git.sur5r.net Git - freertos/blob - FreeRTOS-Plus/Source/FreeRTOS-Plus-UDP/portable/NetworkInterface/WinPCap/NetworkInterface.c

   1 /*\r
   2  * FreeRTOS+UDP V1.0.0 (C) 2013 Real Time Engineers ltd.\r
   3  *\r
   4  * This file is part of the FreeRTOS+UDP distribution.  The FreeRTOS+UDP license\r
   5  * terms are different to the FreeRTOS license terms.\r
   6  *\r
   7  * FreeRTOS+UDP uses a dual license model that allows the software to be used \r
   8  * under a standard GPL open source license, or a commercial license.  The \r
   9  * standard GPL license (unlike the modified GPL license under which FreeRTOS \r
  10  * itself is distributed) requires that all software statically linked with \r
  11  * FreeRTOS+UDP is also distributed under the same GPL V2 license terms.  \r
  12  * Details of both license options follow:\r
  13  *\r
  14  * - Open source licensing -\r
  15  * FreeRTOS+UDP is a free download and may be used, modified, evaluated and\r
  16  * distributed without charge provided the user adheres to version two of the\r
  17  * GNU General Public License (GPL) and does not remove the copyright notice or\r
  18  * this text.  The GPL V2 text is available on the gnu.org web site, and on the\r
  19  * following URL: http://www.FreeRTOS.org/gpl-2.0.txt.\r
  20  *\r
  21  * - Commercial licensing -\r
  22  * Businesses and individuals that for commercial or other reasons cannot comply\r
  23  * with the terms of the GPL V2 license must obtain a commercial license before \r
  24  * incorporating FreeRTOS+UDP into proprietary software for distribution in any \r
  25  * form.  Commercial licenses can be purchased from http://shop.freertos.org/udp \r
  26  * and do not require any source files to be changed.\r
  27  *\r
  28  * FreeRTOS+UDP is distributed in the hope that it will be useful.  You cannot\r
  29  * use FreeRTOS+UDP unless you agree that you use the software 'as is'.\r
  30  * FreeRTOS+UDP is provided WITHOUT ANY WARRANTY; without even the implied\r
  31  * warranties of NON-INFRINGEMENT, MERCHANTABILITY or FITNESS FOR A PARTICULAR\r
  32  * PURPOSE. Real Time Engineers Ltd. disclaims all conditions and terms, be they\r
  33  * implied, expressed, or statutory.\r
  34  *\r
  35  * 1 tab == 4 spaces!\r
  36  *\r
  37  * http://www.FreeRTOS.org\r
  38  * http://www.FreeRTOS.org/udp\r
  39  *\r
  40  */\r
  41 \r
  42 /* WinPCap includes. */\r
  43 #define HAVE_REMOTE\r
  44 #include "pcap.h"\r
  45 \r
  46 /* Standard includes. */\r
  47 #include <stdint.h>\r
  48 \r
  49 /* FreeRTOS includes. */\r
  50 #include "FreeRTOS.h"\r
  51 #include "task.h"\r
  52 #include "queue.h"\r
  53 #include "semphr.h"\r
  54 \r
  55 /* FreeRTOS+UDP includes. */\r
  56 #include "FreeRTOS_UDP_IP.h"\r
  57 #include "FreeRTOS_IP_Private.h"\r
  58 #include "FreeRTOS_Sockets.h"\r
  59 #include "NetworkBufferManagement.h"\r
  60 \r
  61 /* Demo includes. */\r
  62 #include "NetworkInterface.h"\r
  63 \r
  64 /* If ipconfigETHERNET_DRIVER_FILTERS_FRAME_TYPES is set to 1, then the Ethernet\r
  65 driver will filter incoming packets and only pass the stack those packets it\r
  66 considers need processing.  In this case ipCONSIDER_FRAME_FOR_PROCESSING() can\r
  67 be #defined away.  If ipconfigETHERNET_DRIVER_FILTERS_FRAME_TYPES is set to 0\r
  68 then the Ethernet driver will pass all received packets to the stack, and the\r
  69 stack must do the filtering itself.  In this case ipCONSIDER_FRAME_FOR_PROCESSING\r
  70 needs to call eConsiderFrameForProcessing. */\r
  71 #if ipconfigETHERNET_DRIVER_FILTERS_FRAME_TYPES != 1\r
  72         #define ipCONSIDER_FRAME_FOR_PROCESSING( pucEthernetBuffer ) eProcessBuffer\r
  73 #else\r
  74         #define ipCONSIDER_FRAME_FOR_PROCESSING( pucEthernetBuffer ) eConsiderFrameForProcessing( ( pucEthernetBuffer ) )\r
  75 #endif\r
  76 \r
  77 /*-----------------------------------------------------------*/\r
  78 \r
  79 /*\r
  80  * Print out a numbered list of network interfaces that are available on the\r
  81  * host computer.\r
  82  */\r
  83 static pcap_if_t * prvPrintAvailableNetworkInterfaces( void );\r
  84 \r
  85 /*\r
  86  * Open the network interface.  The number of the interface to be opened is set\r
