NetServices Stack source
Dependents: HelloWorld ServoInterfaceBoardExample1 4180_Lab4
pbuf.c
00001 /** 00002 * @file 00003 * Packet buffer management 00004 * 00005 * Packets are built from the pbuf data structure. It supports dynamic 00006 * memory allocation for packet contents or can reference externally 00007 * managed packet contents both in RAM and ROM. Quick allocation for 00008 * incoming packets is provided through pools with fixed sized pbufs. 00009 * 00010 * A packet may span over multiple pbufs, chained as a singly linked 00011 * list. This is called a "pbuf chain". 00012 * 00013 * Multiple packets may be queued, also using this singly linked list. 00014 * This is called a "packet queue". 00015 * 00016 * So, a packet queue consists of one or more pbuf chains, each of 00017 * which consist of one or more pbufs. CURRENTLY, PACKET QUEUES ARE 00018 * NOT SUPPORTED!!! Use helper structs to queue multiple packets. 00019 * 00020 * The differences between a pbuf chain and a packet queue are very 00021 * precise but subtle. 00022 * 00023 * The last pbuf of a packet has a ->tot_len field that equals the 00024 * ->len field. It can be found by traversing the list. If the last 00025 * pbuf of a packet has a ->next field other than NULL, more packets 00026 * are on the queue. 00027 * 00028 * Therefore, looping through a pbuf of a single packet, has an 00029 * loop end condition (tot_len == p->len), NOT (next == NULL). 00030 */ 00031 00032 /* 00033 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 00034 * All rights reserved. 00035 * 00036 * Redistribution and use in source and binary forms, with or without modification, 00037 * are permitted provided that the following conditions are met: 00038 * 00039 * 1. Redistributions of source code must retain the above copyright notice, 00040 * this list of conditions and the following disclaimer. 00041 * 2. Redistributions in binary form must reproduce the above copyright notice, 00042 * this list of conditions and the following disclaimer in the documentation 00043 * and/or other materials provided with the distribution. 00044 * 3. The name of the author may not be used to endorse or promote products 00045 * derived from this software without specific prior written permission. 00046 * 00047 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 00048 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00049 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 00050 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00051 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 00052 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00053 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00054 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 00055 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 00056 * OF SUCH DAMAGE. 00057 * 00058 * This file is part of the lwIP TCP/IP stack. 00059 * 00060 * Author: Adam Dunkels <adam@sics.se> 00061 * 00062 */ 00063 00064 #include "lwip/opt.h" 00065 00066 #include "lwip/stats.h" 00067 #include "lwip/def.h" 00068 #include "lwip/mem.h" 00069 #include "lwip/memp.h" 00070 #include "lwip/pbuf.h" 00071 #include "lwip/sys.h" 00072 #include "arch/perf.h" 00073 #if TCP_QUEUE_OOSEQ 00074 #include "lwip/tcp_impl.h" 00075 #endif 00076 #if LWIP_CHECKSUM_ON_COPY 00077 #include "lwip/inet_chksum.h" 00078 #endif 00079 00080 #include <string.h> 00081 00082 #define SIZEOF_STRUCT_PBUF LWIP_MEM_ALIGN_SIZE(sizeof(struct pbuf)) 00083 /* Since the pool is created in memp, PBUF_POOL_BUFSIZE will be automatically 00084 aligned there. Therefore, PBUF_POOL_BUFSIZE_ALIGNED can be used here. */ 00085 #define PBUF_POOL_BUFSIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE) 00086 00087 #if !LWIP_TCP || !TCP_QUEUE_OOSEQ || NO_SYS 00088 #define PBUF_POOL_IS_EMPTY() 00089 #else /* !LWIP_TCP || !TCP_QUEUE_OOSEQ || NO_SYS */ 00090 /** Define this to 0 to prevent freeing ooseq pbufs when the PBUF_POOL is empty */ 00091 #ifndef PBUF_POOL_FREE_OOSEQ 00092 #define PBUF_POOL_FREE_OOSEQ 1 00093 #endif /* PBUF_POOL_FREE_OOSEQ */ 00094 00095 #if PBUF_POOL_FREE_OOSEQ 00096 #include "lwip/tcpip.h" 00097 #define PBUF_POOL_IS_EMPTY() pbuf_pool_is_empty() 00098 static u8_t pbuf_free_ooseq_queued; 00099 /** 00100 * Attempt to reclaim some memory from queued out-of-sequence TCP segments 00101 * if we run out of pool pbufs. It's better to give priority to new packets 00102 * if we're running out. 00103 * 00104 * This must be done in the correct thread context therefore this function 00105 * can only be used with NO_SYS=0 and through tcpip_callback. 