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FreeRTOS-Plus-TCP/source/FreeRTOS_TCP_IP.c
Tony Josi 0c232efb4a Fix MISRA violations (#1159)
2024-06-18 12:24:23 +05:30

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/*
* 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_TCP_IP.c
* @brief Module which handles the TCP connections for FreeRTOS+TCP.
* It depends on FreeRTOS_TCP_WIN.c, which handles the TCP windowing
* schemes.
*
* Endianness: in this module all ports and IP addresses are stored in
* host byte-order, except fields in the IP-packets
*/
/* Standard includes. */
#include <stdint.h>
#include <stdio.h>
/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "semphr.h"
/* FreeRTOS+TCP includes. */
#include "FreeRTOS_IP.h"
#include "FreeRTOS_Sockets.h"
#include "FreeRTOS_IP_Private.h"
#include "FreeRTOS_IP_Utils.h"
#include "FreeRTOS_UDP_IP.h"
#include "FreeRTOS_DHCP.h"
#include "NetworkInterface.h"
#include "NetworkBufferManagement.h"
#include "FreeRTOS_ARP.h"
#include "FreeRTOS_TCP_Reception.h"
#include "FreeRTOS_TCP_Transmission.h"
#include "FreeRTOS_TCP_State_Handling.h"
#include "FreeRTOS_TCP_Utils.h"
/* Just make sure the contents doesn't get compiled if TCP is not enabled. */
#if ipconfigUSE_TCP == 1
/** @brief When closing a socket an event is posted to the Network Event Queue.
* If the queue is full, then the event is not posted and the socket
* can be orphaned. To prevent this, the below variable is used to keep
* track of any socket which needs to be closed. This variable can be
* accessed by the IP task only. Thus, preventing any race condition.
*/
/* MISRA Ref 8.9.1 [File scoped variables] */
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-89 */
/* coverity[misra_c_2012_rule_8_9_violation] */
static FreeRTOS_Socket_t * xSocketToClose = NULL;
/** @brief When a connection is coming in on a reusable socket, and the
* SYN phase times out, the socket must be put back into eTCP_LISTEN
* mode, so it can accept a new connection again.
* This variable can be accessed by the IP task only. Thus, preventing any
* race condition.
*/
/* MISRA Ref 8.9.1 [File scoped variables] */
/* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-89 */
/* 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 */
static IPv46_Address_t xGetSourceAddrFromBuffer( const uint8_t * const pucEthernetBuffer );
/*-----------------------------------------------------------*/
/** @brief Close the socket another time.
*
* @param[in] pxSocket The socket to be checked.
*/
/* coverity[single_use] */
void vSocketCloseNextTime( FreeRTOS_Socket_t * pxSocket )
{
if( ( xSocketToClose != NULL ) && ( xSocketToClose != pxSocket ) )
{
( void ) vSocketClose( xSocketToClose );
}
xSocketToClose = pxSocket;
}
/*-----------------------------------------------------------*/
/** @brief Postpone a call to FreeRTOS_listen() to avoid recursive calls.
*
* @param[in] pxSocket The socket to be checked.
*/
/* coverity[single_use] */
void vSocketListenNextTime( FreeRTOS_Socket_t * pxSocket )
{
if( ( xSocketToListen != NULL ) && ( xSocketToListen != pxSocket ) )
{
( void ) FreeRTOS_listen( ( Socket_t ) xSocketToListen, ( BaseType_t ) ( xSocketToListen->u.xTCP.usBacklog ) );
}
xSocketToListen = pxSocket;
}
/*-----------------------------------------------------------*/
/**
* @brief As soon as a TCP socket timer expires, this function will be called
* (from xTCPTimerCheck). It can send a delayed ACK or new data.
*
* @param[in] pxSocket socket to be checked.
*
* @return 0 on success, a negative error code on failure. A negative value will be
* returned in case the hang-protection has put the socket in a wait-close state.
