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lwip/core/pbuf.c@0:d616ece2d859, 2010-09-18 (annotated)

Committer:: mbed714
Date:: Sat Sep 18 23:05:49 2010 +0000
Revision:: 0:d616ece2d859

Who changed what in which revision?

User	Revision	Line number	New contents of line
mbed714	0:d616ece2d859	1	/**
mbed714	0:d616ece2d859	2	* @file
mbed714	0:d616ece2d859	3	* Packet buffer management
mbed714	0:d616ece2d859	4	*
mbed714	0:d616ece2d859	5	* Packets are built from the pbuf data structure. It supports dynamic
mbed714	0:d616ece2d859	6	* memory allocation for packet contents or can reference externally
mbed714	0:d616ece2d859	7	* managed packet contents both in RAM and ROM. Quick allocation for
mbed714	0:d616ece2d859	8	* incoming packets is provided through pools with fixed sized pbufs.
mbed714	0:d616ece2d859	9	*
mbed714	0:d616ece2d859	10	* A packet may span over multiple pbufs, chained as a singly linked
mbed714	0:d616ece2d859	11	* list. This is called a "pbuf chain".
mbed714	0:d616ece2d859	12	*
mbed714	0:d616ece2d859	13	* Multiple packets may be queued, also using this singly linked list.
mbed714	0:d616ece2d859	14	* This is called a "packet queue".
mbed714	0:d616ece2d859	15	*
mbed714	0:d616ece2d859	16	* So, a packet queue consists of one or more pbuf chains, each of
mbed714	0:d616ece2d859	17	* which consist of one or more pbufs. CURRENTLY, PACKET QUEUES ARE
mbed714	0:d616ece2d859	18	* NOT SUPPORTED!!! Use helper structs to queue multiple packets.
mbed714	0:d616ece2d859	19	*
mbed714	0:d616ece2d859	20	* The differences between a pbuf chain and a packet queue are very
mbed714	0:d616ece2d859	21	* precise but subtle.
mbed714	0:d616ece2d859	22	*
mbed714	0:d616ece2d859	23	* The last pbuf of a packet has a ->tot_len field that equals the
mbed714	0:d616ece2d859	24	* ->len field. It can be found by traversing the list. If the last
mbed714	0:d616ece2d859	25	* pbuf of a packet has a ->next field other than NULL, more packets
mbed714	0:d616ece2d859	26	* are on the queue.
mbed714	0:d616ece2d859	27	*
mbed714	0:d616ece2d859	28	* Therefore, looping through a pbuf of a single packet, has an
mbed714	0:d616ece2d859	29	* loop end condition (tot_len == p->len), NOT (next == NULL).
mbed714	0:d616ece2d859	30	*/
mbed714	0:d616ece2d859	31
mbed714	0:d616ece2d859	32	/*
mbed714	0:d616ece2d859	33	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
mbed714	0:d616ece2d859	34	* All rights reserved.
mbed714	0:d616ece2d859	35	*
mbed714	0:d616ece2d859	36	* Redistribution and use in source and binary forms, with or without modification,
mbed714	0:d616ece2d859	37	* are permitted provided that the following conditions are met:
mbed714	0:d616ece2d859	38	*
mbed714	0:d616ece2d859	39	* 1. Redistributions of source code must retain the above copyright notice,
mbed714	0:d616ece2d859	40	* this list of conditions and the following disclaimer.
mbed714	0:d616ece2d859	41	* 2. Redistributions in binary form must reproduce the above copyright notice,
mbed714	0:d616ece2d859	42	* this list of conditions and the following disclaimer in the documentation
mbed714	0:d616ece2d859	43	* and/or other materials provided with the distribution.
mbed714	0:d616ece2d859	44	* 3. The name of the author may not be used to endorse or promote products
mbed714	0:d616ece2d859	45	* derived from this software without specific prior written permission.
mbed714	0:d616ece2d859	46	*
mbed714	0:d616ece2d859	47	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
mbed714	0:d616ece2d859	48	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
mbed714	0:d616ece2d859	49	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
mbed714	0:d616ece2d859	50	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
mbed714	0:d616ece2d859	51	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
mbed714	0:d616ece2d859	52	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
mbed714	0:d616ece2d859	53	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
mbed714	0:d616ece2d859	54	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
mbed714	0:d616ece2d859	55	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
mbed714	0:d616ece2d859	56	* OF SUCH DAMAGE.
mbed714	0:d616ece2d859	57	*
mbed714	0:d616ece2d859	58	* This file is part of the lwIP TCP/IP stack.
mbed714	0:d616ece2d859	59	*
mbed714	0:d616ece2d859	60	* Author: Adam Dunkels <adam@sics.se>
mbed714	0:d616ece2d859	61	*
mbed714	0:d616ece2d859	62	*/
mbed714	0:d616ece2d859	63
mbed714	0:d616ece2d859	64	#include "lwip/opt.h"
mbed714	0:d616ece2d859	65
mbed714	0:d616ece2d859	66	#include "lwip/stats.h"
mbed714	0:d616ece2d859	67	#include "lwip/def.h"
mbed714	0:d616ece2d859	68	#include "lwip/mem.h"
mbed714	0:d616ece2d859	69	#include "lwip/memp.h"
mbed714	0:d616ece2d859	70	#include "lwip/pbuf.h"
mbed714	0:d616ece2d859	71	#include "lwip/sys.h"
mbed714	0:d616ece2d859	72	#include "arch/perf.h"
mbed714	0:d616ece2d859	73	#if TCP_QUEUE_OOSEQ
mbed714	0:d616ece2d859	74	#include "lwip/tcp_impl.h"
mbed714	0:d616ece2d859	75	#endif
mbed714	0:d616ece2d859	76	#if LWIP_CHECKSUM_ON_COPY
mbed714	0:d616ece2d859	77	#include "lwip/inet_chksum.h"
mbed714	0:d616ece2d859	78	#endif
mbed714	0:d616ece2d859	79
mbed714	0:d616ece2d859	80	#include <string.h>
mbed714	0:d616ece2d859	81
mbed714	0:d616ece2d859	82	#define SIZEOF_STRUCT_PBUF LWIP_MEM_ALIGN_SIZE(sizeof(struct pbuf))
mbed714	0:d616ece2d859	83	/* Since the pool is created in memp, PBUF_POOL_BUFSIZE will be automatically
mbed714	0:d616ece2d859	84	aligned there. Therefore, PBUF_POOL_BUFSIZE_ALIGNED can be used here. */
mbed714	0:d616ece2d859	85	#define PBUF_POOL_BUFSIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE)
mbed714	0:d616ece2d859	86
mbed714	0:d616ece2d859	87	#if !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS
mbed714	0:d616ece2d859	88	#define PBUF_POOL_IS_EMPTY()
mbed714	0:d616ece2d859	89	#else /* !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS */
mbed714	0:d616ece2d859	90	/** Define this to 0 to prevent freeing ooseq pbufs when the PBUF_POOL is empty */
mbed714	0:d616ece2d859	91	#ifndef PBUF_POOL_FREE_OOSEQ
mbed714	0:d616ece2d859	92	#define PBUF_POOL_FREE_OOSEQ 1
mbed714	0:d616ece2d859	93	#endif /* PBUF_POOL_FREE_OOSEQ */
mbed714	0:d616ece2d859	94
mbed714	0:d616ece2d859	95	#if PBUF_POOL_FREE_OOSEQ
mbed714	0:d616ece2d859	96	#include "lwip/tcpip.h"
mbed714	0:d616ece2d859	97	#define PBUF_POOL_IS_EMPTY() pbuf_pool_is_empty()
mbed714	0:d616ece2d859	98	static u8_t pbuf_free_ooseq_queued;
mbed714	0:d616ece2d859	99	/**
mbed714	0:d616ece2d859	100	* Attempt to reclaim some memory from queued out-of-sequence TCP segments
mbed714	0:d616ece2d859	101	* if we run out of pool pbufs. It's better to give priority to new packets
mbed714	0:d616ece2d859	102	* if we're running out.
mbed714	0:d616ece2d859	103	*
mbed714	0:d616ece2d859	104	* This must be done in the correct thread context therefore this function
mbed714	0:d616ece2d859	105	* can only be used with NO_SYS=0 and through tcpip_callback.
mbed714	0:d616ece2d859	106	*/
mbed714	0:d616ece2d859	107	static void
mbed714	0:d616ece2d859	108	pbuf_free_ooseq(void* arg)
mbed714	0:d616ece2d859	109	{
mbed714	0:d616ece2d859	110	struct tcp_pcb* pcb;
mbed714	0:d616ece2d859	111	SYS_ARCH_DECL_PROTECT(old_level);
mbed714	0:d616ece2d859	112	LWIP_UNUSED_ARG(arg);
mbed714	0:d616ece2d859	113
mbed714	0:d616ece2d859	114	SYS_ARCH_PROTECT(old_level);
mbed714	0:d616ece2d859	115	pbuf_free_ooseq_queued = 0;
mbed714	0:d616ece2d859	116	SYS_ARCH_UNPROTECT(old_level);
mbed714	0:d616ece2d859	117
mbed714	0:d616ece2d859	118	for (pcb = tcp_active_pcbs; NULL != pcb; pcb = pcb->next) {
mbed714	0:d616ece2d859	119	if (NULL != pcb->ooseq) {
mbed714	0:d616ece2d859	120	/** Free the ooseq pbufs of one PCB only */
mbed714	0:d616ece2d859	121	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free_ooseq: freeing out-of-sequence pbufs\n"));
mbed714	0:d616ece2d859	122	tcp_segs_free(pcb->ooseq);
mbed714	0:d616ece2d859	123	pcb->ooseq = NULL;
mbed714	0:d616ece2d859	124	return;
mbed714	0:d616ece2d859	125	}
mbed714	0:d616ece2d859	126	}
mbed714	0:d616ece2d859	127	}
mbed714	0:d616ece2d859	128
mbed714	0:d616ece2d859	129	/** Queue a call to pbuf_free_ooseq if not already queued. */
mbed714	0:d616ece2d859	130	static void
mbed714	0:d616ece2d859	131	pbuf_pool_is_empty(void)
mbed714	0:d616ece2d859	132	{
mbed714	0:d616ece2d859	133	u8_t queued;
mbed714	0:d616ece2d859	134	SYS_ARCH_DECL_PROTECT(old_level);
mbed714	0:d616ece2d859	135
mbed714	0:d616ece2d859	136	SYS_ARCH_PROTECT(old_level);
mbed714	0:d616ece2d859	137	queued = pbuf_free_ooseq_queued;
mbed714	0:d616ece2d859	138	pbuf_free_ooseq_queued = 1;
mbed714	0:d616ece2d859	139	SYS_ARCH_UNPROTECT(old_level);
mbed714	0:d616ece2d859	140
mbed714	0:d616ece2d859	141	if(!queued) {
mbed714	0:d616ece2d859	142	/* queue a call to pbuf_free_ooseq if not already queued */
mbed714	0:d616ece2d859	143	if(tcpip_callback_with_block(pbuf_free_ooseq, NULL, 0) != ERR_OK) {
mbed714	0:d616ece2d859	144	SYS_ARCH_PROTECT(old_level);
mbed714	0:d616ece2d859	145	pbuf_free_ooseq_queued = 0;
mbed714	0:d616ece2d859	146	SYS_ARCH_UNPROTECT(old_level);
mbed714	0:d616ece2d859	147	}
mbed714	0:d616ece2d859	148	}
mbed714	0:d616ece2d859	149	}
mbed714	0:d616ece2d859	150	#endif /* PBUF_POOL_FREE_OOSEQ */
mbed714	0:d616ece2d859	151	#endif /* !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS */
mbed714	0:d616ece2d859	152
mbed714	0:d616ece2d859	153	/**
mbed714	0:d616ece2d859	154	* Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
mbed714	0:d616ece2d859	155	*
mbed714	0:d616ece2d859	156	* The actual memory allocated for the pbuf is determined by the
mbed714	0:d616ece2d859	157	* layer at which the pbuf is allocated and the requested size
mbed714	0:d616ece2d859	158	* (from the size parameter).