00106 */ 00107 static void 00108 pbuf_free_ooseq(void* arg) 00109 { 00110 struct tcp_pcb* pcb; 00111 SYS_ARCH_DECL_PROTECT(old_level); 00112 LWIP_UNUSED_ARG(arg); 00113 00114 SYS_ARCH_PROTECT(old_level); 00115 pbuf_free_ooseq_queued = 0; 00116 SYS_ARCH_UNPROTECT(old_level); 00117 00118 for (pcb = tcp_active_pcbs; NULL != pcb; pcb = pcb->next) { 00119 if (NULL != pcb->ooseq) { 00120 /** Free the ooseq pbufs of one PCB only */ 00121 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free_ooseq: freeing out-of-sequence pbufs\n")); 00122 tcp_segs_free(pcb->ooseq); 00123 pcb->ooseq = NULL; 00124 return; 00125 } 00126 } 00127 } 00128 00129 /** Queue a call to pbuf_free_ooseq if not already queued. */ 00130 static void 00131 pbuf_pool_is_empty(void) 00132 { 00133 u8_t queued; 00134 SYS_ARCH_DECL_PROTECT(old_level); 00135 00136 SYS_ARCH_PROTECT(old_level); 00137 queued = pbuf_free_ooseq_queued; 00138 pbuf_free_ooseq_queued = 1; 00139 SYS_ARCH_UNPROTECT(old_level); 00140 00141 if(!queued) { 00142 /* queue a call to pbuf_free_ooseq if not already queued */ 00143 if(tcpip_callback_with_block(pbuf_free_ooseq, NULL, 0) != ERR_OK) { 00144 SYS_ARCH_PROTECT(old_level); 00145 pbuf_free_ooseq_queued = 0; 00146 SYS_ARCH_UNPROTECT(old_level); 00147 } 00148 } 00149 } 00150 #endif /* PBUF_POOL_FREE_OOSEQ */ 00151 #endif /* !LWIP_TCP || !TCP_QUEUE_OOSEQ || NO_SYS */ 00152 00153 /** 00154 * Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type). 00155 * 00156 * The actual memory allocated for the pbuf is determined by the 00157 * layer at which the pbuf is allocated and the requested size 00158 * (from the size parameter). 00159 * 00160 * @param layer flag to define header size 00161 * @param length size of the pbuf's payload 00162 * @param type this parameter decides how and where the pbuf 00163 * should be allocated as follows: 00164 * 00165 * - PBUF_RAM: buffer memory for pbuf is allocated as one large 00166 * chunk. This includes protocol headers as well. 00167 * - PBUF_ROM: no buffer memory is allocated for the pbuf, even for 00168 * protocol headers. Additional headers must be prepended 00169 * by allocating another pbuf and chain in to the front of 00170 * the ROM pbuf. It is assumed that the memory used is really 00171 * similar to ROM in that it is immutable and will not be 00172 * changed. Memory which is dynamic should generally not 00173 * be attached to PBUF_ROM pbufs. Use PBUF_REF instead. 00174 * - PBUF_REF: no buffer memory is allocated for the pbuf, even for 00175 * protocol headers. It is assumed that the pbuf is only 00176 * being used in a single thread. If the pbuf gets queued, 00177 * then pbuf_take should be called to copy the buffer. 00178 * - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from 00179 * the pbuf pool that is allocated during pbuf_init(). 00180 * 00181 * @return the allocated pbuf. If multiple pbufs where allocated, this 00182 * is the first pbuf of a pbuf chain. 00183 */ 00184 struct pbuf * 00185 pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type) 00186 { 00187 struct pbuf *p, *q, *r; 00188 u16_t offset; 00189 s32_t rem_len; /* remaining length */ 00190 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length)); 00191 00192 /* determine header offset */ 00193 offset = 0; 00194 switch (layer) { 00195 case PBUF_TRANSPORT: 00196 /* add room for transport (often TCP) layer header */ 00197 offset += PBUF_TRANSPORT_HLEN; 00198 /* FALLTHROUGH */ 00199 case PBUF_IP: 00200 /* add room for IP layer header */ 00201 offset += PBUF_IP_HLEN; 00202 /* FALLTHROUGH */ 00203 case PBUF_LINK: 00204 /* add room for link layer header */ 00205 offset += PBUF_LINK_HLEN; 00206 break; 00207 case PBUF_RAW: 00208 break; 00209 default: 00210 LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0); 00211 return NULL; 00212 } 00213 00214 switch (type) { 00215 case PBUF_POOL: 00216 /* allocate head of pbuf chain into p */ 00217 p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL); 00218 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p)); 00219 if (p == NULL) { 00220 PBUF_POOL_IS_EMPTY(); 00221 return NULL; 00222 } 00223 p->type = type; 00224 p->next = NULL; 00225 00226 /* make the payload pointer point 'offset' bytes into pbuf data memory */ 00227 p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + (SIZEOF_STRUCT_PBUF + offset))); 00228 LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned", 00229 ((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0); 00230 /* the total length of the pbuf chain is the requested size */ 00231 p->tot_len = length; 00232 /* set the length of the first pbuf in the chain */ 00233 p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)); 00234 LWIP_ASSERT("check p->payload + p->len does not overflow pbuf", 00235 ((u8_t*)p->payload + p->len <= 00236 (u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED)); 00237 LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT", 00238 (PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 ); 00239 /* set reference count (needed here in case we fail) */ 00240 p->ref = 1; 00241 00242 /* now allocate the tail of the pbuf chain */ 00243 00244 /* remember first pbuf for linkage in next iteration */ 00245 r = p; 00246 /* remaining length to be allocated */ 00247 rem_len = length - p->len; 00248 /* any remaining pbufs to be allocated? */ 00249 while (rem_len > 0) { 00250 q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL); 00251 if (q == NULL) { 00252 PBUF_POOL_IS_EMPTY(); 00253 /* free chain so far allocated */ 00254 pbuf_free(p); 00255 /* bail out unsuccesfully */ 00256 return NULL; 00257 } 00258 q->type = type; 00259 q->flags = 0; 00260 q->next = NULL; 00261 /* make previous pbuf point to this pbuf */ 00262 r->next = q; 00263 /* set total length of this pbuf and next in chain */ 00264 LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff); 