WeatherStation - Web server based weather station using Sparkfun W…

Users » AdamGreen » Code » WeatherStation

Adam Green / Mbed 2 deprecated WeatherStation

Web server based weather station using Sparkfun Weather Meters.

Dependencies: FatFileSystem mbed WeatherMeters SDFileSystem

NetStack/lwip/core/pbuf.c@0:616601bde9fb, 2012-02-23 (annotated)

Committer:: AdamGreen
Date:: Thu Feb 23 21:38:39 2012 +0000
Revision:: 0:616601bde9fb

Who changed what in which revision?

User	Revision	Line number	New contents of line
AdamGreen	0:616601bde9fb	1	/**
AdamGreen	0:616601bde9fb	2	* @file
AdamGreen	0:616601bde9fb	3	* Packet buffer management
AdamGreen	0:616601bde9fb	4	*
AdamGreen	0:616601bde9fb	5	* Packets are built from the pbuf data structure. It supports dynamic
AdamGreen	0:616601bde9fb	6	* memory allocation for packet contents or can reference externally
AdamGreen	0:616601bde9fb	7	* managed packet contents both in RAM and ROM. Quick allocation for
AdamGreen	0:616601bde9fb	8	* incoming packets is provided through pools with fixed sized pbufs.
AdamGreen	0:616601bde9fb	9	*
AdamGreen	0:616601bde9fb	10	* A packet may span over multiple pbufs, chained as a singly linked
AdamGreen	0:616601bde9fb	11	* list. This is called a "pbuf chain".
AdamGreen	0:616601bde9fb	12	*
AdamGreen	0:616601bde9fb	13	* Multiple packets may be queued, also using this singly linked list.
AdamGreen	0:616601bde9fb	14	* This is called a "packet queue".
AdamGreen	0:616601bde9fb	15	*
AdamGreen	0:616601bde9fb	16	* So, a packet queue consists of one or more pbuf chains, each of
AdamGreen	0:616601bde9fb	17	* which consist of one or more pbufs. CURRENTLY, PACKET QUEUES ARE
AdamGreen	0:616601bde9fb	18	* NOT SUPPORTED!!! Use helper structs to queue multiple packets.
AdamGreen	0:616601bde9fb	19	*
AdamGreen	0:616601bde9fb	20	* The differences between a pbuf chain and a packet queue are very
AdamGreen	0:616601bde9fb	21	* precise but subtle.
AdamGreen	0:616601bde9fb	22	*
AdamGreen	0:616601bde9fb	23	* The last pbuf of a packet has a ->tot_len field that equals the
AdamGreen	0:616601bde9fb	24	* ->len field. It can be found by traversing the list. If the last
AdamGreen	0:616601bde9fb	25	* pbuf of a packet has a ->next field other than NULL, more packets
AdamGreen	0:616601bde9fb	26	* are on the queue.
AdamGreen	0:616601bde9fb	27	*
AdamGreen	0:616601bde9fb	28	* Therefore, looping through a pbuf of a single packet, has an
AdamGreen	0:616601bde9fb	29	* loop end condition (tot_len == p->len), NOT (next == NULL).
AdamGreen	0:616601bde9fb	30	*/
AdamGreen	0:616601bde9fb	31
AdamGreen	0:616601bde9fb	32	/*
AdamGreen	0:616601bde9fb	33	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
AdamGreen	0:616601bde9fb	34	* All rights reserved.
AdamGreen	0:616601bde9fb	35	*
AdamGreen	0:616601bde9fb	36	* Redistribution and use in source and binary forms, with or without modification,
AdamGreen	0:616601bde9fb	37	* are permitted provided that the following conditions are met:
AdamGreen	0:616601bde9fb	38	*
AdamGreen	0:616601bde9fb	39	* 1. Redistributions of source code must retain the above copyright notice,
AdamGreen	0:616601bde9fb	40	* this list of conditions and the following disclaimer.
AdamGreen	0:616601bde9fb	41	* 2. Redistributions in binary form must reproduce the above copyright notice,
AdamGreen	0:616601bde9fb	42	* this list of conditions and the following disclaimer in the documentation
AdamGreen	0:616601bde9fb	43	* and/or other materials provided with the distribution.
AdamGreen	0:616601bde9fb	44	* 3. The name of the author may not be used to endorse or promote products
AdamGreen	0:616601bde9fb	45	* derived from this software without specific prior written permission.
AdamGreen	0:616601bde9fb	46	*
AdamGreen	0:616601bde9fb	47	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
AdamGreen	0:616601bde9fb	48	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
AdamGreen	0:616601bde9fb	49	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
AdamGreen	0:616601bde9fb	50	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
AdamGreen	0:616601bde9fb	51	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
AdamGreen	0:616601bde9fb	52	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
AdamGreen	0:616601bde9fb	53	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
AdamGreen	0:616601bde9fb	54	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
AdamGreen	0:616601bde9fb	55	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
AdamGreen	0:616601bde9fb	56	* OF SUCH DAMAGE.
AdamGreen	0:616601bde9fb	57	*
AdamGreen	0:616601bde9fb	58	* This file is part of the lwIP TCP/IP stack.
AdamGreen	0:616601bde9fb	59	*
AdamGreen	0:616601bde9fb	60	* Author: Adam Dunkels <adam@sics.se>
AdamGreen	0:616601bde9fb	61	*
AdamGreen	0:616601bde9fb	62	*/
AdamGreen	0:616601bde9fb	63
AdamGreen	0:616601bde9fb	64	#include "lwip/opt.h"
AdamGreen	0:616601bde9fb	65
AdamGreen	0:616601bde9fb	66	#include "lwip/stats.h"
AdamGreen	0:616601bde9fb	67	#include "lwip/def.h"
AdamGreen	0:616601bde9fb	68	#include "lwip/mem.h"
AdamGreen	0:616601bde9fb	69	#include "lwip/memp.h"
AdamGreen	0:616601bde9fb	70	#include "lwip/pbuf.h"
AdamGreen	0:616601bde9fb	71	#include "lwip/sys.h"
AdamGreen	0:616601bde9fb	72	#include "arch/perf.h"
AdamGreen	0:616601bde9fb	73	#if TCP_QUEUE_OOSEQ
AdamGreen	0:616601bde9fb	74	#include "lwip/tcp_impl.h"
AdamGreen	0:616601bde9fb	75	#endif
AdamGreen	0:616601bde9fb	76	#if LWIP_CHECKSUM_ON_COPY
AdamGreen	0:616601bde9fb	77	#include "lwip/inet_chksum.h"
AdamGreen	0:616601bde9fb	78	#endif
AdamGreen	0:616601bde9fb	79
AdamGreen	0:616601bde9fb	80	#include <string.h>
AdamGreen	0:616601bde9fb	81
AdamGreen	0:616601bde9fb	82	#define SIZEOF_STRUCT_PBUF LWIP_MEM_ALIGN_SIZE(sizeof(struct pbuf))
AdamGreen	0:616601bde9fb	83	/* Since the pool is created in memp, PBUF_POOL_BUFSIZE will be automatically
AdamGreen	0:616601bde9fb	84	aligned there. Therefore, PBUF_POOL_BUFSIZE_ALIGNED can be used here. */
AdamGreen	0:616601bde9fb	85	#define PBUF_POOL_BUFSIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE)
AdamGreen	0:616601bde9fb	86
AdamGreen	0:616601bde9fb	87	#if !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS
AdamGreen	0:616601bde9fb	88	#define PBUF_POOL_IS_EMPTY()
AdamGreen	0:616601bde9fb	89	#else /* !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS */
AdamGreen	0:616601bde9fb	90	/** Define this to 0 to prevent freeing ooseq pbufs when the PBUF_POOL is empty */
AdamGreen	0:616601bde9fb	91	#ifndef PBUF_POOL_FREE_OOSEQ
AdamGreen	0:616601bde9fb	92	#define PBUF_POOL_FREE_OOSEQ 1
AdamGreen	0:616601bde9fb	93	#endif /* PBUF_POOL_FREE_OOSEQ */
AdamGreen	0:616601bde9fb	94
AdamGreen	0:616601bde9fb	95	#if PBUF_POOL_FREE_OOSEQ
AdamGreen	0:616601bde9fb	96	#include "lwip/tcpip.h"
AdamGreen	0:616601bde9fb	97	#define PBUF_POOL_IS_EMPTY() pbuf_pool_is_empty()
AdamGreen	0:616601bde9fb	98	static u8_t pbuf_free_ooseq_queued;
AdamGreen	0:616601bde9fb	99	/**
AdamGreen	0:616601bde9fb	100	* Attempt to reclaim some memory from queued out-of-sequence TCP segments
AdamGreen	0:616601bde9fb	101	* if we run out of pool pbufs. It's better to give priority to new packets
AdamGreen	0:616601bde9fb	102	* if we're running out.
AdamGreen	0:616601bde9fb	103	*
AdamGreen	0:616601bde9fb	104	* This must be done in the correct thread context therefore this function
AdamGreen	0:616601bde9fb	105	* can only be used with NO_SYS=0 and through tcpip_callback.
AdamGreen	0:616601bde9fb	106	*/
AdamGreen	0:616601bde9fb	107	static void
AdamGreen	0:616601bde9fb	108	pbuf_free_ooseq(void* arg)
AdamGreen	0:616601bde9fb	109	{
AdamGreen	0:616601bde9fb	110	struct tcp_pcb* pcb;
AdamGreen	0:616601bde9fb	111	SYS_ARCH_DECL_PROTECT(old_level);
AdamGreen	0:616601bde9fb	112	LWIP_UNUSED_ARG(arg);
AdamGreen	0:616601bde9fb	113
AdamGreen	0:616601bde9fb	114	SYS_ARCH_PROTECT(old_level);
AdamGreen	0:616601bde9fb	115	pbuf_free_ooseq_queued = 0;
AdamGreen	0:616601bde9fb	116	SYS_ARCH_UNPROTECT(old_level);
AdamGreen	0:616601bde9fb	117
AdamGreen	0:616601bde9fb	118	for (pcb = tcp_active_pcbs; NULL != pcb; pcb = pcb->next) {
AdamGreen	0:616601bde9fb	119	if (NULL != pcb->ooseq) {
AdamGreen	0:616601bde9fb	120	/** Free the ooseq pbufs of one PCB only */
AdamGreen	0:616601bde9fb	121	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free_ooseq: freeing out-of-sequence pbufs\n"));
AdamGreen	0:616601bde9fb	122	tcp_segs_free(pcb->ooseq);
AdamGreen	0:616601bde9fb	123	pcb->ooseq = NULL;
AdamGreen	0:616601bde9fb	124	return;
AdamGreen	0:616601bde9fb	125	}
AdamGreen	0:616601bde9fb	126	}
AdamGreen	0:616601bde9fb	127	}
AdamGreen	0:616601bde9fb	128
AdamGreen	0:616601bde9fb	129	/** Queue a call to pbuf_free_ooseq if not already queued. */
