Joshua Wise's Git repositories - netwatch.git/blob

1 /*

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 struct tcp_hdr {

214 PACK_STRUCT_FIELD(u16_t src);

215 PACK_STRUCT_FIELD(u16_t dest);

216 PACK_STRUCT_FIELD(u32_t seqno);

217 PACK_STRUCT_FIELD(u32_t ackno);

218 PACK_STRUCT_FIELD(u16_t _hdrlen_rsvd_flags);

219 PACK_STRUCT_FIELD(u16_t wnd);

220 PACK_STRUCT_FIELD(u16_t chksum);

221 PACK_STRUCT_FIELD(u16_t urgp);

222 } PACK_STRUCT_STRUCT;

223 PACK_STRUCT_END

224 #ifdef PACK_STRUCT_USE_INCLUDES

225 # include "arch/epstruct.h"

226 #endif

227

228 #define TCPH_OFFSET(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) >> 8)

229 #define TCPH_HDRLEN(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) >> 12)

230 #define TCPH_FLAGS(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) & TCP_FLAGS)

231

232 #define TCPH_OFFSET_SET(phdr, offset) (phdr)->_hdrlen_rsvd_flags = htons(((offset) << 8) | TCPH_FLAGS(phdr))

233 #define TCPH_HDRLEN_SET(phdr, len) (phdr)->_hdrlen_rsvd_flags = htons(((len) << 12) | TCPH_FLAGS(phdr))

234 #define TCPH_FLAGS_SET(phdr, flags) (phdr)->_hdrlen_rsvd_flags = htons((ntohs((phdr)->_hdrlen_rsvd_flags) & ~TCP_FLAGS) | (flags))

235 #define TCPH_SET_FLAG(phdr, flags ) (phdr)->_hdrlen_rsvd_flags = htons(ntohs((phdr)->_hdrlen_rsvd_flags) | (flags))

236 #define TCPH_UNSET_FLAG(phdr, flags) (phdr)->_hdrlen_rsvd_flags = htons(ntohs((phdr)->_hdrlen_rsvd_flags) | (TCPH_FLAGS(phdr) & ~(flags)) )

237

238 #define TCP_TCPLEN(seg) ((seg)->len + ((TCPH_FLAGS((seg)->tcphdr) & TCP_FIN || \

239 TCPH_FLAGS((seg)->tcphdr) & TCP_SYN)? 1: 0))

240

241 enum tcp_state {

242 CLOSED = 0,

243 LISTEN = 1,

244 SYN_SENT = 2,

245 SYN_RCVD = 3,

246 ESTABLISHED = 4,

247 FIN_WAIT_1 = 5,

248 FIN_WAIT_2 = 6,

249 CLOSE_WAIT = 7,

250 CLOSING = 8,

251 LAST_ACK = 9,

252 TIME_WAIT = 10

253 };

254

255 /** Flags used on input processing, not on pcb->flags

256 */

257 #define TF_RESET (u8_t)0x08U /* Connection was reset. */

258 #define TF_CLOSED (u8_t)0x10U /* Connection was sucessfully closed. */

259 #define TF_GOT_FIN (u8_t)0x20U /* Connection was closed by the remote end. */

260

261 /**

262 * members common to struct tcp_pcb and struct tcp_listen_pcb

263 */

264 #define TCP_PCB_COMMON(type) \

265 type *next; /* for the linked list */ \

266 enum tcp_state state; /* TCP state */ \

267 u8_t prio; \

268 void *callback_arg; \

269 /* ports are in host byte order */ \

270 u16_t local_port

271

272 /* the TCP protocol control block */

273 struct tcp_pcb {

274 /** common PCB members */

275 IP_PCB;

276 /** protocol specific PCB members */

277 TCP_PCB_COMMON(struct tcp_pcb);

278

279 /* ports are in host byte order */

280 u16_t remote_port;

281

282 u8_t flags;

283 #define TF_ACK_DELAY (u8_t)0x01U /* Delayed ACK. */

284 #define TF_ACK_NOW (u8_t)0x02U /* Immediate ACK. */

285 #define TF_INFR (u8_t)0x04U /* In fast recovery. */

286 #define TF_FIN (u8_t)0x20U /* Connection was closed locally (FIN segment enqueued). */

