NetServices Stack source
Dependents: HelloWorld ServoInterfaceBoardExample1 4180_Lab4
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 /** Function prototype for tcp accept callback functions. Called when a new 00053 * connection can be accepted on a listening pcb. 00054 * 00055 * @param arg Additional argument to pass to the callback function (@see tcp_arg()) 00056 * @param newpcb The new connection pcb 00057 * @param err An error code if there has been an error accepting. 00058 * Only return ERR_ABRT if you have called tcp_abort from within the 00059 * callback function! 00060 */ 00061 typedef err_t (*tcp_accept_fn)(void *arg, struct tcp_pcb *newpcb, err_t err); 00062 00063 /** Function prototype for tcp receive callback functions. Called when data has 00064 * been received. 00065 * 00066 * @param arg Additional argument to pass to the callback function (@see tcp_arg()) 00067 * @param tpcb The connection pcb which received data 00068 * @param p The received data (or NULL when the connection has been closed!) 00069 * @param err An error code if there has been an error receiving 00070 * Only return ERR_ABRT if you have called tcp_abort from within the 00071 * callback function! 00072 */ 00073 typedef err_t (*tcp_recv_fn)(void *arg, struct tcp_pcb *tpcb, 00074 struct pbuf *p, err_t err); 00075 00076 /** Function prototype for tcp sent callback functions. Called when sent data has 00077 * been acknowledged by the remote side. Use it to free corresponding resources. 00078 * This also means that the pcb has now space available to send new data. 00079 * 00080 * @param arg Additional argument to pass to the callback function (@see tcp_arg()) 00081 * @param tpcb The connection pcb for which data has been acknowledged 00082 * @param len The amount of bytes acknowledged 00083 * @return ERR_OK: try to send some data by calling tcp_output 00084 * Only return ERR_ABRT if you have called tcp_abort from within the 00085 * callback function! 00086 */ 00087 typedef err_t (*tcp_sent_fn)(void *arg, struct tcp_pcb *tpcb, 00088 u16_t len); 00089 00090 /** Function prototype for tcp poll callback functions. Called periodically as 00091 * specified by @see tcp_poll. 00092 * 00093 * @param arg Additional argument to pass to the callback function (@see tcp_arg()) 00094 * @param tpcb tcp pcb 00095 * @return ERR_OK: try to send some data by calling tcp_output 00096 * Only return ERR_ABRT if you have called tcp_abort from within the 00097 * callback function! 00098 */ 00099 typedef err_t (*tcp_poll_fn)(void *arg, struct tcp_pcb *tpcb); 00100 00101 /** Function prototype for tcp error callback functions. Called when the pcb 00102 * receives a RST or is unexpectedly closed for any other reason. 00103 * 00104 * @note The corresponding pcb is already freed when this callback is called! 00105 * 00106 * @param arg Additional argument to pass to the callback function (@see tcp_arg()) 00107 * @param err Error code to indicate why the pcb has been closed 00108 * ERR_ABRT: aborted through tcp_abort or by a TCP timer 00109 * ERR_RST: the connection was reset by the remote host 00110 */ 00111 typedef void (*tcp_err_fn)(void *arg, err_t err); 00112 00113 /** Function prototype for tcp connected callback functions. Called when a pcb 00114 * is connected to the remote side after initiating a connection attempt by 00115 * calling tcp_connect(). 