Transmission Control Protocol for IP See also TCP. More...

Functions
static u16_t	tcp_new_port (void)
	Allocate a new local TCP port.
void	tcp_init (void)
	Initialize this module.
void	tcp_tmr (void)
	Called periodically to dispatch TCP timers.
static void	tcp_remove_listener (struct tcp_pcb list, struct tcp_pcb_listen lpcb)
	Called when a listen pcb is closed.
static void	tcp_listen_closed (struct tcp_pcb *pcb)
	Called when a listen pcb is closed.
void	tcp_backlog_delayed (struct tcp_pcb *pcb)
	Delay accepting a connection in respect to the listen backlog: the number of outstanding connections is increased until tcp_backlog_accepted() is called.
void	tcp_backlog_accepted (struct tcp_pcb *pcb)
	A delayed-accept a connection is accepted (or closed/aborted): decreases the number of outstanding connections after calling tcp_backlog_delayed().
static err_t	tcp_close_shutdown (struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
	Closes the TX side of a connection held by the PCB.
err_t	tcp_close (struct tcp_pcb *pcb)
	Closes the connection held by the PCB.
err_t	tcp_shutdown (struct tcp_pcb *pcb, int shut_rx, int shut_tx)
	Causes all or part of a full-duplex connection of this PCB to be shut down.
void	tcp_abandon (struct tcp_pcb *pcb, int reset)
	Abandons a connection and optionally sends a RST to the remote host.
void	tcp_abort (struct tcp_pcb *pcb)
	Aborts the connection by sending a RST (reset) segment to the remote host.
err_t	tcp_bind (struct tcp_pcb pcb, const ip_addr_t ipaddr, u16_t port)
	Binds the connection to a local port number and IP address.
static err_t	tcp_accept_null (void arg, struct tcp_pcb pcb, err_t err)
	Default accept callback if no accept callback is specified by the user.
struct tcp_pcb *	tcp_listen_with_backlog (struct tcp_pcb *pcb, u8_t backlog)
	Set the state of the connection to be LISTEN, which means that it is able to accept incoming connections.
struct tcp_pcb *	tcp_listen_with_backlog_and_err (struct tcp_pcb pcb, u8_t backlog, err_t err)
	Set the state of the connection to be LISTEN, which means that it is able to accept incoming connections.
u32_t	tcp_update_rcv_ann_wnd (struct tcp_pcb *pcb)
	Update the state that tracks the available window space to advertise.
void	tcp_recved (struct tcp_pcb *pcb, u16_t len)
	This function should be called by the application when it has processed the data.
err_t	tcp_connect (struct tcp_pcb pcb, const ip_addr_t ipaddr, u16_t port, tcp_connected_fn connected)
	Connects to another host.
void	tcp_slowtmr (void)
	Called every 500 ms and implements the retransmission timer and the timer that removes PCBs that have been in TIME-WAIT for enough time.
void	tcp_fasttmr (void)
	Is called every TCP_FAST_INTERVAL (250 ms) and process data previously "refused" by upper layer (application) and sends delayed ACKs.
void	tcp_txnow (void)
	Call tcp_output for all active pcbs that have TF_NAGLEMEMERR set.
err_t	tcp_process_refused_data (struct tcp_pcb *pcb)
	Pass pcb->refused_data to the recv callback.
void	tcp_segs_free (struct tcp_seg *seg)
	Deallocates a list of TCP segments (tcp_seg structures).
void	tcp_seg_free (struct tcp_seg *seg)
	Frees a TCP segment (tcp_seg structure).
void	tcp_setprio (struct tcp_pcb *pcb, u8_t prio)
	Sets the priority of a connection.
struct tcp_seg *	tcp_seg_copy (struct tcp_seg *seg)
	Returns a copy of the given TCP segment.
err_t	tcp_recv_null (void arg, struct tcp_pcb pcb, struct pbuf *p, err_t err)
	Default receive callback that is called if the user didn't register a recv callback for the pcb.
static void	tcp_kill_prio (u8_t prio)
	Kills the oldest active connection that has the same or lower priority than 'prio'.
static void	tcp_kill_state (enum tcp_state state)
	Kills the oldest connection that is in specific state.
static void	tcp_kill_timewait (void)
	Kills the oldest connection that is in TIME_WAIT state.
struct tcp_pcb *	tcp_alloc (u8_t prio)
	Allocate a new tcp_pcb structure.
struct tcp_pcb *	tcp_new (void)
	Creates a new TCP protocol control block but doesn't place it on any of the TCP PCB lists.
struct tcp_pcb *	tcp_new_ip_type (u8_t type)
	Creates a new TCP protocol control block but doesn't place it on any of the TCP PCB lists.
void	tcp_arg (struct tcp_pcb pcb, void arg)
	Used to specify the argument that should be passed callback functions.
void	tcp_recv (struct tcp_pcb *pcb, tcp_recv_fn recv)
	Used to specify the function that should be called when a TCP connection receives data.
void	tcp_sent (struct tcp_pcb *pcb, tcp_sent_fn sent)
	Used to specify the function that should be called when TCP data has been successfully delivered to the remote host.
void	tcp_err (struct tcp_pcb *pcb, tcp_err_fn err)
	Used to specify the function that should be called when a fatal error has occurred on the connection.
void	tcp_accept (struct tcp_pcb *pcb, tcp_accept_fn accept)
	Used for specifying the function that should be called when a LISTENing connection has been connected to another host.
void	tcp_poll (struct tcp_pcb *pcb, tcp_poll_fn poll, u8_t interval)
	Used to specify the function that should be called periodically from TCP.
void	tcp_pcb_purge (struct tcp_pcb *pcb)
	Purges a TCP PCB.
void	tcp_pcb_remove (struct tcp_pcb *pcblist, struct tcp_pcb pcb)
	Purges the PCB and removes it from a PCB list.
u32_t	tcp_next_iss (struct tcp_pcb *pcb)
	Calculates a new initial sequence number for new connections.
u16_t	tcp_eff_send_mss_impl (u16_t sendmss, const ip_addr_t dest#if LWIP_IPV6\|\|LWIP_IPV4_SRC_ROUTING, const ip_addr_t src#endif)
	Calculates the effective send mss that can be used for a specific IP address by using ip_route to determine the netif used to send to the address and calculating the minimum of TCP_MSS and that netif's mtu (if set).
static void	tcp_netif_ip_addr_changed_pcblist (const ip_addr_t old_addr, struct tcp_pcb pcb_list)
	Helper function for tcp_netif_ip_addr_changed() that iterates a pcb list.
void	tcp_netif_ip_addr_changed (const ip_addr_t old_addr, const ip_addr_t new_addr)
	This function is called from netif.c when address is changed or netif is removed.
void	tcp_debug_print (struct tcp_hdr *tcphdr)
	Print a tcp header for debugging purposes.
void	tcp_debug_print_state (enum tcp_state s)
	Print a tcp state for debugging purposes.
void	tcp_debug_print_flags (u8_t flags)
	Print tcp flags for debugging purposes.
void	tcp_debug_print_pcbs (void)
	Print all tcp_pcbs in every list for debugging purposes.
s16_t	tcp_pcbs_sane (void)
	Check state consistency of the tcp_pcb lists.
Variables
struct tcp_pcb *	tcp_bound_pcbs
	List of all TCP PCBs bound but not yet (connected \|\| listening)
union tcp_listen_pcbs_t	tcp_listen_pcbs
	List of all TCP PCBs in LISTEN state.
struct tcp_pcb *	tcp_active_pcbs
	List of all TCP PCBs that are in a state in which they accept or send data.
struct tcp_pcb *	tcp_tw_pcbs
	List of all TCP PCBs in TIME-WAIT state.
struct tcp_pcb **const	tcp_pcb_lists []
	An array with all (non-temporary) PCB lists, mainly used for smaller code size.
static u8_t	tcp_timer
	Timer counter to handle calling slow-timer from tcp_tmr()

