git.sur5r.net Git - freertos/blob - FreeRTOS-Plus/Source/FreeRTOS-Plus-UDP/FreeRTOS_UDP_IP.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 /* Standard includes. */\r
  43 #include <stdint.h>\r
  44 \r
  45 /* FreeRTOS includes. */\r
  46 #include "FreeRTOS.h"\r
  47 #include "task.h"\r
  48 #include "queue.h"\r
  49 #include "semphr.h"\r
  50 #include "timers.h"\r
  51 \r
  52 /* FreeRTOS+UDP includes. */\r
  53 #include "FreeRTOS_UDP_IP.h"\r
  54 #include "FreeRTOS_IP_Private.h"\r
  55 #include "FreeRTOS_Sockets.h"\r
  56 #include "FreeRTOS_DHCP.h"\r
  57 #include "NetworkInterface.h"\r
  58 #include "NetworkBufferManagement.h"\r
  59 \r
  60 /* Sanity check the configuration. */\r
  61 #if configUSE_TIMERS != 1\r
  62         #error configUSE_TIMERS must be set to 1 in FreeRTOSConfig.h to use this file\r
  63 #endif\r
  64 \r
  65 #if configTICK_RATE_HZ > 1000\r
  66         #error configTICK_RATE_HZ must be less than 1000 to use FreeRTOS+UDP\r
  67 #endif\r
  68 \r
  69 #if ( ipconfigEVENT_QUEUE_LENGTH < ( ipconfigNUM_NETWORK_BUFFERS + 5 ) )\r
  70         #error The ipconfigEVENT_QUEUE_LENGTH parameter must be at least ipconfigNUM_NETWORK_BUFFERS + 5\r
  71 #endif\r
  72 \r
  73 #if ipconfigCAN_FRAGMENT_OUTGOING_PACKETS == 1 && ipconfigSUPPORT_OUTGOING_PINGS == 1\r
  74         #error ipconfigSUPPORT_OUTGOING_PINGS can only be set to 1 if ipconfigCAN_FRAGMENT_OUTGOING_PACKETS is set to 0 as IP fragmentation is not supported for ICMP (ping) packets\r
  75 #endif\r
  76 \r
  77 #if ( ipconfigNETWORK_MTU < 46 )\r
  78         #error ipconfigNETWORK_MTU must be at least 46.\r
  79 #endif\r
  80 /*-----------------------------------------------------------*/\r
  81 \r
  82 /* The IP header length in bytes. */\r
  83 #define ipIP_HEADER_LENGTH              ( 20 )\r
  84 \r
  85 /* IP protocol definitions. */\r
  86 #define ipPROTOCOL_ICMP                 ( 1 )\r
  87 #define ipPROTOCOL_UDP                  ( 17 )\r
  88 \r
  89 /* ICMP protocol definitions. */\r
  90 #define ipICMP_ECHO_REQUEST             ( ( uint16_t ) 8 )\r
  91 #define ipICMP_ECHO_REPLY               ( ( uint16_t ) 0 )\r
  92 \r
  93 /* The expected IP version and header length coded into the IP header itself. */\r
  94 #define ipIP_VERSION_AND_HEADER_LENGTH_BYTE ( ( uint8_t ) 0x45 )\r
  95 \r
  96 /* Time delay between repeated attempts to initialise the network hardware. */\r
  97 #define ipINITIALISATION_RETRY_DELAY    ( ( ( portTickType ) 3000 ) / portTICK_RATE_MS )\r
  98 \r
  99 /* The local MAC address is accessed from within xDefaultPartUDPPacketHeader,\r
 100 rather than duplicated in its own variable. */\r
 101 #define ipLOCAL_MAC_ADDRESS ( xDefaultPartUDPPacketHeader )\r
 102 \r
 103 /* The local IP address is accessed from within xDefaultPartUDPPacketHeader,\r
 104 rather than duplicated in its own variable. */\r
 105 #define ipLOCAL_IP_ADDRESS_POINTER ( ( uint32_t * ) &( xDefaultPartUDPPacketHeader[ 20 ] ) )\r
 106 \r
 107 /* Defines how often the ARP timer callback function is executed.  The time is\r
 108 shorted in the Windows simulator as simulated time is not real time. */\r
 109 #ifdef _WINDOWS_\r
 110         #define ipARP_TIMER_PERIOD_MS   ( 500 ) /* For windows simulator builds. */\r
 111 #else\r
 112         #define ipARP_TIMER_PERIOD_MS   ( 10000 )\r
 113 #endif\r
 114 \r
 115 /* If ipconfigETHERNET_DRIVER_FILTERS_FRAME_TYPES is set to 1, then the Ethernet\r
 116 driver will filter incoming packets and only pass the stack those packets it\r
 117 considers need processing.  In this case ipCONSIDER_FRAME_FOR_PROCESSING() can\r
 118 be #defined away.  If ipconfigETHERNET_DRIVER_FILTERS_FRAME_TYPES is set to 0\r
 119 then the Ethernet driver will pass all received packets to the stack, and the\r
 120 stack must do the filtering itself.  In this case ipCONSIDER_FRAME_FOR_PROCESSING\r
 121 needs to call eConsiderFrameForProcessing. */\r
 122 #if ipconfigETHERNET_DRIVER_FILTERS_FRAME_TYPES == 0\r
 123         #define ipCONSIDER_FRAME_FOR_PROCESSING( pucEthernetBuffer ) eConsiderFrameForProcessing( ( pucEthernetBuffer ) )\r
 124 #else\r
 125         #define ipCONSIDER_FRAME_FOR_PROCESSING( pucEthernetBuffer ) eProcessBuffer\r
 126 #endif\r
 127 \r
 128 /* When the age of an entry in the ARP table reaches this value (it counts down\r
 129 to zero, so this is an old entry) an ARP request will be sent to see if the\r
 130 entry is still valid and can therefore be refreshed. */\r
 131 #define ipMAX_ARP_AGE_BEFORE_NEW_ARP_REQUEST            ( 3 )\r
 132 \r
 133 /* Number of bits to shift to divide by 8.  Used to remove the need for a\r
 134 divide. */\r
 135 #define ipSHIFT_TO_DIVIDE_BY_8                                          ( 3U )\r
 136 \r
 137 /* The bit set in the IP header flags to indicate that the IP packet contains\r
 138 a fragment of the eventual total payload, and that more fragments will follow. */\r
 139 #define ipMORE_FRAGMENTS_FLAG_BIT                                       ( 0x2000U )\r
 140 \r
 141 /* ICMP packets are sent using the same function as UDP packets.  The port\r
 142 number is used to distinguish between the two, as 0 is an invalid UDP port. */\r
 143 #define ipPACKET_CONTAINS_ICMP_DATA                                     ( 0 )\r
 144 \r
 145 /* The character used to fill ICMP echo requests, and therefore also the\r
 146 character expected to fill ICMP echo replies. */\r
 147 #define ipECHO_DATA_FILL_BYTE                                           'x'\r
 148 \r
 149 #if( ipconfigBYTE_ORDER == FREERTOS_LITTLE_ENDIAN )\r
 150         #define ipFRAGMENT_OFFSET_BIT_MASK                              ( ( uint16_t ) 0xff0f ) /* The bits in the two byte IP header field that make up the fragment offset value. */\r
 151 #else\r
 152         #define ipFRAGMENT_OFFSET_BIT_MASK                              ( ( uint16_t ) 0x0fff ) /* The bits in the two byte IP header field that make up the fragment offset value. */\r
 153         #if ipconfigCAN_FRAGMENT_OUTGOING_PACKETS == 1\r
 154                 #warning Fragment offsets have not been tested on big endian machines.\r
 155         #endif /* ipconfigCAN_FRAGMENT_OUTGOING_PACKETS */\r
 156 #endif /* ipconfigBYTE_ORDER */\r
 157 \r
 158 /*-----------------------------------------------------------*/\r
 159 /* Miscellaneous structure and definitions. */\r
 160 /*-----------------------------------------------------------*/\r
 161 \r
 162 typedef struct xARP_CACHE_TABLE_ROW\r
 163 {\r
 164         uint32_t ulIPAddress;           /* The IP address of an ARP cache entry. */\r
 165         xMACAddress_t xMACAddress;  /* The MAC address of an ARP cache entry. */\r
 166         uint8_t ucAge;                          /* A value that is periodically decremented but can also be refreshed by active communication.  The ARP cache entry is removed if the value reaches zero. */\r
 167 } xARPCacheRow_t;\r
 168 \r
 169 typedef enum\r
 170 {\r
 171         eARPCacheMiss = 0,                      /* An ARP table lookup did not find a valid entry. */\r
 172         eARPCacheHit,                           /* An ARP table lookup found a valid entry. */\r
 173         eCantSendPacket                         /* There is no IP address, or an ARP is still in progress, so the packet cannot be sent. */\r
 174 } eARPLookupResult_t;\r
 175 \r
 176 typedef enum\r
 177 {\r
 178         eNotFragment = 0,                       /* The IP packet being sent is not part of a fragment. */\r
 179         eFirstFragment,                         /* The IP packet being sent is the first in a set of fragmented packets. */\r
 180         eFollowingFragment                      /* The IP packet being sent is part of a set of fragmented packets. */\r
 181 } eIPFragmentStatus_t;\r
 182 \r
 183 \r
 184 /*-----------------------------------------------------------*/\r
 185 \r
 186 /*\r
 187  * Called when new data is available from the network interface.\r
 188  */\r
 189 static void prvProcessEthernetPacket( xNetworkBufferDescriptor_t * const pxNetworkBuffer );\r
 190 \r
 191 /*\r
 192  * Called when the application has generated a UDP packet to send.\r
 193  */\r
 194 static void prvProcessGeneratedPacket( xNetworkBufferDescriptor_t * const pxNetworkBuffer );\r
 195 \r
 196 /*\r
 197  * Processes incoming ARP packets.\r
 198  */\r
 199 static eFrameProcessingResult_t prvProcessARPPacket( xARPPacket_t * const pxARPFrame );\r
 200 \r
 201 /*\r
 202  * Process incoming IP packets.\r
 203  */\r
 204 static eFrameProcessingResult_t prvProcessIPPacket( const xIPPacket_t * const pxIPPacket, xNetworkBufferDescriptor_t * const pxNetworkBuffer );\r
 205 \r
 206 /*\r
 207  * Process incoming ICMP packets.\r
 208  */\r
 209 #if ( ipconfigREPLY_TO_INCOMING_PINGS == 1 ) || ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )\r
 210         static eFrameProcessingResult_t prvProcessICMPPacket( xICMPPacket_t * const pxICMPPacket );\r
 211 #endif /* ( ipconfigREPLY_TO_INCOMING_PINGS == 1 ) || ( ipconfigSUPPORT_OUTGOING_PINGS == 1 ) */\r
 212 \r
 213 /*\r
 214  * Swap the source and destination addresses in an already constructed Ethernet\r
 215  * frame, and send the frame to the network.\r
 216  */\r
 217 static void prvReturnEthernetFrame( xNetworkBufferDescriptor_t * const pxNetworkBuffer );\r
 218 \r
 219 /*\r
 220  * Return the checksum generated over usDataLengthBytes from pucNextData.\r
 221  */\r
 222 static uint16_t prvGenerateChecksum( const uint8_t * const pucNextData, const uint16_t usDataLengthBytes );\r
 223 \r
 224 /*\r
 225  * The callback function that is assigned to all periodic processing timers -\r
 226  * namely the DHCP timer and the ARP timer.\r
 227  */\r
 228 void vIPFunctionsTimerCallback( xTimerHandle xTimer );\r
 229 \r
 230 /*\r
 231  * Reduce the age count in each entry within the ARP cache.  An entry is no\r
 232  * longer considered valid and is deleted if its age reaches zero.\r
 233  */\r
 234 static void prvAgeARPCache( void );\r
 235 \r
 236 /*\r
 237  * If ulIPAddress is already in the ARP cache table then reset the age of the\r
 238  * entry back to its maximum value.  If ulIPAddress is not already in the ARP\r
 239  * cache table then add it - replacing the oldest current entry if there is not\r
 240  * a free space available.\r
 241  */\r
 242 static void prvRefreshARPCacheEntry( const xMACAddress_t * const pxMACAddress, const uint32_t ulIPAddress );\r
 243 \r
 244 /*\r
 245  * Creates the pseudo header necessary then generate the checksum over the UDP\r
 246  * packet.  Returns the calculated checksum.\r
 247  */\r
 248 static uint16_t prvGenerateUDPChecksum( const xUDPPacket_t * const pxUDPPacket );\r
 249 \r
 250 /*\r
 251  * Look for ulIPAddress in the ARP cache.  If the IP address exists, copy the\r
 252  * associated MAC address into pxMACAddress, refresh the ARP cache entry's\r
 253  * age, and return eARPCacheHit.  If the IP address does not exist in the ARP\r
 254  * cache return eARPCacheMiss.  If the packet cannot be sent for any reason\r
 255  * (maybe DHCP is still in process, or the addressing needs a gateway but there\r
 256  * isn't a gateway defined) then return eCantSendPacket.\r
 257  */\r
 258 static eARPLookupResult_t prvGetARPCacheEntry( uint32_t *pulIPAddress, xMACAddress_t * const pxMACAddress );\r
 259 \r
 260 /*\r
 261  * The main UDP/IP stack processing task.  This task receives commands/events\r
 262  * from the network hardware drivers, tasks that are using sockets, and software\r
 263  * timers (such as the ARP timer).\r
 264  */\r
 265 static void prvIPTask( void *pvParameters );\r
 266 \r
 267 /*\r
 268  * Send out an ARP request for the IP address contained in pxNetworkBuffer, and\r
 269  * add an entry into the ARP table that indicates that an ARP reply is\r
 270  * outstanding so re-transmissions can be generated.\r
 271  */\r
 272 static void prvGenerateARPRequestPacket( xNetworkBufferDescriptor_t * const pxNetworkBuffer );\r
 273 \r
 274 /*\r
 275  * Called when outgoing packets are fragmented and require a fragment offset in\r
 276  * their IP headers.  Set the fragment offset (which includes the IP flags) and\r
 277  * length from the data passed in the pxFragmentParameters structure.\r
 278  */\r
 279  #if ipconfigCAN_FRAGMENT_OUTGOING_PACKETS == 1\r
 280         static void prvCalculateFragmentOffsetAndLength( xIPFragmentParameters_t *pxFragmentParameters, uint16_t *pusFragmentOffset, uint16_t *pusFragmentLength );\r
 281 #endif /* ipconfigCAN_FRAGMENT_OUTGOING_PACKETS */\r
 282 \r
 283 /*\r
 284  * Complete the pxUDPPacket header with the information passed in\r
 285  * pxNetworkBuffer.  ucSocketOptions are passed in case the options include\r
 286  * disabling the checksum.\r
