X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=FreeRTOS-Plus%2FSource%2FFreeRTOS-Plus-TCP%2FFreeRTOS_DNS.c;h=ad0c3a4a020357e8ee345f0d493a02d7b0c4120c;hb=HEAD;hp=4ba27963e1ca67342db6dc4ef244d43d13196b03;hpb=e48883ece99cbc67ceae53c3bf85969734c4e853;p=freertos diff --git a/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/FreeRTOS_DNS.c b/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/FreeRTOS_DNS.c index 4ba27963e..ad0c3a4a0 100644 --- a/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/FreeRTOS_DNS.c +++ b/FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/FreeRTOS_DNS.c @@ -1,1209 +1,1556 @@ -/* - * FreeRTOS+TCP V2.0.1 - * Copyright (C) 2017 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://www.FreeRTOS.org - * http://aws.amazon.com/freertos - * - * 1 tab == 4 spaces! - */ - -/* Standard includes. */ -#include - -/* FreeRTOS includes. */ -#include "FreeRTOS.h" -#include "task.h" -#include "queue.h" -#include "list.h" -#include "semphr.h" - -/* FreeRTOS+TCP includes. */ -#include "FreeRTOS_IP.h" -#include "FreeRTOS_Sockets.h" -#include "FreeRTOS_IP_Private.h" -#include "FreeRTOS_UDP_IP.h" -#include "FreeRTOS_DNS.h" -#include "NetworkBufferManagement.h" -#include "NetworkInterface.h" -#include "IPTraceMacroDefaults.h" - -/* Exclude the entire file if DNS is not enabled. */ -#if( ipconfigUSE_DNS != 0 ) - -#if( ipconfigBYTE_ORDER == pdFREERTOS_LITTLE_ENDIAN ) - #define dnsDNS_PORT 0x3500u - #define dnsONE_QUESTION 0x0100u - #define dnsOUTGOING_FLAGS 0x0001u /* Standard query. */ - #define dnsRX_FLAGS_MASK 0x0f80u /* The bits of interest in the flags field of incoming DNS messages. */ - #define dnsEXPECTED_RX_FLAGS 0x0080u /* Should be a response, without any errors. */ -#else - #define dnsDNS_PORT 0x0035u - #define dnsONE_QUESTION 0x0001u - #define dnsOUTGOING_FLAGS 0x0100u /* Standard query. */ - #define dnsRX_FLAGS_MASK 0x800fu /* The bits of interest in the flags field of incoming DNS messages. */ - #define dnsEXPECTED_RX_FLAGS 0x8000u /* Should be a response, without any errors. */ - -#endif /* ipconfigBYTE_ORDER */ - -/* The maximum number of times a DNS request should be sent out if a response -is not received, before giving up. */ -#ifndef ipconfigDNS_REQUEST_ATTEMPTS - #define ipconfigDNS_REQUEST_ATTEMPTS 5 -#endif - -/* If the top two bits in the first character of a name field are set then the -name field is an offset to the string, rather than the string itself. */ -#define dnsNAME_IS_OFFSET ( ( uint8_t ) 0xc0 ) - -/* NBNS flags. */ -#define dnsNBNS_FLAGS_RESPONSE 0x8000u -#define dnsNBNS_FLAGS_OPCODE_MASK 0x7800u -#define dnsNBNS_FLAGS_OPCODE_QUERY 0x0000u -#define dnsNBNS_FLAGS_OPCODE_REGISTRATION 0x2800u - -/* Host types. */ -#define dnsTYPE_A_HOST 0x0001u -#define dnsCLASS_IN 0x0001u - -/* LLMNR constants. */ -#define dnsLLMNR_TTL_VALUE 300000u -#define dnsLLMNR_FLAGS_IS_REPONSE 0x8000u - -/* NBNS constants. */ -#define dnsNBNS_TTL_VALUE 3600u /* 1 hour valid */ -#define dnsNBNS_TYPE_NET_BIOS 0x0020u -#define dnsNBNS_CLASS_IN 0x0001u -#define dnsNBNS_NAME_FLAGS 0x6000u -#define dnsNBNS_ENCODED_NAME_LENGTH 32 - -/* If the queried NBNS name matches with the device's name, -the query will be responded to with these flags: */ -#define dnsNBNS_QUERY_RESPONSE_FLAGS 0x8500u - -/* - * Create a socket and bind it to the standard DNS port number. Return the - * the created socket - or NULL if the socket could not be created or bound. - */ -static Socket_t prvCreateDNSSocket( void ); - -/* - * Create the DNS message in the zero copy buffer passed in the first parameter. - */ -static size_t prvCreateDNSMessage( uint8_t *pucUDPPayloadBuffer, const char *pcHostName, TickType_t xIdentifier ); - -/* - * Simple routine that jumps over the NAME field of a resource record. - */ -static uint8_t *prvSkipNameField( uint8_t *pucByte ); - -/* - * Process a response packet from a DNS server. - */ -static uint32_t prvParseDNSReply( uint8_t *pucUDPPayloadBuffer, TickType_t xIdentifier ); - -/* - * Prepare and send a message to a DNS server. 'xReadTimeOut_ms' will be passed as - * zero, in case the user has supplied a call-back function. - */ -static uint32_t prvGetHostByName( const char *pcHostName, TickType_t xIdentifier, TickType_t xReadTimeOut_ms ); - -/* - * The NBNS and the LLMNR protocol share this reply function. - */ -#if( ( ipconfigUSE_NBNS == 1 ) || ( ipconfigUSE_LLMNR == 1 ) ) - static void prvReplyDNSMessage( NetworkBufferDescriptor_t *pxNetworkBuffer, BaseType_t lNetLength ); -#endif - -#if( ipconfigUSE_NBNS == 1 ) - static portINLINE void prvTreatNBNS( uint8_t *pucUDPPayloadBuffer, uint32_t ulIPAddress ); -#endif /* ipconfigUSE_NBNS */ - -#if( ipconfigUSE_DNS_CACHE == 1 ) - static uint8_t *prvReadNameField( uint8_t *pucByte, char *pcName, BaseType_t xLen ); - static void prvProcessDNSCache( const char *pcName, uint32_t *pulIP, BaseType_t xLookUp ); - - typedef struct xDNS_CACHE_TABLE_ROW - { - uint32_t ulIPAddress; /* The IP address of an ARP cache entry. */ - char pcName[ipconfigDNS_CACHE_NAME_LENGTH]; /* The name of the host */ - 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. */ - } DNSCacheRow_t; - - static DNSCacheRow_t xDNSCache[ ipconfigDNS_CACHE_ENTRIES ]; -#endif /* ipconfigUSE_DNS_CACHE == 1 */ - -#if( ipconfigUSE_LLMNR == 1 ) - const MACAddress_t xLLMNR_MacAdress = { { 0x01, 0x00, 0x5e, 0x00, 0x00, 0xfc } }; -#endif /* ipconfigUSE_LLMNR == 1 */ - -/*-----------------------------------------------------------*/ - -#include "pack_struct_start.h" -struct xDNSMessage -{ - uint16_t usIdentifier; - uint16_t usFlags; - uint16_t usQuestions; - uint16_t usAnswers; - uint16_t usAuthorityRRs; - uint16_t usAdditionalRRs; -} -#include "pack_struct_end.h" -typedef struct xDNSMessage DNSMessage_t; - -/* A DNS query consists of a header, as described in 'struct xDNSMessage' -It is followed by 1 or more queries, each one consisting of a name and a tail, -with two fields: type and class -*/ -#include "pack_struct_start.h" -struct xDNSTail -{ - uint16_t usType; - uint16_t usClass; -} -#include "pack_struct_end.h" -typedef struct xDNSTail DNSTail_t; - -#if( ipconfigUSE_LLMNR == 1 ) - - #include "pack_struct_start.h" - struct xLLMNRAnswer - { - uint8_t ucNameCode; - uint8_t ucNameOffset; /* The name is not repeated in the answer, only the offset is given with "0xc0 " */ - uint16_t usType; - uint16_t usClass; - uint32_t ulTTL; - uint16_t usDataLength; - uint32_t ulIPAddress; - } - #include "pack_struct_end.h" - typedef struct xLLMNRAnswer LLMNRAnswer_t; - -#endif /* ipconfigUSE_LLMNR == 1 */ - -#if( ipconfigUSE_NBNS == 1 ) - - #include "pack_struct_start.h" - struct xNBNSRequest - { - uint16_t usRequestId; - uint16_t usFlags; - uint16_t ulRequestCount; - uint16_t usAnswerRSS; - uint16_t usAuthRSS; - uint16_t usAdditionalRSS; - uint8_t ucNameSpace; - uint8_t ucName[ dnsNBNS_ENCODED_NAME_LENGTH ]; - uint8_t ucNameZero; - uint16_t usType; - uint16_t usClass; - } - #include "pack_struct_end.h" - typedef struct xNBNSRequest NBNSRequest_t; - - #include "pack_struct_start.h" - struct xNBNSAnswer - { - uint16_t usType; - uint16_t usClass; - uint32_t ulTTL; - uint16_t usDataLength; - uint16_t usNbFlags; /* NetBIOS flags 0x6000 : IP-address, big-endian */ - uint32_t ulIPAddress; - } - #include "pack_struct_end.h" - typedef struct xNBNSAnswer NBNSAnswer_t; - -#endif /* ipconfigUSE_NBNS == 1 */ - -/*-----------------------------------------------------------*/ - -#if( ipconfigUSE_DNS_CACHE == 1 ) - uint32_t FreeRTOS_dnslookup( const char *pcHostName ) - { - uint32_t ulIPAddress = 0UL; - prvProcessDNSCache( pcHostName, &ulIPAddress, pdTRUE ); - return ulIPAddress; - } -#endif /* ipconfigUSE_DNS_CACHE == 1 */ -/*-----------------------------------------------------------*/ - -#if( ipconfigDNS_USE_CALLBACKS != 0 ) - - typedef struct xDNS_Callback { - TickType_t xRemaningTime; /* Timeout in ms */ - FOnDNSEvent pCallbackFunction; /* Function to be called when the address has been found or when a timeout has beeen reached */ - TimeOut_t xTimeoutState; - void *pvSearchID; - struct xLIST_ITEM xListItem; - char pcName[ 1 ]; - } DNSCallback_t; - - static List_t xCallbackList; - - /* Define FreeRTOS_gethostbyname() as a normal blocking call. */ - uint32_t FreeRTOS_gethostbyname( const char *pcHostName ) - { - return FreeRTOS_gethostbyname_a( pcHostName, ( FOnDNSEvent ) NULL, ( void* )NULL, 0 ); - } - /*-----------------------------------------------------------*/ - - /* Initialise the list of call-back structures. */ - void vDNSInitialise( void ); - void vDNSInitialise( void ) - { - vListInitialise( &xCallbackList ); - } - /*-----------------------------------------------------------*/ - - /* Iterate through the list of call-back structures and remove - old entries which have reached a timeout. - As soon as the list hase become empty, the DNS timer will be stopped - In case pvSearchID is supplied, the user wants to cancel a DNS request - */ - void vDNSCheckCallBack( void *pvSearchID ); - void vDNSCheckCallBack( void *pvSearchID ) - { - const ListItem_t *pxIterator; - const MiniListItem_t* xEnd = ( const MiniListItem_t* )listGET_END_MARKER( &xCallbackList ); - - vTaskSuspendAll(); - { - for( pxIterator = ( const ListItem_t * ) listGET_NEXT( xEnd ); - pxIterator != ( const ListItem_t * ) xEnd; - ) - { - DNSCallback_t *pxCallback = ( DNSCallback_t * ) listGET_LIST_ITEM_OWNER( pxIterator ); - /* Move to the next item because we might remove this item */ - pxIterator = ( const ListItem_t * ) listGET_NEXT( pxIterator ); - if( ( pvSearchID != NULL ) && ( pvSearchID == pxCallback->pvSearchID ) ) - { - uxListRemove( &pxCallback->xListItem ); - vPortFree( pxCallback ); - } - else if( xTaskCheckForTimeOut( &pxCallback->xTimeoutState, &pxCallback->xRemaningTime ) != pdFALSE ) - { - pxCallback->pCallbackFunction( pxCallback->pcName, pxCallback->pvSearchID, 0 ); - uxListRemove( &pxCallback->xListItem ); - vPortFree( ( void * ) pxCallback ); - } - } - } - xTaskResumeAll(); - - if( listLIST_IS_EMPTY( &xCallbackList ) ) - { - vIPSetDnsTimerEnableState( pdFALSE ); - } - } - /*-----------------------------------------------------------*/ - - void FreeRTOS_gethostbyname_cancel( void *pvSearchID ) - { - /* _HT_ Should better become a new API call to have the IP-task remove the callback */ - vDNSCheckCallBack( pvSearchID ); - } - /*-----------------------------------------------------------*/ - - /* FreeRTOS_gethostbyname_a() was called along with callback parameters. - Store them in a list for later reference. */ - static void vDNSSetCallBack( const char *pcHostName, void *pvSearchID, FOnDNSEvent pCallbackFunction, TickType_t xTimeout, TickType_t xIdentifier ); - static void vDNSSetCallBack( const char *pcHostName, void *pvSearchID, FOnDNSEvent pCallbackFunction, TickType_t xTimeout, TickType_t xIdentifier ) - { - size_t lLength = strlen( pcHostName ); - DNSCallback_t *pxCallback = ( DNSCallback_t * )pvPortMalloc( sizeof( *pxCallback ) + lLength ); - - /* Translate from ms to number of clock ticks. */ - xTimeout /= portTICK_PERIOD_MS; - if( pxCallback != NULL ) - { - if( listLIST_IS_EMPTY( &xCallbackList ) ) - { - /* This is the first one, start the DNS timer to check for timeouts */ - vIPReloadDNSTimer( FreeRTOS_min_uint32( 1000U, xTimeout ) ); - } - strcpy( pxCallback->pcName, pcHostName ); - pxCallback->pCallbackFunction = pCallbackFunction; - pxCallback->pvSearchID = pvSearchID; - pxCallback->xRemaningTime = xTimeout; - vTaskSetTimeOutState( &pxCallback->xTimeoutState ); - listSET_LIST_ITEM_OWNER( &( pxCallback->xListItem ), ( void* ) pxCallback ); - listSET_LIST_ITEM_VALUE( &( pxCallback->xListItem ), xIdentifier ); - vTaskSuspendAll(); - { - vListInsertEnd( &xCallbackList, &pxCallback->xListItem ); - } - xTaskResumeAll(); - } - } - /*-----------------------------------------------------------*/ - - /* A DNS reply was received, see if there is any matching entry and - call the handler. */ - static void vDNSDoCallback( TickType_t xIdentifier, const char *pcName, uint32_t ulIPAddress ); - static void vDNSDoCallback( TickType_t xIdentifier, const char *pcName, uint32_t ulIPAddress ) - { - const ListItem_t *pxIterator; - const MiniListItem_t* xEnd = ( const MiniListItem_t* )listGET_END_MARKER( &xCallbackList ); - - vTaskSuspendAll(); - { - for( pxIterator = ( const ListItem_t * ) listGET_NEXT( xEnd ); - pxIterator != ( const ListItem_t * ) xEnd; - pxIterator = ( const ListItem_t * ) listGET_NEXT( pxIterator ) ) - { - if( listGET_LIST_ITEM_VALUE( pxIterator ) == xIdentifier ) - { - DNSCallback_t *pxCallback = ( DNSCallback_t * ) listGET_LIST_ITEM_OWNER( pxIterator ); - pxCallback->pCallbackFunction( pcName, pxCallback->pvSearchID, ulIPAddress ); - uxListRemove( &pxCallback->xListItem ); - vPortFree( pxCallback ); - if( listLIST_IS_EMPTY( &xCallbackList ) ) - { - vIPSetDnsTimerEnableState( pdFALSE ); - } - break; - } - } - } - xTaskResumeAll(); - } - -#endif /* ipconfigDNS_USE_CALLBACKS != 0 */ -/*-----------------------------------------------------------*/ - -#if( ipconfigDNS_USE_CALLBACKS == 0 ) -uint32_t FreeRTOS_gethostbyname( const char *pcHostName ) -#else -uint32_t FreeRTOS_gethostbyname_a( const char *pcHostName, FOnDNSEvent pCallback, void *pvSearchID, TickType_t xTimeout ) -#endif -{ -uint32_t ulIPAddress = 0UL; -static uint16_t usIdentifier = 0u; -TickType_t xReadTimeOut_ms = 1200U; -/* Generate a unique identifier for this query. Keep it in a local variable - as gethostbyname() may be called from different threads */ -TickType_t xIdentifier = ( TickType_t )usIdentifier++; - - /* If the supplied hostname is IP address, convert it to uint32_t - and return. */ - #if( ipconfigINCLUDE_FULL_INET_ADDR == 1 ) - { - ulIPAddress = FreeRTOS_inet_addr( pcHostName ); - } - #endif /* ipconfigINCLUDE_FULL_INET_ADDR == 1 */ - - /* If a DNS cache is used then check the cache before issuing another DNS - request. */ - #if( ipconfigUSE_DNS_CACHE == 1 ) - { - if( ulIPAddress == 0UL ) - { - ulIPAddress = FreeRTOS_dnslookup( pcHostName ); - if( ulIPAddress != 0 ) - { - FreeRTOS_debug_printf( ( "FreeRTOS_gethostbyname: found '%s' in cache: %lxip\n", pcHostName, ulIPAddress ) ); - } - else - { - /* prvGetHostByName will be called to start a DNS lookup */ - } - } - } - #endif /* ipconfigUSE_DNS_CACHE == 1 */ - - #if( ipconfigDNS_USE_CALLBACKS != 0 ) - { - if( pCallback != NULL ) - { - if( ulIPAddress == 0UL ) - { - /* The user has provided a callback function, so do not block on recvfrom() */ - xReadTimeOut_ms = 0; - vDNSSetCallBack( pcHostName, pvSearchID, pCallback, xTimeout, ( TickType_t ) xIdentifier ); - } - else - { - /* The IP address is known, do the call-back now. */ - pCallback( pcHostName, pvSearchID, ulIPAddress ); - } - } - } - #endif - - if( ulIPAddress == 0UL) - { - ulIPAddress = prvGetHostByName( pcHostName, xIdentifier, xReadTimeOut_ms ); - } - - return ulIPAddress; -} -/*-----------------------------------------------------------*/ - -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; -} -/*-----------------------------------------------------------*/ - -static size_t prvCreateDNSMessage( uint8_t *pucUDPPayloadBuffer, const char *pcHostName, TickType_t xIdentifier ) -{ -DNSMessage_t *pxDNSMessageHeader; -uint8_t *pucStart, *pucByte; -DNSTail_t *pxTail; -static const DNSMessage_t xDefaultPartDNSHeader = -{ - 0, /* The identifier will be overwritten. */ - dnsOUTGOING_FLAGS, /* Flags set for standard query. */ - dnsONE_QUESTION, /* One question is being asked. */ - 0, /* No replies are included. */ - 0, /* No authorities. */ - 0 /* No additional authorities. */ -}; - - /* Copy in the const part of the header. */ - memcpy( ( void * ) pucUDPPayloadBuffer, ( void * ) &xDefaultPartDNSHeader, sizeof( xDefaultPartDNSHeader ) ); - - /* Write in a unique identifier. */ - pxDNSMessageHeader = ( DNSMessage_t * ) pucUDPPayloadBuffer; - pxDNSMessageHeader->usIdentifier = ( uint16_t ) xIdentifier; - - /* Create the resource record at the end of the header. First - find the end of the header. */ - pucStart = pucUDPPayloadBuffer + sizeof( xDefaultPartDNSHeader ); - - /* Leave a gap for the first length bytes. */ - pucByte = pucStart + 1; - - /* Copy in the host name. */ - strcpy( ( char * ) pucByte, pcHostName ); - - /* Mark the end of the string. */ - pucByte += strlen( pcHostName ); - *pucByte = 0x00u; - - /* Walk the string to replace the '.' characters with byte counts. - pucStart holds the address of the byte count. Walking the string - starts after the byte count position. */ - pucByte = pucStart; - - do - { - pucByte++; - - while( ( *pucByte != 0x00 ) && ( *pucByte != '.' ) ) - { - pucByte++; - } - - /* Fill in the byte count, then move the pucStart pointer up to - the found byte position. */ - *pucStart = ( uint8_t ) ( ( uint32_t ) pucByte - ( uint32_t ) pucStart ); - ( *pucStart )--; - - pucStart = pucByte; - - } while( *pucByte != 0x00 ); - - /* Finish off the record. */ - - pxTail = (DNSTail_t *)( pucByte + 1 ); - - vSetField16( pxTail, DNSTail_t, usType, dnsTYPE_A_HOST ); /* Type A: host */ - vSetField16( pxTail, DNSTail_t, usClass, dnsCLASS_IN ); /* 1: Class IN */ - - /* Return the total size of the generated message, which is the space from - the last written byte to the beginning of the buffer. */ - return ( ( uint32_t ) pucByte - ( uint32_t ) pucUDPPayloadBuffer + 1 ) + sizeof( *pxTail ); -} -/*-----------------------------------------------------------*/ - -#if( ipconfigUSE_DNS_CACHE == 1 ) - - static uint8_t *prvReadNameField( uint8_t *pucByte, char *pcName, BaseType_t xLen ) - { - BaseType_t xNameLen = 0; - /* Determine if the name is the fully coded name, or an offset to the name - elsewhere in the message. */ - if( ( *pucByte & dnsNAME_IS_OFFSET ) == dnsNAME_IS_OFFSET ) - { - /* Jump over the two byte offset. */ - pucByte += sizeof( uint16_t ); - - } - else - { - /* pucByte points to the full name. Walk over the string. */ - while( *pucByte != 0x00 ) - { - BaseType_t xCount; - if( xNameLen && xNameLen < xLen - 1 ) - pcName[xNameLen++] = '.'; - for( xCount = *(pucByte++); xCount--; pucByte++ ) - { - if( xNameLen < xLen - 1 ) - pcName[xNameLen++] = *( ( char * ) pucByte ); - } - } - - pucByte++; - } - - return pucByte; - } -#endif /* ipconfigUSE_DNS_CACHE == 1 */ -/*-----------------------------------------------------------*/ - -static uint8_t *prvSkipNameField( uint8_t *pucByte ) -{ - /* Determine if the name is the fully coded name, or an offset to the name - elsewhere in the message. */ - if( ( *pucByte & dnsNAME_IS_OFFSET ) == dnsNAME_IS_OFFSET ) - { - /* Jump over the two byte offset. */ - pucByte += sizeof( uint16_t ); - - } - else - { - /* pucByte points to the full name. Walk over the string. */ - while( *pucByte != 0x00 ) - { - /* The number of bytes to jump for each name section is stored in the byte - before the name section. */ - pucByte += ( *pucByte + 1 ); - } - - pucByte++; - } - - return pucByte; -} -/*-----------------------------------------------------------*/ - -uint32_t ulDNSHandlePacket( NetworkBufferDescriptor_t *pxNetworkBuffer ) -{ -uint8_t *pucUDPPayloadBuffer = pxNetworkBuffer->pucEthernetBuffer + sizeof( UDPPacket_t ); -DNSMessage_t *pxDNSMessageHeader = ( DNSMessage_t * ) pucUDPPayloadBuffer; - - prvParseDNSReply( pucUDPPayloadBuffer, ( uint32_t ) pxDNSMessageHeader->usIdentifier ); - - /* The packet was not consumed. */ - return pdFAIL; -} -/*-----------------------------------------------------------*/ - -#if( ipconfigUSE_NBNS == 1 ) - - uint32_t ulNBNSHandlePacket (NetworkBufferDescriptor_t *pxNetworkBuffer ) - { - UDPPacket_t *pxUDPPacket = ( UDPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer; - uint8_t *pucUDPPayloadBuffer = pxNetworkBuffer->pucEthernetBuffer + sizeof( *pxUDPPacket ); - - prvTreatNBNS( pucUDPPayloadBuffer, pxUDPPacket->xIPHeader.ulSourceIPAddress ); - - /* The packet was not consumed. */ - return pdFAIL; - } - -#endif /* ipconfigUSE_NBNS */ -/*-----------------------------------------------------------*/ - -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; -} -/*-----------------------------------------------------------*/ - -#if( ipconfigUSE_NBNS == 1 ) - - 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 ); - } - } - } - } - -#endif /* ipconfigUSE_NBNS */ -/*-----------------------------------------------------------*/ - -static Socket_t prvCreateDNSSocket( void ) -{ -static Socket_t xSocket = NULL; -struct freertos_sockaddr xAddress; -BaseType_t xReturn; -TickType_t xTimeoutTime = pdMS_TO_TICKS( 200 ); - - /* This must be the first time this function has been called. Create - the socket. */ - xSocket = FreeRTOS_socket( FREERTOS_AF_INET, FREERTOS_SOCK_DGRAM, FREERTOS_IPPROTO_UDP ); - - /* Auto bind the port. */ - xAddress.sin_port = 0u; - xReturn = FreeRTOS_bind( xSocket, &xAddress, sizeof( xAddress ) ); - - /* Check the bind was successful, and clean up if not. */ - if( xReturn != 0 ) - { - FreeRTOS_closesocket( xSocket ); - xSocket = NULL; - } - else - { - /* Set the send and receive timeouts. */ - FreeRTOS_setsockopt( xSocket, 0, FREERTOS_SO_RCVTIMEO, ( void * ) &xTimeoutTime, sizeof( TickType_t ) ); - FreeRTOS_setsockopt( xSocket, 0, FREERTOS_SO_SNDTIMEO, ( void * ) &xTimeoutTime, sizeof( TickType_t ) ); - } - - return xSocket; -} -/*-----------------------------------------------------------*/ - -#if( ( ipconfigUSE_NBNS == 1 ) || ( ipconfigUSE_LLMNR == 1 ) ) - - 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 ); - } - -#endif /* ipconfigUSE_NBNS == 1 || ipconfigUSE_LLMNR == 1 */ -/*-----------------------------------------------------------*/ - -#if( ipconfigUSE_DNS_CACHE == 1 ) - - static void prvProcessDNSCache( const char *pcName, uint32_t *pulIP, BaseType_t xLookUp ) - { - BaseType_t x; - BaseType_t xFound = pdFALSE; - static BaseType_t xFreeEntry = 0; - - /* For