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jeremybenn |
/**
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* @file
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* Packet buffer management
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*
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* Packets are built from the pbuf data structure. It supports dynamic
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* memory allocation for packet contents or can reference externally
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* managed packet contents both in RAM and ROM. Quick allocation for
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* incoming packets is provided through pools with fixed sized pbufs.
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*
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* A packet may span over multiple pbufs, chained as a singly linked
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* list. This is called a "pbuf chain".
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*
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* Multiple packets may be queued, also using this singly linked list.
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* This is called a "packet queue".
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*
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* So, a packet queue consists of one or more pbuf chains, each of
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* which consist of one or more pbufs. CURRENTLY, PACKET QUEUES ARE
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* NOT SUPPORTED!!! Use helper structs to queue multiple packets.
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*
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* The differences between a pbuf chain and a packet queue are very
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* precise but subtle.
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*
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* The last pbuf of a packet has a ->tot_len field that equals the
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* ->len field. It can be found by traversing the list. If the last
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* pbuf of a packet has a ->next field other than NULL, more packets
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* are on the queue.
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*
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* Therefore, looping through a pbuf of a single packet, has an
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* loop end condition (tot_len == p->len), NOT (next == NULL).
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*/
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/*
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* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without modification,
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* are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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* OF SUCH DAMAGE.
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*
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* This file is part of the lwIP TCP/IP stack.
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*
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* Author: Adam Dunkels <adam@sics.se>
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*
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*/
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#include "lwip/opt.h"
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#include "lwip/stats.h"
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#include "lwip/def.h"
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#include "lwip/mem.h"
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#include "lwip/memp.h"
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#include "lwip/pbuf.h"
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#include "lwip/sys.h"
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#include "arch/perf.h"
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#include <string.h>
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#define SIZEOF_STRUCT_PBUF LWIP_MEM_ALIGN_SIZE(sizeof(struct pbuf))
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/* Since the pool is created in memp, PBUF_POOL_BUFSIZE will be automatically
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aligned there. Therefore, PBUF_POOL_BUFSIZE_ALIGNED can be used here. */
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#define PBUF_POOL_BUFSIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE)
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/**
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* Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
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*
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* The actual memory allocated for the pbuf is determined by the
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* layer at which the pbuf is allocated and the requested size
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* (from the size parameter).
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*
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* @param layer flag to define header size
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* @param length size of the pbuf's payload
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* @param type this parameter decides how and where the pbuf
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* should be allocated as follows:
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*
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* - PBUF_RAM: buffer memory for pbuf is allocated as one large
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* chunk. This includes protocol headers as well.
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* - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
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* protocol headers. Additional headers must be prepended
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* by allocating another pbuf and chain in to the front of
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* the ROM pbuf. It is assumed that the memory used is really
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* similar to ROM in that it is immutable and will not be
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* changed. Memory which is dynamic should generally not
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* be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
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* - PBUF_REF: no buffer memory is allocated for the pbuf, even for
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* protocol headers. It is assumed that the pbuf is only
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* being used in a single thread. If the pbuf gets queued,
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* then pbuf_take should be called to copy the buffer.
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* - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
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* the pbuf pool that is allocated during pbuf_init().
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*
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* @return the allocated pbuf. If multiple pbufs where allocated, this
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* is the first pbuf of a pbuf chain.
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*/
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struct pbuf *
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pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
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{
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struct pbuf *p, *q, *r;
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u16_t offset;
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s32_t rem_len; /* remaining length */
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LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE | 3, ("pbuf_alloc(length=%"U16_F")\n", length));
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/* determine header offset */
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offset = 0;
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switch (layer) {
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case PBUF_TRANSPORT:
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/* add room for transport (often TCP) layer header */
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offset += PBUF_TRANSPORT_HLEN;
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/* FALLTHROUGH */
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case PBUF_IP:
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/* add room for IP layer header */
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offset += PBUF_IP_HLEN;
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/* FALLTHROUGH */
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case PBUF_LINK:
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/* add room for link layer header */
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offset += PBUF_LINK_HLEN;
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break;
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case PBUF_RAW:
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break;
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default:
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LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0);
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return NULL;
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}
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switch (type) {
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case PBUF_POOL:
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/* allocate head of pbuf chain into p */
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p = memp_malloc(MEMP_PBUF_POOL);
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LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE | 3, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
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if (p == NULL) {
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return NULL;
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}
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p->type = type;
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p->next = NULL;
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/* make the payload pointer point 'offset' bytes into pbuf data memory */
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p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + (SIZEOF_STRUCT_PBUF + offset)));
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LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned",
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((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