*
* @note Sequence of calling (normally) :
* IP-Task:
* xTCPTimerCheck() // Check all sockets ( declared in FreeRTOS_Sockets.c )
* xTCPSocketCheck() // Either send a delayed ACK or call prvTCPSendPacket()
* prvTCPSendPacket() // Either send a SYN or call prvTCPSendRepeated ( regular messages )
* prvTCPSendRepeated() // Send at most 8 messages on a row
* prvTCPReturnPacket() // Prepare for returning
* xNetworkInterfaceOutput() // Sends data to the NIC ( declared in portable/NetworkInterface/xxx )
*/
BaseType_t xTCPSocketCheck( FreeRTOS_Socket_t * pxSocket )
{
BaseType_t xResult = 0;
BaseType_t xReady = pdFALSE;
if( ( pxSocket->u.xTCP.eTCPState >= eESTABLISHED ) && ( pxSocket->u.xTCP.txStream != NULL ) )
{
/* The API FreeRTOS_send() might have added data to the TX stream. Add
* this data to the windowing system so it can be transmitted. */
prvTCPAddTxData( pxSocket );
}
#if ( ipconfigUSE_TCP_WIN == 1 )
{
if( pxSocket->u.xTCP.pxAckMessage != NULL )
{
/* The first task of this regular socket check is to send-out delayed
* ACK's. */
if( pxSocket->u.xTCP.bits.bUserShutdown == pdFALSE_UNSIGNED )
{
/* Earlier data was received but not yet acknowledged. This
* function is called when the TCP timer for the socket expires, the
* ACK may be sent now. */
if( pxSocket->u.xTCP.eTCPState != eCLOSED )
{
if( ( xTCPWindowLoggingLevel > 1 ) && ipconfigTCP_MAY_LOG_PORT( pxSocket->usLocalPort ) )
{
FreeRTOS_debug_printf( ( "Send[%u->%u] del ACK %u SEQ %u (len %u)\n",
pxSocket->usLocalPort,
pxSocket->u.xTCP.usRemotePort,
( unsigned ) ( pxSocket->u.xTCP.xTCPWindow.rx.ulCurrentSequenceNumber - pxSocket->u.xTCP.xTCPWindow.rx.ulFirstSequenceNumber ),
( unsigned ) ( pxSocket->u.xTCP.xTCPWindow.ulOurSequenceNumber - pxSocket->u.xTCP.xTCPWindow.tx.ulFirstSequenceNumber ),
( unsigned ) ( uxIPHeaderSizeSocket( pxSocket ) + ipSIZE_OF_TCP_HEADER ) ) );
}
prvTCPReturnPacket( pxSocket, pxSocket->u.xTCP.pxAckMessage, ( uint32_t ) ( uxIPHeaderSizeSocket( pxSocket ) + ipSIZE_OF_TCP_HEADER ), ipconfigZERO_COPY_TX_DRIVER );
#if ( ipconfigZERO_COPY_TX_DRIVER != 0 )
{
/* The ownership has been passed to the SEND routine,
* clear the pointer to it. */
pxSocket->u.xTCP.pxAckMessage = NULL;
}
#endif /* ipconfigZERO_COPY_TX_DRIVER */
}
if( prvTCPNextTimeout( pxSocket ) > 1U )
{
/* Tell the code below that this function is ready. */
xReady = pdTRUE;
}
}
else
{
/* The user wants to perform an active shutdown(), skip sending
* the delayed ACK. The function prvTCPSendPacket() will send the
* FIN along with the ACK's. */
}
if( pxSocket->u.xTCP.pxAckMessage != NULL )
{
vReleaseNetworkBufferAndDescriptor( pxSocket->u.xTCP.pxAckMessage );
pxSocket->u.xTCP.pxAckMessage = NULL;
}
}
}
#endif /* ipconfigUSE_TCP_WIN */
if( xReady == pdFALSE )
{
/* The second task of this regular socket check is sending out data. */
if( ( pxSocket->u.xTCP.eTCPState >= eESTABLISHED ) ||
( pxSocket->u.xTCP.eTCPState == eCONNECT_SYN ) )
{
( void ) prvTCPSendPacket( pxSocket );
}
/* Set the time-out for the next wakeup for this socket. */
( void ) prvTCPNextTimeout( pxSocket );
#if ( ipconfigTCP_HANG_PROTECTION == 1 )
{
/* In all (non-connected) states in which keep-alive messages can not be sent
* the anti-hang protocol will close sockets that are 'hanging'. */
xResult = prvTCPStatusAgeCheck( pxSocket );
}
#endif
}
return xResult;
}
/*-----------------------------------------------------------*/
/**
* @brief 'Touch' the socket to keep it alive/updated.
