_t xNetworkBufferSemaphore = NULL;
+
+/*-----------------------------------------------------------*/
+
+BaseType_t xNetworkBuffersInitialise( void )
+{
+BaseType_t xReturn, x;
+
+       /* Only initialise the buffers and their associated kernel objects if they
+       have not been initialised before. */
+       if( xNetworkBufferSemaphore == NULL )
+       {
+               xNetworkBufferSemaphore = xSemaphoreCreateCounting( ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS, ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS );
+               configASSERT( xNetworkBufferSemaphore );
+
+               if( xNetworkBufferSemaphore != NULL )
+               {
+                       #if ( configQUEUE_REGISTRY_SIZE > 0 )
+                       {
+                               vQueueAddToRegistry( xNetworkBufferSemaphore, "NetBufSem" );
+                       }
+                       #endif /* configQUEUE_REGISTRY_SIZE */
+
+                       /* If the trace recorder code is included name the semaphore for viewing
+                       in FreeRTOS+Trace.  */
+                       #if( ipconfigINCLUDE_EXAMPLE_FREERTOS_PLUS_TRACE_CALLS == 1 )
+                       {
+                               extern QueueHandle_t xNetworkEventQueue;
+                               vTraceSetQueueName( xNetworkEventQueue, "IPStackEvent" );
+                               vTraceSetQueueName( xNetworkBufferSemaphore, "NetworkBufferCount" );
+                       }
+                       #endif /*  ipconfigINCLUDE_EXAMPLE_FREERTOS_PLUS_TRACE_CALLS == 1 */
+
+                       vListInitialise( &xFreeBuffersList );
+
+                       /* Initialise all the network buffers.  No storage is allocated to
+                       the buffers yet. */
+                       for( x = 0; x < ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS; x++ )
+                       {
+                               /* Initialise and set the owner of the buffer list items. */
+                               xNetworkBufferDescriptors[ x ].pucEthernetBuffer = NULL;
+                               vListInitialiseItem( &( xNetworkBufferDescriptors[ x ].xBufferListItem ) );
+                               listSET_LIST_ITEM_OWNER( &( xNetworkBufferDescriptors[ x ].xBufferListItem ), &xNetworkBufferDescriptors[ x ] );
+
+                               /* Currently, all buffers are available for use. */
+                               vListInsert( &xFreeBuffersList, &( xNetworkBufferDescriptors[ x ].xBufferListItem ) );
+                       }
+
+                       uxMinimumFreeNetworkBuffers = ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS;
+               }
+       }
+
+       if( xNetworkBufferSemaphore == NULL )
+       {
+               xReturn = pdFAIL;
+       }
+       else
+       {
+               xReturn = pdPASS;
+       }
+
+       return xReturn;
+}
+/*-----------------------------------------------------------*/
+
+uint8_t *pucGetNetworkBuffer( size_t *pxRequestedSizeBytes )
+{
+uint8_t *pucEthernetBuffer;
+size_t xSize = *pxRequestedSizeBytes;
+
+       if( xSize < baMINIMAL_BUFFER_SIZE )
+       {
+               /* Buffers must be at least large enough to hold a TCP-packet with
+               headers, or an ARP packet, in case TCP is not included. */
+               xSize = baMINIMAL_BUFFER_SIZE;
+       }
+
+       /* Round up xSize to the nearest multiple of N bytes,
+       where N equals 'sizeof( size_t )'. */
+       if( ( xSize & ( sizeof( size_t ) - 1u ) ) != 0u )
+       {
+               xSize = ( xSize | ( sizeof( size_t ) - 1u ) ) + 1u;
+       }
+       *pxRequestedSizeBytes = xSize;
+
+       /* Allocate a buffer large enough to store the requested Ethernet frame size
+       and a pointer to a network buffer structure (hence the addition of
+       ipBUFFER_PADDING bytes). */
+       pucEthernetBuffer = ( uint8_t * ) pvPortMalloc( xSize + ipBUFFER_PADDING );
+       configASSERT( pucEthernetBuffer );
+
+       if( pucEthernetBuffer != NULL )
+       {
+               /* Enough space is left at the start of the buffer to place a pointer to
+               the network buffer structure that references this Ethernet buffer.