00265 q->tot_len = (u16_t)rem_len; 00266 /* this pbuf length is pool size, unless smaller sized tail */ 00267 q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED); 00268 q->payload = (void *)((u8_t *)q + SIZEOF_STRUCT_PBUF); 00269 LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned", 00270 ((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0); 00271 LWIP_ASSERT("check p->payload + p->len does not overflow pbuf", 00272 ((u8_t*)p->payload + p->len <= 00273 (u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED)); 00274 q->ref = 1; 00275 /* calculate remaining length to be allocated */ 00276 rem_len -= q->len; 00277 /* remember this pbuf for linkage in next iteration */ 00278 r = q; 00279 } 00280 /* end of chain */ 00281 /*r->next = NULL;*/ 00282 00283 break; 00284 case PBUF_RAM: 00285 /* If pbuf is to be allocated in RAM, allocate memory for it. */ 00286 p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length)); 00287 if (p == NULL) { 00288 return NULL; 00289 } 00290 /* Set up internal structure of the pbuf. */ 00291 p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + SIZEOF_STRUCT_PBUF + offset)); 00292 p->len = p->tot_len = length; 00293 p->next = NULL; 00294 p->type = type; 00295 00296 LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned", 00297 ((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0); 00298 break; 00299 /* pbuf references existing (non-volatile static constant) ROM payload? */ 00300 case PBUF_ROM: 00301 /* pbuf references existing (externally allocated) RAM payload? */ 00302 case PBUF_REF: 00303 /* only allocate memory for the pbuf structure */ 00304 p = (struct pbuf *)memp_malloc(MEMP_PBUF); 00305 if (p == NULL) { 00306 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS, 00307 ("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n", 00308 (type == PBUF_ROM) ? "ROM" : "REF")); 00309 return NULL; 00310 } 00311 /* caller must set this field properly, afterwards */ 00312 p->payload = NULL; 00313 p->len = p->tot_len = length; 00314 p->next = NULL; 00315 p->type = type; 00316 break; 00317 default: 00318 LWIP_ASSERT("pbuf_alloc: erroneous type", 0); 00319 return NULL; 00320 } 00321 /* set reference count */ 00322 p->ref = 1; 00323 /* set flags */ 00324 p->flags = 0; 00325 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p)); 00326 return p; 00327 } 00328 00329 #if LWIP_SUPPORT_CUSTOM_PBUF 00330 /** Initialize a custom pbuf (already allocated). 00331 * 00332 * @param layer flag to define header size 00333 * @param length size of the pbuf's payload 00334 * @param type type of the pbuf (only used to treat the pbuf accordingly, as 00335 * this function allocates no memory) 00336 * @param p pointer to the custom pbuf to initialize (already allocated) 00337 * @param payload_mem pointer to the buffer that is used for payload and headers, 00338 * must be at least big enough to hold 'length' plus the header size, 00339 * may be NULL if set later 00340 * @param payload_mem_len the size of the 'payload_mem' buffer, must be at least 00341 * big enough to hold 'length' plus the header size 00342 */ 00343 struct pbuf* 00344 pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type, struct pbuf_custom *p, 00345 void *payload_mem, u16_t payload_mem_len) 00346 { 00347 u16_t offset; 00348 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloced_custom(length=%"U16_F")\n", length)); 00349 00350 /* determine header offset */ 00351 offset = 0; 00352 switch (l) { 00353 case PBUF_TRANSPORT: 00354 /* add room for transport (often TCP) layer header */ 00355 offset += PBUF_TRANSPORT_HLEN; 00356 /* FALLTHROUGH */ 00357 case PBUF_IP: 00358 /* add room for IP layer header */ 00359 offset += PBUF_IP_HLEN; 00360 /* FALLTHROUGH */ 00361 case PBUF_LINK: 00362 /* add room for link layer header */ 00363 offset += PBUF_LINK_HLEN; 00364 break; 00365 case PBUF_RAW: 00366 break; 00367 default: 00368 LWIP_ASSERT("pbuf_alloced_custom: bad pbuf layer", 0); 00369 return NULL; 00370 } 00371 00372 if (LWIP_MEM_ALIGN_SIZE(offset) + length < payload_mem_len) { 00373 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_WARNING, ("pbuf_alloced_custom(length=%"U16_F") buffer too short\n", length)); 00374 return NULL; 00375 } 00376 00377 p->pbuf.next = NULL; 00378 if (payload_mem != NULL) { 00379 p->pbuf.payload = LWIP_MEM_ALIGN((void *)((u8_t *)payload_mem + offset)); 00380 } else { 00381 p->pbuf.payload = NULL; 00382 } 00383 p->pbuf.flags = PBUF_FLAG_IS_CUSTOM; 00384 p->pbuf.len = p->pbuf.tot_len = length; 00385 p->pbuf.type = type; 00386 p->pbuf.ref = 1; 00387 return &p->pbuf; 00388 } 00389 #endif /* LWIP_SUPPORT_CUSTOM_PBUF */ 00390 00391 /** 00392 * Shrink a pbuf chain to a desired length. 00393 * 00394 * @param p pbuf to shrink. 00395 * @param new_len desired new length of pbuf chain 00396 * 00397 * Depending on the desired length, the first few pbufs in a chain might 00398 * be skipped and left unchanged. The new last pbuf in the chain will be 00399 * resized, and any remaining pbufs will be freed. 00400 * 00401 * @note If the pbuf is ROM/REF, only the ->tot_len and ->len fields are adjusted. 00402 * @note May not be called on a packet queue. 