diff options
Diffstat (limited to 'FreeRTOS-Labs/Source/FreeRTOS-Plus-TCP/FreeRTOS_ARP.c')
| -rw-r--r-- | FreeRTOS-Labs/Source/FreeRTOS-Plus-TCP/FreeRTOS_ARP.c | 653 |
1 files changed, 653 insertions, 0 deletions
diff --git a/FreeRTOS-Labs/Source/FreeRTOS-Plus-TCP/FreeRTOS_ARP.c b/FreeRTOS-Labs/Source/FreeRTOS-Plus-TCP/FreeRTOS_ARP.c new file mode 100644 index 000000000..fb8a3b4f2 --- /dev/null +++ b/FreeRTOS-Labs/Source/FreeRTOS-Plus-TCP/FreeRTOS_ARP.c @@ -0,0 +1,653 @@ +/*
+ * FreeRTOS+TCP 191100 experimental
+ * Copyright (C) 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * http://aws.amazon.com/freertos
+ * http://www.FreeRTOS.org
+ */
+
+/* Standard includes. */
+#include <stdint.h>
+#include <stdio.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+#include "queue.h"
+#include "semphr.h"
+
+/* FreeRTOS+TCP includes. */
+#include "FreeRTOS_IP.h"
+#include "FreeRTOS_Sockets.h"
+#include "FreeRTOS_IP_Private.h"
+#include "FreeRTOS_ARP.h"
+#include "FreeRTOS_UDP_IP.h"
+#include "FreeRTOS_DHCP.h"
+#if( ipconfigUSE_LLMNR == 1 )
+ #include "FreeRTOS_DNS.h"
+#endif /* ipconfigUSE_LLMNR */
+#include "NetworkInterface.h"
+#include "NetworkBufferManagement.h"
+
+
+/* When the age of an entry in the ARP table reaches this value (it counts down
+to zero, so this is an old entry) an ARP request will be sent to see if the
+entry is still valid and can therefore be refreshed. */
+#define arpMAX_ARP_AGE_BEFORE_NEW_ARP_REQUEST ( 3 )
+
+/* The time between gratuitous ARPs. */
+#ifndef arpGRATUITOUS_ARP_PERIOD
+ #define arpGRATUITOUS_ARP_PERIOD ( pdMS_TO_TICKS( 20000 ) )
+#endif
+
+/*-----------------------------------------------------------*/
+
+/*
+ * Lookup an MAC address in the ARP cache from the IP address.
+ */
+static eARPLookupResult_t prvCacheLookup( uint32_t ulAddressToLookup, MACAddress_t * const pxMACAddress );
+
+/*-----------------------------------------------------------*/
+
+/* The ARP cache. */
+static ARPCacheRow_t xARPCache[ ipconfigARP_CACHE_ENTRIES ];
+
+/* The time at which the last gratuitous ARP was sent. Gratuitous ARPs are used
+to ensure ARP tables are up to date and to detect IP address conflicts. */
+static TickType_t xLastGratuitousARPTime = ( TickType_t ) 0;
+
+/*
+ * IP-clash detection is currently only used internally. When DHCP doesn't respond, the
+ * driver can try out a random LinkLayer IP address (169.254.x.x). It will send out a
+ * gratuitos ARP message and, after a period of time, check the variables here below:
+ */
+#if( ipconfigARP_USE_CLASH_DETECTION != 0 )
+ /* Becomes non-zero if another device responded to a gratuitos ARP message. */
+ BaseType_t xARPHadIPClash;
+ /* MAC-address of the other device containing the same IP-address. */
+ MACAddress_t xARPClashMacAddress;
+#endif /* ipconfigARP_USE_CLASH_DETECTION */
+
+/* Part of the Ethernet and ARP headers are always constant when sending an IPv4
+ARP packet. This array defines the constant parts, allowing this part of the
+packet to be filled in using a simple memcpy() instead of individual writes. */
+static const uint8_t xDefaultPartARPPacketHeader[] =
+{
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* Ethernet destination address. */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* Ethernet source address. */
+ 0x08, 0x06, /* Ethernet frame type (ipARP_FRAME_TYPE). */
+ 0x00, 0x01, /* usHardwareType (ipARP_HARDWARE_TYPE_ETHERNET). */
+ 0x08, 0x00, /* usProtocolType. */