AdamGreen	0:616601bde9fb	130	static void
AdamGreen	0:616601bde9fb	131	pbuf_pool_is_empty(void)
AdamGreen	0:616601bde9fb	132	{
AdamGreen	0:616601bde9fb	133	u8_t queued;
AdamGreen	0:616601bde9fb	134	SYS_ARCH_DECL_PROTECT(old_level);
AdamGreen	0:616601bde9fb	135
AdamGreen	0:616601bde9fb	136	SYS_ARCH_PROTECT(old_level);
AdamGreen	0:616601bde9fb	137	queued = pbuf_free_ooseq_queued;
AdamGreen	0:616601bde9fb	138	pbuf_free_ooseq_queued = 1;
AdamGreen	0:616601bde9fb	139	SYS_ARCH_UNPROTECT(old_level);
AdamGreen	0:616601bde9fb	140
AdamGreen	0:616601bde9fb	141	if(!queued) {
AdamGreen	0:616601bde9fb	142	/* queue a call to pbuf_free_ooseq if not already queued */
AdamGreen	0:616601bde9fb	143	if(tcpip_callback_with_block(pbuf_free_ooseq, NULL, 0) != ERR_OK) {
AdamGreen	0:616601bde9fb	144	SYS_ARCH_PROTECT(old_level);
AdamGreen	0:616601bde9fb	145	pbuf_free_ooseq_queued = 0;
AdamGreen	0:616601bde9fb	146	SYS_ARCH_UNPROTECT(old_level);
AdamGreen	0:616601bde9fb	147	}
AdamGreen	0:616601bde9fb	148	}
AdamGreen	0:616601bde9fb	149	}
AdamGreen	0:616601bde9fb	150	#endif /* PBUF_POOL_FREE_OOSEQ */
AdamGreen	0:616601bde9fb	151	#endif /* !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS */
AdamGreen	0:616601bde9fb	152
AdamGreen	0:616601bde9fb	153	/**
AdamGreen	0:616601bde9fb	154	* Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
AdamGreen	0:616601bde9fb	155	*
AdamGreen	0:616601bde9fb	156	* The actual memory allocated for the pbuf is determined by the
AdamGreen	0:616601bde9fb	157	* layer at which the pbuf is allocated and the requested size
AdamGreen	0:616601bde9fb	158	* (from the size parameter).
AdamGreen	0:616601bde9fb	159	*
AdamGreen	0:616601bde9fb	160	* @param layer flag to define header size
AdamGreen	0:616601bde9fb	161	* @param length size of the pbuf's payload
AdamGreen	0:616601bde9fb	162	* @param type this parameter decides how and where the pbuf
AdamGreen	0:616601bde9fb	163	* should be allocated as follows:
AdamGreen	0:616601bde9fb	164	*
AdamGreen	0:616601bde9fb	165	* - PBUF_RAM: buffer memory for pbuf is allocated as one large
AdamGreen	0:616601bde9fb	166	* chunk. This includes protocol headers as well.
AdamGreen	0:616601bde9fb	167	* - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
AdamGreen	0:616601bde9fb	168	* protocol headers. Additional headers must be prepended
AdamGreen	0:616601bde9fb	169	* by allocating another pbuf and chain in to the front of
AdamGreen	0:616601bde9fb	170	* the ROM pbuf. It is assumed that the memory used is really
AdamGreen	0:616601bde9fb	171	* similar to ROM in that it is immutable and will not be
AdamGreen	0:616601bde9fb	172	* changed. Memory which is dynamic should generally not
AdamGreen	0:616601bde9fb	173	* be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
AdamGreen	0:616601bde9fb	174	* - PBUF_REF: no buffer memory is allocated for the pbuf, even for
AdamGreen	0:616601bde9fb	175	* protocol headers. It is assumed that the pbuf is only
AdamGreen	0:616601bde9fb	176	* being used in a single thread. If the pbuf gets queued,
AdamGreen	0:616601bde9fb	177	* then pbuf_take should be called to copy the buffer.
AdamGreen	0:616601bde9fb	178	* - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
AdamGreen	0:616601bde9fb	179	* the pbuf pool that is allocated during pbuf_init().
AdamGreen	0:616601bde9fb	180	*
AdamGreen	0:616601bde9fb	181	* @return the allocated pbuf. If multiple pbufs where allocated, this
AdamGreen	0:616601bde9fb	182	* is the first pbuf of a pbuf chain.
AdamGreen	0:616601bde9fb	183	*/
AdamGreen	0:616601bde9fb	184	struct pbuf *
AdamGreen	0:616601bde9fb	185	pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
AdamGreen	0:616601bde9fb	186	{
AdamGreen	0:616601bde9fb	187	struct pbuf p, q, *r;
AdamGreen	0:616601bde9fb	188	u16_t offset;
AdamGreen	0:616601bde9fb	189	s32_t rem_len; /* remaining length */
AdamGreen	0:616601bde9fb	190	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
AdamGreen	0:616601bde9fb	191
AdamGreen	0:616601bde9fb	192	/* determine header offset */
AdamGreen	0:616601bde9fb	193	offset = 0;
AdamGreen	0:616601bde9fb	194	switch (layer) {
AdamGreen	0:616601bde9fb	195	case PBUF_TRANSPORT:
AdamGreen	0:616601bde9fb	196	/* add room for transport (often TCP) layer header */
AdamGreen	0:616601bde9fb	197	offset += PBUF_TRANSPORT_HLEN;
AdamGreen	0:616601bde9fb	198	/* FALLTHROUGH */
AdamGreen	0:616601bde9fb	199	case PBUF_IP:
AdamGreen	0:616601bde9fb	200	/* add room for IP layer header */
AdamGreen	0:616601bde9fb	201	offset += PBUF_IP_HLEN;
AdamGreen	0:616601bde9fb	202	/* FALLTHROUGH */
AdamGreen	0:616601bde9fb	203	case PBUF_LINK:
AdamGreen	0:616601bde9fb	204	/* add room for link layer header */
AdamGreen	0:616601bde9fb	205	offset += PBUF_LINK_HLEN;
AdamGreen	0:616601bde9fb	206	break;
AdamGreen	0:616601bde9fb	207	case PBUF_RAW:
AdamGreen	0:616601bde9fb	208	break;
AdamGreen	0:616601bde9fb	209	default:
AdamGreen	0:616601bde9fb	210	LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0);
AdamGreen	0:616601bde9fb	211	return NULL;
AdamGreen	0:616601bde9fb	212	}
AdamGreen	0:616601bde9fb	213
AdamGreen	0:616601bde9fb	214	switch (type) {
AdamGreen	0:616601bde9fb	215	case PBUF_POOL:
AdamGreen	0:616601bde9fb	216	/* allocate head of pbuf chain into p */
AdamGreen	0:616601bde9fb	217	p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
AdamGreen	0:616601bde9fb	218	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
AdamGreen	0:616601bde9fb	219	if (p == NULL) {
AdamGreen	0:616601bde9fb	220	PBUF_POOL_IS_EMPTY();
AdamGreen	0:616601bde9fb	221	return NULL;
AdamGreen	0:616601bde9fb	222	}
AdamGreen	0:616601bde9fb	223	p->type = type;
AdamGreen	0:616601bde9fb	224	p->next = NULL;
AdamGreen	0:616601bde9fb	225
AdamGreen	0:616601bde9fb	226	/* make the payload pointer point 'offset' bytes into pbuf data memory */
AdamGreen	0:616601bde9fb	227	p->payload = LWIP_MEM_ALIGN((void )((u8_t )p + (SIZEOF_STRUCT_PBUF + offset)));
AdamGreen	0:616601bde9fb	228	LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned",
AdamGreen	0:616601bde9fb	229	((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
AdamGreen	0:616601bde9fb	230	/* the total length of the pbuf chain is the requested size */
AdamGreen	0:616601bde9fb	231	p->tot_len = length;
AdamGreen	0:616601bde9fb	232	/* set the length of the first pbuf in the chain */
AdamGreen	0:616601bde9fb	233	p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
AdamGreen	0:616601bde9fb	234	LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
AdamGreen	0:616601bde9fb	235	((u8_t*)p->payload + p->len <=
AdamGreen	0:616601bde9fb	236	(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
AdamGreen	0:616601bde9fb	237	LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT",
AdamGreen	0:616601bde9fb	238	(PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 );
AdamGreen	0:616601bde9fb	239	/* set reference count (needed here in case we fail) */
AdamGreen	0:616601bde9fb	240	p->ref = 1;
AdamGreen	0:616601bde9fb	241
AdamGreen	0:616601bde9fb	242	/* now allocate the tail of the pbuf chain */
AdamGreen	0:616601bde9fb	243
AdamGreen	0:616601bde9fb	244	/* remember first pbuf for linkage in next iteration */
AdamGreen	0:616601bde9fb	245	r = p;
AdamGreen	0:616601bde9fb	246	/* remaining length to be allocated */
AdamGreen	0:616601bde9fb	247	rem_len = length - p->len;
AdamGreen	0:616601bde9fb	248	/* any remaining pbufs to be allocated? */
AdamGreen	0:616601bde9fb	249	while (rem_len > 0) {
AdamGreen	0:616601bde9fb	250	q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
AdamGreen	0:616601bde9fb	251	if (q == NULL) {
AdamGreen	0:616601bde9fb	252	PBUF_POOL_IS_EMPTY();
AdamGreen	0:616601bde9fb	253	/* free chain so far allocated */
AdamGreen	0:616601bde9fb	254	pbuf_free(p);
AdamGreen	0:616601bde9fb	255	/* bail out unsuccesfully */
AdamGreen	0:616601bde9fb	256	return NULL;
AdamGreen	0:616601bde9fb	257	}
AdamGreen	0:616601bde9fb	258	q->type = type;
AdamGreen	0:616601bde9fb	259	q->flags = 0;
AdamGreen	0:616601bde9fb	260	q->next = NULL;
AdamGreen	0:616601bde9fb	261	/* make previous pbuf point to this pbuf */
AdamGreen	0:616601bde9fb	262	r->next = q;
AdamGreen	0:616601bde9fb	263	/* set total length of this pbuf and next in chain */
AdamGreen	0:616601bde9fb	264	LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff);
AdamGreen	0:616601bde9fb	265	q->tot_len = (u16_t)rem_len;
AdamGreen	0:616601bde9fb	266	/* this pbuf length is pool size, unless smaller sized tail */
AdamGreen	0:616601bde9fb	267	q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
AdamGreen	0:616601bde9fb	268	q->payload = (void )((u8_t )q + SIZEOF_STRUCT_PBUF);
AdamGreen	0:616601bde9fb	269	LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
