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lwip/core/pbuf.c@0:b2805b6888dc, 2016-06-20 (annotated)

Committer:
robert_jw
Date:
Mon Jun 20 01:40:20 2016 +0000
Revision:
0:b2805b6888dc
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Who changed what in which revision?

UserRevisionLine numberNew contents of line
robert_jw 0:b2805b6888dc 1 /**
robert_jw 0:b2805b6888dc 2 * @file
robert_jw 0:b2805b6888dc 3 * Packet buffer management
robert_jw 0:b2805b6888dc 4 *
robert_jw 0:b2805b6888dc 5 * Packets are built from the pbuf data structure. It supports dynamic
robert_jw 0:b2805b6888dc 6 * memory allocation for packet contents or can reference externally
robert_jw 0:b2805b6888dc 7 * managed packet contents both in RAM and ROM. Quick allocation for
robert_jw 0:b2805b6888dc 8 * incoming packets is provided through pools with fixed sized pbufs.
robert_jw 0:b2805b6888dc 9 *
robert_jw 0:b2805b6888dc 10 * A packet may span over multiple pbufs, chained as a singly linked
robert_jw 0:b2805b6888dc 11 * list. This is called a "pbuf chain".
robert_jw 0:b2805b6888dc 12 *
robert_jw 0:b2805b6888dc 13 * Multiple packets may be queued, also using this singly linked list.
robert_jw 0:b2805b6888dc 14 * This is called a "packet queue".
robert_jw 0:b2805b6888dc 15 *
robert_jw 0:b2805b6888dc 16 * So, a packet queue consists of one or more pbuf chains, each of
robert_jw 0:b2805b6888dc 17 * which consist of one or more pbufs. CURRENTLY, PACKET QUEUES ARE
robert_jw 0:b2805b6888dc 18 * NOT SUPPORTED!!! Use helper structs to queue multiple packets.
robert_jw 0:b2805b6888dc 19 *
robert_jw 0:b2805b6888dc 20 * The differences between a pbuf chain and a packet queue are very
robert_jw 0:b2805b6888dc 21 * precise but subtle.
robert_jw 0:b2805b6888dc 22 *
robert_jw 0:b2805b6888dc 23 * The last pbuf of a packet has a ->tot_len field that equals the
robert_jw 0:b2805b6888dc 24 * ->len field. It can be found by traversing the list. If the last
robert_jw 0:b2805b6888dc 25 * pbuf of a packet has a ->next field other than NULL, more packets
robert_jw 0:b2805b6888dc 26 * are on the queue.
robert_jw 0:b2805b6888dc 27 *
robert_jw 0:b2805b6888dc 28 * Therefore, looping through a pbuf of a single packet, has an
robert_jw 0:b2805b6888dc 29 * loop end condition (tot_len == p->len), NOT (next == NULL).
robert_jw 0:b2805b6888dc 30 */
robert_jw 0:b2805b6888dc 31
robert_jw 0:b2805b6888dc 32 /*
robert_jw 0:b2805b6888dc 33 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
robert_jw 0:b2805b6888dc 34 * All rights reserved.
robert_jw 0:b2805b6888dc 35 *
robert_jw 0:b2805b6888dc 36 * Redistribution and use in source and binary forms, with or without modification,
robert_jw 0:b2805b6888dc 37 * are permitted provided that the following conditions are met:
robert_jw 0:b2805b6888dc 38 *
robert_jw 0:b2805b6888dc 39 * 1. Redistributions of source code must retain the above copyright notice,
robert_jw 0:b2805b6888dc 40 * this list of conditions and the following disclaimer.
robert_jw 0:b2805b6888dc 41 * 2. Redistributions in binary form must reproduce the above copyright notice,
robert_jw 0:b2805b6888dc 42 * this list of conditions and the following disclaimer in the documentation
robert_jw 0:b2805b6888dc 43 * and/or other materials provided with the distribution.
robert_jw 0:b2805b6888dc 44 * 3. The name of the author may not be used to endorse or promote products
robert_jw 0:b2805b6888dc 45 * derived from this software without specific prior written permission.
robert_jw 0:b2805b6888dc 46 *
robert_jw 0:b2805b6888dc 47 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
robert_jw 0:b2805b6888dc 48 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
robert_jw 0:b2805b6888dc 49 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
robert_jw 0:b2805b6888dc 50 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
robert_jw 0:b2805b6888dc 51 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
robert_jw 0:b2805b6888dc 52 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
robert_jw 0:b2805b6888dc 53 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
robert_jw 0:b2805b6888dc 54 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
robert_jw 0:b2805b6888dc 55 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
robert_jw 0:b2805b6888dc 56 * OF SUCH DAMAGE.
robert_jw 0:b2805b6888dc 57 *
robert_jw 0:b2805b6888dc 58 * This file is part of the lwIP TCP/IP stack.
robert_jw 0:b2805b6888dc 59 *
robert_jw 0:b2805b6888dc 60 * Author: Adam Dunkels <adam@sics.se>
robert_jw 0:b2805b6888dc 61 *
robert_jw 0:b2805b6888dc 62 */
robert_jw 0:b2805b6888dc 63
robert_jw 0:b2805b6888dc 64 #include "lwip/opt.h"
robert_jw 0:b2805b6888dc 65
robert_jw 0:b2805b6888dc 66 #include "lwip/stats.h"
robert_jw 0:b2805b6888dc 67 #include "lwip/def.h"
robert_jw 0:b2805b6888dc 68 #include "lwip/mem.h"
robert_jw 0:b2805b6888dc 69 #include "lwip/memp.h"
robert_jw 0:b2805b6888dc 70 #include "lwip/pbuf.h"
robert_jw 0:b2805b6888dc 71 #include "lwip/sys.h"
robert_jw 0:b2805b6888dc 72 #include "arch/perf.h"
robert_jw 0:b2805b6888dc 73 #if TCP_QUEUE_OOSEQ
robert_jw 0:b2805b6888dc 74 #include "lwip/tcp_impl.h"
robert_jw 0:b2805b6888dc 75 #endif
robert_jw 0:b2805b6888dc 76 #if LWIP_CHECKSUM_ON_COPY
robert_jw 0:b2805b6888dc 77 #include "lwip/inet_chksum.h"
robert_jw 0:b2805b6888dc 78 #endif
robert_jw 0:b2805b6888dc 79
robert_jw 0:b2805b6888dc 80 #include <string.h>
robert_jw 0:b2805b6888dc 81
robert_jw 0:b2805b6888dc 82 #define SIZEOF_STRUCT_PBUF LWIP_MEM_ALIGN_SIZE(sizeof(struct pbuf))
robert_jw 0:b2805b6888dc 83 /* Since the pool is created in memp, PBUF_POOL_BUFSIZE will be automatically
robert_jw 0:b2805b6888dc 84 aligned there. Therefore, PBUF_POOL_BUFSIZE_ALIGNED can be used here. */
robert_jw 0:b2805b6888dc 85 #define PBUF_POOL_BUFSIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE)
robert_jw 0:b2805b6888dc 86
robert_jw 0:b2805b6888dc 87 #if !LWIP_TCP || !TCP_QUEUE_OOSEQ || NO_SYS
robert_jw 0:b2805b6888dc 88 #define PBUF_POOL_IS_EMPTY()
robert_jw 0:b2805b6888dc 89 #else /* !LWIP_TCP || !TCP_QUEUE_OOSEQ || NO_SYS */
robert_jw 0:b2805b6888dc 90 /** Define this to 0 to prevent freeing ooseq pbufs when the PBUF_POOL is empty */
robert_jw 0:b2805b6888dc 91 #ifndef PBUF_POOL_FREE_OOSEQ
robert_jw 0:b2805b6888dc 92 #define PBUF_POOL_FREE_OOSEQ 1
robert_jw 0:b2805b6888dc 93 #endif /* PBUF_POOL_FREE_OOSEQ */
robert_jw 0:b2805b6888dc 94
robert_jw 0:b2805b6888dc 95 #if PBUF_POOL_FREE_OOSEQ
robert_jw 0:b2805b6888dc 96 #include "lwip/tcpip.h"
robert_jw 0:b2805b6888dc 97 #define PBUF_POOL_IS_EMPTY() pbuf_pool_is_empty()
robert_jw 0:b2805b6888dc 98 static u8_t pbuf_free_ooseq_queued;
robert_jw 0:b2805b6888dc 99 /**
robert_jw 0:b2805b6888dc 100 * Attempt to reclaim some memory from queued out-of-sequence TCP segments
robert_jw 0:b2805b6888dc 101 * if we run out of pool pbufs. It's better to give priority to new packets
robert_jw 0:b2805b6888dc 102 * if we're running out.
robert_jw 0:b2805b6888dc 103 *
robert_jw 0:b2805b6888dc 104 * This must be done in the correct thread context therefore this function
robert_jw 0:b2805b6888dc 105 * can only be used with NO_SYS=0 and through tcpip_callback.
robert_jw 0:b2805b6888dc 106 */
robert_jw 0:b2805b6888dc 107 static void
robert_jw 0:b2805b6888dc 108 pbuf_free_ooseq(void* arg)
robert_jw 0:b2805b6888dc 109 {
robert_jw 0:b2805b6888dc 110 struct tcp_pcb* pcb;
robert_jw 0:b2805b6888dc 111 SYS_ARCH_DECL_PROTECT(old_level);
robert_jw 0:b2805b6888dc 112 LWIP_UNUSED_ARG(arg);
robert_jw 0:b2805b6888dc 113
robert_jw 0:b2805b6888dc 114 SYS_ARCH_PROTECT(old_level);
robert_jw 0:b2805b6888dc 115 pbuf_free_ooseq_queued = 0;
robert_jw 0:b2805b6888dc 116 SYS_ARCH_UNPROTECT(old_level);
robert_jw 0:b2805b6888dc 117
robert_jw 0:b2805b6888dc 118 for (pcb = tcp_active_pcbs; NULL != pcb; pcb = pcb->next) {
robert_jw 0:b2805b6888dc 119 if (NULL != pcb->ooseq) {
robert_jw 0:b2805b6888dc 120 /** Free the ooseq pbufs of one PCB only */
robert_jw 0:b2805b6888dc 121 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free_ooseq: freeing out-of-sequence pbufs\n"));
robert_jw 0:b2805b6888dc 122 tcp_segs_free(pcb->ooseq);
robert_jw 0:b2805b6888dc 123 pcb->ooseq = NULL;
robert_jw 0:b2805b6888dc 124 return;
robert_jw 0:b2805b6888dc 125 }
robert_jw 0:b2805b6888dc 126 }
robert_jw 0:b2805b6888dc 127 }
robert_jw 0:b2805b6888dc 128
robert_jw 0:b2805b6888dc 129 /** Queue a call to pbuf_free_ooseq if not already queued. */
robert_jw 0:b2805b6888dc 130 static void
robert_jw 0:b2805b6888dc 131 pbuf_pool_is_empty(void)
robert_jw 0:b2805b6888dc 132 {
robert_jw 0:b2805b6888dc 133 u8_t queued;
robert_jw 0:b2805b6888dc 134 SYS_ARCH_DECL_PROTECT(old_level);
robert_jw 0:b2805b6888dc 135
robert_jw 0:b2805b6888dc 136 SYS_ARCH_PROTECT(old_level);
robert_jw 0:b2805b6888dc 137 queued = pbuf_free_ooseq_queued;
robert_jw 0:b2805b6888dc 138 pbuf_free_ooseq_queued = 1;
robert_jw 0:b2805b6888dc 139 SYS_ARCH_UNPROTECT(old_level);
robert_jw 0:b2805b6888dc 140
robert_jw 0:b2805b6888dc 141 if(!queued) {
robert_jw 0:b2805b6888dc 142 /* queue a call to pbuf_free_ooseq if not already queued */
robert_jw 0:b2805b6888dc 143 if(tcpip_callback_with_block(pbuf_free_ooseq, NULL, 0) != ERR_OK) {
robert_jw 0:b2805b6888dc 144 SYS_ARCH_PROTECT(old_level);
robert_jw 0:b2805b6888dc 145 pbuf_free_ooseq_queued = 0;
robert_jw 0:b2805b6888dc 146 SYS_ARCH_UNPROTECT(old_level);
robert_jw 0:b2805b6888dc 147 }
robert_jw 0:b2805b6888dc 148 }
robert_jw 0:b2805b6888dc 149 }
robert_jw 0:b2805b6888dc 150 #endif /* PBUF_POOL_FREE_OOSEQ */
robert_jw 0:b2805b6888dc 151 #endif /* !LWIP_TCP || !TCP_QUEUE_OOSEQ || NO_SYS */
robert_jw 0:b2805b6888dc 152
robert_jw 0:b2805b6888dc 153 /**
robert_jw 0:b2805b6888dc 154 * Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
robert_jw 0:b2805b6888dc 155 *
robert_jw 0:b2805b6888dc 156 * The actual memory allocated for the pbuf is determined by the
robert_jw 0:b2805b6888dc 157 * layer at which the pbuf is allocated and the requested size
robert_jw 0:b2805b6888dc 158 * (from the size parameter).