+ ipMAC_ADDRESS_LENGTH_BYTES, /* ucHardwareAddressLength. */
+ ipIP_ADDRESS_LENGTH_BYTES, /* ucProtocolAddressLength. */
+ 0x00, 0x01, /* usOperation (ipARP_REQUEST). */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* xSenderHardwareAddress. */
+ 0x00, 0x00, 0x00, 0x00, /* ulSenderProtocolAddress. */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 /* xTargetHardwareAddress. */
+};
+
+/*-----------------------------------------------------------*/
+
+eFrameProcessingResult_t eARPProcessPacket( ARPPacket_t * const pxARPFrame )
+{
+eFrameProcessingResult_t eReturn = eReleaseBuffer;
+ARPHeader_t *pxARPHeader;
+uint32_t ulTargetProtocolAddress, ulSenderProtocolAddress;
+
+ pxARPHeader = &( pxARPFrame->xARPHeader );
+
+ /* The field ulSenderProtocolAddress is badly aligned, copy byte-by-byte. */
+ memcpy( ( void *)&( ulSenderProtocolAddress ), ( void * )pxARPHeader->ucSenderProtocolAddress, sizeof( ulSenderProtocolAddress ) );
+ /* The field ulTargetProtocolAddress is well-aligned, a 32-bits copy. */
+ ulTargetProtocolAddress = pxARPHeader->ulTargetProtocolAddress;
+
+ traceARP_PACKET_RECEIVED();
+
+ /* Don't do anything if the local IP address is zero because
+ that means a DHCP request has not completed. */
+ if( *ipLOCAL_IP_ADDRESS_POINTER != 0UL )
+ {
+ switch( pxARPHeader->usOperation )
+ {
+ case ipARP_REQUEST :
+ /* The packet contained an ARP request. Was it for the IP
+ address of the node running this code? */
+ if( ulTargetProtocolAddress == *ipLOCAL_IP_ADDRESS_POINTER )
+ {
+ iptraceSENDING_ARP_REPLY( ulSenderProtocolAddress );
+
+ /* The request is for the address of this node. Add the
+ entry into the ARP cache, or refresh the entry if it
+ already exists. */
+ vARPRefreshCacheEntry( &( pxARPHeader->xSenderHardwareAddress ), ulSenderProtocolAddress );
+
+ /* Generate a reply payload in the same buffer. */
+ pxARPHeader->usOperation = ( uint16_t ) ipARP_REPLY;
+ if( ulTargetProtocolAddress == ulSenderProtocolAddress )
+ {
+ /* A double IP address is detected! */
+ /* Give the sources MAC address the value of the broadcast address, will be swapped later */
+ memcpy( pxARPFrame->xEthernetHeader.xSourceAddress.ucBytes, xBroadcastMACAddress.ucBytes, sizeof( xBroadcastMACAddress ) );
+ memset( pxARPHeader->xTargetHardwareAddress.ucBytes, '\0', sizeof( MACAddress_t ) );
+ pxARPHeader->ulTargetProtocolAddress = 0UL;
+ }
+ else
+ {
+ memcpy( pxARPHeader->xTargetHardwareAddress.ucBytes, pxARPHeader->xSenderHardwareAddress.ucBytes, sizeof( MACAddress_t ) );
+ pxARPHeader->ulTargetProtocolAddress = ulSenderProtocolAddress;
+ }
+ memcpy( pxARPHeader->xSenderHardwareAddress.ucBytes, ( void * ) ipLOCAL_MAC_ADDRESS, sizeof( MACAddress_t ) );
+ memcpy( ( void* )pxARPHeader->ucSenderProtocolAddress, ( void* )ipLOCAL_IP_ADDRESS_POINTER, sizeof( pxARPHeader->ucSenderProtocolAddress ) );
+
+ eReturn = eReturnEthernetFrame;
+ }
+ break;
+
+ case ipARP_REPLY :
+ iptracePROCESSING_RECEIVED_ARP_REPLY( ulTargetProtocolAddress );
+ vARPRefreshCacheEntry( &( pxARPHeader->xSenderHardwareAddress ), ulSenderProtocolAddress );
+ /* Process received ARP frame to see if there is a clash. */
+ #if( ipconfigARP_USE_CLASH_DETECTION != 0 )
+ {
+ if( ulSenderProtocolAddress == *ipLOCAL_IP_ADDRESS_POINTER )
+ {
+ xARPHadIPClash = pdTRUE;
+ memcpy( xARPClashMacAddress.ucBytes, pxARPHeader->xSenderHardwareAddress.ucBytes, sizeof( xARPClashMacAddress.ucBytes ) );
+ }
+ }
+ #endif /* ipconfigARP_USE_CLASH_DETECTION */