Detailed Description

Transmission Control Protocol for IP See also TCP.

Definition in file lwip_tcp.c.

Function Documentation

void tcp_abandon	(	struct tcp_pcb *	pcb,
		int	reset
	)

Abandons a connection and optionally sends a RST to the remote host.

Deletes the local protocol control block. This is done when a connection is killed because of shortage of memory.

Parameters:

pcb	the tcp_pcb to abort
reset	boolean to indicate whether a reset should be sent

Definition at line 464 of file lwip_tcp.c.

static err_t tcp_accept_null	(	void *	arg,
		struct tcp_pcb *	pcb,
		err_t	err
	)		`[static]`

Default accept callback if no accept callback is specified by the user.

Definition at line 631 of file lwip_tcp.c.

struct tcp_pcb* tcp_alloc ( u8_t prio ) [read]

Allocate a new tcp_pcb structure.

Parameters:

prio	priority for the new pcb

Returns:: a new tcp_pcb that initially is in state CLOSED

Definition at line 1549 of file lwip_tcp.c.

static err_t tcp_close_shutdown	(	struct tcp_pcb *	pcb,
		u8_t	rst_on_unacked_data
	)		`[static]`

Closes the TX side of a connection held by the PCB.

For tcp_close(), a RST is sent if the application didn't receive all data (tcp_recved() not called for all data passed to recv callback).

