NetServices Stack source

Dependents:   HelloWorld ServoInterfaceBoardExample1 4180_Lab4

Committer:
donatien
Date:
Fri Jun 11 16:05:15 2010 +0000
Revision:
0:632c9925f013
Child:
5:dd63a1e02b1b

        

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donatien 0:632c9925f013 1 /**
donatien 0:632c9925f013 2 * @file
donatien 0:632c9925f013 3 * Packet buffer management
donatien 0:632c9925f013 4 *
donatien 0:632c9925f013 5 * Packets are built from the pbuf data structure. It supports dynamic
donatien 0:632c9925f013 6 * memory allocation for packet contents or can reference externally
donatien 0:632c9925f013 7 * managed packet contents both in RAM and ROM. Quick allocation for
donatien 0:632c9925f013 8 * incoming packets is provided through pools with fixed sized pbufs.
donatien 0:632c9925f013 9 *
donatien 0:632c9925f013 10 * A packet may span over multiple pbufs, chained as a singly linked
donatien 0:632c9925f013 11 * list. This is called a "pbuf chain".
donatien 0:632c9925f013 12 *
donatien 0:632c9925f013 13 * Multiple packets may be queued, also using this singly linked list.
donatien 0:632c9925f013 14 * This is called a "packet queue".
donatien 0:632c9925f013 15 *
donatien 0:632c9925f013 16 * So, a packet queue consists of one or more pbuf chains, each of
donatien 0:632c9925f013 17 * which consist of one or more pbufs. CURRENTLY, PACKET QUEUES ARE
donatien 0:632c9925f013 18 * NOT SUPPORTED!!! Use helper structs to queue multiple packets.
donatien 0:632c9925f013 19 *
donatien 0:632c9925f013 20 * The differences between a pbuf chain and a packet queue are very
donatien 0:632c9925f013 21 * precise but subtle.
donatien 0:632c9925f013 22 *
donatien 0:632c9925f013 23 * The last pbuf of a packet has a ->tot_len field that equals the
donatien 0:632c9925f013 24 * ->len field. It can be found by traversing the list. If the last
donatien 0:632c9925f013 25 * pbuf of a packet has a ->next field other than NULL, more packets
donatien 0:632c9925f013 26 * are on the queue.
donatien 0:632c9925f013 27 *
donatien 0:632c9925f013 28 * Therefore, looping through a pbuf of a single packet, has an
donatien 0:632c9925f013 29 * loop end condition (tot_len == p->len), NOT (next == NULL).
donatien 0:632c9925f013 30 */
donatien 0:632c9925f013 31
donatien 0:632c9925f013 32 /*
donatien 0:632c9925f013 33 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
donatien 0:632c9925f013 34 * All rights reserved.
donatien 0:632c9925f013 35 *
donatien 0:632c9925f013 36 * Redistribution and use in source and binary forms, with or without modification,
donatien 0:632c9925f013 37 * are permitted provided that the following conditions are met:
donatien 0:632c9925f013 38 *
donatien 0:632c9925f013 39 * 1. Redistributions of source code must retain the above copyright notice,
donatien 0:632c9925f013 40 * this list of conditions and the following disclaimer.
donatien 0:632c9925f013 41 * 2. Redistributions in binary form must reproduce the above copyright notice,
donatien 0:632c9925f013 42 * this list of conditions and the following disclaimer in the documentation
donatien 0:632c9925f013 43 * and/or other materials provided with the distribution.
donatien 0:632c9925f013 44 * 3. The name of the author may not be used to endorse or promote products
donatien 0:632c9925f013 45 * derived from this software without specific prior written permission.
donatien 0:632c9925f013 46 *
donatien 0:632c9925f013 47 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
donatien 0:632c9925f013 48 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
donatien 0:632c9925f013 49 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
donatien 0:632c9925f013 50 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
donatien 0:632c9925f013 51 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
donatien 0:632c9925f013 52 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
donatien 0:632c9925f013 53 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
donatien 0:632c9925f013 54 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
donatien 0:632c9925f013 55 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
donatien 0:632c9925f013 56 * OF SUCH DAMAGE.
donatien 0:632c9925f013 57 *
donatien 0:632c9925f013 58 * This file is part of the lwIP TCP/IP stack.
donatien 0:632c9925f013 59 *
donatien 0:632c9925f013 60 * Author: Adam Dunkels <adam@sics.se>
donatien 0:632c9925f013 61 *
donatien 0:632c9925f013 62 */
donatien 0:632c9925f013 63
donatien 0:632c9925f013 64 #include "lwip/opt.h"
donatien 0:632c9925f013 65
donatien 0:632c9925f013 66 #include "lwip/stats.h"
donatien 0:632c9925f013 67 #include "lwip/def.h"
donatien 0:632c9925f013 68 #include "lwip/mem.h"
donatien 0:632c9925f013 69 #include "lwip/memp.h"
donatien 0:632c9925f013 70 #include "lwip/pbuf.h"
donatien 0:632c9925f013 71 #include "lwip/sys.h"
donatien 0:632c9925f013 72 #include "arch/perf.h"
donatien 0:632c9925f013 73 #if TCP_QUEUE_OOSEQ
donatien 0:632c9925f013 74 #include "lwip/tcp_impl.h"
donatien 0:632c9925f013 75 #endif
donatien 0:632c9925f013 76
donatien 0:632c9925f013 77 #include <string.h>
donatien 0:632c9925f013 78
donatien 0:632c9925f013 79 #define SIZEOF_STRUCT_PBUF LWIP_MEM_ALIGN_SIZE(sizeof(struct pbuf))
donatien 0:632c9925f013 80 /* Since the pool is created in memp, PBUF_POOL_BUFSIZE will be automatically
donatien 0:632c9925f013 81 aligned there. Therefore, PBUF_POOL_BUFSIZE_ALIGNED can be used here. */
donatien 0:632c9925f013 82 #define PBUF_POOL_BUFSIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE)
donatien 0:632c9925f013 83
donatien 0:632c9925f013 84 #if !TCP_QUEUE_OOSEQ || NO_SYS
donatien 0:632c9925f013 85 #define PBUF_POOL_IS_EMPTY()
donatien 0:632c9925f013 86 #else /* !TCP_QUEUE_OOSEQ || NO_SYS */
donatien 0:632c9925f013 87 /** Define this to 0 to prevent freeing ooseq pbufs when the PBUF_POOL is empty */
donatien 0:632c9925f013 88 #ifndef PBUF_POOL_FREE_OOSEQ
donatien 0:632c9925f013 89 #define PBUF_POOL_FREE_OOSEQ 1
donatien 0:632c9925f013 90 #endif /* PBUF_POOL_FREE_OOSEQ */
donatien 0:632c9925f013 91
donatien 0:632c9925f013 92 #if PBUF_POOL_FREE_OOSEQ
donatien 0:632c9925f013 93 #include "lwip/tcpip.h"
donatien 0:632c9925f013 94 #define PBUF_POOL_IS_EMPTY() pbuf_pool_is_empty()
donatien 0:632c9925f013 95 static u8_t pbuf_free_ooseq_queued;
donatien 0:632c9925f013 96 /**
donatien 0:632c9925f013 97 * Attempt to reclaim some memory from queued out-of-sequence TCP segments
donatien 0:632c9925f013 98 * if we run out of pool pbufs. It's better to give priority to new packets
donatien 0:632c9925f013 99 * if we're running out.
donatien 0:632c9925f013 100 *
donatien 0:632c9925f013 101 * This must be done in the correct thread context therefore this function
donatien 0:632c9925f013 102 * can only be used with NO_SYS=0 and through tcpip_callback.