  87  * by the configNETWORK_INTERFACE_TO_USE constant in FreeRTOSConfig.h.\r
  88  */\r
  89 static void prvOpenSelectedNetworkInterface( pcap_if_t *pxAllNetworkInterfaces );\r
  90 \r
  91 /*\r
  92  * Configure the capture filter to allow blocking reads, and to filter out\r
  93  * packets that are not of interest to this demo.\r
  94  */\r
  95 static void prvConfigureCaptureBehaviour( void );\r
  96 \r
  97 /*\r
  98  * A function that simulates Ethernet interrupts by periodically polling the\r
  99  * WinPCap interface for new data.\r
 100  */\r
 101 static void prvInterruptSimulatorTask( void *pvParameters );\r
 102 \r
 103 /* The interface being used by WinPCap. */\r
 104 static pcap_t *pxOpenedInterfaceHandle = NULL;\r
 105 \r
 106 /*-----------------------------------------------------------*/\r
 107 \r
 108 /* Required by the WinPCap library. */\r
 109 static char cErrorBuffer[ PCAP_ERRBUF_SIZE ];\r
 110 \r
 111 /* When statically allocated network buffers are used (as opposed to having\r
 112 the buffer payloads allocated and freed as required) the actual buffer storage\r
 113 areas must be defined in the portable layer.  This is because different\r
 114 microcontrollers have different location, size and alignment requirements.  In\r
 115 this case the network buffers are declared in NetworkInterface.c because, as\r
 116 this file is only used on Windows machines, wasting a few bytes in buffers that\r
 117 never get used does not matter (the buffers will not get used if the dynamic\r
 118 payload allocation file is included in the project). */\r
 119 static uint8_t ucBuffers[ ipconfigNUM_NETWORK_BUFFERS ][ ipTOTAL_ETHERNET_FRAME_SIZE ];\r
 120 \r
 121 /* The queue used to communicate Ethernet events with the IP task. */\r
 122 extern xQueueHandle xNetworkEventQueue;\r
 123 \r
 124 /* Protect the PCAP interface as it is accessed from two tasks (an interrupt\r
 125 simulator is used as real interrupts cannot be obtained from the Ethernet as\r
 126 would normally be the case). */\r
 127 xSemaphoreHandle xPCAPMutex = NULL;\r
 128 \r
 129 /*-----------------------------------------------------------*/\r
 130 \r
 131 portBASE_TYPE xNetworkInterfaceInitialise( void )\r
 132 {\r
 133 portBASE_TYPE xReturn = pdFALSE;\r
 134 pcap_if_t *pxAllNetworkInterfaces;\r
 135 \r
 136         if( xPCAPMutex == NULL )\r
 137         {\r
 138                 xPCAPMutex = xSemaphoreCreateMutex();\r
 139                 configASSERT( xPCAPMutex );\r
 140         }\r
 141 \r
 142         /* Query the computer the simulation is being executed on to find the\r
 143         network interfaces it has installed. */\r
 144         pxAllNetworkInterfaces = prvPrintAvailableNetworkInterfaces();\r
 145 \r
 146         /* Open the network interface.  The number of the interface to be opened is\r
 147         set by the configNETWORK_INTERFACE_TO_USE constant in FreeRTOSConfig.h.\r
 148         Calling this function will set the pxOpenedInterfaceHandle variable.  If,\r
 149         after calling this function, pxOpenedInterfaceHandle is equal to NULL, then\r
 150         the interface could not be opened. */\r
 151         if( pxAllNetworkInterfaces != NULL )\r
 152         {\r
 153                 prvOpenSelectedNetworkInterface( pxAllNetworkInterfaces );\r
 154         }\r
 155 \r
 156         if( pxOpenedInterfaceHandle != NULL )\r
 157         {\r
 158                 xReturn = pdPASS;\r
 159         }\r
 160 \r
 161         return xReturn;\r
 162 }\r
 163 /*-----------------------------------------------------------*/\r
 164 \r
 165 #if updconfigLOOPBACK_ETHERNET_PACKETS == 1\r
 166 \r
 167         portBASE_TYPE xNetworkInterfaceOutput( xNetworkBufferDescriptor_t * const pxNetworkBuffer )\r
 168         {\r
 169         xEthernetHeader_t *pxEthernetHeader;\r
 170         xIPStackEvent_t xRxEvent = { eEthernetRxEvent, NULL };\r
 171         extern uint8_t xDefaultPartUDPPacketHeader[];\r
 172         static const xMACAddress_t xBroadcastMACAddress = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };\r
 173         portBASE_TYPE xCanLoopback;\r
 174 \r
 175                 pxEthernetHeader = ( xEthernetHeader_t * ) pxNetworkBuffer->pucEthernetBuffer;\r
 176 \r