mbed714	0:d616ece2d859	159	*
mbed714	0:d616ece2d859	160	* @param layer flag to define header size
mbed714	0:d616ece2d859	161	* @param length size of the pbuf's payload
mbed714	0:d616ece2d859	162	* @param type this parameter decides how and where the pbuf
mbed714	0:d616ece2d859	163	* should be allocated as follows:
mbed714	0:d616ece2d859	164	*
mbed714	0:d616ece2d859	165	* - PBUF_RAM: buffer memory for pbuf is allocated as one large
mbed714	0:d616ece2d859	166	* chunk. This includes protocol headers as well.
mbed714	0:d616ece2d859	167	* - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
mbed714	0:d616ece2d859	168	* protocol headers. Additional headers must be prepended
mbed714	0:d616ece2d859	169	* by allocating another pbuf and chain in to the front of
mbed714	0:d616ece2d859	170	* the ROM pbuf. It is assumed that the memory used is really
mbed714	0:d616ece2d859	171	* similar to ROM in that it is immutable and will not be
mbed714	0:d616ece2d859	172	* changed. Memory which is dynamic should generally not
mbed714	0:d616ece2d859	173	* be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
mbed714	0:d616ece2d859	174	* - PBUF_REF: no buffer memory is allocated for the pbuf, even for
mbed714	0:d616ece2d859	175	* protocol headers. It is assumed that the pbuf is only
mbed714	0:d616ece2d859	176	* being used in a single thread. If the pbuf gets queued,
mbed714	0:d616ece2d859	177	* then pbuf_take should be called to copy the buffer.
mbed714	0:d616ece2d859	178	* - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
mbed714	0:d616ece2d859	179	* the pbuf pool that is allocated during pbuf_init().
mbed714	0:d616ece2d859	180	*
mbed714	0:d616ece2d859	181	* @return the allocated pbuf. If multiple pbufs where allocated, this
mbed714	0:d616ece2d859	182	* is the first pbuf of a pbuf chain.
mbed714	0:d616ece2d859	183	*/
mbed714	0:d616ece2d859	184	struct pbuf *
mbed714	0:d616ece2d859	185	pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
mbed714	0:d616ece2d859	186	{
mbed714	0:d616ece2d859	187	struct pbuf p, q, *r;
mbed714	0:d616ece2d859	188	u16_t offset;
mbed714	0:d616ece2d859	189	s32_t rem_len; /* remaining length */
mbed714	0:d616ece2d859	190	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
mbed714	0:d616ece2d859	191
mbed714	0:d616ece2d859	192	/* determine header offset */
mbed714	0:d616ece2d859	193	offset = 0;
mbed714	0:d616ece2d859	194	switch (layer) {
mbed714	0:d616ece2d859	195	case PBUF_TRANSPORT:
mbed714	0:d616ece2d859	196	/* add room for transport (often TCP) layer header */
mbed714	0:d616ece2d859	197	offset += PBUF_TRANSPORT_HLEN;
mbed714	0:d616ece2d859	198	/* FALLTHROUGH */
mbed714	0:d616ece2d859	199	case PBUF_IP:
mbed714	0:d616ece2d859	200	/* add room for IP layer header */
mbed714	0:d616ece2d859	201	offset += PBUF_IP_HLEN;
mbed714	0:d616ece2d859	202	/* FALLTHROUGH */
mbed714	0:d616ece2d859	203	case PBUF_LINK:
mbed714	0:d616ece2d859	204	/* add room for link layer header */
mbed714	0:d616ece2d859	205	offset += PBUF_LINK_HLEN;
mbed714	0:d616ece2d859	206	break;
mbed714	0:d616ece2d859	207	case PBUF_RAW:
mbed714	0:d616ece2d859	208	break;
mbed714	0:d616ece2d859	209	default:
mbed714	0:d616ece2d859	210	LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0);
mbed714	0:d616ece2d859	211	return NULL;
mbed714	0:d616ece2d859	212	}
mbed714	0:d616ece2d859	213
mbed714	0:d616ece2d859	214	switch (type) {
mbed714	0:d616ece2d859	215	case PBUF_POOL:
mbed714	0:d616ece2d859	216	/* allocate head of pbuf chain into p */
mbed714	0:d616ece2d859	217	p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
mbed714	0:d616ece2d859	218	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
mbed714	0:d616ece2d859	219	if (p == NULL) {
mbed714	0:d616ece2d859	220	PBUF_POOL_IS_EMPTY();
mbed714	0:d616ece2d859	221	return NULL;
mbed714	0:d616ece2d859	222	}
mbed714	0:d616ece2d859	223	p->type = type;
mbed714	0:d616ece2d859	224	p->next = NULL;
mbed714	0:d616ece2d859	225
mbed714	0:d616ece2d859	226	/* make the payload pointer point 'offset' bytes into pbuf data memory */
mbed714	0:d616ece2d859	227	p->payload = LWIP_MEM_ALIGN((void )((u8_t )p + (SIZEOF_STRUCT_PBUF + offset)));
mbed714	0:d616ece2d859	228	LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned",
mbed714	0:d616ece2d859	229	((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
mbed714	0:d616ece2d859	230	/* the total length of the pbuf chain is the requested size */
mbed714	0:d616ece2d859	231	p->tot_len = length;
mbed714	0:d616ece2d859	232	/* set the length of the first pbuf in the chain */
mbed714	0:d616ece2d859	233	p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
mbed714	0:d616ece2d859	234	LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
mbed714	0:d616ece2d859	235	((u8_t*)p->payload + p->len <=
mbed714	0:d616ece2d859	236	(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
mbed714	0:d616ece2d859	237	LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT",
mbed714	0:d616ece2d859	238	(PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 );
mbed714	0:d616ece2d859	239	/* set reference count (needed here in case we fail) */
mbed714	0:d616ece2d859	240	p->ref = 1;
mbed714	0:d616ece2d859	241
mbed714	0:d616ece2d859	242	/* now allocate the tail of the pbuf chain */
mbed714	0:d616ece2d859	243
mbed714	0:d616ece2d859	244	/* remember first pbuf for linkage in next iteration */
mbed714	0:d616ece2d859	245	r = p;
mbed714	0:d616ece2d859	246	/* remaining length to be allocated */
mbed714	0:d616ece2d859	247	rem_len = length - p->len;
mbed714	0:d616ece2d859	248	/* any remaining pbufs to be allocated? */
mbed714	0:d616ece2d859	249	while (rem_len > 0) {
mbed714	0:d616ece2d859	250	q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
mbed714	0:d616ece2d859	251	if (q == NULL) {
mbed714	0:d616ece2d859	252	PBUF_POOL_IS_EMPTY();
mbed714	0:d616ece2d859	253	/* free chain so far allocated */
mbed714	0:d616ece2d859	254	pbuf_free(p);
mbed714	0:d616ece2d859	255	/* bail out unsuccesfully */
mbed714	0:d616ece2d859	256	return NULL;
mbed714	0:d616ece2d859	257	}
mbed714	0:d616ece2d859	258	q->type = type;
mbed714	0:d616ece2d859	259	q->flags = 0;
mbed714	0:d616ece2d859	260	q->next = NULL;
mbed714	0:d616ece2d859	261	/* make previous pbuf point to this pbuf */
mbed714	0:d616ece2d859	262	r->next = q;
mbed714	0:d616ece2d859	263	/* set total length of this pbuf and next in chain */
mbed714	0:d616ece2d859	264	LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff);
mbed714	0:d616ece2d859	265	q->tot_len = (u16_t)rem_len;
mbed714	0:d616ece2d859	266	/* this pbuf length is pool size, unless smaller sized tail */
mbed714	0:d616ece2d859	267	q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
mbed714	0:d616ece2d859	268	q->payload = (void )((u8_t )q + SIZEOF_STRUCT_PBUF);
mbed714	0:d616ece2d859	269	LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
mbed714	0:d616ece2d859	270	((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
mbed714	0:d616ece2d859	271	LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
mbed714	0:d616ece2d859	272	((u8_t*)p->payload + p->len <=
mbed714	0:d616ece2d859	273	(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
mbed714	0:d616ece2d859	274	q->ref = 1;
mbed714	0:d616ece2d859	275	/* calculate remaining length to be allocated */
mbed714	0:d616ece2d859	276	rem_len -= q->len;
mbed714	0:d616ece2d859	277	/* remember this pbuf for linkage in next iteration */
mbed714	0:d616ece2d859	278	r = q;
mbed714	0:d616ece2d859	279	}
mbed714	0:d616ece2d859	280	/* end of chain */
mbed714	0:d616ece2d859	281	/r->next = NULL;/
mbed714	0:d616ece2d859	282
mbed714	0:d616ece2d859	283	break;
mbed714	0:d616ece2d859	284	case PBUF_RAM:
mbed714	0:d616ece2d859	285	/* If pbuf is to be allocated in RAM, allocate memory for it. */
mbed714	0:d616ece2d859	286	p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
mbed714	0:d616ece2d859	287	if (p == NULL) {
mbed714	0:d616ece2d859	288	return NULL;
mbed714	0:d616ece2d859	289	}
mbed714	0:d616ece2d859	290	/* Set up internal structure of the pbuf. */
mbed714	0:d616ece2d859	291	p->payload = LWIP_MEM_ALIGN((void )((u8_t )p + SIZEOF_STRUCT_PBUF + offset));
mbed714	0:d616ece2d859	292	p->len = p->tot_len = length;
mbed714	0:d616ece2d859	293	p->next = NULL;
mbed714	0:d616ece2d859	294	p->type = type;
mbed714	0:d616ece2d859	295
mbed714	0:d616ece2d859	296	LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
mbed714	0:d616ece2d859	297	((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
mbed714	0:d616ece2d859	298	break;
mbed714	0:d616ece2d859	299	/* pbuf references existing (non-volatile static constant) ROM payload? */
mbed714	0:d616ece2d859	300	case PBUF_ROM:
mbed714	0:d616ece2d859	301	/* pbuf references existing (externally allocated) RAM payload? */
mbed714	0:d616ece2d859	302	case PBUF_REF:
mbed714	0:d616ece2d859	303	/* only allocate memory for the pbuf structure */
mbed714	0:d616ece2d859	304	p = (struct pbuf *)memp_malloc(MEMP_PBUF);
mbed714	0:d616ece2d859	305	if (p == NULL) {
mbed714	0:d616ece2d859	306	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
mbed714	0:d616ece2d859	307	("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n",
mbed714	0:d616ece2d859	308	(type == PBUF_ROM) ? "ROM" : "REF"));
mbed714	0:d616ece2d859	309	return NULL;
mbed714	0:d616ece2d859	310	}
mbed714	0:d616ece2d859	311	/* caller must set this field properly, afterwards */
mbed714	0:d616ece2d859	312	p->payload = NULL;
mbed714	0:d616ece2d859	313	p->len = p->tot_len = length;
mbed714	0:d616ece2d859	314	p->next = NULL;
mbed714	0:d616ece2d859	315	p->type = type;
mbed714	0:d616ece2d859	316	break;
mbed714	0:d616ece2d859	317	default:
mbed714	0:d616ece2d859	318	LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
mbed714	0:d616ece2d859	319	return NULL;
mbed714	0:d616ece2d859	320	}
mbed714	0:d616ece2d859	321	/* set reference count */
mbed714	0:d616ece2d859	322	p->ref = 1;
mbed714	0:d616ece2d859	323	/* set flags */
mbed714	0:d616ece2d859	324	p->flags = 0;
mbed714	0:d616ece2d859	325	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
mbed714	0:d616ece2d859	326	return p;
mbed714	0:d616ece2d859	327	}
mbed714	0:d616ece2d859	328
mbed714	0:d616ece2d859	329	#if LWIP_SUPPORT_CUSTOM_PBUF
mbed714	0:d616ece2d859	330	/** Initialize a custom pbuf (already allocated).