*
* @param[in] pxSocket The socket to be updated.
*
* @note This is used for anti-hanging protection and TCP keep-alive messages.
* Called in two places: after receiving a packet and after a state change.
* The socket's alive timer may be reset.
*/
void prvTCPTouchSocket( struct xSOCKET * pxSocket )
{
#if ( ipconfigTCP_HANG_PROTECTION == 1 )
{
pxSocket->u.xTCP.xLastActTime = xTaskGetTickCount();
}
#endif
#if ( ipconfigTCP_KEEP_ALIVE == 1 )
{
pxSocket->u.xTCP.bits.bWaitKeepAlive = pdFALSE_UNSIGNED;
pxSocket->u.xTCP.bits.bSendKeepAlive = pdFALSE_UNSIGNED;
pxSocket->u.xTCP.ucKeepRepCount = 0U;
pxSocket->u.xTCP.xLastAliveTime = xTaskGetTickCount();
}
#endif
( void ) pxSocket;
}
/*-----------------------------------------------------------*/
static BaseType_t vTCPRemoveTCPChild( const FreeRTOS_Socket_t * pxChildSocket )
{
BaseType_t xReturn = pdFALSE;
/* 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] */
const ListItem_t * pxEnd = ( ( const ListItem_t * ) &( xBoundTCPSocketsList.xListEnd ) );
/* 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] */
const ListItem_t * pxIterator = ( const ListItem_t * ) listGET_HEAD_ENTRY( &xBoundTCPSocketsList );
while( pxIterator != pxEnd )
{
FreeRTOS_Socket_t * pxSocket;
pxSocket = ( ( FreeRTOS_Socket_t * ) listGET_LIST_ITEM_OWNER( pxIterator ) );
pxIterator = ( ListItem_t * ) listGET_NEXT( pxIterator );
if( ( pxSocket != pxChildSocket ) && ( pxSocket->usLocalPort == pxChildSocket->usLocalPort ) )
{
if( pxSocket->u.xTCP.pxPeerSocket == pxChildSocket ) /**< for server socket: child, for child socket: parent */
{
pxSocket->u.xTCP.pxPeerSocket = NULL;
xReturn = pdTRUE;
break;
}
}
}
return xReturn;
}
/**
* @brief Changing to a new state. Centralised here to do specific actions such as
* resetting the alive timer, calling the user's OnConnect handler to notify
* that a socket has got (dis)connected, and setting bit to unblock a call to
* FreeRTOS_select().
*
* @param[in] pxSocket The socket whose state we are trying to change.
* @param[in] eTCPState The state to which we want to change to.
*/
void vTCPStateChange( FreeRTOS_Socket_t * pxSocket,
enum eTCP_STATE eTCPState )
{
FreeRTOS_Socket_t * xParent = pxSocket;
BaseType_t bBefore = tcpNOW_CONNECTED( ( BaseType_t ) pxSocket->u.xTCP.eTCPState ); /* Was it connected ? */
BaseType_t bAfter = tcpNOW_CONNECTED( ( BaseType_t ) eTCPState ); /* Is it connected now ? */
eIPTCPState_t xPreviousState = pxSocket->u.xTCP.eTCPState;
#if ( ipconfigUSE_CALLBACKS == 1 )
FreeRTOS_Socket_t * xConnected = NULL;
#endif
if( ( ( xPreviousState == eCONNECT_SYN ) ||
( xPreviousState == eSYN_FIRST ) ||
( xPreviousState == eSYN_RECEIVED ) ) &&
( eTCPState == eCLOSE_WAIT ) )
{
/* A socket was in the connecting phase but something
* went wrong and it should be closed. */
#if ( ipconfigHAS_DEBUG_PRINTF != 0 )
FreeRTOS_debug_printf( ( "Move from %s to %s\n",
FreeRTOS_GetTCPStateName( ( UBaseType_t ) xPreviousState ),
FreeRTOS_GetTCPStateName( eTCPState ) ) );
#endif
/* Set the flag to show that it was connected before and that the
* status has changed now. This will cause the control flow to go
* in the below if condition.*/
bBefore = pdTRUE;
}
/* Has the connected status changed? */