robert_jw 0:b2805b6888dc 159 *
robert_jw 0:b2805b6888dc 160 * @param layer flag to define header size
robert_jw 0:b2805b6888dc 161 * @param length size of the pbuf's payload
robert_jw 0:b2805b6888dc 162 * @param type this parameter decides how and where the pbuf
robert_jw 0:b2805b6888dc 163 * should be allocated as follows:
robert_jw 0:b2805b6888dc 164 *
robert_jw 0:b2805b6888dc 165 * - PBUF_RAM: buffer memory for pbuf is allocated as one large
robert_jw 0:b2805b6888dc 166 * chunk. This includes protocol headers as well.
robert_jw 0:b2805b6888dc 167 * - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
robert_jw 0:b2805b6888dc 168 * protocol headers. Additional headers must be prepended
robert_jw 0:b2805b6888dc 169 * by allocating another pbuf and chain in to the front of
robert_jw 0:b2805b6888dc 170 * the ROM pbuf. It is assumed that the memory used is really
robert_jw 0:b2805b6888dc 171 * similar to ROM in that it is immutable and will not be
robert_jw 0:b2805b6888dc 172 * changed. Memory which is dynamic should generally not
robert_jw 0:b2805b6888dc 173 * be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
robert_jw 0:b2805b6888dc 174 * - PBUF_REF: no buffer memory is allocated for the pbuf, even for
robert_jw 0:b2805b6888dc 175 * protocol headers. It is assumed that the pbuf is only
robert_jw 0:b2805b6888dc 176 * being used in a single thread. If the pbuf gets queued,
robert_jw 0:b2805b6888dc 177 * then pbuf_take should be called to copy the buffer.
robert_jw 0:b2805b6888dc 178 * - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
robert_jw 0:b2805b6888dc 179 * the pbuf pool that is allocated during pbuf_init().
robert_jw 0:b2805b6888dc 180 *
robert_jw 0:b2805b6888dc 181 * @return the allocated pbuf. If multiple pbufs where allocated, this
robert_jw 0:b2805b6888dc 182 * is the first pbuf of a pbuf chain.
robert_jw 0:b2805b6888dc 183 */
robert_jw 0:b2805b6888dc 184 struct pbuf *
robert_jw 0:b2805b6888dc 185 pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
robert_jw 0:b2805b6888dc 186 {
robert_jw 0:b2805b6888dc 187 struct pbuf *p, *q, *r;
robert_jw 0:b2805b6888dc 188 u16_t offset;
robert_jw 0:b2805b6888dc 189 s32_t rem_len; /* remaining length */
robert_jw 0:b2805b6888dc 190 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
robert_jw 0:b2805b6888dc 191
robert_jw 0:b2805b6888dc 192 /* determine header offset */
robert_jw 0:b2805b6888dc 193 offset = 0;
robert_jw 0:b2805b6888dc 194 switch (layer) {
robert_jw 0:b2805b6888dc 195 case PBUF_TRANSPORT:
robert_jw 0:b2805b6888dc 196 /* add room for transport (often TCP) layer header */
robert_jw 0:b2805b6888dc 197 offset += PBUF_TRANSPORT_HLEN;
robert_jw 0:b2805b6888dc 198 /* FALLTHROUGH */
robert_jw 0:b2805b6888dc 199 case PBUF_IP:
robert_jw 0:b2805b6888dc 200 /* add room for IP layer header */
robert_jw 0:b2805b6888dc 201 offset += PBUF_IP_HLEN;
robert_jw 0:b2805b6888dc 202 /* FALLTHROUGH */
robert_jw 0:b2805b6888dc 203 case PBUF_LINK:
robert_jw 0:b2805b6888dc 204 /* add room for link layer header */
robert_jw 0:b2805b6888dc 205 offset += PBUF_LINK_HLEN;
robert_jw 0:b2805b6888dc 206 break;
robert_jw 0:b2805b6888dc 207 case PBUF_RAW:
robert_jw 0:b2805b6888dc 208 break;
robert_jw 0:b2805b6888dc 209 default:
robert_jw 0:b2805b6888dc 210 LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0);
robert_jw 0:b2805b6888dc 211 return NULL;
robert_jw 0:b2805b6888dc 212 }
robert_jw 0:b2805b6888dc 213
robert_jw 0:b2805b6888dc 214 switch (type) {
robert_jw 0:b2805b6888dc 215 case PBUF_POOL:
robert_jw 0:b2805b6888dc 216 /* allocate head of pbuf chain into p */
robert_jw 0:b2805b6888dc 217 p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
robert_jw 0:b2805b6888dc 218 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
robert_jw 0:b2805b6888dc 219 if (p == NULL) {
robert_jw 0:b2805b6888dc 220 PBUF_POOL_IS_EMPTY();
robert_jw 0:b2805b6888dc 221 return NULL;
robert_jw 0:b2805b6888dc 222 }
robert_jw 0:b2805b6888dc 223 p->type = type;
robert_jw 0:b2805b6888dc 224 p->next = NULL;
robert_jw 0:b2805b6888dc 225
robert_jw 0:b2805b6888dc 226 /* make the payload pointer point 'offset' bytes into pbuf data memory */
robert_jw 0:b2805b6888dc 227 p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + (SIZEOF_STRUCT_PBUF + offset)));
robert_jw 0:b2805b6888dc 228 LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned",
robert_jw 0:b2805b6888dc 229 ((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
robert_jw 0:b2805b6888dc 230 /* the total length of the pbuf chain is the requested size */
robert_jw 0:b2805b6888dc 231 p->tot_len = length;
robert_jw 0:b2805b6888dc 232 /* set the length of the first pbuf in the chain */
robert_jw 0:b2805b6888dc 233 p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
robert_jw 0:b2805b6888dc 234 LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
robert_jw 0:b2805b6888dc 235 ((u8_t*)p->payload + p->len <=
robert_jw 0:b2805b6888dc 236 (u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
robert_jw 0:b2805b6888dc 237 LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT",
robert_jw 0:b2805b6888dc 238 (PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 );
robert_jw 0:b2805b6888dc 239 /* set reference count (needed here in case we fail) */
robert_jw 0:b2805b6888dc 240 p->ref = 1;
robert_jw 0:b2805b6888dc 241
robert_jw 0:b2805b6888dc 242 /* now allocate the tail of the pbuf chain */
robert_jw 0:b2805b6888dc 243
robert_jw 0:b2805b6888dc 244 /* remember first pbuf for linkage in next iteration */
robert_jw 0:b2805b6888dc 245 r = p;
robert_jw 0:b2805b6888dc 246 /* remaining length to be allocated */
robert_jw 0:b2805b6888dc 247 rem_len = length - p->len;
robert_jw 0:b2805b6888dc 248 /* any remaining pbufs to be allocated? */
robert_jw 0:b2805b6888dc 249 while (rem_len > 0) {
robert_jw 0:b2805b6888dc 250 q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
robert_jw 0:b2805b6888dc 251 if (q == NULL) {
robert_jw 0:b2805b6888dc 252 PBUF_POOL_IS_EMPTY();
robert_jw 0:b2805b6888dc 253 /* free chain so far allocated */
robert_jw 0:b2805b6888dc 254 pbuf_free(p);
robert_jw 0:b2805b6888dc 255 /* bail out unsuccesfully */
robert_jw 0:b2805b6888dc 256 return NULL;
robert_jw 0:b2805b6888dc 257 }
robert_jw 0:b2805b6888dc 258 q->type = type;
robert_jw 0:b2805b6888dc 259 q->flags = 0;
robert_jw 0:b2805b6888dc 260 q->next = NULL;
robert_jw 0:b2805b6888dc 261 /* make previous pbuf point to this pbuf */
robert_jw 0:b2805b6888dc 262 r->next = q;
robert_jw 0:b2805b6888dc 263 /* set total length of this pbuf and next in chain */
robert_jw 0:b2805b6888dc 264 LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff);
robert_jw 0:b2805b6888dc 265 q->tot_len = (u16_t)rem_len;
robert_jw 0:b2805b6888dc 266 /* this pbuf length is pool size, unless smaller sized tail */
robert_jw 0:b2805b6888dc 267 q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
robert_jw 0:b2805b6888dc 268 q->payload = (void *)((u8_t *)q + SIZEOF_STRUCT_PBUF);
robert_jw 0:b2805b6888dc 269 LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
robert_jw 0:b2805b6888dc 270 ((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
robert_jw 0:b2805b6888dc 271 LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
robert_jw 0:b2805b6888dc 272 ((u8_t*)p->payload + p->len <=
robert_jw 0:b2805b6888dc 273 (u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
robert_jw 0:b2805b6888dc 274 q->ref = 1;
robert_jw 0:b2805b6888dc 275 /* calculate remaining length to be allocated */
robert_jw 0:b2805b6888dc 276 rem_len -= q->len;
robert_jw 0:b2805b6888dc 277 /* remember this pbuf for linkage in next iteration */
robert_jw 0:b2805b6888dc 278 r = q;
robert_jw 0:b2805b6888dc 279 }
robert_jw 0:b2805b6888dc 280 /* end of chain */
robert_jw 0:b2805b6888dc 281 /*r->next = NULL;*/
robert_jw 0:b2805b6888dc 282
robert_jw 0:b2805b6888dc 283 break;
robert_jw 0:b2805b6888dc 284 case PBUF_RAM:
robert_jw 0:b2805b6888dc 285 /* If pbuf is to be allocated in RAM, allocate memory for it. */
robert_jw 0:b2805b6888dc 286 p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
robert_jw 0:b2805b6888dc 287 if (p == NULL) {
robert_jw 0:b2805b6888dc 288 return NULL;
robert_jw 0:b2805b6888dc 289 }
robert_jw 0:b2805b6888dc 290 /* Set up internal structure of the pbuf. */
robert_jw 0:b2805b6888dc 291 p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + SIZEOF_STRUCT_PBUF + offset));
robert_jw 0:b2805b6888dc 292 p->len = p->tot_len = length;
robert_jw 0:b2805b6888dc 293 p->next = NULL;
robert_jw 0:b2805b6888dc 294 p->type = type;
robert_jw 0:b2805b6888dc 295
robert_jw 0:b2805b6888dc 296 LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
robert_jw 0:b2805b6888dc 297 ((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
robert_jw 0:b2805b6888dc 298 break;
robert_jw 0:b2805b6888dc 299 /* pbuf references existing (non-volatile static constant) ROM payload? */
robert_jw 0:b2805b6888dc 300 case PBUF_ROM:
robert_jw 0:b2805b6888dc 301 /* pbuf references existing (externally allocated) RAM payload? */
robert_jw 0:b2805b6888dc 302 case PBUF_REF:
robert_jw 0:b2805b6888dc 303 /* only allocate memory for the pbuf structure */
robert_jw 0:b2805b6888dc 304 p = (struct pbuf *)memp_malloc(MEMP_PBUF);
robert_jw 0:b2805b6888dc 305 if (p == NULL) {
robert_jw 0:b2805b6888dc 306 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
robert_jw 0:b2805b6888dc 307 ("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n",
robert_jw 0:b2805b6888dc 308 (type == PBUF_ROM) ? "ROM" : "REF"));
robert_jw 0:b2805b6888dc 309 return NULL;
robert_jw 0:b2805b6888dc 310 }
robert_jw 0:b2805b6888dc 311 /* caller must set this field properly, afterwards */
robert_jw 0:b2805b6888dc 312 p->payload = NULL;
robert_jw 0:b2805b6888dc 313 p->len = p->tot_len = length;
robert_jw 0:b2805b6888dc 314 p->next = NULL;
robert_jw 0:b2805b6888dc 315 p->type = type;
robert_jw 0:b2805b6888dc 316 break;
robert_jw 0:b2805b6888dc 317 default:
robert_jw 0:b2805b6888dc 318 LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
robert_jw 0:b2805b6888dc 319 return NULL;
robert_jw 0:b2805b6888dc 320 }
robert_jw 0:b2805b6888dc 321 /* set reference count */
robert_jw 0:b2805b6888dc 322 p->ref = 1;
robert_jw 0:b2805b6888dc 323 /* set flags */
robert_jw 0:b2805b6888dc 324 p->flags = 0;
robert_jw 0:b2805b6888dc 325 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
robert_jw 0:b2805b6888dc 326 return p;
robert_jw 0:b2805b6888dc 327 }
robert_jw 0:b2805b6888dc 328
robert_jw 0:b2805b6888dc 329 #if LWIP_SUPPORT_CUSTOM_PBUF
robert_jw 0:b2805b6888dc 330 /** Initialize a custom pbuf (already allocated).
