#include "lwip/opt.h"
#include "lwip/def.h"
#include "lwip/mem.h"
#include "lwip/memp.h"
#include "lwip/snmp.h"
#include "lwip/tcp.h"
#include "lwip/debug.h"
#include "lwip/stats.h"
#include <string.h>
Go to the source code of this file.
Defines |
#define | TCP_LOCAL_PORT_RANGE_START 4096 |
#define | TCP_LOCAL_PORT_RANGE_END 0x7fff |
Functions |
void | tcp_tmr (void) |
err_t | tcp_close (struct tcp_pcb *pcb) |
void | tcp_abandon (struct tcp_pcb *pcb, int reset) |
err_t | tcp_bind (struct tcp_pcb *pcb, struct ip_addr *ipaddr, u16_t port) |
struct tcp_pcb * | tcp_listen_with_backlog (struct tcp_pcb *pcb, u8_t backlog) |
u32_t | tcp_update_rcv_ann_wnd (struct tcp_pcb *pcb) |
void | tcp_recved (struct tcp_pcb *pcb, u16_t len) |
err_t | tcp_connect (struct tcp_pcb *pcb, struct ip_addr *ipaddr, u16_t port, err_t(*connected)(void *arg, struct tcp_pcb *tpcb, err_t err)) |
void | tcp_slowtmr (void) |
void | tcp_fasttmr (void) |
u8_t | tcp_segs_free (struct tcp_seg *seg) |
u8_t | tcp_seg_free (struct tcp_seg *seg) |
void | tcp_setprio (struct tcp_pcb *pcb, u8_t prio) |
struct tcp_seg * | tcp_seg_copy (struct tcp_seg *seg) |
err_t | tcp_recv_null (void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err) |
struct tcp_pcb * | tcp_alloc (u8_t prio) |
struct tcp_pcb * | tcp_new (void) |
void | tcp_arg (struct tcp_pcb *pcb, void *arg) |
void | tcp_recv (struct tcp_pcb *pcb, err_t(*recv)(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err)) |
void | tcp_sent (struct tcp_pcb *pcb, err_t(*sent)(void *arg, struct tcp_pcb *tpcb, u16_t len)) |
void | tcp_err (struct tcp_pcb *pcb, void(*errf)(void *arg, err_t err)) |
void | tcp_accept (struct tcp_pcb *pcb, err_t(*accept)(void *arg, struct tcp_pcb *newpcb, err_t err)) |
void | tcp_poll (struct tcp_pcb *pcb, err_t(*poll)(void *arg, struct tcp_pcb *tpcb), u8_t interval) |
void | tcp_pcb_purge (struct tcp_pcb *pcb) |
void | tcp_pcb_remove (struct tcp_pcb **pcblist, struct tcp_pcb *pcb) |
u32_t | tcp_next_iss (void) |
u16_t | tcp_eff_send_mss (u16_t sendmss, struct ip_addr *addr) |
const char * | tcp_debug_state_str (enum tcp_state s) |
Variables |
const char * | tcp_state_str [] |
u32_t | tcp_ticks |
const u8_t | tcp_backoff [13] |
const u8_t | tcp_persist_backoff [7] = { 3, 6, 12, 24, 48, 96, 120 } |
struct tcp_pcb * | tcp_bound_pcbs |
union tcp_listen_pcbs_t | tcp_listen_pcbs |
struct tcp_pcb * | tcp_active_pcbs |
struct tcp_pcb * | tcp_tw_pcbs |
struct tcp_pcb * | tcp_tmp_pcb |
Detailed Description
Transmission Control Protocol for IP
This file contains common functions for the TCP implementation, such as functinos for manipulating the data structures and the TCP timer functions. TCP functions related to input and output is found in tcp_in.c and tcp_out.c respectively.
Definition in file 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 213 of file tcp.c.
void tcp_accept |
( |
struct tcp_pcb * |
pcb, |
|
|
err_t(*)(void *arg, struct tcp_pcb *newpcb, err_t err) |
accept | |
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) |
| | |
Used for specifying the function that should be called when a LISTENing connection has been connected to another host.
- Parameters:
-
| pcb | tcp_pcb to set the accept callback |
| accept | callback function to call for this pcb when LISTENing connection has been connected to another host |
Definition at line 1160 of file tcp.c.
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 1005 of file tcp.c.
void tcp_arg |
( |
struct tcp_pcb * |
pcb, |
|
|
void * |
arg | |
|
) |
| | |
Used to specify the argument that should be passed callback functions.
- Parameters:
-
| pcb | tcp_pcb to set the callback argument |
| arg | void pointer argument to pass to callback functions |
Definition at line 1102 of file tcp.c.
Binds the connection to a local portnumber and IP address. If the IP address is not given (i.e., ipaddr == NULL), the IP address of the outgoing network interface is used instead.
- Parameters:
-
| pcb | the tcp_pcb to bind (no check is done whether this pcb is already bound!) |
| ipaddr | the local ip address to bind to (use IP_ADDR_ANY to bind to any local address |
| port | the local port to bind to |
- Returns:
- ERR_USE if the port is already in use ERR_OK if bound
Definition at line 276 of file tcp.c.
err_t tcp_close |
( |
struct tcp_pcb * |
pcb |
) |
|
Closes the connection held by the PCB.
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:
-
- Returns:
- ERR_OK if connection has been closed another err_t if closing failed and pcb is not freed
Definition at line 127 of file tcp.c.
err_t tcp_connect |
( |
struct tcp_pcb * |
pcb, |
|
|
struct ip_addr * |
ipaddr, |
|
|
u16_t |
port, |
|
|
err_t(*)(void *arg, struct tcp_pcb *tpcb, err_t err) |
connected | |
|
) |
| | |
Connects to another host. The function given as the "connected" argument will be called when the connection has been established.
