tcp.h File Reference

#include "kernel.h"

Data Structures
struct	tcp_ip_pseudo_header_t
union	tcp_segment_flags_t
struct	tcp_segment
struct	tcp_options_t
struct	tcp_ordered_list_t
struct	tcp_conn_t

Macros
#define	TCP_WINDOW_SIZE   65535
#define	TCP_PACKET_SIZE_OFF   5

Enumerations
enum	tcp_state_flags_t {   TCP_FIN = 1 , TCP_SYN = 2 , TCP_RST = 4 , TCP_PSH = 8 ,   TCP_ACK = 16 , TCP_URG = 32 , TCP_ECE = 64 , TCP_CWR = 128 }
enum	tcp_opt_t { TCP_OPT_END = 0 , TCP_OPT_NOP = 1 , TCP_OPT_MSS = 2 }
enum	tcp_state_t {   TCP_LISTEN = 0 , TCP_SYN_SENT = 1 , TCP_SYN_RECEIVED = 2 , TCP_ESTABLISHED = 3 ,   TCP_FIN_WAIT_1 = 4 , TCP_FIN_WAIT_2 = 5 , TCP_CLOSE_WAIT = 6 , TCP_CLOSING = 7 ,   TCP_LAST_ACK = 8 , TCP_TIME_WAIT = 9 }
enum	tcp_error_t { TCP_CONN_RESET = 1 , TCP_CONN_REFUSED = 2 , TCP_CONN_CLOSING = 3 }
enum	tcp_port_type_t { TCP_PORT_LOCAL , TCP_PORT_REMOTE }
	Port types, either a local or remote port. More...
enum	tcp_error_code_t {   TCP_ERROR_ALREADY_CLOSING = -1 , TCP_ERROR_PORT_IN_USE = -2 , TCP_ERROR_NETWORK_DOWN = -3 , TCP_ERROR_INVALID_CONNECTION = -4 ,   TCP_ERROR_WRITE_TOO_LARGE = -5 , TCP_ERROR_NOT_CONNECTED = -6 , TCP_ERROR_OUT_OF_DESCRIPTORS = -7 , TCP_ERROR_OUT_OF_MEMORY = -8 ,   TCP_ERROR_INVALID_SOCKET = -9 , TCP_ERROR_CONNECTION_FAILED = -10 , TCP_LAST_ERROR = -11 }
	Error codes which can be returned by socket functions. More...

Functions
struct tcp_ip_pseudo_header_t	__attribute__ ((packed)) tcp_ip_pseudo_header_t
void	tcp_handle_packet ([[maybe_unused]] ip_packet_t *encap_packet, tcp_segment_t *segment, size_t len)
	TCP handler called by the IP layer. More...
void	tcp_init ()
	Initialise TCP protocol, must happen after IP. More...
int	connect (uint32_t target_addr, uint16_t target_port, uint16_t source_port, bool blocking)
	Connect to a TCP port at a given IPv4 address. More...
int	closesocket (int socket)
	Close a TCP connection. More...
int	send (int socket, const void *buffer, uint32_t length)
	Send data to an open socket. More...
int	recv (int socket, void *buffer, uint32_t maxlen, bool blocking, uint32_t timeout)
	Receive data from an open socket. The data is buffered, and this function will fill the buffer when there is data in the buffer to read. More...
bool	is_connected (int socket)
	Returns true if the socket is connected. More...
const char *	socket_error (int error_code)
	Return the error description associated with an error code. More...
void	tcp_idle ()
	Idle loop ran from timer ISR. More...

Variables
typedef	__attribute__
	System Description Table Header. More...
uint32_t	src
uint32_t	dst
uint8_t	reserved
uint8_t	protocol
uint16_t	len
uint8_t	body []
uint8_t	bits1
uint8_t	bits2
struct {
uint8_t   reserved:4
uint8_t   off:4
uint8_t   fin:1
uint8_t   syn:1
uint8_t   rst:1
uint8_t   psh:1
uint8_t   ack:1
uint8_t   urg:1
uint8_t   ece:1
uint8_t   cwr:1
};
uint16_t	src_port
uint16_t	dst_port
uint32_t	seq
tcp_segment_flags_t	flags
uint16_t	window_size
uint16_t	checksum
uint16_t	urgent
uint8_t	options [0]
uint8_t	payload []

Detailed Description

Author

Craig Edwards (craig.nosp@m.edwa.nosp@m.rds@b.nosp@m.rain.nosp@m.box.c.nosp@m.c)

Copyright

Copyright (c) 2012-2023

Macro Definition Documentation

TCP_PACKET_SIZE_OFF

#define TCP_PACKET_SIZE_OFF   5

TCP_WINDOW_SIZE

#define TCP_WINDOW_SIZE   65535

Enumeration Type Documentation

tcp_error_code_t

enum tcp_error_code_t

Error codes which can be returned by socket functions.

