2 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
5 * Redistribution and use in source and binary forms, with or without modification,
6 * are permitted provided that the following conditions are met:
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.
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
27 * This file is part of the lwIP TCP/IP stack.
29 * Author: Adam Dunkels <adam@sics.se>
32 #ifndef __LWIP_TCP_H__
33 #define __LWIP_TCP_H__
37 #if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
40 #include "lwip/pbuf.h"
42 #include "lwip/icmp.h"
45 #include "lwip/ip6_addr.h"
53 /** Function prototype for tcp accept callback functions. Called when a new
54 * connection can be accepted on a listening pcb.
56 * @param arg Additional argument to pass to the callback function (@see tcp_arg())
57 * @param newpcb The new connection pcb
58 * @param err An error code if there has been an error accepting.
59 * Only return ERR_ABRT if you have called tcp_abort from within the
62 typedef err_t (*tcp_accept_fn)(void *arg, struct tcp_pcb *newpcb, err_t err);
64 /** Function prototype for tcp receive callback functions. Called when data has
67 * @param arg Additional argument to pass to the callback function (@see tcp_arg())
68 * @param tpcb The connection pcb which received data
69 * @param p The received data (or NULL when the connection has been closed!)
70 * @param err An error code if there has been an error receiving
71 * Only return ERR_ABRT if you have called tcp_abort from within the
74 typedef err_t (*tcp_recv_fn)(void *arg, struct tcp_pcb *tpcb,
75 struct pbuf *p, err_t err);
77 /** Function prototype for tcp sent callback functions. Called when sent data has
78 * been acknowledged by the remote side. Use it to free corresponding resources.
79 * This also means that the pcb has now space available to send new data.
81 * @param arg Additional argument to pass to the callback function (@see tcp_arg())
82 * @param tpcb The connection pcb for which data has been acknowledged
83 * @param len The amount of bytes acknowledged
84 * @return ERR_OK: try to send some data by calling tcp_output
85 * Only return ERR_ABRT if you have called tcp_abort from within the
88 typedef err_t (*tcp_sent_fn)(void *arg, struct tcp_pcb *tpcb,
91 /** Function prototype for tcp poll callback functions. Called periodically as
92 * specified by @see tcp_poll.
94 * @param arg Additional argument to pass to the callback function (@see tcp_arg())
96 * @return ERR_OK: try to send some data by calling tcp_output
97 * Only return ERR_ABRT if you have called tcp_abort from within the
100 typedef err_t (*tcp_poll_fn)(void *arg, struct tcp_pcb *tpcb);
102 /** Function prototype for tcp error callback functions. Called when the pcb
103 * receives a RST or is unexpectedly closed for any other reason.
105 * @note The corresponding pcb is already freed when this callback is called!
107 * @param arg Additional argument to pass to the callback function (@see tcp_arg())
108 * @param err Error code to indicate why the pcb has been closed
109 * ERR_ABRT: aborted through tcp_abort or by a TCP timer
110 * ERR_RST: the connection was reset by the remote host
112 typedef void (*tcp_err_fn)(void *arg, err_t err);
114 /** Function prototype for tcp connected callback functions. Called when a pcb
115 * is connected to the remote side after initiating a connection attempt by
116 * calling tcp_connect().
118 * @param arg Additional argument to pass to the callback function (@see tcp_arg())
119 * @param tpcb The connection pcb which is connected
120 * @param err An unused error code, always ERR_OK currently ;-) TODO!
121 * Only return ERR_ABRT if you have called tcp_abort from within the
124 * @note When a connection attempt fails, the error callback is currently called!
126 typedef err_t (*tcp_connected_fn)(void *arg, struct tcp_pcb *tpcb, err_t err);
142 #if LWIP_CALLBACK_API
143 /* Function to call when a listener has been connected.
144 * @param arg user-supplied argument (tcp_pcb.callback_arg)
145 * @param pcb a new tcp_pcb that now is connected
146 * @param err an error argument (TODO: that is current always ERR_OK?)
