mirror of
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP
synced 2025-10-20 22:10:04 +08:00
1ab6eb8885
* Update source location for coverity * Add coverage checker * Add build check with default configuration * Fix build combination and DNS error * uncrustified and fixed cmakelists * This commit updates version number in all files to Development-Branch * Update version number macros * This commit fixes a typo in version number macro * Added a 'critical section' to prevent a race condition in stream buffers * Uncrustify: triggered by comment. * Fixed unit-tests by adding mocked functions * Initial commit of file README.md * Update README.md * Fix the title of README file in coverity * Addressed issue comments * Update command * Add details about remaining exception * Move file to original location * Remove use of sudo in commands * Fix links; added coverity version note * Update README.md * Remove CMake installation instructions * Update manifest/history and copyright year * Update kernel version to 10.4.5 * Update remaining copyright year instances * Update the version number macros * Update license header titles * Remove kernel license header and add TCP header Co-authored-by: GitHub Action <action@github.com> Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
954 lines
40 KiB
C
954 lines
40 KiB
C
/*
|
|
* FreeRTOS+TCP <DEVELOPMENT BRANCH>
|
|
* Copyright (C) 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
|
|
*
|
|
* SPDX-License-Identifier: MIT
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
/**
|
|
* @file FreeRTOS_DNS_Parser.c
|
|
* @brief Implements the DNS message parser
|
|
*/
|
|
|
|
/* FreeRTOS includes. */
|
|
#include "FreeRTOS.h"
|
|
/* FreeRTOS+TCP includes. */
|
|
#include "FreeRTOS_IP.h"
|
|
#include "FreeRTOS_IP_Private.h"
|
|
|
|
#include "FreeRTOS_DNS_Globals.h"
|
|
#include "FreeRTOS_DNS_Parser.h"
|
|
#include "FreeRTOS_DNS_Cache.h"
|
|
#include "FreeRTOS_DNS_Callback.h"
|
|
|
|
#include "NetworkBufferManagement.h"
|
|
|
|
#include <string.h>
|
|
|
|
#if ( ipconfigUSE_DNS != 0 )
|
|
|
|
/** @brief The list of all callback structures. */
|
|
|
|
/**
|
|
* @brief Read the Name field out of a DNS response packet.
|
|
*
|
|
* @param[in] pucByte: Pointer to the DNS response.
|
|
* @param[in] uxRemainingBytes: Length of the DNS response.
|
|
* @param[out] pcName: The pointer in which the name in the DNS response will be returned.
|
|
* @param[in] uxDestLen: Size of the pcName array.
|
|
*
|
|
* @return If a fully formed name was found, then return the number of bytes processed in pucByte.
|
|
*/
|
|
size_t DNS_ReadNameField( const uint8_t * pucByte,
|
|
size_t uxRemainingBytes,
|
|
char * pcName,
|
|
size_t uxDestLen )
|
|
{
|
|
size_t uxNameLen = 0U;
|
|
size_t uxIndex = 0U;
|
|
size_t uxSourceLen = uxRemainingBytes;
|
|
|
|
/* uxCount gets the values from pucByte and counts down to 0.
|
|
* No need to have a different type than that of pucByte */
|
|
size_t uxCount;
|
|
|
|
if( uxSourceLen == ( size_t ) 0U )
|
|
{
|
|
/* Return 0 value in case of error. */
|
|
uxIndex = 0U;
|
|
}
|
|
|
|
/* Determine if the name is the fully coded name, or an offset to the name
|
|
* elsewhere in the message. */
|
|
else if( ( pucByte[ uxIndex ] & dnsNAME_IS_OFFSET ) == dnsNAME_IS_OFFSET )
|
|
{
|
|
/* Jump over the two byte offset. */
|
|
if( uxSourceLen > sizeof( uint16_t ) )
|
|
{
|
|
uxIndex += sizeof( uint16_t );
|
|
}
|
|
else
|
|
{
|
|
