Helper functions for TCP. More...

#include "core/net.h"
#include "core/socket.h"
#include "core/tcp.h"
#include "core/tcp_misc.h"
#include "core/tcp_timer.h"
#include "core/ip.h"
#include "ipv4/ipv4.h"
#include "ipv6/ipv6.h"
#include "mibs/mib2_module.h"
#include "mibs/tcp_mib_module.h"
#include "date_time.h"
#include "debug.h"
#include "hash/md5.h"

Macros
#define	TRACE_LEVEL TCP_TRACE_LEVEL

Functions
error_t	tcpSendSegment (Socket *socket, uint8_t flags, uint32_t seqNum, uint32_t ackNum, size_t length, bool_t addToQueue)
	Send a TCP segment. More...

error_t	tcpSendResetSegment (Socket *socket, uint32_t seqNum)
	Send a TCP reset segment. More...

error_t	tcpRejectSegment (NetInterface interface, const IpPseudoHeader pseudoHeader, const TcpHeader *segment, size_t length)
	Send a TCP reset in response to an invalid segment. More...

error_t	tcpAddOption (TcpHeader segment, uint8_t kind, const void value, uint8_t length)
	Append an option to the TCP header. More...

const TcpOption *	tcpGetOption (const TcpHeader *segment, uint8_t kind)
	Search the TCP header for a given option. More...

uint32_t	tcpGenerateInitialSeqNum (const IpAddr localIpAddr, uint16_t localPort, const IpAddr remoteIpAddr, uint16_t remotePort)
	Initial sequence number generation. More...

error_t	tcpCheckSeqNum (Socket socket, const TcpHeader segment, size_t length)
	Test the sequence number of an incoming segment. More...

error_t	tcpCheckSyn (Socket socket, const TcpHeader segment, size_t length)
	Check the SYN bit of an incoming segment. More...

error_t	tcpCheckAck (Socket socket, const TcpHeader segment, size_t length)
	Test the ACK field of an incoming segment. More...

bool_t	tcpIsDuplicateSyn (Socket socket, const IpPseudoHeader pseudoHeader, const TcpHeader *segment)
	Test whether the incoming SYN segment is a duplicate. More...

bool_t	tcpIsDuplicateAck (Socket socket, const TcpHeader segment, size_t length)
	Test whether the incoming acknowledgment is a duplicate. More...

void	tcpFastRetransmit (Socket *socket)
	Fast retransmit procedure. More...

void	tcpFastRecovery (Socket socket, const TcpHeader segment, uint_t n)
	Fast recovery procedure. More...

void	tcpFastLossRecovery (Socket socket, const TcpHeader segment)
	Fast loss recovery procedure. More...

void	tcpProcessSegmentData (Socket socket, const TcpHeader segment, const NetBuffer *buffer, size_t offset, size_t length)
	Process the segment text. More...

void	tcpDeleteControlBlock (Socket *socket)
	Delete TCB structure. More...

void	tcpUpdateRetransmitQueue (Socket *socket)
	Remove acknowledged segments from retransmission queue. More...

void	tcpFlushRetransmitQueue (Socket *socket)
	Flush retransmission queue. More...

void	tcpFlushSynQueue (Socket *socket)
	Flush SYN queue. More...

void	tcpUpdateSackBlocks (Socket socket, uint32_t leftEdge, uint32_t *rightEdge)
	Update the list of non-contiguous blocks that have been received. More...

void	tcpUpdateSendWindow (Socket socket, const TcpHeader segment)
	Update send window. More...

void	tcpUpdateReceiveWindow (Socket *socket)
	Update receive window so as to avoid Silly Window Syndrome. More...

bool_t	tcpComputeRto (Socket *socket)
	Compute retransmission timeout. More...

error_t	tcpRetransmitSegment (Socket *socket)
	TCP segment retransmission. More...

error_t	tcpNagleAlgo (Socket *socket, uint_t flags)
	Nagle algorithm implementation. More...

void	tcpChangeState (Socket *socket, TcpState newState)
	Update TCP FSM current state. More...

