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Remove duplicate TCP code
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@HTRamsey
HTRamsey committed Feb 2, 2024
1 parent 826e261 commit ad8645c
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Showing 12 changed files with 283 additions and 676 deletions.
6 changes: 3 additions & 3 deletions source/FreeRTOS_Sockets.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4925,7 +4925,7 @@ void vSocketWakeUpUser( FreeRTOS_Socket_t * pxSocket )
*
* @return The socket which was found.
*/
FreeRTOS_Socket_t * pxTCPSocketLookup( uint32_t ulLocalIP,
FreeRTOS_Socket_t * pxTCPSocketLookup( IPv46_Address_t xLocalIP,
UBaseType_t uxLocalPort,
IPv46_Address_t xRemoteIP,
UBaseType_t uxRemotePort )
Expand All @@ -4938,8 +4938,8 @@ void vSocketWakeUpUser( FreeRTOS_Socket_t * pxSocket )
/* coverity[misra_c_2012_rule_11_3_violation] */
const ListItem_t * pxEnd = ( ( const ListItem_t * ) &( xBoundTCPSocketsList.xListEnd ) );

/* __XX__ TODO ulLocalIP is not used, for misra compliance*/
( void ) ulLocalIP;
/* __XX__ TODO xLocalIP is not used, for misra compliance*/
( void ) xLocalIP;

for( pxIterator = listGET_NEXT( pxEnd );
pxIterator != pxEnd;
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270 changes: 240 additions & 30 deletions source/FreeRTOS_TCP_IP.c
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Original file line number Diff line number Diff line change
Expand Up @@ -87,15 +87,6 @@
/* coverity[misra_c_2012_rule_8_9_violation] */
_static FreeRTOS_Socket_t * xSocketToListen = NULL;

#if ( ipconfigHAS_DEBUG_PRINTF != 0 )

/*
* For logging and debugging: make a string showing the TCP flags.
*/
const char * prvTCPFlagMeaning( UBaseType_t xFlags );
#endif /* ipconfigHAS_DEBUG_PRINTF != 0 */


/*-----------------------------------------------------------*/


Expand Down Expand Up @@ -646,37 +637,256 @@
* prvTCPReturnPacket() // Prepare for returning
* xNetworkInterfaceOutput() // Sends data to the NIC
*/
BaseType_t xProcessReceivedTCPPacket( NetworkBufferDescriptor_t * pxDescriptor )
BaseType_t xProcessReceivedTCPPacket( NetworkBufferDescriptor_t * pxNetworkBuffer )
{
/* Function might modify the parameter. */
const NetworkBufferDescriptor_t * pxNetworkBuffer = pxDescriptor;
BaseType_t xResult = pdPASS;
FreeRTOS_Socket_t * pxSocket;
IPv46_Address_t xLocalIP;
IPv46_Address_t xRemoteIP;
TCPHeader_t * pxTCPHeader = ( ( TCPHeader_t * ) &( pxNetworkBuffer->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER + uxIPHeaderSizePacket( pxNetworkBuffer ) ] ) );
const uint16_t ucTCPFlags = pxTCPHeader->ucTCPFlags;

configASSERT( pxNetworkBuffer != NULL );
configASSERT( pxNetworkBuffer->pucEthernetBuffer != NULL );

BaseType_t xResult;