00116 * 00117 * @param arg Additional argument to pass to the callback function (@see tcp_arg()) 00118 * @param tpcb The connection pcb which is connected 00119 * @param err An unused error code, always ERR_OK currently ;-) TODO! 00120 * Only return ERR_ABRT if you have called tcp_abort from within the 00121 * callback function! 00122 * 00123 * @note When a connection attempt fails, the error callback is currently called! 00124 */ 00125 typedef err_t (*tcp_connected_fn)(void *arg, struct tcp_pcb *tpcb, err_t err); 00126 00127 enum tcp_state { 00128 CLOSED = 0, 00129 LISTEN = 1, 00130 SYN_SENT = 2, 00131 SYN_RCVD = 3, 00132 ESTABLISHED = 4, 00133 FIN_WAIT_1 = 5, 00134 FIN_WAIT_2 = 6, 00135 CLOSE_WAIT = 7, 00136 CLOSING = 8, 00137 LAST_ACK = 9, 00138 TIME_WAIT = 10 00139 }; 00140 00141 #if LWIP_CALLBACK_API 00142 /* Function to call when a listener has been connected. 00143 * @param arg user-supplied argument (tcp_pcb.callback_arg) 00144 * @param pcb a new tcp_pcb that now is connected 00145 * @param err an error argument (TODO: that is current always ERR_OK?) 00146 * @return ERR_OK: accept the new connection, 00147 * any other err_t abortsthe new connection 00148 */ 00149 #define DEF_ACCEPT_CALLBACK tcp_accept_fn accept; 00150 #else /* LWIP_CALLBACK_API */ 00151 #define DEF_ACCEPT_CALLBACK 00152 #endif /* LWIP_CALLBACK_API */ 00153 00154 /** 00155 * members common to struct tcp_pcb and struct tcp_listen_pcb 00156 */ 00157 #define TCP_PCB_COMMON(type) \ 00158 type *next; /* for the linked list */ \ 00159 enum tcp_state state; /* TCP state */ \ 00160 u8_t prio; \ 00161 void *callback_arg; \ 00162 /* the accept callback for listen- and normal pcbs, if LWIP_CALLBACK_API */ \ 00163 DEF_ACCEPT_CALLBACK \ 00164 /* ports are in host byte order */ \ 00165 u16_t local_port 00166 00167 00168 /* the TCP protocol control block */ 00169 struct tcp_pcb { 00170 /** common PCB members */ 00171 IP_PCB; 00172 /** protocol specific PCB members */ 00173 TCP_PCB_COMMON(struct tcp_pcb); 00174 00175 /* ports are in host byte order */ 00176 u16_t remote_port; 00177 00178 u8_t flags; 00179 #define TF_ACK_DELAY ((u8_t)0x01U) /* Delayed ACK. */ 00180 #define TF_ACK_NOW ((u8_t)0x02U) /* Immediate ACK. */ 00181 #define TF_INFR ((u8_t)0x04U) /* In fast recovery. */ 00182 #define TF_TIMESTAMP ((u8_t)0x08U) /* Timestamp option enabled */ 00183 #define TF_RXCLOSED ((u8_t)0x10U) /* rx closed by tcp_shutdown */ 00184 #define TF_FIN ((u8_t)0x20U) /* Connection was closed locally (FIN segment enqueued). */ 00185 #define TF_NODELAY ((u8_t)0x40U) /* Disable Nagle algorithm */ 00186 #define TF_NAGLEMEMERR ((u8_t)0x80U) /* nagle enabled, memerr, try to output to prevent delayed ACK to happen */ 00187 00188 /* the rest of the fields are in host byte order 00189 as we have to do some math with them */ 00190 /* receiver variables */ 00191 u32_t rcv_nxt; /* next seqno expected */ 00192 u16_t rcv_wnd; /* receiver window available */ 00193 u16_t