minix/lib/liblwip/include/lwip/tcp.h

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/*
* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* This file is part of the lwIP TCP/IP stack.
*
* Author: Adam Dunkels <adam@sics.se>
*
*/
#ifndef __LWIP_TCP_H__
#define __LWIP_TCP_H__
#include "lwip/opt.h"
#if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
#include "lwip/sys.h"
#include "lwip/mem.h"
#include "lwip/pbuf.h"
#include "lwip/ip.h"
#include "lwip/icmp.h"
#include "lwip/err.h"
#ifdef __cplusplus
extern "C" {
#endif
struct tcp_pcb;
/** Function prototype for tcp accept callback functions. Called when a new
* connection can be accepted on a listening pcb.
*
* @param arg Additional argument to pass to the callback function (@see tcp_arg())
* @param newpcb The new connection pcb
* @param err An error code if there has been an error accepting.
* Only return ERR_ABRT if you have called tcp_abort from within the
* callback function!
*/
typedef err_t (*tcp_accept_fn)(void *arg, struct tcp_pcb *newpcb, err_t err);
/** Function prototype for tcp receive callback functions. Called when data has
* been received.
*
* @param arg Additional argument to pass to the callback function (@see tcp_arg())
* @param tpcb The connection pcb which received data
* @param p The received data (or NULL when the connection has been closed!)
* @param err An error code if there has been an error receiving
* Only return ERR_ABRT if you have called tcp_abort from within the
* callback function!
*/
typedef err_t (*tcp_recv_fn)(void *arg, struct tcp_pcb *tpcb,
struct pbuf *p, err_t err);
/** Function prototype for tcp sent callback functions. Called when sent data has
* been acknowledged by the remote side. Use it to free corresponding resources.
* This also means that the pcb has now space available to send new data.
*
* @param arg Additional argument to pass to the callback function (@see tcp_arg())
* @param tpcb The connection pcb for which data has been acknowledged
* @param len The amount of bytes acknowledged
* @return ERR_OK: try to send some data by calling tcp_output
* Only return ERR_ABRT if you have called tcp_abort from within the
* callback function!
*/
typedef err_t (*tcp_sent_fn)(void *arg, struct tcp_pcb *tpcb,
u16_t len);
/** Function prototype for tcp poll callback functions. Called periodically as
* specified by @see tcp_poll.
*
* @param arg Additional argument to pass to the callback function (@see tcp_arg())
* @param tpcb tcp pcb
* @return ERR_OK: try to send some data by calling tcp_output
* Only return ERR_ABRT if you have called tcp_abort from within the
* callback function!
*/
typedef err_t (*tcp_poll_fn)(void *arg, struct tcp_pcb *tpcb);
/** Function prototype for tcp error callback functions. Called when the pcb
* receives a RST or is unexpectedly closed for any other reason.
*
* @note The corresponding pcb is already freed when this callback is called!
*
* @param arg Additional argument to pass to the callback function (@see tcp_arg())
* @param err Error code to indicate why the pcb has been closed
* ERR_ABRT: aborted through tcp_abort or by a TCP timer
* ERR_RST: the connection was reset by the remote host
*/
typedef void (*tcp_err_fn)(void *arg, err_t err);
/** Function prototype for tcp connected callback functions. Called when a pcb
* is connected to the remote side after initiating a connection attempt by
* calling tcp_connect().
*
* @param arg Additional argument to pass to the callback function (@see tcp_arg())
* @param tpcb The connection pcb which is connected
* @param err An unused error code, always ERR_OK currently ;-) TODO!
* Only return ERR_ABRT if you have called tcp_abort from within the
* callback function!
*
* @note When a connection attempt fails, the error callback is currently called!
*/
typedef err_t (*tcp_connected_fn)(void *arg, struct tcp_pcb *tpcb, err_t err);
enum tcp_state {
CLOSED = 0,
LISTEN = 1,
SYN_SENT = 2,
SYN_RCVD = 3,
ESTABLISHED = 4,
FIN_WAIT_1 = 5,
FIN_WAIT_2 = 6,
CLOSE_WAIT = 7,
CLOSING = 8,
LAST_ACK = 9,
TIME_WAIT = 10
};
#if LWIP_CALLBACK_API
/* Function to call when a listener has been connected.
* @param arg user-supplied argument (tcp_pcb.callback_arg)
* @param pcb a new tcp_pcb that now is connected
* @param err an error argument (TODO: that is current always ERR_OK?)