147 * @return ERR_OK: accept the new connection,
148 * any other err_t abortsthe new connection
150 #define DEF_ACCEPT_CALLBACK tcp_accept_fn accept;
151 #else /* LWIP_CALLBACK_API */
152 #define DEF_ACCEPT_CALLBACK
153 #endif /* LWIP_CALLBACK_API */
156 * members common to struct tcp_pcb and struct tcp_listen_pcb
158 #define TCP_PCB_COMMON(type) \
159 type *next; /* for the linked list */ \
160 void *callback_arg; \
161 /* the accept callback for listen- and normal pcbs, if LWIP_CALLBACK_API */ \
162 DEF_ACCEPT_CALLBACK \
163 enum tcp_state state; /* TCP state */ \
165 /* ports are in host byte order */ \
169 /* the TCP protocol control block */
171 /** common PCB members */
173 /** protocol specific PCB members */
174 TCP_PCB_COMMON(struct tcp_pcb);
176 /* ports are in host byte order */
180 #define TF_ACK_DELAY ((u8_t)0x01U) /* Delayed ACK. */
181 #define TF_ACK_NOW ((u8_t)0x02U) /* Immediate ACK. */
182 #define TF_INFR ((u8_t)0x04U) /* In fast recovery. */
183 #define TF_TIMESTAMP ((u8_t)0x08U) /* Timestamp option enabled */
184 #define TF_RXCLOSED ((u8_t)0x10U) /* rx closed by tcp_shutdown */
185 #define TF_FIN ((u8_t)0x20U) /* Connection was closed locally (FIN segment enqueued). */
186 #define TF_NODELAY ((u8_t)0x40U) /* Disable Nagle algorithm */
187 #define TF_NAGLEMEMERR ((u8_t)0x80U) /* nagle enabled, memerr, try to output to prevent delayed ACK to happen */
189 /* the rest of the fields are in host byte order
190 as we have to do some math with them */
193 u8_t polltmr, pollinterval;
197 /* receiver variables */
198 u32_t rcv_nxt; /* next seqno expected */
199 u16_t rcv_wnd; /* receiver window available */
200 u16_t rcv_ann_wnd; /* receiver window to announce */
201 u32_t rcv_ann_right_edge; /* announced right edge of window */
203 /* Retransmission timer. */
206 u16_t mss; /* maximum segment size */
208 /* RTT (round trip time) estimation variables */
209 u32_t rttest; /* RTT estimate in 500ms ticks */
210 u32_t rtseq; /* sequence number being timed */
211 s16_t sa, sv; /* @todo document this */
213 s16_t rto; /* retransmission time-out */
214 u8_t nrtx; /* number of retransmissions */
216 /* fast retransmit/recovery */
218 u32_t lastack; /* Highest acknowledged seqno. */
220 /* congestion avoidance/control variables */
224 /* sender variables */
225 u32_t snd_nxt; /* next new seqno to be sent */
226 u32_t snd_wl1, snd_wl2; /* Sequence and acknowledgement numbers of last
228 u32_t snd_lbb; /* Sequence number of next byte to be buffered. */
229 u16_t snd_wnd; /* sender window */
233 u16_t snd_buf; /* Available buffer space for sending (in bytes). */
234 #define TCP_SNDQUEUELEN_OVERFLOW (0xffffU-3)
235 u16_t snd_queuelen; /* Available buffer space for sending (in tcp_segs). */
238 /* Extra bytes available at the end of the last pbuf in unsent. */
239 u16_t unsent_oversize;
240 #endif /* TCP_OVERSIZE */
242 /* These are ordered by sequence number: */
243 struct tcp_seg *unsent; /* Unsent (queued) segments. */
244 struct tcp_seg *unacked; /* Sent but unacknowledged segments. */
246 struct tcp_seg *ooseq; /* Received out of sequence segments. */
247 #endif /* TCP_QUEUE_OOSEQ */
249 struct pbuf *refused_data; /* Data previously received but not yet taken by upper layer */
251 #if LWIP_CALLBACK_API
252 /* Function to be called when more send buffer space is available. */
254 /* Function to be called when (in-sequence) data has arrived. */
256 /* Function to be called when a connection has been set up. */
257 tcp_connected_fn connected;
258 /* Function which is called periodically. */
260 /* Function to be called whenever a fatal error occurs. */
262 #endif /* LWIP_CALLBACK_API */