AdamGreen	0:616601bde9fb	270	((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
AdamGreen	0:616601bde9fb	271	LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
AdamGreen	0:616601bde9fb	272	((u8_t*)p->payload + p->len <=
AdamGreen	0:616601bde9fb	273	(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
AdamGreen	0:616601bde9fb	274	q->ref = 1;
AdamGreen	0:616601bde9fb	275	/* calculate remaining length to be allocated */
AdamGreen	0:616601bde9fb	276	rem_len -= q->len;
AdamGreen	0:616601bde9fb	277	/* remember this pbuf for linkage in next iteration */
AdamGreen	0:616601bde9fb	278	r = q;
AdamGreen	0:616601bde9fb	279	}
AdamGreen	0:616601bde9fb	280	/* end of chain */
AdamGreen	0:616601bde9fb	281	/r->next = NULL;/
AdamGreen	0:616601bde9fb	282
AdamGreen	0:616601bde9fb	283	break;
AdamGreen	0:616601bde9fb	284	case PBUF_RAM:
AdamGreen	0:616601bde9fb	285	/* If pbuf is to be allocated in RAM, allocate memory for it. */
AdamGreen	0:616601bde9fb	286	p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
AdamGreen	0:616601bde9fb	287	if (p == NULL) {
AdamGreen	0:616601bde9fb	288	return NULL;
AdamGreen	0:616601bde9fb	289	}
AdamGreen	0:616601bde9fb	290	/* Set up internal structure of the pbuf. */
AdamGreen	0:616601bde9fb	291	p->payload = LWIP_MEM_ALIGN((void )((u8_t )p + SIZEOF_STRUCT_PBUF + offset));
AdamGreen	0:616601bde9fb	292	p->len = p->tot_len = length;
AdamGreen	0:616601bde9fb	293	p->next = NULL;
AdamGreen	0:616601bde9fb	294	p->type = type;
AdamGreen	0:616601bde9fb	295
AdamGreen	0:616601bde9fb	296	LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
AdamGreen	0:616601bde9fb	297	((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
AdamGreen	0:616601bde9fb	298	break;
AdamGreen	0:616601bde9fb	299	/* pbuf references existing (non-volatile static constant) ROM payload? */
AdamGreen	0:616601bde9fb	300	case PBUF_ROM:
AdamGreen	0:616601bde9fb	301	/* pbuf references existing (externally allocated) RAM payload? */
AdamGreen	0:616601bde9fb	302	case PBUF_REF:
AdamGreen	0:616601bde9fb	303	/* only allocate memory for the pbuf structure */
AdamGreen	0:616601bde9fb	304	p = (struct pbuf *)memp_malloc(MEMP_PBUF);
AdamGreen	0:616601bde9fb	305	if (p == NULL) {
AdamGreen	0:616601bde9fb	306	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
AdamGreen	0:616601bde9fb	307	("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n",
AdamGreen	0:616601bde9fb	308	(type == PBUF_ROM) ? "ROM" : "REF"));
AdamGreen	0:616601bde9fb	309	return NULL;
AdamGreen	0:616601bde9fb	310	}
AdamGreen	0:616601bde9fb	311	/* caller must set this field properly, afterwards */
AdamGreen	0:616601bde9fb	312	p->payload = NULL;
AdamGreen	0:616601bde9fb	313	p->len = p->tot_len = length;
AdamGreen	0:616601bde9fb	314	p->next = NULL;
AdamGreen	0:616601bde9fb	315	p->type = type;
AdamGreen	0:616601bde9fb	316	break;
AdamGreen	0:616601bde9fb	317	default:
AdamGreen	0:616601bde9fb	318	LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
AdamGreen	0:616601bde9fb	319	return NULL;
AdamGreen	0:616601bde9fb	320	}
AdamGreen	0:616601bde9fb	321	/* set reference count */
AdamGreen	0:616601bde9fb	322	p->ref = 1;
AdamGreen	0:616601bde9fb	323	/* set flags */
AdamGreen	0:616601bde9fb	324	p->flags = 0;
AdamGreen	0:616601bde9fb	325	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
AdamGreen	0:616601bde9fb	326	return p;
AdamGreen	0:616601bde9fb	327	}
AdamGreen	0:616601bde9fb	328
AdamGreen	0:616601bde9fb	329	#if LWIP_SUPPORT_CUSTOM_PBUF
AdamGreen	0:616601bde9fb	330	/** Initialize a custom pbuf (already allocated).
AdamGreen	0:616601bde9fb	331	*
AdamGreen	0:616601bde9fb	332	* @param layer flag to define header size
AdamGreen	0:616601bde9fb	333	* @param length size of the pbuf's payload
AdamGreen	0:616601bde9fb	334	* @param type type of the pbuf (only used to treat the pbuf accordingly, as
AdamGreen	0:616601bde9fb	335	* this function allocates no memory)
AdamGreen	0:616601bde9fb	336	* @param p pointer to the custom pbuf to initialize (already allocated)
AdamGreen	0:616601bde9fb	337	* @param payload_mem pointer to the buffer that is used for payload and headers,
AdamGreen	0:616601bde9fb	338	* must be at least big enough to hold 'length' plus the header size,
AdamGreen	0:616601bde9fb	339	* may be NULL if set later
AdamGreen	0:616601bde9fb	340	* @param payload_mem_len the size of the 'payload_mem' buffer, must be at least
AdamGreen	0:616601bde9fb	341	* big enough to hold 'length' plus the header size
AdamGreen	0:616601bde9fb	342	*/
AdamGreen	0:616601bde9fb	343	struct pbuf*
AdamGreen	0:616601bde9fb	344	pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type, struct pbuf_custom *p,
AdamGreen	0:616601bde9fb	345	void *payload_mem, u16_t payload_mem_len)
AdamGreen	0:616601bde9fb	346	{
AdamGreen	0:616601bde9fb	347	u16_t offset;
AdamGreen	0:616601bde9fb	348	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloced_custom(length=%"U16_F")\n", length));
AdamGreen	0:616601bde9fb	349
AdamGreen	0:616601bde9fb	350	/* determine header offset */
AdamGreen	0:616601bde9fb	351	offset = 0;
AdamGreen	0:616601bde9fb	352	switch (l) {
AdamGreen	0:616601bde9fb	353	case PBUF_TRANSPORT:
AdamGreen	0:616601bde9fb	354	/* add room for transport (often TCP) layer header */
AdamGreen	0:616601bde9fb	355	offset += PBUF_TRANSPORT_HLEN;
AdamGreen	0:616601bde9fb	356	/* FALLTHROUGH */
AdamGreen	0:616601bde9fb	357	case PBUF_IP:
AdamGreen	0:616601bde9fb	358	/* add room for IP layer header */
AdamGreen	0:616601bde9fb	359	offset += PBUF_IP_HLEN;
AdamGreen	0:616601bde9fb	360	/* FALLTHROUGH */
AdamGreen	0:616601bde9fb	361	case PBUF_LINK:
AdamGreen	0:616601bde9fb	362	/* add room for link layer header */
AdamGreen	0:616601bde9fb	363	offset += PBUF_LINK_HLEN;
AdamGreen	0:616601bde9fb	364	break;
AdamGreen	0:616601bde9fb	365	case PBUF_RAW:
AdamGreen	0:616601bde9fb	366	break;
AdamGreen	0:616601bde9fb	367	default:
AdamGreen	0:616601bde9fb	368	LWIP_ASSERT("pbuf_alloced_custom: bad pbuf layer", 0);
AdamGreen	0:616601bde9fb	369	return NULL;
AdamGreen	0:616601bde9fb	370	}
AdamGreen	0:616601bde9fb	371
AdamGreen	0:616601bde9fb	372	if (LWIP_MEM_ALIGN_SIZE(offset) + length < payload_mem_len) {
AdamGreen	0:616601bde9fb	373	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_WARNING, ("pbuf_alloced_custom(length=%"U16_F") buffer too short\n", length));
AdamGreen	0:616601bde9fb	374	return NULL;
AdamGreen	0:616601bde9fb	375	}
AdamGreen	0:616601bde9fb	376
AdamGreen	0:616601bde9fb	377	p->pbuf.next = NULL;
AdamGreen	0:616601bde9fb	378	if (payload_mem != NULL) {
AdamGreen	0:616601bde9fb	379	p->pbuf.payload = LWIP_MEM_ALIGN((void )((u8_t )payload_mem + offset));
AdamGreen	0:616601bde9fb	380	} else {
AdamGreen	0:616601bde9fb	381	p->pbuf.payload = NULL;
AdamGreen	0:616601bde9fb	382	}
AdamGreen	0:616601bde9fb	383	p->pbuf.flags = PBUF_FLAG_IS_CUSTOM;
AdamGreen	0:616601bde9fb	384	p->pbuf.len = p->pbuf.tot_len = length;
AdamGreen	0:616601bde9fb	385	p->pbuf.type = type;
AdamGreen	0:616601bde9fb	386	p->pbuf.ref = 1;
AdamGreen	0:616601bde9fb	387	return &p->pbuf;
AdamGreen	0:616601bde9fb	388	}
AdamGreen	0:616601bde9fb	389	#endif /* LWIP_SUPPORT_CUSTOM_PBUF */
AdamGreen	0:616601bde9fb	390
AdamGreen	0:616601bde9fb	391	/**
AdamGreen	0:616601bde9fb	392	* Shrink a pbuf chain to a desired length.
AdamGreen	0:616601bde9fb	393	*
AdamGreen	0:616601bde9fb	394	* @param p pbuf to shrink.
AdamGreen	0:616601bde9fb	395	* @param new_len desired new length of pbuf chain
AdamGreen	0:616601bde9fb	396	*
AdamGreen	0:616601bde9fb	397	* Depending on the desired length, the first few pbufs in a chain might
AdamGreen	0:616601bde9fb	398	* be skipped and left unchanged. The new last pbuf in the chain will be
AdamGreen	0:616601bde9fb	399	* resized, and any remaining pbufs will be freed.
AdamGreen	0:616601bde9fb	400	*
AdamGreen	0:616601bde9fb	401	* @note If the pbuf is ROM/REF, only the ->tot_len and ->len fields are adjusted.
AdamGreen	0:616601bde9fb	402	* @note May not be called on a packet queue.
AdamGreen	0:616601bde9fb	403	*
AdamGreen	0:616601bde9fb	404	* @note Despite its name, pbuf_realloc cannot grow the size of a pbuf (chain).
AdamGreen	0:616601bde9fb	405	*/
AdamGreen	0:616601bde9fb	406	void
AdamGreen	0:616601bde9fb	407	pbuf_realloc(struct pbuf *p, u16_t new_len)
AdamGreen	0:616601bde9fb	408	{
AdamGreen	0:616601bde9fb	409	struct pbuf *q;
AdamGreen	0:616601bde9fb	410	u16_t rem_len; /* remaining length */
AdamGreen	0:616601bde9fb	411	s32_t grow;
AdamGreen	0:616601bde9fb	412
AdamGreen	0:616601bde9fb	413	LWIP_ASSERT("pbuf_realloc: p != NULL", p != NULL);
AdamGreen	0:616601bde9fb	414	LWIP_ASSERT("pbuf_realloc: sane p->type", p->type == PBUF_POOL \|\|
AdamGreen	0:616601bde9fb	415	p->type == PBUF_ROM \|\|
AdamGreen	0:616601bde9fb	416	p->type == PBUF_RAM \|\|