robert_jw 0:b2805b6888dc 331 *
robert_jw 0:b2805b6888dc 332 * @param layer flag to define header size
robert_jw 0:b2805b6888dc 333 * @param length size of the pbuf's payload
robert_jw 0:b2805b6888dc 334 * @param type type of the pbuf (only used to treat the pbuf accordingly, as
robert_jw 0:b2805b6888dc 335 * this function allocates no memory)
robert_jw 0:b2805b6888dc 336 * @param p pointer to the custom pbuf to initialize (already allocated)
robert_jw 0:b2805b6888dc 337 * @param payload_mem pointer to the buffer that is used for payload and headers,
robert_jw 0:b2805b6888dc 338 * must be at least big enough to hold 'length' plus the header size,
robert_jw 0:b2805b6888dc 339 * may be NULL if set later
robert_jw 0:b2805b6888dc 340 * @param payload_mem_len the size of the 'payload_mem' buffer, must be at least
robert_jw 0:b2805b6888dc 341 * big enough to hold 'length' plus the header size
robert_jw 0:b2805b6888dc 342 */
robert_jw 0:b2805b6888dc 343 struct pbuf*
robert_jw 0:b2805b6888dc 344 pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type, struct pbuf_custom *p,
robert_jw 0:b2805b6888dc 345 void *payload_mem, u16_t payload_mem_len)
robert_jw 0:b2805b6888dc 346 {
robert_jw 0:b2805b6888dc 347 u16_t offset;
robert_jw 0:b2805b6888dc 348 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloced_custom(length=%"U16_F")\n", length));
robert_jw 0:b2805b6888dc 349
robert_jw 0:b2805b6888dc 350 /* determine header offset */
robert_jw 0:b2805b6888dc 351 offset = 0;
robert_jw 0:b2805b6888dc 352 switch (l) {
robert_jw 0:b2805b6888dc 353 case PBUF_TRANSPORT:
robert_jw 0:b2805b6888dc 354 /* add room for transport (often TCP) layer header */
robert_jw 0:b2805b6888dc 355 offset += PBUF_TRANSPORT_HLEN;
robert_jw 0:b2805b6888dc 356 /* FALLTHROUGH */
robert_jw 0:b2805b6888dc 357 case PBUF_IP:
robert_jw 0:b2805b6888dc 358 /* add room for IP layer header */
robert_jw 0:b2805b6888dc 359 offset += PBUF_IP_HLEN;
robert_jw 0:b2805b6888dc 360 /* FALLTHROUGH */
robert_jw 0:b2805b6888dc 361 case PBUF_LINK:
robert_jw 0:b2805b6888dc 362 /* add room for link layer header */
robert_jw 0:b2805b6888dc 363 offset += PBUF_LINK_HLEN;
robert_jw 0:b2805b6888dc 364 break;
robert_jw 0:b2805b6888dc 365 case PBUF_RAW:
robert_jw 0:b2805b6888dc 366 break;
robert_jw 0:b2805b6888dc 367 default:
robert_jw 0:b2805b6888dc 368 LWIP_ASSERT("pbuf_alloced_custom: bad pbuf layer", 0);
robert_jw 0:b2805b6888dc 369 return NULL;
robert_jw 0:b2805b6888dc 370 }
robert_jw 0:b2805b6888dc 371
robert_jw 0:b2805b6888dc 372 if (LWIP_MEM_ALIGN_SIZE(offset) + length < payload_mem_len) {
robert_jw 0:b2805b6888dc 373 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_WARNING, ("pbuf_alloced_custom(length=%"U16_F") buffer too short\n", length));
robert_jw 0:b2805b6888dc 374 return NULL;
robert_jw 0:b2805b6888dc 375 }
robert_jw 0:b2805b6888dc 376
robert_jw 0:b2805b6888dc 377 p->pbuf.next = NULL;
robert_jw 0:b2805b6888dc 378 if (payload_mem != NULL) {
robert_jw 0:b2805b6888dc 379 p->pbuf.payload = (void *)((u8_t *)payload_mem + offset);
robert_jw 0:b2805b6888dc 380 } else {
robert_jw 0:b2805b6888dc 381 p->pbuf.payload = NULL;
robert_jw 0:b2805b6888dc 382 }
robert_jw 0:b2805b6888dc 383 p->pbuf.flags = PBUF_FLAG_IS_CUSTOM;
robert_jw 0:b2805b6888dc 384 p->pbuf.len = p->pbuf.tot_len = length;
robert_jw 0:b2805b6888dc 385 p->pbuf.type = type;
robert_jw 0:b2805b6888dc 386 p->pbuf.ref = 1;
robert_jw 0:b2805b6888dc 387 return &p->pbuf;
robert_jw 0:b2805b6888dc 388 }
robert_jw 0:b2805b6888dc 389 #endif /* LWIP_SUPPORT_CUSTOM_PBUF */
robert_jw 0:b2805b6888dc 390
robert_jw 0:b2805b6888dc 391 /**
robert_jw 0:b2805b6888dc 392 * Shrink a pbuf chain to a desired length.
robert_jw 0:b2805b6888dc 393 *
robert_jw 0:b2805b6888dc 394 * @param p pbuf to shrink.
robert_jw 0:b2805b6888dc 395 * @param new_len desired new length of pbuf chain
robert_jw 0:b2805b6888dc 396 *
robert_jw 0:b2805b6888dc 397 * Depending on the desired length, the first few pbufs in a chain might
robert_jw 0:b2805b6888dc 398 * be skipped and left unchanged. The new last pbuf in the chain will be
robert_jw 0:b2805b6888dc 399 * resized, and any remaining pbufs will be freed.
robert_jw 0:b2805b6888dc 400 *
robert_jw 0:b2805b6888dc 401 * @note If the pbuf is ROM/REF, only the ->tot_len and ->len fields are adjusted.
robert_jw 0:b2805b6888dc 402 * @note May not be called on a packet queue.
robert_jw 0:b2805b6888dc 403 *
robert_jw 0:b2805b6888dc 404 * @note Despite its name, pbuf_realloc cannot grow the size of a pbuf (chain).