* @return ERR_OK: accept the new connection,
* any other err_t abortsthe new connection
*/
#define DEF_ACCEPT_CALLBACK tcp_accept_fn accept;
#else /* LWIP_CALLBACK_API */
#define DEF_ACCEPT_CALLBACK
#endif /* LWIP_CALLBACK_API */
/**
* members common to struct tcp_pcb and struct tcp_listen_pcb
*/
#define TCP_PCB_COMMON(type) \
type *next; /* for the linked list */ \
enum tcp_state state; /* TCP state */ \
u8_t prio; \
void *callback_arg; \
/* the accept callback for listen- and normal pcbs, if LWIP_CALLBACK_API */ \
DEF_ACCEPT_CALLBACK \
/* ports are in host byte order */ \
u16_t local_port
/* the TCP protocol control block */
struct tcp_pcb {
/** common PCB members */
IP_PCB;
/** protocol specific PCB members */
TCP_PCB_COMMON(struct tcp_pcb);
/* ports are in host byte order */
u16_t remote_port;
u8_t flags;
#define TF_ACK_DELAY ((u8_t)0x01U) /* Delayed ACK. */
#define TF_ACK_NOW ((u8_t)0x02U) /* Immediate ACK. */
#define TF_INFR ((u8_t)0x04U) /* In fast recovery. */
#define TF_TIMESTAMP ((u8_t)0x08U) /* Timestamp option enabled */
#define TF_RXCLOSED ((u8_t)0x10U) /* rx closed by tcp_shutdown */
#define TF_FIN ((u8_t)0x20U) /* Connection was closed locally (FIN segment enqueued). */
#define TF_NODELAY ((u8_t)0x40U) /* Disable Nagle algorithm */
#define TF_NAGLEMEMERR ((u8_t)0x80U) /* nagle enabled, memerr, try to output to prevent delayed ACK to happen */
/* the rest of the fields are in host byte order
as we have to do some math with them */
/* receiver variables */
u32_t rcv_nxt; /* next seqno expected */
u16_t rcv_wnd; /* receiver window available */
u16_t rcv_ann_wnd; /* receiver window to announce */
u32_t rcv_ann_right_edge; /* announced right edge of window */
/* Timers */
u32_t tmr;
u8_t polltmr, pollinterval;
/* Retransmission timer. */
s16_t rtime;
u16_t mss; /* maximum segment size */
/* RTT (round trip time) estimation variables */
u32_t rttest; /* RTT estimate in 500ms ticks */
u32_t rtseq; /* sequence number being timed */
s16_t sa, sv; /* @todo document this */
s16_t rto; /* retransmission time-out */
u8_t nrtx; /* number of retransmissions */
/* fast retransmit/recovery */
u32_t lastack; /* Highest acknowledged seqno. */
u8_t dupacks;
/* congestion avoidance/control variables */
u16_t cwnd;
u16_t ssthresh;
/* sender variables */
u32_t snd_nxt; /* next new seqno to be sent */
u16_t snd_wnd; /* sender window */
u32_t snd_wl1, snd_wl2; /* Sequence and acknowledgement numbers of last
window update. */
u32_t snd_lbb; /* Sequence number of next byte to be buffered. */
u16_t acked;
u16_t snd_buf; /* Available buffer space for sending (in bytes). */
#define TCP_SNDQUEUELEN_OVERFLOW (0xffff-3)
u16_t snd_queuelen; /* Available buffer space for sending (in tcp_segs). */
#if TCP_OVERSIZE
/* Extra bytes available at the end of the last pbuf in unsent. */
u16_t unsent_oversize;
#endif /* TCP_OVERSIZE */
/* These are ordered by sequence number: */
struct tcp_seg *unsent; /* Unsent (queued) segments. */
struct tcp_seg *unacked; /* Sent but unacknowledged segments. */
#if TCP_QUEUE_OOSEQ
struct tcp_seg *ooseq; /* Received out of sequence segments. */
#endif /* TCP_QUEUE_OOSEQ */
struct pbuf *refused_data; /* Data previously received but not yet taken by upper layer */
#if LWIP_CALLBACK_API
/* Function to be called when more send buffer space is available. */
tcp_sent_fn sent;
/* Function to be called when (in-sequence) data has arrived. */
