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 (at) sics.se> 30 * 31 */ 32 #ifndef __LWIP_TCP_IMPL_H__ 33 #define __LWIP_TCP_IMPL_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/tcp.h" 40 #include "lwip/sys.h" 41 #include "lwip/mem.h" 42 #include "lwip/pbuf.h" 43 #include "lwip/ip.h" 44 #include "lwip/icmp.h" 45 #include "lwip/err.h" 46 47 #ifdef __cplusplus 48 extern "C" { 49 #endif 50 51 /* Functions for interfacing with TCP: */ 52 53 /* Lower layer interface to TCP: */ 54 #define tcp_init() /* Compatibility define, no init needed. */ 55 void tcp_tmr (void); /* Must be called every 56 TCP_TMR_INTERVAL 57 ms. (Typically 250 ms). */ 58 /* It is also possible to call these two functions at the right 59 intervals (instead of calling tcp_tmr()). */ 60 void tcp_slowtmr (void); 61 void tcp_fasttmr (void); 62 63 64 /* Only used by IP to pass a TCP segment to TCP: */ 65 void tcp_input (struct pbuf *p, struct netif *inp); 66 /* Used within the TCP code only: */ 67 struct tcp_pcb * tcp_alloc (u8_t prio); 68 void tcp_abandon (struct tcp_pcb *pcb, int reset); 69 err_t tcp_send_empty_ack(struct tcp_pcb *pcb); 70 void tcp_rexmit (struct tcp_pcb *pcb); 71 void tcp_rexmit_rto (struct tcp_pcb *pcb); 72 void tcp_rexmit_fast (struct tcp_pcb *pcb); 73 u32_t tcp_update_rcv_ann_wnd(struct tcp_pcb *pcb); 74 75 /** 76 * This is the Nagle algorithm: try to combine user data to send as few TCP 77 * segments as possible. Only send if 78 * - no previously transmitted data on the connection remains unacknowledged or 79 * - the TF_NODELAY flag is set (nagle algorithm turned off for this pcb) or 80 * - the only unsent segment is at least pcb->mss bytes long (or there is more 81 * than one unsent segment - with lwIP, this can happen although unsent->len < mss) 82 * - or if we are in fast-retransmit (TF_INFR) 83 */ 84 #define tcp_do_output_nagle(tpcb) ((((tpcb)->unacked == NULL) || \ 85 ((tpcb)->flags & (TF_NODELAY | TF_INFR)) || \ 86 (((tpcb)->unsent != NULL) && (((tpcb)->unsent->next != NULL) || \ 87 ((tpcb)->unsent->len >= (tpcb)->mss))) \ 88 ) ? 1 : 0) 89 #define tcp_output_nagle(tpcb) (tcp_do_output_nagle(tpcb) ? tcp_output(tpcb) : ERR_OK) 90 91 92 #define TCP_SEQ_LT(a,b) ((s32_t)((a)-(b)) < 0) 93 #define TCP_SEQ_LEQ(a,b) ((s32_t)((a)-(b)) <= 0) 94 #define TCP_SEQ_GT(a,b) ((s32_t)((a)-(b)) > 0) 95 #define TCP_SEQ_GEQ(a,b) ((s32_t)((a)-(b)) >= 0) 96 /* is b<=a<=c? */ 97 #if 0 /* see bug #10548 */ 98 #define TCP_SEQ_BETWEEN(a,b,c) ((c)-(b) >= (a)-(b)) 99 #endif 100 #define TCP_SEQ_BETWEEN(a,b,c) (TCP_SEQ_GEQ(a,b) && TCP_SEQ_LEQ(a,c)) 101 #define TCP_FIN 0x01U 102 #define TCP_SYN 0x02U 103 #define TCP_RST 0x04U 104 #define TCP_PSH 0x08U 105 #define TCP_ACK 0x10U 106 #define TCP_URG 0x20U 107 #define TCP_ECE 0x40U 108 #define TCP_CWR 0x80U 109 110 #define TCP_FLAGS 0x3fU 111 112 /* Length of the TCP header, excluding options. */ 113 #define TCP_HLEN 20 114 115 #ifndef TCP_TMR_INTERVAL 116 #define TCP_TMR_INTERVAL 250 /* The TCP timer interval in milliseconds. */ 117 #endif /* TCP_TMR_INTERVAL */ 118 119 #ifndef TCP_FAST_INTERVAL 120 #define TCP_FAST_INTERVAL TCP_TMR_INTERVAL /* the fine grained timeout in