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lwip_pbuf.c
00001 /** 00002 * @file 00003 * Packet buffer management 00004 */ 00005 00006 /** 00007 * @defgroup pbuf Packet buffers (PBUF) 00008 * @ingroup infrastructure 00009 * 00010 * Packets are built from the pbuf data structure. It supports dynamic 00011 * memory allocation for packet contents or can reference externally 00012 * managed packet contents both in RAM and ROM. Quick allocation for 00013 * incoming packets is provided through pools with fixed sized pbufs. 00014 * 00015 * A packet may span over multiple pbufs, chained as a singly linked 00016 * list. This is called a "pbuf chain". 00017 * 00018 * Multiple packets may be queued, also using this singly linked list. 00019 * This is called a "packet queue". 00020 * 00021 * So, a packet queue consists of one or more pbuf chains, each of 00022 * which consist of one or more pbufs. CURRENTLY, PACKET QUEUES ARE 00023 * NOT SUPPORTED!!! Use helper structs to queue multiple packets. 00024 * 00025 * The differences between a pbuf chain and a packet queue are very 00026 * precise but subtle. 00027 * 00028 * The last pbuf of a packet has a ->tot_len field that equals the 00029 * ->len field. It can be found by traversing the list. If the last 00030 * pbuf of a packet has a ->next field other than NULL, more packets 00031 * are on the queue. 00032 * 00033 * Therefore, looping through a pbuf of a single packet, has an 00034 * loop end condition (tot_len == p->len), NOT (next == NULL). 00035 */ 00036 00037 /* 00038 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 00039 * All rights reserved. 00040 * 00041 * Redistribution and use in source and binary forms, with or without modification, 00042 * are permitted provided that the following conditions are met: 00043 * 00044 * 1. Redistributions of source code must retain the above copyright notice, 00045 * this list of conditions and the following disclaimer. 00046 * 2. Redistributions in binary form must reproduce the above copyright notice, 00047 * this list of conditions and the following disclaimer in the documentation 00048 * and/or other materials provided with the distribution. 00049 * 3. The name of the author may not be used to endorse or promote products 00050 * derived from this software without specific prior written permission. 00051 * 00052 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 00053 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00054 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 00055 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00056 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 00057 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00058 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00059 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 00060 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 00061 * OF SUCH DAMAGE. 00062 * 00063 * This file is part of the lwIP TCP/IP stack. 00064 * 00065 * Author: Adam Dunkels <adam@sics.se> 00066 * 00067 */ 00068 00069 #include "lwip/opt.h" 00070 00071 #include "lwip/stats.h" 00072 #include "lwip/def.h" 00073 #include "lwip/mem.h" 00074 #include "lwip/memp.h" 00075 #include "lwip/pbuf.h" 00076 #include "lwip/sys.h" 00077 #if LWIP_TCP && TCP_QUEUE_OOSEQ 00078 #include "lwip/priv/tcp_priv.h" 00079 #endif 00080 #if LWIP_CHECKSUM_ON_COPY 00081 #include "lwip/inet_chksum.h" 00082 #endif 00083 00084 #include <string.h> 00085 00086 #define SIZEOF_STRUCT_PBUF LWIP_MEM_ALIGN_SIZE(sizeof(struct pbuf)) 00087 /* Since the pool is created in memp, PBUF_POOL_BUFSIZE will be automatically 00088 aligned there. Therefore, PBUF_POOL_BUFSIZE_ALIGNED can be used here. */ 00089 #define PBUF_POOL_BUFSIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE) 00090 00091 #if !LWIP_TCP || !TCP_QUEUE_OOSEQ || !PBUF_POOL_FREE_OOSEQ 00092 #define PBUF_POOL_IS_EMPTY() 00093 #else /* !LWIP_TCP || !TCP_QUEUE_OOSEQ || !PBUF_POOL_FREE_OOSEQ */ 00094 00095 #if !NO_SYS 00096 #ifndef PBUF_POOL_FREE_OOSEQ_QUEUE_CALL 00097 #include "lwip/tcpip.h" 00098 #define PBUF_POOL_FREE_OOSEQ_QUEUE_CALL() do { \ 00099 if (tcpip_callback_with_block(pbuf_free_ooseq_callback, NULL, 0) != ERR_OK) { \ 00100 SYS_ARCH_PROTECT(old_level); \ 00101 pbuf_free_ooseq_pending = 0; \ 00102 SYS_ARCH_UNPROTECT(old_level); \ 00103 } } while(0) 00104 #endif /* PBUF_POOL_FREE_OOSEQ_QUEUE_CALL */ 00105 #endif /* !NO_SYS */ 00106 00107 volatile u8_t pbuf_free_ooseq_pending; 00108 #define PBUF_POOL_IS_EMPTY() pbuf_pool_is_empty() 00109 00110 /** 00111 * Attempt to reclaim some memory from queued out-of-sequence TCP segments 00112 * if we run out of pool pbufs. It's better to give priority to new packets 00113 * if we're running out. 00114 * 00115 * This must be done in the correct thread context therefore this function 00116 * can only be used with NO_SYS=0 and through tcpip_callback. 00117 */ 00118 #if !NO_SYS 00119 static 00120 #endif /* !NO_SYS */ 00121 void 00122 pbuf_free_ooseq(void) 00123 { 00124 struct tcp_pcb* pcb; 00125 SYS_ARCH_SET(pbuf_free_ooseq_pending, 0); 00126 00127 for (pcb = tcp_active_pcbs; NULL != pcb; pcb = pcb->next) { 00128 if (NULL != pcb->ooseq) { 00129 /** Free the ooseq pbufs of one PCB only */ 00130 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free_ooseq: freeing out-of-sequence pbufs\n")); 00131 tcp_segs_free(pcb->ooseq); 00132 pcb->ooseq = NULL; 00133 return; 00134 } 00135 } 00136 } 00137 00138 #if !NO_SYS 00139 /** 00140 * Just a callback function for tcpip_callback() that calls pbuf_free_ooseq(). 00141 */ 00142 static void 00143 pbuf_free_ooseq_callback(void *arg) 00144 { 00145 LWIP_UNUSED_ARG(arg); 00146 pbuf_free_ooseq(); 00147 } 00148 #endif /* !NO_SYS */ 00149 00150 /** Queue a call to pbuf_free_ooseq if not already queued. */ 00151 static void 00152 pbuf_pool_is_empty(void) 00153 { 00154 #ifndef PBUF_POOL_FREE_OOSEQ_QUEUE_CALL 00155 SYS_ARCH_SET(pbuf_free_ooseq_pending, 1); 00156 #else /* PBUF_POOL_FREE_OOSEQ_QUEUE_CALL */ 00157 u8_t queued; 00158 SYS_ARCH_DECL_PROTECT(old_level); 00159 SYS_ARCH_PROTECT(old_level); 00160 queued = pbuf_free_ooseq_pending; 00161 pbuf_free_ooseq_pending = 1; 00162 SYS_ARCH_UNPROTECT(old_level); 00163 00164 if (!queued) { 00165 /* queue a call to pbuf_free_ooseq if not already queued */ 00166 PBUF_POOL_FREE_OOSEQ_QUEUE_CALL(); 00167 } 00168 #endif /* PBUF_POOL_FREE_OOSEQ_QUEUE_CALL */ 00169 } 00170 #endif /* !LWIP_TCP || !TCP_QUEUE_OOSEQ || !PBUF_POOL_FREE_OOSEQ */ 00171 00172 /** 00173 * @ingroup pbuf 00174 * Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type). 