static uint32_t prvParseDNSReply( uint8_t *pucUDPPayloadBuffer, TickType_t xIdentifier )
{
DNSMessage_t *pxDNSMessageHeader;
uint32_t ulIPAddress = 0UL;
#if( ipconfigUSE_LLMNR == 1 )
char *pcRequestedName = NULL;
#endif
uint8_t *pucByte;
uint16_t x, usDataLength, usQuestions;
#if( ipconfigUSE_LLMNR == 1 )
uint16_t usType = 0, usClass = 0;
#endif
#if( ipconfigUSE_DNS_CACHE == 1 )
char pcName[128] = ""; /*_RB_ What is the significance of 128? Probably too big to go on the stack for a small MCU but don't know how else it could be made re-entrant. Might be necessary. */
#endif
pxDNSMessageHeader = ( DNSMessage_t * ) pucUDPPayloadBuffer;
if( pxDNSMessageHeader->usIdentifier == ( uint16_t ) xIdentifier )
{
/* Start at the first byte after the header. */
pucByte = pucUDPPayloadBuffer + sizeof( DNSMessage_t );
/* Skip any question records. */
usQuestions = FreeRTOS_ntohs( pxDNSMessageHeader->usQuestions );
for( x = 0; x < usQuestions; x++ )
{
#if( ipconfigUSE_LLMNR == 1 )
{
if( x == 0 )
{
pcRequestedName = ( char * ) pucByte;
}
}
#endif
#if( ipconfigUSE_DNS_CACHE == 1 )
if( x == 0 )
{
pucByte = prvReadNameField( pucByte, pcName, sizeof( pcName ) );
}
else
#endif /* ipconfigUSE_DNS_CACHE */
{
/* Skip the variable length pcName field. */
pucByte = prvSkipNameField( pucByte );
}
#if( ipconfigUSE_LLMNR == 1 )
{
/* usChar2u16 returns value in host endianness. */
usType = usChar2u16( pucByte );
usClass = usChar2u16( pucByte + 2 );
}
#endif /* ipconfigUSE_LLMNR */
/* Skip the type and class fields. */
pucByte += sizeof( uint32_t );
}
/* Search through the answers records. */
pxDNSMessageHeader->usAnswers = FreeRTOS_ntohs( pxDNSMessageHeader->usAnswers );
if( ( pxDNSMessageHeader->usFlags & dnsRX_FLAGS_MASK ) == dnsEXPECTED_RX_FLAGS )
{
for( x = 0; x < pxDNSMessageHeader->usAnswers; x++ )
{
pucByte = prvSkipNameField( pucByte );
/* Is the type field that of an A record? */
if( usChar2u16( pucByte ) == dnsTYPE_A_HOST )
{
/* This is the required record. Skip the type, class, and
time to live fields, plus the first byte of the data
length. */
pucByte += ( sizeof( uint32_t ) + sizeof( uint32_t ) + sizeof( uint8_t ) );
/* Sanity check the data length. */
if( ( size_t ) *pucByte == sizeof( uint32_t ) )
{
/* Skip the second byte of the length. */
pucByte++;
/* Copy the IP address out of the record. */
memcpy( ( void * ) &ulIPAddress, ( void * ) pucByte, sizeof( uint32_t ) );
#if( ipconfigUSE_DNS_CACHE == 1 )
{
prvProcessDNSCache( pcName, &ulIPAddress, pdFALSE );
}
#endif /* ipconfigUSE_DNS_CACHE */
#if( ipconfigDNS_USE_CALLBACKS != 0 )
{
/* See if any asynchronous call was made to FreeRTOS_gethostbyname_a() */
vDNSDoCallback( ( TickType_t ) pxDNSMessageHeader->usIdentifier, pcName, ulIPAddress );
}
#endif /* ipconfigDNS_USE_CALLBACKS != 0 */
}
break;
}
else
{
/* Skip the type, class and time to live fields. */
pucByte += ( sizeof( uint32_t ) + sizeof( uint32_t ) );
/* Determine the length of the data in the field. */
memcpy( ( void * ) &usDataLength, ( void * ) pucByte, sizeof( uint16_t ) );
usDataLength = FreeRTOS_ntohs( usDataLength );
/* Jump over the data length bytes, and the data itself. */
pucByte += usDataLength + sizeof( uint16_t );
}
}
}
#if( ipconfigUSE_LLMNR == 1 )
else if( ( usQuestions != ( uint16_t )0u ) && ( usType == ( uint16_t )dnsTYPE_A_HOST ) && ( usClass == ( uint16_t )dnsCLASS_IN ) )
{
/* If this is not a reply to our DNS request, it might an LLMNR
request. */
if( xApplicationDNSQueryHook ( ( pcRequestedName + 1 ) ) )
{
int16_t usLength;
NetworkBufferDescriptor_t *pxNewBuffer = NULL;
NetworkBufferDescriptor_t *pxNetworkBuffer = pxUDPPayloadBuffer_to_NetworkBuffer( pucUDPPayloadBuffer );
LLMNRAnswer_t *pxAnswer;
if( ( xBufferAllocFixedSize == pdFALSE ) && ( pxNetworkBuffer != NULL ) )
{
BaseType_t xDataLength = pxNetworkBuffer->xDataLength + sizeof( UDPHeader_t ) +
sizeof( EthernetHeader_t ) + sizeof( IPHeader_t );
/* The field xDataLength was set to the length of the UDP payload.