 287  */\r
 288 static void prvCompleteUDPHeader( xNetworkBufferDescriptor_t *pxNetworkBuffer, xUDPPacket_t *pxUDPPacket, uint8_t ucSocketOptions );\r
 289 \r
 290 /*\r
 291  * Send the event eEvent to the IP task event queue, using a block time of\r
 292  * zero.  Return pdPASS if the message was sent successfully, otherwise return\r
 293  * pdFALSE.\r
 294 */\r
 295 static portBASE_TYPE prvSendEventToIPTask( eIPEvent_t eEvent );\r
 296 \r
 297 /*\r
 298  * Generate and send an ARP request for the IP address passed in ulIPAddress.\r
 299  */\r
 300 static void prvOutputARPRequest( uint32_t ulIPAddress );\r
 301 \r
 302 /*\r
 303  * Turns around an incoming ping request to convert it into a ping reply.\r
 304  */\r
 305 #if ( ipconfigREPLY_TO_INCOMING_PINGS == 1 )\r
 306         static eFrameProcessingResult_t prvProcessICMPEchoRequest( xICMPPacket_t * const pxICMPPacket );\r
 307 #endif /* ipconfigREPLY_TO_INCOMING_PINGS */\r
 308 \r
 309 /*\r
 310  * Processes incoming ping replies.  The application callback function\r
 311  * vApplicationPingReplyHook() is called with the results.\r
 312  */\r
 313 #if ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )\r
 314         static void prvProcessICMPEchoReply( xICMPPacket_t * const pxICMPPacket );\r
 315 #endif /* ipconfigSUPPORT_OUTGOING_PINGS */\r
 316 \r
 317 /*\r
 318  * Called to create a network connection when the stack is first started, or\r
 319  * when the network connection is lost.\r
 320  */\r
 321 static void prvProcessNetworkDownEvent( void );\r
 322 \r
 323 /*-----------------------------------------------------------*/\r
 324 \r
 325 /* The queue used to pass events into the UDP task for processing. */\r
 326 xQueueHandle xNetworkEventQueue = NULL;\r
 327 \r
 328 /* The ARP cache. */\r
 329 static xARPCacheRow_t xARPCache[ ipconfigARP_CACHE_ENTRIES ];\r
 330 \r
 331 /* The timer that triggers ARP events. */\r
 332 static xTimerHandle xARPTimer = NULL;\r
 333 \r
 334 /* Used to ensure network down events cannot be missed when they cannot be\r
 335 posted to the network event queue because the network event queue is already\r
 336 full. */\r
 337 static portBASE_TYPE xNetworkDownEventPending = pdFALSE;\r
 338 \r
 339 /* For convenience, a MAC address of all zeros and another of all 0xffs are\r
 340 defined const for quick reference. */\r
 341 static const xMACAddress_t xNullMACAddress = { { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 } };\r
 342 static const xMACAddress_t xBroadcastMACAddress = { { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff } };\r
 343 \r
 344 /* Part of the Ethernet and IP headers are always constant when sending an IPv4\r
 345 UDP packet.  This array defines the constant parts, allowing this part of the\r
 346 packet to be filled in using a simple memcpy() instead of individual writes. */\r
 347 uint8_t xDefaultPartUDPPacketHeader[] =\r
 348 {\r
 349         0x00, 0x00, 0x00, 0x00, 0x00, 0x00,     /* Ethernet source MAC address. */\r
 350         0x08, 0x00,                                                     /* Ethernet frame type. */\r
 351         ipIP_VERSION_AND_HEADER_LENGTH_BYTE,    /* ucVersionHeaderLength. */\r
 352         0x00,                                                                   /* ucDifferentiatedServicesCode. */\r
 353         0x00, 0x00,                                                     /* usLength. */\r
 354         0x00, 0x00,                                                     /* usIdentification. */\r
 355         0x00, 0x00,                                                     /* usFragmentOffset. */\r
 356         updconfigIP_TIME_TO_LIVE,                               /* ucTimeToLive */\r
 357         ipPROTOCOL_UDP,                                                 /* ucProtocol. */\r
 358         0x00, 0x00,                                                     /* usHeaderChecksum. */\r
 359         0x00, 0x00, 0x00, 0x00                                  /* Source IP address. */\r
 360 };\r
 361 \r
 362 /* Part of the Ethernet and ARP headers are always constant when sending an IPv4\r
 363 ARP packet.  This array defines the constant parts, allowing this part of the\r
 364 packet to be filled in using a simple memcpy() instead of individual writes. */\r
 365 static const uint8_t xDefaultPartARPPacketHeader[] =\r
 366 {\r
 367         0xff, 0xff, 0xff, 0xff, 0xff, 0xff,     /* Ethernet destination address. */\r
 368         0x00, 0x00, 0x00, 0x00, 0x00, 0x00,     /* Ethernet source address. */\r
 369         0x08, 0x06,                                                     /* Ethernet frame type (ipARP_TYPE). */\r
 370         0x00, 0x01,                                                     /* usHardwareType (ipARP_HARDWARE_TYPE_ETHERNET). */\r
 371         0x08, 0x00,                                                             /* usProtocolType. */\r
 372         ipMAC_ADDRESS_LENGTH_BYTES,                     /* ucHardwareAddressLength. */\r
 373         ipIP_ADDRESS_LENGTH_BYTES,                              /* ucProtocolAddressLength. */\r
 374         0x00, 0x01,                                                     /* usOperation (ipARP_REQUEST). */\r
 375         0x00, 0x00, 0x00, 0x00, 0x00, 0x00,     /* xSenderHardwareAddress. */\r
 376         0x00, 0x00, 0x00, 0x00,                                 /* ulSenderProtocolAddress. */\r
 377         0x00, 0x00, 0x00, 0x00, 0x00, 0x00      /* xTargetHardwareAddress. */\r
 378 };\r
 379 \r
 380 /* Structure that stores the netmask, gateway address and DNS server addresses. */\r
 381 static xNetworkAddressingParameters_t xNetworkAddressing = { 0, 0, 0, 0 };\r
 382 \r
 383 /*-----------------------------------------------------------*/\r
 384 \r
 385 static void prvIPTask( void *pvParameters )\r
 386 {\r
 387 xIPStackEvent_t xReceivedEvent;\r
 388 \r
 389         /* Just to prevent compiler warnings about unused parameters. */\r
 390         ( void ) pvParameters;\r
 391 \r
 392         /* Create the ARP timer, but don't start it until the network has\r
 393         connected. */\r
 394         xARPTimer = xTimerCreate(       ( const signed char * const ) "ARPTimer", ( ipARP_TIMER_PERIOD_MS / portTICK_RATE_MS ), pdTRUE, ( void * ) eARPTimerEvent, vIPFunctionsTimerCallback );\r
 395         configASSERT( xARPTimer );\r
 396 \r
 397         /* Generate a dummy message to say that the network connection has gone\r
 398         down.  This will cause this task to initialise the network interface.  After\r
 399         this it is the responsibility of the network interface hardware driver to\r
 400         send this message if a previously connected network is disconnected. */\r
 401         FreeRTOS_NetworkDown();\r
 402 \r
 403         /* Loop, processing IP events. */\r
 404         for( ;; )\r
 405         {\r
 406                 /* Wait until there is something to do. */\r
 407                 if( xQueueReceive( xNetworkEventQueue, ( void * ) &xReceivedEvent, portMAX_DELAY ) == pdPASS )\r
 408                 {\r
 409                         iptraceNETWORK_EVENT_RECEIVED( xReceivedEvent.eEventType );\r
 410 \r
 411                         switch( xReceivedEvent.eEventType )\r
 412                         {\r
 413                                 case eNetworkDownEvent :\r
 414                                         /* Attempt to establish a connection. */\r
 415                                         prvProcessNetworkDownEvent();\r
 416                                         break;\r
 417 \r
 418                                 case eEthernetRxEvent :\r
 419                                         /* The network hardware driver has received a new packet.\r
 420                                         A pointer to the received buffer is located in the pvData\r
 421                                         member of the received event structure. */\r
 422                                         prvProcessEthernetPacket( ( xNetworkBufferDescriptor_t * ) ( xReceivedEvent.pvData ) );\r
 423                                         break;\r
 424 \r
 425                                 case eARPTimerEvent :\r
 426                                         /* The ARP timer has expired, process the ARP cache. */\r
 427                                         prvAgeARPCache();\r
 428                                         break;\r
 429 \r
 430                                 case eStackTxEvent :\r
 431                                         /* The network stack has generated a packet to send.  A\r
 432                                         pointer to the generated buffer is located in the pvData\r
 433                                         member of the received event structure. */\r
 434                                         prvProcessGeneratedPacket( ( xNetworkBufferDescriptor_t * ) ( xReceivedEvent.pvData ) );\r
 435                                         break;\r
 436 \r
 437                                 case eDHCPEvent:\r
 438                                         /* The DHCP state machine needs processing. */\r
 439                                         #if ipconfigUSE_DHCP == 1\r
 440                                         {\r
 441                                                 vDHCPProcess( pdFALSE, ( xMACAddress_t * ) ipLOCAL_MAC_ADDRESS, ipLOCAL_IP_ADDRESS_POINTER, &xNetworkAddressing );\r
 442                                         }\r
 443                                         #endif\r
 444                                         break;\r
 445 \r
 446                                 default :\r
 447                                         /* Should not get here. */\r
 448                                         break;\r
 449                         }\r
 450 \r
 451                         if( xNetworkDownEventPending != pdFALSE )\r
 452                         {\r
 453                                 /* A network down event could not be posted to the network\r
 454                                 event queue because the queue was full.  Try posting again. */\r
 455                                 FreeRTOS_NetworkDown();\r
 456                         }\r
 457                 }\r
 458         }\r
 459 }\r
 460 /*-----------------------------------------------------------*/\r
 461 \r
 462 void FreeRTOS_NetworkDown( void )\r
 463 {\r
 464 static const xIPStackEvent_t xNetworkDownEvent = { eNetworkDownEvent, NULL };\r
 465 const portTickType xDontBlock = 0;\r
 466 \r
 467         /* Simply send the network task the appropriate event. */\r
 468         if( xQueueSendToBack( xNetworkEventQueue, &xNetworkDownEvent, xDontBlock ) != pdPASS )\r
 469         {\r
 470                 xNetworkDownEventPending = pdTRUE;\r
 471         }\r
 472         else\r
 473         {\r
 474                 xNetworkDownEventPending = pdFALSE;\r
 475         }\r
 476 \r
 477         iptraceNETWORK_DOWN();\r
 478 }\r
 479 /*-----------------------------------------------------------*/\r
 480 \r
 481 portBASE_TYPE FreeRTOS_NetworkDownFromISR( void )\r
 482 {\r
 483 static const xIPStackEvent_t xNetworkDownEvent = { eNetworkDownEvent, NULL };\r
 484 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;\r
 485 \r
 486         /* Simply send the network task the appropriate event. */\r
 487         if( xQueueSendToBackFromISR( xNetworkEventQueue, &xNetworkDownEvent, &xHigherPriorityTaskWoken ) != pdPASS )\r
 488         {\r
 489                 xNetworkDownEventPending = pdTRUE;\r
 490         }\r
 491         else\r
 492         {\r
 493                 xNetworkDownEventPending = pdFALSE;\r
 494         }\r
 495         iptraceNETWORK_DOWN();\r
 496 \r
 497         return xHigherPriorityTaskWoken;\r
 498 }\r
 499 /*-----------------------------------------------------------*/\r
 500 \r
 501 void *FreeRTOS_GetUDPPayloadBuffer( size_t xRequestedSizeBytes, portTickType xBlockTimeTicks )\r
 502 {\r
 503 xNetworkBufferDescriptor_t *pxNetworkBuffer;\r
 504 void *pvReturn;\r
 505 \r
 506         /* Cap the block time.  The reason for this is explained where\r
 507         ipconfigMAX_SEND_BLOCK_TIME_TICKS is defined (assuming an official\r
 508         FreeRTOSIPConfig.h header file is being used). */\r
 509         if( xBlockTimeTicks > ipconfigMAX_SEND_BLOCK_TIME_TICKS )\r
 510         {\r
 511                 xBlockTimeTicks = ipconfigMAX_SEND_BLOCK_TIME_TICKS;\r
 512         }\r
 513 \r
 514         /* Obtain a network buffer with the required amount of storage. */\r
 515         pxNetworkBuffer = pxNetworkBufferGet( sizeof( xUDPPacket_t ) + xRequestedSizeBytes, xBlockTimeTicks );\r
 516 \r
 517         if( pxNetworkBuffer != NULL )\r
 518         {\r
