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lwip/core/pbuf.c@0:281d6ff68967, 2010-11-19 (annotated)

Committer:: hexley
Date:: Fri Nov 19 01:54:45 2010 +0000
Revision:: 0:281d6ff68967

Who changed what in which revision?

User	Revision	Line number	New contents of line
hexley	0:281d6ff68967	1	/**
hexley	0:281d6ff68967	2	* @file
hexley	0:281d6ff68967	3	* Packet buffer management
hexley	0:281d6ff68967	4	*
hexley	0:281d6ff68967	5	* Packets are built from the pbuf data structure. It supports dynamic
hexley	0:281d6ff68967	6	* memory allocation for packet contents or can reference externally
hexley	0:281d6ff68967	7	* managed packet contents both in RAM and ROM. Quick allocation for
hexley	0:281d6ff68967	8	* incoming packets is provided through pools with fixed sized pbufs.
hexley	0:281d6ff68967	9	*
hexley	0:281d6ff68967	10	* A packet may span over multiple pbufs, chained as a singly linked
hexley	0:281d6ff68967	11	* list. This is called a "pbuf chain".
hexley	0:281d6ff68967	12	*
hexley	0:281d6ff68967	13	* Multiple packets may be queued, also using this singly linked list.
hexley	0:281d6ff68967	14	* This is called a "packet queue".
hexley	0:281d6ff68967	15	*
hexley	0:281d6ff68967	16	* So, a packet queue consists of one or more pbuf chains, each of
hexley	0:281d6ff68967	17	* which consist of one or more pbufs. CURRENTLY, PACKET QUEUES ARE
hexley	0:281d6ff68967	18	* NOT SUPPORTED!!! Use helper structs to queue multiple packets.
hexley	0:281d6ff68967	19	*
hexley	0:281d6ff68967	20	* The differences between a pbuf chain and a packet queue are very
hexley	0:281d6ff68967	21	* precise but subtle.
hexley	0:281d6ff68967	22	*
hexley	0:281d6ff68967	23	* The last pbuf of a packet has a ->tot_len field that equals the
hexley	0:281d6ff68967	24	* ->len field. It can be found by traversing the list. If the last
hexley	0:281d6ff68967	25	* pbuf of a packet has a ->next field other than NULL, more packets
hexley	0:281d6ff68967	26	* are on the queue.
hexley	0:281d6ff68967	27	*
hexley	0:281d6ff68967	28	* Therefore, looping through a pbuf of a single packet, has an
hexley	0:281d6ff68967	29	* loop end condition (tot_len == p->len), NOT (next == NULL).
hexley	0:281d6ff68967	30	*/
hexley	0:281d6ff68967	31
hexley	0:281d6ff68967	32	/*
hexley	0:281d6ff68967	33	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
hexley	0:281d6ff68967	34	* All rights reserved.
hexley	0:281d6ff68967	35	*
hexley	0:281d6ff68967	36	* Redistribution and use in source and binary forms, with or without modification,
hexley	0:281d6ff68967	37	* are permitted provided that the following conditions are met:
hexley	0:281d6ff68967	38	*
hexley	0:281d6ff68967	39	* 1. Redistributions of source code must retain the above copyright notice,
hexley	0:281d6ff68967	40	* this list of conditions and the following disclaimer.
hexley	0:281d6ff68967	41	* 2. Redistributions in binary form must reproduce the above copyright notice,
hexley	0:281d6ff68967	42	* this list of conditions and the following disclaimer in the documentation
hexley	0:281d6ff68967	43	* and/or other materials provided with the distribution.
hexley	0:281d6ff68967	44	* 3. The name of the author may not be used to endorse or promote products
hexley	0:281d6ff68967	45	* derived from this software without specific prior written permission.
hexley	0:281d6ff68967	46	*
hexley	0:281d6ff68967	47	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
hexley	0:281d6ff68967	48	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
hexley	0:281d6ff68967	49	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
hexley	0:281d6ff68967	50	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
hexley	0:281d6ff68967	51	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
hexley	0:281d6ff68967	52	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
hexley	0:281d6ff68967	53	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
hexley	0:281d6ff68967	54	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
hexley	0:281d6ff68967	55	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
hexley	0:281d6ff68967	56	* OF SUCH DAMAGE.
hexley	0:281d6ff68967	57	*
hexley	0:281d6ff68967	58	* This file is part of the lwIP TCP/IP stack.
hexley	0:281d6ff68967	59	*
hexley	0:281d6ff68967	60	* Author: Adam Dunkels <adam@sics.se>
hexley	0:281d6ff68967	61	*
hexley	0:281d6ff68967	62	*/
hexley	0:281d6ff68967	63
hexley	0:281d6ff68967	64	#include "lwip/opt.h"
hexley	0:281d6ff68967	65
hexley	0:281d6ff68967	66	#include "lwip/stats.h"
hexley	0:281d6ff68967	67	#include "lwip/def.h"
hexley	0:281d6ff68967	68	#include "lwip/mem.h"
hexley	0:281d6ff68967	69	#include "lwip/memp.h"
hexley	0:281d6ff68967	70	#include "lwip/pbuf.h"
hexley	0:281d6ff68967	71	#include "lwip/sys.h"
hexley	0:281d6ff68967	72	#include "arch/perf.h"
hexley	0:281d6ff68967	73	#if TCP_QUEUE_OOSEQ
hexley	0:281d6ff68967	74	#include "lwip/tcp_impl.h"
hexley	0:281d6ff68967	75	#endif
hexley	0:281d6ff68967	76	#if LWIP_CHECKSUM_ON_COPY
hexley	0:281d6ff68967	77	#include "lwip/inet_chksum.h"
hexley	0:281d6ff68967	78	#endif
hexley	0:281d6ff68967	79
hexley	0:281d6ff68967	80	#include <string.h>
hexley	0:281d6ff68967	81
hexley	0:281d6ff68967	82	#define SIZEOF_STRUCT_PBUF LWIP_MEM_ALIGN_SIZE(sizeof(struct pbuf))
hexley	0:281d6ff68967	83	/* Since the pool is created in memp, PBUF_POOL_BUFSIZE will be automatically
hexley	0:281d6ff68967	84	aligned there. Therefore, PBUF_POOL_BUFSIZE_ALIGNED can be used here. */
hexley	0:281d6ff68967	85	#define PBUF_POOL_BUFSIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE)
hexley	0:281d6ff68967	86
hexley	0:281d6ff68967	87	#if !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS
hexley	0:281d6ff68967	88	#define PBUF_POOL_IS_EMPTY()
hexley	0:281d6ff68967	89	#else /* !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS */
hexley	0:281d6ff68967	90	/** Define this to 0 to prevent freeing ooseq pbufs when the PBUF_POOL is empty */
hexley	0:281d6ff68967	91	#ifndef PBUF_POOL_FREE_OOSEQ
hexley	0:281d6ff68967	92	#define PBUF_POOL_FREE_OOSEQ 1
hexley	0:281d6ff68967	93	#endif /* PBUF_POOL_FREE_OOSEQ */
hexley	0:281d6ff68967	94
hexley	0:281d6ff68967	95	#if PBUF_POOL_FREE_OOSEQ
hexley	0:281d6ff68967	96	#include "lwip/tcpip.h"
hexley	0:281d6ff68967	97	#define PBUF_POOL_IS_EMPTY() pbuf_pool_is_empty()
hexley	0:281d6ff68967	98	static u8_t pbuf_free_ooseq_queued;
hexley	0:281d6ff68967	99	/**
hexley	0:281d6ff68967	100	* Attempt to reclaim some memory from queued out-of-sequence TCP segments
hexley	0:281d6ff68967	101	* if we run out of pool pbufs. It's better to give priority to new packets
hexley	0:281d6ff68967	102	* if we're running out.
hexley	0:281d6ff68967	103	*
hexley	0:281d6ff68967	104	* This must be done in the correct thread context therefore this function
hexley	0:281d6ff68967	105	* can only be used with NO_SYS=0 and through tcpip_callback.
hexley	0:281d6ff68967	106	*/
hexley	0:281d6ff68967	107	static void
hexley	0:281d6ff68967	108	pbuf_free_ooseq(void* arg)
hexley	0:281d6ff68967	109	{
hexley	0:281d6ff68967	110	struct tcp_pcb* pcb;
hexley	0:281d6ff68967	111	SYS_ARCH_DECL_PROTECT(old_level);
hexley	0:281d6ff68967	112	LWIP_UNUSED_ARG(arg);
hexley	0:281d6ff68967	113
hexley	0:281d6ff68967	114	SYS_ARCH_PROTECT(old_level);
hexley	0:281d6ff68967	115	pbuf_free_ooseq_queued = 0;
hexley	0:281d6ff68967	116	SYS_ARCH_UNPROTECT(old_level);
hexley	0:281d6ff68967	117
hexley	0:281d6ff68967	118	for (pcb = tcp_active_pcbs; NULL != pcb; pcb = pcb->next) {
hexley	0:281d6ff68967	119	if (NULL != pcb->ooseq) {
hexley	0:281d6ff68967	120	/** Free the ooseq pbufs of one PCB only */
hexley	0:281d6ff68967	121	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free_ooseq: freeing out-of-sequence pbufs\n"));
hexley	0:281d6ff68967	122	tcp_segs_free(pcb->ooseq);
hexley	0:281d6ff68967	123	pcb->ooseq = NULL;
hexley	0:281d6ff68967	124	return;
hexley	0:281d6ff68967	125	}
hexley	0:281d6ff68967	126	}
hexley	0:281d6ff68967	127	}
hexley	0:281d6ff68967	128
hexley	0:281d6ff68967	129	/** Queue a call to pbuf_free_ooseq if not already queued. */
hexley	0:281d6ff68967	130	static void
hexley	0:281d6ff68967	131	pbuf_pool_is_empty(void)
hexley	0:281d6ff68967	132	{
hexley	0:281d6ff68967	133	u8_t queued;
hexley	0:281d6ff68967	134	SYS_ARCH_DECL_PROTECT(old_level);
hexley	0:281d6ff68967	135
hexley	0:281d6ff68967	136	SYS_ARCH_PROTECT(old_level);
hexley	0:281d6ff68967	137	queued = pbuf_free_ooseq_queued;
hexley	0:281d6ff68967	138	pbuf_free_ooseq_queued = 1;
hexley	0:281d6ff68967	139	SYS_ARCH_UNPROTECT(old_level);
hexley	0:281d6ff68967	140
hexley	0:281d6ff68967	141	if(!queued) {
hexley	0:281d6ff68967	142	/* queue a call to pbuf_free_ooseq if not already queued */
hexley	0:281d6ff68967	143	if(tcpip_callback_with_block(pbuf_free_ooseq, NULL, 0) != ERR_OK) {
hexley	0:281d6ff68967	144	SYS_ARCH_PROTECT(old_level);
hexley	0:281d6ff68967	145	pbuf_free_ooseq_queued = 0;
hexley	0:281d6ff68967	146	SYS_ARCH_UNPROTECT(old_level);
hexley	0:281d6ff68967	147	}
hexley	0:281d6ff68967	148	}
hexley	0:281d6ff68967	149	}
hexley	0:281d6ff68967	150	#endif /* PBUF_POOL_FREE_OOSEQ */
hexley	0:281d6ff68967	151	#endif /* !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS */
hexley	0:281d6ff68967	152
hexley	0:281d6ff68967	153	/**
hexley	0:281d6ff68967	154	* Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
hexley	0:281d6ff68967	155	*
hexley	0:281d6ff68967	156	* The actual memory allocated for the pbuf is determined by the
hexley	0:281d6ff68967	157	* layer at which the pbuf is allocated and the requested size
hexley	0:281d6ff68967	158	* (from the size parameter).