The answer (reply) will be longer than the request, so the packet
must be duplicaed into a bigger buffer */
pxNetworkBuffer->xDataLength = xDataLength;
pxNewBuffer = pxDuplicateNetworkBufferWithDescriptor( pxNetworkBuffer, xDataLength + 16 );
if( pxNewBuffer != NULL )
{
BaseType_t xOffset1, xOffset2;
xOffset1 = ( BaseType_t ) ( pucByte - pucUDPPayloadBuffer );
xOffset2 = ( BaseType_t ) ( ( ( uint8_t * ) pcRequestedName ) - pucUDPPayloadBuffer );
pxNetworkBuffer = pxNewBuffer;
pucUDPPayloadBuffer = pxNetworkBuffer->pucEthernetBuffer + ipUDP_PAYLOAD_OFFSET_IPv4;
pucByte = pucUDPPayloadBuffer + xOffset1;
pcRequestedName = ( char * ) ( pucUDPPayloadBuffer + xOffset2 );
pxDNSMessageHeader = ( DNSMessage_t * ) pucUDPPayloadBuffer;
}
else
{
/* Just to indicate that the message may not be answered. */
pxNetworkBuffer = NULL;
}
}
if( pxNetworkBuffer != NULL )
{
pxAnswer = (LLMNRAnswer_t *)pucByte;
/* Leave 'usIdentifier' and 'usQuestions' untouched. */
vSetField16( pxDNSMessageHeader, DNSMessage_t, usFlags, dnsLLMNR_FLAGS_IS_REPONSE ); /* Set the response flag */
vSetField16( pxDNSMessageHeader, DNSMessage_t, usAnswers, 1 ); /* Provide a single answer */
vSetField16( pxDNSMessageHeader, DNSMessage_t, usAuthorityRRs, 0 ); /* No authority */
vSetField16( pxDNSMessageHeader, DNSMessage_t, usAdditionalRRs, 0 ); /* No additional info */
pxAnswer->ucNameCode = dnsNAME_IS_OFFSET;
pxAnswer->ucNameOffset = ( uint8_t )( pcRequestedName - ( char * ) pucUDPPayloadBuffer );
vSetField16( pxAnswer, LLMNRAnswer_t, usType, dnsTYPE_A_HOST ); /* Type A: host */
vSetField16( pxAnswer, LLMNRAnswer_t, usClass, dnsCLASS_IN ); /* 1: Class IN */
vSetField32( pxAnswer, LLMNRAnswer_t, ulTTL, dnsLLMNR_TTL_VALUE );
vSetField16( pxAnswer, LLMNRAnswer_t, usDataLength, 4 );
vSetField32( pxAnswer, LLMNRAnswer_t, ulIPAddress, FreeRTOS_ntohl( *ipLOCAL_IP_ADDRESS_POINTER ) );
usLength = ( int16_t ) ( sizeof( *pxAnswer ) + ( size_t ) ( pucByte - pucUDPPayloadBuffer ) );
prvReplyDNSMessage( pxNetworkBuffer, usLength );
if( pxNewBuffer != NULL )
{
vReleaseNetworkBufferAndDescriptor( pxNewBuffer );
}
}
}
}
#endif /* ipconfigUSE_LLMNR == 1 */
}
return ulIPAddress;
}
static void prvTreatNBNS( uint8_t *pucUDPPayloadBuffer, uint32_t ulIPAddress )
{
uint16_t usFlags, usType, usClass;
uint8_t *pucSource, *pucTarget;
uint8_t ucByte;
uint8_t ucNBNSName[ 17 ];
usFlags = usChar2u16( pucUDPPayloadBuffer + offsetof( NBNSRequest_t, usFlags ) );
if( ( usFlags & dnsNBNS_FLAGS_OPCODE_MASK ) == dnsNBNS_FLAGS_OPCODE_QUERY )
{
usType = usChar2u16( pucUDPPayloadBuffer + offsetof( NBNSRequest_t, usType ) );
usClass = usChar2u16( pucUDPPayloadBuffer + offsetof( NBNSRequest_t, usClass ) );
/* Not used for now */
( void )usClass;
/* For NBNS a name is 16 bytes long, written with capitals only.