/* 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] */
switch( ( ( const EthernetHeader_t * ) pxNetworkBuffer->pucEthernetBuffer )->usFrameType )
if( pxNetworkBuffer->xDataLength < ( ipSIZE_OF_ETH_HEADER + uxIPHeaderSizePacket( pxNetworkBuffer ) + ipSIZE_OF_TCP_HEADER ) )
{
#if ( ipconfigUSE_IPv4 != 0 )
case ipIPv4_FRAME_TYPE:
xResult = xProcessReceivedTCPPacket_IPV4( pxDescriptor );
break;
#endif /* ( ipconfigUSE_IPv4 != 0 ) */
xResult = pdFAIL;
}
else
{
/* 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] */
switch( ( ( const EthernetHeader_t * ) pxNetworkBuffer->pucEthernetBuffer )->usFrameType )
{
#if ipconfigIS_ENABLED( ipconfigUSE_IPv4 )
case ipIPv4_FRAME_TYPE:
{
const IPHeader_t * const pxIPHeader = ( ( const IPHeader_t * ) &( pxNetworkBuffer->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER ] ) );
xLocalIP.xIPAddress.ulIP_IPv4 = FreeRTOS_htonl( pxIPHeader->ulDestinationIPAddress );
xLocalIP.xIs_IPv6 = pdFALSE;
xRemoteIP.xIPAddress.ulIP_IPv4 = FreeRTOS_htonl( pxIPHeader->ulSourceIPAddress );
xRemoteIP.xIs_IPv6 = pdFALSE;
break;
}
#endif

#if ipconfigIS_ENABLED( ipconfigUSE_IPv6 )
case ipIPv6_FRAME_TYPE:
{
const IPHeader_IPv6_t * const pxIPHeader_IPv6 = ( ( const IPHeader_IPv6_t * ) &( pxNetworkBuffer->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER ] ) );
( void ) memcpy( xLocalIP.xIPAddress.xIP_IPv6.ucBytes, pxIPHeader_IPv6->xDestinationAddress.ucBytes, sizeof( IPv6_Address_t ) );
xLocalIP.xIs_IPv6 = pdTRUE;
( void ) memcpy( xRemoteIP.xIPAddress.xIP_IPv6.ucBytes, pxIPHeader_IPv6->xSourceAddress.ucBytes, sizeof( IPv6_Address_t ) );
xRemoteIP.xIs_IPv6 = pdTRUE;
break;
}
#endif

#if ( ipconfigUSE_IPv6 != 0 )
case ipIPv6_FRAME_TYPE:
xResult = xProcessReceivedTCPPacket_IPV6( pxDescriptor );
default:
/* Shouldn't reach here */
configASSERT( pdFALSE );
xResult = pdFAIL;
break;
#endif /* ( ipconfigUSE_IPv6 != 0 ) */
}
}

default:
/* Shouldn't reach here */
if( xResult != pdFAIL )
{
const uint16_t usLocalPort = FreeRTOS_htons( pxTCPHeader->usDestinationPort );
const uint16_t usRemotePort = FreeRTOS_htons( pxTCPHeader->usSourcePort );

pxSocket = ( FreeRTOS_Socket_t * ) pxTCPSocketLookup( xLocalIP, usLocalPort, xRemoteIP, usRemotePort );

if( ( pxSocket == NULL ) || ( prvTCPSocketIsActive( pxSocket->u.xTCP.eTCPState ) == pdFALSE ) )
{
/* A TCP messages is received but either there is no socket with the
* given port number or the there is a socket, but it is in one of these
* non-active states: eCLOSED, eCLOSE_WAIT, eFIN_WAIT_2, eCLOSING, or
* eTIME_WAIT. */

FreeRTOS_debug_printf( ( "TCP: No active socket on port %d (%xip:%d)\n", usLocalPort, ( unsigned ) xRemoteIP.xIPAddress.ulIP_IPv4, usRemotePort ) );

/* Send a RST to all packets that can not be handled. As a result
* the other party will get a ECONN error. There are two exceptions:
* 1) A packet that already has the RST flag set.
* 2) A packet that only has the ACK flag set.
* A packet with only the ACK flag set might be the last ACK in
* a three-way hand-shake that closes a connection. */
if( ( ( ucTCPFlags & tcpTCP_FLAG_CTRL ) != tcpTCP_FLAG_ACK ) &&
( ( ucTCPFlags & tcpTCP_FLAG_RST ) == 0U ) )
{
( void ) prvTCPSendReset( pxNetworkBuffer );
}