hexley	0:281d6ff68967	159	*
hexley	0:281d6ff68967	160	* @param layer flag to define header size
hexley	0:281d6ff68967	161	* @param length size of the pbuf's payload
hexley	0:281d6ff68967	162	* @param type this parameter decides how and where the pbuf
hexley	0:281d6ff68967	163	* should be allocated as follows:
hexley	0:281d6ff68967	164	*
hexley	0:281d6ff68967	165	* - PBUF_RAM: buffer memory for pbuf is allocated as one large
hexley	0:281d6ff68967	166	* chunk. This includes protocol headers as well.
hexley	0:281d6ff68967	167	* - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
hexley	0:281d6ff68967	168	* protocol headers. Additional headers must be prepended
hexley	0:281d6ff68967	169	* by allocating another pbuf and chain in to the front of
hexley	0:281d6ff68967	170	* the ROM pbuf. It is assumed that the memory used is really
hexley	0:281d6ff68967	171	* similar to ROM in that it is immutable and will not be
hexley	0:281d6ff68967	172	* changed. Memory which is dynamic should generally not
hexley	0:281d6ff68967	173	* be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
hexley	0:281d6ff68967	174	* - PBUF_REF: no buffer memory is allocated for the pbuf, even for
hexley	0:281d6ff68967	175	* protocol headers. It is assumed that the pbuf is only
hexley	0:281d6ff68967	176	* being used in a single thread. If the pbuf gets queued,
hexley	0:281d6ff68967	177	* then pbuf_take should be called to copy the buffer.
hexley	0:281d6ff68967	178	* - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
hexley	0:281d6ff68967	179	* the pbuf pool that is allocated during pbuf_init().
hexley	0:281d6ff68967	180	*
hexley	0:281d6ff68967	181	* @return the allocated pbuf. If multiple pbufs where allocated, this
hexley	0:281d6ff68967	182	* is the first pbuf of a pbuf chain.
hexley	0:281d6ff68967	183	*/
hexley	0:281d6ff68967	184	struct pbuf *
hexley	0:281d6ff68967	185	pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
hexley	0:281d6ff68967	186	{
hexley	0:281d6ff68967	187	struct pbuf p, q, *r;
hexley	0:281d6ff68967	188	u16_t offset;
hexley	0:281d6ff68967	189	s32_t rem_len; /* remaining length */
hexley	0:281d6ff68967	190	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
hexley	0:281d6ff68967	191
hexley	0:281d6ff68967	192	/* determine header offset */
hexley	0:281d6ff68967	193	offset = 0;
hexley	0:281d6ff68967	194	switch (layer) {
hexley	0:281d6ff68967	195	case PBUF_TRANSPORT:
hexley	0:281d6ff68967	196	/* add room for transport (often TCP) layer header */
hexley	0:281d6ff68967	197	offset += PBUF_TRANSPORT_HLEN;
hexley	0:281d6ff68967	198	/* FALLTHROUGH */
hexley	0:281d6ff68967	199	case PBUF_IP:
hexley	0:281d6ff68967	200	/* add room for IP layer header */
hexley	0:281d6ff68967	201	offset += PBUF_IP_HLEN;
hexley	0:281d6ff68967	202	/* FALLTHROUGH */
hexley	0:281d6ff68967	203	case PBUF_LINK:
hexley	0:281d6ff68967	204	/* add room for link layer header */
hexley	0:281d6ff68967	205	offset += PBUF_LINK_HLEN;
hexley	0:281d6ff68967	206	break;
hexley	0:281d6ff68967	207	case PBUF_RAW:
hexley	0:281d6ff68967	208	break;
hexley	0:281d6ff68967	209	default:
hexley	0:281d6ff68967	210	LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0);
hexley	0:281d6ff68967	211	return NULL;
hexley	0:281d6ff68967	212	}
hexley	0:281d6ff68967	213
hexley	0:281d6ff68967	214	switch (type) {
hexley	0:281d6ff68967	215	case PBUF_POOL:
hexley	0:281d6ff68967	216	/* allocate head of pbuf chain into p */
hexley	0:281d6ff68967	217	p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
hexley	0:281d6ff68967	218	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
hexley	0:281d6ff68967	219	if (p == NULL) {
hexley	0:281d6ff68967	220	PBUF_POOL_IS_EMPTY();
hexley	0:281d6ff68967	221	return NULL;
hexley	0:281d6ff68967	222	}
hexley	0:281d6ff68967	223	p->type = type;
hexley	0:281d6ff68967	224	p->next = NULL;
hexley	0:281d6ff68967	225
hexley	0:281d6ff68967	226	/* make the payload pointer point 'offset' bytes into pbuf data memory */
hexley	0:281d6ff68967	227	p->payload = LWIP_MEM_ALIGN((void )((u8_t )p + (SIZEOF_STRUCT_PBUF + offset)));
hexley	0:281d6ff68967	228	LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned",
hexley	0:281d6ff68967	229	((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
hexley	0:281d6ff68967	230	/* the total length of the pbuf chain is the requested size */
hexley	0:281d6ff68967	231	p->tot_len = length;
hexley	0:281d6ff68967	232	/* set the length of the first pbuf in the chain */
hexley	0:281d6ff68967	233	p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
hexley	0:281d6ff68967	234	LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
hexley	0:281d6ff68967	235	((u8_t*)p->payload + p->len <=
hexley	0:281d6ff68967	236	(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
hexley	0:281d6ff68967	237	LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT",
hexley	0:281d6ff68967	238	(PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 );
hexley	0:281d6ff68967	239	/* set reference count (needed here in case we fail) */
hexley	0:281d6ff68967	240	p->ref = 1;
hexley	0:281d6ff68967	241
hexley	0:281d6ff68967	242	/* now allocate the tail of the pbuf chain */
hexley	0:281d6ff68967	243
hexley	0:281d6ff68967	244	/* remember first pbuf for linkage in next iteration */
hexley	0:281d6ff68967	245	r = p;
hexley	0:281d6ff68967	246	/* remaining length to be allocated */
hexley	0:281d6ff68967	247	rem_len = length - p->len;
hexley	0:281d6ff68967	248	/* any remaining pbufs to be allocated? */
hexley	0:281d6ff68967	249	while (rem_len > 0) {
hexley	0:281d6ff68967	250	q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
hexley	0:281d6ff68967	251	if (q == NULL) {
hexley	0:281d6ff68967	252	PBUF_POOL_IS_EMPTY();
hexley	0:281d6ff68967	253	/* free chain so far allocated */
hexley	0:281d6ff68967	254	pbuf_free(p);
hexley	0:281d6ff68967	255	/* bail out unsuccesfully */
hexley	0:281d6ff68967	256	return NULL;
hexley	0:281d6ff68967	257	}
hexley	0:281d6ff68967	258	q->type = type;
hexley	0:281d6ff68967	259	q->flags = 0;
hexley	0:281d6ff68967	260	q->next = NULL;
hexley	0:281d6ff68967	261	/* make previous pbuf point to this pbuf */
hexley	0:281d6ff68967	262	r->next = q;
hexley	0:281d6ff68967	263	/* set total length of this pbuf and next in chain */
hexley	0:281d6ff68967	264	LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff);
hexley	0:281d6ff68967	265	q->tot_len = (u16_t)rem_len;
hexley	0:281d6ff68967	266	/* this pbuf length is pool size, unless smaller sized tail */
hexley	0:281d6ff68967	267	q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
hexley	0:281d6ff68967	268	q->payload = (void )((u8_t )q + SIZEOF_STRUCT_PBUF);
hexley	0:281d6ff68967	269	LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
hexley	0:281d6ff68967	270	((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
hexley	0:281d6ff68967	271	LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
hexley	0:281d6ff68967	272	((u8_t*)p->payload + p->len <=
hexley	0:281d6ff68967	273	(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
hexley	0:281d6ff68967	274	q->ref = 1;
hexley	0:281d6ff68967	275	/* calculate remaining length to be allocated */
hexley	0:281d6ff68967	276	rem_len -= q->len;
hexley	0:281d6ff68967	277	/* remember this pbuf for linkage in next iteration */
hexley	0:281d6ff68967	278	r = q;
hexley	0:281d6ff68967	279	}
hexley	0:281d6ff68967	280	/* end of chain */
hexley	0:281d6ff68967	281	/r->next = NULL;/
hexley	0:281d6ff68967	282
hexley	0:281d6ff68967	283	break;
hexley	0:281d6ff68967	284	case PBUF_RAM:
hexley	0:281d6ff68967	285	/* If pbuf is to be allocated in RAM, allocate memory for it. */
hexley	0:281d6ff68967	286	p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
hexley	0:281d6ff68967	287	if (p == NULL) {
hexley	0:281d6ff68967	288	return NULL;
hexley	0:281d6ff68967	289	}
hexley	0:281d6ff68967	290	/* Set up internal structure of the pbuf. */
hexley	0:281d6ff68967	291	p->payload = LWIP_MEM_ALIGN((void )((u8_t )p + SIZEOF_STRUCT_PBUF + offset));
hexley	0:281d6ff68967	292	p->len = p->tot_len = length;
hexley	0:281d6ff68967	293	p->next = NULL;
hexley	0:281d6ff68967	294	p->type = type;
hexley	0:281d6ff68967	295
hexley	0:281d6ff68967	296	LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
hexley	0:281d6ff68967	297	((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
hexley	0:281d6ff68967	298	break;
hexley	0:281d6ff68967	299	/* pbuf references existing (non-volatile static constant) ROM payload? */
hexley	0:281d6ff68967	300	case PBUF_ROM:
hexley	0:281d6ff68967	301	/* pbuf references existing (externally allocated) RAM payload? */
hexley	0:281d6ff68967	302	case PBUF_REF:
hexley	0:281d6ff68967	303	/* only allocate memory for the pbuf structure */
hexley	0:281d6ff68967	304	p = (struct pbuf *)memp_malloc(MEMP_PBUF);
hexley	0:281d6ff68967	305	if (p == NULL) {
hexley	0:281d6ff68967	306	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
hexley	0:281d6ff68967	307	("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n",
hexley	0:281d6ff68967	308	(type == PBUF_ROM) ? "ROM" : "REF"));
hexley	0:281d6ff68967	309	return NULL;
hexley	0:281d6ff68967	310	}
hexley	0:281d6ff68967	311	/* caller must set this field properly, afterwards */
hexley	0:281d6ff68967	312	p->payload = NULL;
hexley	0:281d6ff68967	313	p->len = p->tot_len = length;
hexley	0:281d6ff68967	314	p->next = NULL;
hexley	0:281d6ff68967	315	p->type = type;
hexley	0:281d6ff68967	316	break;
hexley	0:281d6ff68967	317	default:
hexley	0:281d6ff68967	318	LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
hexley	0:281d6ff68967	319	return NULL;
hexley	0:281d6ff68967	320	}
hexley	0:281d6ff68967	321	/* set reference count */
hexley	0:281d6ff68967	322	p->ref = 1;
hexley	0:281d6ff68967	323	/* set flags */
hexley	0:281d6ff68967	324	p->flags = 0;
hexley	0:281d6ff68967	325	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
hexley	0:281d6ff68967	326	return p;
hexley	0:281d6ff68967	327	}
hexley	0:281d6ff68967	328
hexley	0:281d6ff68967	329	#if LWIP_SUPPORT_CUSTOM_PBUF
hexley	0:281d6ff68967	330	/** Initialize a custom pbuf (already allocated).
