FreeRTOS/Common/ethernet/lwIP_130/src/include/lwip/tcp.h

   1 /*
   2  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without modification,
   6  * are permitted provided that the following conditions are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright notice,
   9  *    this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright notice,
  11  *    this list of conditions and the following disclaimer in the documentation
  12  *    and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  19  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  21  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  24  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  25  * OF SUCH DAMAGE.
  26  *
  27  * This file is part of the lwIP TCP/IP stack.
  28  *
  29  * Author: Adam Dunkels <adam@sics.se>
  30  *
  31  */
  32 #ifndef __LWIP_TCP_H__
  33 #define __LWIP_TCP_H__
  34
  35 #include "lwip/opt.h"
  36
  37 #if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
  38
  39 #include "lwip/sys.h"
  40 #include "lwip/mem.h"
  41 #include "lwip/pbuf.h"
  42 #include "lwip/ip.h"
  43 #include "lwip/icmp.h"
  44 #include "lwip/err.h"
  45
  46 #ifdef __cplusplus
  47 extern "C" {
  48 #endif
  49
  50 struct tcp_pcb;
  51
  52 /* Functions for interfacing with TCP: */
  53
  54 /* Lower layer interface to TCP: */
  55 #define tcp_init() /* Compatibility define, not init needed. */
  56 void             tcp_tmr     (void);  /* Must be called every
  57                                          TCP_TMR_INTERVAL
  58                                          ms. (Typically 250 ms). */
  59 /* Application program's interface: */
  60 struct tcp_pcb * tcp_new     (void);
  61 struct tcp_pcb * tcp_alloc   (u8_t prio);
  62
  63 void             tcp_arg     (struct tcp_pcb *pcb, void *arg);
  64 void             tcp_accept  (struct tcp_pcb *pcb,
  65                               err_t (* accept)(void *arg, struct tcp_pcb *newpcb,
  66                  err_t err));
  67 void             tcp_recv    (struct tcp_pcb *pcb,
  68                               err_t (* recv)(void *arg, struct tcp_pcb *tpcb,
  69                               struct pbuf *p, err_t err));
  70 void             tcp_sent    (struct tcp_pcb *pcb,
  71                               err_t (* sent)(void *arg, struct tcp_pcb *tpcb,
  72                               u16_t len));
  73 void             tcp_poll    (struct tcp_pcb *pcb,
  74                               err_t (* poll)(void *arg, struct tcp_pcb *tpcb),
  75                               u8_t interval);
  76 void             tcp_err     (struct tcp_pcb *pcb,
  77                               void (* err)(void *arg, err_t err));
  78
  79 #define          tcp_mss(pcb)      ((pcb)->mss)
  80 #define          tcp_sndbuf(pcb)   ((pcb)->snd_buf)
  81
  82 #if TCP_LISTEN_BACKLOG
  83 #define          tcp_accepted(pcb) (((struct tcp_pcb_listen *)(pcb))->accepts_pending--)
  84 #else  /* TCP_LISTEN_BACKLOG */
  85 #define          tcp_accepted(pcb)
  86 #endif /* TCP_LISTEN_BACKLOG */
  87
  88 void             tcp_recved  (struct tcp_pcb *pcb, u16_t len);
  89 err_t            tcp_bind    (struct tcp_pcb *pcb, struct ip_addr *ipaddr,
  90                               u16_t port);
  91 err_t            tcp_connect (struct tcp_pcb *pcb, struct ip_addr *ipaddr,
  92                               u16_t port, err_t (* connected)(void *arg,
  93                               struct tcp_pcb *tpcb,
