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mongoose/test/freertos-tcp/FreeRTOS_TCP_IP.c

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/*
* FreeRTOS+TCP V2.3.2
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* 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_UDP_IP.h"
#include "FreeRTOS_DHCP.h"
#include "NetworkInterface.h"
#include "NetworkBufferManagement.h"
#include "FreeRTOS_ARP.h"
/* Just make sure the contents doesn't get compiled if TCP is not enabled. */
#if ipconfigUSE_TCP == 1
/*lint -e750 local macro not referenced [MISRA 2012 Rule 2.5, advisory] */
/*
* The meaning of the TCP flags:
*/
#define tcpTCP_FLAG_FIN ( ( uint8_t ) 0x01U ) /**< No more data from sender. */
#define tcpTCP_FLAG_SYN ( ( uint8_t ) 0x02U ) /**< Synchronize sequence numbers. */
#define tcpTCP_FLAG_RST ( ( uint8_t ) 0x04U ) /**< Reset the connection. */
#define tcpTCP_FLAG_PSH ( ( uint8_t ) 0x08U ) /**< Push function: please push buffered data to the recv application. */
#define tcpTCP_FLAG_ACK ( ( uint8_t ) 0x10U ) /**< Acknowledgment field is significant. */
#define tcpTCP_FLAG_URG ( ( uint8_t ) 0x20U ) /**< Urgent pointer field is significant. */
#define tcpTCP_FLAG_ECN ( ( uint8_t ) 0x40U ) /**< ECN-Echo. */
#define tcpTCP_FLAG_CWR ( ( uint8_t ) 0x80U ) /**< Congestion Window Reduced. */
#define tcpTCP_FLAG_CTRL ( ( uint8_t ) 0x1FU ) /**< A mask to filter all protocol flags. */
/*
* A few values of the TCP options:
*/
#define tcpTCP_OPT_END 0U /**< End of TCP options list. */
#define tcpTCP_OPT_NOOP 1U /**< "No-operation" TCP option. */
#define tcpTCP_OPT_MSS 2U /**< Maximum segment size TCP option. */
#define tcpTCP_OPT_WSOPT 3U /**< TCP Window Scale Option (3-byte long). */
#define tcpTCP_OPT_SACK_P 4U /**< Advertise that SACK is permitted. */
#define tcpTCP_OPT_SACK_A 5U /**< SACK option with first/last. */
#define tcpTCP_OPT_TIMESTAMP 8U /**< Time-stamp option. */
#define tcpTCP_OPT_MSS_LEN 4U /**< Length of TCP MSS option. */
#define tcpTCP_OPT_WSOPT_LEN 3U /**< Length of TCP WSOPT option. */
#define tcpTCP_OPT_TIMESTAMP_LEN 10 /**< fixed length of the time-stamp option. */
#ifndef ipconfigTCP_ACK_EARLIER_PACKET
#define ipconfigTCP_ACK_EARLIER_PACKET 1 /**< Acknowledge an earlier packet. */
#endif
/** @brief
* The macro tcpNOW_CONNECTED() is use to determine if the connection makes a
* transition from connected to non-connected and vice versa.
* tcpNOW_CONNECTED() returns true when the status has one of these values:
* eESTABLISHED, eFIN_WAIT_1, eFIN_WAIT_2, eCLOSING, eLAST_ACK, eTIME_WAIT
* Technically the connection status is closed earlier, but the library wants
* to prevent that the socket will be deleted before the last ACK has been
* and thus causing a 'RST' packet on either side.
*/
#define tcpNOW_CONNECTED( status ) \
( ( ( ( status ) >= ( BaseType_t ) eESTABLISHED ) && ( ( status ) != ( BaseType_t ) eCLOSE_WAIT ) ) ? 1 : 0 )
/** @brief
* The highest 4 bits in the TCP offset byte indicate the total length of the
* TCP header, divided by 4.
*/
#define tcpVALID_BITS_IN_TCP_OFFSET_BYTE ( 0xF0U )
/*
* Acknowledgements to TCP data packets may be delayed as long as more is being expected.
* A normal delay would be 200ms. Here a much shorter delay of 20 ms is being used to
* gain performance.
*/
#define tcpDELAYED_ACK_SHORT_DELAY_MS ( 2 ) /**< Should not become smaller than 1. */
#define tcpDELAYED_ACK_LONGER_DELAY_MS ( 20 ) /**< Longer delay for ACK. */
/** @brief
* The MSS (Maximum Segment Size) will be taken as large as possible. However, packets with
* an MSS of 1460 bytes won't be transported through the internet. The MSS will be reduced
* to 1400 bytes.
*/
#define tcpREDUCED_MSS_THROUGH_INTERNET ( 1400 )
/** @brief
* 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.
*/
#define tcpTCP_OFFSET_LENGTH_BITS ( 0xf0U )
#define tcpTCP_OFFSET_STANDARD_LENGTH ( 0x50U ) /**< Standard TCP packet offset. */
/** @brief
* Each TCP socket is checked regularly to see if it can send data packets.
* By default, the maximum number of packets sent during one check is limited to 8.
* This amount may be further limited by setting the socket's TX window size.
*/
#if ( !defined( SEND_REPEATED_COUNT ) )
#define SEND_REPEATED_COUNT ( 8 )
#endif /* !defined( SEND_REPEATED_COUNT ) */
/** @brief
* Define a maximum period of time (ms) to leave a TCP-socket unattended.
* When a TCP timer expires, retries and keep-alive messages will be checked.
*/
#ifndef tcpMAXIMUM_TCP_WAKEUP_TIME_MS
#define tcpMAXIMUM_TCP_WAKEUP_TIME_MS 20000U
#endif
/* Two macro's that were introduced to work with both IPv4 and IPv6. */
#define xIPHeaderSize( pxNetworkBuffer ) ( ipSIZE_OF_IPv4_HEADER ) /**< Size of IP Header. */
#define uxIPHeaderSizeSocket( pxSocket ) ( ipSIZE_OF_IPv4_HEADER ) /**< Size of IP Header socket. */
/*
* Returns true if the socket must be checked. Non-active sockets are waiting
* for user action, either connect() or close().
*/
static BaseType_t prvTCPSocketIsActive( eIPTCPState_t xStatus );
/*
* Either sends a SYN or calls prvTCPSendRepeated (for regular messages).
*/
static int32_t prvTCPSendPacket( FreeRTOS_Socket_t * pxSocket );
/*
* Try to send a series of messages.
*/
static int32_t prvTCPSendRepeated( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t ** ppxNetworkBuffer );
/*
* Return or send a packet to the other party.
*/
static void prvTCPReturnPacket( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t * pxDescriptor,
uint32_t ulLen,
BaseType_t xReleaseAfterSend );
/*
* Initialise the data structures which keep track of the TCP windowing system.
*/
static void prvTCPCreateWindow( FreeRTOS_Socket_t * pxSocket );
/*
* Let ARP look-up the MAC-address of the peer and initialise the first SYN
* packet.
*/
static BaseType_t prvTCPPrepareConnect( FreeRTOS_Socket_t * pxSocket );
#if ( ipconfigHAS_DEBUG_PRINTF != 0 )
/*
* For logging and debugging: make a string showing the TCP flags.
*/
static const char * prvTCPFlagMeaning( UBaseType_t xFlags );
#endif /* ipconfigHAS_DEBUG_PRINTF != 0 */
/*
* Parse the TCP option(s) received, if present.
*/
_static void prvCheckOptions( FreeRTOS_Socket_t * pxSocket,
const NetworkBufferDescriptor_t * pxNetworkBuffer );
/*
* Identify and deal with a single TCP header option, advancing the pointer to
* the header. This function returns pdTRUE or pdFALSE depending on whether the
* caller should continue to parse more header options or break the loop.
*/
_static size_t prvSingleStepTCPHeaderOptions( const uint8_t * const pucPtr,
size_t uxTotalLength,
FreeRTOS_Socket_t * const pxSocket,
BaseType_t xHasSYNFlag );
#if ( ipconfigUSE_TCP_WIN == 1 )
/*
* Skip past TCP header options when doing Selective ACK, until there are no
* more options left.
*/
_static void prvReadSackOption( const uint8_t * const pucPtr,
size_t uxIndex,
FreeRTOS_Socket_t * const pxSocket );
#endif /* ( ipconfigUSE_TCP_WIN == 1 ) */
/*
* Set the initial properties in the options fields, like the preferred
* value of MSS and whether SACK allowed. Will be transmitted in the state
* 'eCONNECT_SYN'.
*/
static UBaseType_t prvSetSynAckOptions( FreeRTOS_Socket_t * pxSocket,
TCPHeader_t * pxTCPHeader );
/*
* For anti-hang 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.
*/
static void prvTCPTouchSocket( FreeRTOS_Socket_t * pxSocket );
/*
* Prepare an outgoing message, if anything has to be sent.
*/
static int32_t prvTCPPrepareSend( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t ** ppxNetworkBuffer,
UBaseType_t uxOptionsLength );
/*
* Calculate when this socket needs to be checked to do (re-)transmissions.
*/
static TickType_t prvTCPNextTimeout( FreeRTOS_Socket_t * pxSocket );
/*
* The API FreeRTOS_send() adds data to the TX stream. Add
* this data to the windowing system to it can be transmitted.
*/
static void prvTCPAddTxData( FreeRTOS_Socket_t * pxSocket );
/*
* Called to handle the closure of a TCP connection.
*/
static BaseType_t prvTCPHandleFin( FreeRTOS_Socket_t * pxSocket,
const NetworkBufferDescriptor_t * pxNetworkBuffer );
/*
* Called from prvTCPHandleState(). Find the TCP payload data and check and
* return its length.
*/
static BaseType_t prvCheckRxData( const NetworkBufferDescriptor_t * pxNetworkBuffer,
uint8_t ** ppucRecvData );
/*
* Called from prvTCPHandleState(). Check if the payload data may be accepted.
* If so, it will be added to the socket's reception queue.
*/
static BaseType_t prvStoreRxData( FreeRTOS_Socket_t * pxSocket,
const uint8_t * pucRecvData,
NetworkBufferDescriptor_t * pxNetworkBuffer,
uint32_t ulReceiveLength );
/*
* Set the TCP options (if any) for the outgoing packet.
*/
static UBaseType_t prvSetOptions( FreeRTOS_Socket_t * pxSocket,
const NetworkBufferDescriptor_t * pxNetworkBuffer );
/*
* Called from prvTCPHandleState() as long as the TCP status is eSYN_RECEIVED to
* eCONNECT_SYN.
*/
static BaseType_t prvHandleSynReceived( FreeRTOS_Socket_t * pxSocket,
const NetworkBufferDescriptor_t * pxNetworkBuffer,
uint32_t ulReceiveLength,
UBaseType_t uxOptionsLength );
/*
* Called from prvTCPHandleState() as long as the TCP status is eESTABLISHED.
*/
static BaseType_t prvHandleEstablished( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t ** ppxNetworkBuffer,
uint32_t ulReceiveLength,
UBaseType_t uxOptionsLength );
/*
* Called from prvTCPHandleState(). There is data to be sent.
* If ipconfigUSE_TCP_WIN is defined, and if only an ACK must be sent, it will
* be checked if it would better be postponed for efficiency.
*/
static BaseType_t prvSendData( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t ** ppxNetworkBuffer,
uint32_t ulReceiveLength,
BaseType_t xByteCount );
/*
* The heart of all: check incoming packet for valid data and acks and do what
* is necessary in each state.
*/
static BaseType_t prvTCPHandleState( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t ** ppxNetworkBuffer );
/*
* Common code for sending a TCP protocol control packet (i.e. no options, no
* payload, just flags).
*/
static BaseType_t prvTCPSendSpecialPacketHelper( NetworkBufferDescriptor_t * pxNetworkBuffer,
uint8_t ucTCPFlags );
/*
* A "challenge ACK" is as per https://tools.ietf.org/html/rfc5961#section-3.2,
* case #3. In summary, an RST was received with a sequence number that is
* unexpected but still within the window.
*/
static BaseType_t prvTCPSendChallengeAck( NetworkBufferDescriptor_t * pxNetworkBuffer );
/*
* Reply to a peer with the RST flag on, in case a packet can not be handled.
*/
static BaseType_t prvTCPSendReset( NetworkBufferDescriptor_t * pxNetworkBuffer );
/*
* Set the initial value for MSS (Maximum Segment Size) to be used.
*/
static void prvSocketSetMSS( FreeRTOS_Socket_t * pxSocket );
/*
* Return either a newly created socket, or the current socket in a connected
* state (depends on the 'bReuseSocket' flag).
*/
static FreeRTOS_Socket_t * prvHandleListen( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t * pxNetworkBuffer );
/*
* After a listening socket receives a new connection, it may duplicate itself.
* The copying takes place in prvTCPSocketCopy.
*/
static BaseType_t prvTCPSocketCopy( FreeRTOS_Socket_t * pxNewSocket,
FreeRTOS_Socket_t * pxSocket );
/*
* prvTCPStatusAgeCheck() will see if the socket has been in a non-connected
* state for too long. If so, the socket will be closed, and -1 will be
* returned.
*/
#if ( ipconfigTCP_HANG_PROTECTION == 1 )
static BaseType_t prvTCPStatusAgeCheck( FreeRTOS_Socket_t * pxSocket );
#endif
static NetworkBufferDescriptor_t * prvTCPBufferResize( const FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t * pxNetworkBuffer,
int32_t lDataLen,
UBaseType_t uxOptionsLength );
#if ( ipconfigUSE_TCP_WIN != 0 )
static uint8_t prvWinScaleFactor( const FreeRTOS_Socket_t * pxSocket );
#endif
/*-----------------------------------------------------------*/
/**
* @brief Check whether the socket is active or not.
*
* @param[in] xStatus: The status of the socket.
*
* @return pdTRUE if the socket must be checked. Non-active sockets
* are waiting for user action, either connect() or close().
*/
static BaseType_t prvTCPSocketIsActive( eIPTCPState_t xStatus )
{
BaseType_t xResult;
switch( xStatus )
{
case eCLOSED:
case eCLOSE_WAIT:
case eFIN_WAIT_2:
case eCLOSING:
case eTIME_WAIT:
xResult = pdFALSE;
break;
case eTCP_LISTEN:
case eCONNECT_SYN:
case eSYN_FIRST:
case eSYN_RECEIVED:
case eESTABLISHED:
case eFIN_WAIT_1:
case eLAST_ACK:
default:
xResult = pdTRUE;
break;
}
return xResult;
}
/*-----------------------------------------------------------*/
#if ( ipconfigTCP_HANG_PROTECTION == 1 )
/**
* @brief Some of the TCP states may only last a certain amount of time.
* This function checks if the socket is 'hanging', i.e. staying
* too long in the same state.
*
* @param[in] The socket to be checked.
*
* @return pdFALSE if no checks are needed, pdTRUE if checks were done, or negative
* in case the socket has reached a critical time-out. The socket will go to
* the eCLOSE_WAIT state.
*/
static BaseType_t prvTCPStatusAgeCheck( FreeRTOS_Socket_t * pxSocket )
{
BaseType_t xResult;
eIPTCPState_t eState = ipNUMERIC_CAST( eIPTCPState_t, pxSocket->u.xTCP.ucTCPState );
switch( eState )
{
case eESTABLISHED:
/* If the 'ipconfigTCP_KEEP_ALIVE' option is enabled, sockets in
* state ESTABLISHED can be protected using keep-alive messages. */
xResult = pdFALSE;
break;
case eCLOSED:
case eTCP_LISTEN:
case eCLOSE_WAIT:
/* These 3 states may last for ever, up to the owner. */
xResult = pdFALSE;
break;
case eCONNECT_SYN:
case eSYN_FIRST:
case eSYN_RECEIVED:
case eFIN_WAIT_1:
case eFIN_WAIT_2:
case eCLOSING:
case eLAST_ACK:
case eTIME_WAIT:
default:
/* All other (non-connected) states will get anti-hanging
* protection. */
xResult = pdTRUE;
break;
}
if( xResult != pdFALSE )
{
/* How much time has past since the last active moment which is
* defined as A) a state change or B) a packet has arrived. */
TickType_t xAge = xTaskGetTickCount() - pxSocket->u.xTCP.xLastActTime;
/* ipconfigTCP_HANG_PROTECTION_TIME is in units of seconds. */
if( xAge > ( ( TickType_t ) ipconfigTCP_HANG_PROTECTION_TIME * ( TickType_t ) configTICK_RATE_HZ ) )
{
#if ( ipconfigHAS_DEBUG_PRINTF == 1 )
{
FreeRTOS_debug_printf( ( "Inactive socket closed: port %u rem %lxip:%u status %s\n",
pxSocket->usLocalPort,
pxSocket->u.xTCP.ulRemoteIP,
pxSocket->u.xTCP.usRemotePort,
FreeRTOS_GetTCPStateName( ( UBaseType_t ) pxSocket->u.xTCP.ucTCPState ) ) );
}
#endif /* ipconfigHAS_DEBUG_PRINTF */
/* Move to eCLOSE_WAIT, user may close the socket. */
vTCPStateChange( pxSocket, eCLOSE_WAIT );
/* When 'bPassQueued' true, this socket is an orphan until it
* gets connected. */
if( pxSocket->u.xTCP.bits.bPassQueued != pdFALSE_UNSIGNED )
{
/* vTCPStateChange() has called FreeRTOS_closesocket()
* in case the socket is not yet owned by the application.
* Return a negative value to inform the caller that
* the socket will be closed in the next cycle. */
xResult = -1;
}
}
}
return xResult;
}
/*-----------------------------------------------------------*/
#endif /* if ( ipconfigTCP_HANG_PROTECTION == 1 ) */
/**
* @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.ucTCPState >= ( uint8_t ) 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.ucTCPState != ( uint8_t ) eCLOSED )
{
if( ( xTCPWindowLoggingLevel > 1 ) && ipconfigTCP_MAY_LOG_PORT( pxSocket->usLocalPort ) )
{
FreeRTOS_debug_printf( ( "Send[%u->%u] del ACK %lu SEQ %lu (len %u)\n",
pxSocket->usLocalPort,
pxSocket->u.xTCP.usRemotePort,
pxSocket->u.xTCP.xTCPWindow.rx.ulCurrentSequenceNumber - pxSocket->u.xTCP.xTCPWindow.rx.ulFirstSequenceNumber,
pxSocket->u.xTCP.xTCPWindow.ulOurSequenceNumber - pxSocket->u.xTCP.xTCPWindow.tx.ulFirstSequenceNumber,
( unsigned ) ipSIZE_OF_IPv4_HEADER + ipSIZE_OF_TCP_HEADER ) );
}
prvTCPReturnPacket( pxSocket, pxSocket->u.xTCP.pxAckMessage, ipSIZE_OF_IPv4_HEADER + 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.ucTCPState >= ( uint8_t ) eESTABLISHED ) ||
( pxSocket->u.xTCP.ucTCPState == ( uint8_t ) 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 prvTCPSendPacket() will be called when the socket time-out has been reached.
*
* @param[in] pxSocket: The socket owning the connection.
*
* @return Number of bytes to be sent.
*
* @note It is only called by xTCPSocketCheck().