00175 * 00176 * The actual memory allocated for the pbuf is determined by the 00177 * layer at which the pbuf is allocated and the requested size 00178 * (from the size parameter). 00179 * 00180 * @param layer flag to define header size 00181 * @param length size of the pbuf's payload 00182 * @param type this parameter decides how and where the pbuf 00183 * should be allocated as follows: 00184 * 00185 * - PBUF_RAM: buffer memory for pbuf is allocated as one large 00186 * chunk. This includes protocol headers as well. 00187 * - PBUF_ROM: no buffer memory is allocated for the pbuf, even for 00188 * protocol headers. Additional headers must be prepended 00189 * by allocating another pbuf and chain in to the front of 00190 * the ROM pbuf. It is assumed that the memory used is really 00191 * similar to ROM in that it is immutable and will not be 00192 * changed. Memory which is dynamic should generally not 00193 * be attached to PBUF_ROM pbufs. Use PBUF_REF instead. 00194 * - PBUF_REF: no buffer memory is allocated for the pbuf, even for 00195 * protocol headers. It is assumed that the pbuf is only 00196 * being used in a single thread. If the pbuf gets queued, 00197 * then pbuf_take should be called to copy the buffer. 00198 * - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from 00199 * the pbuf pool that is allocated during pbuf_init(). 00200 * 00201 * @return the allocated pbuf. If multiple pbufs where allocated, this 00202 * is the first pbuf of a pbuf chain. 00203 */ 00204 struct pbuf * 00205 pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type) 00206 { 00207 struct pbuf *p, *q, *r; 00208 u16_t offset; 00209 s32_t rem_len; /* remaining length */ 00210 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length)); 00211 00212 /* determine header offset */ 00213 switch (layer) { 00214 case PBUF_TRANSPORT: 00215 /* add room for transport (often TCP) layer header */ 00216 offset = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN + PBUF_TRANSPORT_HLEN; 00217 break; 00218 case PBUF_IP: 00219 /* add room for IP layer header */ 00220 offset = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN; 00221 break; 00222 case PBUF_LINK: 00223 /* add room for link layer header */ 00224 offset = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN; 00225 break; 00226 case PBUF_RAW_TX: 00227 /* add room for encapsulating link layer headers (e.g. 802.11) */ 00228 offset = PBUF_LINK_ENCAPSULATION_HLEN; 00229 break; 00230 case PBUF_RAW: 00231 /* no offset (e.g. RX buffers or chain successors) */ 00232 offset = 0; 00233 break; 00234 default: 00235 LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0); 00236 return NULL; 00237 } 00238 00239 switch (type) { 00240 case PBUF_POOL: 00241 /* allocate head of pbuf chain into p */ 00242 p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL); 00243 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p)); 00244 if (p == NULL) { 00245 PBUF_POOL_IS_EMPTY(); 00246 return NULL; 00247 } 00248 p->type = type; 00249 p->next = NULL; 00250 00251 /* make the payload pointer point 'offset' bytes into pbuf data memory */ 00252 p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + (SIZEOF_STRUCT_PBUF + offset))); 00253 LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned", 00254 ((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0); 00255 /* the total length of the pbuf chain is the requested size */ 00256 p->tot_len = length; 00257 /* set the length of the first pbuf in the chain */ 00258 p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)); 00259 LWIP_ASSERT("check p->payload + p->len does not overflow pbuf", 00260 ((u8_t*)p->payload + p->len <= 00261 (u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED)); 00262 LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT", 00263 (PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 ); 00264 /* set reference count (needed here in case we fail) */ 00265 p->ref = 1; 00266 00267 /* now allocate the tail of the pbuf chain */ 00268 00269 /* remember first pbuf for linkage in next iteration */ 00270 r = p; 00271 /* remaining length to be allocated */ 00272 rem_len = length - p->len; 00273 /* any remaining pbufs to be allocated? */ 00274 while (rem_len > 0) { 00275 q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL); 00276 if (q == NULL) { 00277 PBUF_POOL_IS_EMPTY(); 00278 /* free chain so far allocated */ 00279 pbuf_free(p); 00280 /* bail out unsuccessfully */ 00281 return NULL; 00282 } 00283 q->type = type; 00284 q->flags = 0; 00285 q->next = NULL; 00286 /* make previous pbuf point to this pbuf */ 00287 r->next = q; 00288 /* set total length of this pbuf and next in chain */ 00289 LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff); 00290 q->tot_len = (u16_t)rem_len; 00291 /* this pbuf length is pool size, unless smaller sized tail */ 00292 q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED); 00293 q->payload = (void *)((u8_t *)q + SIZEOF_STRUCT_PBUF); 00294 LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned", 00295 ((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0); 00296 LWIP_ASSERT("check p->payload + p->len does not overflow pbuf", 00297 ((u8_t*)p->payload + p->len <= 00298 (u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED)); 00299 q->ref = 1; 00300 /* calculate remaining length to be allocated */ 00301 rem_len -= q->len; 00302 /* remember this pbuf for linkage in next iteration */ 00303 r = q; 00304 } 00305 /* end of chain */ 00306 /*r->next = NULL;*/ 00307 00308 break; 00309 case PBUF_RAM: 00310 /* If pbuf is to be allocated in RAM, allocate memory for it. */ 00311 