+ break;
+
+ default :
+ /* Invalid. */
+ break;
+ }
+ }
+
+ return eReturn;
+}
+/*-----------------------------------------------------------*/
+
+#if( ipconfigUSE_ARP_REMOVE_ENTRY != 0 )
+
+ uint32_t ulARPRemoveCacheEntryByMac( const MACAddress_t * pxMACAddress )
+ {
+ BaseType_t x;
+ uint32_t lResult = 0;
+
+ /* For each entry in the ARP cache table. */
+ for( x = 0; x < ipconfigARP_CACHE_ENTRIES; x++ )
+ {
+ if( ( memcmp( xARPCache[ x ].xMACAddress.ucBytes, pxMACAddress->ucBytes, sizeof( pxMACAddress->ucBytes ) ) == 0 ) )
+ {
+ lResult = xARPCache[ x ].ulIPAddress;
+ memset( &xARPCache[ x ], '\0', sizeof( xARPCache[ x ] ) );
+ break;
+ }
+ }
+
+ return lResult;
+ }
+
+#endif /* ipconfigUSE_ARP_REMOVE_ENTRY != 0 */
+/*-----------------------------------------------------------*/
+
+void vARPRefreshCacheEntry( const MACAddress_t * pxMACAddress, const uint32_t ulIPAddress )
+{
+BaseType_t x = 0;
+BaseType_t xIpEntry = -1;
+BaseType_t xMacEntry = -1;
+BaseType_t xUseEntry = 0;
+uint8_t ucMinAgeFound = 0U;
+
+ #if( ipconfigARP_STORES_REMOTE_ADDRESSES == 0 )
+ /* Only process the IP address if it is on the local network.
+ Unless: when '*ipLOCAL_IP_ADDRESS_POINTER' equals zero, the IP-address
+ and netmask are still unknown. */
+ if( ( ( ulIPAddress & xNetworkAddressing.ulNetMask ) == ( ( *ipLOCAL_IP_ADDRESS_POINTER ) & xNetworkAddressing.ulNetMask ) ) ||
+ ( *ipLOCAL_IP_ADDRESS_POINTER == 0ul ) )
+ #else
+ /* If ipconfigARP_STORES_REMOTE_ADDRESSES is non-zero, IP addresses with
+ a different netmask will also be stored. After when replying to a UDP
+ message from a different netmask, the IP address can be looped up and a
+ reply sent. This option is useful for systems with multiple gateways,
+ the reply will surely arrive. If ipconfigARP_STORES_REMOTE_ADDRESSES is
+ zero the the gateway address is the only option. */
+ if( pdTRUE )
+ #endif
+ {
+ /* Start with the maximum possible number. */
+ ucMinAgeFound--;
+
+ /* For each entry in the ARP cache table. */
+ for( x = 0; x < ipconfigARP_CACHE_ENTRIES; x++ )
+ {
+ /* Does this line in the cache table hold an entry for the IP
+ address being queried? */
+ if( xARPCache[ x ].ulIPAddress == ulIPAddress )
+ {
+ if( pxMACAddress == NULL )
+ {
+ /* In case the parameter pxMACAddress is NULL, an entry will be reserved to
+ indicate that there is an outstanding ARP request, This entry will have
+ "ucValid == pdFALSE". */
+ xIpEntry = x;
+ break;
+ }
+
+ /* See if the MAC-address also matches. */
+ if( memcmp( xARPCache[ x ].xMACAddress.ucBytes, pxMACAddress->ucBytes, sizeof( pxMACAddress->ucBytes ) ) == 0 )
+ {
+ /* This function will be called for each received packet
+ As this is by far the most common path the coding standard
+ is relaxed in this case and a return is permitted as an
+ optimisation. */
+ xARPCache[ x ].ucAge = ( uint8_t ) ipconfigMAX_ARP_AGE;
+ xARPCache[ x ].ucValid = ( uint8_t ) pdTRUE;
+ return;
+ }
+
+ /* Found an entry containing ulIPAddress, but the MAC address
+ doesn't match. Might be an entry with ucValid=pdFALSE, waiting
+ for an ARP reply. Still want to see if there is match with the
+ given MAC address.ucBytes. If found, either of the two entries
+ must be cleared. */
+ xIpEntry = x;
+ }
+ else if( ( pxMACAddress != NULL ) && ( memcmp( xARPCache[ x ].xMACAddress.ucBytes, pxMACAddress->ucBytes, sizeof( pxMACAddress->ucBytes ) ) == 0 ) )
+ {
+ /* Found an entry with the given MAC-address, but the IP-address