milliseconds */ 121 #endif /* TCP_FAST_INTERVAL */ 122 123 #ifndef TCP_SLOW_INTERVAL 124 #define TCP_SLOW_INTERVAL (2*TCP_TMR_INTERVAL) /* the coarse grained timeout in milliseconds */ 125 #endif /* TCP_SLOW_INTERVAL */ 126 127 #define TCP_FIN_WAIT_TIMEOUT 20000 /* milliseconds */ 128 #define TCP_SYN_RCVD_TIMEOUT 20000 /* milliseconds */ 129 130 #define TCP_OOSEQ_TIMEOUT 6U /* x RTO */ 131 132 #ifndef TCP_MSL 133 #define TCP_MSL 60000UL /* The maximum segment lifetime in milliseconds */ 134 #endif 135 136 /* Keepalive values, compliant with RFC 1122. Don't change this unless you know what you're doing */ 137 #ifndef TCP_KEEPIDLE_DEFAULT 138 #define TCP_KEEPIDLE_DEFAULT 7200000UL /* Default KEEPALIVE timer in milliseconds */ 139 #endif 140 141 #ifndef TCP_KEEPINTVL_DEFAULT 142 #define TCP_KEEPINTVL_DEFAULT 75000UL /* Default Time between KEEPALIVE probes in milliseconds */ 143 #endif 144 145 #ifndef TCP_KEEPCNT_DEFAULT 146 #define TCP_KEEPCNT_DEFAULT 9U /* Default Counter for KEEPALIVE probes */ 147 #endif 148 149 #define TCP_MAXIDLE TCP_KEEPCNT_DEFAULT * TCP_KEEPINTVL_DEFAULT /* Maximum KEEPALIVE probe time */ 150 151 /* Fields are (of course) in network byte order. 152 * Some fields are converted to host byte order in tcp_input(). 153 */ 154 #ifdef PACK_STRUCT_USE_INCLUDES 155 # include "arch/bpstruct.h" 156 #endif 157 PACK_STRUCT_BEGIN 158 struct tcp_hdr { 159 PACK_STRUCT_FIELD(u16_t src); 160 PACK_STRUCT_FIELD(u16_t dest); 161 PACK_STRUCT_FIELD(u32_t seqno); 162 PACK_STRUCT_FIELD(u32_t ackno); 163 PACK_STRUCT_FIELD(u16_t _hdrlen_rsvd_flags); 164 PACK_STRUCT_FIELD(u16_t wnd); 165 PACK_STRUCT_FIELD(u16_t chksum); 166 PACK_STRUCT_FIELD(u16_t urgp); 167 } PACK_STRUCT_STRUCT; 168 PACK_STRUCT_END 169 #ifdef PACK_STRUCT_USE_INCLUDES 170 # include "arch/epstruct.h" 171 #endif 172 173 #define TCPH_OFFSET(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) >> 8) 174 #define TCPH_HDRLEN(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) >> 12) 175 #define TCPH_FLAGS(phdr) (ntohs((phdr)->_hdrlen_rsvd_flags) & TCP_FLAGS) 176 177 #define TCPH_OFFSET_SET(phdr, offset) (phdr)->_hdrlen_rsvd_flags = htons(((offset) << 8) | TCPH_FLAGS(phdr)) 178 #define TCPH_HDRLEN_SET(phdr, len) (phdr)->_hdrlen_rsvd_flags = htons(((len) << 12) | TCPH_FLAGS(phdr)) 179 #define TCPH_FLAGS_SET(phdr, flags) (phdr)->_hdrlen_rsvd_flags = (((phdr)->_hdrlen_rsvd_flags & PP_HTONS((u16_t)(~(u16_t)(TCP_FLAGS)))) | htons(flags)) 180 #define TCPH_HDRLEN_FLAGS_SET(phdr, len, flags) (phdr)->_hdrlen_rsvd_flags = htons(((len) << 12) | (flags)) 181 182 #define TCPH_SET_FLAG(phdr, flags ) (phdr)->_hdrlen_rsvd_flags = ((phdr)->_hdrlen_rsvd_flags | htons(flags)) 183 #define TCPH_UNSET_FLAG(phdr, flags) (phdr)->_hdrlen_rsvd_flags = htons(ntohs((phdr)->_hdrlen_rsvd_flags) | (TCPH_FLAGS(phdr) & ~(flags)) ) 184 185 #define TCP_TCPLEN(seg) ((seg)->len + ((TCPH_FLAGS((seg)->tcphdr) & (TCP_FIN | TCP_SYN)) != 0)) 186 187 /** Flags used on input processing, not on pcb->flags 188 */ 189 #define TF_RESET (u8_t)0x08U /* Connection was reset. */ 190 #define TF_CLOSED (u8_t)0x10U /* Connection was sucessfully closed. */ 191 #define TF_GOT_FIN (u8_t)0x20U /* Connection was closed by the remote end. */ 192 193 194 #if LWIP_EVENT_API 195 196 #define TCP_EVENT_ACCEPT(pcb,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\ 197 LWIP_EVENT_ACCEPT, NULL, 0, err) 198 #define TCP_EVENT_SENT(pcb,space,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\ 199 LWIP_EVENT_SENT, NULL, space, ERR_OK) 200 #define TCP_EVENT_RECV(pcb,p,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\ 201 LWIP_EVENT_RECV, (p), 0, (err)) 202 #define TCP_EVENT_CLOSED(pcb,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\ 203 LWIP_EVENT_RECV, NULL, 0, ERR_OK) 204 #define TCP_EVENT_CONNECTED(pcb,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\ 205 LWIP_EVENT_CONNECTED, NULL, 0, (err)) 206 #define TCP_EVENT_POLL(pcb,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\ 207 LWIP_EVENT_POLL, NULL, 0, ERR_OK) 208 #define TCP_EVENT_ERR(errf,arg,err) lwip_tcp_event((arg), NULL, \ 209 LWIP_EVENT_ERR, NULL, 0, (err)) 210 211 #else /* LWIP_EVENT_API */ 212 213 #define TCP_EVENT_ACCEPT(pcb,err,ret) \ 214 do { \ 215 if((pcb)->accept != NULL) \ 216 (ret) = (pcb)->accept((pcb)->callback_arg,(pcb),(err)); \ 217 else (ret) = ERR_ARG; \ 218 } while (0) 219 220 #define TCP_EVENT_SENT(pcb,space,ret) \ 221 do { \ 222 if((pcb)->sent != NULL) \ 223 (ret) = (pcb)->sent((pcb)->callback_arg,(pcb),(space)); \ 224 else (ret) = ERR_OK; \ 225 } while (0) 226 227 #define TCP_EVENT_RECV(pcb,p,err,ret) \ 228 do { \ 229 if((pcb)->recv != NULL) { \ 230 (ret) = (pcb)->recv((pcb)->callback_arg,(pcb),(p),(err));\ 231 } else { \ 232 (ret) = tcp_recv_null(NULL, (pcb), (p), (err)); \ 233 } \ 234 } while (0) 235 236 #define TCP_EVENT_CLOSED(pcb,ret) \ 237 do { \ 238 if(((pcb)->recv != NULL)) { \ 239 (ret) = (pcb)->recv((pcb)->callback_arg,(pcb),NULL,ERR_OK);\ 240 } else { \ 241 (ret) = ERR_OK; \ 242 } \ 243 } while (0) 244 245 #define TCP_EVENT_CONNECTED(pcb,err,ret) \ 246 do { \ 247 if((pcb)->connected != NULL) \ 248 (ret) = (pcb)->connected((pcb)->callback_arg,(pcb),(err)); \ 249 else (ret) = ERR_OK; \ 250 } while (0) 251 252 #define TCP_EVENT_POLL(pcb,ret) \ 253 do { \ 254 if((pcb)->poll != NULL) \ 255 (ret) = (pcb)->poll((pcb)->callback_arg,(pcb)); \ 256 else (ret) = ERR_OK; \ 257 } while (0) 258 259 #define TCP_EVENT_ERR(errf,arg,err) \ 260 do { \ 261 if((errf) != NULL) \ 262 (errf)((arg),(err)); \ 263 } while (0) 264 265 #endif /* LWIP_EVENT_API */ 266 267 /** Enabled extra-check for TCP_OVERSIZE if LWIP_DEBUG is enabled */ 268 #if TCP_OVERSIZE && defined(LWIP_DEBUG) 269 #define TCP_OVERSIZE_DBGCHECK 1 270 #else 271 #define TCP_OVERSIZE_DBGCHECK 0 272 #endif 273 274 /** Don't generate checksum on copy if CHECKSUM_GEN_TCP is disabled */ 275 #define TCP_CHECKSUM_ON_COPY (LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_TCP) 276 277 /* This structure represents a TCP segment on the unsent, unacked and ooseq queues */ 278 struct tcp_seg { 279 struct tcp_seg *next; /* used when putting segements on a queue */ 280 struct pbuf *p; /* buffer containing data + TCP header */ 281 u16_t len; /* the TCP length of this segment */ 282 #if TCP_OVERSIZE_DBGCHECK 283 u16_t oversize_left; /* Extra