if( bBefore != bAfter )
{
/* if bPassQueued is true, this socket is an orphan until it gets connected. */
if( pxSocket->u.xTCP.bits.bPassQueued != pdFALSE_UNSIGNED )
{
/* Find it's parent if the reuse bit is not set. */
if( pxSocket->u.xTCP.bits.bReuseSocket == pdFALSE_UNSIGNED )
{
xParent = pxSocket->u.xTCP.pxPeerSocket;
configASSERT( xParent != NULL );
}
}
/* Is the socket connected now ? */
if( bAfter != pdFALSE )
{
/* if bPassQueued is true, this socket is an orphan until it gets connected. */
if( pxSocket->u.xTCP.bits.bPassQueued != pdFALSE_UNSIGNED )
{
if( xParent != NULL )
{
/* The child socket has got connected. See if the parent
* ( the listening socket ) should be signalled, or if a
* call-back must be made, in which case 'xConnected' will
* be set to the parent socket. */
if( xParent->u.xTCP.pxPeerSocket == NULL )
{
xParent->u.xTCP.pxPeerSocket = pxSocket;
}
xParent->xEventBits |= ( EventBits_t ) eSOCKET_ACCEPT;
#if ( ipconfigSUPPORT_SELECT_FUNCTION == 1 )
{
/* Library support FreeRTOS_select(). Receiving a new
* connection is being translated as a READ event. */
if( ( xParent->xSelectBits & ( ( EventBits_t ) eSELECT_READ ) ) != 0U )
{
xParent->xEventBits |= ( ( EventBits_t ) eSELECT_READ ) << SOCKET_EVENT_BIT_COUNT;
}
}
#endif
#if ( ipconfigUSE_CALLBACKS == 1 )
{
if( ( ipconfigIS_VALID_PROG_ADDRESS( xParent->u.xTCP.pxHandleConnected ) ) &&
( xParent->u.xTCP.bits.bReuseSocket == pdFALSE_UNSIGNED ) )
{
/* The listening socket does not become connected itself, in stead
* a child socket is created.
* Postpone a call the OnConnect event until the end of this function. */
xConnected = xParent;
}
}
#endif
}
/* Don't need to access the parent socket anymore, so the
* reference 'pxPeerSocket' may be cleared. */
pxSocket->u.xTCP.pxPeerSocket = NULL;
pxSocket->u.xTCP.bits.bPassQueued = pdFALSE_UNSIGNED;
/* When true, this socket may be returned in a call to accept(). */
pxSocket->u.xTCP.bits.bPassAccept = pdTRUE_UNSIGNED;
}
else
{
/* An active connect() has succeeded. In this case there is no
* ( listening ) parent socket. Signal the now connected socket. */
pxSocket->xEventBits |= ( EventBits_t ) eSOCKET_CONNECT;
#if ( ipconfigSUPPORT_SELECT_FUNCTION == 1 )
{
if( ( pxSocket->xSelectBits & ( ( EventBits_t ) eSELECT_WRITE ) ) != 0U )
{
pxSocket->xEventBits |= ( ( EventBits_t ) eSELECT_WRITE ) << SOCKET_EVENT_BIT_COUNT;
}
}
#endif
}
}
else /* bAfter == pdFALSE, connection is closed. */
{
/* Notify/wake-up the socket-owner by setting the event bits. */
xParent->xEventBits |= ( EventBits_t ) eSOCKET_CLOSED;
#if ( ipconfigSUPPORT_SELECT_FUNCTION == 1 )
{
if( ( xParent->xSelectBits & ( EventBits_t ) eSELECT_EXCEPT ) != 0U )
{
xParent->xEventBits |= ( ( EventBits_t ) eSELECT_EXCEPT ) << SOCKET_EVENT_BIT_COUNT;
}
}
#endif
}
#if ( ipconfigUSE_CALLBACKS == 1 )
{
if( ( ipconfigIS_VALID_PROG_ADDRESS( pxSocket->u.xTCP.pxHandleConnected ) ) && ( xConnected == NULL ) )
{
/* The 'connected' state has changed, call the user handler. */
xConnected = pxSocket;
}
}
#endif /* ipconfigUSE_CALLBACKS */
if( prvTCPSocketIsActive( pxSocket->u.xTCP.eTCPState ) == 0 )
{
/* Now the socket isn't in an active state anymore so it
* won't need further attention of the IP-task.