 519                 /* Leave space for the UPD header. */\r
 520                 pvReturn = ( void * ) &( pxNetworkBuffer->pucEthernetBuffer[ ipUDP_PAYLOAD_OFFSET ] );\r
 521         }\r
 522         else\r
 523         {\r
 524                 pvReturn = NULL;\r
 525         }\r
 526 \r
 527         return ( void * ) pvReturn;\r
 528 }\r
 529 /*-----------------------------------------------------------*/\r
 530 \r
 531 void FreeRTOS_ReleaseUDPPayloadBuffer( void *pvBuffer )\r
 532 {\r
 533 uint8_t *pucBuffer;\r
 534 \r
 535         /* Obtain the network buffer from the zero copy pointer. */\r
 536         pucBuffer = ( uint8_t * ) pvBuffer;\r
 537         pucBuffer -= ( ipBUFFER_PADDING + sizeof( xUDPPacket_t ) );\r
 538 \r
 539         vNetworkBufferRelease( * ( ( xNetworkBufferDescriptor_t ** ) pucBuffer ) );\r
 540 }\r
 541 /*-----------------------------------------------------------*/\r
 542 \r
 543 uint8_t * FreeRTOS_GetMACAddress( void )\r
 544 {\r
 545         return ipLOCAL_MAC_ADDRESS;\r
 546 }\r
 547 /*-----------------------------------------------------------*/\r
 548 \r
 549 portBASE_TYPE FreeRTOS_IPInit( const uint8_t ucIPAddress[ ipIP_ADDRESS_LENGTH_BYTES ], const uint8_t ucNetMask[ ipIP_ADDRESS_LENGTH_BYTES ], const uint8_t ucGatewayAddress[ ipIP_ADDRESS_LENGTH_BYTES ], const uint8_t ucDNSServerAddress[ ipIP_ADDRESS_LENGTH_BYTES ], const uint8_t ucMACAddress[ ipMAC_ADDRESS_LENGTH_BYTES ] )\r
 550 {\r
 551 static portBASE_TYPE xReturn = pdFALSE;\r
 552 \r
 553         /* Only create the IP event queue if it has not already been created, in\r
 554         case this function is called more than once. */\r
 555         if( xNetworkEventQueue == NULL )\r
 556         {\r
 557                 xNetworkEventQueue = xQueueCreate( ipconfigEVENT_QUEUE_LENGTH, sizeof( xIPStackEvent_t ) );\r
 558                 configASSERT( xNetworkEventQueue );\r
 559                 vQueueAddToRegistry( xNetworkEventQueue, ( signed char * ) "NetEvnt" );\r
 560         }\r
 561 \r
 562         if( xNetworkBuffersInitialise() == pdPASS )\r
 563         {\r
 564                 if( xNetworkEventQueue != NULL )\r
 565                 {\r
 566                         /* xReturn is static to ensure the network interface is not\r
 567                         initialised     twice. */\r
 568                         if( xReturn == pdFALSE )\r
 569                         {\r
 570                                 /* Store the local IP and MAC address. */\r
 571                                 xNetworkAddressing.ulDefaultIPAddress = FreeRTOS_inet_addr_quick( ucIPAddress[ 0 ], ucIPAddress[ 1 ], ucIPAddress[ 2 ], ucIPAddress[ 3 ] );\r
 572                                 xNetworkAddressing.ulNetMask = FreeRTOS_inet_addr_quick( ucNetMask[ 0 ], ucNetMask[ 1 ], ucNetMask[ 2 ], ucNetMask[ 3 ] );\r
 573                                 xNetworkAddressing.ulGatewayAddress = FreeRTOS_inet_addr_quick( ucGatewayAddress[ 0 ], ucGatewayAddress[ 1 ], ucGatewayAddress[ 2 ], ucGatewayAddress[ 3 ] );\r
 574                                 xNetworkAddressing.ulDNSServerAddress = FreeRTOS_inet_addr_quick( ucDNSServerAddress[ 0 ], ucDNSServerAddress[ 1 ], ucDNSServerAddress[ 2 ], ucDNSServerAddress[ 3 ] );\r
 575 \r
 576                                 #if ipconfigUSE_DHCP == 1\r
 577                                 {\r
 578                                         /* The IP address is not set until DHCP completes. */\r
 579                                         *ipLOCAL_IP_ADDRESS_POINTER = 0x00UL;\r
 580                                 }\r
 581                                 #else\r
 582                                 {\r
 583                                         *ipLOCAL_IP_ADDRESS_POINTER = xNetworkAddressing.ulDefaultIPAddress;\r
 584                                 }\r
 585                                 #endif /* ipconfigUSE_DHCP == 1 */\r
 586 \r
 587                                 /* The MAC address is stored in the start of the default packet\r
 588                                 header fragment, which is used when sending UDP packets. */\r
 589                                 memcpy( ( void * ) ipLOCAL_MAC_ADDRESS, ( void * ) ucMACAddress, ( size_t ) ipMAC_ADDRESS_LENGTH_BYTES );\r
 590 \r
 591                                 /* Prepare the sockets interface. */\r
 592                                 FreeRTOS_SocketsInit();\r
 593 \r
 594                                 /* Create the task that processes Ethernet and stack events. */\r
 595                                 xReturn = xTaskCreate( prvIPTask, ( const signed char * const ) "UDP/IP", ipconfigUDP_TASK_STACK_SIZE_WORDS, NULL, ipconfigUDP_TASK_PRIORITY, NULL );\r
 596                         }\r
 597                 }\r
 598         }\r
 599 \r
 600         return xReturn;\r
 601 }\r
 602 /*-----------------------------------------------------------*/\r
 603 \r
 604 void FreeRTOS_GetAddressConfiguration( uint32_t *pulIPAddress, uint32_t *pulNetMask, uint32_t *pulGatewayAddress, uint32_t *pulDNSServerAddress )\r
 605 {\r
 606         if( pulIPAddress != NULL )\r
 607         {\r
 608                 *pulIPAddress = *ipLOCAL_IP_ADDRESS_POINTER;\r
 609         }\r
 610 \r
 611         if( pulNetMask != NULL )\r
 612         {\r
 613                 *pulNetMask = xNetworkAddressing.ulNetMask;\r
 614         }\r
 615 \r
 616         if( pulGatewayAddress != NULL )\r
 617         {\r
 618                 *pulGatewayAddress = xNetworkAddressing.ulGatewayAddress;\r
 619         }\r
 620 \r
 621         if( pulDNSServerAddress != NULL )\r
 622         {\r
 623                 *pulDNSServerAddress = xNetworkAddressing.ulDNSServerAddress;\r
 624         }\r
 625 }\r
 626 /*-----------------------------------------------------------*/\r
 627 \r
 628 #if ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )\r
 629 \r
 630         portBASE_TYPE FreeRTOS_SendPingRequest( uint32_t ulIPAddress, size_t xNumberOfBytesToSend, portTickType xBlockTimeTicks )\r
 631         {\r
 632         xNetworkBufferDescriptor_t *pxNetworkBuffer;\r
 633         xICMPHeader_t *pxICMPHeader;\r
 634         portBASE_TYPE xReturn = pdFAIL;\r
 635         static uint16_t usSequenceNumber = 0;\r
 636         uint8_t *pucChar;\r
 637         xIPStackEvent_t xStackTxEvent = { eStackTxEvent, NULL };\r
 638 \r
 639                 if( xNumberOfBytesToSend < ( ( ipconfigNETWORK_MTU - sizeof( xIPHeader_t ) ) - sizeof( xICMPHeader_t ) ) )\r
 640                 {\r
 641                         pxNetworkBuffer = pxNetworkBufferGet( xNumberOfBytesToSend + sizeof( xICMPPacket_t ), xBlockTimeTicks );\r
 642 \r
 643                         if( pxNetworkBuffer != NULL )\r
 644                         {\r
 645                                 pxICMPHeader = ( xICMPHeader_t * ) &( pxNetworkBuffer->pucEthernetBuffer[ ipIP_PAYLOAD_OFFSET ] );\r
 646                                 usSequenceNumber++;\r
 647 \r
 648                                 /* Fill in the basic header information. */\r
 649                                 pxICMPHeader->ucTypeOfMessage = ipICMP_ECHO_REQUEST;\r
 650                                 pxICMPHeader->ucTypeOfService = 0;\r
 651                                 pxICMPHeader->usIdentifier = usSequenceNumber;\r
 652                                 pxICMPHeader->usSequenceNumber = usSequenceNumber;\r
 653                                 pxICMPHeader->usChecksum = 0;\r
 654 \r
 655                                 /* Find the start of the data. */\r
 656                                 pucChar = ( uint8_t * ) pxICMPHeader;\r
 657                                 pucChar += sizeof( xICMPHeader_t );\r
 658 \r
 659                                 /* Just memset the data to a fixed value. */\r
 660                                 memset( ( void * ) pucChar, ( int ) ipECHO_DATA_FILL_BYTE, xNumberOfBytesToSend );\r
 661 \r
 662                                 /* The message is complete, calculate the checksum. */\r
 663                                 pxICMPHeader->usChecksum = prvGenerateChecksum( ( uint8_t * ) pxICMPHeader, ( uint16_t ) ( xNumberOfBytesToSend + sizeof( xICMPHeader_t ) ) );\r
 664 \r
 665                                 /* Complete the network buffer information. */\r
 666                                 pxNetworkBuffer->ulIPAddress = ulIPAddress;\r
 667                                 pxNetworkBuffer->usPort = ipPACKET_CONTAINS_ICMP_DATA;\r
 668                                 pxNetworkBuffer->xDataLength = xNumberOfBytesToSend + sizeof( xICMPHeader_t );\r
 669 \r
 670                                 /* Send to the stack. */\r
 671                                 xStackTxEvent.pvData = pxNetworkBuffer;\r
 672                                 if( xQueueSendToBack( xNetworkEventQueue, &xStackTxEvent, xBlockTimeTicks ) != pdPASS )\r
 673                                 {\r
 674                                         vNetworkBufferRelease( pxNetworkBuffer );\r
 675                                         iptraceSTACK_TX_EVENT_LOST( ipSTACK_TX_EVENT );\r
 676                                 }\r
 677                                 else\r
 678                                 {\r
 679                                         xReturn = usSequenceNumber;\r
 680                                 }\r
 681                         }\r
 682                 }\r
 683                 else\r
 684                 {\r
 685                         /* The requested number of bytes will not fit in the available space\r
 686                         in the network buffer.  Outgoing fragmentation is only supported for\r
 687                         UDP packets. */\r
 688                 }\r
 689 \r
 690                 return xReturn;\r
 691         }\r
 692 \r
 693 #endif /* ipconfigSUPPORT_OUTGOING_PINGS == 1 */\r
 694 \r
 695 /*-----------------------------------------------------------*/\r
 696 \r
 697 static portBASE_TYPE prvSendEventToIPTask( eIPEvent_t eEvent )\r
 698 {\r
 699 xIPStackEvent_t xEventMessage;\r
 700 const portTickType xDontBlock = 0;\r
 701 portBASE_TYPE xReturn;\r
 702 \r
 703         xEventMessage.eEventType = eEvent;\r
 704         xReturn = xQueueSendToBack( xNetworkEventQueue, &xEventMessage, xDontBlock );\r
 705 \r
 706         if( xReturn != pdPASS )\r
 707         {\r
 708                 iptraceSTACK_TX_EVENT_LOST( ipARP_TIMER_EVENT );\r
 709         }\r
 710 \r
 711         return xReturn;\r
 712 }\r
 713 /*-----------------------------------------------------------*/\r
 714 \r
 715 void vIPFunctionsTimerCallback( xTimerHandle xTimer )\r
 716 {\r
 717 eIPEvent_t eMessage;\r
 718 \r
 719         /* This time can be used to send more than one type of message to the IP\r
 720         task.  The message ID is stored in the ID of the timer.  The strange\r
 721         casting is to avoid compiler warnings. */\r
 722         eMessage = ( eIPEvent_t ) ( ( int ) pvTimerGetTimerID( xTimer ) );\r
 723 \r
 724         prvSendEventToIPTask( eMessage );\r
 725 }\r
 726 /*-----------------------------------------------------------*/\r
 727 \r
 728 static void prvOutputARPRequest( uint32_t ulIPAddress )\r
 729 {\r
 730 xNetworkBufferDescriptor_t *pxNetworkBuffer;\r
 731 \r
 732         /* This is called from the context of the IP event task, so a block time\r
 733         must not be used. */\r
 734         pxNetworkBuffer = pxNetworkBufferGet( sizeof( xARPPacket_t ), 0 );\r
 735         if( pxNetworkBuffer != NULL )\r
 736         {\r
 737                 pxNetworkBuffer->ulIPAddress = ulIPAddress;\r
 738                 prvGenerateARPRequestPacket( pxNetworkBuffer );\r
 739                 xNetworkInterfaceOutput( pxNetworkBuffer );\r
 740         }\r
 741 }\r
 742 /*-----------------------------------------------------------*/\r
 743 \r
 744 static void prvAgeARPCache( void )\r
 745 {\r
 746 portBASE_TYPE x;\r
 747 \r
 748         /* Loop through each entry in the ARP cache. */\r
 749         for( x = 0; x < ipconfigARP_CACHE_ENTRIES; x++ )\r
 750         {\r
 751                 /* If the entry is valid (its age is greater than zero). */\r
 752                 if( xARPCache[ x ].ucAge > 0U )\r
 753                 {\r
 754                         /* Decrement the age value of the entry in this ARP cache table row.\r
 755                         When the age reaches zero it is no longer considered valid. */\r
 756                         ( xARPCache[ x ].ucAge )--;\r
 757 \r
 758                         /* If the entry has a MAC address of 0, then it is waiting an ARP\r
 759                         reply, and the ARP request should be retransmitted. */\r
 760                         if( memcmp( ( void * ) &xNullMACAddress, ( void * ) &( xARPCache[ x ].xMACAddress ), sizeof( xMACAddress_t ) ) == 0 )\r
