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lwip/src/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);
/* Functions for interfacing with TCP: */
/* Lower layer interface to TCP: */
#define tcp_init() /* Compatibility define, not init needed. */
void tcp_tmr (void); /* Must be called every
TCP_TMR_INTERVAL
ms. (Typically 250 ms). */
/* Application program's interface: */
struct tcp_pcb * tcp_new (void);
struct tcp_pcb * tcp_alloc (u8_t prio);
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)->mss)
#define tcp_sndbuf(pcb) ((pcb)->snd_buf)
#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) (((struct tcp_pcb_listen *)(pcb))->accepts_pending--)
#else /* TCP_LISTEN_BACKLOG */
#define tcp_accepted(pcb) LWIP_UNUSED_ARG(pcb);
#endif /* TCP_LISTEN_BACKLOG */
void tcp_recved (struct tcp_pcb *pcb, u16_t len);
err_t tcp_bind (struct tcp_pcb *pcb, struct ip_addr *ipaddr,
u16_t port);
err_t tcp_connect (struct tcp_pcb *pcb, struct ip_addr *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_abandon (struct tcp_pcb *pcb, int reset);
#define tcp_abort(pcb) tcp_abandon((pcb), 1)
err_t tcp_close (struct tcp_pcb *pcb);
/* Flags for "apiflags" parameter in tcp_write and tcp_enqueue */
#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
/* It is also possible to call these two functions at the right
intervals (instead of calling tcp_tmr()). */
void tcp_slowtmr (void);
void tcp_fasttmr (void);
/* Only used by IP to pass a TCP segment to TCP: */
void tcp_input (struct pbuf *p, struct netif *inp);
/* Used within the TCP code only: */
err_t tcp_send_empty_ack(struct tcp_pcb *pcb);
err_t tcp_output (struct tcp_pcb *pcb);
void tcp_rexmit (struct tcp_pcb *pcb);
void tcp_rexmit_rto (struct tcp_pcb *pcb);
void tcp_rexmit_fast (struct tcp_pcb *pcb);
u32_t tcp_update_rcv_ann_wnd(struct tcp_pcb *pcb);
/**
* This is the Nagle algorithm: try to combine user data to send as few TCP
* segments as possible. Only send if
* - no previously transmitted data on the connection remains unacknowledged or
* - the TF_NODELAY flag is set (nagle algorithm turned off for this pcb) or
* - the only unsent segment is at least pcb->mss bytes long (or there is more
* than one unsent segment - with lwIP, this can happen although unsent->len < mss)
* - or if we are in fast-retransmit (TF_INFR)
*/
#define tcp_do_output_nagle(tpcb) ((((tpcb)->unacked == NULL) || \
((tpcb)->flags & (TF_NODELAY | TF_INFR)) || \
(((tpcb)->unsent != NULL) && (((tpcb)->unsent->next != NULL) || \
((tpcb)->unsent->len >= (tpcb)->mss))) \
) ? 1 : 0)
#define tcp_output_nagle(tpcb) (tcp_do_output_nagle(tpcb) ? tcp_output(tpcb) : ERR_OK)
#define TCP_SEQ_LT(a,b) ((s32_t)((a)-(b)) < 0)
#define TCP_SEQ_LEQ(a,b) ((s32_t)((a)-(b)) <= 0)
#define TCP_SEQ_GT(a,b) ((s32_t)((a)-(b)) > 0)
#define TCP_SEQ_GEQ(a,b) ((s32_t)((a)-(b)) >= 0)
/* is b<=a<=c? */
#if 0 /* see bug #10548 */
#define TCP_SEQ_BETWEEN(a,b,c) ((c)-(b) >= (a)-(b))
#endif
#define TCP_SEQ_BETWEEN(a,b,c) (TCP_SEQ_GEQ(a,b) && TCP_SEQ_LEQ(a,c))
#define TCP_FIN 0x01U
#define TCP_SYN 0x02U
#define TCP_RST 0x04U
#define TCP_PSH 0x08U
#define TCP_ACK 0x10U
#define TCP_URG 0x20U
#define TCP_ECE 0x40U
#define TCP_CWR 0x80U
#define TCP_FLAGS 0x3fU
/* Length of the TCP header, excluding options. */
#define TCP_HLEN 20
#ifndef TCP_TMR_INTERVAL
#define TCP_TMR_INTERVAL 250 /* The TCP timer interval in milliseconds. */
#endif /* TCP_TMR_INTERVAL */
#ifndef TCP_FAST_INTERVAL