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/* the total length of the pbuf chain is the requested size */
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p->tot_len = length;
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/* set the length of the first pbuf in the chain */
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p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
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LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
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((u8_t*)p->payload + p->len <=
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(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
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/* set reference count (needed here in case we fail) */
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p->ref = 1;
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/* now allocate the tail of the pbuf chain */
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/* remember first pbuf for linkage in next iteration */
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r = p;
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/* remaining length to be allocated */
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rem_len = length - p->len;
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/* any remaining pbufs to be allocated? */
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while (rem_len > 0) {
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q = memp_malloc(MEMP_PBUF_POOL);
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if (q == NULL) {
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/* free chain so far allocated */
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pbuf_free(p);
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/* bail out unsuccesfully */
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return NULL;
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}
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q->type = type;
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q->flags = 0;
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q->next = NULL;
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/* make previous pbuf point to this pbuf */
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r->next = q;
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/* set total length of this pbuf and next in chain */
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LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff);
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q->tot_len = (u16_t)rem_len;
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/* this pbuf length is pool size, unless smaller sized tail */
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q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
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q->payload = (void *)((u8_t *)q + SIZEOF_STRUCT_PBUF);
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LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
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((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
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LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
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((u8_t*)p->payload + p->len <=
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(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
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198 |
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q->ref = 1;
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199 |
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/* calculate remaining length to be allocated */
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200 |
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rem_len -= q->len;
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201 |
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/* remember this pbuf for linkage in next iteration */
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202 |
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r = q;
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}
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/* end of chain */
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/*r->next = NULL;*/
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206 |
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break;
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case PBUF_RAM:
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/* If pbuf is to be allocated in RAM, allocate memory for it. */
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p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
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if (p == NULL) {
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212 |
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return NULL;
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213 |
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}
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214 |
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/* Set up internal structure of the pbuf. */
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p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + SIZEOF_STRUCT_PBUF + offset));
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216 |
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p->len = p->tot_len = length;
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p->next = NULL;
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218 |
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p->type = type;
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219 |
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220 |
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LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
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((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
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break;
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223 |
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/* pbuf references existing (non-volatile static constant) ROM payload? */
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224 |
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case PBUF_ROM:
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225 |
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/* pbuf references existing (externally allocated) RAM payload? */
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226 |
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case PBUF_REF:
|
227 |
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/* only allocate memory for the pbuf structure */
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p = memp_malloc(MEMP_PBUF);
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229 |
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if (p == NULL) {
|
230 |
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LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE | 2, ("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n",
|
231 |
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(type == PBUF_ROM) ? "ROM" : "REF"));
|
232 |
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return NULL;
|
233 |
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}
|
234 |
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/* caller must set this field properly, afterwards */
|
235 |
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p->payload = NULL;
|
236 |
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p->len = p->tot_len = length;
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237 |
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p->next = NULL;
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238 |
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p->type = type;
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239 |
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break;
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240 |
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default:
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241 |
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LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
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242 |
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return NULL;
|
243 |
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}
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244 |
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/* set reference count */
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245 |
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p->ref = 1;
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246 |
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/* set flags */
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247 |
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p->flags = 0;
|
248 |
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LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE | 3, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
|
249 |
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return p;
|
250 |
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}
|
251 |
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|
252 |
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|
253 |
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/**
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254 |
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* Shrink a pbuf chain to a desired length.
|
255 |
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*
|
256 |
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* @param p pbuf to shrink.
|
257 |
|
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* @param new_len desired new length of pbuf chain
|
258 |
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*
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259 |
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* Depending on the desired length, the first few pbufs in a chain might
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260 |
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* be skipped and left unchanged. The new last pbuf in the chain will be
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* resized, and any remaining pbufs will be freed.
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262 |
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*
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263 |
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* @note If the pbuf is ROM/REF, only the ->tot_len and ->len fields are adjusted.
|
264 |
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* @note May not be called on a packet queue.
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265 |
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*
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266 |
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* @note Despite its name, pbuf_realloc cannot grow the size of a pbuf (chain).