hexley	0:281d6ff68967	331	*
hexley	0:281d6ff68967	332	* @param layer flag to define header size
hexley	0:281d6ff68967	333	* @param length size of the pbuf's payload
hexley	0:281d6ff68967	334	* @param type type of the pbuf (only used to treat the pbuf accordingly, as
hexley	0:281d6ff68967	335	* this function allocates no memory)
hexley	0:281d6ff68967	336	* @param p pointer to the custom pbuf to initialize (already allocated)
hexley	0:281d6ff68967	337	* @param payload_mem pointer to the buffer that is used for payload and headers,
hexley	0:281d6ff68967	338	* must be at least big enough to hold 'length' plus the header size,
hexley	0:281d6ff68967	339	* may be NULL if set later
hexley	0:281d6ff68967	340	* @param payload_mem_len the size of the 'payload_mem' buffer, must be at least
hexley	0:281d6ff68967	341	* big enough to hold 'length' plus the header size
hexley	0:281d6ff68967	342	*/
hexley	0:281d6ff68967	343	struct pbuf*
hexley	0:281d6ff68967	344	pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type, struct pbuf_custom *p,
hexley	0:281d6ff68967	345	void *payload_mem, u16_t payload_mem_len)
hexley	0:281d6ff68967	346	{
hexley	0:281d6ff68967	347	u16_t offset;
hexley	0:281d6ff68967	348	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloced_custom(length=%"U16_F")\n", length));
hexley	0:281d6ff68967	349
hexley	0:281d6ff68967	350	/* determine header offset */
hexley	0:281d6ff68967	351	offset = 0;
hexley	0:281d6ff68967	352	switch (l) {
hexley	0:281d6ff68967	353	case PBUF_TRANSPORT:
hexley	0:281d6ff68967	354	/* add room for transport (often TCP) layer header */
hexley	0:281d6ff68967	355	offset += PBUF_TRANSPORT_HLEN;
hexley	0:281d6ff68967	356	/* FALLTHROUGH */
hexley	0:281d6ff68967	357	case PBUF_IP:
hexley	0:281d6ff68967	358	/* add room for IP layer header */
hexley	0:281d6ff68967	359	offset += PBUF_IP_HLEN;
hexley	0:281d6ff68967	360	/* FALLTHROUGH */
hexley	0:281d6ff68967	361	case PBUF_LINK:
hexley	0:281d6ff68967	362	/* add room for link layer header */
hexley	0:281d6ff68967	363	offset += PBUF_LINK_HLEN;
hexley	0:281d6ff68967	364	break;
hexley	0:281d6ff68967	365	case PBUF_RAW:
hexley	0:281d6ff68967	366	break;
hexley	0:281d6ff68967	367	default:
hexley	0:281d6ff68967	368	LWIP_ASSERT("pbuf_alloced_custom: bad pbuf layer", 0);
hexley	0:281d6ff68967	369	return NULL;
hexley	0:281d6ff68967	370	}
hexley	0:281d6ff68967	371
hexley	0:281d6ff68967	372	if (LWIP_MEM_ALIGN_SIZE(offset) + length < payload_mem_len) {
hexley	0:281d6ff68967	373	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_WARNING, ("pbuf_alloced_custom(length=%"U16_F") buffer too short\n", length));
hexley	0:281d6ff68967	374	return NULL;
hexley	0:281d6ff68967	375	}
hexley	0:281d6ff68967	376
hexley	0:281d6ff68967	377	p->pbuf.next = NULL;
hexley	0:281d6ff68967	378	if (payload_mem != NULL) {
hexley	0:281d6ff68967	379	p->pbuf.payload = LWIP_MEM_ALIGN((void )((u8_t )payload_mem + offset));
hexley	0:281d6ff68967	380	} else {
hexley	0:281d6ff68967	381	p->pbuf.payload = NULL;
hexley	0:281d6ff68967	382	}
hexley	0:281d6ff68967	383	p->pbuf.flags = PBUF_FLAG_IS_CUSTOM;
hexley	0:281d6ff68967	384	p->pbuf.len = p->pbuf.tot_len = length;
hexley	0:281d6ff68967	385	p->pbuf.type = type;
hexley	0:281d6ff68967	386	p->pbuf.ref = 1;
hexley	0:281d6ff68967	387	return &p->pbuf;
hexley	0:281d6ff68967	388	}
hexley	0:281d6ff68967	389	#endif /* LWIP_SUPPORT_CUSTOM_PBUF */
hexley	0:281d6ff68967	390
hexley	0:281d6ff68967	391	/**
hexley	0:281d6ff68967	392	* Shrink a pbuf chain to a desired length.
hexley	0:281d6ff68967	393	*
hexley	0:281d6ff68967	394	* @param p pbuf to shrink.
hexley	0:281d6ff68967	395	* @param new_len desired new length of pbuf chain
hexley	0:281d6ff68967	396	*
hexley	0:281d6ff68967	397	* Depending on the desired length, the first few pbufs in a chain might
hexley	0:281d6ff68967	398	* be skipped and left unchanged. The new last pbuf in the chain will be
hexley	0:281d6ff68967	399	* resized, and any remaining pbufs will be freed.
hexley	0:281d6ff68967	400	*
hexley	0:281d6ff68967	401	* @note If the pbuf is ROM/REF, only the ->tot_len and ->len fields are adjusted.
hexley	0:281d6ff68967	402	* @note May not be called on a packet queue.
hexley	0:281d6ff68967	403	*
hexley	0:281d6ff68967	404	* @note Despite its name, pbuf_realloc cannot grow the size of a pbuf (chain).