  94                               err_t err));
  95
  96 struct tcp_pcb * tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog);
  97 #define          tcp_listen(pcb) tcp_listen_with_backlog(pcb, TCP_DEFAULT_LISTEN_BACKLOG)
  98
  99 void             tcp_abort   (struct tcp_pcb *pcb);
 100 err_t            tcp_close   (struct tcp_pcb *pcb);
 101
 102 /* Flags for "apiflags" parameter in tcp_write and tcp_enqueue */
 103 #define TCP_WRITE_FLAG_COPY 0x01
 104 #define TCP_WRITE_FLAG_MORE 0x02
 105
 106 err_t            tcp_write   (struct tcp_pcb *pcb, const void *dataptr, u16_t len,
 107                               u8_t apiflags);
 108
 109 void             tcp_setprio (struct tcp_pcb *pcb, u8_t prio);
 110
 111 #define TCP_PRIO_MIN    1
 112 #define TCP_PRIO_NORMAL 64
 113 #define TCP_PRIO_MAX    127
 114
 115 /* It is also possible to call these two functions at the right
 116    intervals (instead of calling tcp_tmr()). */
 117 void             tcp_slowtmr (void);
 118 void             tcp_fasttmr (void);
 119
 120
 121 /* Only used by IP to pass a TCP segment to TCP: */
 122 void             tcp_input   (struct pbuf *p, struct netif *inp);
 123 /* Used within the TCP code only: */
 124 err_t            tcp_output  (struct tcp_pcb *pcb);
 125 void             tcp_rexmit  (struct tcp_pcb *pcb);
 126 void             tcp_rexmit_rto  (struct tcp_pcb *pcb);
 127
 128 /**
 129  * This is the Nagle algorithm: inhibit the sending of new TCP
 130  * segments when new outgoing data arrives from the user if any
 131  * previously transmitted data on the connection remains
 132  * unacknowledged.
 133  */
 134 #define tcp_do_output_nagle(tpcb) ((((tpcb)->unacked == NULL) || \
 135                             ((tpcb)->flags & TF_NODELAY) || \
 136                             (((tpcb)->unsent != NULL) && ((tpcb)->unsent->next != NULL))) ? \
 137                                 1 : 0)
 138 #define tcp_output_nagle(tpcb) (tcp_do_output_nagle(tpcb) ? tcp_output(tpcb) : ERR_OK)
 139
 140
 141 /** This returns a TCP header option for MSS in an u32_t */
 142 #define TCP_BUILD_MSS_OPTION()  htonl(((u32_t)2 << 24) | \
 143                                 ((u32_t)4 << 16) | \
 144                                 (((u32_t)TCP_MSS / 256) << 8) | \
 145                                 (TCP_MSS & 255))
 146
 147 #define TCP_SEQ_LT(a,b)     ((s32_t)((a)-(b)) < 0)
 148 #define TCP_SEQ_LEQ(a,b)    ((s32_t)((a)-(b)) <= 0)
 149 #define TCP_SEQ_GT(a,b)     ((s32_t)((a)-(b)) > 0)
 150 #define TCP_SEQ_GEQ(a,b)    ((s32_t)((a)-(b)) >= 0)
 151 /* is b<=a<=c? */
 152 #if 0 /* see bug #10548 */
 153 #define TCP_SEQ_BETWEEN(a,b,c) ((c)-(b) >= (a)-(b))
 154 #endif
 155 #define TCP_SEQ_BETWEEN(a,b,c) (TCP_SEQ_GEQ(a,b) && TCP_SEQ_LEQ(a,c))
 156 #define TCP_FIN 0x01U
 157 #define TCP_SYN 0x02U
 158 #define TCP_RST 0x04U
 159 #define TCP_PSH 0x08U
 160 #define TCP_ACK 0x10U
 161 #define TCP_URG 0x20U
 162 #define TCP_ECE 0x40U
 163 #define TCP_CWR 0x80U
 164
 165 #define TCP_FLAGS 0x3fU
 166
 167 /* Length of the TCP header, excluding options. */
 168 #define TCP_HLEN 20
 169
 170 #ifndef TCP_TMR_INTERVAL
 171 #define TCP_TMR_INTERVAL       250  /* The TCP timer interval in milliseconds. */
 172 #endif /* TCP_TMR_INTERVAL */
 173
 174 #ifndef TCP_FAST_INTERVAL
 175 #define TCP_FAST_INTERVAL      TCP_TMR_INTERVAL /* the fine grained timeout in milliseconds */
 176 #endif /* TCP_FAST_INTERVAL */
 177