+ is different. Continue looping to find a possible match with
+ ulIPAddress. */
+ #if( ipconfigARP_STORES_REMOTE_ADDRESSES != 0 )
+ /* If ARP stores the MAC address of IP addresses outside the
+ network, than the MAC address of the gateway should not be
+ overwritten. */
+ BaseType_t bIsLocal[ 2 ];
+ bIsLocal[ 0 ] = ( ( xARPCache[ x ].ulIPAddress & xNetworkAddressing.ulNetMask ) == ( ( *ipLOCAL_IP_ADDRESS_POINTER ) & xNetworkAddressing.ulNetMask ) );
+ bIsLocal[ 1 ] = ( ( ulIPAddress & xNetworkAddressing.ulNetMask ) == ( ( *ipLOCAL_IP_ADDRESS_POINTER ) & xNetworkAddressing.ulNetMask ) );
+ if( bIsLocal[ 0 ] == bIsLocal[ 1 ] )
+ {
+ xMacEntry = x;
+ }
+ #else
+ xMacEntry = x;
+ #endif
+ }
+ /* _HT_
+ Shouldn't we test for xARPCache[ x ].ucValid == pdFALSE here ? */
+ else if( xARPCache[ x ].ucAge < ucMinAgeFound )
+ {
+ /* As the table is traversed, remember the table row that
+ contains the oldest entry (the lowest age count, as ages are
+ decremented to zero) so the row can be re-used if this function
+ needs to add an entry that does not already exist. */
+ ucMinAgeFound = xARPCache[ x ].ucAge;
+ xUseEntry = x;
+ }
+ }
+
+ if( xMacEntry >= 0 )
+ {
+ xUseEntry = xMacEntry;
+
+ if( xIpEntry >= 0 )
+ {
+ /* Both the MAC address as well as the IP address were found in
+ different locations: clear the entry which matches the
+ IP-address */
+ memset( &xARPCache[ xIpEntry ], '\0', sizeof( xARPCache[ xIpEntry ] ) );
+ }
+ }
+ else if( xIpEntry >= 0 )
+ {
+ /* An entry containing the IP-address was found, but it had a different MAC address */
+ xUseEntry = xIpEntry;
+ }
+
+ /* If the entry was not found, we use the oldest entry and set the IPaddress */
+ xARPCache[ xUseEntry ].ulIPAddress = ulIPAddress;
+
+ if( pxMACAddress != NULL )
+ {
+ memcpy( xARPCache[ xUseEntry ].xMACAddress.ucBytes, pxMACAddress->ucBytes, sizeof( pxMACAddress->ucBytes ) );
+
+ iptraceARP_TABLE_ENTRY_CREATED( ulIPAddress, (*pxMACAddress) );
+ /* And this entry does not need immediate attention */
+ xARPCache[ xUseEntry ].ucAge = ( uint8_t ) ipconfigMAX_ARP_AGE;
+ xARPCache[ xUseEntry ].ucValid = ( uint8_t ) pdTRUE;
+ }
+ else if( xIpEntry < 0 )
+ {
+ xARPCache[ xUseEntry ].ucAge = ( uint8_t ) ipconfigMAX_ARP_RETRANSMISSIONS;
+ xARPCache[ xUseEntry ].ucValid = ( uint8_t ) pdFALSE;
+ }
+ }
+}
+/*-----------------------------------------------------------*/
+
+#if( ipconfigUSE_ARP_REVERSED_LOOKUP == 1 )
+ eARPLookupResult_t eARPGetCacheEntryByMac( MACAddress_t * const pxMACAddress, uint32_t *pulIPAddress )
+ {
+ BaseType_t x;
+ eARPLookupResult_t eReturn = eARPCacheMiss;
+
+ /* Loop through each entry in the ARP cache. */
+ for( x = 0; x < ipconfigARP_CACHE_ENTRIES; x++ )
+ {
+ /* Does this row in the ARP cache table hold an entry for the MAC
+ address being searched? */
+ if( memcmp( pxMACAddress->ucBytes, xARPCache[ x ].xMACAddress.ucBytes, sizeof( MACAddress_t ) ) == 0 )
+ {
+ *pulIPAddress = xARPCache[ x ].ulIPAddress;
+ eReturn = eARPCacheHit;
+ break;
+ }
+ }
+
+ return eReturn;
+ }
+#endif /* ipconfigUSE_ARP_REVERSED_LOOKUP */
+
+/*-----------------------------------------------------------*/
+
+eARPLookupResult_t eARPGetCacheEntry( uint32_t *pulIPAddress, MACAddress_t * const pxMACAddress )
+{
+eARPLookupResult_t eReturn;
+uint32_t ulAddressToLookup;
+
+#if( ipconfigUSE_LLMNR == 1 )
+ if( *pulIPAddress == ipLLMNR_IP_ADDR ) /* Is in network byte order. */
+ {
+ /* The LLMNR IP-address has a fixed virtual MAC address. */
