RFC 793 Transmission Control Protocol. More...

Collaboration diagram for TCP:

Defines
#define	TCP_COLLECT_INADV 8
#define	TCP_COLLECT_SLIMIT 256
#define	TCP_BACKLOG_MAX 8
#define	TCP_BACKLOG_TIME 5
#define	TCP_RTTO_MIN 200
#define	TCP_RTTO_MAX 20000
#define	min(a, b) ((a>b)?b:a)
#define	max(a, b) ((a>b)?a:b)
Functions
int	NutTcpInput (NUTDEVICE dev, NETBUF nb)
	Process incoming TCP segments from IP layer.
int	NutTcpStatePassiveOpenEvent (TCPSOCKET *sock)
	Initiated by the application.
int	NutTcpStateActiveOpenEvent (TCPSOCKET *sock)
	Initiated by the application.
int	NutTcpStateCloseEvent (TCPSOCKET *sock)
	Socket close by application.
int	NutTcpStateWindowEvent (TCPSOCKET *sock)
	Initiated by the application.
int	NutTcpStateRetranTimeout (TCPSOCKET *sock)
	Retransmit a segment after ACK timeout.
void	NutTcpSm (void *arg)
	TCP state machine thread.
void	NutTcpStateMachine (NETBUF *nb)
	Process incoming TCP segments.
int	NutTcpInitStateMachine (void)
	Start TCP state machine.
int	NutTcpAbortSocket (TCPSOCKET *sock, uint16_t last_error)
	Closes socket with error.
void	NutTcpCalcRtt (TCPSOCKET *sock)
Variables
HANDLE	tcp_in_rdy
NETBUF *volatile	tcp_in_nbq

Detailed Description

RFC 793 Transmission Control Protocol.

TCP provides reliable, in-sequence delivery of a full-duplex stream of octets. It is used by applications which need a reliable, connection-oriented data transport.

Applications should call the TCP Socket API when using this protocol.

Todo:: Use an indirect call for NutTcpInput(). Right now, the whole TCP code is linked to any application, even if only UDP is used.

Define Documentation

#define TCP_COLLECT_INADV 8

Definition at line 155 of file tcpsm.c.

#define TCP_COLLECT_SLIMIT 256

Definition at line 159 of file tcpsm.c.

#define TCP_BACKLOG_MAX 8

Definition at line 163 of file tcpsm.c.

#define TCP_BACKLOG_TIME 5

Definition at line 168 of file tcpsm.c.

#define TCP_RTTO_MIN 200

Definition at line 74 of file tcputil.c.

Referenced by NutTcpCalcRtt().

#define TCP_RTTO_MAX 20000

Definition at line 77 of file tcputil.c.

Referenced by NutTcpCalcRtt().

#define min	(	a,
		b
	)	((a>b)?b:a)

Definition at line 80 of file tcputil.c.

Referenced by NutTcpCalcRtt().

#define max	(	a,
		b
	)	((a>b)?a:b)

Definition at line 81 of file tcputil.c.

Referenced by ADCEnableChannel(), and NutTcpCalcRtt().

Function Documentation

int NutTcpInput	(	NUTDEVICE *	dev,
		NETBUF *	nb
	)

Process incoming TCP segments from IP layer.

Warning:: The caller must take care not to pass broadcast or multicast segments.

Note:: This routine is called by the IP layer on incoming TCP segments. Applications typically do not call this function.

Definition at line 148 of file tcpin.c.

References _NETBUF::nb_ap, _NETBUF::nb_flags, _NETBUF::nb_tp, NBAF_UNICAST, NutNetBufFree(), NutTcpStateMachine(), _NBDATA::sz, tcphdr::th_off, and _NBDATA::vp.

Referenced by NutTcpCreateSocket().

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int NutTcpStatePassiveOpenEvent ( TCPSOCKET * sock )

Initiated by the application.

Parameters:

sock	Socket descriptor. This pointer must have been retrieved by calling NutTcpCreateSocket().

Returns:: 0 if granted, error code otherwise.

Definition at line 803 of file tcpsm.c.

References EISCONN, ETIMEDOUT, NutEventWait(), tcp_socket::so_last_error, tcp_socket::so_local_port, tcp_socket::so_pc_tq, tcp_socket::so_read_to, tcp_socket::so_state, TCPS_CLOSED, and TCPS_LISTEN.

