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/**
* @file
* TCP API (to be used from TCPIP thread)\n
* See also @ref tcp_raw
*/
/*
* 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_HDR_TCP_H
#define LWIP_HDR_TCP_H
#include "lwip/opt.h"
#if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
#include "lwip/tcpbase.h"
#include "lwip/mem.h"
#include "lwip/pbuf.h"
#include "lwip/ip.h"
#include "lwip/icmp.h"
#include "lwip/err.h"
#include "lwip/ip6.h"
#include "lwip/ip6_addr.h"
#ifdef __cplusplus
extern "C" {
#endif
struct tcp_pcb;
struct tcp_pcb_listen;
/** 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);
#if LWIP_WND_SCALE
#define RCV_WND_SCALE(pcb, wnd) (((wnd) >> (pcb)->rcv_scale))
#define SND_WND_SCALE(pcb, wnd) (((wnd) << (pcb)->snd_scale))
#define TCPWND16(x) ((u16_t)LWIP_MIN((x), 0xFFFF))
#define TCP_WND_MAX(pcb) ((tcpwnd_size_t)(((pcb)->flags & TF_WND_SCALE) ? TCP_WND : TCPWND16(TCP_WND)))
#else
#define RCV_WND_SCALE(pcb, wnd) (wnd)
#define SND_WND_SCALE(pcb, wnd) (wnd)
#define TCPWND16(x) (x)
#define TCP_WND_MAX(pcb) TCP_WND
#endif
/* Increments a tcpwnd_size_t and holds at max value rather than rollover */
#define TCP_WND_INC(wnd, inc) do { \
if ((tcpwnd_size_t)(wnd + inc) >= wnd) { \
wnd = (tcpwnd_size_t)(wnd + inc); \
} else { \
wnd = (tcpwnd_size_t)-1; \
} \
} while(0)
#if LWIP_TCP_SACK_OUT
/** SACK ranges to include in ACK packets.
* SACK entry is invalid if left==right. */
struct tcp_sack_range {
/** Left edge of the SACK: the first acknowledged sequence number. */
u32_t left;
/** Right edge of the SACK: the last acknowledged sequence number +1 (so first NOT acknowledged). */
u32_t right;
};
#endif /* LWIP_TCP_SACK_OUT */
/** Function prototype for deallocation of arguments. Called *just before* the
* pcb is freed, so don't expect to be able to do anything with this pcb!
*
* @param id ext arg id (allocated via @ref tcp_ext_arg_alloc_id)
* @param data pointer to the data (set via @ref tcp_ext_arg_set before)
*/
typedef void (*tcp_extarg_callback_pcb_destroyed_fn)(u8_t id, void *data);
/** Function prototype to transition arguments from a listening pcb to an accepted pcb
*
* @param id ext arg id (allocated via @ref tcp_ext_arg_alloc_id)
* @param lpcb the listening pcb accepting a connection
* @param cpcb the newly allocated connection pcb
* @return ERR_OK if OK, any error if connection should be dropped
*/
typedef err_t (*tcp_extarg_callback_passive_open_fn)(u8_t id, struct tcp_pcb_listen *lpcb, struct tcp_pcb *cpcb);
/** A table of callback functions that is invoked for ext arguments */
struct tcp_ext_arg_callbacks {
/** @ref tcp_extarg_callback_pcb_destroyed_fn */
tcp_extarg_callback_pcb_destroyed_fn destroy;
/** @ref tcp_extarg_callback_passive_open_fn */
tcp_extarg_callback_passive_open_fn passive_open;
};
#define LWIP_TCP_PCB_NUM_EXT_ARG_ID_INVALID 0xFF
#if LWIP_TCP_PCB_NUM_EXT_ARGS
/* This is the structure for ext args in tcp pcbs (used as array) */
struct tcp_pcb_ext_args {
const struct tcp_ext_arg_callbacks *callbacks;
void *data;
};
/* This is a helper define to prevent zero size arrays if disabled */
#define TCP_PCB_EXTARGS struct tcp_pcb_ext_args ext_args[LWIP_TCP_PCB_NUM_EXT_ARGS];
#else
#define TCP_PCB_EXTARGS
#endif
typedef u16_t tcpflags_t;
#define TCP_ALLFLAGS 0xffffU
/**
* members common to struct tcp_pcb and struct tcp_listen_pcb
*/
#define TCP_PCB_COMMON(type) \
type *next; /* for the linked list */ \
void *callback_arg; \
TCP_PCB_EXTARGS \
enum tcp_state state; /* TCP state */ \
u8_t prio; \
/* ports are in host byte order */ \
u16_t local_port