 178 #ifndef TCP_SLOW_INTERVAL
 179 #define TCP_SLOW_INTERVAL      (2*TCP_TMR_INTERVAL)  /* the coarse grained timeout in milliseconds */
 180 #endif /* TCP_SLOW_INTERVAL */
 181
 182 #define TCP_FIN_WAIT_TIMEOUT 20000 /* milliseconds */
 183 #define TCP_SYN_RCVD_TIMEOUT 20000 /* milliseconds */
 184
 185 #define TCP_OOSEQ_TIMEOUT        6U /* x RTO */
 186
 187 #ifndef TCP_MSL
 188 #define TCP_MSL 60000U /* The maximum segment lifetime in milliseconds */
 189 #endif
 190
 191 /* Keepalive values, compliant with RFC 1122. Don't change this unless you know what you're doing */
 192 #ifndef  TCP_KEEPIDLE_DEFAULT
 193 #define  TCP_KEEPIDLE_DEFAULT     7200000UL /* Default KEEPALIVE timer in milliseconds */
 194 #endif
 195
 196 #ifndef  TCP_KEEPINTVL_DEFAULT
 197 #define  TCP_KEEPINTVL_DEFAULT    75000UL   /* Default Time between KEEPALIVE probes in milliseconds */
 198 #endif
 199
 200 #ifndef  TCP_KEEPCNT_DEFAULT
 201 #define  TCP_KEEPCNT_DEFAULT      9U        /* Default Counter for KEEPALIVE probes */
 202 #endif
 203
 204 #define  TCP_MAXIDLE              TCP_KEEPCNT_DEFAULT * TCP_KEEPINTVL_DEFAULT  /* Maximum KEEPALIVE probe time */
 205
 206 /* Fields are (of course) in network byte order.
 207  * Some fields are converted to host byte order in tcp_input().
 208  */
 209 #ifdef PACK_STRUCT_USE_INCLUDES
 210 #  include "arch/bpstruct.h"
 211 #endif
 212 PACK_STRUCT_BEGIN
 213 #if (defined(__MWERKS__)  || defined(__CWCC__))
 214         #pragma options align= packed
 215 #endif
 216 struct tcp_hdr {
 217   PACK_STRUCT_FIELD(u16_t src);
 218   PACK_STRUCT_FIELD(u16_t dest);
 219   PACK_STRUCT_FIELD(u32_t seqno);
 220   PACK_STRUCT_FIELD(u32_t ackno);
 221   PACK_STRUCT_FIELD(u16_t _hdrlen_rsvd_flags);
 222   PACK_STRUCT_FIELD(u16_t wnd);
 223   PACK_STRUCT_FIELD(u16_t chksum);
 224   PACK_STRUCT_FIELD(u16_t urgp);
 225 } PACK_STRUCT_STRUCT;
 226 PACK_STRUCT_END
 227 #ifdef PACK_STRUCT_USE_INCLUDES
 228 #  include "arch/epstruct.h"
 229 #endif
 230
 231 #define TCPH_OFFSET(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) >> 8)
 232 #define TCPH_HDRLEN(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) >> 12)
 233 #define TCPH_FLAGS(phdr)  (ntohs((phdr)->_hdrlen_rsvd_flags) & TCP_FLAGS)
 234
 235 #define TCPH_OFFSET_SET(phdr, offset) (phdr)->_hdrlen_rsvd_flags = htons(((offset) << 8) | TCPH_FLAGS(phdr))
 236 #define TCPH_HDRLEN_SET(phdr, len) (phdr)->_hdrlen_rsvd_flags = htons(((len) << 12) | TCPH_FLAGS(phdr))
 237 #define TCPH_FLAGS_SET(phdr, flags) (phdr)->_hdrlen_rsvd_flags = htons((ntohs((phdr)->_hdrlen_rsvd_flags) & ~TCP_FLAGS) | (flags))
 238 #define TCPH_SET_FLAG(phdr, flags ) (phdr)->_hdrlen_rsvd_flags = htons(ntohs((phdr)->_hdrlen_rsvd_flags) | (flags))
 239 #define TCPH_UNSET_FLAG(phdr, flags) (phdr)->_hdrlen_rsvd_flags = htons(ntohs((phdr)->_hdrlen_rsvd_flags) | (TCPH_FLAGS(phdr) & ~(flags)) )
 240
 241 #define TCP_TCPLEN(seg) ((seg)->len + ((TCPH_FLAGS((seg)->tcphdr) & TCP_FIN || \
 242           TCPH_FLAGS((seg)->tcphdr) & TCP_SYN)? 1: 0))
 243
 244 enum tcp_state {
 245   CLOSED      = 0,
 246   LISTEN      = 1,
 247   SYN_SENT    = 2,
 248   SYN_RCVD    = 3,
 249   ESTABLISHED = 4,
 250   FIN_WAIT_1  = 5,
 251   FIN_WAIT_2  = 6,
 252   CLOSE_WAIT  = 7,
 253   CLOSING     = 8,
 254   LAST_ACK    = 9,
 255   TIME_WAIT   = 10
 256 };
 257
 258 /** Flags used on input processing, not on pcb->flags
 259 */
 260 #define TF_RESET     (u8_t)0x08U   /* Connection was reset. */