*/
static int32_t prvTCPSendPacket( FreeRTOS_Socket_t * pxSocket )
{
int32_t lResult = 0;
UBaseType_t uxOptionsLength, uxIntermediateResult = 0;
NetworkBufferDescriptor_t * pxNetworkBuffer;
if( pxSocket->u.xTCP.ucTCPState != ( uint8_t ) eCONNECT_SYN )
{
/* The connection is in a state other than SYN. */
pxNetworkBuffer = NULL;
/* prvTCPSendRepeated() will only create a network buffer if necessary,
* i.e. when data must be sent to the peer. */
lResult = prvTCPSendRepeated( pxSocket, &pxNetworkBuffer );
if( pxNetworkBuffer != NULL )
{
vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );
}
}
else
{
if( pxSocket->u.xTCP.ucRepCount >= 3U )
{
/* The connection is in the SYN status. The packet will be repeated
* to most 3 times. When there is no response, the socket get the
* status 'eCLOSE_WAIT'. */
FreeRTOS_debug_printf( ( "Connect: giving up %lxip:%u\n",
pxSocket->u.xTCP.ulRemoteIP, /* IP address of remote machine. */
pxSocket->u.xTCP.usRemotePort ) ); /* Port on remote machine. */
vTCPStateChange( pxSocket, eCLOSE_WAIT );
}
else if( ( pxSocket->u.xTCP.bits.bConnPrepared != pdFALSE_UNSIGNED ) || ( prvTCPPrepareConnect( pxSocket ) == pdTRUE ) )
{
ProtocolHeaders_t * pxProtocolHeaders;
const UBaseType_t uxHeaderSize = ipSIZE_OF_IPv4_HEADER;
/* Or else, if the connection has been prepared, or can be prepared
* now, proceed to send the packet with the SYN flag.
* prvTCPPrepareConnect() prepares 'xPacket' and returns pdTRUE if
* the Ethernet address of the peer or the gateway is found. */
pxProtocolHeaders = ipCAST_PTR_TO_TYPE_PTR( ProtocolHeaders_t, &( pxSocket->u.xTCP.xPacket.u.ucLastPacket[ ipSIZE_OF_ETH_HEADER + uxHeaderSize ] ) );
/* About to send a SYN packet. Call prvSetSynAckOptions() to set
* the proper options: The size of MSS and whether SACK's are
* allowed. */
uxOptionsLength = prvSetSynAckOptions( pxSocket, &( pxProtocolHeaders->xTCPHeader ) );
/* Return the number of bytes to be sent. */
uxIntermediateResult = uxIPHeaderSizeSocket( pxSocket ) + ipSIZE_OF_TCP_HEADER + uxOptionsLength;
lResult = ( int32_t ) uxIntermediateResult;
/* Set the TCP offset field: ipSIZE_OF_TCP_HEADER equals 20 and
* uxOptionsLength is always a multiple of 4. The complete expression
* would be:
* ucTCPOffset = ( ( ipSIZE_OF_TCP_HEADER + uxOptionsLength ) / 4 ) << 4 */
pxProtocolHeaders->xTCPHeader.ucTCPOffset = ( uint8_t ) ( ( ipSIZE_OF_TCP_HEADER + uxOptionsLength ) << 2 );
/* Repeat Count is used for a connecting socket, to limit the number
* of tries. */
pxSocket->u.xTCP.ucRepCount++;
/* Send the SYN message to make a connection. The messages is
* stored in the socket field 'xPacket'. It will be wrapped in a
* pseudo network buffer descriptor before it will be sent. */
prvTCPReturnPacket( pxSocket, NULL, ( uint32_t ) lResult, pdFALSE );
}
else
{
/* Nothing to do. */
}
}
/* Return the total number of bytes sent. */
return lResult;
}
/*-----------------------------------------------------------*/
/**
* @brief prvTCPSendRepeated will try to send a series of messages, as
* long as there is data to be sent and as long as the transmit
* window isn't full.
*
* @param[in] pxSocket: The socket owning the connection.
* @param[in,out] ppxNetworkBuffer: Pointer to pointer to the network buffer.
*
* @return Total number of bytes sent.
*/
static int32_t prvTCPSendRepeated( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t ** ppxNetworkBuffer )
{
UBaseType_t uxIndex;
int32_t lResult = 0;
UBaseType_t uxOptionsLength = 0U;
int32_t xSendLength;
for( uxIndex = 0U; uxIndex < ( UBaseType_t ) SEND_REPEATED_COUNT; uxIndex++ )
{
/* prvTCPPrepareSend() might allocate a network buffer if there is data
* to be sent. */
xSendLength = prvTCPPrepareSend( pxSocket, ppxNetworkBuffer, uxOptionsLength );
if( xSendLength <= 0 )
{
break;
}
/* And return the packet to the peer. */
prvTCPReturnPacket( pxSocket, *ppxNetworkBuffer, ( uint32_t ) xSendLength, ipconfigZERO_COPY_TX_DRIVER );
#if ( ipconfigZERO_COPY_TX_DRIVER != 0 )
{
*ppxNetworkBuffer = NULL;
}
#endif /* ipconfigZERO_COPY_TX_DRIVER */
lResult += xSendLength;
}
/* Return the total number of bytes sent. */
return lResult;
}
/*-----------------------------------------------------------*/
/**
* @brief Return (or send) a packet to the peer. The data is stored in pxBuffer,
* which may either point to a real network buffer or to a TCP socket field
* called 'xTCP.xPacket'. A temporary xNetworkBuffer will be used to pass
* the data to the NIC.
*
* @param[in] pxSocket: The socket owning the connection.
* @param[in] pxDescriptor: The network buffer descriptor carrying the packet.
* @param[in] ulLen: Length of the packet being sent.
* @param[in] xReleaseAfterSend: pdTRUE if the ownership of the descriptor is
* transferred to the network interface.
*/
static void prvTCPReturnPacket( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t * pxDescriptor,
uint32_t ulLen,
BaseType_t xReleaseAfterSend )
{
TCPPacket_t * pxTCPPacket;
IPHeader_t * pxIPHeader;
BaseType_t xDoRelease = xReleaseAfterSend;
EthernetHeader_t * pxEthernetHeader;
uint32_t ulFrontSpace, ulSpace, ulSourceAddress, ulWinSize;
const TCPWindow_t * pxTCPWindow;
NetworkBufferDescriptor_t * pxNetworkBuffer = pxDescriptor;
NetworkBufferDescriptor_t xTempBuffer;
/* memcpy() helper variables for MISRA Rule 21.15 compliance*/
const void * pvCopySource;
void * pvCopyDest;
/* For sending, a pseudo network buffer will be used, as explained above. */
if( pxNetworkBuffer == NULL )
{
pxNetworkBuffer = &xTempBuffer;
#if ( ipconfigUSE_LINKED_RX_MESSAGES != 0 )
{
pxNetworkBuffer->pxNextBuffer = NULL;
}
#endif
pxNetworkBuffer->pucEthernetBuffer = pxSocket->u.xTCP.xPacket.u.ucLastPacket;
pxNetworkBuffer->xDataLength = sizeof( pxSocket->u.xTCP.xPacket.u.ucLastPacket );
xDoRelease = pdFALSE;
}
#if ( ipconfigZERO_COPY_TX_DRIVER != 0 )
{
if( xDoRelease == pdFALSE )
{
pxNetworkBuffer = pxDuplicateNetworkBufferWithDescriptor( pxNetworkBuffer, ( size_t ) pxNetworkBuffer->xDataLength );
if( pxNetworkBuffer == NULL )
{
FreeRTOS_debug_printf( ( "prvTCPReturnPacket: duplicate failed\n" ) );
}
xDoRelease = pdTRUE;
}
}
#endif /* ipconfigZERO_COPY_TX_DRIVER */
#ifndef __COVERITY__
if( pxNetworkBuffer != NULL )
#endif
{
/* Map the ethernet buffer onto a TCPPacket_t struct for easy access to the fields. */
pxTCPPacket = ipCAST_PTR_TO_TYPE_PTR( TCPPacket_t, pxNetworkBuffer->pucEthernetBuffer );
pxIPHeader = &pxTCPPacket->xIPHeader;
pxEthernetHeader = &pxTCPPacket->xEthernetHeader;
/* Fill the packet, using hton translations. */
if( pxSocket != NULL )
{
/* Calculate the space in the RX buffer in order to advertise the
* size of this socket's reception window. */
pxTCPWindow = &( pxSocket->u.xTCP.xTCPWindow );
if( pxSocket->u.xTCP.rxStream != NULL )
{
/* An RX stream was created already, see how much space is
* available. */
ulFrontSpace = ( uint32_t ) uxStreamBufferFrontSpace( pxSocket->u.xTCP.rxStream );
}
else
{
/* No RX stream has been created, the full stream size is
* available. */
ulFrontSpace = ( uint32_t ) pxSocket->u.xTCP.uxRxStreamSize;
}
/* Take the minimum of the RX buffer space and the RX window size. */
ulSpace = FreeRTOS_min_uint32( pxTCPWindow->xSize.ulRxWindowLength, ulFrontSpace );
if( ( pxSocket->u.xTCP.bits.bLowWater != pdFALSE_UNSIGNED ) || ( pxSocket->u.xTCP.bits.bRxStopped != pdFALSE_UNSIGNED ) )
{
/* The low-water mark was reached, meaning there was little
* space left. The socket will wait until the application has read
* or flushed the incoming data, and 'zero-window' will be
* advertised. */
ulSpace = 0U;
}
/* If possible, advertise an RX window size of at least 1 MSS, otherwise
* the peer might start 'zero window probing', i.e. sending small packets
* (1, 2, 4, 8... bytes). */
if( ( ulSpace < pxSocket->u.xTCP.usCurMSS ) && ( ulFrontSpace >= pxSocket->u.xTCP.usCurMSS ) )
{
ulSpace = pxSocket->u.xTCP.usCurMSS;
}
/* Avoid overflow of the 16-bit win field. */
#if ( ipconfigUSE_TCP_WIN != 0 )
{
ulWinSize = ( ulSpace >> pxSocket->u.xTCP.ucMyWinScaleFactor );
}
#else
{
ulWinSize = ulSpace;
}
#endif
if( ulWinSize > 0xfffcUL )
{
ulWinSize = 0xfffcUL;
}
pxTCPPacket->xTCPHeader.usWindow = FreeRTOS_htons( ( uint16_t ) ulWinSize );
/* The new window size has been advertised, switch off the flag. */
pxSocket->u.xTCP.bits.bWinChange = pdFALSE_UNSIGNED;
/* Later on, when deciding to delay an ACK, a precise estimate is needed
* of the free RX space. At this moment, 'ulHighestRxAllowed' would be the
* highest sequence number minus 1 that the socket will accept. */
pxSocket->u.xTCP.ulHighestRxAllowed = pxTCPWindow->rx.ulCurrentSequenceNumber + ulSpace;
#if ( ipconfigTCP_KEEP_ALIVE == 1 )
if( pxSocket->u.xTCP.bits.bSendKeepAlive != pdFALSE_UNSIGNED )
{
/* Sending a keep-alive packet, send the current sequence number
* minus 1, which will be recognised as a keep-alive packet and
* responded to by acknowledging the last byte. */
pxSocket->u.xTCP.bits.bSendKeepAlive = pdFALSE_UNSIGNED;
pxSocket->u.xTCP.bits.bWaitKeepAlive = pdTRUE_UNSIGNED;
pxTCPPacket->xTCPHeader.ulSequenceNumber = pxSocket->u.xTCP.xTCPWindow.ulOurSequenceNumber - 1UL;
pxTCPPacket->xTCPHeader.ulSequenceNumber = FreeRTOS_htonl( pxTCPPacket->xTCPHeader.ulSequenceNumber );
}
else
#endif /* if ( ipconfigTCP_KEEP_ALIVE == 1 ) */
{
pxTCPPacket->xTCPHeader.ulSequenceNumber = FreeRTOS_htonl( pxSocket->u.xTCP.xTCPWindow.ulOurSequenceNumber );
if( ( pxTCPPacket->xTCPHeader.ucTCPFlags & ( uint8_t ) tcpTCP_FLAG_FIN ) != 0U )
{
/* Suppress FIN in case this packet carries earlier data to be
* retransmitted. */
uint32_t ulDataLen = ( uint32_t ) ( ulLen - ( ipSIZE_OF_TCP_HEADER + ipSIZE_OF_IPv4_HEADER ) );
if( ( pxTCPWindow->ulOurSequenceNumber + ulDataLen ) != pxTCPWindow->tx.ulFINSequenceNumber )
{
pxTCPPacket->xTCPHeader.ucTCPFlags &= ( ( uint8_t ) ~tcpTCP_FLAG_FIN );
FreeRTOS_debug_printf( ( "Suppress FIN for %lu + %lu < %lu\n",
pxTCPWindow->ulOurSequenceNumber - pxTCPWindow->tx.ulFirstSequenceNumber,
ulDataLen,
pxTCPWindow->tx.ulFINSequenceNumber - pxTCPWindow->tx.ulFirstSequenceNumber ) );
}
}
}
/* Tell which sequence number is expected next time */
pxTCPPacket->xTCPHeader.ulAckNr = FreeRTOS_htonl( pxTCPWindow->rx.ulCurrentSequenceNumber );
}
else
{
/* Sending data without a socket, probably replying with a RST flag
* Just swap the two sequence numbers. */
vFlip_32( pxTCPPacket->xTCPHeader.ulSequenceNumber, pxTCPPacket->xTCPHeader.ulAckNr );
}
pxIPHeader->ucTimeToLive = ( uint8_t ) ipconfigTCP_TIME_TO_LIVE;
pxIPHeader->usLength = FreeRTOS_htons( ulLen );
if( ( pxSocket == NULL ) || ( *ipLOCAL_IP_ADDRESS_POINTER == 0UL ) )
{
/* When pxSocket is NULL, this function is called by prvTCPSendReset()
* and the IP-addresses must be swapped.
* Also swap the IP-addresses in case the IP-tack doesn't have an
* IP-address yet, i.e. when ( *ipLOCAL_IP_ADDRESS_POINTER == 0UL ). */
ulSourceAddress = pxIPHeader->ulDestinationIPAddress;
}
else
{
ulSourceAddress = *ipLOCAL_IP_ADDRESS_POINTER;
}
pxIPHeader->ulDestinationIPAddress = pxIPHeader->ulSourceIPAddress;
pxIPHeader->ulSourceIPAddress = ulSourceAddress;
vFlip_16( pxTCPPacket->xTCPHeader.usSourcePort, pxTCPPacket->xTCPHeader.usDestinationPort );
/* Just an increasing number. */
pxIPHeader->usIdentification = FreeRTOS_htons( usPacketIdentifier );
usPacketIdentifier++;
pxIPHeader->usFragmentOffset = 0U;
/* Important: tell NIC driver how many bytes must be sent. */
pxNetworkBuffer->xDataLength = ulLen + ipSIZE_OF_ETH_HEADER;
#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 );
/* calculate the TCP checksum for an outgoing packet. */
( void ) usGenerateProtocolChecksum( ( uint8_t * ) pxTCPPacket, pxNetworkBuffer->xDataLength, pdTRUE );
/* A calculated checksum of 0 must be inverted as 0 means the checksum
* is disabled. */
if( pxTCPPacket->xTCPHeader.usChecksum == 0U )
{
pxTCPPacket->xTCPHeader.usChecksum = 0xffffU;
}
}
#endif /* if ( ipconfigDRIVER_INCLUDED_TX_IP_CHECKSUM == 0 ) */
#if ( ipconfigUSE_LINKED_RX_MESSAGES != 0 )
{
pxNetworkBuffer->pxNextBuffer = NULL;
}
#endif
/* Fill in the destination MAC addresses. */
( void ) memcpy( ( void * ) ( &( pxEthernetHeader->xDestinationAddress ) ),
( const void * ) ( &( pxEthernetHeader->xSourceAddress ) ),
sizeof( pxEthernetHeader->xDestinationAddress ) );
/*
* Use helper variables for memcpy() to remain
* compliant with MISRA Rule 21.15. These should be
* optimized away.
*/
/* The source MAC addresses is fixed to 'ipLOCAL_MAC_ADDRESS'. */
pvCopySource = ipLOCAL_MAC_ADDRESS;
pvCopyDest = &pxEthernetHeader->xSourceAddress;
( void ) memcpy( pvCopyDest, pvCopySource, ( size_t ) ipMAC_ADDRESS_LENGTH_BYTES );
#if defined( ipconfigETHERNET_MINIMUM_PACKET_BYTES )
{
if( pxNetworkBuffer->xDataLength < ( size_t ) ipconfigETHERNET_MINIMUM_PACKET_BYTES )
{
BaseType_t xIndex;
for( xIndex = ( BaseType_t ) pxNetworkBuffer->xDataLength; xIndex < ( BaseType_t ) ipconfigETHERNET_MINIMUM_PACKET_BYTES; xIndex++ )
{
pxNetworkBuffer->pucEthernetBuffer[ xIndex ] = 0U;
}
pxNetworkBuffer->xDataLength = ( size_t ) ipconfigETHERNET_MINIMUM_PACKET_BYTES;
}
}
#endif /* if defined( ipconfigETHERNET_MINIMUM_PACKET_BYTES ) */
/* Send! */
iptraceNETWORK_INTERFACE_OUTPUT( pxNetworkBuffer->xDataLength, pxNetworkBuffer->pucEthernetBuffer );
( void ) xNetworkInterfaceOutput( pxNetworkBuffer, xDoRelease );
if( xDoRelease == pdFALSE )
{
/* Swap-back some fields, as pxBuffer probably points to a socket field
* containing the packet header. */
vFlip_16( pxTCPPacket->xTCPHeader.usSourcePort, pxTCPPacket->xTCPHeader.usDestinationPort );
pxTCPPacket->xIPHeader.ulSourceIPAddress = pxTCPPacket->xIPHeader.ulDestinationIPAddress;
( void ) memcpy( ( void * ) ( pxEthernetHeader->xSourceAddress.ucBytes ), ( const void * ) ( pxEthernetHeader->xDestinationAddress.ucBytes ), ( size_t ) ipMAC_ADDRESS_LENGTH_BYTES );
}
else
{
/* Nothing to do: the buffer has been passed to DMA and will be released after use */
}
} /* if( pxNetworkBuffer != NULL ) */
}
/*-----------------------------------------------------------*/
/**
* @brief Create the TCP window for the given socket.
*
* @param[in] pxSocket: The socket for which the window is being created.
*
* @note The SYN event is very important: the sequence numbers, which have a kind of
* random starting value, are being synchronized. The sliding window manager
* (in FreeRTOS_TCP_WIN.c) needs to know them, along with the Maximum Segment
* Size (MSS).
*/
static void prvTCPCreateWindow( FreeRTOS_Socket_t * pxSocket )
{
if( xTCPWindowLoggingLevel != 0 )
{
FreeRTOS_debug_printf( ( "Limits (using): TCP Win size %u Water %u <= %u <= %u\n",
( unsigned ) pxSocket->u.xTCP.uxRxWinSize * ipconfigTCP_MSS,
( unsigned ) pxSocket->u.xTCP.uxLittleSpace,
( unsigned ) pxSocket->u.xTCP.uxEnoughSpace,
( unsigned ) pxSocket->u.xTCP.uxRxStreamSize ) );
}
vTCPWindowCreate(
&pxSocket->u.xTCP.xTCPWindow,
ipconfigTCP_MSS * pxSocket->u.xTCP.uxRxWinSize,
ipconfigTCP_MSS * pxSocket->u.xTCP.uxTxWinSize,
pxSocket->u.xTCP.xTCPWindow.rx.ulCurrentSequenceNumber,
pxSocket->u.xTCP.xTCPWindow.ulOurSequenceNumber,
( uint32_t ) pxSocket->u.xTCP.usInitMSS );
}
/*-----------------------------------------------------------*/
/**
* @brief Let ARP look-up the MAC-address of the peer and initialise the first SYN
* packet.