+ memcpy( pxMACAddress->ucBytes, xLLMNR_MacAdress.ucBytes, sizeof( MACAddress_t ) );
+ eReturn = eARPCacheHit;
+ }
+ else
+#endif
+ if( ( *pulIPAddress == ipBROADCAST_IP_ADDRESS ) || /* Is it the general broadcast address 255.255.255.255? */
+ ( *pulIPAddress == xNetworkAddressing.ulBroadcastAddress ) )/* Or a local broadcast address, eg 192.168.1.255? */
+ {
+ /* This is a broadcast so uses the broadcast MAC address. */
+ memcpy( pxMACAddress->ucBytes, xBroadcastMACAddress.ucBytes, sizeof( MACAddress_t ) );
+ eReturn = eARPCacheHit;
+ }
+ else if( *ipLOCAL_IP_ADDRESS_POINTER == 0UL )
+ {
+ /* The IP address has not yet been assigned, so there is nothing that
+ can be done. */
+ eReturn = eCantSendPacket;
+ }
+ else
+ {
+ eReturn = eARPCacheMiss;
+
+ if( ( *pulIPAddress & xNetworkAddressing.ulNetMask ) != ( ( *ipLOCAL_IP_ADDRESS_POINTER ) & xNetworkAddressing.ulNetMask ) )
+ {
+#if( ipconfigARP_STORES_REMOTE_ADDRESSES == 1 )
+ eReturn = prvCacheLookup( *pulIPAddress, pxMACAddress );
+
+ if( eReturn == eARPCacheHit )
+ {
+ /* The stack is configured to store 'remote IP addresses', i.e. addresses
+ belonging to a different the netmask. prvCacheLookup() returned a hit, so
+ the MAC address is known */
+ }
+ else
+#endif
+ {
+ /* The IP address is off the local network, so look up the
+ hardware address of the router, if any. */
+ if( xNetworkAddressing.ulGatewayAddress != ( uint32_t )0u )
+ {
+ ulAddressToLookup = xNetworkAddressing.ulGatewayAddress;
+ }
+ else
+ {
+ ulAddressToLookup = *pulIPAddress;
+ }
+ }
+ }
+ else
+ {
+ /* The IP address is on the local network, so lookup the requested
+ IP address directly. */
+ ulAddressToLookup = *pulIPAddress;
+ }
+
+ if( eReturn == eARPCacheMiss )
+ {
+ if( ulAddressToLookup == 0UL )
+ {
+ /* The address is not on the local network, and there is not a
+ router. */
+ eReturn = eCantSendPacket;
+ }
+ else
+ {
+ eReturn = prvCacheLookup( ulAddressToLookup, pxMACAddress );
+
+ if( eReturn == eARPCacheMiss )
+ {
+ /* It might be that the ARP has to go to the gateway. */
+ *pulIPAddress = ulAddressToLookup;
+ }
+ }
+ }
+ }
+
+ return eReturn;
+}
+
+/*-----------------------------------------------------------*/
+
+static eARPLookupResult_t prvCacheLookup( uint32_t ulAddressToLookup, MACAddress_t * const pxMACAddress )
+{
+BaseType_t x;
+eARPLookupResult_t eReturn = eARPCacheMiss;
+
+ /* Loop through each entry in the ARP cache. */
+ for( x = 0; x < ipconfigARP_CACHE_ENTRIES; x++ )
+ {
+ /* Does this row in the ARP cache table hold an entry for the IP address
+ being queried? */
+ if( xARPCache[ x ].ulIPAddress == ulAddressToLookup )
+ {
+ /* A matching valid entry was found. */
+ if( xARPCache[ x ].ucValid == ( uint8_t ) pdFALSE )
+ {
+ /* This entry is waiting an ARP reply, so is not valid. */
+ eReturn = eCantSendPacket;
+ }
+ else
+ {
+ /* A valid entry was found. */
+ memcpy( pxMACAddress->ucBytes, xARPCache[ x ].xMACAddress.ucBytes, sizeof( MACAddress_t ) );
+ eReturn = eARPCacheHit;
+ }
+ break;
+ }
+ }
+
+ return eReturn;
+}
+/*-----------------------------------------------------------*/
+
+void vARPAgeCache( void )
+{
+BaseType_t x;
+TickType_t xTimeNow;
+
+ /* Loop through each entry in the ARP cache. */
+ for( x = 0; x < ipconfigARP_CACHE_ENTRIES; x++ )
+ {
+ /* If the entry is valid (its age is greater than zero). */
+ if( xARPCache[ x ].ucAge > 0U )
+ {
+ /* Decrement the age value of the entry in this ARP cache table row.
