ESP8266
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 
61 typedef err_t (*tcp_accept_fn)(void *arg, struct tcp_pcb *newpcb, err_t err);
62 
73 typedef err_t (*tcp_recv_fn)(void *arg, struct tcp_pcb *tpcb,
74  struct pbuf *p, err_t err);
75 
87 typedef err_t (*tcp_sent_fn)(void *arg, struct tcp_pcb *tpcb,
88  u16_t len);
89 
99 typedef err_t (*tcp_poll_fn)(void *arg, struct tcp_pcb *tpcb);
100 
111 typedef void (*tcp_err_fn)(void *arg, err_t err);
112 
125 typedef err_t (*tcp_connected_fn)(void *arg, struct tcp_pcb *tpcb, err_t err);
126 
127 enum tcp_state {
128  CLOSED = 0,
129  LISTEN = 1,
130  SYN_SENT = 2,
131  SYN_RCVD = 3,
132  ESTABLISHED = 4,
133  FIN_WAIT_1 = 5,
134  FIN_WAIT_2 = 6,
135  CLOSE_WAIT = 7,
136  CLOSING = 8,
137  LAST_ACK = 9,
138  TIME_WAIT = 10
139 };
140 
141 #if LWIP_CALLBACK_API
142  /* Function to call when a listener has been connected.
143  * @param arg user-supplied argument (tcp_pcb.callback_arg)
144  * @param pcb a new tcp_pcb that now is connected
145  * @param err an error argument (TODO: that is current always ERR_OK?)
146  * @return ERR_OK: accept the new connection,
147  * any other err_t abortsthe new connection
148  */
149 #define DEF_ACCEPT_CALLBACK tcp_accept_fn accept;
150 #else /* LWIP_CALLBACK_API */
151 #define DEF_ACCEPT_CALLBACK
152 #endif /* LWIP_CALLBACK_API */
153 
157 #define TCP_PCB_COMMON(type) \
158  type *next; /* for the linked list */ \
159  enum tcp_state state; /* TCP state */ \
160  u8_t prio; \
161  void *callback_arg; \
162  /* the accept callback for listen- and normal pcbs, if LWIP_CALLBACK_API */ \
163  DEF_ACCEPT_CALLBACK \
164  /* ports are in host byte order */ \
165  u16_t local_port
166 
167 
168 /* the TCP protocol control block */
169 struct tcp_pcb {
171  IP_PCB;
173  TCP_PCB_COMMON(struct tcp_pcb);
174 
175  /* ports are in host byte order */
176  u16_t remote_port;
177 
178  u8_t flags;
179 #define TF_ACK_DELAY ((u8_t)0x01U) /* Delayed ACK. */
180 #define TF_ACK_NOW ((u8_t)0x02U) /* Immediate ACK. */
181 #define TF_INFR ((u8_t)0x04U) /* In fast recovery. */
182 #define TF_TIMESTAMP ((u8_t)0x08U) /* Timestamp option enabled */
183 #define TF_RXCLOSED ((u8_t)0x10U) /* rx closed by tcp_shutdown */
184 #define TF_FIN ((u8_t)0x20U) /* Connection was closed locally (FIN segment enqueued). */
185 #define TF_NODELAY ((u8_t)0x40U) /* Disable Nagle algorithm */
186 #define TF_NAGLEMEMERR ((u8_t)0x80U) /* nagle enabled, memerr, try to output to prevent delayed ACK to happen */
187 
188  /* the rest of the fields are in host byte order
189  as we have to do some math with them */
190  /* receiver variables */
191  u32_t rcv_nxt; /* next seqno expected */
192  u16_t rcv_wnd; /* receiver window available */
193  u16_t rcv_ann_wnd; /* receiver window to announce */
194  u32_t rcv_ann_right_edge; /* announced right edge of window */
195 
196  /* Timers */
197  u32_t tmr;
198  u8_t polltmr, pollinterval;
199 
200  /* Retransmission timer. */
201  s16_t rtime;
202 
203  u16_t mss; /* maximum segment size */