Make sure that the copy is terminated with a zero. */
pucTarget = ucNBNSName + sizeof(ucNBNSName ) - 2;
pucTarget[ 1 ] = '\0';
/* Start with decoding the last 2 bytes. */
pucSource = pucUDPPayloadBuffer + ( offsetof( NBNSRequest_t, ucName ) + ( dnsNBNS_ENCODED_NAME_LENGTH - 2 ) );
for( ;; )
{
ucByte = ( uint8_t ) ( ( ( pucSource[ 0 ] - 0x41 ) << 4 ) | ( pucSource[ 1 ] - 0x41 ) );
/* Make sure there are no trailing spaces in the name. */
if( ( ucByte == ' ' ) && ( pucTarget[ 1 ] == '\0' ) )
{
ucByte = '\0';
}
*pucTarget = ucByte;
if( pucTarget == ucNBNSName )
{
break;
}
pucTarget -= 1;
pucSource -= 2;
}
#if( ipconfigUSE_DNS_CACHE == 1 )
{
if( ( usFlags & dnsNBNS_FLAGS_RESPONSE ) != 0 )
{
/* If this is a response from another device,
add the name to the DNS cache */
prvProcessDNSCache( ( char * ) ucNBNSName, &ulIPAddress, pdFALSE );
}
}
#else
{
/* Avoid compiler warnings. */
( void ) ulIPAddress;
}
#endif /* ipconfigUSE_DNS_CACHE */
if( ( ( usFlags & dnsNBNS_FLAGS_RESPONSE ) == 0 ) &&
( usType == dnsNBNS_TYPE_NET_BIOS ) &&
( xApplicationDNSQueryHook( ( const char * ) ucNBNSName ) != pdFALSE ) )
{
uint16_t usLength;
DNSMessage_t *pxMessage;
NBNSAnswer_t *pxAnswer;
/* Someone is looking for a device with ucNBNSName,
prepare a positive reply. */
NetworkBufferDescriptor_t *pxNetworkBuffer = pxUDPPayloadBuffer_to_NetworkBuffer( pucUDPPayloadBuffer );
if( ( xBufferAllocFixedSize == pdFALSE ) && ( pxNetworkBuffer != NULL ) )
{
NetworkBufferDescriptor_t *pxNewBuffer;
BaseType_t xDataLength = pxNetworkBuffer->xDataLength + sizeof( UDPHeader_t ) +
sizeof( EthernetHeader_t ) + sizeof( IPHeader_t );
/* The field xDataLength was set to the length of the UDP payload.
The answer (reply) will be longer than the request, so the packet
must be duplicated into a bigger buffer */
pxNetworkBuffer->xDataLength = xDataLength;
pxNewBuffer = pxDuplicateNetworkBufferWithDescriptor( pxNetworkBuffer, xDataLength + 16 );
if( pxNewBuffer != NULL )
{
pucUDPPayloadBuffer = pxNewBuffer->pucEthernetBuffer + sizeof( UDPPacket_t );
pxNetworkBuffer = pxNewBuffer;
}
else
{
/* Just prevent that a reply will be sent */
pxNetworkBuffer = NULL;
}
}
/* Should not occur: pucUDPPayloadBuffer is part of a xNetworkBufferDescriptor */
if( pxNetworkBuffer != NULL )
{
pxMessage = (DNSMessage_t *)pucUDPPayloadBuffer;
/* As the fields in the structures are not word-aligned, we have to
copy the values byte-by-byte using macro's vSetField16() and vSetField32() */
vSetField16( pxMessage, DNSMessage_t, usFlags, dnsNBNS_QUERY_RESPONSE_FLAGS ); /* 0x8500 */
vSetField16( pxMessage, DNSMessage_t, usQuestions, 0 );
vSetField16( pxMessage, DNSMessage_t, usAnswers, 1 );
vSetField16( pxMessage, DNSMessage_t, usAuthorityRRs, 0 );
vSetField16( pxMessage, DNSMessage_t, usAdditionalRRs, 0 );
pxAnswer = (NBNSAnswer_t *)( pucUDPPayloadBuffer + offsetof( NBNSRequest_t, usType ) );
vSetField16( pxAnswer, NBNSAnswer_t, usType, usType ); /* Type */
vSetField16( pxAnswer, NBNSAnswer_t, usClass, dnsNBNS_CLASS_IN ); /* Class */
vSetField32( pxAnswer, NBNSAnswer_t, ulTTL, dnsNBNS_TTL_VALUE );
vSetField16( pxAnswer, NBNSAnswer_t, usDataLength, 6 ); /* 6 bytes including the length field */
vSetField16( pxAnswer, NBNSAnswer_t, usNbFlags, dnsNBNS_NAME_FLAGS );