 177                 if( memcmp( ( void * ) &( pxEthernetHeader->xDestinationAddress ), ( void * ) &xBroadcastMACAddress, sizeof( xMACAddress_t ) ) == 0 )\r
 178                 {\r
 179                         /* This is a broadcast. */\r
 180                         xCanLoopback = pdTRUE;\r
 181                 }\r
 182                 else if( memcmp( ( void * ) &( pxEthernetHeader->xDestinationAddress ), ( void * ) xDefaultPartUDPPacketHeader, sizeof( xMACAddress_t ) ) == 0 )\r
 183                 {\r
 184                         /* This is being sent to itself. */\r
 185                         xCanLoopback = pdTRUE;\r
 186                 }\r
 187                 else\r
 188                 {\r
 189                         /* This is being sent externally. */\r
 190                         xCanLoopback = pdFALSE;\r
 191                 }\r
 192 \r
 193                 iptraceNETWORK_INTERFACE_TRANSMIT();\r
 194 \r
 195                 if( xCanLoopback == pdTRUE )\r
 196                 {\r
 197                         /* Just loop the frame back to the input queue.  Here the loopback\r
 198                         is sending a message to itself, so a block time cannot be used for\r
 199                         fear of deadlocking. */\r
 200                         xRxEvent.pvData = ( void * ) pxNetworkBuffer;\r
 201                         if( xQueueSendToBack( xNetworkEventQueue, &xRxEvent, ( portTickType ) 0 ) == pdFALSE )\r
 202                         {\r
 203                                 vNetworkBufferRelease( pxNetworkBuffer );\r
 204                                 iptraceETHERNET_RX_EVENT_LOST();\r
 205                         }\r
 206                 }\r
 207                 else\r
 208                 {\r
 209                         /* Send the packet. */\r
 210                         xSemaphoreTake( xPCAPMutex, portMAX_DELAY );\r
 211                         {\r
 212                                 pcap_sendpacket( pxOpenedInterfaceHandle, pxNetworkBuffer->pucEthernetBuffer, pxNetworkBuffer->xDataLength );\r
 213                         }\r
 214                         xSemaphoreGive( xPCAPMutex );\r
 215 \r
 216                         /* The buffer has been transmitted so can be released. */\r
 217                         vNetworkBufferRelease( pxNetworkBuffer );\r
 218                 }\r
 219 \r
 220                 return pdPASS;\r
 221         }\r
 222 \r
 223 #else /* updconfigLOOPBACK_ETHERNET_PACKETS == 1 */\r
 224 \r
 225         portBASE_TYPE xNetworkInterfaceOutput( xNetworkBufferDescriptor_t * const pxNetworkBuffer )\r
 226         {\r
 227                 xSemaphoreTake( xPCAPMutex, portMAX_DELAY );\r
 228                 {\r
 229                         iptraceNETWORK_INTERFACE_TRANSMIT();\r
 230                         pcap_sendpacket( pxOpenedInterfaceHandle, pxNetworkBuffer->pucEthernetBuffer, pxNetworkBuffer->xDataLength );\r
 231                 }\r
 232                 xSemaphoreGive( xPCAPMutex );\r
 233 \r
 234                 /* The buffer has been transmitted so can be released. */\r
 235                 vNetworkBufferRelease( pxNetworkBuffer );\r
 236 \r
 237                 return pdPASS;\r
 238         }\r
 239 \r
 240 #endif /* updconfigLOOPBACK_ETHERNET_PACKETS == 1 */\r
 241 /*-----------------------------------------------------------*/\r
 242 \r
 243 static pcap_if_t * prvPrintAvailableNetworkInterfaces( void )\r
 244 {\r
 245 pcap_if_t * pxAllNetworkInterfaces = NULL, *xInterface;\r
 246 long lInterfaceNumber = 1;\r
 247 \r
 248     if( pcap_findalldevs_ex( PCAP_SRC_IF_STRING, NULL, &pxAllNetworkInterfaces, cErrorBuffer ) == -1 )\r
 249     {\r
 250         printf( "\r\nCould not obtain a list of network interfaces\r\n%s\r\n", cErrorBuffer );\r
 251         pxAllNetworkInterfaces = NULL;\r
 252     }\r
 253 \r
 254         if( pxAllNetworkInterfaces != NULL )\r
 255         {\r
 256                 /* Print out the list of network interfaces.  The first in the list\r
 257                 is interface '1', not interface '0'. */\r
 258                 for( xInterface = pxAllNetworkInterfaces; xInterface != NULL; xInterface = xInterface->next )\r
 259                 {\r
 260                         printf( "%d. %s", lInterfaceNumber, xInterface->name );\r