hexley	0:281d6ff68967	405	*/
hexley	0:281d6ff68967	406	void
hexley	0:281d6ff68967	407	pbuf_realloc(struct pbuf *p, u16_t new_len)
hexley	0:281d6ff68967	408	{
hexley	0:281d6ff68967	409	struct pbuf *q;
hexley	0:281d6ff68967	410	u16_t rem_len; /* remaining length */
hexley	0:281d6ff68967	411	s32_t grow;
hexley	0:281d6ff68967	412
hexley	0:281d6ff68967	413	LWIP_ASSERT("pbuf_realloc: p != NULL", p != NULL);
hexley	0:281d6ff68967	414	LWIP_ASSERT("pbuf_realloc: sane p->type", p->type == PBUF_POOL \|\|
hexley	0:281d6ff68967	415	p->type == PBUF_ROM \|\|
hexley	0:281d6ff68967	416	p->type == PBUF_RAM \|\|
hexley	0:281d6ff68967	417	p->type == PBUF_REF);
hexley	0:281d6ff68967	418
hexley	0:281d6ff68967	419	/* desired length larger than current length? */
hexley	0:281d6ff68967	420	if (new_len >= p->tot_len) {
hexley	0:281d6ff68967	421	/* enlarging not yet supported */
hexley	0:281d6ff68967	422	return;
hexley	0:281d6ff68967	423	}
hexley	0:281d6ff68967	424
hexley	0:281d6ff68967	425	/* the pbuf chain grows by (new_len - p->tot_len) bytes
hexley	0:281d6ff68967	426	* (which may be negative in case of shrinking) */
hexley	0:281d6ff68967	427	grow = new_len - p->tot_len;
hexley	0:281d6ff68967	428
hexley	0:281d6ff68967	429	/* first, step over any pbufs that should remain in the chain */
hexley	0:281d6ff68967	430	rem_len = new_len;
hexley	0:281d6ff68967	431	q = p;
hexley	0:281d6ff68967	432	/* should this pbuf be kept? */
hexley	0:281d6ff68967	433	while (rem_len > q->len) {
hexley	0:281d6ff68967	434	/* decrease remaining length by pbuf length */
hexley	0:281d6ff68967	435	rem_len -= q->len;
hexley	0:281d6ff68967	436	/* decrease total length indicator */
hexley	0:281d6ff68967	437	LWIP_ASSERT("grow < max_u16_t", grow < 0xffff);
hexley	0:281d6ff68967	438	q->tot_len += (u16_t)grow;
hexley	0:281d6ff68967	439	/* proceed to next pbuf in chain */
hexley	0:281d6ff68967	440	q = q->next;
hexley	0:281d6ff68967	441	LWIP_ASSERT("pbuf_realloc: q != NULL", q != NULL);
hexley	0:281d6ff68967	442	}
hexley	0:281d6ff68967	443	/* we have now reached the new last pbuf (in q) */
hexley	0:281d6ff68967	444	/* rem_len == desired length for pbuf q */
hexley	0:281d6ff68967	445
hexley	0:281d6ff68967	446	/* shrink allocated memory for PBUF_RAM */
hexley	0:281d6ff68967	447	/* (other types merely adjust their length fields */
hexley	0:281d6ff68967	448	if ((q->type == PBUF_RAM) && (rem_len != q->len)) {
hexley	0:281d6ff68967	449	/* reallocate and adjust the length of the pbuf that will be split */
hexley	0:281d6ff68967	450	q = (struct pbuf )mem_trim(q, (u16_t)((u8_t )q->payload - (u8_t *)q) + rem_len);
hexley	0:281d6ff68967	451	LWIP_ASSERT("mem_trim returned q == NULL", q != NULL);
hexley	0:281d6ff68967	452	}
hexley	0:281d6ff68967	453	/* adjust length fields for new last pbuf */
hexley	0:281d6ff68967	454	q->len = rem_len;
hexley	0:281d6ff68967	455	q->tot_len = q->len;
hexley	0:281d6ff68967	456
hexley	0:281d6ff68967	457	/* any remaining pbufs in chain? */
hexley	0:281d6ff68967	458	if (q->next != NULL) {
hexley	0:281d6ff68967	459	/* free remaining pbufs in chain */
hexley	0:281d6ff68967	460	pbuf_free(q->next);
hexley	0:281d6ff68967	461	}
hexley	0:281d6ff68967	462	/* q is last packet in chain */
hexley	0:281d6ff68967	463	q->next = NULL;
hexley	0:281d6ff68967	464
hexley	0:281d6ff68967	465	}
hexley	0:281d6ff68967	466
hexley	0:281d6ff68967	467	/**
hexley	0:281d6ff68967	468	* Adjusts the payload pointer to hide or reveal headers in the payload.
hexley	0:281d6ff68967	469	*
hexley	0:281d6ff68967	470	* Adjusts the ->payload pointer so that space for a header
hexley	0:281d6ff68967	471	* (dis)appears in the pbuf payload.
hexley	0:281d6ff68967	472	*
hexley	0:281d6ff68967	473	* The ->payload, ->tot_len and ->len fields are adjusted.
hexley	0:281d6ff68967	474	*
hexley	0:281d6ff68967	475	* @param p pbuf to change the header size.
hexley	0:281d6ff68967	476	* @param header_size_increment Number of bytes to increment header size which
hexley	0:281d6ff68967	477	* increases the size of the pbuf. New space is on the front.
hexley	0:281d6ff68967	478	* (Using a negative value decreases the header size.)
hexley	0:281d6ff68967	479	* If hdr_size_inc is 0, this function does nothing and returns succesful.
hexley	0:281d6ff68967	480	*
hexley	0:281d6ff68967	481	* PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so
hexley	0:281d6ff68967	482	* the call will fail. A check is made that the increase in header size does
hexley	0:281d6ff68967	483	* not move the payload pointer in front of the start of the buffer.
hexley	0:281d6ff68967	484	* @return non-zero on failure, zero on success.
hexley	0:281d6ff68967	485	*
hexley	0:281d6ff68967	486	*/
hexley	0:281d6ff68967	487	u8_t
hexley	0:281d6ff68967	488	pbuf_header(struct pbuf *p, s16_t header_size_increment)
hexley	0:281d6ff68967	489	{
hexley	0:281d6ff68967	490	u16_t type;
hexley	0:281d6ff68967	491	void *payload;
hexley	0:281d6ff68967	492	u16_t increment_magnitude;
hexley	0:281d6ff68967	493
hexley	0:281d6ff68967	494	LWIP_ASSERT("p != NULL", p != NULL);
hexley	0:281d6ff68967	495	if ((header_size_increment == 0) \|\| (p == NULL)) {
hexley	0:281d6ff68967	496	return 0;
hexley	0:281d6ff68967	497	}
hexley	0:281d6ff68967	498
hexley	0:281d6ff68967	499	if (header_size_increment < 0){
hexley	0:281d6ff68967	500	increment_magnitude = -header_size_increment;
hexley	0:281d6ff68967	501	/* Check that we aren't going to move off the end of the pbuf */
hexley	0:281d6ff68967	502	LWIP_ERROR("increment_magnitude <= p->len", (increment_magnitude <= p->len), return 1;);
hexley	0:281d6ff68967	503	} else {
hexley	0:281d6ff68967	504	increment_magnitude = header_size_increment;
hexley	0:281d6ff68967	505	#if 0
hexley	0:281d6ff68967	506	/* Can't assert these as some callers speculatively call
hexley	0:281d6ff68967	507	pbuf_header() to see if it's OK. Will return 1 below instead. */
hexley	0:281d6ff68967	508	/* Check that we've got the correct type of pbuf to work with */
hexley	0:281d6ff68967	509	LWIP_ASSERT("p->type == PBUF_RAM \|\| p->type == PBUF_POOL",
hexley	0:281d6ff68967	510	p->type == PBUF_RAM \|\| p->type == PBUF_POOL);
hexley	0:281d6ff68967	511	/* Check that we aren't going to move off the beginning of the pbuf */
hexley	0:281d6ff68967	512	LWIP_ASSERT("p->payload - increment_magnitude >= p + SIZEOF_STRUCT_PBUF",
hexley	0:281d6ff68967	513	(u8_t )p->payload - increment_magnitude >= (u8_t )p + SIZEOF_STRUCT_PBUF);
hexley	0:281d6ff68967	514	#endif
hexley	0:281d6ff68967	515	}
hexley	0:281d6ff68967	516
hexley	0:281d6ff68967	517	type = p->type;
hexley	0:281d6ff68967	518	/* remember current payload pointer */
hexley	0:281d6ff68967	519	payload = p->payload;
hexley	0:281d6ff68967	520
hexley	0:281d6ff68967	521	/* pbuf types containing payloads? */
hexley	0:281d6ff68967	522	if (type == PBUF_RAM \|\| type == PBUF_POOL) {
hexley	0:281d6ff68967	523	/* set new payload pointer */
hexley	0:281d6ff68967	524	p->payload = (u8_t *)p->payload - header_size_increment;
hexley	0:281d6ff68967	525	/* boundary check fails? */
hexley	0:281d6ff68967	526	if ((u8_t )p->payload < (u8_t )p + SIZEOF_STRUCT_PBUF) {
hexley	0:281d6ff68967	527	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
hexley	0:281d6ff68967	528	("pbuf_header: failed as %p < %p (not enough space for new header size)\n",
hexley	0:281d6ff68967	529	(void )p->payload, (void )(p + 1)));
hexley	0:281d6ff68967	530	/* restore old payload pointer */
hexley	0:281d6ff68967	531	p->payload = payload;
hexley	0:281d6ff68967	532	/* bail out unsuccesfully */
hexley	0:281d6ff68967	533	return 1;
hexley	0:281d6ff68967	534	}
hexley	0:281d6ff68967	535	/* pbuf types refering to external payloads? */
hexley	0:281d6ff68967	536	} else if (type == PBUF_REF \|\| type == PBUF_ROM) {
hexley	0:281d6ff68967	537	/* hide a header in the payload? */
hexley	0:281d6ff68967	538	if ((header_size_increment < 0) && (increment_magnitude <= p->len)) {
hexley	0:281d6ff68967	539	/* increase payload pointer */
hexley	0:281d6ff68967	540	p->payload = (u8_t *)p->payload - header_size_increment;
hexley	0:281d6ff68967	541	} else {
hexley	0:281d6ff68967	542	/* cannot expand payload to front (yet!)
hexley	0:281d6ff68967	543	* bail out unsuccesfully */
hexley	0:281d6ff68967	544	return 1;
hexley	0:281d6ff68967	545	}
hexley	0:281d6ff68967	546	} else {
hexley	0:281d6ff68967	547	/* Unknown type */
hexley	0:281d6ff68967	548	LWIP_ASSERT("bad pbuf type", 0);
hexley	0:281d6ff68967	549	return 1;
hexley	0:281d6ff68967	550	}
hexley	0:281d6ff68967	551	/* modify pbuf length fields */
hexley	0:281d6ff68967	552	p->len += header_size_increment;
hexley	0:281d6ff68967	553	p->tot_len += header_size_increment;
hexley	0:281d6ff68967	554
hexley	0:281d6ff68967	555	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_header: old %p new %p (%"S16_F")\n",
hexley	0:281d6ff68967	556	(void )payload, (void )p->payload, header_size_increment));
hexley	0:281d6ff68967	557
hexley	0:281d6ff68967	558	return 0;
hexley	0:281d6ff68967	559	}
hexley	0:281d6ff68967	560
hexley	0:281d6ff68967	561	/**
hexley	0:281d6ff68967	562	* Dereference a pbuf chain or queue and deallocate any no-longer-used
hexley	0:281d6ff68967	563	* pbufs at the head of this chain or queue.
hexley	0:281d6ff68967	564	*
hexley	0:281d6ff68967	565	* Decrements the pbuf reference count. If it reaches zero, the pbuf is
hexley	0:281d6ff68967	566	* deallocated.
hexley	0:281d6ff68967	567	*
hexley	0:281d6ff68967	568	* For a pbuf chain, this is repeated for each pbuf in the chain,
hexley	0:281d6ff68967	569	* up to the first pbuf which has a non-zero reference count after
hexley	0:281d6ff68967	570	* decrementing. So, when all reference counts are one, the whole
hexley	0:281d6ff68967	571	* chain is free'd.
hexley	0:281d6ff68967	572	*
hexley	0:281d6ff68967	573	* @param p The pbuf (chain) to be dereferenced.
hexley	0:281d6ff68967	574	*
hexley	0:281d6ff68967	575	* @return the number of pbufs that were de-allocated
hexley	0:281d6ff68967	576	* from the head of the chain.
