ZG2100NetIfSource - ZG2100 Network interface source

Users » donatien » Code » ZG2100NetIfSource

ZG2100 Network interface source

lwip/core/pbuf.c@0:b802fc31f1db, 2010-07-09 (annotated)

Committer:: donatien
Date:: Fri Jul 09 15:37:23 2010 +0000
Revision:: 0:b802fc31f1db
Child:: 1:3a7c15057192

Who changed what in which revision?

User	Revision	Line number	New contents of line
donatien	0:b802fc31f1db	1	/**
donatien	0:b802fc31f1db	2	* @file
donatien	0:b802fc31f1db	3	* Packet buffer management
donatien	0:b802fc31f1db	4	*
donatien	0:b802fc31f1db	5	* Packets are built from the pbuf data structure. It supports dynamic
donatien	0:b802fc31f1db	6	* memory allocation for packet contents or can reference externally
donatien	0:b802fc31f1db	7	* managed packet contents both in RAM and ROM. Quick allocation for
donatien	0:b802fc31f1db	8	* incoming packets is provided through pools with fixed sized pbufs.
donatien	0:b802fc31f1db	9	*
donatien	0:b802fc31f1db	10	* A packet may span over multiple pbufs, chained as a singly linked
donatien	0:b802fc31f1db	11	* list. This is called a "pbuf chain".
donatien	0:b802fc31f1db	12	*
donatien	0:b802fc31f1db	13	* Multiple packets may be queued, also using this singly linked list.
donatien	0:b802fc31f1db	14	* This is called a "packet queue".
donatien	0:b802fc31f1db	15	*
donatien	0:b802fc31f1db	16	* So, a packet queue consists of one or more pbuf chains, each of
donatien	0:b802fc31f1db	17	* which consist of one or more pbufs. CURRENTLY, PACKET QUEUES ARE
donatien	0:b802fc31f1db	18	* NOT SUPPORTED!!! Use helper structs to queue multiple packets.
donatien	0:b802fc31f1db	19	*
donatien	0:b802fc31f1db	20	* The differences between a pbuf chain and a packet queue are very
donatien	0:b802fc31f1db	21	* precise but subtle.
donatien	0:b802fc31f1db	22	*
donatien	0:b802fc31f1db	23	* The last pbuf of a packet has a ->tot_len field that equals the
donatien	0:b802fc31f1db	24	* ->len field. It can be found by traversing the list. If the last
donatien	0:b802fc31f1db	25	* pbuf of a packet has a ->next field other than NULL, more packets
donatien	0:b802fc31f1db	26	* are on the queue.
donatien	0:b802fc31f1db	27	*
donatien	0:b802fc31f1db	28	* Therefore, looping through a pbuf of a single packet, has an
donatien	0:b802fc31f1db	29	* loop end condition (tot_len == p->len), NOT (next == NULL).
donatien	0:b802fc31f1db	30	*/
donatien	0:b802fc31f1db	31
donatien	0:b802fc31f1db	32	/*
donatien	0:b802fc31f1db	33	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
donatien	0:b802fc31f1db	34	* All rights reserved.
donatien	0:b802fc31f1db	35	*
donatien	0:b802fc31f1db	36	* Redistribution and use in source and binary forms, with or without modification,
donatien	0:b802fc31f1db	37	* are permitted provided that the following conditions are met:
donatien	0:b802fc31f1db	38	*
donatien	0:b802fc31f1db	39	* 1. Redistributions of source code must retain the above copyright notice,
donatien	0:b802fc31f1db	40	* this list of conditions and the following disclaimer.
donatien	0:b802fc31f1db	41	* 2. Redistributions in binary form must reproduce the above copyright notice,
donatien	0:b802fc31f1db	42	* this list of conditions and the following disclaimer in the documentation
donatien	0:b802fc31f1db	43	* and/or other materials provided with the distribution.
donatien	0:b802fc31f1db	44	* 3. The name of the author may not be used to endorse or promote products
donatien	0:b802fc31f1db	45	* derived from this software without specific prior written permission.