tcp_recv_fn recv;
/* Function to be called when a connection has been set up. */
tcp_connected_fn connected;
/* Function which is called periodically. */
tcp_poll_fn poll;
/* Function to be called whenever a fatal error occurs. */
tcp_err_fn errf;
#endif /* LWIP_CALLBACK_API */
#if LWIP_TCP_TIMESTAMPS
u32_t ts_lastacksent;
u32_t ts_recent;
#endif /* LWIP_TCP_TIMESTAMPS */
/* idle time before KEEPALIVE is sent */
u32_t keep_idle;
#if LWIP_TCP_KEEPALIVE
u32_t keep_intvl;
u32_t keep_cnt;
#endif /* LWIP_TCP_KEEPALIVE */
/* Persist timer counter */
u32_t persist_cnt;
/* Persist timer back-off */
u8_t persist_backoff;
/* KEEPALIVE counter */
u8_t keep_cnt_sent;
};
struct tcp_pcb_listen {
/* Common members of all PCB types */
IP_PCB;
/* Protocol specific PCB members */
TCP_PCB_COMMON(struct tcp_pcb_listen);
#if TCP_LISTEN_BACKLOG
u8_t backlog;
u8_t accepts_pending;
#endif /* TCP_LISTEN_BACKLOG */
};
#if LWIP_EVENT_API
enum lwip_event {
LWIP_EVENT_ACCEPT,
LWIP_EVENT_SENT,
LWIP_EVENT_RECV,
LWIP_EVENT_CONNECTED,
LWIP_EVENT_POLL,
LWIP_EVENT_ERR
};
err_t lwip_tcp_event(void *arg, struct tcp_pcb *pcb,
enum lwip_event,
struct pbuf *p,
u16_t size,
err_t err);
#endif /* LWIP_EVENT_API */
/* Application program's interface: */
struct tcp_pcb * tcp_new (void);
void tcp_arg (struct tcp_pcb *pcb, void *arg);
void tcp_accept (struct tcp_pcb *pcb, tcp_accept_fn accept);
void tcp_recv (struct tcp_pcb *pcb, tcp_recv_fn recv);
void tcp_sent (struct tcp_pcb *pcb, tcp_sent_fn sent);
void tcp_poll (struct tcp_pcb *pcb, tcp_poll_fn poll, u8_t interval);
void tcp_err (struct tcp_pcb *pcb, tcp_err_fn err);
#define tcp_mss(pcb) (((pcb)->flags & TF_TIMESTAMP) ? ((pcb)->mss - 12) : (pcb)->mss)
#define tcp_sndbuf(pcb) ((pcb)->snd_buf)
#define tcp_sndqueuelen(pcb) ((pcb)->snd_queuelen)
#define tcp_nagle_disable(pcb) ((pcb)->flags |= TF_NODELAY)
#define tcp_nagle_enable(pcb) ((pcb)->flags &= ~TF_NODELAY)
#define tcp_nagle_disabled(pcb) (((pcb)->flags & TF_NODELAY) != 0)
#if TCP_LISTEN_BACKLOG
#define tcp_accepted(pcb) do { \
LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", pcb->state == LISTEN); \
(((struct tcp_pcb_listen *)(pcb))->accepts_pending--); } while(0)
#else /* TCP_LISTEN_BACKLOG */
#define tcp_accepted(pcb) LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", \
pcb->state == LISTEN)
#endif /* TCP_LISTEN_BACKLOG */
void tcp_recved (struct tcp_pcb *pcb, u16_t len);
err_t tcp_bind (struct tcp_pcb *pcb, ip_addr_t *ipaddr,
u16_t port);
err_t tcp_connect (struct tcp_pcb *pcb, ip_addr_t *ipaddr,
u16_t port, tcp_connected_fn connected);
struct tcp_pcb * tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog);
#define tcp_listen(pcb) tcp_listen_with_backlog(pcb, TCP_DEFAULT_LISTEN_BACKLOG)
void tcp_abort (struct tcp_pcb *pcb);
err_t tcp_close (struct tcp_pcb *pcb);
err_t tcp_shutdown(struct tcp_pcb *pcb, int shut_rx, int shut_tx);
/* Flags for "apiflags" parameter in tcp_write */
#define TCP_WRITE_FLAG_COPY 0x01
#define TCP_WRITE_FLAG_MORE 0x02
err_t tcp_write (struct tcp_pcb *pcb, const void *dataptr, u16_t len,
u8_t apiflags);
void tcp_setprio (struct tcp_pcb *pcb, u8_t prio);
#define TCP_PRIO_MIN 1
#define TCP_PRIO_NORMAL 64
#define TCP_PRIO_MAX 127
err_t tcp_output (struct tcp_pcb *pcb);
const char* tcp_debug_state_str(enum tcp_state s);
#ifdef __cplusplus
}
#endif
#endif /* LWIP_TCP */
#endif /* __LWIP_TCP_H__ */