* Setting time-out to zero means that the socket won't get checked during
* timer events. */
pxSocket->u.xTCP.usTimeout = 0U;
}
}
/* Fill in the new state. */
pxSocket->u.xTCP.eTCPState = eTCPState;
if( ( eTCPState == eCLOSED ) ||
( eTCPState == eCLOSE_WAIT ) )
{
BaseType_t xMustClear = pdFALSE;
BaseType_t xHasCleared = pdFALSE;
if( ( xParent == pxSocket ) && ( pxSocket->u.xTCP.pxPeerSocket != NULL ) )
{
xParent = pxSocket->u.xTCP.pxPeerSocket;
}
if( ( xParent->u.xTCP.pxPeerSocket != NULL ) &&
( xParent->u.xTCP.pxPeerSocket == pxSocket ) )
{
xMustClear = pdTRUE;
( void ) xMustClear;
}
/* Socket goes to status eCLOSED because of a RST.
* When nobody owns the socket yet, delete it. */
FreeRTOS_printf( ( "vTCPStateChange: Closing (Queued %d, Accept %d Reuse %d)\n",
pxSocket->u.xTCP.bits.bPassQueued,
pxSocket->u.xTCP.bits.bPassAccept,
pxSocket->u.xTCP.bits.bReuseSocket ) );
FreeRTOS_printf( ( "vTCPStateChange: me %p parent %p peer %p clear %d\n",
( void * ) pxSocket,
( void * ) xParent,
xParent ? ( void * ) xParent->u.xTCP.pxPeerSocket : NULL,
( int ) xMustClear ) );
vTaskSuspendAll();
{
if( ( pxSocket->u.xTCP.bits.bPassQueued != pdFALSE_UNSIGNED ) ||
( pxSocket->u.xTCP.bits.bPassAccept != pdFALSE_UNSIGNED ) )
{
if( pxSocket->u.xTCP.bits.bReuseSocket == pdFALSE_UNSIGNED )
{
xHasCleared = vTCPRemoveTCPChild( pxSocket );
( void ) xHasCleared;
pxSocket->u.xTCP.bits.bPassQueued = pdFALSE_UNSIGNED;
pxSocket->u.xTCP.bits.bPassAccept = pdFALSE_UNSIGNED;
configASSERT( xIsCallingFromIPTask() != pdFALSE );
vSocketCloseNextTime( pxSocket );
}
}
}
( void ) xTaskResumeAll();
FreeRTOS_printf( ( "vTCPStateChange: xHasCleared = %d\n",
( int ) xHasCleared ) );
}
if( ( eTCPState == eCLOSE_WAIT ) && ( pxSocket->u.xTCP.bits.bReuseSocket == pdTRUE_UNSIGNED ) )
{
switch( xPreviousState )
{
case eSYN_FIRST: /* 3 (server) Just created, must ACK the SYN request */
case eSYN_RECEIVED: /* 4 (server) waiting for a confirming connection request */
FreeRTOS_debug_printf( ( "Restoring a reuse socket port %u\n", pxSocket->usLocalPort ) );
/* Go back into listening mode. Set the TCP status to 'eCLOSED',
* otherwise FreeRTOS_listen() will refuse the action. */
pxSocket->u.xTCP.eTCPState = eCLOSED;
/* vSocketListenNextTime() makes sure that FreeRTOS_listen() will be called
* before the IP-task handles any new message. */
vSocketListenNextTime( pxSocket );
break;
default:
/* Nothing to do. */
break;
}
}
/* Touch the alive timers because moving to another state. */
prvTCPTouchSocket( pxSocket );
#if ( ipconfigHAS_DEBUG_PRINTF == 1 )
{
if( ( xTCPWindowLoggingLevel >= 0 ) && ( ipconfigTCP_MAY_LOG_PORT( pxSocket->usLocalPort ) ) )
{
char pcBuffer[ 40 ];
switch( pxSocket->bits.bIsIPv6 ) /* LCOV_EXCL_BR_LINE */
{
#if ( ipconfigUSE_IPv4 != 0 )
case pdFALSE_UNSIGNED:
{
uint32_t ulIPAddress = FreeRTOS_ntohl( pxSocket->u.xTCP.xRemoteIP.ulIP_IPv4 );
FreeRTOS_inet_ntop( FREERTOS_AF_INET4,
( const uint8_t * ) &ulIPAddress,
pcBuffer,
sizeof( pcBuffer ) );
}
break;
#endif /* ( ipconfigUSE_IPv4 != 0 ) */
#if ( ipconfigUSE_IPv6 != 0 )