 261 #define TF_CLOSED    (u8_t)0x10U   /* Connection was sucessfully closed. */
 262 #define TF_GOT_FIN   (u8_t)0x20U   /* Connection was closed by the remote end. */
 263
 264 /**
 265  * members common to struct tcp_pcb and struct tcp_listen_pcb
 266  */
 267 #define TCP_PCB_COMMON(type) \
 268   type *next; /* for the linked list */ \
 269   enum tcp_state state; /* TCP state */ \
 270   u8_t prio; \
 271   void *callback_arg; \
 272   /* ports are in host byte order */ \
 273   u16_t local_port
 274
 275 /* the TCP protocol control block */
 276 struct tcp_pcb {
 277 /** common PCB members */
 278   IP_PCB;
 279 /** protocol specific PCB members */
 280   TCP_PCB_COMMON(struct tcp_pcb);
 281
 282   /* ports are in host byte order */
 283   u16_t remote_port;
 284
 285   u8_t flags;
 286 #define TF_ACK_DELAY   (u8_t)0x01U   /* Delayed ACK. */
 287 #define TF_ACK_NOW     (u8_t)0x02U   /* Immediate ACK. */
 288 #define TF_INFR        (u8_t)0x04U   /* In fast recovery. */
 289 #define TF_FIN         (u8_t)0x20U   /* Connection was closed locally (FIN segment enqueued). */
 290 #define TF_NODELAY     (u8_t)0x40U   /* Disable Nagle algorithm */
 291 #define TF_NAGLEMEMERR (u8_t)0x80U /* nagle enabled, memerr, try to output to prevent delayed ACK to happen */
 292
 293   /* the rest of the fields are in host byte order
 294      as we have to do some math with them */
 295   /* receiver variables */
 296   u32_t rcv_nxt;   /* next seqno expected */
 297   u16_t rcv_wnd;   /* receiver window */
 298   u16_t rcv_ann_wnd; /* announced receive window */
 299
 300   /* Timers */
 301   u32_t tmr;
 302   u8_t polltmr, pollinterval;
 303
 304   /* Retransmission timer. */
 305   s16_t rtime;
 306
 307   u16_t mss;   /* maximum segment size */
 308
 309   /* RTT (round trip time) estimation variables */
 310   u32_t rttest; /* RTT estimate in 500ms ticks */
 311   u32_t rtseq;  /* sequence number being timed */
 312   s16_t sa, sv; /* @todo document this */
 313
 314   s16_t rto;    /* retransmission time-out */
 315   u8_t nrtx;    /* number of retransmissions */
 316
 317   /* fast retransmit/recovery */
 318   u32_t lastack; /* Highest acknowledged seqno. */
 319   u8_t dupacks;
 320
 321   /* congestion avoidance/control variables */
 322   u16_t cwnd;
 323   u16_t ssthresh;
 324
 325   /* sender variables */
 326   u32_t snd_nxt,   /* next seqno to be sent */
 327     snd_max;       /* Highest seqno sent. */
 328   u16_t snd_wnd;   /* sender window */
 329   u32_t snd_wl1, snd_wl2, /* Sequence and acknowledgement numbers of last
 330                              window update. */
 331     snd_lbb;       /* Sequence number of next byte to be buffered. */
 332
 333   u16_t acked;
 334
 335   u16_t snd_buf;   /* Available buffer space for sending (in bytes). */
 336 #define TCP_SNDQUEUELEN_OVERFLOW (0xffff-3)
 337   u16_t snd_queuelen; /* Available buffer space for sending (in tcp_segs). */
 338
 339
 340   /* These are ordered by sequence number: */
 341   struct tcp_seg *unsent;   /* Unsent (queued) segments. */
 342   struct tcp_seg *unacked;  /* Sent but unacknowledged segments. */
 343 #if TCP_QUEUE_OOSEQ
 344   struct tcp_seg *ooseq;    /* Received out of sequence segments. */
 345 #endif /* TCP_QUEUE_OOSEQ */
 346
 347   struct pbuf *refused_data; /* Data previously received but not yet taken by upper layer */
 348
 349 #if LWIP_CALLBACK_API
 350   /* Function to be called when more send buffer space is available.