 761                         {\r
 762                                 prvOutputARPRequest( xARPCache[ x ].ulIPAddress );\r
 763                         }\r
 764                         else if( xARPCache[ x ].ucAge <= ipMAX_ARP_AGE_BEFORE_NEW_ARP_REQUEST )\r
 765                         {\r
 766                                 /* This entry will get removed soon.  See if the MAC address is\r
 767                                 still valid to prevent this happening. */\r
 768                                 iptraceARP_TABLE_ENTRY_WILL_EXPIRE( xARPCache[ x ].ulIPAddress );\r
 769                                 prvOutputARPRequest( xARPCache[ x ].ulIPAddress );\r
 770                         }\r
 771                         else\r
 772                         {\r
 773                                 /* The age has just ticked down, with nothing to do. */\r
 774                         }\r
 775 \r
 776                         if( xARPCache[ x ].ucAge == 0 )\r
 777                         {\r
 778                                 /* The entry is no longer valid.  Wipe it out. */\r
 779                                 iptraceARP_TABLE_ENTRY_EXPIRED( xARPCache[ x ].ulIPAddress );\r
 780                                 xARPCache[ x ].ulIPAddress = 0UL;\r
 781                         }\r
 782                 }\r
 783         }\r
 784 }\r
 785 /*-----------------------------------------------------------*/\r
 786 \r
 787 static eARPLookupResult_t prvGetARPCacheEntry( uint32_t *pulIPAddress, xMACAddress_t * const pxMACAddress )\r
 788 {\r
 789 portBASE_TYPE x;\r
 790 eARPLookupResult_t eReturn;\r
 791 uint32_t ulAddressToLookup;\r
 792 \r
 793         if( *pulIPAddress == ipBROADCAST_IP_ADDRESS )\r
 794         {\r
 795                 /* This is a broadcast so uses the broadcast MAC address. */\r
 796                 memcpy( ( void * ) pxMACAddress, &xBroadcastMACAddress, sizeof( xMACAddress_t ) );\r
 797                 eReturn = eARPCacheHit;\r
 798         }\r
 799         else if( *ipLOCAL_IP_ADDRESS_POINTER == 0UL )\r
 800         {\r
 801                 /* The IP address has not yet been assigned, so there is nothing that\r
 802                 can be done. */\r
 803                 eReturn = eCantSendPacket;\r
 804         }\r
 805         else\r
 806         {\r
 807                 if( ( *pulIPAddress & xNetworkAddressing.ulNetMask ) != ( ( *ipLOCAL_IP_ADDRESS_POINTER ) & xNetworkAddressing.ulNetMask ) )\r
 808                 {\r
 809                         /* The IP address is off the local network, so look up the hardware\r
 810                         address of the router, if any. */\r
 811                         ulAddressToLookup = xNetworkAddressing.ulGatewayAddress;\r
 812                 }\r
 813                 else\r
 814                 {\r
 815                         /* The IP address is on the local network, so lookup the requested\r
 816                         IP address directly. */\r
 817                         ulAddressToLookup = *pulIPAddress;\r
 818                 }\r
 819 \r
 820                 if( ulAddressToLookup == 0UL )\r
 821                 {\r
 822                         /* The address is not on the local network, and there is not a\r
 823                         router. */\r
 824                         eReturn = eCantSendPacket;\r
 825                 }\r
 826                 else\r
 827                 {\r
 828                         eReturn = eARPCacheMiss;\r
 829 \r
 830                         /* Loop through each entry in the ARP cache. */\r
 831                         for( x = 0; x < ipconfigARP_CACHE_ENTRIES; x++ )\r
 832                         {\r
 833                                 /* Does this row in the ARP cache table hold an entry for the IP\r
 834                                 address being queried? */\r
 835                                 if( xARPCache[ x ].ulIPAddress == ulAddressToLookup )\r
 836                                 {\r
 837                                         /* The IP address matched.  Is there a valid MAC address? */\r
 838                                         if( memcmp( ( void * ) &xNullMACAddress, ( void * ) &( xARPCache[ x ].xMACAddress ), sizeof( xMACAddress_t ) ) == 0 )\r
 839                                         {\r
 840                                                 /* This entry is waiting an ARP reply, so is not valid. */\r
 841                                                 eReturn = eCantSendPacket;\r
 842                                         }\r
 843                                         else\r
 844                                         {\r
 845                                                 /* A valid entry was found. */\r
 846                                                 memcpy( pxMACAddress, &( xARPCache[ x ].xMACAddress ), sizeof( xMACAddress_t ) );\r
 847                                                 eReturn = eARPCacheHit;\r
 848                                         }\r
 849                                 }\r
 850 \r
 851                                 if( eReturn != eARPCacheMiss )\r
 852                                 {\r
 853                                         break;\r
 854                                 }\r
 855                         }\r
 856 \r
 857                         if( eReturn == eARPCacheMiss )\r
 858                         {\r
 859                                 /* It might be that the ARP has to go to the gateway. */\r
 860                                 *pulIPAddress = ulAddressToLookup;\r
 861                         }\r
 862                 }\r
 863         }\r
 864 \r
 865         return eReturn;\r
 866 }\r
 867 /*-----------------------------------------------------------*/\r
 868 \r
 869 static void prvRefreshARPCacheEntry( const xMACAddress_t * const pxMACAddress, const uint32_t ulIPAddress )\r
 870 {\r
 871 portBASE_TYPE x, xEntryFound = pdFALSE, xOldestEntry = 0;\r
 872 uint8_t ucMinAgeFound = 0U;\r
 873 \r
 874         /* Only process the IP address if it is on the local network. */\r
 875         if( ( ulIPAddress & xNetworkAddressing.ulNetMask ) == ( ( *ipLOCAL_IP_ADDRESS_POINTER ) & xNetworkAddressing.ulNetMask ) )\r
 876         {\r
 877                 /* Start with the maximum possible number. */\r
 878                 ucMinAgeFound--;\r
 879 \r
 880                 /* For each entry in the ARP cache table. */\r
 881                 for( x = 0; x < ipconfigARP_CACHE_ENTRIES; x++ )\r
 882                 {\r
 883                         /* Does this line in the cache table hold an entry for the IP\r
 884                         address being queried? */\r
 885                         if( xARPCache[ x ].ulIPAddress == ulIPAddress )\r
 886                         {\r
 887                                 /* If the MAC address is all zeros then the refresh is due to\r
 888                                 an ARP reply, so in effect this is a new entry in the ARP\r
 889                                 cache. */\r
 890                                 if( memcmp( &( xARPCache[ x ].xMACAddress ), &xNullMACAddress, sizeof( xMACAddress_t ) ) == 0 )\r
 891                                 {\r
 892                                         iptraceARP_TABLE_ENTRY_CREATED( xARPCache[ x ].ulIPAddress, *pxMACAddress );\r
 893                                 }\r
 894 \r
 895                                 /* Refresh the cache entry so the entry's age is back to its\r
 896                                 maximum value. */\r
 897                                 xARPCache[ x ].ucAge = ipconfigMAX_ARP_AGE;\r
 898                                 memcpy( &( xARPCache[ x ].xMACAddress ), pxMACAddress, sizeof( xMACAddress_t ) );\r
 899                                 xEntryFound = pdTRUE;\r
 900                                 break;\r
 901                         }\r
 902                         else\r
 903                         {\r
 904                                 /* As the table is traversed, remember the table row that\r
 905                                 contains the oldest entry (the lowest age count, as ages are\r
 906                                 decremented to zero) so the row can be re-used if this function\r
 907                                 needs to add an entry that does not already exist. */\r
 908                                 if( xARPCache[ x ].ucAge < ucMinAgeFound )\r
 909                                 {\r
 910                                         ucMinAgeFound = xARPCache[ x ].ucAge;\r
 911                                         xOldestEntry = x;\r
 912                                 }\r
 913                         }\r
 914                 }\r
 915 \r
 916                 if( xEntryFound == pdFALSE )\r
 917                 {\r
 918                         /* The wanted entry does not already exist.  Add the entry into the\r
 919                         cache, replacing the oldest entry (which might be an empty entry). */\r
 920                         xARPCache[ xOldestEntry ].ulIPAddress = ulIPAddress;\r
 921                         memcpy( &( xARPCache[ xOldestEntry ].xMACAddress ), pxMACAddress, sizeof( xMACAddress_t ) );\r
 922 \r
 923                         /* If the MAC address is all zeros, then this entry is not yet\r
 924                         complete but still waiting the reply from an ARP request.  When this\r
 925                         is the case     the age is set to a much lower value as an ARP\r
 926                         retransmission will be generated each time the ARP timer is called\r
 927                         while the reply is still outstanding. */\r
 928                         if( pxMACAddress == &xNullMACAddress )\r
 929                         {\r
 930                                 xARPCache[ xOldestEntry ].ucAge = ipconfigMAX_ARP_RETRANSMISSIONS;\r
 931                         }\r
 932                         else\r
 933                         {\r
 934                                 iptraceARP_TABLE_ENTRY_CREATED( xARPCache[ xOldestEntry ].ulIPAddress, xARPCache[ xOldestEntry ].xMACAddress );\r
 935                                 xARPCache[ xOldestEntry ].ucAge = ipconfigMAX_ARP_AGE;\r
 936                         }\r
 937                 }\r
 938         }\r
 939 }\r
 940 /*-----------------------------------------------------------*/\r
 941 \r
 942 #if ipconfigCAN_FRAGMENT_OUTGOING_PACKETS == 1\r
 943 \r
 944         static void prvCalculateFragmentOffsetAndLength( xIPFragmentParameters_t *pxFragmentParameters, uint16_t *pusFragmentOffset, uint16_t *pusFragmentLength )\r
 945         {\r
 946                 *pusFragmentOffset = pxFragmentParameters->usFragmentedPacketOffset;\r
 947 \r
 948                 if( *pusFragmentOffset != 0 )\r
 949                 {\r
 950                         /* Take into account that the payload has had a UDP header added in the\r
 951                         first fragment of the set. */\r
 952                         *pusFragmentOffset += sizeof( xUDPHeader_t );\r
 953                 }\r
 954 \r
 955                 /* The offset is defined in multiples of 8 bytes. */\r
 956                 *pusFragmentOffset >>= ipSHIFT_TO_DIVIDE_BY_8;\r
 957                 *pusFragmentLength = pxFragmentParameters->usFragmentLength;\r
 958 \r
 959                 if( ( pxFragmentParameters->ucSocketOptions & FREERTOS_NOT_LAST_IN_FRAGMENTED_PACKET ) != 0 )\r
 960                 {\r
 961                         /* Set the more fragments flag. */\r
 962                         *pusFragmentOffset |= ipMORE_FRAGMENTS_FLAG_BIT;\r
 963                 }\r
 964         }\r
 965 \r
 966 #endif\r
 967 /*-----------------------------------------------------------*/\r
 968 \r
 969 static void prvCompleteUDPHeader( xNetworkBufferDescriptor_t *pxNetworkBuffer, xUDPPacket_t *pxUDPPacket, uint8_t ucSocketOptions )\r
 970 {\r
 971 xUDPHeader_t *pxUDPHeader;\r
 972 \r
 973         pxUDPHeader = &( pxUDPPacket->xUDPHeader );\r
 974 \r
 975         pxUDPHeader->usDestinationPort = pxNetworkBuffer->usPort;\r
 976         pxUDPHeader->usSourcePort = pxNetworkBuffer->usBoundPort;\r
 977         pxUDPHeader->usLength = ( uint16_t ) ( pxNetworkBuffer->xDataLength + sizeof( xUDPHeader_t ) );\r
 978         pxUDPHeader->usLength = FreeRTOS_htons( pxUDPPacket->xUDPHeader.usLength );\r
 979         pxUDPHeader->usChecksum = 0;\r
 980 \r
 981         if( ( ucSocketOptions & FREERTOS_SO_UDPCKSUM_OUT ) != 0U )\r
 982         {\r
 983                 pxUDPHeader->usChecksum = prvGenerateUDPChecksum( pxUDPPacket );\r
 984                 if( pxUDPHeader->usChecksum == 0x00 )\r
