SAMV71 Xplained Ultra Software Package 1.0

tcp.h

00001   /*
00002  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
00003  * All rights reserved. 
00004  * 
00005  * Redistribution and use in source and binary forms, with or without modification, 
00006  * are permitted provided that the following conditions are met:
00007  *
00008  * 1. Redistributions of source code must retain the above copyright notice,
00009  *    this list of conditions and the following disclaimer.
00010  * 2. Redistributions in binary form must reproduce the above copyright notice,
00011  *    this list of conditions and the following disclaimer in the documentation
00012  *    and/or other materials provided with the distribution.
00013  * 3. The name of the author may not be used to endorse or promote products
00014  *    derived from this software without specific prior written permission. 
00015  *
00016  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
00017  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
00018  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
00019  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
00020  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
00021  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
00022  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
00023  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
00024  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
00025  * OF SUCH DAMAGE.
00026  *
00027  * This file is part of the lwIP TCP/IP stack.
00028  * 
00029  * Author: Adam Dunkels <adam@sics.se>
00030  *
00031  */
00032 #ifndef __LWIP_TCP_H__
00033 #define __LWIP_TCP_H__
00034 
00035 #include "lwip/opt.h"
00036 
00037 #if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
00038 
00039 #include "lwip/sys.h"
00040 #include "lwip/mem.h"
00041 #include "lwip/pbuf.h"
00042 #include "lwip/ip.h"
00043 #include "lwip/icmp.h"
00044 #include "lwip/err.h"
00045 
00046 #ifdef __cplusplus
00047 extern "C" {
00048 #endif
00049 
00050 struct tcp_pcb;
00051 
00052 /* Functions for interfacing with TCP: */
00053 
00054 /* Lower layer interface to TCP: */
00055 #define tcp_init() /* Compatibility define, not init needed. */
00056 void             tcp_tmr     (void);  /* Must be called every
00057                                          TCP_TMR_INTERVAL
00058                                          ms. (Typically 250 ms). */
00059 /* Application program's interface: */
00060 struct tcp_pcb * tcp_new     (void);
00061 struct tcp_pcb * tcp_alloc   (u8_t prio);
00062 
00063 void             tcp_arg     (struct tcp_pcb *pcb, void *arg);
00064 void             tcp_accept  (struct tcp_pcb *pcb,
00065                               err_t (* accept)(void *arg, struct tcp_pcb *newpcb,
00066                  err_t err));
00067 void             tcp_recv    (struct tcp_pcb *pcb,
00068                               err_t (* recv)(void *arg, struct tcp_pcb *tpcb,
00069                               struct pbuf *p, err_t err));
00070 void             tcp_sent    (struct tcp_pcb *pcb,
00071                               err_t (* sent)(void *arg, struct tcp_pcb *tpcb,
00072                               u16_t len));
00073 void             tcp_poll    (struct tcp_pcb *pcb,
00074                               err_t (* poll)(void *arg, struct tcp_pcb *tpcb),
00075                               u8_t interval);
00076 void             tcp_err     (struct tcp_pcb *pcb,
00077                               void (* err)(void *arg, err_t err));
00078 
00079 #define          tcp_mss(pcb)      ((pcb)->mss)
00080 #define          tcp_sndbuf(pcb)   ((pcb)->snd_buf)
00081 #define          tcp_nagle_disable(pcb)  ((pcb)->flags |= TF_NODELAY)
00082 #define          tcp_nagle_enable(pcb) ((pcb)->flags &= ~TF_NODELAY)
00083 #define          tcp_nagle_disabled(pcb) (((pcb)->flags & TF_NODELAY) != 0)
00084 
00085 #if TCP_LISTEN_BACKLOG
00086 #define          tcp_accepted(pcb) (((struct tcp_pcb_listen *)(pcb))->accepts_pending--)