 351    * @param arg user-supplied argument (tcp_pcb.callback_arg)
 352    * @param pcb the tcp_pcb which has send buffer space available
 353    * @param space the amount of bytes available
 354    * @return ERR_OK: try to send some data by calling tcp_output
 355    */
 356   err_t (* sent)(void *arg, struct tcp_pcb *pcb, u16_t space);
 357
 358   /* Function to be called when (in-sequence) data has arrived.
 359    * @param arg user-supplied argument (tcp_pcb.callback_arg)
 360    * @param pcb the tcp_pcb for which data has arrived
 361    * @param p the packet buffer which arrived
 362    * @param err an error argument (TODO: that is current always ERR_OK?)
 363    * @return ERR_OK: try to send some data by calling tcp_output
 364    */
 365   err_t (* recv)(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err);
 366
 367   /* Function to be called when a connection has been set up.
 368    * @param arg user-supplied argument (tcp_pcb.callback_arg)
 369    * @param pcb the tcp_pcb that now is connected
 370    * @param err an error argument (TODO: that is current always ERR_OK?)
 371    * @return value is currently ignored
 372    */
 373   err_t (* connected)(void *arg, struct tcp_pcb *pcb, err_t err);
 374
 375   /* Function to call when a listener has been connected.
 376    * @param arg user-supplied argument (tcp_pcb.callback_arg)
 377    * @param pcb a new tcp_pcb that now is connected
 378    * @param err an error argument (TODO: that is current always ERR_OK?)
 379    * @return ERR_OK: accept the new connection,
 380    *                 any other err_t abortsthe new connection
 381    */
 382   err_t (* accept)(void *arg, struct tcp_pcb *newpcb, err_t err);
 383
 384   /* Function which is called periodically.
 385    * The period can be adjusted in multiples of the TCP slow timer interval
 386    * by changing tcp_pcb.polltmr.
 387    * @param arg user-supplied argument (tcp_pcb.callback_arg)
 388    * @param pcb the tcp_pcb to poll for
 389    * @return ERR_OK: try to send some data by calling tcp_output
 390    */
 391   err_t (* poll)(void *arg, struct tcp_pcb *pcb);
 392
 393   /* Function to be called whenever a fatal error occurs.
 394    * There is no pcb parameter since most of the times, the pcb is
 395    * already deallocated (or there is no pcb) when this function is called.
 396    * @param arg user-supplied argument (tcp_pcb.callback_arg)
 397    * @param err an indication why the error callback is called:
 398    *            ERR_ABRT: aborted through tcp_abort or by a TCP timer
 399    *            ERR_RST: the connection was reset by the remote host
 400    */
 401   void (* errf)(void *arg, err_t err);
 402 #endif /* LWIP_CALLBACK_API */
 403
 404   /* idle time before KEEPALIVE is sent */
 405   u32_t keep_idle;
 406 #if LWIP_TCP_KEEPALIVE
 407   u32_t keep_intvl;
 408   u32_t keep_cnt;
 409 #endif /* LWIP_TCP_KEEPALIVE */
 410
 411   /* Persist timer counter */
 412   u32_t persist_cnt;
 413   /* Persist timer back-off */
 414   u8_t persist_backoff;
 415
 416   /* KEEPALIVE counter */
 417   u8_t keep_cnt_sent;
 418 };
 419
 420 struct tcp_pcb_listen {
 421 /* Common members of all PCB types */
 422   IP_PCB;
 423 /* Protocol specific PCB members */
 424   TCP_PCB_COMMON(struct tcp_pcb_listen);
 425
 426 #if LWIP_CALLBACK_API
 427   /* Function to call when a listener has been connected.
