tcp.h File Reference

TCP protocol definitions. More...

#include <sys/types.h>
#include <stdint.h>

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Data Structures
struct	tcphdr
	TCP protocol header structure. More...
struct	_TCPPSEUDOHDR
	TCP pseudo header structure. More...
Defines
#define	TH_FIN   0x01
	Finishing transmission.
#define	TH_SYN   0x02
	Synchronizing sequence numbers.
#define	TH_RST   0x04
	Reset connection.
#define	TH_PUSH   0x08
	Push data to application level.
#define	TH_ACK   0x10
	Acknowledge field is valid.
#define	TH_URG   0x20
	Urgent data present.
#define	TH_FLAGS   (TH_FIN | TH_SYN | TH_RST | TH_ACK | TH_URG)
	TCP flag mask.
#define	TCPOPT_EOL   0
	End of options.
#define	TCPOPT_NOP   1
	Nothing.
#define	TCPOPT_MAXSEG   2
	Maximum segment size.
#define	TCPOLEN_MAXSEG   4
	Maximum segment size length.
#define	TCPOPT_WINDOW   3
	Receive window.
#define	TCPOLEN_WINDOW   3
	Receive window length.
#define	TCP_MSS   536
	Default maximum segment size. The maximum size of an IP datagram, that will not become fragmented, is 576. The maximum IP datagram for Ethernet is 1500. Reduce this number by 40, 20 bytes TCP header and 20 bytes IP header.
#define	TCP_WINSIZE   3216
	Default window size. It's recommended to set this 6 times the maximum segment size.
#define	TCP_MAXWIN   65535
	Largest value for (unscaled) window.
#define	TTCP_CLIENT_SND_WND   4096
	Default send window for T/TCP client.
#define	TCP_MAX_WINSHIFT   14
	Maximum window shift.
#define	TCP_MAXHLEN   (0xf<<2)
	Maximum length of header in bytes.
#define	TCP_MAXOLEN   (TCP_MAXHLEN - sizeof(struct tcphdr))
	Maximum space left for options.
#define	TCP_NODELAY   0x01
	Don't delay send to coalesce segments.
#define	TCP_MAXSEG   0x02
	Set maximum segment size.
#define	TCP_NOPUSH   0x04
	Don't push last block of write.
#define	TCP_NOOPT   0x08
	Don't use TCP options.
Typedefs
typedef struct tcphdr	TCPHDR
	TCP protocol header type.
typedef struct _TCPPSEUDOHDR	TCPPSEUDOHDR
	TCP pseudo header type.

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Detailed Description

TCP protocol definitions.

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Define Documentation

#define TH_FIN   0x01

Finishing transmission.

Referenced by NutDumpTcpHeader(), and NutTcpOutput().

#define TH_SYN   0x02

Synchronizing sequence numbers.

Referenced by NutDumpTcpHeader(), NutTcpOutput(), and NutTcpReject().

#define TH_RST   0x04

Reset connection.

Referenced by NutDumpTcpHeader(), and NutTcpReject().

#define TH_PUSH   0x08

Push data to application level.

Referenced by NutDumpTcpHeader(), and NutTcpOutput().

#define TH_ACK   0x10

Acknowledge field is valid.

Referenced by NutDumpTcpHeader(), NutTcpOutput(), and NutTcpReject().

#define TH_URG   0x20

Urgent data present.

Referenced by NutDumpTcpHeader().

#define TH_FLAGS   (TH_FIN | TH_SYN | TH_RST | TH_ACK | TH_URG)

TCP flag mask.

#define TCPOPT_EOL   0

End of options.

#define TCPOPT_NOP   1

Nothing.

#define TCPOPT_MAXSEG   2

Maximum segment size.

Referenced by NutTcpOutput().

#define TCPOLEN_MAXSEG   4

Maximum segment size length.

Referenced by NutTcpOutput().

#define TCPOPT_WINDOW   3

Receive window.

#define TCPOLEN_WINDOW   3

Receive window length.

#define TCP_MSS   536

Default maximum segment size. The maximum size of an IP datagram, that will not become fragmented, is 576. The maximum IP datagram for Ethernet is 1500. Reduce this number by 40, 20 bytes TCP header and 20 bytes IP header.

Referenced by NutTcpCreateSocket().

#define TCP_WINSIZE   3216

Default window size. It's recommended to set this 6 times the maximum segment size.

Referenced by NutTcpCreateSocket().

#define TCP_MAXWIN   65535

Largest value for (unscaled) window.

#define TTCP_CLIENT_SND_WND   4096

Default send window for T/TCP client.

#define TCP_MAX_WINSHIFT   14

Maximum window shift.

#define TCP_MAXHLEN   (0xf<<2)

Maximum length of header in bytes.

#define TCP_MAXOLEN   (TCP_MAXHLEN - sizeof(struct tcphdr))

Maximum space left for options.

#define TCP_NODELAY   0x01

Don't delay send to coalesce segments.

#define TCP_MAXSEG   0x02

Set maximum segment size.

Examples:

ftpd/ftpserv.c.

Referenced by NutFtpDataConnect(), NutTcpGetSockOpt(), NutTcpSetSockOpt(), and StreamClientAccept().

#define TCP_NOPUSH   0x04

Don't push last block of write.

#define TCP_NOOPT   0x08

Don't use TCP options.

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Typedef Documentation

TCPHDR

TCP protocol header type.

TCPPSEUDOHDR

TCP pseudo header type.