00403 * 00404 * @note Despite its name, pbuf_realloc cannot grow the size of a pbuf (chain). 00405 */ 00406 void 00407 pbuf_realloc(struct pbuf *p, u16_t new_len) 00408 { 00409 struct pbuf *q; 00410 u16_t rem_len; /* remaining length */ 00411 s32_t grow; 00412 00413 LWIP_ASSERT("pbuf_realloc: p != NULL", p != NULL); 00414 LWIP_ASSERT("pbuf_realloc: sane p->type", p->type == PBUF_POOL || 00415 p->type == PBUF_ROM || 00416 p->type == PBUF_RAM || 00417 p->type == PBUF_REF); 00418 00419 /* desired length larger than current length? */ 00420 if (new_len >= p->tot_len) { 00421 /* enlarging not yet supported */ 00422 return; 00423 } 00424 00425 /* the pbuf chain grows by (new_len - p->tot_len) bytes 00426 * (which may be negative in case of shrinking) */ 00427 grow = new_len - p->tot_len; 00428 00429 /* first, step over any pbufs that should remain in the chain */ 00430 rem_len = new_len; 00431 q = p; 00432 /* should this pbuf be kept? */ 00433 while (rem_len > q->len) { 00434 /* decrease remaining length by pbuf length */ 00435 rem_len -= q->len; 00436 /* decrease total length indicator */ 00437 LWIP_ASSERT("grow < max_u16_t", grow < 0xffff); 00438 q->tot_len += (u16_t)grow; 00439 /* proceed to next pbuf in chain */ 00440 q = q->next; 00441 LWIP_ASSERT("pbuf_realloc: q != NULL", q != NULL); 00442 } 00443 /* we have now reached the new last pbuf (in q) */ 00444 /* rem_len == desired length for pbuf q */ 00445 00446 /* shrink allocated memory for PBUF_RAM */ 00447 /* (other types merely adjust their length fields */ 00448 if ((q->type == PBUF_RAM) && (rem_len != q->len)) { 00449 /* reallocate and adjust the length of the pbuf that will be split */ 00450 q = (struct pbuf *)mem_trim(q, (u16_t)((u8_t *)q->payload - (u8_t *)q) + rem_len); 00451 LWIP_ASSERT("mem_trim returned q == NULL", q != NULL); 00452 } 00453 /* adjust length fields for new last pbuf */ 00454 q->len = rem_len; 00455 q->tot_len = q->len; 00456 00457 /* any remaining pbufs in chain? */ 00458 if (q->next != NULL) { 00459 /* free remaining pbufs in chain */ 00460 pbuf_free(q->next); 00461 } 00462 /* q is last packet in chain */ 00463 q->next = NULL; 00464 00465 } 00466 00467 /** 00468 * Adjusts the payload pointer to hide or reveal headers in the payload. 00469 * 00470 * Adjusts the ->payload pointer so that space for a header 00471 * (dis)appears in the pbuf payload. 00472 * 00473 * The ->payload, ->tot_len and ->len fields are adjusted. 00474 * 00475 * @param p pbuf to change the header size. 00476 * @param header_size_increment Number of bytes to increment header size which 00477 * increases the size of the pbuf. New space is on the front. 00478 * (Using a negative value decreases the header size.) 00479 * If hdr_size_inc is 0, this function does nothing and returns succesful. 00480 * 00481 * PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so 00482 * the call will fail. A check is made that the increase in header size does 00483 * not move the payload pointer in front of the start of the buffer. 00484 * @return non-zero on failure, zero on success. 00485 * 00486 */ 00487 u8_t 00488 pbuf_header(struct pbuf *p, s16_t header_size_increment) 00489 { 00490 u16_t type; 00491 void *payload; 00492 u16_t increment_magnitude; 00493 00494 LWIP_ASSERT("p != NULL", p != NULL); 00495 if ((header_size_increment == 0) || (p == NULL)) { 00496 return 0; 00497 } 00498 00499 if (header_size_increment < 0){ 00500 increment_magnitude = -header_size_increment; 00501 /* Check that we aren't going to move off the end of the pbuf */ 00502 LWIP_ERROR("increment_magnitude <= p->len", (increment_magnitude <= p->len), return 1;); 00503 } else { 00504 increment_magnitude = header_size_increment; 00505 #if 0 00506 /* Can't assert these as some callers speculatively call 00507 pbuf_header() to see if it's OK. Will return 1 below instead. */ 00508 /* Check that we've got the correct type of pbuf to work with */ 00509 LWIP_ASSERT("p->type == PBUF_RAM || p->type == PBUF_POOL", 00510 p->type == PBUF_RAM || p->type == PBUF_POOL); 00511 /* Check that we aren't going to move off the beginning of the pbuf */ 00512 LWIP_ASSERT("p->payload - increment_magnitude >= p + SIZEOF_STRUCT_PBUF", 00513 (u8_t *)p->payload - increment_magnitude >= (u8_t *)p + SIZEOF_STRUCT_PBUF); 00514 #endif 00515 } 00516 00517 type = p->type; 00518 /* remember current payload pointer */ 00519 payload = p->payload; 00520 00521 /* pbuf types containing payloads? */ 00522 if (type == PBUF_RAM || type == PBUF_POOL) { 00523 /* set new payload pointer */ 00524 p->payload = (u8_t *)p->payload - header_size_increment; 00525 /* boundary check fails? */ 00526 if ((u8_t *)p->payload < (u8_t *)p + SIZEOF_STRUCT_PBUF) { 00527 LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS, 00528 ("pbuf_header: failed as %p < %p (not enough space for new header size)\n", 00529 (void *)p->payload, (void *)(p + 1))); 00530 /* restore old payload pointer */ 00531 p->payload = payload; 00532 /* bail out unsuccesfully */ 00533 return 1; 00534 } 00535 /* pbuf types refering to external payloads? */ 00536 } else if (type == PBUF_REF || type == PBUF_ROM) { 00537 /* hide a header in the payload? */ 00538 if ((header_size_increment < 0) && (increment_magnitude <= p->len)) { 00539 /* increase payload pointer */ 00540 p->payload = (u8_t *)p->payload - header_size_increment; 00541 } else { 00542 /* cannot expand payload to front (yet!) 00543 * bail out unsuccesfully */ 00544 return 1; 00545 } 00546 } else { 00547 /* Unknown type */ 00548 LWIP_ASSERT("bad pbuf type", 0); 00549 return 1; 00550 } 00551 /* modify pbuf length fields */ 00552 p->len += header_size_increment; 00553 p->tot_len += header_size_increment; 00554 00555 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_header: old %p new %p (%"S16_F")\n", 00556 (void *)payload, (void *)p->payload, header_size_increment)); 00557 00558 return 0; 00559 } 00560 00561 /** 00562 * Dereference a pbuf chain or queue and deallocate any no-longer-used 00563 * pbufs at the head of this chain or queue. 00564 * 00565 * Decrements the pbuf reference count. If it reaches zero, the pbuf is 00566 * deallocated. 00567 * 00568 * For a pbuf chain, this is repeated for each pbuf in the chain, 00569 * up to the first pbuf which has a non-zero reference count after 00570 * decrementing. So, when all reference counts are one, the whole 00571 * chain is free'd. 00572 * 00573 * @param p The pbuf (chain) to be dereferenced. 00574 * 00575 * @return the number of pbufs that were de-allocated 00576 * from the head of the chain. 00577 * 00578 * @note MUST NOT be called on a packet queue (Not verified to work yet). 00579 * @note the reference counter of a pbuf equals the number of pointers 00580 * that refer to the pbuf (or into the pbuf). 00581 * 00582 * @internal examples: 00583 * 00584 * Assuming existing chains a->b->c with the following reference 00585 * counts, calling pbuf_free(a) results in: 00586 * 00587 * 1->2->3 becomes ...1->3 00588 * 3->3->3 becomes 2->3->3 00589 * 1->1->2 becomes ......1 00590 * 2->1->1 becomes 1->1->1 00591 * 1->1->1 becomes ....... 00592 * 00593 */ 00594 u8_t 00595 pbuf_free(struct pbuf *p) 00596 { 00597 u16_t type; 00598 struct pbuf *q; 00599 u8_t count; 00600 00601 if (p == NULL) { 00602 LWIP_ASSERT("p != NULL", p != NULL); 00603 /* if assertions are disabled, proceed with debug output */ 00604 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS, 00605 ("pbuf_free(p == NULL) was called.\n")); 00606 return 0; 00607 } 00608 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free(%p)\n", (void *)p)); 00609 00610 PERF_START; 00611 00612 LWIP_ASSERT("pbuf_free: sane type", 00613 p->type == PBUF_RAM || p->type == PBUF_ROM || 00614 p->type == PBUF_REF || p->type == PBUF_POOL); 00615 00616 count = 0; 00617 /* de-allocate all consecutive pbufs from the head of the chain that 00618 * obtain a zero reference count after decrementing*/ 00619 while (p != NULL) { 00620 u16_t ref; 00621 SYS_ARCH_DECL_PROTECT(old_level); 00622 /* Since decrementing ref cannot be guaranteed to be a single machine operation 00623 * we must protect it. We put the new ref into a local variable to prevent 00624 * further protection. */ 00625 SYS_ARCH_PROTECT(old_level); 00626 /* all pbufs in a chain are referenced at least once */ 00627 LWIP_ASSERT("pbuf_free: p->ref > 0", p->ref > 0); 00628 /* decrease reference count (number of pointers to pbuf) */ 00629 ref = --(p->ref); 00630 SYS_ARCH_UNPROTECT(old_level); 00631 /* this pbuf is no longer referenced to? */ 00632 if (ref == 0) { 00633 /* remember next pbuf in chain for next iteration */ 00634 q = p->next; 00635 LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free: deallocating %p\n", (void *)p)); 00636 type = p->type; 00637 #if LWIP_SUPPORT_CUSTOM_PBUF 00638 /* is this a custom pbuf? */ 00639 if ((p->flags & PBUF_FLAG_IS_CUSTOM) != 0) { 00640 struct pbuf_custom *pc = (struct pbuf_custom*)p; 00641 LWIP_ASSERT("pc->custom_free_function != NULL", pc->custom_free_function != NULL); 00642 pc->custom_free_function(p); 00643 } else 00644 #endif /* LWIP_SUPPORT_CUSTOM_PBUF */ 00645 { 00646 /* is this a pbuf from the pool? */ 00647 if (type == PBUF_POOL) { 00648 memp_free(MEMP_PBUF_POOL, p); 00649 /* is this a ROM or RAM referencing pbuf? */ 00650 } else if (type == PBUF_ROM || type == PBUF_REF) { 00651 memp_free(MEMP_PBUF, p); 00652 /* type == PBUF_RAM */ 00653 } else { 00654 mem_free(p); 00655 } 00656 } 00657 count++; 00658 /* proceed to next pbuf */ 00659 p = q; 00660 /* p->ref > 0, this pbuf is still referenced to */ 00661 /* (and so the remaining pbufs in chain as well) */ 00662 } else { 00663 LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref)); 00664 /* stop walking through the chain */ 00665 p = NULL; 00666 } 00667 } 00668 PERF_STOP("pbuf_free"); 00669 /* return number of de-allocated pbufs */ 00670 return count; 00671 } 00672 00673 /** 00674 * Count number of pbufs in a chain 00675 * 00676 * @param p first pbuf of chain 00677 * @return the number of pbufs in a chain 00678 */ 00679 00680 u8_t 00681 pbuf_clen(struct pbuf *p) 00682 { 00683 u8_t len; 00684 00685 len = 0; 00686 while (p != NULL) { 00687 ++len; 00688 p = p->next; 00689 } 00690 return len; 00691 } 00692 00693 /** 00694 * Increment the reference count of the pbuf. 00695 * 00696 * @param p pbuf to increase reference counter of 00697 * 00698 */ 00699 void 00700 pbuf_ref(struct pbuf *p) 00701 { 00702 SYS_ARCH_DECL_PROTECT(old_level); 00703 /* pbuf given? */ 00704 if (p != NULL) { 00705 SYS_ARCH_PROTECT(old_level); 00706 ++(p->ref); 00707 SYS_ARCH_UNPROTECT(old_level); 00708 } 00709 } 00710 00711 /** 00712 * Concatenate two pbufs (each may be a pbuf chain) and take over 00713 * the caller's reference of the tail pbuf. 00714 * 00715 * @note The caller MAY NOT reference the tail pbuf afterwards. 