|
267 |
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*/
|
268 |
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void
|
269 |
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pbuf_realloc(struct pbuf *p, u16_t new_len)
|
270 |
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{
|
271 |
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struct pbuf *q;
|
272 |
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u16_t rem_len; /* remaining length */
|
273 |
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s32_t grow;
|
274 |
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|
275 |
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LWIP_ASSERT("pbuf_realloc: sane p->type", p->type == PBUF_POOL ||
|
276 |
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p->type == PBUF_ROM ||
|
277 |
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p->type == PBUF_RAM ||
|
278 |
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p->type == PBUF_REF);
|
279 |
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|
280 |
|
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/* desired length larger than current length? */
|
281 |
|
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if (new_len >= p->tot_len) {
|
282 |
|
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/* enlarging not yet supported */
|
283 |
|
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return;
|
284 |
|
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}
|
285 |
|
|
|
286 |
|
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/* the pbuf chain grows by (new_len - p->tot_len) bytes
|
287 |
|
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* (which may be negative in case of shrinking) */
|
288 |
|
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grow = new_len - p->tot_len;
|
289 |
|
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|
290 |
|
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/* first, step over any pbufs that should remain in the chain */
|
291 |
|
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rem_len = new_len;
|
292 |
|
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q = p;
|
293 |
|
|
/* should this pbuf be kept? */
|
294 |
|
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while (rem_len > q->len) {
|
295 |
|
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/* decrease remaining length by pbuf length */
|
296 |
|
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rem_len -= q->len;
|
297 |
|
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/* decrease total length indicator */
|
298 |
|
|
LWIP_ASSERT("grow < max_u16_t", grow < 0xffff);
|
299 |
|
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q->tot_len += (u16_t)grow;
|
300 |
|
|
/* proceed to next pbuf in chain */
|
301 |
|
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q = q->next;
|
302 |
|
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}
|
303 |
|
|
/* we have now reached the new last pbuf (in q) */
|
304 |
|
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/* rem_len == desired length for pbuf q */
|
305 |
|
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|
306 |
|
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/* shrink allocated memory for PBUF_RAM */
|
307 |
|
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/* (other types merely adjust their length fields */
|
308 |
|
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if ((q->type == PBUF_RAM) && (rem_len != q->len)) {
|
309 |
|
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/* reallocate and adjust the length of the pbuf that will be split */
|
310 |
|
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q = mem_realloc(q, (u8_t *)q->payload - (u8_t *)q + rem_len);
|
311 |
|
|
LWIP_ASSERT("mem_realloc give q == NULL", q != NULL);
|
312 |
|
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}
|
313 |
|
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/* adjust length fields for new last pbuf */
|
314 |
|
|
q->len = rem_len;
|
315 |
|
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q->tot_len = q->len;
|
316 |
|
|
|
317 |
|
|
/* any remaining pbufs in chain? */
|
318 |
|
|
if (q->next != NULL) {
|
319 |
|
|
/* free remaining pbufs in chain */
|
320 |
|
|
pbuf_free(q->next);
|
321 |
|
|
}
|
322 |
|
|
/* q is last packet in chain */
|
323 |
|
|
q->next = NULL;
|
324 |
|
|
|
325 |
|
|
}
|
326 |
|
|
|
327 |
|
|
/**
|
328 |
|
|
* Adjusts the payload pointer to hide or reveal headers in the payload.
|
329 |
|
|
*
|
330 |
|
|
* Adjusts the ->payload pointer so that space for a header
|
331 |
|
|
* (dis)appears in the pbuf payload.
|
332 |
|
|
*
|
333 |
|
|
* The ->payload, ->tot_len and ->len fields are adjusted.
|
334 |
|
|
*
|
335 |
|
|
* @param p pbuf to change the header size.
|
336 |
|
|
* @param header_size_increment Number of bytes to increment header size which
|
337 |
|
|
* increases the size of the pbuf. New space is on the front.
|
338 |
|
|
* (Using a negative value decreases the header size.)
|
339 |
|
|
* If hdr_size_inc is 0, this function does nothing and returns succesful.
|
340 |
|
|
*
|
341 |
|
|
* PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so
|
342 |
|
|
* the call will fail. A check is made that the increase in header size does
|
343 |
|
|
* not move the payload pointer in front of the start of the buffer.
|
344 |
|
|
* @return non-zero on failure, zero on success.