vSetField32( pxAnswer, NBNSAnswer_t, ulIPAddress, FreeRTOS_ntohl( *ipLOCAL_IP_ADDRESS_POINTER ) );
usLength = ( uint16_t ) ( offsetof( NBNSRequest_t, usType ) + sizeof( NBNSAnswer_t ) );
prvReplyDNSMessage( pxNetworkBuffer, usLength );
}
}
}
}
XStatus emacps_send_message(xemacpsif_s *xemacpsif, NetworkBufferDescriptor_t *pxFirstBuffer, int iReleaseAfterSend )
{
NetworkBufferDescriptor_t *pxBuffer;
int head = xemacpsif->txHead;
int tail = xemacpsif->txTail;
int iHasSent = 0;
uint32_t ulBaseAddress = xemacpsif->emacps.Config.BaseAddress;
#if( ipconfigZERO_COPY_TX_DRIVER != 0 )
if( iReleaseAfterSend == pdFALSE )
{
NetworkBufferDescriptor_t *pxNewBuffer;
pxNewBuffer = pxDuplicateNetworkBufferWithDescriptor( pxFirstBuffer, pxFirstBuffer->xDataLength );
if( pxNewBuffer )
{
pxFirstBuffer = pxNewBuffer;
iReleaseAfterSend = pdTRUE;
}
}
#endif
/* Although it looks like more that 1 message can be sent,
this possibility is NOT being used and not yet tested. */
for( pxBuffer = pxFirstBuffer; pxBuffer != NULL; )
{
NetworkBufferDescriptor_t *pxNextBuffer;
if( ( head == tail ) && ( xemacpsif->txSegments[ head ].flags & XEMACPS_TXBUF_USED_MASK ) == 0 )
{
// FreeRTOS_printf( ( "emacps_send_message: All TX buffers full\n" ) );
break;
}
if( xValidLength( pxBuffer->xDataLength ) )
{
/* Just a sanity check, the TX buffer will be assigned permanently. */
#if( ipconfigZERO_COPY_TX_DRIVER == 0 )
if( pxDMA_tx_buffers[ head ] != NULL )
#endif
{
uint32_t flags = 0;
#if( ipconfigZERO_COPY_TX_DRIVER != 0 )
/* Move the message to unbuffered space in RAM. */
pxDMA_tx_buffers[ head ] = ( uint32_t )pxBuffer->pucEthernetBuffer;
if( ucIsCachedMemory( pxBuffer->pucEthernetBuffer ) != 0 )
{
Xil_DCacheFlushRange( ( unsigned )pxBuffer->pucEthernetBuffer, pxBuffer->xDataLength );
}
#else
/* Copy the message to unbuffered space in RAM. */
memcpy( pxDMA_tx_buffers[ head ], pxBuffer->pucEthernetBuffer, pxBuffer->xDataLength );
#endif
/* Packets will be sent one-by-one, so for each packet
the TXBUF_LAST bit will be set. */
flags |= XEMACPS_TXBUF_LAST_MASK;
flags |= ( pxBuffer->xDataLength & XEMACPS_TXBUF_LEN_MASK );
if( head == ( ipconfigNIC_N_TX_DESC - 1 ) )
{
flags |= XEMACPS_TXBUF_WRAP_MASK;
}
/* Copy the address of the buffer and set the flags. */
xemacpsif->txSegments[ head ].address = ( uint32_t )pxDMA_tx_buffers[ head ];
xemacpsif->txSegments[ head ].flags = flags;
iHasSent = pdTRUE;
}
if( ++head == ipconfigNIC_N_TX_DESC )
{
head = 0;
}
}
/* Make a copy of the next field, before pxBuffer gets deleted */
pxNextBuffer = pxBuffer->pxNextBuffer;
#if( ipconfigZERO_COPY_TX_DRIVER == 0 )
if( iReleaseAfterSend != pdFALSE )
{
vReleaseNetworkBufferAndDescriptor( pxBuffer );
}
#endif
pxBuffer = pxNextBuffer;
}
/* Update the TX-head index. These variable are declared volatile so they will be
accessed as little as possible. */
xemacpsif->txHead = head;
/* Data Synchronization Barrier */
dsb();
if( iHasSent != pdFALSE )
{
/* Make STARTTX high */
uint32_t ulValue = XEmacPs_ReadReg( ulBaseAddress, XEMACPS_NWCTRL_OFFSET);
/* Start transmit */
xemacpsif->txBusy = pdTRUE;
XEmacPs_WriteReg( ulBaseAddress, XEMACPS_NWCTRL_OFFSET, ( ulValue | XEMACPS_NWCTRL_STARTTX_MASK ) );
}
dsb();
return 0;
}
