TCP (Transmission Control Protocol) More...
Go to the source code of this file.
Data Structures | |
| struct | _TcpQueueItem | 
| Retransmission queue item.  More... | |
| struct | _TcpSynQueueItem | 
| SYN queue item.  More... | |
| struct | TcpSackBlock | 
| SACK block.  More... | |
| struct | TcpTxBuffer | 
| Transmit buffer.  More... | |
| struct | TcpRxBuffer | 
| Receive buffer.  More... | |
Typedefs | |
| typedef struct _TcpQueueItem | TcpQueueItem | 
| Retransmission queue item.  More... | |
| typedef struct _TcpSynQueueItem | TcpSynQueueItem | 
| SYN queue item.  More... | |
Enumerations | |
| enum | TcpState {  TCP_STATE_CLOSED = 0, TCP_STATE_LISTEN = 1, TCP_STATE_SYN_SENT = 2, TCP_STATE_SYN_RECEIVED = 3, TCP_STATE_ESTABLISHED = 4, TCP_STATE_CLOSE_WAIT = 5, TCP_STATE_LAST_ACK = 6, TCP_STATE_FIN_WAIT_1 = 7, TCP_STATE_FIN_WAIT_2 = 8, TCP_STATE_CLOSING = 9, TCP_STATE_TIME_WAIT = 10 }  | 
| TCP FSM states.  More... | |
| enum | TcpCongestState { TCP_CONGEST_STATE_IDLE = 0, TCP_CONGEST_STATE_RECOVERY = 1, TCP_CONGEST_STATE_LOSS_RECOVERY = 2 } | 
| TCP congestion states.  More... | |
| enum | TcpFlags {  TCP_FLAG_FIN = 0x01, TCP_FLAG_SYN = 0x02, TCP_FLAG_RST = 0x04, TCP_FLAG_PSH = 0x08, TCP_FLAG_ACK = 0x10, TCP_FLAG_URG = 0x20 }  | 
| TCP control flags.  More... | |
| enum | TcpOptionKind {  TCP_OPTION_END = 0, TCP_OPTION_NOP = 1, TCP_OPTION_MAX_SEGMENT_SIZE = 2, TCP_OPTION_WINDOW_SCALE_FACTOR = 3, TCP_OPTION_SACK_PERMITTED = 4, TCP_OPTION_SACK = 5, TCP_OPTION_TIMESTAMP = 8 }  | 
| TCP option types.  More... | |
Functions | |
| error_t | tcpInit (void) | 
| TCP related initialization.  More... | |
| error_t | tcpSetInitialRto (NetInterface *interface, systime_t initialRto) | 
| Set TCP initial retransmission timeout.  More... | |
| uint16_t | tcpGetDynamicPort (void) | 
| Get an ephemeral port number.  More... | |
| error_t | tcpConnect (Socket *socket, const IpAddr *remoteIpAddr, uint16_t remotePort) | 
| Establish a TCP connection.  More... | |
| error_t | tcpListen (Socket *socket, uint_t backlog) | 
| Place a socket in the listening state.  More... | |
| Socket * | tcpAccept (Socket *socket, IpAddr *clientIpAddr, uint16_t *clientPort) | 
| Permit an incoming connection attempt on a TCP socket.  More... | |
| error_t | tcpSend (Socket *socket, const uint8_t *data, size_t length, size_t *written, uint_t flags) | 
| Send data to a connected socket.  More... | |
| error_t | tcpReceive (Socket *socket, uint8_t *data, size_t size, size_t *received, uint_t flags) | 
| Receive data from a connected socket.  More... | |
| error_t | tcpShutdown (Socket *socket, uint_t how) | 
| Shutdown gracefully reception, transmission, or both.  More... | |
| error_t | tcpAbort (Socket *socket) | 
| Abort an existing TCP connection.  More... | |
| TcpState | tcpGetState (Socket *socket) | 
| Get the current state of the TCP FSM.  More... | |
| Socket * | tcpKillOldestConnection (void) | 
| Kill the oldest socket in the TIME-WAIT state.  More... | |
Variables | |
| typedef | __packed_struct | 
| TCP header.  More... | |
| uint16_t | destPort | 
| uint32_t | seqNum | 
| uint32_t | ackNum | 
| uint8_t | reserved1 | 
| uint8_t | dataOffset | 
| uint8_t | flags | 
| uint8_t | reserved2 | 
| uint16_t | window | 
| uint16_t | checksum | 
| uint16_t | urgentPointer | 
| uint8_t | options [] | 
| TcpHeader | |
| uint8_t | length | 
| uint8_t | value [] | 
| TcpOption | |
| systime_t | tcpTickCounter | 
Detailed Description
TCP (Transmission Control Protocol)
License
SPDX-License-Identifier: GPL-2.0-or-later
Copyright (C) 2010-2025 Oryx Embedded SARL. All rights reserved.
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.
- Version
 - 2.5.4
 