void	tcpUpdateEvents (Socket *socket)
	Update TCP related events. More...

uint_t	tcpWaitForEvents (Socket *socket, uint_t eventMask, systime_t timeout)
	Wait for a particular TCP event. More...

void	tcpWriteTxBuffer (Socket socket, uint32_t seqNum, const uint8_t data, size_t length)
	Copy incoming data to the send buffer. More...

error_t	tcpReadTxBuffer (Socket socket, uint32_t seqNum, NetBuffer buffer, size_t length)
	Copy data from the send buffer. More...

void	tcpWriteRxBuffer (Socket socket, uint32_t seqNum, const NetBuffer data, size_t dataOffset, size_t length)
	Copy incoming data to the receive buffer. More...

void	tcpReadRxBuffer (Socket socket, uint32_t seqNum, uint8_t data, size_t length)
	Copy data from the receive buffer. More...

void	tcpDumpHeader (const TcpHeader *segment, size_t length, uint32_t iss, uint32_t irs)
	Dump TCP header for debugging purpose. More...

Detailed Description

Helper functions for TCP.

License

SPDX-License-Identifier: GPL-2.0-or-later

This file is part of CycloneTCP Open.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

Author: Oryx Embedded SARL (www.oryx-embedded.com)

Version: 2.4.4

Definition in file tcp_misc.c.

Macro Definition Documentation

◆ TRACE_LEVEL

#define TRACE_LEVEL TCP_TRACE_LEVEL

Definition at line 32 of file tcp_misc.c.

Function Documentation

◆ tcpAddOption()

error_t tcpAddOption	(	TcpHeader *	segment,
		uint8_t	kind,
		const void *	value,
		uint8_t	length
	)

Append an option to the TCP header.

Parameters

[in]	segment	Pointer to the TCP header
[in]	kind	Option code
[in]	value	Option value
[in]	length	Length of the option value, in bytes

Returns: Error code

Definition at line 554 of file tcp_misc.c.

◆ tcpChangeState()

void tcpChangeState	(	Socket *	socket,
		TcpState	newState
	)

Update TCP FSM current state.

Parameters

[in]	socket	Handle referencing the socket
[in]	newState	New TCP state to switch to

Definition at line 2021 of file tcp_misc.c.

◆ tcpCheckAck()

error_t tcpCheckAck	(	Socket *	socket,
		const TcpHeader *	segment,
		size_t	length
	)

Test the ACK field of an incoming segment.

Parameters

[in]	socket	Handle referencing the current socket
[in]	segment	Pointer to the TCP segment to check
[in]	length	Length of the segment data

Returns: NO_ERROR if the acknowledgment is acceptable, ERROR_FAILURE otherwise

Definition at line 844 of file tcp_misc.c.

◆ tcpCheckSeqNum()

error_t tcpCheckSeqNum	(	Socket *	socket,
		const TcpHeader *	segment,
		size_t	length
	)

Test the sequence number of an incoming segment.

Parameters

[in]	socket	Handle referencing the current socket
[in]	segment	Pointer to the TCP segment to check
[in]	length	Length of the segment data

Returns: NO_ERROR if the incoming segment is acceptable, ERROR_FAILURE otherwise

Definition at line 719 of file tcp_misc.c.

◆ tcpCheckSyn()

error_t tcpCheckSyn	(	Socket *	socket,
		const TcpHeader *	segment,
		size_t	length
	)

Check the SYN bit of an incoming segment.

Parameters

[in]	socket	Handle referencing the current socket
[in]	segment	Pointer to the TCP segment to check
[in]	length	Length of the segment data

Returns: ERROR_FAILURE if the SYN is in the window, NO_ERROR otherwise

Definition at line 810 of file tcp_misc.c.

◆ tcpComputeRto()

bool_t tcpComputeRto ( Socket * socket )

Compute retransmission timeout.

Parameters

[in] socket Handle referencing the socket

Returns: TRUE if the RTT measurement is complete, else FALSE

Definition at line 1675 of file tcp_misc.c.

◆ tcpDeleteControlBlock()

void tcpDeleteControlBlock ( Socket * socket )

Delete TCB structure.