287 #define TF_NODELAY (u8_t)0x40U /* Disable Nagle algorithm */

288 #define TF_NAGLEMEMERR (u8_t)0x80U /* nagle enabled, memerr, try to output to prevent delayed ACK to happen */

289

290 /* the rest of the fields are in host byte order

291 as we have to do some math with them */

292 /* receiver variables */

293 u32_t rcv_nxt; /* next seqno expected */

294 u16_t rcv_wnd; /* receiver window */

295 u16_t rcv_ann_wnd; /* announced receive window */

296

297 /* Timers */

298 u32_t tmr;

299 u8_t polltmr, pollinterval;

300

301 /* Retransmission timer. */

302 s16_t rtime;

303

304 u16_t mss; /* maximum segment size */

305

306 /* RTT (round trip time) estimation variables */

307 u32_t rttest; /* RTT estimate in 500ms ticks */

308 u32_t rtseq; /* sequence number being timed */

309 s16_t sa, sv; /* @todo document this */

310

311 s16_t rto; /* retransmission time-out */

312 u8_t nrtx; /* number of retransmissions */

313

314 /* fast retransmit/recovery */

315 u32_t lastack; /* Highest acknowledged seqno. */

316 u8_t dupacks;

317

318 /* congestion avoidance/control variables */

319 u16_t cwnd;

320 u16_t ssthresh;

321

322 /* sender variables */

323 u32_t snd_nxt, /* next seqno to be sent */

324 snd_max; /* Highest seqno sent. */

325 u16_t snd_wnd; /* sender window */

326 u32_t snd_wl1, snd_wl2, /* Sequence and acknowledgement numbers of last

327 window update. */

328 snd_lbb; /* Sequence number of next byte to be buffered. */

329

330 u16_t acked;

331

332 u16_t snd_buf; /* Available buffer space for sending (in bytes). */

333 #define TCP_SNDQUEUELEN_OVERFLOW (0xffff-3)

334 u16_t snd_queuelen; /* Available buffer space for sending (in tcp_segs). */

335

336

337 /* These are ordered by sequence number: */

338 struct tcp_seg *unsent; /* Unsent (queued) segments. */

339 struct tcp_seg *unacked; /* Sent but unacknowledged segments. */

340 #if TCP_QUEUE_OOSEQ

341 struct tcp_seg *ooseq; /* Received out of sequence segments. */

342 #endif /* TCP_QUEUE_OOSEQ */

343

344 struct pbuf *refused_data; /* Data previously received but not yet taken by upper layer */

345

346 #if LWIP_CALLBACK_API

347 /* Function to be called when more send buffer space is available.

348 * @param arg user-supplied argument (tcp_pcb.callback_arg)

349 * @param pcb the tcp_pcb which has send buffer space available

350 * @param space the amount of bytes available

351 * @return ERR_OK: try to send some data by calling tcp_output

352 */

353 err_t (* sent)(void *arg, struct tcp_pcb *pcb, u16_t space);

354

355 /* Function to be called when (in-sequence) data has arrived.

356 * @param arg user-supplied argument (tcp_pcb.callback_arg)

357 * @param pcb the tcp_pcb for which data has arrived

358 * @param p the packet buffer which arrived

359 * @param err an error argument (TODO: that is current always ERR_OK?)

360 * @return ERR_OK: try to send some data by calling tcp_output

361 */

362 err_t (* recv)(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err);

363

364 /* Function to be called when a connection has been set up.

365 * @param arg user-supplied argument (tcp_pcb.callback_arg)

366 * @param pcb the tcp_pcb that now is connected

367 * @param err an error argument (TODO: that is current always ERR_OK?)

368 * @return value is currently ignored

369 */

370 err_t (* connected)(void *arg, struct tcp_pcb *pcb, err_t err);

371

372 /* Function to call when a listener has been connected.

373 * @param arg user-supplied argument (tcp_pcb.callback_arg)

374 * @param pcb a new tcp_pcb that now is connected

375 * @param err an error argument (TODO: that is current always ERR_OK?)

376 * @return ERR_OK: accept the new connection,

377 * any other err_t abortsthe new connection

378 */

379 err_t (* accept)(void *arg, struct tcp_pcb *newpcb, err_t err);

380

381 /* Function which is called periodically.