p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length)); 00312 if (p == NULL) { 00313 return NULL; 00314 } 00315 /* Set up internal structure of the pbuf. */ 00316 p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + SIZEOF_STRUCT_PBUF + offset)); 00317 p->len = p->tot_len = length; 00318 p->next = NULL; 00319 p->type = type; 00320 00321 LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned", 00322 ((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0); 00323 break; 00324 /* pbuf references existing (non-volatile static constant) ROM payload? */ 00325 case PBUF_ROM: 00326 /* pbuf references existing (externally allocated) RAM payload? */ 00327 case PBUF_REF: 00328 /* only allocate memory for the pbuf structure */ 00329 p = (struct pbuf *)memp_malloc(MEMP_PBUF); 00330 if (p == NULL) { 00331 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS, 00332 ("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n", 00333 (type == PBUF_ROM) ? "ROM" : "REF")); 00334 return NULL; 00335 } 00336 /* caller must set this field properly, afterwards */ 00337 p->payload = NULL; 00338 p->len = p->tot_len = length; 00339 p->next = NULL; 00340 p->type = type; 00341 break; 00342 default: 00343 LWIP_ASSERT("pbuf_alloc: erroneous type", 0); 00344 return NULL; 00345 } 00346 /* set reference count */ 00347 p->ref = 1; 00348 /* set flags */ 00349 p->flags = 0; 00350 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p)); 00351 return p; 00352 } 00353 00354 #if LWIP_SUPPORT_CUSTOM_PBUF 00355 /** 00356 * @ingroup pbuf 00357 * Initialize a custom pbuf (already allocated). 00358 * 00359 * @param l flag to define header size 00360 * @param length size of the pbuf's payload 00361 * @param type type of the pbuf (only used to treat the pbuf accordingly, as 00362 * this function allocates no memory) 00363 * @param p pointer to the custom pbuf to initialize (already allocated) 00364 * @param payload_mem pointer to the buffer that is used for payload and headers, 00365 * must be at least big enough to hold 'length' plus the header size, 00366 * may be NULL if set later. 00367 * ATTENTION: The caller is responsible for correct alignment of this buffer!! 00368 * @param payload_mem_len the size of the 'payload_mem' buffer, must be at least 00369 * big enough to hold 'length' plus the header size 00370 */ 00371 struct pbuf* 00372 pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type, struct pbuf_custom *p, 00373 void *payload_mem, u16_t payload_mem_len) 00374 { 00375 u16_t offset; 00376 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloced_custom(length=%"U16_F")\n", length)); 00377 00378 /* determine header offset */ 00379 switch (l) { 00380 case PBUF_TRANSPORT: 00381 /* add room for transport (often TCP) layer header */ 00382 offset = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN + PBUF_TRANSPORT_HLEN; 00383 break; 00384 case PBUF_IP: 00385 /* add room for IP layer header */ 00386 offset = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN; 00387 break; 00388 case PBUF_LINK: 00389 /* add room for link layer header */ 00390 offset = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN; 00391 break; 00392 case PBUF_RAW_TX: 00393 /* add room for encapsulating link layer headers (e.g. 802.11) */ 00394 offset = PBUF_LINK_ENCAPSULATION_HLEN; 00395 break; 00396 case PBUF_RAW: 00397 offset = 0; 00398 break; 00399 default: 00400 LWIP_ASSERT("pbuf_alloced_custom: bad pbuf layer", 0); 00401 return NULL; 00402 } 00403 00404 if (LWIP_MEM_ALIGN_SIZE(offset) + length > payload_mem_len) { 00405 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_WARNING, ("pbuf_alloced_custom(length=%"U16_F") buffer too short\n", length)); 00406 return NULL; 00407 } 00408 00409 p->pbuf.next = NULL; 00410 if (payload_mem != NULL) { 00411 p->pbuf.payload = (u8_t *)payload_mem + LWIP_MEM_ALIGN_SIZE(offset); 00412 } else { 00413 p->pbuf.payload = NULL; 00414 } 00415 p->pbuf.flags = PBUF_FLAG_IS_CUSTOM; 00416 p->pbuf.len = p->pbuf.tot_len = length; 00417 p->pbuf.type = type; 00418 p->pbuf.ref = 1; 00419 return &p->pbuf; 00420 } 00421 #endif /* LWIP_SUPPORT_CUSTOM_PBUF */ 00422 00423 /** 00424 * @ingroup pbuf 00425 * Shrink a pbuf chain to a desired length. 00426 * 00427 * @param p pbuf to shrink. 00428 * @param new_len desired new length of pbuf chain 00429 * 00430 * Depending on the desired length, the first few pbufs in a chain might 00431 * be skipped and left unchanged. The new last pbuf in the chain will be 00432 * resized, and any remaining pbufs will be freed. 00433 * 00434 * @note If the pbuf is ROM/REF, only the ->tot_len and ->len fields are adjusted. 00435 * @note May not be called on a packet queue. 00436 * 00437 * @note Despite its name, pbuf_realloc cannot grow the size of a pbuf (chain). 00438 */ 00439 void 00440 pbuf_realloc(struct pbuf *p, u16_t new_len) 00441 { 00442 struct pbuf *q; 00443 u16_t rem_len; /* remaining length */ 00444 s32_t grow; 00445 00446 LWIP_ASSERT("pbuf_realloc: p != NULL", p != NULL); 00447 LWIP_ASSERT("pbuf_realloc: sane p->type", p->type == PBUF_POOL || 00448 p->type == PBUF_ROM || 00449 p->type == PBUF_RAM || 00450 p->type == PBUF_REF); 00451 00452 /* desired length larger than current length? */ 00453 if (new_len >= p->tot_len) { 00454 /* enlarging not yet supported */ 00455 return; 00456 } 00457 00458 /* the pbuf chain grows by (new_len - p->tot_len) bytes 00459 * (which may be negative in case of shrinking) */ 00460 grow = new_len - p->tot_len; 00461 00462 /* first, step over any pbufs that should remain in the chain */ 00463 rem_len = new_len; 00464 q = p; 00465 /* should this pbuf be kept? */ 00466 while (rem_len > q->len) { 00467 /* decrease remaining length by pbuf length */ 00468 rem_len -= q->len; 00469 /* decrease total length indicator */ 00470 LWIP_ASSERT("grow < max_u16_t", grow < 0xffff); 00471 q->tot_len += (u16_t)grow; 00472 /* proceed to next pbuf in chain */ 00473 q = q->next; 00474 LWIP_ASSERT("pbuf_realloc: q != NULL", q != NULL); 00475 } 00476 /* we have now reached the new last pbuf (in q) */ 00477 /* rem_len == desired length for pbuf q */ 