Parameters

[in] socket Handle referencing the socket

Definition at line 1371 of file tcp_misc.c.

◆ tcpDumpHeader()

void tcpDumpHeader	(	const TcpHeader *	segment,
		size_t	length,
		uint32_t	iss,
		uint32_t	irs
	)

Dump TCP header for debugging purpose.

Parameters

[in]	segment	Pointer to the TCP header
[in]	length	Length of the segment data
[in]	iss	Initial send sequence number (needed to compute relative SEQ number)
[in]	irs	Initial receive sequence number (needed to compute relative ACK number)

Definition at line 2388 of file tcp_misc.c.

◆ tcpFastLossRecovery()

void tcpFastLossRecovery	(	Socket *	socket,
		const TcpHeader *	segment
	)

Fast loss recovery procedure.

Parameters

[in]	socket	Handle referencing the current socket
[in]	segment	Pointer to the incoming TCP segment

Definition at line 1265 of file tcp_misc.c.

◆ tcpFastRecovery()

void tcpFastRecovery	(	Socket *	socket,
		const TcpHeader *	segment,
		uint_t	n
	)

Fast recovery procedure.

Parameters

[in]	socket	Handle referencing the current socket
[in]	segment	Pointer to the incoming TCP segment
[in]	n	Number of bytes acknowledged by the incoming ACK

Definition at line 1216 of file tcp_misc.c.

◆ tcpFastRetransmit()

void tcpFastRetransmit ( Socket * socket )

Fast retransmit procedure.

Parameters

[in] socket Handle referencing the current socket

Definition at line 1177 of file tcp_misc.c.

◆ tcpFlushRetransmitQueue()

void tcpFlushRetransmitQueue ( Socket * socket )

Flush retransmission queue.

Parameters

[in] socket Handle referencing the socket

Definition at line 1474 of file tcp_misc.c.

◆ tcpFlushSynQueue()

void tcpFlushSynQueue ( Socket * socket )

Flush SYN queue.

Parameters

[in] socket Handle referencing the socket

Definition at line 1503 of file tcp_misc.c.

◆ tcpGenerateInitialSeqNum()

uint32_t tcpGenerateInitialSeqNum	(	const IpAddr *	localIpAddr,
		uint16_t	localPort,
		const IpAddr *	remoteIpAddr,
		uint16_t	remotePort
	)

Initial sequence number generation.

Parameters

[in]	localIpAddr	Local IP address
[in]	localPort	Local port
[in]	remoteIpAddr	Remote IP address
[in]	remotePort	Remote port

Returns: Value of the initial sequence number

Definition at line 683 of file tcp_misc.c.

◆ tcpGetOption()

const TcpOption* tcpGetOption	(	const TcpHeader *	segment,
		uint8_t	kind
	)

Search the TCP header for a given option.

Parameters

[in]	segment	Pointer to the TCP header
[in]	kind	Code of the option to find

Returns: If the specified option is found, a pointer to the corresponding option is returned. Otherwise NULL pointer is returned

Definition at line 617 of file tcp_misc.c.

◆ tcpIsDuplicateAck()

bool_t tcpIsDuplicateAck	(	Socket *	socket,
		const TcpHeader *	segment,
		size_t	length
	)

Test whether the incoming acknowledgment is a duplicate.

Parameters

[in]	socket	Handle referencing the current socket
[in]	segment	Pointer to the TCP segment to check
[in]	length	Length of the segment data

Returns: TRUE if the ACK is duplicate, else FALSE

Definition at line 1134 of file tcp_misc.c.

◆ tcpIsDuplicateSyn()

bool_t tcpIsDuplicateSyn	(	Socket *	socket,
		const IpPseudoHeader *	pseudoHeader,
		const TcpHeader *	segment
	)

Test whether the incoming SYN segment is a duplicate.

Parameters

[in]	socket	Handle referencing the current socket
[in]	pseudoHeader	TCP pseudo header
[in]	segment	Pointer to the TCP segment to check

Returns: TRUE if the SYN segment is duplicate, else FALSE

Definition at line 1058 of file tcp_misc.c.