hexley	0:281d6ff68967	577	*
hexley	0:281d6ff68967	578	* @note MUST NOT be called on a packet queue (Not verified to work yet).
hexley	0:281d6ff68967	579	* @note the reference counter of a pbuf equals the number of pointers
hexley	0:281d6ff68967	580	* that refer to the pbuf (or into the pbuf).
hexley	0:281d6ff68967	581	*
hexley	0:281d6ff68967	582	* @internal examples:
hexley	0:281d6ff68967	583	*
hexley	0:281d6ff68967	584	* Assuming existing chains a->b->c with the following reference
hexley	0:281d6ff68967	585	* counts, calling pbuf_free(a) results in:
hexley	0:281d6ff68967	586	*
hexley	0:281d6ff68967	587	* 1->2->3 becomes ...1->3
hexley	0:281d6ff68967	588	* 3->3->3 becomes 2->3->3
hexley	0:281d6ff68967	589	* 1->1->2 becomes ......1
hexley	0:281d6ff68967	590	* 2->1->1 becomes 1->1->1
hexley	0:281d6ff68967	591	* 1->1->1 becomes .......
hexley	0:281d6ff68967	592	*
hexley	0:281d6ff68967	593	*/
hexley	0:281d6ff68967	594	u8_t
hexley	0:281d6ff68967	595	pbuf_free(struct pbuf *p)
hexley	0:281d6ff68967	596	{
hexley	0:281d6ff68967	597	u16_t type;
hexley	0:281d6ff68967	598	struct pbuf *q;
hexley	0:281d6ff68967	599	u8_t count;
hexley	0:281d6ff68967	600
hexley	0:281d6ff68967	601	if (p == NULL) {
hexley	0:281d6ff68967	602	LWIP_ASSERT("p != NULL", p != NULL);
hexley	0:281d6ff68967	603	/* if assertions are disabled, proceed with debug output */
hexley	0:281d6ff68967	604	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
hexley	0:281d6ff68967	605	("pbuf_free(p == NULL) was called.\n"));
hexley	0:281d6ff68967	606	return 0;
hexley	0:281d6ff68967	607	}
hexley	0:281d6ff68967	608	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free(%p)\n", (void *)p));
hexley	0:281d6ff68967	609
hexley	0:281d6ff68967	610	PERF_START;
hexley	0:281d6ff68967	611
hexley	0:281d6ff68967	612	LWIP_ASSERT("pbuf_free: sane type",
hexley	0:281d6ff68967	613	p->type == PBUF_RAM \|\| p->type == PBUF_ROM \|\|
hexley	0:281d6ff68967	614	p->type == PBUF_REF \|\| p->type == PBUF_POOL);
hexley	0:281d6ff68967	615
hexley	0:281d6ff68967	616	count = 0;
hexley	0:281d6ff68967	617	/* de-allocate all consecutive pbufs from the head of the chain that
hexley	0:281d6ff68967	618	* obtain a zero reference count after decrementing*/
hexley	0:281d6ff68967	619	while (p != NULL) {
hexley	0:281d6ff68967	620	u16_t ref;
hexley	0:281d6ff68967	621	SYS_ARCH_DECL_PROTECT(old_level);
hexley	0:281d6ff68967	622	/* Since decrementing ref cannot be guaranteed to be a single machine operation
hexley	0:281d6ff68967	623	* we must protect it. We put the new ref into a local variable to prevent
hexley	0:281d6ff68967	624	* further protection. */
hexley	0:281d6ff68967	625	SYS_ARCH_PROTECT(old_level);
hexley	0:281d6ff68967	626	/* all pbufs in a chain are referenced at least once */
hexley	0:281d6ff68967	627	LWIP_ASSERT("pbuf_free: p->ref > 0", p->ref > 0);
hexley	0:281d6ff68967	628	/* decrease reference count (number of pointers to pbuf) */
hexley	0:281d6ff68967	629	ref = --(p->ref);
hexley	0:281d6ff68967	630	SYS_ARCH_UNPROTECT(old_level);
hexley	0:281d6ff68967	631	/* this pbuf is no longer referenced to? */
hexley	0:281d6ff68967	632	if (ref == 0) {
hexley	0:281d6ff68967	633	/* remember next pbuf in chain for next iteration */
hexley	0:281d6ff68967	634	q = p->next;
hexley	0:281d6ff68967	635	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free: deallocating %p\n", (void *)p));
hexley	0:281d6ff68967	636	type = p->type;
hexley	0:281d6ff68967	637	#if LWIP_SUPPORT_CUSTOM_PBUF
hexley	0:281d6ff68967	638	/* is this a custom pbuf? */
hexley	0:281d6ff68967	639	if ((p->flags & PBUF_FLAG_IS_CUSTOM) != 0) {
hexley	0:281d6ff68967	640	struct pbuf_custom pc = (struct pbuf_custom)p;
hexley	0:281d6ff68967	641	LWIP_ASSERT("pc->custom_free_function != NULL", pc->custom_free_function != NULL);
hexley	0:281d6ff68967	642	pc->custom_free_function(p);
hexley	0:281d6ff68967	643	} else
hexley	0:281d6ff68967	644	#endif /* LWIP_SUPPORT_CUSTOM_PBUF */
hexley	0:281d6ff68967	645	{
hexley	0:281d6ff68967	646	/* is this a pbuf from the pool? */
hexley	0:281d6ff68967	647	if (type == PBUF_POOL) {
hexley	0:281d6ff68967	648	memp_free(MEMP_PBUF_POOL, p);
hexley	0:281d6ff68967	649	/* is this a ROM or RAM referencing pbuf? */
hexley	0:281d6ff68967	650	} else if (type == PBUF_ROM \|\| type == PBUF_REF) {
hexley	0:281d6ff68967	651	memp_free(MEMP_PBUF, p);
hexley	0:281d6ff68967	652	/* type == PBUF_RAM */
hexley	0:281d6ff68967	653	} else {
hexley	0:281d6ff68967	654	mem_free(p);
hexley	0:281d6ff68967	655	}
hexley	0:281d6ff68967	656	}
hexley	0:281d6ff68967	657	count++;
hexley	0:281d6ff68967	658	/* proceed to next pbuf */
hexley	0:281d6ff68967	659	p = q;
hexley	0:281d6ff68967	660	/* p->ref > 0, this pbuf is still referenced to */
hexley	0:281d6ff68967	661	/* (and so the remaining pbufs in chain as well) */
hexley	0:281d6ff68967	662	} else {
hexley	0:281d6ff68967	663	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref));
hexley	0:281d6ff68967	664	/* stop walking through the chain */
hexley	0:281d6ff68967	665	p = NULL;
hexley	0:281d6ff68967	666	}
hexley	0:281d6ff68967	667	}
hexley	0:281d6ff68967	668	PERF_STOP("pbuf_free");
hexley	0:281d6ff68967	669	/* return number of de-allocated pbufs */
hexley	0:281d6ff68967	670	return count;
hexley	0:281d6ff68967	671	}
hexley	0:281d6ff68967	672
hexley	0:281d6ff68967	673	/**
hexley	0:281d6ff68967	674	* Count number of pbufs in a chain
hexley	0:281d6ff68967	675	*
hexley	0:281d6ff68967	676	* @param p first pbuf of chain
hexley	0:281d6ff68967	677	* @return the number of pbufs in a chain
hexley	0:281d6ff68967	678	*/
hexley	0:281d6ff68967	679
hexley	0:281d6ff68967	680	u8_t
hexley	0:281d6ff68967	681	pbuf_clen(struct pbuf *p)
hexley	0:281d6ff68967	682	{
hexley	0:281d6ff68967	683	u8_t len;
hexley	0:281d6ff68967	684
hexley	0:281d6ff68967	685	len = 0;
hexley	0:281d6ff68967	686	while (p != NULL) {
hexley	0:281d6ff68967	687	++len;
hexley	0:281d6ff68967	688	p = p->next;
hexley	0:281d6ff68967	689	}
hexley	0:281d6ff68967	690	return len;
hexley	0:281d6ff68967	691	}
hexley	0:281d6ff68967	692
hexley	0:281d6ff68967	693	/**
hexley	0:281d6ff68967	694	* Increment the reference count of the pbuf.
hexley	0:281d6ff68967	695	*
hexley	0:281d6ff68967	696	* @param p pbuf to increase reference counter of
hexley	0:281d6ff68967	697	*
hexley	0:281d6ff68967	698	*/
hexley	0:281d6ff68967	699	void
hexley	0:281d6ff68967	700	pbuf_ref(struct pbuf *p)
hexley	0:281d6ff68967	701	{
hexley	0:281d6ff68967	702	SYS_ARCH_DECL_PROTECT(old_level);
hexley	0:281d6ff68967	703	/* pbuf given? */
hexley	0:281d6ff68967	704	if (p != NULL) {
hexley	0:281d6ff68967	705	SYS_ARCH_PROTECT(old_level);
hexley	0:281d6ff68967	706	++(p->ref);
hexley	0:281d6ff68967	707	SYS_ARCH_UNPROTECT(old_level);
hexley	0:281d6ff68967	708	}
hexley	0:281d6ff68967	709	}
hexley	0:281d6ff68967	710
hexley	0:281d6ff68967	711	/**
hexley	0:281d6ff68967	712	* Concatenate two pbufs (each may be a pbuf chain) and take over
hexley	0:281d6ff68967	713	* the caller's reference of the tail pbuf.
hexley	0:281d6ff68967	714	*
hexley	0:281d6ff68967	715	* @note The caller MAY NOT reference the tail pbuf afterwards.
hexley	0:281d6ff68967	716	* Use pbuf_chain() for that purpose.