 428    * @param arg user-supplied argument (tcp_pcb.callback_arg)
 429    * @param pcb a new tcp_pcb that now is connected
 430    * @param err an error argument (TODO: that is current always ERR_OK?)
 431    * @return ERR_OK: accept the new connection,
 432    *                 any other err_t abortsthe new connection
 433    */
 434   err_t (* accept)(void *arg, struct tcp_pcb *newpcb, err_t err);
 435 #endif /* LWIP_CALLBACK_API */
 436 #if TCP_LISTEN_BACKLOG
 437   u8_t backlog;
 438   u8_t accepts_pending;
 439 #endif /* TCP_LISTEN_BACKLOG */
 440 };
 441
 442 #if LWIP_EVENT_API
 443
 444 enum lwip_event {
 445   LWIP_EVENT_ACCEPT,
 446   LWIP_EVENT_SENT,
 447   LWIP_EVENT_RECV,
 448   LWIP_EVENT_CONNECTED,
 449   LWIP_EVENT_POLL,
 450   LWIP_EVENT_ERR
 451 };
 452
 453 err_t lwip_tcp_event(void *arg, struct tcp_pcb *pcb,
 454          enum lwip_event,
 455          struct pbuf *p,
 456          u16_t size,
 457          err_t err);
 458
 459 #define TCP_EVENT_ACCEPT(pcb,err,ret)    ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
 460                 LWIP_EVENT_ACCEPT, NULL, 0, err)
 461 #define TCP_EVENT_SENT(pcb,space,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
 462                    LWIP_EVENT_SENT, NULL, space, ERR_OK)
 463 #define TCP_EVENT_RECV(pcb,p,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
 464                 LWIP_EVENT_RECV, (p), 0, (err))
 465 #define TCP_EVENT_CONNECTED(pcb,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
 466                 LWIP_EVENT_CONNECTED, NULL, 0, (err))
 467 #define TCP_EVENT_POLL(pcb,ret)       ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
 468                 LWIP_EVENT_POLL, NULL, 0, ERR_OK)
 469 #define TCP_EVENT_ERR(errf,arg,err)  lwip_tcp_event((arg), NULL, \
 470                 LWIP_EVENT_ERR, NULL, 0, (err))
 471 #else /* LWIP_EVENT_API */
 472 #define TCP_EVENT_ACCEPT(pcb,err,ret)     \
 473                         if((pcb)->accept != NULL) \
 474                         (ret = (pcb)->accept((pcb)->callback_arg,(pcb),(err)))
 475 #define TCP_EVENT_SENT(pcb,space,ret) \
 476                         if((pcb)->sent != NULL) \
 477                         (ret = (pcb)->sent((pcb)->callback_arg,(pcb),(space)))
 478 #define TCP_EVENT_RECV(pcb,p,err,ret) \
 479                         if((pcb)->recv != NULL) \
 480                         { ret = (pcb)->recv((pcb)->callback_arg,(pcb),(p),(err)); } else { \
 481                           ret = ERR_OK; \
 482                           if (p) pbuf_free(p); }
 483 #define TCP_EVENT_CONNECTED(pcb,err,ret) \
 484                         if((pcb)->connected != NULL) \
 485                         (ret = (pcb)->connected((pcb)->callback_arg,(pcb),(err)))
 486 #define TCP_EVENT_POLL(pcb,ret) \
 487                         if((pcb)->poll != NULL) \
 488                         (ret = (pcb)->poll((pcb)->callback_arg,(pcb)))
 489 #define TCP_EVENT_ERR(errf,arg,err) \
 490                         if((errf) != NULL) \
 491                         (errf)((arg),(err))
 492 #endif /* LWIP_EVENT_API */
 493
 494 /* This structure represents a TCP segment on the unsent and unacked queues */
 495 struct tcp_seg {
 496   struct tcp_seg *next;    /* used when putting segements on a queue */