uxIndex = 0U;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* 'uxIndex' points to the full name. Walk over the string. */
|
|
while( ( uxIndex < uxSourceLen ) && ( pucByte[ uxIndex ] != ( uint8_t ) 0x00U ) )
|
|
{
|
|
/* If this is not the first time through the loop, then add a
|
|
* separator in the output. */
|
|
if( ( uxNameLen > 0U ) )
|
|
{
|
|
if( uxNameLen >= uxDestLen )
|
|
{
|
|
uxIndex = 0U;
|
|
/* coverity[break_stmt] : Break statement terminating the loop */
|
|
break;
|
|
}
|
|
|
|
pcName[ uxNameLen ] = '.';
|
|
uxNameLen++;
|
|
}
|
|
|
|
/* Process the first/next sub-string. */
|
|
uxCount = ( size_t ) pucByte[ uxIndex ];
|
|
uxIndex++;
|
|
|
|
if( ( uxIndex + uxCount ) > uxSourceLen )
|
|
{
|
|
uxIndex = 0U;
|
|
break;
|
|
}
|
|
|
|
while( uxCount-- != 0U )
|
|
{
|
|
if( uxNameLen >= uxDestLen )
|
|
{
|
|
uxIndex = 0U;
|
|
break;
|
|
|
|
/* break out of inner loop here
|
|
* break out of outer loop at the test uxNameLen >= uxDestLen. */
|
|
}
|
|
|
|
pcName[ uxNameLen ] = ( char ) pucByte[ uxIndex ];
|
|
uxNameLen++;
|
|
uxIndex++;
|
|
}
|
|
}
|
|
|
|
/* Confirm that a fully formed name was found. */
|
|
if( uxIndex > 0U )
|
|
{
|
|
/* Here, there is no need to check for pucByte[ uxindex ] == 0 because:
|
|
* When we break out of the above while loop, uxIndex is made 0 thereby
|
|
* failing above check. Whenever we exit the loop otherwise, either
|
|
* pucByte[ uxIndex ] == 0 (which makes the check here unnecessary) or
|
|
* uxIndex >= uxSourceLen (which makes sure that we do not go in the 'if'
|
|
* case).
|
|
*/
|
|
if( ( uxNameLen < uxDestLen ) && ( uxIndex < uxSourceLen ) )
|
|
{
|
|
pcName[ uxNameLen ] = '\0';
|
|
uxIndex++;
|
|
}
|
|
else
|
|
{
|
|
uxIndex = 0U;
|
|
}
|
|
}
|
|
}
|
|
|
|
return uxIndex;
|
|
}
|
|
|
|
/**
|
|
* @brief Simple routine that jumps over the NAME field of a resource record.
|
|
*
|
|
* @param[in] pucByte: The pointer to the resource record.
|
|
* @param[in] uxLength: Length of the resource record.
|
|
*
|
|
* @return It returns the number of bytes read, or zero when an error has occurred.
|
|
*/
|
|
size_t DNS_SkipNameField( const uint8_t * pucByte,
|
|
size_t uxLength )
|
|
{
|
|
size_t uxChunkLength;
|
|
size_t uxSourceLenCpy = uxLength;
|
|
size_t uxIndex = 0U;
|
|
|
|
if( uxSourceLenCpy == 0U )
|
|
{
|
|
uxIndex = 0U;
|
|
}
|
|
|
|
/* Determine if the name is the fully coded name, or an offset to the name
|
|
* elsewhere in the message. */
|
|
else if( ( pucByte[ uxIndex ] & dnsNAME_IS_OFFSET ) == dnsNAME_IS_OFFSET )
|
|
{
|
|
/* Jump over the two byte offset. */
|
|
if( uxSourceLenCpy > sizeof( uint16_t ) )
|
|
{
|
|
uxIndex += sizeof( uint16_t );
|
|
}
|
|
else
|
|
{
|
|
uxIndex = 0U;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* pucByte points to the full name. Walk over the string. */
|
|
while( ( pucByte[ uxIndex ] != 0U ) && ( uxSourceLenCpy > 1U ) )
|
|
{
|
|
/* Conversion to size_t causes addition to be done
|
|
* in size_t */
|
|
uxChunkLength = ( ( size_t ) pucByte[ uxIndex ] ) + 1U;
|
|
|
|
if( uxSourceLenCpy > uxChunkLength )
|
|
{
|
|
uxSourceLenCpy -= uxChunkLength;
|
|
uxIndex += uxChunkLength;
|
|
}
|
|
else
|
|
{
|
|
uxIndex = 0U;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Confirm that a fully formed name was found. */
|
|
if( uxIndex > 0U )
|
|
{
|
|
if( pucByte[ uxIndex ] == 0U )
|
|
{
|
|
uxIndex++;
|
|
}
|
|
else
|
|
{
|
|
uxIndex = 0U;
|
|
}
|
|
}
|
|
}
|
|
|
|
return uxIndex;
|
|
}
|
|
|
|
/**
|
|
* @brief Process a response packet from a DNS server, or an LLMNR reply.