mbed714	0:d616ece2d859	331	*
mbed714	0:d616ece2d859	332	* @param layer flag to define header size
mbed714	0:d616ece2d859	333	* @param length size of the pbuf's payload
mbed714	0:d616ece2d859	334	* @param type type of the pbuf (only used to treat the pbuf accordingly, as
mbed714	0:d616ece2d859	335	* this function allocates no memory)
mbed714	0:d616ece2d859	336	* @param p pointer to the custom pbuf to initialize (already allocated)
mbed714	0:d616ece2d859	337	* @param payload_mem pointer to the buffer that is used for payload and headers,
mbed714	0:d616ece2d859	338	* must be at least big enough to hold 'length' plus the header size,
mbed714	0:d616ece2d859	339	* may be NULL if set later
mbed714	0:d616ece2d859	340	* @param payload_mem_len the size of the 'payload_mem' buffer, must be at least
mbed714	0:d616ece2d859	341	* big enough to hold 'length' plus the header size
mbed714	0:d616ece2d859	342	*/
mbed714	0:d616ece2d859	343	struct pbuf*
mbed714	0:d616ece2d859	344	pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type, struct pbuf_custom *p,
mbed714	0:d616ece2d859	345	void *payload_mem, u16_t payload_mem_len)
mbed714	0:d616ece2d859	346	{
mbed714	0:d616ece2d859	347	u16_t offset;
mbed714	0:d616ece2d859	348	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloced_custom(length=%"U16_F")\n", length));
mbed714	0:d616ece2d859	349
mbed714	0:d616ece2d859	350	/* determine header offset */
mbed714	0:d616ece2d859	351	offset = 0;
mbed714	0:d616ece2d859	352	switch (l) {
mbed714	0:d616ece2d859	353	case PBUF_TRANSPORT:
mbed714	0:d616ece2d859	354	/* add room for transport (often TCP) layer header */
mbed714	0:d616ece2d859	355	offset += PBUF_TRANSPORT_HLEN;
mbed714	0:d616ece2d859	356	/* FALLTHROUGH */
mbed714	0:d616ece2d859	357	case PBUF_IP:
mbed714	0:d616ece2d859	358	/* add room for IP layer header */
mbed714	0:d616ece2d859	359	offset += PBUF_IP_HLEN;
mbed714	0:d616ece2d859	360	/* FALLTHROUGH */
mbed714	0:d616ece2d859	361	case PBUF_LINK:
mbed714	0:d616ece2d859	362	/* add room for link layer header */
mbed714	0:d616ece2d859	363	offset += PBUF_LINK_HLEN;
mbed714	0:d616ece2d859	364	break;
mbed714	0:d616ece2d859	365	case PBUF_RAW:
mbed714	0:d616ece2d859	366	break;
mbed714	0:d616ece2d859	367	default:
mbed714	0:d616ece2d859	368	LWIP_ASSERT("pbuf_alloced_custom: bad pbuf layer", 0);
mbed714	0:d616ece2d859	369	return NULL;
mbed714	0:d616ece2d859	370	}
mbed714	0:d616ece2d859	371
mbed714	0:d616ece2d859	372	if (LWIP_MEM_ALIGN_SIZE(offset) + length < payload_mem_len) {
mbed714	0:d616ece2d859	373	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_WARNING, ("pbuf_alloced_custom(length=%"U16_F") buffer too short\n", length));
mbed714	0:d616ece2d859	374	return NULL;
mbed714	0:d616ece2d859	375	}
mbed714	0:d616ece2d859	376
mbed714	0:d616ece2d859	377	p->pbuf.next = NULL;
mbed714	0:d616ece2d859	378	if (payload_mem != NULL) {
mbed714	0:d616ece2d859	379	p->pbuf.payload = LWIP_MEM_ALIGN((void )((u8_t )payload_mem + offset));
mbed714	0:d616ece2d859	380	} else {
mbed714	0:d616ece2d859	381	p->pbuf.payload = NULL;
mbed714	0:d616ece2d859	382	}
mbed714	0:d616ece2d859	383	p->pbuf.flags = PBUF_FLAG_IS_CUSTOM;
mbed714	0:d616ece2d859	384	p->pbuf.len = p->pbuf.tot_len = length;
mbed714	0:d616ece2d859	385	p->pbuf.type = type;
mbed714	0:d616ece2d859	386	p->pbuf.ref = 1;
mbed714	0:d616ece2d859	387	return &p->pbuf;
mbed714	0:d616ece2d859	388	}
mbed714	0:d616ece2d859	389	#endif /* LWIP_SUPPORT_CUSTOM_PBUF */
mbed714	0:d616ece2d859	390
mbed714	0:d616ece2d859	391	/**
mbed714	0:d616ece2d859	392	* Shrink a pbuf chain to a desired length.
mbed714	0:d616ece2d859	393	*
mbed714	0:d616ece2d859	394	* @param p pbuf to shrink.
mbed714	0:d616ece2d859	395	* @param new_len desired new length of pbuf chain
mbed714	0:d616ece2d859	396	*
mbed714	0:d616ece2d859	397	* Depending on the desired length, the first few pbufs in a chain might
mbed714	0:d616ece2d859	398	* be skipped and left unchanged. The new last pbuf in the chain will be
mbed714	0:d616ece2d859	399	* resized, and any remaining pbufs will be freed.
mbed714	0:d616ece2d859	400	*
mbed714	0:d616ece2d859	401	* @note If the pbuf is ROM/REF, only the ->tot_len and ->len fields are adjusted.
mbed714	0:d616ece2d859	402	* @note May not be called on a packet queue.
mbed714	0:d616ece2d859	403	*
mbed714	0:d616ece2d859	404	* @note Despite its name, pbuf_realloc cannot grow the size of a pbuf (chain).
