static uint32_t prvGetHostByName( const char *pcHostName, TickType_t xIdentifier, TickType_t xReadTimeOut_ms )
{
struct freertos_sockaddr xAddress;
Socket_t xDNSSocket;
uint32_t ulIPAddress = 0UL;
uint8_t *pucUDPPayloadBuffer;
static uint32_t ulAddressLength;
BaseType_t xAttempt;
int32_t lBytes;
size_t xPayloadLength, xExpectedPayloadLength;
TickType_t xWriteTimeOut_ms = 100U;
#if( ipconfigUSE_LLMNR == 1 )
BaseType_t bHasDot = pdFALSE;
#endif /* ipconfigUSE_LLMNR == 1 */
/* If LLMNR is being used then determine if the host name includes a '.' -
if not then LLMNR can be used as the lookup method. */
#if( ipconfigUSE_LLMNR == 1 )
{
const char *pucPtr;
for( pucPtr = pcHostName; *pucPtr; pucPtr++ )
{
if( *pucPtr == '.' )
{
bHasDot = pdTRUE;
break;
}
}
}
#endif /* ipconfigUSE_LLMNR == 1 */
/* Two is added at the end for the count of characters in the first
subdomain part and the string end byte. */
xExpectedPayloadLength = sizeof( DNSMessage_t ) + strlen( pcHostName ) + sizeof( uint16_t ) + sizeof( uint16_t ) + 2u;
xDNSSocket = prvCreateDNSSocket();
if( xDNSSocket != NULL )
{
FreeRTOS_setsockopt( xDNSSocket, 0, FREERTOS_SO_SNDTIMEO, ( void * ) &xWriteTimeOut_ms, sizeof( TickType_t ) );
FreeRTOS_setsockopt( xDNSSocket, 0, FREERTOS_SO_RCVTIMEO, ( void * ) &xReadTimeOut_ms, sizeof( TickType_t ) );
for( xAttempt = 0; xAttempt < ipconfigDNS_REQUEST_ATTEMPTS; xAttempt++ )
{
/* Get a buffer. This uses a maximum delay, but the delay will be
capped to ipconfigUDP_MAX_SEND_BLOCK_TIME_TICKS so the return value
still needs to be tested. */
pucUDPPayloadBuffer = ( uint8_t * ) FreeRTOS_GetUDPPayloadBuffer( xExpectedPayloadLength, portMAX_DELAY );
if( pucUDPPayloadBuffer != NULL )
{
/* Create the message in the obtained buffer. */
xPayloadLength = prvCreateDNSMessage( pucUDPPayloadBuffer, pcHostName, xIdentifier );
iptraceSENDING_DNS_REQUEST();
/* Obtain the DNS server address. */
FreeRTOS_GetAddressConfiguration( NULL, NULL, NULL, &ulIPAddress );
/* Send the DNS message. */
#if( ipconfigUSE_LLMNR == 1 )
if( bHasDot == pdFALSE )
{
/* Use LLMNR addressing. */
( ( DNSMessage_t * ) pucUDPPayloadBuffer) -> usFlags = 0;
xAddress.sin_addr = ipLLMNR_IP_ADDR; /* Is in network byte order. */
xAddress.sin_port = FreeRTOS_ntohs( ipLLMNR_PORT );
}
else
#endif
{
/* Use DNS server. */
xAddress.sin_addr = ulIPAddress;
xAddress.sin_port = dnsDNS_PORT;
}
ulIPAddress = 0UL;
if( FreeRTOS_sendto( xDNSSocket, pucUDPPayloadBuffer, xPayloadLength, FREERTOS_ZERO_COPY, &xAddress, sizeof( xAddress ) ) != 0 )
{
/* Wait for the reply. */
lBytes = FreeRTOS_recvfrom( xDNSSocket, &pucUDPPayloadBuffer, 0, FREERTOS_ZERO_COPY, &xAddress, &ulAddressLength );
if( lBytes > 0 )
{
/* The reply was received. Process it. */
ulIPAddress = prvParseDNSReply( pucUDPPayloadBuffer, xIdentifier );
/* Finished with the buffer. The zero copy interface