donatien 0:632c9925f013 103 */
donatien 0:632c9925f013 104 static void
donatien 0:632c9925f013 105 pbuf_free_ooseq(void* arg)
donatien 0:632c9925f013 106 {
donatien 0:632c9925f013 107 struct tcp_pcb* pcb;
donatien 0:632c9925f013 108 SYS_ARCH_DECL_PROTECT(old_level);
donatien 0:632c9925f013 109 LWIP_UNUSED_ARG(arg);
donatien 0:632c9925f013 110
donatien 0:632c9925f013 111 SYS_ARCH_PROTECT(old_level);
donatien 0:632c9925f013 112 pbuf_free_ooseq_queued = 0;
donatien 0:632c9925f013 113 SYS_ARCH_UNPROTECT(old_level);
donatien 0:632c9925f013 114
donatien 0:632c9925f013 115 for (pcb = tcp_active_pcbs; NULL != pcb; pcb = pcb->next) {
donatien 0:632c9925f013 116 if (NULL != pcb->ooseq) {
donatien 0:632c9925f013 117 /** Free the ooseq pbufs of one PCB only */
donatien 0:632c9925f013 118 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free_ooseq: freeing out-of-sequence pbufs\n"));
donatien 0:632c9925f013 119 tcp_segs_free(pcb->ooseq);
donatien 0:632c9925f013 120 pcb->ooseq = NULL;
donatien 0:632c9925f013 121 return;
donatien 0:632c9925f013 122 }
donatien 0:632c9925f013 123 }
donatien 0:632c9925f013 124 }
donatien 0:632c9925f013 125
donatien 0:632c9925f013 126 /** Queue a call to pbuf_free_ooseq if not already queued. */
donatien 0:632c9925f013 127 static void
donatien 0:632c9925f013 128 pbuf_pool_is_empty(void)
donatien 0:632c9925f013 129 {
donatien 0:632c9925f013 130 u8_t queued;
donatien 0:632c9925f013 131 SYS_ARCH_DECL_PROTECT(old_level);
donatien 0:632c9925f013 132
donatien 0:632c9925f013 133 SYS_ARCH_PROTECT(old_level);
donatien 0:632c9925f013 134 queued = pbuf_free_ooseq_queued;
donatien 0:632c9925f013 135 pbuf_free_ooseq_queued = 1;
donatien 0:632c9925f013 136 SYS_ARCH_UNPROTECT(old_level);
donatien 0:632c9925f013 137
donatien 0:632c9925f013 138 if(!queued) {
donatien 0:632c9925f013 139 /* queue a call to pbuf_free_ooseq if not already queued */
donatien 0:632c9925f013 140 if(tcpip_callback_with_block(pbuf_free_ooseq, NULL, 0) != ERR_OK) {
donatien 0:632c9925f013 141 SYS_ARCH_PROTECT(old_level);
donatien 0:632c9925f013 142 pbuf_free_ooseq_queued = 0;
donatien 0:632c9925f013 143 SYS_ARCH_UNPROTECT(old_level);
donatien 0:632c9925f013 144 }
donatien 0:632c9925f013 145 }
donatien 0:632c9925f013 146 }
donatien 0:632c9925f013 147 #endif /* PBUF_POOL_FREE_OOSEQ */
donatien 0:632c9925f013 148 #endif /* !TCP_QUEUE_OOSEQ || NO_SYS */
donatien 0:632c9925f013 149
donatien 0:632c9925f013 150 /**
donatien 0:632c9925f013 151 * Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
donatien 0:632c9925f013 152 *
donatien 0:632c9925f013 153 * The actual memory allocated for the pbuf is determined by the
donatien 0:632c9925f013 154 * layer at which the pbuf is allocated and the requested size
donatien 0:632c9925f013 155 * (from the size parameter).
donatien 0:632c9925f013 156 *
donatien 0:632c9925f013 157 * @param layer flag to define header size
donatien 0:632c9925f013 158 * @param length size of the pbuf's payload
donatien 0:632c9925f013 159 * @param type this parameter decides how and where the pbuf
donatien 0:632c9925f013 160 * should be allocated as follows:
donatien 0:632c9925f013 161 *
donatien 0:632c9925f013 162 * - PBUF_RAM: buffer memory for pbuf is allocated as one large
donatien 0:632c9925f013 163 * chunk. This includes protocol headers as well.
donatien 0:632c9925f013 164 * - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
donatien 0:632c9925f013 165 * protocol headers. Additional headers must be prepended
donatien 0:632c9925f013 166 * by allocating another pbuf and chain in to the front of
donatien 0:632c9925f013 167 * the ROM pbuf. It is assumed that the memory used is really
donatien 0:632c9925f013 168 * similar to ROM in that it is immutable and will not be
donatien 0:632c9925f013 169 * changed. Memory which is dynamic should generally not
donatien 0:632c9925f013 170 * be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
donatien 0:632c9925f013 171 * - PBUF_REF: no buffer memory is allocated for the pbuf, even for
donatien 0:632c9925f013 172 * protocol headers. It is assumed that the pbuf is only
donatien 0:632c9925f013 173 * being used in a single thread. If the pbuf gets queued,
donatien 0:632c9925f013 174 * then pbuf_take should be called to copy the buffer.
donatien 0:632c9925f013 175 * - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
donatien 0:632c9925f013 176 * the pbuf pool that is allocated during pbuf_init().
donatien 0:632c9925f013 177 *
donatien 0:632c9925f013 178 * @return the allocated pbuf. If multiple pbufs where allocated, this
donatien 0:632c9925f013 179 * is the first pbuf of a pbuf chain.
donatien 0:632c9925f013 180 */
donatien 0:632c9925f013 181 struct pbuf *
donatien 0:632c9925f013 182 pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
donatien 0:632c9925f013 183 {
donatien 0:632c9925f013 184 struct pbuf *p, *q, *r;
donatien 0:632c9925f013 185 u16_t offset;
donatien 0:632c9925f013 186 s32_t rem_len; /* remaining length */
donatien 0:632c9925f013 187 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
donatien 0:632c9925f013 188
donatien 0:632c9925f013 189 /* determine header offset */
donatien 0:632c9925f013 190 offset = 0;
donatien 0:632c9925f013 191 switch (layer) {
donatien 0:632c9925f013 192 case PBUF_TRANSPORT:
donatien 0:632c9925f013 193 /* add room for transport (often TCP) layer header */
donatien 0:632c9925f013 194 offset += PBUF_TRANSPORT_HLEN;
donatien 0:632c9925f013 195 /* FALLTHROUGH */
donatien 0:632c9925f013 196 case PBUF_IP:
donatien 0:632c9925f013 197 /* add room for IP layer header */
donatien 0:632c9925f013 198 offset += PBUF_IP_HLEN;
donatien 0:632c9925f013 199 /* FALLTHROUGH */
donatien 0:632c9925f013 200 case PBUF_LINK:
donatien 0:632c9925f013 201 /* add room for link layer header */
donatien 0:632c9925f013 202 offset += PBUF_LINK_HLEN;
donatien 0:632c9925f013 203 break;
donatien 0:632c9925f013 204 case PBUF_RAW:
donatien 0:632c9925f013 205 break;
donatien 0:632c9925f013 206 default:
donatien 0:632c9925f013 207 LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0);
donatien 0:632c9925f013 208 return NULL;
donatien 0:632c9925f013 209 }
donatien 0:632c9925f013 210
donatien 0:632c9925f013 211 switch (type) {
donatien 0:632c9925f013 212 case PBUF_POOL:
donatien 0:632c9925f013 213 /* allocate head of pbuf chain into p */
donatien 0:632c9925f013 214 p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
donatien 0:632c9925f013 215 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
donatien 0:632c9925f013 216 if (p == NULL) {
donatien 0:632c9925f013 217 PBUF_POOL_IS_EMPTY();
donatien 0:632c9925f013 218 return NULL;
donatien 0:632c9925f013 219 }
donatien 0:632c9925f013 220 p->type = type;
donatien 0:632c9925f013 221 p->next = NULL;
donatien 0:632c9925f013 222
donatien 0:632c9925f013 223 /* make the payload pointer point 'offset' bytes into pbuf data memory */
donatien 0:632c9925f013 224 p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + (SIZEOF_STRUCT_PBUF + offset)));