|
345 |
|
|
*
|
346 |
|
|
*/
|
347 |
|
|
u8_t
|
348 |
|
|
pbuf_header(struct pbuf *p, s16_t header_size_increment)
|
349 |
|
|
{
|
350 |
|
|
u16_t type;
|
351 |
|
|
void *payload;
|
352 |
|
|
u16_t increment_magnitude;
|
353 |
|
|
|
354 |
|
|
LWIP_ASSERT("p != NULL", p != NULL);
|
355 |
|
|
if ((header_size_increment == 0) || (p == NULL))
|
356 |
|
|
return 0;
|
357 |
|
|
|
358 |
|
|
if (header_size_increment < 0){
|
359 |
|
|
increment_magnitude = -header_size_increment;
|
360 |
|
|
/* Check that we aren't going to move off the end of the pbuf */
|
361 |
|
|
LWIP_ERROR("increment_magnitude <= p->len", (increment_magnitude <= p->len), return 1;);
|
362 |
|
|
} else {
|
363 |
|
|
increment_magnitude = header_size_increment;
|
364 |
|
|
#if 0
|
365 |
|
|
/* Can't assert these as some callers speculatively call
|
366 |
|
|
pbuf_header() to see if it's OK. Will return 1 below instead. */
|
367 |
|
|
/* Check that we've got the correct type of pbuf to work with */
|
368 |
|
|
LWIP_ASSERT("p->type == PBUF_RAM || p->type == PBUF_POOL",
|
369 |
|
|
p->type == PBUF_RAM || p->type == PBUF_POOL);
|
370 |
|
|
/* Check that we aren't going to move off the beginning of the pbuf */
|
371 |
|
|
LWIP_ASSERT("p->payload - increment_magnitude >= p + SIZEOF_STRUCT_PBUF",
|
372 |
|
|
(u8_t *)p->payload - increment_magnitude >= (u8_t *)p + SIZEOF_STRUCT_PBUF);
|
373 |
|
|
#endif
|
374 |
|
|
}
|
375 |
|
|
|
376 |
|
|
type = p->type;
|
377 |
|
|
/* remember current payload pointer */
|
378 |
|
|
payload = p->payload;
|
379 |
|
|
|
380 |
|
|
/* pbuf types containing payloads? */
|
381 |
|
|
if (type == PBUF_RAM || type == PBUF_POOL) {
|
382 |
|
|
/* set new payload pointer */
|
383 |
|
|
p->payload = (u8_t *)p->payload - header_size_increment;
|
384 |
|
|
/* boundary check fails? */
|
385 |
|
|
if ((u8_t *)p->payload < (u8_t *)p + SIZEOF_STRUCT_PBUF) {
|
386 |
|
|
LWIP_DEBUGF( PBUF_DEBUG | 2, ("pbuf_header: failed as %p < %p (not enough space for new header size)\n",
|
387 |
|
|
(void *)p->payload,
|
388 |
|
|
(void *)(p + 1)));\
|
389 |
|
|
/* restore old payload pointer */
|
390 |
|
|
p->payload = payload;
|
391 |
|
|
/* bail out unsuccesfully */
|
392 |
|
|
return 1;
|
393 |
|
|
}
|
394 |
|
|
/* pbuf types refering to external payloads? */
|
395 |
|
|
} else if (type == PBUF_REF || type == PBUF_ROM) {
|
396 |
|
|
/* hide a header in the payload? */
|
397 |
|
|
if ((header_size_increment < 0) && (increment_magnitude <= p->len)) {
|
398 |
|
|
/* increase payload pointer */
|
399 |
|
|
p->payload = (u8_t *)p->payload - header_size_increment;
|
400 |
|
|
} else {
|
401 |
|
|
/* cannot expand payload to front (yet!)
|
402 |
|
|
* bail out unsuccesfully */
|
403 |
|
|
return 1;
|
404 |
|
|
}
|
405 |
|
|
}
|
406 |
|
|
else {
|
407 |
|
|
/* Unknown type */
|
408 |
|
|
LWIP_ASSERT("bad pbuf type", 0);
|
409 |
|
|
return 1;
|
410 |
|
|
}
|
411 |
|
|
/* modify pbuf length fields */
|
412 |
|
|
p->len += header_size_increment;
|
413 |
|
|
p->tot_len += header_size_increment;
|
414 |
|
|
|
415 |
|
|
LWIP_DEBUGF(PBUF_DEBUG, ("pbuf_header: old %p new %p (%"S16_F")\n",
|
416 |
|
|
(void *)payload, (void *)p->payload, header_size_increment));
|
417 |
|
|
|
418 |
|
|
return 0;
|
419 |
|
|
}
|
420 |
|
|
|
421 |
|
|
/**
|
422 |
|
|
* Dereference a pbuf chain or queue and deallocate any no-longer-used
|
423 |
|
|
* pbufs at the head of this chain or queue.
|
424 |
|
|
*
|
425 |
|
|
* Decrements the pbuf reference count. If it reaches zero, the pbuf is
|
426 |
|
|
* deallocated.
|
427 |
|
|
*
|
428 |
|
|
* For a pbuf chain, this is repeated for each pbuf in the chain,
|
429 |
|
|
* up to the first pbuf which has a non-zero reference count after
|
430 |
|
|
* decrementing. So, when all reference counts are one, the whole
|
431 |
|
|
* chain is free'd.
|
432 |
|
|
*
|
433 |
|
|
* @param p The pbuf (chain) to be dereferenced.
|
434 |
|
|
*
|
435 |
|
|
* @return the number of pbufs that were de-allocated
|
436 |
|
|
* from the head of the chain.
|
437 |
|
|
*
|
438 |
|
|
* @note MUST NOT be called on a packet queue (Not verified to work yet).
|
439 |
|
|
* @note the reference counter of a pbuf equals the number of pointers
|
440 |
|
|
* that refer to the pbuf (or into the pbuf).