00087 #else  /* TCP_LISTEN_BACKLOG */
00088 #define          tcp_accepted(pcb)
00089 #endif /* TCP_LISTEN_BACKLOG */
00090 
00091 void             tcp_recved  (struct tcp_pcb *pcb, u16_t len);
00092 err_t            tcp_bind    (struct tcp_pcb *pcb, struct ip_addr *ipaddr,
00093                               u16_t port);
00094 err_t            tcp_connect (struct tcp_pcb *pcb, struct ip_addr *ipaddr,
00095                               u16_t port, err_t (* connected)(void *arg,
00096                               struct tcp_pcb *tpcb,
00097                               err_t err));
00098 
00099 struct tcp_pcb * tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog);
00100 #define          tcp_listen(pcb) tcp_listen_with_backlog(pcb, TCP_DEFAULT_LISTEN_BACKLOG)
00101 
00102 void             tcp_abandon (struct tcp_pcb *pcb, int reset);
00103 #define          tcp_abort(pcb) tcp_abandon((pcb), 1)
00104 err_t            tcp_close   (struct tcp_pcb *pcb);
00105 
00106 /* Flags for "apiflags" parameter in tcp_write and tcp_enqueue */
00107 #define TCP_WRITE_FLAG_COPY 0x01
00108 #define TCP_WRITE_FLAG_MORE 0x02
00109 
00110 err_t            tcp_write   (struct tcp_pcb *pcb, const void *dataptr, u16_t len,
00111                               u8_t apiflags);
00112 
00113 void             tcp_setprio (struct tcp_pcb *pcb, u8_t prio);
00114 
00115 #define TCP_PRIO_MIN    1
00116 #define TCP_PRIO_NORMAL 64
00117 #define TCP_PRIO_MAX    127
00118 
00119 /* It is also possible to call these two functions at the right
00120    intervals (instead of calling tcp_tmr()). */
00121 void             tcp_slowtmr (void);
00122 void             tcp_fasttmr (void);
00123 
00124 
00125 /* Only used by IP to pass a TCP segment to TCP: */
00126 void             tcp_input   (struct pbuf *p, struct netif *inp);
00127 /* Used within the TCP code only: */
00128 err_t            tcp_send_empty_ack(struct tcp_pcb *pcb);
00129 err_t            tcp_output  (struct tcp_pcb *pcb);
00130 void             tcp_rexmit  (struct tcp_pcb *pcb);
00131 void             tcp_rexmit_rto  (struct tcp_pcb *pcb);
00132 void             tcp_rexmit_fast (struct tcp_pcb *pcb);
00133 u32_t            tcp_update_rcv_ann_wnd(struct tcp_pcb *pcb);
00134 
00135 /**
00136  * This is the Nagle algorithm: try to combine user data to send as few TCP
00137  * segments as possible. Only send if
00138  * - no previously transmitted data on the connection remains unacknowledged or
00139  * - the TF_NODELAY flag is set (nagle algorithm turned off for this pcb) or
00140  * - the only unsent segment is at least pcb->mss bytes long (or there is more
00141  *   than one unsent segment - with lwIP, this can happen although unsent->len < mss)
00142  * - or if we are in fast-retransmit (TF_INFR)
00143  */
00144 #define tcp_do_output_nagle(tpcb) ((((tpcb)->unacked == NULL) || \
00145                             ((tpcb)->flags & (TF_NODELAY | TF_INFR)) || \
00146                             (((tpcb)->unsent != NULL) && (((tpcb)->unsent->next != NULL) || \
00147                               ((tpcb)->unsent->len >= (tpcb)->mss))) \
00148                             ) ? 1 : 0)
00149 #define tcp_output_nagle(tpcb) (tcp_do_output_nagle(tpcb) ? tcp_output(tpcb) : ERR_OK)
00150 
00151 
00152 #define TCP_SEQ_LT(a,b)     ((s32_t)((a)-(b)) < 0)
00153 #define TCP_SEQ_LEQ(a,b)    ((s32_t)((a)-(b)) <= 0)
00154 #define TCP_SEQ_GT(a,b)     ((s32_t)((a)-(b)) > 0)
00155 #define TCP_SEQ_GEQ(a,b)    ((s32_t)((a)-(b)) >= 0)
00156 /* is b<=a<=c? */
00157 #if 0 /* see bug #10548 */
00158 #define TCP_SEQ_BETWEEN(a,b,c) ((c)-(b) >= (a)-(b))
00159 #endif
00160 #define TCP_SEQ_BETWEEN(a,b,c) (TCP_SEQ_GEQ(a,b) && TCP_SEQ_LEQ(a,c))
00161 #define TCP_FIN 0x01U
00162 #define TCP_SYN 0x02U
00163 #define TCP_RST 0x04U
00164 #define TCP_PSH 0x08U
00165 #define TCP_ACK 0x10U
00166 #define TCP_URG 0x20U
00167 #define TCP_ECE 0x40U
00168 #define TCP_CWR 0x80U
00169 
00170 #define TCP_FLAGS 0x3fU
00171 
00172 /* Length of the TCP header, excluding options. */
00173 #define TCP_HLEN 20