 985                 {\r
 986                         /* A calculated checksum of 0 must be inverted as 0 means the\r
 987                         checksum is disabled. */\r
 988                         pxUDPHeader->usChecksum = 0xffffU;\r
 989                 }\r
 990         }\r
 991 }\r
 992 /*-----------------------------------------------------------*/\r
 993 \r
 994 #if ipconfigCAN_FRAGMENT_OUTGOING_PACKETS == 1\r
 995 \r
 996         static void prvProcessGeneratedPacket( xNetworkBufferDescriptor_t * const pxNetworkBuffer )\r
 997         {\r
 998         xUDPPacket_t *pxUDPPacket;\r
 999         xUDPHeader_t *pxUDPHeader;\r
1000         xIPHeader_t *pxIPHeader;\r
1001         eARPLookupResult_t eReturned;\r
1002         eIPFragmentStatus_t eFragmentStatus;\r
1003         uint16_t usFragmentOffset = 0, usFragmentLength;\r
1004         xIPFragmentParameters_t *pxFragmentParameters;\r
1005         static uint16_t usPacketIdentifier = 0U;\r
1006 \r
1007                 /* Map the UDP packet onto the start of the frame. */\r
1008                 pxUDPPacket = ( xUDPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer;\r
1009 \r
1010                 /* Determine the ARP cache status for the requested IP address. */\r
1011                 eReturned = prvGetARPCacheEntry( &( pxNetworkBuffer->ulIPAddress ), &( pxUDPPacket->xEthernetHeader.xDestinationAddress ) );\r
1012 \r
1013                 if( eReturned != eCantSendPacket )\r
1014                 {\r
1015                         if( eReturned == eARPCacheHit )\r
1016                         {\r
1017                                 iptraceSENDING_UDP_PACKET( pxNetworkBuffer->ulIPAddress );\r
1018 \r
1019                                 /* Create short cuts to the data within the packet. */\r
1020                                 pxUDPHeader = &( pxUDPPacket->xUDPHeader );\r
1021                                 pxIPHeader = &( pxUDPPacket->xIPHeader );\r
1022                                 pxFragmentParameters = ( xIPFragmentParameters_t * ) &( pxNetworkBuffer->pucEthernetBuffer[ ipFRAGMENTATION_PARAMETERS_OFFSET ] );\r
1023 \r
1024                                 /* IP header source and destination addresses must be set\r
1025                                 before the UDP checksum is calculated. */\r
1026                                 pxIPHeader->ulDestinationIPAddress = pxNetworkBuffer->ulIPAddress;\r
1027                                 pxIPHeader->ulSourceIPAddress = *ipLOCAL_IP_ADDRESS_POINTER;\r
1028 \r
1029                                 /* If the packet is not fragmented, or if the packet is the\r
1030                                 first in a fragmented packet, then a UDP header is required. */\r
1031                                 if( ( pxFragmentParameters->ucSocketOptions & FREERTOS_FRAGMENTED_PACKET ) == 0 )\r
1032                                 {\r
1033                                         eFragmentStatus = eNotFragment;\r
1034 \r
1035                                         #if ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )\r
1036                                         {\r
1037                                                 /* Is it possible that the packet is not actually a UDP\r
1038                                                 packet after all, but an ICMP packet. */\r
1039                                                 if( pxNetworkBuffer->usPort != ipPACKET_CONTAINS_ICMP_DATA )\r
1040                                                 {\r
1041                                                         prvCompleteUDPHeader( pxNetworkBuffer, pxUDPPacket, pxFragmentParameters->ucSocketOptions );\r
1042                                                 }\r
1043                                         }\r
1044                                         #else /* ipconfigSUPPORT_OUTGOING_PINGS */\r
1045                                         {\r
1046                                                 prvCompleteUDPHeader( pxNetworkBuffer, pxUDPPacket, pxFragmentParameters->ucSocketOptions );\r
1047                                         }\r
1048                                         #endif /* ipconfigSUPPORT_OUTGOING_PINGS */\r
1049 \r
1050 \r
1051                                         usFragmentLength = 0U;\r
1052 \r
1053                                         /* The identifier is incremented as this is a new and\r
1054                                         unfragmented IP packet. */\r
1055                                         usPacketIdentifier++;\r
1056                                 }\r
1057                                 else if( pxFragmentParameters->usFragmentedPacketOffset == 0 )\r
1058                                 {\r
1059                                         eFragmentStatus = eFirstFragment;\r
1060                                         prvCalculateFragmentOffsetAndLength( pxFragmentParameters, &usFragmentOffset, &usFragmentLength );\r
1061                                         /* Note FREERTOS_SO_UDPCKSUM_OUT is used because checksums\r
1062                                         cannot currently be used on fragmented packets. */\r
1063                                         pxFragmentParameters->ucSocketOptions &= ~FREERTOS_SO_UDPCKSUM_OUT;\r
1064                                         prvCompleteUDPHeader( pxNetworkBuffer, pxUDPPacket, pxFragmentParameters->ucSocketOptions );\r
1065 \r
1066                                         /* The identifier is incremented because, although this is a\r
1067                                         fragmented packet, it is the first in the fragmentation\r
1068                                         set. */\r
1069                                         usPacketIdentifier++;\r
1070                                 }\r
1071                                 else\r
1072                                 {\r
1073                                         eFragmentStatus = eFollowingFragment;\r
1074                                         prvCalculateFragmentOffsetAndLength( pxFragmentParameters, &usFragmentOffset, &usFragmentLength );\r
1075                                 }\r
1076 \r
1077                                 /* memcpy() the constant parts of the header information into the\r
1078                                 correct location within the packet.  This fills in:\r
1079                                         xEthernetHeader.xSourceAddress\r
1080                                         xEthernetHeader.usFrameType\r
1081                                         xIPHeader.ucVersionHeaderLength\r
1082                                         xIPHeader.ucDifferentiatedServicesCode\r
1083                                         xIPHeader.usLength\r
1084                                         xIPHeader.usIdentification\r
1085                                         xIPHeader.usFragmentOffset\r
1086                                         xIPHeader.ucTimeToLive\r
1087                                         xIPHeader.ucProtocol\r
1088                                 and\r
1089                                         xIPHeader.usHeaderChecksum\r
1090                                 */\r
1091                                 memcpy( ( void *) &( pxUDPPacket->xEthernetHeader.xSourceAddress ), ( void * ) xDefaultPartUDPPacketHeader, sizeof( xDefaultPartUDPPacketHeader ) );\r
1092 \r
1093                                 /* The fragment status is used to complete the length and\r
1094                                 fragment offset fields. */\r
1095                                 if( eFragmentStatus == eNotFragment )\r
1096                                 {\r
1097                                         pxIPHeader->usLength = ( uint16_t ) ( pxNetworkBuffer->xDataLength + sizeof( xIPHeader_t ) + sizeof( xUDPHeader_t ) );\r
1098                                 }\r
1099                                 else if( eFragmentStatus == eFirstFragment )\r
1100                                 {\r
1101                                         pxIPHeader->usFragmentOffset = FreeRTOS_htons( usFragmentOffset );\r
1102                                         pxIPHeader->usLength = ( uint16_t ) ( usFragmentLength + sizeof( xIPHeader_t ) + sizeof( xUDPHeader_t ) );\r
1103                                 }\r
1104                                 else\r
1105                                 {\r
1106                                         pxIPHeader->usFragmentOffset = FreeRTOS_htons( usFragmentOffset );\r
1107                                         pxIPHeader->usLength = ( uint16_t ) ( usFragmentLength + sizeof( xIPHeader_t ) );\r
1108                                 }\r
1109 \r
1110                                 /* The total transmit size adds on the Ethernet header. */\r
1111                                 pxNetworkBuffer->xDataLength = pxIPHeader->usLength + sizeof( xEthernetHeader_t );\r
1112                                 pxIPHeader->usLength = FreeRTOS_htons( pxIPHeader->usLength );\r
1113                                 pxIPHeader->ulDestinationIPAddress = pxNetworkBuffer->ulIPAddress;\r
1114                                 pxIPHeader->usIdentification = usPacketIdentifier;\r
1115                                 pxIPHeader->usHeaderChecksum = prvGenerateChecksum( ( uint8_t * ) &( pxIPHeader->ucVersionHeaderLength ), ipIP_HEADER_LENGTH );\r
1116                         }\r
1117                         else if ( eReturned == eARPCacheMiss )\r
1118                         {\r
1119                                 /* Send an ARP for the required IP address. */\r
1120                                 iptracePACKET_DROPPED_TO_GENERATE_ARP( pxNetworkBuffer->ulIPAddress );\r
1121                                 prvGenerateARPRequestPacket( pxNetworkBuffer );\r
1122 \r
1123                                 /* Add an entry to the ARP table with a null hardware address.\r
1124                                 This allows the ARP timer to know that an ARP reply is\r
1125                                 outstanding, and perform retransmissions if necessary. */\r
1126                                 prvRefreshARPCacheEntry( &xNullMACAddress, pxNetworkBuffer->ulIPAddress );\r
1127                         }\r
1128                         else\r
1129                         {\r
1130                                 /* The lookup indicated that an ARP request has already been\r
1131                                 sent out for the queried IP address. */\r
1132                                 eReturned = eCantSendPacket;\r
1133                         }\r
1134                 }\r
1135 \r
1136                 if( eReturned != eCantSendPacket )\r
1137                 {\r
1138                         /* The network driver is responsible for freeing the network buffer\r
1139                         after the packet has been sent. */\r
1140                         xNetworkInterfaceOutput( pxNetworkBuffer );\r
1141                 }\r
1142                 else\r
1143                 {\r
1144                         /* The packet can't be sent (DHCP not completed?).  Just drop the\r
1145                         packet. */\r
1146                         vNetworkBufferRelease( pxNetworkBuffer );\r
1147                 }\r
1148         }\r
1149 \r
1150 #else /* ipconfigCAN_FRAGMENT_OUTGOING_PACKETS == 1 */\r
1151 \r
1152         static void prvProcessGeneratedPacket( xNetworkBufferDescriptor_t * const pxNetworkBuffer )\r
1153         {\r
1154         xUDPPacket_t *pxUDPPacket;\r
1155         xIPHeader_t *pxIPHeader;\r
1156         eARPLookupResult_t eReturned;\r
1157 \r
1158                 /* Map the UDP packet onto the start of the frame. */\r
1159                 pxUDPPacket = ( xUDPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer;\r
1160 \r
1161                 /* Determine the ARP cache status for the requested IP address. */\r
1162                 eReturned = prvGetARPCacheEntry( &( pxNetworkBuffer->ulIPAddress ), &( pxUDPPacket->xEthernetHeader.xDestinationAddress ) );\r
1163                 if( eReturned != eCantSendPacket )\r
1164                 {\r
1165                         if( eReturned == eARPCacheHit )\r
1166                         {\r
1167                                 iptraceSENDING_UDP_PACKET( pxNetworkBuffer->ulIPAddress );\r
1168 \r
1169                                 /* Create short cuts to the data within the packet. */\r
1170                                 pxIPHeader = &( pxUDPPacket->xIPHeader );\r
1171 \r
1172                                 /* IP header source and destination addresses must be set before\r
1173                                 the     UDP checksum is calculated.  The socket options, which\r