rcv_ann_wnd; /* receiver window to announce */ 00194 u32_t rcv_ann_right_edge; /* announced right edge of window */ 00195 00196 /* Timers */ 00197 u32_t tmr; 00198 u8_t polltmr, pollinterval; 00199 00200 /* Retransmission timer. */ 00201 s16_t rtime; 00202 00203 u16_t mss; /* maximum segment size */ 00204 00205 /* RTT (round trip time) estimation variables */ 00206 u32_t rttest; /* RTT estimate in 500ms ticks */ 00207 u32_t rtseq; /* sequence number being timed */ 00208 s16_t sa, sv; /* @todo document this */ 00209 00210 s16_t rto; /* retransmission time-out */ 00211 u8_t nrtx; /* number of retransmissions */ 00212 00213 /* fast retransmit/recovery */ 00214 u32_t lastack; /* Highest acknowledged seqno. */ 00215 u8_t dupacks; 00216 00217 /* congestion avoidance/control variables */ 00218 u16_t cwnd; 00219 u16_t ssthresh; 00220 00221 /* sender variables */ 00222 u32_t snd_nxt; /* next new seqno to be sent */ 00223 u16_t snd_wnd; /* sender window */ 00224 u32_t snd_wl1, snd_wl2; /* Sequence and acknowledgement numbers of last 00225 window update. */ 00226 u32_t snd_lbb; /* Sequence number of next byte to be buffered. */ 00227 00228 u16_t acked; 00229 00230 u16_t snd_buf; /* Available buffer space for sending (in bytes). */ 00231 #define TCP_SNDQUEUELEN_OVERFLOW (0xffff-3) 00232 u16_t snd_queuelen; /* Available buffer space for sending (in tcp_segs). */ 00233 00234 #if TCP_OVERSIZE 00235 /* Extra bytes available at the end of the last pbuf in unsent. */ 00236 u16_t unsent_oversize; 00237 #endif /* TCP_OVERSIZE */ 00238 00239 /* These are ordered by sequence number: */ 00240 struct tcp_seg *unsent; /* Unsent (queued) segments. */ 00241 struct tcp_seg *unacked; /* Sent but unacknowledged segments. */ 00242 #if TCP_QUEUE_OOSEQ 00243 struct tcp_seg *ooseq; /* Received out of sequence segments. */ 00244 #endif /* TCP_QUEUE_OOSEQ */ 00245 00246 struct pbuf *refused_data; /* Data previously received but not yet taken by upper layer */ 00247 00248 #if LWIP_CALLBACK_API 00249 /* Function to be called when more send buffer space is available. */ 00250 tcp_sent_fn sent; 00251 /* Function to be called when (in-sequence) data has arrived. */ 00252 tcp_recv_fn recv; 00253 /* Function to be called when a connection has been set up. */ 00254 tcp_connected_fn connected; 00255 /* Function which is called periodically. */ 00256 tcp_poll_fn poll; 00257 /* Function to be called whenever a fatal error occurs. */ 00258 tcp_err_fn errf; 00259 #endif /* LWIP_CALLBACK_API */ 00260 00261 #if LWIP_TCP_TIMESTAMPS 00262 u32_t ts_lastacksent; 00263 u32_t ts_recent; 00264 #endif /* LWIP_TCP_TIMESTAMPS */ 00265 00266 /* idle time before KEEPALIVE is sent */ 00267 u32_t keep_idle; 00268 #if LWIP_TCP_KEEPALIVE 00269 u32_t keep_intvl; 00270 u32_t keep_cnt; 00271 #endif /* LWIP_TCP_KEEPALIVE */ 00272 00273 /* Persist timer counter */ 00274 u32_t persist_cnt; 00275 /* Persist timer back-off */ 00276 u8_t persist_backoff; 00277 00278 /* KEEPALIVE counter */ 00279 u8_t keep_cnt_sent; 00280 }; 00281 00282 struct tcp_pcb_listen { 00283 /* Common members of all PCB types */ 00284 IP_PCB; 00285 /* Protocol specific PCB members */ 00286 TCP_PCB_COMMON(struct