*
* @param[in] pxSocket: The socket owning the TCP connection. The first packet shall
* be created in this socket.
*
* @return pdTRUE: if the packet was successfully created and the first SYN can be sent.
* Else pdFALSE.
*
* @note Connecting sockets have a special state: eCONNECT_SYN. In this phase,
* the Ethernet address of the target will be found using ARP. In case the
* target IP address is not within the netmask, the hardware address of the
* gateway will be used.
*/
static BaseType_t prvTCPPrepareConnect( FreeRTOS_Socket_t * pxSocket )
{
TCPPacket_t * pxTCPPacket;
IPHeader_t * pxIPHeader;
eARPLookupResult_t eReturned;
uint32_t ulRemoteIP;
MACAddress_t xEthAddress;
BaseType_t xReturn = pdTRUE;
uint32_t ulInitialSequenceNumber = 0;
#if ( ipconfigHAS_PRINTF != 0 )
{
/* Only necessary for nicer logging. */
( void ) memset( xEthAddress.ucBytes, 0, sizeof( xEthAddress.ucBytes ) );
}
#endif /* ipconfigHAS_PRINTF != 0 */
ulRemoteIP = FreeRTOS_htonl( pxSocket->u.xTCP.ulRemoteIP );
/* Determine the ARP cache status for the requested IP address. */
eReturned = eARPGetCacheEntry( &( ulRemoteIP ), &( xEthAddress ) );
switch( eReturned )
{
case eARPCacheHit: /* An ARP table lookup found a valid entry. */
break; /* We can now prepare the SYN packet. */
case eARPCacheMiss: /* An ARP table lookup did not find a valid entry. */
case eCantSendPacket: /* There is no IP address, or an ARP is still in progress. */
default:
/* Count the number of times it could not find the ARP address. */
pxSocket->u.xTCP.ucRepCount++;
FreeRTOS_debug_printf( ( "ARP for %lxip (using %lxip): rc=%d %02X:%02X:%02X %02X:%02X:%02X\n",
pxSocket->u.xTCP.ulRemoteIP,
FreeRTOS_htonl( ulRemoteIP ),
eReturned,
xEthAddress.ucBytes[ 0 ],
xEthAddress.ucBytes[ 1 ],
xEthAddress.ucBytes[ 2 ],
xEthAddress.ucBytes[ 3 ],
xEthAddress.ucBytes[ 4 ],
xEthAddress.ucBytes[ 5 ] ) );
/* And issue a (new) ARP request */
FreeRTOS_OutputARPRequest( ulRemoteIP );
xReturn = pdFALSE;
break;
}
if( xReturn != pdFALSE )
{
/* Get a difficult-to-predict initial sequence number for this 4-tuple. */
ulInitialSequenceNumber = ulApplicationGetNextSequenceNumber( *ipLOCAL_IP_ADDRESS_POINTER,
pxSocket->usLocalPort,
pxSocket->u.xTCP.ulRemoteIP,
pxSocket->u.xTCP.usRemotePort );
/* Check for a random number generation error. */
if( ulInitialSequenceNumber == 0UL )
{
xReturn = pdFALSE;
}
}
if( xReturn != pdFALSE )
{
uint16_t usLength;
/* The MAC-address of the peer (or gateway) has been found,
* now prepare the initial TCP packet and some fields in the socket. Map
* the buffer onto the TCPPacket_t struct to easily access it's field. */
pxTCPPacket = ipCAST_PTR_TO_TYPE_PTR( TCPPacket_t, pxSocket->u.xTCP.xPacket.u.ucLastPacket );
pxIPHeader = &pxTCPPacket->xIPHeader;
/* reset the retry counter to zero. */
pxSocket->u.xTCP.ucRepCount = 0U;
/* And remember that the connect/SYN data are prepared. */
pxSocket->u.xTCP.bits.bConnPrepared = pdTRUE_UNSIGNED;
/* Now that the Ethernet address is known, the initial packet can be
* prepared. */
( void ) memset( pxSocket->u.xTCP.xPacket.u.ucLastPacket, 0, sizeof( pxSocket->u.xTCP.xPacket.u.ucLastPacket ) );
/* Write the Ethernet address in Source, because it will be swapped by
* prvTCPReturnPacket(). */
( void ) memcpy( ( void * ) ( &pxTCPPacket->xEthernetHeader.xSourceAddress ), ( const void * ) ( &xEthAddress ), sizeof( xEthAddress ) );
/* 'ipIPv4_FRAME_TYPE' is already in network-byte-order. */
pxTCPPacket->xEthernetHeader.usFrameType = ipIPv4_FRAME_TYPE;
pxIPHeader->ucVersionHeaderLength = 0x45U;
usLength = ( uint16_t ) ( sizeof( TCPPacket_t ) - sizeof( pxTCPPacket->xEthernetHeader ) );
pxIPHeader->usLength = FreeRTOS_htons( usLength );
pxIPHeader->ucTimeToLive = ( uint8_t ) ipconfigTCP_TIME_TO_LIVE;
pxIPHeader->ucProtocol = ( uint8_t ) ipPROTOCOL_TCP;
/* Addresses and ports will be stored swapped because prvTCPReturnPacket
* will swap them back while replying. */
pxIPHeader->ulDestinationIPAddress = *ipLOCAL_IP_ADDRESS_POINTER;
pxIPHeader->ulSourceIPAddress = FreeRTOS_htonl( pxSocket->u.xTCP.ulRemoteIP );
pxTCPPacket->xTCPHeader.usSourcePort = FreeRTOS_htons( pxSocket->u.xTCP.usRemotePort );
pxTCPPacket->xTCPHeader.usDestinationPort = FreeRTOS_htons( pxSocket->usLocalPort );
/* We are actively connecting, so the peer's Initial Sequence Number (ISN)
* isn't known yet. */
pxSocket->u.xTCP.xTCPWindow.rx.ulCurrentSequenceNumber = 0UL;
/* Start with ISN (Initial Sequence Number). */
pxSocket->u.xTCP.xTCPWindow.ulOurSequenceNumber = ulInitialSequenceNumber;
/* The TCP header size is 20 bytes, divided by 4 equals 5, which is put in
* the high nibble of the TCP offset field. */
pxTCPPacket->xTCPHeader.ucTCPOffset = 0x50U;
/* Only set the SYN flag. */
pxTCPPacket->xTCPHeader.ucTCPFlags = tcpTCP_FLAG_SYN;
/* Set the values of usInitMSS / usCurMSS for this socket. */
prvSocketSetMSS( pxSocket );
/* The initial sequence numbers at our side are known. Later
* vTCPWindowInit() will be called to fill in the peer's sequence numbers, but
* first wait for a SYN+ACK reply. */
prvTCPCreateWindow( pxSocket );
}
return xReturn;
}
/*-----------------------------------------------------------*/
/* For logging and debugging: make a string showing the TCP flags
*/
#if ( ipconfigHAS_DEBUG_PRINTF != 0 )
/**
* @brief Print out the value of flags in a human readable manner.
*
* @param[in] xFlags: The TCP flags.
*
* @return The string containing the flags.
*/
static const char * prvTCPFlagMeaning( UBaseType_t xFlags )
{
static char retString[ 10 ];
size_t uxFlags = ( size_t ) xFlags;
( void ) snprintf( retString,
sizeof( retString ), "%c%c%c%c%c%c%c%c",
( ( uxFlags & ( size_t ) tcpTCP_FLAG_FIN ) != 0 ) ? 'F' : '.', /* 0x0001: No more data from sender */
( ( uxFlags & ( size_t ) tcpTCP_FLAG_SYN ) != 0 ) ? 'S' : '.', /* 0x0002: Synchronize sequence numbers */
( ( uxFlags & ( size_t ) tcpTCP_FLAG_RST ) != 0 ) ? 'R' : '.', /* 0x0004: Reset the connection */
( ( uxFlags & ( size_t ) tcpTCP_FLAG_PSH ) != 0 ) ? 'P' : '.', /* 0x0008: Push function: please push buffered data to the recv application */
( ( uxFlags & ( size_t ) tcpTCP_FLAG_ACK ) != 0 ) ? 'A' : '.', /* 0x0010: Acknowledgment field is significant */
( ( uxFlags & ( size_t ) tcpTCP_FLAG_URG ) != 0 ) ? 'U' : '.', /* 0x0020: Urgent pointer field is significant */
( ( uxFlags & ( size_t ) tcpTCP_FLAG_ECN ) != 0 ) ? 'E' : '.', /* 0x0040: ECN-Echo */
( ( uxFlags & ( size_t ) tcpTCP_FLAG_CWR ) != 0 ) ? 'C' : '.' ); /* 0x0080: Congestion Window Reduced */
return retString;
}
/*-----------------------------------------------------------*/
#endif /* ipconfigHAS_DEBUG_PRINTF */
/**
* @brief Parse the TCP option(s) received, if present.
*
* @param[in] pxSocket: The socket handling the connection.
* @param[in] pxNetworkBuffer: The network buffer containing the TCP
* packet.
*
* @note It has already been verified that:
* ((pxTCPHeader->ucTCPOffset & 0xf0) > 0x50), meaning that
* the TP header is longer than the usual 20 (5 x 4) bytes.
*/
_static void prvCheckOptions( FreeRTOS_Socket_t * pxSocket,
const NetworkBufferDescriptor_t * pxNetworkBuffer )
{
size_t uxTCPHeaderOffset = ipSIZE_OF_ETH_HEADER + xIPHeaderSize( pxNetworkBuffer );
const ProtocolHeaders_t * pxProtocolHeaders = ipCAST_PTR_TO_TYPE_PTR( ProtocolHeaders_t,
&( pxNetworkBuffer->pucEthernetBuffer[ uxTCPHeaderOffset ] ) );
const TCPHeader_t * pxTCPHeader;
const uint8_t * pucPtr;
BaseType_t xHasSYNFlag;
/* Offset in the network packet where the first option byte is stored. */
size_t uxOptionOffset = uxTCPHeaderOffset + ( sizeof( TCPHeader_t ) - sizeof( pxTCPHeader->ucOptdata ) );
size_t uxOptionsLength;
size_t uxResult;
uint8_t ucLength;
pxTCPHeader = &( pxProtocolHeaders->xTCPHeader );
/* A character pointer to iterate through the option data */
pucPtr = pxTCPHeader->ucOptdata;
if( pxTCPHeader->ucTCPOffset <= ( 5U << 4U ) )
{
/* Avoid integer underflow in computation of ucLength. */
}
else
{
ucLength = ( ( ( pxTCPHeader->ucTCPOffset >> 4U ) - 5U ) << 2U );
uxOptionsLength = ( size_t ) ucLength;
if( pxNetworkBuffer->xDataLength > uxOptionOffset )
{
/* Validate options size calculation. */
if( ( pxNetworkBuffer->xDataLength > uxOptionOffset ) &&
( uxOptionsLength <= ( pxNetworkBuffer->xDataLength - uxOptionOffset ) ) )
{
if( ( pxTCPHeader->ucTCPFlags & tcpTCP_FLAG_SYN ) != ( uint8_t ) 0U )
{
xHasSYNFlag = pdTRUE;
}
else
{
xHasSYNFlag = pdFALSE;
}
/* The length check is only necessary in case the option data are
* corrupted, we don't like to run into invalid memory and crash. */
for( ; ; )
{
if( uxOptionsLength == 0U )
{
/* coverity[break_stmt] : Break statement terminating the loop */
break;
}
uxResult = prvSingleStepTCPHeaderOptions( pucPtr, uxOptionsLength, pxSocket, xHasSYNFlag );
if( uxResult == 0UL )
{
break;
}
uxOptionsLength -= uxResult;
pucPtr = &( pucPtr[ uxResult ] );
}
}
}
}
}
/*-----------------------------------------------------------*/
/**
* @brief Identify and deal with a single TCP header option, advancing the pointer to
* the header.
*
* @param[in] pucPtr: Pointer to the TCP packet options.
* @param[in] uxTotalLength: Length of the TCP packet options.
* @param[in] pxSocket: Socket handling the connection.
* @param[in] xHasSYNFlag: Whether the header has SYN flag or not.
*
* @return This function returns pdTRUE or pdFALSE depending on whether the caller
* should continue to parse more header options or break the loop.
*/
_static size_t prvSingleStepTCPHeaderOptions( const uint8_t * const pucPtr,
size_t uxTotalLength,
FreeRTOS_Socket_t * const pxSocket,
BaseType_t xHasSYNFlag )
{
UBaseType_t uxNewMSS;
size_t uxRemainingOptionsBytes = uxTotalLength;
uint8_t ucLen;
size_t uxIndex;
TCPWindow_t * pxTCPWindow = &( pxSocket->u.xTCP.xTCPWindow );
BaseType_t xReturn = pdFALSE;
if( pucPtr[ 0U ] == tcpTCP_OPT_END )
{
/* End of options. */
uxIndex = 0U;
}
else if( pucPtr[ 0U ] == tcpTCP_OPT_NOOP )
{
/* NOP option, inserted to make the length a multiple of 4. */
uxIndex = 1U;
}
else if( uxRemainingOptionsBytes < 2U )
{
/* Any other well-formed option must be at least two bytes: the option
* type byte followed by a length byte. */
uxIndex = 0U;
}
#if ( ipconfigUSE_TCP_WIN != 0 )
else if( pucPtr[ 0 ] == tcpTCP_OPT_WSOPT )
{
/* The TCP Window Scale Option. */
/* Confirm that the option fits in the remaining buffer space. */
if( ( uxRemainingOptionsBytes < tcpTCP_OPT_WSOPT_LEN ) || ( pucPtr[ 1 ] != tcpTCP_OPT_WSOPT_LEN ) )
{
uxIndex = 0U;
}
else
{
/* Option is only valid in SYN phase. */
if( xHasSYNFlag != 0 )
{
pxSocket->u.xTCP.ucPeerWinScaleFactor = pucPtr[ 2 ];
pxSocket->u.xTCP.bits.bWinScaling = pdTRUE_UNSIGNED;
}
uxIndex = tcpTCP_OPT_WSOPT_LEN;
}
}
#endif /* ipconfigUSE_TCP_WIN */
else if( pucPtr[ 0 ] == tcpTCP_OPT_MSS )
{
/* Confirm that the option fits in the remaining buffer space. */
if( ( uxRemainingOptionsBytes < tcpTCP_OPT_MSS_LEN ) || ( pucPtr[ 1 ] != tcpTCP_OPT_MSS_LEN ) )
{
uxIndex = 0U;
}
else
{
/* An MSS option with the correct option length. FreeRTOS_htons()
* is not needed here because usChar2u16() already returns a host
* endian number. */
uxNewMSS = usChar2u16( &( pucPtr[ 2 ] ) );
if( pxSocket->u.xTCP.usInitMSS != uxNewMSS )
{
/* Perform a basic check on the the new MSS. */
if( uxNewMSS == 0U )
{
uxIndex = 0U;
/* Return Condition found. */
xReturn = pdTRUE;
}
else
{
FreeRTOS_debug_printf( ( "MSS change %u -> %lu\n", pxSocket->u.xTCP.usInitMSS, uxNewMSS ) );
}
}
/* If a 'return' condition has not been found. */
if( xReturn == pdFALSE )
{
if( pxSocket->u.xTCP.usInitMSS > uxNewMSS )
{
/* our MSS was bigger than the MSS of the other party: adapt it. */
pxSocket->u.xTCP.bits.bMssChange = pdTRUE_UNSIGNED;
if( pxSocket->u.xTCP.usCurMSS > uxNewMSS )
{
/* The peer advertises a smaller MSS than this socket was
* using. Use that as well. */
FreeRTOS_debug_printf( ( "Change mss %d => %lu\n", pxSocket->u.xTCP.usCurMSS, uxNewMSS ) );
pxSocket->u.xTCP.usCurMSS = ( uint16_t ) uxNewMSS;
}
pxTCPWindow->xSize.ulRxWindowLength = ( ( uint32_t ) uxNewMSS ) * ( pxTCPWindow->xSize.ulRxWindowLength / ( ( uint32_t ) uxNewMSS ) );
pxTCPWindow->usMSSInit = ( uint16_t ) uxNewMSS;
pxTCPWindow->usMSS = ( uint16_t ) uxNewMSS;
pxSocket->u.xTCP.usInitMSS = ( uint16_t ) uxNewMSS;
pxSocket->u.xTCP.usCurMSS = ( uint16_t ) uxNewMSS;
}
uxIndex = tcpTCP_OPT_MSS_LEN;
}
}
}
else
{
/* All other options have a length field, so that we easily
* can skip past them. */
ucLen = pucPtr[ 1 ];
uxIndex = 0U;
if( ( ucLen < ( uint8_t ) 2U ) || ( uxRemainingOptionsBytes < ( size_t ) ucLen ) )
{
/* If the length field is too small or too big, the options are
* malformed, don't process them further.
*/
}
else
{
#if ( ipconfigUSE_TCP_WIN == 1 )
{
/* Selective ACK: the peer has received a packet but it is missing
* earlier packets. At least this packet does not need retransmission
* anymore. ulTCPWindowTxSack( ) takes care of this administration.
*/
if( pucPtr[ 0U ] == tcpTCP_OPT_SACK_A )
{
ucLen -= 2U;
uxIndex += 2U;
while( ucLen >= ( uint8_t ) 8U )
{
prvReadSackOption( pucPtr, uxIndex, pxSocket );
uxIndex += 8U;
ucLen -= 8U;
}
/* ucLen should be 0 by now. */
}
}
#endif /* ipconfigUSE_TCP_WIN == 1 */
uxIndex += ( size_t ) ucLen;
}
}
return uxIndex;
}
/*-----------------------------------------------------------*/
#if ( ipconfigUSE_TCP_WIN == 1 )
/**
* @brief Skip past TCP header options when doing Selective ACK, until there are no
* more options left.
*
* @param[in] pucPtr: Pointer to the TCP packet options.
* @param[in] uxIndex: Index of options in the TCP packet options.
* @param[in] pxSocket: Socket handling the TCP connection.
*/
_static void prvReadSackOption( const uint8_t * const pucPtr,
size_t uxIndex,
FreeRTOS_Socket_t * const pxSocket )
{
uint32_t ulFirst = ulChar2u32( &( pucPtr[ uxIndex ] ) );
uint32_t ulLast = ulChar2u32( &( pucPtr[ uxIndex + 4U ] ) );
uint32_t ulCount = ulTCPWindowTxSack( &( pxSocket->u.xTCP.xTCPWindow ), ulFirst, ulLast );
/* ulTCPWindowTxSack( ) returns the number of bytes which have been acked
* starting from the head position. Advance the tail pointer in txStream.