 497   struct pbuf *p;          /* buffer containing data + TCP header */
 498   void *dataptr;           /* pointer to the TCP data in the pbuf */
 499   u16_t len;               /* the TCP length of this segment */
 500   struct tcp_hdr *tcphdr;  /* the TCP header */
 501 };
 502
 503 /* Internal functions and global variables: */
 504 struct tcp_pcb *tcp_pcb_copy(struct tcp_pcb *pcb);
 505 void tcp_pcb_purge(struct tcp_pcb *pcb);
 506 void tcp_pcb_remove(struct tcp_pcb **pcblist, struct tcp_pcb *pcb);
 507
 508 u8_t tcp_segs_free(struct tcp_seg *seg);
 509 u8_t tcp_seg_free(struct tcp_seg *seg);
 510 struct tcp_seg *tcp_seg_copy(struct tcp_seg *seg);
 511
 512 #define tcp_ack(pcb)     if((pcb)->flags & TF_ACK_DELAY) { \
 513                             (pcb)->flags &= ~TF_ACK_DELAY; \
 514                             (pcb)->flags |= TF_ACK_NOW; \
 515                             tcp_output(pcb); \
 516                          } else { \
 517                             (pcb)->flags |= TF_ACK_DELAY; \
 518                          }
 519
 520 #define tcp_ack_now(pcb) (pcb)->flags |= TF_ACK_NOW; \
 521                          tcp_output(pcb)
 522
 523 err_t tcp_send_ctrl(struct tcp_pcb *pcb, u8_t flags);
 524 err_t tcp_enqueue(struct tcp_pcb *pcb, void *dataptr, u16_t len,
 525     u8_t flags, u8_t apiflags,
 526                 u8_t *optdata, u8_t optlen);
 527
 528 void tcp_rexmit_seg(struct tcp_pcb *pcb, struct tcp_seg *seg);
 529
 530 void tcp_rst(u32_t seqno, u32_t ackno,
 531        struct ip_addr *local_ip, struct ip_addr *remote_ip,
 532        u16_t local_port, u16_t remote_port);
 533
 534 u32_t tcp_next_iss(void);
 535
 536 void tcp_keepalive(struct tcp_pcb *pcb);
 537 void tcp_zero_window_probe(struct tcp_pcb *pcb);
 538
 539 #if TCP_CALCULATE_EFF_SEND_MSS
 540 u16_t tcp_eff_send_mss(u16_t sendmss, struct ip_addr *addr);
 541 #endif /* TCP_CALCULATE_EFF_SEND_MSS */
 542
 543 extern struct tcp_pcb *tcp_input_pcb;
 544 extern u32_t tcp_ticks;
 545
 546 #if TCP_DEBUG || TCP_INPUT_DEBUG || TCP_OUTPUT_DEBUG
 547 void tcp_debug_print(struct tcp_hdr *tcphdr);
 548 void tcp_debug_print_flags(u8_t flags);
 549 void tcp_debug_print_state(enum tcp_state s);
 550 void tcp_debug_print_pcbs(void);
 551 s16_t tcp_pcbs_sane(void);
 552 #else
 553 #  define tcp_debug_print(tcphdr)
 554 #  define tcp_debug_print_flags(flags)
 555 #  define tcp_debug_print_state(s)
 556 #  define tcp_debug_print_pcbs()
 557 #  define tcp_pcbs_sane() 1
 558 #endif /* TCP_DEBUG */
 559
 560 #if NO_SYS
 561 #define tcp_timer_needed()
 562 #else
 563 void tcp_timer_needed(void);
 564 #endif
 565
 566 /* The TCP PCB lists. */
 567 union tcp_listen_pcbs_t { /* List of all TCP PCBs in LISTEN state. */
 568   struct tcp_pcb_listen *listen_pcbs;
 569   struct tcp_pcb *pcbs;
 570 };
 571 extern union tcp_listen_pcbs_t tcp_listen_pcbs;
 572 extern struct tcp_pcb *tcp_active_pcbs;  /* List of all TCP PCBs that are in a
 573               state in which they accept or send
 574               data. */
 575 extern struct tcp_pcb *tcp_tw_pcbs;      /* List of all TCP PCBs in TIME-WAIT. */
 576
 577 extern struct tcp_pcb *tcp_tmp_pcb;      /* Only used for temporary storage. */
 578
 579 /* Axioms about the above lists:
 580    1) Every TCP PCB that is not CLOSED is in one of the lists.