|
|
*
|
|
* @param[in] pucUDPPayloadBuffer: The DNS response received as a UDP
|
|
* payload.
|
|
* @param[in] uxBufferLength: Length of the UDP payload buffer.
|
|
* @param[in] xExpected: indicates whether the identifier in the reply
|
|
* was expected, and thus if the DNS cache may be
|
|
* updated with the reply.
|
|
*
|
|
* @return The IP address in the DNS response if present and if xExpected is set to pdTRUE.
|
|
* An error code (dnsPARSE_ERROR) if there was an error in the DNS response.
|
|
* 0 if xExpected set to pdFALSE.
|
|
*/
|
|
uint32_t DNS_ParseDNSReply( uint8_t * pucUDPPayloadBuffer,
|
|
size_t uxBufferLength,
|
|
BaseType_t xExpected )
|
|
{
|
|
DNSMessage_t * pxDNSMessageHeader;
|
|
uint32_t ulIPAddress = 0U;
|
|
|
|
#if ( ipconfigUSE_LLMNR == 1 )
|
|
char * pcRequestedName = NULL;
|
|
#endif
|
|
uint8_t * pucByte;
|
|
size_t uxSourceBytesRemaining;
|
|
uint16_t x;
|
|
uint16_t usQuestions;
|
|
BaseType_t xReturn = pdTRUE;
|
|
|
|
#if ( ipconfigUSE_LLMNR == 1 )
|
|
uint16_t usType = 0U;
|
|
uint16_t usClass = 0U;
|
|
#endif
|
|
#if ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 )
|
|
BaseType_t xDoStore = xExpected;
|
|
char pcName[ ipconfigDNS_CACHE_NAME_LENGTH ] = "";
|
|
#endif
|
|
|
|
/* Ensure that the buffer is of at least minimal DNS message length. */
|
|
if( uxBufferLength < sizeof( DNSMessage_t ) )
|
|
{
|
|
xReturn = pdFALSE;
|
|
}
|
|
else
|
|
{
|
|
uxSourceBytesRemaining = uxBufferLength;
|
|
|
|
/* Parse the DNS message header. Map the byte stream onto a structure
|
|
* for easier access. */
|
|
|
|
/* MISRA Ref 11.3.1 [Misaligned access] */
|
|
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
|
|
/* coverity[misra_c_2012_rule_11_3_violation] */
|
|
pxDNSMessageHeader = ( ( DNSMessage_t * )
|
|
pucUDPPayloadBuffer );
|
|
|
|
/* Introduce a do {} while (0) to allow the use of breaks. */
|
|
do
|
|
{
|
|
size_t uxBytesRead = 0U;
|
|
size_t uxResult;
|
|
|
|
/* 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 = 0U; x < usQuestions; x++ )
|
|
{
|
|
#if ( ipconfigUSE_LLMNR == 1 )
|
|
{
|
|
if( x == 0U )
|
|
{
|
|
pcRequestedName = ( char * ) pucByte;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 )
|
|
if( x == 0U )
|
|
{
|
|
uxResult = DNS_ReadNameField( pucByte,
|
|
uxSourceBytesRemaining,
|
|
pcName,
|
|
sizeof( pcName ) );
|
|
}
|
|
else
|
|
#endif /* ipconfigUSE_DNS_CACHE || ipconfigDNS_USE_CALLBACKS */
|
|
{
|
|
/* Skip the variable length pcName field. */
|
|
uxResult = DNS_SkipNameField( pucByte,
|
|
uxSourceBytesRemaining );
|
|
}
|
|
|
|
/* Check for a malformed response. */
|
|
if( uxResult == 0U )
|
|
{
|
|
xReturn = pdFALSE;
|
|
break;
|
|
}
|
|
|
|
uxBytesRead += uxResult;
|
|
pucByte = &( pucByte[ uxResult ] );
|
|
uxSourceBytesRemaining -= uxResult;
|
|
|
|
/* 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 = &( pucByte[ sizeof( uint32_t ) ] );
|
|
uxSourceBytesRemaining -= sizeof( uint32_t );
|
|
}
|
|
else
|
|
{
|
|
xReturn = pdFALSE;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if( xReturn == pdFALSE )
|
|
{
|
|
/* No need to proceed. Break out of the do-while loop. */
|
|
break;
|
|
}
|
|
|
|
/* Search through the answer records. */
|
|
pxDNSMessageHeader->usAnswers =
|
|
FreeRTOS_ntohs( pxDNSMessageHeader->usAnswers );
|
|
|
|