00174 
00175 #ifndef TCP_TMR_INTERVAL
00176 #define TCP_TMR_INTERVAL       250  /* The TCP timer interval in milliseconds. */
00177 #endif /* TCP_TMR_INTERVAL */
00178 
00179 #ifndef TCP_FAST_INTERVAL
00180 #define TCP_FAST_INTERVAL      TCP_TMR_INTERVAL /* the fine grained timeout in milliseconds */
00181 #endif /* TCP_FAST_INTERVAL */
00182 
00183 #ifndef TCP_SLOW_INTERVAL
00184 #define TCP_SLOW_INTERVAL      (2*TCP_TMR_INTERVAL)  /* the coarse grained timeout in milliseconds */
00185 #endif /* TCP_SLOW_INTERVAL */
00186 
00187 #define TCP_FIN_WAIT_TIMEOUT 20000 /* milliseconds */
00188 #define TCP_SYN_RCVD_TIMEOUT 20000 /* milliseconds */
00189 
00190 #define TCP_OOSEQ_TIMEOUT        6U /* x RTO */
00191 
00192 #ifndef TCP_MSL
00193 #define TCP_MSL 60000UL /* The maximum segment lifetime in milliseconds */
00194 #endif
00195 
00196 /* Keepalive values, compliant with RFC 1122. Don't change this unless you know what you're doing */
00197 #ifndef  TCP_KEEPIDLE_DEFAULT
00198 #define  TCP_KEEPIDLE_DEFAULT     7200000UL /* Default KEEPALIVE timer in milliseconds */
00199 #endif
00200 
00201 #ifndef  TCP_KEEPINTVL_DEFAULT
00202 #define  TCP_KEEPINTVL_DEFAULT    75000UL   /* Default Time between KEEPALIVE probes in milliseconds */
00203 #endif
00204 
00205 #ifndef  TCP_KEEPCNT_DEFAULT
00206 #define  TCP_KEEPCNT_DEFAULT      9U        /* Default Counter for KEEPALIVE probes */
00207 #endif
00208 
00209 #define  TCP_MAXIDLE              TCP_KEEPCNT_DEFAULT * TCP_KEEPINTVL_DEFAULT  /* Maximum KEEPALIVE probe time */
00210 
00211 /* Fields are (of course) in network byte order.
00212  * Some fields are converted to host byte order in tcp_input().
00213  */
00214 #ifdef PACK_STRUCT_USE_INCLUDES
00215 #  include "arch/bpstruct.h"
00216 #endif
00217 PACK_STRUCT_BEGIN
00218 struct tcp_hdr {
00219   PACK_STRUCT_FIELD(u16_t src);
00220   PACK_STRUCT_FIELD(u16_t dest);
00221   PACK_STRUCT_FIELD(u32_t seqno);
00222   PACK_STRUCT_FIELD(u32_t ackno);
00223   PACK_STRUCT_FIELD(u16_t _hdrlen_rsvd_flags);
00224   PACK_STRUCT_FIELD(u16_t wnd);
00225   PACK_STRUCT_FIELD(u16_t chksum);
00226   PACK_STRUCT_FIELD(u16_t urgp);
00227 } PACK_STRUCT_STRUCT;
00228 PACK_STRUCT_END
00229 #ifdef PACK_STRUCT_USE_INCLUDES
00230 #  include "arch/epstruct.h"
00231 #endif
00232 
00233 #define TCPH_OFFSET(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) >> 8)
00234 #define TCPH_HDRLEN(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) >> 12)
00235 #define TCPH_FLAGS(phdr)  (ntohs((phdr)->_hdrlen_rsvd_flags) & TCP_FLAGS)
00236 
00237 #define TCPH_OFFSET_SET(phdr, offset) (phdr)->_hdrlen_rsvd_flags = htons(((offset) << 8) | TCPH_FLAGS(phdr))
00238 #define TCPH_HDRLEN_SET(phdr, len) (phdr)->_hdrlen_rsvd_flags = htons(((len) << 12) | TCPH_FLAGS(phdr))
00239 #define TCPH_FLAGS_SET(phdr, flags) (phdr)->_hdrlen_rsvd_flags = (((phdr)->_hdrlen_rsvd_flags & htons((u16_t)(~(u16_t)(TCP_FLAGS)))) | htons(flags))
00240 #define TCPH_SET_FLAG(phdr, flags ) (phdr)->_hdrlen_rsvd_flags = ((phdr)->_hdrlen_rsvd_flags | htons(flags))
00241 #define TCPH_UNSET_FLAG(phdr, flags) (phdr)->_hdrlen_rsvd_flags = htons(ntohs((phdr)->_hdrlen_rsvd_flags) | (TCPH_FLAGS(phdr) & ~(flags)) )
00242 
00243 #define TCP_TCPLEN(seg) ((seg)->len + ((TCPH_FLAGS((seg)->tcphdr) & (TCP_FIN | TCP_SYN)) != 0))
00244 
00245 enum tcp_state {
00246   CLOSED      = 0,
00247   LISTEN      = 1,
00248   SYN_SENT    = 2,
00249   SYN_RCVD    = 3,
00250   ESTABLISHED = 4,
00251   FIN_WAIT_1  = 5,
00252   FIN_WAIT_2  = 6,
00253   CLOSE_WAIT  = 7,
00254   CLOSING     = 8,
00255   LAST_ACK    = 9,
00256   TIME_WAIT   = 10
00257 };
00258 
00259 /** Flags used on input processing, not on pcb->flags
00260 */
00261 #define TF_RESET     (u8_t)0x08U   /* Connection was reset. */
00262 #define TF_CLOSED    (u8_t)0x10U   /* Connection was sucessfully closed. */
00263 #define TF_GOT_FIN   (u8_t)0x20U   /* Connection was closed by the remote end. */
00264 
00265 
00266 #if LWIP_CALLBACK_API
00267   /* Function to call when a listener has been connected.