00478 00479 /* shrink allocated memory for PBUF_RAM */ 00480 /* (other types merely adjust their length fields */ 00481 if ((q->type == PBUF_RAM) && (rem_len != q->len) 00482 #if LWIP_SUPPORT_CUSTOM_PBUF 00483 && ((q->flags & PBUF_FLAG_IS_CUSTOM) == 0) 00484 #endif /* LWIP_SUPPORT_CUSTOM_PBUF */ 00485 ) { 00486 /* reallocate and adjust the length of the pbuf that will be split */ 00487 q = (struct pbuf *)mem_trim(q, (u16_t)((u8_t *)q->payload - (u8_t *)q) + rem_len); 00488 LWIP_ASSERT("mem_trim returned q == NULL", q != NULL); 00489 } 00490 /* adjust length fields for new last pbuf */ 00491 q->len = rem_len; 00492 q->tot_len = q->len; 00493 00494 /* any remaining pbufs in chain? */ 00495 if (q->next != NULL) { 00496 /* free remaining pbufs in chain */ 00497 pbuf_free(q->next); 00498 } 00499 /* q is last packet in chain */ 00500 q->next = NULL; 00501 00502 } 00503 00504 /** 00505 * Adjusts the payload pointer to hide or reveal headers in the payload. 00506 * @see pbuf_header. 00507 * 00508 * @param p pbuf to change the header size. 00509 * @param header_size_increment Number of bytes to increment header size. 00510 * @param force Allow 'header_size_increment > 0' for PBUF_REF/PBUF_ROM types 00511 * 00512 * @return non-zero on failure, zero on success. 00513 * 00514 */ 00515 static u8_t 00516 pbuf_header_impl(struct pbuf *p, s16_t header_size_increment, u8_t force) 00517 { 00518 u16_t type; 00519 void *payload; 00520 u16_t increment_magnitude; 00521 00522 LWIP_ASSERT("p != NULL", p != NULL); 00523 if ((header_size_increment == 0) || (p == NULL)) { 00524 return 0; 00525 } 00526 00527 if (header_size_increment < 0) { 00528 increment_magnitude = -header_size_increment; 00529 /* Check that we aren't going to move off the end of the pbuf */ 00530 LWIP_ERROR("increment_magnitude <= p->len", (increment_magnitude <= p->len), return 1;); 00531 } else { 00532 increment_magnitude = header_size_increment; 00533 #if 0 00534 /* Can't assert these as some callers speculatively call 00535 pbuf_header() to see if it's OK. Will return 1 below instead. */ 00536 /* Check that we've got the correct type of pbuf to work with */ 00537 LWIP_ASSERT("p->type == PBUF_RAM || p->type == PBUF_POOL", 00538 p->type == PBUF_RAM || p->type == PBUF_POOL); 00539 /* Check that we aren't going to move off the beginning of the pbuf */ 00540 LWIP_ASSERT("p->payload - increment_magnitude >= p + SIZEOF_STRUCT_PBUF", 00541 (u8_t *)p->payload - increment_magnitude >= (u8_t *)p + SIZEOF_STRUCT_PBUF); 00542 #endif 00543 } 00544 00545 type = p->type; 00546 /* remember current payload pointer */ 00547 payload = p->payload; 00548 00549 /* pbuf types containing payloads? */ 00550 if (type == PBUF_RAM || type == PBUF_POOL) { 00551 /* set new payload pointer */ 00552 p->payload = (u8_t *)p->payload - header_size_increment; 00553 /* boundary check fails? */ 00554 if ((u8_t *)p->payload < (u8_t *)p + SIZEOF_STRUCT_PBUF) { 00555 LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, 00556 ("pbuf_header: failed as %p < %p (not enough space for new header size)\n", 00557 (void *)p->payload, (void *)((u8_t *)p + SIZEOF_STRUCT_PBUF))); 00558 /* restore old payload pointer */ 00559 p->payload = payload; 00560 /* bail out unsuccessfully */ 00561 return 1; 00562 } 00563 /* pbuf types referring to external payloads? */ 00564 } else if (type == PBUF_REF || type == PBUF_ROM) { 00565 /* hide a header in the payload? */ 00566 if ((header_size_increment < 0) && (increment_magnitude <= p->len)) { 00567 /* increase payload pointer */ 00568 p->payload = (u8_t *)p->payload - header_size_increment; 00569 } else if ((header_size_increment > 0) && force) { 00570 p->payload = (u8_t *)p->payload - header_size_increment; 00571 } else { 00572 /* cannot expand payload to front (yet!) 00573 * bail out unsuccessfully */ 00574 return 1; 00575 } 00576 } else { 00577 /* Unknown type */ 00578 LWIP_ASSERT("bad pbuf type", 0); 00579 return 1; 00580 } 00581 /* modify pbuf length fields */ 00582 p->len += header_size_increment; 00583 p->tot_len += header_size_increment; 00584 00585 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_header: old %p new %p (%"S16_F")\n", 00586 (void *)payload, (void *)p->payload, header_size_increment)); 00587 00588 return 0; 00589 } 00590 00591 /** 00592 * Adjusts the payload pointer to hide or reveal headers in the payload. 00593 * 00594 * Adjusts the ->payload pointer so that space for a header 00595 * (dis)appears in the pbuf payload. 00596 * 00597 * The ->payload, ->tot_len and ->len fields are adjusted. 00598 * 00599 * @param p pbuf to change the header size. 00600 * @param header_size_increment Number of bytes to increment header size which 00601 * increases the size of the pbuf. New space is on the front. 00602 * (Using a negative value decreases the header size.) 00603 * If hdr_size_inc is 0, this function does nothing and returns successful. 00604 * 00605 * PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so 00606 * the call will fail. A check is made that the increase in header size does 00607 * not move the payload pointer in front of the start of the buffer. 00608 * @return non-zero on failure, zero on success. 00609 * 00610 */ 00611 u8_t 00612 pbuf_header(struct pbuf *p, s16_t header_size_increment) 00613 { 00614 return pbuf_header_impl(p, header_size_increment, 0); 00615 } 00616 00617 /** 00618 * Same as pbuf_header but does not check if 'header_size > 0' is allowed. 00619 * This is used internally only, to allow PBUF_REF for RX. 00620 */ 00621 u8_t 00622 pbuf_header_force(struct pbuf *p, s16_t header_size_increment) 00623 { 00624 return pbuf_header_impl(p, header_size_increment, 1); 00625 } 00626 00627 /** 00628 * @ingroup pbuf 00629 * Dereference a pbuf chain or queue and deallocate any no-longer-used 00630 * pbufs at the head of this chain or queue. 00631 * 00632 * Decrements the pbuf reference count. If it reaches zero, the pbuf is 00633 * deallocated. 00634 * 00635 * For a pbuf chain, this is repeated for each pbuf in the chain, 00636 * up to the first pbuf which has a non-zero reference count after 00637 * decrementing. So, when all reference counts are one, the whole 00638 * chain is free'd. 00639 * 00640 * @param p The pbuf (chain) to be dereferenced. 