*/
if( ( pxSocket->u.xTCP.txStream != NULL ) && ( ulCount > 0U ) )
{
/* Just advancing the tail index, 'ulCount' bytes have been confirmed. */
( void ) uxStreamBufferGet( pxSocket->u.xTCP.txStream, 0, NULL, ( size_t ) ulCount, pdFALSE );
pxSocket->xEventBits |= ( EventBits_t ) eSOCKET_SEND;
#if ipconfigSUPPORT_SELECT_FUNCTION == 1
{
if( ( pxSocket->xSelectBits & ( EventBits_t ) eSELECT_WRITE ) != 0U )
{
/* The field 'xEventBits' is used to store regular socket events
* (at most 8), as well as 'select events', which will be left-shifted.
*/
pxSocket->xEventBits |= ( ( EventBits_t ) eSELECT_WRITE ) << SOCKET_EVENT_BIT_COUNT;
}
}
#endif
/* In case the socket owner has installed an OnSent handler,
* call it now. */
#if ( ipconfigUSE_CALLBACKS == 1 )
{
if( ipconfigIS_VALID_PROG_ADDRESS( pxSocket->u.xTCP.pxHandleSent ) )
{
pxSocket->u.xTCP.pxHandleSent( pxSocket, ulCount );
}
}
#endif /* ipconfigUSE_CALLBACKS == 1 */
}
}
#endif /* ( ipconfigUSE_TCP_WIN != 0 ) */
/*-----------------------------------------------------------*/
#if ( ipconfigUSE_TCP_WIN != 0 )
/**
* @brief Get the window scaling factor for the TCP connection.
*
* @param[in] pxSocket: The socket owning the TCP connection.
*
* @return The scaling factor.
*/
static uint8_t prvWinScaleFactor( const FreeRTOS_Socket_t * pxSocket )
{
size_t uxWinSize;
uint8_t ucFactor;
/* 'xTCP.uxRxWinSize' is the size of the reception window in units of MSS. */
uxWinSize = pxSocket->u.xTCP.uxRxWinSize * ( size_t ) pxSocket->u.xTCP.usInitMSS;
ucFactor = 0U;
while( uxWinSize > 0xffffUL )
{
/* Divide by two and increase the binary factor by 1. */
uxWinSize >>= 1;
ucFactor++;
}
FreeRTOS_debug_printf( ( "prvWinScaleFactor: uxRxWinSize %u MSS %u Factor %u\n",
( unsigned ) pxSocket->u.xTCP.uxRxWinSize,
( unsigned ) pxSocket->u.xTCP.usInitMSS,
ucFactor ) );
return ucFactor;
}
#endif /* if ( ipconfigUSE_TCP_WIN != 0 ) */
/*-----------------------------------------------------------*/
/**
* @brief When opening a TCP connection, while SYN's are being sent, the parties may
* communicate what MSS (Maximum Segment Size) they intend to use, whether Selective
* ACK's ( SACK ) are supported, and the size of the reception window ( WSOPT ).
*
* @param[in] pxSocket: The socket being used for communication. It is used to set
* the MSS.
* @param[in,out] pxTCPHeader: The TCP packet header being used in the SYN transmission.
* The MSS and corresponding options shall be set in this
* header itself.
*
* @return The option length after the TCP header was updated.
*
* @note MSS is the net size of the payload, an is always smaller than MTU.
*/
static UBaseType_t prvSetSynAckOptions( FreeRTOS_Socket_t * pxSocket,
TCPHeader_t * pxTCPHeader )
{
uint16_t usMSS = pxSocket->u.xTCP.usInitMSS;
UBaseType_t uxOptionsLength;
/* We send out the TCP Maximum Segment Size option with our SYN[+ACK]. */
pxTCPHeader->ucOptdata[ 0 ] = ( uint8_t ) tcpTCP_OPT_MSS;
pxTCPHeader->ucOptdata[ 1 ] = ( uint8_t ) tcpTCP_OPT_MSS_LEN;
pxTCPHeader->ucOptdata[ 2 ] = ( uint8_t ) ( usMSS >> 8 );
pxTCPHeader->ucOptdata[ 3 ] = ( uint8_t ) ( usMSS & 0xffU );
#if ( ipconfigUSE_TCP_WIN != 0 )
{
pxSocket->u.xTCP.ucMyWinScaleFactor = prvWinScaleFactor( pxSocket );
pxTCPHeader->ucOptdata[ 4 ] = tcpTCP_OPT_NOOP;
pxTCPHeader->ucOptdata[ 5 ] = ( uint8_t ) ( tcpTCP_OPT_WSOPT );
pxTCPHeader->ucOptdata[ 6 ] = ( uint8_t ) ( tcpTCP_OPT_WSOPT_LEN );
pxTCPHeader->ucOptdata[ 7 ] = ( uint8_t ) pxSocket->u.xTCP.ucMyWinScaleFactor;
uxOptionsLength = 8U;
}
#else
{
uxOptionsLength = 4U;
}
#endif /* if ( ipconfigUSE_TCP_WIN != 0 ) */
#if ( ipconfigUSE_TCP_WIN != 0 )
{
pxTCPHeader->ucOptdata[ uxOptionsLength ] = tcpTCP_OPT_NOOP;
pxTCPHeader->ucOptdata[ uxOptionsLength + 1U ] = tcpTCP_OPT_NOOP;
pxTCPHeader->ucOptdata[ uxOptionsLength + 2U ] = tcpTCP_OPT_SACK_P; /* 4: Sack-Permitted Option. */
pxTCPHeader->ucOptdata[ uxOptionsLength + 3U ] = 2U; /* 2: length of this option. */
uxOptionsLength += 4U;
}
#endif /* ipconfigUSE_TCP_WIN == 0 */
return uxOptionsLength; /* bytes, not words. */
}
/**
* @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.
*/
static void prvTCPTouchSocket( FreeRTOS_Socket_t * 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;
}
/*-----------------------------------------------------------*/
/**
* @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 = NULL;
BaseType_t bBefore = ipNUMERIC_CAST( BaseType_t, tcpNOW_CONNECTED( ( BaseType_t ) pxSocket->u.xTCP.ucTCPState ) ); /* Was it connected ? */
BaseType_t bAfter = ipNUMERIC_CAST( BaseType_t, tcpNOW_CONNECTED( ( BaseType_t ) eTCPState ) ); /* Is it connected now ? */
#if ( ipconfigHAS_DEBUG_PRINTF != 0 )
BaseType_t xPreviousState = ( BaseType_t ) pxSocket->u.xTCP.ucTCPState;
#endif
#if ( ipconfigUSE_CALLBACKS == 1 )
FreeRTOS_Socket_t * xConnected = NULL;
#endif
/* Has the connected status changed? */
if( bBefore != bAfter )
{
/* 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 )
{
/* Now that it is connected, find it's parent. */
if( pxSocket->u.xTCP.bits.bReuseSocket != pdFALSE_UNSIGNED )
{
xParent = pxSocket;
}
else
{
xParent = pxSocket->u.xTCP.pxPeerSocket;
configASSERT( xParent != NULL );
}
if( xParent != NULL )
{
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
{
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 a semaphore. */
pxSocket->xEventBits |= ( EventBits_t ) eSOCKET_CLOSED;
#if ( ipconfigSUPPORT_SELECT_FUNCTION == 1 )
{
if( ( pxSocket->xSelectBits & ( EventBits_t ) eSELECT_EXCEPT ) != 0U )
{
pxSocket->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( ipNUMERIC_CAST( eIPTCPState_t, pxSocket->u.xTCP.ucTCPState ) ) == 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;
}
}
else
{
if( ( eTCPState == eCLOSED ) ||
( eTCPState == eCLOSE_WAIT ) )
{
/* Socket goes to status eCLOSED because of a RST.
* When nobody owns the socket yet, delete it. */
if( ( pxSocket->u.xTCP.bits.bPassQueued != pdFALSE_UNSIGNED ) ||
( pxSocket->u.xTCP.bits.bPassAccept != pdFALSE_UNSIGNED ) )
{
FreeRTOS_debug_printf( ( "vTCPStateChange: Closing socket\n" ) );
if( pxSocket->u.xTCP.bits.bReuseSocket == pdFALSE_UNSIGNED )
{
( void ) FreeRTOS_closesocket( pxSocket );
}
}
}
}
/* Fill in the new state. */
pxSocket->u.xTCP.ucTCPState = ( uint8_t ) eTCPState;
/* 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 ) ) )
{
FreeRTOS_debug_printf( ( "Socket %d -> %lxip:%u State %s->%s\n",
pxSocket->usLocalPort,
pxSocket->u.xTCP.ulRemoteIP,
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 Check if the size of a network buffer is big enough to hold the outgoing message.
* Allocate a new bigger network buffer when necessary.
*
* @param[in] pxSocket: Socket whose buffer is being resized.
* @param[in] pxNetworkBuffer: The network buffer whose size is being increased.
* @param[in] lDataLen: Length of the data to be put in the buffer.
* @param[in] uxOptionsLength: Length of options.
*
* @return If the resizing is successful: The new buffer with the size being asked for
* with old data copied in it.
* Else, NULL.
*
* @note The old network buffer will be released if the resizing is successful and
* cannot be used any longer.
*/
static NetworkBufferDescriptor_t * prvTCPBufferResize( const FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t * pxNetworkBuffer,
int32_t lDataLen,
UBaseType_t uxOptionsLength )
{
NetworkBufferDescriptor_t * pxReturn;
size_t uxNeeded;
BaseType_t xResize;
if( xBufferAllocFixedSize != pdFALSE )
{
/* Network buffers are created with a fixed size and can hold the largest
* MTU. */
uxNeeded = ( size_t ) ipTOTAL_ETHERNET_FRAME_SIZE;
/* and therefore, the buffer won't be too small.
* Only ask for a new network buffer in case none was supplied. */
if( pxNetworkBuffer == NULL )
{
xResize = pdTRUE;
}
else
{
xResize = pdFALSE;
}
}
else
{
/* Network buffers are created with a variable size. See if it must
* grow. */
uxNeeded = ipNUMERIC_CAST( size_t, ipSIZE_OF_ETH_HEADER + uxIPHeaderSizeSocket( pxSocket ) + ipSIZE_OF_TCP_HEADER + uxOptionsLength ) + lDataLen;
if( uxNeeded < sizeof( pxSocket->u.xTCP.xPacket.u.ucLastPacket ) )
{
uxNeeded = sizeof( pxSocket->u.xTCP.xPacket.u.ucLastPacket );
}
/* In case we were called from a TCP timer event, a buffer must be
* created. Otherwise, test 'xDataLength' of the provided buffer. */
if( ( pxNetworkBuffer == NULL ) || ( pxNetworkBuffer->xDataLength < uxNeeded ) )
{
xResize = pdTRUE;
}
else
{
xResize = pdFALSE;
}
}
if( xResize != pdFALSE )
{
/* The caller didn't provide a network buffer or the provided buffer is
* too small. As we must send-out a data packet, a buffer will be created
* here. */
pxReturn = pxGetNetworkBufferWithDescriptor( uxNeeded, 0U );
if( pxReturn != NULL )
{
/* Set the actual packet size, in case the returned buffer is larger. */
pxReturn->xDataLength = uxNeeded;
/* Copy the existing data to the new created buffer. */
if( pxNetworkBuffer != NULL )
{
/* Either from the previous buffer... */
( void ) memcpy( pxReturn->pucEthernetBuffer, pxNetworkBuffer->pucEthernetBuffer, pxNetworkBuffer->xDataLength );
/* ...and release it. */
vReleaseNetworkBufferAndDescriptor( pxNetworkBuffer );
}
else
{
/* Or from the socket field 'xTCP.xPacket'. */
( void ) memcpy( pxReturn->pucEthernetBuffer, pxSocket->u.xTCP.xPacket.u.ucLastPacket, sizeof( pxSocket->u.xTCP.xPacket.u.ucLastPacket ) );
}
}
}
else
{
/* xResize is false, the network buffer provided was big enough. */
configASSERT( pxNetworkBuffer != NULL ); /* to tell lint: when xResize is false, pxNetworkBuffer is not NULL. */
pxReturn = pxNetworkBuffer;
pxNetworkBuffer->xDataLength = ( size_t ) ( ipSIZE_OF_ETH_HEADER + uxIPHeaderSizeSocket( pxSocket ) + ipSIZE_OF_TCP_HEADER + uxOptionsLength ) + ( size_t ) lDataLen;
}
return pxReturn;
}
/*-----------------------------------------------------------*/
/**
* @brief Prepare an outgoing message, in case anything has to be sent.
*
* @param[in] pxSocket: The socket owning the connection.
* @param[in,out] ppxNetworkBuffer: Pointer to the pointer to the network buffer.
* @param[in] uxOptionsLength: The length of the TCP options.
*
* @return Length of the data to be sent if everything is correct. Else, -1
* is returned in case of any error.
*/
static int32_t prvTCPPrepareSend( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t ** ppxNetworkBuffer,
UBaseType_t uxOptionsLength )
{
int32_t lDataLen;
uint8_t * pucEthernetBuffer, * pucSendData;
ProtocolHeaders_t * pxProtocolHeaders;
size_t uxOffset;
uint32_t ulDataGot, ulDistance;
TCPWindow_t * pxTCPWindow;
NetworkBufferDescriptor_t * pxNewBuffer;
int32_t lStreamPos;
UBaseType_t uxIntermediateResult = 0;
if( ( *ppxNetworkBuffer ) != NULL )
{
/* A network buffer descriptor was already supplied */
pucEthernetBuffer = ( *ppxNetworkBuffer )->pucEthernetBuffer;
}
else
{
/* For now let it point to the last packet header */
pucEthernetBuffer = pxSocket->u.xTCP.xPacket.u.ucLastPacket;
}
/* Map the ethernet buffer onto the ProtocolHeader_t struct for easy access to the fields. */
pxProtocolHeaders = ipCAST_PTR_TO_TYPE_PTR( ProtocolHeaders_t, &( pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER + uxIPHeaderSizeSocket( pxSocket ) ] ) );
pxTCPWindow = &( pxSocket->u.xTCP.xTCPWindow );
lDataLen = 0;
lStreamPos = 0;
pxProtocolHeaders->xTCPHeader.ucTCPFlags |= tcpTCP_FLAG_ACK;
if( pxSocket->u.xTCP.txStream != NULL )
{
/* ulTCPWindowTxGet will return the amount of data which may be sent
* along with the position in the txStream.
* Why check for MSS > 1 ?
* Because some TCP-stacks (like uIP) use it for flow-control. */
if( pxSocket->u.xTCP.usCurMSS > 1U )
{
lDataLen = ( int32_t ) ulTCPWindowTxGet( pxTCPWindow, pxSocket->u.xTCP.ulWindowSize, &lStreamPos );
}
if( lDataLen > 0 )
{
/* Check if the current network buffer is big enough, if not,
* resize it. */
pxNewBuffer = prvTCPBufferResize( pxSocket, *ppxNetworkBuffer, lDataLen, uxOptionsLength );
if( pxNewBuffer != NULL )
{
*ppxNetworkBuffer = pxNewBuffer;
pucEthernetBuffer = pxNewBuffer->pucEthernetBuffer;
/* Map the byte stream onto ProtocolHeaders_t struct for easy
* access to the fields. */
pxProtocolHeaders = ipCAST_PTR_TO_TYPE_PTR( ProtocolHeaders_t, &( pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER + uxIPHeaderSizeSocket( pxSocket ) ] ) );
pucSendData = &( pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER + uxIPHeaderSizeSocket( pxSocket ) + ipSIZE_OF_TCP_HEADER + uxOptionsLength ] );
/* Translate the position in txStream to an offset from the tail
* marker. */
uxOffset = uxStreamBufferDistance( pxSocket->u.xTCP.txStream, pxSocket->u.xTCP.txStream->uxTail, ( size_t ) lStreamPos );
/* Here data is copied from the txStream in 'peek' mode. Only
* when the packets are acked, the tail marker will be updated. */
ulDataGot = ( uint32_t ) uxStreamBufferGet( pxSocket->u.xTCP.txStream, uxOffset, pucSendData, ( size_t ) lDataLen, pdTRUE );
#if ( ipconfigHAS_DEBUG_PRINTF != 0 )
{
if( ulDataGot != ( uint32_t ) lDataLen )
{
FreeRTOS_debug_printf( ( "uxStreamBufferGet: pos %d offs %u only %u != %d\n",
( int ) lStreamPos, ( unsigned ) uxOffset, ( unsigned ) ulDataGot, ( int ) lDataLen ) );
}
}
#endif
/* If the owner of the socket requests a closure, add the FIN
* flag to the last packet. */
if( ( pxSocket->u.xTCP.bits.bCloseRequested != pdFALSE_UNSIGNED ) && ( pxSocket->u.xTCP.bits.bFinSent == pdFALSE_UNSIGNED ) )
{
ulDistance = ( uint32_t ) uxStreamBufferDistance( pxSocket->u.xTCP.txStream, ( size_t ) lStreamPos, pxSocket->u.xTCP.txStream->uxHead );
if( ulDistance == ulDataGot )
{
#if ( ipconfigHAS_DEBUG_PRINTF == 1 )
{
/* the order of volatile accesses is undefined
* so such workaround */
size_t uxHead = pxSocket->u.xTCP.txStream->uxHead;
size_t uxMid = pxSocket->u.xTCP.txStream->uxMid;
size_t uxTail = pxSocket->u.xTCP.txStream->uxTail;
FreeRTOS_debug_printf( ( "CheckClose %u <= %u (%u <= %u <= %u)\n",
( unsigned ) ulDataGot, ( unsigned ) ulDistance,
( unsigned ) uxTail, ( unsigned ) uxMid, ( unsigned ) uxHead ) );
}
#endif /* if ( ipconfigHAS_DEBUG_PRINTF == 1 ) */
/* Although the socket sends a FIN, it will stay in
* ESTABLISHED until all current data has been received or
* delivered. */
pxProtocolHeaders->xTCPHeader.ucTCPFlags |= tcpTCP_FLAG_FIN;
pxTCPWindow->tx.ulFINSequenceNumber = pxTCPWindow->ulOurSequenceNumber + ( uint32_t ) lDataLen;
pxSocket->u.xTCP.bits.bFinSent = pdTRUE_UNSIGNED;
}
}
}
else
{
lDataLen = -1;
}
}
}
if( ( lDataLen >= 0 ) && ( pxSocket->u.xTCP.ucTCPState == ( uint8_t ) eESTABLISHED ) )
{
/* See if the socket owner wants to shutdown this connection. */
if( ( pxSocket->u.xTCP.bits.bUserShutdown != pdFALSE_UNSIGNED ) &&
( xTCPWindowTxDone( pxTCPWindow ) != pdFALSE ) )
{
pxSocket->u.xTCP.bits.bUserShutdown = pdFALSE_UNSIGNED;
pxProtocolHeaders->xTCPHeader.ucTCPFlags |= tcpTCP_FLAG_FIN;
pxSocket->u.xTCP.bits.bFinSent = pdTRUE_UNSIGNED;
pxSocket->u.xTCP.bits.bWinChange = pdTRUE_UNSIGNED;
pxTCPWindow->tx.ulFINSequenceNumber = pxTCPWindow->tx.ulCurrentSequenceNumber;
vTCPStateChange( pxSocket, eFIN_WAIT_1 );
}
#if ( ipconfigTCP_KEEP_ALIVE != 0 )
{
if( pxSocket->u.xTCP.ucKeepRepCount > 3U ) /*_RB_ Magic number. */
{
FreeRTOS_debug_printf( ( "keep-alive: giving up %lxip:%u\n",
pxSocket->u.xTCP.ulRemoteIP, /* IP address of remote machine. */
pxSocket->u.xTCP.usRemotePort ) ); /* Port on remote machine. */
vTCPStateChange( pxSocket, eCLOSE_WAIT );
lDataLen = -1;
}
if( ( lDataLen == 0 ) && ( pxSocket->u.xTCP.bits.bWinChange == pdFALSE_UNSIGNED ) )
{
/* If there is no data to be sent, and no window-update message,
* we might want to send a keep-alive message. */
TickType_t xAge = xTaskGetTickCount() - pxSocket->u.xTCP.xLastAliveTime;
TickType_t xMax;
xMax = ( ( TickType_t ) ipconfigTCP_KEEP_ALIVE_INTERVAL * ( TickType_t ) configTICK_RATE_HZ );
if( pxSocket->u.xTCP.ucKeepRepCount != ( uint8_t ) 0U )
{
xMax = ( TickType_t ) ( 3U * configTICK_RATE_HZ );
}
if( xAge > xMax )
{
pxSocket->u.xTCP.xLastAliveTime = xTaskGetTickCount();
if( xTCPWindowLoggingLevel != 0 )
{
FreeRTOS_debug_printf( ( "keep-alive: %lxip:%u count %u\n",
pxSocket->u.xTCP.ulRemoteIP,
pxSocket->u.xTCP.usRemotePort,
pxSocket->u.xTCP.ucKeepRepCount ) );
}
pxSocket->u.xTCP.bits.bSendKeepAlive = pdTRUE_UNSIGNED;
pxSocket->u.xTCP.usTimeout = ( ( uint16_t ) pdMS_TO_TICKS( 2500U ) );
pxSocket->u.xTCP.ucKeepRepCount++;
}
}
}
#endif /* ipconfigTCP_KEEP_ALIVE */
}
/* Anything to send, a change of the advertised window size, or maybe send a
* keep-alive message? */
if( ( lDataLen > 0 ) ||
( pxSocket->u.xTCP.bits.bWinChange != pdFALSE_UNSIGNED ) ||
( pxSocket->u.xTCP.bits.bSendKeepAlive != pdFALSE_UNSIGNED ) )
{
pxProtocolHeaders->xTCPHeader.ucTCPFlags &= ( ( uint8_t ) ~tcpTCP_FLAG_PSH );
pxProtocolHeaders->xTCPHeader.ucTCPOffset = ( uint8_t ) ( ( ipSIZE_OF_TCP_HEADER + uxOptionsLength ) << 2 ); /*_RB_ "2" needs comment. */
pxProtocolHeaders->xTCPHeader.ucTCPFlags |= ( uint8_t ) tcpTCP_FLAG_ACK;
if( lDataLen != 0L )
{
pxProtocolHeaders->xTCPHeader.ucTCPFlags |= ( uint8_t ) tcpTCP_FLAG_PSH;
}
uxIntermediateResult = uxIPHeaderSizeSocket( pxSocket ) + ipSIZE_OF_TCP_HEADER + uxOptionsLength;
lDataLen += ( int32_t ) uxIntermediateResult;
}
return lDataLen;
}
/*-----------------------------------------------------------*/
/**
* @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.