+               Return a pointer to the start of the Ethernet buffer itself. */
+               pucEthernetBuffer += ipBUFFER_PADDING;
+       }
+
+       return pucEthernetBuffer;
+}
+/*-----------------------------------------------------------*/
+
+void vReleaseNetworkBuffer( uint8_t *pucEthernetBuffer )
+{
+       /* There is space before the Ethernet buffer in which a pointer to the
+       network buffer that references this Ethernet buffer is stored.  Remove the
+       space before freeing the buffer. */
+       if( pucEthernetBuffer != NULL )
+       {
+               pucEthernetBuffer -= ipBUFFER_PADDING;
+               vPortFree( ( void * ) pucEthernetBuffer );
+       }
+}
+/*-----------------------------------------------------------*/
+
+NetworkBufferDescriptor_t *pxGetNetworkBufferWithDescriptor( size_t xRequestedSizeBytes, TickType_t xBlockTimeTicks )
+{
+NetworkBufferDescriptor_t *pxReturn = NULL;
+size_t uxCount;
+
+       if( xNetworkBufferSemaphore != NULL )
+       {
+               if( ( xRequestedSizeBytes != 0u ) && ( xRequestedSizeBytes < ( size_t ) baMINIMAL_BUFFER_SIZE ) )
+               {
+                       /* ARP packets can replace application packets, so the storage must be
+                       at least large enough to hold an ARP. */
+                       xRequestedSizeBytes = baMINIMAL_BUFFER_SIZE;
+               }
+
+               /* Add 2 bytes to xRequestedSizeBytes and round up xRequestedSizeBytes
+               to the nearest multiple of N bytes, where N equals 'sizeof( size_t )'. */
+               xRequestedSizeBytes += 2u;
+               if( ( xRequestedSizeBytes & ( sizeof( size_t ) - 1u ) ) != 0u )
+               {
+                       xRequestedSizeBytes = ( xRequestedSizeBytes | ( sizeof( size_t ) - 1u ) ) + 1u;
+               }
+
+               /* If there is a semaphore available, there is a network buffer available. */
+               if( xSemaphoreTake( xNetworkBufferSemaphore, xBlockTimeTicks ) == pdPASS )
+               {
+                       /* Protect the structure as it is accessed from tasks and interrupts. */
+                       taskENTER_CRITICAL();
+                       {
+                               pxReturn = ( NetworkBufferDescriptor_t * ) listGET_OWNER_OF_HEAD_ENTRY( &xFreeBuffersList );
+                               uxListRemove( &( pxReturn->xBufferListItem ) );
+                       }
+                       taskEXIT_CRITICAL();
+
+                       /* Reading UBaseType_t, no critical section needed. */
+                       uxCount = listCURRENT_LIST_LENGTH( &xFreeBuffersList );
+
+                       if( uxMinimumFreeNetworkBuffers > uxCount )
+                       {
+                               uxMinimumFreeNetworkBuffers = uxCount;
+                       }
+
+                       /* Allocate storage of exactly the requested size to the buffer. */
+                       configASSERT( pxReturn->pucEthernetBuffer == NULL );
+                       if( xRequestedSizeBytes > 0 )
+                       {
+                               /* Extra space is obtained so a pointer to the network buffer can
+                               be stored at the beginning of the buffer. */
+                               pxReturn->pucEthernetBuffer = ( uint8_t * ) pvPortMalloc( xRequestedSizeBytes + ipBUFFER_PADDING );
+
+                               if( pxReturn->pucEthernetBuffer == NULL )
+                               {
+                                       /* The attempt to allocate storage for the buffer payload failed,
+                                       so the network buffer structure cannot be used and must be
+                                       released. */
+                                       vReleaseNetworkBufferAndDescriptor( pxReturn );
+                                       pxReturn = NULL;
+                               }
+                               else
+                               {
+                                       /* Store a pointer to the network buffer structure in the
+                                       buffer storage area, then move the buffer pointer on past the
+                                       stored pointer so the pointer value is not overwritten by the
+                                       application when the buffer is used. */
+                                       *( ( NetworkBufferDescriptor_t ** ) ( pxReturn->pucEthernetBuffer ) ) = pxReturn;
+                                       pxReturn->pucEthernetBuffer += ipBUFFER_PADDING;