00268    * @param arg user-supplied argument (tcp_pcb.callback_arg)
00269    * @param pcb a new tcp_pcb that now is connected
00270    * @param err an error argument (TODO: that is current always ERR_OK?)
00271    * @return ERR_OK: accept the new connection,
00272    *                 any other err_t abortsthe new connection
00273    */
00274 #define DEF_ACCEPT_CALLBACK  err_t (* accept)(void *arg, struct tcp_pcb *newpcb, err_t err)
00275 #else /* LWIP_CALLBACK_API */
00276 #define DEF_ACCEPT_CALLBACK
00277 #endif /* LWIP_CALLBACK_API */
00278 
00279 /**
00280  * members common to struct tcp_pcb and struct tcp_listen_pcb
00281  */
00282 #define TCP_PCB_COMMON(type) \
00283   type *next; /* for the linked list */ \
00284   enum tcp_state state; /* TCP state */ \
00285   u8_t prio; \
00286   void *callback_arg; \
00287   /* ports are in host byte order */ \
00288   u16_t local_port; \
00289   /* the accept callback for listen- and normal pcbs, if LWIP_CALLBACK_API */ \
00290   DEF_ACCEPT_CALLBACK
00291 
00292 
00293 /* the TCP protocol control block */
00294 struct tcp_pcb {
00295 /** common PCB members */
00296   IP_PCB;
00297 /** protocol specific PCB members */
00298   TCP_PCB_COMMON(struct tcp_pcb);
00299 
00300   /* ports are in host byte order */
00301   u16_t remote_port;
00302   
00303   u8_t flags;
00304 #define TF_ACK_DELAY   ((u8_t)0x01U)   /* Delayed ACK. */
00305 #define TF_ACK_NOW     ((u8_t)0x02U)   /* Immediate ACK. */
00306 #define TF_INFR        ((u8_t)0x04U)   /* In fast recovery. */
00307 #define TF_TIMESTAMP   ((u8_t)0x08U)   /* Timestamp option enabled */
00308 #define TF_FIN         ((u8_t)0x20U)   /* Connection was closed locally (FIN segment enqueued). */
00309 #define TF_NODELAY     ((u8_t)0x40U)   /* Disable Nagle algorithm */
00310 #define TF_NAGLEMEMERR ((u8_t)0x80U)   /* nagle enabled, memerr, try to output to prevent delayed ACK to happen */
00311 
00312   /* the rest of the fields are in host byte order
00313      as we have to do some math with them */
00314   /* receiver variables */
00315   u32_t rcv_nxt;   /* next seqno expected */
00316   u16_t rcv_wnd;   /* receiver window available */
00317   u16_t rcv_ann_wnd; /* receiver window to announce */
00318   u32_t rcv_ann_right_edge; /* announced right edge of window */
00319 
00320   /* Timers */
00321   u32_t tmr;
00322   u8_t polltmr, pollinterval;
00323   
00324   /* Retransmission timer. */
00325   s16_t rtime;
00326   
00327   u16_t mss;   /* maximum segment size */
00328   
00329   /* RTT (round trip time) estimation variables */
00330   u32_t rttest; /* RTT estimate in 500ms ticks */
00331   u32_t rtseq;  /* sequence number being timed */
00332   s16_t sa, sv; /* @todo document this */
00333 
00334   s16_t rto;    /* retransmission time-out */
00335   u8_t nrtx;    /* number of retransmissions */
00336 
00337   /* fast retransmit/recovery */
00338   u32_t lastack; /* Highest acknowledged seqno. */
00339   u8_t dupacks;
00340   
00341   /* congestion avoidance/control variables */
00342   u16_t cwnd;  
00343   u16_t ssthresh;
00344 