*/
static TickType_t prvTCPNextTimeout( FreeRTOS_Socket_t * pxSocket )
{
TickType_t ulDelayMs = ( TickType_t ) tcpMAXIMUM_TCP_WAKEUP_TIME_MS;
if( pxSocket->u.xTCP.ucTCPState == ( uint8_t ) 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 )
{
ulDelayMs = ( 3000UL << ( pxSocket->u.xTCP.ucRepCount - 1U ) );
}
else
{
ulDelayMs = 11000UL;
}
}
else
{
/* Still in the ARP phase: check every half second. */
ulDelayMs = 500UL;
}
FreeRTOS_debug_printf( ( "Connect[%lxip:%u]: next timeout %u: %lu ms\n",
pxSocket->u.xTCP.ulRemoteIP, pxSocket->u.xTCP.usRemotePort,
pxSocket->u.xTCP.ucRepCount, 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 = 1UL;
}
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 );
}
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 The API FreeRTOS_send() adds data to the TX stream. Add
* this data to the windowing system to it can be transmitted.
*
* @param[in] pxSocket: The socket owning the connection.
*/
static void prvTCPAddTxData( FreeRTOS_Socket_t * pxSocket )
{
int32_t lCount, lLength;
/* A txStream has been created already, see if the socket has new data for
* the sliding window.
*
* uxStreamBufferMidSpace() returns the distance between rxHead and rxMid. It
* contains new Tx data which has not been passed to the sliding window yet.
* The oldest data not-yet-confirmed can be found at rxTail. */
lLength = ( int32_t ) uxStreamBufferMidSpace( pxSocket->u.xTCP.txStream );
if( lLength > 0 )
{
/* All data between txMid and rxHead will now be passed to the sliding
* window manager, so it can start transmitting them.
*
* Hand over the new data to the sliding window handler. It will be
* split-up in chunks of 1460 bytes each (or less, depending on
* ipconfigTCP_MSS). */
lCount = lTCPWindowTxAdd( &pxSocket->u.xTCP.xTCPWindow,
( uint32_t ) lLength,
( int32_t ) pxSocket->u.xTCP.txStream->uxMid,
( int32_t ) pxSocket->u.xTCP.txStream->LENGTH );
/* Move the rxMid pointer forward up to rxHead. */
if( lCount > 0 )
{
vStreamBufferMoveMid( pxSocket->u.xTCP.txStream, ( size_t ) lCount );
}
}
}
/*-----------------------------------------------------------*/
/**
* @brief prvTCPHandleFin() will be called to handle connection closure. The
* closure starts when either a FIN has been received and accepted,
* or when the socket has sent a FIN flag to the peer. Before being
* called, it has been checked that both reception and transmission
* are complete.
*
* @param[in] pxSocket: Socket owning the the connection.
* @param[in] pxNetworkBuffer: The network buffer carrying the TCP packet.
*
* @return Length of the packet to be sent.
*/
static BaseType_t prvTCPHandleFin( FreeRTOS_Socket_t * pxSocket,
const NetworkBufferDescriptor_t * pxNetworkBuffer )
{
/* Map the ethernet buffer onto the ProtocolHeader_t struct for easy access to the fields. */
ProtocolHeaders_t * pxProtocolHeaders = ipCAST_PTR_TO_TYPE_PTR( ProtocolHeaders_t,
&( pxNetworkBuffer->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER + xIPHeaderSize( pxNetworkBuffer ) ] ) );
TCPHeader_t * pxTCPHeader = &( pxProtocolHeaders->xTCPHeader );
uint8_t ucIntermediateResult = 0, ucTCPFlags = pxTCPHeader->ucTCPFlags;
TCPWindow_t * pxTCPWindow = &pxSocket->u.xTCP.xTCPWindow;
BaseType_t xSendLength = 0;
uint32_t ulAckNr = FreeRTOS_ntohl( pxTCPHeader->ulAckNr );
if( ( ucTCPFlags & tcpTCP_FLAG_FIN ) != 0U )
{
pxTCPWindow->rx.ulCurrentSequenceNumber = pxTCPWindow->rx.ulFINSequenceNumber + 1U;
}
if( pxSocket->u.xTCP.bits.bFinSent == pdFALSE_UNSIGNED )
{
/* We haven't yet replied with a FIN, do so now. */
pxTCPWindow->tx.ulFINSequenceNumber = pxTCPWindow->tx.ulCurrentSequenceNumber;
pxSocket->u.xTCP.bits.bFinSent = pdTRUE_UNSIGNED;
}
else
{
/* We did send a FIN already, see if it's ACK'd. */
if( ulAckNr == ( pxTCPWindow->tx.ulFINSequenceNumber + 1UL ) )
{
pxSocket->u.xTCP.bits.bFinAcked = pdTRUE_UNSIGNED;
}
}
if( pxSocket->u.xTCP.bits.bFinAcked == pdFALSE_UNSIGNED )
{
pxTCPWindow->tx.ulCurrentSequenceNumber = pxTCPWindow->tx.ulFINSequenceNumber;
pxTCPHeader->ucTCPFlags = ( uint8_t ) tcpTCP_FLAG_ACK | ( uint8_t ) tcpTCP_FLAG_FIN;
/* And wait for the final ACK. */
vTCPStateChange( pxSocket, eLAST_ACK );
}
else
{
/* Our FIN has been ACK'd, the outgoing sequence number is now fixed. */
pxTCPWindow->tx.ulCurrentSequenceNumber = pxTCPWindow->tx.ulFINSequenceNumber + 1U;
if( pxSocket->u.xTCP.bits.bFinRecv == pdFALSE_UNSIGNED )
{
/* We have sent out a FIN but the peer hasn't replied with a FIN
* yet. Do nothing for the moment. */
pxTCPHeader->ucTCPFlags = 0U;
}
else
{
if( pxSocket->u.xTCP.bits.bFinLast == pdFALSE_UNSIGNED )
{
/* This is the third of the three-way hand shake: the last
* ACK. */
pxTCPHeader->ucTCPFlags = tcpTCP_FLAG_ACK;
}
else
{
/* The other party started the closure, so we just wait for the
* last ACK. */
pxTCPHeader->ucTCPFlags = 0U;
}
/* And wait for the user to close this socket. */
vTCPStateChange( pxSocket, eCLOSE_WAIT );
}
}
pxTCPWindow->ulOurSequenceNumber = pxTCPWindow->tx.ulCurrentSequenceNumber;
if( pxTCPHeader->ucTCPFlags != 0U )
{
ucIntermediateResult = uxIPHeaderSizeSocket( pxSocket ) + ipSIZE_OF_TCP_HEADER + pxTCPWindow->ucOptionLength;
xSendLength = ( BaseType_t ) ucIntermediateResult;
}
pxTCPHeader->ucTCPOffset = ( uint8_t ) ( ( ipSIZE_OF_TCP_HEADER + pxTCPWindow->ucOptionLength ) << 2 );
if( xTCPWindowLoggingLevel != 0 )
{
FreeRTOS_debug_printf( ( "TCP: send FIN+ACK (ack %lu, cur/nxt %lu/%lu) ourSeqNr %lu | Rx %lu\n",
ulAckNr - pxTCPWindow->tx.ulFirstSequenceNumber,
pxTCPWindow->tx.ulCurrentSequenceNumber - pxTCPWindow->tx.ulFirstSequenceNumber,
pxTCPWindow->ulNextTxSequenceNumber - pxTCPWindow->tx.ulFirstSequenceNumber,
pxTCPWindow->ulOurSequenceNumber - pxTCPWindow->tx.ulFirstSequenceNumber,
pxTCPWindow->rx.ulCurrentSequenceNumber - pxTCPWindow->rx.ulFirstSequenceNumber ) );
}
return xSendLength;
}
/*-----------------------------------------------------------*/
/**
* @brief prvCheckRxData(): called from prvTCPHandleState(). The
* first thing that will be done is find the TCP payload data
* and check the length of this data.
*
* @param[in] pxNetworkBuffer: The network buffer holding the received data.
* @param[out] ppucRecvData: It will point to first byte of the TCP payload.
*
* @return Length of the received buffer.
*/
static BaseType_t prvCheckRxData( const NetworkBufferDescriptor_t * pxNetworkBuffer,
uint8_t ** ppucRecvData )
{
/* Map the ethernet buffer onto the ProtocolHeader_t struct for easy access to the fields. */
const ProtocolHeaders_t * pxProtocolHeaders = ipCAST_PTR_TO_TYPE_PTR( ProtocolHeaders_t,
&( pxNetworkBuffer->pucEthernetBuffer[ ( size_t ) ipSIZE_OF_ETH_HEADER + xIPHeaderSize( pxNetworkBuffer ) ] ) );
const TCPHeader_t * pxTCPHeader = &( pxProtocolHeaders->xTCPHeader );
int32_t lLength, lTCPHeaderLength, lReceiveLength, lUrgentLength;
/* Map the buffer onto an IPHeader_t struct for easy access to fields. */
const IPHeader_t * pxIPHeader = ipCAST_CONST_PTR_TO_CONST_TYPE_PTR( IPHeader_t, &( pxNetworkBuffer->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER ] ) );
const size_t xIPHeaderLength = ipSIZE_OF_IPv4_HEADER;
uint16_t usLength;
uint8_t ucIntermediateResult = 0;
/* Determine the length and the offset of the user-data sent to this
* node.
*
* The size of the TCP header is given in a multiple of 4-byte words (single
* byte, needs no ntoh() translation). A shift-right 2: is the same as
* (offset >> 4) * 4. */
ucIntermediateResult = ( pxTCPHeader->ucTCPOffset & tcpVALID_BITS_IN_TCP_OFFSET_BYTE ) >> 2;
lTCPHeaderLength = ( int32_t ) ucIntermediateResult;
/* Let pucRecvData point to the first byte received. */
*ppucRecvData = &( pxNetworkBuffer->pucEthernetBuffer[ ( size_t ) ipSIZE_OF_ETH_HEADER + xIPHeaderLength + ( size_t ) lTCPHeaderLength ] );
/* Calculate lReceiveLength - the length of the TCP data received. This is
* equal to the total packet length minus:
* ( LinkLayer length (14) + IP header length (20) + size of TCP header(20 +) ).*/
lReceiveLength = ipNUMERIC_CAST( int32_t, pxNetworkBuffer->xDataLength ) - ( int32_t ) ipSIZE_OF_ETH_HEADER;
usLength = FreeRTOS_htons( pxIPHeader->usLength );
lLength = ( int32_t ) usLength;
if( lReceiveLength > lLength )
{
/* More bytes were received than the reported length, often because of
* padding bytes at the end. */
lReceiveLength = lLength;
}
/* Subtract the size of the TCP and IP headers and the actual data size is
* known. */
if( lReceiveLength > ( lTCPHeaderLength + ( int32_t ) xIPHeaderLength ) )
{
lReceiveLength -= ( lTCPHeaderLength + ( int32_t ) xIPHeaderLength );
}
else
{
lReceiveLength = 0;
}
/* Urgent Pointer:
* This field communicates the current value of the urgent pointer as a
* positive offset from the sequence number in this segment. The urgent
* pointer points to the sequence number of the octet following the urgent
* data. This field is only be interpreted in segments with the URG control
* bit set. */
if( ( pxTCPHeader->ucTCPFlags & tcpTCP_FLAG_URG ) != 0U )
{
/* Although we ignore the urgent data, we have to skip it. */
lUrgentLength = ( int32_t ) FreeRTOS_htons( pxTCPHeader->usUrgent );
*ppucRecvData += lUrgentLength;
lReceiveLength -= FreeRTOS_min_int32( lReceiveLength, lUrgentLength );
}
return ( BaseType_t ) lReceiveLength;
}
/*-----------------------------------------------------------*/
/**
* @brief prvStoreRxData(): called from prvTCPHandleState().
* The second thing is to do is check if the payload data may
* be accepted. If so, they will be added to the reception queue.
*
* @param[in] pxSocket: The socket owning the connection.
* @param[in] pucRecvData: Pointer to received data.
* @param[in] pxNetworkBuffer: The network buffer descriptor.
* @param[in] ulReceiveLength: The length of the received data.
*
* @return 0 on success, -1 on failure of storing data.
*/
static BaseType_t prvStoreRxData( FreeRTOS_Socket_t * pxSocket,
const uint8_t * pucRecvData,
NetworkBufferDescriptor_t * pxNetworkBuffer,
uint32_t ulReceiveLength )
{
/* Map the ethernet buffer onto the ProtocolHeader_t struct for easy access to the fields. */
const ProtocolHeaders_t * pxProtocolHeaders = ipCAST_CONST_PTR_TO_CONST_TYPE_PTR( ProtocolHeaders_t,
&( pxNetworkBuffer->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER + xIPHeaderSize( pxNetworkBuffer ) ] ) );
const TCPHeader_t * pxTCPHeader = &pxProtocolHeaders->xTCPHeader;
TCPWindow_t * pxTCPWindow = &pxSocket->u.xTCP.xTCPWindow;
uint32_t ulSequenceNumber, ulSpace;
int32_t lOffset, lStored;
BaseType_t xResult = 0;
ulSequenceNumber = FreeRTOS_ntohl( pxTCPHeader->ulSequenceNumber );
if( ( ulReceiveLength > 0U ) && ( pxSocket->u.xTCP.ucTCPState >= ( uint8_t ) eSYN_RECEIVED ) )
{
/* See if way may accept the data contents and forward it to the socket
* owner.
*
* If it can't be "accept"ed it may have to be stored and send a selective
* ack (SACK) option to confirm it. In that case, lTCPAddRxdata() will be
* called later to store an out-of-order packet (in case lOffset is
* negative). */
if( pxSocket->u.xTCP.rxStream != NULL )
{
ulSpace = ( uint32_t ) uxStreamBufferGetSpace( pxSocket->u.xTCP.rxStream );
}
else
{
ulSpace = ( uint32_t ) pxSocket->u.xTCP.uxRxStreamSize;
}
lOffset = lTCPWindowRxCheck( pxTCPWindow, ulSequenceNumber, ulReceiveLength, ulSpace );
if( lOffset >= 0 )
{
/* New data has arrived and may be made available to the user. See
* if the head marker in rxStream may be advanced, only if lOffset == 0.
* In case the low-water mark is reached, bLowWater will be set
* "low-water" here stands for "little space". */
lStored = lTCPAddRxdata( pxSocket, ( uint32_t ) lOffset, pucRecvData, ulReceiveLength );
if( lStored != ( int32_t ) ulReceiveLength )
{
FreeRTOS_debug_printf( ( "lTCPAddRxdata: stored %ld / %lu bytes? ?\n", lStored, ulReceiveLength ) );
/* Received data could not be stored. The socket's flag
* bMallocError has been set. The socket now has the status
* eCLOSE_WAIT and a RST packet will be sent back. */
( void ) prvTCPSendReset( pxNetworkBuffer );
xResult = -1;
}
}
/* After a missing packet has come in, higher packets may be passed to
* the user. */
#if ( ipconfigUSE_TCP_WIN == 1 )
{
/* Now lTCPAddRxdata() will move the rxHead pointer forward
* so data becomes available to the user immediately
* In case the low-water mark is reached, bLowWater will be set. */
if( ( xResult == 0 ) && ( pxTCPWindow->ulUserDataLength > 0UL ) )
{
( void ) lTCPAddRxdata( pxSocket, 0UL, NULL, pxTCPWindow->ulUserDataLength );
pxTCPWindow->ulUserDataLength = 0;
}
}
#endif /* ipconfigUSE_TCP_WIN */
}
else
{
pxTCPWindow->ucOptionLength = 0U;
}
return xResult;
}
/*-----------------------------------------------------------*/
/**
* @brief Set the TCP options (if any) for the outgoing packet.
*
* @param[in] pxSocket: The socket owning the connection.
* @param[in] pxNetworkBuffer: The network buffer holding the packet.