 581    2) A PCB is only in one of the lists.
 582    3) All PCBs in the tcp_listen_pcbs list is in LISTEN state.
 583    4) All PCBs in the tcp_tw_pcbs list is in TIME-WAIT state.
 584 */
 585
 586 /* Define two macros, TCP_REG and TCP_RMV that registers a TCP PCB
 587    with a PCB list or removes a PCB from a list, respectively. */
 588 #if 0
 589 #define TCP_REG(pcbs, npcb) do {\
 590                             LWIP_DEBUGF(TCP_DEBUG, ("TCP_REG %p local port %d\n", npcb, npcb->local_port)); \
 591                             for(tcp_tmp_pcb = *pcbs; \
 592           tcp_tmp_pcb != NULL; \
 593         tcp_tmp_pcb = tcp_tmp_pcb->next) { \
 594                                 LWIP_ASSERT("TCP_REG: already registered\n", tcp_tmp_pcb != npcb); \
 595                             } \
 596                             LWIP_ASSERT("TCP_REG: pcb->state != CLOSED", npcb->state != CLOSED); \
 597                             npcb->next = *pcbs; \
 598                             LWIP_ASSERT("TCP_REG: npcb->next != npcb", npcb->next != npcb); \
 599                             *(pcbs) = npcb; \
 600                             LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \
 601               tcp_timer_needed(); \
 602                             } while(0)
 603 #define TCP_RMV(pcbs, npcb) do { \
 604                             LWIP_ASSERT("TCP_RMV: pcbs != NULL", *pcbs != NULL); \
 605                             LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removing %p from %p\n", npcb, *pcbs)); \
 606                             if(*pcbs == npcb) { \
 607                                *pcbs = (*pcbs)->next; \
 608                             } else for(tcp_tmp_pcb = *pcbs; tcp_tmp_pcb != NULL; tcp_tmp_pcb = tcp_tmp_pcb->next) { \
 609                                if(tcp_tmp_pcb->next != NULL && tcp_tmp_pcb->next == npcb) { \
 610                                   tcp_tmp_pcb->next = npcb->next; \
 611                                   break; \
 612                                } \
 613                             } \
 614                             npcb->next = NULL; \
 615                             LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \
 616                             LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removed %p from %p\n", npcb, *pcbs)); \
 617                             } while(0)
 618
 619 #else /* LWIP_DEBUG */
 620 #define TCP_REG(pcbs, npcb) do { \
 621                             npcb->next = *pcbs; \
 622                             *(pcbs) = npcb; \
 623               tcp_timer_needed(); \
 624                             } while(0)
 625 #define TCP_RMV(pcbs, npcb) do { \
 626                             if(*(pcbs) == npcb) { \
 627                                (*(pcbs)) = (*pcbs)->next; \
 628                             } else for(tcp_tmp_pcb = *pcbs; tcp_tmp_pcb != NULL; tcp_tmp_pcb = tcp_tmp_pcb->next) { \
 629                                if(tcp_tmp_pcb->next != NULL && tcp_tmp_pcb->next == npcb) { \
 630                                   tcp_tmp_pcb->next = npcb->next; \
 631                                   break; \
 632                                } \
 633                             } \
 634                             npcb->next = NULL; \
 635                             } while(0)
 636 #endif /* LWIP_DEBUG */
 637
 638 #ifdef __cplusplus
 639 }
 640 #endif
 641
 642 #endif /* LWIP_TCP */
 643
 644 #endif /* __LWIP_TCP_H__ */