mbed714	0:d616ece2d859	405	*/
mbed714	0:d616ece2d859	406	void
mbed714	0:d616ece2d859	407	pbuf_realloc(struct pbuf *p, u16_t new_len)
mbed714	0:d616ece2d859	408	{
mbed714	0:d616ece2d859	409	struct pbuf *q;
mbed714	0:d616ece2d859	410	u16_t rem_len; /* remaining length */
mbed714	0:d616ece2d859	411	s32_t grow;
mbed714	0:d616ece2d859	412
mbed714	0:d616ece2d859	413	LWIP_ASSERT("pbuf_realloc: p != NULL", p != NULL);
mbed714	0:d616ece2d859	414	LWIP_ASSERT("pbuf_realloc: sane p->type", p->type == PBUF_POOL \|\|
mbed714	0:d616ece2d859	415	p->type == PBUF_ROM \|\|
mbed714	0:d616ece2d859	416	p->type == PBUF_RAM \|\|
mbed714	0:d616ece2d859	417	p->type == PBUF_REF);
mbed714	0:d616ece2d859	418
mbed714	0:d616ece2d859	419	/* desired length larger than current length? */
mbed714	0:d616ece2d859	420	if (new_len >= p->tot_len) {
mbed714	0:d616ece2d859	421	/* enlarging not yet supported */
mbed714	0:d616ece2d859	422	return;
mbed714	0:d616ece2d859	423	}
mbed714	0:d616ece2d859	424
mbed714	0:d616ece2d859	425	/* the pbuf chain grows by (new_len - p->tot_len) bytes
mbed714	0:d616ece2d859	426	* (which may be negative in case of shrinking) */
mbed714	0:d616ece2d859	427	grow = new_len - p->tot_len;
mbed714	0:d616ece2d859	428
mbed714	0:d616ece2d859	429	/* first, step over any pbufs that should remain in the chain */
mbed714	0:d616ece2d859	430	rem_len = new_len;
mbed714	0:d616ece2d859	431	q = p;
mbed714	0:d616ece2d859	432	/* should this pbuf be kept? */
mbed714	0:d616ece2d859	433	while (rem_len > q->len) {
mbed714	0:d616ece2d859	434	/* decrease remaining length by pbuf length */
mbed714	0:d616ece2d859	435	rem_len -= q->len;
mbed714	0:d616ece2d859	436	/* decrease total length indicator */
mbed714	0:d616ece2d859	437	LWIP_ASSERT("grow < max_u16_t", grow < 0xffff);
mbed714	0:d616ece2d859	438	q->tot_len += (u16_t)grow;
mbed714	0:d616ece2d859	439	/* proceed to next pbuf in chain */
mbed714	0:d616ece2d859	440	q = q->next;
mbed714	0:d616ece2d859	441	LWIP_ASSERT("pbuf_realloc: q != NULL", q != NULL);
mbed714	0:d616ece2d859	442	}
mbed714	0:d616ece2d859	443	/* we have now reached the new last pbuf (in q) */
mbed714	0:d616ece2d859	444	/* rem_len == desired length for pbuf q */
mbed714	0:d616ece2d859	445
mbed714	0:d616ece2d859	446	/* shrink allocated memory for PBUF_RAM */
mbed714	0:d616ece2d859	447	/* (other types merely adjust their length fields */
mbed714	0:d616ece2d859	448	if ((q->type == PBUF_RAM) && (rem_len != q->len)) {
mbed714	0:d616ece2d859	449	/* reallocate and adjust the length of the pbuf that will be split */
mbed714	0:d616ece2d859	450	q = (struct pbuf )mem_trim(q, (u16_t)((u8_t )q->payload - (u8_t *)q) + rem_len);
mbed714	0:d616ece2d859	451	LWIP_ASSERT("mem_trim returned q == NULL", q != NULL);
mbed714	0:d616ece2d859	452	}
mbed714	0:d616ece2d859	453	/* adjust length fields for new last pbuf */
mbed714	0:d616ece2d859	454	q->len = rem_len;
mbed714	0:d616ece2d859	455	q->tot_len = q->len;
mbed714	0:d616ece2d859	456
mbed714	0:d616ece2d859	457	/* any remaining pbufs in chain? */
mbed714	0:d616ece2d859	458	if (q->next != NULL) {
mbed714	0:d616ece2d859	459	/* free remaining pbufs in chain */
mbed714	0:d616ece2d859	460	pbuf_free(q->next);
mbed714	0:d616ece2d859	461	}
mbed714	0:d616ece2d859	462	/* q is last packet in chain */
mbed714	0:d616ece2d859	463	q->next = NULL;
mbed714	0:d616ece2d859	464
mbed714	0:d616ece2d859	465	}
mbed714	0:d616ece2d859	466
mbed714	0:d616ece2d859	467	/**
mbed714	0:d616ece2d859	468	* Adjusts the payload pointer to hide or reveal headers in the payload.
mbed714	0:d616ece2d859	469	*
mbed714	0:d616ece2d859	470	* Adjusts the ->payload pointer so that space for a header
mbed714	0:d616ece2d859	471	* (dis)appears in the pbuf payload.
mbed714	0:d616ece2d859	472	*
mbed714	0:d616ece2d859	473	* The ->payload, ->tot_len and ->len fields are adjusted.
mbed714	0:d616ece2d859	474	*
mbed714	0:d616ece2d859	475	* @param p pbuf to change the header size.
mbed714	0:d616ece2d859	476	* @param header_size_increment Number of bytes to increment header size which
mbed714	0:d616ece2d859	477	* increases the size of the pbuf. New space is on the front.
mbed714	0:d616ece2d859	478	* (Using a negative value decreases the header size.)
mbed714	0:d616ece2d859	479	* If hdr_size_inc is 0, this function does nothing and returns succesful.
mbed714	0:d616ece2d859	480	*
mbed714	0:d616ece2d859	481	* PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so
mbed714	0:d616ece2d859	482	* the call will fail. A check is made that the increase in header size does
mbed714	0:d616ece2d859	483	* not move the payload pointer in front of the start of the buffer.
mbed714	0:d616ece2d859	484	* @return non-zero on failure, zero on success.
mbed714	0:d616ece2d859	485	*
mbed714	0:d616ece2d859	486	*/
mbed714	0:d616ece2d859	487	u8_t
mbed714	0:d616ece2d859	488	pbuf_header(struct pbuf *p, s16_t header_size_increment)
mbed714	0:d616ece2d859	489	{
mbed714	0:d616ece2d859	490	u16_t type;
mbed714	0:d616ece2d859	491	void *payload;
mbed714	0:d616ece2d859	492	u16_t increment_magnitude;
mbed714	0:d616ece2d859	493
mbed714	0:d616ece2d859	494	LWIP_ASSERT("p != NULL", p != NULL);
mbed714	0:d616ece2d859	495	if ((header_size_increment == 0) \|\| (p == NULL)) {
mbed714	0:d616ece2d859	496	return 0;
mbed714	0:d616ece2d859	497	}
mbed714	0:d616ece2d859	498
mbed714	0:d616ece2d859	499	if (header_size_increment < 0){
mbed714	0:d616ece2d859	500	increment_magnitude = -header_size_increment;
mbed714	0:d616ece2d859	501	/* Check that we aren't going to move off the end of the pbuf */
mbed714	0:d616ece2d859	502	LWIP_ERROR("increment_magnitude <= p->len", (increment_magnitude <= p->len), return 1;);
mbed714	0:d616ece2d859	503	} else {
mbed714	0:d616ece2d859	504	increment_magnitude = header_size_increment;
mbed714	0:d616ece2d859	505	#if 0
mbed714	0:d616ece2d859	506	/* Can't assert these as some callers speculatively call
mbed714	0:d616ece2d859	507	pbuf_header() to see if it's OK. Will return 1 below instead. */
mbed714	0:d616ece2d859	508	/* Check that we've got the correct type of pbuf to work with */
mbed714	0:d616ece2d859	509	LWIP_ASSERT("p->type == PBUF_RAM \|\| p->type == PBUF_POOL",
mbed714	0:d616ece2d859	510	p->type == PBUF_RAM \|\| p->type == PBUF_POOL);
mbed714	0:d616ece2d859	511	/* Check that we aren't going to move off the beginning of the pbuf */
mbed714	0:d616ece2d859	512	LWIP_ASSERT("p->payload - increment_magnitude >= p + SIZEOF_STRUCT_PBUF",
mbed714	0:d616ece2d859	513	(u8_t )p->payload - increment_magnitude >= (u8_t )p + SIZEOF_STRUCT_PBUF);
mbed714	0:d616ece2d859	514	#endif
mbed714	0:d616ece2d859	515	}
mbed714	0:d616ece2d859	516
mbed714	0:d616ece2d859	517	type = p->type;
mbed714	0:d616ece2d859	518	/* remember current payload pointer */
mbed714	0:d616ece2d859	519	payload = p->payload;
mbed714	0:d616ece2d859	520
mbed714	0:d616ece2d859	521	/* pbuf types containing payloads? */
mbed714	0:d616ece2d859	522	if (type == PBUF_RAM \|\| type == PBUF_POOL) {
mbed714	0:d616ece2d859	523	/* set new payload pointer */
mbed714	0:d616ece2d859	524	p->payload = (u8_t *)p->payload - header_size_increment;
mbed714	0:d616ece2d859	525	/* boundary check fails? */
mbed714	0:d616ece2d859	526	if ((u8_t )p->payload < (u8_t )p + SIZEOF_STRUCT_PBUF) {
mbed714	0:d616ece2d859	527	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
mbed714	0:d616ece2d859	528	("pbuf_header: failed as %p < %p (not enough space for new header size)\n",
mbed714	0:d616ece2d859	529	(void )p->payload, (void )(p + 1)));
mbed714	0:d616ece2d859	530	/* restore old payload pointer */
mbed714	0:d616ece2d859	531	p->payload = payload;
mbed714	0:d616ece2d859	532	/* bail out unsuccesfully */
mbed714	0:d616ece2d859	533	return 1;
mbed714	0:d616ece2d859	534	}
mbed714	0:d616ece2d859	535	/* pbuf types refering to external payloads? */
mbed714	0:d616ece2d859	536	} else if (type == PBUF_REF \|\| type == PBUF_ROM) {
mbed714	0:d616ece2d859	537	/* hide a header in the payload? */
mbed714	0:d616ece2d859	538	if ((header_size_increment < 0) && (increment_magnitude <= p->len)) {
mbed714	0:d616ece2d859	539	/* increase payload pointer */
mbed714	0:d616ece2d859	540	p->payload = (u8_t *)p->payload - header_size_increment;
mbed714	0:d616ece2d859	541	} else {
mbed714	0:d616ece2d859	542	/* cannot expand payload to front (yet!)
mbed714	0:d616ece2d859	543	* bail out unsuccesfully */
mbed714	0:d616ece2d859	544	return 1;
mbed714	0:d616ece2d859	545	}
mbed714	0:d616ece2d859	546	} else {
mbed714	0:d616ece2d859	547	/* Unknown type */
mbed714	0:d616ece2d859	548	LWIP_ASSERT("bad pbuf type", 0);
mbed714	0:d616ece2d859	549	return 1;
mbed714	0:d616ece2d859	550	}
mbed714	0:d616ece2d859	551	/* modify pbuf length fields */
mbed714	0:d616ece2d859	552	p->len += header_size_increment;
mbed714	0:d616ece2d859	553	p->tot_len += header_size_increment;
mbed714	0:d616ece2d859	554
mbed714	0:d616ece2d859	555	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_header: old %p new %p (%"S16_F")\n",
mbed714	0:d616ece2d859	556	(void )payload, (void )p->payload, header_size_increment));
mbed714	0:d616ece2d859	557
mbed714	0:d616ece2d859	558	return 0;
mbed714	0:d616ece2d859	559	}
mbed714	0:d616ece2d859	560
mbed714	0:d616ece2d859	561	/**
mbed714	0:d616ece2d859	562	* Dereference a pbuf chain or queue and deallocate any no-longer-used
mbed714	0:d616ece2d859	563	* pbufs at the head of this chain or queue.
mbed714	0:d616ece2d859	564	*
mbed714	0:d616ece2d859	565	* Decrements the pbuf reference count. If it reaches zero, the pbuf is
mbed714	0:d616ece2d859	566	* deallocated.
mbed714	0:d616ece2d859	567	*
mbed714	0:d616ece2d859	568	* For a pbuf chain, this is repeated for each pbuf in the chain,
mbed714	0:d616ece2d859	569	* up to the first pbuf which has a non-zero reference count after
mbed714	0:d616ece2d859	570	* decrementing. So, when all reference counts are one, the whole
mbed714	0:d616ece2d859	571	* chain is free'd.
mbed714	0:d616ece2d859	572	*
mbed714	0:d616ece2d859	573	* @param p The pbuf (chain) to be dereferenced.
mbed714	0:d616ece2d859	574	*
mbed714	0:d616ece2d859	575	* @return the number of pbufs that were de-allocated
mbed714	0:d616ece2d859	576	* from the head of the chain.