382 * The period can be adjusted in multiples of the TCP slow timer interval

383 * by changing tcp_pcb.polltmr.

384 * @param arg user-supplied argument (tcp_pcb.callback_arg)

385 * @param pcb the tcp_pcb to poll for

386 * @return ERR_OK: try to send some data by calling tcp_output

387 */

388 err_t (* poll)(void *arg, struct tcp_pcb *pcb);

389

390 /* Function to be called whenever a fatal error occurs.

391 * There is no pcb parameter since most of the times, the pcb is

392 * already deallocated (or there is no pcb) when this function is called.

393 * @param arg user-supplied argument (tcp_pcb.callback_arg)

394 * @param err an indication why the error callback is called:

395 * ERR_ABRT: aborted through tcp_abort or by a TCP timer

396 * ERR_RST: the connection was reset by the remote host

397 */

398 void (* errf)(void *arg, err_t err);

399 #endif /* LWIP_CALLBACK_API */

400

401 /* idle time before KEEPALIVE is sent */

402 u32_t keep_idle;

403 #if LWIP_TCP_KEEPALIVE

404 u32_t keep_intvl;

405 u32_t keep_cnt;

406 #endif /* LWIP_TCP_KEEPALIVE */

407

408 /* Persist timer counter */

409 u32_t persist_cnt;

410 /* Persist timer back-off */

411 u8_t persist_backoff;

412

413 /* KEEPALIVE counter */

414 u8_t keep_cnt_sent;

415 };

416

417 struct tcp_pcb_listen {

418 /* Common members of all PCB types */

419 IP_PCB;

420 /* Protocol specific PCB members */

421 TCP_PCB_COMMON(struct tcp_pcb_listen);

422

423 #if LWIP_CALLBACK_API

424 /* Function to call when a listener has been connected.

425 * @param arg user-supplied argument (tcp_pcb.callback_arg)

426 * @param pcb a new tcp_pcb that now is connected

427 * @param err an error argument (TODO: that is current always ERR_OK?)

428 * @return ERR_OK: accept the new connection,

429 * any other err_t abortsthe new connection

430 */

431 err_t (* accept)(void *arg, struct tcp_pcb *newpcb, err_t err);

432 #endif /* LWIP_CALLBACK_API */

433 #if TCP_LISTEN_BACKLOG

434 u8_t backlog;

435 u8_t accepts_pending;

436 #endif /* TCP_LISTEN_BACKLOG */

437 };

438

439 #if LWIP_EVENT_API

440

441 enum lwip_event {

442 LWIP_EVENT_ACCEPT,

443 LWIP_EVENT_SENT,

444 LWIP_EVENT_RECV,

445 LWIP_EVENT_CONNECTED,

446 LWIP_EVENT_POLL,

447 LWIP_EVENT_ERR

448 };

449

450 err_t lwip_tcp_event(void *arg, struct tcp_pcb *pcb,

451 enum lwip_event,

452 struct pbuf *p,

453 u16_t size,

454 err_t err);

455

456 #define TCP_EVENT_ACCEPT(pcb,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\

457 LWIP_EVENT_ACCEPT, NULL, 0, err)

458 #define TCP_EVENT_SENT(pcb,space,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\

459 LWIP_EVENT_SENT, NULL, space, ERR_OK)

460 #define TCP_EVENT_RECV(pcb,p,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\

461 LWIP_EVENT_RECV, (p), 0, (err))

462 #define TCP_EVENT_CONNECTED(pcb,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\

463 LWIP_EVENT_CONNECTED, NULL, 0, (err))

464 #define TCP_EVENT_POLL(pcb,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\

465 LWIP_EVENT_POLL, NULL, 0, ERR_OK)

466 #define TCP_EVENT_ERR(errf,arg,err) lwip_tcp_event((arg), NULL, \

467 LWIP_EVENT_ERR, NULL, 0, (err))

468 #else /* LWIP_EVENT_API */

469 #define TCP_EVENT_ACCEPT(pcb,err,ret) \

470 if((pcb)->accept != NULL) \

471 (ret = (pcb)->accept((pcb)->callback_arg,(pcb),(err)))

472 #define TCP_EVENT_SENT(pcb,space,ret) \

473 if((pcb)->sent != NULL) \

474 (ret = (pcb)->sent((pcb)->callback_arg,(pcb),(space)))