 261 \r
 262                         if( xInterface->description != NULL )\r
 263                         {\r
 264                                 printf( " (%s)\r\n", xInterface->description );\r
 265                         }\r
 266                         else\r
 267                         {\r
 268                                 printf( " (No description available)\r\n") ;\r
 269                         }\r
 270 \r
 271                         lInterfaceNumber++;\r
 272                 }\r
 273         }\r
 274 \r
 275     if( lInterfaceNumber == 1 )\r
 276     {\r
 277                 /* The interface number was never incremented, so the above for() loop\r
 278                 did not execute meaning no interfaces were found. */\r
 279         printf( " \r\nNo network interfaces were found.\r\n" );\r
 280         pxAllNetworkInterfaces = NULL;\r
 281     }\r
 282 \r
 283         printf( "\r\nThe interface that will be opened is set by configNETWORK_INTERFACE_TO_USE which should be defined in FreeRTOSConfig.h\r\n" );\r
 284         printf( "Attempting to open interface number %d.\r\n", configNETWORK_INTERFACE_TO_USE );\r
 285 \r
 286     if( ( configNETWORK_INTERFACE_TO_USE < 1L ) || ( configNETWORK_INTERFACE_TO_USE > lInterfaceNumber ) )\r
 287     {\r
 288         printf("\r\nconfigNETWORK_INTERFACE_TO_USE is not in the valid range.\r\n" );\r
 289 \r
 290                 if( pxAllNetworkInterfaces != NULL )\r
 291                 {\r
 292                         /* Free the device list, as no devices are going to be opened. */\r
 293                         pcap_freealldevs( pxAllNetworkInterfaces );\r
 294                         pxAllNetworkInterfaces = NULL;\r
 295                 }\r
 296     }\r
 297 \r
 298         return pxAllNetworkInterfaces;\r
 299 }\r
 300 /*-----------------------------------------------------------*/\r
 301 \r
 302 static void prvOpenSelectedNetworkInterface( pcap_if_t *pxAllNetworkInterfaces )\r
 303 {\r
 304 pcap_if_t *xInterface;\r
 305 long x;\r
 306 \r
 307     /* Walk the list of devices until the selected device is located. */\r
 308         xInterface = pxAllNetworkInterfaces;\r
 309     for( x = 0L; x < ( configNETWORK_INTERFACE_TO_USE - 1L ); x++ )\r
 310         {\r
 311                 xInterface = xInterface->next;\r
 312         }\r
 313 \r
 314     /* Open the selected interface. */\r
 315         pxOpenedInterfaceHandle = pcap_open(    xInterface->name,               /* The name of the selected interface. */\r
 316                                                                                         ipTOTAL_ETHERNET_FRAME_SIZE,    /* The size of the packet to capture. */\r
 317                                                                                         PCAP_OPENFLAG_PROMISCUOUS,      /* Open in promiscious mode as the MAC and\r
 318                                                                                                                                                 IP address is going to be "simulated", and\r
 319                                                                                                                                                 not be the real MAC and IP address.  This allows\r
 320                                                                                                                                                 trafic to the simulated IP address to be routed\r
 321                                                                                                                                                 to uIP, and trafic to the real IP address to be\r
 322                                                                                                                                                 routed to the Windows TCP/IP stack. */\r
 323                                                                                         0x00L,                                  /* The read time out. */\r
 324                                                                                         NULL,                                   /* No authentication is required as this is\r