hexley	0:281d6ff68967	717	*
hexley	0:281d6ff68967	718	* @see pbuf_chain()
hexley	0:281d6ff68967	719	*/
hexley	0:281d6ff68967	720
hexley	0:281d6ff68967	721	void
hexley	0:281d6ff68967	722	pbuf_cat(struct pbuf h, struct pbuf t)
hexley	0:281d6ff68967	723	{
hexley	0:281d6ff68967	724	struct pbuf *p;
hexley	0:281d6ff68967	725
hexley	0:281d6ff68967	726	LWIP_ERROR("(h != NULL) && (t != NULL) (programmer violates API)",
hexley	0:281d6ff68967	727	((h != NULL) && (t != NULL)), return;);
hexley	0:281d6ff68967	728
hexley	0:281d6ff68967	729	/* proceed to last pbuf of chain */
hexley	0:281d6ff68967	730	for (p = h; p->next != NULL; p = p->next) {
hexley	0:281d6ff68967	731	/* add total length of second chain to all totals of first chain */
hexley	0:281d6ff68967	732	p->tot_len += t->tot_len;
hexley	0:281d6ff68967	733	}
hexley	0:281d6ff68967	734	/* { p is last pbuf of first h chain, p->next == NULL } */
hexley	0:281d6ff68967	735	LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len);
hexley	0:281d6ff68967	736	LWIP_ASSERT("p->next == NULL", p->next == NULL);
hexley	0:281d6ff68967	737	/* add total length of second chain to last pbuf total of first chain */
hexley	0:281d6ff68967	738	p->tot_len += t->tot_len;
hexley	0:281d6ff68967	739	/* chain last pbuf of head (p) with first of tail (t) */
hexley	0:281d6ff68967	740	p->next = t;
hexley	0:281d6ff68967	741	/* p->next now references t, but the caller will drop its reference to t,
hexley	0:281d6ff68967	742	* so netto there is no change to the reference count of t.
hexley	0:281d6ff68967	743	*/
hexley	0:281d6ff68967	744	}
hexley	0:281d6ff68967	745
hexley	0:281d6ff68967	746	/**
hexley	0:281d6ff68967	747	* Chain two pbufs (or pbuf chains) together.
hexley	0:281d6ff68967	748	*
hexley	0:281d6ff68967	749	* The caller MUST call pbuf_free(t) once it has stopped
hexley	0:281d6ff68967	750	* using it. Use pbuf_cat() instead if you no longer use t.
hexley	0:281d6ff68967	751	*
hexley	0:281d6ff68967	752	* @param h head pbuf (chain)
hexley	0:281d6ff68967	753	* @param t tail pbuf (chain)
hexley	0:281d6ff68967	754	* @note The pbufs MUST belong to the same packet.
hexley	0:281d6ff68967	755	* @note MAY NOT be called on a packet queue.
hexley	0:281d6ff68967	756	*
hexley	0:281d6ff68967	757	* The ->tot_len fields of all pbufs of the head chain are adjusted.
hexley	0:281d6ff68967	758	* The ->next field of the last pbuf of the head chain is adjusted.
hexley	0:281d6ff68967	759	* The ->ref field of the first pbuf of the tail chain is adjusted.
hexley	0:281d6ff68967	760	*
hexley	0:281d6ff68967	761	*/
hexley	0:281d6ff68967	762	void
hexley	0:281d6ff68967	763	pbuf_chain(struct pbuf h, struct pbuf t)
hexley	0:281d6ff68967	764	{
hexley	0:281d6ff68967	765	pbuf_cat(h, t);
hexley	0:281d6ff68967	766	/* t is now referenced by h */
hexley	0:281d6ff68967	767	pbuf_ref(t);
hexley	0:281d6ff68967	768	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_chain: %p references %p\n", (void )h, (void )t));
hexley	0:281d6ff68967	769	}
hexley	0:281d6ff68967	770
hexley	0:281d6ff68967	771	/**
hexley	0:281d6ff68967	772	* Dechains the first pbuf from its succeeding pbufs in the chain.
hexley	0:281d6ff68967	773	*
hexley	0:281d6ff68967	774	* Makes p->tot_len field equal to p->len.
hexley	0:281d6ff68967	775	* @param p pbuf to dechain
hexley	0:281d6ff68967	776	* @return remainder of the pbuf chain, or NULL if it was de-allocated.
hexley	0:281d6ff68967	777	* @note May not be called on a packet queue.
hexley	0:281d6ff68967	778	*/
hexley	0:281d6ff68967	779	struct pbuf *
hexley	0:281d6ff68967	780	pbuf_dechain(struct pbuf *p)
hexley	0:281d6ff68967	781	{
hexley	0:281d6ff68967	782	struct pbuf *q;
hexley	0:281d6ff68967	783	u8_t tail_gone = 1;
hexley	0:281d6ff68967	784	/* tail */
hexley	0:281d6ff68967	785	q = p->next;
hexley	0:281d6ff68967	786	/* pbuf has successor in chain? */
hexley	0:281d6ff68967	787	if (q != NULL) {
hexley	0:281d6ff68967	788	/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
hexley	0:281d6ff68967	789	LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len);
hexley	0:281d6ff68967	790	/* enforce invariant if assertion is disabled */
hexley	0:281d6ff68967	791	q->tot_len = p->tot_len - p->len;
hexley	0:281d6ff68967	792	/* decouple pbuf from remainder */
hexley	0:281d6ff68967	793	p->next = NULL;
hexley	0:281d6ff68967	794	/* total length of pbuf p is its own length only */
hexley	0:281d6ff68967	795	p->tot_len = p->len;
hexley	0:281d6ff68967	796	/* q is no longer referenced by p, free it */
hexley	0:281d6ff68967	797	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_dechain: unreferencing %p\n", (void *)q));
hexley	0:281d6ff68967	798	tail_gone = pbuf_free(q);
hexley	0:281d6ff68967	799	if (tail_gone > 0) {
hexley	0:281d6ff68967	800	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE,
hexley	0:281d6ff68967	801	("pbuf_dechain: deallocated %p (as it is no longer referenced)\n", (void *)q));
hexley	0:281d6ff68967	802	}
hexley	0:281d6ff68967	803	/* return remaining tail or NULL if deallocated */
hexley	0:281d6ff68967	804	}
hexley	0:281d6ff68967	805	/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
hexley	0:281d6ff68967	806	LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len);
hexley	0:281d6ff68967	807	return ((tail_gone > 0) ? NULL : q);
hexley	0:281d6ff68967	808	}
hexley	0:281d6ff68967	809
hexley	0:281d6ff68967	810	/**
hexley	0:281d6ff68967	811	*
hexley	0:281d6ff68967	812	* Create PBUF_RAM copies of pbufs.
hexley	0:281d6ff68967	813	*
hexley	0:281d6ff68967	814	* Used to queue packets on behalf of the lwIP stack, such as
hexley	0:281d6ff68967	815	* ARP based queueing.
hexley	0:281d6ff68967	816	*
hexley	0:281d6ff68967	817	* @note You MUST explicitly use p = pbuf_take(p);
hexley	0:281d6ff68967	818	*
hexley	0:281d6ff68967	819	* @note Only one packet is copied, no packet queue!
hexley	0:281d6ff68967	820	*
hexley	0:281d6ff68967	821	* @param p_to pbuf destination of the copy
hexley	0:281d6ff68967	822	* @param p_from pbuf source of the copy
hexley	0:281d6ff68967	823	*
hexley	0:281d6ff68967	824	* @return ERR_OK if pbuf was copied
hexley	0:281d6ff68967	825	* ERR_ARG if one of the pbufs is NULL or p_to is not big
hexley	0:281d6ff68967	826	* enough to hold p_from
hexley	0:281d6ff68967	827	*/
hexley	0:281d6ff68967	828	err_t
hexley	0:281d6ff68967	829	pbuf_copy(struct pbuf p_to, struct pbuf p_from)
hexley	0:281d6ff68967	830	{
hexley	0:281d6ff68967	831	u16_t offset_to=0, offset_from=0, len;
hexley	0:281d6ff68967	832
hexley	0:281d6ff68967	833	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_copy(%p, %p)\n",
hexley	0:281d6ff68967	834	(void)p_to, (void)p_from));
hexley	0:281d6ff68967	835
hexley	0:281d6ff68967	836	/* is the target big enough to hold the source? */
hexley	0:281d6ff68967	837	LWIP_ERROR("pbuf_copy: target not big enough to hold source", ((p_to != NULL) &&
hexley	0:281d6ff68967	838	(p_from != NULL) && (p_to->tot_len >= p_from->tot_len)), return ERR_ARG;);
hexley	0:281d6ff68967	839
hexley	0:281d6ff68967	840	/* iterate through pbuf chain */
hexley	0:281d6ff68967	841	do
hexley	0:281d6ff68967	842	{
hexley	0:281d6ff68967	843	LWIP_ASSERT("p_to != NULL", p_to != NULL);
hexley	0:281d6ff68967	844	/* copy one part of the original chain */
hexley	0:281d6ff68967	845	if ((p_to->len - offset_to) >= (p_from->len - offset_from)) {
hexley	0:281d6ff68967	846	/* complete current p_from fits into current p_to */
hexley	0:281d6ff68967	847	len = p_from->len - offset_from;
hexley	0:281d6ff68967	848	} else {
hexley	0:281d6ff68967	849	/* current p_from does not fit into current p_to */
hexley	0:281d6ff68967	850	len = p_to->len - offset_to;
hexley	0:281d6ff68967	851	}
hexley	0:281d6ff68967	852	MEMCPY((u8_t)p_to->payload + offset_to, (u8_t)p_from->payload + offset_from, len);
hexley	0:281d6ff68967	853	offset_to += len;
hexley	0:281d6ff68967	854	offset_from += len;
hexley	0:281d6ff68967	855	LWIP_ASSERT("offset_to <= p_to->len", offset_to <= p_to->len);
hexley	0:281d6ff68967	856	if (offset_to == p_to->len) {
hexley	0:281d6ff68967	857	/* on to next p_to (if any) */
hexley	0:281d6ff68967	858	offset_to = 0;
hexley	0:281d6ff68967	859	p_to = p_to->next;
hexley	0:281d6ff68967	860	}
hexley	0:281d6ff68967	861	LWIP_ASSERT("offset_from <= p_from->len", offset_from <= p_from->len);
hexley	0:281d6ff68967	862	if (offset_from >= p_from->len) {
hexley	0:281d6ff68967	863	/* on to next p_from (if any) */
hexley	0:281d6ff68967	864	offset_from = 0;
hexley	0:281d6ff68967	865	p_from = p_from->next;
hexley	0:281d6ff68967	866	}
hexley	0:281d6ff68967	867
hexley	0:281d6ff68967	868	if((p_from != NULL) && (p_from->len == p_from->tot_len)) {
hexley	0:281d6ff68967	869	/* don't copy more than one packet! */
hexley	0:281d6ff68967	870	LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
hexley	0:281d6ff68967	871	(p_from->next == NULL), return ERR_VAL;);
hexley	0:281d6ff68967	872	}
hexley	0:281d6ff68967	873	if((p_to != NULL) && (p_to->len == p_to->tot_len)) {
hexley	0:281d6ff68967	874	/* don't copy more than one packet! */
hexley	0:281d6ff68967	875	LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
hexley	0:281d6ff68967	876	(p_to->next == NULL), return ERR_VAL;);
hexley	0:281d6ff68967	877	}
hexley	0:281d6ff68967	878	} while (p_from);
hexley	0:281d6ff68967	879	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_copy: end of chain reached.\n"));
hexley	0:281d6ff68967	880	return ERR_OK;
hexley	0:281d6ff68967	881	}
hexley	0:281d6ff68967	882
hexley	0:281d6ff68967	883	/**
hexley	0:281d6ff68967	884	* Copy (part of) the contents of a packet buffer
hexley	0:281d6ff68967	885	* to an application supplied buffer.