mbed714	0:d616ece2d859	577	*
mbed714	0:d616ece2d859	578	* @note MUST NOT be called on a packet queue (Not verified to work yet).
mbed714	0:d616ece2d859	579	* @note the reference counter of a pbuf equals the number of pointers
mbed714	0:d616ece2d859	580	* that refer to the pbuf (or into the pbuf).
mbed714	0:d616ece2d859	581	*
mbed714	0:d616ece2d859	582	* @internal examples:
mbed714	0:d616ece2d859	583	*
mbed714	0:d616ece2d859	584	* Assuming existing chains a->b->c with the following reference
mbed714	0:d616ece2d859	585	* counts, calling pbuf_free(a) results in:
mbed714	0:d616ece2d859	586	*
mbed714	0:d616ece2d859	587	* 1->2->3 becomes ...1->3
mbed714	0:d616ece2d859	588	* 3->3->3 becomes 2->3->3
mbed714	0:d616ece2d859	589	* 1->1->2 becomes ......1
mbed714	0:d616ece2d859	590	* 2->1->1 becomes 1->1->1
mbed714	0:d616ece2d859	591	* 1->1->1 becomes .......
mbed714	0:d616ece2d859	592	*
mbed714	0:d616ece2d859	593	*/
mbed714	0:d616ece2d859	594	u8_t
mbed714	0:d616ece2d859	595	pbuf_free(struct pbuf *p)
mbed714	0:d616ece2d859	596	{
mbed714	0:d616ece2d859	597	u16_t type;
mbed714	0:d616ece2d859	598	struct pbuf *q;
mbed714	0:d616ece2d859	599	u8_t count;
mbed714	0:d616ece2d859	600
mbed714	0:d616ece2d859	601	if (p == NULL) {
mbed714	0:d616ece2d859	602	LWIP_ASSERT("p != NULL", p != NULL);
mbed714	0:d616ece2d859	603	/* if assertions are disabled, proceed with debug output */
mbed714	0:d616ece2d859	604	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
mbed714	0:d616ece2d859	605	("pbuf_free(p == NULL) was called.\n"));
mbed714	0:d616ece2d859	606	return 0;
mbed714	0:d616ece2d859	607	}
mbed714	0:d616ece2d859	608	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free(%p)\n", (void *)p));
mbed714	0:d616ece2d859	609
mbed714	0:d616ece2d859	610	PERF_START;
mbed714	0:d616ece2d859	611
mbed714	0:d616ece2d859	612	LWIP_ASSERT("pbuf_free: sane type",
mbed714	0:d616ece2d859	613	p->type == PBUF_RAM \|\| p->type == PBUF_ROM \|\|
mbed714	0:d616ece2d859	614	p->type == PBUF_REF \|\| p->type == PBUF_POOL);
mbed714	0:d616ece2d859	615
mbed714	0:d616ece2d859	616	count = 0;
mbed714	0:d616ece2d859	617	/* de-allocate all consecutive pbufs from the head of the chain that
mbed714	0:d616ece2d859	618	* obtain a zero reference count after decrementing*/
mbed714	0:d616ece2d859	619	while (p != NULL) {
mbed714	0:d616ece2d859	620	u16_t ref;
mbed714	0:d616ece2d859	621	SYS_ARCH_DECL_PROTECT(old_level);
mbed714	0:d616ece2d859	622	/* Since decrementing ref cannot be guaranteed to be a single machine operation
mbed714	0:d616ece2d859	623	* we must protect it. We put the new ref into a local variable to prevent
mbed714	0:d616ece2d859	624	* further protection. */
mbed714	0:d616ece2d859	625	SYS_ARCH_PROTECT(old_level);
mbed714	0:d616ece2d859	626	/* all pbufs in a chain are referenced at least once */
mbed714	0:d616ece2d859	627	LWIP_ASSERT("pbuf_free: p->ref > 0", p->ref > 0);
mbed714	0:d616ece2d859	628	/* decrease reference count (number of pointers to pbuf) */
mbed714	0:d616ece2d859	629	ref = --(p->ref);
mbed714	0:d616ece2d859	630	SYS_ARCH_UNPROTECT(old_level);
mbed714	0:d616ece2d859	631	/* this pbuf is no longer referenced to? */
mbed714	0:d616ece2d859	632	if (ref == 0) {
mbed714	0:d616ece2d859	633	/* remember next pbuf in chain for next iteration */
mbed714	0:d616ece2d859	634	q = p->next;
mbed714	0:d616ece2d859	635	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free: deallocating %p\n", (void *)p));
mbed714	0:d616ece2d859	636	type = p->type;
mbed714	0:d616ece2d859	637	#if LWIP_SUPPORT_CUSTOM_PBUF
mbed714	0:d616ece2d859	638	/* is this a custom pbuf? */
mbed714	0:d616ece2d859	639	if ((p->flags & PBUF_FLAG_IS_CUSTOM) != 0) {
mbed714	0:d616ece2d859	640	struct pbuf_custom pc = (struct pbuf_custom)p;
mbed714	0:d616ece2d859	641	LWIP_ASSERT("pc->custom_free_function != NULL", pc->custom_free_function != NULL);
mbed714	0:d616ece2d859	642	pc->custom_free_function(p);
mbed714	0:d616ece2d859	643	} else
mbed714	0:d616ece2d859	644	#endif /* LWIP_SUPPORT_CUSTOM_PBUF */
mbed714	0:d616ece2d859	645	{
mbed714	0:d616ece2d859	646	/* is this a pbuf from the pool? */
mbed714	0:d616ece2d859	647	if (type == PBUF_POOL) {
mbed714	0:d616ece2d859	648	memp_free(MEMP_PBUF_POOL, p);
mbed714	0:d616ece2d859	649	/* is this a ROM or RAM referencing pbuf? */
mbed714	0:d616ece2d859	650	} else if (type == PBUF_ROM \|\| type == PBUF_REF) {
mbed714	0:d616ece2d859	651	memp_free(MEMP_PBUF, p);
mbed714	0:d616ece2d859	652	/* type == PBUF_RAM */
mbed714	0:d616ece2d859	653	} else {
mbed714	0:d616ece2d859	654	mem_free(p);
mbed714	0:d616ece2d859	655	}
mbed714	0:d616ece2d859	656	}
mbed714	0:d616ece2d859	657	count++;
mbed714	0:d616ece2d859	658	/* proceed to next pbuf */
mbed714	0:d616ece2d859	659	p = q;
mbed714	0:d616ece2d859	660	/* p->ref > 0, this pbuf is still referenced to */
mbed714	0:d616ece2d859	661	/* (and so the remaining pbufs in chain as well) */
mbed714	0:d616ece2d859	662	} else {
mbed714	0:d616ece2d859	663	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref));
mbed714	0:d616ece2d859	664	/* stop walking through the chain */
mbed714	0:d616ece2d859	665	p = NULL;
mbed714	0:d616ece2d859	666	}
mbed714	0:d616ece2d859	667	}
mbed714	0:d616ece2d859	668	PERF_STOP("pbuf_free");
mbed714	0:d616ece2d859	669	/* return number of de-allocated pbufs */
mbed714	0:d616ece2d859	670	return count;
mbed714	0:d616ece2d859	671	}
mbed714	0:d616ece2d859	672
mbed714	0:d616ece2d859	673	/**
mbed714	0:d616ece2d859	674	* Count number of pbufs in a chain
mbed714	0:d616ece2d859	675	*
mbed714	0:d616ece2d859	676	* @param p first pbuf of chain
mbed714	0:d616ece2d859	677	* @return the number of pbufs in a chain
mbed714	0:d616ece2d859	678	*/
mbed714	0:d616ece2d859	679
mbed714	0:d616ece2d859	680	u8_t
mbed714	0:d616ece2d859	681	pbuf_clen(struct pbuf *p)
mbed714	0:d616ece2d859	682	{
mbed714	0:d616ece2d859	683	u8_t len;
mbed714	0:d616ece2d859	684
mbed714	0:d616ece2d859	685	len = 0;
mbed714	0:d616ece2d859	686	while (p != NULL) {
mbed714	0:d616ece2d859	687	++len;
mbed714	0:d616ece2d859	688	p = p->next;
mbed714	0:d616ece2d859	689	}
mbed714	0:d616ece2d859	690	return len;
mbed714	0:d616ece2d859	691	}
mbed714	0:d616ece2d859	692
mbed714	0:d616ece2d859	693	/**
mbed714	0:d616ece2d859	694	* Increment the reference count of the pbuf.
mbed714	0:d616ece2d859	695	*
mbed714	0:d616ece2d859	696	* @param p pbuf to increase reference counter of
mbed714	0:d616ece2d859	697	*
mbed714	0:d616ece2d859	698	*/
mbed714	0:d616ece2d859	699	void
mbed714	0:d616ece2d859	700	pbuf_ref(struct pbuf *p)
mbed714	0:d616ece2d859	701	{
mbed714	0:d616ece2d859	702	SYS_ARCH_DECL_PROTECT(old_level);
mbed714	0:d616ece2d859	703	/* pbuf given? */
mbed714	0:d616ece2d859	704	if (p != NULL) {
mbed714	0:d616ece2d859	705	SYS_ARCH_PROTECT(old_level);
mbed714	0:d616ece2d859	706	++(p->ref);
mbed714	0:d616ece2d859	707	SYS_ARCH_UNPROTECT(old_level);
mbed714	0:d616ece2d859	708	}
mbed714	0:d616ece2d859	709	}
mbed714	0:d616ece2d859	710
mbed714	0:d616ece2d859	711	/**
mbed714	0:d616ece2d859	712	* Concatenate two pbufs (each may be a pbuf chain) and take over
mbed714	0:d616ece2d859	713	* the caller's reference of the tail pbuf.
mbed714	0:d616ece2d859	714	*
mbed714	0:d616ece2d859	715	* @note The caller MAY NOT reference the tail pbuf afterwards.
mbed714	0:d616ece2d859	716	* Use pbuf_chain() for that purpose.