Listening pcbs are freed and may not be referenced any more. Connection pcbs are freed if not yet connected and may not be referenced any more. If a connection is established (at least SYN received or in a closing state), the connection is closed, and put in a closing state. The pcb is then automatically freed in tcp_slowtmr(). It is therefore unsafe to reference it.

Parameters:

pcb	the tcp_pcb to close

Returns:: ERR_OK if connection has been closed another err_t if closing failed and pcb is not freed

Definition at line 265 of file lwip_tcp.c.

void tcp_debug_print ( struct tcp_hdr * tcphdr )

Print a tcp header for debugging purposes.

Parameters:

tcphdr pointer to a struct tcp_hdr

Definition at line 2036 of file lwip_tcp.c.

void tcp_debug_print_flags ( u8_t flags )

Print tcp flags for debugging purposes.

Parameters:

flags tcp flags, all active flags are printed

Definition at line 2083 of file lwip_tcp.c.

void tcp_debug_print_pcbs ( void )

Print all tcp_pcbs in every list for debugging purposes.

Definition at line 2116 of file lwip_tcp.c.

void tcp_debug_print_state ( enum tcp_state s )

Print a tcp state for debugging purposes.

Parameters:

s	enum tcp_state to print

Definition at line 2072 of file lwip_tcp.c.

u16_t tcp_eff_send_mss_impl	(	u16_t	sendmss,
		const ip_addr_t *dest#if LWIP_IPV6\|\|	LWIP_IPV4_SRC_ROUTING,
		const ip_addr_t *src#	endif
	)

Calculates the effective send mss that can be used for a specific IP address by using ip_route to determine the netif used to send to the address and calculating the minimum of TCP_MSS and that netif's mtu (if set).

Definition at line 1910 of file lwip_tcp.c.

void tcp_fasttmr ( void )

Is called every TCP_FAST_INTERVAL (250 ms) and process data previously "refused" by upper layer (application) and sends delayed ACKs.

Automatically called from tcp_tmr().

Definition at line 1245 of file lwip_tcp.c.

void tcp_init ( void )

Initialize this module.

Definition at line 145 of file lwip_tcp.c.

static void tcp_kill_prio ( u8_t prio ) [static]

Kills the oldest active connection that has the same or lower priority than 'prio'.

Parameters:

prio	minimum priority

Definition at line 1458 of file lwip_tcp.c.

static void tcp_kill_state ( enum tcp_state state ) [static]

Kills the oldest connection that is in specific state.

Called from tcp_alloc() for LAST_ACK and CLOSING if no more connections are available.

Definition at line 1489 of file lwip_tcp.c.

static void tcp_kill_timewait ( void ) [static]

Kills the oldest connection that is in TIME_WAIT state.

Called from tcp_alloc() if no more connections are available.

Definition at line 1521 of file lwip_tcp.c.

static void tcp_listen_closed ( struct tcp_pcb * pcb ) [static]

Called when a listen pcb is closed.

Iterates all pcb lists and removes the closed listener pcb from pcb->listener if matching.

Definition at line 188 of file lwip_tcp.c.

void tcp_netif_ip_addr_changed	(	const ip_addr_t *	old_addr,
		const ip_addr_t *	new_addr
	)

This function is called from netif.c when address is changed or netif is removed.

Parameters:

old_addr	IP address of the netif before change
new_addr	IP address of the netif after change or NULL if netif has been removed

Definition at line 2000 of file lwip_tcp.c.

static void tcp_netif_ip_addr_changed_pcblist	(	const ip_addr_t *	old_addr,
		struct tcp_pcb *	pcb_list
	)		`[static]`

Helper function for tcp_netif_ip_addr_changed() that iterates a pcb list.

Definition at line 1971 of file lwip_tcp.c.

static u16_t tcp_new_port ( void ) [static]

Allocate a new local TCP port.

Returns:: a new (free) local TCP port number

Definition at line 832 of file lwip_tcp.c.

u32_t tcp_next_iss ( struct tcp_pcb * pcb )

Calculates a new initial sequence number for new connections.

Returns:: u32_t pseudo random sequence number

Definition at line 1889 of file lwip_tcp.c.

void tcp_pcb_purge ( struct tcp_pcb * pcb )

Purges a TCP PCB.

Removes any buffered data and frees the buffer memory (pcb->ooseq, pcb->unsent and pcb->unacked are freed).

Parameters:

pcb	tcp_pcb to purge. The pcb itself is not deallocated!

Definition at line 1805 of file lwip_tcp.c.

void tcp_pcb_remove	(	struct tcp_pcb **	pcblist,
		struct tcp_pcb *	pcb
	)

Purges the PCB and removes it from a PCB list.