robert_jw 0:b2805b6888dc 405 */
robert_jw 0:b2805b6888dc 406 void
robert_jw 0:b2805b6888dc 407 pbuf_realloc(struct pbuf *p, u16_t new_len)
robert_jw 0:b2805b6888dc 408 {
robert_jw 0:b2805b6888dc 409 struct pbuf *q;
robert_jw 0:b2805b6888dc 410 u16_t rem_len; /* remaining length */
robert_jw 0:b2805b6888dc 411 s32_t grow;
robert_jw 0:b2805b6888dc 412
robert_jw 0:b2805b6888dc 413 LWIP_ASSERT("pbuf_realloc: p != NULL", p != NULL);
robert_jw 0:b2805b6888dc 414 LWIP_ASSERT("pbuf_realloc: sane p->type", p->type == PBUF_POOL ||
robert_jw 0:b2805b6888dc 415 p->type == PBUF_ROM ||
robert_jw 0:b2805b6888dc 416 p->type == PBUF_RAM ||
robert_jw 0:b2805b6888dc 417 p->type == PBUF_REF);
robert_jw 0:b2805b6888dc 418
robert_jw 0:b2805b6888dc 419 /* desired length larger than current length? */
robert_jw 0:b2805b6888dc 420 if (new_len >= p->tot_len) {
robert_jw 0:b2805b6888dc 421 /* enlarging not yet supported */
robert_jw 0:b2805b6888dc 422 return;
robert_jw 0:b2805b6888dc 423 }
robert_jw 0:b2805b6888dc 424
robert_jw 0:b2805b6888dc 425 /* the pbuf chain grows by (new_len - p->tot_len) bytes
robert_jw 0:b2805b6888dc 426 * (which may be negative in case of shrinking) */
robert_jw 0:b2805b6888dc 427 grow = new_len - p->tot_len;
robert_jw 0:b2805b6888dc 428
robert_jw 0:b2805b6888dc 429 /* first, step over any pbufs that should remain in the chain */
robert_jw 0:b2805b6888dc 430 rem_len = new_len;
robert_jw 0:b2805b6888dc 431 q = p;
robert_jw 0:b2805b6888dc 432 /* should this pbuf be kept? */
robert_jw 0:b2805b6888dc 433 while (rem_len > q->len) {
robert_jw 0:b2805b6888dc 434 /* decrease remaining length by pbuf length */
robert_jw 0:b2805b6888dc 435 rem_len -= q->len;
robert_jw 0:b2805b6888dc 436 /* decrease total length indicator */
robert_jw 0:b2805b6888dc 437 LWIP_ASSERT("grow < max_u16_t", grow < 0xffff);
robert_jw 0:b2805b6888dc 438 q->tot_len += (u16_t)grow;
robert_jw 0:b2805b6888dc 439 /* proceed to next pbuf in chain */
robert_jw 0:b2805b6888dc 440 q = q->next;
robert_jw 0:b2805b6888dc 441 LWIP_ASSERT("pbuf_realloc: q != NULL", q != NULL);
robert_jw 0:b2805b6888dc 442 }
robert_jw 0:b2805b6888dc 443 /* we have now reached the new last pbuf (in q) */
robert_jw 0:b2805b6888dc 444 /* rem_len == desired length for pbuf q */
robert_jw 0:b2805b6888dc 445
robert_jw 0:b2805b6888dc 446 /* shrink allocated memory for PBUF_RAM */
robert_jw 0:b2805b6888dc 447 /* (other types merely adjust their length fields */
robert_jw 0:b2805b6888dc 448 if ((q->type == PBUF_RAM) && (rem_len != q->len)) {
robert_jw 0:b2805b6888dc 449 /* reallocate and adjust the length of the pbuf that will be split */
robert_jw 0:b2805b6888dc 450 q = (struct pbuf *)mem_trim(q, (u16_t)((u8_t *)q->payload - (u8_t *)q) + rem_len);
robert_jw 0:b2805b6888dc 451 LWIP_ASSERT("mem_trim returned q == NULL", q != NULL);
robert_jw 0:b2805b6888dc 452 }
robert_jw 0:b2805b6888dc 453 /* adjust length fields for new last pbuf */
robert_jw 0:b2805b6888dc 454 q->len = rem_len;
robert_jw 0:b2805b6888dc 455 q->tot_len = q->len;
robert_jw 0:b2805b6888dc 456
robert_jw 0:b2805b6888dc 457 /* any remaining pbufs in chain? */
robert_jw 0:b2805b6888dc 458 if (q->next != NULL) {
robert_jw 0:b2805b6888dc 459 /* free remaining pbufs in chain */
robert_jw 0:b2805b6888dc 460 pbuf_free(q->next);
robert_jw 0:b2805b6888dc 461 }
robert_jw 0:b2805b6888dc 462 /* q is last packet in chain */
robert_jw 0:b2805b6888dc 463 q->next = NULL;
robert_jw 0:b2805b6888dc 464
robert_jw 0:b2805b6888dc 465 }
robert_jw 0:b2805b6888dc 466
robert_jw 0:b2805b6888dc 467 /**
robert_jw 0:b2805b6888dc 468 * Adjusts the payload pointer to hide or reveal headers in the payload.
robert_jw 0:b2805b6888dc 469 *
robert_jw 0:b2805b6888dc 470 * Adjusts the ->payload pointer so that space for a header
robert_jw 0:b2805b6888dc 471 * (dis)appears in the pbuf payload.
robert_jw 0:b2805b6888dc 472 *
robert_jw 0:b2805b6888dc 473 * The ->payload, ->tot_len and ->len fields are adjusted.
robert_jw 0:b2805b6888dc 474 *
robert_jw 0:b2805b6888dc 475 * @param p pbuf to change the header size.
robert_jw 0:b2805b6888dc 476 * @param header_size_increment Number of bytes to increment header size which
robert_jw 0:b2805b6888dc 477 * increases the size of the pbuf. New space is on the front.
robert_jw 0:b2805b6888dc 478 * (Using a negative value decreases the header size.)
robert_jw 0:b2805b6888dc 479 * If hdr_size_inc is 0, this function does nothing and returns succesful.
robert_jw 0:b2805b6888dc 480 *
robert_jw 0:b2805b6888dc 481 * PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so
robert_jw 0:b2805b6888dc 482 * the call will fail. A check is made that the increase in header size does
robert_jw 0:b2805b6888dc 483 * not move the payload pointer in front of the start of the buffer.
robert_jw 0:b2805b6888dc 484 * @return non-zero on failure, zero on success.
robert_jw 0:b2805b6888dc 485 *
robert_jw 0:b2805b6888dc 486 */
robert_jw 0:b2805b6888dc 487 u8_t
robert_jw 0:b2805b6888dc 488 pbuf_header(struct pbuf *p, s16_t header_size_increment)
robert_jw 0:b2805b6888dc 489 {
robert_jw 0:b2805b6888dc 490 u16_t type;
robert_jw 0:b2805b6888dc 491 void *payload;
robert_jw 0:b2805b6888dc 492 u16_t increment_magnitude;
robert_jw 0:b2805b6888dc 493
robert_jw 0:b2805b6888dc 494 LWIP_ASSERT("p != NULL", p != NULL);
robert_jw 0:b2805b6888dc 495 if ((header_size_increment == 0) || (p == NULL)) {
robert_jw 0:b2805b6888dc 496 return 0;
robert_jw 0:b2805b6888dc 497 }
robert_jw 0:b2805b6888dc 498
robert_jw 0:b2805b6888dc 499 if (header_size_increment < 0){
robert_jw 0:b2805b6888dc 500 increment_magnitude = -header_size_increment;
robert_jw 0:b2805b6888dc 501 /* Check that we aren't going to move off the end of the pbuf */
robert_jw 0:b2805b6888dc 502 LWIP_ERROR("increment_magnitude <= p->len", (increment_magnitude <= p->len), return 1;);
robert_jw 0:b2805b6888dc 503 } else {
robert_jw 0:b2805b6888dc 504 increment_magnitude = header_size_increment;
robert_jw 0:b2805b6888dc 505 #if 0
robert_jw 0:b2805b6888dc 506 /* Can't assert these as some callers speculatively call
robert_jw 0:b2805b6888dc 507 pbuf_header() to see if it's OK. Will return 1 below instead. */
robert_jw 0:b2805b6888dc 508 /* Check that we've got the correct type of pbuf to work with */
robert_jw 0:b2805b6888dc 509 LWIP_ASSERT("p->type == PBUF_RAM || p->type == PBUF_POOL",
robert_jw 0:b2805b6888dc 510 p->type == PBUF_RAM || p->type == PBUF_POOL);
robert_jw 0:b2805b6888dc 511 /* Check that we aren't going to move off the beginning of the pbuf */
robert_jw 0:b2805b6888dc 512 LWIP_ASSERT("p->payload - increment_magnitude >= p + SIZEOF_STRUCT_PBUF",
robert_jw 0:b2805b6888dc 513 (u8_t *)p->payload - increment_magnitude >= (u8_t *)p + SIZEOF_STRUCT_PBUF);
robert_jw 0:b2805b6888dc 514 #endif
robert_jw 0:b2805b6888dc 515 }
robert_jw 0:b2805b6888dc 516
robert_jw 0:b2805b6888dc 517 type = p->type;
robert_jw 0:b2805b6888dc 518 /* remember current payload pointer */
robert_jw 0:b2805b6888dc 519 payload = p->payload;
robert_jw 0:b2805b6888dc 520
robert_jw 0:b2805b6888dc 521 /* pbuf types containing payloads? */
robert_jw 0:b2805b6888dc 522 if (type == PBUF_RAM || type == PBUF_POOL) {
robert_jw 0:b2805b6888dc 523 /* set new payload pointer */
robert_jw 0:b2805b6888dc 524 p->payload = (u8_t *)p->payload - header_size_increment;
robert_jw 0:b2805b6888dc 525 /* boundary check fails? */
robert_jw 0:b2805b6888dc 526 if ((u8_t *)p->payload < (u8_t *)p + SIZEOF_STRUCT_PBUF) {
robert_jw 0:b2805b6888dc 527 LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
robert_jw 0:b2805b6888dc 528 ("pbuf_header: failed as %p < %p (not enough space for new header size)\n",
robert_jw 0:b2805b6888dc 529 (void *)p->payload, (void *)(p + 1)));
robert_jw 0:b2805b6888dc 530 /* restore old payload pointer */
robert_jw 0:b2805b6888dc 531 p->payload = payload;
robert_jw 0:b2805b6888dc 532 /* bail out unsuccesfully */
robert_jw 0:b2805b6888dc 533 return 1;
robert_jw 0:b2805b6888dc 534 }
robert_jw 0:b2805b6888dc 535 /* pbuf types refering to external payloads? */
robert_jw 0:b2805b6888dc 536 } else if (type == PBUF_REF || type == PBUF_ROM) {
robert_jw 0:b2805b6888dc 537 /* hide a header in the payload? */
robert_jw 0:b2805b6888dc 538 if ((header_size_increment < 0) && (increment_magnitude <= p->len)) {
robert_jw 0:b2805b6888dc 539 /* increase payload pointer */
robert_jw 0:b2805b6888dc 540 p->payload = (u8_t *)p->payload - header_size_increment;
robert_jw 0:b2805b6888dc 541 } else {
robert_jw 0:b2805b6888dc 542 /* cannot expand payload to front (yet!)
robert_jw 0:b2805b6888dc 543 * bail out unsuccesfully */
robert_jw 0:b2805b6888dc 544 return 1;
robert_jw 0:b2805b6888dc 545 }
robert_jw 0:b2805b6888dc 546 } else {
robert_jw 0:b2805b6888dc 547 /* Unknown type */
robert_jw 0:b2805b6888dc 548 LWIP_ASSERT("bad pbuf type", 0);
robert_jw 0:b2805b6888dc 549 return 1;
robert_jw 0:b2805b6888dc 550 }
robert_jw 0:b2805b6888dc 551 /* modify pbuf length fields */
robert_jw 0:b2805b6888dc 552 p->len += header_size_increment;
robert_jw 0:b2805b6888dc 553 p->tot_len += header_size_increment;
robert_jw 0:b2805b6888dc 554
robert_jw 0:b2805b6888dc 555 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_header: old %p new %p (%"S16_F")\n",
robert_jw 0:b2805b6888dc 556 (void *)payload, (void *)p->payload, header_size_increment));
robert_jw 0:b2805b6888dc 557
robert_jw 0:b2805b6888dc 558 return 0;
robert_jw 0:b2805b6888dc 559 }
robert_jw 0:b2805b6888dc 560
robert_jw 0:b2805b6888dc 561 /**
robert_jw 0:b2805b6888dc 562 * Dereference a pbuf chain or queue and deallocate any no-longer-used
robert_jw 0:b2805b6888dc 563 * pbufs at the head of this chain or queue.
robert_jw 0:b2805b6888dc 564 *
robert_jw 0:b2805b6888dc 565 * Decrements the pbuf reference count. If it reaches zero, the pbuf is
robert_jw 0:b2805b6888dc 566 * deallocated.
robert_jw 0:b2805b6888dc 567 *
robert_jw 0:b2805b6888dc 568 * For a pbuf chain, this is repeated for each pbuf in the chain,
robert_jw 0:b2805b6888dc 569 * up to the first pbuf which has a non-zero reference count after
robert_jw 0:b2805b6888dc 570 * decrementing. So, when all reference counts are one, the whole
robert_jw 0:b2805b6888dc 571 * chain is free'd.
robert_jw 0:b2805b6888dc 572 *
robert_jw 0:b2805b6888dc 573 * @param p The pbuf (chain) to be dereferenced.