donatien 0:632c9925f013 225 LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned",
donatien 0:632c9925f013 226 ((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
donatien 0:632c9925f013 227 /* the total length of the pbuf chain is the requested size */
donatien 0:632c9925f013 228 p->tot_len = length;
donatien 0:632c9925f013 229 /* set the length of the first pbuf in the chain */
donatien 0:632c9925f013 230 p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
donatien 0:632c9925f013 231 LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
donatien 0:632c9925f013 232 ((u8_t*)p->payload + p->len <=
donatien 0:632c9925f013 233 (u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
donatien 0:632c9925f013 234 LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT",
donatien 0:632c9925f013 235 (PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 );
donatien 0:632c9925f013 236 /* set reference count (needed here in case we fail) */
donatien 0:632c9925f013 237 p->ref = 1;
donatien 0:632c9925f013 238
donatien 0:632c9925f013 239 /* now allocate the tail of the pbuf chain */
donatien 0:632c9925f013 240
donatien 0:632c9925f013 241 /* remember first pbuf for linkage in next iteration */
donatien 0:632c9925f013 242 r = p;
donatien 0:632c9925f013 243 /* remaining length to be allocated */
donatien 0:632c9925f013 244 rem_len = length - p->len;
donatien 0:632c9925f013 245 /* any remaining pbufs to be allocated? */
donatien 0:632c9925f013 246 while (rem_len > 0) {
donatien 0:632c9925f013 247 q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
donatien 0:632c9925f013 248 if (q == NULL) {
donatien 0:632c9925f013 249 PBUF_POOL_IS_EMPTY();
donatien 0:632c9925f013 250 /* free chain so far allocated */
donatien 0:632c9925f013 251 pbuf_free(p);
donatien 0:632c9925f013 252 /* bail out unsuccesfully */
donatien 0:632c9925f013 253 return NULL;
donatien 0:632c9925f013 254 }
donatien 0:632c9925f013 255 q->type = type;
donatien 0:632c9925f013 256 q->flags = 0;
donatien 0:632c9925f013 257 q->next = NULL;
donatien 0:632c9925f013 258 /* make previous pbuf point to this pbuf */
donatien 0:632c9925f013 259 r->next = q;
donatien 0:632c9925f013 260 /* set total length of this pbuf and next in chain */
donatien 0:632c9925f013 261 LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff);
donatien 0:632c9925f013 262 q->tot_len = (u16_t)rem_len;
donatien 0:632c9925f013 263 /* this pbuf length is pool size, unless smaller sized tail */
donatien 0:632c9925f013 264 q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
donatien 0:632c9925f013 265 q->payload = (void *)((u8_t *)q + SIZEOF_STRUCT_PBUF);
donatien 0:632c9925f013 266 LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
donatien 0:632c9925f013 267 ((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
donatien 0:632c9925f013 268 LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
donatien 0:632c9925f013 269 ((u8_t*)p->payload + p->len <=
donatien 0:632c9925f013 270 (u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
donatien 0:632c9925f013 271 q->ref = 1;
donatien 0:632c9925f013 272 /* calculate remaining length to be allocated */
donatien 0:632c9925f013 273 rem_len -= q->len;
donatien 0:632c9925f013 274 /* remember this pbuf for linkage in next iteration */
donatien 0:632c9925f013 275 r = q;
donatien 0:632c9925f013 276 }
donatien 0:632c9925f013 277 /* end of chain */
donatien 0:632c9925f013 278 /*r->next = NULL;*/
donatien 0:632c9925f013 279
donatien 0:632c9925f013 280 break;
donatien 0:632c9925f013 281 case PBUF_RAM:
donatien 0:632c9925f013 282 /* If pbuf is to be allocated in RAM, allocate memory for it. */
donatien 0:632c9925f013 283 p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
donatien 0:632c9925f013 284 if (p == NULL) {
donatien 0:632c9925f013 285 return NULL;
donatien 0:632c9925f013 286 }
donatien 0:632c9925f013 287 /* Set up internal structure of the pbuf. */
donatien 0:632c9925f013 288 p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + SIZEOF_STRUCT_PBUF + offset));
donatien 0:632c9925f013 289 p->len = p->tot_len = length;
donatien 0:632c9925f013 290 p->next = NULL;
donatien 0:632c9925f013 291 p->type = type;
donatien 0:632c9925f013 292
donatien 0:632c9925f013 293 LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
donatien 0:632c9925f013 294 ((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
donatien 0:632c9925f013 295 break;
donatien 0:632c9925f013 296 /* pbuf references existing (non-volatile static constant) ROM payload? */
donatien 0:632c9925f013 297 case PBUF_ROM:
donatien 0:632c9925f013 298 /* pbuf references existing (externally allocated) RAM payload? */
donatien 0:632c9925f013 299 case PBUF_REF:
donatien 0:632c9925f013 300 /* only allocate memory for the pbuf structure */
donatien 0:632c9925f013 301 p = (struct pbuf *)memp_malloc(MEMP_PBUF);
donatien 0:632c9925f013 302 if (p == NULL) {
donatien 0:632c9925f013 303 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
donatien 0:632c9925f013 304 ("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n",
donatien 0:632c9925f013 305 (type == PBUF_ROM) ? "ROM" : "REF"));
donatien 0:632c9925f013 306 return NULL;
donatien 0:632c9925f013 307 }
donatien 0:632c9925f013 308 /* caller must set this field properly, afterwards */
donatien 0:632c9925f013 309 p->payload = NULL;
donatien 0:632c9925f013 310 p->len = p->tot_len = length;
donatien 0:632c9925f013 311 p->next = NULL;
donatien 0:632c9925f013 312 p->type = type;
donatien 0:632c9925f013 313 break;
donatien 0:632c9925f013 314 default:
donatien 0:632c9925f013 315 LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
donatien 0:632c9925f013 316 return NULL;
donatien 0:632c9925f013 317 }
donatien 0:632c9925f013 318 /* set reference count */
donatien 0:632c9925f013 319 p->ref = 1;
donatien 0:632c9925f013 320 /* set flags */
donatien 0:632c9925f013 321 p->flags = 0;
donatien 0:632c9925f013 322 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
donatien 0:632c9925f013 323 return p;
donatien 0:632c9925f013 324 }
donatien 0:632c9925f013 325
donatien 0:632c9925f013 326
donatien 0:632c9925f013 327 /**
donatien 0:632c9925f013 328 * Shrink a pbuf chain to a desired length.
donatien 0:632c9925f013 329 *
donatien 0:632c9925f013 330 * @param p pbuf to shrink.
donatien 0:632c9925f013 331 * @param new_len desired new length of pbuf chain
donatien 0:632c9925f013 332 *
donatien 0:632c9925f013 333 * Depending on the desired length, the first few pbufs in a chain might
donatien 0:632c9925f013 334 * be skipped and left unchanged. The new last pbuf in the chain will be
donatien 0:632c9925f013 335 * resized, and any remaining pbufs will be freed.
donatien 0:632c9925f013 336 *
donatien 0:632c9925f013 337 * @note If the pbuf is ROM/REF, only the ->tot_len and ->len fields are adjusted.
donatien 0:632c9925f013 338 * @note May not be called on a packet queue.
donatien 0:632c9925f013 339 *
donatien 0:632c9925f013 340 * @note Despite its name, pbuf_realloc cannot grow the size of a pbuf (chain).
