static portBASE_TYPE xBlockChecksum(BlockCheckOp enOperation,
unsigned portLONG ulBlockAddr,
GSA_BLOCK_SIZE BlockSize)
{
unsigned portLONG ulDataSum;
//set checksum field to 0 if applying checksum
if (enOperation == OP_BLOCK_CHECK_APPLY) ((Header *)ulBlockAddr)->Checksum = 0;
//add header data value together
ulDataSum = ulAddToSum(0, ulBlockAddr, sizeof(Header) / sizeof(short));
//add tree info data value together
ulDataSum = ulAddToSum(ulDataSum,
ulBlockAddr + BlockSize - sizeof(TreeInfo),
sizeof(TreeInfo) / sizeof(short));
//return verification result if verifying
if (enOperation == OP_BLOCK_CHECK_VERIFY) return xVerifyChecksum(ulDataSum);
//assign checksum value
((Header *)ulBlockAddr)->Checksum = usGenerateChecksum(ulDataSum);
//return don't care value as pdPASS
return pdPASS;
}
void vGMACGenerateChecksum( uint8_t *apBuffer )
{
ProtocolPacket_t *xProtPacket = (ProtocolPacket_t *)apBuffer;
if ( xProtPacket->xTCPPacket.xEthernetHeader.usFrameType == ipIPv4_FRAME_TYPE )
{
IPHeader_t *pxIPHeader = &( xProtPacket->xTCPPacket.xIPHeader );
/* Calculate the IP header checksum. */
pxIPHeader->usHeaderChecksum = 0x00;
pxIPHeader->usHeaderChecksum = usGenerateChecksum( 0u, ( uint8_t * ) &( pxIPHeader->ucVersionHeaderLength ), ipSIZE_OF_IPv4_HEADER );
pxIPHeader->usHeaderChecksum = ~FreeRTOS_htons( pxIPHeader->usHeaderChecksum );
/* Calculate the TCP checksum for an outgoing packet. */
usGenerateProtocolChecksum( ( uint8_t * ) apBuffer, pdTRUE );
}
}
static void prvReplyDNSMessage( NetworkBufferDescriptor_t *pxNetworkBuffer, BaseType_t lNetLength )
{
UDPPacket_t *pxUDPPacket;
IPHeader_t *pxIPHeader;
UDPHeader_t *pxUDPHeader;
pxUDPPacket = (UDPPacket_t *) pxNetworkBuffer->pucEthernetBuffer;
pxIPHeader = &pxUDPPacket->xIPHeader;
pxUDPHeader = &pxUDPPacket->xUDPHeader;
/* HT: started using defines like 'ipSIZE_OF_xxx' */
pxIPHeader->usLength = FreeRTOS_htons( lNetLength + ipSIZE_OF_IPv4_HEADER + ipSIZE_OF_UDP_HEADER );
/* HT:endian: should not be translated, copying from packet to packet */
pxIPHeader->ulDestinationIPAddress = pxIPHeader->ulSourceIPAddress;
pxIPHeader->ulSourceIPAddress = *ipLOCAL_IP_ADDRESS_POINTER;
pxIPHeader->ucTimeToLive = ipconfigUDP_TIME_TO_LIVE;
pxIPHeader->usIdentification = FreeRTOS_htons( usPacketIdentifier );
usPacketIdentifier++;
pxUDPHeader->usLength = FreeRTOS_htons( lNetLength + ipSIZE_OF_UDP_HEADER );
vFlip_16( pxUDPPacket->xUDPHeader.usSourcePort, pxUDPPacket->xUDPHeader.usDestinationPort );
#if( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
{
/* calculate the IP header checksum */
pxIPHeader->usHeaderChecksum = 0x00;
pxIPHeader->usHeaderChecksum = usGenerateChecksum( 0UL, ( uint8_t * ) &( pxIPHeader->ucVersionHeaderLength ), ipSIZE_OF_IPv4_HEADER );
pxIPHeader->usHeaderChecksum = ~FreeRTOS_htons( pxIPHeader->usHeaderChecksum );
/* calculate the UDP checksum for outgoing package */
usGenerateProtocolChecksum( ( uint8_t* ) pxUDPPacket, pdTRUE );
}
#endif
/* Important: tell NIC driver how many bytes must be sent */
pxNetworkBuffer->xDataLength = ( size_t ) ( lNetLength + ipSIZE_OF_IPv4_HEADER + ipSIZE_OF_UDP_HEADER + ipSIZE_OF_ETH_HEADER );
/* This function will fill in the eth addresses and send the packet */
vReturnEthernetFrame( pxNetworkBuffer, pdFALSE );
}
void vProcessGeneratedUDPPacket( xNetworkBufferDescriptor_t * const pxNetworkBuffer )
{
xUDPPacket_t *pxUDPPacket;
xIPHeader_t *pxIPHeader;
eARPLookupResult_t eReturned;
uint32_t ulIPAddress = pxNetworkBuffer->ulIPAddress;
/* Map the UDP packet onto the start of the frame. */
pxUDPPacket = ( xUDPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer;
/* Determine the ARP cache status for the requested IP address. */
eReturned = eARPGetCacheEntry( &( ulIPAddress ), &( pxUDPPacket->xEthernetHeader.xDestinationAddress ) );
if( eReturned != eCantSendPacket )
{
if( eReturned == eARPCacheHit )
{
#if( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
uint8_t xSocketOptions;
#endif