1174                                 specify whether a checksum should be calculated or not, are\r
1175                                 passed in the as yet unused part of the packet data. */\r
1176                                 pxIPHeader->ulDestinationIPAddress = pxNetworkBuffer->ulIPAddress;\r
1177                                 pxIPHeader->ulSourceIPAddress = *ipLOCAL_IP_ADDRESS_POINTER;\r
1178 \r
1179                                 #if ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )\r
1180                                 {\r
1181                                         /* Is it possible that the packet is not actually a UDP packet\r
1182                                         after all, but an ICMP packet. */\r
1183                                         if( pxNetworkBuffer->usPort != ipPACKET_CONTAINS_ICMP_DATA )\r
1184                                         {\r
1185                                                 prvCompleteUDPHeader( pxNetworkBuffer, pxUDPPacket, pxNetworkBuffer->pucEthernetBuffer[ ipSOCKET_OPTIONS_OFFSET ] );\r
1186                                         }\r
1187                                 }\r
1188                                 #else /* ipconfigSUPPORT_OUTGOING_PINGS */\r
1189                                 {\r
1190                                         prvCompleteUDPHeader( pxNetworkBuffer, pxUDPPacket, pxNetworkBuffer->pucEthernetBuffer[ ipSOCKET_OPTIONS_OFFSET ] );\r
1191                                 }\r
1192                                 #endif /* ipconfigSUPPORT_OUTGOING_PINGS */\r
1193 \r
1194                                 /* memcpy() the constant parts of the header information into\r
1195                                 the     correct location within the packet.  This fills in:\r
1196                                         xEthernetHeader.xSourceAddress\r
1197                                         xEthernetHeader.usFrameType\r
1198                                         xIPHeader.ucVersionHeaderLength\r
1199                                         xIPHeader.ucDifferentiatedServicesCode\r
1200                                         xIPHeader.usLength\r
1201                                         xIPHeader.usIdentification\r
1202                                         xIPHeader.usFragmentOffset\r
1203                                         xIPHeader.ucTimeToLive\r
1204                                         xIPHeader.ucProtocol\r
1205                                 and\r
1206                                         xIPHeader.usHeaderChecksum\r
1207                                 */\r
1208                                 memcpy( ( void *) &( pxUDPPacket->xEthernetHeader.xSourceAddress ), ( void * ) xDefaultPartUDPPacketHeader, sizeof( xDefaultPartUDPPacketHeader ) );\r
1209 \r
1210                                 #if ipconfigSUPPORT_OUTGOING_PINGS == 1\r
1211                                 {\r
1212                                         if( pxNetworkBuffer->usPort == ipPACKET_CONTAINS_ICMP_DATA )\r
1213                                         {\r
1214                                                 pxIPHeader->ucProtocol = ipPROTOCOL_ICMP;\r
1215                                                 pxIPHeader->usLength = ( uint16_t ) ( pxNetworkBuffer->xDataLength + sizeof( xIPHeader_t ) );\r
1216                                         }\r
1217                                         else\r
1218                                         {\r
1219                                                 pxIPHeader->usLength = ( uint16_t ) ( pxNetworkBuffer->xDataLength + sizeof( xIPHeader_t ) + sizeof( xUDPHeader_t ) );\r
1220                                         }\r
1221                                 }\r
1222                                 #else /* ipconfigSUPPORT_OUTGOING_PINGS */\r
1223                                 {\r
1224                                         pxIPHeader->usLength = ( uint16_t ) ( pxNetworkBuffer->xDataLength + sizeof( xIPHeader_t ) + sizeof( xUDPHeader_t ) );\r
1225                                 }\r
1226                                 #endif /* ipconfigSUPPORT_OUTGOING_PINGS */\r
1227 \r
1228                                 /* The total transmit size adds on the Ethernet header. */\r
1229                                 pxNetworkBuffer->xDataLength = pxIPHeader->usLength + sizeof( xEthernetHeader_t );\r
1230                                 pxIPHeader->usLength = FreeRTOS_htons( pxIPHeader->usLength );\r
1231                                 pxIPHeader->ulDestinationIPAddress = pxNetworkBuffer->ulIPAddress;\r
1232                                 pxIPHeader->usHeaderChecksum = prvGenerateChecksum( ( uint8_t * ) &( pxIPHeader->ucVersionHeaderLength ), ipIP_HEADER_LENGTH );\r
1233                         }\r
1234                         else if ( eReturned == eARPCacheMiss )\r
1235                         {\r
1236                                 /* Generate an ARP for the required IP address. */\r
1237                                 iptracePACKET_DROPPED_TO_GENERATE_ARP( pxNetworkBuffer->ulIPAddress );\r
1238                                 prvGenerateARPRequestPacket( pxNetworkBuffer );\r
1239 \r
1240                                 /* Add an entry to the ARP table with a null hardware address.\r
1241                                 This allows the ARP timer to know that an ARP reply is\r
1242                                 outstanding, and perform retransmissions if necessary. */\r
1243                                 prvRefreshARPCacheEntry( &xNullMACAddress, pxNetworkBuffer->ulIPAddress );\r
1244                         }\r
1245                         else\r
1246                         {\r
1247                                 /* The lookup indicated that an ARP request has already been\r
1248                                 sent out for the queried IP address. */\r
1249                                 eReturned = eCantSendPacket;\r
1250                         }\r
1251                 }\r
1252 \r
1253                 if( eReturned != eCantSendPacket )\r
1254                 {\r
1255                         /* The network driver is responsible for freeing the network buffer\r
1256                         after the packet has been sent. */\r
1257                         xNetworkInterfaceOutput( pxNetworkBuffer );\r
1258                 }\r
1259                 else\r
1260                 {\r
1261                         /* The packet can't be sent (DHCP not completed?).  Just drop the\r
1262                         packet. */\r
1263                         vNetworkBufferRelease( pxNetworkBuffer );\r
1264                 }\r
1265         }\r
1266 \r
1267 \r
1268 #endif /* ipconfigCAN_FRAGMENT_OUTGOING_PACKETS == 1 */\r
1269 /*-----------------------------------------------------------*/\r
1270 \r
1271 static void prvGenerateARPRequestPacket( xNetworkBufferDescriptor_t * const pxNetworkBuffer )\r
1272 {\r
1273 xARPPacket_t *pxARPPacket;\r
1274 \r
1275         pxARPPacket = ( xARPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer;\r
1276 \r
1277         /* memcpy the const part of the header information into the correct\r
1278         location in the packet.  This copies:\r
1279                 xEthernetHeader.ulDestinationAddress\r
1280                 xEthernetHeader.usFrameType;\r
1281                 xARPHeader.usHardwareType;\r
1282                 xARPHeader.usProtocolType;\r
1283                 xARPHeader.ucHardwareAddressLength;\r
1284                 xARPHeader.ucProtocolAddressLength;\r
1285                 xARPHeader.usOperation;\r
1286                 xARPHeader.xTargetHardwareAddress;\r
1287         */\r
1288         memcpy( ( void * ) &( pxARPPacket->xEthernetHeader ), ( void * ) xDefaultPartARPPacketHeader, sizeof( xDefaultPartARPPacketHeader ) );\r
1289         memcpy( ( void * ) &( pxARPPacket->xEthernetHeader.xSourceAddress ) , ( void * ) ipLOCAL_MAC_ADDRESS, ( size_t ) ipMAC_ADDRESS_LENGTH_BYTES );\r
1290         memcpy( ( void * ) &( pxARPPacket->xARPHeader.xSenderHardwareAddress ), ( void * ) ipLOCAL_MAC_ADDRESS, ( size_t ) ipMAC_ADDRESS_LENGTH_BYTES );\r
1291         pxARPPacket->xARPHeader.ulSenderProtocolAddress = *ipLOCAL_IP_ADDRESS_POINTER;\r
1292         pxARPPacket->xARPHeader.ulTargetProtocolAddress = pxNetworkBuffer->ulIPAddress;\r
1293 \r
1294         pxNetworkBuffer->xDataLength = sizeof( xARPPacket_t );\r
1295 \r
1296         iptraceCREATING_ARP_REQUEST( ulIPAddress );\r
1297 }\r
1298 /*-----------------------------------------------------------*/\r
1299 \r
1300 eFrameProcessingResult_t eConsiderFrameForProcessing( const uint8_t * const pucEthernetBuffer )\r
1301 {\r
1302 eFrameProcessingResult_t eReturn;\r
1303 const xEthernetHeader_t *pxEthernetHeader;\r
1304 \r
1305         pxEthernetHeader = ( const xEthernetHeader_t * ) pucEthernetBuffer;\r
1306 \r
1307         if( memcmp( ( void * ) &xBroadcastMACAddress, ( void * ) &( pxEthernetHeader->xDestinationAddress ), sizeof( xMACAddress_t ) ) == 0 )\r
1308         {\r
1309                 /* The packet was a broadcast - process it. */\r
1310                 eReturn = eProcessBuffer;\r
1311         }\r
1312         else if( memcmp( ( void * ) ipLOCAL_MAC_ADDRESS, ( void * ) &( pxEthernetHeader->xDestinationAddress ), sizeof( xMACAddress_t ) ) == 0 )\r
1313         {\r
1314                 /* The packet was to this node directly - process it. */\r
1315                 eReturn = eProcessBuffer;\r
1316         }\r
1317         else\r
1318         {\r
1319                 /* The packet was not a broadcast, or for this node, just release\r
1320                 the buffer without taking any other action. */\r
1321                 eReturn = eReleaseBuffer;\r
1322         }\r
1323 \r
1324         #if ipconfigFILTER_OUT_NON_ETHERNET_II_FRAMES == 1\r
1325         {\r
1326                 uint16_t usFrameType;\r
1327 \r
1328                         if( eReturn == eProcessBuffer )\r
1329                         {\r
1330                                 usFrameType = pxEthernetHeader->usFrameType;\r
1331                                 usFrameType = FreeRTOS_ntohs( usFrameType );\r
1332 \r
1333                                 if( usFrameType <= 0x600U )\r
1334                                 {\r
1335                                         /* Not an Ethernet II frame. */\r
1336                                         eReturn = eReleaseBuffer;\r
1337                                 }\r
1338                         }\r
1339         }\r
1340         #endif /* ipconfigFILTER_OUT_NON_ETHERNET_II_FRAMES == 1  */\r
1341 \r
1342         return eReturn;\r
1343 }\r
1344 /*-----------------------------------------------------------*/\r
1345 \r
1346 static void prvProcessNetworkDownEvent( void )\r
1347 {\r
1348         /* Stop the ARP timer while there is no network. */\r
1349         xTimerStop( xARPTimer, portMAX_DELAY );\r
1350 \r
1351         #if ipconfigUSE_NETWORK_EVENT_HOOK == 1\r
1352         {\r
1353                 static portBASE_TYPE xCallEventHook = pdFALSE;\r
1354 \r
1355                 /* The first network down event is generated by the IP stack\r
1356                 itself to initialise the network hardware, so do not call the\r
1357                 network down event the first time through. */\r
1358                 if( xCallEventHook == pdFALSE )\r
1359                 {\r
1360                         vApplicationIPNetworkEventHook( eNetworkDown );\r
1361                 }\r
1362                 xCallEventHook = pdTRUE;\r
1363         }\r
1364         #endif\r
1365 \r
1366         /* The network has been disconnected (or is being\r
1367         initialised for the first time).  Perform whatever hardware\r
1368         processing is necessary to bring it up again, or wait for it\r
1369         to be available again.  This is hardware dependent. */\r
1370         if( xNetworkInterfaceInitialise() != pdPASS )\r
1371         {\r
1372                 /* Ideally the network interface initialisation function\r
1373                 will only return when the network is available.  In case\r
1374                 this is not the case, wait a while before retrying the\r
1375                 initialisation. */\r
1376                 vTaskDelay( ipINITIALISATION_RETRY_DELAY );\r
1377                 FreeRTOS_NetworkDown();\r
1378         }\r
1379         else\r
1380         {\r
1381                 /* Start the ARP timer. */\r
1382                 xTimerStart( xARPTimer, portMAX_DELAY );\r
1383 \r
1384                 #if ipconfigUSE_DHCP == 1\r
1385                 {\r
1386                         /* The network is not up until DHCP has completed. */\r