AdamGreen	0:616601bde9fb	417	p->type == PBUF_REF);
AdamGreen	0:616601bde9fb	418
AdamGreen	0:616601bde9fb	419	/* desired length larger than current length? */
AdamGreen	0:616601bde9fb	420	if (new_len >= p->tot_len) {
AdamGreen	0:616601bde9fb	421	/* enlarging not yet supported */
AdamGreen	0:616601bde9fb	422	return;
AdamGreen	0:616601bde9fb	423	}
AdamGreen	0:616601bde9fb	424
AdamGreen	0:616601bde9fb	425	/* the pbuf chain grows by (new_len - p->tot_len) bytes
AdamGreen	0:616601bde9fb	426	* (which may be negative in case of shrinking) */
AdamGreen	0:616601bde9fb	427	grow = new_len - p->tot_len;
AdamGreen	0:616601bde9fb	428
AdamGreen	0:616601bde9fb	429	/* first, step over any pbufs that should remain in the chain */
AdamGreen	0:616601bde9fb	430	rem_len = new_len;
AdamGreen	0:616601bde9fb	431	q = p;
AdamGreen	0:616601bde9fb	432	/* should this pbuf be kept? */
AdamGreen	0:616601bde9fb	433	while (rem_len > q->len) {
AdamGreen	0:616601bde9fb	434	/* decrease remaining length by pbuf length */
AdamGreen	0:616601bde9fb	435	rem_len -= q->len;
AdamGreen	0:616601bde9fb	436	/* decrease total length indicator */
AdamGreen	0:616601bde9fb	437	LWIP_ASSERT("grow < max_u16_t", grow < 0xffff);
AdamGreen	0:616601bde9fb	438	q->tot_len += (u16_t)grow;
AdamGreen	0:616601bde9fb	439	/* proceed to next pbuf in chain */
AdamGreen	0:616601bde9fb	440	q = q->next;
AdamGreen	0:616601bde9fb	441	LWIP_ASSERT("pbuf_realloc: q != NULL", q != NULL);
AdamGreen	0:616601bde9fb	442	}
AdamGreen	0:616601bde9fb	443	/* we have now reached the new last pbuf (in q) */
AdamGreen	0:616601bde9fb	444	/* rem_len == desired length for pbuf q */
AdamGreen	0:616601bde9fb	445
AdamGreen	0:616601bde9fb	446	/* shrink allocated memory for PBUF_RAM */
AdamGreen	0:616601bde9fb	447	/* (other types merely adjust their length fields */
AdamGreen	0:616601bde9fb	448	if ((q->type == PBUF_RAM) && (rem_len != q->len)) {
AdamGreen	0:616601bde9fb	449	/* reallocate and adjust the length of the pbuf that will be split */
AdamGreen	0:616601bde9fb	450	q = (struct pbuf )mem_trim(q, (u16_t)((u8_t )q->payload - (u8_t *)q) + rem_len);
AdamGreen	0:616601bde9fb	451	LWIP_ASSERT("mem_trim returned q == NULL", q != NULL);
AdamGreen	0:616601bde9fb	452	}
AdamGreen	0:616601bde9fb	453	/* adjust length fields for new last pbuf */
AdamGreen	0:616601bde9fb	454	q->len = rem_len;
AdamGreen	0:616601bde9fb	455	q->tot_len = q->len;
AdamGreen	0:616601bde9fb	456
AdamGreen	0:616601bde9fb	457	/* any remaining pbufs in chain? */
AdamGreen	0:616601bde9fb	458	if (q->next != NULL) {
AdamGreen	0:616601bde9fb	459	/* free remaining pbufs in chain */
AdamGreen	0:616601bde9fb	460	pbuf_free(q->next);
AdamGreen	0:616601bde9fb	461	}
AdamGreen	0:616601bde9fb	462	/* q is last packet in chain */
AdamGreen	0:616601bde9fb	463	q->next = NULL;
AdamGreen	0:616601bde9fb	464
AdamGreen	0:616601bde9fb	465	}
AdamGreen	0:616601bde9fb	466
AdamGreen	0:616601bde9fb	467	/**
AdamGreen	0:616601bde9fb	468	* Adjusts the payload pointer to hide or reveal headers in the payload.
AdamGreen	0:616601bde9fb	469	*
AdamGreen	0:616601bde9fb	470	* Adjusts the ->payload pointer so that space for a header
AdamGreen	0:616601bde9fb	471	* (dis)appears in the pbuf payload.
AdamGreen	0:616601bde9fb	472	*
AdamGreen	0:616601bde9fb	473	* The ->payload, ->tot_len and ->len fields are adjusted.
AdamGreen	0:616601bde9fb	474	*
AdamGreen	0:616601bde9fb	475	* @param p pbuf to change the header size.
AdamGreen	0:616601bde9fb	476	* @param header_size_increment Number of bytes to increment header size which
AdamGreen	0:616601bde9fb	477	* increases the size of the pbuf. New space is on the front.
AdamGreen	0:616601bde9fb	478	* (Using a negative value decreases the header size.)
AdamGreen	0:616601bde9fb	479	* If hdr_size_inc is 0, this function does nothing and returns succesful.
AdamGreen	0:616601bde9fb	480	*
AdamGreen	0:616601bde9fb	481	* PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so
AdamGreen	0:616601bde9fb	482	* the call will fail. A check is made that the increase in header size does
AdamGreen	0:616601bde9fb	483	* not move the payload pointer in front of the start of the buffer.
AdamGreen	0:616601bde9fb	484	* @return non-zero on failure, zero on success.
AdamGreen	0:616601bde9fb	485	*
AdamGreen	0:616601bde9fb	486	*/
AdamGreen	0:616601bde9fb	487	u8_t
AdamGreen	0:616601bde9fb	488	pbuf_header(struct pbuf *p, s16_t header_size_increment)
AdamGreen	0:616601bde9fb	489	{
AdamGreen	0:616601bde9fb	490	u16_t type;
AdamGreen	0:616601bde9fb	491	void *payload;
AdamGreen	0:616601bde9fb	492	u16_t increment_magnitude;
AdamGreen	0:616601bde9fb	493
AdamGreen	0:616601bde9fb	494	LWIP_ASSERT("p != NULL", p != NULL);
AdamGreen	0:616601bde9fb	495	if ((header_size_increment == 0) \|\| (p == NULL)) {
AdamGreen	0:616601bde9fb	496	return 0;
AdamGreen	0:616601bde9fb	497	}
AdamGreen	0:616601bde9fb	498
AdamGreen	0:616601bde9fb	499	if (header_size_increment < 0){
AdamGreen	0:616601bde9fb	500	increment_magnitude = -header_size_increment;
AdamGreen	0:616601bde9fb	501	/* Check that we aren't going to move off the end of the pbuf */
AdamGreen	0:616601bde9fb	502	LWIP_ERROR("increment_magnitude <= p->len", (increment_magnitude <= p->len), return 1;);
AdamGreen	0:616601bde9fb	503	} else {
AdamGreen	0:616601bde9fb	504	increment_magnitude = header_size_increment;
AdamGreen	0:616601bde9fb	505	#if 0
AdamGreen	0:616601bde9fb	506	/* Can't assert these as some callers speculatively call
AdamGreen	0:616601bde9fb	507	pbuf_header() to see if it's OK. Will return 1 below instead. */
AdamGreen	0:616601bde9fb	508	/* Check that we've got the correct type of pbuf to work with */
AdamGreen	0:616601bde9fb	509	LWIP_ASSERT("p->type == PBUF_RAM \|\| p->type == PBUF_POOL",
AdamGreen	0:616601bde9fb	510	p->type == PBUF_RAM \|\| p->type == PBUF_POOL);
AdamGreen	0:616601bde9fb	511	/* Check that we aren't going to move off the beginning of the pbuf */
AdamGreen	0:616601bde9fb	512	LWIP_ASSERT("p->payload - increment_magnitude >= p + SIZEOF_STRUCT_PBUF",
AdamGreen	0:616601bde9fb	513	(u8_t )p->payload - increment_magnitude >= (u8_t )p + SIZEOF_STRUCT_PBUF);
AdamGreen	0:616601bde9fb	514	#endif
AdamGreen	0:616601bde9fb	515	}
AdamGreen	0:616601bde9fb	516
AdamGreen	0:616601bde9fb	517	type = p->type;
AdamGreen	0:616601bde9fb	518	/* remember current payload pointer */
AdamGreen	0:616601bde9fb	519	payload = p->payload;
AdamGreen	0:616601bde9fb	520
AdamGreen	0:616601bde9fb	521	/* pbuf types containing payloads? */
AdamGreen	0:616601bde9fb	522	if (type == PBUF_RAM \|\| type == PBUF_POOL) {
AdamGreen	0:616601bde9fb	523	/* set new payload pointer */
AdamGreen	0:616601bde9fb	524	p->payload = (u8_t *)p->payload - header_size_increment;
AdamGreen	0:616601bde9fb	525	/* boundary check fails? */
AdamGreen	0:616601bde9fb	526	if ((u8_t )p->payload < (u8_t )p + SIZEOF_STRUCT_PBUF) {
AdamGreen	0:616601bde9fb	527	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
AdamGreen	0:616601bde9fb	528	("pbuf_header: failed as %p < %p (not enough space for new header size)\n",
AdamGreen	0:616601bde9fb	529	(void )p->payload, (void )(p + 1)));
AdamGreen	0:616601bde9fb	530	/* restore old payload pointer */
AdamGreen	0:616601bde9fb	531	p->payload = payload;
AdamGreen	0:616601bde9fb	532	/* bail out unsuccesfully */
AdamGreen	0:616601bde9fb	533	return 1;
AdamGreen	0:616601bde9fb	534	}
AdamGreen	0:616601bde9fb	535	/* pbuf types refering to external payloads? */
AdamGreen	0:616601bde9fb	536	} else if (type == PBUF_REF \|\| type == PBUF_ROM) {
AdamGreen	0:616601bde9fb	537	/* hide a header in the payload? */
AdamGreen	0:616601bde9fb	538	if ((header_size_increment < 0) && (increment_magnitude <= p->len)) {
AdamGreen	0:616601bde9fb	539	/* increase payload pointer */
AdamGreen	0:616601bde9fb	540	p->payload = (u8_t *)p->payload - header_size_increment;
AdamGreen	0:616601bde9fb	541	} else {
AdamGreen	0:616601bde9fb	542	/* cannot expand payload to front (yet!)
AdamGreen	0:616601bde9fb	543	* bail out unsuccesfully */
AdamGreen	0:616601bde9fb	544	return 1;
AdamGreen	0:616601bde9fb	545	}
AdamGreen	0:616601bde9fb	546	} else {
AdamGreen	0:616601bde9fb	547	/* Unknown type */
AdamGreen	0:616601bde9fb	548	LWIP_ASSERT("bad pbuf type", 0);
AdamGreen	0:616601bde9fb	549	return 1;
AdamGreen	0:616601bde9fb	550	}
AdamGreen	0:616601bde9fb	551	/* modify pbuf length fields */
AdamGreen	0:616601bde9fb	552	p->len += header_size_increment;
AdamGreen	0:616601bde9fb	553	p->tot_len += header_size_increment;
AdamGreen	0:616601bde9fb	554
AdamGreen	0:616601bde9fb	555	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_header: old %p new %p (%"S16_F")\n",
AdamGreen	0:616601bde9fb	556	(void )payload, (void )p->payload, header_size_increment));