each entry in the DNS cache table. */ - for( x = 0; x < ipconfigDNS_CACHE_ENTRIES; x++ ) - { - if( xDNSCache[ x ].pcName[ 0 ] == 0 ) - { - break; - } - - if( strncmp( xDNSCache[ x ].pcName, pcName, sizeof( xDNSCache[ x ].pcName ) ) == 0 ) - { - /* Is this function called for a lookup or to add/update an IP address? */ - if( xLookUp != pdFALSE ) - { - *pulIP = xDNSCache[ x ].ulIPAddress; - } - else - { - xDNSCache[ x ].ulIPAddress = *pulIP; - } - - xFound = pdTRUE; - break; - } - } - - if( xFound == pdFALSE ) - { - if( xLookUp != pdFALSE ) - { - *pulIP = 0; - } - else - { - /* Called to add or update an item */ - strncpy( xDNSCache[ xFreeEntry ].pcName, pcName, sizeof( xDNSCache[ xFreeEntry ].pcName ) ); - xDNSCache[ xFreeEntry ].ulIPAddress = *pulIP; - - xFreeEntry++; - if( xFreeEntry == ipconfigDNS_CACHE_ENTRIES ) - { - xFreeEntry = 0; - } - } - } - - if( ( xLookUp == 0 ) || ( *pulIP != 0 ) ) - { - FreeRTOS_debug_printf( ( "prvProcessDNSCache: %s: '%s' @ %lxip\n", xLookUp ? "look-up" : "add", pcName, FreeRTOS_ntohl( *pulIP ) ) ); - } - } - -#endif /* ipconfigUSE_DNS_CACHE */ - -#endif /* ipconfigUSE_DNS != 0 */ - - +/* + * FreeRTOS+TCP V2.2.1 + * Copyright (C) 2017 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 + +/* FreeRTOS includes. */ +#include "FreeRTOS.h" +#include "task.h" +#include "queue.h" +#include "list.h" +#include "semphr.h" + +/* FreeRTOS+TCP includes. */ +#include "FreeRTOS_IP.h" +#include "FreeRTOS_Sockets.h" +#include "FreeRTOS_IP_Private.h" +#include "FreeRTOS_UDP_IP.h" +#include "FreeRTOS_DNS.h" +#include "NetworkBufferManagement.h" +#include "NetworkInterface.h" +#include "IPTraceMacroDefaults.h" + +/* Exclude the entire file if DNS is not enabled. */ +#if( ipconfigUSE_DNS != 0 ) + +#if( ipconfigBYTE_ORDER == pdFREERTOS_LITTLE_ENDIAN ) + #define dnsDNS_PORT 0x3500u + #define dnsONE_QUESTION 0x0100u + #define dnsOUTGOING_FLAGS 0x0001u /* Standard query. */ + #define dnsRX_FLAGS_MASK 0x0f80u /* The bits of interest in the flags field of incoming DNS messages. */ + #define dnsEXPECTED_RX_FLAGS 0x0080u /* Should be a response, without any errors. */ +#else + #define dnsDNS_PORT 0x0035u + #define dnsONE_QUESTION 0x0001u + #define dnsOUTGOING_FLAGS 0x0100u /* Standard query. */ + #define dnsRX_FLAGS_MASK 0x800fu /* The bits of interest in the flags field of incoming DNS messages. */ + #define dnsEXPECTED_RX_FLAGS 0x8000u /* Should be a response, without any errors. */ + +#endif /* ipconfigBYTE_ORDER */ + +/* The maximum number of times a DNS request should be sent out if a response +is not received, before giving up. */ +#ifndef ipconfigDNS_REQUEST_ATTEMPTS + #define ipconfigDNS_REQUEST_ATTEMPTS 5 +#endif + +/* If the top two bits in the first character of a name field are set then the +name field is an offset to the string, rather than the string itself. */ +#define dnsNAME_IS_OFFSET ( ( uint8_t ) 0xc0 ) + +/* NBNS flags. */ +#define dnsNBNS_FLAGS_RESPONSE 0x8000u +#define dnsNBNS_FLAGS_OPCODE_MASK 0x7800u +#define dnsNBNS_FLAGS_OPCODE_QUERY 0x0000u +#define dnsNBNS_FLAGS_OPCODE_REGISTRATION 0x2800u + +/* Host types. */ +#define dnsTYPE_A_HOST 0x01u +#define dnsCLASS_IN 0x01u + +/* LLMNR constants. */ +#define dnsLLMNR_TTL_VALUE 300000uL +#define dnsLLMNR_FLAGS_IS_REPONSE 0x8000u + +/* NBNS constants. */ +#define dnsNBNS_TTL_VALUE 3600uL /* 1 hour valid */ +#define dnsNBNS_TYPE_NET_BIOS 0x0020u +#define dnsNBNS_CLASS_IN 0x01u +#define dnsNBNS_NAME_FLAGS 0x6000u +#define dnsNBNS_ENCODED_NAME_LENGTH 32 + +/* If the queried NBNS name matches with the device's name, +the query will be responded to with these flags: */ +#define dnsNBNS_QUERY_RESPONSE_FLAGS ( 0x8500u ) + +/* Flag DNS parsing errors in situations where an IPv4 address is the return +type. */ +#define dnsPARSE_ERROR 0uL + +/* + * Create a socket and bind it to the standard DNS port number. Return the + * the created socket - or NULL if the socket could not be created or bound. + */ +static Socket_t prvCreateDNSSocket( void ); + +/* + * Create the DNS message in the zero copy buffer passed in the first parameter. + */ +static size_t prvCreateDNSMessage( uint8_t *pucUDPPayloadBuffer, + const char *pcHostName, + TickType_t uxIdentifier ); + +/* + * Simple routine that jumps over the NAME field of a resource record. + */ +static uint8_t * prvSkipNameField( uint8_t *pucByte, + size_t uxSourceLen ); + +/* + * Process a response packet from a DNS server. + * The parameter 'xExpected' indicates whether the identifier in the reply + * was expected, and thus if the DNS cache may be updated with the reply. + */ +static uint32_t prvParseDNSReply( uint8_t *pucUDPPayloadBuffer, + size_t uxBufferLength, + BaseType_t xExpected ); + +/* + * Prepare and send a message to a DNS server. 'uxReadTimeOut_ticks' will be passed as + * zero, in case the user has supplied a call-back function. + */ +static uint32_t prvGetHostByName( const char *pcHostName, + TickType_t uxIdentifier, + TickType_t uxReadTimeOut_ticks ); + +/* + * The NBNS and the LLMNR protocol share this reply function. + */ +#if( ( ipconfigUSE_NBNS == 1 ) || ( ipconfigUSE_LLMNR == 1 ) ) + static void prvReplyDNSMessage( NetworkBufferDescriptor_t *pxNetworkBuffer, + BaseType_t lNetLength ); +#endif + +#if( ipconfigUSE_NBNS == 1 ) + static portINLINE void prvTreatNBNS( uint8_t *pucUDPPayloadBuffer, + size_t uxBufferLength, + uint32_t ulIPAddress ); +#endif /* ipconfigUSE_NBNS */ + + +#if( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 ) + static uint8_t * prvReadNameField( uint8_t *pucByte, + size_t uxSourceLen, + char *pcName, + size_t uxLen ); +#endif /* ipconfigUSE_DNS_CACHE || ipconfigDNS_USE_CALLBACKS */ + +#if( ipconfigUSE_DNS_CACHE == 1 ) + static void prvProcessDNSCache( const char *pcName, + uint32_t *pulIP, + uint32_t ulTTL, + BaseType_t xLookUp ); + + typedef struct xDNS_CACHE_TABLE_ROW + { + uint32_t ulIPAddress; /* The IP address of an ARP cache entry. */ + char pcName[ ipconfigDNS_CACHE_NAME_LENGTH ]; /* The name of the host */ + uint32_t ulTTL; /* Time-to-Live (in seconds) from the DNS server. */ + uint32_t ulTimeWhenAddedInSeconds; + } DNSCacheRow_t; + + static DNSCacheRow_t xDNSCache[ ipconfigDNS_CACHE_ENTRIES ]; + + void FreeRTOS_dnsclear() + { + memset( xDNSCache, 0x0, sizeof( xDNSCache ) ); + } +#endif /* ipconfigUSE_DNS_CACHE == 1 */ + +#if( ipconfigUSE_LLMNR == 1 ) + const MACAddress_t xLLMNR_MacAdress = { { 0x01, 0x00, 0x5e, 0x00, 0x00, 0xfc } }; +#endif /* ipconfigUSE_LLMNR == 1 */ + +/*-----------------------------------------------------------*/ + +#include "pack_struct_start.h" +struct xDNSMessage +{ + uint16_t usIdentifier; + uint16_t usFlags; + uint16_t usQuestions; + uint16_t usAnswers; + uint16_t usAuthorityRRs; + uint16_t usAdditionalRRs; +} +#include "pack_struct_end.h" +typedef struct xDNSMessage DNSMessage_t; + +/* A DNS query consists of a header, as described in 'struct xDNSMessage' +It is followed by 1 or more queries, each one consisting of a name and a tail, +with two fields: type and class +*/ +#include "pack_struct_start.h" +struct xDNSTail +{ + uint16_t usType; + uint16_t usClass; +} +#include "pack_struct_end.h" +typedef struct xDNSTail DNSTail_t; + +/* DNS answer record header. */ +#include "pack_struct_start.h" +struct xDNSAnswerRecord +{ + uint16_t usType; + uint16_t usClass; + uint32_t ulTTL; + uint16_t usDataLength; +} +#include "pack_struct_end.h" +typedef struct xDNSAnswerRecord DNSAnswerRecord_t; + +#if( ipconfigUSE_LLMNR == 1 ) + + #include "pack_struct_start.h" + struct xLLMNRAnswer + { + uint8_t ucNameCode; + uint8_t ucNameOffset; /* The name is not repeated in the answer, only the offset is given with "0xc0 " */ + uint16_t usType; + uint16_t usClass; + uint32_t ulTTL; + uint16_t usDataLength; + uint32_t ulIPAddress; + } + #include "pack_struct_end.h" + typedef struct xLLMNRAnswer LLMNRAnswer_t; + +#endif /* ipconfigUSE_LLMNR == 1 */ + +#if( ipconfigUSE_NBNS == 1 ) + + #include "pack_struct_start.h" + struct xNBNSRequest + { + uint16_t usRequestId; + uint16_t usFlags; + uint16_t ulRequestCount; + uint16_t usAnswerRSS; + uint16_t usAuthRSS; + uint16_t usAdditionalRSS; + uint8_t ucNameSpace; + uint8_t ucName[ dnsNBNS_ENCODED_NAME_LENGTH ]; + uint8_t ucNameZero; + uint16_t usType; + uint16_t usClass; + } + #include "pack_struct_end.h" + typedef struct xNBNSRequest NBNSRequest_t; + + #include "pack_struct_start.h" + struct xNBNSAnswer + { + uint16_t usType; + uint16_t usClass; + uint32_t ulTTL; + uint16_t usDataLength; + uint16_t usNbFlags; /* NetBIOS flags 0x6000 : IP-address, big-endian */ + uint32_t ulIPAddress; + } + #include "pack_struct_end.h" + typedef struct xNBNSAnswer NBNSAnswer_t; + + #endif /* ipconfigUSE_NBNS == 1 */ + +/*-----------------------------------------------------------*/ + +#if( ipconfigUSE_DNS_CACHE == 1 ) + uint32_t FreeRTOS_dnslookup( const char *pcHostName ) + { + uint32_t ulIPAddress = 0uL; + + prvProcessDNSCache( pcHostName, &ulIPAddress, 0, pdTRUE ); + return ulIPAddress; + } +#endif /* ipconfigUSE_DNS_CACHE == 1 */ +/*-----------------------------------------------------------*/ + +#if( ipconfigDNS_USE_CALLBACKS == 1 ) + + typedef struct xDNS_Callback + { + TickType_t uxRemaningTime; /* Timeout in ms */ + FOnDNSEvent pCallbackFunction; /* Function to be called when the address has been found or when a timeout has beeen reached */ + TimeOut_t uxTimeoutState; + void *pvSearchID; + struct xLIST_ITEM xListItem; + char pcName[ 1 ]; + } DNSCallback_t; + + static List_t xCallbackList; + + /* Define FreeRTOS_gethostbyname() as a normal blocking call. */ + uint32_t FreeRTOS_gethostbyname( const char *pcHostName ) + { + return FreeRTOS_gethostbyname_a( pcHostName, ( FOnDNSEvent ) NULL, ( void * ) NULL, 0 ); + } + /*-----------------------------------------------------------*/ + + /* Initialise the list of call-back structures. */ + void vDNSInitialise( void ); + void vDNSInitialise( void ) + { + vListInitialise( &xCallbackList ); + } + /*-----------------------------------------------------------*/ + + /* Iterate through the list of call-back structures and remove + old entries which have reached a timeout. + As soon as the list hase become empty, the DNS timer will be stopped + In case pvSearchID is supplied, the user wants to cancel a DNS request + */ + void vDNSCheckCallBack( void *pvSearchID ); + void vDNSCheckCallBack( void *pvSearchID ) + { + const ListItem_t *pxIterator; + const MiniListItem_t * xEnd = ( const MiniListItem_t * ) listGET_END_MARKER( &xCallbackList ); + + vTaskSuspendAll(); + { + for( pxIterator = ( const ListItem_t * ) listGET_NEXT( xEnd ); + pxIterator != ( const ListItem_t * ) xEnd; + ) + { + DNSCallback_t *pxCallback = ( DNSCallback_t * ) listGET_LIST_ITEM_OWNER( pxIterator ); + + /* Move to the next item because we might remove this item */ + pxIterator = ( const ListItem_t * ) listGET_NEXT( pxIterator ); + + if( ( pvSearchID != NULL ) && ( pvSearchID == pxCallback->pvSearchID ) ) + { + uxListRemove( &pxCallback->xListItem ); + vPortFree( pxCallback ); + } + else if( xTaskCheckForTimeOut( &pxCallback->uxTimeoutState, &pxCallback->uxRemaningTime ) != pdFALSE ) + { + pxCallback->pCallbackFunction( pxCallback->pcName, pxCallback->pvSearchID, 0 ); + uxListRemove( &pxCallback->xListItem ); + vPortFree( ( void * ) pxCallback ); + } + } + } + xTaskResumeAll(); + + if( listLIST_IS_EMPTY( &xCallbackList ) ) + { + vIPSetDnsTimerEnableState( pdFALSE ); + } + } + /*-----------------------------------------------------------*/ + + void FreeRTOS_gethostbyname_cancel( void *pvSearchID ) + { + /* _HT_ Should better become a new API call to have the IP-task remove the callback */ + vDNSCheckCallBack( pvSearchID ); + } + /*-----------------------------------------------------------*/ + + /* FreeRTOS_gethostbyname_a() was called along with callback parameters. + Store them in a list for later reference. */ + static void vDNSSetCallBack( const char *pcHostName, + void *pvSearchID, + FOnDNSEvent pCallbackFunction, + TickType_t uxTimeout, + TickType_t uxIdentifier ); + static void vDNSSetCallBack( const char *pcHostName, + void *pvSearchID, + FOnDNSEvent pCallbackFunction, + TickType_t uxTimeout, + TickType_t uxIdentifier ) + { + size_t lLength = strlen( pcHostName ); + DNSCallback_t *pxCallback = ( DNSCallback_t * ) pvPortMalloc( sizeof( *pxCallback ) + lLength ); + + /* Translate from ms to number of clock ticks. */ + uxTimeout /= portTICK_PERIOD_MS; + + if( pxCallback != NULL ) + { + if( listLIST_IS_EMPTY( &xCallbackList ) ) + { + /* This is the first one, start the DNS timer to check for timeouts */ + vIPReloadDNSTimer( FreeRTOS_min_uint32( 1000U, uxTimeout ) ); + } + + strcpy( pxCallback->pcName, pcHostName ); + pxCallback->pCallbackFunction = pCallbackFunction; + pxCallback->pvSearchID = pvSearchID; + pxCallback->uxRemaningTime = uxTimeout; + vTaskSetTimeOutState( &pxCallback->uxTimeoutState ); + listSET_LIST_ITEM_OWNER( &( pxCallback->xListItem ), ( void * ) pxCallback ); + listSET_LIST_ITEM_VALUE( &( pxCallback->xListItem ), uxIdentifier ); + vTaskSuspendAll(); + { + vListInsertEnd( &xCallbackList, &pxCallback->xListItem ); + } + xTaskResumeAll(); + } + } + /*-----------------------------------------------------------*/ + + /* A DNS reply was received, see if there is any matching entry and + call the handler. Returns pdTRUE if uxIdentifier was recognised. */ + static BaseType_t xDNSDoCallback( TickType_t uxIdentifier, + const char *pcName, + uint32_t ulIPAddress ); + static BaseType_t xDNSDoCallback( TickType_t uxIdentifier, + const char *pcName, + uint32_t ulIPAddress ) + { + BaseType_t xResult = pdFALSE; + const ListItem_t *pxIterator; + const MiniListItem_t * xEnd = ( const MiniListItem_t * ) listGET_END_MARKER( &xCallbackList ); + + vTaskSuspendAll(); + { + for( pxIterator = ( const ListItem_t * ) listGET_NEXT( xEnd ); + pxIterator != ( const ListItem_t * ) xEnd; + pxIterator = ( const ListItem_t * ) listGET_NEXT( pxIterator ) ) + { + /* The cast will take away the 'configLIST_VOLATILE' */ + if( uxIdentifier == ( TickType_t ) listGET_LIST_ITEM_VALUE( pxIterator ) ) + { + DNSCallback_t *pxCallback = ( DNSCallback_t * ) listGET_LIST_ITEM_OWNER( pxIterator ); + + pxCallback->pCallbackFunction( pcName, pxCallback->pvSearchID, ulIPAddress ); + uxListRemove( &pxCallback->xListItem ); + vPortFree( pxCallback ); + + if( listLIST_IS_EMPTY( &xCallbackList ) ) + { + /* The list of outstanding requests is empty. No need for periodic polling. */ + vIPSetDnsTimerEnableState( pdFALSE ); + } + + xResult = pdTRUE; + break; + } + } + } + xTaskResumeAll(); + return xResult; + } + +#endif /* ipconfigDNS_USE_CALLBACKS == 1 */ +/*-----------------------------------------------------------*/ + +#if( ipconfigDNS_USE_CALLBACKS == 0 ) + uint32_t FreeRTOS_gethostbyname( const char *pcHostName ) +#else + uint32_t FreeRTOS_gethostbyname_a( const char *pcHostName, + FOnDNSEvent pCallback, + void *pvSearchID, + TickType_t uxTimeout ) +#endif +{ +uint32_t ulIPAddress = 0uL; +TickType_t uxReadTimeOut_ticks = ipconfigDNS_RECEIVE_BLOCK_TIME_TICKS; +TickType_t uxIdentifier = 0u; +BaseType_t xHasRandom = pdFALSE; + + if( pcHostName != NULL ) + { + /* If the supplied hostname is IP address, convert it to uint32_t + and return. */ + #if( ipconfigINCLUDE_FULL_INET_ADDR == 1 ) + { + ulIPAddress = FreeRTOS_inet_addr( pcHostName ); + } + #endif /* ipconfigINCLUDE_FULL_INET_ADDR == 1 */ + + /* If a DNS cache is used then check the cache before issuing another DNS + request. */ + #if( ipconfigUSE_DNS_CACHE == 1 ) + { + if( ulIPAddress == 0uL ) + { + ulIPAddress = FreeRTOS_dnslookup( pcHostName ); + + if( ulIPAddress != 0 ) + { + FreeRTOS_debug_printf( ( "FreeRTOS_gethostbyname: found '%s' in cache: %lxip\n", pcHostName, ulIPAddress ) ); + } + else + { + /* prvGetHostByName will be called to start a DNS lookup. */ + } + } + } + #endif /* ipconfigUSE_DNS_CACHE == 1 */ + + /* Generate a unique identifier. */ + if( ulIPAddress == 0uL ) + { + uint32_t ulNumber; + + xHasRandom = xApplicationGetRandomNumber( &( ulNumber ) ); + /* DNS identifiers are 16-bit. */ + uxIdentifier = ( TickType_t ) ( ulNumber & 0xffffu ); + /* ipconfigRAND32() may not return a non-zero value. */ + } + + #if( ipconfigDNS_USE_CALLBACKS == 1 ) + { + if( pCallback != NULL ) + { + if( ulIPAddress == 0uL ) + { + /* The user has provided a callback function, so do not block on recvfrom() */ + if( xHasRandom != pdFALSE ) + { + uxReadTimeOut_ticks = 0u; + vDNSSetCallBack( pcHostName, pvSearchID, pCallback, uxTimeout, uxIdentifier ); + } + } + else + { + /* The IP address is known, do the call-back now. */ + pCallback( pcHostName, pvSearchID, ulIPAddress ); + } + } + } + #endif /* if ( ipconfigDNS_USE_CALLBACKS == 1 ) */ + + if( ( ulIPAddress == 0uL ) && ( xHasRandom != pdFALSE ) ) + { + ulIPAddress = prvGetHostByName( pcHostName, uxIdentifier, uxReadTimeOut_ticks ); + } + } + return ulIPAddress; +} +/*-----------------------------------------------------------*/ + +static uint32_t prvGetHostByName( const char *pcHostName, + TickType_t uxIdentifier, + TickType_t uxReadTimeOut_ticks ) +{ +struct freertos_sockaddr xAddress; +Socket_t xDNSSocket; +uint32_t ulIPAddress = 0uL; +uint8_t *pucUDPPayloadBuffer; +uint32_t ulAddressLength = sizeof( struct freertos_sockaddr ); +BaseType_t xAttempt; +int32_t lBytes; +size_t uxPayloadLength, uxExpectedPayloadLength; +TickType_t uxWriteTimeOut_ticks = ipconfigDNS_SEND_BLOCK_TIME_TICKS; + +#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. */ + uxExpectedPayloadLength = 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 * ) &uxWriteTimeOut_ticks, sizeof( TickType_t ) ); + FreeRTOS_setsockopt( xDNSSocket, 0, FREERTOS_SO_RCVTIMEO, ( void * ) &uxReadTimeOut_ticks, 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( uxExpectedPayloadLength, portMAX_DELAY ); + + if( pucUDPPayloadBuffer != NULL ) + { + /* Create the message in the obtained buffer. */ + uxPayloadLength = prvCreateDNSMessage( pucUDPPayloadBuffer, pcHostName, uxIdentifier ); + + 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, uxPayloadLength, 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 ) + { + BaseType_t xExpected; + DNSMessage_t *pxDNSMessageHeader = ( DNSMessage_t * ) pucUDPPayloadBuffer; + + /* See if the identifiers match. */ + if( uxIdentifier == ( TickType_t ) pxDNSMessageHeader->usIdentifier ) + { + xExpected = pdTRUE; + } + else + { + /* The reply was not expected. */ + xExpected = pdFALSE; + } + + /* The reply was received. Process it. */ + #if( ipconfigDNS_USE_CALLBACKS == 0 ) + /* It is useless to analyse the unexpected reply + unless asynchronous look-ups are enabled. */ + if( xExpected != pdFALSE ) + #endif /* ipconfigDNS_USE_CALLBACKS == 0 */ + { + ulIPAddress = prvParseDNSReply( pucUDPPayloadBuffer, ( size_t ) lBytes, xExpected ); + } + + /* 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 ); + } + } + + if( uxReadTimeOut_ticks == 0u ) + { + /* This DNS lookup is asynchronous, using a call-back: + send the request only once. */ + break; + } + } + + /* Finished with the socket. */ + FreeRTOS_closesocket( xDNSSocket ); + } + + return ulIPAddress; +} +/*-----------------------------------------------------------*/ + +static size_t prvCreateDNSMessage( uint8_t *pucUDPPayloadBuffer, + const char *pcHostName, + TickType_t uxIdentifier ) +{ +DNSMessage_t *pxDNSMessageHeader; +uint8_t *pucStart, *pucByte; +DNSTail_t *pxTail; +static const DNSMessage_t xDefaultPartDNSHeader = +{ + 0, /* The identifier will be overwritten. */ + dnsOUTGOING_FLAGS, /* Flags set for standard query. */ + dnsONE_QUESTION, /* One question is being asked. */ + 0, /* No replies are included. */ + 0, /* No authorities. */ + 0 /* No additional authorities. */ +}; + + /* Copy in the const part of the header. */ + memcpy( ( void * ) pucUDPPayloadBuffer, ( void * ) &xDefaultPartDNSHeader, sizeof( xDefaultPartDNSHeader ) ); + + /* Write in a unique identifier. */ + pxDNSMessageHeader = ( DNSMessage_t * ) pucUDPPayloadBuffer; + pxDNSMessageHeader->usIdentifier = ( uint16_t ) uxIdentifier; + + /* Create the resource record at the end of the header. First + find the end of the header. */ + pucStart = pucUDPPayloadBuffer + sizeof( xDefaultPartDNSHeader ); + + /* Leave a gap for the first length bytes. */ + pucByte = pucStart + 1; + + /* Copy in the host name. */ + strcpy( ( char * ) pucByte, pcHostName ); + + /* Mark the end of the string. */ + pucByte += strlen( pcHostName ); + *pucByte = 0x00u; + + /* Walk the string to replace the '.' characters with byte counts. + pucStart holds the address of the byte count. Walking the string + starts after the byte count position. */ + pucByte = pucStart; + + do + { + pucByte++; + + while( ( *pucByte != 0x00 ) && ( *pucByte != '.' ) ) + { + pucByte++; + } + + /* Fill in the byte count, then move the pucStart pointer up to + the found byte position. */ + *pucStart = ( uint8_t ) ( ( uint32_t ) pucByte - ( uint32_t ) pucStart ); + ( *pucStart )--; + + pucStart = pucByte; + } while( *pucByte != 0x00 ); + + /* Finish off the record. */ + + pxTail = ( DNSTail_t * ) ( pucByte + 1 ); + + vSetField16( pxTail, DNSTail_t, usType, dnsTYPE_A_HOST ); /* Type A: host */ + vSetField16( pxTail, DNSTail_t, usClass, dnsCLASS_IN ); /* 1: Class IN */ + + /* Return the total size of the generated message, which is the space from + the last written byte to the beginning of the buffer. */ + return ( ( uint32_t ) pucByte - ( uint32_t ) pucUDPPayloadBuffer + 1 ) + sizeof( *pxTail ); +} +/*-----------------------------------------------------------*/ + +#if( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 ) + + static uint8_t * prvReadNameField( uint8_t *pucByte, + size_t uxSourceLen, + char *pcName, + size_t uxDestLen ) + { + size_t uxNameLen = 0; + BaseType_t xCount; + + if( 0 == uxSourceLen ) + { + return NULL; + } + + /* Determine if the name is the fully coded name, or an offset to the name + elsewhere in the message. */ + if( ( *pucByte & dnsNAME_IS_OFFSET ) == dnsNAME_IS_OFFSET ) + { + /* Jump over the two byte offset. */ + if( uxSourceLen > sizeof( uint16_t ) ) + { + pucByte += sizeof( uint16_t ); + } + else + { + pucByte = NULL; + } + } + else + { + /* pucByte points to the full name. Walk over the string. */ + while( ( NULL != pucByte ) && ( *pucByte != 0x00u ) && ( uxSourceLen > 1u ) ) + { + /* If this is not the first time through the loop, then add a + separator in the output. */ + if( ( uxNameLen > 0 ) && ( uxNameLen < ( uxDestLen - 1u ) ) ) + { + pcName[ uxNameLen++ ] = '.'; + } + + /* Process the first/next sub-string. */ + for( xCount = *( pucByte++ ), uxSourceLen--; + xCount-- && uxSourceLen > 1u; + pucByte++, uxSourceLen-- ) + { + if( uxNameLen < uxDestLen - 1u ) + { + pcName[ uxNameLen++ ] = *( ( char * ) pucByte ); + } + else + { + /* DNS name is too big for the provided buffer. */ + pucByte = NULL; + break; + } + } + } + + /* Confirm that a fully formed name was found. */ + if( NULL != pucByte ) + { + if( 0x00 == *pucByte ) + { + pucByte++; + uxSourceLen--; + pcName[ uxNameLen++ ] = '\0'; + } + else + { + pucByte = NULL; + } + } + } + + return pucByte; + } +#endif /* ipconfigUSE_DNS_CACHE || ipconfigDNS_USE_CALLBACKS */ +/*-----------------------------------------------------------*/ + +static uint8_t * prvSkipNameField( uint8_t *pucByte, + size_t uxSourceLen ) +{ +size_t uxChunkLength; + + if( 0u == uxSourceLen ) + { + return NULL; + } + + /* Determine if the name is the fully coded name, or an offset to the name + elsewhere in the message. */ + if( ( *pucByte & dnsNAME_IS_OFFSET ) == dnsNAME_IS_OFFSET ) + { + /* Jump over the two byte offset. */ + if( uxSourceLen > sizeof( uint16_t ) ) + { + pucByte += sizeof( uint16_t ); + } + else + { + pucByte = NULL; + } + } + else + { + /* pucByte points to the full name. Walk over the string. */ + while( ( *pucByte != 0x00u ) && ( uxSourceLen > 1u ) ) + { + uxChunkLength = *pucByte + 1u; + + if( uxSourceLen > uxChunkLength ) + { + uxSourceLen -= uxChunkLength; + pucByte += uxChunkLength; + } + else + { + pucByte = NULL; + break; + } + } + + /* Confirm that a fully formed name was found. */ + if( NULL != pucByte ) + { + if( 0x00u == *pucByte ) + { + pucByte++; + } + else + { + pucByte = NULL; + } + } + } + + return pucByte; +} +/*-----------------------------------------------------------*/ + +/* The function below will only be called : +when ipconfigDNS_USE_CALLBACKS == 1 +when ipconfigUSE_LLMNR == 1 +for testing purposes, by the module iot_test_freertos_tcp.c +*/ +uint32_t ulDNSHandlePacket( NetworkBufferDescriptor_t *pxNetworkBuffer ) +{ +DNSMessage_t *pxDNSMessageHeader; +size_t uxPayloadSize; + + /* Only proceed if the payload length indicated in the header + appears to be valid. */ + if( pxNetworkBuffer->xDataLength >= sizeof( UDPPacket_t ) ) + { + uxPayloadSize = pxNetworkBuffer->xDataLength - sizeof( UDPPacket_t ); + + if( uxPayloadSize >= sizeof( DNSMessage_t ) ) + { + pxDNSMessageHeader = + ( DNSMessage_t * ) ( pxNetworkBuffer->pucEthernetBuffer + sizeof( UDPPacket_t ) ); + + /* The parameter pdFALSE indicates that the reply was not expected. */ + prvParseDNSReply( ( uint8_t * ) pxDNSMessageHeader, + uxPayloadSize, + pdFALSE ); + } + } + + /* The packet was not consumed. */ + return pdFAIL; +} +/*-----------------------------------------------------------*/ + +#if( ipconfigUSE_NBNS == 1 ) + + uint32_t ulNBNSHandlePacket( NetworkBufferDescriptor_t * pxNetworkBuffer ) + { + UDPPacket_t *pxUDPPacket = ( UDPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer; + uint8_t *pucUDPPayloadBuffer = pxNetworkBuffer->pucEthernetBuffer + sizeof( UDPPacket_t ); + size_t uxPayloadSize = pxNetworkBuffer->xDataLength - sizeof( UDPPacket_t ); + + /* The network buffer data length has already been set to the + length of the UDP payload. */ + prvTreatNBNS( pucUDPPayloadBuffer, + uxPayloadSize, + pxUDPPacket->xIPHeader.ulSourceIPAddress ); + + /* The packet was not consumed. */ + return pdFAIL; + } + +#endif /* ipconfigUSE_NBNS */ +/*-----------------------------------------------------------*/ + +static uint32_t prvParseDNSReply( uint8_t *pucUDPPayloadBuffer, + size_t uxBufferLength, + BaseType_t xExpected ) +{ +DNSMessage_t *pxDNSMessageHeader; +DNSAnswerRecord_t *pxDNSAnswerRecord; +uint32_t ulIPAddress = 0uL; +#if( ipconfigUSE_LLMNR == 1 ) + char *pcRequestedName = NULL; +#endif +uint8_t *pucByte; +size_t uxSourceBytesRemaining; +uint16_t x, usDataLength, usQuestions; +BaseType_t xDoStore = xExpected; +#if( ipconfigUSE_LLMNR == 1 ) + uint16_t usType = 0, usClass = 0; +#endif +#if( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 ) + char pcName[ ipconfigDNS_CACHE_NAME_LENGTH ] = ""; +#endif + + /* Ensure that the buffer is of at least minimal DNS message length. */ + if( uxBufferLength < sizeof( DNSMessage_t ) ) + { + return dnsPARSE_ERROR; + } + + uxSourceBytesRemaining = uxBufferLength; + + /* Parse the DNS message header. */ + pxDNSMessageHeader = ( DNSMessage_t * ) pucUDPPayloadBuffer; + + /* Introduce a do {} while (0) to allow the use of breaks. */ + do + { + /* Start at the first byte after the header. */ + pucByte = pucUDPPayloadBuffer + sizeof( DNSMessage_t ); + uxSourceBytesRemaining -= 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 ) || ( ipconfigDNS_USE_CALLBACKS == 1 ) + if( x == 0 ) + { + pucByte = prvReadNameField( pucByte, + uxSourceBytesRemaining, + pcName, + sizeof( pcName ) ); + + /* Check for a malformed response. */ + if( NULL == pucByte ) + { + return dnsPARSE_ERROR; + } + + uxSourceBytesRemaining = ( pucUDPPayloadBuffer + uxBufferLength ) - pucByte; + } + else +#endif /* ipconfigUSE_DNS_CACHE || ipconfigDNS_USE_CALLBACKS */ + { + /* Skip the variable length pcName field. */ + pucByte = prvSkipNameField( pucByte, + uxSourceBytesRemaining ); + + /* Check for a malformed response. */ + if( NULL == pucByte ) + { + return dnsPARSE_ERROR; + } + + uxSourceBytesRemaining = ( size_t ) + ( pucUDPPayloadBuffer + uxBufferLength - pucByte ); + } + + /* Check the remaining buffer size. */ + if( uxSourceBytesRemaining >= sizeof( uint32_t ) ) + { + #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 ); + uxSourceBytesRemaining -= sizeof( uint32_t ); + } + else + { + /* Malformed response. */ + return dnsPARSE_ERROR; + } + } + + /* Search through the answer 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, + uxSourceBytesRemaining ); + + /* Check for a malformed response. */ + if( NULL == pucByte ) + { + return dnsPARSE_ERROR; + } + + uxSourceBytesRemaining = ( size_t ) + ( pucUDPPayloadBuffer + uxBufferLength - pucByte ); + + /* Is there enough data for an IPv4 A record answer and, if so, + is this an A record? */ + if( ( uxSourceBytesRemaining >= ( sizeof( DNSAnswerRecord_t ) + sizeof( uint32_t ) ) ) && + ( usChar2u16( pucByte ) == dnsTYPE_A_HOST ) ) + { + /* This is the required record type and is of sufficient size. */ + pxDNSAnswerRecord = ( DNSAnswerRecord_t * ) pucByte; + + /* Sanity check the data length of an IPv4 answer. */ + if( FreeRTOS_ntohs( pxDNSAnswerRecord->usDataLength ) == sizeof( uint32_t ) ) + { + /* Copy