*
* @return Length of the TCP options after they are set.
*/
static UBaseType_t prvSetOptions( FreeRTOS_Socket_t * pxSocket,
const NetworkBufferDescriptor_t * pxNetworkBuffer )
{
/* Map the ethernet buffer onto the ProtocolHeader_t struct for easy access to the fields. */
ProtocolHeaders_t * pxProtocolHeaders = ipCAST_PTR_TO_TYPE_PTR( ProtocolHeaders_t,
&( pxNetworkBuffer->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER + xIPHeaderSize( pxNetworkBuffer ) ] ) );
TCPHeader_t * pxTCPHeader = &pxProtocolHeaders->xTCPHeader;
const TCPWindow_t * pxTCPWindow = &pxSocket->u.xTCP.xTCPWindow;
UBaseType_t uxOptionsLength = pxTCPWindow->ucOptionLength;
/* memcpy() helper variables for MISRA Rule 21.15 compliance*/
const void * pvCopySource;
void * pvCopyDest;
#if ( ipconfigUSE_TCP_WIN == 1 )
if( uxOptionsLength != 0U )
{
/* TCP options must be sent because a packet which is out-of-order
* was received. */
if( xTCPWindowLoggingLevel >= 0 )
{
FreeRTOS_debug_printf( ( "SACK[%d,%d]: optlen %lu sending %lu - %lu\n",
pxSocket->usLocalPort,
pxSocket->u.xTCP.usRemotePort,
uxOptionsLength,
FreeRTOS_ntohl( pxTCPWindow->ulOptionsData[ 1 ] ) - pxSocket->u.xTCP.xTCPWindow.rx.ulFirstSequenceNumber,
FreeRTOS_ntohl( pxTCPWindow->ulOptionsData[ 2 ] ) - pxSocket->u.xTCP.xTCPWindow.rx.ulFirstSequenceNumber ) );
}
/*
* Use helper variables for memcpy() source & dest to remain
* compliant with MISRA Rule 21.15. These should be
* optimized away.
*/
pvCopySource = pxTCPWindow->ulOptionsData;
pvCopyDest = pxTCPHeader->ucOptdata;
( void ) memcpy( pvCopyDest, pvCopySource, ( size_t ) uxOptionsLength );
/* The header length divided by 4, goes into the higher nibble,
* effectively a shift-left 2. */
pxTCPHeader->ucTCPOffset = ( uint8_t ) ( ( ipSIZE_OF_TCP_HEADER + uxOptionsLength ) << 2 );
}
else
#endif /* ipconfigUSE_TCP_WIN */
if( ( pxSocket->u.xTCP.ucTCPState >= ( EventBits_t ) eESTABLISHED ) && ( pxSocket->u.xTCP.bits.bMssChange != pdFALSE_UNSIGNED ) )
{
/* TCP options must be sent because the MSS has changed. */
pxSocket->u.xTCP.bits.bMssChange = pdFALSE_UNSIGNED;
if( xTCPWindowLoggingLevel >= 0 )
{
FreeRTOS_debug_printf( ( "MSS: sending %d\n", pxSocket->u.xTCP.usCurMSS ) );
}
pxTCPHeader->ucOptdata[ 0 ] = tcpTCP_OPT_MSS;
pxTCPHeader->ucOptdata[ 1 ] = tcpTCP_OPT_MSS_LEN;
pxTCPHeader->ucOptdata[ 2 ] = ( uint8_t ) ( ( pxSocket->u.xTCP.usCurMSS ) >> 8 );
pxTCPHeader->ucOptdata[ 3 ] = ( uint8_t ) ( ( pxSocket->u.xTCP.usCurMSS ) & 0xffU );
uxOptionsLength = 4U;
pxTCPHeader->ucTCPOffset = ( uint8_t ) ( ( ipSIZE_OF_TCP_HEADER + uxOptionsLength ) << 2 );
}
else
{
/* Nothing. */
}
return uxOptionsLength;
}
/*-----------------------------------------------------------*/
/**
* @brief prvHandleSynReceived(): called from prvTCPHandleState(). Called
* from the states: eSYN_RECEIVED and eCONNECT_SYN. If the flags
* received are correct, the socket will move to eESTABLISHED.
*
* @param[in] pxSocket: The socket handling the connection.
* @param[in] pxNetworkBuffer: The pointer to the network buffer carrying
* the packet.
* @param[in] ulReceiveLength: Length in bytes of the data received.
* @param[in] uxOptionsLength: Length of the TCP options in bytes.
*
* @return Length of the data to be sent.
*/
static BaseType_t prvHandleSynReceived( FreeRTOS_Socket_t * pxSocket,
const NetworkBufferDescriptor_t * pxNetworkBuffer,
uint32_t ulReceiveLength,
UBaseType_t uxOptionsLength )
{
/* Map the ethernet buffer onto the ProtocolHeader_t struct for easy access to the fields. */
ProtocolHeaders_t * pxProtocolHeaders = ipCAST_PTR_TO_TYPE_PTR( ProtocolHeaders_t,
&( pxNetworkBuffer->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER + uxIPHeaderSizeSocket( pxSocket ) ] ) );
TCPHeader_t * pxTCPHeader = &pxProtocolHeaders->xTCPHeader;
TCPWindow_t * pxTCPWindow = &pxSocket->u.xTCP.xTCPWindow;
uint8_t ucTCPFlags = pxTCPHeader->ucTCPFlags;
uint32_t ulSequenceNumber = FreeRTOS_ntohl( pxTCPHeader->ulSequenceNumber );
BaseType_t xSendLength = 0;
UBaseType_t uxIntermediateResult = 0U;
/* Either expect a ACK or a SYN+ACK. */
uint8_t ucExpect = tcpTCP_FLAG_ACK;
const uint8_t ucFlagsMask = tcpTCP_FLAG_ACK | tcpTCP_FLAG_RST | tcpTCP_FLAG_SYN | tcpTCP_FLAG_FIN;
if( pxSocket->u.xTCP.ucTCPState == ( uint8_t ) eCONNECT_SYN )
{
ucExpect |= tcpTCP_FLAG_SYN;
}
if( ( ucTCPFlags & ucFlagsMask ) != ucExpect )
{
/* eSYN_RECEIVED: flags 0010 expected, not 0002. */
/* eSYN_RECEIVED: flags ACK expected, not SYN. */
FreeRTOS_debug_printf( ( "%s: flags %04X expected, not %04X\n",
( pxSocket->u.xTCP.ucTCPState == ( uint8_t ) eSYN_RECEIVED ) ? "eSYN_RECEIVED" : "eCONNECT_SYN",
ucExpect, ucTCPFlags ) );
/* In case pxSocket is not yet owned by the application, a closure
* of the socket will be scheduled for the next cycle. */
vTCPStateChange( pxSocket, eCLOSE_WAIT );
/* Send RST with the expected sequence and ACK numbers,
* otherwise the packet will be ignored. */
pxTCPWindow->ulOurSequenceNumber = FreeRTOS_htonl( pxTCPHeader->ulAckNr );
pxTCPWindow->rx.ulCurrentSequenceNumber = ulSequenceNumber;
pxTCPHeader->ucTCPFlags |= tcpTCP_FLAG_RST;
uxIntermediateResult = uxIPHeaderSizeSocket( pxSocket ) + ipSIZE_OF_TCP_HEADER + uxOptionsLength;
xSendLength = ( BaseType_t ) uxIntermediateResult;
pxTCPHeader->ucTCPOffset = ( uint8_t ) ( ( ipSIZE_OF_TCP_HEADER + uxOptionsLength ) << 2 );
}
else
{
pxTCPWindow->usPeerPortNumber = pxSocket->u.xTCP.usRemotePort;
pxTCPWindow->usOurPortNumber = pxSocket->usLocalPort;
if( pxSocket->u.xTCP.ucTCPState == ( uint8_t ) eCONNECT_SYN )
{
/* Map the Last packet onto the ProtocolHeader_t struct for easy access to the fields. */
ProtocolHeaders_t * pxLastHeaders = ipCAST_PTR_TO_TYPE_PTR( ProtocolHeaders_t,
&( pxSocket->u.xTCP.xPacket.u.ucLastPacket[ ipSIZE_OF_ETH_HEADER + uxIPHeaderSizeSocket( pxSocket ) ] ) );
/* Clear the SYN flag in lastPacket. */
pxLastHeaders->xTCPHeader.ucTCPFlags = tcpTCP_FLAG_ACK;
pxProtocolHeaders->xTCPHeader.ucTCPFlags = tcpTCP_FLAG_ACK;
/* This socket was the one connecting actively so now perform the
* synchronisation. */
vTCPWindowInit( &pxSocket->u.xTCP.xTCPWindow,
ulSequenceNumber, pxSocket->u.xTCP.xTCPWindow.ulOurSequenceNumber, ( uint32_t ) pxSocket->u.xTCP.usCurMSS );
pxTCPWindow->rx.ulHighestSequenceNumber = ulSequenceNumber + 1U;
pxTCPWindow->rx.ulCurrentSequenceNumber = ulSequenceNumber + 1U;
pxTCPWindow->tx.ulCurrentSequenceNumber++; /* because we send a TCP_SYN [ | TCP_ACK ]; */
pxTCPWindow->ulNextTxSequenceNumber++;
}
else if( ulReceiveLength == 0U )
{
pxTCPWindow->rx.ulCurrentSequenceNumber = ulSequenceNumber;
}
else
{
/* Nothing. */
}
/* The SYN+ACK has been confirmed, increase the next sequence number by
* 1. */
pxTCPWindow->ulOurSequenceNumber = pxTCPWindow->tx.ulFirstSequenceNumber + 1U;
#if ( ipconfigUSE_TCP_WIN == 1 )
{
FreeRTOS_debug_printf( ( "TCP: %s %d => %lxip:%d set ESTAB (scaling %u)\n",
( pxSocket->u.xTCP.ucTCPState == ( uint8_t ) eCONNECT_SYN ) ? "active" : "passive",
pxSocket->usLocalPort,
pxSocket->u.xTCP.ulRemoteIP,
pxSocket->u.xTCP.usRemotePort,
( unsigned ) pxSocket->u.xTCP.bits.bWinScaling ) );
}
#endif /* ipconfigUSE_TCP_WIN */
if( ( pxSocket->u.xTCP.ucTCPState == ( EventBits_t ) eCONNECT_SYN ) || ( ulReceiveLength != 0UL ) )
{
pxTCPHeader->ucTCPFlags = tcpTCP_FLAG_ACK;
uxIntermediateResult = uxIPHeaderSizeSocket( pxSocket ) + ( size_t ) ipSIZE_OF_TCP_HEADER + uxOptionsLength;
xSendLength = ( BaseType_t ) uxIntermediateResult;
pxTCPHeader->ucTCPOffset = ( uint8_t ) ( ( ipSIZE_OF_TCP_HEADER + uxOptionsLength ) << 2 );
}
#if ( ipconfigUSE_TCP_WIN != 0 )
{
if( pxSocket->u.xTCP.bits.bWinScaling == pdFALSE_UNSIGNED )
{
/* The other party did not send a scaling factor.
* A shifting factor in this side must be canceled. */
pxSocket->u.xTCP.ucMyWinScaleFactor = 0;
pxSocket->u.xTCP.ucPeerWinScaleFactor = 0;
}
}
#endif /* ipconfigUSE_TCP_WIN */
/* This was the third step of connecting: SYN, SYN+ACK, ACK so now the
* connection is established. */
vTCPStateChange( pxSocket, eESTABLISHED );
}
return xSendLength;
}
/*-----------------------------------------------------------*/
/**
* @brief prvHandleEstablished(): called from prvTCPHandleState()
* Called if the status is eESTABLISHED. Data reception has been handled
* earlier. Here the ACK's from peer will be checked, and if a FIN is received,
* the code will check if it may be accepted, i.e. if all expected data has been
* completely received.
*
* @param[in] pxSocket: The socket owning the connection.
* @param[in,out] ppxNetworkBuffer: Pointer to pointer to the network buffer.
* @param[in] ulReceiveLength: The length of the received packet.
* @param[in] uxOptionsLength: Length of TCP options.
*
* @return The send length of the packet to be sent.
*/
static BaseType_t prvHandleEstablished( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t ** ppxNetworkBuffer,
uint32_t ulReceiveLength,
UBaseType_t uxOptionsLength )
{
/* Map the buffer onto the ProtocolHeader_t struct for easy access to the fields. */
ProtocolHeaders_t * pxProtocolHeaders = ipCAST_PTR_TO_TYPE_PTR( ProtocolHeaders_t,
&( ( *ppxNetworkBuffer )->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER + uxIPHeaderSizeSocket( pxSocket ) ] ) );
TCPHeader_t * pxTCPHeader = &pxProtocolHeaders->xTCPHeader;
TCPWindow_t * pxTCPWindow = &pxSocket->u.xTCP.xTCPWindow;
uint8_t ucTCPFlags = pxTCPHeader->ucTCPFlags;
uint32_t ulSequenceNumber = FreeRTOS_ntohl( pxTCPHeader->ulSequenceNumber ), ulCount, ulIntermediateResult = 0;
BaseType_t xSendLength = 0, xMayClose = pdFALSE, bRxComplete, bTxDone;
int32_t lDistance, lSendResult;
uint16_t usWindow;
UBaseType_t uxIntermediateResult = 0;
/* Remember the window size the peer is advertising. */
usWindow = FreeRTOS_ntohs( pxTCPHeader->usWindow );
pxSocket->u.xTCP.ulWindowSize = ( uint32_t ) usWindow;
#if ( ipconfigUSE_TCP_WIN != 0 )
{
pxSocket->u.xTCP.ulWindowSize =
( pxSocket->u.xTCP.ulWindowSize << pxSocket->u.xTCP.ucPeerWinScaleFactor );
}
#endif /* ipconfigUSE_TCP_WIN */
if( ( ucTCPFlags & ( uint8_t ) tcpTCP_FLAG_ACK ) != 0U )
{
ulCount = ulTCPWindowTxAck( pxTCPWindow, FreeRTOS_ntohl( pxTCPHeader->ulAckNr ) );
/* ulTCPWindowTxAck() returns the number of bytes which have been acked,
* starting at 'tx.ulCurrentSequenceNumber'. Advance the tail pointer in
* txStream. */
if( ( pxSocket->u.xTCP.txStream != NULL ) && ( ulCount > 0U ) )
{
/* Just advancing the tail index, 'ulCount' bytes have been
* confirmed, and because there is new space in the txStream, the
* user/owner should be woken up. */
/* _HT_ : only in case the socket's waiting? */
if( uxStreamBufferGet( pxSocket->u.xTCP.txStream, 0U, NULL, ( size_t ) ulCount, pdFALSE ) != 0U )
{
pxSocket->xEventBits |= ( EventBits_t ) eSOCKET_SEND;
#if ipconfigSUPPORT_SELECT_FUNCTION == 1
{
if( ( pxSocket->xSelectBits & ( ( EventBits_t ) eSELECT_WRITE ) ) != 0U )
{
pxSocket->xEventBits |= ( ( EventBits_t ) eSELECT_WRITE ) << SOCKET_EVENT_BIT_COUNT;
}
}
#endif
/* In case the socket owner has installed an OnSent handler,
* call it now. */
#if ( ipconfigUSE_CALLBACKS == 1 )
{
if( ipconfigIS_VALID_PROG_ADDRESS( pxSocket->u.xTCP.pxHandleSent ) )
{
pxSocket->u.xTCP.pxHandleSent( ( Socket_t ) pxSocket, ulCount );
}
}
#endif /* ipconfigUSE_CALLBACKS == 1 */
}
}
}
/* If this socket has a stream for transmission, add the data to the
* outgoing segment(s). */
if( pxSocket->u.xTCP.txStream != NULL )
{
prvTCPAddTxData( pxSocket );
}
pxSocket->u.xTCP.xTCPWindow.ulOurSequenceNumber = pxTCPWindow->tx.ulCurrentSequenceNumber;
if( ( pxSocket->u.xTCP.bits.bFinAccepted != pdFALSE_UNSIGNED ) || ( ( ucTCPFlags & ( uint8_t ) tcpTCP_FLAG_FIN ) != 0U ) )
{
/* Peer is requesting to stop, see if we're really finished. */
xMayClose = pdTRUE;
/* Checks are only necessary if we haven't sent a FIN yet. */
if( pxSocket->u.xTCP.bits.bFinSent == pdFALSE_UNSIGNED )
{
/* xTCPWindowTxDone returns true when all Tx queues are empty. */
bRxComplete = xTCPWindowRxEmpty( pxTCPWindow );
bTxDone = xTCPWindowTxDone( pxTCPWindow );
if( ( bRxComplete == 0 ) || ( bTxDone == 0 ) )
{
/* Refusing FIN: Rx incomplete 1 optlen 4 tx done 1. */
FreeRTOS_debug_printf( ( "Refusing FIN[%u,%u]: RxCompl %lu tx done %ld\n",
pxSocket->usLocalPort,
pxSocket->u.xTCP.usRemotePort,
bRxComplete, bTxDone ) );
xMayClose = pdFALSE;
}
else
{
ulIntermediateResult = ulSequenceNumber + ulReceiveLength - pxTCPWindow->rx.ulCurrentSequenceNumber;
lDistance = ( int32_t ) ulIntermediateResult;
if( lDistance > 1 )
{
FreeRTOS_debug_printf( ( "Refusing FIN: Rx not complete %ld (cur %lu high %lu)\n",
lDistance, pxTCPWindow->rx.ulCurrentSequenceNumber - pxTCPWindow->rx.ulFirstSequenceNumber,
pxTCPWindow->rx.ulHighestSequenceNumber - pxTCPWindow->rx.ulFirstSequenceNumber ) );
xMayClose = pdFALSE;
}
}
}
if( xTCPWindowLoggingLevel > 0 )
{
FreeRTOS_debug_printf( ( "TCP: FIN received, mayClose = %ld (Rx %lu Len %ld, Tx %lu)\n",
xMayClose, ulSequenceNumber - pxSocket->u.xTCP.xTCPWindow.rx.ulFirstSequenceNumber, ulReceiveLength,
pxTCPWindow->tx.ulCurrentSequenceNumber - pxSocket->u.xTCP.xTCPWindow.tx.ulFirstSequenceNumber ) );
}
if( xMayClose != pdFALSE )
{
pxSocket->u.xTCP.bits.bFinAccepted = pdTRUE_UNSIGNED;
xSendLength = prvTCPHandleFin( pxSocket, *ppxNetworkBuffer );
}
}
if( xMayClose == pdFALSE )
{
pxTCPHeader->ucTCPFlags = tcpTCP_FLAG_ACK;
if( ulReceiveLength != 0U )
{
uxIntermediateResult = uxIPHeaderSizeSocket( pxSocket ) + ipSIZE_OF_TCP_HEADER + uxOptionsLength;
xSendLength = ( BaseType_t ) uxIntermediateResult;
/* TCP-offset equals '( ( length / 4 ) << 4 )', resulting in a shift-left 2 */
pxTCPHeader->ucTCPOffset = ( uint8_t ) ( ( ipSIZE_OF_TCP_HEADER + uxOptionsLength ) << 2 );
if( pxSocket->u.xTCP.bits.bFinSent != pdFALSE_UNSIGNED )
{
pxTCPWindow->tx.ulCurrentSequenceNumber = pxTCPWindow->tx.ulFINSequenceNumber;
}
}
/* Now get data to be transmitted. */
/* _HT_ patch: since the MTU has be fixed at 1500 in stead of 1526, TCP
* can not send-out both TCP options and also a full packet. Sending
* options (SACK) is always more urgent than sending data, which can be
* sent later. */
if( uxOptionsLength == 0U )
{
/* prvTCPPrepareSend might allocate a bigger network buffer, if
* necessary. */
lSendResult = prvTCPPrepareSend( pxSocket, ppxNetworkBuffer, uxOptionsLength );
if( lSendResult > 0 )
{
xSendLength = ( BaseType_t ) lSendResult;
}
}
}
return xSendLength;
}
/*-----------------------------------------------------------*/
/**
* @brief Called from prvTCPHandleState(). There is data to be sent. If
* ipconfigUSE_TCP_WIN is defined, and if only an ACK must be sent, it will be
* checked if it would better be postponed for efficiency.