204 
205  /* RTT (round trip time) estimation variables */
206  u32_t rttest; /* RTT estimate in 500ms ticks */
207  u32_t rtseq; /* sequence number being timed */
208  s16_t sa, sv; /* @todo document this */
209 
210  s16_t rto; /* retransmission time-out */
211  u8_t nrtx; /* number of retransmissions */
212 
213  /* fast retransmit/recovery */
214  u32_t lastack; /* Highest acknowledged seqno. */
215  u8_t dupacks;
216 
217  /* congestion avoidance/control variables */
218  u16_t cwnd;
219  u16_t ssthresh;
220 
221  /* sender variables */
222  u32_t snd_nxt; /* next new seqno to be sent */
223  u16_t snd_wnd; /* sender window */
224  u32_t snd_wl1, snd_wl2; /* Sequence and acknowledgement numbers of last
225  window update. */
226  u32_t snd_lbb; /* Sequence number of next byte to be buffered. */
227 
228  u16_t acked;
229 
230  u16_t snd_buf; /* Available buffer space for sending (in bytes). */
231 #define TCP_SNDQUEUELEN_OVERFLOW (0xffff-3)
232  u16_t snd_queuelen; /* Available buffer space for sending (in tcp_segs). */
233 
234 #if TCP_OVERSIZE
235  /* Extra bytes available at the end of the last pbuf in unsent. */
236  u16_t unsent_oversize;
237 #endif /* TCP_OVERSIZE */
238 
239  /* These are ordered by sequence number: */
240  struct tcp_seg *unsent; /* Unsent (queued) segments. */
241  struct tcp_seg *unacked; /* Sent but unacknowledged segments. */
242 #if TCP_QUEUE_OOSEQ
243  struct tcp_seg *ooseq; /* Received out of sequence segments. */
244 #endif /* TCP_QUEUE_OOSEQ */
245 
246  struct pbuf *refused_data; /* Data previously received but not yet taken by upper layer */
247 
248 #if LWIP_CALLBACK_API
249  /* Function to be called when more send buffer space is available. */
250  tcp_sent_fn sent;
251  /* Function to be called when (in-sequence) data has arrived. */
252  tcp_recv_fn recv;
253  /* Function to be called when a connection has been set up. */
254  tcp_connected_fn connected;
255  /* Function which is called periodically. */
256  tcp_poll_fn poll;
257  /* Function to be called whenever a fatal error occurs. */
258  tcp_err_fn errf;
259 #endif /* LWIP_CALLBACK_API */
260 
261 #if LWIP_TCP_TIMESTAMPS
262  u32_t ts_lastacksent;
263  u32_t ts_recent;
264 #endif /* LWIP_TCP_TIMESTAMPS */
265 
266  /* idle time before KEEPALIVE is sent */
267  u32_t keep_idle;
268 #if LWIP_TCP_KEEPALIVE
269  u32_t keep_intvl;
270  u32_t keep_cnt;
271 #endif /* LWIP_TCP_KEEPALIVE */
272 
273  /* Persist timer counter */
274  u32_t persist_cnt;
275  /* Persist timer back-off */
276  u8_t persist_backoff;
277 
278  /* KEEPALIVE counter */
279  u8_t keep_cnt_sent;
280 };
281 
282 struct tcp_pcb_listen {
283 /* Common members of all PCB types */
284  IP_PCB;
285 /* Protocol specific PCB members */
286  TCP_PCB_COMMON(struct tcp_pcb_listen);
287 
288 #if TCP_LISTEN_BACKLOG
289  u8_t backlog;
290  u8_t accepts_pending;
291 #endif /* TCP_LISTEN_BACKLOG */
292 };
293 
294 #if LWIP_EVENT_API
295 
296 enum lwip_event {
297  LWIP_EVENT_ACCEPT,
298  LWIP_EVENT_SENT,
299  LWIP_EVENT_RECV,