tcp_pcb_listen); 00287 00288 #if TCP_LISTEN_BACKLOG 00289 u8_t backlog; 00290 u8_t accepts_pending; 00291 #endif /* TCP_LISTEN_BACKLOG */ 00292 }; 00293 00294 #if LWIP_EVENT_API 00295 00296 enum lwip_event { 00297 LWIP_EVENT_ACCEPT, 00298 LWIP_EVENT_SENT, 00299 LWIP_EVENT_RECV, 00300 LWIP_EVENT_CONNECTED, 00301 LWIP_EVENT_POLL, 00302 LWIP_EVENT_ERR 00303 }; 00304 00305 err_t lwip_tcp_event(void *arg, struct tcp_pcb *pcb, 00306 enum lwip_event, 00307 struct pbuf *p, 00308 u16_t size, 00309 err_t err); 00310 00311 #endif /* LWIP_EVENT_API */ 00312 00313 /* Application program's interface: */ 00314 struct tcp_pcb * tcp_new (void); 00315 00316 void tcp_arg (struct tcp_pcb *pcb, void *arg); 00317 void tcp_accept (struct tcp_pcb *pcb, tcp_accept_fn accept); 00318 void tcp_recv (struct tcp_pcb *pcb, tcp_recv_fn recv); 00319 void tcp_sent (struct tcp_pcb *pcb, tcp_sent_fn sent); 00320 void tcp_poll (struct tcp_pcb *pcb, tcp_poll_fn poll, u8_t interval); 00321 void tcp_err (struct tcp_pcb *pcb, tcp_err_fn err); 00322 00323 #define tcp_mss(pcb) (((pcb)->flags & TF_TIMESTAMP) ? ((pcb)->mss - 12) : (pcb)->mss) 00324 #define tcp_sndbuf(pcb) ((pcb)->snd_buf) 00325 #define tcp_sndqueuelen(pcb) ((pcb)->snd_queuelen) 00326 #define tcp_nagle_disable(pcb) ((pcb)->flags |= TF_NODELAY) 00327 #define tcp_nagle_enable(pcb) ((pcb)->flags &= ~TF_NODELAY) 00328 #define tcp_nagle_disabled(pcb) (((pcb)->flags & TF_NODELAY) != 0) 00329 00330 #if TCP_LISTEN_BACKLOG 00331 #define tcp_accepted(pcb) do { \ 00332 LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", pcb->state == LISTEN); \ 00333 (((struct tcp_pcb_listen *)(pcb))->accepts_pending--); } while(0) 00334 #else /* TCP_LISTEN_BACKLOG */ 00335 #define tcp_accepted(pcb) LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", \ 00336 pcb->state == LISTEN) 00337 #endif /* TCP_LISTEN_BACKLOG */ 00338 00339 void tcp_recved (struct tcp_pcb *pcb, u16_t len); 00340 err_t tcp_bind (struct tcp_pcb *pcb, ip_addr_t *ipaddr, 00341 u16_t port); 00342 err_t tcp_connect (struct tcp_pcb *pcb, ip_addr_t *ipaddr, 00343 u16_t port, tcp_connected_fn connected); 00344 00345 struct tcp_pcb * tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog); 00346 #define tcp_listen(pcb) tcp_listen_with_backlog(pcb, TCP_DEFAULT_LISTEN_BACKLOG) 00347 00348 void tcp_abort (struct tcp_pcb *pcb); 00349 err_t tcp_close (struct tcp_pcb *pcb); 00350 err_t tcp_shutdown(struct tcp_pcb *pcb, int shut_rx, int shut_tx); 00351 00352 /* Flags for "apiflags" parameter in tcp_write */ 00353 #define TCP_WRITE_FLAG_COPY 0x01 00354 #define TCP_WRITE_FLAG_MORE 0x02 00355 00356 err_t tcp_write (struct tcp_pcb *pcb, const void *dataptr, u16_t len, 00357 u8_t apiflags); 00358 00359 void tcp_setprio (struct tcp_pcb *pcb, u8_t prio); 00360 00361 #define TCP_PRIO_MIN 1 00362 #define TCP_PRIO_NORMAL 64 00363 #define TCP_PRIO_MAX 127 00364 00365 err_t tcp_output (struct tcp_pcb *pcb); 00366 00367 00368 const char* tcp_debug_state_str(enum tcp_state s); 00369 00370 00371 #ifdef __cplusplus 00372 } 00373 #endif 00374 00375 #endif /* LWIP_TCP */ 00376 00377 #endif /* __LWIP_TCP_H__ */
Generated on Tue Jul 12 2022 11:52:58 by
![doxygen](doxygen.png)