#define TCP_FAST_INTERVAL TCP_TMR_INTERVAL /* the fine grained timeout in milliseconds */
#endif /* TCP_FAST_INTERVAL */
#ifndef TCP_SLOW_INTERVAL
#define TCP_SLOW_INTERVAL (2*TCP_TMR_INTERVAL) /* the coarse grained timeout in milliseconds */
#endif /* TCP_SLOW_INTERVAL */
#define TCP_FIN_WAIT_TIMEOUT 20000 /* milliseconds */
#define TCP_SYN_RCVD_TIMEOUT 20000 /* milliseconds */
#define TCP_OOSEQ_TIMEOUT 6U /* x RTO */
#ifndef TCP_MSL
#define TCP_MSL 60000UL /* The maximum segment lifetime in milliseconds */
#endif
/* Keepalive values, compliant with RFC 1122. Don't change this unless you know what you're doing */
#ifndef TCP_KEEPIDLE_DEFAULT
#define TCP_KEEPIDLE_DEFAULT 7200000UL /* Default KEEPALIVE timer in milliseconds */
#endif
#ifndef TCP_KEEPINTVL_DEFAULT
#define TCP_KEEPINTVL_DEFAULT 75000UL /* Default Time between KEEPALIVE probes in milliseconds */
#endif
#ifndef TCP_KEEPCNT_DEFAULT
#define TCP_KEEPCNT_DEFAULT 9U /* Default Counter for KEEPALIVE probes */
#endif
#define TCP_MAXIDLE TCP_KEEPCNT_DEFAULT * TCP_KEEPINTVL_DEFAULT /* Maximum KEEPALIVE probe time */
/* Fields are (of course) in network byte order.
* Some fields are converted to host byte order in tcp_input().
*/
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/bpstruct.h"
#endif
PACK_STRUCT_BEGIN
struct tcp_hdr {
PACK_STRUCT_FIELD(u16_t src);
PACK_STRUCT_FIELD(u16_t dest);
PACK_STRUCT_FIELD(u32_t seqno);
PACK_STRUCT_FIELD(u32_t ackno);
PACK_STRUCT_FIELD(u16_t _hdrlen_rsvd_flags);
PACK_STRUCT_FIELD(u16_t wnd);
PACK_STRUCT_FIELD(u16_t chksum);
PACK_STRUCT_FIELD(u16_t urgp);
} PACK_STRUCT_STRUCT;
PACK_STRUCT_END
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/epstruct.h"
#endif
#define TCPH_OFFSET(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) >> 8)
#define TCPH_HDRLEN(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) >> 12)
#define TCPH_FLAGS(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) & TCP_FLAGS)
#define TCPH_OFFSET_SET(phdr, offset) (phdr)->_hdrlen_rsvd_flags = htons(((offset) << 8) | TCPH_FLAGS(phdr))
#define TCPH_HDRLEN_SET(phdr, len) (phdr)->_hdrlen_rsvd_flags = htons(((len) << 12) | TCPH_FLAGS(phdr))
#define TCPH_FLAGS_SET(phdr, flags) (phdr)->_hdrlen_rsvd_flags = (((phdr)->_hdrlen_rsvd_flags & htons((u16_t)(~(u16_t)(TCP_FLAGS)))) | htons(flags))
#define TCPH_SET_FLAG(phdr, flags ) (phdr)->_hdrlen_rsvd_flags = ((phdr)->_hdrlen_rsvd_flags | htons(flags))
#define TCPH_UNSET_FLAG(phdr, flags) (phdr)->_hdrlen_rsvd_flags = htons(ntohs((phdr)->_hdrlen_rsvd_flags) | (TCPH_FLAGS(phdr) & ~(flags)) )
#define TCP_TCPLEN(seg) ((seg)->len + ((TCPH_FLAGS((seg)->tcphdr) & (TCP_FIN | TCP_SYN)) != 0))
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
};
/** Flags used on input processing, not on pcb->flags
*/
#define TF_RESET (u8_t)0x08U /* Connection was reset. */
#define TF_CLOSED (u8_t)0x10U /* Connection was sucessfully closed. */
#define TF_GOT_FIN (u8_t)0x20U /* Connection was closed by the remote end. */
#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; \
/* ports are in host byte order */ \
u16_t local_port; \
/* the accept callback for listen- and normal pcbs, if LWIP_CALLBACK_API */ \
DEF_ACCEPT_CALLBACK
/* 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_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). */
/* 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);
#define TCP_EVENT_ACCEPT(pcb,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
LWIP_EVENT_ACCEPT, NULL, 0, err)