donatien 0:632c9925f013 341 */
donatien 0:632c9925f013 342 void
donatien 0:632c9925f013 343 pbuf_realloc(struct pbuf *p, u16_t new_len)
donatien 0:632c9925f013 344 {
donatien 0:632c9925f013 345 struct pbuf *q;
donatien 0:632c9925f013 346 u16_t rem_len; /* remaining length */
donatien 0:632c9925f013 347 s32_t grow;
donatien 0:632c9925f013 348
donatien 0:632c9925f013 349 LWIP_ASSERT("pbuf_realloc: p != NULL", p != NULL);
donatien 0:632c9925f013 350 LWIP_ASSERT("pbuf_realloc: sane p->type", p->type == PBUF_POOL ||
donatien 0:632c9925f013 351 p->type == PBUF_ROM ||
donatien 0:632c9925f013 352 p->type == PBUF_RAM ||
donatien 0:632c9925f013 353 p->type == PBUF_REF);
donatien 0:632c9925f013 354
donatien 0:632c9925f013 355 /* desired length larger than current length? */
donatien 0:632c9925f013 356 if (new_len >= p->tot_len) {
donatien 0:632c9925f013 357 /* enlarging not yet supported */
donatien 0:632c9925f013 358 return;
donatien 0:632c9925f013 359 }
donatien 0:632c9925f013 360
donatien 0:632c9925f013 361 /* the pbuf chain grows by (new_len - p->tot_len) bytes
donatien 0:632c9925f013 362 * (which may be negative in case of shrinking) */
donatien 0:632c9925f013 363 grow = new_len - p->tot_len;
donatien 0:632c9925f013 364
donatien 0:632c9925f013 365 /* first, step over any pbufs that should remain in the chain */
donatien 0:632c9925f013 366 rem_len = new_len;
donatien 0:632c9925f013 367 q = p;
donatien 0:632c9925f013 368 /* should this pbuf be kept? */
donatien 0:632c9925f013 369 while (rem_len > q->len) {
donatien 0:632c9925f013 370 /* decrease remaining length by pbuf length */
donatien 0:632c9925f013 371 rem_len -= q->len;
donatien 0:632c9925f013 372 /* decrease total length indicator */
donatien 0:632c9925f013 373 LWIP_ASSERT("grow < max_u16_t", grow < 0xffff);
donatien 0:632c9925f013 374 q->tot_len += (u16_t)grow;
donatien 0:632c9925f013 375 /* proceed to next pbuf in chain */
donatien 0:632c9925f013 376 q = q->next;
donatien 0:632c9925f013 377 LWIP_ASSERT("pbuf_realloc: q != NULL", q != NULL);
donatien 0:632c9925f013 378 }
donatien 0:632c9925f013 379 /* we have now reached the new last pbuf (in q) */
donatien 0:632c9925f013 380 /* rem_len == desired length for pbuf q */
donatien 0:632c9925f013 381
donatien 0:632c9925f013 382 /* shrink allocated memory for PBUF_RAM */
donatien 0:632c9925f013 383 /* (other types merely adjust their length fields */
donatien 0:632c9925f013 384 if ((q->type == PBUF_RAM) && (rem_len != q->len)) {
donatien 0:632c9925f013 385 /* reallocate and adjust the length of the pbuf that will be split */
donatien 0:632c9925f013 386 q = (struct pbuf *)mem_trim(q, (u16_t)((u8_t *)q->payload - (u8_t *)q) + rem_len);
donatien 0:632c9925f013 387 LWIP_ASSERT("mem_trim returned q == NULL", q != NULL);
donatien 0:632c9925f013 388 }
donatien 0:632c9925f013 389 /* adjust length fields for new last pbuf */
donatien 0:632c9925f013 390 q->len = rem_len;
donatien 0:632c9925f013 391 q->tot_len = q->len;
donatien 0:632c9925f013 392
donatien 0:632c9925f013 393 /* any remaining pbufs in chain? */
donatien 0:632c9925f013 394 if (q->next != NULL) {
donatien 0:632c9925f013 395 /* free remaining pbufs in chain */
donatien 0:632c9925f013 396 pbuf_free(q->next);
donatien 0:632c9925f013 397 }
donatien 0:632c9925f013 398 /* q is last packet in chain */
donatien 0:632c9925f013 399 q->next = NULL;
donatien 0:632c9925f013 400
donatien 0:632c9925f013 401 }
donatien 0:632c9925f013 402
donatien 0:632c9925f013 403 /**
donatien 0:632c9925f013 404 * Adjusts the payload pointer to hide or reveal headers in the payload.
donatien 0:632c9925f013 405 *
donatien 0:632c9925f013 406 * Adjusts the ->payload pointer so that space for a header
donatien 0:632c9925f013 407 * (dis)appears in the pbuf payload.
donatien 0:632c9925f013 408 *
donatien 0:632c9925f013 409 * The ->payload, ->tot_len and ->len fields are adjusted.
donatien 0:632c9925f013 410 *
donatien 0:632c9925f013 411 * @param p pbuf to change the header size.
donatien 0:632c9925f013 412 * @param header_size_increment Number of bytes to increment header size which
donatien 0:632c9925f013 413 * increases the size of the pbuf. New space is on the front.
donatien 0:632c9925f013 414 * (Using a negative value decreases the header size.)
donatien 0:632c9925f013 415 * If hdr_size_inc is 0, this function does nothing and returns succesful.
donatien 0:632c9925f013 416 *
donatien 0:632c9925f013 417 * PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so
donatien 0:632c9925f013 418 * the call will fail. A check is made that the increase in header size does
donatien 0:632c9925f013 419 * not move the payload pointer in front of the start of the buffer.
donatien 0:632c9925f013 420 * @return non-zero on failure, zero on success.
donatien 0:632c9925f013 421 *
donatien 0:632c9925f013 422 */
donatien 0:632c9925f013 423 u8_t
donatien 0:632c9925f013 424 pbuf_header(struct pbuf *p, s16_t header_size_increment)
donatien 0:632c9925f013 425 {
donatien 0:632c9925f013 426 u16_t type;
donatien 0:632c9925f013 427 void *payload;
donatien 0:632c9925f013 428 u16_t increment_magnitude;
donatien 0:632c9925f013 429
donatien 0:632c9925f013 430 LWIP_ASSERT("p != NULL", p != NULL);
donatien 0:632c9925f013 431 if ((header_size_increment == 0) || (p == NULL))
donatien 0:632c9925f013 432 return 0;
donatien 0:632c9925f013 433
donatien 0:632c9925f013 434 if (header_size_increment < 0){
donatien 0:632c9925f013 435 increment_magnitude = -header_size_increment;
donatien 0:632c9925f013 436 /* Check that we aren't going to move off the end of the pbuf */
donatien 0:632c9925f013 437 LWIP_ERROR("increment_magnitude <= p->len", (increment_magnitude <= p->len), return 1;);
donatien 0:632c9925f013 438 } else {
donatien 0:632c9925f013 439 increment_magnitude = header_size_increment;
donatien 0:632c9925f013 440 #if 0
donatien 0:632c9925f013 441 /* Can't assert these as some callers speculatively call
donatien 0:632c9925f013 442 pbuf_header() to see if it's OK. Will return 1 below instead. */
donatien 0:632c9925f013 443 /* Check that we've got the correct type of pbuf to work with */
donatien 0:632c9925f013 444 LWIP_ASSERT("p->type == PBUF_RAM || p->type == PBUF_POOL",
donatien 0:632c9925f013 445 p->type == PBUF_RAM || p->type == PBUF_POOL);
donatien 0:632c9925f013 446 /* Check that we aren't going to move off the beginning of the pbuf */
donatien 0:632c9925f013 447 LWIP_ASSERT("p->payload - increment_magnitude >= p + SIZEOF_STRUCT_PBUF",
donatien 0:632c9925f013 448 (u8_t *)p->payload - increment_magnitude >= (u8_t *)p + SIZEOF_STRUCT_PBUF);
donatien 0:632c9925f013 449 #endif
donatien 0:632c9925f013 450 }
donatien 0:632c9925f013 451
donatien 0:632c9925f013 452 type = p->type;
donatien 0:632c9925f013 453 /* remember current payload pointer */
donatien 0:632c9925f013 454 payload = p->payload;
donatien 0:632c9925f013 455
donatien 0:632c9925f013 456 /* pbuf types containing payloads? */
donatien 0:632c9925f013 457 if (type == PBUF_RAM || type == PBUF_POOL) {
donatien 0:632c9925f013 458 /* set new payload pointer */
donatien 0:632c9925f013 459 p->payload = (u8_t *)p->payload - header_size_increment;
donatien 0:632c9925f013 460 /* boundary check fails? */
donatien 0:632c9925f013 461 if ((u8_t *)p->payload < (u8_t *)p + SIZEOF_STRUCT_PBUF) {
donatien 0:632c9925f013 462 LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
donatien 0:632c9925f013 463 ("pbuf_header: failed as %p < %p (not enough space for new header size)\n",
donatien 0:632c9925f013 464 (void *)p->payload, (void *)(p + 1)));
donatien 0:632c9925f013 465 /* restore old payload pointer */
donatien 0:632c9925f013 466 p->payload = payload;
donatien 0:632c9925f013 467 /* bail out unsuccesfully */
donatien 0:632c9925f013 468 return 1;
donatien 0:632c9925f013 469 }
donatien 0:632c9925f013 470 /* pbuf types refering to external payloads? */
donatien 0:632c9925f013 471 } else if (type == PBUF_REF || type == PBUF_ROM) {
donatien 0:632c9925f013 472 /* hide a header in the payload? */
donatien 0:632c9925f013 473 if ((header_size_increment < 0) && (increment_magnitude <= p->len)) {
donatien 0:632c9925f013 474 /* increase payload pointer */
donatien 0:632c9925f013 475 p->payload = (u8_t *)p->payload - header_size_increment;
donatien 0:632c9925f013 476 } else {
donatien 0:632c9925f013 477 /* cannot expand payload to front (yet!)