hexley	0:281d6ff68967	886	*
hexley	0:281d6ff68967	887	* @param buf the pbuf from which to copy data
hexley	0:281d6ff68967	888	* @param dataptr the application supplied buffer
hexley	0:281d6ff68967	889	* @param len length of data to copy (dataptr must be big enough). No more
hexley	0:281d6ff68967	890	* than buf->tot_len will be copied, irrespective of len
hexley	0:281d6ff68967	891	* @param offset offset into the packet buffer from where to begin copying len bytes
hexley	0:281d6ff68967	892	* @return the number of bytes copied, or 0 on failure
hexley	0:281d6ff68967	893	*/
hexley	0:281d6ff68967	894	u16_t
hexley	0:281d6ff68967	895	pbuf_copy_partial(struct pbuf buf, void dataptr, u16_t len, u16_t offset)
hexley	0:281d6ff68967	896	{
hexley	0:281d6ff68967	897	struct pbuf *p;
hexley	0:281d6ff68967	898	u16_t left;
hexley	0:281d6ff68967	899	u16_t buf_copy_len;
hexley	0:281d6ff68967	900	u16_t copied_total = 0;
hexley	0:281d6ff68967	901
hexley	0:281d6ff68967	902	LWIP_ERROR("pbuf_copy_partial: invalid buf", (buf != NULL), return 0;);
hexley	0:281d6ff68967	903	LWIP_ERROR("pbuf_copy_partial: invalid dataptr", (dataptr != NULL), return 0;);
hexley	0:281d6ff68967	904
hexley	0:281d6ff68967	905	left = 0;
hexley	0:281d6ff68967	906
hexley	0:281d6ff68967	907	if((buf == NULL) \|\| (dataptr == NULL)) {
hexley	0:281d6ff68967	908	return 0;
hexley	0:281d6ff68967	909	}
hexley	0:281d6ff68967	910
hexley	0:281d6ff68967	911	/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
hexley	0:281d6ff68967	912	for(p = buf; len != 0 && p != NULL; p = p->next) {
hexley	0:281d6ff68967	913	if ((offset != 0) && (offset >= p->len)) {
hexley	0:281d6ff68967	914	/* don't copy from this buffer -> on to the next */
hexley	0:281d6ff68967	915	offset -= p->len;
hexley	0:281d6ff68967	916	} else {
hexley	0:281d6ff68967	917	/* copy from this buffer. maybe only partially. */
hexley	0:281d6ff68967	918	buf_copy_len = p->len - offset;
hexley	0:281d6ff68967	919	if (buf_copy_len > len)
hexley	0:281d6ff68967	920	buf_copy_len = len;
hexley	0:281d6ff68967	921	/* copy the necessary parts of the buffer */
hexley	0:281d6ff68967	922	MEMCPY(&((char)dataptr)[left], &((char)p->payload)[offset], buf_copy_len);
hexley	0:281d6ff68967	923	copied_total += buf_copy_len;
hexley	0:281d6ff68967	924	left += buf_copy_len;
hexley	0:281d6ff68967	925	len -= buf_copy_len;
hexley	0:281d6ff68967	926	offset = 0;
hexley	0:281d6ff68967	927	}
hexley	0:281d6ff68967	928	}
hexley	0:281d6ff68967	929	return copied_total;
hexley	0:281d6ff68967	930	}
hexley	0:281d6ff68967	931
hexley	0:281d6ff68967	932	/**
hexley	0:281d6ff68967	933	* Copy application supplied data into a pbuf.
hexley	0:281d6ff68967	934	* This function can only be used to copy the equivalent of buf->tot_len data.
hexley	0:281d6ff68967	935	*
hexley	0:281d6ff68967	936	* @param buf pbuf to fill with data
hexley	0:281d6ff68967	937	* @param dataptr application supplied data buffer
hexley	0:281d6ff68967	938	* @param len length of the application supplied data buffer
hexley	0:281d6ff68967	939	*
hexley	0:281d6ff68967	940	* @return ERR_OK if successful, ERR_MEM if the pbuf is not big enough
hexley	0:281d6ff68967	941	*/
hexley	0:281d6ff68967	942	err_t
hexley	0:281d6ff68967	943	pbuf_take(struct pbuf buf, const void dataptr, u16_t len)
hexley	0:281d6ff68967	944	{
hexley	0:281d6ff68967	945	struct pbuf *p;
hexley	0:281d6ff68967	946	u16_t buf_copy_len;
hexley	0:281d6ff68967	947	u16_t total_copy_len = len;
hexley	0:281d6ff68967	948	u16_t copied_total = 0;
hexley	0:281d6ff68967	949
hexley	0:281d6ff68967	950	LWIP_ERROR("pbuf_take: invalid buf", (buf != NULL), return 0;);
hexley	0:281d6ff68967	951	LWIP_ERROR("pbuf_take: invalid dataptr", (dataptr != NULL), return 0;);
hexley	0:281d6ff68967	952
hexley	0:281d6ff68967	953	if ((buf == NULL) \|\| (dataptr == NULL) \|\| (buf->tot_len < len)) {
hexley	0:281d6ff68967	954	return ERR_ARG;
hexley	0:281d6ff68967	955	}
hexley	0:281d6ff68967	956
hexley	0:281d6ff68967	957	/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
hexley	0:281d6ff68967	958	for(p = buf; total_copy_len != 0; p = p->next) {
hexley	0:281d6ff68967	959	LWIP_ASSERT("pbuf_take: invalid pbuf", p != NULL);
hexley	0:281d6ff68967	960	buf_copy_len = total_copy_len;
hexley	0:281d6ff68967	961	if (buf_copy_len > p->len) {
hexley	0:281d6ff68967	962	/* this pbuf cannot hold all remaining data */
hexley	0:281d6ff68967	963	buf_copy_len = p->len;
hexley	0:281d6ff68967	964	}
hexley	0:281d6ff68967	965	/* copy the necessary parts of the buffer */
hexley	0:281d6ff68967	966	MEMCPY(p->payload, &((char*)dataptr)[copied_total], buf_copy_len);
hexley	0:281d6ff68967	967	total_copy_len -= buf_copy_len;
hexley	0:281d6ff68967	968	copied_total += buf_copy_len;
hexley	0:281d6ff68967	969	}
hexley	0:281d6ff68967	970	LWIP_ASSERT("did not copy all data", total_copy_len == 0 && copied_total == len);
hexley	0:281d6ff68967	971	return ERR_OK;
hexley	0:281d6ff68967	972	}
hexley	0:281d6ff68967	973
hexley	0:281d6ff68967	974	/**
hexley	0:281d6ff68967	975	* Creates a single pbuf out of a queue of pbufs.
hexley	0:281d6ff68967	976	*
hexley	0:281d6ff68967	977	* @remark: Either the source pbuf 'p' is freed by this function or the original
hexley	0:281d6ff68967	978	* pbuf 'p' is returned, therefore the caller has to check the result!
hexley	0:281d6ff68967	979	*
hexley	0:281d6ff68967	980	* @param p the source pbuf
hexley	0:281d6ff68967	981	* @param layer pbuf_layer of the new pbuf
hexley	0:281d6ff68967	982	*
hexley	0:281d6ff68967	983	* @return a new, single pbuf (p->next is NULL)
hexley	0:281d6ff68967	984	* or the old pbuf if allocation fails
hexley	0:281d6ff68967	985	*/
hexley	0:281d6ff68967	986	struct pbuf*
hexley	0:281d6ff68967	987	pbuf_coalesce(struct pbuf *p, pbuf_layer layer)
hexley	0:281d6ff68967	988	{
hexley	0:281d6ff68967	989	struct pbuf *q;
hexley	0:281d6ff68967	990	err_t err;
hexley	0:281d6ff68967	991	if (p->next == NULL) {
hexley	0:281d6ff68967	992	return p;
hexley	0:281d6ff68967	993	}
hexley	0:281d6ff68967	994	q = pbuf_alloc(layer, p->tot_len, PBUF_RAM);
hexley	0:281d6ff68967	995	if (q == NULL) {
hexley	0:281d6ff68967	996	/* @todo: what do we do now? */
hexley	0:281d6ff68967	997	return p;
hexley	0:281d6ff68967	998	}
hexley	0:281d6ff68967	999	err = pbuf_copy(q, p);
hexley	0:281d6ff68967	1000	LWIP_ASSERT("pbuf_copy failed", err == ERR_OK);
hexley	0:281d6ff68967	1001	pbuf_free(p);
hexley	0:281d6ff68967	1002	return q;
hexley	0:281d6ff68967	1003	}
hexley	0:281d6ff68967	1004
hexley	0:281d6ff68967	1005	#if LWIP_CHECKSUM_ON_COPY
hexley	0:281d6ff68967	1006	/**
hexley	0:281d6ff68967	1007	* Copies data into a single pbuf (not into a pbuf queue!) and updates
hexley	0:281d6ff68967	1008	* the checksum while copying
hexley	0:281d6ff68967	1009	*
hexley	0:281d6ff68967	1010	* @param p the pbuf to copy data into
hexley	0:281d6ff68967	1011	* @param start_offset offset of p->payload where to copy the data to
hexley	0:281d6ff68967	1012	* @param dataptr data to copy into the pbuf
hexley	0:281d6ff68967	1013	* @param len length of data to copy into the pbuf
hexley	0:281d6ff68967	1014	* @param chksum pointer to the checksum which is updated
hexley	0:281d6ff68967	1015	* @return ERR_OK if successful, another error if the data does not fit
hexley	0:281d6ff68967	1016	* within the (first) pbuf (no pbuf queues!)