donatien	0:b802fc31f1db	46	*
donatien	0:b802fc31f1db	47	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
donatien	0:b802fc31f1db	48	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
donatien	0:b802fc31f1db	49	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
donatien	0:b802fc31f1db	50	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
donatien	0:b802fc31f1db	51	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
donatien	0:b802fc31f1db	52	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
donatien	0:b802fc31f1db	53	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
donatien	0:b802fc31f1db	54	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
donatien	0:b802fc31f1db	55	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
donatien	0:b802fc31f1db	56	* OF SUCH DAMAGE.
donatien	0:b802fc31f1db	57	*
donatien	0:b802fc31f1db	58	* This file is part of the lwIP TCP/IP stack.
donatien	0:b802fc31f1db	59	*
donatien	0:b802fc31f1db	60	* Author: Adam Dunkels <adam@sics.se>
donatien	0:b802fc31f1db	61	*
donatien	0:b802fc31f1db	62	*/
donatien	0:b802fc31f1db	63
donatien	0:b802fc31f1db	64	#include "lwip/opt.h"
donatien	0:b802fc31f1db	65
donatien	0:b802fc31f1db	66	#include "lwip/stats.h"
donatien	0:b802fc31f1db	67	#include "lwip/def.h"
donatien	0:b802fc31f1db	68	#include "lwip/mem.h"
donatien	0:b802fc31f1db	69	#include "lwip/memp.h"
donatien	0:b802fc31f1db	70	#include "lwip/pbuf.h"
donatien	0:b802fc31f1db	71	#include "lwip/sys.h"
donatien	0:b802fc31f1db	72	#include "arch/perf.h"
donatien	0:b802fc31f1db	73	#if TCP_QUEUE_OOSEQ
donatien	0:b802fc31f1db	74	#include "lwip/tcp_impl.h"
donatien	0:b802fc31f1db	75	#endif
donatien	0:b802fc31f1db	76
donatien	0:b802fc31f1db	77	#include <string.h>
donatien	0:b802fc31f1db	78
donatien	0:b802fc31f1db	79	#define SIZEOF_STRUCT_PBUF LWIP_MEM_ALIGN_SIZE(sizeof(struct pbuf))
donatien	0:b802fc31f1db	80	/* Since the pool is created in memp, PBUF_POOL_BUFSIZE will be automatically
donatien	0:b802fc31f1db	81	aligned there. Therefore, PBUF_POOL_BUFSIZE_ALIGNED can be used here. */
donatien	0:b802fc31f1db	82	#define PBUF_POOL_BUFSIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE)
donatien	0:b802fc31f1db	83
donatien	0:b802fc31f1db	84	#if !TCP_QUEUE_OOSEQ \|\| NO_SYS
donatien	0:b802fc31f1db	85	#define PBUF_POOL_IS_EMPTY()
donatien	0:b802fc31f1db	86	#else /* !TCP_QUEUE_OOSEQ \|\| NO_SYS */
donatien	0:b802fc31f1db	87	/** Define this to 0 to prevent freeing ooseq pbufs when the PBUF_POOL is empty */
donatien	0:b802fc31f1db	88	#ifndef PBUF_POOL_FREE_OOSEQ
donatien	0:b802fc31f1db	89	#define PBUF_POOL_FREE_OOSEQ 1
donatien	0:b802fc31f1db	90	#endif /* PBUF_POOL_FREE_OOSEQ */
donatien	0:b802fc31f1db	91
donatien	0:b802fc31f1db	92	#if PBUF_POOL_FREE_OOSEQ
donatien	0:b802fc31f1db	93	#include "lwip/tcpip.h"
donatien	0:b802fc31f1db	94	#define PBUF_POOL_IS_EMPTY() pbuf_pool_is_empty()
donatien	0:b802fc31f1db	95	static u8_t pbuf_free_ooseq_queued;
donatien	0:b802fc31f1db	96	/**
donatien	0:b802fc31f1db	97	* Attempt to reclaim some memory from queued out-of-sequence TCP segments
donatien	0:b802fc31f1db	98	* if we run out of pool pbufs. It's better to give priority to new packets
donatien	0:b802fc31f1db	99	* if we're running out.