◆ tcpNagleAlgo()

error_t tcpNagleAlgo	(	Socket *	socket,
		uint_t	flags
	)

Nagle algorithm implementation.

Parameters

[in]	socket	Handle referencing the socket
[in]	flags	Set of flags that influences the behavior of this function

Returns: Error code

Definition at line 1900 of file tcp_misc.c.

◆ tcpProcessSegmentData()

void tcpProcessSegmentData	(	Socket *	socket,
		const TcpHeader *	segment,
		const NetBuffer *	buffer,
		size_t	offset,
		size_t	length
	)

Process the segment text.

Parameters

[in]	socket	Handle referencing the current socket
[in]	segment	Pointer to the TCP header
[in]	buffer	Multi-part buffer containing the incoming TCP segment
[in]	offset	Offset to the first data byte
[in]	length	Length of the segment data

Definition at line 1303 of file tcp_misc.c.

◆ tcpReadRxBuffer()

void tcpReadRxBuffer	(	Socket *	socket,
		uint32_t	seqNum,
		uint8_t *	data,
		size_t	length
	)

Copy data from the receive buffer.

Parameters

[in]	socket	Handle referencing the socket
[in]	seqNum	Sequence number of the first data to read
[out]	data	Pointer to the output buffer
[in]	length	Number of data to read

Definition at line 2353 of file tcp_misc.c.

◆ tcpReadTxBuffer()

error_t tcpReadTxBuffer	(	Socket *	socket,
		uint32_t	seqNum,
		NetBuffer *	buffer,
		size_t	length
	)

Copy data from the send buffer.

Parameters

[in]	socket	Handle referencing the socket
[in]	seqNum	Sequence number of the first data to read
[out]	buffer	Pointer to the output buffer
[in]	length	Number of data to read

Returns: Error code

Definition at line 2274 of file tcp_misc.c.

◆ tcpRejectSegment()

error_t tcpRejectSegment	(	NetInterface *	interface,
		const IpPseudoHeader *	pseudoHeader,
		const TcpHeader *	segment,
		size_t	length
	)

Send a TCP reset in response to an invalid segment.

Parameters

[in]	interface	Underlying network interface
[in]	pseudoHeader	TCP pseudo header describing the incoming segment
[in]	segment	Incoming TCP segment
[in]	length	Length of the incoming segment data

Returns: Error code

Definition at line 404 of file tcp_misc.c.

◆ tcpRetransmitSegment()

error_t tcpRetransmitSegment ( Socket * socket )

TCP segment retransmission.

Parameters

[in] socket Handle referencing the socket

Returns: Error code

Definition at line 1744 of file tcp_misc.c.

◆ tcpSendResetSegment()

error_t tcpSendResetSegment	(	Socket *	socket,
		uint32_t	seqNum
	)

Send a TCP reset segment.

Parameters

[in]	socket	Handle referencing a socket
[in]	seqNum	Sequence number

Returns: Error code

Definition at line 371 of file tcp_misc.c.

◆ tcpSendSegment()

error_t tcpSendSegment	(	Socket *	socket,
		uint8_t	flags,
		uint32_t	seqNum,
		uint32_t	ackNum,
		size_t	length,
		bool_t	addToQueue
	)

Send a TCP segment.

Parameters

[in]	socket	Handle referencing a socket
[in]	flags	Value that contains bitwise OR of flags (see TcpFlags enumeration)
[in]	seqNum	Sequence number
[in]	ackNum	Acknowledgment number
[in]	length	Length of the segment data
[in]	addToQueue	Add the segment to retransmission queue

Returns: Error code

Definition at line 68 of file tcp_misc.c.

◆ tcpUpdateEvents()

void tcpUpdateEvents ( Socket * socket )

Update TCP related events.

Parameters

[in] socket Handle referencing the socket

Definition at line 2052 of file tcp_misc.c.

◆ tcpUpdateReceiveWindow()

void tcpUpdateReceiveWindow ( Socket * socket )

Update receive window so as to avoid Silly Window Syndrome.