1387                         vDHCPProcess( pdTRUE, ( xMACAddress_t * ) ipLOCAL_MAC_ADDRESS, ipLOCAL_IP_ADDRESS_POINTER, &xNetworkAddressing );\r
1388                         prvSendEventToIPTask( eDHCPEvent );\r
1389                 }\r
1390                 #else\r
1391                 {\r
1392                         #if ipconfigUSE_NETWORK_EVENT_HOOK == 1\r
1393                         {\r
1394                                 vApplicationIPNetworkEventHook( eNetworkUp );\r
1395                         }\r
1396                         #endif /* ipconfigUSE_NETWORK_EVENT_HOOK */\r
1397 \r
1398                         /* Static configuration is being used, so the network is now up. */\r
1399                         #if ipconfigFREERTOS_PLUS_NABTO == 1\r
1400                         {\r
1401                                 vStartNabtoTask();\r
1402                         }\r
1403                         #endif /* ipconfigFREERTOS_PLUS_NABTO */\r
1404                 }\r
1405                 #endif\r
1406         }\r
1407 }\r
1408 /*-----------------------------------------------------------*/\r
1409 \r
1410 static void prvProcessEthernetPacket( xNetworkBufferDescriptor_t * const pxNetworkBuffer )\r
1411 {\r
1412 xEthernetHeader_t *pxEthernetHeader;\r
1413 volatile eFrameProcessingResult_t eReturned; /* Volatile to prevent complier warnings when ipCONSIDER_FRAME_FOR_PROCESSING just sets it to eProcessBuffer. */\r
1414 \r
1415         configASSERT( pxNetworkBuffer );\r
1416 \r
1417         /* Interpret the Ethernet frame. */\r
1418         eReturned = ipCONSIDER_FRAME_FOR_PROCESSING( pxNetworkBuffer->pucEthernetBuffer );\r
1419         pxEthernetHeader = ( xEthernetHeader_t * ) pxNetworkBuffer->pucEthernetBuffer;\r
1420 \r
1421         if( eReturned == eProcessBuffer )\r
1422         {\r
1423                 /* Interpret the received Ethernet packet. */\r
1424                 switch ( pxEthernetHeader->usFrameType )\r
1425                 {\r
1426                         case ipARP_TYPE :\r
1427                                 /* The Ethernet frame contains an ARP packet. */\r
1428                                 eReturned = prvProcessARPPacket( ( xARPPacket_t * ) pxEthernetHeader );\r
1429                                 break;\r
1430 \r
1431                         case ipIP_TYPE  :\r
1432                                 /* The Ethernet frame contains an IP packet. */\r
1433                                 eReturned = prvProcessIPPacket( ( xIPPacket_t * ) pxEthernetHeader, pxNetworkBuffer );\r
1434                                 break;\r
1435 \r
1436                         default :\r
1437                                 /* No other packet types are handled.  Nothing to do. */\r
1438                                 eReturned = eReleaseBuffer;\r
1439                                 break;\r
1440                 }\r
1441         }\r
1442 \r
1443         /* Perform any actions that resulted from processing the Ethernet\r
1444         frame. */\r
1445         switch( eReturned )\r
1446         {\r
1447                 case eReturnEthernetFrame :\r
1448                         /* The Ethernet frame will have been updated (maybe it was\r
1449                         an ARP request or a PING request?) and should be sent back to\r
1450                         its source. */\r
1451                         prvReturnEthernetFrame( pxNetworkBuffer );\r
1452                         /* The buffer must be released once\r
1453                         the frame has been transmitted. */\r
1454                         break;\r
1455 \r
1456                 case eFrameConsumed :\r
1457                         /* The frame is in use somewhere, don't release the buffer\r
1458                         yet. */\r
1459                         break;\r
1460 \r
1461                 default :\r
1462                         /* The frame is not being used anywhere, and the\r
1463                         xNetworkBufferDescriptor_t structure containing the frame should just be\r
1464                         released back to the list of free buffers. */\r
1465                         vNetworkBufferRelease( pxNetworkBuffer );\r
1466                         break;\r
1467         }\r
1468 }\r
1469 /*-----------------------------------------------------------*/\r
1470 \r
1471 static eFrameProcessingResult_t prvProcessIPPacket( const xIPPacket_t * const pxIPPacket, xNetworkBufferDescriptor_t * const pxNetworkBuffer )\r
1472 {\r
1473 eFrameProcessingResult_t eReturn = eReleaseBuffer;\r
1474 const xIPHeader_t * pxIPHeader;\r
1475 xUDPPacket_t *pxUDPPacket;\r
1476 portBASE_TYPE xChecksumIsCorrect;\r
1477 \r
1478         pxIPHeader = &( pxIPPacket->xIPHeader );\r
1479 \r
1480         /* Is the packet for this node? */\r
1481         if( ( pxIPHeader->ulDestinationIPAddress == *ipLOCAL_IP_ADDRESS_POINTER ) || ( pxIPHeader->ulDestinationIPAddress == ipBROADCAST_IP_ADDRESS ) || ( *ipLOCAL_IP_ADDRESS_POINTER == 0 ) )\r
1482         {\r
1483                 /* Ensure the frame is IPv4 with no options bytes, and that the incoming\r
1484                 packet is not fragmented (only outgoing packets can be fragmented) as\r
1485                 these are the only handled IP frames currently. */\r
1486                 if( ( pxIPHeader->ucVersionHeaderLength == ipIP_VERSION_AND_HEADER_LENGTH_BYTE ) && ( ( pxIPHeader->usFragmentOffset & ipFRAGMENT_OFFSET_BIT_MASK ) == 0U ) )\r
1487                 {\r
1488                         /* Is the IP header checksum correct? */\r
1489                         if( prvGenerateChecksum( ( uint8_t * ) &( pxIPHeader->ucVersionHeaderLength ), ipIP_HEADER_LENGTH ) == 0 )\r
1490                         {\r
1491                                 /* Add the IP and MAC addresses to the ARP table if they are not\r
1492                                 already there - otherwise refresh the age of the existing\r
1493                                 entry. */\r
1494                                 prvRefreshARPCacheEntry( &( pxIPPacket->xEthernetHeader.xSourceAddress ), pxIPHeader->ulSourceIPAddress );\r
1495                                 switch( pxIPHeader->ucProtocol )\r
1496                                 {\r
1497                                         case ipPROTOCOL_ICMP :\r
1498 \r
1499                                                 /* The IP packet contained an ICMP frame.  Don't bother\r
1500                                                 checking the ICMP checksum, as if it is wrong then the\r
1501                                                 wrong data will also be returned, and the source of the\r
1502                                                 ping will know something went wrong because it will not\r
1503                                                 be able to validate what it receives. */\r
1504                                                 #if ( ipconfigREPLY_TO_INCOMING_PINGS == 1 ) || ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )\r
1505                                                 {\r
1506                                                         if( pxIPHeader->ulDestinationIPAddress == *ipLOCAL_IP_ADDRESS_POINTER )\r
1507                                                         {\r
1508                                                                 eReturn = prvProcessICMPPacket( ( xICMPPacket_t * ) ( pxNetworkBuffer->pucEthernetBuffer ) );\r
1509                                                         }\r
1510                                                 }\r
1511                                                 #endif /* ( ipconfigREPLY_TO_INCOMING_PINGS == 1 ) || ( ipconfigSUPPORT_OUTGOING_PINGS == 1 ) */\r
1512                                                 break;\r
1513 \r
1514                                         case ipPROTOCOL_UDP :\r
1515 \r
1516                                                 /* The IP packet contained a UDP frame. */\r
1517                                                 pxUDPPacket = ( xUDPPacket_t * ) ( pxNetworkBuffer->pucEthernetBuffer );\r
1518 \r
1519                                                 /* Note the header values required prior to the\r
1520                                                 checksum generation as the checksum pseudo header\r
1521                                                 may clobber some of these values. */\r
1522                                                 pxNetworkBuffer->xDataLength = FreeRTOS_ntohs( pxUDPPacket->xUDPHeader.usLength ) - sizeof( xUDPHeader_t );\r
1523                                                 pxNetworkBuffer->usPort = pxUDPPacket->xUDPHeader.usSourcePort;\r
1524                                                 pxNetworkBuffer->ulIPAddress = pxUDPPacket->xIPHeader.ulSourceIPAddress;\r
1525 \r
1526                                                 /* Is the checksum required? */\r
1527                                                 if( pxUDPPacket->xUDPHeader.usChecksum == 0 )\r
1528                                                 {\r
1529                                                         xChecksumIsCorrect = pdTRUE;\r
1530                                                 }\r
1531                                                 else if( prvGenerateUDPChecksum( pxUDPPacket ) == 0 )\r
1532                                                 {\r
1533                                                         xChecksumIsCorrect = pdTRUE;\r
1534                                                 }\r
1535                                                 else\r
1536                                                 {\r
1537                                                         xChecksumIsCorrect = pdFALSE;\r
1538                                                 }\r
1539 \r
1540                                                 /* Is the checksum correct? */\r
1541                                                 if( xChecksumIsCorrect == pdTRUE )\r
1542                                                 {\r
1543                                                         /* Pass the packet payload to the UDP sockets\r
1544                                                         implementation. */\r
1545                                                         if( xProcessReceivedUDPPacket( pxNetworkBuffer, pxUDPPacket->xUDPHeader.usDestinationPort ) == pdPASS )\r
1546                                                         {\r
1547                                                                 eReturn = eFrameConsumed;\r
1548                                                         }\r
1549                                                 }\r
1550                                                 break;\r
1551 \r
1552                                         default :\r
1553 \r
1554                                                 /* Not a supported frame type. */\r
1555                                                 break;\r
1556                                 }\r
1557                         }\r
1558                 }\r
1559         }\r
1560 \r
1561         return eReturn;\r
1562 }\r
1563 /*-----------------------------------------------------------*/\r
1564 \r
1565 static uint16_t prvGenerateUDPChecksum( const xUDPPacket_t * const pxUDPPacket )\r
1566 {\r
1567 xPseudoHeader_t *pxPseudoHeader;\r
1568 uint16_t usLength, usReturn;\r
1569 \r
1570         /* Map the pseudo header into the correct place within the real IP\r
1571         header. */\r
1572         pxPseudoHeader = ( xPseudoHeader_t * ) &( pxUDPPacket->xIPHeader.ucTimeToLive );\r
1573 \r
1574         /* Ordering here is important so as not to overwrite data that is required\r
1575         but has not yet been used as the pseudo header overlaps the information\r
1576         that is being copied into it. */\r
1577         pxPseudoHeader->ulSourceAddress = pxUDPPacket->xIPHeader.ulSourceIPAddress;\r
1578         pxPseudoHeader->ulDestinationAddress = pxUDPPacket->xIPHeader.ulDestinationIPAddress;\r
1579         pxPseudoHeader->ucZeros = 0x00;\r
1580         pxPseudoHeader->ucProtocol = ipPROTOCOL_UDP;\r
1581         pxPseudoHeader->usUDPLength = pxUDPPacket->xUDPHeader.usLength;\r
1582 \r
1583         usLength = FreeRTOS_ntohs( pxPseudoHeader->usUDPLength );\r
1584         usReturn = prvGenerateChecksum( ( uint8_t * ) pxPseudoHeader, usLength + sizeof( xPseudoHeader_t ) );\r
1585 \r
1586         return usReturn;\r
1587 }\r
1588 /*-----------------------------------------------------------*/\r
1589 \r
1590 #if ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )\r
1591 \r
1592         static void prvProcessICMPEchoReply( xICMPPacket_t * const pxICMPPacket )\r
1593         {\r