donatien	0:b802fc31f1db	100	*
donatien	0:b802fc31f1db	101	* This must be done in the correct thread context therefore this function
donatien	0:b802fc31f1db	102	* can only be used with NO_SYS=0 and through tcpip_callback.
donatien	0:b802fc31f1db	103	*/
donatien	0:b802fc31f1db	104	static void
donatien	0:b802fc31f1db	105	pbuf_free_ooseq(void* arg)
donatien	0:b802fc31f1db	106	{
donatien	0:b802fc31f1db	107	struct tcp_pcb* pcb;
donatien	0:b802fc31f1db	108	SYS_ARCH_DECL_PROTECT(old_level);
donatien	0:b802fc31f1db	109	LWIP_UNUSED_ARG(arg);
donatien	0:b802fc31f1db	110
donatien	0:b802fc31f1db	111	SYS_ARCH_PROTECT(old_level);
donatien	0:b802fc31f1db	112	pbuf_free_ooseq_queued = 0;
donatien	0:b802fc31f1db	113	SYS_ARCH_UNPROTECT(old_level);
donatien	0:b802fc31f1db	114
donatien	0:b802fc31f1db	115	for (pcb = tcp_active_pcbs; NULL != pcb; pcb = pcb->next) {
donatien	0:b802fc31f1db	116	if (NULL != pcb->ooseq) {
donatien	0:b802fc31f1db	117	/** Free the ooseq pbufs of one PCB only */
donatien	0:b802fc31f1db	118	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free_ooseq: freeing out-of-sequence pbufs\n"));
donatien	0:b802fc31f1db	119	tcp_segs_free(pcb->ooseq);
donatien	0:b802fc31f1db	120	pcb->ooseq = NULL;
donatien	0:b802fc31f1db	121	return;
donatien	0:b802fc31f1db	122	}
donatien	0:b802fc31f1db	123	}
donatien	0:b802fc31f1db	124	}
donatien	0:b802fc31f1db	125
donatien	0:b802fc31f1db	126	/** Queue a call to pbuf_free_ooseq if not already queued. */
donatien	0:b802fc31f1db	127	static void
donatien	0:b802fc31f1db	128	pbuf_pool_is_empty(void)
donatien	0:b802fc31f1db	129	{
donatien	0:b802fc31f1db	130	u8_t queued;
donatien	0:b802fc31f1db	131	SYS_ARCH_DECL_PROTECT(old_level);
donatien	0:b802fc31f1db	132
donatien	0:b802fc31f1db	133	SYS_ARCH_PROTECT(old_level);
donatien	0:b802fc31f1db	134	queued = pbuf_free_ooseq_queued;
donatien	0:b802fc31f1db	135	pbuf_free_ooseq_queued = 1;
donatien	0:b802fc31f1db	136	SYS_ARCH_UNPROTECT(old_level);
donatien	0:b802fc31f1db	137
donatien	0:b802fc31f1db	138	if(!queued) {
donatien	0:b802fc31f1db	139	/* queue a call to pbuf_free_ooseq if not already queued */
donatien	0:b802fc31f1db	140	if(tcpip_callback_with_block(pbuf_free_ooseq, NULL, 0) != ERR_OK) {
donatien	0:b802fc31f1db	141	SYS_ARCH_PROTECT(old_level);
donatien	0:b802fc31f1db	142	pbuf_free_ooseq_queued = 0;
donatien	0:b802fc31f1db	143	SYS_ARCH_UNPROTECT(old_level);
donatien	0:b802fc31f1db	144	}
donatien	0:b802fc31f1db	145	}
donatien	0:b802fc31f1db	146	}
donatien	0:b802fc31f1db	147	#endif /* PBUF_POOL_FREE_OOSEQ */
donatien	0:b802fc31f1db	148	#endif /* !TCP_QUEUE_OOSEQ \|\| NO_SYS */
donatien	0:b802fc31f1db	149
donatien	0:b802fc31f1db	150	/**
donatien	0:b802fc31f1db	151	* Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
donatien	0:b802fc31f1db	152	*
donatien	0:b802fc31f1db	153	* The actual memory allocated for the pbuf is determined by the
donatien	0:b802fc31f1db	154	* layer at which the pbuf is allocated and the requested size
donatien	0:b802fc31f1db	155	* (from the size parameter).