00641 * 00642 * @return the number of pbufs that were de-allocated 00643 * from the head of the chain. 00644 * 00645 * @note MUST NOT be called on a packet queue (Not verified to work yet). 00646 * @note the reference counter of a pbuf equals the number of pointers 00647 * that refer to the pbuf (or into the pbuf). 00648 * 00649 * @internal examples: 00650 * 00651 * Assuming existing chains a->b->c with the following reference 00652 * counts, calling pbuf_free(a) results in: 00653 * 00654 * 1->2->3 becomes ...1->3 00655 * 3->3->3 becomes 2->3->3 00656 * 1->1->2 becomes ......1 00657 * 2->1->1 becomes 1->1->1 00658 * 1->1->1 becomes ....... 00659 * 00660 */ 00661 u8_t 00662 pbuf_free(struct pbuf *p) 00663 { 00664 u16_t type; 00665 struct pbuf *q; 00666 u8_t count; 00667 00668 if (p == NULL) { 00669 LWIP_ASSERT("p != NULL", p != NULL); 00670 /* if assertions are disabled, proceed with debug output */ 00671 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS, 00672 ("pbuf_free(p == NULL) was called.\n")); 00673 return 0; 00674 } 00675 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free(%p)\n", (void *)p)); 00676 00677 PERF_START; 00678 00679 LWIP_ASSERT("pbuf_free: sane type", 00680 p->type == PBUF_RAM || p->type == PBUF_ROM || 00681 p->type == PBUF_REF || p->type == PBUF_POOL); 00682 00683 count = 0; 00684 /* de-allocate all consecutive pbufs from the head of the chain that 00685 * obtain a zero reference count after decrementing*/ 00686 while (p != NULL) { 00687 u16_t ref; 00688 SYS_ARCH_DECL_PROTECT(old_level); 00689 /* Since decrementing ref cannot be guaranteed to be a single machine operation 00690 * we must protect it. We put the new ref into a local variable to prevent 00691 * further protection. */ 00692 SYS_ARCH_PROTECT(old_level); 00693 /* all pbufs in a chain are referenced at least once */ 00694 LWIP_ASSERT("pbuf_free: p->ref > 0", p->ref > 0); 00695 /* decrease reference count (number of pointers to pbuf) */ 00696 ref = --(p->ref); 00697 SYS_ARCH_UNPROTECT(old_level); 00698 /* this pbuf is no longer referenced to? */ 00699 if (ref == 0) { 00700 /* remember next pbuf in chain for next iteration */ 00701 q = p->next; 00702 LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free: deallocating %p\n", (void *)p)); 00703 type = p->type; 00704 #if LWIP_SUPPORT_CUSTOM_PBUF 00705 /* is this a custom pbuf? */ 00706 if ((p->flags & PBUF_FLAG_IS_CUSTOM) != 0) { 00707 struct pbuf_custom *pc = (struct pbuf_custom*)p; 00708 LWIP_ASSERT("pc->custom_free_function != NULL", pc->custom_free_function != NULL); 00709 pc->custom_free_function(p); 00710 } else 00711 #endif /* LWIP_SUPPORT_CUSTOM_PBUF */ 00712 { 00713 /* is this a pbuf from the pool? */ 00714 if (type == PBUF_POOL) { 00715 memp_free(MEMP_PBUF_POOL, p); 00716 /* is this a ROM or RAM referencing pbuf? */ 00717 } else if (type == PBUF_ROM || type == PBUF_REF) { 00718 memp_free(MEMP_PBUF, p); 00719 /* type == PBUF_RAM */ 00720 } else { 00721 mem_free(p); 00722 } 00723 } 00724 count++; 00725 /* proceed to next pbuf */ 00726 p = q; 00727 /* p->ref > 0, this pbuf is still referenced to */ 00728 /* (and so the remaining pbufs in chain as well) */ 00729 } else { 00730 LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref)); 00731 /* stop walking through the chain */ 00732 p = NULL; 00733 } 00734 } 00735 PERF_STOP("pbuf_free"); 00736 /* return number of de-allocated pbufs */ 00737 return count; 00738 } 00739 00740 /** 00741 * Count number of pbufs in a chain 00742 * 00743 * @param p first pbuf of chain 00744 * @return the number of pbufs in a chain 00745 */ 00746 u8_t 00747 pbuf_clen(struct pbuf *p) 00748 { 00749 u8_t len; 00750 00751 len = 0; 00752 while (p != NULL) { 00753 ++len; 00754 p = p->next; 00755 } 00756 return len; 00757 } 00758 00759 /** 00760 * @ingroup pbuf 00761 * Increment the reference count of the pbuf. 00762 * 00763 * @param p pbuf to increase reference counter of 00764 * 00765 */ 00766 void 00767 pbuf_ref(struct pbuf *p) 00768 { 00769 SYS_ARCH_DECL_PROTECT(old_level); 00770 /* pbuf given? */ 00771 if (p != NULL) { 00772 SYS_ARCH_PROTECT(old_level); 00773 ++(p->ref); 00774 SYS_ARCH_UNPROTECT(old_level); 00775 } 00776 } 00777 00778 /** 00779 * @ingroup pbuf 00780 * Concatenate two pbufs (each may be a pbuf chain) and take over 00781 * the caller's reference of the tail pbuf. 00782 * 00783 * @note The caller MAY NOT reference the tail pbuf afterwards. 00784 * Use pbuf_chain() for that purpose. 00785 * 00786 * @see pbuf_chain() 00787 */ 00788 void 00789 pbuf_cat(struct pbuf *h, struct pbuf *t) 00790 { 00791 struct pbuf *p; 00792 00793 LWIP_ERROR("(h != NULL) && (t != NULL) (programmer violates API)", 00794 ((h != NULL) && (t != NULL)), return;); 00795 00796 /* proceed to last pbuf of chain */ 00797 for (p = h; p->next != NULL; p = p->next) { 00798 /* add total length of second chain to all totals of first chain */ 00799 p->tot_len += t->tot_len; 00800 } 00801 /* { p is last pbuf of first h chain, p->next == NULL } */ 00802 LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len); 00803 LWIP_ASSERT("p->next == NULL", p->next == NULL); 00804 /* add total length of second chain to last pbuf total of first chain */ 00805 p->tot_len += t->tot_len; 00806 /* chain last pbuf of head (p) with first of tail (t) */ 00807 p->next = t; 00808 /* p->next now references t, but the caller will drop its reference to t, 00809 * so netto there is no change to the reference count of t. 00810 */ 00811 } 00812 00813 /** 00814 * @ingroup pbuf 00815 * Chain two pbufs (or pbuf chains) together. 00816 * 00817 * The caller MUST call pbuf_free(t) once it has stopped 00818 * using it. Use pbuf_cat() instead if you no longer use t. 00819 * 00820 * @param h head pbuf (chain) 00821 * @param t tail pbuf (chain) 00822 * @note The pbufs MUST belong to the same packet. 00823 * @note MAY NOT be called on a packet queue. 00824 * 00825 * The ->tot_len fields of all pbufs of the head chain are adjusted. 