--- /dev/null
+/*
+ * 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;
+
+/* 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,
+ err_t (* accept)(void *arg, struct tcp_pcb *newpcb,
+ err_t err));
+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_poll (struct tcp_pcb *pcb,
+ err_t (* poll)(void *arg, struct tcp_pcb *tpcb),
+ u8_t interval);
+void tcp_err (struct tcp_pcb *pcb,
+ void (* err)(void *arg, err_t err));
+
+#define tcp_mss(pcb) ((pcb)->mss)
+#define tcp_sndbuf(pcb) ((pcb)->snd_buf)
+
+#if TCP_LISTEN_BACKLOG
+#define tcp_accepted(pcb) (((struct tcp_pcb_listen *)(pcb))->accepts_pending--)
+#else /* TCP_LISTEN_BACKLOG */
+#define tcp_accepted(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, err_t (* connected)(void *arg,
+ struct tcp_pcb *tpcb,
+ err_t err));
+
+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);
+
+/* 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_output (struct tcp_pcb *pcb);
+void tcp_rexmit (struct tcp_pcb *pcb);
+void tcp_rexmit_rto (struct tcp_pcb *pcb);
+
+/**
+ * This is the Nagle algorithm: inhibit the sending of new TCP
+ * segments when new outgoing data arrives from the user if any
+ * previously transmitted data on the connection remains
+ * unacknowledged.
+ */
+#define tcp_do_output_nagle(tpcb) ((((tpcb)->unacked == NULL) || \
+ ((tpcb)->flags & TF_NODELAY) || \
+ (((tpcb)->unsent != NULL) && ((tpcb)->unsent->next != NULL))) ? \
+ 1 : 0)
+#define tcp_output_nagle(tpcb) (tcp_do_output_nagle(tpcb) ? tcp_output(tpcb) : ERR_OK)
+
+
+/** This returns a TCP header option for MSS in an u32_t */
+#define TCP_BUILD_MSS_OPTION() htonl(((u32_t)2 << 24) | \
+ ((u32_t)4 << 16) | \
+ (((u32_t)TCP_MSS / 256) << 8) | \
+ (TCP_MSS & 255))
+
+#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 60000U /* 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 = htons((ntohs((phdr)->_hdrlen_rsvd_flags) & ~TCP_FLAGS) | (flags))
+#define TCPH_SET_FLAG(phdr, flags ) (phdr)->_hdrlen_rsvd_flags = htons(ntohs((phdr)->_hdrlen_rsvd_flags) | (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 || \
+ TCPH_FLAGS((seg)->tcphdr) & TCP_SYN)? 1: 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. */
+
+/**
+ * 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 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_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 */
+ u16_t rcv_ann_wnd; /* announced receive 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 seqno to be sent */
+ snd_max; /* Highest seqno sent. */
+ u16_t snd_wnd; /* sender window */
+ u32_t snd_wl1, snd_wl2, /* Sequence and acknowledgement numbers of last
+ window update. */
+ 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.
+ * @param arg user-supplied argument (tcp_pcb.callback_arg)
+ * @param pcb the tcp_pcb which has send buffer space available
+ * @param space the amount of bytes available
+ * @return ERR_OK: try to send some data by calling tcp_output
+ */
+ err_t (* sent)(void *arg, struct tcp_pcb *pcb, u16_t space);
+
+ /* Function to be called when (in-sequence) data has arrived.
+ * @param arg user-supplied argument (tcp_pcb.callback_arg)
+ * @param pcb the tcp_pcb for which data has arrived
+ * @param p the packet buffer which arrived
+ * @param err an error argument (TODO: that is current always ERR_OK?)
+ * @return ERR_OK: try to send some data by calling tcp_output
+ */
+ err_t (* recv)(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err);
+
+ /* Function to be called when a connection has been set up.
+ * @param arg user-supplied argument (tcp_pcb.callback_arg)
+ * @param pcb the tcp_pcb that now is connected
+ * @param err an error argument (TODO: that is current always ERR_OK?)
+ * @return value is currently ignored
+ */
+ err_t (* connected)(void *arg, struct tcp_pcb *pcb, err_t err);
+
+ /* 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
+ */
+ err_t (* accept)(void *arg, struct tcp_pcb *newpcb, err_t err);
+
+ /* Function which is called periodically.
+ * The period can be adjusted in multiples of the TCP slow timer interval
+ * by changing tcp_pcb.polltmr.
+ * @param arg user-supplied argument (tcp_pcb.callback_arg)
+ * @param pcb the tcp_pcb to poll for
+ * @return ERR_OK: try to send some data by calling tcp_output
+ */
+ err_t (* poll)(void *arg, struct tcp_pcb *pcb);
+
+ /* Function to be called whenever a fatal error occurs.
+ * There is no pcb parameter since most of the times, the pcb is
+ * already deallocated (or there is no pcb) when this function is called.
+ * @param arg user-supplied argument (tcp_pcb.callback_arg)
+ * @param err an indication why the error callback is called:
+ * ERR_ABRT: aborted through tcp_abort or by a TCP timer
+ * ERR_RST: the connection was reset by the remote host
+ */
+ void (* errf)(void *arg, err_t err);
+#endif /* LWIP_CALLBACK_API */
+
+ /* 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 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
+ */
+ err_t (* accept)(void *arg, struct tcp_pcb *newpcb, err_t err);
+#endif /* LWIP_CALLBACK_API */
+#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) \
+ if((pcb)->accept != NULL) \
+ (ret = (pcb)->accept((pcb)->callback_arg,(pcb),(err)))
+#define TCP_EVENT_SENT(pcb,space,ret) \
+ if((pcb)->sent != NULL) \
+ (ret = (pcb)->sent((pcb)->callback_arg,(pcb),(space)))
+#define TCP_EVENT_RECV(pcb,p,err,ret) \
+ if((pcb)->recv != NULL) \
+ { ret = (pcb)->recv((pcb)->callback_arg,(pcb),(p),(err)); } else { \
+ ret = ERR_OK; \
+ if (p) pbuf_free(p); }
+#define TCP_EVENT_CONNECTED(pcb,err,ret) \
+ if((pcb)->connected != NULL) \
+ (ret = (pcb)->connected((pcb)->callback_arg,(pcb),(err)))
+#define TCP_EVENT_POLL(pcb,ret) \
+ if((pcb)->poll != NULL) \
+ (ret = (pcb)->poll((pcb)->callback_arg,(pcb)))
+#define TCP_EVENT_ERR(errf,arg,err) \
+ if((errf) != NULL) \
+ (errf)((arg),(err))
+#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 */
+ struct tcp_hdr *tcphdr; /* the TCP header */
+};
+
+/* 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) if((pcb)->flags & TF_ACK_DELAY) { \
+ (pcb)->flags &= ~TF_ACK_DELAY; \
+ (pcb)->flags |= TF_ACK_NOW; \
+ tcp_output(pcb); \
+ } else { \
+ (pcb)->flags |= TF_ACK_DELAY; \
+ }
+
+#define tcp_ack_now(pcb) (pcb)->flags |= TF_ACK_NOW; \
+ tcp_output(pcb)
+
+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 *optdata, u8_t optlen);
+
+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 */
+
+extern struct tcp_pcb *tcp_input_pcb;
+extern u32_t tcp_ticks;
+
+#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 */
+
+#if NO_SYS
+#define tcp_timer_needed()
+#else
+void tcp_timer_needed(void);
+#endif
+
+/* 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 != NULL && 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 != NULL && 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__ */