AdamGreen	0:616601bde9fb	557
AdamGreen	0:616601bde9fb	558	return 0;
AdamGreen	0:616601bde9fb	559	}
AdamGreen	0:616601bde9fb	560
AdamGreen	0:616601bde9fb	561	/**
AdamGreen	0:616601bde9fb	562	* Dereference a pbuf chain or queue and deallocate any no-longer-used
AdamGreen	0:616601bde9fb	563	* pbufs at the head of this chain or queue.
AdamGreen	0:616601bde9fb	564	*
AdamGreen	0:616601bde9fb	565	* Decrements the pbuf reference count. If it reaches zero, the pbuf is
AdamGreen	0:616601bde9fb	566	* deallocated.
AdamGreen	0:616601bde9fb	567	*
AdamGreen	0:616601bde9fb	568	* For a pbuf chain, this is repeated for each pbuf in the chain,
AdamGreen	0:616601bde9fb	569	* up to the first pbuf which has a non-zero reference count after
AdamGreen	0:616601bde9fb	570	* decrementing. So, when all reference counts are one, the whole
AdamGreen	0:616601bde9fb	571	* chain is free'd.
AdamGreen	0:616601bde9fb	572	*
AdamGreen	0:616601bde9fb	573	* @param p The pbuf (chain) to be dereferenced.
AdamGreen	0:616601bde9fb	574	*
AdamGreen	0:616601bde9fb	575	* @return the number of pbufs that were de-allocated
AdamGreen	0:616601bde9fb	576	* from the head of the chain.
AdamGreen	0:616601bde9fb	577	*
AdamGreen	0:616601bde9fb	578	* @note MUST NOT be called on a packet queue (Not verified to work yet).
AdamGreen	0:616601bde9fb	579	* @note the reference counter of a pbuf equals the number of pointers
AdamGreen	0:616601bde9fb	580	* that refer to the pbuf (or into the pbuf).
AdamGreen	0:616601bde9fb	581	*
AdamGreen	0:616601bde9fb	582	* @internal examples:
AdamGreen	0:616601bde9fb	583	*
AdamGreen	0:616601bde9fb	584	* Assuming existing chains a->b->c with the following reference
AdamGreen	0:616601bde9fb	585	* counts, calling pbuf_free(a) results in:
AdamGreen	0:616601bde9fb	586	*
AdamGreen	0:616601bde9fb	587	* 1->2->3 becomes ...1->3
AdamGreen	0:616601bde9fb	588	* 3->3->3 becomes 2->3->3
AdamGreen	0:616601bde9fb	589	* 1->1->2 becomes ......1
AdamGreen	0:616601bde9fb	590	* 2->1->1 becomes 1->1->1
AdamGreen	0:616601bde9fb	591	* 1->1->1 becomes .......
AdamGreen	0:616601bde9fb	592	*
AdamGreen	0:616601bde9fb	593	*/
AdamGreen	0:616601bde9fb	594	u8_t
AdamGreen	0:616601bde9fb	595	pbuf_free(struct pbuf *p)
AdamGreen	0:616601bde9fb	596	{
AdamGreen	0:616601bde9fb	597	u16_t type;
AdamGreen	0:616601bde9fb	598	struct pbuf *q;
AdamGreen	0:616601bde9fb	599	u8_t count;
AdamGreen	0:616601bde9fb	600
AdamGreen	0:616601bde9fb	601	if (p == NULL) {
AdamGreen	0:616601bde9fb	602	LWIP_ASSERT("p != NULL", p != NULL);
AdamGreen	0:616601bde9fb	603	/* if assertions are disabled, proceed with debug output */
AdamGreen	0:616601bde9fb	604	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
AdamGreen	0:616601bde9fb	605	("pbuf_free(p == NULL) was called.\n"));
AdamGreen	0:616601bde9fb	606	return 0;
AdamGreen	0:616601bde9fb	607	}
AdamGreen	0:616601bde9fb	608	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free(%p)\n", (void *)p));
AdamGreen	0:616601bde9fb	609
AdamGreen	0:616601bde9fb	610	PERF_START;
AdamGreen	0:616601bde9fb	611
AdamGreen	0:616601bde9fb	612	LWIP_ASSERT("pbuf_free: sane type",
AdamGreen	0:616601bde9fb	613	p->type == PBUF_RAM \|\| p->type == PBUF_ROM \|\|
AdamGreen	0:616601bde9fb	614	p->type == PBUF_REF \|\| p->type == PBUF_POOL);
AdamGreen	0:616601bde9fb	615
AdamGreen	0:616601bde9fb	616	count = 0;
AdamGreen	0:616601bde9fb	617	/* de-allocate all consecutive pbufs from the head of the chain that
AdamGreen	0:616601bde9fb	618	* obtain a zero reference count after decrementing*/
AdamGreen	0:616601bde9fb	619	while (p != NULL) {
AdamGreen	0:616601bde9fb	620	u16_t ref;
AdamGreen	0:616601bde9fb	621	SYS_ARCH_DECL_PROTECT(old_level);
AdamGreen	0:616601bde9fb	622	/* Since decrementing ref cannot be guaranteed to be a single machine operation
AdamGreen	0:616601bde9fb	623	* we must protect it. We put the new ref into a local variable to prevent
AdamGreen	0:616601bde9fb	624	* further protection. */
AdamGreen	0:616601bde9fb	625	SYS_ARCH_PROTECT(old_level);
AdamGreen	0:616601bde9fb	626	/* all pbufs in a chain are referenced at least once */
AdamGreen	0:616601bde9fb	627	LWIP_ASSERT("pbuf_free: p->ref > 0", p->ref > 0);
AdamGreen	0:616601bde9fb	628	/* decrease reference count (number of pointers to pbuf) */
AdamGreen	0:616601bde9fb	629	ref = --(p->ref);
AdamGreen	0:616601bde9fb	630	SYS_ARCH_UNPROTECT(old_level);
AdamGreen	0:616601bde9fb	631	/* this pbuf is no longer referenced to? */
AdamGreen	0:616601bde9fb	632	if (ref == 0) {
AdamGreen	0:616601bde9fb	633	/* remember next pbuf in chain for next iteration */
AdamGreen	0:616601bde9fb	634	q = p->next;
AdamGreen	0:616601bde9fb	635	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free: deallocating %p\n", (void *)p));
AdamGreen	0:616601bde9fb	636	type = p->type;
AdamGreen	0:616601bde9fb	637	#if LWIP_SUPPORT_CUSTOM_PBUF
AdamGreen	0:616601bde9fb	638	/* is this a custom pbuf? */
AdamGreen	0:616601bde9fb	639	if ((p->flags & PBUF_FLAG_IS_CUSTOM) != 0) {
AdamGreen	0:616601bde9fb	640	struct pbuf_custom pc = (struct pbuf_custom)p;
AdamGreen	0:616601bde9fb	641	LWIP_ASSERT("pc->custom_free_function != NULL", pc->custom_free_function != NULL);
AdamGreen	0:616601bde9fb	642	pc->custom_free_function(p);
AdamGreen	0:616601bde9fb	643	} else
AdamGreen	0:616601bde9fb	644	#endif /* LWIP_SUPPORT_CUSTOM_PBUF */
AdamGreen	0:616601bde9fb	645	{
AdamGreen	0:616601bde9fb	646	/* is this a pbuf from the pool? */
AdamGreen	0:616601bde9fb	647	if (type == PBUF_POOL) {
AdamGreen	0:616601bde9fb	648	memp_free(MEMP_PBUF_POOL, p);
AdamGreen	0:616601bde9fb	649	/* is this a ROM or RAM referencing pbuf? */
AdamGreen	0:616601bde9fb	650	} else if (type == PBUF_ROM \|\| type == PBUF_REF) {
AdamGreen	0:616601bde9fb	651	memp_free(MEMP_PBUF, p);
AdamGreen	0:616601bde9fb	652	/* type == PBUF_RAM */
AdamGreen	0:616601bde9fb	653	} else {
AdamGreen	0:616601bde9fb	654	mem_free(p);
AdamGreen	0:616601bde9fb	655	}
AdamGreen	0:616601bde9fb	656	}
AdamGreen	0:616601bde9fb	657	count++;
AdamGreen	0:616601bde9fb	658	/* proceed to next pbuf */
AdamGreen	0:616601bde9fb	659	p = q;
AdamGreen	0:616601bde9fb	660	/* p->ref > 0, this pbuf is still referenced to */
AdamGreen	0:616601bde9fb	661	/* (and so the remaining pbufs in chain as well) */
AdamGreen	0:616601bde9fb	662	} else {
AdamGreen	0:616601bde9fb	663	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref));
AdamGreen	0:616601bde9fb	664	/* stop walking through the chain */
AdamGreen	0:616601bde9fb	665	p = NULL;
AdamGreen	0:616601bde9fb	666	}
AdamGreen	0:616601bde9fb	667	}
AdamGreen	0:616601bde9fb	668	PERF_STOP("pbuf_free");
AdamGreen	0:616601bde9fb	669	/* return number of de-allocated pbufs */
AdamGreen	0:616601bde9fb	670	return count;
AdamGreen	0:616601bde9fb	671	}
AdamGreen	0:616601bde9fb	672
AdamGreen	0:616601bde9fb	673	/**
AdamGreen	0:616601bde9fb	674	* Count number of pbufs in a chain
AdamGreen	0:616601bde9fb	675	*
AdamGreen	0:616601bde9fb	676	* @param p first pbuf of chain
AdamGreen	0:616601bde9fb	677	* @return the number of pbufs in a chain
AdamGreen	0:616601bde9fb	678	*/
AdamGreen	0:616601bde9fb	679
AdamGreen	0:616601bde9fb	680	u8_t
AdamGreen	0:616601bde9fb	681	pbuf_clen(struct pbuf *p)
AdamGreen	0:616601bde9fb	682	{
AdamGreen	0:616601bde9fb	683	u8_t len;
AdamGreen	0:616601bde9fb	684
AdamGreen	0:616601bde9fb	685	len = 0;
AdamGreen	0:616601bde9fb	686	while (p != NULL) {
AdamGreen	0:616601bde9fb	687	++len;
AdamGreen	0:616601bde9fb	688	p = p->next;
AdamGreen	0:616601bde9fb	689	}
AdamGreen	0:616601bde9fb	690	return len;
AdamGreen	0:616601bde9fb	691	}
AdamGreen	0:616601bde9fb	692
AdamGreen	0:616601bde9fb	693	/**
AdamGreen	0:616601bde9fb	694	* Increment the reference count of the pbuf.
AdamGreen	0:616601bde9fb	695	*
AdamGreen	0:616601bde9fb	696	* @param p pbuf to increase reference counter of
AdamGreen	0:616601bde9fb	697	*
AdamGreen	0:616601bde9fb	698	*/
AdamGreen	0:616601bde9fb	699	void
AdamGreen	0:616601bde9fb	700	pbuf_ref(struct pbuf *p)
AdamGreen	0:616601bde9fb	701	{
AdamGreen	0:616601bde9fb	702	SYS_ARCH_DECL_PROTECT(old_level);
AdamGreen	0:616601bde9fb	703	/* pbuf given? */
AdamGreen	0:616601bde9fb	704	if (p != NULL) {
AdamGreen	0:616601bde9fb	705	SYS_ARCH_PROTECT(old_level);
AdamGreen	0:616601bde9fb	706	++(p->ref);
AdamGreen	0:616601bde9fb	707	SYS_ARCH_UNPROTECT(old_level);
AdamGreen	0:616601bde9fb	708	}
AdamGreen	0:616601bde9fb	709	}
AdamGreen	0:616601bde9fb	710
AdamGreen	0:616601bde9fb	711	/**
AdamGreen	0:616601bde9fb	712	* Concatenate two pbufs (each may be a pbuf chain) and take over
AdamGreen	0:616601bde9fb	713	* the caller's reference of the tail pbuf.
AdamGreen	0:616601bde9fb	714	*
AdamGreen	0:616601bde9fb	715	* @note The caller MAY NOT reference the tail pbuf afterwards.