00826 * The ->next field of the last pbuf of the head chain is adjusted. 00827 * The ->ref field of the first pbuf of the tail chain is adjusted. 00828 * 00829 */ 00830 void 00831 pbuf_chain(struct pbuf *h, struct pbuf *t) 00832 { 00833 pbuf_cat(h, t); 00834 /* t is now referenced by h */ 00835 pbuf_ref(t); 00836 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_chain: %p references %p\n", (void *)h, (void *)t)); 00837 } 00838 00839 /** 00840 * Dechains the first pbuf from its succeeding pbufs in the chain. 00841 * 00842 * Makes p->tot_len field equal to p->len. 00843 * @param p pbuf to dechain 00844 * @return remainder of the pbuf chain, or NULL if it was de-allocated. 00845 * @note May not be called on a packet queue. 00846 */ 00847 struct pbuf * 00848 pbuf_dechain(struct pbuf *p) 00849 { 00850 struct pbuf *q; 00851 u8_t tail_gone = 1; 00852 /* tail */ 00853 q = p->next; 00854 /* pbuf has successor in chain? */ 00855 if (q != NULL) { 00856 /* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */ 00857 LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len); 00858 /* enforce invariant if assertion is disabled */ 00859 q->tot_len = p->tot_len - p->len; 00860 /* decouple pbuf from remainder */ 00861 p->next = NULL; 00862 /* total length of pbuf p is its own length only */ 00863 p->tot_len = p->len; 00864 /* q is no longer referenced by p, free it */ 00865 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_dechain: unreferencing %p\n", (void *)q)); 00866 tail_gone = pbuf_free(q); 00867 if (tail_gone > 0) { 00868 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, 00869 ("pbuf_dechain: deallocated %p (as it is no longer referenced)\n", (void *)q)); 00870 } 00871 /* return remaining tail or NULL if deallocated */ 00872 } 00873 /* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */ 00874 LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len); 00875 return ((tail_gone > 0) ? NULL : q); 00876 } 00877 00878 /** 00879 * @ingroup pbuf 00880 * Create PBUF_RAM copies of pbufs. 00881 * 00882 * Used to queue packets on behalf of the lwIP stack, such as 00883 * ARP based queueing. 00884 * 00885 * @note You MUST explicitly use p = pbuf_take(p); 00886 * 00887 * @note Only one packet is copied, no packet queue! 00888 * 00889 * @param p_to pbuf destination of the copy 00890 * @param p_from pbuf source of the copy 00891 * 00892 * @return ERR_OK if pbuf was copied 00893 * ERR_ARG if one of the pbufs is NULL or p_to is not big 00894 * enough to hold p_from 00895 */ 00896 err_t 00897 pbuf_copy(struct pbuf *p_to, struct pbuf *p_from) 00898 { 00899 u16_t offset_to=0, offset_from=0, len; 00900 00901 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy(%p, %p)\n", 00902 (void*)p_to, (void*)p_from)); 00903 00904 /* is the target big enough to hold the source? */ 00905 LWIP_ERROR("pbuf_copy: target not big enough to hold source", ((p_to != NULL) && 00906 (p_from != NULL) && (p_to->tot_len >= p_from->tot_len)), return ERR_ARG;); 00907 00908 /* iterate through pbuf chain */ 00909 do 00910 { 00911 /* copy one part of the original chain */ 00912 if ((p_to->len - offset_to) >= (p_from->len - offset_from)) { 00913 /* complete current p_from fits into current p_to */ 00914 len = p_from->len - offset_from; 00915 } else { 00916 /* current p_from does not fit into current p_to */ 00917 len = p_to->len - offset_to; 00918 } 00919 MEMCPY((u8_t*)p_to->payload + offset_to, (u8_t*)p_from->payload + offset_from, len); 00920 offset_to += len; 00921 offset_from += len; 00922 LWIP_ASSERT("offset_to <= p_to->len", offset_to <= p_to->len); 00923 LWIP_ASSERT("offset_from <= p_from->len", offset_from <= p_from->len); 00924 if (offset_from >= p_from->len) { 00925 /* on to next p_from (if any) */ 00926 offset_from = 0; 00927 p_from = p_from->next; 00928 } 00929 if (offset_to == p_to->len) { 00930 /* on to next p_to (if any) */ 00931 offset_to = 0; 00932 p_to = p_to->next; 00933 LWIP_ERROR("p_to != NULL", (p_to != NULL) || (p_from == NULL) , return ERR_ARG;); 00934 } 00935 00936 if ((p_from != NULL) && (p_from->len == p_from->tot_len)) { 00937 /* don't copy more than one packet! */ 00938 LWIP_ERROR("pbuf_copy() does not allow packet queues!", 00939 (p_from->next == NULL), return ERR_VAL;); 00940 } 00941 if ((p_to != NULL) && (p_to->len == p_to->tot_len)) { 00942 /* don't copy more than one packet! */ 00943 LWIP_ERROR("pbuf_copy() does not allow packet queues!", 00944 (p_to->next == NULL), return ERR_VAL;); 00945 } 00946 } while (p_from); 00947 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy: end of chain reached.\n")); 00948 return ERR_OK; 00949 } 00950 00951 /** 00952 * @ingroup pbuf 00953 * Copy (part of) the contents of a packet buffer 00954 * to an application supplied buffer. 00955 * 00956 * @param buf the pbuf from which to copy data 00957 * @param dataptr the application supplied buffer 00958 * @param len length of data to copy (dataptr must be big enough). No more 00959 * than buf->tot_len will be copied, irrespective of len 00960 * @param offset offset into the packet buffer from where to begin copying len bytes 00961 * @return the number of bytes copied, or 0 on failure 00962 */ 00963 u16_t 00964 pbuf_copy_partial(struct pbuf *buf, void *dataptr, u16_t len, u16_t offset) 00965 { 00966 struct pbuf *p; 00967 u16_t left; 00968 u16_t buf_copy_len; 00969 u16_t copied_total = 0; 00970 00971 LWIP_ERROR("pbuf_copy_partial: invalid buf", (buf != NULL), return 0;); 00972 LWIP_ERROR("pbuf_copy_partial: invalid dataptr", (dataptr != NULL), return 0;); 00973 00974 left = 0; 00975 00976 if ((buf == NULL) || (dataptr == NULL)) { 00977 return 0; 00978 } 00979 00980 /* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */ 00981 for (p = buf; len != 0 && p != NULL; p = p->next) { 00982 if ((offset != 0) && (offset >= p->len)) { 00983 /* don't copy from this buffer -> on to the next */ 00984 offset -= p->len; 00985 } else { 00986 /* copy from this buffer. maybe only partially. */ 00987 buf_copy_len = p->len - offset; 00988 if (buf_copy_len > len) 00989 buf_copy_len = len; 00990 /* copy the necessary parts of the buffer */ 00991 MEMCPY(&((char*)dataptr)[left], &((char*)p->payload)[offset], buf_copy_len); 00992 copied_total += buf_copy_len; 00993 left += buf_copy_len; 00994 len -= buf_copy_len; 00995 offset = 0; 00996 } 00997 } 00998 return copied_total; 00999 } 01000 01001 #if LWIP_TCP && TCP_QUEUE_OOSEQ && LWIP_WND_SCALE 01002 /** 01003 * This method modifies a 'pbuf chain', so that its total length is 01004 * smaller than 64K. The remainder of the original pbuf chain is stored 01005 * in *rest. 01006 * This function never creates new pbufs, but splits an existing chain 01007 * in two parts. The tot_len of the modified packet queue will likely be 01008 * smaller than 64K. 01009 * 'packet queues' are not supported by this function. 