#define TCP_EVENT_SENT(pcb,space,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
LWIP_EVENT_SENT, NULL, space, ERR_OK)
#define TCP_EVENT_RECV(pcb,p,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
LWIP_EVENT_RECV, (p), 0, (err))
#define TCP_EVENT_CONNECTED(pcb,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
LWIP_EVENT_CONNECTED, NULL, 0, (err))
#define TCP_EVENT_POLL(pcb,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
LWIP_EVENT_POLL, NULL, 0, ERR_OK)
#define TCP_EVENT_ERR(errf,arg,err) lwip_tcp_event((arg), NULL, \
LWIP_EVENT_ERR, NULL, 0, (err))
#else /* LWIP_EVENT_API */
#define TCP_EVENT_ACCEPT(pcb,err,ret) \
do { \
if((pcb)->accept != NULL) \
(ret) = (pcb)->accept((pcb)->callback_arg,(pcb),(err)); \
else (ret) = ERR_OK; \
} while (0)
#define TCP_EVENT_SENT(pcb,space,ret) \
do { \
if((pcb)->sent != NULL) \
(ret) = (pcb)->sent((pcb)->callback_arg,(pcb),(space)); \
else (ret) = ERR_OK; \
} while (0)
#define TCP_EVENT_RECV(pcb,p,err,ret) \
do { \
if((pcb)->recv != NULL) { \
(ret) = (pcb)->recv((pcb)->callback_arg,(pcb),(p),(err)); \
} else { \
(ret) = tcp_recv_null(NULL, (pcb), (p), (err)); \
} \
} while (0)
#define TCP_EVENT_CONNECTED(pcb,err,ret) \
do { \
if((pcb)->connected != NULL) \
(ret) = (pcb)->connected((pcb)->callback_arg,(pcb),(err)); \
else (ret) = ERR_OK; \
} while (0)
#define TCP_EVENT_POLL(pcb,ret) \
do { \
if((pcb)->poll != NULL) \
(ret) = (pcb)->poll((pcb)->callback_arg,(pcb)); \
else (ret) = ERR_OK; \
} while (0)
#define TCP_EVENT_ERR(errf,arg,err) \
do { \
if((errf) != NULL) \
(errf)((arg),(err)); \
} while (0)
#endif /* LWIP_EVENT_API */
/* This structure represents a TCP segment on the unsent and unacked queues */
struct tcp_seg {
struct tcp_seg *next; /* used when putting segements on a queue */
struct pbuf *p; /* buffer containing data + TCP header */
void *dataptr; /* pointer to the TCP data in the pbuf */
u16_t len; /* the TCP length of this segment */
u8_t flags;
#define TF_SEG_OPTS_MSS (u8_t)0x01U /* Include MSS option. */
#define TF_SEG_OPTS_TS (u8_t)0x02U /* Include timestamp option. */
struct tcp_hdr *tcphdr; /* the TCP header */
};
#define LWIP_TCP_OPT_LENGTH(flags) \
(flags & TF_SEG_OPTS_MSS ? 4 : 0) + \
(flags & TF_SEG_OPTS_TS ? 12 : 0)
/** This returns a TCP header option for MSS in an u32_t */
#define TCP_BUILD_MSS_OPTION(x) (x) = htonl(((u32_t)2 << 24) | \
((u32_t)4 << 16) | \
(((u32_t)TCP_MSS / 256) << 8) | \
(TCP_MSS & 255))
/* Internal functions and global variables: */
struct tcp_pcb *tcp_pcb_copy(struct tcp_pcb *pcb);
void tcp_pcb_purge(struct tcp_pcb *pcb);
void tcp_pcb_remove(struct tcp_pcb **pcblist, struct tcp_pcb *pcb);
u8_t tcp_segs_free(struct tcp_seg *seg);
u8_t tcp_seg_free(struct tcp_seg *seg);
struct tcp_seg *tcp_seg_copy(struct tcp_seg *seg);
#define tcp_ack(pcb) \
do { \
if((pcb)->flags & TF_ACK_DELAY) { \
(pcb)->flags &= ~TF_ACK_DELAY; \
(pcb)->flags |= TF_ACK_NOW; \
} \
else { \
(pcb)->flags |= TF_ACK_DELAY; \
} \
} while (0)
#define tcp_ack_now(pcb) \
do { \
(pcb)->flags |= TF_ACK_NOW; \
} while (0)
err_t tcp_send_ctrl(struct tcp_pcb *pcb, u8_t flags);
err_t tcp_enqueue(struct tcp_pcb *pcb, void *dataptr, u16_t len,
u8_t flags, u8_t apiflags, u8_t optflags);
void tcp_rexmit_seg(struct tcp_pcb *pcb, struct tcp_seg *seg);
void tcp_rst(u32_t seqno, u32_t ackno,
struct ip_addr *local_ip, struct ip_addr *remote_ip,
u16_t local_port, u16_t remote_port);
u32_t tcp_next_iss(void);
void tcp_keepalive(struct tcp_pcb *pcb);
void tcp_zero_window_probe(struct tcp_pcb *pcb);