if( ( pxDNSMessageHeader->usFlags & dnsRX_FLAGS_MASK )
|
|
== dnsEXPECTED_RX_FLAGS )
|
|
{
|
|
ulIPAddress = parseDNSAnswer( pxDNSMessageHeader,
|
|
pucByte,
|
|
uxSourceBytesRemaining,
|
|
&uxBytesRead
|
|
#if ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 )
|
|
,
|
|
pcName,
|
|
xDoStore
|
|
#endif
|
|
);
|
|
}
|
|
|
|
#if ( ipconfigUSE_LLMNR == 1 )
|
|
|
|
/* No need to check that pcRequestedName != NULL since sQuestions != 0, then
|
|
* pcRequestedName is assigned with this statement
|
|
* "pcRequestedName = ( char * ) pucByte;" */
|
|
else if( ( usQuestions != ( uint16_t ) 0U ) &&
|
|
( 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 ] ) ) != pdFALSE )
|
|
{
|
|
int16_t usLength;
|
|
NetworkBufferDescriptor_t * pxNewBuffer = NULL;
|
|
NetworkBufferDescriptor_t * pxNetworkBuffer =
|
|
pxUDPPayloadBuffer_to_NetworkBuffer( pucUDPPayloadBuffer );
|
|
LLMNRAnswer_t * pxAnswer;
|
|
uint8_t * pucNewBuffer = NULL;
|
|
|
|
if( pxNetworkBuffer != NULL )
|
|
{
|
|
if( xBufferAllocFixedSize == pdFALSE )
|
|
{
|
|
size_t uxDataLength = uxBufferLength +
|
|
sizeof( UDPHeader_t ) +
|
|
sizeof( EthernetHeader_t ) +
|
|
sizeof( IPHeader_t );
|
|
|
|
/* Set the size of the outgoing packet. */
|
|
pxNetworkBuffer->xDataLength = uxDataLength;
|
|
pxNewBuffer = pxDuplicateNetworkBufferWithDescriptor( pxNetworkBuffer,
|
|
uxDataLength +
|
|
sizeof( LLMNRAnswer_t ) );
|
|
|
|
if( pxNewBuffer != NULL )
|
|
{
|
|
BaseType_t xOffset1, xOffset2;
|
|
|
|
xOffset1 = ( BaseType_t ) ( pucByte - pucUDPPayloadBuffer );
|
|
xOffset2 = ( BaseType_t ) ( ( ( uint8_t * ) pcRequestedName ) - pucUDPPayloadBuffer );
|
|
|
|
pxNetworkBuffer = pxNewBuffer;
|
|
pucNewBuffer = &( pxNetworkBuffer->pucEthernetBuffer[ ipUDP_PAYLOAD_OFFSET_IPv4 ] );
|
|
|
|
pucByte = &( pucNewBuffer[ xOffset1 ] );
|
|
pcRequestedName = ( char * ) &( pucNewBuffer[ xOffset2 ] );
|
|
pxDNSMessageHeader = ( ( DNSMessage_t * ) pucNewBuffer );
|
|
}
|
|
else
|
|
{
|
|
/* Just to indicate that the message may not be answered. */
|
|
pxNetworkBuffer = NULL;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
pucNewBuffer = &( pxNetworkBuffer->pucEthernetBuffer[ ipUDP_PAYLOAD_OFFSET_IPv4 ] );
|
|
}
|
|
}
|
|
|
|
if( ( pxNetworkBuffer != NULL ) )
|
|
{
|
|
pxAnswer = ( ( LLMNRAnswer_t * ) pucByte );
|
|
/* We leave 'usIdentifier' and 'usQuestions' untouched */
|
|
#ifndef _lint
|
|
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 */
|
|
#endif /* lint */
|
|
|
|
pxAnswer->ucNameCode = dnsNAME_IS_OFFSET;
|
|
pxAnswer->ucNameOffset = ( uint8_t ) ( pcRequestedName - ( char * ) pucNewBuffer );
|
|
|
|
#ifndef _lint
|
|
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 ) );
|
|
#endif /* lint */
|
|
usLength = ( int16_t ) ( sizeof( *pxAnswer ) + ( size_t ) ( pucByte - pucNewBuffer ) );
|
|
|
|
prepareReplyDNSMessage( pxNetworkBuffer, usLength );
|
|
/* This function will fill in the eth addresses and send the packet */
|
|
vReturnEthernetFrame( pxNetworkBuffer, pdFALSE );
|
|
|
|
if( pxNewBuffer != NULL )
|
|
{
|
|
vReleaseNetworkBufferAndDescriptor( pxNewBuffer );
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Not an expected reply. */
|
|
}
|
|
#endif /* ipconfigUSE_LLMNR == 1 */
|
|
( void ) uxBytesRead;
|
|
} while( ipFALSE_BOOL );
|
|
}
|
|
|
|
if( xReturn == pdFALSE )
|
|
{
|
|