01010 * 01011 * @param p the pbuf queue to be split 01012 * @param rest pointer to store the remainder (after the first 64K) 01013 */ 01014 void pbuf_split_64k(struct pbuf *p, struct pbuf **rest) 01015 { 01016 *rest = NULL; 01017 if ((p != NULL) && (p->next != NULL)) { 01018 u16_t tot_len_front = p->len; 01019 struct pbuf *i = p; 01020 struct pbuf *r = p->next; 01021 01022 /* continue until the total length (summed up as u16_t) overflows */ 01023 while ((r != NULL) && ((u16_t)(tot_len_front + r->len) > tot_len_front)) { 01024 tot_len_front += r->len; 01025 i = r; 01026 r = r->next; 01027 } 01028 /* i now points to last packet of the first segment. Set next 01029 pointer to NULL */ 01030 i->next = NULL; 01031 01032 if (r != NULL) { 01033 /* Update the tot_len field in the first part */ 01034 for (i = p; i != NULL; i = i->next) { 01035 i->tot_len -= r->tot_len; 01036 LWIP_ASSERT("tot_len/len mismatch in last pbuf", 01037 (i->next != NULL) || (i->tot_len == i->len)); 01038 } 01039 if (p->flags & PBUF_FLAG_TCP_FIN) { 01040 r->flags |= PBUF_FLAG_TCP_FIN; 01041 } 01042 01043 /* tot_len field in rest does not need modifications */ 01044 /* reference counters do not need modifications */ 01045 *rest = r; 01046 } 01047 } 01048 } 01049 #endif /* LWIP_TCP && TCP_QUEUE_OOSEQ && LWIP_WND_SCALE */ 01050 01051 /** 01052 * @ingroup pbuf 01053 * Skip a number of bytes at the start of a pbuf 01054 * 01055 * @param in input pbuf 01056 * @param in_offset offset to skip 01057 * @param out_offset resulting offset in the returned pbuf 01058 * @return the pbuf in the queue where the offset is 01059 */ 01060 struct pbuf* 01061 pbuf_skip(struct pbuf* in, u16_t in_offset, u16_t* out_offset) 01062 { 01063 u16_t offset_left = in_offset; 01064 struct pbuf* q = in; 01065 01066 /* get the correct pbuf */ 01067 while ((q != NULL) && (q->len <= offset_left)) { 01068 offset_left -= q->len; 01069 q = q->next; 01070 } 01071 if (out_offset != NULL) { 01072 *out_offset = offset_left; 01073 } 01074 return q; 01075 } 01076 01077 /** 01078 * @ingroup pbuf 01079 * Copy application supplied data into a pbuf. 01080 * This function can only be used to copy the equivalent of buf->tot_len data. 01081 * 01082 * @param buf pbuf to fill with data 01083 * @param dataptr application supplied data buffer 01084 * @param len length of the application supplied data buffer 01085 * 01086 * @return ERR_OK if successful, ERR_MEM if the pbuf is not big enough 01087 */ 01088 err_t 01089 pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len) 01090 { 01091 struct pbuf *p; 01092 u16_t buf_copy_len; 01093 u16_t total_copy_len = len; 01094 u16_t copied_total = 0; 01095 01096 LWIP_ERROR("pbuf_take: invalid buf", (buf != NULL), return ERR_ARG;); 01097 LWIP_ERROR("pbuf_take: invalid dataptr", (dataptr != NULL), return ERR_ARG;); 01098 LWIP_ERROR("pbuf_take: buf not large enough", (buf->tot_len >= len), return ERR_MEM;); 01099 01100 if ((buf == NULL) || (dataptr == NULL) || (buf->tot_len < len)) { 01101 return ERR_ARG; 01102 } 01103 01104 /* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */ 01105 for (p = buf; total_copy_len != 0; p = p->next) { 01106 LWIP_ASSERT("pbuf_take: invalid pbuf", p != NULL); 01107 buf_copy_len = total_copy_len; 01108 if (buf_copy_len > p->len) { 01109 /* this pbuf cannot hold all remaining data */ 01110 buf_copy_len = p->len; 01111 } 01112 /* copy the necessary parts of the buffer */ 01113 MEMCPY(p->payload, &((const char*)dataptr)[copied_total], buf_copy_len); 01114 total_copy_len -= buf_copy_len; 01115 copied_total += buf_copy_len; 01116 } 01117 LWIP_ASSERT("did not copy all data", total_copy_len == 0 && copied_total == len); 01118 return ERR_OK; 01119 } 01120 01121 /** 01122 * @ingroup pbuf 01123 * Same as pbuf_take() but puts data at an offset 01124 * 01125 * @param buf pbuf to fill with data 01126 * @param dataptr application supplied data buffer 01127 * @param len length of the application supplied data buffer 01128 * @param offset offset in pbuf where to copy dataptr to 01129 * 01130 * @return ERR_OK if successful, ERR_MEM if the pbuf is not big enough 01131 */ 01132 err_t 01133 pbuf_take_at(struct pbuf *buf, const void *dataptr, u16_t len, u16_t offset) 01134 { 01135 u16_t target_offset; 01136 struct pbuf* q = pbuf_skip(buf, offset, &target_offset); 01137 01138 /* return requested data if pbuf is OK */ 01139 if ((q != NULL) && (q->tot_len >= target_offset + len)) { 01140 u16_t remaining_len = len; 01141 const u8_t* src_ptr = (const u8_t*)dataptr; 01142 /* copy the part that goes into the first pbuf */ 01143 u16_t first_copy_len = LWIP_MIN(q->len - target_offset, len); 01144 MEMCPY(((u8_t*)q->payload) + target_offset, dataptr, first_copy_len); 01145 remaining_len -= first_copy_len; 01146 src_ptr += first_copy_len; 01147 if (remaining_len > 0) { 01148 return pbuf_take(q->next, src_ptr, remaining_len); 01149 } 01150 return ERR_OK; 01151 } 01152 return ERR_MEM; 01153 } 01154 01155 /** 01156 * @ingroup pbuf 01157 * Creates a single pbuf out of a queue of pbufs. 01158 * 01159 * @remark: Either the source pbuf 'p' is freed by this function or the original 01160 * pbuf 'p' is returned, therefore the caller has to check the result! 