mbed714	0:d616ece2d859	717	*
mbed714	0:d616ece2d859	718	* @see pbuf_chain()
mbed714	0:d616ece2d859	719	*/
mbed714	0:d616ece2d859	720
mbed714	0:d616ece2d859	721	void
mbed714	0:d616ece2d859	722	pbuf_cat(struct pbuf h, struct pbuf t)
mbed714	0:d616ece2d859	723	{
mbed714	0:d616ece2d859	724	struct pbuf *p;
mbed714	0:d616ece2d859	725
mbed714	0:d616ece2d859	726	LWIP_ERROR("(h != NULL) && (t != NULL) (programmer violates API)",
mbed714	0:d616ece2d859	727	((h != NULL) && (t != NULL)), return;);
mbed714	0:d616ece2d859	728
mbed714	0:d616ece2d859	729	/* proceed to last pbuf of chain */
mbed714	0:d616ece2d859	730	for (p = h; p->next != NULL; p = p->next) {
mbed714	0:d616ece2d859	731	/* add total length of second chain to all totals of first chain */
mbed714	0:d616ece2d859	732	p->tot_len += t->tot_len;
mbed714	0:d616ece2d859	733	}
mbed714	0:d616ece2d859	734	/* { p is last pbuf of first h chain, p->next == NULL } */
mbed714	0:d616ece2d859	735	LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len);
mbed714	0:d616ece2d859	736	LWIP_ASSERT("p->next == NULL", p->next == NULL);
mbed714	0:d616ece2d859	737	/* add total length of second chain to last pbuf total of first chain */
mbed714	0:d616ece2d859	738	p->tot_len += t->tot_len;
mbed714	0:d616ece2d859	739	/* chain last pbuf of head (p) with first of tail (t) */
mbed714	0:d616ece2d859	740	p->next = t;
mbed714	0:d616ece2d859	741	/* p->next now references t, but the caller will drop its reference to t,
mbed714	0:d616ece2d859	742	* so netto there is no change to the reference count of t.
mbed714	0:d616ece2d859	743	*/
mbed714	0:d616ece2d859	744	}
mbed714	0:d616ece2d859	745
mbed714	0:d616ece2d859	746	/**
mbed714	0:d616ece2d859	747	* Chain two pbufs (or pbuf chains) together.
mbed714	0:d616ece2d859	748	*
mbed714	0:d616ece2d859	749	* The caller MUST call pbuf_free(t) once it has stopped
mbed714	0:d616ece2d859	750	* using it. Use pbuf_cat() instead if you no longer use t.
mbed714	0:d616ece2d859	751	*
mbed714	0:d616ece2d859	752	* @param h head pbuf (chain)
mbed714	0:d616ece2d859	753	* @param t tail pbuf (chain)
mbed714	0:d616ece2d859	754	* @note The pbufs MUST belong to the same packet.
mbed714	0:d616ece2d859	755	* @note MAY NOT be called on a packet queue.
mbed714	0:d616ece2d859	756	*
mbed714	0:d616ece2d859	757	* The ->tot_len fields of all pbufs of the head chain are adjusted.
mbed714	0:d616ece2d859	758	* The ->next field of the last pbuf of the head chain is adjusted.
mbed714	0:d616ece2d859	759	* The ->ref field of the first pbuf of the tail chain is adjusted.
mbed714	0:d616ece2d859	760	*
mbed714	0:d616ece2d859	761	*/
mbed714	0:d616ece2d859	762	void
mbed714	0:d616ece2d859	763	pbuf_chain(struct pbuf h, struct pbuf t)
mbed714	0:d616ece2d859	764	{
mbed714	0:d616ece2d859	765	pbuf_cat(h, t);
mbed714	0:d616ece2d859	766	/* t is now referenced by h */
mbed714	0:d616ece2d859	767	pbuf_ref(t);
mbed714	0:d616ece2d859	768	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_chain: %p references %p\n", (void )h, (void )t));
mbed714	0:d616ece2d859	769	}
mbed714	0:d616ece2d859	770
mbed714	0:d616ece2d859	771	/**
mbed714	0:d616ece2d859	772	* Dechains the first pbuf from its succeeding pbufs in the chain.
mbed714	0:d616ece2d859	773	*
mbed714	0:d616ece2d859	774	* Makes p->tot_len field equal to p->len.
mbed714	0:d616ece2d859	775	* @param p pbuf to dechain
mbed714	0:d616ece2d859	776	* @return remainder of the pbuf chain, or NULL if it was de-allocated.
mbed714	0:d616ece2d859	777	* @note May not be called on a packet queue.
mbed714	0:d616ece2d859	778	*/
mbed714	0:d616ece2d859	779	struct pbuf *
mbed714	0:d616ece2d859	780	pbuf_dechain(struct pbuf *p)
mbed714	0:d616ece2d859	781	{
mbed714	0:d616ece2d859	782	struct pbuf *q;
mbed714	0:d616ece2d859	783	u8_t tail_gone = 1;
mbed714	0:d616ece2d859	784	/* tail */
mbed714	0:d616ece2d859	785	q = p->next;
mbed714	0:d616ece2d859	786	/* pbuf has successor in chain? */
mbed714	0:d616ece2d859	787	if (q != NULL) {
mbed714	0:d616ece2d859	788	/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
mbed714	0:d616ece2d859	789	LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len);
mbed714	0:d616ece2d859	790	/* enforce invariant if assertion is disabled */
mbed714	0:d616ece2d859	791	q->tot_len = p->tot_len - p->len;
mbed714	0:d616ece2d859	792	/* decouple pbuf from remainder */
mbed714	0:d616ece2d859	793	p->next = NULL;
mbed714	0:d616ece2d859	794	/* total length of pbuf p is its own length only */
mbed714	0:d616ece2d859	795	p->tot_len = p->len;
mbed714	0:d616ece2d859	796	/* q is no longer referenced by p, free it */
mbed714	0:d616ece2d859	797	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_dechain: unreferencing %p\n", (void *)q));
mbed714	0:d616ece2d859	798	tail_gone = pbuf_free(q);
mbed714	0:d616ece2d859	799	if (tail_gone > 0) {
mbed714	0:d616ece2d859	800	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE,
mbed714	0:d616ece2d859	801	("pbuf_dechain: deallocated %p (as it is no longer referenced)\n", (void *)q));
mbed714	0:d616ece2d859	802	}
mbed714	0:d616ece2d859	803	/* return remaining tail or NULL if deallocated */
mbed714	0:d616ece2d859	804	}
mbed714	0:d616ece2d859	805	/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
mbed714	0:d616ece2d859	806	LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len);
mbed714	0:d616ece2d859	807	return ((tail_gone > 0) ? NULL : q);
mbed714	0:d616ece2d859	808	}
mbed714	0:d616ece2d859	809
mbed714	0:d616ece2d859	810	/**
mbed714	0:d616ece2d859	811	*
mbed714	0:d616ece2d859	812	* Create PBUF_RAM copies of pbufs.
mbed714	0:d616ece2d859	813	*
mbed714	0:d616ece2d859	814	* Used to queue packets on behalf of the lwIP stack, such as
mbed714	0:d616ece2d859	815	* ARP based queueing.
mbed714	0:d616ece2d859	816	*
mbed714	0:d616ece2d859	817	* @note You MUST explicitly use p = pbuf_take(p);
mbed714	0:d616ece2d859	818	*
mbed714	0:d616ece2d859	819	* @note Only one packet is copied, no packet queue!
mbed714	0:d616ece2d859	820	*
mbed714	0:d616ece2d859	821	* @param p_to pbuf destination of the copy
mbed714	0:d616ece2d859	822	* @param p_from pbuf source of the copy
mbed714	0:d616ece2d859	823	*
mbed714	0:d616ece2d859	824	* @return ERR_OK if pbuf was copied
mbed714	0:d616ece2d859	825	* ERR_ARG if one of the pbufs is NULL or p_to is not big
mbed714	0:d616ece2d859	826	* enough to hold p_from
mbed714	0:d616ece2d859	827	*/
mbed714	0:d616ece2d859	828	err_t
mbed714	0:d616ece2d859	829	pbuf_copy(struct pbuf p_to, struct pbuf p_from)
mbed714	0:d616ece2d859	830	{
mbed714	0:d616ece2d859	831	u16_t offset_to=0, offset_from=0, len;
mbed714	0:d616ece2d859	832
mbed714	0:d616ece2d859	833	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_copy(%p, %p)\n",
mbed714	0:d616ece2d859	834	(void)p_to, (void)p_from));
mbed714	0:d616ece2d859	835
mbed714	0:d616ece2d859	836	/* is the target big enough to hold the source? */
mbed714	0:d616ece2d859	837	LWIP_ERROR("pbuf_copy: target not big enough to hold source", ((p_to != NULL) &&
mbed714	0:d616ece2d859	838	(p_from != NULL) && (p_to->tot_len >= p_from->tot_len)), return ERR_ARG;);
mbed714	0:d616ece2d859	839
mbed714	0:d616ece2d859	840	/* iterate through pbuf chain */
mbed714	0:d616ece2d859	841	do
mbed714	0:d616ece2d859	842	{
mbed714	0:d616ece2d859	843	LWIP_ASSERT("p_to != NULL", p_to != NULL);
mbed714	0:d616ece2d859	844	/* copy one part of the original chain */
mbed714	0:d616ece2d859	845	if ((p_to->len - offset_to) >= (p_from->len - offset_from)) {
mbed714	0:d616ece2d859	846	/* complete current p_from fits into current p_to */
mbed714	0:d616ece2d859	847	len = p_from->len - offset_from;
mbed714	0:d616ece2d859	848	} else {
mbed714	0:d616ece2d859	849	/* current p_from does not fit into current p_to */
mbed714	0:d616ece2d859	850	len = p_to->len - offset_to;
mbed714	0:d616ece2d859	851	}
mbed714	0:d616ece2d859	852	MEMCPY((u8_t)p_to->payload + offset_to, (u8_t)p_from->payload + offset_from, len);
mbed714	0:d616ece2d859	853	offset_to += len;
mbed714	0:d616ece2d859	854	offset_from += len;
mbed714	0:d616ece2d859	855	LWIP_ASSERT("offset_to <= p_to->len", offset_to <= p_to->len);
mbed714	0:d616ece2d859	856	if (offset_to == p_to->len) {
mbed714	0:d616ece2d859	857	/* on to next p_to (if any) */
mbed714	0:d616ece2d859	858	offset_to = 0;
mbed714	0:d616ece2d859	859	p_to = p_to->next;
mbed714	0:d616ece2d859	860	}
mbed714	0:d616ece2d859	861	LWIP_ASSERT("offset_from <= p_from->len", offset_from <= p_from->len);
mbed714	0:d616ece2d859	862	if (offset_from >= p_from->len) {
mbed714	0:d616ece2d859	863	/* on to next p_from (if any) */
mbed714	0:d616ece2d859	864	offset_from = 0;
mbed714	0:d616ece2d859	865	p_from = p_from->next;
mbed714	0:d616ece2d859	866	}
mbed714	0:d616ece2d859	867
mbed714	0:d616ece2d859	868	if((p_from != NULL) && (p_from->len == p_from->tot_len)) {
mbed714	0:d616ece2d859	869	/* don't copy more than one packet! */
mbed714	0:d616ece2d859	870	LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
mbed714	0:d616ece2d859	871	(p_from->next == NULL), return ERR_VAL;);
mbed714	0:d616ece2d859	872	}
mbed714	0:d616ece2d859	873	if((p_to != NULL) && (p_to->len == p_to->tot_len)) {
mbed714	0:d616ece2d859	874	/* don't copy more than one packet! */
mbed714	0:d616ece2d859	875	LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
mbed714	0:d616ece2d859	876	(p_to->next == NULL), return ERR_VAL;);
mbed714	0:d616ece2d859	877	}
mbed714	0:d616ece2d859	878	} while (p_from);
mbed714	0:d616ece2d859	879	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_copy: end of chain reached.\n"));
mbed714	0:d616ece2d859	880	return ERR_OK;
mbed714	0:d616ece2d859	881	}
mbed714	0:d616ece2d859	882
mbed714	0:d616ece2d859	883	/**
mbed714	0:d616ece2d859	884	* Copy (part of) the contents of a packet buffer
mbed714	0:d616ece2d859	885	* to an application supplied buffer.