/* There was an error while parsing the DNS response. Return error code. */
|
|
ulIPAddress = ( uint32_t ) dnsPARSE_ERROR;
|
|
}
|
|
else if( xExpected == pdFALSE )
|
|
{
|
|
/* Do not return a valid IP-address in case the reply was not expected. */
|
|
ulIPAddress = 0U;
|
|
}
|
|
else
|
|
{
|
|
/* The IP-address found will be returned. */
|
|
}
|
|
|
|
#if ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 )
|
|
( void ) xDoStore;
|
|
#endif
|
|
|
|
return ulIPAddress;
|
|
}
|
|
|
|
/**
|
|
* @brief perform a dns lookup in the local cache
|
|
* @param[in] pxDNSMessageHeader DNS header
|
|
* @param pucByte buffer
|
|
* @param uxSourceBytesRemaining remaining bytes in pucByte
|
|
* @param[out] uxBytesRead total bytes consumed by the function
|
|
* @param pcName update the cache and /or send to callback
|
|
* @param xDoStore whether to update the cache
|
|
* @return ip address extracted from the frame or zero if not found
|
|
*/
|
|
uint32_t parseDNSAnswer( const DNSMessage_t * pxDNSMessageHeader,
|
|
uint8_t * pucByte,
|
|
size_t uxSourceBytesRemaining,
|
|
size_t * uxBytesRead
|
|
#if ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 )
|
|
,
|
|
const char * pcName,
|
|
BaseType_t xDoStore
|
|
#endif
|
|
)
|
|
{
|
|
uint16_t x;
|
|
size_t uxResult;
|
|
const uint16_t usCount = ( uint16_t ) ipconfigDNS_CACHE_ADDRESSES_PER_ENTRY;
|
|
uint16_t usNumARecordsStored = 0;
|
|
BaseType_t xReturn = pdTRUE;
|
|
uint16_t usType = 0U;
|
|
const DNSAnswerRecord_t * pxDNSAnswerRecord;
|
|
const void * pvCopySource;
|
|
void * pvCopyDest;
|
|
const size_t uxAddressLength = ipSIZE_OF_IPv4_ADDRESS;
|
|
uint32_t ulIPAddress = 0U;
|
|
uint32_t ulReturnIPAddress = 0U;
|
|
uint16_t usDataLength;
|
|
uint8_t * pucBuffer = pucByte;
|
|
size_t uxRxSourceByteRemaining = uxSourceBytesRemaining;
|
|
|
|
for( x = 0U; x < pxDNSMessageHeader->usAnswers; x++ )
|
|
{
|
|
BaseType_t xDoAccept;
|
|
|
|
if( usNumARecordsStored >= usCount )
|
|
{
|
|
/* Only count ipconfigDNS_CACHE_ADDRESSES_PER_ENTRY number of records. */
|
|
break;
|
|
}
|
|
|
|
uxResult = DNS_SkipNameField( pucBuffer,
|
|
uxRxSourceByteRemaining );
|
|
|
|
/* Check for a malformed response. */
|
|
if( uxResult == 0U )
|
|
{
|
|
xReturn = pdFALSE;
|
|
break;
|
|
}
|
|
|
|
*uxBytesRead += uxResult;
|
|
pucBuffer = &( pucBuffer[ uxResult ] );
|
|
uxRxSourceByteRemaining -= uxResult;
|
|
|
|
/* Is there enough data for an IPv4 A record answer and, if so,
|
|
* is this an A record? */
|
|
if( uxRxSourceByteRemaining < sizeof( uint16_t ) )
|
|
{
|
|
xReturn = pdFALSE;
|
|
break;
|
|
}
|
|
|
|
usType = usChar2u16( pucBuffer );
|
|
|
|
if( usType == ( uint16_t ) dnsTYPE_A_HOST )
|
|
{
|
|
if( uxRxSourceByteRemaining >= ( sizeof( DNSAnswerRecord_t ) + uxAddressLength ) )
|
|
{
|
|
xDoAccept = pdTRUE;
|
|
}
|
|
else
|
|
{
|
|
xDoAccept = pdFALSE;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Unknown host type. */
|
|
xDoAccept = pdFALSE;
|
|
}
|
|
|
|
if( xDoAccept != pdFALSE )
|
|
{
|
|
/* This is the required record type and is of sufficient size. */
|
|
|
|
/* Mapping pucBuffer to a DNSAnswerRecord allows easy access of the
|
|
* fields of the structure. */
|
|
|
|
/* MISRA Ref 11.3.1 [Misaligned access] */
|
|
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
|
|
/* coverity[misra_c_2012_rule_11_3_violation] */