475 #define TCP_EVENT_RECV(pcb,p,err,ret) \

476 if((pcb)->recv != NULL) \

477 { ret = (pcb)->recv((pcb)->callback_arg,(pcb),(p),(err)); } else { \

478 ret = ERR_OK; \

479 if (p) pbuf_free(p); }

480 #define TCP_EVENT_CONNECTED(pcb,err,ret) \

481 if((pcb)->connected != NULL) \

482 (ret = (pcb)->connected((pcb)->callback_arg,(pcb),(err)))

483 #define TCP_EVENT_POLL(pcb,ret) \

484 if((pcb)->poll != NULL) \

485 (ret = (pcb)->poll((pcb)->callback_arg,(pcb)))

486 #define TCP_EVENT_ERR(errf,arg,err) \

487 if((errf) != NULL) \

488 (errf)((arg),(err))

489 #endif /* LWIP_EVENT_API */

490

491 /* This structure represents a TCP segment on the unsent and unacked queues */

492 struct tcp_seg {

493 struct tcp_seg *next; /* used when putting segements on a queue */

494 struct pbuf *p; /* buffer containing data + TCP header */

495 void *dataptr; /* pointer to the TCP data in the pbuf */

496 u16_t len; /* the TCP length of this segment */

497 struct tcp_hdr *tcphdr; /* the TCP header */

498 };

499

500 /* Internal functions and global variables: */

501 struct tcp_pcb *tcp_pcb_copy(struct tcp_pcb *pcb);

502 void tcp_pcb_purge(struct tcp_pcb *pcb);

503 void tcp_pcb_remove(struct tcp_pcb **pcblist, struct tcp_pcb *pcb);

504

505 u8_t tcp_segs_free(struct tcp_seg *seg);

506 u8_t tcp_seg_free(struct tcp_seg *seg);

507 struct tcp_seg *tcp_seg_copy(struct tcp_seg *seg);

508

509 #define tcp_ack(pcb) if((pcb)->flags & TF_ACK_DELAY) { \

510 (pcb)->flags &= ~TF_ACK_DELAY; \

511 (pcb)->flags |= TF_ACK_NOW; \

512 tcp_output(pcb); \

513 } else { \

514 (pcb)->flags |= TF_ACK_DELAY; \

515 }

516

517 #define tcp_ack_now(pcb) (pcb)->flags |= TF_ACK_NOW; \

518 tcp_output(pcb)

519

520 err_t tcp_send_ctrl(struct tcp_pcb *pcb, u8_t flags);

521 err_t tcp_enqueue(struct tcp_pcb *pcb, void *dataptr, u16_t len,

522 u8_t flags, u8_t apiflags,

523 u8_t *optdata, u8_t optlen);

524

525 void tcp_rexmit_seg(struct tcp_pcb *pcb, struct tcp_seg *seg);

526

527 void tcp_rst(u32_t seqno, u32_t ackno,

528 struct ip_addr *local_ip, struct ip_addr *remote_ip,

529 u16_t local_port, u16_t remote_port);

530

531 u32_t tcp_next_iss(void);

532

533 void tcp_keepalive(struct tcp_pcb *pcb);

534 void tcp_zero_window_probe(struct tcp_pcb *pcb);

535

536 #if TCP_CALCULATE_EFF_SEND_MSS

537 u16_t tcp_eff_send_mss(u16_t sendmss, struct ip_addr *addr);

538 #endif /* TCP_CALCULATE_EFF_SEND_MSS */

539

540 extern struct tcp_pcb *tcp_input_pcb;

541 extern u32_t tcp_ticks;

542

543 #if TCP_DEBUG || TCP_INPUT_DEBUG || TCP_OUTPUT_DEBUG

544 void tcp_debug_print(struct tcp_hdr *tcphdr);

545 void tcp_debug_print_flags(u8_t flags);

546 void tcp_debug_print_state(enum tcp_state s);

547 void tcp_debug_print_pcbs(void);

548 s16_t tcp_pcbs_sane(void);

549 #else

550 # define tcp_debug_print(tcphdr)

551 # define tcp_debug_print_flags(flags)

552 # define tcp_debug_print_state(s)

553 # define tcp_debug_print_pcbs()