00716 * Use pbuf_chain() for that purpose. 00717 * 00718 * @see pbuf_chain() 00719 */ 00720 00721 void 00722 pbuf_cat(struct pbuf *h, struct pbuf *t) 00723 { 00724 struct pbuf *p; 00725 00726 LWIP_ERROR("(h != NULL) && (t != NULL) (programmer violates API)", 00727 ((h != NULL) && (t != NULL)), return;); 00728 00729 /* proceed to last pbuf of chain */ 00730 for (p = h; p->next != NULL; p = p->next) { 00731 /* add total length of second chain to all totals of first chain */ 00732 p->tot_len += t->tot_len; 00733 } 00734 /* { p is last pbuf of first h chain, p->next == NULL } */ 00735 LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len); 00736 LWIP_ASSERT("p->next == NULL", p->next == NULL); 00737 /* add total length of second chain to last pbuf total of first chain */ 00738 p->tot_len += t->tot_len; 00739 /* chain last pbuf of head (p) with first of tail (t) */ 00740 p->next = t; 00741 /* p->next now references t, but the caller will drop its reference to t, 00742 * so netto there is no change to the reference count of t. 00743 */ 00744 } 00745 00746 /** 00747 * Chain two pbufs (or pbuf chains) together. 00748 * 00749 * The caller MUST call pbuf_free(t) once it has stopped 00750 * using it. Use pbuf_cat() instead if you no longer use t. 00751 * 00752 * @param h head pbuf (chain) 00753 * @param t tail pbuf (chain) 00754 * @note The pbufs MUST belong to the same packet. 00755 * @note MAY NOT be called on a packet queue. 00756 * 00757 * The ->tot_len fields of all pbufs of the head chain are adjusted. 00758 * The ->next field of the last pbuf of the head chain is adjusted. 00759 * The ->ref field of the first pbuf of the tail chain is adjusted. 00760 * 00761 */ 00762 void 00763 pbuf_chain(struct pbuf *h, struct pbuf *t) 00764 { 00765 pbuf_cat(h, t); 00766 /* t is now referenced by h */ 00767 pbuf_ref(t); 00768 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_chain: %p references %p\n", (void *)h, (void *)t)); 00769 } 00770 00771 /** 00772 * Dechains the first pbuf from its succeeding pbufs in the chain. 00773 * 00774 * Makes p->tot_len field equal to p->len. 00775 * @param p pbuf to dechain 00776 * @return remainder of the pbuf chain, or NULL if it was de-allocated. 00777 * @note May not be called on a packet queue. 00778 */ 00779 struct pbuf * 00780 pbuf_dechain(struct pbuf *p) 00781 { 00782 struct pbuf *q; 00783 u8_t tail_gone = 1; 00784 /* tail */ 00785 q = p->next; 00786 /* pbuf has successor in chain? */ 00787 if (q != NULL) { 00788 /* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */ 00789 LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len); 00790 /* enforce invariant if assertion is disabled */ 00791 q->tot_len = p->tot_len - p->len; 00792 /* decouple pbuf from remainder */ 00793 p->next = NULL; 00794 /* total length of pbuf p is its own length only */ 00795 p->tot_len = p->len; 00796 /* q is no longer referenced by p, free it */ 00797 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_dechain: unreferencing %p\n", (void *)q)); 00798 tail_gone = pbuf_free(q); 00799 if (tail_gone > 0) { 00800 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, 00801 ("pbuf_dechain: deallocated %p (as it is no longer referenced)\n", (void *)q)); 00802 } 00803 /* return remaining tail or NULL if deallocated */ 00804 } 00805 /* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */ 00806 LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len); 00807 return ((tail_gone > 0) ? NULL : q); 00808 } 00809 00810 /** 00811 * 00812 * Create PBUF_RAM copies of pbufs. 00813 * 00814 * Used to queue packets on behalf of the lwIP stack, such as 00815 * ARP based queueing. 00816 * 00817 * @note You MUST explicitly use p = pbuf_take(p); 00818 * 00819 * @note Only one packet is copied, no packet queue! 00820 * 00821 * @param p_to pbuf destination of the copy 00822 * @param p_from pbuf source of the copy 00823 * 00824 * @return ERR_OK if pbuf was copied 00825 * ERR_ARG if one of the pbufs is NULL or p_to is not big 00826 * enough to hold p_from 00827 */ 00828 err_t 00829 pbuf_copy(struct pbuf *p_to, struct pbuf *p_from) 00830 { 00831 u16_t offset_to=0, offset_from=0, len; 00832 00833 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy(%p, %p)\n", 00834 (void*)p_to, (void*)p_from)); 00835 00836 /* is the target big enough to hold the source? */ 00837 LWIP_ERROR("pbuf_copy: target not big enough to hold source", ((p_to != NULL) && 00838 (p_from != NULL) && (p_to->tot_len >= p_from->tot_len)), return ERR_ARG;); 00839 00840 /* iterate through pbuf chain */ 00841 do 00842 { 00843 LWIP_ASSERT("p_to != NULL", p_to != NULL); 00844 /* copy one part of the original chain */ 00845 if ((p_to->len - offset_to) >= (p_from->len - offset_from)) { 00846 /* complete current p_from fits into current p_to */ 00847 len = p_from->len - offset_from; 00848 } else { 00849 /* current p_from does not fit into current p_to */ 00850 len = p_to->len - offset_to; 00851 } 00852 MEMCPY((u8_t*)p_to->payload + offset_to, (u8_t*)p_from->payload + offset_from, len); 00853 offset_to += len; 00854 offset_from += len; 00855 LWIP_ASSERT("offset_to <= p_to->len", offset_to <= p_to->len); 00856 if (offset_to == p_to->len) { 00857 /* on to next p_to (if any) */ 00858 offset_to = 0; 00859 p_to = p_to->next; 00860 } 00861 LWIP_ASSERT("offset_from <= p_from->len", offset_from <= p_from->len); 00862 if (offset_from >= p_from->len) { 00863 /* on to next p_from (if any) */ 00864 offset_from = 0; 00865 p_from = p_from->next; 00866 } 00867 00868 if((p_from != NULL) && (p_from->len == p_from->tot_len)) { 00869 /* don't copy more than one packet! */ 00870 LWIP_ERROR("pbuf_copy() does not allow packet queues!\n", 00871 (p_from->next == NULL), return ERR_VAL;); 00872 } 00873 if((p_to != NULL) && (p_to->len == p_to->tot_len)) { 00874 /* don't copy more than one packet! */ 00875 LWIP_ERROR("pbuf_copy() does not allow packet queues!\n", 00876 (p_to->next == NULL), return ERR_VAL;); 00877 } 00878 } while (p_from); 00879 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy: end of chain reached.\n")); 00880 return ERR_OK; 00881 } 00882 00883 /** 00884 * Copy (part of) the contents of a packet buffer 00885 * to an application supplied buffer. 00886 * 00887 * @param buf the pbuf from which to copy data 00888 * @param dataptr the application supplied buffer 00889 * @param len length of data to copy (dataptr must be big enough). No more 00890 * than buf->tot_len will be copied, irrespective of len 00891 * @param offset offset into the packet buffer from where to begin copying len bytes 00892 * @return the number of bytes copied, or 0 on failure 00893 */ 00894 u16_t 00895 pbuf_copy_partial(struct pbuf *buf, void *dataptr, u16_t len, u16_t offset) 00896 { 00897 struct pbuf *p; 00898 u16_t left; 00899 u16_t buf_copy_len; 00900 u16_t copied_total = 0; 00901 00902 LWIP_ERROR("pbuf_copy_partial: invalid buf", (buf != NULL), return 0;); 00903 LWIP_ERROR("pbuf_copy_partial: invalid dataptr", (dataptr != NULL), return 0;); 00904 00905 left = 0; 00906 00907 if((buf == NULL) || (dataptr == NULL)) { 00908 return 0; 00909 } 00910 00911 /* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */ 00912 for(p = buf; len != 0 && p != NULL; p = p->next) { 00913 if ((offset != 0) && (offset >= p->len)) { 00914 /* don't copy from this buffer -> on to the next */ 00915 offset -= p->len; 00916 } else { 00917 /* copy from this buffer. maybe only partially. */ 00918 buf_copy_len = p->len - offset; 00919 if (buf_copy_len > len) 00920 buf_copy_len = len; 00921 /* copy the necessary parts of the buffer */ 00922 MEMCPY(&((char*)dataptr)[left], &((char*)p->payload)[offset], buf_copy_len); 00923 copied_total += buf_copy_len; 00924 left += buf_copy_len; 00925 len -= buf_copy_len; 00926 offset = 0; 00927 } 00928 } 00929 return copied_total; 00930 } 00931 00932 /** 00933 * Copy application supplied data into a pbuf. 00934 * This function can only be used to copy the equivalent of buf->tot_len data. 00935 * 00936 * @param buf pbuf to fill with data 00937 * @param dataptr application supplied data buffer 00938 * @param len length of the application supplied data buffer 00939 * 00940 * @return ERR_OK if successful, ERR_MEM if the pbuf is not big enough 00941 */ 00942 err_t 00943 pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len) 00944 { 00945 struct pbuf *p; 00946 u16_t buf_copy_len; 00947 u16_t total_copy_len = len; 00948 u16_t copied_total = 0; 00949 00950 LWIP_ERROR("pbuf_take: invalid buf", (buf != NULL), return 0;); 00951 LWIP_ERROR("pbuf_take: invalid dataptr", (dataptr != NULL), return 0;); 00952 00953 if ((buf == NULL) || (dataptr == NULL) || (buf->tot_len < len)) { 00954 return ERR_ARG; 00955 } 00956 00957 /* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */ 00958 for(p = buf; total_copy_len != 0; p = p->next) { 00959 LWIP_ASSERT("pbuf_take: invalid pbuf", p != NULL); 00960 buf_copy_len = total_copy_len; 00961 if (buf_copy_len > p->len) { 00962 /* this pbuf cannot hold all remaining data */ 00963 buf_copy_len = p->len; 00964 } 00965 /* copy the necessary parts of the buffer */ 00966 MEMCPY(p->payload, &((char*)dataptr)[copied_total], buf_copy_len); 00967 total_copy_len -= buf_copy_len; 00968 copied_total += buf_copy_len; 00969 } 00970 LWIP_ASSERT("did not copy all data", total_copy_len == 0 && copied_total == len); 00971 return ERR_OK; 00972 } 00973 00974 /** 00975 * Creates a single pbuf out of a queue of pbufs. 00976 * 00977 * @remark: Either the source pbuf 'p' is freed by this function or the original 00978 * pbuf 'p' is returned, therefore the caller has to check the result! 