00345   /* sender variables */
00346   u32_t snd_nxt;   /* next new seqno to be sent */
00347   u16_t snd_wnd;   /* sender window */
00348   u32_t snd_wl1, snd_wl2; /* Sequence and acknowledgement numbers of last
00349                              window update. */
00350   u32_t snd_lbb;       /* Sequence number of next byte to be buffered. */
00351 
00352   u16_t acked;
00353   
00354   u16_t snd_buf;   /* Available buffer space for sending (in bytes). */
00355 #define TCP_SNDQUEUELEN_OVERFLOW (0xffff-3)
00356   u16_t snd_queuelen; /* Available buffer space for sending (in tcp_segs). */
00357   
00358   
00359   /* These are ordered by sequence number: */
00360   struct tcp_seg *unsent;   /* Unsent (queued) segments. */
00361   struct tcp_seg *unacked;  /* Sent but unacknowledged segments. */
00362 #if TCP_QUEUE_OOSEQ  
00363   struct tcp_seg *ooseq;    /* Received out of sequence segments. */
00364 #endif /* TCP_QUEUE_OOSEQ */
00365 
00366   struct pbuf *refused_data; /* Data previously received but not yet taken by upper layer */
00367 
00368 #if LWIP_CALLBACK_API
00369   /* Function to be called when more send buffer space is available.
00370    * @param arg user-supplied argument (tcp_pcb.callback_arg)
00371    * @param pcb the tcp_pcb which has send buffer space available
00372    * @param space the amount of bytes available
00373    * @return ERR_OK: try to send some data by calling tcp_output
00374    */
00375   err_t (* sent)(void *arg, struct tcp_pcb *pcb, u16_t space);
00376   
00377   /* Function to be called when (in-sequence) data has arrived.
00378    * @param arg user-supplied argument (tcp_pcb.callback_arg)
00379    * @param pcb the tcp_pcb for which data has arrived
00380    * @param p the packet buffer which arrived
00381    * @param err an error argument (TODO: that is current always ERR_OK?)
00382    * @return ERR_OK: try to send some data by calling tcp_output
00383    */
00384   err_t (* recv)(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err);
00385 
00386   /* Function to be called when a connection has been set up.
00387    * @param arg user-supplied argument (tcp_pcb.callback_arg)
00388    * @param pcb the tcp_pcb that now is connected
00389    * @param err an error argument (TODO: that is current always ERR_OK?)
00390    * @return value is currently ignored
00391    */
00392   err_t (* connected)(void *arg, struct tcp_pcb *pcb, err_t err);
00393 
00394   /* Function which is called periodically.
00395    * The period can be adjusted in multiples of the TCP slow timer interval
00396    * by changing tcp_pcb.polltmr.
00397    * @param arg user-supplied argument (tcp_pcb.callback_arg)
00398    * @param pcb the tcp_pcb to poll for
00399    * @return ERR_OK: try to send some data by calling tcp_output
00400    */
00401   err_t (* poll)(void *arg, struct tcp_pcb *pcb);
00402 
00403   /* Function to be called whenever a fatal error occurs.
00404    * There is no pcb parameter since most of the times, the pcb is
00405    * already deallocated (or there is no pcb) when this function is called.