donatien 0:632c9925f013 478 * bail out unsuccesfully */
donatien 0:632c9925f013 479 return 1;
donatien 0:632c9925f013 480 }
donatien 0:632c9925f013 481 }
donatien 0:632c9925f013 482 else {
donatien 0:632c9925f013 483 /* Unknown type */
donatien 0:632c9925f013 484 LWIP_ASSERT("bad pbuf type", 0);
donatien 0:632c9925f013 485 return 1;
donatien 0:632c9925f013 486 }
donatien 0:632c9925f013 487 /* modify pbuf length fields */
donatien 0:632c9925f013 488 p->len += header_size_increment;
donatien 0:632c9925f013 489 p->tot_len += header_size_increment;
donatien 0:632c9925f013 490
donatien 0:632c9925f013 491 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_header: old %p new %p (%"S16_F")\n",
donatien 0:632c9925f013 492 (void *)payload, (void *)p->payload, header_size_increment));
donatien 0:632c9925f013 493
donatien 0:632c9925f013 494 return 0;
donatien 0:632c9925f013 495 }
donatien 0:632c9925f013 496
donatien 0:632c9925f013 497 /**
donatien 0:632c9925f013 498 * Dereference a pbuf chain or queue and deallocate any no-longer-used
donatien 0:632c9925f013 499 * pbufs at the head of this chain or queue.
donatien 0:632c9925f013 500 *
donatien 0:632c9925f013 501 * Decrements the pbuf reference count. If it reaches zero, the pbuf is
donatien 0:632c9925f013 502 * deallocated.
donatien 0:632c9925f013 503 *
donatien 0:632c9925f013 504 * For a pbuf chain, this is repeated for each pbuf in the chain,
donatien 0:632c9925f013 505 * up to the first pbuf which has a non-zero reference count after
donatien 0:632c9925f013 506 * decrementing. So, when all reference counts are one, the whole
donatien 0:632c9925f013 507 * chain is free'd.
donatien 0:632c9925f013 508 *
donatien 0:632c9925f013 509 * @param p The pbuf (chain) to be dereferenced.
donatien 0:632c9925f013 510 *
donatien 0:632c9925f013 511 * @return the number of pbufs that were de-allocated
donatien 0:632c9925f013 512 * from the head of the chain.
donatien 0:632c9925f013 513 *
donatien 0:632c9925f013 514 * @note MUST NOT be called on a packet queue (Not verified to work yet).
donatien 0:632c9925f013 515 * @note the reference counter of a pbuf equals the number of pointers
donatien 0:632c9925f013 516 * that refer to the pbuf (or into the pbuf).
donatien 0:632c9925f013 517 *
donatien 0:632c9925f013 518 * @internal examples:
donatien 0:632c9925f013 519 *
donatien 0:632c9925f013 520 * Assuming existing chains a->b->c with the following reference
donatien 0:632c9925f013 521 * counts, calling pbuf_free(a) results in:
donatien 0:632c9925f013 522 *
donatien 0:632c9925f013 523 * 1->2->3 becomes ...1->3
donatien 0:632c9925f013 524 * 3->3->3 becomes 2->3->3
donatien 0:632c9925f013 525 * 1->1->2 becomes ......1
donatien 0:632c9925f013 526 * 2->1->1 becomes 1->1->1
donatien 0:632c9925f013 527 * 1->1->1 becomes .......
donatien 0:632c9925f013 528 *
donatien 0:632c9925f013 529 */
donatien 0:632c9925f013 530 u8_t
donatien 0:632c9925f013 531 pbuf_free(struct pbuf *p)
donatien 0:632c9925f013 532 {
donatien 0:632c9925f013 533 u16_t type;
donatien 0:632c9925f013 534 struct pbuf *q;
donatien 0:632c9925f013 535 u8_t count;
donatien 0:632c9925f013 536
donatien 0:632c9925f013 537 if (p == NULL) {
donatien 0:632c9925f013 538 LWIP_ASSERT("p != NULL", p != NULL);
donatien 0:632c9925f013 539 /* if assertions are disabled, proceed with debug output */
donatien 0:632c9925f013 540 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
donatien 0:632c9925f013 541 ("pbuf_free(p == NULL) was called.\n"));
donatien 0:632c9925f013 542 return 0;
donatien 0:632c9925f013 543 }
donatien 0:632c9925f013 544 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free(%p)\n", (void *)p));
donatien 0:632c9925f013 545
donatien 0:632c9925f013 546 PERF_START;
donatien 0:632c9925f013 547
donatien 0:632c9925f013 548 LWIP_ASSERT("pbuf_free: sane type",
donatien 0:632c9925f013 549 p->type == PBUF_RAM || p->type == PBUF_ROM ||
donatien 0:632c9925f013 550 p->type == PBUF_REF || p->type == PBUF_POOL);
donatien 0:632c9925f013 551
donatien 0:632c9925f013 552 count = 0;
donatien 0:632c9925f013 553 /* de-allocate all consecutive pbufs from the head of the chain that
donatien 0:632c9925f013 554 * obtain a zero reference count after decrementing*/
donatien 0:632c9925f013 555 while (p != NULL) {
donatien 0:632c9925f013 556 u16_t ref;
donatien 0:632c9925f013 557 SYS_ARCH_DECL_PROTECT(old_level);
donatien 0:632c9925f013 558 /* Since decrementing ref cannot be guaranteed to be a single machine operation
donatien 0:632c9925f013 559 * we must protect it. We put the new ref into a local variable to prevent
donatien 0:632c9925f013 560 * further protection. */
donatien 0:632c9925f013 561 SYS_ARCH_PROTECT(old_level);
donatien 0:632c9925f013 562 /* all pbufs in a chain are referenced at least once */
donatien 0:632c9925f013 563 LWIP_ASSERT("pbuf_free: p->ref > 0", p->ref > 0);
donatien 0:632c9925f013 564 /* decrease reference count (number of pointers to pbuf) */
donatien 0:632c9925f013 565 ref = --(p->ref);
donatien 0:632c9925f013 566 SYS_ARCH_UNPROTECT(old_level);
donatien 0:632c9925f013 567 /* this pbuf is no longer referenced to? */
donatien 0:632c9925f013 568 if (ref == 0) {
donatien 0:632c9925f013 569 /* remember next pbuf in chain for next iteration */
donatien 0:632c9925f013 570 q = p->next;
donatien 0:632c9925f013 571 LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free: deallocating %p\n", (void *)p));
donatien 0:632c9925f013 572 type = p->type;
donatien 0:632c9925f013 573 /* is this a pbuf from the pool? */
donatien 0:632c9925f013 574 if (type == PBUF_POOL) {
donatien 0:632c9925f013 575 memp_free(MEMP_PBUF_POOL, p);
donatien 0:632c9925f013 576 /* is this a ROM or RAM referencing pbuf? */
donatien 0:632c9925f013 577 } else if (type == PBUF_ROM || type == PBUF_REF) {
donatien 0:632c9925f013 578 memp_free(MEMP_PBUF, p);
donatien 0:632c9925f013 579 /* type == PBUF_RAM */
donatien 0:632c9925f013 580 } else {
donatien 0:632c9925f013 581 mem_free(p);
donatien 0:632c9925f013 582 }