*
* @param[in] pxSocket: The socket owning the TCP connection.
* @param[in] ppxNetworkBuffer: Pointer to pointer to the network buffer.
* @param[in] ulReceiveLength: The length of the received buffer.
* @param[in] xByteCount: Length of the data to be sent.
*
* @return The number of bytes actually sent.
*/
static BaseType_t prvSendData( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t ** ppxNetworkBuffer,
uint32_t ulReceiveLength,
BaseType_t xByteCount )
{
/* Map the buffer onto the ProtocolHeader_t struct for easy access to the fields. */
const ProtocolHeaders_t * pxProtocolHeaders = ipCAST_PTR_TO_TYPE_PTR( ProtocolHeaders_t,
&( ( *ppxNetworkBuffer )->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER + xIPHeaderSize( *ppxNetworkBuffer ) ] ) );
const TCPHeader_t * pxTCPHeader = &pxProtocolHeaders->xTCPHeader;
const TCPWindow_t * pxTCPWindow = &pxSocket->u.xTCP.xTCPWindow;
/* Find out what window size we may advertised. */
int32_t lRxSpace;
BaseType_t xSendLength = xByteCount;
uint32_t ulRxBufferSpace;
#if ( ipconfigUSE_TCP_WIN == 1 )
#if ( ipconfigTCP_ACK_EARLIER_PACKET == 0 )
const int32_t lMinLength = 0;
#else
int32_t lMinLength;
#endif
#endif
/* Set the time-out field, so that we'll be called by the IP-task in case no
* next message will be received. */
ulRxBufferSpace = pxSocket->u.xTCP.ulHighestRxAllowed - pxTCPWindow->rx.ulCurrentSequenceNumber;
lRxSpace = ( int32_t ) ulRxBufferSpace;
#if ipconfigUSE_TCP_WIN == 1
{
#if ( ipconfigTCP_ACK_EARLIER_PACKET != 0 )
{
lMinLength = ( ( int32_t ) 2 ) * ( ( int32_t ) pxSocket->u.xTCP.usCurMSS );
}
#endif /* ipconfigTCP_ACK_EARLIER_PACKET */
/* In case we're receiving data continuously, we might postpone sending
* an ACK to gain performance. */
/* lint e9007 is OK because 'uxIPHeaderSizeSocket()' has no side-effects. */
if( ( ulReceiveLength > 0U ) && /* Data was sent to this socket. */
( lRxSpace >= lMinLength ) && /* There is Rx space for more data. */
( pxSocket->u.xTCP.bits.bFinSent == pdFALSE_UNSIGNED ) && /* Not in a closure phase. */
( xSendLength == uxIPHeaderSizeSocket( pxSocket ) + ipSIZE_OF_TCP_HEADER ) && /* No Tx data or options to be sent. */
( pxSocket->u.xTCP.ucTCPState == ( uint8_t ) eESTABLISHED ) && /* Connection established. */
( pxTCPHeader->ucTCPFlags == tcpTCP_FLAG_ACK ) ) /* There are no other flags than an ACK. */
{
if( pxSocket->u.xTCP.pxAckMessage != *ppxNetworkBuffer )
{
/* There was still a delayed in queue, delete it. */
if( pxSocket->u.xTCP.pxAckMessage != NULL )
{
vReleaseNetworkBufferAndDescriptor( pxSocket->u.xTCP.pxAckMessage );
}
pxSocket->u.xTCP.pxAckMessage = *ppxNetworkBuffer;
}
if( ( ulReceiveLength < ( uint32_t ) pxSocket->u.xTCP.usCurMSS ) || /* Received a small message. */
( lRxSpace < ipNUMERIC_CAST( int32_t, 2U * pxSocket->u.xTCP.usCurMSS ) ) ) /* There are less than 2 x MSS space in the Rx buffer. */
{
pxSocket->u.xTCP.usTimeout = ( uint16_t ) tcpDELAYED_ACK_SHORT_DELAY_MS;
}
else
{
/* Normally a delayed ACK should wait 200 ms for a next incoming
* packet. Only wait 20 ms here to gain performance. A slow ACK
* for full-size message. */
pxSocket->u.xTCP.usTimeout = ( uint16_t ) ipMS_TO_MIN_TICKS( tcpDELAYED_ACK_LONGER_DELAY_MS );
}
if( ( xTCPWindowLoggingLevel > 1 ) && ( ipconfigTCP_MAY_LOG_PORT( pxSocket->usLocalPort ) ) )
{
FreeRTOS_debug_printf( ( "Send[%u->%u] del ACK %lu SEQ %lu (len %lu) tmout %u d %lu\n",
pxSocket->usLocalPort,
pxSocket->u.xTCP.usRemotePort,
pxTCPWindow->rx.ulCurrentSequenceNumber - pxTCPWindow->rx.ulFirstSequenceNumber,
pxSocket->u.xTCP.xTCPWindow.ulOurSequenceNumber - pxTCPWindow->tx.ulFirstSequenceNumber,
xSendLength,
pxSocket->u.xTCP.usTimeout, lRxSpace ) );
}
*ppxNetworkBuffer = NULL;
xSendLength = 0;
}
else if( pxSocket->u.xTCP.pxAckMessage != NULL )
{
/* As an ACK is not being delayed, remove any earlier delayed ACK
* message. */
if( pxSocket->u.xTCP.pxAckMessage != *ppxNetworkBuffer )
{
vReleaseNetworkBufferAndDescriptor( pxSocket->u.xTCP.pxAckMessage );
}
pxSocket->u.xTCP.pxAckMessage = NULL;
}
else
{
/* The ack will not be postponed, and there was no stored ack ( in 'pxAckMessage' ). */
}
}
#else /* if ipconfigUSE_TCP_WIN == 1 */
{
/* Remove compiler warnings. */
( void ) ulReceiveLength;
( void ) pxTCPHeader;
( void ) lRxSpace;
}
#endif /* ipconfigUSE_TCP_WIN */
if( xSendLength != 0 )
{
if( ( xTCPWindowLoggingLevel > 1 ) && ( ipconfigTCP_MAY_LOG_PORT( pxSocket->usLocalPort ) ) )
{
FreeRTOS_debug_printf( ( "Send[%u->%u] imm ACK %lu SEQ %lu (len %lu)\n",
pxSocket->usLocalPort,
pxSocket->u.xTCP.usRemotePort,
pxTCPWindow->rx.ulCurrentSequenceNumber - pxTCPWindow->rx.ulFirstSequenceNumber,
pxTCPWindow->ulOurSequenceNumber - pxTCPWindow->tx.ulFirstSequenceNumber,
xSendLength ) );
}
/* Set the parameter 'xReleaseAfterSend' to the value of
* ipconfigZERO_COPY_TX_DRIVER. */
prvTCPReturnPacket( pxSocket, *ppxNetworkBuffer, ( uint32_t ) xSendLength, ipconfigZERO_COPY_TX_DRIVER );
#if ( ipconfigZERO_COPY_TX_DRIVER != 0 )
{
/* The driver has taken ownership of the Network Buffer. */
*ppxNetworkBuffer = NULL;
}
#endif
}
return xSendLength;
}
/*-----------------------------------------------------------*/
/**
* @brief Check incoming packets for valid data and handle the state of the
* TCP connection and respond according to the situation.
*
* @param[in] pxSocket: The socket whose connection state is being handled.
* @param[in] ppxNetworkBuffer: The network buffer descriptor holding the
* packet received from the peer.
*
* @return If the data is correct and some packet was sent to the peer, then
* the number of bytes sent is returned, or else a negative value is
* returned indicating an error.
*
* @note prvTCPHandleState() is the most important function of this TCP stack
* We've tried to keep it (relatively short) by putting a lot of code in
* the static functions above:
*
* prvCheckRxData()
* prvStoreRxData()
* prvSetOptions()
* prvHandleSynReceived()
* prvHandleEstablished()
* prvSendData()
*
* As these functions are declared static, and they're called from one location
* only, most compilers will inline them, thus avoiding a call and return.
*/
static BaseType_t prvTCPHandleState( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t ** ppxNetworkBuffer )
{
/* Map the buffer onto the ProtocolHeader_t struct for easy access to the fields. */
ProtocolHeaders_t * pxProtocolHeaders = ipCAST_PTR_TO_TYPE_PTR( ProtocolHeaders_t,
&( ( *ppxNetworkBuffer )->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER + xIPHeaderSize( *ppxNetworkBuffer ) ] ) );
TCPHeader_t * pxTCPHeader = &( pxProtocolHeaders->xTCPHeader );
BaseType_t xSendLength = 0;
uint32_t ulReceiveLength; /* Number of bytes contained in the TCP message. */
uint8_t * pucRecvData;
uint32_t ulSequenceNumber = FreeRTOS_ntohl( pxTCPHeader->ulSequenceNumber );
/* uxOptionsLength: the size of the options to be sent (always a multiple of
* 4 bytes)
* 1. in the SYN phase, we shall communicate the MSS
* 2. in case of a SACK, Selective ACK, ack a segment which comes in
* out-of-order. */
UBaseType_t uxOptionsLength = 0U;
uint8_t ucTCPFlags = pxTCPHeader->ucTCPFlags;
TCPWindow_t * pxTCPWindow = &( pxSocket->u.xTCP.xTCPWindow );
UBaseType_t uxIntermediateResult = 0;
/* First get the length and the position of the received data, if any.
* pucRecvData will point to the first byte of the TCP payload. */
ulReceiveLength = ( uint32_t ) prvCheckRxData( *ppxNetworkBuffer, &pucRecvData );
if( pxSocket->u.xTCP.ucTCPState >= ( uint8_t ) eESTABLISHED )
{
if( pxTCPWindow->rx.ulCurrentSequenceNumber == ( ulSequenceNumber + 1UL ) )
{
/* This is most probably a keep-alive message from peer. Setting
* 'bWinChange' doesn't cause a window-size-change, the flag is used
* here to force sending an immediate ACK. */
pxSocket->u.xTCP.bits.bWinChange = pdTRUE_UNSIGNED;
}
}
/* Keep track of the highest sequence number that might be expected within
* this connection. */
if( ( ( int32_t ) ( ulSequenceNumber + ulReceiveLength - pxTCPWindow->rx.ulHighestSequenceNumber ) ) > 0L )
{
pxTCPWindow->rx.ulHighestSequenceNumber = ulSequenceNumber + ulReceiveLength;
}
/* Storing data may result in a fatal error if malloc() fails. */
if( prvStoreRxData( pxSocket, pucRecvData, *ppxNetworkBuffer, ulReceiveLength ) < 0 )
{
xSendLength = -1;
}
else
{
uxOptionsLength = prvSetOptions( pxSocket, *ppxNetworkBuffer );
if( ( pxSocket->u.xTCP.ucTCPState == ( uint8_t ) eSYN_RECEIVED ) && ( ( ucTCPFlags & ( uint8_t ) tcpTCP_FLAG_CTRL ) == ( uint8_t ) tcpTCP_FLAG_SYN ) )
{
FreeRTOS_debug_printf( ( "eSYN_RECEIVED: ACK expected, not SYN: peer missed our SYN+ACK\n" ) );
/* In eSYN_RECEIVED a simple ACK is expected, but apparently the
* 'SYN+ACK' didn't arrive. Step back to the previous state in which
* a first incoming SYN is handled. The SYN was counted already so
* decrease it first. */
vTCPStateChange( pxSocket, eSYN_FIRST );
}
if( ( ( ucTCPFlags & tcpTCP_FLAG_FIN ) != 0U ) && ( pxSocket->u.xTCP.bits.bFinRecv == pdFALSE_UNSIGNED ) )
{
/* It's the first time a FIN has been received, remember its
* sequence number. */
pxTCPWindow->rx.ulFINSequenceNumber = ulSequenceNumber + ulReceiveLength;
pxSocket->u.xTCP.bits.bFinRecv = pdTRUE_UNSIGNED;
/* Was peer the first one to send a FIN? */
if( pxSocket->u.xTCP.bits.bFinSent == pdFALSE_UNSIGNED )
{
/* If so, don't send the-last-ACK. */
pxSocket->u.xTCP.bits.bFinLast = pdTRUE_UNSIGNED;
}
}
switch( ipNUMERIC_CAST( eIPTCPState_t, pxSocket->u.xTCP.ucTCPState ) )
{
case eCLOSED: /* (server + client) no connection state at all. */
/* Nothing to do for a closed socket, except waiting for the
* owner. */
break;
case eTCP_LISTEN: /* (server) waiting for a connection request from
* any remote TCP and port. */
/* The listen state was handled in xProcessReceivedTCPPacket().
* Should not come here. */
break;
case eSYN_FIRST: /* (server) Just received a SYN request for a server
* socket. */
/* A new socket has been created, reply with a SYN+ACK.
* Acknowledge with seq+1 because the SYN is seen as pseudo data
* with len = 1. */
uxOptionsLength = prvSetSynAckOptions( pxSocket, pxTCPHeader );
pxTCPHeader->ucTCPFlags = ( uint8_t ) tcpTCP_FLAG_SYN | ( uint8_t ) tcpTCP_FLAG_ACK;
uxIntermediateResult = uxIPHeaderSizeSocket( pxSocket ) + ipSIZE_OF_TCP_HEADER + uxOptionsLength;
xSendLength = ( BaseType_t ) uxIntermediateResult;
/* Set the TCP offset field: ipSIZE_OF_TCP_HEADER equals 20 and
* uxOptionsLength is a multiple of 4. The complete expression is:
* ucTCPOffset = ( ( ipSIZE_OF_TCP_HEADER + uxOptionsLength ) / 4 ) << 4 */
pxTCPHeader->ucTCPOffset = ( uint8_t ) ( ( ipSIZE_OF_TCP_HEADER + uxOptionsLength ) << 2 );
vTCPStateChange( pxSocket, eSYN_RECEIVED );
pxTCPWindow->rx.ulHighestSequenceNumber = ulSequenceNumber + 1UL;
pxTCPWindow->rx.ulCurrentSequenceNumber = ulSequenceNumber + 1UL;
pxTCPWindow->ulNextTxSequenceNumber = pxTCPWindow->tx.ulFirstSequenceNumber + 1UL;
pxTCPWindow->tx.ulCurrentSequenceNumber = pxTCPWindow->tx.ulFirstSequenceNumber + 1UL; /* because we send a TCP_SYN. */
break;
case eCONNECT_SYN: /* (client) also called SYN_SENT: we've just send a
* SYN, expect a SYN+ACK and send a ACK now. */
/* Fall through */
case eSYN_RECEIVED: /* (server) we've had a SYN, replied with SYN+SCK
* expect a ACK and do nothing. */
xSendLength = prvHandleSynReceived( pxSocket, *( ppxNetworkBuffer ), ulReceiveLength, uxOptionsLength );
break;
case eESTABLISHED: /* (server + client) an open connection, data
* received can be delivered to the user. The normal
* state for the data transfer phase of the connection
* The closing states are also handled here with the
* use of some flags. */
xSendLength = prvHandleEstablished( pxSocket, ppxNetworkBuffer, ulReceiveLength, uxOptionsLength );
break;
case eLAST_ACK: /* (server + client) waiting for an acknowledgement
* of the connection termination request previously
* sent to the remote TCP (which includes an
* acknowledgement of its connection termination
* request). */
/* Fall through */
case eFIN_WAIT_1: /* (server + client) waiting for a connection termination request from the remote TCP,
* or an acknowledgement of the connection termination request previously sent. */
/* Fall through */
case eFIN_WAIT_2: /* (server + client) waiting for a connection termination request from the remote TCP. */
xSendLength = prvTCPHandleFin( pxSocket, *ppxNetworkBuffer );
break;
case eCLOSE_WAIT: /* (server + client) waiting for a connection
* termination request from the local user. Nothing to
* do, connection is closed, wait for owner to close
* this socket. */
break;
case eCLOSING: /* (server + client) waiting for a connection
* termination request acknowledgement from the remote
* TCP. */
break;
case eTIME_WAIT: /* (either server or client) waiting for enough time
* to pass to be sure the remote TCP received the
* acknowledgement of its connection termination
* request. [According to RFC 793 a connection can stay
* in TIME-WAIT for a maximum of four minutes known as
* a MSL (maximum segment lifetime).] These states are
* implemented implicitly by settings flags like
* 'bFinSent', 'bFinRecv', and 'bFinAcked'. */
break;
default:
/* No more known states. */
break;
}
}
if( xSendLength > 0 )
{
xSendLength = prvSendData( pxSocket, ppxNetworkBuffer, ulReceiveLength, xSendLength );
}
return xSendLength;
}
/*-----------------------------------------------------------*/
/**
* @brief Common code for sending a TCP protocol control packet (i.e. no options, no
* payload, just flags).
*
* @param[in] pxNetworkBuffer: The network buffer received from the peer.
* @param[in] ucTCPFlags: The flags to determine what kind of packet this is.
*
* @return pdFAIL always indicating that the packet was not consumed.
*/
static BaseType_t prvTCPSendSpecialPacketHelper( NetworkBufferDescriptor_t * pxNetworkBuffer,
uint8_t ucTCPFlags )
{
#if ( ipconfigIGNORE_UNKNOWN_PACKETS == 1 )
/* Configured to ignore unknown packets just suppress a compiler warning. */
( void ) pxNetworkBuffer;
( void ) ucTCPFlags;
#else
{
/* Map the ethernet buffer onto the TCPPacket_t struct for easy access to the fields. */
TCPPacket_t * pxTCPPacket = ipCAST_PTR_TO_TYPE_PTR( TCPPacket_t, pxNetworkBuffer->pucEthernetBuffer );
const uint32_t ulSendLength =
( ipSIZE_OF_IPv4_HEADER + ipSIZE_OF_TCP_HEADER ); /* Plus 0 options. */
pxTCPPacket->xTCPHeader.ucTCPFlags = ucTCPFlags;
pxTCPPacket->xTCPHeader.ucTCPOffset = ( ipSIZE_OF_TCP_HEADER ) << 2;
prvTCPReturnPacket( NULL, pxNetworkBuffer, ulSendLength, pdFALSE );
}
#endif /* !ipconfigIGNORE_UNKNOWN_PACKETS */
/* The packet was not consumed. */
return pdFAIL;
}
/*-----------------------------------------------------------*/
/**
* @brief A "challenge ACK" is as per https://tools.ietf.org/html/rfc5961#section-3.2,
* case #3. In summary, an RST was received with a sequence number that is
* unexpected but still within the window.