|
441 |
|
|
*
|
442 |
|
|
* @internal examples:
|
443 |
|
|
*
|
444 |
|
|
* Assuming existing chains a->b->c with the following reference
|
445 |
|
|
* counts, calling pbuf_free(a) results in:
|
446 |
|
|
*
|
447 |
|
|
* 1->2->3 becomes ...1->3
|
448 |
|
|
* 3->3->3 becomes 2->3->3
|
449 |
|
|
* 1->1->2 becomes ......1
|
450 |
|
|
* 2->1->1 becomes 1->1->1
|
451 |
|
|
* 1->1->1 becomes .......
|
452 |
|
|
*
|
453 |
|
|
*/
|
454 |
|
|
u8_t
|
455 |
|
|
pbuf_free(struct pbuf *p)
|
456 |
|
|
{
|
457 |
|
|
u16_t type;
|
458 |
|
|
struct pbuf *q;
|
459 |
|
|
u8_t count;
|
460 |
|
|
|
461 |
|
|
if (p == NULL) {
|
462 |
|
|
LWIP_ASSERT("p != NULL", p != NULL);
|
463 |
|
|
/* if assertions are disabled, proceed with debug output */
|
464 |
|
|
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE | 2, ("pbuf_free(p == NULL) was called.\n"));
|
465 |
|
|
return 0;
|
466 |
|
|
}
|
467 |
|
|
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE | 3, ("pbuf_free(%p)\n", (void *)p));
|
468 |
|
|
|
469 |
|
|
PERF_START;
|
470 |
|
|
|
471 |
|
|
LWIP_ASSERT("pbuf_free: sane type",
|
472 |
|
|
p->type == PBUF_RAM || p->type == PBUF_ROM ||
|
473 |
|
|
p->type == PBUF_REF || p->type == PBUF_POOL);
|
474 |
|
|
|
475 |
|
|
count = 0;
|
476 |
|
|
/* de-allocate all consecutive pbufs from the head of the chain that
|
477 |
|
|
* obtain a zero reference count after decrementing*/
|
478 |
|
|
while (p != NULL) {
|
479 |
|
|
u16_t ref;
|
480 |
|
|
SYS_ARCH_DECL_PROTECT(old_level);
|
481 |
|
|
/* Since decrementing ref cannot be guaranteed to be a single machine operation
|
482 |
|
|
* we must protect it. We put the new ref into a local variable to prevent
|
483 |
|
|
* further protection. */
|
484 |
|
|
SYS_ARCH_PROTECT(old_level);
|
485 |
|
|
/* all pbufs in a chain are referenced at least once */
|
486 |
|
|
LWIP_ASSERT("pbuf_free: p->ref > 0", p->ref > 0);
|
487 |
|
|
/* decrease reference count (number of pointers to pbuf) */
|
488 |
|
|
ref = --(p->ref);
|
489 |
|
|
SYS_ARCH_UNPROTECT(old_level);
|
490 |
|
|
/* this pbuf is no longer referenced to? */
|
491 |
|
|
if (ref == 0) {
|
492 |
|
|
/* remember next pbuf in chain for next iteration */
|
493 |
|
|
q = p->next;
|
494 |
|
|
LWIP_DEBUGF( PBUF_DEBUG | 2, ("pbuf_free: deallocating %p\n", (void *)p));
|
495 |
|
|
type = p->type;
|
496 |
|
|
/* is this a pbuf from the pool? */
|
497 |
|
|
if (type == PBUF_POOL) {
|
498 |
|
|
memp_free(MEMP_PBUF_POOL, p);
|
499 |
|
|
/* is this a ROM or RAM referencing pbuf? */
|
500 |
|
|
} else if (type == PBUF_ROM || type == PBUF_REF) {
|
501 |
|
|
memp_free(MEMP_PBUF, p);
|
502 |
|
|
/* type == PBUF_RAM */
|
503 |
|
|
} else {
|
504 |
|
|
mem_free(p);
|
505 |
|
|
}
|
506 |
|
|
count++;
|
507 |
|
|
/* proceed to next pbuf */
|
508 |
|
|
p = q;
|
509 |
|
|
/* p->ref > 0, this pbuf is still referenced to */
|
510 |
|
|
/* (and so the remaining pbufs in chain as well) */
|
511 |
|
|
} else {
|
512 |
|
|
LWIP_DEBUGF( PBUF_DEBUG | 2, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref));
|
513 |
|
|
/* stop walking through the chain */
|
514 |
|
|
p = NULL;
|
515 |
|
|
}
|
516 |
|
|
}
|
517 |
|
|
PERF_STOP("pbuf_free");
|
518 |
|
|
/* return number of de-allocated pbufs */
|
519 |
|
|
return count;
|
520 |
|
|
}
|
521 |
|
|
|
522 |
|
|
/**
|
523 |
|
|
* Count number of pbufs in a chain
|
524 |
|
|
*
|
525 |
|
|
* @param p first pbuf of chain
|
526 |
|
|
* @return the number of pbufs in a chain
|
527 |
|
|
*/
|
528 |
|
|
|
529 |
|
|
u8_t
|
530 |
|
|
pbuf_clen(struct pbuf *p)
|
531 |
|
|
{
|
532 |
|
|
u8_t len;
|
533 |
|
|
|
534 |
|
|
len = 0;
|
535 |
|
|
while (p != NULL) {
|
536 |
|
|
++len;
|
537 |
|
|
p = p->next;
|
538 |
|
|
}
|
539 |
|
|
return len;
|
540 |
|
|
}
|
541 |
|
|
|
542 |
|
|
/**
|
543 |
|
|
* Increment the reference count of the pbuf.