robert_jw 0:b2805b6888dc 574 *
robert_jw 0:b2805b6888dc 575 * @return the number of pbufs that were de-allocated
robert_jw 0:b2805b6888dc 576 * from the head of the chain.
robert_jw 0:b2805b6888dc 577 *
robert_jw 0:b2805b6888dc 578 * @note MUST NOT be called on a packet queue (Not verified to work yet).
robert_jw 0:b2805b6888dc 579 * @note the reference counter of a pbuf equals the number of pointers
robert_jw 0:b2805b6888dc 580 * that refer to the pbuf (or into the pbuf).
robert_jw 0:b2805b6888dc 581 *
robert_jw 0:b2805b6888dc 582 * @internal examples:
robert_jw 0:b2805b6888dc 583 *
robert_jw 0:b2805b6888dc 584 * Assuming existing chains a->b->c with the following reference
robert_jw 0:b2805b6888dc 585 * counts, calling pbuf_free(a) results in:
robert_jw 0:b2805b6888dc 586 *
robert_jw 0:b2805b6888dc 587 * 1->2->3 becomes ...1->3
robert_jw 0:b2805b6888dc 588 * 3->3->3 becomes 2->3->3
robert_jw 0:b2805b6888dc 589 * 1->1->2 becomes ......1
robert_jw 0:b2805b6888dc 590 * 2->1->1 becomes 1->1->1
robert_jw 0:b2805b6888dc 591 * 1->1->1 becomes .......
robert_jw 0:b2805b6888dc 592 *
robert_jw 0:b2805b6888dc 593 */
robert_jw 0:b2805b6888dc 594 u8_t
robert_jw 0:b2805b6888dc 595 pbuf_free(struct pbuf *p)
robert_jw 0:b2805b6888dc 596 {
robert_jw 0:b2805b6888dc 597 u16_t type;
robert_jw 0:b2805b6888dc 598 struct pbuf *q;
robert_jw 0:b2805b6888dc 599 u8_t count;
robert_jw 0:b2805b6888dc 600
robert_jw 0:b2805b6888dc 601 if (p == NULL) {
robert_jw 0:b2805b6888dc 602 LWIP_ASSERT("p != NULL", p != NULL);
robert_jw 0:b2805b6888dc 603 /* if assertions are disabled, proceed with debug output */
robert_jw 0:b2805b6888dc 604 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
robert_jw 0:b2805b6888dc 605 ("pbuf_free(p == NULL) was called.\n"));
robert_jw 0:b2805b6888dc 606 return 0;
robert_jw 0:b2805b6888dc 607 }
robert_jw 0:b2805b6888dc 608 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free(%p)\n", (void *)p));
robert_jw 0:b2805b6888dc 609
robert_jw 0:b2805b6888dc 610 PERF_START;
robert_jw 0:b2805b6888dc 611
robert_jw 0:b2805b6888dc 612 LWIP_ASSERT("pbuf_free: sane type",
robert_jw 0:b2805b6888dc 613 p->type == PBUF_RAM || p->type == PBUF_ROM ||
robert_jw 0:b2805b6888dc 614 p->type == PBUF_REF || p->type == PBUF_POOL);
robert_jw 0:b2805b6888dc 615
robert_jw 0:b2805b6888dc 616 count = 0;
robert_jw 0:b2805b6888dc 617 /* de-allocate all consecutive pbufs from the head of the chain that
robert_jw 0:b2805b6888dc 618 * obtain a zero reference count after decrementing*/
robert_jw 0:b2805b6888dc 619 while (p != NULL) {
robert_jw 0:b2805b6888dc 620 u16_t ref;
robert_jw 0:b2805b6888dc 621 SYS_ARCH_DECL_PROTECT(old_level);
robert_jw 0:b2805b6888dc 622 /* Since decrementing ref cannot be guaranteed to be a single machine operation
robert_jw 0:b2805b6888dc 623 * we must protect it. We put the new ref into a local variable to prevent
robert_jw 0:b2805b6888dc 624 * further protection. */
robert_jw 0:b2805b6888dc 625 SYS_ARCH_PROTECT(old_level);
robert_jw 0:b2805b6888dc 626 /* all pbufs in a chain are referenced at least once */
robert_jw 0:b2805b6888dc 627 LWIP_ASSERT("pbuf_free: p->ref > 0", p->ref > 0);
robert_jw 0:b2805b6888dc 628 /* decrease reference count (number of pointers to pbuf) */
robert_jw 0:b2805b6888dc 629 ref = --(p->ref);
robert_jw 0:b2805b6888dc 630 SYS_ARCH_UNPROTECT(old_level);
robert_jw 0:b2805b6888dc 631 /* this pbuf is no longer referenced to? */
robert_jw 0:b2805b6888dc 632 if (ref == 0) {
robert_jw 0:b2805b6888dc 633 /* remember next pbuf in chain for next iteration */
robert_jw 0:b2805b6888dc 634 q = p->next;
robert_jw 0:b2805b6888dc 635 LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free: deallocating %p\n", (void *)p));
robert_jw 0:b2805b6888dc 636 type = p->type;
robert_jw 0:b2805b6888dc 637 #if LWIP_SUPPORT_CUSTOM_PBUF
robert_jw 0:b2805b6888dc 638 /* is this a custom pbuf? */
robert_jw 0:b2805b6888dc 639 if ((p->flags & PBUF_FLAG_IS_CUSTOM) != 0) {
robert_jw 0:b2805b6888dc 640 struct pbuf_custom *pc = (struct pbuf_custom*)p;
robert_jw 0:b2805b6888dc 641 LWIP_ASSERT("pc->custom_free_function != NULL", pc->custom_free_function != NULL);
robert_jw 0:b2805b6888dc 642 pc->custom_free_function(p);
robert_jw 0:b2805b6888dc 643 } else
robert_jw 0:b2805b6888dc 644 #endif /* LWIP_SUPPORT_CUSTOM_PBUF */
robert_jw 0:b2805b6888dc 645 {
robert_jw 0:b2805b6888dc 646 /* is this a pbuf from the pool? */
robert_jw 0:b2805b6888dc 647 if (type == PBUF_POOL) {
robert_jw 0:b2805b6888dc 648 memp_free(MEMP_PBUF_POOL, p);
robert_jw 0:b2805b6888dc 649 /* is this a ROM or RAM referencing pbuf? */
robert_jw 0:b2805b6888dc 650 } else if (type == PBUF_ROM || type == PBUF_REF) {
robert_jw 0:b2805b6888dc 651 memp_free(MEMP_PBUF, p);
robert_jw 0:b2805b6888dc 652 /* type == PBUF_RAM */
robert_jw 0:b2805b6888dc 653 } else {
robert_jw 0:b2805b6888dc 654 mem_free(p);
robert_jw 0:b2805b6888dc 655 }
robert_jw 0:b2805b6888dc 656 }
robert_jw 0:b2805b6888dc 657 count++;
robert_jw 0:b2805b6888dc 658 /* proceed to next pbuf */
robert_jw 0:b2805b6888dc 659 p = q;
robert_jw 0:b2805b6888dc 660 /* p->ref > 0, this pbuf is still referenced to */
robert_jw 0:b2805b6888dc 661 /* (and so the remaining pbufs in chain as well) */
robert_jw 0:b2805b6888dc 662 } else {
robert_jw 0:b2805b6888dc 663 LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref));
robert_jw 0:b2805b6888dc 664 /* stop walking through the chain */
robert_jw 0:b2805b6888dc 665 p = NULL;
robert_jw 0:b2805b6888dc 666 }
robert_jw 0:b2805b6888dc 667 }
robert_jw 0:b2805b6888dc 668 PERF_STOP("pbuf_free");
robert_jw 0:b2805b6888dc 669 /* return number of de-allocated pbufs */
robert_jw 0:b2805b6888dc 670 return count;
robert_jw 0:b2805b6888dc 671 }
robert_jw 0:b2805b6888dc 672
robert_jw 0:b2805b6888dc 673 /**
robert_jw 0:b2805b6888dc 674 * Count number of pbufs in a chain
robert_jw 0:b2805b6888dc 675 *
robert_jw 0:b2805b6888dc 676 * @param p first pbuf of chain
robert_jw 0:b2805b6888dc 677 * @return the number of pbufs in a chain
robert_jw 0:b2805b6888dc 678 */
robert_jw 0:b2805b6888dc 679
robert_jw 0:b2805b6888dc 680 u8_t
robert_jw 0:b2805b6888dc 681 pbuf_clen(struct pbuf *p)
robert_jw 0:b2805b6888dc 682 {
robert_jw 0:b2805b6888dc 683 u8_t len;
robert_jw 0:b2805b6888dc 684
robert_jw 0:b2805b6888dc 685 len = 0;
robert_jw 0:b2805b6888dc 686 while (p != NULL) {
robert_jw 0:b2805b6888dc 687 ++len;
robert_jw 0:b2805b6888dc 688 p = p->next;
robert_jw 0:b2805b6888dc 689 }
robert_jw 0:b2805b6888dc 690 return len;
robert_jw 0:b2805b6888dc 691 }
robert_jw 0:b2805b6888dc 692
robert_jw 0:b2805b6888dc 693 /**
robert_jw 0:b2805b6888dc 694 * Increment the reference count of the pbuf.
robert_jw 0:b2805b6888dc 695 *
robert_jw 0:b2805b6888dc 696 * @param p pbuf to increase reference counter of
robert_jw 0:b2805b6888dc 697 *
robert_jw 0:b2805b6888dc 698 */
robert_jw 0:b2805b6888dc 699 void
robert_jw 0:b2805b6888dc 700 pbuf_ref(struct pbuf *p)
robert_jw 0:b2805b6888dc 701 {
robert_jw 0:b2805b6888dc 702 SYS_ARCH_DECL_PROTECT(old_level);
robert_jw 0:b2805b6888dc 703 /* pbuf given? */
robert_jw 0:b2805b6888dc 704 if (p != NULL) {
robert_jw 0:b2805b6888dc 705 SYS_ARCH_PROTECT(old_level);
robert_jw 0:b2805b6888dc 706 ++(p->ref);
robert_jw 0:b2805b6888dc 707 SYS_ARCH_UNPROTECT(old_level);
robert_jw 0:b2805b6888dc 708 }
robert_jw 0:b2805b6888dc 709 }
robert_jw 0:b2805b6888dc 710
robert_jw 0:b2805b6888dc 711 /**
robert_jw 0:b2805b6888dc 712 * Concatenate two pbufs (each may be a pbuf chain) and take over
robert_jw 0:b2805b6888dc 713 * the caller's reference of the tail pbuf.
robert_jw 0:b2805b6888dc 714 *
robert_jw 0:b2805b6888dc 715 * @note The caller MAY NOT reference the tail pbuf afterwards.
robert_jw 0:b2805b6888dc 716 * Use pbuf_chain() for that purpose.