#if TCP_CALCULATE_EFF_SEND_MSS
u16_t tcp_eff_send_mss(u16_t sendmss, struct ip_addr *addr);
#endif /* TCP_CALCULATE_EFF_SEND_MSS */
#if LWIP_CALLBACK_API
err_t tcp_recv_null(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err);
#endif /* LWIP_CALLBACK_API */
extern struct tcp_pcb *tcp_input_pcb;
extern u32_t tcp_ticks;
const char* tcp_debug_state_str(enum tcp_state s);
#if TCP_DEBUG || TCP_INPUT_DEBUG || TCP_OUTPUT_DEBUG
void tcp_debug_print(struct tcp_hdr *tcphdr);
void tcp_debug_print_flags(u8_t flags);
void tcp_debug_print_state(enum tcp_state s);
void tcp_debug_print_pcbs(void);
s16_t tcp_pcbs_sane(void);
#else
# define tcp_debug_print(tcphdr)
# define tcp_debug_print_flags(flags)
# define tcp_debug_print_state(s)
# define tcp_debug_print_pcbs()
# define tcp_pcbs_sane() 1
#endif /* TCP_DEBUG */
void tcp_timer_needed(void);
/* The TCP PCB lists. */
union tcp_listen_pcbs_t { /* List of all TCP PCBs in LISTEN state. */
struct tcp_pcb_listen *listen_pcbs;
struct tcp_pcb *pcbs;
};
extern union tcp_listen_pcbs_t tcp_listen_pcbs;
extern struct tcp_pcb *tcp_active_pcbs; /* List of all TCP PCBs that are in a
state in which they accept or send
data. */
extern struct tcp_pcb *tcp_tw_pcbs; /* List of all TCP PCBs in TIME-WAIT. */
extern struct tcp_pcb *tcp_tmp_pcb; /* Only used for temporary storage. */
/* Axioms about the above lists:
1) Every TCP PCB that is not CLOSED is in one of the lists.
2) A PCB is only in one of the lists.
3) All PCBs in the tcp_listen_pcbs list is in LISTEN state.
4) All PCBs in the tcp_tw_pcbs list is in TIME-WAIT state.
*/
/* Define two macros, TCP_REG and TCP_RMV that registers a TCP PCB
with a PCB list or removes a PCB from a list, respectively. */
#if 0
#define TCP_REG(pcbs, npcb) do {\
LWIP_DEBUGF(TCP_DEBUG, ("TCP_REG %p local port %d\n", npcb, npcb->local_port)); \
for(tcp_tmp_pcb = *pcbs; \
tcp_tmp_pcb != NULL; \
tcp_tmp_pcb = tcp_tmp_pcb->next) { \
LWIP_ASSERT("TCP_REG: already registered\n", tcp_tmp_pcb != npcb); \
} \
LWIP_ASSERT("TCP_REG: pcb->state != CLOSED", npcb->state != CLOSED); \
npcb->next = *pcbs; \
LWIP_ASSERT("TCP_REG: npcb->next != npcb", npcb->next != npcb); \
*(pcbs) = npcb; \
LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \
tcp_timer_needed(); \
} while(0)
#define TCP_RMV(pcbs, npcb) do { \
LWIP_ASSERT("TCP_RMV: pcbs != NULL", *pcbs != NULL); \
LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removing %p from %p\n", npcb, *pcbs)); \
if(*pcbs == npcb) { \
*pcbs = (*pcbs)->next; \
} else for(tcp_tmp_pcb = *pcbs; tcp_tmp_pcb != NULL; tcp_tmp_pcb = tcp_tmp_pcb->next) { \
if(tcp_tmp_pcb->next == npcb) { \
tcp_tmp_pcb->next = npcb->next; \
break; \
} \
} \
npcb->next = NULL; \
LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \
LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removed %p from %p\n", npcb, *pcbs)); \
} while(0)
#else /* LWIP_DEBUG */
#define TCP_REG(pcbs, npcb) \
do { \
npcb->next = *pcbs; \
*(pcbs) = npcb; \
tcp_timer_needed(); \
} while (0)
#define TCP_RMV(pcbs, npcb) \
do { \
if(*(pcbs) == npcb) { \
(*(pcbs)) = (*pcbs)->next; \
} \
else { \
for(tcp_tmp_pcb = *pcbs; \
tcp_tmp_pcb != NULL; \
tcp_tmp_pcb = tcp_tmp_pcb->next) { \
if(tcp_tmp_pcb->next == npcb) { \
tcp_tmp_pcb->next = npcb->next; \
break; \
} \
} \
} \
npcb->next = NULL; \
} while(0)
#endif /* LWIP_DEBUG */
#ifdef __cplusplus
}
#endif
#endif /* LWIP_TCP */
#endif /* __LWIP_TCP_H__ */
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