donatien	0:b802fc31f1db	156	*
donatien	0:b802fc31f1db	157	* @param layer flag to define header size
donatien	0:b802fc31f1db	158	* @param length size of the pbuf's payload
donatien	0:b802fc31f1db	159	* @param type this parameter decides how and where the pbuf
donatien	0:b802fc31f1db	160	* should be allocated as follows:
donatien	0:b802fc31f1db	161	*
donatien	0:b802fc31f1db	162	* - PBUF_RAM: buffer memory for pbuf is allocated as one large
donatien	0:b802fc31f1db	163	* chunk. This includes protocol headers as well.
donatien	0:b802fc31f1db	164	* - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
donatien	0:b802fc31f1db	165	* protocol headers. Additional headers must be prepended
donatien	0:b802fc31f1db	166	* by allocating another pbuf and chain in to the front of
donatien	0:b802fc31f1db	167	* the ROM pbuf. It is assumed that the memory used is really
donatien	0:b802fc31f1db	168	* similar to ROM in that it is immutable and will not be
donatien	0:b802fc31f1db	169	* changed. Memory which is dynamic should generally not
donatien	0:b802fc31f1db	170	* be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
donatien	0:b802fc31f1db	171	* - PBUF_REF: no buffer memory is allocated for the pbuf, even for
donatien	0:b802fc31f1db	172	* protocol headers. It is assumed that the pbuf is only
donatien	0:b802fc31f1db	173	* being used in a single thread. If the pbuf gets queued,
donatien	0:b802fc31f1db	174	* then pbuf_take should be called to copy the buffer.
donatien	0:b802fc31f1db	175	* - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
donatien	0:b802fc31f1db	176	* the pbuf pool that is allocated during pbuf_init().
donatien	0:b802fc31f1db	177	*
donatien	0:b802fc31f1db	178	* @return the allocated pbuf. If multiple pbufs where allocated, this
donatien	0:b802fc31f1db	179	* is the first pbuf of a pbuf chain.
donatien	0:b802fc31f1db	180	*/
donatien	0:b802fc31f1db	181	struct pbuf *
donatien	0:b802fc31f1db	182	pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
donatien	0:b802fc31f1db	183	{
donatien	0:b802fc31f1db	184	struct pbuf p, q, *r;
donatien	0:b802fc31f1db	185	u16_t offset;
donatien	0:b802fc31f1db	186	s32_t rem_len; /* remaining length */
donatien	0:b802fc31f1db	187	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
donatien	0:b802fc31f1db	188
donatien	0:b802fc31f1db	189	/* determine header offset */
donatien	0:b802fc31f1db	190	offset = 0;
donatien	0:b802fc31f1db	191	switch (layer) {
donatien	0:b802fc31f1db	192	case PBUF_TRANSPORT:
donatien	0:b802fc31f1db	193	/* add room for transport (often TCP) layer header */
donatien	0:b802fc31f1db	194	offset += PBUF_TRANSPORT_HLEN;
donatien	0:b802fc31f1db	195	/* FALLTHROUGH */
donatien	0:b802fc31f1db	196	case PBUF_IP:
donatien	0:b802fc31f1db	197	/* add room for IP layer header */
donatien	0:b802fc31f1db	198	offset += PBUF_IP_HLEN;
donatien	0:b802fc31f1db	199	/* FALLTHROUGH */
donatien	0:b802fc31f1db	200	case PBUF_LINK:
donatien	0:b802fc31f1db	201	/* add room for link layer header */
donatien	0:b802fc31f1db	202	offset += PBUF_LINK_HLEN;
donatien	0:b802fc31f1db	203	break;
donatien	0:b802fc31f1db	204	case PBUF_RAW:
donatien	0:b802fc31f1db	205	break;
donatien	0:b802fc31f1db	206	default:
donatien	0:b802fc31f1db	207	LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0);
donatien	0:b802fc31f1db	208	return NULL;
donatien	0:b802fc31f1db	209	}
donatien	0:b802fc31f1db	210
