1 /** 2 * @file 3 * TCP internal implementations (do not use in application code) 4 */ 5 6 /* 7 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without modification, 11 * are permitted provided that the following conditions are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright notice, 14 * this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright notice, 16 * this list of conditions and the following disclaimer in the documentation 17 * and/or other materials provided with the distribution. 18 * 3. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 24 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 26 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 29 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 30 * OF SUCH DAMAGE. 31 * 32 * This file is part of the lwIP TCP/IP stack. 33 * 34 * Author: Adam Dunkels <adam@sics.se> 35 * 36 */ 37 #ifndef LWIP_HDR_TCP_PRIV_H 38 #define LWIP_HDR_TCP_PRIV_H 39 40 #include "lwip/opt.h" 41 42 #if LWIP_TCP /* don't build if not configured for use in lwipopts.h */ 43 44 #include "lwip/tcp.h" 45 #include "lwip/mem.h" 46 #include "lwip/pbuf.h" 47 #include "lwip/ip.h" 48 #include "lwip/icmp.h" 49 #include "lwip/err.h" 50 #include "lwip/ip6.h" 51 #include "lwip/ip6_addr.h" 52 #include "lwip/prot/tcp.h" 53 54 #ifdef __cplusplus 55 extern "C" { 56 #endif 57 58 /* Functions for interfacing with TCP: */ 59 60 /* Lower layer interface to TCP: */ 61 void tcp_init (void); /* Initialize this module. */ 62 void tcp_tmr (void); /* Must be called every 63 TCP_TMR_INTERVAL 64 ms. (Typically 250 ms). */ 65 /* It is also possible to call these two functions at the right 66 intervals (instead of calling tcp_tmr()). */ 67 void tcp_slowtmr (void); 68 void tcp_fasttmr (void); 69 70 /* Call this from a netif driver (watch out for threading issues!) that has 71 returned a memory error on transmit and now has free buffers to send more. 72 This iterates all active pcbs that had an error and tries to call 73 tcp_output, so use this with care as it might slow down the system. */ 74 void tcp_txnow (void); 75 76 /* Only used by IP to pass a TCP segment to TCP: */ 77 void tcp_input (struct pbuf *p, struct netif *inp); 78 /* Used within the TCP code only: */ 79 struct tcp_pcb * tcp_alloc (u8_t prio); 80 void tcp_abandon (struct tcp_pcb *pcb, int reset); 81 err_t tcp_send_empty_ack(struct tcp_pcb *pcb); 82 void tcp_rexmit (struct tcp_pcb *pcb); 83 void tcp_rexmit_rto (struct tcp_pcb *pcb); 84 void tcp_rexmit_fast (struct tcp_pcb *pcb); 85 u32_t tcp_update_rcv_ann_wnd(struct tcp_pcb *pcb); 86 err_t tcp_process_refused_data(struct tcp_pcb *pcb); 87 88 /** 89 * This is the Nagle algorithm: try to combine user data to send as few TCP 90 * segments as possible. Only send if 91 * - no previously transmitted data on the connection remains unacknowledged or 92 * - the TF_NODELAY flag is set (nagle algorithm turned off for this pcb) or 93 * - the only unsent segment is at least pcb->mss bytes long (or there is more 94 * than one unsent segment - with lwIP, this can happen although unsent->len < mss) 95 * - or if we are in fast-retransmit (TF_INFR) 96 */ 97 #define tcp_do_output_nagle(tpcb) ((((tpcb)->unacked == NULL) || \ 98 ((tpcb)->flags & (TF_NODELAY | TF_INFR)) || \ 99 (((tpcb)->unsent != NULL) && (((tpcb)->unsent->next != NULL) || \ 100 ((tpcb)->unsent->len >= (tpcb)->mss))) || \ 101 ((tcp_sndbuf(tpcb) == 0) || (tcp_sndqueuelen(tpcb) >= TCP_SND_QUEUELEN)) \ 102 ) ? 1 : 0) 103 #define tcp_output_nagle(tpcb) (tcp_do_output_nagle(tpcb) ? tcp_output(tpcb) : ERR_OK) 104 105 106 #define TCP_SEQ_LT(a,b) ((s32_t)((u32_t)(a) - (u32_t)(b)) < 0) 107 #define TCP_SEQ_LEQ(a,b) ((s32_t)((u32_t)(a) - (u32_t)(b)) <= 0) 108 #define TCP_SEQ_GT(a,b) ((s32_t)((u32_t)(a) - (u32_t)(b)) > 0) 109 #define TCP_SEQ_GEQ(a,b) ((s32_t)((u32_t)(a) - (u32_t)(b)) >= 0) 110 /* is b<=a<=c? */ 111 #if 0 /* see bug #10548 */ 112 #define TCP_SEQ_BETWEEN(a,b,c) ((c)-(b) >= (a)-(b)) 113 #endif 114 #define TCP_SEQ_BETWEEN(a,b,c) (TCP_SEQ_GEQ(a,b) && TCP_SEQ_LEQ(a,c)) 115 116 #ifndef TCP_TMR_INTERVAL 117 #define TCP_TMR_INTERVAL 250 /* The TCP timer interval in milliseconds. */ 118 #endif /* TCP_TMR_INTERVAL */ 119 120 #ifndef TCP_FAST_INTERVAL 121 #define TCP_FAST_INTERVAL TCP_TMR_INTERVAL /* the fine grained timeout in milliseconds */ 122 #endif /* TCP_FAST_INTERVAL */ 123 124 #ifndef TCP_SLOW_INTERVAL 125 #define TCP_SLOW_INTERVAL (2*TCP_TMR_INTERVAL) /* the coarse grained timeout in milliseconds */ 126 #endif /* TCP_SLOW_INTERVAL */ 127 128 #define TCP_FIN_WAIT_TIMEOUT 20000 /* milliseconds */ 129 #define TCP_SYN_RCVD_TIMEOUT 20000 /* milliseconds */ 130 131 #define TCP_OOSEQ_TIMEOUT 6U /* x RTO */ 132 133 #ifndef TCP_MSL 134 #define TCP_MSL 60000UL /* The maximum segment lifetime in milliseconds */ 135 #endif 136 137 /* Keepalive values, compliant with RFC 1122. Don't change this unless you know what you're doing */ 138 #ifndef TCP_KEEPIDLE_DEFAULT 139 #define TCP_KEEPIDLE_DEFAULT 7200000UL /* Default KEEPALIVE timer in milliseconds */ 140 #endif 141 142 #ifndef TCP_KEEPINTVL_DEFAULT 143 #define TCP_KEEPINTVL_DEFAULT 75000UL /* Default Time between KEEPALIVE probes in milliseconds */ 144 #endif 145 146 #ifndef TCP_KEEPCNT_DEFAULT 147 #define TCP_KEEPCNT_DEFAULT 9U /* Default Counter for KEEPALIVE probes */ 148 #endif 149 150 #define TCP_MAXIDLE TCP_KEEPCNT_DEFAULT * TCP_KEEPINTVL_DEFAULT /* Maximum KEEPALIVE probe time */ 151 152 #define TCP_TCPLEN(seg) ((seg)->len + (((TCPH_FLAGS((seg)->tcphdr) & (TCP_FIN | TCP_SYN)) != 0) ? 