+ When the age reaches zero it is no longer considered valid. */
+ ( xARPCache[ x ].ucAge )--;
+
+ /* If the entry is not yet valid, then it is waiting an ARP
+ reply, and the ARP request should be retransmitted. */
+ if( xARPCache[ x ].ucValid == ( uint8_t ) pdFALSE )
+ {
+ FreeRTOS_OutputARPRequest( xARPCache[ x ].ulIPAddress );
+ }
+ else if( xARPCache[ x ].ucAge <= ( uint8_t ) arpMAX_ARP_AGE_BEFORE_NEW_ARP_REQUEST )
+ {
+ /* This entry will get removed soon. See if the MAC address is
+ still valid to prevent this happening. */
+ iptraceARP_TABLE_ENTRY_WILL_EXPIRE( xARPCache[ x ].ulIPAddress );
+ FreeRTOS_OutputARPRequest( xARPCache[ x ].ulIPAddress );
+ }
+ else
+ {
+ /* The age has just ticked down, with nothing to do. */
+ }
+
+ if( xARPCache[ x ].ucAge == 0u )
+ {
+ /* The entry is no longer valid. Wipe it out. */
+ iptraceARP_TABLE_ENTRY_EXPIRED( xARPCache[ x ].ulIPAddress );
+ xARPCache[ x ].ulIPAddress = 0UL;
+ }
+ }
+ }
+
+ xTimeNow = xTaskGetTickCount ();
+
+ if( ( xLastGratuitousARPTime == ( TickType_t ) 0 ) || ( ( xTimeNow - xLastGratuitousARPTime ) > ( TickType_t ) arpGRATUITOUS_ARP_PERIOD ) )
+ {
+ FreeRTOS_OutputARPRequest( *ipLOCAL_IP_ADDRESS_POINTER );
+ xLastGratuitousARPTime = xTimeNow;
+ }
+}
+/*-----------------------------------------------------------*/
+
+void vARPSendGratuitous( void )
+{
+ /* Setting xLastGratuitousARPTime to 0 will force a gratuitous ARP the next
+ time vARPAgeCache() is called. */
+ xLastGratuitousARPTime = ( TickType_t ) 0;
+
+ /* Let the IP-task call vARPAgeCache(). */
+ xSendEventToIPTask( eARPTimerEvent );
+}
+
+/*-----------------------------------------------------------*/
+void FreeRTOS_OutputARPRequest( uint32_t ulIPAddress )
+{
+NetworkBufferDescriptor_t *pxNetworkBuffer;
+
+ /* This is called from the context of the IP event task, so a block time
+ must not be used. */
+ pxNetworkBuffer = pxGetNetworkBufferWithDescriptor( sizeof( ARPPacket_t ), ( TickType_t ) 0 );
+
+ if( pxNetworkBuffer != NULL )
+ {
+ pxNetworkBuffer->ulIPAddress = ulIPAddress;
+ vARPGenerateRequestPacket( pxNetworkBuffer );
+
+ #if defined( ipconfigETHERNET_MINIMUM_PACKET_BYTES )
+ {
+ if( pxNetworkBuffer->xDataLength < ( size_t ) ipconfigETHERNET_MINIMUM_PACKET_BYTES )
+ {
+ BaseType_t xIndex;
+
+ for( xIndex = ( BaseType_t ) pxNetworkBuffer->xDataLength; xIndex < ( BaseType_t ) ipconfigETHERNET_MINIMUM_PACKET_BYTES; xIndex++ )
+ {
+ pxNetworkBuffer->pucEthernetBuffer[ xIndex ] = 0u;
+ }
+ pxNetworkBuffer->xDataLength = ( size_t ) ipconfigETHERNET_MINIMUM_PACKET_BYTES;
+ }
+ }
+ #endif
+