00406    * @param arg user-supplied argument (tcp_pcb.callback_arg)
00407    * @param err an indication why the error callback is called:
00408    *            ERR_ABRT: aborted through tcp_abort or by a TCP timer
00409    *            ERR_RST: the connection was reset by the remote host
00410    */
00411   void (* errf)(void *arg, err_t err);
00412 #endif /* LWIP_CALLBACK_API */
00413 
00414 #if LWIP_TCP_TIMESTAMPS
00415   u32_t ts_lastacksent;
00416   u32_t ts_recent;
00417 #endif /* LWIP_TCP_TIMESTAMPS */
00418 
00419   /* idle time before KEEPALIVE is sent */
00420   u32_t keep_idle;
00421 #if LWIP_TCP_KEEPALIVE
00422   u32_t keep_intvl;
00423   u32_t keep_cnt;
00424 #endif /* LWIP_TCP_KEEPALIVE */
00425   
00426   /* Persist timer counter */
00427   u32_t persist_cnt;
00428   /* Persist timer back-off */
00429   u8_t persist_backoff;
00430 
00431   /* KEEPALIVE counter */
00432   u8_t keep_cnt_sent;
00433 };
00434 
00435 struct tcp_pcb_listen {  
00436 /* Common members of all PCB types */
00437   IP_PCB;
00438 /* Protocol specific PCB members */
00439   TCP_PCB_COMMON(struct tcp_pcb_listen);
00440 
00441 #if TCP_LISTEN_BACKLOG
00442   u8_t backlog;
00443   u8_t accepts_pending;
00444 #endif /* TCP_LISTEN_BACKLOG */
00445 };
00446 
00447 #if LWIP_EVENT_API
00448 
00449 enum lwip_event {
00450   LWIP_EVENT_ACCEPT,
00451   LWIP_EVENT_SENT,
00452   LWIP_EVENT_RECV,
00453   LWIP_EVENT_CONNECTED,
00454   LWIP_EVENT_POLL,
00455   LWIP_EVENT_ERR
00456 };
00457 
00458 err_t lwip_tcp_event(void *arg, struct tcp_pcb *pcb,
00459          enum lwip_event,
00460          struct pbuf *p,
00461          u16_t size,
00462          err_t err);
00463 
00464 #define TCP_EVENT_ACCEPT(pcb,err,ret)    ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
00465                 LWIP_EVENT_ACCEPT, NULL, 0, err)
00466 #define TCP_EVENT_SENT(pcb,space,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
00467                    LWIP_EVENT_SENT, NULL, space, ERR_OK)
00468 #define TCP_EVENT_RECV(pcb,p,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
00469                 LWIP_EVENT_RECV, (p), 0, (err))
00470 #define TCP_EVENT_CONNECTED(pcb,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
00471                 LWIP_EVENT_CONNECTED, NULL, 0, (err))
00472 #define TCP_EVENT_POLL(pcb,ret)       ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
00473                 LWIP_EVENT_POLL, NULL, 0, ERR_OK)
00474 #define TCP_EVENT_ERR(errf,arg,err)  lwip_tcp_event((arg), NULL, \
00475                 LWIP_EVENT_ERR, NULL, 0, (err))
00476 #else /* LWIP_EVENT_API */
00477 
00478 #define TCP_EVENT_ACCEPT(pcb,err,ret)                          \
00479   do {                                                         \
00480     if((pcb)->accept != NULL)                                  \
00481       (ret) = (pcb)->accept((pcb)->callback_arg,(pcb),(err));  \
00482     else (ret) = ERR_OK;                                       \
00483   } while (0)
00484 
00485 #define TCP_EVENT_SENT(pcb,space,ret)                          \
00486   do {                                                         \
00487     if((pcb)->sent != NULL)                                    \
00488       (ret) = (pcb)->sent((pcb)->callback_arg,(pcb),(space));  \
00489     else (ret) = ERR_OK;                                       \
00490   } while (0)
00491 
00492 #define TCP_EVENT_RECV(pcb,p,err,ret)                           \
00493   do {                                                          \
00494     if((pcb)->recv != NULL) {                                   \
00495       (ret) = (pcb)->recv((pcb)->callback_arg,(pcb),(p),(err)); \
00496     } else {                                                    \
00497       (ret) = tcp_recv_null(NULL, (pcb), (p), (err));           \
00498     }                                                           \
00499   } while (0)
00500 
00501 #define TCP_EVENT_CONNECTED(pcb,err,ret)                         \
00502   do {                                                           \
00503     if((pcb)->connected != NULL)                                 \
00504       (ret) = (pcb)->connected((pcb)->callback_arg,(pcb),(err)); \
00505     else (ret) = ERR_OK;                                         \
00506   } while (0)
00507 
00508 #define TCP_EVENT_POLL(pcb,ret)                                \
00509   do {                                                         \
00510     if((pcb)->poll != NULL)                                    \
00511       (ret) = (pcb)->poll((pcb)->callback_arg,(pcb));          \
00512     else (ret) = ERR_OK;                                       \
00513   } while (0)
00514 
00515 #define TCP_EVENT_ERR(errf,arg,err)                            \
00516   do {                                                         \
00517     if((errf) != NULL)                                         \
00518       (errf)((arg),(err));                                     \