Enumerator
TCP_ERROR_ALREADY_CLOSING
TCP_ERROR_PORT_IN_USE
TCP_ERROR_NETWORK_DOWN
TCP_ERROR_INVALID_CONNECTION
TCP_ERROR_WRITE_TOO_LARGE
TCP_ERROR_NOT_CONNECTED
TCP_ERROR_OUT_OF_DESCRIPTORS
TCP_ERROR_OUT_OF_MEMORY
TCP_ERROR_INVALID_SOCKET
TCP_ERROR_CONNECTION_FAILED
TCP_LAST_ERROR

tcp_error_t

enum tcp_error_t

Enumerator
TCP_CONN_RESET
TCP_CONN_REFUSED
TCP_CONN_CLOSING

tcp_opt_t

enum tcp_opt_t

Enumerator
TCP_OPT_END
TCP_OPT_NOP
TCP_OPT_MSS

tcp_port_type_t

enum tcp_port_type_t

Port types, either a local or remote port.

Enumerator
TCP_PORT_LOCAL
TCP_PORT_REMOTE

tcp_state_flags_t

enum tcp_state_flags_t

Enumerator
TCP_FIN
TCP_SYN
TCP_RST
TCP_PSH
TCP_ACK
TCP_URG
TCP_ECE
TCP_CWR

tcp_state_t

enum tcp_state_t

Enumerator
TCP_LISTEN
TCP_SYN_SENT
TCP_SYN_RECEIVED
TCP_ESTABLISHED
TCP_FIN_WAIT_1
TCP_FIN_WAIT_2
TCP_CLOSE_WAIT
TCP_CLOSING
TCP_LAST_ACK
TCP_TIME_WAIT

Function Documentation

__attribute__()

struct tcp_ip_pseudo_header_t __attribute__

(

(packed)

)

closesocket()

int closesocket

(

int

socket

)

Close a TCP connection.

Parameters

socket

socket descriptor to close

Returns

zero on success, error code on error

connect()

int connect	(	uint32_t	target_addr,
		uint16_t	target_port,
		uint16_t	source_port,
		bool	blocking
	)

Connect to a TCP port at a given IPv4 address.

Parameters

target_addr	Target address to connect to
target_port	Target port to connect to
source_port	Our source port to use, or 0 to choose automatically
blocking	Set to true if this call is to block until the connection is established or errors

Returns

Zero or positive file descriptor number on success, negative for error

is_connected()

bool is_connected

(

int

socket

)

Returns true if the socket is connected.

Parameters

socket

socket descriptor from connect()

Returns

true if socket is connected, false if not. This will return false if connect() hasn't succeeded yet.

recv()

int recv	(	int	socket,
		void *	buffer,
		uint32_t	maxlen,
		bool	blocking,
		uint32_t	timeout
	)

Receive data from an open socket. The data is buffered, and this function will fill the buffer when there is data in the buffer to read.

Parameters

socket	socket descriptor from connect()
buffer	buffer to receive data to
maxlen	maximum size of data to receive to buffer
blocking	true if this call should block until the buffer has data
timeout	read timeout when blocking (seconds)

Returns

int number of bytes received

send()

int send	(	int	socket,
		const void *	buffer,
		uint32_t	length
	)

Send data to an open socket.

Parameters

socket	socket descriptor from connect()
buffer	buffer to send
length	number of bytes to send

Returns

int number of bytes written

socket_error()

const char* socket_error

(

int

error_code

)

Return the error description associated with an error code.

Note

Invalid error codes return the constant "No error".

Parameters

error_code

error code

Returns

const char* description

tcp_handle_packet()

void tcp_handle_packet	(	[[maybe_unused] ] ip_packet_t *	encap_packet,
		tcp_segment_t *	segment,
		size_t	len
	)

TCP handler called by the IP layer.

Parameters

encap_packet	encapsulating IP packet
segment	TCP segment
len	length of TCP segment including header

tcp_idle()

void tcp_idle

(

)

Idle loop ran from timer ISR.

tcp_init()

void tcp_init

(

)

Initialise TCP protocol, must happen after IP.

Variable Documentation

struct { ... }

__attribute__

enum tcp_opt_t __attribute__

System Description Table Header.

A disk partition table consisiting of four partition_t.

Structure for an IP packet.

Long filename entry, overlays a directory_entry_t. These entries repeat before a non-lfn entry, each holding up to 13 UCS-2 characters. Note that they are not stored in order, the 'order' attribute indicates which order they go in.

FAT32 BIOS parameter block (BPB), stored in the boot sector of the drive.

A directory entry, e.g. file, volume label, directory, long filename entry.

Root System Description Table.

ack

uint32_t ack

bits1

uint8_t bits1

bits2

uint8_t bits2

body

uint8_t body[]

checksum

uint16_t checksum

cwr

uint8_t cwr

dst

uint32_t dst

dst_port

uint16_t dst_port

ece

uint8_t ece

fin

uint8_t fin

flags

tcp_segment_flags_t flags

len

uint16_t len

off

uint8_t off

options

uint8_t options[0]

payload

uint8_t payload[]

protocol

uint8_t protocol

psh

uint8_t psh

reserved

uint8_t reserved

rst

uint8_t rst

seq

uint32_t seq

src

uint32_t src

src_port

uint16_t src_port

syn

uint8_t syn

urg

uint8_t urg

urgent

uint16_t urgent

window_size

uint16_t window_size