*
* @param[in] pxNetworkBuffer: The network buffer descriptor with the packet.
*
* @return Returns the value back from #prvTCPSendSpecialPacketHelper.
*/
static BaseType_t prvTCPSendChallengeAck( NetworkBufferDescriptor_t * pxNetworkBuffer )
{
return prvTCPSendSpecialPacketHelper( pxNetworkBuffer, tcpTCP_FLAG_ACK );
}
/*-----------------------------------------------------------*/
/**
* @brief Send a RST (Reset) to peer in case the packet cannot be handled.
*
* @param[in] pxNetworkBuffer: The network buffer descriptor with the packet.
*
* @return Returns the value back from #prvTCPSendSpecialPacketHelper.
*/
static BaseType_t prvTCPSendReset( NetworkBufferDescriptor_t * pxNetworkBuffer )
{
return prvTCPSendSpecialPacketHelper( pxNetworkBuffer,
( uint8_t ) tcpTCP_FLAG_ACK | ( uint8_t ) tcpTCP_FLAG_RST );
}
/*-----------------------------------------------------------*/
/**
* @brief Set the MSS (Maximum segment size) associated with the given socket.
*
* @param[in] pxSocket: The socket whose MSS is to be set.
*/
static void prvSocketSetMSS( FreeRTOS_Socket_t * pxSocket )
{
uint32_t ulMSS = ipconfigTCP_MSS;
if( ( ( FreeRTOS_ntohl( pxSocket->u.xTCP.ulRemoteIP ) ^ *ipLOCAL_IP_ADDRESS_POINTER ) & xNetworkAddressing.ulNetMask ) != 0UL )
{
/* Data for this peer will pass through a router, and maybe through
* the internet. Limit the MSS to 1400 bytes or less. */
ulMSS = FreeRTOS_min_uint32( ( uint32_t ) tcpREDUCED_MSS_THROUGH_INTERNET, ulMSS );
}
FreeRTOS_debug_printf( ( "prvSocketSetMSS: %lu bytes for %lxip:%u\n", ulMSS, pxSocket->u.xTCP.ulRemoteIP, pxSocket->u.xTCP.usRemotePort ) );
pxSocket->u.xTCP.usInitMSS = ( uint16_t ) ulMSS;
pxSocket->u.xTCP.usCurMSS = ( uint16_t ) ulMSS;
}
/*-----------------------------------------------------------*/
/**
* @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 )
{
/* Function might modify the parameter. */
NetworkBufferDescriptor_t * pxNetworkBuffer = pxDescriptor;
/* Map the buffer onto a ProtocolHeaders_t struct for easy access to the fields. */
const ProtocolHeaders_t * pxProtocolHeaders = ipCAST_CONST_PTR_TO_CONST_TYPE_PTR( ProtocolHeaders_t,
&( pxNetworkBuffer->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER + xIPHeaderSize( pxNetworkBuffer ) ] ) );
FreeRTOS_Socket_t * pxSocket;
uint16_t ucTCPFlags = pxProtocolHeaders->xTCPHeader.ucTCPFlags;
uint32_t ulLocalIP;
uint16_t xLocalPort = FreeRTOS_htons( pxProtocolHeaders->xTCPHeader.usDestinationPort );
uint16_t xRemotePort = FreeRTOS_htons( pxProtocolHeaders->xTCPHeader.usSourcePort );
uint32_t ulRemoteIP;
uint32_t ulSequenceNumber = FreeRTOS_ntohl( pxProtocolHeaders->xTCPHeader.ulSequenceNumber );
uint32_t ulAckNumber = FreeRTOS_ntohl( pxProtocolHeaders->xTCPHeader.ulAckNr );
BaseType_t xResult = pdPASS;
configASSERT( pxNetworkBuffer != NULL );
configASSERT( pxNetworkBuffer->pucEthernetBuffer != NULL );
const IPHeader_t * pxIPHeader;
/* Check for a minimum packet size. */
if( pxNetworkBuffer->xDataLength < ( ipSIZE_OF_ETH_HEADER + xIPHeaderSize( pxNetworkBuffer ) + ipSIZE_OF_TCP_HEADER ) )
{
xResult = pdFAIL;
}
else
{
/* Map the ethernet buffer onto the IPHeader_t struct for easy access to the fields. */
pxIPHeader = ipCAST_CONST_PTR_TO_CONST_TYPE_PTR( IPHeader_t, &( pxNetworkBuffer->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER ] ) );
ulLocalIP = FreeRTOS_htonl( pxIPHeader->ulDestinationIPAddress );
ulRemoteIP = FreeRTOS_htonl( pxIPHeader->ulSourceIPAddress );
/* Find the destination socket, and if not found: return a socket listing to
* the destination PORT. */
pxSocket = ( FreeRTOS_Socket_t * ) pxTCPSocketLookup( ulLocalIP, xLocalPort, ulRemoteIP, xRemotePort );
if( ( pxSocket == NULL ) || ( prvTCPSocketIsActive( ipNUMERIC_CAST( eIPTCPState_t, pxSocket->u.xTCP.ucTCPState ) ) == 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 (%lxip:%d)\n", xLocalPort, ulRemoteIP, xRemotePort ) );
/* 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.ucTCPState == ( uint8_t ) 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 %lxip:%u to port %u\n",
prvTCPFlagMeaning( ( UBaseType_t ) ucTCPFlags ), ulRemoteIP, xRemotePort, xLocalPort ) );
}
#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.ucTCPState == 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 %lxip:%u for %u\n", ulRemoteIP, xRemotePort, xLocalPort ) );
/* Implement https://tools.ietf.org/html/rfc5961#section-3.2. */
if( pxSocket->u.xTCP.ucTCPState == ( uint8_t ) eCONNECT_SYN )
{
/* 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 + 1UL ) )
{
vTCPStateChange( pxSocket, eCLOSED );
}
}
else
{
/* 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( ( ulSequenceNumber > pxSocket->u.xTCP.xTCPWindow.rx.ulCurrentSequenceNumber ) &&
( ulSequenceNumber < ( pxSocket->u.xTCP.xTCPWindow.rx.ulCurrentSequenceNumber +
pxSocket->u.xTCP.xTCPWindow.xSize.ulRxWindowLength ) ) )
{
/* Send a challenge ACK. */
( void ) prvTCPSendChallengeAck( pxNetworkBuffer );
}
else
{
/* Nothing. */
}
}
/* Otherwise, do nothing. In any case, the packet cannot be handled. */
xResult = pdFAIL;
}
else if( ( ( ucTCPFlags & tcpTCP_FLAG_CTRL ) == tcpTCP_FLAG_SYN ) && ( pxSocket->u.xTCP.ucTCPState >= ( uint8_t ) eESTABLISHED ) )
{
/* SYN flag while this socket is already connected. */
FreeRTOS_debug_printf( ( "TCP: SYN unexpected from %lxip:%u\n", ulRemoteIP, xRemotePort ) );
/* 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 );
}
}
}
if( xResult != pdFAIL )
{
uint16_t usWindow;
/* pxSocket is not NULL when xResult != pdFAIL. */
configASSERT( pxSocket != NULL );
/* 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( ( pxProtocolHeaders->xTCPHeader.ucTCPOffset & tcpTCP_OFFSET_LENGTH_BITS ) > tcpTCP_OFFSET_STANDARD_LENGTH )
{
prvCheckOptions( pxSocket, pxNetworkBuffer );
}
usWindow = FreeRTOS_ntohs( pxProtocolHeaders->xTCPHeader.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 );
/* Return pdPASS to tell that the network buffer is 'consumed'. */
xResult = pdPASS;
}
}
/* pdPASS being returned means the buffer has been consumed. */
return xResult;
}
/*-----------------------------------------------------------*/
/**
* @brief Handle 'listen' event on the given socket.
*
* @param[in] pxSocket: The socket on which the listen occurred.
* @param[in] pxNetworkBuffer: The network buffer carrying the packet.
*
* @return If a new socket/duplicate socket is created, then the pointer to
* that socket is returned or else, a NULL pointer is returned.
*/
static FreeRTOS_Socket_t * prvHandleListen( FreeRTOS_Socket_t * pxSocket,
NetworkBufferDescriptor_t * pxNetworkBuffer )
{
/* Map the ethernet buffer onto a TCPPacket_t struct for easy access to the fields. */
const TCPPacket_t * pxTCPPacket = ipCAST_CONST_PTR_TO_CONST_TYPE_PTR( TCPPacket_t, pxNetworkBuffer->pucEthernetBuffer );
FreeRTOS_Socket_t * pxReturn = NULL;
uint32_t ulInitialSequenceNumber;
/* Assume that a new Initial Sequence Number will be required. Request
* it now in order to fail out if necessary. */
ulInitialSequenceNumber = ulApplicationGetNextSequenceNumber( *ipLOCAL_IP_ADDRESS_POINTER,
pxSocket->usLocalPort,
pxTCPPacket->xIPHeader.ulSourceIPAddress,
pxTCPPacket->xTCPHeader.usSourcePort );
/* A pure SYN (without ACK) has come in, create a new socket to answer
* it. */
if( ulInitialSequenceNumber != 0UL )
{
if( pxSocket->u.xTCP.bits.bReuseSocket != pdFALSE_UNSIGNED )
{
/* The flag bReuseSocket indicates that the same instance of the
* listening socket should be used for the connection. */
pxReturn = pxSocket;
pxSocket->u.xTCP.bits.bPassQueued = pdTRUE_UNSIGNED;
pxSocket->u.xTCP.pxPeerSocket = pxSocket;
}
else
{
/* The socket does not have the bReuseSocket flag set meaning create a
* new socket when a connection comes in. */
pxReturn = NULL;
if( pxSocket->u.xTCP.usChildCount >= pxSocket->u.xTCP.usBacklog )
{
FreeRTOS_printf( ( "Check: Socket %u already has %u / %u child%s\n",
pxSocket->usLocalPort,
pxSocket->u.xTCP.usChildCount,
pxSocket->u.xTCP.usBacklog,
( pxSocket->u.xTCP.usChildCount == 1U ) ? "" : "ren" ) );
( void ) prvTCPSendReset( pxNetworkBuffer );
}
else
{
FreeRTOS_Socket_t * pxNewSocket = ( FreeRTOS_Socket_t * )
FreeRTOS_socket( FREERTOS_AF_INET, FREERTOS_SOCK_STREAM, FREERTOS_IPPROTO_TCP );
if( ( pxNewSocket == NULL ) || ( pxNewSocket == FREERTOS_INVALID_SOCKET ) )
{
FreeRTOS_debug_printf( ( "TCP: Listen: new socket failed\n" ) );
( void ) prvTCPSendReset( pxNetworkBuffer );
}
else if( prvTCPSocketCopy( pxNewSocket, pxSocket ) != pdFALSE )
{
/* The socket will be connected immediately, no time for the
* owner to setsockopt's, therefore copy properties of the server
* socket to the new socket. Only the binding might fail (due to
* lack of resources). */
pxReturn = pxNewSocket;
}
else
{
/* Copying failed somehow. */
}
}
}
}
if( ( ulInitialSequenceNumber != 0U ) && ( pxReturn != NULL ) )
{
/* Map the byte stream onto the ProtocolHeaders_t for easy access to the fields. */
const ProtocolHeaders_t * pxProtocolHeaders = ipCAST_CONST_PTR_TO_CONST_TYPE_PTR( ProtocolHeaders_t,
&( pxNetworkBuffer->pucEthernetBuffer[ ipSIZE_OF_ETH_HEADER + xIPHeaderSize( pxNetworkBuffer ) ] ) );
pxReturn->u.xTCP.usRemotePort = FreeRTOS_htons( pxTCPPacket->xTCPHeader.usSourcePort );
pxReturn->u.xTCP.ulRemoteIP = FreeRTOS_htonl( pxTCPPacket->xIPHeader.ulSourceIPAddress );
pxReturn->u.xTCP.xTCPWindow.ulOurSequenceNumber = ulInitialSequenceNumber;
/* Here is the SYN action. */
pxReturn->u.xTCP.xTCPWindow.rx.ulCurrentSequenceNumber = FreeRTOS_ntohl( pxProtocolHeaders->xTCPHeader.ulSequenceNumber );
prvSocketSetMSS( pxReturn );
prvTCPCreateWindow( pxReturn );
vTCPStateChange( pxReturn, eSYN_FIRST );
/* Make a copy of the header up to the TCP header. It is needed later
* on, whenever data must be sent to the peer. */
( void ) memcpy( ( void * ) pxReturn->u.xTCP.xPacket.u.ucLastPacket,
( const void * ) pxNetworkBuffer->pucEthernetBuffer,
sizeof( pxReturn->u.xTCP.xPacket.u.ucLastPacket ) );
}
return pxReturn;
}
/*-----------------------------------------------------------*/
/**
* @brief Duplicates a socket after a listening socket receives a connection and bind
* the new socket to the same port as the listening socket.
* Also, let the new socket inherit all properties from the listening socket.
*
* @param[in] pxNewSocket: Pointer to the new socket.
* @param[in] pxSocket: Pointer to the socket being duplicated.
*
* @return If all steps all successful, then pdTRUE is returned. Else, pdFALSE.
*/
static BaseType_t prvTCPSocketCopy( FreeRTOS_Socket_t * pxNewSocket,
FreeRTOS_Socket_t * pxSocket )
{
struct freertos_sockaddr xAddress;
BaseType_t xResult;
pxNewSocket->xReceiveBlockTime = pxSocket->xReceiveBlockTime;
pxNewSocket->xSendBlockTime = pxSocket->xSendBlockTime;
pxNewSocket->ucSocketOptions = pxSocket->ucSocketOptions;
pxNewSocket->u.xTCP.uxRxStreamSize = pxSocket->u.xTCP.uxRxStreamSize;
pxNewSocket->u.xTCP.uxTxStreamSize = pxSocket->u.xTCP.uxTxStreamSize;
pxNewSocket->u.xTCP.uxLittleSpace = pxSocket->u.xTCP.uxLittleSpace;
pxNewSocket->u.xTCP.uxEnoughSpace = pxSocket->u.xTCP.uxEnoughSpace;
pxNewSocket->u.xTCP.uxRxWinSize = pxSocket->u.xTCP.uxRxWinSize;
pxNewSocket->u.xTCP.uxTxWinSize = pxSocket->u.xTCP.uxTxWinSize;
#if ( ipconfigSOCKET_HAS_USER_SEMAPHORE == 1 )
{
pxNewSocket->pxUserSemaphore = pxSocket->pxUserSemaphore;
}
#endif /* ipconfigSOCKET_HAS_USER_SEMAPHORE */
#if ( ipconfigUSE_CALLBACKS == 1 )
{
/* In case call-backs are used, copy them from parent to child. */
pxNewSocket->u.xTCP.pxHandleConnected = pxSocket->u.xTCP.pxHandleConnected;
pxNewSocket->u.xTCP.pxHandleReceive = pxSocket->u.xTCP.pxHandleReceive;
pxNewSocket->u.xTCP.pxHandleSent = pxSocket->u.xTCP.pxHandleSent;
}
#endif /* ipconfigUSE_CALLBACKS */
#if ( ipconfigSUPPORT_SELECT_FUNCTION == 1 )
{
/* Child socket of listening sockets will inherit the Socket Set
* Otherwise the owner has no chance of including it into the set. */
if( pxSocket->pxSocketSet != NULL )
{
pxNewSocket->pxSocketSet = pxSocket->pxSocketSet;
pxNewSocket->xSelectBits = pxSocket->xSelectBits | ( ( EventBits_t ) eSELECT_READ ) | ( ( EventBits_t ) eSELECT_EXCEPT );
}
}
#endif /* ipconfigSUPPORT_SELECT_FUNCTION */
/* And bind it to the same local port as its parent. */
xAddress.sin_addr = *ipLOCAL_IP_ADDRESS_POINTER;
xAddress.sin_port = FreeRTOS_htons( pxSocket->usLocalPort );
#if ( ipconfigTCP_HANG_PROTECTION == 1 )
{
/* Only when there is anti-hanging protection, a socket may become an
* orphan temporarily. Once this socket is really connected, the owner of
* the server socket will be notified. */
/* When bPassQueued is true, the socket is an orphan until it gets
* connected. */
pxNewSocket->u.xTCP.bits.bPassQueued = pdTRUE_UNSIGNED;
pxNewSocket->u.xTCP.pxPeerSocket = pxSocket;
}
#else
{
/* A reference to the new socket may be stored and the socket is marked
* as 'passable'. */
/* When bPassAccept is true, this socket may be returned in a call to
* accept(). */
pxNewSocket->u.xTCP.bits.bPassAccept = pdTRUE_UNSIGNED;
if( pxSocket->u.xTCP.pxPeerSocket == NULL )
{
pxSocket->u.xTCP.pxPeerSocket = pxNewSocket;
}
}
#endif /* if ( ipconfigTCP_HANG_PROTECTION == 1 ) */
pxSocket->u.xTCP.usChildCount++;
FreeRTOS_debug_printf( ( "Gain: Socket %u now has %u / %u child%s\n",
pxSocket->usLocalPort,
pxSocket->u.xTCP.usChildCount,
pxSocket->u.xTCP.usBacklog,
( pxSocket->u.xTCP.usChildCount == 1U ) ? "" : "ren" ) );
/* Now bind the child socket to the same port as the listening socket. */
if( vSocketBind( pxNewSocket, &xAddress, sizeof( xAddress ), pdTRUE ) != 0 )
{
FreeRTOS_debug_printf( ( "TCP: Listen: new socket bind error\n" ) );
( void ) FreeRTOS_closesocket( pxNewSocket );
xResult = pdFALSE;
}
else
{
xResult = pdTRUE;
}
return xResult;
}
/*-----------------------------------------------------------*/
#if ( ( ipconfigHAS_DEBUG_PRINTF != 0 ) || ( ipconfigHAS_PRINTF != 0 ) )
const char * FreeRTOS_GetTCPStateName( UBaseType_t ulState )
{
static const char * const pcStateNames[] =
{
"eCLOSED",
"eTCP_LISTEN",
"eCONNECT_SYN",
"eSYN_FIRST",
"eSYN_RECEIVED",
"eESTABLISHED",
"eFIN_WAIT_1",
"eFIN_WAIT_2",
"eCLOSE_WAIT",
"eCLOSING",
"eLAST_ACK",
"eTIME_WAIT",
"eUNKNOWN",
};
BaseType_t xIndex = ( BaseType_t ) ulState;
if( ( xIndex < 0 ) || ( xIndex >= ARRAY_SIZE( pcStateNames ) ) )
{
/* The last item is called 'eUNKNOWN' */
xIndex = ARRAY_SIZE( pcStateNames );
xIndex--;
}
return pcStateNames[ xIndex ];
}
#endif /* ( ( ipconfigHAS_DEBUG_PRINTF != 0 ) || ( ipconfigHAS_PRINTF != 0 ) ) */
/*-----------------------------------------------------------*/
/**
* @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;
const ListItem_t * pxEndTCP = listGET_END_MARKER( &xBoundTCPSocketsList );
/* 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 = ipCAST_PTR_TO_TYPE_PTR( 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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