00519   } while (0)
00520 
00521 #endif /* LWIP_EVENT_API */
00522 
00523 /* This structure represents a TCP segment on the unsent and unacked queues */
00524 struct tcp_seg {
00525   struct tcp_seg *next;    /* used when putting segements on a queue */
00526   struct pbuf *p;          /* buffer containing data + TCP header */
00527   void *dataptr;           /* pointer to the TCP data in the pbuf */
00528   u16_t len;               /* the TCP length of this segment */
00529   u8_t  flags;
00530 #define TF_SEG_OPTS_MSS   (u8_t)0x01U   /* Include MSS option. */
00531 #define TF_SEG_OPTS_TS    (u8_t)0x02U   /* Include timestamp option. */
00532   struct tcp_hdr *tcphdr;  /* the TCP header */
00533 };
00534 
00535 #define LWIP_TCP_OPT_LENGTH(flags)              \
00536   (flags & TF_SEG_OPTS_MSS ? 4  : 0) +          \
00537   (flags & TF_SEG_OPTS_TS  ? 12 : 0)
00538 
00539 /** This returns a TCP header option for MSS in an u32_t */
00540 #define TCP_BUILD_MSS_OPTION(x) (x) = htonl(((u32_t)2 << 24) |          \
00541                                             ((u32_t)4 << 16) |          \
00542                                             (((u32_t)TCP_MSS / 256) << 8) | \
00543                                             (TCP_MSS & 255))
00544 
00545 /* Internal functions and global variables: */
00546 struct tcp_pcb *tcp_pcb_copy(struct tcp_pcb *pcb);
00547 void tcp_pcb_purge(struct tcp_pcb *pcb);
00548 void tcp_pcb_remove(struct tcp_pcb **pcblist, struct tcp_pcb *pcb);
00549 
00550 u8_t tcp_segs_free(struct tcp_seg *seg);
00551 u8_t tcp_seg_free(struct tcp_seg *seg);
00552 struct tcp_seg *tcp_seg_copy(struct tcp_seg *seg);
00553 
00554 #define tcp_ack(pcb)                               \
00555   do {                                             \
00556     if((pcb)->flags & TF_ACK_DELAY) {              \
00557       (pcb)->flags &= ~TF_ACK_DELAY;               \
00558       (pcb)->flags |= TF_ACK_NOW;                  \
00559       tcp_output(pcb);                             \
00560     }                                              \
00561     else {                                         \
00562       (pcb)->flags |= TF_ACK_DELAY;                \
00563     }                                              \
00564   } while (0)
00565 
00566 #define tcp_ack_now(pcb)                           \
00567   do {                                             \
00568     (pcb)->flags |= TF_ACK_NOW;                    \
00569     tcp_output(pcb);                               \
00570   } while (0)
00571 
00572 err_t tcp_send_ctrl(struct tcp_pcb *pcb, u8_t flags);
00573 err_t tcp_enqueue(struct tcp_pcb *pcb, void *dataptr, u16_t len,
00574                   u8_t flags, u8_t apiflags, u8_t optflags);
00575 
00576 void tcp_rexmit_seg(struct tcp_pcb *pcb, struct tcp_seg *seg);
00577 
00578 void tcp_rst(u32_t seqno, u32_t ackno,
00579        struct ip_addr *local_ip, struct ip_addr *remote_ip,
00580        u16_t local_port, u16_t remote_port);
00581 
00582 u32_t tcp_next_iss(void);
00583 
00584 void tcp_keepalive(struct tcp_pcb *pcb);
00585 void tcp_zero_window_probe(struct tcp_pcb *pcb);
00586 
00587 #if TCP_CALCULATE_EFF_SEND_MSS
00588 u16_t tcp_eff_send_mss(u16_t sendmss, struct ip_addr *addr);
00589 #endif /* TCP_CALCULATE_EFF_SEND_MSS */
00590 
00591 #if LWIP_CALLBACK_API
00592 err_t tcp_recv_null(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err);
00593 #endif /* LWIP_CALLBACK_API */
00594 
00595 extern struct tcp_pcb *tcp_input_pcb;
00596 extern u32_t tcp_ticks;
00597 
00598 const char* tcp_debug_state_str(enum tcp_state s);
00599 #if TCP_DEBUG || TCP_INPUT_DEBUG || TCP_OUTPUT_DEBUG
00600 void tcp_debug_print(struct tcp_hdr *tcphdr);
00601 void tcp_debug_print_flags(u8_t flags);
00602 void tcp_debug_print_state(enum tcp_state s);
00603 void tcp_debug_print_pcbs(void);
00604 s16_t tcp_pcbs_sane(void);
00605 #else
00606 #  define tcp_debug_print(tcphdr)
00607 #  define tcp_debug_print_flags(flags)
00608 #  define tcp_debug_print_state(s)
00609 #  define tcp_debug_print_pcbs()
00610 #  define tcp_pcbs_sane() 1
00611 #endif /* TCP_DEBUG */
00612 
00613 #if NO_SYS
00614 #define tcp_timer_needed()
00615 #else
00616 void tcp_timer_needed(void);
00617 #endif
00618 
00619 /* The TCP PCB lists. */
00620 union tcp_listen_pcbs_t { /* List of all TCP PCBs in LISTEN state. */
00621   struct tcp_pcb_listen *listen_pcbs; 
00622   struct tcp_pcb *pcbs;
00623 };
00624 extern union tcp_listen_pcbs_t tcp_listen_pcbs;
00625 extern struct tcp_pcb *tcp_active_pcbs;  /* List of all TCP PCBs that are in a
00626               state in which they accept or send
00627               data. */
00628 extern struct tcp_pcb *tcp_tw_pcbs;      /* List of all TCP PCBs in TIME-WAIT. */
00629 
00630 extern struct tcp_pcb *tcp_tmp_pcb;      /* Only used for temporary storage. */
00631 
00632 /* Axioms about the above lists:   
00633    1) Every TCP PCB that is not CLOSED is in one of the lists.
