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IPv6/Multi: do the ICMP checksum calculations in the same way as for TCP and UDP. #240

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Merged
merged 2 commits into from
May 11, 2021
Merged

IPv6/Multi: do the ICMP checksum calculations in the same way as for TCP and UDP. #240

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8400f49
Do the ICMP checksum calculations in the same way as for TCP and UDP.
May 7, 2021
39a8f2a
ICMPv6 : calculate checksum only when not done by the network interface.
May 7, 2021
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52 changes: 32 additions & 20 deletions FreeRTOS_IP.c
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Original file line number Diff line number Diff line change
Expand Up @@ -260,7 +260,8 @@ static eFrameProcessingResult_t prvProcessIPPacket( IPPacket_t * pxIPPacket,
* Turns around an incoming ping request to convert it into a ping reply.
*/
#if ( ipconfigREPLY_TO_INCOMING_PINGS == 1 )
static eFrameProcessingResult_t prvProcessICMPEchoRequest( ICMPPacket_t * const pxICMPPacket );
static eFrameProcessingResult_t prvProcessICMPEchoRequest( ICMPPacket_t * const pxICMPPacket,
NetworkBufferDescriptor_t * const pxNetworkBuffer );
#endif /* ipconfigREPLY_TO_INCOMING_PINGS */

/*
Expand Down Expand Up @@ -3038,11 +3039,11 @@ static eFrameProcessingResult_t prvProcessIPPacket( IPPacket_t * pxIPPacket,
*
* @param[in,out] pxICMPPacket: The IP packet that contains the ICMP message.
*/
static eFrameProcessingResult_t prvProcessICMPEchoRequest( ICMPPacket_t * const pxICMPPacket )
static eFrameProcessingResult_t prvProcessICMPEchoRequest( ICMPPacket_t * const pxICMPPacket,
NetworkBufferDescriptor_t * const pxNetworkBuffer )
{
ICMPHeader_t * pxICMPHeader;
IPHeader_t * pxIPHeader;
uint16_t usRequest;
uint32_t ulIPAddress;

pxICMPHeader = &( pxICMPPacket->xICMPHeader );
Expand All @@ -3060,22 +3061,32 @@ static eFrameProcessingResult_t prvProcessIPPacket( IPPacket_t * pxIPPacket,
pxIPHeader->ulDestinationIPAddress = pxIPHeader->ulSourceIPAddress;
pxIPHeader->ulSourceIPAddress = ulIPAddress;

/* Update the checksum because the ucTypeOfMessage member in the header
* has been changed to ipICMP_ECHO_REPLY. This is faster than calling
* usGenerateChecksum(). */

/* due to compiler warning "integer operation result is out of range" */
/* 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

usRequest = ( uint16_t ) ( ( uint16_t ) ipICMP_ECHO_REQUEST << 8 );
#if ( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
{
/* calculate the IP header checksum, in case the driver won't do that. */
pxIPHeader->usHeaderChecksum = 0x00U;
pxIPHeader->usHeaderChecksum = usGenerateChecksum( 0U, ( uint8_t * ) &( pxIPHeader->ucVersionHeaderLength ), ipSIZE_OF_IPv4_HEADER );
pxIPHeader->usHeaderChecksum = ~FreeRTOS_htons( pxIPHeader->usHeaderChecksum );

if( pxICMPHeader->usChecksum >= FreeRTOS_htons( 0xFFFFU - usRequest ) )
{
pxICMPHeader->usChecksum = pxICMPHeader->usChecksum + FreeRTOS_htons( usRequest + 1U );
}
else
{
pxICMPHeader->usChecksum = pxICMPHeader->usChecksum + FreeRTOS_htons( usRequest );
}
/* calculate the ICMP checksum for an outgoing packet. */
( void ) usGenerateProtocolChecksum( ( uint8_t * ) pxICMPPacket, pxNetworkBuffer->xDataLength, pdTRUE );
}
#else
{
/* Many EMAC peripherals will only calculate the ICMP checksum
* correctly if the field is nulled beforehand. */
pxICMPHeader->usChecksum = 0U;
}
#endif /* if ( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 ) */

return eReturnEthernetFrame;
}
Expand Down Expand Up @@ -3111,7 +3122,7 @@ static eFrameProcessingResult_t prvProcessIPPacket( IPPacket_t * pxIPPacket,
case ipICMP_ECHO_REQUEST:
#if ( ipconfigREPLY_TO_INCOMING_PINGS == 1 )
{
eReturn = prvProcessICMPEchoRequest( pxICMPPacket );
eReturn = prvProcessICMPEchoRequest( pxICMPPacket, pxNetworkBuffer );
}
#endif /* ( ipconfigREPLY_TO_INCOMING_PINGS == 1 ) */
break;
Expand Down Expand Up @@ -3394,7 +3405,7 @@ static BaseType_t prvChecksumProtocolChecks( size_t uxBufferLength,
#if ( ipconfigUSE_IPv6 != 0 )
else if( pxSet->ucProtocol == ( uint8_t ) ipPROTOCOL_ICMP_IPv6 )
{
prvChecksumICMPv6Checks( uxBufferLength, pxSet );
xReturn = prvChecksumICMPv6Checks( uxBufferLength, pxSet );
}
#endif /* if ( ipconfigUSE_IPv6 != 0 ) */
else
Expand Down Expand Up @@ -3469,7 +3480,8 @@ static void prvChecksumProtocolCalculate( BaseType_t xOutgoingPacket,
* 36..38 three zero's
* 39 Next Header, i.e. the protocol type. */

pulHeader[ 0 ] = FreeRTOS_htonl( pxSet->usProtocolBytes );
pulHeader[ 0 ] = ( uint32_t ) pxSet->usProtocolBytes;
pulHeader[ 0 ] = FreeRTOS_htonl( pulHeader[ 0 ] );
pulHeader[ 1 ] = ( uint32_t ) pxSet->pxIPPacket_IPv6->ucNextHeader;
pulHeader[ 1 ] = FreeRTOS_htonl( pulHeader[ 1 ] );

Expand Down
15 changes: 12 additions & 3 deletions FreeRTOS_ND.c
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Original file line number Diff line number Diff line change
Expand Up @@ -477,9 +477,18 @@
/* Important: tell NIC driver how many bytes must be sent */
pxNetworkBuffer->xDataLength = ( size_t ) ( ipSIZE_OF_ETH_HEADER + ipSIZE_OF_IPv6_HEADER + uxICMPSize );

pxICMPHeader_IPv6->usChecksum = 0;
/* calculate the UDP checksum for outgoing package */
( void ) usGenerateProtocolChecksum( pxNetworkBuffer->pucEthernetBuffer, pxNetworkBuffer->xDataLength, pdTRUE );
#if ( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 )
{
/* calculate the UDP checksum for outgoing package */
( void ) usGenerateProtocolChecksum( pxNetworkBuffer->pucEthernetBuffer, pxNetworkBuffer->xDataLength, pdTRUE );
}
#else
{
/* Many EMAC peripherals will only calculate the ICMP checksum
* correctly if the field is nulled beforehand. */
pxICMPHeader_IPv6->usChecksum = 0;
}
#endif

/* This function will fill in the Ethernet addresses and send the packet */
vReturnEthernetFrame( pxNetworkBuffer, pdFALSE );
Expand Down