donatien 0:632c9925f013 583 count++;
donatien 0:632c9925f013 584 /* proceed to next pbuf */
donatien 0:632c9925f013 585 p = q;
donatien 0:632c9925f013 586 /* p->ref > 0, this pbuf is still referenced to */
donatien 0:632c9925f013 587 /* (and so the remaining pbufs in chain as well) */
donatien 0:632c9925f013 588 } else {
donatien 0:632c9925f013 589 LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref));
donatien 0:632c9925f013 590 /* stop walking through the chain */
donatien 0:632c9925f013 591 p = NULL;
donatien 0:632c9925f013 592 }
donatien 0:632c9925f013 593 }
donatien 0:632c9925f013 594 PERF_STOP("pbuf_free");
donatien 0:632c9925f013 595 /* return number of de-allocated pbufs */
donatien 0:632c9925f013 596 return count;
donatien 0:632c9925f013 597 }
donatien 0:632c9925f013 598
donatien 0:632c9925f013 599 /**
donatien 0:632c9925f013 600 * Count number of pbufs in a chain
donatien 0:632c9925f013 601 *
donatien 0:632c9925f013 602 * @param p first pbuf of chain
donatien 0:632c9925f013 603 * @return the number of pbufs in a chain
donatien 0:632c9925f013 604 */
donatien 0:632c9925f013 605
donatien 0:632c9925f013 606 u8_t
donatien 0:632c9925f013 607 pbuf_clen(struct pbuf *p)
donatien 0:632c9925f013 608 {
donatien 0:632c9925f013 609 u8_t len;
donatien 0:632c9925f013 610
donatien 0:632c9925f013 611 len = 0;
donatien 0:632c9925f013 612 while (p != NULL) {
donatien 0:632c9925f013 613 ++len;
donatien 0:632c9925f013 614 p = p->next;
donatien 0:632c9925f013 615 }
donatien 0:632c9925f013 616 return len;
donatien 0:632c9925f013 617 }
donatien 0:632c9925f013 618
donatien 0:632c9925f013 619 /**
donatien 0:632c9925f013 620 * Increment the reference count of the pbuf.
donatien 0:632c9925f013 621 *
donatien 0:632c9925f013 622 * @param p pbuf to increase reference counter of
donatien 0:632c9925f013 623 *
donatien 0:632c9925f013 624 */
donatien 0:632c9925f013 625 void
donatien 0:632c9925f013 626 pbuf_ref(struct pbuf *p)
donatien 0:632c9925f013 627 {
donatien 0:632c9925f013 628 SYS_ARCH_DECL_PROTECT(old_level);
donatien 0:632c9925f013 629 /* pbuf given? */
donatien 0:632c9925f013 630 if (p != NULL) {
donatien 0:632c9925f013 631 SYS_ARCH_PROTECT(old_level);
donatien 0:632c9925f013 632 ++(p->ref);
donatien 0:632c9925f013 633 SYS_ARCH_UNPROTECT(old_level);
donatien 0:632c9925f013 634 }
donatien 0:632c9925f013 635 }
donatien 0:632c9925f013 636
donatien 0:632c9925f013 637 /**
donatien 0:632c9925f013 638 * Concatenate two pbufs (each may be a pbuf chain) and take over
donatien 0:632c9925f013 639 * the caller's reference of the tail pbuf.
donatien 0:632c9925f013 640 *
donatien 0:632c9925f013 641 * @note The caller MAY NOT reference the tail pbuf afterwards.
donatien 0:632c9925f013 642 * Use pbuf_chain() for that purpose.
donatien 0:632c9925f013 643 *
donatien 0:632c9925f013 644 * @see pbuf_chain()
donatien 0:632c9925f013 645 */
donatien 0:632c9925f013 646
donatien 0:632c9925f013 647 void
donatien 0:632c9925f013 648 pbuf_cat(struct pbuf *h, struct pbuf *t)
donatien 0:632c9925f013 649 {
donatien 0:632c9925f013 650 struct pbuf *p;
donatien 0:632c9925f013 651
donatien 0:632c9925f013 652 LWIP_ERROR("(h != NULL) && (t != NULL) (programmer violates API)",
donatien 0:632c9925f013 653 ((h != NULL) && (t != NULL)), return;);
donatien 0:632c9925f013 654
donatien 0:632c9925f013 655 /* proceed to last pbuf of chain */
donatien 0:632c9925f013 656 for (p = h; p->next != NULL; p = p->next) {
donatien 0:632c9925f013 657 /* add total length of second chain to all totals of first chain */
donatien 0:632c9925f013 658 p->tot_len += t->tot_len;
donatien 0:632c9925f013 659 }
donatien 0:632c9925f013 660 /* { p is last pbuf of first h chain, p->next == NULL } */
donatien 0:632c9925f013 661 LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len);
donatien 0:632c9925f013 662 LWIP_ASSERT("p->next == NULL", p->next == NULL);
donatien 0:632c9925f013 663 /* add total length of second chain to last pbuf total of first chain */
donatien 0:632c9925f013 664 p->tot_len += t->tot_len;
donatien 0:632c9925f013 665 /* chain last pbuf of head (p) with first of tail (t) */
donatien 0:632c9925f013 666 p->next = t;
donatien 0:632c9925f013 667 /* p->next now references t, but the caller will drop its reference to t,
donatien 0:632c9925f013 668 * so netto there is no change to the reference count of t.
donatien 0:632c9925f013 669 */
donatien 0:632c9925f013 670 }
donatien 0:632c9925f013 671
donatien 0:632c9925f013 672 /**
donatien 0:632c9925f013 673 * Chain two pbufs (or pbuf chains) together.
donatien 0:632c9925f013 674 *
donatien 0:632c9925f013 675 * The caller MUST call pbuf_free(t) once it has stopped
donatien 0:632c9925f013 676 * using it. Use pbuf_cat() instead if you no longer use t.
donatien 0:632c9925f013 677 *
donatien 0:632c9925f013 678 * @param h head pbuf (chain)
donatien 0:632c9925f013 679 * @param t tail pbuf (chain)
donatien 0:632c9925f013 680 * @note The pbufs MUST belong to the same packet.
donatien 0:632c9925f013 681 * @note MAY NOT be called on a packet queue.
donatien 0:632c9925f013 682 *
donatien 0:632c9925f013 683 * The ->tot_len fields of all pbufs of the head chain are adjusted.
donatien 0:632c9925f013 684 * The ->next field of the last pbuf of the head chain is adjusted.
donatien 0:632c9925f013 685 * The ->ref field of the first pbuf of the tail chain is adjusted.
donatien 0:632c9925f013 686 *
donatien 0:632c9925f013 687 */
donatien 0:632c9925f013 688 void
donatien 0:632c9925f013 689 pbuf_chain(struct pbuf *h, struct pbuf *t)
donatien 0:632c9925f013 690 {
donatien 0:632c9925f013 691 pbuf_cat(h, t);
donatien 0:632c9925f013 692 /* t is now referenced by h */
donatien 0:632c9925f013 693 pbuf_ref(t);
donatien 0:632c9925f013 694 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_chain: %p references %p\n", (void *)h, (void *)t));
donatien 0:632c9925f013 695 }
donatien 0:632c9925f013 696
donatien 0:632c9925f013 697 /**
donatien 0:632c9925f013 698 * Dechains the first pbuf from its succeeding pbufs in the chain.