|
|
pxDNSAnswerRecord = ( ( DNSAnswerRecord_t * ) pucBuffer );
|
|
|
|
/* Sanity check the data length of an IPv4 answer. */
|
|
if( FreeRTOS_ntohs( pxDNSAnswerRecord->usDataLength ) ==
|
|
( uint16_t ) uxAddressLength )
|
|
{
|
|
/* Copy the IP address out of the record. Using different pointers
|
|
* to copy only the portion we want is intentional here. */
|
|
|
|
/*
|
|
* Use helper variables for memcpy() to remain
|
|
* compliant with MISRA Rule 21.15. These should be
|
|
* optimized away.
|
|
*/
|
|
pvCopySource = &pucBuffer[ sizeof( DNSAnswerRecord_t ) ];
|
|
pvCopyDest = &ulIPAddress;
|
|
( void ) memcpy( pvCopyDest, pvCopySource, uxAddressLength );
|
|
|
|
#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 )
|
|
{
|
|
char cBuffer[ 16 ];
|
|
|
|
/* The reply will only be stored in the DNS cache when the
|
|
* request was issued by this device. */
|
|
if( xDoStore != pdFALSE )
|
|
{
|
|
( void ) FreeRTOS_dns_update(
|
|
pcName,
|
|
&ulIPAddress,
|
|
pxDNSAnswerRecord->ulTTL );
|
|
usNumARecordsStored++; /* Track # of A records stored */
|
|
}
|
|
|
|
( void ) FreeRTOS_inet_ntop( FREERTOS_AF_INET,
|
|
( const void * ) &( ulIPAddress ),
|
|
cBuffer,
|
|
( socklen_t ) sizeof( cBuffer ) );
|
|
/* Show what has happened. */
|
|
FreeRTOS_printf( ( "DNS[0x%04lX]: The answer to '%s' (%s) will%s be stored\n",
|
|
( UBaseType_t ) pxDNSMessageHeader->usIdentifier,
|
|
pcName,
|
|
cBuffer,
|
|
( xDoStore != 0 ) ? "" : " NOT" ) );
|
|
}
|
|
#endif /* ipconfigUSE_DNS_CACHE */
|
|
|
|
if( ( ulReturnIPAddress == 0U ) && ( ulIPAddress != 0U ) )
|
|
{
|
|
/* Remember the first IP-address that is found. */
|
|
ulReturnIPAddress = ulIPAddress;
|
|
}
|
|
}
|
|
|
|
pucBuffer = &( pucBuffer[ sizeof( DNSAnswerRecord_t ) + uxAddressLength ] );
|
|
uxRxSourceByteRemaining -= ( sizeof( DNSAnswerRecord_t ) + uxAddressLength );
|
|
}
|
|
else if( uxRxSourceByteRemaining >= sizeof( DNSAnswerRecord_t ) )
|
|
{
|
|
/* It's not an A record, so skip it. Get the header location
|
|
* and then jump over the header. */
|
|
/* Cast the response to DNSAnswerRecord for easy access to fields of the DNS response. */
|
|
|
|
/* MISRA Ref 11.3.1 [Misaligned access] */
|
|
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
|
|
/* coverity[misra_c_2012_rule_11_3_violation] */
|
|
pxDNSAnswerRecord = ( ( DNSAnswerRecord_t * ) pucBuffer );
|
|
|
|
pucBuffer = &( pucBuffer[ sizeof( DNSAnswerRecord_t ) ] );
|
|
uxRxSourceByteRemaining -= sizeof( DNSAnswerRecord_t );
|
|
|
|
/* Determine the length of the answer data from the header. */
|
|
usDataLength = FreeRTOS_ntohs( pxDNSAnswerRecord->usDataLength );
|
|
|
|
/* Jump over the answer. */
|
|
if( uxRxSourceByteRemaining >= usDataLength )
|
|
{
|
|
pucBuffer = &( pucBuffer[ usDataLength ] );
|
|
uxRxSourceByteRemaining -= usDataLength;
|
|
}
|
|
else
|
|
{
|
|
/* Malformed response. */
|
|
xReturn = pdFALSE;
|
|
break;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Do nothing */
|
|
}
|
|
}
|
|
|
|
return ( xReturn != 0 ) ? ulReturnIPAddress : 0U;
|
|
}
|
|
|
|
#if ( ( ipconfigUSE_NBNS == 1 ) || ( ipconfigUSE_LLMNR == 1 ) )
|
|
|
|
/**
|
|
* @brief Send a DNS message to be used in NBNS or LLMNR
|
|
*
|
|
* @param[in] pxNetworkBuffer: The network buffer descriptor with the DNS message.