mbed714	0:d616ece2d859	886	*
mbed714	0:d616ece2d859	887	* @param buf the pbuf from which to copy data
mbed714	0:d616ece2d859	888	* @param dataptr the application supplied buffer
mbed714	0:d616ece2d859	889	* @param len length of data to copy (dataptr must be big enough). No more
mbed714	0:d616ece2d859	890	* than buf->tot_len will be copied, irrespective of len
mbed714	0:d616ece2d859	891	* @param offset offset into the packet buffer from where to begin copying len bytes
mbed714	0:d616ece2d859	892	* @return the number of bytes copied, or 0 on failure
mbed714	0:d616ece2d859	893	*/
mbed714	0:d616ece2d859	894	u16_t
mbed714	0:d616ece2d859	895	pbuf_copy_partial(struct pbuf buf, void dataptr, u16_t len, u16_t offset)
mbed714	0:d616ece2d859	896	{
mbed714	0:d616ece2d859	897	struct pbuf *p;
mbed714	0:d616ece2d859	898	u16_t left;
mbed714	0:d616ece2d859	899	u16_t buf_copy_len;
mbed714	0:d616ece2d859	900	u16_t copied_total = 0;
mbed714	0:d616ece2d859	901
mbed714	0:d616ece2d859	902	LWIP_ERROR("pbuf_copy_partial: invalid buf", (buf != NULL), return 0;);
mbed714	0:d616ece2d859	903	LWIP_ERROR("pbuf_copy_partial: invalid dataptr", (dataptr != NULL), return 0;);
mbed714	0:d616ece2d859	904
mbed714	0:d616ece2d859	905	left = 0;
mbed714	0:d616ece2d859	906
mbed714	0:d616ece2d859	907	if((buf == NULL) \|\| (dataptr == NULL)) {
mbed714	0:d616ece2d859	908	return 0;
mbed714	0:d616ece2d859	909	}
mbed714	0:d616ece2d859	910
mbed714	0:d616ece2d859	911	/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
mbed714	0:d616ece2d859	912	for(p = buf; len != 0 && p != NULL; p = p->next) {
mbed714	0:d616ece2d859	913	if ((offset != 0) && (offset >= p->len)) {
mbed714	0:d616ece2d859	914	/* don't copy from this buffer -> on to the next */
mbed714	0:d616ece2d859	915	offset -= p->len;
mbed714	0:d616ece2d859	916	} else {
mbed714	0:d616ece2d859	917	/* copy from this buffer. maybe only partially. */
mbed714	0:d616ece2d859	918	buf_copy_len = p->len - offset;
mbed714	0:d616ece2d859	919	if (buf_copy_len > len)
mbed714	0:d616ece2d859	920	buf_copy_len = len;
mbed714	0:d616ece2d859	921	/* copy the necessary parts of the buffer */
mbed714	0:d616ece2d859	922	MEMCPY(&((char)dataptr)[left], &((char)p->payload)[offset], buf_copy_len);
mbed714	0:d616ece2d859	923	copied_total += buf_copy_len;
mbed714	0:d616ece2d859	924	left += buf_copy_len;
mbed714	0:d616ece2d859	925	len -= buf_copy_len;
mbed714	0:d616ece2d859	926	offset = 0;
mbed714	0:d616ece2d859	927	}
mbed714	0:d616ece2d859	928	}
mbed714	0:d616ece2d859	929	return copied_total;
mbed714	0:d616ece2d859	930	}
mbed714	0:d616ece2d859	931
mbed714	0:d616ece2d859	932	/**
mbed714	0:d616ece2d859	933	* Copy application supplied data into a pbuf.
mbed714	0:d616ece2d859	934	* This function can only be used to copy the equivalent of buf->tot_len data.
mbed714	0:d616ece2d859	935	*
mbed714	0:d616ece2d859	936	* @param buf pbuf to fill with data
mbed714	0:d616ece2d859	937	* @param dataptr application supplied data buffer
mbed714	0:d616ece2d859	938	* @param len length of the application supplied data buffer
mbed714	0:d616ece2d859	939	*
mbed714	0:d616ece2d859	940	* @return ERR_OK if successful, ERR_MEM if the pbuf is not big enough
mbed714	0:d616ece2d859	941	*/
mbed714	0:d616ece2d859	942	err_t
mbed714	0:d616ece2d859	943	pbuf_take(struct pbuf buf, const void dataptr, u16_t len)
mbed714	0:d616ece2d859	944	{
mbed714	0:d616ece2d859	945	struct pbuf *p;
mbed714	0:d616ece2d859	946	u16_t buf_copy_len;
mbed714	0:d616ece2d859	947	u16_t total_copy_len = len;
mbed714	0:d616ece2d859	948	u16_t copied_total = 0;
mbed714	0:d616ece2d859	949
mbed714	0:d616ece2d859	950	LWIP_ERROR("pbuf_take: invalid buf", (buf != NULL), return 0;);
mbed714	0:d616ece2d859	951	LWIP_ERROR("pbuf_take: invalid dataptr", (dataptr != NULL), return 0;);
mbed714	0:d616ece2d859	952
mbed714	0:d616ece2d859	953	if ((buf == NULL) \|\| (dataptr == NULL) \|\| (buf->tot_len < len)) {
mbed714	0:d616ece2d859	954	return ERR_ARG;
mbed714	0:d616ece2d859	955	}
mbed714	0:d616ece2d859	956
mbed714	0:d616ece2d859	957	/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
mbed714	0:d616ece2d859	958	for(p = buf; total_copy_len != 0; p = p->next) {
mbed714	0:d616ece2d859	959	LWIP_ASSERT("pbuf_take: invalid pbuf", p != NULL);
mbed714	0:d616ece2d859	960	buf_copy_len = total_copy_len;
mbed714	0:d616ece2d859	961	if (buf_copy_len > p->len) {
mbed714	0:d616ece2d859	962	/* this pbuf cannot hold all remaining data */
mbed714	0:d616ece2d859	963	buf_copy_len = p->len;
mbed714	0:d616ece2d859	964	}
mbed714	0:d616ece2d859	965	/* copy the necessary parts of the buffer */
mbed714	0:d616ece2d859	966	MEMCPY(p->payload, &((char*)dataptr)[copied_total], buf_copy_len);
mbed714	0:d616ece2d859	967	total_copy_len -= buf_copy_len;
mbed714	0:d616ece2d859	968	copied_total += buf_copy_len;
mbed714	0:d616ece2d859	969	}
mbed714	0:d616ece2d859	970	LWIP_ASSERT("did not copy all data", total_copy_len == 0 && copied_total == len);
mbed714	0:d616ece2d859	971	return ERR_OK;
mbed714	0:d616ece2d859	972	}
mbed714	0:d616ece2d859	973
mbed714	0:d616ece2d859	974	/**
mbed714	0:d616ece2d859	975	* Creates a single pbuf out of a queue of pbufs.
mbed714	0:d616ece2d859	976	*
mbed714	0:d616ece2d859	977	* @remark: Either the source pbuf 'p' is freed by this function or the original
mbed714	0:d616ece2d859	978	* pbuf 'p' is returned, therefore the caller has to check the result!
mbed714	0:d616ece2d859	979	*
mbed714	0:d616ece2d859	980	* @param p the source pbuf
mbed714	0:d616ece2d859	981	* @param layer pbuf_layer of the new pbuf
mbed714	0:d616ece2d859	982	*
mbed714	0:d616ece2d859	983	* @return a new, single pbuf (p->next is NULL)
mbed714	0:d616ece2d859	984	* or the old pbuf if allocation fails
mbed714	0:d616ece2d859	985	*/
mbed714	0:d616ece2d859	986	struct pbuf*
mbed714	0:d616ece2d859	987	pbuf_coalesce(struct pbuf *p, pbuf_layer layer)
mbed714	0:d616ece2d859	988	{
mbed714	0:d616ece2d859	989	struct pbuf *q;
mbed714	0:d616ece2d859	990	err_t err;
mbed714	0:d616ece2d859	991	if (p->next == NULL) {
mbed714	0:d616ece2d859	992	return p;
mbed714	0:d616ece2d859	993	}
mbed714	0:d616ece2d859	994	q = pbuf_alloc(layer, p->tot_len, PBUF_RAM);
mbed714	0:d616ece2d859	995	if (q == NULL) {
mbed714	0:d616ece2d859	996	/* @todo: what do we do now? */
mbed714	0:d616ece2d859	997	return p;
mbed714	0:d616ece2d859	998	}
mbed714	0:d616ece2d859	999	err = pbuf_copy(q, p);
mbed714	0:d616ece2d859	1000	LWIP_ASSERT("pbuf_copy failed", err == ERR_OK);
mbed714	0:d616ece2d859	1001	pbuf_free(p);
mbed714	0:d616ece2d859	1002	return q;
mbed714	0:d616ece2d859	1003	}
mbed714	0:d616ece2d859	1004
mbed714	0:d616ece2d859	1005	#if LWIP_CHECKSUM_ON_COPY
mbed714	0:d616ece2d859	1006	/**
mbed714	0:d616ece2d859	1007	* Copies data into a single pbuf (not into a pbuf queue!) and updates
mbed714	0:d616ece2d859	1008	* the checksum while copying
mbed714	0:d616ece2d859	1009	*
mbed714	0:d616ece2d859	1010	* @param p the pbuf to copy data into
mbed714	0:d616ece2d859	1011	* @param start_offset offset of p->payload where to copy the data to
mbed714	0:d616ece2d859	1012	* @param dataptr data to copy into the pbuf
mbed714	0:d616ece2d859	1013	* @param len length of data to copy into the pbuf
mbed714	0:d616ece2d859	1014	* @param chksum pointer to the checksum which is updated
mbed714	0:d616ece2d859	1015	* @return ERR_OK if successful, another error if the data does not fit
mbed714	0:d616ece2d859	1016	* within the (first) pbuf (no pbuf queues!)