1U : 0U)) 153 154 /** Flags used on input processing, not on pcb->flags 155 */ 156 #define TF_RESET (u8_t)0x08U /* Connection was reset. */ 157 #define TF_CLOSED (u8_t)0x10U /* Connection was successfully closed. */ 158 #define TF_GOT_FIN (u8_t)0x20U /* Connection was closed by the remote end. */ 159 160 161 #if LWIP_EVENT_API 162 163 #define TCP_EVENT_ACCEPT(lpcb,pcb,arg,err,ret) ret = lwip_tcp_event(arg, (pcb),\ 164 LWIP_EVENT_ACCEPT, NULL, 0, err) 165 #define TCP_EVENT_SENT(pcb,space,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\ 166 LWIP_EVENT_SENT, NULL, space, ERR_OK) 167 #define TCP_EVENT_RECV(pcb,p,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\ 168 LWIP_EVENT_RECV, (p), 0, (err)) 169 #define TCP_EVENT_CLOSED(pcb,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\ 170 LWIP_EVENT_RECV, NULL, 0, ERR_OK) 171 #define TCP_EVENT_CONNECTED(pcb,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\ 172 LWIP_EVENT_CONNECTED, NULL, 0, (err)) 173 #define TCP_EVENT_POLL(pcb,ret) do { if ((pcb)->state != SYN_RCVD) { \ 174 ret = lwip_tcp_event((pcb)->callback_arg, (pcb), LWIP_EVENT_POLL, NULL, 0, ERR_OK); \ 175 } else { \ 176 ret = ERR_ARG; } } while(0) 177 #define TCP_EVENT_ERR(last_state,errf,arg,err) do { if (last_state != SYN_RCVD) { \ 178 lwip_tcp_event((arg), NULL, LWIP_EVENT_ERR, NULL, 0, (err)); } } while(0) 179 180 #else /* LWIP_EVENT_API */ 181 182 #define TCP_EVENT_ACCEPT(lpcb,pcb,arg,err,ret) \ 183 do { \ 184 if((lpcb)->accept != NULL) \ 185 (ret) = (lpcb)->accept((arg),(pcb),(err)); \ 186 else (ret) = ERR_ARG; \ 187 } while (0) 188 189 #define TCP_EVENT_SENT(pcb,space,ret) \ 190 do { \ 191 if((pcb)->sent != NULL) \ 192 (ret) = (pcb)->sent((pcb)->callback_arg,(pcb),(space)); \ 193 else (ret) = ERR_OK; \ 194 } while (0) 195 196 #define TCP_EVENT_RECV(pcb,p,err,ret) \ 197 do { \ 198 if((pcb)->recv != NULL) { \ 199 (ret) = (pcb)->recv((pcb)->callback_arg,(pcb),(p),(err));\ 200 } else { \ 201 (ret) = tcp_recv_null(NULL, (pcb), (p), (err)); \ 202 } \ 203 } while (0) 204 205 #define TCP_EVENT_CLOSED(pcb,ret) \ 206 do { \ 207 if(((pcb)->recv != NULL)) { \ 208 (ret) = (pcb)->recv((pcb)->callback_arg,(pcb),NULL,ERR_OK);\ 209 } else { \ 210 (ret) = ERR_OK; \ 211 } \ 212 } while (0) 213 214 #define TCP_EVENT_CONNECTED(pcb,err,ret) \ 215 do { \ 216 if((pcb)->connected != NULL) \ 217 (ret) = (pcb)->connected((pcb)->callback_arg,(pcb),(err)); \ 218 else (ret) = ERR_OK; \ 219 } while (0) 220 221 #define TCP_EVENT_POLL(pcb,ret) \ 222 do { \ 223 if((pcb)->poll != NULL) \ 224 (ret) = (pcb)->poll((pcb)->callback_arg,(pcb)); \ 225 else (ret) = ERR_OK; \ 226 } while (0) 227 228 #define TCP_EVENT_ERR(last_state,errf,arg,err) \ 229 do { \ 230 LWIP_UNUSED_ARG(last_state); \ 231 if((errf) != NULL) \ 232 (errf)((arg),(err)); \ 233 } while (0) 234 235 #endif /* LWIP_EVENT_API */ 236 237 /** Enabled extra-check for TCP_OVERSIZE if LWIP_DEBUG is enabled */ 238 #if TCP_OVERSIZE && defined(LWIP_DEBUG) 239 #define TCP_OVERSIZE_DBGCHECK 1 240 #else 241 #define TCP_OVERSIZE_DBGCHECK 0 242 #endif 243 244 /** Don't generate checksum on copy if CHECKSUM_GEN_TCP is disabled */ 245 #define TCP_CHECKSUM_ON_COPY (LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_TCP) 246 247 /* This structure represents a TCP segment on the unsent, unacked and ooseq queues */ 248 struct tcp_seg { 249 struct tcp_seg *next; /* used when putting segments on a queue */ 250 struct pbuf *p; /* buffer containing data + TCP header */ 251 u16_t len; /* the TCP length of this segment */ 252 #if TCP_OVERSIZE_DBGCHECK 253 u16_t oversize_left; /* Extra bytes available at the end of the last 254 pbuf in unsent (used for asserting vs. 255 tcp_pcb.unsent_oversize only) */ 256 #endif /* TCP_OVERSIZE_DBGCHECK */ 257 #if TCP_CHECKSUM_ON_COPY 258 u16_t chksum; 259 u8_t chksum_swapped; 260 #endif /* TCP_CHECKSUM_ON_COPY */ 261 u8_t flags; 262 #define TF_SEG_OPTS_MSS (u8_t)0x01U /* Include MSS option. */ 263 #define TF_SEG_OPTS_TS (u8_t)0x02U /* Include timestamp option. */ 264 #define TF_SEG_DATA_CHECKSUMMED (u8_t)0x04U /* ALL data (not the header) is 265 checksummed into 'chksum' */ 266 #define TF_SEG_OPTS_WND_SCALE (u8_t)0x08U /* Include WND SCALE option */ 267 struct tcp_hdr *tcphdr; /* the TCP header */ 268 }; 269 270 #define LWIP_TCP_OPT_EOL 0 271 #define LWIP_TCP_OPT_NOP 1 272 #define LWIP_TCP_OPT_MSS 2 273 #define LWIP_TCP_OPT_WS 3 274 #define LWIP_TCP_OPT_TS 8 275 276 #define LWIP_TCP_OPT_LEN_MSS 4 277 #if LWIP_TCP_TIMESTAMPS 278 #define LWIP_TCP_OPT_LEN_TS 10 279 #define LWIP_TCP_OPT_LEN_TS_OUT 12 /* aligned for output (includes NOP padding) */ 280 #else 281 #define LWIP_TCP_OPT_LEN_TS_OUT 0 282 #endif 283 #if LWIP_WND_SCALE 284 #define LWIP_TCP_OPT_LEN_WS 3 285 #define LWIP_TCP_OPT_LEN_WS_OUT 4 /* aligned for output (includes NOP padding) */ 286 #else 287 #define LWIP_TCP_OPT_LEN_WS_OUT 0 288 #endif 289 290 #define LWIP_TCP_OPT_LENGTH(flags) \ 291 (flags & TF_SEG_OPTS_MSS ? LWIP_TCP_OPT_LEN_MSS : 0) + \ 292 (flags & TF_SEG_OPTS_TS ? LWIP_TCP_OPT_LEN_TS_OUT : 0) + \ 293 (flags & TF_SEG_OPTS_WND_SCALE ? LWIP_TCP_OPT_LEN_WS_OUT : 0) 294 295 /** This returns a TCP header option for MSS in an u32_t */ 296 #define TCP_BUILD_MSS_OPTION(mss) lwip_htonl(0x02040000 | ((mss) & 0xFFFF)) 297 298 #if LWIP_WND_SCALE 299 #define TCPWNDSIZE_F U32_F 300 #define TCPWND_MAX 0xFFFFFFFFU 301 #define TCPWND_CHECK16(x) LWIP_ASSERT("window size > 0xFFFF", (x) <= 0xFFFF) 302 #define TCPWND_MIN16(x) ((u16_t)LWIP_MIN((x), 0xFFFF)) 303 #else /* LWIP_WND_SCALE */ 304 #define TCPWNDSIZE_F U16_F 305 #define TCPWND_MAX 0xFFFFU 306 #define TCPWND_CHECK16(x) 307 #define TCPWND_MIN16(x) x 308 #endif /* LWIP_WND_SCALE */ 309 310 /* Global variables: */ 311 extern struct tcp_pcb *tcp_input_pcb; 312 extern u32_t tcp_ticks; 313 extern u8_t tcp_active_pcbs_changed; 314 315 /* The TCP PCB lists. */ 316 union tcp_listen_pcbs_t { /* List of all TCP PCBs in LISTEN state. */ 317 struct tcp_pcb_listen *listen_pcbs; 318 struct tcp_pcb *pcbs; 319 }; 320 extern struct tcp_pcb *tcp_bound_pcbs; 321 extern union tcp_listen_pcbs_t tcp_listen_pcbs; 322 extern struct tcp_pcb *tcp_active_pcbs; /* List of all TCP PCBs that are in a 323 state in which they accept or send 324 data. */ 325 extern struct tcp_pcb *tcp_tw_pcbs; /* List of all TCP PCBs in TIME-WAIT. */ 326 327 #define NUM_TCP_PCB_LISTS_NO_TIME_WAIT 3 328 #define NUM_TCP_PCB_LISTS 4 329 extern struct tcp_pcb ** const tcp_pcb_lists[NUM_TCP_PCB_LISTS]; 330 331 /* Axioms about the above lists: 332 1) Every TCP PCB that is not CLOSED is in one of the lists. 