Any delayed ACKs are sent first.

Parameters:

pcblist	PCB list to purge.
pcb	tcp_pcb to purge. The pcb itself is NOT deallocated!

Definition at line 1854 of file lwip_tcp.c.

s16_t tcp_pcbs_sane ( void )

Check state consistency of the tcp_pcb lists.

Definition at line 2148 of file lwip_tcp.c.

err_t tcp_process_refused_data ( struct tcp_pcb * pcb )

Pass pcb->refused_data to the recv callback.

Definition at line 1305 of file lwip_tcp.c.

err_t tcp_recv_null	(	void *	arg,
		struct tcp_pcb *	pcb,
		struct pbuf *	p,
		err_t	err
	)

Default receive callback that is called if the user didn't register a recv callback for the pcb.

Definition at line 1438 of file lwip_tcp.c.

static void tcp_remove_listener	(	struct tcp_pcb *	list,
		struct tcp_pcb_listen *	lpcb
	)		`[static]`

Called when a listen pcb is closed.

Iterates one pcb list and removes the closed listener pcb from pcb->listener if matching.

Definition at line 173 of file lwip_tcp.c.

struct tcp_seg* tcp_seg_copy ( struct tcp_seg * seg ) [read]

Returns a copy of the given TCP segment.

The pbuf and data are not copied, only the pointers

Parameters:

seg	the old tcp_seg

Returns:: a copy of seg

Definition at line 1418 of file lwip_tcp.c.

void tcp_seg_free ( struct tcp_seg * seg )

Frees a TCP segment (tcp_seg structure).

Parameters:

seg	single tcp_seg to free

Definition at line 1384 of file lwip_tcp.c.

void tcp_segs_free ( struct tcp_seg * seg )

Deallocates a list of TCP segments (tcp_seg structures).

Parameters:

seg	tcp_seg list of TCP segments to free

Definition at line 1369 of file lwip_tcp.c.

void tcp_setprio	(	struct tcp_pcb *	pcb,
		u8_t	prio
	)

Sets the priority of a connection.

Parameters:

pcb	the tcp_pcb to manipulate
prio	new priority

Definition at line 1404 of file lwip_tcp.c.

void tcp_slowtmr ( void )

Called every 500 ms and implements the retransmission timer and the timer that removes PCBs that have been in TIME-WAIT for enough time.

It also increments various timers such as the inactivity timer in each PCB.

Automatically called from tcp_tmr().

Definition at line 980 of file lwip_tcp.c.

void tcp_tmr ( void )

Called periodically to dispatch TCP timers.

Definition at line 156 of file lwip_tcp.c.

void tcp_txnow ( void )

Call tcp_output for all active pcbs that have TF_NAGLEMEMERR set.

Definition at line 1292 of file lwip_tcp.c.

u32_t tcp_update_rcv_ann_wnd ( struct tcp_pcb * pcb )

Update the state that tracks the available window space to advertise.

Returns how much extra window would be advertised if we sent an update now.

Definition at line 753 of file lwip_tcp.c.

Variable Documentation

struct tcp_pcb* tcp_active_pcbs

List of all TCP PCBs that are in a state in which they accept or send data.

Definition at line 124 of file lwip_tcp.c.

struct tcp_pcb* tcp_bound_pcbs

List of all TCP PCBs bound but not yet (connected || listening)

Definition at line 119 of file lwip_tcp.c.

union tcp_listen_pcbs_t tcp_listen_pcbs

List of all TCP PCBs in LISTEN state.

Definition at line 121 of file lwip_tcp.c.

struct tcp_pcb** const tcp_pcb_lists[]

Initial value:

 {&tcp_listen_pcbs.pcbs, &tcp_bound_pcbs,
  &tcp_active_pcbs, &tcp_tw_pcbs}

An array with all (non-temporary) PCB lists, mainly used for smaller code size.

Definition at line 129 of file lwip_tcp.c.

u8_t tcp_timer [static]

Timer counter to handle calling slow-timer from tcp_tmr()

Definition at line 135 of file lwip_tcp.c.

struct tcp_pcb* tcp_tw_pcbs

List of all TCP PCBs in TIME-WAIT state.

Definition at line 126 of file lwip_tcp.c.

Type:	Library
Created:	15 Jan 2020
Imports:	12
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	0
Followers:	2

lwip_tcp.c File Reference

Functions

Variables

Detailed Description

Function Documentation

Variable Documentation

Repository toolbox

Repository details

Important Information for this Arm website

lwip_tcp.c File Reference

Functions

Variables

Detailed Description

Function Documentation

Variable Documentation

Repository toolbox

Repository details

Important Information for this Arm website

Access Warning