554 # define tcp_pcbs_sane() 1

555 #endif /* TCP_DEBUG */

556

557 #if NO_SYS

558 #define tcp_timer_needed()

559 #else

560 void tcp_timer_needed(void);

561 #endif

562

563 /* The TCP PCB lists. */

564 union tcp_listen_pcbs_t { /* List of all TCP PCBs in LISTEN state. */

565 struct tcp_pcb_listen *listen_pcbs;

566 struct tcp_pcb *pcbs;

567 };

568 extern union tcp_listen_pcbs_t tcp_listen_pcbs;

569 extern struct tcp_pcb *tcp_active_pcbs; /* List of all TCP PCBs that are in a

570 state in which they accept or send

571 data. */

572 extern struct tcp_pcb *tcp_tw_pcbs; /* List of all TCP PCBs in TIME-WAIT. */

573

574 extern struct tcp_pcb *tcp_tmp_pcb; /* Only used for temporary storage. */

575

576 /* Axioms about the above lists:

577 1) Every TCP PCB that is not CLOSED is in one of the lists.

578 2) A PCB is only in one of the lists.

579 3) All PCBs in the tcp_listen_pcbs list is in LISTEN state.

580 4) All PCBs in the tcp_tw_pcbs list is in TIME-WAIT state.

581 */

582

583 /* Define two macros, TCP_REG and TCP_RMV that registers a TCP PCB

584 with a PCB list or removes a PCB from a list, respectively. */

585 #if 0

586 #define TCP_REG(pcbs, npcb) do {\

587 LWIP_DEBUGF(TCP_DEBUG, ("TCP_REG %p local port %d\n", npcb, npcb->local_port)); \

588 for(tcp_tmp_pcb = *pcbs; \

589 tcp_tmp_pcb != NULL; \

590 tcp_tmp_pcb = tcp_tmp_pcb->next) { \

591 LWIP_ASSERT("TCP_REG: already registered\n", tcp_tmp_pcb != npcb); \

592 } \

593 LWIP_ASSERT("TCP_REG: pcb->state != CLOSED", npcb->state != CLOSED); \

594 npcb->next = *pcbs; \

595 LWIP_ASSERT("TCP_REG: npcb->next != npcb", npcb->next != npcb); \

596 *(pcbs) = npcb; \

597 LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \

598 tcp_timer_needed(); \

599 } while(0)

600 #define TCP_RMV(pcbs, npcb) do { \

601 LWIP_ASSERT("TCP_RMV: pcbs != NULL", *pcbs != NULL); \

602 LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removing %p from %p\n", npcb, *pcbs)); \

603 if(*pcbs == npcb) { \

604 *pcbs = (*pcbs)->next; \

605 } else for(tcp_tmp_pcb = *pcbs; tcp_tmp_pcb != NULL; tcp_tmp_pcb = tcp_tmp_pcb->next) { \

606 if(tcp_tmp_pcb->next != NULL && tcp_tmp_pcb->next == npcb) { \

607 tcp_tmp_pcb->next = npcb->next; \

608 break; \

609 } \

610 } \

611 npcb->next = NULL; \

612 LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \

613 LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removed %p from %p\n", npcb, *pcbs)); \

614 } while(0)

615

616 #else /* LWIP_DEBUG */

617 #define TCP_REG(pcbs, npcb) do { \

618 npcb->next = *pcbs; \

619 *(pcbs) = npcb; \

620 tcp_timer_needed(); \

621 } while(0)

622 #define TCP_RMV(pcbs, npcb) do { \

623 if(*(pcbs) == npcb) { \

624 (*(pcbs)) = (*pcbs)->next; \

625 } else for(tcp_tmp_pcb = *pcbs; tcp_tmp_pcb != NULL; tcp_tmp_pcb = tcp_tmp_pcb->next) { \

626 if(tcp_tmp_pcb->next != NULL && tcp_tmp_pcb->next == npcb) { \

627 tcp_tmp_pcb->next = npcb->next; \

628 break; \

629 } \

630 } \

631 npcb->next = NULL; \

632 } while(0)

633 #endif /* LWIP_DEBUG */

634

635 #ifdef __cplusplus

636 }

637 #endif

638

639 #endif /* LWIP_TCP */

640

641 #endif /* __LWIP_TCP_H__ */