+
+                                       /* Store the actual size of the allocated buffer, which may be
+                                       greater than the original requested size. */
+                                       pxReturn->xDataLength = xRequestedSizeBytes;
+
+                                       #if( ipconfigUSE_LINKED_RX_MESSAGES != 0 )
+                                       {
+                                               /* make sure the buffer is not linked */
+                                               pxReturn->pxNextBuffer = NULL;
+                                       }
+                                       #endif /* ipconfigUSE_LINKED_RX_MESSAGES */
+                               }
+                       }
+                       else
+                       {
+                               /* A descriptor is being returned without an associated buffer being
+                               allocated. */
+                       }
+               }
+       }
+
+       if( pxReturn == NULL )
+       {
+               iptraceFAILED_TO_OBTAIN_NETWORK_BUFFER();
+       }
+       else
+       {
+               iptraceNETWORK_BUFFER_OBTAINED( pxReturn );
+       }
+
+       return pxReturn;
+}
+/*-----------------------------------------------------------*/
+
+void vReleaseNetworkBufferAndDescriptor( NetworkBufferDescriptor_t * const pxNetworkBuffer )
+{
+BaseType_t xListItemAlreadyInFreeList;
+
+       /* Ensure the buffer is returned to the list of free buffers before the
+       counting semaphore is 'given' to say a buffer is available.  Release the
+       storage allocated to the buffer payload.  THIS FILE SHOULD NOT BE USED
+       IF THE PROJECT INCLUDES A MEMORY ALLOCATOR THAT WILL FRAGMENT THE HEAP
+       MEMORY.  For example, heap_2 must not be used, heap_4 can be used. */
+       vReleaseNetworkBuffer( pxNetworkBuffer->pucEthernetBuffer );
+       pxNetworkBuffer->pucEthernetBuffer = NULL;
+
+       taskENTER_CRITICAL();
+       {
+               xListItemAlreadyInFreeList = listIS_CONTAINED_WITHIN( &xFreeBuffersList, &( pxNetworkBuffer->xBufferListItem ) );
+
+               if( xListItemAlreadyInFreeList == pdFALSE )
+               {
+                       vListInsertEnd( &xFreeBuffersList, &( pxNetworkBuffer->xBufferListItem ) );
+               }
+       }
+       taskEXIT_CRITICAL();
+
+       /*
+        * Update the network state machine, unless the program fails to release its 'xNetworkBufferSemaphore'.
+        * The program should only try to release its semaphore if 'xListItemAlreadyInFreeList' is false.
+        */
+       if( xListItemAlreadyInFreeList == pdFALSE )
+       {
+               if ( xSemaphoreGive( xNetworkBufferSemaphore ) == pdTRUE )
+               {
+                       iptraceNETWORK_BUFFER_RELEASED( pxNetworkBuffer );
+               }
+       }
+       else
+       {
+               iptraceNETWORK_BUFFER_RELEASED( pxNetworkBuffer );
+       }
+}
+/*-----------------------------------------------------------*/
+
+/*
+ * Returns the number of free network buffers
+ */
+UBaseType_t uxGetNumberOfFreeNetworkBuffers( void )
+{
+       return listCURRENT_LIST_LENGTH( &xFreeBuffersList );
+}
+/*-----------------------------------------------------------*/
+
+UBaseType_t uxGetMinimumFreeNetworkBuffers( void )
+{
+       return uxMinimumFreeNetworkBuffers;
+}
+/*-----------------------------------------------------------*/
+
+NetworkBufferDescriptor_t *pxResizeNetworkBufferWithDescriptor( NetworkBufferDescriptor_t * pxNetworkBuffer, size_t xNewSizeBytes )
+{
+size_t xOriginalLength;
+uint8_t *pucBuffer;
+
+       xOriginalLength = pxNetworkBuffer->xDataLength + ipBUFFER_PADDING;
+       xNewSizeBytes = xNewSizeBytes + ipBUFFER_PADDING;
+
+       pucBuffer = pucGetNetworkBuffer( &( xNewSizeBytes ) );
+
+       if( pucBuffer == NULL )
+       {
+               /* In case the allocation fails, return NULL. */
+               pxNetworkBuffer = NULL;
+       }
+       else
+       {
+               pxNetworkBuffer->xDataLength = xNewSizeBytes;
+               if( xNewSizeBytes > xOriginalLength )
+               {
+                       xNewSizeBytes = xOriginalLength;
+               }
+
+               memcpy( pucBuffer - ipBUFFER_PADDING, pxNetworkBuffer->pucEthernetBuffer - ipBUFFER_PADDING, xNewSizeBytes );
+               vReleaseNetworkBuffer( pxNetworkBuffer->pucEthernetBuffer );
+               pxNetworkBuffer->pucEthernetBuffer = pucBuffer;
+       }
+
+       return pxNetworkBuffer;
+}
+