- Parameters:
-
| pcb | the tcp_pcb used to establish the connection |
| ipaddr | the remote ip address to connect to |
| port | the remote tcp port to connect to |
| connected | callback function to call when connected (or on error) |
- Returns:
- ERR_VAL if invalid arguments are given ERR_OK if connect request has been sent other err_t values if connect request couldn't be sent
Definition at line 514 of file tcp.c.
Calcluates the effective send mss that can be used for a specific IP address by using ip_route to determin 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 1304 of file tcp.c.
void tcp_err |
( |
struct tcp_pcb * |
pcb, |
|
|
void(*)(void *arg, err_t err) |
errf | |
|
) |
| | |
Used to specify the function that should be called when a fatal error has occured on the connection.
- Parameters:
-
| pcb | tcp_pcb to set the err callback |
| errf | callback function to call for this pcb when a fatal error has occured on the connection |
Definition at line 1145 of file 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 817 of file tcp.c.
Set the state of the connection to be LISTEN, which means that it is able to accept incoming connections. The protocol control block is reallocated in order to consume less memory. Setting the connection to LISTEN is an irreversible process.
- Parameters:
-
| pcb | the original tcp_pcb |
| backlog | the incoming connections queue limit |
- Returns:
- tcp_pcb used for listening, consumes less memory.
- Note:
- The original tcp_pcb is freed. This function therefore has to be called like this: tpcb = tcp_listen(tpcb);
Definition at line 366 of file tcp.c.
struct tcp_pcb* tcp_new |
( |
void |
|
) |
[read] |
Creates a new TCP protocol control block but doesn't place it on any of the TCP PCB lists. The pcb is not put on any list until binding using tcp_bind().
Definition at line 1089 of file tcp.c.
u32_t tcp_next_iss |
( |
void |
|
) |
|
Calculates a new initial sequence number for new connections.
- Returns:
- u32_t pseudo random sequence number
Definition at line 1289 of file 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 1191 of file 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 1256 of file tcp.c.
void tcp_poll |
( |
struct tcp_pcb * |
pcb, |
|
|
err_t(*)(void *arg, struct tcp_pcb *tpcb) |
poll, |
|
|
u8_t |
interval | |
|
) |
| | |
Used to specify the function that should be called periodically from TCP. The interval is specified in terms of the TCP coarse timer interval, which is called twice a second.
Definition at line 1175 of file tcp.c.
void tcp_recv |
( |
struct tcp_pcb * |
pcb, |
|
|
err_t(*)(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err) |
recv | |
|
) |
| | |
Used to specify the function that should be called when a TCP connection receives data.
- Parameters:
-
| pcb | tcp_pcb to set the recv callback |
| recv | callback function to call for this pcb when data is received |
Definition at line 1116 of file 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 925 of file tcp.c.
This function should be called by the application when it has processed the data. The purpose is to advertise a larger window when the data has been processed.
- Parameters:
-
| pcb | the tcp_pcb for which data is read |
| len | the amount of bytes that have been read by the application |
Definition at line 438 of file tcp.c.
Returns a copy of the given TCP segment. The pbuf and data are not copied, only the pointers
- Parameters:
-
- Returns:
- a copy of seg
Definition at line 905 of file tcp.c.
Frees a TCP segment (tcp_seg structure).
- Parameters:
-
- Returns:
- the number of pbufs that were deallocated
Definition at line 868 of file tcp.c.
Deallocates a list of TCP segments (tcp_seg structures).
- Parameters:
-
| seg | tcp_seg list of TCP segments to free |
- Returns:
- the number of pbufs that were deallocated
Definition at line 849 of file tcp.c.
void tcp_sent |
( |
struct tcp_pcb * |
pcb, |
|
|
err_t(*)(void *arg, struct tcp_pcb *tpcb, u16_t len) |
sent | |
|
) |
| | |
Used to specify the function that should be called when TCP data has been successfully delivered to the remote host.
- Parameters:
-
| pcb | tcp_pcb to set the sent callback |
| sent | callback function to call for this pcb when data is successfully sent |
Definition at line 1130 of file tcp.c.
Sets the priority of a connection.
- Parameters:
-
| pcb | the tcp_pcb to manipulate |
| prio | new priority |
Definition at line 891 of file 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 577 of file tcp.c.
Called periodically to dispatch TCP timers.
Definition at line 100 of file 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 408 of file tcp.c.
Variable Documentation
List of all TCP PCBs that are in a state in which they accept or send data.
Definition at line 86 of file tcp.c.
const u8_t tcp_backoff[13] |
Initial value:
{ 1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7}
Definition at line 73 of file tcp.c.
List of all TCP PCBs bound but not yet (connected || listening)
Definition at line 81 of file tcp.c.
List of all TCP PCBs in LISTEN state
Definition at line 83 of file tcp.c.
const char* tcp_state_str[] |
Initial value: {
"CLOSED",
"LISTEN",
"SYN_SENT",
"SYN_RCVD",
"ESTABLISHED",
"FIN_WAIT_1",
"FIN_WAIT_2",
"CLOSE_WAIT",
"CLOSING",
"LAST_ACK",
"TIME_WAIT"
}
Definition at line 57 of file tcp.c.
List of all TCP PCBs in TIME-WAIT state
Definition at line 88 of file tcp.c.