hexley	0:281d6ff68967	1017	*/
hexley	0:281d6ff68967	1018	err_t
hexley	0:281d6ff68967	1019	pbuf_fill_chksum(struct pbuf p, u16_t start_offset, const void dataptr,
hexley	0:281d6ff68967	1020	u16_t len, u16_t *chksum)
hexley	0:281d6ff68967	1021	{
hexley	0:281d6ff68967	1022	u32_t acc;
hexley	0:281d6ff68967	1023	u16_t copy_chksum;
hexley	0:281d6ff68967	1024	char *dst_ptr;
hexley	0:281d6ff68967	1025	LWIP_ASSERT("p != NULL", p != NULL);
hexley	0:281d6ff68967	1026	LWIP_ASSERT("dataptr != NULL", dataptr != NULL);
hexley	0:281d6ff68967	1027	LWIP_ASSERT("chksum != NULL", chksum != NULL);
hexley	0:281d6ff68967	1028	LWIP_ASSERT("len != 0", len != 0);
hexley	0:281d6ff68967	1029
hexley	0:281d6ff68967	1030	if ((start_offset >= p->len) \|\| (start_offset + len > p->len)) {
hexley	0:281d6ff68967	1031	return ERR_ARG;
hexley	0:281d6ff68967	1032	}
hexley	0:281d6ff68967	1033
hexley	0:281d6ff68967	1034	dst_ptr = ((char*)p->payload) + start_offset;
hexley	0:281d6ff68967	1035	copy_chksum = LWIP_CHKSUM_COPY(dst_ptr, dataptr, len);
hexley	0:281d6ff68967	1036	if ((start_offset & 1) != 0) {
hexley	0:281d6ff68967	1037	copy_chksum = SWAP_BYTES_IN_WORD(copy_chksum);
hexley	0:281d6ff68967	1038	}
hexley	0:281d6ff68967	1039	acc = *chksum;
hexley	0:281d6ff68967	1040	acc += copy_chksum;
hexley	0:281d6ff68967	1041	*chksum = FOLD_U32T(acc);
hexley	0:281d6ff68967	1042	return ERR_OK;
hexley	0:281d6ff68967	1043	}
hexley	0:281d6ff68967	1044	#endif /* LWIP_CHECKSUM_ON_COPY */
hexley	0:281d6ff68967	1045
hexley	0:281d6ff68967	1046	/** Get one byte from the specified position in a pbuf
hexley	0:281d6ff68967	1047	* WARNING: returns zero for offset >= p->tot_len
hexley	0:281d6ff68967	1048	*
hexley	0:281d6ff68967	1049	* @param p pbuf to parse
hexley	0:281d6ff68967	1050	* @param offset offset into p of the byte to return
hexley	0:281d6ff68967	1051	* @return byte at an offset into p OR ZERO IF 'offset' >= p->tot_len
hexley	0:281d6ff68967	1052	*/
hexley	0:281d6ff68967	1053	u8_t
hexley	0:281d6ff68967	1054	pbuf_get_at(struct pbuf* p, u16_t offset)
hexley	0:281d6ff68967	1055	{
hexley	0:281d6ff68967	1056	u16_t copy_from = offset;
hexley	0:281d6ff68967	1057	struct pbuf* q = p;
hexley	0:281d6ff68967	1058
hexley	0:281d6ff68967	1059	/* get the correct pbuf */
hexley	0:281d6ff68967	1060	while ((q != NULL) && (q->len <= copy_from)) {
hexley	0:281d6ff68967	1061	copy_from -= q->len;
hexley	0:281d6ff68967	1062	q = q->next;
hexley	0:281d6ff68967	1063	}
hexley	0:281d6ff68967	1064	/* return requested data if pbuf is OK */
hexley	0:281d6ff68967	1065	if ((q != NULL) && (q->len > copy_from)) {
hexley	0:281d6ff68967	1066	return ((u8_t*)q->payload)[copy_from];
hexley	0:281d6ff68967	1067	}
hexley	0:281d6ff68967	1068	return 0;
hexley	0:281d6ff68967	1069	}
hexley	0:281d6ff68967	1070
hexley	0:281d6ff68967	1071	/** Compare pbuf contents at specified offset with memory s2, both of length n
hexley	0:281d6ff68967	1072	*
hexley	0:281d6ff68967	1073	* @param p pbuf to compare
hexley	0:281d6ff68967	1074	* @param offset offset into p at wich to start comparing
hexley	0:281d6ff68967	1075	* @param s2 buffer to compare
hexley	0:281d6ff68967	1076	* @param n length of buffer to compare
hexley	0:281d6ff68967	1077	* @return zero if equal, nonzero otherwise
hexley	0:281d6ff68967	1078	* (0xffff if p is too short, diffoffset+1 otherwise)
hexley	0:281d6ff68967	1079	*/
hexley	0:281d6ff68967	1080	u16_t
hexley	0:281d6ff68967	1081	pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n)
hexley	0:281d6ff68967	1082	{
hexley	0:281d6ff68967	1083	u16_t start = offset;
hexley	0:281d6ff68967	1084	struct pbuf* q = p;
hexley	0:281d6ff68967	1085
hexley	0:281d6ff68967	1086	/* get the correct pbuf */
hexley	0:281d6ff68967	1087	while ((q != NULL) && (q->len <= start)) {
hexley	0:281d6ff68967	1088	start -= q->len;
hexley	0:281d6ff68967	1089	q = q->next;
hexley	0:281d6ff68967	1090	}
hexley	0:281d6ff68967	1091	/* return requested data if pbuf is OK */
hexley	0:281d6ff68967	1092	if ((q != NULL) && (q->len > start)) {
hexley	0:281d6ff68967	1093	u16_t i;
hexley	0:281d6ff68967	1094	for(i = 0; i < n; i++) {
hexley	0:281d6ff68967	1095	u8_t a = pbuf_get_at(q, start + i);
hexley	0:281d6ff68967	1096	u8_t b = ((u8_t*)s2)[i];
hexley	0:281d6ff68967	1097	if (a != b) {
hexley	0:281d6ff68967	1098	return i+1;
hexley	0:281d6ff68967	1099	}
hexley	0:281d6ff68967	1100	}
hexley	0:281d6ff68967	1101	return 0;
hexley	0:281d6ff68967	1102	}
hexley	0:281d6ff68967	1103	return 0xffff;
hexley	0:281d6ff68967	1104	}
hexley	0:281d6ff68967	1105
hexley	0:281d6ff68967	1106	/** Find occurrence of mem (with length mem_len) in pbuf p, starting at offset
hexley	0:281d6ff68967	1107	* start_offset.
hexley	0:281d6ff68967	1108	*
hexley	0:281d6ff68967	1109	* @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
hexley	0:281d6ff68967	1110	* return value 'not found'
hexley	0:281d6ff68967	1111	* @param mem search for the contents of this buffer
hexley	0:281d6ff68967	1112	* @param mem_len length of 'mem'
hexley	0:281d6ff68967	1113	* @param start_offset offset into p at which to start searching
hexley	0:281d6ff68967	1114	* @return 0xFFFF if substr was not found in p or the index where it was found
hexley	0:281d6ff68967	1115	*/
hexley	0:281d6ff68967	1116	u16_t
hexley	0:281d6ff68967	1117	pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset)
hexley	0:281d6ff68967	1118	{
hexley	0:281d6ff68967	1119	u16_t i;
hexley	0:281d6ff68967	1120	u16_t max = p->tot_len - mem_len;
hexley	0:281d6ff68967	1121	if (p->tot_len >= mem_len + start_offset) {
hexley	0:281d6ff68967	1122	for(i = start_offset; i <= max; ) {
hexley	0:281d6ff68967	1123	u16_t plus = pbuf_memcmp(p, i, mem, mem_len);
hexley	0:281d6ff68967	1124	if (plus == 0) {
hexley	0:281d6ff68967	1125	return i;
hexley	0:281d6ff68967	1126	} else {
hexley	0:281d6ff68967	1127	i += plus;
hexley	0:281d6ff68967	1128	}
hexley	0:281d6ff68967	1129	}
hexley	0:281d6ff68967	1130	}
hexley	0:281d6ff68967	1131	return 0xFFFF;
hexley	0:281d6ff68967	1132	}
hexley	0:281d6ff68967	1133
hexley	0:281d6ff68967	1134	/** Find occurrence of substr with length substr_len in pbuf p, start at offset
hexley	0:281d6ff68967	1135	* start_offset
hexley	0:281d6ff68967	1136	* WARNING: in contrast to strstr(), this one does not stop at the first \0 in
hexley	0:281d6ff68967	1137	* the pbuf/source string!
hexley	0:281d6ff68967	1138	*
hexley	0:281d6ff68967	1139	* @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
hexley	0:281d6ff68967	1140	* return value 'not found'
hexley	0:281d6ff68967	1141	* @param substr string to search for in p, maximum length is 0xFFFE
hexley	0:281d6ff68967	1142	* @return 0xFFFF if substr was not found in p or the index where it was found
hexley	0:281d6ff68967	1143	*/
hexley	0:281d6ff68967	1144	u16_t
hexley	0:281d6ff68967	1145	pbuf_strstr(struct pbuf* p, const char* substr)
hexley	0:281d6ff68967	1146	{
hexley	0:281d6ff68967	1147	size_t substr_len;
hexley	0:281d6ff68967	1148	if ((substr == NULL) \|\| (substr[0] == 0) \|\| (p->tot_len == 0xFFFF)) {
hexley	0:281d6ff68967	1149	return 0xFFFF;
hexley	0:281d6ff68967	1150	}
hexley	0:281d6ff68967	1151	substr_len = strlen(substr);
hexley	0:281d6ff68967	1152	if (substr_len >= 0xFFFF) {
hexley	0:281d6ff68967	1153	return 0xFFFF;
hexley	0:281d6ff68967	1154	}
hexley	0:281d6ff68967	1155	return pbuf_memfind(p, substr, (u16_t)substr_len, 0);
hexley	0:281d6ff68967	1156	}

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Type:	Library
Created:	19 Nov 2010
Imports:	44
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	0
Followers:	1

lwip/core/pbuf.c@0:281d6ff68967, 2010-11-19 (annotated)

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