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Add macro checks for DNS Cache to fix build issue #1200

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Add macro checks for DNS Cache to fix build issue #1200

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dfb94b4
Add macro checks for DNS Cache to fix build issue
kar-rahul-aws Oct 28, 2024
7021950
Fix CI check failure
kar-rahul-aws Oct 28, 2024
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1 change: 1 addition & 0 deletions .github/.cSpellWords.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -89,6 +89,7 @@ BLXNS
bmcr
BMSR
BPDG
BPIALL
brgintclr
brginten
brgintstat
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206 changes: 109 additions & 97 deletions source/FreeRTOS_DNS_Parser.c
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Expand Up @@ -56,110 +56,114 @@
*
* @return If a fully formed name was found, then return the number of bytes processed in pucByte.
*/
size_t DNS_ReadNameField( ParseSet_t * pxSet,
size_t uxDestLen )
{
size_t uxNameLen = 0U;
size_t uxIndex = 0U;
size_t uxSourceLen = pxSet->uxSourceBytesRemaining;
const uint8_t * pucByte = pxSet->pucByte;

/* 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 ( ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 ) )

if( uxSourceLen == ( size_t ) 0U )
size_t DNS_ReadNameField( ParseSet_t * pxSet,
size_t uxDestLen )
{
/* Return 0 value in case of error. */
uxIndex = 0U;
}
size_t uxNameLen = 0U;
size_t uxIndex = 0U;
size_t uxSourceLen = pxSet->uxSourceBytesRemaining;
const uint8_t * pucByte = pxSet->pucByte;

/* 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
/* 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;
}
}
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 ) )
{
/*
* uxNameLen can never be greater than uxDestLen, since there are checks
* outside this condition, so the check is removed.
*/
pxSet->pcName[ uxNameLen ] = '.';
uxNameLen++;
}

/* Process the first/next sub-string. */
uxCount = ( size_t ) pucByte[ uxIndex ];

/* uxIndex should point to the first character now, unless uxCount
* is an offset field. */
uxIndex++;

if( ( uxIndex + uxCount ) > uxSourceLen )
/* 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 = 0U;
break;
uxIndex += sizeof( uint16_t );
}

if( ( uxNameLen + uxCount ) >= uxDestLen )
else
{
uxIndex = 0U;
break;
}

while( uxCount-- != 0U )
{
/*
* uxNameLen can never be greater than uxDestLen, since there are checks
* outside this condition, so the check is removed.
*/
pxSet->pcName[ uxNameLen ] = ( char ) pucByte[ uxIndex ];
uxNameLen++;
uxIndex++;
}
}

/* Confirm that a fully formed name was found. */
if( uxIndex > 0U )
else
{
/* 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( uxIndex < uxSourceLen )
/* 'uxIndex' points to the full name. Walk over the string. */
while( ( uxIndex < uxSourceLen ) && ( pucByte[ uxIndex ] != ( uint8_t ) 0x00U ) )
{
pxSet->pcName[ uxNameLen ] = '\0';
/* If this is not the first time through the loop, then add a
* separator in the output. */
if( ( uxNameLen > 0U ) )
{
/*
* uxNameLen can never be greater than uxDestLen, since there are checks
* outside this condition, so the check is removed.
*/
pxSet->pcName[ uxNameLen ] = '.';
uxNameLen++;
}

/* Process the first/next sub-string. */
uxCount = ( size_t ) pucByte[ uxIndex ];

/* uxIndex should point to the first character now, unless uxCount
* is an offset field. */
uxIndex++;

if( ( uxIndex + uxCount ) > uxSourceLen )
{
uxIndex = 0U;
break;
}

if( ( uxNameLen + uxCount ) >= uxDestLen )
{
uxIndex = 0U;
break;
}

while( uxCount-- != 0U )
{
/*
* uxNameLen can never be greater than uxDestLen, since there are checks
* outside this condition, so the check is removed.
*/
pxSet->pcName[ uxNameLen ] = ( char ) pucByte[ uxIndex ];
uxNameLen++;
uxIndex++;
}
}
else

/* Confirm that a fully formed name was found. */
if( uxIndex > 0U )
{
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( uxIndex < uxSourceLen )
{
pxSet->pcName[ uxNameLen ] = '\0';
uxIndex++;
}
else
{
uxIndex = 0U;
}
}
}
}

return uxIndex;
}
return uxIndex;
}
#endif /* ( ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 ) ) */