/* The packet can't be handled. */
xResult = pdFAIL;
break;
}
else
{
pxSocket->u.xTCP.ucRepCount = 0U;

if( pxSocket->u.xTCP.eTCPState == eTCP_LISTEN )
{
/* The matching socket is in a listening state. Test if the peer
* has set the SYN flag. */
if( ( ucTCPFlags & tcpTCP_FLAG_CTRL ) != tcpTCP_FLAG_SYN )
{
/* What happens: maybe after a reboot, a client doesn't know the
* connection had gone. Send a RST in order to get a new connect
* request. */
#if ipconfigIS_ENABLED( ipconfigHAS_DEBUG_PRINTF )
FreeRTOS_debug_printf( ( "TCP: Server can't handle flags: %s from %xip:%u to port %u\n",
prvTCPFlagMeaning( ( UBaseType_t ) ucTCPFlags ), ( unsigned ) xRemoteIP.xIPAddress.ulIP_IPv4, usRemotePort, usLocalPort ) );
#endif

if( ( ucTCPFlags & tcpTCP_FLAG_RST ) == 0U )
{
( void ) prvTCPSendReset( pxNetworkBuffer );
}

xResult = pdFAIL;
}
else
{
/* prvHandleListen() will either return a newly created socket
* (if bReuseSocket is false), otherwise it returns the current
* socket which will later get connected. */
pxSocket = prvHandleListen( pxSocket, pxNetworkBuffer );

if( pxSocket == NULL )
{
xResult = pdFAIL;
}
}
} /* if( pxSocket->u.xTCP.eTCPState == eTCP_LISTEN ). */
else
{
/* This is not a socket in listening mode. Check for the RST
* flag. */
if( ( ucTCPFlags & tcpTCP_FLAG_RST ) != 0U )
{
FreeRTOS_debug_printf( ( "TCP: RST received from %xip:%u for %u\n", ( unsigned ) xRemoteIP.xIPAddress.ulIP_IPv4, usRemotePort, usLocalPort ) );

/* Implement https://tools.ietf.org/html/rfc5961#section-3.2. */
if( pxSocket->u.xTCP.eTCPState == eCONNECT_SYN )
{
const uint32_t ulAckNumber = FreeRTOS_ntohl( pxTCPHeader->ulAckNr );
/* Per the above RFC, "In the SYN-SENT state ... the RST is
* acceptable if the ACK field acknowledges the SYN." */
if( ulAckNumber == ( pxSocket->u.xTCP.xTCPWindow.ulOurSequenceNumber + 1U ) )
{
vTCPStateChange( pxSocket, eCLOSED );
}
}
else
{
const uint32_t ulSequenceNumber = FreeRTOS_ntohl( pxTCPHeader->ulSequenceNumber );
/* Check whether the packet matches the next expected sequence number. */
if( ulSequenceNumber == pxSocket->u.xTCP.xTCPWindow.rx.ulCurrentSequenceNumber )
{
vTCPStateChange( pxSocket, eCLOSED );
}
/* Otherwise, check whether the packet is within the receive window. */
else if( ( xSequenceGreaterThan( ulSequenceNumber, pxSocket->u.xTCP.xTCPWindow.rx.ulCurrentSequenceNumber ) != pdFALSE ) &&
( xSequenceLessThan( ulSequenceNumber, pxSocket->u.xTCP.xTCPWindow.rx.ulCurrentSequenceNumber +
pxSocket->u.xTCP.xTCPWindow.xSize.ulRxWindowLength ) != pdFALSE ) )
{
/* Send a challenge ACK. */
( void ) prvTCPSendChallengeAck( pxNetworkBuffer );
}
else
{
/* Nothing. */
}
}