Parameters

[in] socket Handle referencing the socket

Definition at line 1636 of file tcp_misc.c.

◆ tcpUpdateRetransmitQueue()

void tcpUpdateRetransmitQueue ( Socket * socket )

Remove acknowledged segments from retransmission queue.

Parameters

[in] socket Handle referencing the socket

Definition at line 1392 of file tcp_misc.c.

◆ tcpUpdateSackBlocks()

void tcpUpdateSackBlocks	(	Socket *	socket,
		uint32_t *	leftEdge,
		uint32_t *	rightEdge
	)

Update the list of non-contiguous blocks that have been received.

Parameters

[in]	socket	Handle referencing the socket
[in,out]	leftEdge	First sequence number occupied by the incoming data
[in,out]	rightEdge	Sequence number immediately following the incoming data

Definition at line 1531 of file tcp_misc.c.

◆ tcpUpdateSendWindow()

void tcpUpdateSendWindow	(	Socket *	socket,
		const TcpHeader *	segment
	)

Update send window.

Parameters

[in]	socket	Handle referencing the socket
[in]	segment	Pointer to the incoming TCP segment

Definition at line 1586 of file tcp_misc.c.

◆ tcpWaitForEvents()

uint_t tcpWaitForEvents	(	Socket *	socket,
		uint_t	eventMask,
		systime_t	timeout
	)

Wait for a particular TCP event.

Parameters

[in]	socket	Handle referencing the socket
[in]	eventMask	Logic OR of all the TCP events that will complete the wait
[in]	timeout	Maximum time to wait

Returns: Logic OR of all the TCP events that satisfied the wait

Definition at line 2200 of file tcp_misc.c.

◆ tcpWriteRxBuffer()

void tcpWriteRxBuffer	(	Socket *	socket,
		uint32_t	seqNum,
		const NetBuffer *	data,
		size_t	dataOffset,
		size_t	length
	)

Copy incoming data to the receive buffer.

Parameters

[in]	socket	Handle referencing the socket
[in]	seqNum	First sequence number occupied by the incoming data
[in]	data	Multi-part buffer containing the incoming data
[in]	dataOffset	Offset to the first data byte
[in]	length	Number of data to write

Definition at line 2318 of file tcp_misc.c.

◆ tcpWriteTxBuffer()

void tcpWriteTxBuffer	(	Socket *	socket,
		uint32_t	seqNum,
		const uint8_t *	data,
		size_t	length
	)

Copy incoming data to the send buffer.

Parameters

[in]	socket	Handle referencing the socket
[in]	seqNum	First sequence number occupied by the incoming data
[in]	data	Data to write
[in]	length	Number of data to write

Definition at line 2238 of file tcp_misc.c.

Macros

Functions

Detailed Description

License

Macro Definition Documentation

◆ TRACE_LEVEL

Function Documentation

◆ tcpAddOption()

◆ tcpChangeState()

◆ tcpCheckAck()

◆ tcpCheckSeqNum()

◆ tcpCheckSyn()

◆ tcpComputeRto()

◆ tcpDeleteControlBlock()

◆ tcpDumpHeader()

◆ tcpFastLossRecovery()

◆ tcpFastRecovery()

◆ tcpFastRetransmit()

◆ tcpFlushRetransmitQueue()

◆ tcpFlushSynQueue()

◆ tcpGenerateInitialSeqNum()

◆ tcpGetOption()

◆ tcpIsDuplicateAck()

◆ tcpIsDuplicateSyn()

◆ tcpNagleAlgo()

◆ tcpProcessSegmentData()

◆ tcpReadRxBuffer()

◆ tcpReadTxBuffer()

◆ tcpRejectSegment()

◆ tcpRetransmitSegment()

◆ tcpSendResetSegment()

◆ tcpSendSegment()

◆ tcpUpdateEvents()

◆ tcpUpdateReceiveWindow()

◆ tcpUpdateRetransmitQueue()

◆ tcpUpdateSackBlocks()

◆ tcpUpdateSendWindow()

◆ tcpWaitForEvents()

◆ tcpWriteRxBuffer()

◆ tcpWriteTxBuffer()