333 2) A PCB is only in one of the lists. 334 3) All PCBs in the tcp_listen_pcbs list is in LISTEN state. 335 4) All PCBs in the tcp_tw_pcbs list is in TIME-WAIT state. 336 */ 337 /* Define two macros, TCP_REG and TCP_RMV that registers a TCP PCB 338 with a PCB list or removes a PCB from a list, respectively. */ 339 #ifndef TCP_DEBUG_PCB_LISTS 340 #define TCP_DEBUG_PCB_LISTS 0 341 #endif 342 #if TCP_DEBUG_PCB_LISTS 343 #define TCP_REG(pcbs, npcb) do {\ 344 struct tcp_pcb *tcp_tmp_pcb; \ 345 LWIP_DEBUGF(TCP_DEBUG, ("TCP_REG %p local port %d\n", (npcb), (npcb)->local_port)); \ 346 for (tcp_tmp_pcb = *(pcbs); \ 347 tcp_tmp_pcb != NULL; \ 348 tcp_tmp_pcb = tcp_tmp_pcb->next) { \ 349 LWIP_ASSERT("TCP_REG: already registered\n", tcp_tmp_pcb != (npcb)); \ 350 } \ 351 LWIP_ASSERT("TCP_REG: pcb->state != CLOSED", ((pcbs) == &tcp_bound_pcbs) || ((npcb)->state != CLOSED)); \ 352 (npcb)->next = *(pcbs); \ 353 LWIP_ASSERT("TCP_REG: npcb->next != npcb", (npcb)->next != (npcb)); \ 354 *(pcbs) = (npcb); \ 355 LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \ 356 tcp_timer_needed(); \ 357 } while(0) 358 #define TCP_RMV(pcbs, npcb) do { \ 359 struct tcp_pcb *tcp_tmp_pcb; \ 360 LWIP_ASSERT("TCP_RMV: pcbs != NULL", *(pcbs) != NULL); \ 361 LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removing %p from %p\n", (npcb), *(pcbs))); \ 362 if(*(pcbs) == (npcb)) { \ 363 *(pcbs) = (*pcbs)->next; \ 364 } else for (tcp_tmp_pcb = *(pcbs); tcp_tmp_pcb != NULL; tcp_tmp_pcb = tcp_tmp_pcb->next) { \ 365 if(tcp_tmp_pcb->next == (npcb)) { \ 366 tcp_tmp_pcb->next = (npcb)->next; \ 367 break; \ 368 } \ 369 } \ 370 (npcb)->next = NULL; \ 371 LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \ 372 LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removed %p from %p\n", (npcb), *(pcbs))); \ 373 } while(0) 374 375 #else /* LWIP_DEBUG */ 376 377 #define TCP_REG(pcbs, npcb) \ 378 do { \ 379 (npcb)->next = *pcbs; \ 380 *(pcbs) = (npcb); \ 381 tcp_timer_needed(); \ 382 } while (0) 383 384 #define TCP_RMV(pcbs, npcb) \ 385 do { \ 386 if(*(pcbs) == (npcb)) { \ 387 (*(pcbs)) = (*pcbs)->next; \ 388 } \ 389 else { \ 390 struct tcp_pcb *tcp_tmp_pcb; \ 391 for (tcp_tmp_pcb = *pcbs; \ 392 tcp_tmp_pcb != NULL; \ 393 tcp_tmp_pcb = tcp_tmp_pcb->next) { \ 394 if(tcp_tmp_pcb->next == (npcb)) { \ 395 tcp_tmp_pcb->next = (npcb)->next; \ 396 break; \ 397 } \ 398 } \ 399 } \ 400 (npcb)->next = NULL; \ 401 } while(0) 402 403 #endif /* LWIP_DEBUG */ 404 405 #define TCP_REG_ACTIVE(npcb) \ 406 do { \ 407 