300  LWIP_EVENT_CONNECTED,
301  LWIP_EVENT_POLL,
302  LWIP_EVENT_ERR
303 };
304 
305 err_t lwip_tcp_event(void *arg, struct tcp_pcb *pcb,
306  enum lwip_event,
307  struct pbuf *p,
308  u16_t size,
309  err_t err);
310 
311 #endif /* LWIP_EVENT_API */
312 
313 /* Application program's interface: */
314 struct tcp_pcb * tcp_new (void)ICACHE_FLASH_ATTR;
315 
316 void tcp_arg (struct tcp_pcb *pcb, void *arg) ICACHE_FLASH_ATTR;
317 void tcp_accept (struct tcp_pcb *pcb, tcp_accept_fn accept) ICACHE_FLASH_ATTR;
318 void tcp_recv (struct tcp_pcb *pcb, tcp_recv_fn recv) ICACHE_FLASH_ATTR;
319 void tcp_sent (struct tcp_pcb *pcb, tcp_sent_fn sent)ICACHE_FLASH_ATTR;
320 void tcp_poll (struct tcp_pcb *pcb, tcp_poll_fn poll, u8_t interval)ICACHE_FLASH_ATTR;
321 void tcp_err (struct tcp_pcb *pcb, tcp_err_fn err)ICACHE_FLASH_ATTR;
322 
323 #define tcp_mss(pcb) (((pcb)->flags & TF_TIMESTAMP) ? ((pcb)->mss - 12) : (pcb)->mss)
324 #define tcp_sndbuf(pcb) ((pcb)->snd_buf)
325 #define tcp_sndqueuelen(pcb) ((pcb)->snd_queuelen)
326 #define tcp_nagle_disable(pcb) ((pcb)->flags |= TF_NODELAY)
327 #define tcp_nagle_enable(pcb) ((pcb)->flags &= ~TF_NODELAY)
328 #define tcp_nagle_disabled(pcb) (((pcb)->flags & TF_NODELAY) != 0)
329 
330 #if TCP_LISTEN_BACKLOG
331 #define tcp_accepted(pcb) do { \
332  LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", pcb->state == LISTEN); \
333  (((struct tcp_pcb_listen *)(pcb))->accepts_pending--); } while(0)
334 #else /* TCP_LISTEN_BACKLOG */
335 #define tcp_accepted(pcb) LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", \
336  pcb->state == LISTEN)
337 #endif /* TCP_LISTEN_BACKLOG */
338 
339 void tcp_recved (struct tcp_pcb *pcb, u16_t len)ICACHE_FLASH_ATTR;
340 err_t tcp_bind (struct tcp_pcb *pcb, ip_addr_t *ipaddr,
341  u16_t port)ICACHE_FLASH_ATTR;
342 err_t tcp_connect (struct tcp_pcb *pcb, ip_addr_t *ipaddr,
343  u16_t port, tcp_connected_fn connected)ICACHE_FLASH_ATTR;
344 
345 struct tcp_pcb * tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog)ICACHE_FLASH_ATTR;
346 #define tcp_listen(pcb) tcp_listen_with_backlog(pcb, TCP_DEFAULT_LISTEN_BACKLOG)
347 
348 void tcp_abort (struct tcp_pcb *pcb)ICACHE_FLASH_ATTR;
349 err_t tcp_close (struct tcp_pcb *pcb)ICACHE_FLASH_ATTR;
350 err_t tcp_shutdown(struct tcp_pcb *pcb, int shut_rx, int shut_tx)ICACHE_FLASH_ATTR;
351 
352 /* Flags for "apiflags" parameter in tcp_write */
353 #define TCP_WRITE_FLAG_COPY 0x01
354 #define TCP_WRITE_FLAG_MORE 0x02
355 
356 err_t tcp_write (struct tcp_pcb *pcb, const void *dataptr, u16_t len,
357  u8_t apiflags)ICACHE_FLASH_ATTR;
358 
359 void tcp_setprio (struct tcp_pcb *pcb, u8_t prio)ICACHE_FLASH_ATTR;
360 
361 #define TCP_PRIO_MIN 1
362 #define TCP_PRIO_NORMAL 64
363 #define TCP_PRIO_MAX 127
364 
365 extern err_t tcp_output(struct tcp_pcb *pcb);
366 
367 
368 const char* tcp_debug_state_str(enum tcp_state s)ICACHE_FLASH_ATTR;
369 
370 
371 #ifdef __cplusplus
372 }
373 #endif
374 
375 #endif /* LWIP_TCP */
376 
377 #endif /* __LWIP_TCP_H__ */
Definition: pbuf.h:76