264 #if LWIP_TCP_TIMESTAMPS
265 u32_t ts_lastacksent;
267 #endif /* LWIP_TCP_TIMESTAMPS */
269 /* idle time before KEEPALIVE is sent */
271 #if LWIP_TCP_KEEPALIVE
274 #endif /* LWIP_TCP_KEEPALIVE */
276 /* Persist timer counter */
278 /* Persist timer back-off */
279 u8_t persist_backoff;
281 /* KEEPALIVE counter */
285 struct tcp_pcb_listen {
286 /* Common members of all PCB types */
288 /* Protocol specific PCB members */
289 TCP_PCB_COMMON(struct tcp_pcb_listen);
291 #if TCP_LISTEN_BACKLOG
293 u8_t accepts_pending;
294 #endif /* TCP_LISTEN_BACKLOG */
296 u8_t accept_any_ip_version;
297 #endif /* LWIP_IPV6 */
306 LWIP_EVENT_CONNECTED,
311 err_t lwip_tcp_event(void *arg, struct tcp_pcb *pcb,
317 #endif /* LWIP_EVENT_API */
319 /* Application program's interface: */
320 struct tcp_pcb * tcp_new (void);
322 void tcp_arg (struct tcp_pcb *pcb, void *arg);
323 void tcp_accept (struct tcp_pcb *pcb, tcp_accept_fn accept);
324 void tcp_recv (struct tcp_pcb *pcb, tcp_recv_fn recv);
325 void tcp_sent (struct tcp_pcb *pcb, tcp_sent_fn sent);
326 void tcp_poll (struct tcp_pcb *pcb, tcp_poll_fn poll, u8_t interval);
327 void tcp_err (struct tcp_pcb *pcb, tcp_err_fn err);
329 #define tcp_mss(pcb) (((pcb)->flags & TF_TIMESTAMP) ? ((pcb)->mss - 12) : (pcb)->mss)
330 #define tcp_sndbuf(pcb) ((pcb)->snd_buf)
331 #define tcp_sndqueuelen(pcb) ((pcb)->snd_queuelen)
332 #define tcp_nagle_disable(pcb) ((pcb)->flags |= TF_NODELAY)
333 #define tcp_nagle_enable(pcb) ((pcb)->flags &= ~TF_NODELAY)
334 #define tcp_nagle_disabled(pcb) (((pcb)->flags & TF_NODELAY) != 0)
336 #if TCP_LISTEN_BACKLOG
337 #define tcp_accepted(pcb) do { \
338 LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", pcb->state == LISTEN); \
339 (((struct tcp_pcb_listen *)(pcb))->accepts_pending--); } while(0)
340 #else /* TCP_LISTEN_BACKLOG */
341 #define tcp_accepted(pcb) LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", \
342 (pcb)->state == LISTEN)
343 #endif /* TCP_LISTEN_BACKLOG */
345 void tcp_recved (struct tcp_pcb *pcb, u16_t len);
346 err_t tcp_bind (struct tcp_pcb *pcb, ip_addr_t *ipaddr,
348 err_t tcp_connect (struct tcp_pcb *pcb, ip_addr_t *ipaddr,
349 u16_t port, tcp_connected_fn connected);
351 struct tcp_pcb * tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog);
352 #define tcp_listen(pcb) tcp_listen_with_backlog(pcb, TCP_DEFAULT_LISTEN_BACKLOG)
354 void tcp_abort (struct tcp_pcb *pcb);
355 err_t tcp_close (struct tcp_pcb *pcb);
356 err_t tcp_shutdown(struct tcp_pcb *pcb, int shut_rx, int shut_tx);
358 /* Flags for "apiflags" parameter in tcp_write */
359 #define TCP_WRITE_FLAG_COPY 0x01
360 #define TCP_WRITE_FLAG_MORE 0x02
362 err_t tcp_write (struct tcp_pcb *pcb, const void *dataptr, u16_t len,
365 void tcp_setprio (struct tcp_pcb *pcb, u8_t prio);
367 #define TCP_PRIO_MIN 1
368 #define TCP_PRIO_NORMAL 64
369 #define TCP_PRIO_MAX 127
371 err_t tcp_output (struct tcp_pcb *pcb);
374 const char* tcp_debug_state_str(enum tcp_state s);
377 struct tcp_pcb * tcp_new_ip6 (void);
378 #define tcp_bind_ip6(pcb, ip6addr, port) \
379 tcp_bind(pcb, ip6_2_ip(ip6addr), port)
380 #define tcp_connect_ip6(pcb, ip6addr, port, connected) \
381 tcp_connect(pcb, ip6_2_ip(ip6addr), port, connected)
382 struct tcp_pcb * tcp_listen_dual_with_backlog(struct tcp_pcb *pcb, u8_t backlog);
383 #define tcp_listen_dual(pcb) tcp_listen_dual_with_backlog(pcb, TCP_DEFAULT_LISTEN_BACKLOG)
384 #else /* LWIP_IPV6 */
385 #define tcp_listen_dual_with_backlog(pcb, backlog) tcp_listen_with_backlog(pcb, backlog)
386 #define tcp_listen_dual(pcb) tcp_listen(pcb)
387 #endif /* LWIP_IPV6 */
394 #endif /* LWIP_TCP */
396 #endif /* __LWIP_TCP_H__ */