AdamGreen	0:616601bde9fb	716	* Use pbuf_chain() for that purpose.
AdamGreen	0:616601bde9fb	717	*
AdamGreen	0:616601bde9fb	718	* @see pbuf_chain()
AdamGreen	0:616601bde9fb	719	*/
AdamGreen	0:616601bde9fb	720
AdamGreen	0:616601bde9fb	721	void
AdamGreen	0:616601bde9fb	722	pbuf_cat(struct pbuf h, struct pbuf t)
AdamGreen	0:616601bde9fb	723	{
AdamGreen	0:616601bde9fb	724	struct pbuf *p;
AdamGreen	0:616601bde9fb	725
AdamGreen	0:616601bde9fb	726	LWIP_ERROR("(h != NULL) && (t != NULL) (programmer violates API)",
AdamGreen	0:616601bde9fb	727	((h != NULL) && (t != NULL)), return;);
AdamGreen	0:616601bde9fb	728
AdamGreen	0:616601bde9fb	729	/* proceed to last pbuf of chain */
AdamGreen	0:616601bde9fb	730	for (p = h; p->next != NULL; p = p->next) {
AdamGreen	0:616601bde9fb	731	/* add total length of second chain to all totals of first chain */
AdamGreen	0:616601bde9fb	732	p->tot_len += t->tot_len;
AdamGreen	0:616601bde9fb	733	}
AdamGreen	0:616601bde9fb	734	/* { p is last pbuf of first h chain, p->next == NULL } */
AdamGreen	0:616601bde9fb	735	LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len);
AdamGreen	0:616601bde9fb	736	LWIP_ASSERT("p->next == NULL", p->next == NULL);
AdamGreen	0:616601bde9fb	737	/* add total length of second chain to last pbuf total of first chain */
AdamGreen	0:616601bde9fb	738	p->tot_len += t->tot_len;
AdamGreen	0:616601bde9fb	739	/* chain last pbuf of head (p) with first of tail (t) */
AdamGreen	0:616601bde9fb	740	p->next = t;
AdamGreen	0:616601bde9fb	741	/* p->next now references t, but the caller will drop its reference to t,
AdamGreen	0:616601bde9fb	742	* so netto there is no change to the reference count of t.
AdamGreen	0:616601bde9fb	743	*/
AdamGreen	0:616601bde9fb	744	}
AdamGreen	0:616601bde9fb	745
AdamGreen	0:616601bde9fb	746	/**
AdamGreen	0:616601bde9fb	747	* Chain two pbufs (or pbuf chains) together.
AdamGreen	0:616601bde9fb	748	*
AdamGreen	0:616601bde9fb	749	* The caller MUST call pbuf_free(t) once it has stopped
AdamGreen	0:616601bde9fb	750	* using it. Use pbuf_cat() instead if you no longer use t.
AdamGreen	0:616601bde9fb	751	*
AdamGreen	0:616601bde9fb	752	* @param h head pbuf (chain)
AdamGreen	0:616601bde9fb	753	* @param t tail pbuf (chain)
AdamGreen	0:616601bde9fb	754	* @note The pbufs MUST belong to the same packet.
AdamGreen	0:616601bde9fb	755	* @note MAY NOT be called on a packet queue.
AdamGreen	0:616601bde9fb	756	*
AdamGreen	0:616601bde9fb	757	* The ->tot_len fields of all pbufs of the head chain are adjusted.
AdamGreen	0:616601bde9fb	758	* The ->next field of the last pbuf of the head chain is adjusted.
AdamGreen	0:616601bde9fb	759	* The ->ref field of the first pbuf of the tail chain is adjusted.
AdamGreen	0:616601bde9fb	760	*
AdamGreen	0:616601bde9fb	761	*/
AdamGreen	0:616601bde9fb	762	void
AdamGreen	0:616601bde9fb	763	pbuf_chain(struct pbuf h, struct pbuf t)
AdamGreen	0:616601bde9fb	764	{
AdamGreen	0:616601bde9fb	765	pbuf_cat(h, t);
AdamGreen	0:616601bde9fb	766	/* t is now referenced by h */
AdamGreen	0:616601bde9fb	767	pbuf_ref(t);
AdamGreen	0:616601bde9fb	768	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_chain: %p references %p\n", (void )h, (void )t));
AdamGreen	0:616601bde9fb	769	}
AdamGreen	0:616601bde9fb	770
AdamGreen	0:616601bde9fb	771	/**
AdamGreen	0:616601bde9fb	772	* Dechains the first pbuf from its succeeding pbufs in the chain.
AdamGreen	0:616601bde9fb	773	*
AdamGreen	0:616601bde9fb	774	* Makes p->tot_len field equal to p->len.
AdamGreen	0:616601bde9fb	775	* @param p pbuf to dechain
AdamGreen	0:616601bde9fb	776	* @return remainder of the pbuf chain, or NULL if it was de-allocated.
AdamGreen	0:616601bde9fb	777	* @note May not be called on a packet queue.
AdamGreen	0:616601bde9fb	778	*/
AdamGreen	0:616601bde9fb	779	struct pbuf *
AdamGreen	0:616601bde9fb	780	pbuf_dechain(struct pbuf *p)
AdamGreen	0:616601bde9fb	781	{
AdamGreen	0:616601bde9fb	782	struct pbuf *q;
AdamGreen	0:616601bde9fb	783	u8_t tail_gone = 1;
AdamGreen	0:616601bde9fb	784	/* tail */
AdamGreen	0:616601bde9fb	785	q = p->next;
AdamGreen	0:616601bde9fb	786	/* pbuf has successor in chain? */
AdamGreen	0:616601bde9fb	787	if (q != NULL) {
AdamGreen	0:616601bde9fb	788	/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
AdamGreen	0:616601bde9fb	789	LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len);
AdamGreen	0:616601bde9fb	790	/* enforce invariant if assertion is disabled */
AdamGreen	0:616601bde9fb	791	q->tot_len = p->tot_len - p->len;
AdamGreen	0:616601bde9fb	792	/* decouple pbuf from remainder */
AdamGreen	0:616601bde9fb	793	p->next = NULL;
AdamGreen	0:616601bde9fb	794	/* total length of pbuf p is its own length only */
AdamGreen	0:616601bde9fb	795	p->tot_len = p->len;
AdamGreen	0:616601bde9fb	796	/* q is no longer referenced by p, free it */
AdamGreen	0:616601bde9fb	797	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_dechain: unreferencing %p\n", (void *)q));
AdamGreen	0:616601bde9fb	798	tail_gone = pbuf_free(q);
AdamGreen	0:616601bde9fb	799	if (tail_gone > 0) {
AdamGreen	0:616601bde9fb	800	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE,
AdamGreen	0:616601bde9fb	801	("pbuf_dechain: deallocated %p (as it is no longer referenced)\n", (void *)q));
AdamGreen	0:616601bde9fb	802	}
AdamGreen	0:616601bde9fb	803	/* return remaining tail or NULL if deallocated */
AdamGreen	0:616601bde9fb	804	}
AdamGreen	0:616601bde9fb	805	/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
AdamGreen	0:616601bde9fb	806	LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len);
AdamGreen	0:616601bde9fb	807	return ((tail_gone > 0) ? NULL : q);
AdamGreen	0:616601bde9fb	808	}
AdamGreen	0:616601bde9fb	809
AdamGreen	0:616601bde9fb	810	/**
AdamGreen	0:616601bde9fb	811	*
AdamGreen	0:616601bde9fb	812	* Create PBUF_RAM copies of pbufs.
AdamGreen	0:616601bde9fb	813	*
AdamGreen	0:616601bde9fb	814	* Used to queue packets on behalf of the lwIP stack, such as
AdamGreen	0:616601bde9fb	815	* ARP based queueing.
AdamGreen	0:616601bde9fb	816	*
AdamGreen	0:616601bde9fb	817	* @note You MUST explicitly use p = pbuf_take(p);
AdamGreen	0:616601bde9fb	818	*
AdamGreen	0:616601bde9fb	819	* @note Only one packet is copied, no packet queue!
AdamGreen	0:616601bde9fb	820	*
AdamGreen	0:616601bde9fb	821	* @param p_to pbuf destination of the copy
AdamGreen	0:616601bde9fb	822	* @param p_from pbuf source of the copy
AdamGreen	0:616601bde9fb	823	*
AdamGreen	0:616601bde9fb	824	* @return ERR_OK if pbuf was copied
AdamGreen	0:616601bde9fb	825	* ERR_ARG if one of the pbufs is NULL or p_to is not big
AdamGreen	0:616601bde9fb	826	* enough to hold p_from
AdamGreen	0:616601bde9fb	827	*/
AdamGreen	0:616601bde9fb	828	err_t
AdamGreen	0:616601bde9fb	829	pbuf_copy(struct pbuf p_to, struct pbuf p_from)
AdamGreen	0:616601bde9fb	830	{
AdamGreen	0:616601bde9fb	831	u16_t offset_to=0, offset_from=0, len;
AdamGreen	0:616601bde9fb	832
AdamGreen	0:616601bde9fb	833	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_copy(%p, %p)\n",
AdamGreen	0:616601bde9fb	834	(void)p_to, (void)p_from));
AdamGreen	0:616601bde9fb	835
AdamGreen	0:616601bde9fb	836	/* is the target big enough to hold the source? */
AdamGreen	0:616601bde9fb	837	LWIP_ERROR("pbuf_copy: target not big enough to hold source", ((p_to != NULL) &&
AdamGreen	0:616601bde9fb	838	(p_from != NULL) && (p_to->tot_len >= p_from->tot_len)), return ERR_ARG;);
AdamGreen	0:616601bde9fb	839
AdamGreen	0:616601bde9fb	840	/* iterate through pbuf chain */
AdamGreen	0:616601bde9fb	841	do
AdamGreen	0:616601bde9fb	842	{
AdamGreen	0:616601bde9fb	843	LWIP_ASSERT("p_to != NULL", p_to != NULL);
AdamGreen	0:616601bde9fb	844	/* copy one part of the original chain */
AdamGreen	0:616601bde9fb	845	if ((p_to->len - offset_to) >= (p_from->len - offset_from)) {
AdamGreen	0:616601bde9fb	846	/* complete current p_from fits into current p_to */
AdamGreen	0:616601bde9fb	847	len = p_from->len - offset_from;
AdamGreen	0:616601bde9fb	848	} else {
AdamGreen	0:616601bde9fb	849	/* current p_from does not fit into current p_to */
AdamGreen	0:616601bde9fb	850	len = p_to->len - offset_to;
AdamGreen	0:616601bde9fb	851	}
AdamGreen	0:616601bde9fb	852	MEMCPY((u8_t)p_to->payload + offset_to, (u8_t)p_from->payload + offset_from, len);
AdamGreen	0:616601bde9fb	853	offset_to += len;
AdamGreen	0:616601bde9fb	854	offset_from += len;
AdamGreen	0:616601bde9fb	855	LWIP_ASSERT("offset_to <= p_to->len", offset_to <= p_to->len);
AdamGreen	0:616601bde9fb	856	if (offset_to == p_to->len) {
AdamGreen	0:616601bde9fb	857	/* on to next p_to (if any) */
AdamGreen	0:616601bde9fb	858	offset_to = 0;
AdamGreen	0:616601bde9fb	859	p_to = p_to->next;
AdamGreen	0:616601bde9fb	860	}