case pdTRUE_UNSIGNED:
FreeRTOS_inet_ntop( FREERTOS_AF_INET6,
pxSocket->u.xTCP.xRemoteIP.xIP_IPv6.ucBytes,
pcBuffer,
sizeof( pcBuffer ) );
break;
#endif /* ( ipconfigUSE_IPv6 != 0 ) */
default: /* LCOV_EXCL_LINE */
/* MISRA 16.4 Compliance */
break; /* LCOV_EXCL_LINE */
}
FreeRTOS_debug_printf( ( "Socket %u -> [%s]:%u State %s->%s\n",
pxSocket->usLocalPort,
pcBuffer,
pxSocket->u.xTCP.usRemotePort,
FreeRTOS_GetTCPStateName( ( UBaseType_t ) xPreviousState ),
FreeRTOS_GetTCPStateName( ( UBaseType_t ) eTCPState ) ) );
}
}
#endif /* ipconfigHAS_DEBUG_PRINTF */
#if ( ipconfigUSE_CALLBACKS == 1 )
{
if( xConnected != NULL )
{
/* The 'connected' state has changed, call the OnConnect handler of the parent. */
xConnected->u.xTCP.pxHandleConnected( ( Socket_t ) xConnected, bAfter );
}
}
#endif
if( xParent != NULL )
{
vSocketWakeUpUser( xParent );
}
}
/*-----------------------------------------------------------*/
/**
* @brief Calculate after how much time this socket needs to be checked again.
*
* @param[in] pxSocket The socket to be checked.
*
* @return The number of clock ticks before the timer expires.
*/
TickType_t prvTCPNextTimeout( struct xSOCKET * pxSocket )
{
TickType_t ulDelayMs = ( TickType_t ) tcpMAXIMUM_TCP_WAKEUP_TIME_MS;
if( pxSocket->u.xTCP.eTCPState == eCONNECT_SYN )
{
/* The socket is actively connecting to a peer. */
if( pxSocket->u.xTCP.bits.bConnPrepared != pdFALSE_UNSIGNED )
{
/* Ethernet address has been found, use progressive timeout for
* active connect(). */
if( pxSocket->u.xTCP.ucRepCount < 3U )
{
if( pxSocket->u.xTCP.ucRepCount == 0U )
{
ulDelayMs = 0U;
}
else
{
ulDelayMs = ( ( uint32_t ) 3000U ) << ( pxSocket->u.xTCP.ucRepCount - 1U );
}
}
else
{
ulDelayMs = 11000U;
}
}
else
{
/* Still in the ARP phase: check every half second. */
ulDelayMs = 500U;
}
FreeRTOS_debug_printf( ( "Connect[%xip:%u]: next timeout %u: %u ms\n",
( unsigned ) pxSocket->u.xTCP.xRemoteIP.ulIP_IPv4, pxSocket->u.xTCP.usRemotePort,
pxSocket->u.xTCP.ucRepCount, ( unsigned ) ulDelayMs ) );
pxSocket->u.xTCP.usTimeout = ( uint16_t ) ipMS_TO_MIN_TICKS( ulDelayMs );
}
else if( pxSocket->u.xTCP.usTimeout == 0U )
{
/* Let the sliding window mechanism decide what time-out is appropriate. */
BaseType_t xResult = xTCPWindowTxHasData( &pxSocket->u.xTCP.xTCPWindow, pxSocket->u.xTCP.ulWindowSize, &ulDelayMs );
if( ulDelayMs == 0U )
{
if( xResult != ( BaseType_t ) 0 )
{
ulDelayMs = 1U;
}
else
{
ulDelayMs = tcpMAXIMUM_TCP_WAKEUP_TIME_MS;
}
}
else
{
/* ulDelayMs contains the time to wait before a re-transmission. */
}
pxSocket->u.xTCP.usTimeout = ( uint16_t ) ipMS_TO_MIN_TICKS( ulDelayMs ); /* LCOV_EXCL_BR_LINE ulDelayMs will not be smaller than 1 */
}
else
{
/* field '.usTimeout' has already been set (by the
* keep-alive/delayed-ACK mechanism). */
}
/* Return the number of clock ticks before the timer expires. */
return ( TickType_t ) pxSocket->u.xTCP.usTimeout;
}
/*-----------------------------------------------------------*/
/**
* @brief IP frame agnostic helper to obtain the source IP Address from a buffer.