iptraceSENDING_UDP_PACKET( pxNetworkBuffer->ulIPAddress );
/* Create short cuts to the data within the packet. */
pxIPHeader = &( pxUDPPacket->xIPHeader );
#if ( ipconfigSUPPORT_OUTGOING_PINGS == 1 )
/* Is it possible that the packet is not actually a UDP packet
after all, but an ICMP packet. */
if( pxNetworkBuffer->usPort != ipPACKET_CONTAINS_ICMP_DATA )
#endif /* ipconfigSUPPORT_OUTGOING_PINGS */
{
xUDPHeader_t *pxUDPHeader;
pxUDPHeader = &( pxUDPPacket->xUDPHeader );
pxUDPHeader->usDestinationPort = pxNetworkBuffer->usPort;
pxUDPHeader->usSourcePort = pxNetworkBuffer->usBoundPort;
pxUDPHeader->usLength = ( uint16_t ) ( pxNetworkBuffer->xDataLength + sizeof( xUDPHeader_t ) );
pxUDPHeader->usLength = FreeRTOS_htons( pxUDPHeader->usLength );
pxUDPHeader->usChecksum = 0;
}
/* memcpy() the constant parts of the header information into
the correct location within the packet. This fills in:
xEthernetHeader.xSourceAddress
xEthernetHeader.usFrameType
xIPHeader.ucVersionHeaderLength
xIPHeader.ucDifferentiatedServicesCode
xIPHeader.usLength
xIPHeader.usIdentification
xIPHeader.usFragmentOffset
xIPHeader.ucTimeToLive
xIPHeader.ucProtocol
and
xIPHeader.usHeaderChecksum
*/
/* Save options now, as they will be overwritten by memcpy */
#if( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
xSocketOptions = pxNetworkBuffer->pucEthernetBuffer[ ipSOCKET_OPTIONS_OFFSET ];
#endif
memcpy( ( void *) &( pxUDPPacket->xEthernetHeader.xSourceAddress ), ( void * ) xDefaultPartUDPPacketHeader.ucBytes, sizeof( xDefaultPartUDPPacketHeader ) );
#if ipconfigSUPPORT_OUTGOING_PINGS == 1
if( pxNetworkBuffer->usPort == ipPACKET_CONTAINS_ICMP_DATA )
{
pxIPHeader->ucProtocol = ipPROTOCOL_ICMP;
pxIPHeader->usLength = ( uint16_t ) ( pxNetworkBuffer->xDataLength + sizeof( xIPHeader_t ) );
}
else
#endif /* ipconfigSUPPORT_OUTGOING_PINGS */
{
pxIPHeader->usLength = ( uint16_t ) ( pxNetworkBuffer->xDataLength + sizeof( xIPHeader_t ) + sizeof( xUDPHeader_t ) );
}
/* The total transmit size adds on the Ethernet header. */
pxNetworkBuffer->xDataLength = pxIPHeader->usLength + sizeof( xEthernetHeader_t );
pxIPHeader->usLength = FreeRTOS_htons( pxIPHeader->usLength );
/* HT:endian: changed back to network endian */
pxIPHeader->ulDestinationIPAddress = pxNetworkBuffer->ulIPAddress;
#if( ipconfigUSE_LLMNR == 1 )
{
/* LLMNR messages are typically used on a LAN and they're
* not supposed to cross routers */
if( pxNetworkBuffer->ulIPAddress == ipLLMNR_IP_ADDR )
{
pxIPHeader->ucTimeToLive = 0x01;
}
}
#endif
#if( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
{
pxIPHeader->usHeaderChecksum = 0;
pxIPHeader->usHeaderChecksum = usGenerateChecksum( 0UL, ( uint8_t * ) &( pxIPHeader->ucVersionHeaderLength ), ipSIZE_OF_IP_HEADER );
pxIPHeader->usHeaderChecksum = ~FreeRTOS_htons( pxIPHeader->usHeaderChecksum );
if( ( xSocketOptions & FREERTOS_SO_UDPCKSUM_OUT ) != 0 )
{
usGenerateProtocolChecksum( (uint8_t*)pxUDPPacket, pdTRUE );
}
else
{
pxUDPPacket->xUDPHeader.usChecksum = 0;
}
}
#endif
}
else if( eReturned == eARPCacheMiss )
{
/* Add an entry to the ARP table with a null hardware address.
This allows the ARP timer to know that an ARP reply is
outstanding, and perform retransmissions if necessary. */
vARPRefreshCacheEntry( NULL, ulIPAddress );
/* Generate an ARP for the required IP address. */
iptracePACKET_DROPPED_TO_GENERATE_ARP( pxNetworkBuffer->ulIPAddress );
pxNetworkBuffer->ulIPAddress = ulIPAddress;
vARPGenerateRequestPacket( pxNetworkBuffer );
}
else
{
/* The lookup indicated that an ARP request has already been
sent out for the queried IP address. */
eReturned = eCantSendPacket;
}
}
if( eReturned != eCantSendPacket )
{
/* The network driver is responsible for freeing the network buffer
after the packet has been sent. */
xNetworkInterfaceOutput( pxNetworkBuffer, pdTRUE );
}
else
{
/* The packet can't be sent (DHCP not completed?). Just drop the
packet. */
vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );
}
}