AdamGreen	0:616601bde9fb	861	LWIP_ASSERT("offset_from <= p_from->len", offset_from <= p_from->len);
AdamGreen	0:616601bde9fb	862	if (offset_from >= p_from->len) {
AdamGreen	0:616601bde9fb	863	/* on to next p_from (if any) */
AdamGreen	0:616601bde9fb	864	offset_from = 0;
AdamGreen	0:616601bde9fb	865	p_from = p_from->next;
AdamGreen	0:616601bde9fb	866	}
AdamGreen	0:616601bde9fb	867
AdamGreen	0:616601bde9fb	868	if((p_from != NULL) && (p_from->len == p_from->tot_len)) {
AdamGreen	0:616601bde9fb	869	/* don't copy more than one packet! */
AdamGreen	0:616601bde9fb	870	LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
AdamGreen	0:616601bde9fb	871	(p_from->next == NULL), return ERR_VAL;);
AdamGreen	0:616601bde9fb	872	}
AdamGreen	0:616601bde9fb	873	if((p_to != NULL) && (p_to->len == p_to->tot_len)) {
AdamGreen	0:616601bde9fb	874	/* don't copy more than one packet! */
AdamGreen	0:616601bde9fb	875	LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
AdamGreen	0:616601bde9fb	876	(p_to->next == NULL), return ERR_VAL;);
AdamGreen	0:616601bde9fb	877	}
AdamGreen	0:616601bde9fb	878	} while (p_from);
AdamGreen	0:616601bde9fb	879	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_copy: end of chain reached.\n"));
AdamGreen	0:616601bde9fb	880	return ERR_OK;
AdamGreen	0:616601bde9fb	881	}
AdamGreen	0:616601bde9fb	882
AdamGreen	0:616601bde9fb	883	/**
AdamGreen	0:616601bde9fb	884	* Copy (part of) the contents of a packet buffer
AdamGreen	0:616601bde9fb	885	* to an application supplied buffer.
AdamGreen	0:616601bde9fb	886	*
AdamGreen	0:616601bde9fb	887	* @param buf the pbuf from which to copy data
AdamGreen	0:616601bde9fb	888	* @param dataptr the application supplied buffer
AdamGreen	0:616601bde9fb	889	* @param len length of data to copy (dataptr must be big enough). No more
AdamGreen	0:616601bde9fb	890	* than buf->tot_len will be copied, irrespective of len
AdamGreen	0:616601bde9fb	891	* @param offset offset into the packet buffer from where to begin copying len bytes
AdamGreen	0:616601bde9fb	892	* @return the number of bytes copied, or 0 on failure
AdamGreen	0:616601bde9fb	893	*/
AdamGreen	0:616601bde9fb	894	u16_t
AdamGreen	0:616601bde9fb	895	pbuf_copy_partial(struct pbuf buf, void dataptr, u16_t len, u16_t offset)
AdamGreen	0:616601bde9fb	896	{
AdamGreen	0:616601bde9fb	897	struct pbuf *p;
AdamGreen	0:616601bde9fb	898	u16_t left;
AdamGreen	0:616601bde9fb	899	u16_t buf_copy_len;
AdamGreen	0:616601bde9fb	900	u16_t copied_total = 0;
AdamGreen	0:616601bde9fb	901
AdamGreen	0:616601bde9fb	902	LWIP_ERROR("pbuf_copy_partial: invalid buf", (buf != NULL), return 0;);
AdamGreen	0:616601bde9fb	903	LWIP_ERROR("pbuf_copy_partial: invalid dataptr", (dataptr != NULL), return 0;);
AdamGreen	0:616601bde9fb	904
AdamGreen	0:616601bde9fb	905	left = 0;
AdamGreen	0:616601bde9fb	906
AdamGreen	0:616601bde9fb	907	if((buf == NULL) \|\| (dataptr == NULL)) {
AdamGreen	0:616601bde9fb	908	return 0;
AdamGreen	0:616601bde9fb	909	}
AdamGreen	0:616601bde9fb	910
AdamGreen	0:616601bde9fb	911	/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
AdamGreen	0:616601bde9fb	912	for(p = buf; len != 0 && p != NULL; p = p->next) {
AdamGreen	0:616601bde9fb	913	if ((offset != 0) && (offset >= p->len)) {
AdamGreen	0:616601bde9fb	914	/* don't copy from this buffer -> on to the next */
AdamGreen	0:616601bde9fb	915	offset -= p->len;
AdamGreen	0:616601bde9fb	916	} else {
AdamGreen	0:616601bde9fb	917	/* copy from this buffer. maybe only partially. */
AdamGreen	0:616601bde9fb	918	buf_copy_len = p->len - offset;
AdamGreen	0:616601bde9fb	919	if (buf_copy_len > len)
AdamGreen	0:616601bde9fb	920	buf_copy_len = len;
AdamGreen	0:616601bde9fb	921	/* copy the necessary parts of the buffer */
AdamGreen	0:616601bde9fb	922	MEMCPY(&((char)dataptr)[left], &((char)p->payload)[offset], buf_copy_len);
AdamGreen	0:616601bde9fb	923	copied_total += buf_copy_len;
AdamGreen	0:616601bde9fb	924	left += buf_copy_len;
AdamGreen	0:616601bde9fb	925	len -= buf_copy_len;
AdamGreen	0:616601bde9fb	926	offset = 0;
AdamGreen	0:616601bde9fb	927	}
AdamGreen	0:616601bde9fb	928	}
AdamGreen	0:616601bde9fb	929	return copied_total;
AdamGreen	0:616601bde9fb	930	}
AdamGreen	0:616601bde9fb	931
AdamGreen	0:616601bde9fb	932	/**
AdamGreen	0:616601bde9fb	933	* Copy application supplied data into a pbuf.
AdamGreen	0:616601bde9fb	934	* This function can only be used to copy the equivalent of buf->tot_len data.
AdamGreen	0:616601bde9fb	935	*
AdamGreen	0:616601bde9fb	936	* @param buf pbuf to fill with data
AdamGreen	0:616601bde9fb	937	* @param dataptr application supplied data buffer
AdamGreen	0:616601bde9fb	938	* @param len length of the application supplied data buffer
AdamGreen	0:616601bde9fb	939	*
AdamGreen	0:616601bde9fb	940	* @return ERR_OK if successful, ERR_MEM if the pbuf is not big enough
AdamGreen	0:616601bde9fb	941	*/
AdamGreen	0:616601bde9fb	942	err_t
AdamGreen	0:616601bde9fb	943	pbuf_take(struct pbuf buf, const void dataptr, u16_t len)
AdamGreen	0:616601bde9fb	944	{
AdamGreen	0:616601bde9fb	945	struct pbuf *p;
AdamGreen	0:616601bde9fb	946	u16_t buf_copy_len;
AdamGreen	0:616601bde9fb	947	u16_t total_copy_len = len;
AdamGreen	0:616601bde9fb	948	u16_t copied_total = 0;
AdamGreen	0:616601bde9fb	949
AdamGreen	0:616601bde9fb	950	LWIP_ERROR("pbuf_take: invalid buf", (buf != NULL), return 0;);
AdamGreen	0:616601bde9fb	951	LWIP_ERROR("pbuf_take: invalid dataptr", (dataptr != NULL), return 0;);
AdamGreen	0:616601bde9fb	952
AdamGreen	0:616601bde9fb	953	if ((buf == NULL) \|\| (dataptr == NULL) \|\| (buf->tot_len < len)) {
AdamGreen	0:616601bde9fb	954	return ERR_ARG;
AdamGreen	0:616601bde9fb	955	}
AdamGreen	0:616601bde9fb	956
AdamGreen	0:616601bde9fb	957	/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
AdamGreen	0:616601bde9fb	958	for(p = buf; total_copy_len != 0; p = p->next) {
AdamGreen	0:616601bde9fb	959	LWIP_ASSERT("pbuf_take: invalid pbuf", p != NULL);
AdamGreen	0:616601bde9fb	960	buf_copy_len = total_copy_len;
AdamGreen	0:616601bde9fb	961	if (buf_copy_len > p->len) {
AdamGreen	0:616601bde9fb	962	/* this pbuf cannot hold all remaining data */
AdamGreen	0:616601bde9fb	963	buf_copy_len = p->len;
AdamGreen	0:616601bde9fb	964	}
AdamGreen	0:616601bde9fb	965	/* copy the necessary parts of the buffer */
AdamGreen	0:616601bde9fb	966	MEMCPY(p->payload, &((char*)dataptr)[copied_total], buf_copy_len);
AdamGreen	0:616601bde9fb	967	total_copy_len -= buf_copy_len;
AdamGreen	0:616601bde9fb	968	copied_total += buf_copy_len;
AdamGreen	0:616601bde9fb	969	}
AdamGreen	0:616601bde9fb	970	LWIP_ASSERT("did not copy all data", total_copy_len == 0 && copied_total == len);
AdamGreen	0:616601bde9fb	971	return ERR_OK;
AdamGreen	0:616601bde9fb	972	}
AdamGreen	0:616601bde9fb	973
AdamGreen	0:616601bde9fb	974	/**
AdamGreen	0:616601bde9fb	975	* Creates a single pbuf out of a queue of pbufs.
AdamGreen	0:616601bde9fb	976	*
AdamGreen	0:616601bde9fb	977	* @remark: Either the source pbuf 'p' is freed by this function or the original
AdamGreen	0:616601bde9fb	978	* pbuf 'p' is returned, therefore the caller has to check the result!
AdamGreen	0:616601bde9fb	979	*
AdamGreen	0:616601bde9fb	980	* @param p the source pbuf
AdamGreen	0:616601bde9fb	981	* @param layer pbuf_layer of the new pbuf
AdamGreen	0:616601bde9fb	982	*
AdamGreen	0:616601bde9fb	983	* @return a new, single pbuf (p->next is NULL)
AdamGreen	0:616601bde9fb	984	* or the old pbuf if allocation fails
AdamGreen	0:616601bde9fb	985	*/
AdamGreen	0:616601bde9fb	986	struct pbuf*
AdamGreen	0:616601bde9fb	987	pbuf_coalesce(struct pbuf *p, pbuf_layer layer)
AdamGreen	0:616601bde9fb	988	{
AdamGreen	0:616601bde9fb	989	struct pbuf *q;
AdamGreen	0:616601bde9fb	990	err_t err;
AdamGreen	0:616601bde9fb	991	if (p->next == NULL) {
AdamGreen	0:616601bde9fb	992	return p;
AdamGreen	0:616601bde9fb	993	}
AdamGreen	0:616601bde9fb	994	q = pbuf_alloc(layer, p->tot_len, PBUF_RAM);
AdamGreen	0:616601bde9fb	995	if (q == NULL) {
AdamGreen	0:616601bde9fb	996	/* @todo: what do we do now? */
AdamGreen	0:616601bde9fb	997	return p;
AdamGreen	0:616601bde9fb	998	}
AdamGreen	0:616601bde9fb	999	err = pbuf_copy(q, p);
AdamGreen	0:616601bde9fb	1000	LWIP_ASSERT("pbuf_copy failed", err == ERR_OK);
AdamGreen	0:616601bde9fb	1001	pbuf_free(p);
AdamGreen	0:616601bde9fb	1002	return q;
AdamGreen	0:616601bde9fb	1003	}
AdamGreen	0:616601bde9fb	1004
AdamGreen	0:616601bde9fb	1005	#if LWIP_CHECKSUM_ON_COPY
AdamGreen	0:616601bde9fb	1006	/**
AdamGreen	0:616601bde9fb	1007	* Copies data into a single pbuf (not into a pbuf queue!) and updates
AdamGreen	0:616601bde9fb	1008	* the checksum while copying
AdamGreen	0:616601bde9fb	1009	*
AdamGreen	0:616601bde9fb	1010	* @param p the pbuf to copy data into