*
* @param[in] pucEthernetBuffer The Ethernet buffer from which the source address will be retrieved.
*
* @return IPv46_Address_t struct containing the source IP address.
*/
static IPv46_Address_t xGetSourceAddrFromBuffer( const uint8_t * const pucEthernetBuffer )
{
IPv46_Address_t xSourceAddr;
/* Map the buffer onto Ethernet Header struct for easy access to fields. */
/* 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] */
const EthernetHeader_t * pxHeader = ( ( const EthernetHeader_t * ) pucEthernetBuffer );
if( pxHeader->usFrameType == ( uint16_t ) ipIPv6_FRAME_TYPE )
{
/* Map the ethernet buffer onto the IPHeader_t struct for easy access to the fields. */
/* 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] */
const IPHeader_IPv6_t * const pxIPHeader_IPv6 = ( ( const IPHeader_IPv6_t * ) &( pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER ] ) );
xSourceAddr.xIs_IPv6 = pdTRUE;
( void ) memcpy( xSourceAddr.xIPAddress.xIP_IPv6.ucBytes, pxIPHeader_IPv6->xSourceAddress.ucBytes, sizeof( IPv6_Address_t ) );
}
else
{
/* Map the ethernet buffer onto the IPHeader_t struct for easy access to the fields. */
/* 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] */
const IPHeader_t * const pxIPHeader = ( ( const IPHeader_t * ) &( pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER ] ) );
xSourceAddr.xIs_IPv6 = pdFALSE;
xSourceAddr.xIPAddress.ulIP_IPv4 = FreeRTOS_htonl( pxIPHeader->ulSourceIPAddress );
}
return xSourceAddr;
}
/**
* @brief Process the received TCP packet.
*
* @param[in] pxDescriptor The descriptor in which the TCP packet is held.
*
* @return If the processing of the packet was successful, then pdPASS is returned
* or else pdFAIL.
*
* @note FreeRTOS_TCP_IP has only 2 public functions, this is the second one:
* xProcessReceivedTCPPacket()
* prvTCPHandleState()
* prvTCPPrepareSend()
* prvTCPReturnPacket()
* xNetworkInterfaceOutput() // Sends data to the NIC
* prvTCPSendRepeated()
* prvTCPReturnPacket() // Prepare for returning
* xNetworkInterfaceOutput() // Sends data to the NIC
*/
BaseType_t xProcessReceivedTCPPacket( NetworkBufferDescriptor_t * pxDescriptor )
{
BaseType_t xResult = pdPASS;
/* Function might modify the parameter. */
NetworkBufferDescriptor_t * pxNetworkBuffer;
size_t uxIPHeaderOffset;
configASSERT( pxDescriptor != NULL );
configASSERT( pxDescriptor->pucEthernetBuffer != NULL );
pxNetworkBuffer = pxDescriptor;
uxIPHeaderOffset = ipSIZE_OF_ETH_HEADER + uxIPHeaderSizePacket( pxNetworkBuffer );
/* Check for a minimum packet size. */
if( pxNetworkBuffer->xDataLength < ( uxIPHeaderOffset + ipSIZE_OF_TCP_HEADER ) )
{
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] */
const TCPHeader_t * pxTCPHeader = ( ( const TCPHeader_t * )
&( pxNetworkBuffer->pucEthernetBuffer[ uxIPHeaderOffset ] ) );
const uint16_t ucTCPFlags = pxTCPHeader->ucTCPFlags;
const uint16_t usLocalPort = FreeRTOS_htons( pxTCPHeader->usDestinationPort );
const uint16_t usRemotePort = FreeRTOS_htons( pxTCPHeader->usSourcePort );
const IPv46_Address_t xRemoteIP = xGetSourceAddrFromBuffer( pxNetworkBuffer->pucEthernetBuffer );
/* Find the destination socket, and if not found: return a socket listening to
* the destination PORT. */
FreeRTOS_Socket_t * pxSocket = pxTCPSocketLookup( 0U, 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 (%d)\n", usLocalPort, 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;