robert_jw 0:b2805b6888dc 717 *
robert_jw 0:b2805b6888dc 718 * @see pbuf_chain()
robert_jw 0:b2805b6888dc 719 */
robert_jw 0:b2805b6888dc 720
robert_jw 0:b2805b6888dc 721 void
robert_jw 0:b2805b6888dc 722 pbuf_cat(struct pbuf *h, struct pbuf *t)
robert_jw 0:b2805b6888dc 723 {
robert_jw 0:b2805b6888dc 724 struct pbuf *p;
robert_jw 0:b2805b6888dc 725
robert_jw 0:b2805b6888dc 726 LWIP_ERROR("(h != NULL) && (t != NULL) (programmer violates API)",
robert_jw 0:b2805b6888dc 727 ((h != NULL) && (t != NULL)), return;);
robert_jw 0:b2805b6888dc 728
robert_jw 0:b2805b6888dc 729 /* proceed to last pbuf of chain */
robert_jw 0:b2805b6888dc 730 for (p = h; p->next != NULL; p = p->next) {
robert_jw 0:b2805b6888dc 731 /* add total length of second chain to all totals of first chain */
robert_jw 0:b2805b6888dc 732 p->tot_len += t->tot_len;
robert_jw 0:b2805b6888dc 733 }
robert_jw 0:b2805b6888dc 734 /* { p is last pbuf of first h chain, p->next == NULL } */
robert_jw 0:b2805b6888dc 735 LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len);
robert_jw 0:b2805b6888dc 736 LWIP_ASSERT("p->next == NULL", p->next == NULL);
robert_jw 0:b2805b6888dc 737 /* add total length of second chain to last pbuf total of first chain */
robert_jw 0:b2805b6888dc 738 p->tot_len += t->tot_len;
robert_jw 0:b2805b6888dc 739 /* chain last pbuf of head (p) with first of tail (t) */
robert_jw 0:b2805b6888dc 740 p->next = t;
robert_jw 0:b2805b6888dc 741 /* p->next now references t, but the caller will drop its reference to t,
robert_jw 0:b2805b6888dc 742 * so netto there is no change to the reference count of t.
robert_jw 0:b2805b6888dc 743 */
robert_jw 0:b2805b6888dc 744 }
robert_jw 0:b2805b6888dc 745
robert_jw 0:b2805b6888dc 746 /**
robert_jw 0:b2805b6888dc 747 * Chain two pbufs (or pbuf chains) together.
robert_jw 0:b2805b6888dc 748 *
robert_jw 0:b2805b6888dc 749 * The caller MUST call pbuf_free(t) once it has stopped
robert_jw 0:b2805b6888dc 750 * using it. Use pbuf_cat() instead if you no longer use t.
robert_jw 0:b2805b6888dc 751 *
robert_jw 0:b2805b6888dc 752 * @param h head pbuf (chain)
robert_jw 0:b2805b6888dc 753 * @param t tail pbuf (chain)
robert_jw 0:b2805b6888dc 754 * @note The pbufs MUST belong to the same packet.
robert_jw 0:b2805b6888dc 755 * @note MAY NOT be called on a packet queue.
robert_jw 0:b2805b6888dc 756 *
robert_jw 0:b2805b6888dc 757 * The ->tot_len fields of all pbufs of the head chain are adjusted.
robert_jw 0:b2805b6888dc 758 * The ->next field of the last pbuf of the head chain is adjusted.
robert_jw 0:b2805b6888dc 759 * The ->ref field of the first pbuf of the tail chain is adjusted.
robert_jw 0:b2805b6888dc 760 *
robert_jw 0:b2805b6888dc 761 */
robert_jw 0:b2805b6888dc 762 void
robert_jw 0:b2805b6888dc 763 pbuf_chain(struct pbuf *h, struct pbuf *t)
robert_jw 0:b2805b6888dc 764 {
robert_jw 0:b2805b6888dc 765 pbuf_cat(h, t);
robert_jw 0:b2805b6888dc 766 /* t is now referenced by h */
robert_jw 0:b2805b6888dc 767 pbuf_ref(t);
robert_jw 0:b2805b6888dc 768 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_chain: %p references %p\n", (void *)h, (void *)t));
robert_jw 0:b2805b6888dc 769 }
robert_jw 0:b2805b6888dc 770
robert_jw 0:b2805b6888dc 771 /**
robert_jw 0:b2805b6888dc 772 * Dechains the first pbuf from its succeeding pbufs in the chain.
robert_jw 0:b2805b6888dc 773 *
robert_jw 0:b2805b6888dc 774 * Makes p->tot_len field equal to p->len.
robert_jw 0:b2805b6888dc 775 * @param p pbuf to dechain
robert_jw 0:b2805b6888dc 776 * @return remainder of the pbuf chain, or NULL if it was de-allocated.
robert_jw 0:b2805b6888dc 777 * @note May not be called on a packet queue.
robert_jw 0:b2805b6888dc 778 */
robert_jw 0:b2805b6888dc 779 struct pbuf *
robert_jw 0:b2805b6888dc 780 pbuf_dechain(struct pbuf *p)
robert_jw 0:b2805b6888dc 781 {
robert_jw 0:b2805b6888dc 782 struct pbuf *q;
robert_jw 0:b2805b6888dc 783 u8_t tail_gone = 1;
robert_jw 0:b2805b6888dc 784 /* tail */
robert_jw 0:b2805b6888dc 785 q = p->next;
robert_jw 0:b2805b6888dc 786 /* pbuf has successor in chain? */
robert_jw 0:b2805b6888dc 787 if (q != NULL) {
robert_jw 0:b2805b6888dc 788 /* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
robert_jw 0:b2805b6888dc 789 LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len);
robert_jw 0:b2805b6888dc 790 /* enforce invariant if assertion is disabled */
robert_jw 0:b2805b6888dc 791 q->tot_len = p->tot_len - p->len;
robert_jw 0:b2805b6888dc 792 /* decouple pbuf from remainder */
robert_jw 0:b2805b6888dc 793 p->next = NULL;
robert_jw 0:b2805b6888dc 794 /* total length of pbuf p is its own length only */
robert_jw 0:b2805b6888dc 795 p->tot_len = p->len;
robert_jw 0:b2805b6888dc 796 /* q is no longer referenced by p, free it */
robert_jw 0:b2805b6888dc 797 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_dechain: unreferencing %p\n", (void *)q));
robert_jw 0:b2805b6888dc 798 tail_gone = pbuf_free(q);
robert_jw 0:b2805b6888dc 799 if (tail_gone > 0) {
robert_jw 0:b2805b6888dc 800 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE,
robert_jw 0:b2805b6888dc 801 ("pbuf_dechain: deallocated %p (as it is no longer referenced)\n", (void *)q));
robert_jw 0:b2805b6888dc 802 }
robert_jw 0:b2805b6888dc 803 /* return remaining tail or NULL if deallocated */
robert_jw 0:b2805b6888dc 804 }
robert_jw 0:b2805b6888dc 805 /* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
robert_jw 0:b2805b6888dc 806 LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len);
robert_jw 0:b2805b6888dc 807 return ((tail_gone > 0) ? NULL : q);
robert_jw 0:b2805b6888dc 808 }
robert_jw 0:b2805b6888dc 809
robert_jw 0:b2805b6888dc 810 /**
robert_jw 0:b2805b6888dc 811 *
robert_jw 0:b2805b6888dc 812 * Create PBUF_RAM copies of pbufs.
robert_jw 0:b2805b6888dc 813 *
robert_jw 0:b2805b6888dc 814 * Used to queue packets on behalf of the lwIP stack, such as
robert_jw 0:b2805b6888dc 815 * ARP based queueing.
robert_jw 0:b2805b6888dc 816 *
robert_jw 0:b2805b6888dc 817 * @note You MUST explicitly use p = pbuf_take(p);
robert_jw 0:b2805b6888dc 818 *
robert_jw 0:b2805b6888dc 819 * @note Only one packet is copied, no packet queue!
robert_jw 0:b2805b6888dc 820 *
robert_jw 0:b2805b6888dc 821 * @param p_to pbuf destination of the copy
robert_jw 0:b2805b6888dc 822 * @param p_from pbuf source of the copy
robert_jw 0:b2805b6888dc 823 *
robert_jw 0:b2805b6888dc 824 * @return ERR_OK if pbuf was copied
robert_jw 0:b2805b6888dc 825 * ERR_ARG if one of the pbufs is NULL or p_to is not big
robert_jw 0:b2805b6888dc 826 * enough to hold p_from
robert_jw 0:b2805b6888dc 827 */
robert_jw 0:b2805b6888dc 828 err_t
robert_jw 0:b2805b6888dc 829 pbuf_copy(struct pbuf *p_to, struct pbuf *p_from)
robert_jw 0:b2805b6888dc 830 {
robert_jw 0:b2805b6888dc 831 u16_t offset_to=0, offset_from=0, len;
robert_jw 0:b2805b6888dc 832
robert_jw 0:b2805b6888dc 833 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy(%p, %p)\n",
robert_jw 0:b2805b6888dc 834 (void*)p_to, (void*)p_from));
robert_jw 0:b2805b6888dc 835
robert_jw 0:b2805b6888dc 836 /* is the target big enough to hold the source? */
robert_jw 0:b2805b6888dc 837 LWIP_ERROR("pbuf_copy: target not big enough to hold source", ((p_to != NULL) &&
robert_jw 0:b2805b6888dc 838 (p_from != NULL) && (p_to->tot_len >= p_from->tot_len)), return ERR_ARG;);
robert_jw 0:b2805b6888dc 839
robert_jw 0:b2805b6888dc 840 /* iterate through pbuf chain */
robert_jw 0:b2805b6888dc 841 do
robert_jw 0:b2805b6888dc 842 {
robert_jw 0:b2805b6888dc 843 LWIP_ASSERT("p_to != NULL", p_to != NULL);
robert_jw 0:b2805b6888dc 844 /* copy one part of the original chain */
robert_jw 0:b2805b6888dc 845 if ((p_to->len - offset_to) >= (p_from->len - offset_from)) {
robert_jw 0:b2805b6888dc 846 /* complete current p_from fits into current p_to */
robert_jw 0:b2805b6888dc 847 len = p_from->len - offset_from;
robert_jw 0:b2805b6888dc 848 } else {
robert_jw 0:b2805b6888dc 849 /* current p_from does not fit into current p_to */
robert_jw 0:b2805b6888dc 850 len = p_to->len - offset_to;
robert_jw 0:b2805b6888dc 851 }
robert_jw 0:b2805b6888dc 852 MEMCPY((u8_t*)p_to->payload + offset_to, (u8_t*)p_from->payload + offset_from, len);
robert_jw 0:b2805b6888dc 853 offset_to += len;
robert_jw 0:b2805b6888dc 854 offset_from += len;
robert_jw 0:b2805b6888dc 855 LWIP_ASSERT("offset_to <= p_to->len", offset_to <= p_to->len);
robert_jw 0:b2805b6888dc 856 if (offset_to == p_to->len) {
robert_jw 0:b2805b6888dc 857 /* on to next p_to (if any) */
robert_jw 0:b2805b6888dc 858 offset_to = 0;
robert_jw 0:b2805b6888dc 859 p_to = p_to->next;
robert_jw 0:b2805b6888dc 860 }
robert_jw 0:b2805b6888dc 861 LWIP_ASSERT("offset_from <= p_from->len", offset_from <= p_from->len);
robert_jw 0:b2805b6888dc 862 if (offset_from >= p_from->len) {
robert_jw 0:b2805b6888dc 863 /* on to next p_from (if any) */
robert_jw 0:b2805b6888dc 864 offset_from = 0;
robert_jw 0:b2805b6888dc 865 p_from = p_from->next;
robert_jw 0:b2805b6888dc 866 }
robert_jw 0:b2805b6888dc 867
robert_jw 0:b2805b6888dc 868 if((p_from != NULL) && (p_from->len == p_from->tot_len)) {
robert_jw 0:b2805b6888dc 869 /* don't copy more than one packet! */
robert_jw 0:b2805b6888dc 870 LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
robert_jw 0:b2805b6888dc 871 (p_from->next == NULL), return ERR_VAL;);
robert_jw 0:b2805b6888dc 872 }
robert_jw 0:b2805b6888dc 873 if((p_to != NULL) && (p_to->len == p_to->tot_len)) {
robert_jw 0:b2805b6888dc 874 /* don't copy more than one packet! */
robert_jw 0:b2805b6888dc 875 LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
robert_jw 0:b2805b6888dc 876 (p_to->next == NULL), return ERR_VAL;);
robert_jw 0:b2805b6888dc 877 }
robert_jw 0:b2805b6888dc 878 } while (p_from);
robert_jw 0:b2805b6888dc 879 LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy: end of chain reached.\n"));
robert_jw 0:b2805b6888dc 880 return ERR_OK;
robert_jw 0:b2805b6888dc 881 }
robert_jw 0:b2805b6888dc 882
robert_jw 0:b2805b6888dc 883 /**
robert_jw 0:b2805b6888dc 884 * Copy (part of) the contents of a packet buffer
robert_jw 0:b2805b6888dc 885 * to an application supplied buffer.