/** the TCP protocol control block for listening pcbs */
struct tcp_pcb_listen {
/** Common members of all PCB types */
IP_PCB;
/** Protocol specific PCB members */
TCP_PCB_COMMON(struct tcp_pcb_listen);
#if LWIP_CALLBACK_API
/* Function to call when a listener has been connected. */
tcp_accept_fn accept;
#endif /* LWIP_CALLBACK_API */
#if TCP_LISTEN_BACKLOG
u8_t backlog;
u8_t accepts_pending;
#endif /* TCP_LISTEN_BACKLOG */
};
/** 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;
tcpflags_t flags;
#define TF_ACK_DELAY 0x01U /* Delayed ACK. */
#define TF_ACK_NOW 0x02U /* Immediate ACK. */
#define TF_INFR 0x04U /* In fast recovery. */
#define TF_CLOSEPEND 0x08U /* If this is set, tcp_close failed to enqueue the FIN (retried in tcp_tmr) */
#define TF_RXCLOSED 0x10U /* rx closed by tcp_shutdown */
#define TF_FIN 0x20U /* Connection was closed locally (FIN segment enqueued). */
#define TF_NODELAY 0x40U /* Disable Nagle algorithm */
#define TF_NAGLEMEMERR 0x80U /* nagle enabled, memerr, try to output to prevent delayed ACK to happen */
#if LWIP_WND_SCALE
#define TF_WND_SCALE 0x0100U /* Window Scale option enabled */
#endif
#if TCP_LISTEN_BACKLOG
#define TF_BACKLOGPEND 0x0200U /* If this is set, a connection pcb has increased the backlog on its listener */
#endif
#if LWIP_TCP_TIMESTAMPS
#define TF_TIMESTAMP 0x0400U /* Timestamp option enabled */
#endif
#define TF_RTO 0x0800U /* RTO timer has fired, in-flight data moved to unsent and being retransmitted */
#if LWIP_TCP_SACK_OUT
#define TF_SACK 0x1000U /* Selective ACKs enabled */
#endif
/* the rest of the fields are in host byte order
as we have to do some math with them */
/* Timers */
u8_t polltmr, pollinterval;
u8_t last_timer;
u32_t tmr;
/* receiver variables */
u32_t rcv_nxt; /* next seqno expected */
tcpwnd_size_t rcv_wnd; /* receiver window available */
tcpwnd_size_t rcv_ann_wnd; /* receiver window to announce */
u32_t rcv_ann_right_edge; /* announced right edge of window */
#if LWIP_TCP_SACK_OUT
/* SACK ranges to include in ACK packets (entry is invalid if left==right) */
struct tcp_sack_range rcv_sacks[LWIP_TCP_MAX_SACK_NUM];
#define LWIP_TCP_SACK_VALID(pcb, idx) ((pcb)->rcv_sacks[idx].left != (pcb)->rcv_sacks[idx].right)
#endif /* LWIP_TCP_SACK_OUT */
/* 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; /* @see "Congestion Avoidance and Control" by Van Jacobson and Karels */
s16_t rto; /* retransmission time-out (in ticks of TCP_SLOW_INTERVAL) */
u8_t nrtx; /* number of retransmissions */
/* fast retransmit/recovery */
u8_t dupacks;
u32_t lastack; /* Highest acknowledged seqno. */
/* congestion avoidance/control variables */
tcpwnd_size_t cwnd;
tcpwnd_size_t ssthresh;
/* first byte following last rto byte */
u32_t rto_end;
/* sender variables */
u32_t snd_nxt; /* next new seqno to be sent */
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. */
tcpwnd_size_t snd_wnd; /* sender window */
tcpwnd_size_t snd_wnd_max; /* the maximum sender window announced by the remote host */
tcpwnd_size_t snd_buf; /* Available buffer space for sending (in bytes). */
#define TCP_SNDQUEUELEN_OVERFLOW (0xffffU-3)
u16_t snd_queuelen; /* Number of pbufs currently in the send buffer. */
#if TCP_OVERSIZE
/* Extra bytes available at the end of the last pbuf in unsent. */
u16_t unsent_oversize;
#endif /* TCP_OVERSIZE */
tcpwnd_size_t bytes_acked;
/* 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 || TCP_LISTEN_BACKLOG
struct tcp_pcb_listen* listener;
#endif /* LWIP_CALLBACK_API || TCP_LISTEN_BACKLOG */
#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 */
u8_t persist_cnt;