TCP_REG(&tcp_active_pcbs, npcb); \ 408 tcp_active_pcbs_changed = 1; \ 409 } while (0) 410 411 #define TCP_RMV_ACTIVE(npcb) \ 412 do { \ 413 TCP_RMV(&tcp_active_pcbs, npcb); \ 414 tcp_active_pcbs_changed = 1; \ 415 } while (0) 416 417 #define TCP_PCB_REMOVE_ACTIVE(pcb) \ 418 do { \ 419 tcp_pcb_remove(&tcp_active_pcbs, pcb); \ 420 tcp_active_pcbs_changed = 1; \ 421 } while (0) 422 423 424 /* Internal functions: */ 425 struct tcp_pcb *tcp_pcb_copy(struct tcp_pcb *pcb); 426 void tcp_pcb_purge(struct tcp_pcb *pcb); 427 void tcp_pcb_remove(struct tcp_pcb **pcblist, struct tcp_pcb *pcb); 428 429 void tcp_segs_free(struct tcp_seg *seg); 430 void tcp_seg_free(struct tcp_seg *seg); 431 struct tcp_seg *tcp_seg_copy(struct tcp_seg *seg); 432 433 #define tcp_ack(pcb) \ 434 do { \ 435 if((pcb)->flags & TF_ACK_DELAY) { \ 436 (pcb)->flags &= ~TF_ACK_DELAY; \ 437 (pcb)->flags |= TF_ACK_NOW; \ 438 } \ 439 else { \ 440 (pcb)->flags |= TF_ACK_DELAY; \ 441 } \ 442 } while (0) 443 444 #define tcp_ack_now(pcb) \ 445 do { \ 446 (pcb)->flags |= TF_ACK_NOW; \ 447 } while (0) 448 449 err_t tcp_send_fin(struct tcp_pcb *pcb); 450 err_t tcp_enqueue_flags(struct tcp_pcb *pcb, u8_t flags); 451 452 void tcp_rexmit_seg(struct tcp_pcb *pcb, struct tcp_seg *seg); 453 454 void tcp_rst(u32_t seqno, u32_t ackno, 455 const ip_addr_t *local_ip, const ip_addr_t *remote_ip, 456 u16_t local_port, u16_t remote_port); 457 458 u32_t tcp_next_iss(struct tcp_pcb *pcb); 459 460 err_t tcp_keepalive(struct tcp_pcb *pcb); 461 err_t tcp_zero_window_probe(struct tcp_pcb *pcb); 462 void tcp_trigger_input_pcb_close(void); 463 464 #if TCP_CALCULATE_EFF_SEND_MSS 465 u16_t tcp_eff_send_mss_netif(u16_t sendmss, struct netif *outif, 466 const ip_addr_t *dest); 467 #define tcp_eff_send_mss(sendmss, src, dest) \ 468 tcp_eff_send_mss_netif(sendmss, ip_route(src, dest), dest) 469 #endif /* TCP_CALCULATE_EFF_SEND_MSS */ 470 471 #if LWIP_CALLBACK_API 472 err_t tcp_recv_null(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err); 473 #endif /* LWIP_CALLBACK_API */ 474 475 #if TCP_DEBUG || TCP_INPUT_DEBUG || TCP_OUTPUT_DEBUG 476 void tcp_debug_print(struct tcp_hdr *tcphdr); 477 void tcp_debug_print_flags(u8_t flags); 478 void tcp_debug_print_state(enum tcp_state s); 479 void tcp_debug_print_pcbs(void); 480 s16_t tcp_pcbs_sane(void); 481 #else 482 # define tcp_debug_print(tcphdr) 483 # define tcp_debug_print_flags(flags) 484 # define tcp_debug_print_state(s) 485 # define tcp_debug_print_pcbs() 486 # define tcp_pcbs_sane() 1 487 #endif /* TCP_DEBUG */ 488 489 /** External function (implemented in timers.c), called when TCP detects 490 * that a timer is needed (i.e. active- or time-wait-pcb found). */ 491 void tcp_timer_needed(void); 492 493 void tcp_netif_ip_addr_changed(const ip_addr_t* old_addr, const ip_addr_t* new_addr); 494 495 #ifdef __cplusplus 496 } 497 #endif 498 499 #endif /* LWIP_TCP */ 500 501 #endif /* LWIP_HDR_TCP_PRIV_H */ 502