robert_jw 0:b2805b6888dc 886 *
robert_jw 0:b2805b6888dc 887 * @param buf the pbuf from which to copy data
robert_jw 0:b2805b6888dc 888 * @param dataptr the application supplied buffer
robert_jw 0:b2805b6888dc 889 * @param len length of data to copy (dataptr must be big enough). No more
robert_jw 0:b2805b6888dc 890 * than buf->tot_len will be copied, irrespective of len
robert_jw 0:b2805b6888dc 891 * @param offset offset into the packet buffer from where to begin copying len bytes
robert_jw 0:b2805b6888dc 892 * @return the number of bytes copied, or 0 on failure
robert_jw 0:b2805b6888dc 893 */
robert_jw 0:b2805b6888dc 894 u16_t
robert_jw 0:b2805b6888dc 895 pbuf_copy_partial(struct pbuf *buf, void *dataptr, u16_t len, u16_t offset)
robert_jw 0:b2805b6888dc 896 {
robert_jw 0:b2805b6888dc 897 struct pbuf *p;
robert_jw 0:b2805b6888dc 898 u16_t left;
robert_jw 0:b2805b6888dc 899 u16_t buf_copy_len;
robert_jw 0:b2805b6888dc 900 u16_t copied_total = 0;
robert_jw 0:b2805b6888dc 901
robert_jw 0:b2805b6888dc 902 LWIP_ERROR("pbuf_copy_partial: invalid buf", (buf != NULL), return 0;);
robert_jw 0:b2805b6888dc 903 LWIP_ERROR("pbuf_copy_partial: invalid dataptr", (dataptr != NULL), return 0;);
robert_jw 0:b2805b6888dc 904
robert_jw 0:b2805b6888dc 905 left = 0;
robert_jw 0:b2805b6888dc 906
robert_jw 0:b2805b6888dc 907 if((buf == NULL) || (dataptr == NULL)) {
robert_jw 0:b2805b6888dc 908 return 0;
robert_jw 0:b2805b6888dc 909 }
robert_jw 0:b2805b6888dc 910
robert_jw 0:b2805b6888dc 911 /* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
robert_jw 0:b2805b6888dc 912 for(p = buf; len != 0 && p != NULL; p = p->next) {
robert_jw 0:b2805b6888dc 913 if ((offset != 0) && (offset >= p->len)) {
robert_jw 0:b2805b6888dc 914 /* don't copy from this buffer -> on to the next */
robert_jw 0:b2805b6888dc 915 offset -= p->len;
robert_jw 0:b2805b6888dc 916 } else {
robert_jw 0:b2805b6888dc 917 /* copy from this buffer. maybe only partially. */
robert_jw 0:b2805b6888dc 918 buf_copy_len = p->len - offset;
robert_jw 0:b2805b6888dc 919 if (buf_copy_len > len)
robert_jw 0:b2805b6888dc 920 buf_copy_len = len;
robert_jw 0:b2805b6888dc 921 /* copy the necessary parts of the buffer */
robert_jw 0:b2805b6888dc 922 MEMCPY(&((char*)dataptr)[left], &((char*)p->payload)[offset], buf_copy_len);
robert_jw 0:b2805b6888dc 923 copied_total += buf_copy_len;
robert_jw 0:b2805b6888dc 924 left += buf_copy_len;
robert_jw 0:b2805b6888dc 925 len -= buf_copy_len;
robert_jw 0:b2805b6888dc 926 offset = 0;
robert_jw 0:b2805b6888dc 927 }
robert_jw 0:b2805b6888dc 928 }
robert_jw 0:b2805b6888dc 929 return copied_total;
robert_jw 0:b2805b6888dc 930 }
robert_jw 0:b2805b6888dc 931
robert_jw 0:b2805b6888dc 932 /**
robert_jw 0:b2805b6888dc 933 * Copy application supplied data into a pbuf.
robert_jw 0:b2805b6888dc 934 * This function can only be used to copy the equivalent of buf->tot_len data.
robert_jw 0:b2805b6888dc 935 *
robert_jw 0:b2805b6888dc 936 * @param buf pbuf to fill with data
robert_jw 0:b2805b6888dc 937 * @param dataptr application supplied data buffer
robert_jw 0:b2805b6888dc 938 * @param len length of the application supplied data buffer
robert_jw 0:b2805b6888dc 939 *
robert_jw 0:b2805b6888dc 940 * @return ERR_OK if successful, ERR_MEM if the pbuf is not big enough
robert_jw 0:b2805b6888dc 941 */
robert_jw 0:b2805b6888dc 942 err_t
robert_jw 0:b2805b6888dc 943 pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len)
robert_jw 0:b2805b6888dc 944 {
robert_jw 0:b2805b6888dc 945 struct pbuf *p;
robert_jw 0:b2805b6888dc 946 u16_t buf_copy_len;
robert_jw 0:b2805b6888dc 947 u16_t total_copy_len = len;
robert_jw 0:b2805b6888dc 948 u16_t copied_total = 0;
robert_jw 0:b2805b6888dc 949
robert_jw 0:b2805b6888dc 950 LWIP_ERROR("pbuf_take: invalid buf", (buf != NULL), return 0;);
robert_jw 0:b2805b6888dc 951 LWIP_ERROR("pbuf_take: invalid dataptr", (dataptr != NULL), return 0;);
robert_jw 0:b2805b6888dc 952
robert_jw 0:b2805b6888dc 953 if ((buf == NULL) || (dataptr == NULL) || (buf->tot_len < len)) {
robert_jw 0:b2805b6888dc 954 return ERR_ARG;
robert_jw 0:b2805b6888dc 955 }
robert_jw 0:b2805b6888dc 956
robert_jw 0:b2805b6888dc 957 /* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
robert_jw 0:b2805b6888dc 958 for(p = buf; total_copy_len != 0; p = p->next) {
robert_jw 0:b2805b6888dc 959 LWIP_ASSERT("pbuf_take: invalid pbuf", p != NULL);
robert_jw 0:b2805b6888dc 960 buf_copy_len = total_copy_len;
robert_jw 0:b2805b6888dc 961 if (buf_copy_len > p->len) {
robert_jw 0:b2805b6888dc 962 /* this pbuf cannot hold all remaining data */
robert_jw 0:b2805b6888dc 963 buf_copy_len = p->len;
robert_jw 0:b2805b6888dc 964 }
robert_jw 0:b2805b6888dc 965 /* copy the necessary parts of the buffer */
robert_jw 0:b2805b6888dc 966 MEMCPY(p->payload, &((char*)dataptr)[copied_total], buf_copy_len);
robert_jw 0:b2805b6888dc 967 total_copy_len -= buf_copy_len;
robert_jw 0:b2805b6888dc 968 copied_total += buf_copy_len;
robert_jw 0:b2805b6888dc 969 }
robert_jw 0:b2805b6888dc 970 LWIP_ASSERT("did not copy all data", total_copy_len == 0 && copied_total == len);
robert_jw 0:b2805b6888dc 971 return ERR_OK;
robert_jw 0:b2805b6888dc 972 }
robert_jw 0:b2805b6888dc 973
robert_jw 0:b2805b6888dc 974 /**
robert_jw 0:b2805b6888dc 975 * Creates a single pbuf out of a queue of pbufs.
robert_jw 0:b2805b6888dc 976 *
robert_jw 0:b2805b6888dc 977 * @remark: Either the source pbuf 'p' is freed by this function or the original
robert_jw 0:b2805b6888dc 978 * pbuf 'p' is returned, therefore the caller has to check the result!
robert_jw 0:b2805b6888dc 979 *
robert_jw 0:b2805b6888dc 980 * @param p the source pbuf
robert_jw 0:b2805b6888dc 981 * @param layer pbuf_layer of the new pbuf
robert_jw 0:b2805b6888dc 982 *
robert_jw 0:b2805b6888dc 983 * @return a new, single pbuf (p->next is NULL)
robert_jw 0:b2805b6888dc 984 * or the old pbuf if allocation fails
robert_jw 0:b2805b6888dc 985 */
robert_jw 0:b2805b6888dc 986 struct pbuf*
robert_jw 0:b2805b6888dc 987 pbuf_coalesce(struct pbuf *p, pbuf_layer layer)
robert_jw 0:b2805b6888dc 988 {
robert_jw 0:b2805b6888dc 989 struct pbuf *q;
robert_jw 0:b2805b6888dc 990 err_t err;
robert_jw 0:b2805b6888dc 991 if (p->next == NULL) {
robert_jw 0:b2805b6888dc 992 return p;
robert_jw 0:b2805b6888dc 993 }
robert_jw 0:b2805b6888dc 994 q = pbuf_alloc(layer, p->tot_len, PBUF_RAM);
robert_jw 0:b2805b6888dc 995 if (q == NULL) {
robert_jw 0:b2805b6888dc 996 /* @todo: what do we do now? */
robert_jw 0:b2805b6888dc 997 return p;
robert_jw 0:b2805b6888dc 998 }
robert_jw 0:b2805b6888dc 999 err = pbuf_copy(q, p);
robert_jw 0:b2805b6888dc 1000 LWIP_ASSERT("pbuf_copy failed", err == ERR_OK);
robert_jw 0:b2805b6888dc 1001 /* next line references err variable even if LWIP_ASSERT is ignored. */
robert_jw 0:b2805b6888dc 1002 (void)err;
robert_jw 0:b2805b6888dc 1003 pbuf_free(p);
robert_jw 0:b2805b6888dc 1004 return q;
robert_jw 0:b2805b6888dc 1005 }
robert_jw 0:b2805b6888dc 1006
robert_jw 0:b2805b6888dc 1007 #if LWIP_CHECKSUM_ON_COPY
robert_jw 0:b2805b6888dc 1008 /**
robert_jw 0:b2805b6888dc 1009 * Copies data into a single pbuf (*not* into a pbuf queue!) and updates
robert_jw 0:b2805b6888dc 1010 * the checksum while copying
robert_jw 0:b2805b6888dc 1011 *
robert_jw 0:b2805b6888dc 1012 * @param p the pbuf to copy data into
robert_jw 0:b2805b6888dc 1013 * @param start_offset offset of p->payload where to copy the data to
robert_jw 0:b2805b6888dc 1014 * @param dataptr data to copy into the pbuf
robert_jw 0:b2805b6888dc 1015 * @param len length of data to copy into the pbuf
robert_jw 0:b2805b6888dc 1016 * @param chksum pointer to the checksum which is updated
robert_jw 0:b2805b6888dc 1017 * @return ERR_OK if successful, another error if the data does not fit
robert_jw 0:b2805b6888dc 1018 * within the (first) pbuf (no pbuf queues!)