donatien	0:b802fc31f1db	211	switch (type) {
donatien	0:b802fc31f1db	212	case PBUF_POOL:
donatien	0:b802fc31f1db	213	/* allocate head of pbuf chain into p */
donatien	0:b802fc31f1db	214	p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
donatien	0:b802fc31f1db	215	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
donatien	0:b802fc31f1db	216	if (p == NULL) {
donatien	0:b802fc31f1db	217	PBUF_POOL_IS_EMPTY();
donatien	0:b802fc31f1db	218	return NULL;
donatien	0:b802fc31f1db	219	}
donatien	0:b802fc31f1db	220	p->type = type;
donatien	0:b802fc31f1db	221	p->next = NULL;
donatien	0:b802fc31f1db	222
donatien	0:b802fc31f1db	223	/* make the payload pointer point 'offset' bytes into pbuf data memory */
donatien	0:b802fc31f1db	224	p->payload = LWIP_MEM_ALIGN((void )((u8_t )p + (SIZEOF_STRUCT_PBUF + offset)));
donatien	0:b802fc31f1db	225	LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned",
donatien	0:b802fc31f1db	226	((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
donatien	0:b802fc31f1db	227	/* the total length of the pbuf chain is the requested size */
donatien	0:b802fc31f1db	228	p->tot_len = length;
donatien	0:b802fc31f1db	229	/* set the length of the first pbuf in the chain */
donatien	0:b802fc31f1db	230	p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
donatien	0:b802fc31f1db	231	LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
donatien	0:b802fc31f1db	232	((u8_t*)p->payload + p->len <=
donatien	0:b802fc31f1db	233	(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
donatien	0:b802fc31f1db	234	LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT",
donatien	0:b802fc31f1db	235	(PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 );
donatien	0:b802fc31f1db	236	/* set reference count (needed here in case we fail) */
donatien	0:b802fc31f1db	237	p->ref = 1;
donatien	0:b802fc31f1db	238
donatien	0:b802fc31f1db	239	/* now allocate the tail of the pbuf chain */
donatien	0:b802fc31f1db	240
donatien	0:b802fc31f1db	241	/* remember first pbuf for linkage in next iteration */
donatien	0:b802fc31f1db	242	r = p;
donatien	0:b802fc31f1db	243	/* remaining length to be allocated */
donatien	0:b802fc31f1db	244	rem_len = length - p->len;
donatien	0:b802fc31f1db	245	/* any remaining pbufs to be allocated? */
donatien	0:b802fc31f1db	246	while (rem_len > 0) {
donatien	0:b802fc31f1db	247	q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
donatien	0:b802fc31f1db	248	if (q == NULL) {
donatien	0:b802fc31f1db	249	PBUF_POOL_IS_EMPTY();
donatien	0:b802fc31f1db	250	/* free chain so far allocated */
donatien	0:b802fc31f1db	251	pbuf_free(p);
donatien	0:b802fc31f1db	252	/* bail out unsuccesfully */
donatien	0:b802fc31f1db	253	return NULL;
donatien	0:b802fc31f1db	254	}
donatien	0:b802fc31f1db	255	q->type = type;
donatien	0:b802fc31f1db	256	q->flags = 0;
donatien	0:b802fc31f1db	257	q->next = NULL;
donatien	0:b802fc31f1db	258	/* make previous pbuf point to this pbuf */
donatien	0:b802fc31f1db	259	r->next = q;
donatien	0:b802fc31f1db	260	/* set total length of this pbuf and next in chain */
donatien	0:b802fc31f1db	261	LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff);
donatien	0:b802fc31f1db	262	q->tot_len = (u16_t)rem_len;
donatien	0:b802fc31f1db	263	/* this pbuf length is pool size, unless smaller sized tail */
donatien	0:b802fc31f1db	264	q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