01161 * 01162 * @param p the source pbuf 01163 * @param layer pbuf_layer of the new pbuf 01164 * 01165 * @return a new, single pbuf (p->next is NULL) 01166 * or the old pbuf if allocation fails 01167 */ 01168 struct pbuf* 01169 pbuf_coalesce(struct pbuf *p, pbuf_layer layer) 01170 { 01171 struct pbuf *q; 01172 err_t err; 01173 if (p->next == NULL) { 01174 return p; 01175 } 01176 q = pbuf_alloc(layer, p->tot_len, PBUF_RAM); 01177 if (q == NULL) { 01178 /* @todo: what do we do now? */ 01179 return p; 01180 } 01181 err = pbuf_copy(q, p); 01182 LWIP_UNUSED_ARG(err); 01183 LWIP_ASSERT("pbuf_copy failed", err == ERR_OK); 01184 pbuf_free(p); 01185 return q; 01186 } 01187 01188 #if LWIP_CHECKSUM_ON_COPY 01189 /** 01190 * Copies data into a single pbuf (*not* into a pbuf queue!) and updates 01191 * the checksum while copying 01192 * 01193 * @param p the pbuf to copy data into 01194 * @param start_offset offset of p->payload where to copy the data to 01195 * @param dataptr data to copy into the pbuf 01196 * @param len length of data to copy into the pbuf 01197 * @param chksum pointer to the checksum which is updated 01198 * @return ERR_OK if successful, another error if the data does not fit 01199 * within the (first) pbuf (no pbuf queues!) 01200 */ 01201 err_t 01202 pbuf_fill_chksum(struct pbuf *p, u16_t start_offset, const void *dataptr, 01203 u16_t len, u16_t *chksum) 01204 { 01205 u32_t acc; 01206 u16_t copy_chksum; 01207 char *dst_ptr; 01208 LWIP_ASSERT("p != NULL", p != NULL); 01209 LWIP_ASSERT("dataptr != NULL", dataptr != NULL); 01210 LWIP_ASSERT("chksum != NULL", chksum != NULL); 01211 LWIP_ASSERT("len != 0", len != 0); 01212 01213 if ((start_offset >= p->len) || (start_offset + len > p->len)) { 01214 return ERR_ARG; 01215 } 01216 01217 dst_ptr = ((char*)p->payload) + start_offset; 01218 copy_chksum = LWIP_CHKSUM_COPY(dst_ptr, dataptr, len); 01219 if ((start_offset & 1) != 0) { 01220 copy_chksum = SWAP_BYTES_IN_WORD(copy_chksum); 01221 } 01222 acc = *chksum; 01223 acc += copy_chksum; 01224 *chksum = FOLD_U32T(acc); 01225 return ERR_OK; 01226 } 01227 #endif /* LWIP_CHECKSUM_ON_COPY */ 01228 01229 /** 01230 * @ingroup pbuf 01231 * Get one byte from the specified position in a pbuf 01232 * WARNING: returns zero for offset >= p->tot_len 01233 * 01234 * @param p pbuf to parse 01235 * @param offset offset into p of the byte to return 01236 * @return byte at an offset into p OR ZERO IF 'offset' >= p->tot_len 01237 */ 01238 u8_t 01239 pbuf_get_at(struct pbuf* p, u16_t offset) 01240 { 01241 u16_t q_idx; 01242 struct pbuf* q = pbuf_skip(p, offset, &q_idx); 01243 01244 /* return requested data if pbuf is OK */ 01245 if ((q != NULL) && (q->len > q_idx)) { 01246 return ((u8_t*)q->payload)[q_idx]; 01247 } 01248 return 0; 01249 } 01250 01251 /** 01252 * @ingroup pbuf 01253 * Put one byte to the specified position in a pbuf 01254 * WARNING: silently ignores offset >= p->tot_len 01255 * 01256 * @param p pbuf to fill 01257 * @param offset offset into p of the byte to write 01258 * @param data byte to write at an offset into p 01259 */ 01260 void 01261 pbuf_put_at(struct pbuf* p, u16_t offset, u8_t data) 01262 { 01263 u16_t q_idx; 01264 struct pbuf* q = pbuf_skip(p, offset, &q_idx); 01265 01266 /* write requested data if pbuf is OK */ 01267 if ((q != NULL) && (q->len > q_idx)) { 01268 ((u8_t*)q->payload)[q_idx] = data; 01269 } 01270 } 01271 01272 /** 01273 * @ingroup pbuf 01274 * Compare pbuf contents at specified offset with memory s2, both of length n 01275 * 01276 * @param p pbuf to compare 01277 * @param offset offset into p at which to start comparing 01278 * @param s2 buffer to compare 01279 * @param n length of buffer to compare 01280 * @return zero if equal, nonzero otherwise 01281 * (0xffff if p is too short, diffoffset+1 otherwise) 01282 */ 01283 u16_t 01284 pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n) 01285 { 01286 u16_t start = offset; 01287 struct pbuf* q = p; 01288 01289 /* get the correct pbuf */ 01290 while ((q != NULL) && (q->len <= start)) { 01291 start -= q->len; 01292 q = q->next; 01293 } 01294 /* return requested data if pbuf is OK */ 01295 if ((q != NULL) && (q->len > start)) { 01296 u16_t i; 01297 for (i = 0; i < n; i++) { 01298 u8_t a = pbuf_get_at(q, start + i); 01299 u8_t b = ((const u8_t*)s2)[i]; 01300 if (a != b) { 01301 return i+1; 01302 } 01303 } 01304 return 0; 01305 } 01306 return 0xffff; 01307 } 01308 01309 /** 01310 * @ingroup pbuf 01311 * Find occurrence of mem (with length mem_len) in pbuf p, starting at offset 01312 * start_offset. 01313 * 01314 * @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as 01315 * return value 'not found' 01316 * @param mem search for the contents of this buffer 01317 * @param mem_len length of 'mem' 01318 * @param start_offset offset into p at which to start searching 01319 * @return 0xFFFF if substr was not found in p or the index where it was found 01320 */ 01321 u16_t 01322 pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset) 01323 { 01324 u16_t i; 01325 u16_t max = p->tot_len - mem_len; 01326 if (p->tot_len >= mem_len + start_offset) { 01327 for (i = start_offset; i <= max; i++) { 01328 u16_t plus = pbuf_memcmp(p, i, mem, mem_len); 01329 if (plus == 0) { 01330 return i; 01331 } 01332 } 01333 } 01334 return 0xFFFF; 01335 } 01336 01337 /** 01338 * Find occurrence of substr with length substr_len in pbuf p, start at offset 01339 * start_offset 01340 * WARNING: in contrast to strstr(), this one does not stop at the first \0 in 01341 * the pbuf/source string! 01342 * 01343 * @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as 01344 * return value 'not found' 01345 * @param substr string to search for in p, maximum length is 0xFFFE 01346 * @return 0xFFFF if substr was not found in p or the index where it was found 01347 */ 01348 u16_t 01349 pbuf_strstr(struct pbuf* p, const char* substr) 01350 { 01351 size_t substr_len; 01352 if ((substr == NULL) || (substr[0] == 0) || (p->tot_len == 0xFFFF)) { 01353 return 0xFFFF; 01354 } 01355 substr_len = strlen(substr); 01356 if (substr_len >= 0xFFFF) { 01357 return 0xFFFF; 01358 } 01359 return pbuf_memfind(p, substr, (u16_t)substr_len, 0); 01360 }
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