donatien 0:632c9925f013 699 *
donatien 0:632c9925f013 700 * Makes p->tot_len field equal to p->len.
donatien 0:632c9925f013 701 * @param p pbuf to dechain
donatien 0:632c9925f013 702 * @return remainder of the pbuf chain, or NULL if it was de-allocated.
donatien 0:632c9925f013 703 * @note May not be called on a packet queue.
donatien 0:632c9925f013 704 */
donatien 0:632c9925f013 705 struct pbuf *
donatien 0:632c9925f013 706 pbuf_dechain(struct pbuf *p)
donatien 0:632c9925f013 707 {
donatien 0:632c9925f013 708 struct pbuf *q;
donatien 0:632c9925f013 709 u8_t tail_gone = 1;
donatien 0:632c9925f013 710 /* tail */
donatien 0:632c9925f013 711 q = p->next;
donatien 0:632c9925f013 712 /* pbuf has successor in chain? */
donatien 0:632c9925f013 713 if (q != NULL) {
donatien 0:632c9925f013 714 /* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
donatien 0:632c9925f013 715 LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len);
donatien 0:632c9925f013 716 /* enforce invariant if assertion is disabled */
donatien 0:632c9925f013 717 q->tot_len = p->tot_len - p->len;
donatien 0:632c9925f013 718 /* decouple pbuf from remainder */
donatien 0:632c9925f013 719 p->next = NULL;
donatien 0:632c9925f013 720 /* total length of pbuf p is its own length only */
donatien 0:632c9925f013 721 p->tot_len = p->len;
donatien 0:632c9925f013 722 /* q is no longer referenced by p, free it */
donatien 0:632c9925f013 723 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_dechain: unreferencing %p\n", (void *)q));
donatien 0:632c9925f013 724 tail_gone = pbuf_free(q);
donatien 0:632c9925f013 725 if (tail_gone > 0) {
donatien 0:632c9925f013 726 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE,
donatien 0:632c9925f013 727 ("pbuf_dechain: deallocated %p (as it is no longer referenced)\n", (void *)q));
donatien 0:632c9925f013 728 }
donatien 0:632c9925f013 729 /* return remaining tail or NULL if deallocated */
donatien 0:632c9925f013 730 }
donatien 0:632c9925f013 731 /* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
donatien 0:632c9925f013 732 LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len);
donatien 0:632c9925f013 733 return ((tail_gone > 0) ? NULL : q);
donatien 0:632c9925f013 734 }
donatien 0:632c9925f013 735
donatien 0:632c9925f013 736 /**
donatien 0:632c9925f013 737 *
donatien 0:632c9925f013 738 * Create PBUF_RAM copies of pbufs.
donatien 0:632c9925f013 739 *
donatien 0:632c9925f013 740 * Used to queue packets on behalf of the lwIP stack, such as
donatien 0:632c9925f013 741 * ARP based queueing.
donatien 0:632c9925f013 742 *
donatien 0:632c9925f013 743 * @note You MUST explicitly use p = pbuf_take(p);
donatien 0:632c9925f013 744 *
donatien 0:632c9925f013 745 * @note Only one packet is copied, no packet queue!
donatien 0:632c9925f013 746 *
donatien 0:632c9925f013 747 * @param p_to pbuf destination of the copy
donatien 0:632c9925f013 748 * @param p_from pbuf source of the copy
donatien 0:632c9925f013 749 *
donatien 0:632c9925f013 750 * @return ERR_OK if pbuf was copied
donatien 0:632c9925f013 751 * ERR_ARG if one of the pbufs is NULL or p_to is not big
donatien 0:632c9925f013 752 * enough to hold p_from
donatien 0:632c9925f013 753 */
donatien 0:632c9925f013 754 err_t
donatien 0:632c9925f013 755 pbuf_copy(struct pbuf *p_to, struct pbuf *p_from)
donatien 0:632c9925f013 756 {
donatien 0:632c9925f013 757 u16_t offset_to=0, offset_from=0, len;
donatien 0:632c9925f013 758
donatien 0:632c9925f013 759 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy(%p, %p)\n",
donatien 0:632c9925f013 760 (void*)p_to, (void*)p_from));
donatien 0:632c9925f013 761
donatien 0:632c9925f013 762 /* is the target big enough to hold the source? */
donatien 0:632c9925f013 763 LWIP_ERROR("pbuf_copy: target not big enough to hold source", ((p_to != NULL) &&
donatien 0:632c9925f013 764 (p_from != NULL) && (p_to->tot_len >= p_from->tot_len)), return ERR_ARG;);
donatien 0:632c9925f013 765
donatien 0:632c9925f013 766 /* iterate through pbuf chain */
donatien 0:632c9925f013 767 do
donatien 0:632c9925f013 768 {
donatien 0:632c9925f013 769 LWIP_ASSERT("p_to != NULL", p_to != NULL);
donatien 0:632c9925f013 770 /* copy one part of the original chain */
donatien 0:632c9925f013 771 if ((p_to->len - offset_to) >= (p_from->len - offset_from)) {
donatien 0:632c9925f013 772 /* complete current p_from fits into current p_to */
donatien 0:632c9925f013 773 len = p_from->len - offset_from;
donatien 0:632c9925f013 774 } else {
donatien 0:632c9925f013 775 /* current p_from does not fit into current p_to */
donatien 0:632c9925f013 776 len = p_to->len - offset_to;
donatien 0:632c9925f013 777 }
donatien 0:632c9925f013 778 MEMCPY((u8_t*)p_to->payload + offset_to, (u8_t*)p_from->payload + offset_from, len);
donatien 0:632c9925f013 779 offset_to += len;
donatien 0:632c9925f013 780 offset_from += len;
donatien 0:632c9925f013 781 LWIP_ASSERT("offset_to <= p_to->len", offset_to <= p_to->len);
donatien 0:632c9925f013 782 if (offset_to == p_to->len) {
donatien 0:632c9925f013 783 /* on to next p_to (if any) */
donatien 0:632c9925f013 784 offset_to = 0;
donatien 0:632c9925f013 785 p_to = p_to->next;
donatien 0:632c9925f013 786 }
donatien 0:632c9925f013 787 LWIP_ASSERT("offset_from <= p_from->len", offset_from <= p_from->len);
donatien 0:632c9925f013 788 if (offset_from >= p_from->len) {
donatien 0:632c9925f013 789 /* on to next p_from (if any) */
donatien 0:632c9925f013 790 offset_from = 0;
donatien 0:632c9925f013 791 p_from = p_from->next;
donatien 0:632c9925f013 792 }
donatien 0:632c9925f013 793
donatien 0:632c9925f013 794 if((p_from != NULL) && (p_from->len == p_from->tot_len)) {
donatien 0:632c9925f013 795 /* don't copy more than one packet! */
donatien 0:632c9925f013 796 LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
donatien 0:632c9925f013 797 (p_from->next == NULL), return ERR_VAL;);
donatien 0:632c9925f013 798 }
donatien 0:632c9925f013 799 if((p_to != NULL) && (p_to->len == p_to->tot_len)) {
donatien 0:632c9925f013 800 /* don't copy more than one packet! */
donatien 0:632c9925f013 801 LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
donatien 0:632c9925f013 802 (p_to->next == NULL), return ERR_VAL;);
donatien 0:632c9925f013 803 }
donatien 0:632c9925f013 804 } while (p_from);
donatien 0:632c9925f013 805 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy: end of chain reached.\n"));
donatien 0:632c9925f013 806 return ERR_OK;
donatien 0:632c9925f013 807 }
donatien 0:632c9925f013 808
donatien 0:632c9925f013 809 /**
donatien 0:632c9925f013 810 * Copy (part of) the contents of a packet buffer
donatien 0:632c9925f013 811 * to an application supplied buffer.