Definition in file tcp.h.
Macro Definition Documentation
◆ TCP_2MSL_TIMER
◆ TCP_CMP_SEQ
◆ TCP_CONGEST_CONTROL_SUPPORT
◆ TCP_DEFAULT_KEEP_ALIVE_IDLE
◆ TCP_DEFAULT_KEEP_ALIVE_INTERVAL
◆ TCP_DEFAULT_KEEP_ALIVE_PROBES
◆ TCP_DEFAULT_MSS
◆ TCP_DEFAULT_PROBE_INTERVAL
◆ TCP_DEFAULT_RX_BUFFER_SIZE
◆ TCP_DEFAULT_SYN_QUEUE_SIZE
◆ TCP_DEFAULT_TX_BUFFER_SIZE
◆ TCP_FAST_RETRANSMIT_THRES
◆ TCP_FIN_WAIT_2_TIMER
◆ TCP_INITIAL_RTO
◆ TCP_INITIAL_WINDOW
◆ TCP_KEEP_ALIVE_SUPPORT
◆ TCP_LOSS_WINDOW
◆ TCP_MAX_HEADER_LENGTH
◆ TCP_MAX_MSS
◆ TCP_MAX_PROBE_INTERVAL
◆ TCP_MAX_RETRIES
◆ TCP_MAX_RTO
◆ TCP_MAX_RX_BUFFER_SIZE
◆ TCP_MAX_SACK_BLOCKS
◆ TCP_MAX_SYN_QUEUE_SIZE
◆ TCP_MAX_TX_BUFFER_SIZE
◆ TCP_MIN_MSS
◆ TCP_MIN_RTO
◆ TCP_OVERRIDE_TIMEOUT
◆ TCP_SACK_SUPPORT
◆ TCP_SECURE_ISN_SUPPORT
◆ TCP_SUPPORT
◆ TCP_TICK_INTERVAL
◆ TCP_WINDOW_SCALE_SUPPORT
Typedef Documentation
◆ TcpQueueItem
| typedef struct _TcpQueueItem TcpQueueItem | 
Retransmission queue item.
◆ TcpSynQueueItem
| typedef struct _TcpSynQueueItem TcpSynQueueItem | 
SYN queue item.
Enumeration Type Documentation
◆ TcpCongestState
| enum TcpCongestState | 
◆ TcpFlags
| enum TcpFlags | 
◆ TcpOptionKind
| enum TcpOptionKind | 
◆ TcpState
| enum TcpState | 
Function Documentation
◆ tcpAbort()
◆ tcpAccept()
Permit an incoming connection attempt on a TCP socket.
- Parameters
 - 
  
[in] socket Handle to a socket previously placed in a listening state [out] clientIpAddr IP address of the client [out] clientPort Port number used by the client  
- Returns
 - Handle to the socket in which the actual connection is made
 
◆ tcpConnect()
◆ tcpGetDynamicPort()
| uint16_t tcpGetDynamicPort | ( | void | ) | 
◆ tcpGetState()
◆ tcpInit()
| error_t tcpInit | ( | void | ) | 
◆ tcpKillOldestConnection()
| Socket* tcpKillOldestConnection | ( | void | ) | 
◆ tcpListen()
Place a socket in the listening state.
Place a socket in a state in which it is listening for an incoming connection
- Parameters
 - 
  
[in] socket Socket to place in the listening state [in] backlog backlog The maximum length of the pending connection queue. If this parameter is zero, then the default backlog value is used instead  
- Returns
 - Error code
 
◆ tcpReceive()
| error_t tcpReceive | ( | Socket * | socket, | 
| uint8_t * | data, | ||
| size_t | size, | ||
| size_t * | received, | ||
| uint_t | flags | ||
| ) | 
Receive data from a connected socket.
- Parameters
 - 
  
[in] socket Handle that identifies a connected socket [out] data Buffer where to store the incoming data [in] size Maximum number of bytes that can be received [out] received Number of bytes that have been received [in] flags Set of flags that influences the behavior of this function  
- Returns
 - Error code
 
◆ tcpSend()
| error_t tcpSend | ( | Socket * | socket, | 
| const uint8_t * | data, | ||
| size_t | length, | ||
| size_t * | written, | ||
| uint_t | flags | ||
| ) | 
Send data to a connected socket.
- Parameters
 - 
  
[in] socket Handle that identifies a connected socket [in] data Pointer to a buffer containing the data to be transmitted [in] length Number of bytes to be transmitted [out] written Actual number of bytes written (optional parameter) [in] flags Set of flags that influences the behavior of this function  
- Returns
 - Error code
 
◆ tcpSetInitialRto()
| error_t tcpSetInitialRto | ( | NetInterface * | interface, | 
| systime_t | initialRto | ||
| ) | 
◆ tcpShutdown()
Shutdown gracefully reception, transmission, or both.
Note that socketShutdown() does not close the socket, and resources attached to the socket will not be freed until socketClose() is invoked
- Parameters
 - 
  
[in] socket Handle to a socket [in] how Flag that describes what types of operation will no longer be allowed  
- Returns
 - Error code
 
Variable Documentation
◆ __packed_struct
| typedef __packed_struct | 