is being used, so the buffer must be freed by the
task. */
FreeRTOS_ReleaseUDPPayloadBuffer( ( void * ) pucUDPPayloadBuffer );
if( ulIPAddress != 0UL )
{
/* All done. */
break;
}
}
}
else
{
/* The message was not sent so the stack will not be
releasing the zero copy - it must be released here. */
FreeRTOS_ReleaseUDPPayloadBuffer( ( void * ) pucUDPPayloadBuffer );
}
}
}
/* Finished with the socket. */
FreeRTOS_closesocket( xDNSSocket );
}
return ulIPAddress;
}
uint32_t FreeRTOS_gethostbyname( const uint8_t *pcHostName )
{
static uint16_t usIdentifier = 0;
struct freertos_sockaddr xAddress;
static xSocket_t xDNSSocket = NULL;
uint32_t ulIPAddress = 0UL;
uint8_t *pucUDPPayloadBuffer;
static uint32_t ulAddressLength;
portBASE_TYPE xAttempt;
int32_t lBytes;
size_t xPayloadLength;
const size_t xExpectedPayloadLength = sizeof( xDNSMessage_t ) + strlen( ( const char * const ) pcHostName ) + sizeof( uint16_t ) + sizeof( uint16_t ) + 2; /* Two for the count of characters in the first subdomain part, and the string end byte */
if( xDNSSocket == NULL )
{
xDNSSocket = prvCreateDNSSocket();
}
if( xDNSSocket != NULL )
{
/* Generate a unique identifier for this query. */
usIdentifier++;
for( xAttempt = 0; xAttempt < dnsMAX_REQUEST_ATTEMPTS; xAttempt++ )
{
/* Get a buffer. This uses a maximum delay, but the delay will be
capped to ipconfigMAX_SEND_BLOCK_TIME_TICKS so the return value
still needs to be tested. */
pucUDPPayloadBuffer = ( uint8_t * ) FreeRTOS_GetUDPPayloadBuffer( xExpectedPayloadLength, portMAX_DELAY );
if( pucUDPPayloadBuffer != NULL )
{
/* Create the message in the obtained buffer. */
xPayloadLength = prvCreateDNSMessage( pucUDPPayloadBuffer, pcHostName, usIdentifier );
iptraceSENDING_DNS_REQUEST();
/* Obtain the DNS server address. */
FreeRTOS_GetAddressConfiguration( NULL, NULL, NULL, &ulIPAddress );
/* Send the DNS message. */
xAddress.sin_addr = ulIPAddress;
xAddress.sin_port = dnsDNS_PORT;
ulIPAddress = 0;
if( FreeRTOS_sendto( xDNSSocket, pucUDPPayloadBuffer, xPayloadLength, FREERTOS_ZERO_COPY, &xAddress, sizeof( xAddress ) ) != 0 )
{
/* Wait for the reply. */
lBytes = FreeRTOS_recvfrom( xDNSSocket, &pucUDPPayloadBuffer, 0, FREERTOS_ZERO_COPY, &xAddress, &ulAddressLength );
if( lBytes > 0 )
{
/* The reply was received. Process it. */
ulIPAddress = prvParseDNSReply( pucUDPPayloadBuffer, usIdentifier );
/* Finished with the buffer. The zero copy interface
is being used, so the buffer must be freed by the
task. */
FreeRTOS_ReleaseUDPPayloadBuffer( ( void * ) pucUDPPayloadBuffer );
if( ulIPAddress != 0 )
{
/* All done. */
break;
}
}
}
else
{
/* The message was not sent so the stack will not be
releasing the zero copy - it must be released here. */
FreeRTOS_ReleaseUDPPayloadBuffer( ( void * ) pucUDPPayloadBuffer );
}
}
}
}
return ulIPAddress;
}