00634    2) A PCB is only in one of the lists.
00635    3) All PCBs in the tcp_listen_pcbs list is in LISTEN state.
00636    4) All PCBs in the tcp_tw_pcbs list is in TIME-WAIT state.
00637 */
00638 
00639 /* Define two macros, TCP_REG and TCP_RMV that registers a TCP PCB
00640    with a PCB list or removes a PCB from a list, respectively. */
00641 #if 0
00642 #define TCP_REG(pcbs, npcb) do {\
00643                             LWIP_DEBUGF(TCP_DEBUG, ("TCP_REG %p local port %d\n", npcb, npcb->local_port)); \
00644                             for(tcp_tmp_pcb = *pcbs; \
00645           tcp_tmp_pcb != NULL; \
00646         tcp_tmp_pcb = tcp_tmp_pcb->next) { \
00647                                 LWIP_ASSERT("TCP_REG: already registered\n", tcp_tmp_pcb != npcb); \
00648                             } \
00649                             LWIP_ASSERT("TCP_REG: pcb->state != CLOSED", npcb->state != CLOSED); \
00650                             npcb->next = *pcbs; \
00651                             LWIP_ASSERT("TCP_REG: npcb->next != npcb", npcb->next != npcb); \
00652                             *(pcbs) = npcb; \
00653                             LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \
00654               tcp_timer_needed(); \
00655                             } while(0)
00656 #define TCP_RMV(pcbs, npcb) do { \
00657                             LWIP_ASSERT("TCP_RMV: pcbs != NULL", *pcbs != NULL); \
00658                             LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removing %p from %p\n", npcb, *pcbs)); \
00659                             if(*pcbs == npcb) { \
00660                                *pcbs = (*pcbs)->next; \
00661                             } else for(tcp_tmp_pcb = *pcbs; tcp_tmp_pcb != NULL; tcp_tmp_pcb = tcp_tmp_pcb->next) { \
00662                                if(tcp_tmp_pcb->next == npcb) { \
00663                                   tcp_tmp_pcb->next = npcb->next; \
00664                                   break; \
00665                                } \
00666                             } \
00667                             npcb->next = NULL; \
00668                             LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \
00669                             LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removed %p from %p\n", npcb, *pcbs)); \
00670                             } while(0)
00671 
00672 #else /* LWIP_DEBUG */
00673 
00674 #define TCP_REG(pcbs, npcb)                        \
00675   do {                                             \
00676     npcb->next = *pcbs;                            \
00677     *(pcbs) = npcb;                                \
00678     tcp_timer_needed();                            \
00679   } while (0)
00680 
00681 #define TCP_RMV(pcbs, npcb)                        \
00682   do {                                             \
00683     if(*(pcbs) == npcb) {                          \
00684       (*(pcbs)) = (*pcbs)->next;                   \
00685     }                                              \
00686     else {                                         \
00687       for(tcp_tmp_pcb = *pcbs;                                         \
00688           tcp_tmp_pcb != NULL;                                         \
00689           tcp_tmp_pcb = tcp_tmp_pcb->next) {                           \
00690         if(tcp_tmp_pcb->next == npcb) {   \
00691           tcp_tmp_pcb->next = npcb->next;          \
00692           break;                                   \
00693         }                                          \
00694       }                                            \
00695     }                                              \
00696     npcb->next = NULL;                             \
00697   } while(0)
00698 
00699 #endif /* LWIP_DEBUG */
00700 
00701 #ifdef __cplusplus
00702 }
00703 #endif
00704 
00705 #endif /* LWIP_TCP */
00706 
00707 #endif /* __LWIP_TCP_H__ */
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