/**
* @brief Simple routine that jumps over the NAME field of a resource record.
Expand Down Expand Up @@ -456,19 +460,23 @@
#if ( ipconfigUSE_IPv6 != 0 )
{
/*logging*/
FreeRTOS_printf( ( "prvParseDNS_HandleLLMNRRequest[%s]: type %04X\n", xSet.pcName, xSet.usType ) );
#if ( ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 ) )
FreeRTOS_printf( ( "prvParseDNS_HandleLLMNRRequest[%s]: type %04X\n", xSet.pcName, xSet.usType ) );
#endif /* ( ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 ) ) */

xEndPoint.usDNSType = ( uint8_t ) xSet.usType;
}
#endif /* ( ipconfigUSE_IPv6 != 0 ) */

/* If this is not a reply to our DNS request, it might be an mDNS or an LLMNR
* request. Ask the application if it uses the name. */
#if ( ipconfigIPv4_BACKWARD_COMPATIBLE == 1 )
xDNSHookReturn = xApplicationDNSQueryHook( xSet.pcName );
#else
xDNSHookReturn = xApplicationDNSQueryHook_Multi( &xEndPoint, xSet.pcName );
#endif
#if ( ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 ) )
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This change forces user to enable CACHE or CALLBACK while using MDNS/LLMNR, which I think is incorrect.

#if ( ipconfigIPv4_BACKWARD_COMPATIBLE == 1 )
xDNSHookReturn = xApplicationDNSQueryHook( xSet.pcName );
#else
xDNSHookReturn = xApplicationDNSQueryHook_Multi( &xEndPoint, xSet.pcName );
#endif /* ( ipconfigIPv4_BACKWARD_COMPATIBLE == 1 ) */
#endif /* ( ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 ) ) */

/* During the early stages of boot or after a DHCP lease expires, our end-point
* may have an IP address of 0.0.0.0. Do not respond to name queries with that address. */
Expand Down Expand Up @@ -735,10 +743,12 @@
&( pxSet->pucByte[ sizeof( DNSAnswerRecord_t ) ] ),
ipSIZE_OF_IPv6_ADDRESS );

if( ppxAddressInfo != NULL )
{
pxNewAddress = pxNew_AddrInfo( pxSet->pcName, FREERTOS_AF_INET6, xIP_Address.xIPAddress.xIP_IPv6.ucBytes );
}
#if ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 )
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@ActoryOu ActoryOu Oct 29, 2024 •
edited
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Could you add some more comments in the code to help developers understand why wrapping this is still working if pxNewAddress is NULL when CACHE/CALLBACK are disabled.

if( ppxAddressInfo != NULL )
{
pxNewAddress = pxNew_AddrInfo( pxSet->pcName, FREERTOS_AF_INET6, xIP_Address.xIPAddress.xIP_IPv6.ucBytes );
}
#endif /* ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 ) */

xIP_Address.xIs_IPv6 = pdTRUE;

Expand All @@ -763,12 +773,14 @@
pvCopyDest = &( pxSet->ulIPAddress );
( void ) memcpy( pvCopyDest, pvCopySource, pxSet->uxAddressLength );

if( ppxAddressInfo != NULL )
{
const uint8_t * ucBytes = ( uint8_t * ) &( pxSet->ulIPAddress );
#if ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 )
if( ppxAddressInfo != NULL )
{
const uint8_t * ucBytes = ( uint8_t * ) &( pxSet->ulIPAddress );

pxNewAddress = pxNew_AddrInfo( pxSet->pcName, FREERTOS_AF_INET4, ucBytes );
}
pxNewAddress = pxNew_AddrInfo( pxSet->pcName, FREERTOS_AF_INET4, ucBytes );
}
#endif /* ( ipconfigUSE_DNS_CACHE == 1 ) || ( ipconfigDNS_USE_CALLBACKS == 1 ) */

xIP_Address.xIPAddress.ulIP_IPv4 = pxSet->ulIPAddress;
xIP_Address.xIs_IPv6 = pdFALSE;
Expand Down
2 changes: 1 addition & 1 deletion test/Coverity/README.md
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Expand Up @@ -13,7 +13,7 @@ see the [MISRA.md](https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA

## Getting Started
### Prerequisites
You can run this on a platform supported by Coverity. The list and other details can be found [here](https://sig-docs.synopsys.com/polaris/topics/c_coverity-compatible-platforms.html).
You can run this on a platform supported by Coverity. The list and other details can be found [here](https://documentation.blackduck.com/bundle/coverity-docs/page/deploy-install-guide/topics/supported_platforms_for_coverity_analysis.html).
To compile and run the Coverity target successfully, you must have the following:

1. CMake version > 3.13.0 (You can check whether you have this by typing `cmake --version`)
Expand Down
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