|
544 |
|
|
*
|
545 |
|
|
* @param p pbuf to increase reference counter of
|
546 |
|
|
*
|
547 |
|
|
*/
|
548 |
|
|
void
|
549 |
|
|
pbuf_ref(struct pbuf *p)
|
550 |
|
|
{
|
551 |
|
|
SYS_ARCH_DECL_PROTECT(old_level);
|
552 |
|
|
/* pbuf given? */
|
553 |
|
|
if (p != NULL) {
|
554 |
|
|
SYS_ARCH_PROTECT(old_level);
|
555 |
|
|
++(p->ref);
|
556 |
|
|
SYS_ARCH_UNPROTECT(old_level);
|
557 |
|
|
}
|
558 |
|
|
}
|
559 |
|
|
|
560 |
|
|
/**
|
561 |
|
|
* Concatenate two pbufs (each may be a pbuf chain) and take over
|
562 |
|
|
* the caller's reference of the tail pbuf.
|
563 |
|
|
*
|
564 |
|
|
* @note The caller MAY NOT reference the tail pbuf afterwards.
|
565 |
|
|
* Use pbuf_chain() for that purpose.
|
566 |
|
|
*
|
567 |
|
|
* @see pbuf_chain()
|
568 |
|
|
*/
|
569 |
|
|
|
570 |
|
|
void
|
571 |
|
|
pbuf_cat(struct pbuf *h, struct pbuf *t)
|
572 |
|
|
{
|
573 |
|
|
struct pbuf *p;
|
574 |
|
|
|
575 |
|
|
LWIP_ERROR("(h != NULL) && (t != NULL) (programmer violates API)",
|
576 |
|
|
((h != NULL) && (t != NULL)), return;);
|
577 |
|
|
|
578 |
|
|
/* proceed to last pbuf of chain */
|
579 |
|
|
for (p = h; p->next != NULL; p = p->next) {
|
580 |
|
|
/* add total length of second chain to all totals of first chain */
|
581 |
|
|
p->tot_len += t->tot_len;
|
582 |
|
|
}
|
583 |
|
|
/* { p is last pbuf of first h chain, p->next == NULL } */
|
584 |
|
|
LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len);
|
585 |
|
|
LWIP_ASSERT("p->next == NULL", p->next == NULL);
|
586 |
|
|
/* add total length of second chain to last pbuf total of first chain */
|
587 |
|
|
p->tot_len += t->tot_len;
|
588 |
|
|
/* chain last pbuf of head (p) with first of tail (t) */
|
589 |
|
|
p->next = t;
|
590 |
|
|
/* p->next now references t, but the caller will drop its reference to t,
|
591 |
|
|
* so netto there is no change to the reference count of t.
|
592 |
|
|
*/
|
593 |
|
|
}
|
594 |
|
|
|
595 |
|
|
/**
|
596 |
|
|
* Chain two pbufs (or pbuf chains) together.
|
597 |
|
|
*
|
598 |
|
|
* The caller MUST call pbuf_free(t) once it has stopped
|
599 |
|
|
* using it. Use pbuf_cat() instead if you no longer use t.
|
600 |
|
|
*
|
601 |
|
|
* @param h head pbuf (chain)
|
602 |
|
|
* @param t tail pbuf (chain)
|
603 |
|
|
* @note The pbufs MUST belong to the same packet.
|
604 |
|
|
* @note MAY NOT be called on a packet queue.
|
605 |
|
|
*
|
606 |
|
|
* The ->tot_len fields of all pbufs of the head chain are adjusted.
|
607 |
|
|
* The ->next field of the last pbuf of the head chain is adjusted.
|
608 |
|
|
* The ->ref field of the first pbuf of the tail chain is adjusted.