|
|
* @param[in] lNetLength: The length of the DNS message.
|
|
*/
|
|
void prepareReplyDNSMessage( NetworkBufferDescriptor_t * pxNetworkBuffer,
|
|
BaseType_t lNetLength )
|
|
{
|
|
UDPPacket_t * pxUDPPacket;
|
|
IPHeader_t * pxIPHeader;
|
|
UDPHeader_t * pxUDPHeader;
|
|
size_t uxDataLength;
|
|
|
|
pxUDPPacket = ( ( UDPPacket_t * )
|
|
pxNetworkBuffer->pucEthernetBuffer );
|
|
pxIPHeader = &pxUDPPacket->xIPHeader;
|
|
pxUDPHeader = &pxUDPPacket->xUDPHeader;
|
|
/* HT: started using defines like 'ipSIZE_OF_xxx' */
|
|
pxIPHeader->usLength = FreeRTOS_htons( ( uint16_t ) 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 );
|
|
|
|
/* The stack doesn't support fragments, so the fragment offset field must always be zero.
|
|
* The header was never memset to zero, so set both the fragment offset and fragmentation flags in one go.
|
|
*/
|
|
#if ( ipconfigFORCE_IP_DONT_FRAGMENT != 0 )
|
|
pxIPHeader->usFragmentOffset = ipFRAGMENT_FLAGS_DONT_FRAGMENT;
|
|
#else
|
|
pxIPHeader->usFragmentOffset = 0U;
|
|
#endif
|
|
usPacketIdentifier++;
|
|
pxUDPHeader->usLength = FreeRTOS_htons( ( uint32_t ) lNetLength +
|
|
ipSIZE_OF_UDP_HEADER );
|
|
vFlip_16( pxUDPHeader->usSourcePort, pxUDPHeader->usDestinationPort );
|
|
|
|
/* Important: tell NIC driver how many bytes must be sent */
|
|
uxDataLength = ( ( 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 = 0U;
|
|
pxIPHeader->usHeaderChecksum = usGenerateChecksum( 0U, ( uint8_t * ) &( pxIPHeader->ucVersionHeaderLength ), ipSIZE_OF_IPv4_HEADER );
|
|
pxIPHeader->usHeaderChecksum = ~FreeRTOS_htons( pxIPHeader->usHeaderChecksum );
|
|
|
|
/* calculate the UDP checksum for outgoing package */
|
|
( void ) usGenerateProtocolChecksum( ( uint8_t * ) pxUDPPacket, uxDataLength, pdTRUE );
|
|
}
|
|
#endif
|
|
|
|
/* Important: tell NIC driver how many bytes must be sent */
|
|
pxNetworkBuffer->xDataLength = uxDataLength;
|
|
}
|
|
|
|
#endif /* ipconfigUSE_NBNS == 1 || ipconfigUSE_LLMNR == 1 */
|
|
|
|
#if ( ipconfigUSE_NBNS == 1 )
|
|
|
|
/**
|
|
* @brief Respond to an NBNS query or an NBNS reply.
|
|
*
|
|
* @param[in] pucPayload: the UDP payload of the NBNS message.
|
|
* @param[in] uxBufferLength: Length of the Buffer.
|
|
* @param[in] ulIPAddress: IP address of the sender.