bytes available at the end of the last 284 pbuf in unsent (used for asserting vs. 285 tcp_pcb.unsent_oversized only) */ 286 #endif /* TCP_OVERSIZE_DBGCHECK */ 287 #if TCP_CHECKSUM_ON_COPY 288 u16_t chksum; 289 u8_t chksum_swapped; 290 #endif /* TCP_CHECKSUM_ON_COPY */ 291 u8_t flags; 292 #define TF_SEG_OPTS_MSS (u8_t)0x01U /* Include MSS option. */ 293 #define TF_SEG_OPTS_TS (u8_t)0x02U /* Include timestamp option. */ 294 #define TF_SEG_DATA_CHECKSUMMED (u8_t)0x04U /* ALL data (not the header) is 295 checksummed into 'chksum' */ 296 struct tcp_hdr *tcphdr; /* the TCP header */ 297 }; 298 299 #define LWIP_TCP_OPT_LENGTH(flags) \ 300 (flags & TF_SEG_OPTS_MSS ? 4 : 0) + \ 301 (flags & TF_SEG_OPTS_TS ? 12 : 0) 302 303 /** This returns a TCP header option for MSS in an u32_t */ 304 #define TCP_BUILD_MSS_OPTION(x) (x) = PP_HTONL(((u32_t)2 << 24) | \ 305 ((u32_t)4 << 16) | \ 306 (((u32_t)TCP_MSS / 256) << 8) | \ 307 (TCP_MSS & 255)) 308 309 /* Global variables: */ 310 extern struct tcp_pcb *tcp_input_pcb; 311 extern u32_t tcp_ticks; 312 313 /* The TCP PCB lists. */ 314 union tcp_listen_pcbs_t { /* List of all TCP PCBs in LISTEN state. */ 315 struct tcp_pcb_listen *listen_pcbs; 316 struct tcp_pcb *pcbs; 317 }; 318 extern struct tcp_pcb *tcp_bound_pcbs; 319 extern union tcp_listen_pcbs_t tcp_listen_pcbs; 320 extern struct tcp_pcb *tcp_active_pcbs; /* List of all TCP PCBs that are in a 321 state in which they accept or send 322 data. */ 323 extern struct tcp_pcb *tcp_tw_pcbs; /* List of all TCP PCBs in TIME-WAIT. */ 324 325 extern struct tcp_pcb *tcp_tmp_pcb; /* Only used for temporary storage. */ 326 327 /* Axioms about the above lists: 328 1) Every TCP PCB that is not CLOSED is in one of the lists. 329 2) A PCB is only in one of the lists. 330 3) All PCBs in the tcp_listen_pcbs list is in LISTEN state. 331 4) All PCBs in the tcp_tw_pcbs list is in TIME-WAIT state. 332 */ 333 /* Define two macros, TCP_REG and TCP_RMV that registers a TCP PCB 334 with a PCB list or removes a PCB from a list, respectively. */ 335 #ifndef TCP_DEBUG_PCB_LISTS 336 #define TCP_DEBUG_PCB_LISTS 0 337 #endif 338 #if TCP_DEBUG_PCB_LISTS 339 #define TCP_REG(pcbs, npcb) do {\ 340 LWIP_DEBUGF(TCP_DEBUG, ("TCP_REG %p local port %d\n", (npcb), (npcb)->local_port)); \ 341 for(tcp_tmp_pcb = *(pcbs); \ 342 tcp_tmp_pcb != NULL; \ 343 tcp_tmp_pcb = tcp_tmp_pcb->next) { \ 344 LWIP_ASSERT("TCP_REG: already registered\n", tcp_tmp_pcb != (npcb)); \ 345 } \ 346 LWIP_ASSERT("TCP_REG: pcb->state != CLOSED", ((pcbs) == &tcp_bound_pcbs) || ((npcb)->state != CLOSED)); \ 347 (npcb)->next = *(pcbs); \ 348 LWIP_ASSERT("TCP_REG: npcb->next != npcb", (npcb)->next != (npcb)); \ 349 *(pcbs) = (npcb); \ 350 LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \ 351 tcp_timer_needed(); \ 352 } while(0) 353 #define TCP_RMV(pcbs, npcb) do { \ 354 LWIP_ASSERT("TCP_RMV: pcbs != NULL", *(pcbs) != NULL); \ 355 LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removing %p from %p\n", (npcb), *(pcbs))); \ 356 if(*(pcbs) == (npcb)) { \ 357 *(pcbs) = (*pcbs)->next; \ 358 } else for(tcp_tmp_pcb = *(pcbs); tcp_tmp_pcb != NULL; tcp_tmp_pcb = tcp_tmp_pcb->next) { \ 