|
609 |
|
|
*
|
610 |
|
|
*/
|
611 |
|
|
void
|
612 |
|
|
pbuf_chain(struct pbuf *h, struct pbuf *t)
|
613 |
|
|
{
|
614 |
|
|
pbuf_cat(h, t);
|
615 |
|
|
/* t is now referenced by h */
|
616 |
|
|
pbuf_ref(t);
|
617 |
|
|
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_FRESH | 2, ("pbuf_chain: %p references %p\n", (void *)h, (void *)t));
|
618 |
|
|
}
|
619 |
|
|
|
620 |
|
|
/**
|
621 |
|
|
* Dechains the first pbuf from its succeeding pbufs in the chain.
|
622 |
|
|
*
|
623 |
|
|
* Makes p->tot_len field equal to p->len.
|
624 |
|
|
* @param p pbuf to dechain
|
625 |
|
|
* @return remainder of the pbuf chain, or NULL if it was de-allocated.
|
626 |
|
|
* @note May not be called on a packet queue.
|
627 |
|
|
*/
|
628 |
|
|
struct pbuf *
|
629 |
|
|
pbuf_dechain(struct pbuf *p)
|
630 |
|
|
{
|
631 |
|
|
struct pbuf *q;
|
632 |
|
|
u8_t tail_gone = 1;
|
633 |
|
|
/* tail */
|
634 |
|
|
q = p->next;
|
635 |
|
|
/* pbuf has successor in chain? */
|
636 |
|
|
if (q != NULL) {
|
637 |
|
|
/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
|
638 |
|
|
LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len);
|
639 |
|
|
/* enforce invariant if assertion is disabled */
|
640 |
|
|
q->tot_len = p->tot_len - p->len;
|
641 |
|
|
/* decouple pbuf from remainder */
|
642 |
|
|
p->next = NULL;
|
643 |
|
|
/* total length of pbuf p is its own length only */
|
644 |
|
|
p->tot_len = p->len;
|
645 |
|
|
/* q is no longer referenced by p, free it */
|
646 |
|
|
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_STATE, ("pbuf_dechain: unreferencing %p\n", (void *)q));
|
647 |
|
|
tail_gone = pbuf_free(q);
|
648 |
|
|
if (tail_gone > 0) {
|
649 |
|
|
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_STATE,
|
650 |
|
|
("pbuf_dechain: deallocated %p (as it is no longer referenced)\n", (void *)q));
|
651 |
|
|
}
|
652 |
|
|
/* return remaining tail or NULL if deallocated */
|
653 |
|
|
}
|
654 |
|
|
/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
|
655 |
|
|
LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len);
|
656 |
|
|
return ((tail_gone > 0) ? NULL : q);
|
657 |
|
|
}
|
658 |
|
|
|
659 |
|
|
/**
|
660 |
|
|
*
|
661 |
|
|
* Create PBUF_RAM copies of pbufs.
|
662 |
|
|
*
|
663 |
|
|
* Used to queue packets on behalf of the lwIP stack, such as
|
664 |
|
|
* ARP based queueing.
|
665 |
|
|
*
|
666 |
|
|
* @note You MUST explicitly use p = pbuf_take(p);
|
667 |
|
|
*
|
668 |
|
|
* @note Only one packet is copied, no packet queue!
|
669 |
|
|
*
|
670 |
|
|
* @param p_to pbuf source of the copy
|
671 |
|
|
* @param p_from pbuf destination of the copy
|
672 |
|
|
*
|
673 |
|
|
* @return ERR_OK if pbuf was copied
|
674 |
|
|
* ERR_ARG if one of the pbufs is NULL or p_to is not big
|
675 |
|
|
* enough to hold p_from
|
676 |
|
|
*/
|
677 |
|
|
err_t
|
678 |
|
|
pbuf_copy(struct pbuf *p_to, struct pbuf *p_from)
|
679 |
|
|
{
|
680 |
|
|
u16_t offset_to=0, offset_from=0, len;
|
681 |
|
|
|
682 |
|
|
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE | 3, ("pbuf_copy(%p, %p)\n",
|
683 |
|
|
(void*)p_to, (void*)p_from));
|
684 |
|
|
|
685 |
|
|
/* is the target big enough to hold the source? */
|
686 |
|
|
LWIP_ERROR("pbuf_copy: target not big enough to hold source", ((p_to != NULL) &&
|
687 |
|
|
(p_from != NULL) && (p_to->tot_len >= p_from->tot_len)), return ERR_ARG;);
|
688 |
|
|
|
689 |
|
|
/* iterate through pbuf chain */
|
690 |
|
|
do
|
691 |
|
|
{
|
692 |
|
|
LWIP_ASSERT("p_to != NULL", p_to != NULL);
|
693 |
|
|
/* copy one part of the original chain */
|