+ xNetworkInterfaceOutput( pxNetworkBuffer, pdTRUE );
+ }
+}
+
+void vARPGenerateRequestPacket( NetworkBufferDescriptor_t * const pxNetworkBuffer )
+{
+ARPPacket_t *pxARPPacket;
+
+ pxARPPacket = ( ARPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer;
+
+ /* memcpy the const part of the header information into the correct
+ location in the packet. This copies:
+ xEthernetHeader.ulDestinationAddress
+ xEthernetHeader.usFrameType;
+ xARPHeader.usHardwareType;
+ xARPHeader.usProtocolType;
+ xARPHeader.ucHardwareAddressLength;
+ xARPHeader.ucProtocolAddressLength;
+ xARPHeader.usOperation;
+ xARPHeader.xTargetHardwareAddress;
+ */
+ memcpy( ( void * ) pxARPPacket, ( void * ) xDefaultPartARPPacketHeader, sizeof( xDefaultPartARPPacketHeader ) );
+ memcpy( ( void * ) pxARPPacket->xEthernetHeader.xSourceAddress.ucBytes , ( void * ) ipLOCAL_MAC_ADDRESS, ( size_t ) ipMAC_ADDRESS_LENGTH_BYTES );
+ memcpy( ( void * ) pxARPPacket->xARPHeader.xSenderHardwareAddress.ucBytes, ( void * ) ipLOCAL_MAC_ADDRESS, ( size_t ) ipMAC_ADDRESS_LENGTH_BYTES );
+
+ memcpy( ( void* )pxARPPacket->xARPHeader.ucSenderProtocolAddress, ( void* )ipLOCAL_IP_ADDRESS_POINTER, sizeof( pxARPPacket->xARPHeader.ucSenderProtocolAddress ) );
+ pxARPPacket->xARPHeader.ulTargetProtocolAddress = pxNetworkBuffer->ulIPAddress;
+
+ pxNetworkBuffer->xDataLength = sizeof( ARPPacket_t );
+
+ iptraceCREATING_ARP_REQUEST( pxNetworkBuffer->ulIPAddress );
+}
+/*-----------------------------------------------------------*/
+
+void FreeRTOS_ClearARP( void )
+{
+ memset( xARPCache, '\0', sizeof( xARPCache ) );
+}
+/*-----------------------------------------------------------*/
+
+#if( ipconfigHAS_PRINTF != 0 ) || ( ipconfigHAS_DEBUG_PRINTF != 0 )
+
+ void FreeRTOS_PrintARPCache( void )
+ {
+ BaseType_t x, xCount = 0;
+
+ /* Loop through each entry in the ARP cache. */
+ for( x = 0; x < ipconfigARP_CACHE_ENTRIES; x++ )
+ {
+ if( ( xARPCache[ x ].ulIPAddress != 0ul ) && ( xARPCache[ x ].ucAge > 0U ) )
+ {
+ /* See if the MAC-address also matches, and we're all happy */
+ FreeRTOS_printf( ( "Arp %2ld: %3u - %16lxip : %02x:%02x:%02x : %02x:%02x:%02x\n",
+ x,
+ xARPCache[ x ].ucAge,
+ xARPCache[ x ].ulIPAddress,
+ xARPCache[ x ].xMACAddress.ucBytes[0],
+ xARPCache[ x ].xMACAddress.ucBytes[1],
+ xARPCache[ x ].xMACAddress.ucBytes[2],
+ xARPCache[ x ].xMACAddress.ucBytes[3],
+ xARPCache[ x ].xMACAddress.ucBytes[4],
+ xARPCache[ x ].xMACAddress.ucBytes[5] ) );
+ xCount++;
+ }
+ }
+
+ FreeRTOS_printf( ( "Arp has %ld entries\n", xCount ) );
+ }
+
+#endif /* ( ipconfigHAS_PRINTF != 0 ) || ( ipconfigHAS_DEBUG_PRINTF != 0 ) */
|