robert_jw 0:b2805b6888dc 1019 */
robert_jw 0:b2805b6888dc 1020 err_t
robert_jw 0:b2805b6888dc 1021 pbuf_fill_chksum(struct pbuf *p, u16_t start_offset, const void *dataptr,
robert_jw 0:b2805b6888dc 1022 u16_t len, u16_t *chksum)
robert_jw 0:b2805b6888dc 1023 {
robert_jw 0:b2805b6888dc 1024 u32_t acc;
robert_jw 0:b2805b6888dc 1025 u16_t copy_chksum;
robert_jw 0:b2805b6888dc 1026 char *dst_ptr;
robert_jw 0:b2805b6888dc 1027 LWIP_ASSERT("p != NULL", p != NULL);
robert_jw 0:b2805b6888dc 1028 LWIP_ASSERT("dataptr != NULL", dataptr != NULL);
robert_jw 0:b2805b6888dc 1029 LWIP_ASSERT("chksum != NULL", chksum != NULL);
robert_jw 0:b2805b6888dc 1030 LWIP_ASSERT("len != 0", len != 0);
robert_jw 0:b2805b6888dc 1031
robert_jw 0:b2805b6888dc 1032 if ((start_offset >= p->len) || (start_offset + len > p->len)) {
robert_jw 0:b2805b6888dc 1033 return ERR_ARG;
robert_jw 0:b2805b6888dc 1034 }
robert_jw 0:b2805b6888dc 1035
robert_jw 0:b2805b6888dc 1036 dst_ptr = ((char*)p->payload) + start_offset;
robert_jw 0:b2805b6888dc 1037 copy_chksum = LWIP_CHKSUM_COPY(dst_ptr, dataptr, len);
robert_jw 0:b2805b6888dc 1038 if ((start_offset & 1) != 0) {
robert_jw 0:b2805b6888dc 1039 copy_chksum = SWAP_BYTES_IN_WORD(copy_chksum);
robert_jw 0:b2805b6888dc 1040 }
robert_jw 0:b2805b6888dc 1041 acc = *chksum;
robert_jw 0:b2805b6888dc 1042 acc += copy_chksum;
robert_jw 0:b2805b6888dc 1043 *chksum = FOLD_U32T(acc);
robert_jw 0:b2805b6888dc 1044 return ERR_OK;
robert_jw 0:b2805b6888dc 1045 }
robert_jw 0:b2805b6888dc 1046 #endif /* LWIP_CHECKSUM_ON_COPY */
robert_jw 0:b2805b6888dc 1047
robert_jw 0:b2805b6888dc 1048 /** Get one byte from the specified position in a pbuf
robert_jw 0:b2805b6888dc 1049 * WARNING: returns zero for offset >= p->tot_len
robert_jw 0:b2805b6888dc 1050 *
robert_jw 0:b2805b6888dc 1051 * @param p pbuf to parse
robert_jw 0:b2805b6888dc 1052 * @param offset offset into p of the byte to return
robert_jw 0:b2805b6888dc 1053 * @return byte at an offset into p OR ZERO IF 'offset' >= p->tot_len
robert_jw 0:b2805b6888dc 1054 */
robert_jw 0:b2805b6888dc 1055 u8_t
robert_jw 0:b2805b6888dc 1056 pbuf_get_at(struct pbuf* p, u16_t offset)
robert_jw 0:b2805b6888dc 1057 {
robert_jw 0:b2805b6888dc 1058 u16_t copy_from = offset;
robert_jw 0:b2805b6888dc 1059 struct pbuf* q = p;
robert_jw 0:b2805b6888dc 1060
robert_jw 0:b2805b6888dc 1061 /* get the correct pbuf */
robert_jw 0:b2805b6888dc 1062 while ((q != NULL) && (q->len <= copy_from)) {
robert_jw 0:b2805b6888dc 1063 copy_from -= q->len;
robert_jw 0:b2805b6888dc 1064 q = q->next;
robert_jw 0:b2805b6888dc 1065 }
robert_jw 0:b2805b6888dc 1066 /* return requested data if pbuf is OK */
robert_jw 0:b2805b6888dc 1067 if ((q != NULL) && (q->len > copy_from)) {
robert_jw 0:b2805b6888dc 1068 return ((u8_t*)q->payload)[copy_from];
robert_jw 0:b2805b6888dc 1069 }
robert_jw 0:b2805b6888dc 1070 return 0;
robert_jw 0:b2805b6888dc 1071 }
robert_jw 0:b2805b6888dc 1072
robert_jw 0:b2805b6888dc 1073 /** Compare pbuf contents at specified offset with memory s2, both of length n
robert_jw 0:b2805b6888dc 1074 *
robert_jw 0:b2805b6888dc 1075 * @param p pbuf to compare
robert_jw 0:b2805b6888dc 1076 * @param offset offset into p at wich to start comparing
robert_jw 0:b2805b6888dc 1077 * @param s2 buffer to compare
robert_jw 0:b2805b6888dc 1078 * @param n length of buffer to compare
robert_jw 0:b2805b6888dc 1079 * @return zero if equal, nonzero otherwise
robert_jw 0:b2805b6888dc 1080 * (0xffff if p is too short, diffoffset+1 otherwise)
robert_jw 0:b2805b6888dc 1081 */
robert_jw 0:b2805b6888dc 1082 u16_t
robert_jw 0:b2805b6888dc 1083 pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n)
robert_jw 0:b2805b6888dc 1084 {
robert_jw 0:b2805b6888dc 1085 u16_t start = offset;
robert_jw 0:b2805b6888dc 1086 struct pbuf* q = p;
robert_jw 0:b2805b6888dc 1087
robert_jw 0:b2805b6888dc 1088 /* get the correct pbuf */
robert_jw 0:b2805b6888dc 1089 while ((q != NULL) && (q->len <= start)) {
robert_jw 0:b2805b6888dc 1090 start -= q->len;
robert_jw 0:b2805b6888dc 1091 q = q->next;
robert_jw 0:b2805b6888dc 1092 }
robert_jw 0:b2805b6888dc 1093 /* return requested data if pbuf is OK */
robert_jw 0:b2805b6888dc 1094 if ((q != NULL) && (q->len > start)) {
robert_jw 0:b2805b6888dc 1095 u16_t i;
robert_jw 0:b2805b6888dc 1096 for(i = 0; i < n; i++) {
robert_jw 0:b2805b6888dc 1097 u8_t a = pbuf_get_at(q, start + i);
robert_jw 0:b2805b6888dc 1098 u8_t b = ((u8_t*)s2)[i];
robert_jw 0:b2805b6888dc 1099 if (a != b) {
robert_jw 0:b2805b6888dc 1100 return i+1;
robert_jw 0:b2805b6888dc 1101 }
robert_jw 0:b2805b6888dc 1102 }
robert_jw 0:b2805b6888dc 1103 return 0;
robert_jw 0:b2805b6888dc 1104 }
robert_jw 0:b2805b6888dc 1105 return 0xffff;
robert_jw 0:b2805b6888dc 1106 }
robert_jw 0:b2805b6888dc 1107
robert_jw 0:b2805b6888dc 1108 /** Find occurrence of mem (with length mem_len) in pbuf p, starting at offset
robert_jw 0:b2805b6888dc 1109 * start_offset.
robert_jw 0:b2805b6888dc 1110 *
robert_jw 0:b2805b6888dc 1111 * @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
robert_jw 0:b2805b6888dc 1112 * return value 'not found'
robert_jw 0:b2805b6888dc 1113 * @param mem search for the contents of this buffer
robert_jw 0:b2805b6888dc 1114 * @param mem_len length of 'mem'
robert_jw 0:b2805b6888dc 1115 * @param start_offset offset into p at which to start searching
robert_jw 0:b2805b6888dc 1116 * @return 0xFFFF if substr was not found in p or the index where it was found
robert_jw 0:b2805b6888dc 1117 */
robert_jw 0:b2805b6888dc 1118 u16_t
robert_jw 0:b2805b6888dc 1119 pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset)
robert_jw 0:b2805b6888dc 1120 {
robert_jw 0:b2805b6888dc 1121 u16_t i;
robert_jw 0:b2805b6888dc 1122 u16_t max = p->tot_len - mem_len;
robert_jw 0:b2805b6888dc 1123 if (p->tot_len >= mem_len + start_offset) {
robert_jw 0:b2805b6888dc 1124 for(i = start_offset; i <= max; ) {
robert_jw 0:b2805b6888dc 1125 u16_t plus = pbuf_memcmp(p, i, mem, mem_len);
robert_jw 0:b2805b6888dc 1126 if (plus == 0) {
robert_jw 0:b2805b6888dc 1127 return i;
robert_jw 0:b2805b6888dc 1128 } else {
robert_jw 0:b2805b6888dc 1129 i += plus;
robert_jw 0:b2805b6888dc 1130 }
robert_jw 0:b2805b6888dc 1131 }
robert_jw 0:b2805b6888dc 1132 }
robert_jw 0:b2805b6888dc 1133 return 0xFFFF;
robert_jw 0:b2805b6888dc 1134 }
robert_jw 0:b2805b6888dc 1135
robert_jw 0:b2805b6888dc 1136 /** Find occurrence of substr with length substr_len in pbuf p, start at offset
robert_jw 0:b2805b6888dc 1137 * start_offset
robert_jw 0:b2805b6888dc 1138 * WARNING: in contrast to strstr(), this one does not stop at the first \0 in
robert_jw 0:b2805b6888dc 1139 * the pbuf/source string!
robert_jw 0:b2805b6888dc 1140 *
robert_jw 0:b2805b6888dc 1141 * @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
robert_jw 0:b2805b6888dc 1142 * return value 'not found'
robert_jw 0:b2805b6888dc 1143 * @param substr string to search for in p, maximum length is 0xFFFE
robert_jw 0:b2805b6888dc 1144 * @return 0xFFFF if substr was not found in p or the index where it was found
robert_jw 0:b2805b6888dc 1145 */
robert_jw 0:b2805b6888dc 1146 u16_t
robert_jw 0:b2805b6888dc 1147 pbuf_strstr(struct pbuf* p, const char* substr)
robert_jw 0:b2805b6888dc 1148 {
robert_jw 0:b2805b6888dc 1149 size_t substr_len;
robert_jw 0:b2805b6888dc 1150 if ((substr == NULL) || (substr[0] == 0) || (p->tot_len == 0xFFFF)) {
robert_jw 0:b2805b6888dc 1151 return 0xFFFF;
robert_jw 0:b2805b6888dc 1152 }
robert_jw 0:b2805b6888dc 1153 substr_len = strlen(substr);
robert_jw 0:b2805b6888dc 1154 if (substr_len >= 0xFFFF) {
robert_jw 0:b2805b6888dc 1155 return 0xFFFF;
robert_jw 0:b2805b6888dc 1156 }
robert_jw 0:b2805b6888dc 1157 return pbuf_memfind(p, substr, (u16_t)substr_len, 0);
robert_jw 0:b2805b6888dc 1158 }