}
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 ( ipconfigHAS_DEBUG_PRINTF == 1 )
{
FreeRTOS_debug_printf( ( "TCP: Server can't handle flags: %s from %u to port %u\n",
prvTCPFlagMeaning( ( UBaseType_t ) ucTCPFlags ), usRemotePort, usLocalPort ) );
}
#endif /* ipconfigHAS_DEBUG_PRINTF */
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 %u for %u\n", 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 %u\n", 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 )
{
uint16_t usWindow;
/* 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 )
{
usWindow = FreeRTOS_ntohs( pxTCPHeader->usWindow );
pxSocket->u.xTCP.ulWindowSize = ( uint32_t ) usWindow;
#if ( ipconfigUSE_TCP_WIN == 1 )
{
/* 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 /* ipconfigUSE_TCP_WIN */
/* 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 ( ipconfigUSE_TCP_WIN == 1 )
{
( 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 );
#ifndef _lint
/* Clear pointers that are freed. */
pxNetworkBuffer = NULL;
#endif
}
/* And finally, calculate when this socket wants to be woken up. */
( void ) prvTCPNextTimeout( pxSocket );
}
}
}
/* pdPASS being returned means the buffer has been consumed. */
return xResult;
}
/*-----------------------------------------------------------*/
/**
* @brief In the API accept(), the user asks is there is a new client? As API's can
* not walk through the xBoundTCPSocketsList the IP-task will do this.
*
* @param[in] pxSocket The socket for which the bound socket list will be iterated.
*
* @return if there is a new client, then pdTRUE is returned or else, pdFALSE.
*/
BaseType_t xTCPCheckNewClient( FreeRTOS_Socket_t * pxSocket )
{
TickType_t uxLocalPort = ( TickType_t ) FreeRTOS_htons( pxSocket->usLocalPort );
const ListItem_t * pxIterator;
FreeRTOS_Socket_t * pxFound;
BaseType_t xResult = pdFALSE;
/* 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] */
const ListItem_t * pxEndTCP = ( ( const ListItem_t * ) &( xBoundTCPSocketsList.xListEnd ) );
/* Here xBoundTCPSocketsList can be accessed safely IP-task is the only one
* who has access. */
for( pxIterator = ( const ListItem_t * ) listGET_HEAD_ENTRY( &xBoundTCPSocketsList );
pxIterator != pxEndTCP;
pxIterator = ( const ListItem_t * ) listGET_NEXT( pxIterator ) )
{
if( listGET_LIST_ITEM_VALUE( pxIterator ) == ( configLIST_VOLATILE TickType_t ) uxLocalPort )
{
pxFound = ( ( FreeRTOS_Socket_t * ) listGET_LIST_ITEM_OWNER( pxIterator ) );
if( ( pxFound->ucProtocol == ( uint8_t ) FREERTOS_IPPROTO_TCP ) && ( pxFound->u.xTCP.bits.bPassAccept != pdFALSE_UNSIGNED ) )
{
pxSocket->u.xTCP.pxPeerSocket = pxFound;
FreeRTOS_debug_printf( ( "xTCPCheckNewClient[0]: client on port %u\n", pxSocket->usLocalPort ) );
xResult = pdTRUE;
break;
}
}
}
return xResult;
}
/*-----------------------------------------------------------*/
#endif /* ipconfigUSE_TCP == 1 */
/* Provide access to private members for testing. */
#ifdef FREERTOS_ENABLE_UNIT_TESTS
#include "freertos_tcp_test_access_tcp_define.h"
#endif
/* Provide access to private members for verification. */
#ifdef FREERTOS_TCP_ENABLE_VERIFICATION
#include "aws_freertos_tcp_verification_access_tcp_define.h"
#endif
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