00979 * 00980 * @param p the source pbuf 00981 * @param layer pbuf_layer of the new pbuf 00982 * 00983 * @return a new, single pbuf (p->next is NULL) 00984 * or the old pbuf if allocation fails 00985 */ 00986 struct pbuf* 00987 pbuf_coalesce(struct pbuf *p, pbuf_layer layer) 00988 { 00989 struct pbuf *q; 00990 err_t err; 00991 if (p->next == NULL) { 00992 return p; 00993 } 00994 q = pbuf_alloc(layer, p->tot_len, PBUF_RAM); 00995 if (q == NULL) { 00996 /* @todo: what do we do now? */ 00997 return p; 00998 } 00999 err = pbuf_copy(q, p); 01000 LWIP_ASSERT("pbuf_copy failed", err == ERR_OK); 01001 pbuf_free(p); 01002 return q; 01003 } 01004 01005 #if LWIP_CHECKSUM_ON_COPY 01006 /** 01007 * Copies data into a single pbuf (*not* into a pbuf queue!) and updates 01008 * the checksum while copying 01009 * 01010 * @param p the pbuf to copy data into 01011 * @param start_offset offset of p->payload where to copy the data to 01012 * @param dataptr data to copy into the pbuf 01013 * @param len length of data to copy into the pbuf 01014 * @param chksum pointer to the checksum which is updated 01015 * @return ERR_OK if successful, another error if the data does not fit 01016 * within the (first) pbuf (no pbuf queues!) 01017 */ 01018 err_t 01019 pbuf_fill_chksum(struct pbuf *p, u16_t start_offset, const void *dataptr, 01020 u16_t len, u16_t *chksum) 01021 { 01022 u32_t acc; 01023 u16_t copy_chksum; 01024 char *dst_ptr; 01025 LWIP_ASSERT("p != NULL", p != NULL); 01026 LWIP_ASSERT("dataptr != NULL", dataptr != NULL); 01027 LWIP_ASSERT("chksum != NULL", chksum != NULL); 01028 LWIP_ASSERT("len != 0", len != 0); 01029 01030 if ((start_offset >= p->len) || (start_offset + len > p->len)) { 01031 return ERR_ARG; 01032 } 01033 01034 dst_ptr = ((char*)p->payload) + start_offset; 01035 copy_chksum = LWIP_CHKSUM_COPY(dst_ptr, dataptr, len); 01036 if ((start_offset & 1) != 0) { 01037 copy_chksum = SWAP_BYTES_IN_WORD(copy_chksum); 01038 } 01039 acc = *chksum; 01040 acc += copy_chksum; 01041 *chksum = FOLD_U32T(acc); 01042 return ERR_OK; 01043 } 01044 #endif /* LWIP_CHECKSUM_ON_COPY */ 01045 01046 /** Get one byte from the specified position in a pbuf 01047 * WARNING: returns zero for offset >= p->tot_len 01048 * 01049 * @param p pbuf to parse 01050 * @param offset offset into p of the byte to return 01051 * @return byte at an offset into p OR ZERO IF 'offset' >= p->tot_len 01052 */ 01053 u8_t 01054 pbuf_get_at(struct pbuf* p, u16_t offset) 01055 { 01056 u16_t copy_from = offset; 01057 struct pbuf* q = p; 01058 01059 /* get the correct pbuf */ 01060 while ((q != NULL) && (q->len <= copy_from)) { 01061 copy_from -= q->len; 01062 q = q->next; 01063 } 01064 /* return requested data if pbuf is OK */ 01065 if ((q != NULL) && (q->len > copy_from)) { 01066 return ((u8_t*)q->payload)[copy_from]; 01067 } 01068 return 0; 01069 } 01070 01071 /** Compare pbuf contents at specified offset with memory s2, both of length n 01072 * 01073 * @param p pbuf to compare 01074 * @param offset offset into p at wich to start comparing 01075 * @param s2 buffer to compare 01076 * @param n length of buffer to compare 01077 * @return zero if equal, nonzero otherwise 01078 * (0xffff if p is too short, diffoffset+1 otherwise) 01079 */ 01080 u16_t 01081 pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n) 01082 { 01083 u16_t start = offset; 01084 struct pbuf* q = p; 01085 01086 /* get the correct pbuf */ 01087 while ((q != NULL) && (q->len <= start)) { 01088 start -= q->len; 01089 q = q->next; 01090 } 01091 /* return requested data if pbuf is OK */ 01092 if ((q != NULL) && (q->len > start)) { 01093 u16_t i; 01094 for(i = 0; i < n; i++) { 01095 u8_t a = pbuf_get_at(q, start + i); 01096 u8_t b = ((u8_t*)s2)[i]; 01097 if (a != b) { 01098 return i+1; 01099 } 01100 } 01101 return 0; 01102 } 01103 return 0xffff; 01104 } 01105 01106 /** Find occurrence of mem (with length mem_len) in pbuf p, starting at offset 01107 * start_offset. 01108 * 01109 * @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as 01110 * return value 'not found' 01111 * @param mem search for the contents of this buffer 01112 * @param mem_len length of 'mem' 01113 * @param start_offset offset into p at which to start searching 01114 * @return 0xFFFF if substr was not found in p or the index where it was found 01115 */ 01116 u16_t 01117 pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset) 01118 { 01119 u16_t i; 01120 u16_t max = p->tot_len - mem_len; 01121 if (p->tot_len >= mem_len + start_offset) { 01122 for(i = start_offset; i <= max; ) { 01123 u16_t plus = pbuf_memcmp(p, i, mem, mem_len); 01124 if (plus == 0) { 01125 return i; 01126 } else { 01127 i += plus; 01128 } 01129 } 01130 } 01131 return 0xFFFF; 01132 } 01133 01134 /** Find occurrence of substr with length substr_len in pbuf p, start at offset 01135 * start_offset 01136 * WARNING: in contrast to strstr(), this one does not stop at the first \0 in 01137 * the pbuf/source string! 01138 * 01139 * @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as 01140 * return value 'not found' 01141 * @param substr string to search for in p, maximum length is 0xFFFE 01142 * @return 0xFFFF if substr was not found in p or the index where it was found 01143 */ 01144 u16_t 01145 pbuf_strstr(struct pbuf* p, const char* substr) 01146 { 01147 size_t substr_len; 01148 if ((substr == NULL) || (substr[0] == 0) || (p->tot_len == 0xFFFF)) { 01149 return 0xFFFF; 01150 } 01151 substr_len = strlen(substr); 01152 if (substr_len >= 0xFFFF) { 01153 return 0xFFFF; 01154 } 01155 return pbuf_memfind(p, substr, (u16_t)substr_len, 0); 01156 }
Generated on Tue Jul 12 2022 11:52:58 by
![doxygen](doxygen.png)