donatien 0:632c9925f013 812 *
donatien 0:632c9925f013 813 * @param buf the pbuf from which to copy data
donatien 0:632c9925f013 814 * @param dataptr the application supplied buffer
donatien 0:632c9925f013 815 * @param len length of data to copy (dataptr must be big enough). No more
donatien 0:632c9925f013 816 * than buf->tot_len will be copied, irrespective of len
donatien 0:632c9925f013 817 * @param offset offset into the packet buffer from where to begin copying len bytes
donatien 0:632c9925f013 818 * @return the number of bytes copied, or 0 on failure
donatien 0:632c9925f013 819 */
donatien 0:632c9925f013 820 u16_t
donatien 0:632c9925f013 821 pbuf_copy_partial(struct pbuf *buf, void *dataptr, u16_t len, u16_t offset)
donatien 0:632c9925f013 822 {
donatien 0:632c9925f013 823 struct pbuf *p;
donatien 0:632c9925f013 824 u16_t left;
donatien 0:632c9925f013 825 u16_t buf_copy_len;
donatien 0:632c9925f013 826 u16_t copied_total = 0;
donatien 0:632c9925f013 827
donatien 0:632c9925f013 828 LWIP_ERROR("pbuf_copy_partial: invalid buf", (buf != NULL), return 0;);
donatien 0:632c9925f013 829 LWIP_ERROR("pbuf_copy_partial: invalid dataptr", (dataptr != NULL), return 0;);
donatien 0:632c9925f013 830
donatien 0:632c9925f013 831 left = 0;
donatien 0:632c9925f013 832
donatien 0:632c9925f013 833 if((buf == NULL) || (dataptr == NULL)) {
donatien 0:632c9925f013 834 return 0;
donatien 0:632c9925f013 835 }
donatien 0:632c9925f013 836
donatien 0:632c9925f013 837 /* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
donatien 0:632c9925f013 838 for(p = buf; len != 0 && p != NULL; p = p->next) {
donatien 0:632c9925f013 839 if ((offset != 0) && (offset >= p->len)) {
donatien 0:632c9925f013 840 /* don't copy from this buffer -> on to the next */
donatien 0:632c9925f013 841 offset -= p->len;
donatien 0:632c9925f013 842 } else {
donatien 0:632c9925f013 843 /* copy from this buffer. maybe only partially. */
donatien 0:632c9925f013 844 buf_copy_len = p->len - offset;
donatien 0:632c9925f013 845 if (buf_copy_len > len)
donatien 0:632c9925f013 846 buf_copy_len = len;
donatien 0:632c9925f013 847 /* copy the necessary parts of the buffer */
donatien 0:632c9925f013 848 MEMCPY(&((char*)dataptr)[left], &((char*)p->payload)[offset], buf_copy_len);
donatien 0:632c9925f013 849 copied_total += buf_copy_len;
donatien 0:632c9925f013 850 left += buf_copy_len;
donatien 0:632c9925f013 851 len -= buf_copy_len;
donatien 0:632c9925f013 852 offset = 0;
donatien 0:632c9925f013 853 }
donatien 0:632c9925f013 854 }
donatien 0:632c9925f013 855 return copied_total;
donatien 0:632c9925f013 856 }
donatien 0:632c9925f013 857
donatien 0:632c9925f013 858 /**
donatien 0:632c9925f013 859 * Copy application supplied data into a pbuf.
donatien 0:632c9925f013 860 * This function can only be used to copy the equivalent of buf->tot_len data.
donatien 0:632c9925f013 861 *
donatien 0:632c9925f013 862 * @param buf pbuf to fill with data
donatien 0:632c9925f013 863 * @param dataptr application supplied data buffer
donatien 0:632c9925f013 864 * @param len length of the application supplied data buffer
donatien 0:632c9925f013 865 *
donatien 0:632c9925f013 866 * @return ERR_OK if successful, ERR_MEM if the pbuf is not big enough
donatien 0:632c9925f013 867 */
donatien 0:632c9925f013 868 err_t
donatien 0:632c9925f013 869 pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len)
donatien 0:632c9925f013 870 {
donatien 0:632c9925f013 871 struct pbuf *p;
donatien 0:632c9925f013 872 u16_t buf_copy_len;
donatien 0:632c9925f013 873 u16_t total_copy_len = len;
donatien 0:632c9925f013 874 u16_t copied_total = 0;
donatien 0:632c9925f013 875
donatien 0:632c9925f013 876 LWIP_ERROR("pbuf_take: invalid buf", (buf != NULL), return 0;);
donatien 0:632c9925f013 877 LWIP_ERROR("pbuf_take: invalid dataptr", (dataptr != NULL), return 0;);
donatien 0:632c9925f013 878
donatien 0:632c9925f013 879 if ((buf == NULL) || (dataptr == NULL) || (buf->tot_len < len)) {
donatien 0:632c9925f013 880 return ERR_ARG;
donatien 0:632c9925f013 881 }
donatien 0:632c9925f013 882
donatien 0:632c9925f013 883 /* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
donatien 0:632c9925f013 884 for(p = buf; total_copy_len != 0; p = p->next) {
donatien 0:632c9925f013 885 LWIP_ASSERT("pbuf_take: invalid pbuf", p != NULL);
donatien 0:632c9925f013 886 buf_copy_len = total_copy_len;
donatien 0:632c9925f013 887 if (buf_copy_len > p->len) {
donatien 0:632c9925f013 888 /* this pbuf cannot hold all remaining data */
donatien 0:632c9925f013 889 buf_copy_len = p->len;
donatien 0:632c9925f013 890 }
donatien 0:632c9925f013 891 /* copy the necessary parts of the buffer */
donatien 0:632c9925f013 892 MEMCPY(p->payload, &((char*)dataptr)[copied_total], buf_copy_len);
donatien 0:632c9925f013 893 total_copy_len -= buf_copy_len;
donatien 0:632c9925f013 894 copied_total += buf_copy_len;
donatien 0:632c9925f013 895 }
donatien 0:632c9925f013 896 LWIP_ASSERT("did not copy all data", total_copy_len == 0 && copied_total == len);
donatien 0:632c9925f013 897 return ERR_OK;
donatien 0:632c9925f013 898 }
donatien 0:632c9925f013 899
donatien 0:632c9925f013 900 /**
donatien 0:632c9925f013 901 * Creates a single pbuf out of a queue of pbufs.
donatien 0:632c9925f013 902 *
donatien 0:632c9925f013 903 * @remark: The source pbuf 'p' is not freed by this function because that can
donatien 0:632c9925f013 904 * be illegal in some places!
donatien 0:632c9925f013 905 *
donatien 0:632c9925f013 906 * @param p the source pbuf
donatien 0:632c9925f013 907 * @param layer pbuf_layer of the new pbuf
donatien 0:632c9925f013 908 *
donatien 0:632c9925f013 909 * @return a new, single pbuf (p->next is NULL)
donatien 0:632c9925f013 910 * or the old pbuf if allocation fails
donatien 0:632c9925f013 911 */
donatien 0:632c9925f013 912 struct pbuf*
donatien 0:632c9925f013 913 pbuf_coalesce(struct pbuf *p, pbuf_layer layer)
donatien 0:632c9925f013 914 {
donatien 0:632c9925f013 915 struct pbuf *q;
donatien 0:632c9925f013 916 err_t err;
donatien 0:632c9925f013 917 if (p->next == NULL) {
donatien 0:632c9925f013 918 return p;
donatien 0:632c9925f013 919 }
donatien 0:632c9925f013 920 q = pbuf_alloc(layer, p->tot_len, PBUF_RAM);
donatien 0:632c9925f013 921 if (q == NULL) {
donatien 0:632c9925f013 922 /* @todo: what do we do now? */
donatien 0:632c9925f013 923 return p;
donatien 0:632c9925f013 924 }
donatien 0:632c9925f013 925 err = pbuf_copy(q, p);
donatien 0:632c9925f013 926 LWIP_ASSERT("pbuf_copy failed", err == ERR_OK);
donatien 0:632c9925f013 927 pbuf_free(p);
donatien 0:632c9925f013 928 return q;
donatien 0:632c9925f013 929 }