359 if(tcp_tmp_pcb->next == (npcb)) { \ 360 tcp_tmp_pcb->next = (npcb)->next; \ 361 break; \ 362 } \ 363 } \ 364 (npcb)->next = NULL; \ 365 LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \ 366 LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removed %p from %p\n", (npcb), *(pcbs))); \ 367 } while(0) 368 369 #else /* LWIP_DEBUG */ 370 371 #define TCP_REG(pcbs, npcb) \ 372 do { \ 373 (npcb)->next = *pcbs; \ 374 *(pcbs) = (npcb); \ 375 tcp_timer_needed(); \ 376 } while (0) 377 378 #define TCP_RMV(pcbs, npcb) \ 379 do { \ 380 if(*(pcbs) == (npcb)) { \ 381 (*(pcbs)) = (*pcbs)->next; \ 382 } \ 383 else { \ 384 for(tcp_tmp_pcb = *pcbs; \ 385 tcp_tmp_pcb != NULL; \ 386 tcp_tmp_pcb = tcp_tmp_pcb->next) { \ 387 if(tcp_tmp_pcb->next == (npcb)) { \ 388 tcp_tmp_pcb->next = (npcb)->next; \ 389 break; \ 390 } \ 391 } \ 392 } \ 393 (npcb)->next = NULL; \ 394 } while(0) 395 396 #endif /* LWIP_DEBUG */ 397 398 399 /* Internal functions: */ 400 struct tcp_pcb *tcp_pcb_copy(struct tcp_pcb *pcb); 401 void tcp_pcb_purge(struct tcp_pcb *pcb); 402 void tcp_pcb_remove(struct tcp_pcb **pcblist, struct tcp_pcb *pcb); 403 404 void tcp_segs_free(struct tcp_seg *seg); 405 void tcp_seg_free(struct tcp_seg *seg); 406 struct tcp_seg *tcp_seg_copy(struct tcp_seg *seg); 407 408 #define tcp_ack(pcb) \ 409 do { \ 410 if((pcb)->flags & TF_ACK_DELAY) { \ 411 (pcb)->flags &= ~TF_ACK_DELAY; \ 412 (pcb)->flags |= TF_ACK_NOW; \ 413 } \ 414 else { \ 415 (pcb)->flags |= TF_ACK_DELAY; \ 416 } \ 417 } while (0) 418 419 #define tcp_ack_now(pcb) \ 420 do { \ 421 (pcb)->flags |= TF_ACK_NOW; \ 422 } while (0) 423 424 err_t tcp_send_fin(struct tcp_pcb *pcb); 425 err_t tcp_enqueue_flags(struct tcp_pcb *pcb, u8_t flags); 426 427 void tcp_rexmit_seg(struct tcp_pcb *pcb, struct tcp_seg *seg); 428 429 void tcp_rst(u32_t seqno, u32_t ackno, 430 ip_addr_t *local_ip, ip_addr_t *remote_ip, 431 u16_t local_port, u16_t remote_port); 432 433 u32_t tcp_next_iss(void); 434 435 void tcp_keepalive(struct tcp_pcb *pcb); 436 void tcp_zero_window_probe(struct tcp_pcb *pcb); 437 438 #if TCP_CALCULATE_EFF_SEND_MSS 439 u16_t tcp_eff_send_mss(u16_t sendmss, ip_addr_t *addr); 440 #endif /* TCP_CALCULATE_EFF_SEND_MSS */ 441 442 #if LWIP_CALLBACK_API 443 err_t tcp_recv_null(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err); 444 #endif /* LWIP_CALLBACK_API */ 445 446 #if TCP_DEBUG || TCP_INPUT_DEBUG || TCP_OUTPUT_DEBUG 447 void tcp_debug_print(struct tcp_hdr *tcphdr); 448 void tcp_debug_print_flags(u8_t flags); 449 void tcp_debug_print_state(enum tcp_state s); 450 void tcp_debug_print_pcbs(void); 451 s16_t tcp_pcbs_sane(void); 452 #else 453 # define tcp_debug_print(tcphdr) 454 # define tcp_debug_print_flags(flags) 455 # define tcp_debug_print_state(s) 456 # define tcp_debug_print_pcbs() 457 # define tcp_pcbs_sane() 1 458 #endif /* TCP_DEBUG */ 459 460 /** External function (implemented in timers.c), called when TCP detects 461 * that a timer is needed (i.e. active- or time-wait-pcb found). */ 462 void tcp_timer_needed(void); 463 464 465 #ifdef __cplusplus 466 } 467 #endif 468 469 #endif /* LWIP_TCP */ 470 471 #endif /* __LWIP_TCP_H__ */ 472