AdamGreen	0:616601bde9fb	1011	* @param start_offset offset of p->payload where to copy the data to
AdamGreen	0:616601bde9fb	1012	* @param dataptr data to copy into the pbuf
AdamGreen	0:616601bde9fb	1013	* @param len length of data to copy into the pbuf
AdamGreen	0:616601bde9fb	1014	* @param chksum pointer to the checksum which is updated
AdamGreen	0:616601bde9fb	1015	* @return ERR_OK if successful, another error if the data does not fit
AdamGreen	0:616601bde9fb	1016	* within the (first) pbuf (no pbuf queues!)
AdamGreen	0:616601bde9fb	1017	*/
AdamGreen	0:616601bde9fb	1018	err_t
AdamGreen	0:616601bde9fb	1019	pbuf_fill_chksum(struct pbuf p, u16_t start_offset, const void dataptr,
AdamGreen	0:616601bde9fb	1020	u16_t len, u16_t *chksum)
AdamGreen	0:616601bde9fb	1021	{
AdamGreen	0:616601bde9fb	1022	u32_t acc;
AdamGreen	0:616601bde9fb	1023	u16_t copy_chksum;
AdamGreen	0:616601bde9fb	1024	char *dst_ptr;
AdamGreen	0:616601bde9fb	1025	LWIP_ASSERT("p != NULL", p != NULL);
AdamGreen	0:616601bde9fb	1026	LWIP_ASSERT("dataptr != NULL", dataptr != NULL);
AdamGreen	0:616601bde9fb	1027	LWIP_ASSERT("chksum != NULL", chksum != NULL);
AdamGreen	0:616601bde9fb	1028	LWIP_ASSERT("len != 0", len != 0);
AdamGreen	0:616601bde9fb	1029
AdamGreen	0:616601bde9fb	1030	if ((start_offset >= p->len) \|\| (start_offset + len > p->len)) {
AdamGreen	0:616601bde9fb	1031	return ERR_ARG;
AdamGreen	0:616601bde9fb	1032	}
AdamGreen	0:616601bde9fb	1033
AdamGreen	0:616601bde9fb	1034	dst_ptr = ((char*)p->payload) + start_offset;
AdamGreen	0:616601bde9fb	1035	copy_chksum = LWIP_CHKSUM_COPY(dst_ptr, dataptr, len);
AdamGreen	0:616601bde9fb	1036	if ((start_offset & 1) != 0) {
AdamGreen	0:616601bde9fb	1037	copy_chksum = SWAP_BYTES_IN_WORD(copy_chksum);
AdamGreen	0:616601bde9fb	1038	}
AdamGreen	0:616601bde9fb	1039	acc = *chksum;
AdamGreen	0:616601bde9fb	1040	acc += copy_chksum;
AdamGreen	0:616601bde9fb	1041	*chksum = FOLD_U32T(acc);
AdamGreen	0:616601bde9fb	1042	return ERR_OK;
AdamGreen	0:616601bde9fb	1043	}
AdamGreen	0:616601bde9fb	1044	#endif /* LWIP_CHECKSUM_ON_COPY */
AdamGreen	0:616601bde9fb	1045
AdamGreen	0:616601bde9fb	1046	/** Get one byte from the specified position in a pbuf
AdamGreen	0:616601bde9fb	1047	* WARNING: returns zero for offset >= p->tot_len
AdamGreen	0:616601bde9fb	1048	*
AdamGreen	0:616601bde9fb	1049	* @param p pbuf to parse
AdamGreen	0:616601bde9fb	1050	* @param offset offset into p of the byte to return
AdamGreen	0:616601bde9fb	1051	* @return byte at an offset into p OR ZERO IF 'offset' >= p->tot_len
AdamGreen	0:616601bde9fb	1052	*/
AdamGreen	0:616601bde9fb	1053	u8_t
AdamGreen	0:616601bde9fb	1054	pbuf_get_at(struct pbuf* p, u16_t offset)
AdamGreen	0:616601bde9fb	1055	{
AdamGreen	0:616601bde9fb	1056	u16_t copy_from = offset;
AdamGreen	0:616601bde9fb	1057	struct pbuf* q = p;
AdamGreen	0:616601bde9fb	1058
AdamGreen	0:616601bde9fb	1059	/* get the correct pbuf */
AdamGreen	0:616601bde9fb	1060	while ((q != NULL) && (q->len <= copy_from)) {
AdamGreen	0:616601bde9fb	1061	copy_from -= q->len;
AdamGreen	0:616601bde9fb	1062	q = q->next;
AdamGreen	0:616601bde9fb	1063	}
AdamGreen	0:616601bde9fb	1064	/* return requested data if pbuf is OK */
AdamGreen	0:616601bde9fb	1065	if ((q != NULL) && (q->len > copy_from)) {
AdamGreen	0:616601bde9fb	1066	return ((u8_t*)q->payload)[copy_from];
AdamGreen	0:616601bde9fb	1067	}
AdamGreen	0:616601bde9fb	1068	return 0;
AdamGreen	0:616601bde9fb	1069	}
AdamGreen	0:616601bde9fb	1070
AdamGreen	0:616601bde9fb	1071	/** Compare pbuf contents at specified offset with memory s2, both of length n
AdamGreen	0:616601bde9fb	1072	*
AdamGreen	0:616601bde9fb	1073	* @param p pbuf to compare
AdamGreen	0:616601bde9fb	1074	* @param offset offset into p at wich to start comparing
AdamGreen	0:616601bde9fb	1075	* @param s2 buffer to compare
AdamGreen	0:616601bde9fb	1076	* @param n length of buffer to compare
AdamGreen	0:616601bde9fb	1077	* @return zero if equal, nonzero otherwise
AdamGreen	0:616601bde9fb	1078	* (0xffff if p is too short, diffoffset+1 otherwise)
AdamGreen	0:616601bde9fb	1079	*/
AdamGreen	0:616601bde9fb	1080	u16_t
AdamGreen	0:616601bde9fb	1081	pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n)
AdamGreen	0:616601bde9fb	1082	{
AdamGreen	0:616601bde9fb	1083	u16_t start = offset;
AdamGreen	0:616601bde9fb	1084	struct pbuf* q = p;
AdamGreen	0:616601bde9fb	1085
AdamGreen	0:616601bde9fb	1086	/* get the correct pbuf */
AdamGreen	0:616601bde9fb	1087	while ((q != NULL) && (q->len <= start)) {
AdamGreen	0:616601bde9fb	1088	start -= q->len;
AdamGreen	0:616601bde9fb	1089	q = q->next;
AdamGreen	0:616601bde9fb	1090	}
AdamGreen	0:616601bde9fb	1091	/* return requested data if pbuf is OK */
AdamGreen	0:616601bde9fb	1092	if ((q != NULL) && (q->len > start)) {
AdamGreen	0:616601bde9fb	1093	u16_t i;
AdamGreen	0:616601bde9fb	1094	for(i = 0; i < n; i++) {
AdamGreen	0:616601bde9fb	1095	u8_t a = pbuf_get_at(q, start + i);
AdamGreen	0:616601bde9fb	1096	u8_t b = ((u8_t*)s2)[i];
AdamGreen	0:616601bde9fb	1097	if (a != b) {
AdamGreen	0:616601bde9fb	1098	return i+1;
AdamGreen	0:616601bde9fb	1099	}
AdamGreen	0:616601bde9fb	1100	}
AdamGreen	0:616601bde9fb	1101	return 0;
AdamGreen	0:616601bde9fb	1102	}
AdamGreen	0:616601bde9fb	1103	return 0xffff;
AdamGreen	0:616601bde9fb	1104	}
AdamGreen	0:616601bde9fb	1105
AdamGreen	0:616601bde9fb	1106	/** Find occurrence of mem (with length mem_len) in pbuf p, starting at offset
AdamGreen	0:616601bde9fb	1107	* start_offset.
AdamGreen	0:616601bde9fb	1108	*
AdamGreen	0:616601bde9fb	1109	* @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
AdamGreen	0:616601bde9fb	1110	* return value 'not found'
AdamGreen	0:616601bde9fb	1111	* @param mem search for the contents of this buffer
AdamGreen	0:616601bde9fb	1112	* @param mem_len length of 'mem'
AdamGreen	0:616601bde9fb	1113	* @param start_offset offset into p at which to start searching
AdamGreen	0:616601bde9fb	1114	* @return 0xFFFF if substr was not found in p or the index where it was found
AdamGreen	0:616601bde9fb	1115	*/
AdamGreen	0:616601bde9fb	1116	u16_t
AdamGreen	0:616601bde9fb	1117	pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset)
AdamGreen	0:616601bde9fb	1118	{
AdamGreen	0:616601bde9fb	1119	u16_t i;
AdamGreen	0:616601bde9fb	1120	u16_t max = p->tot_len - mem_len;
AdamGreen	0:616601bde9fb	1121	if (p->tot_len >= mem_len + start_offset) {
AdamGreen	0:616601bde9fb	1122	for(i = start_offset; i <= max; ) {
AdamGreen	0:616601bde9fb	1123	u16_t plus = pbuf_memcmp(p, i, mem, mem_len);
AdamGreen	0:616601bde9fb	1124	if (plus == 0) {
AdamGreen	0:616601bde9fb	1125	return i;
AdamGreen	0:616601bde9fb	1126	} else {
AdamGreen	0:616601bde9fb	1127	i += plus;
AdamGreen	0:616601bde9fb	1128	}
AdamGreen	0:616601bde9fb	1129	}
AdamGreen	0:616601bde9fb	1130	}
AdamGreen	0:616601bde9fb	1131	return 0xFFFF;
AdamGreen	0:616601bde9fb	1132	}
AdamGreen	0:616601bde9fb	1133
AdamGreen	0:616601bde9fb	1134	/** Find occurrence of substr with length substr_len in pbuf p, start at offset
AdamGreen	0:616601bde9fb	1135	* start_offset
AdamGreen	0:616601bde9fb	1136	* WARNING: in contrast to strstr(), this one does not stop at the first \0 in
AdamGreen	0:616601bde9fb	1137	* the pbuf/source string!
AdamGreen	0:616601bde9fb	1138	*
AdamGreen	0:616601bde9fb	1139	* @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
AdamGreen	0:616601bde9fb	1140	* return value 'not found'
AdamGreen	0:616601bde9fb	1141	* @param substr string to search for in p, maximum length is 0xFFFE
AdamGreen	0:616601bde9fb	1142	* @return 0xFFFF if substr was not found in p or the index where it was found
AdamGreen	0:616601bde9fb	1143	*/
AdamGreen	0:616601bde9fb	1144	u16_t
AdamGreen	0:616601bde9fb	1145	pbuf_strstr(struct pbuf* p, const char* substr)
AdamGreen	0:616601bde9fb	1146	{
AdamGreen	0:616601bde9fb	1147	size_t substr_len;
AdamGreen	0:616601bde9fb	1148	if ((substr == NULL) \|\| (substr[0] == 0) \|\| (p->tot_len == 0xFFFF)) {
AdamGreen	0:616601bde9fb	1149	return 0xFFFF;
AdamGreen	0:616601bde9fb	1150	}
AdamGreen	0:616601bde9fb	1151	substr_len = strlen(substr);
AdamGreen	0:616601bde9fb	1152	if (substr_len >= 0xFFFF) {
AdamGreen	0:616601bde9fb	1153	return 0xFFFF;
AdamGreen	0:616601bde9fb	1154	}
AdamGreen	0:616601bde9fb	1155	return pbuf_memfind(p, substr, (u16_t)substr_len, 0);
AdamGreen	0:616601bde9fb	1156	}

Repository toolbox

Export to desktop IDE

Build repository

Repository details

Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	23 Feb 2012
Imports:	113
Forks:	0
Commits:	2
Dependents:	0
Dependencies:	4
Followers:	6

NetStack/lwip/core/pbuf.c@0:616601bde9fb, 2012-02-23 (annotated)

Who changed what in which revision?

Repository toolbox

Repository details

Important Information for this Arm website

Access Warning