 325                                                                                                                                                 not a remote capture session. */\r
 326                                                                                         cErrorBuffer\r
 327                                                                            );\r
 328 \r
 329     if ( pxOpenedInterfaceHandle == NULL )\r
 330     {\r
 331         printf( "\r\n%s is not supported by WinPcap and cannot be opened\r\n", xInterface->name );\r
 332     }\r
 333         else\r
 334         {\r
 335                 /* Configure the capture filter to allow blocking reads, and to filter\r
 336                 out packets that are not of interest to this demo. */\r
 337                 prvConfigureCaptureBehaviour();\r
 338         }\r
 339 \r
 340         /* The device list is no longer required. */\r
 341         pcap_freealldevs( pxAllNetworkInterfaces );\r
 342 }\r
 343 /*-----------------------------------------------------------*/\r
 344 \r
 345 static void prvConfigureCaptureBehaviour( void )\r
 346 {\r
 347 struct bpf_program xFilterCode;\r
 348 const long lMinBytesToCopy = 10L, lBlocking = 1L;\r
 349 unsigned long ulNetMask;\r
 350 \r
 351         /* Unblock a read as soon as anything is received. */\r
 352         pcap_setmintocopy( pxOpenedInterfaceHandle, lMinBytesToCopy );\r
 353 \r
 354         /* Allow blocking. */\r
 355         pcap_setnonblock( pxOpenedInterfaceHandle, lBlocking, cErrorBuffer );\r
 356 \r
 357         /* Set up a filter so only the packets of interest are passed to the IP\r
 358         stack.  cErrorBuffer is used for convenience to create the string.  Don't\r
 359         confuse this with an error message. *//*_RB_ This should not use the #defined constants. *//*_RB_ Constants should not be used, but passed through a generic network API. */\r
 360         sprintf( cErrorBuffer, "broadcast or multicast or ether host %x:%x:%x:%x:%x:%x", configMAC_ADDR0, configMAC_ADDR1, configMAC_ADDR2, configMAC_ADDR3, configMAC_ADDR4, configMAC_ADDR5 );\r
 361 \r
 362         /*_RB_ Constants should not be used, but passed through a generic network API. */\r
 363         ulNetMask = ( configNET_MASK3 << 24UL ) | ( configNET_MASK2 << 16UL ) | ( configNET_MASK1 << 8L ) | configNET_MASK0;\r
 364 \r
 365         if( pcap_compile(pxOpenedInterfaceHandle, &xFilterCode, cErrorBuffer, 1, ulNetMask ) < 0 )\r
 366     {\r
 367         printf("\r\nThe packet filter string is invalid\r\n" );\r
 368     }\r
 369         else\r
 370         {\r
 371                 if( pcap_setfilter( pxOpenedInterfaceHandle, &xFilterCode ) < 0 )\r
 372                 {\r
 373                         printf( "\r\nAn error occurred setting the packet filter.\r\n" );\r
 374                 }\r
 375         }\r
 376 \r
 377         /* Create a task that simulates an interrupt in a real system.  This will\r
 378         block waiting for packets, then send a message to the uIP task when data\r
 379         is available. */\r
 380         xTaskCreate( prvInterruptSimulatorTask, ( signed char * ) "MAC_ISR", configMINIMAL_STACK_SIZE, NULL, configMAC_ISR_SIMULATOR_PRIORITY, NULL );\r
 381 }\r
 382 /*-----------------------------------------------------------*/\r
 383 \r
 384 static void prvInterruptSimulatorTask( void *pvParameters )\r
 385 {\r
 386 static struct pcap_pkthdr *pxHeader;\r
 387 const uint8_t *pucPacketData;\r
 388 long lResult;\r
 389 xNetworkBufferDescriptor_t *pxNetworkBuffer;\r
 390 xIPStackEvent_t xRxEvent = { eEthernetRxEvent, NULL };\r
 391 eFrameProcessingResult_t eResult;\r
 392 \r
 393         /* Just to kill the compiler warning. */\r
 394         ( void ) pvParameters;\r
 395 \r
 396         for( ;; )\r
 397         {\r
 398                 /* Get the next packet. */\r
 399                 xSemaphoreTake( xPCAPMutex, portMAX_DELAY );\r
 400                 {\r
 401                         lResult = pcap_next_ex( pxOpenedInterfaceHandle, &pxHeader, &pucPacketData );\r
 402                 }\r
 403                 xSemaphoreGive( xPCAPMutex );\r
 404 \r
 405                 if( lResult == 1 )\r
 406                 {\r
 407                         eResult = ipCONSIDER_FRAME_FOR_PROCESSING( pucPacketData );\r