Referenced by NutTcpAccept().

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int NutTcpStateActiveOpenEvent ( TCPSOCKET * sock )

Initiated by the application.

The caller must make sure, that the socket is in closed state.

Parameters:

sock	Socket descriptor. This pointer must have been retrieved by calling NutTcpCreateSocket().

Returns:: 0 if granted, -1 otherwise.

Definition at line 847 of file tcpsm.c.

References NutEventWait(), tcp_socket::so_ac_tq, tcp_socket::so_state, TCPS_CLOSE_WAIT, TCPS_ESTABLISHED, and TCPS_SYN_SENT.

Referenced by NutTcpConnect().

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int NutTcpStateCloseEvent ( TCPSOCKET * sock )

Socket close by application.

If socket is in state SYN_RECEIVED or ESTABLISHED, it is changed to FINWAIT1.

No further data sending is accepted. Receiving is still allowed.

Parameters:

sock	Socket descriptor. This pointer must have been retrieved by calling NutTcpCreateSocket().

Definition at line 879 of file tcpsm.c.

References EALREADY, ENOTCONN, NutTcpDestroySocket(), NutThreadYield(), tcp_socket::so_last_error, tcp_socket::so_state, TCPS_CLOSE_WAIT, TCPS_CLOSED, TCPS_CLOSING, TCPS_ESTABLISHED, TCPS_FIN_WAIT_1, TCPS_FIN_WAIT_2, TCPS_LAST_ACK, TCPS_LISTEN, TCPS_SYN_RECEIVED, TCPS_SYN_SENT, and TCPS_TIME_WAIT.

Referenced by NutTcpCloseSocket().

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int NutTcpStateWindowEvent ( TCPSOCKET * sock )

Initiated by the application.

Parameters:

sock	Socket descriptor. This pointer must have been retrieved by calling NutTcpCreateSocket().

Definition at line 934 of file tcpsm.c.

References NutTcpOutput(), SO_ACK, SO_FORCE, and tcp_socket::so_tx_flags.

Referenced by NutTcpReceive().

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int NutTcpStateRetranTimeout ( TCPSOCKET * sock )

Retransmit a segment after ACK timeout.

This function is called by the TCP timer.

Parameters:

sock	Socket descriptor. This pointer must have been retrieved by calling NutTcpCreateSocket().

Returns:: Nonzero if socket was aborted due to reach of retransmit limit or network error.

Definition at line 959 of file tcpsm.c.

References __tcp_trf, __tcp_trs, ENETDOWN, ETIMEDOUT, IPPROTO_TCP, _NETBUF::nb_next, NutDumpTcpHeader(), NutGetMillis(), NutIpOutput(), NutTcpAbortSocket(), tcp_socket::so_remote_addr, tcp_socket::so_retran_time, tcp_socket::so_retransmits, tcp_socket::so_tx_nbq, and TCP_RETRIES_MAX.

Referenced by NutTcpSm().

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NutTcpSm ( void * arg )

TCP state machine thread.

The TCP state machine serves two purposes: It processes incoming TCP segments and handles TCP timers.

Definition at line 1671 of file tcpsm.c.

References __tcp_trf, __tcp_trs, ip::ip_src, _NETBUF::nb_next, _NETBUF::nb_nw, _NETBUF::nb_tp, NutDumpTcpHeader(), NutEventWait(), NutGetMillis(), NutTcpDestroySocket(), NutTcpFindSocket(), NutTcpOutput(), NutTcpReject(), NutTcpStateRetranTimeout(), NutThreadSetPriority(), SO_ACK, SO_FORCE, tcp_socket::so_next, tcp_socket::so_retran_time, tcp_socket::so_rtto, tcp_socket::so_state, tcp_socket::so_time_wait, tcp_socket::so_tx_flags, tcp_socket::so_tx_nbq, tcp_in_nbq, tcp_in_rdy, TCPS_FIN_WAIT_2, TCPS_LISTEN, TCPS_SYN_RECEIVED, TCPS_TIME_WAIT, tcphdr::th_dport, tcphdr::th_sport, and _NBDATA::vp.

Referenced by NutTcpInitStateMachine().

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void NutTcpStateMachine ( NETBUF * nb )

Process incoming TCP segments.

All incoming TCP packets are passed to this routine. They will be added to a global queue and processed by the TCP state machine, which is running on a separate thread.