the IP address out of the record. */ + memcpy( &ulIPAddress, + pucByte + sizeof( DNSAnswerRecord_t ), + sizeof( uint32_t ) ); + + #if( ipconfigDNS_USE_CALLBACKS == 1 ) + { + /* See if any asynchronous call was made to FreeRTOS_gethostbyname_a() */ + if( xDNSDoCallback( ( TickType_t ) pxDNSMessageHeader->usIdentifier, pcName, ulIPAddress ) != pdFALSE ) + { + /* This device has requested this DNS look-up. + The result may be stored in the DNS cache. */ + xDoStore = pdTRUE; + } + } + #endif /* ipconfigDNS_USE_CALLBACKS == 1 */ + #if( ipconfigUSE_DNS_CACHE == 1 ) + { + /* The reply will only be stored in the DNS cache when the + request was issued by this device. */ + if( xDoStore != pdFALSE ) + { + prvProcessDNSCache( pcName, &ulIPAddress, pxDNSAnswerRecord->ulTTL, pdFALSE ); + } + + /* Show what has happened. */ + FreeRTOS_printf( ( "DNS[0x%04X]: The answer to '%s' (%xip) will%s be stored\n", + ( unsigned ) pxDNSMessageHeader->usIdentifier, + pcName, + ( unsigned ) FreeRTOS_ntohl( ulIPAddress ), + ( xDoStore != 0 ) ? "" : " NOT" ) ); + } + #endif /* ipconfigUSE_DNS_CACHE */ + } + + pucByte += sizeof( DNSAnswerRecord_t ) + sizeof( uint32_t ); + uxSourceBytesRemaining -= ( sizeof( DNSAnswerRecord_t ) + sizeof( uint32_t ) ); + break; + } + else if( uxSourceBytesRemaining >= sizeof( DNSAnswerRecord_t ) ) + { + /* It's not an A record, so skip it. Get the header location + and then jump over the header. */ + pxDNSAnswerRecord = ( DNSAnswerRecord_t * ) pucByte; + pucByte += sizeof( DNSAnswerRecord_t ); + uxSourceBytesRemaining -= sizeof( DNSAnswerRecord_t ); + + /* Determine the length of the answer data from the header. */ + usDataLength = FreeRTOS_ntohs( pxDNSAnswerRecord->usDataLength ); + + /* Jump over the answer. */ + if( uxSourceBytesRemaining >= usDataLength ) + { + pucByte += usDataLength; + uxSourceBytesRemaining -= usDataLength; + } + else + { + /* Malformed response. */ + return dnsPARSE_ERROR; + } + } + } + } + +#if( ipconfigUSE_LLMNR == 1 ) + else if( usQuestions && ( usType == dnsTYPE_A_HOST ) && ( usClass == 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 = uxBufferLength + sizeof( UDPHeader_t ) + sizeof( EthernetHeader_t ) + sizeof( IPHeader_t ); + + /* Set the size of the outgoing packet. */ + pxNetworkBuffer->xDataLength = xDataLength; + pxNewBuffer = pxDuplicateNetworkBufferWithDescriptor( pxNetworkBuffer, xDataLength + sizeof( LLMNRAnswer_t ) ); + + 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; + + /* We 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 */ + } while( 0 ); + + if( xExpected == pdFALSE ) + { + /* Do not return a valid IP-address in case the reply was not expected. */ + ulIPAddress = 0uL; + } + + return ulIPAddress; +} +/*-----------------------------------------------------------*/ + +#if( ipconfigUSE_NBNS == 1 ) + + static void prvTreatNBNS( uint8_t *pucUDPPayloadBuffer, + size_t uxBufferLength, + uint32_t ulIPAddress ) + { + uint16_t usFlags, usType, usClass; + uint8_t *pucSource, *pucTarget; + uint8_t ucByte; + uint8_t ucNBNSName[ 17 ]; + + /* Check for minimum buffer size. */ + if( uxBufferLength < sizeof( NBNSRequest_t ) ) + { + return; + } + + /* Read the request flags in host endianness. */ + 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, 0, 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; + + /* The field xDataLength was set to the total length of the UDP packet, + i.e. the payload size plus sizeof( UDPPacket_t ). */ + pxNewBuffer = pxDuplicateNetworkBufferWithDescriptor( pxNetworkBuffer, pxNetworkBuffer->xDataLength + sizeof( NBNSAnswer_t ) ); + + 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 ); + } + } + } + } + +#endif /* ipconfigUSE_NBNS */ +/*-----------------------------------------------------------*/ + +static Socket_t prvCreateDNSSocket( void ) +{ +Socket_t xSocket = NULL; +struct freertos_sockaddr xAddress; +BaseType_t xReturn; + + /* This must be the first time this function has been called. Create + the socket. */ + xSocket = FreeRTOS_socket( FREERTOS_AF_INET, FREERTOS_SOCK_DGRAM, FREERTOS_IPPROTO_UDP ); + + /* Auto bind the port. */ + xAddress.sin_port = 0u; + xReturn = FreeRTOS_bind( xSocket, &xAddress, sizeof( xAddress ) ); + + /* Check the bind was successful, and clean up if not. */ + if( xReturn != 0 ) + { + FreeRTOS_closesocket( xSocket ); + xSocket = NULL; + } + else + { + /* The send and receive timeouts will be set later on. */ + } + + return xSocket; +} +/*-----------------------------------------------------------*/ + +#if( ( ipconfigUSE_NBNS == 1 ) || ( ipconfigUSE_LLMNR == 1 ) ) + + 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 ); + + /* 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 ); + + #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, pxNetworkBuffer->xDataLength, pdTRUE ); + } + #endif + + /* This function will fill in the eth addresses and send the packet */ + vReturnEthernetFrame( pxNetworkBuffer, pdFALSE ); + } + +#endif /* ipconfigUSE_NBNS == 1 || ipconfigUSE_LLMNR == 1 */ +/*-----------------------------------------------------------*/ + +#if( ipconfigUSE_DNS_CACHE == 1 ) + + static void prvProcessDNSCache( const char *pcName, + uint32_t *pulIP, + uint32_t ulTTL, + BaseType_t xLookUp ) + { + BaseType_t x; + BaseType_t xFound = pdFALSE; + uint32_t ulCurrentTimeSeconds = ( xTaskGetTickCount() / portTICK_PERIOD_MS ) / 1000; + static BaseType_t xFreeEntry = 0; + configASSERT(pcName); + + /* For each entry in the DNS cache table. */ + for( x = 0; x < ipconfigDNS_CACHE_ENTRIES; x++ ) + { + if( xDNSCache[ x ].pcName[ 0 ] == 0 ) + { + continue; + } + + if( 0 == strcmp( xDNSCache[ x ].pcName, pcName ) ) + { + /* Is this function called for a lookup or to add/update an IP address? */ + if( xLookUp != pdFALSE ) + { + /* Confirm that the record is still fresh. */ + if( ulCurrentTimeSeconds < ( xDNSCache[ x ].ulTimeWhenAddedInSeconds + FreeRTOS_ntohl( xDNSCache[ x ].ulTTL ) ) ) + { + *pulIP = xDNSCache[ x ].ulIPAddress; + } + else + { + /* Age out the old cached record. */ + xDNSCache[ x ].pcName[ 0 ] = 0; + } + } + else + { + xDNSCache[ x ].ulIPAddress = *pulIP; + xDNSCache[ x ].ulTTL = ulTTL; + xDNSCache[ x ].ulTimeWhenAddedInSeconds = ulCurrentTimeSeconds; + } + + xFound = pdTRUE; + break; + } + } + + if( xFound == pdFALSE ) + { + if( xLookUp != pdFALSE ) + { + *pulIP = 0; + } + else + { + /* Add or update the item. */ + if( strlen( pcName ) < ipconfigDNS_CACHE_NAME_LENGTH ) + { + strcpy( xDNSCache[ xFreeEntry ].pcName, pcName ); + + xDNSCache[ xFreeEntry ].ulIPAddress = *pulIP; + xDNSCache[ xFreeEntry ].ulTTL = ulTTL; + xDNSCache[ xFreeEntry ].ulTimeWhenAddedInSeconds = ulCurrentTimeSeconds; + + xFreeEntry++; + + if( xFreeEntry == ipconfigDNS_CACHE_ENTRIES ) + { + xFreeEntry = 0; + } + } + } + } + + if( ( xLookUp == 0 ) || ( *pulIP != 0 ) ) + { + FreeRTOS_debug_printf( ( "prvProcessDNSCache: %s: '%s' @ %lxip\n", xLookUp ? "look-up" : "add", pcName, FreeRTOS_ntohl( *pulIP ) ) ); + } + } + +#endif /* ipconfigUSE_DNS_CACHE */ + +#endif /* ipconfigUSE_DNS != 0 */ + +/*-----------------------------------------------------------*/ + +/* Provide access to private members for testing. */ +#ifdef AMAZON_FREERTOS_ENABLE_UNIT_TESTS + #include "iot_freertos_tcp_test_access_dns_define.h" +#endif +