 408                         if( eResult == eProcessBuffer )\r
 409                         {\r
 410                                 /* Will the data fit into the frame buffer? */\r
 411                                 if( pxHeader->len <= ipTOTAL_ETHERNET_FRAME_SIZE )\r
 412                                 {\r
 413                                         /* Obtain a buffer into which the data can be placed.  This\r
 414                                         is only an interrupt simulator, not a real interrupt, so it\r
 415                                         is ok to call the task level function here.  */\r
 416                                         xSemaphoreTake( xPCAPMutex, portMAX_DELAY );\r
 417                                         {\r
 418                                                 pxNetworkBuffer = pxNetworkBufferGet( pxHeader->len, 0 );\r
 419                                         }\r
 420                                         xSemaphoreGive( xPCAPMutex );\r
 421 \r
 422                                         if( pxNetworkBuffer != NULL )\r
 423                                         {\r
 424                                                 memcpy( pxNetworkBuffer->pucEthernetBuffer, pucPacketData, pxHeader->len );\r
 425                                                 pxNetworkBuffer->xDataLength = ( size_t ) pxHeader->len;\r
 426                                                 xRxEvent.pvData = ( void * ) pxNetworkBuffer;\r
 427 \r
 428                                                 /* Data was received and stored.  Send a message to the IP\r
 429                                                 task to let it know. */\r
 430                                                 if( xQueueSendToBack( xNetworkEventQueue, &xRxEvent, ( portTickType ) 0 ) == pdFALSE )\r
 431                                                 {\r
 432                                                         /* The buffer could not be sent to the stack so\r
 433                                                         must be released again.  This is only an interrupt\r
 434                                                         simulator, not a real interrupt, so it is ok to use\r
 435                                                         the task level function here. */\r
 436                                                         vNetworkBufferRelease( pxNetworkBuffer );\r
 437                                                         iptraceETHERNET_RX_EVENT_LOST();\r
 438                                                 }\r
 439                                         }\r
 440                                         else\r
 441                                         {\r
 442                                                 iptraceETHERNET_RX_EVENT_LOST();\r
 443                                         }\r
 444                                 }\r
 445                                 else\r
 446                                 {\r
 447                                         /* Log that a packet was dropped because it would have\r
 448                                         overflowed the buffer. */\r
 449                                 }\r
 450                         }\r
 451                 }\r
 452                 else\r
 453                 {\r
 454                         /* There is no real way of simulating an interrupt.  Make sure\r
 455                         other tasks can run. */\r
 456                         vTaskDelay( configWINDOWS_MAC_INTERRUPT_SIMULATOR_DELAY );\r
 457                 }\r
 458         }\r
 459 }\r
 460 /*-----------------------------------------------------------*/\r
 461 \r
 462 #if configUSE_STATIC_BUFFERS == 1\r
 463         void vNetworkInterfaceAllocateRAMToBuffers( xNetworkBufferDescriptor_t pxNetworkBuffers[ ipconfigNUM_NETWORK_BUFFERS ] )\r
 464         {\r
 465         portBASE_TYPE x;\r
 466 \r
 467                 for( x = 0; x < ipconfigNUM_NETWORK_BUFFERS; x++ )\r
 468                 {\r
 469                         pxNetworkBuffers[ x ].pucEthernetBuffer = &( ucBuffers[ x ][ 0 ] );\r
 470                 }\r
 471         }\r
 472 #endif\r
 473 /*-----------------------------------------------------------*/\r