mbed714	0:d616ece2d859	1017	*/
mbed714	0:d616ece2d859	1018	err_t
mbed714	0:d616ece2d859	1019	pbuf_fill_chksum(struct pbuf p, u16_t start_offset, const void dataptr,
mbed714	0:d616ece2d859	1020	u16_t len, u16_t *chksum)
mbed714	0:d616ece2d859	1021	{
mbed714	0:d616ece2d859	1022	u32_t acc;
mbed714	0:d616ece2d859	1023	u16_t copy_chksum;
mbed714	0:d616ece2d859	1024	char *dst_ptr;
mbed714	0:d616ece2d859	1025	LWIP_ASSERT("p != NULL", p != NULL);
mbed714	0:d616ece2d859	1026	LWIP_ASSERT("dataptr != NULL", dataptr != NULL);
mbed714	0:d616ece2d859	1027	LWIP_ASSERT("chksum != NULL", chksum != NULL);
mbed714	0:d616ece2d859	1028	LWIP_ASSERT("len != 0", len != 0);
mbed714	0:d616ece2d859	1029
mbed714	0:d616ece2d859	1030	if ((start_offset >= p->len) \|\| (start_offset + len > p->len)) {
mbed714	0:d616ece2d859	1031	return ERR_ARG;
mbed714	0:d616ece2d859	1032	}
mbed714	0:d616ece2d859	1033
mbed714	0:d616ece2d859	1034	dst_ptr = ((char*)p->payload) + start_offset;
mbed714	0:d616ece2d859	1035	copy_chksum = LWIP_CHKSUM_COPY(dst_ptr, dataptr, len);
mbed714	0:d616ece2d859	1036	if ((start_offset & 1) != 0) {
mbed714	0:d616ece2d859	1037	copy_chksum = SWAP_BYTES_IN_WORD(copy_chksum);
mbed714	0:d616ece2d859	1038	}
mbed714	0:d616ece2d859	1039	acc = *chksum;
mbed714	0:d616ece2d859	1040	acc += copy_chksum;
mbed714	0:d616ece2d859	1041	*chksum = FOLD_U32T(acc);
mbed714	0:d616ece2d859	1042	return ERR_OK;
mbed714	0:d616ece2d859	1043	}
mbed714	0:d616ece2d859	1044	#endif /* LWIP_CHECKSUM_ON_COPY */
mbed714	0:d616ece2d859	1045
mbed714	0:d616ece2d859	1046	/** Get one byte from the specified position in a pbuf
mbed714	0:d616ece2d859	1047	* WARNING: returns zero for offset >= p->tot_len
mbed714	0:d616ece2d859	1048	*
mbed714	0:d616ece2d859	1049	* @param p pbuf to parse
mbed714	0:d616ece2d859	1050	* @param offset offset into p of the byte to return
mbed714	0:d616ece2d859	1051	* @return byte at an offset into p OR ZERO IF 'offset' >= p->tot_len
mbed714	0:d616ece2d859	1052	*/
mbed714	0:d616ece2d859	1053	u8_t
mbed714	0:d616ece2d859	1054	pbuf_get_at(struct pbuf* p, u16_t offset)
mbed714	0:d616ece2d859	1055	{
mbed714	0:d616ece2d859	1056	u16_t copy_from = offset;
mbed714	0:d616ece2d859	1057	struct pbuf* q = p;
mbed714	0:d616ece2d859	1058
mbed714	0:d616ece2d859	1059	/* get the correct pbuf */
mbed714	0:d616ece2d859	1060	while ((q != NULL) && (q->len <= copy_from)) {
mbed714	0:d616ece2d859	1061	copy_from -= q->len;
mbed714	0:d616ece2d859	1062	q = q->next;
mbed714	0:d616ece2d859	1063	}
mbed714	0:d616ece2d859	1064	/* return requested data if pbuf is OK */
mbed714	0:d616ece2d859	1065	if ((q != NULL) && (q->len > copy_from)) {
mbed714	0:d616ece2d859	1066	return ((u8_t*)q->payload)[copy_from];
mbed714	0:d616ece2d859	1067	}
mbed714	0:d616ece2d859	1068	return 0;
mbed714	0:d616ece2d859	1069	}
mbed714	0:d616ece2d859	1070
mbed714	0:d616ece2d859	1071	/** Compare pbuf contents at specified offset with memory s2, both of length n
mbed714	0:d616ece2d859	1072	*
mbed714	0:d616ece2d859	1073	* @param p pbuf to compare
mbed714	0:d616ece2d859	1074	* @param offset offset into p at wich to start comparing
mbed714	0:d616ece2d859	1075	* @param s2 buffer to compare
mbed714	0:d616ece2d859	1076	* @param n length of buffer to compare
mbed714	0:d616ece2d859	1077	* @return zero if equal, nonzero otherwise
mbed714	0:d616ece2d859	1078	* (0xffff if p is too short, diffoffset+1 otherwise)
mbed714	0:d616ece2d859	1079	*/
mbed714	0:d616ece2d859	1080	u16_t
mbed714	0:d616ece2d859	1081	pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n)
mbed714	0:d616ece2d859	1082	{
mbed714	0:d616ece2d859	1083	u16_t start = offset;
mbed714	0:d616ece2d859	1084	struct pbuf* q = p;
mbed714	0:d616ece2d859	1085
mbed714	0:d616ece2d859	1086	/* get the correct pbuf */
mbed714	0:d616ece2d859	1087	while ((q != NULL) && (q->len <= start)) {
mbed714	0:d616ece2d859	1088	start -= q->len;
mbed714	0:d616ece2d859	1089	q = q->next;
mbed714	0:d616ece2d859	1090	}
mbed714	0:d616ece2d859	1091	/* return requested data if pbuf is OK */
mbed714	0:d616ece2d859	1092	if ((q != NULL) && (q->len > start)) {
mbed714	0:d616ece2d859	1093	u16_t i;
mbed714	0:d616ece2d859	1094	for(i = 0; i < n; i++) {
mbed714	0:d616ece2d859	1095	u8_t a = pbuf_get_at(q, start + i);
mbed714	0:d616ece2d859	1096	u8_t b = ((u8_t*)s2)[i];
mbed714	0:d616ece2d859	1097	if (a != b) {
mbed714	0:d616ece2d859	1098	return i+1;
mbed714	0:d616ece2d859	1099	}
mbed714	0:d616ece2d859	1100	}
mbed714	0:d616ece2d859	1101	return 0;
mbed714	0:d616ece2d859	1102	}
mbed714	0:d616ece2d859	1103	return 0xffff;
mbed714	0:d616ece2d859	1104	}
mbed714	0:d616ece2d859	1105
mbed714	0:d616ece2d859	1106	/** Find occurrence of mem (with length mem_len) in pbuf p, starting at offset
mbed714	0:d616ece2d859	1107	* start_offset.
mbed714	0:d616ece2d859	1108	*
mbed714	0:d616ece2d859	1109	* @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
mbed714	0:d616ece2d859	1110	* return value 'not found'
mbed714	0:d616ece2d859	1111	* @param mem search for the contents of this buffer
mbed714	0:d616ece2d859	1112	* @param mem_len length of 'mem'
mbed714	0:d616ece2d859	1113	* @param start_offset offset into p at which to start searching
mbed714	0:d616ece2d859	1114	* @return 0xFFFF if substr was not found in p or the index where it was found
mbed714	0:d616ece2d859	1115	*/
mbed714	0:d616ece2d859	1116	u16_t
mbed714	0:d616ece2d859	1117	pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset)
mbed714	0:d616ece2d859	1118	{
mbed714	0:d616ece2d859	1119	u16_t i;
mbed714	0:d616ece2d859	1120	u16_t max = p->tot_len - mem_len;
mbed714	0:d616ece2d859	1121	if (p->tot_len >= mem_len + start_offset) {
mbed714	0:d616ece2d859	1122	for(i = start_offset; i <= max; ) {
mbed714	0:d616ece2d859	1123	u16_t plus = pbuf_memcmp(p, i, mem, mem_len);
mbed714	0:d616ece2d859	1124	if (plus == 0) {
mbed714	0:d616ece2d859	1125	return i;
mbed714	0:d616ece2d859	1126	} else {
mbed714	0:d616ece2d859	1127	i += plus;
mbed714	0:d616ece2d859	1128	}
mbed714	0:d616ece2d859	1129	}
mbed714	0:d616ece2d859	1130	}
mbed714	0:d616ece2d859	1131	return 0xFFFF;
mbed714	0:d616ece2d859	1132	}
mbed714	0:d616ece2d859	1133
mbed714	0:d616ece2d859	1134	/** Find occurrence of substr with length substr_len in pbuf p, start at offset
mbed714	0:d616ece2d859	1135	* start_offset
mbed714	0:d616ece2d859	1136	* WARNING: in contrast to strstr(), this one does not stop at the first \0 in
mbed714	0:d616ece2d859	1137	* the pbuf/source string!
mbed714	0:d616ece2d859	1138	*
mbed714	0:d616ece2d859	1139	* @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
mbed714	0:d616ece2d859	1140	* return value 'not found'
mbed714	0:d616ece2d859	1141	* @param substr string to search for in p, maximum length is 0xFFFE
mbed714	0:d616ece2d859	1142	* @return 0xFFFF if substr was not found in p or the index where it was found
mbed714	0:d616ece2d859	1143	*/
mbed714	0:d616ece2d859	1144	u16_t
mbed714	0:d616ece2d859	1145	pbuf_strstr(struct pbuf* p, const char* substr)
mbed714	0:d616ece2d859	1146	{
mbed714	0:d616ece2d859	1147	size_t substr_len;
mbed714	0:d616ece2d859	1148	if ((substr == NULL) \|\| (substr[0] == 0) \|\| (p->tot_len == 0xFFFF)) {
mbed714	0:d616ece2d859	1149	return 0xFFFF;
mbed714	0:d616ece2d859	1150	}
mbed714	0:d616ece2d859	1151	substr_len = strlen(substr);
mbed714	0:d616ece2d859	1152	if (substr_len >= 0xFFFF) {
mbed714	0:d616ece2d859	1153	return 0xFFFF;
mbed714	0:d616ece2d859	1154	}
mbed714	0:d616ece2d859	1155	return pbuf_memfind(p, substr, (u16_t)substr_len, 0);
mbed714	0:d616ece2d859	1156	}

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Type:	Library
Created:	18 Sep 2010
Imports:	1
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	0
Followers:	1

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lwip/core/pbuf.c@0:d616ece2d859, 2010-09-18 (annotated)

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