694 |
|
|
if ((p_to->len - offset_to) >= (p_from->len - offset_from)) {
|
695 |
|
|
/* complete current p_from fits into current p_to */
|
696 |
|
|
len = p_from->len - offset_from;
|
697 |
|
|
} else {
|
698 |
|
|
/* current p_from does not fit into current p_to */
|
699 |
|
|
len = p_to->len - offset_to;
|
700 |
|
|
}
|
701 |
|
|
MEMCPY((u8_t*)p_to->payload + offset_to, (u8_t*)p_from->payload + offset_from, len);
|
702 |
|
|
offset_to += len;
|
703 |
|
|
offset_from += len;
|
704 |
|
|
LWIP_ASSERT("offset_to <= p_to->len", offset_to <= p_to->len);
|
705 |
|
|
if (offset_to == p_to->len) {
|
706 |
|
|
/* on to next p_to (if any) */
|
707 |
|
|
offset_to = 0;
|
708 |
|
|
p_to = p_to->next;
|
709 |
|
|
}
|
710 |
|
|
LWIP_ASSERT("offset_from <= p_from->len", offset_from <= p_from->len);
|
711 |
|
|
if (offset_from >= p_from->len) {
|
712 |
|
|
/* on to next p_from (if any) */
|
713 |
|
|
offset_from = 0;
|
714 |
|
|
p_from = p_from->next;
|
715 |
|
|
}
|
716 |
|
|
|
717 |
|
|
if((p_from != NULL) && (p_from->len == p_from->tot_len)) {
|
718 |
|
|
/* don't copy more than one packet! */
|
719 |
|
|
LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
|
720 |
|
|
(p_from->next == NULL), return ERR_VAL;);
|
721 |
|
|
}
|
722 |
|
|
if((p_to != NULL) && (p_to->len == p_to->tot_len)) {
|
723 |
|
|
/* don't copy more than one packet! */
|
724 |
|
|
LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
|
725 |
|
|
(p_to->next == NULL), return ERR_VAL;);
|
726 |
|
|
}
|
727 |
|
|
} while (p_from);
|
728 |
|
|
LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE | 1, ("pbuf_copy: end of chain reached.\n"));
|
729 |
|
|
return ERR_OK;
|
730 |
|
|
}
|
731 |
|
|
|
732 |
|
|
/**
|
733 |
|
|
* Copy (part of) the contents of a packet buffer
|
734 |
|
|
* to an application supplied buffer.
|
735 |
|
|
*
|
736 |
|
|
* @param buf the pbuf from which to copy data
|
737 |
|
|
* @param dataptr the application supplied buffer
|
738 |
|
|
* @param len length of data to copy (dataptr must be big enough)
|
739 |
|
|
* @param offset offset into the packet buffer from where to begin copying len bytes
|
740 |
|
|
*/
|
741 |
|
|
u16_t
|
742 |
|
|
pbuf_copy_partial(struct pbuf *buf, void *dataptr, u16_t len, u16_t offset)
|
743 |
|
|
{
|
744 |
|
|
struct pbuf *p;
|
745 |
|
|
u16_t left;
|
746 |
|
|
u16_t buf_copy_len;
|
747 |
|
|
u16_t copied_total = 0;
|
748 |
|
|
|
749 |
|
|
LWIP_ERROR("netbuf_copy_partial: invalid buf", (buf != NULL), return 0;);
|
750 |
|
|
LWIP_ERROR("netbuf_copy_partial: invalid dataptr", (dataptr != NULL), return 0;);
|
751 |
|
|
|
752 |
|
|
left = 0;
|
753 |
|
|
|
754 |
|
|
if((buf == NULL) || (dataptr == NULL)) {
|
755 |
|
|
return 0;
|
756 |
|
|
}
|
757 |
|
|
|
758 |
|
|
/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
|
759 |
|
|
for(p = buf; len != 0 && p != NULL; p = p->next) {
|
760 |
|
|
if ((offset != 0) && (offset >= p->len)) {
|
761 |
|
|
/* don't copy from this buffer -> on to the next */
|
762 |
|
|
offset -= p->len;
|
763 |
|
|
} else {
|
764 |
|
|
/* copy from this buffer. maybe only partially. */
|
765 |
|
|
buf_copy_len = p->len - offset;
|
766 |
|
|
if (buf_copy_len > len)
|
767 |
|
|
buf_copy_len = len;
|
768 |
|
|
/* copy the necessary parts of the buffer */
|
769 |
|
|
MEMCPY(&((char*)dataptr)[left], &((char*)p->payload)[offset], buf_copy_len);
|
770 |
|
|
copied_total += buf_copy_len;
|
771 |
|
|
left += buf_copy_len;
|
772 |
|
|
len -= buf_copy_len;
|
773 |
|
|
offset = 0;
|
774 |
|
|
}
|
775 |
|
|
}
|
776 |
|
|
return copied_total;
|
777 |
|
|
}
|