/* Otherwise, do nothing. In any case, the packet cannot be handled. */
xResult = pdFAIL;
}
/* Check whether there is a pure SYN amongst the TCP flags while the connection is established. */
else if( ( ( ucTCPFlags & tcpTCP_FLAG_CTRL ) == tcpTCP_FLAG_SYN ) && ( pxSocket->u.xTCP.eTCPState >= eESTABLISHED ) )
{
/* SYN flag while this socket is already connected. */
FreeRTOS_debug_printf( ( "TCP: SYN unexpected from %xip:%u\n", ( unsigned ) xRemoteIP.xIPAddress.ulIP_IPv4, usRemotePort ) );

/* The packet cannot be handled. */
xResult = pdFAIL;
}
else
{
/* Update the copy of the TCP header only (skipping eth and IP
* headers). It might be used later on, whenever data must be sent
* to the peer. */
const size_t uxOffset = ipSIZE_OF_ETH_HEADER + uxIPHeaderSizeSocket( pxSocket );
( void ) memcpy( ( void * ) ( &( pxSocket->u.xTCP.xPacket.u.ucLastPacket[ uxOffset ] ) ),
( const void * ) ( &( pxNetworkBuffer->pucEthernetBuffer[ uxOffset ] ) ),
ipSIZE_OF_TCP_HEADER );
/* Clear flags that are set by the peer, and set the ACK flag. */
pxSocket->u.xTCP.xPacket.u.ucLastPacket[ uxOffset + ipTCP_FLAGS_OFFSET ] = tcpTCP_FLAG_ACK;
}
}
}
}

if( xResult != pdFAIL )
{
/* pxSocket is not NULL when xResult != pdFAIL. */
configASSERT( pxSocket != NULL ); /* LCOV_EXCL_LINE ,this branch will not be hit*/

/* Touch the alive timers because we received a message for this
* socket. */
prvTCPTouchSocket( pxSocket );

/* Parse the TCP option(s), if present. */

/* _HT_ : if we're in the SYN phase, and peer does not send a MSS option,
* then we MUST assume an MSS size of 536 bytes for backward compatibility. */

/* When there are no TCP options, the TCP offset equals 20 bytes, which is stored as
* the number 5 (words) in the higher nibble of the TCP-offset byte. */
if( ( pxTCPHeader->ucTCPOffset & tcpTCP_OFFSET_LENGTH_BITS ) > tcpTCP_OFFSET_STANDARD_LENGTH )
{
xResult = prvCheckOptions( pxSocket, pxNetworkBuffer );
}

if( xResult != pdFAIL )
{
const uint16_t usWindow = FreeRTOS_ntohs( pxTCPHeader->usWindow );
pxSocket->u.xTCP.ulWindowSize = usWindow;
#if ipconfigIS_ENABLED( ipconfigUSE_TCP_WIN )
/* rfc1323 : The Window field in a SYN (i.e., a <SYN> or <SYN,ACK>)
* segment itself is never scaled. */
if( ( ucTCPFlags & ( uint8_t ) tcpTCP_FLAG_SYN ) == 0U )
{
pxSocket->u.xTCP.ulWindowSize =
( pxSocket->u.xTCP.ulWindowSize << pxSocket->u.xTCP.ucPeerWinScaleFactor );
}
#endif

/* In prvTCPHandleState() the incoming messages will be handled
* depending on the current state of the connection. */
if( prvTCPHandleState( pxSocket, &pxNetworkBuffer ) > 0 )
{
/* prvTCPHandleState() has sent a message, see if there are more to
* be transmitted. */
#if ipconfigIS_ENABLED( ipconfigUSE_TCP_WIN )
( void ) prvTCPSendRepeated( pxSocket, &pxNetworkBuffer );
#endif /* ipconfigUSE_TCP_WIN */
}

if( pxNetworkBuffer != NULL )
{
/* We must check if the buffer is unequal to NULL, because the
* socket might keep a reference to it in case a delayed ACK must be
* sent. */
vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );
}

/* And finally, calculate when this socket wants to be woken up. */
( void ) prvTCPNextTimeout( pxSocket );
}
}

return xResult;
Expand Down
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