/* Persist timer back-off */
u8_t persist_backoff;
/* Number of persist probes */
u8_t persist_probe;
/* KEEPALIVE counter */
u8_t keep_cnt_sent;
#if LWIP_WND_SCALE
u8_t snd_scale;
u8_t rcv_scale;
#endif
};
#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);
struct tcp_pcb * tcp_new_ip_type (u8_t type);
void tcp_arg (struct tcp_pcb *pcb, void *arg);
#if LWIP_CALLBACK_API
void tcp_recv (struct tcp_pcb *pcb, tcp_recv_fn recv);
void tcp_sent (struct tcp_pcb *pcb, tcp_sent_fn sent);
void tcp_err (struct tcp_pcb *pcb, tcp_err_fn err);
void tcp_accept (struct tcp_pcb *pcb, tcp_accept_fn accept);
#endif /* LWIP_CALLBACK_API */
void tcp_poll (struct tcp_pcb *pcb, tcp_poll_fn poll, u8_t interval);
#define tcp_set_flags(pcb, set_flags) do { (pcb)->flags = (tcpflags_t)((pcb)->flags | (set_flags)); } while(0)
#define tcp_clear_flags(pcb, clr_flags) do { (pcb)->flags = (tcpflags_t)((pcb)->flags & (tcpflags_t)(~(clr_flags) & TCP_ALLFLAGS)); } while(0)
#define tcp_is_flag_set(pcb, flag) (((pcb)->flags & (flag)) != 0)
#if LWIP_TCP_TIMESTAMPS
#define tcp_mss(pcb) (((pcb)->flags & TF_TIMESTAMP) ? ((pcb)->mss - 12) : (pcb)->mss)
#else /* LWIP_TCP_TIMESTAMPS */
/** @ingroup tcp_raw */
#define tcp_mss(pcb) ((pcb)->mss)
#endif /* LWIP_TCP_TIMESTAMPS */
/** @ingroup tcp_raw */
#define tcp_sndbuf(pcb) (TCPWND16((pcb)->snd_buf))
/** @ingroup tcp_raw */
#define tcp_sndqueuelen(pcb) ((pcb)->snd_queuelen)
/** @ingroup tcp_raw */
#define tcp_nagle_disable(pcb) tcp_set_flags(pcb, TF_NODELAY)
/** @ingroup tcp_raw */
#define tcp_nagle_enable(pcb) tcp_clear_flags(pcb, TF_NODELAY)
/** @ingroup tcp_raw */
#define tcp_nagle_disabled(pcb) tcp_is_flag_set(pcb, TF_NODELAY)
#if TCP_LISTEN_BACKLOG
#define tcp_backlog_set(pcb, new_backlog) do { \
LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", (pcb)->state == LISTEN); \
((struct tcp_pcb_listen *)(pcb))->backlog = ((new_backlog) ? (new_backlog) : 1); } while(0)
void tcp_backlog_delayed(struct tcp_pcb* pcb);
void tcp_backlog_accepted(struct tcp_pcb* pcb);
#else /* TCP_LISTEN_BACKLOG */
#define tcp_backlog_set(pcb, new_backlog)
#define tcp_backlog_delayed(pcb)
#define tcp_backlog_accepted(pcb)
#endif /* TCP_LISTEN_BACKLOG */
#define tcp_accepted(pcb) do { LWIP_UNUSED_ARG(pcb); } while(0) /* compatibility define, not needed any more */
void tcp_recved (struct tcp_pcb *pcb, u16_t len);
err_t tcp_bind (struct tcp_pcb *pcb, const ip_addr_t *ipaddr,
u16_t port);
void tcp_bind_netif(struct tcp_pcb *pcb, const struct netif *netif);
err_t tcp_connect (struct tcp_pcb *pcb, const ip_addr_t *ipaddr,
u16_t port, tcp_connected_fn connected);
struct tcp_pcb * tcp_listen_with_backlog_and_err(struct tcp_pcb *pcb, u8_t backlog, err_t *err);
struct tcp_pcb * tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog);
/** @ingroup tcp_raw */
#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);
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);
err_t tcp_output (struct tcp_pcb *pcb);
err_t tcp_tcp_get_tcp_addrinfo(struct tcp_pcb *pcb, int local, ip_addr_t *addr, u16_t *port);
#define tcp_dbg_get_tcp_state(pcb) ((pcb)->state)
/* for compatibility with older implementation */
#define tcp_new_ip6() tcp_new_ip_type(IPADDR_TYPE_V6)
#if LWIP_TCP_PCB_NUM_EXT_ARGS
u8_t tcp_ext_arg_alloc_id(void);
void tcp_ext_arg_set_callbacks(struct tcp_pcb *pcb, uint8_t id, const struct tcp_ext_arg_callbacks * const callbacks);
void tcp_ext_arg_set(struct tcp_pcb *pcb, uint8_t id, void *arg);
void *tcp_ext_arg_get(const struct tcp_pcb *pcb, uint8_t id);
#endif
#ifdef __cplusplus
}
#endif
#endif /* LWIP_TCP */
#endif /* LWIP_HDR_TCP_H */