1594         ePingReplyStatus_t eStatus = eSuccess;\r
1595         uint16_t usDataLength, usCount;\r
1596         uint8_t *pucByte;\r
1597 \r
1598                 /* Find the total length of the IP packet. */\r
1599                 usDataLength = pxICMPPacket->xIPHeader.usLength;\r
1600                 usDataLength = FreeRTOS_ntohs( usDataLength );\r
1601 \r
1602                 /* Remove the length of the IP headers to obtain the length of the ICMP\r
1603                 message itself. */\r
1604                 usDataLength -= sizeof( xIPHeader_t );\r
1605 \r
1606                 if( prvGenerateChecksum( ( uint8_t * ) &( pxICMPPacket->xICMPHeader ), usDataLength ) != 0 )\r
1607                 {\r
1608                         eStatus = eInvalidChecksum;\r
1609                 }\r
1610                 else\r
1611                 {\r
1612                         /* Remove the length of the ICMP header, to obtain the length of\r
1613                         data contained in the ping. */\r
1614                         usDataLength -= sizeof( xICMPHeader_t );\r
1615 \r
1616                         /* Find the first byte of the data within the ICMP packet. */\r
1617                         pucByte = ( uint8_t * ) pxICMPPacket;\r
1618                         pucByte += sizeof( xICMPPacket_t );\r
1619 \r
1620                         /* Check each byte. */\r
1621                         for( usCount = 0; usCount < usDataLength; usCount++ )\r
1622                         {\r
1623                                 if( *pucByte != ipECHO_DATA_FILL_BYTE )\r
1624                                 {\r
1625                                         eStatus = eInvalidData;\r
1626                                         break;\r
1627                                 }\r
1628 \r
1629                                 pucByte++;\r
1630                         }\r
1631                 }\r
1632 \r
1633                 vApplicationPingReplyHook( eStatus, pxICMPPacket->xICMPHeader.usIdentifier );\r
1634         }\r
1635 \r
1636 #endif\r
1637 /*-----------------------------------------------------------*/\r
1638 \r
1639 #if ( ipconfigREPLY_TO_INCOMING_PINGS == 1 )\r
1640 \r
1641         static eFrameProcessingResult_t prvProcessICMPEchoRequest( xICMPPacket_t * const pxICMPPacket )\r
1642         {\r
1643         xICMPHeader_t *pxICMPHeader;\r
1644         xIPHeader_t *pxIPHeader;\r
1645 \r
1646                 iptraceSENDING_PING_REPLY( pxIPHeader->ulSourceIPAddress );\r
1647 \r
1648                 pxICMPHeader = &( pxICMPPacket->xICMPHeader );\r
1649                 pxIPHeader = &( pxICMPPacket->xIPHeader );\r
1650 \r
1651                 /* The checksum can be checked here - but a ping reply should be\r
1652                 returned even if the checksum is incorrect so the other end can\r
1653                 tell that the ping was received - even if the ping reply contains\r
1654                 invalid data. */\r
1655                 pxICMPHeader->ucTypeOfMessage = ipICMP_ECHO_REPLY;\r
1656                 pxIPHeader->ulDestinationIPAddress = pxIPHeader->ulSourceIPAddress;\r
1657                 pxIPHeader->ulSourceIPAddress = *ipLOCAL_IP_ADDRESS_POINTER;\r
1658 \r
1659                 /* Update the checksum because the ucTypeOfMessage member in the\r
1660                 header has been changed to ipICMP_ECHO_REPLY. */\r
1661                 if( pxICMPHeader->usChecksum >= FreeRTOS_htons( ( ( uint16_t ) 0xffffU ) - ( ipICMP_ECHO_REQUEST << ( ( uint16_t ) 8U ) ) ) )\r
1662                 {\r
1663                         pxICMPHeader->usChecksum += FreeRTOS_htons( ipICMP_ECHO_REQUEST << ( ( uint16_t ) 8U ) ) + ( uint16_t ) 1U;\r
1664                 }\r
1665                 else\r
1666                 {\r
1667                         pxICMPHeader->usChecksum += FreeRTOS_htons( ipICMP_ECHO_REQUEST << ( ( uint16_t ) 8U ) );\r
1668                 }\r
1669 \r
1670                 return eReturnEthernetFrame;\r
1671         }\r
1672 \r
1673 #endif /* ipconfigREPLY_TO_INCOMING_PINGS == 1 */\r
1674 \r
1675 /*-----------------------------------------------------------*/\r
1676 \r
1677 #if ( ipconfigREPLY_TO_INCOMING_PINGS == 1 ) || ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )\r
1678 \r
1679         static eFrameProcessingResult_t prvProcessICMPPacket( xICMPPacket_t * const pxICMPPacket )\r
1680         {\r
1681         eFrameProcessingResult_t eReturn = eReleaseBuffer;\r
1682 \r
1683                 iptraceICMP_PACKET_RECEIVED();\r
1684 \r
1685                 switch( pxICMPPacket->xICMPHeader.ucTypeOfMessage )\r
1686                 {\r
1687                         case ipICMP_ECHO_REQUEST        :\r
1688                                 #if ( ipconfigREPLY_TO_INCOMING_PINGS == 1 )\r
1689                                 {\r
1690                                         eReturn = prvProcessICMPEchoRequest( pxICMPPacket );\r
1691                                 }\r
1692                                 #endif /* ( ipconfigREPLY_TO_INCOMING_PINGS == 1 ) */\r
1693                                 break;\r
1694 \r
1695                         case ipICMP_ECHO_REPLY          :\r
1696                                 #if ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )\r
1697                                 {\r
1698                                         prvProcessICMPEchoReply( pxICMPPacket );\r
1699                                 }\r
1700                                 #endif /* ipconfigSUPPORT_OUTGOING_PINGS */\r
1701                                 break;\r
1702 \r
1703                         default :\r
1704                                 break;\r
1705                 }\r
1706 \r
1707                 return eReturn;\r
1708         }\r
1709 \r
1710 #endif /* ( ipconfigREPLY_TO_INCOMING_PINGS == 1 ) || ( ipconfigSUPPORT_OUTGOING_PINGS == 1 ) */\r
1711 /*-----------------------------------------------------------*/\r
1712 \r
1713 static uint16_t prvGenerateChecksum( const uint8_t * const pucNextData, const uint16_t usDataLengthBytes )\r
1714 {\r
1715 uint32_t ulChecksum = 0;\r
1716 uint16_t us, usDataLength16BitWords, *pusNextData;\r
1717 \r
1718         /* There are half as many 16 bit words than bytes. */\r
1719         usDataLength16BitWords = ( usDataLengthBytes >> 1U );\r
1720 \r
1721         pusNextData = ( uint16_t * ) pucNextData;\r
1722 \r
1723         for( us = 0U; us < usDataLength16BitWords; us++ )\r
1724         {\r
1725                 ulChecksum += ( uint32_t ) pusNextData[ us ];\r
1726         }\r
1727 \r
1728         if( ( usDataLengthBytes & 0x01U ) != 0x00 )\r
1729         {\r
1730                 /* There is one byte left over. */\r
1731                 #if ipconfigBYTE_ORDER == FREERTOS_LITTLE_ENDIAN\r
1732                 {\r
1733                         ulChecksum += ( uint32_t ) pucNextData[ usDataLengthBytes - 1 ];\r
1734                 }\r
1735                 #else\r
1736                 {\r
1737                         us = ( uint16_t ) pucNextData[ usDataLengthBytes - 1 ];\r
1738                         ulChecksum += ( uint32_t ) ( us << 8 );\r
1739                 }\r
1740                 #endif\r
1741         }\r
1742 \r
1743         while( ( ulChecksum >> 16UL ) != 0x00UL )\r
1744         {\r
1745                 ulChecksum = ( ulChecksum & 0xffffUL ) + ( ulChecksum >> 16UL );\r
1746         }\r
1747 \r
1748         return ~( ( uint16_t ) ulChecksum );\r
1749 }\r
1750 /*-----------------------------------------------------------*/\r
1751 \r
1752 static void prvReturnEthernetFrame( xNetworkBufferDescriptor_t * const pxNetworkBuffer )\r
1753 {\r
1754 xEthernetHeader_t *pxEthernetHeader;\r
1755 \r
1756         pxEthernetHeader = ( xEthernetHeader_t * ) ( pxNetworkBuffer->pucEthernetBuffer );\r
1757 \r
1758         /* Swap source and destination MAC addresses. */\r
1759         memcpy( ( void * ) &( pxEthernetHeader->xDestinationAddress ), ( void * ) &( pxEthernetHeader->xSourceAddress ), sizeof( pxEthernetHeader->xDestinationAddress ) );\r
1760         memcpy( ( void * ) &( pxEthernetHeader->xSourceAddress) , ( void * ) ipLOCAL_MAC_ADDRESS, ( size_t ) ipMAC_ADDRESS_LENGTH_BYTES );\r
1761 \r
1762         /* Send! */\r
1763         xNetworkInterfaceOutput( pxNetworkBuffer );\r
1764 }\r
1765 /*-----------------------------------------------------------*/\r
1766 \r
1767 static eFrameProcessingResult_t prvProcessARPPacket( xARPPacket_t * const pxARPFrame )\r
1768 {\r
1769 eFrameProcessingResult_t eReturn = eReleaseBuffer;\r
1770 xARPHeader_t *pxARPHeader;\r
1771 \r
1772         pxARPHeader = &( pxARPFrame->xARPHeader );\r
1773 \r
1774         traceARP_PACKET_RECEIVED();\r
1775 \r
1776         /* Sanity check the protocol type.  Don't do anything if the local IP\r
1777         address is zero because that means a DHCP request has not completed. */\r
1778         if( ( pxARPHeader->usProtocolType == ipARP_PROTOCOL_TYPE ) && ( *ipLOCAL_IP_ADDRESS_POINTER != 0UL ) )\r
1779         {\r
1780                 switch( pxARPHeader->usOperation )\r
1781                 {\r
1782                         case ipARP_REQUEST      :\r
1783                                 /* The packet contained an ARP request.  Was it for the IP\r
1784                                 address of the node running this code? */\r
1785                                 if( pxARPHeader->ulTargetProtocolAddress == *ipLOCAL_IP_ADDRESS_POINTER )\r
1786                                 {\r
1787                                         iptraceSENDING_ARP_REPLY( pxARPHeader->ulSenderProtocolAddress );\r
1788 \r
1789                                         /* The request is for the address of this node.  Add the\r
1790                                         entry into the ARP cache, or refresh the entry if it\r
1791                                         already exists. */\r
1792                                         prvRefreshARPCacheEntry( &( pxARPHeader->xSenderHardwareAddress ), pxARPHeader->ulSenderProtocolAddress );\r
1793 \r
1794                                         /* Generate a reply payload in the same buffer. */\r
1795                                         pxARPHeader->usOperation = ipARP_REPLY;\r
1796                                         memcpy( ( void * )  &( pxARPHeader->xTargetHardwareAddress ), ( void * ) &( pxARPHeader->xSenderHardwareAddress ), sizeof( xMACAddress_t ) );\r
1797                                         pxARPHeader->ulTargetProtocolAddress = pxARPHeader->ulSenderProtocolAddress;\r
1798                                         memcpy( ( void * ) &( pxARPHeader->xSenderHardwareAddress ), ( void * ) ipLOCAL_MAC_ADDRESS, sizeof( xMACAddress_t ) );\r
1799                                         pxARPHeader->ulSenderProtocolAddress = *ipLOCAL_IP_ADDRESS_POINTER;\r
1800 \r
1801                                         eReturn = eReturnEthernetFrame;\r
1802                                 }\r
1803                                 break;\r
1804 \r
1805                         case ipARP_REPLY :\r
1806                                 iptracePROCESSING_RECEIVED_ARP_REPLY( pxARPHeader->ulTargetProtocolAddress );\r
1807                                 prvRefreshARPCacheEntry( &( pxARPHeader->xSenderHardwareAddress ), pxARPHeader->ulSenderProtocolAddress );\r
1808                                 break;\r
1809 \r
1810                         default :\r
1811                                 /* Invalid. */\r
1812                                 break;\r
1813                 }\r
1814         }\r
1815 \r
1816         return eReturn;\r
1817 }\r
1818 /*-----------------------------------------------------------*/\r
1819 \r
1820 #if( ipconfigBYTE_ORDER == FREERTOS_LITTLE_ENDIAN )\r
1821         uint16_t FreeRTOS_htons( uint16_t usIn )\r
1822         {\r
1823                 return  ( ( usIn & ( uint16_t ) 0x00ff ) << ( uint16_t ) 8U ) |\r
1824                                 ( ( usIn & ( uint16_t ) 0xff00 ) >> ( uint16_t ) 8U );\r
1825         }\r
1826 #endif /* ipconfigBYTE_ORDER == FREERTOS_LITTLE_ENDIAN */\r
1827 /*-----------------------------------------------------------*/\r
1828 \r
1829 #if( ipconfigBYTE_ORDER == FREERTOS_LITTLE_ENDIAN )\r
1830         uint32_t FreeRTOS_htonl( uint32_t ulIn )\r
1831         {\r
1832                 return  ( ( ulIn & 0x000000ffUL ) << 24UL ) |\r
1833                                 ( ( ulIn & 0x0000ff00UL ) << 8UL  ) |\r
1834                                 ( ( ulIn & 0x00ff0000UL ) >> 8UL  ) |\r
1835                                 ( ( ulIn & 0xff000000UL ) >> 24UL );\r
1836         }\r
1837 #endif /* ipconfigBYTE_ORDER == FREERTOS_LITTLE_ENDIAN */\r
1838 \r
1839 /*-----------------------------------------------------------*/\r
1840 \r