|
|
*/
|
|
void DNS_TreatNBNS( uint8_t * pucPayload,
|
|
size_t uxBufferLength,
|
|
uint32_t ulIPAddress )
|
|
{
|
|
uint16_t usFlags;
|
|
uint16_t usType;
|
|
uint16_t usClass;
|
|
uint8_t * pucSource;
|
|
uint8_t * pucTarget;
|
|
uint8_t ucByte;
|
|
uint8_t ucNBNSName[ 17 ];
|
|
uint8_t * pucUDPPayloadBuffer = pucPayload;
|
|
NetworkBufferDescriptor_t * pxNetworkBuffer;
|
|
|
|
/* 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 ) - 2U ] );
|
|
pucTarget[ 1 ] = ( uint8_t ) 0U;
|
|
|
|
/* Start with decoding the last 2 bytes. */
|
|
pucSource = &( pucUDPPayloadBuffer[ ( dnsNBNS_ENCODED_NAME_LENGTH - 2 ) +
|
|
offsetof( NBNSRequest_t, ucName ) ] );
|
|
|
|
for( ; ; )
|
|
{
|
|
const uint8_t ucCharA = ( uint8_t ) 0x41U;
|
|
|
|
ucByte = ( ( uint8_t ) ( ( pucSource[ 0 ] - ucCharA ) << 4 ) ) |
|
|
( pucSource[ 1 ] - ucCharA );
|
|
|
|
/* Make sure there are no trailing spaces in the name. */
|
|
if( ( ucByte == ( uint8_t ) ' ' ) && ( pucTarget[ 1 ] == 0U ) )
|
|
{
|
|
ucByte = 0U;
|
|
}
|
|
|
|
*pucTarget = ucByte;
|
|
|
|
if( pucTarget == ucNBNSName )
|
|
{
|
|
break;
|
|
}
|
|
|
|
pucTarget -= 1;
|
|
pucSource -= 2;
|
|
}
|
|
|
|
#if ( ipconfigUSE_DNS_CACHE == 1 )
|
|
{
|
|
if( ( usFlags & dnsNBNS_FLAGS_RESPONSE ) != 0U )
|
|
{
|
|
/* If this is a response from another device,
|
|
* add the name to the DNS cache */
|
|
( void ) FreeRTOS_dns_update( ( char * ) ucNBNSName, &( ulIPAddress ), 0 );
|
|
}
|
|
}
|
|
#else
|
|
{
|
|
/* Avoid compiler warnings. */
|
|
( void ) ulIPAddress;
|
|
}
|
|
#endif /* ipconfigUSE_DNS_CACHE */
|
|
|
|
if( ( ( usFlags & dnsNBNS_FLAGS_RESPONSE ) == 0U ) &&
|
|
( usType == dnsNBNS_TYPE_NET_BIOS ) &&
|
|
( xApplicationDNSQueryHook( ( const char * ) ucNBNSName ) != pdFALSE ) )
|
|
{
|
|
uint16_t usLength;
|
|
DNSMessage_t * pxMessage;
|
|
NBNSAnswer_t * pxAnswer;
|
|
NetworkBufferDescriptor_t * pxNewBuffer = NULL;
|
|
|
|
/* Someone is looking for a device with ucNBNSName,
|
|
* prepare a positive reply. */
|
|
pxNetworkBuffer = pxUDPPayloadBuffer_to_NetworkBuffer( pucUDPPayloadBuffer );
|
|
|
|
if( ( xBufferAllocFixedSize == pdFALSE ) &&
|
|
( pxNetworkBuffer != NULL ) )
|
|
{
|
|
/* 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() */
|
|
#ifndef _lint
|
|
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 );
|
|
#else
|
|
( void ) pxMessage;
|
|
#endif
|
|
|
|
pxAnswer = ( ( NBNSAnswer_t * ) &( pucUDPPayloadBuffer[ offsetof( NBNSRequest_t, usType ) ] ) );
|
|
|
|
#ifndef _lint
|
|
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 ) );
|
|
#else
|
|
( void ) pxAnswer;
|
|
#endif
|
|
|
|
usLength = ( uint16_t ) ( sizeof( NBNSAnswer_t ) + ( size_t ) offsetof( NBNSRequest_t, usType ) );
|
|
|
|
prepareReplyDNSMessage( pxNetworkBuffer, ( BaseType_t ) usLength );
|
|
/* This function will fill in the eth addresses and send the packet */
|
|
vReturnEthernetFrame( pxNetworkBuffer, pdFALSE );
|
|
|
|
if( pxNewBuffer != NULL )
|
|
{
|
|
vReleaseNetworkBufferAndDescriptor( pxNewBuffer );
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#endif /* ipconfigUSE_NBNS */
|
|
#endif /* ipconfigUSE_DNS != 0 */
|