donatien	0:b802fc31f1db	265	q->payload = (void )((u8_t )q + SIZEOF_STRUCT_PBUF);
donatien	0:b802fc31f1db	266	LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
donatien	0:b802fc31f1db	267	((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
donatien	0:b802fc31f1db	268	LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
donatien	0:b802fc31f1db	269	((u8_t*)p->payload + p->len <=
donatien	0:b802fc31f1db	270	(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
donatien	0:b802fc31f1db	271	q->ref = 1;
donatien	0:b802fc31f1db	272	/* calculate remaining length to be allocated */
donatien	0:b802fc31f1db	273	rem_len -= q->len;
donatien	0:b802fc31f1db	274	/* remember this pbuf for linkage in next iteration */
donatien	0:b802fc31f1db	275	r = q;
donatien	0:b802fc31f1db	276	}
donatien	0:b802fc31f1db	277	/* end of chain */
donatien	0:b802fc31f1db	278	/r->next = NULL;/
donatien	0:b802fc31f1db	279
donatien	0:b802fc31f1db	280	break;
donatien	0:b802fc31f1db	281	case PBUF_RAM:
donatien	0:b802fc31f1db	282	/* If pbuf is to be allocated in RAM, allocate memory for it. */
donatien	0:b802fc31f1db	283	p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
donatien	0:b802fc31f1db	284	if (p == NULL) {
donatien	0:b802fc31f1db	285	return NULL;
donatien	0:b802fc31f1db	286	}
donatien	0:b802fc31f1db	287	/* Set up internal structure of the pbuf. */
donatien	0:b802fc31f1db	288	p->payload = LWIP_MEM_ALIGN((void )((u8_t )p + SIZEOF_STRUCT_PBUF + offset));
donatien	0:b802fc31f1db	289	p->len = p->tot_len = length;
donatien	0:b802fc31f1db	290	p->next = NULL;
donatien	0:b802fc31f1db	291	p->type = type;
donatien	0:b802fc31f1db	292
donatien	0:b802fc31f1db	293	LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
donatien	0:b802fc31f1db	294	((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
donatien	0:b802fc31f1db	295	break;
donatien	0:b802fc31f1db	296	/* pbuf references existing (non-volatile static constant) ROM payload? */
donatien	0:b802fc31f1db	297	case PBUF_ROM:
donatien	0:b802fc31f1db	298	/* pbuf references existing (externally allocated) RAM payload? */
donatien	0:b802fc31f1db	299	case PBUF_REF:
donatien	0:b802fc31f1db	300	/* only allocate memory for the pbuf structure */
donatien	0:b802fc31f1db	301	p = (struct pbuf *)memp_malloc(MEMP_PBUF);
donatien	0:b802fc31f1db	302	if (p == NULL) {
donatien	0:b802fc31f1db	303	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
donatien	0:b802fc31f1db	304	("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n",
donatien	0:b802fc31f1db	305	(type == PBUF_ROM) ? "ROM" : "REF"));
donatien	0:b802fc31f1db	306	return NULL;
donatien	0:b802fc31f1db	307	}
donatien	0:b802fc31f1db	308	/* caller must set this field properly, afterwards */
donatien	0:b802fc31f1db	309	p->payload = NULL;
donatien	0:b802fc31f1db	310	p->len = p->tot_len = length;
donatien	0:b802fc31f1db	311	p->next = NULL;
donatien	0:b802fc31f1db	312	p->type = type;
donatien	0:b802fc31f1db	313	break;
donatien	0:b802fc31f1db	314	default:
donatien	0:b802fc31f1db	315	LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
donatien	0:b802fc31f1db	316	return NULL;
donatien	0:b802fc31f1db	317	}
donatien	0:b802fc31f1db	318	/* set reference count */
donatien	0:b802fc31f1db	319	p->ref = 1;
donatien	0:b802fc31f1db	320	/* set flags */
donatien	0:b802fc31f1db	321	p->flags = 0;
donatien	0:b802fc31f1db	322	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
donatien	0:b802fc31f1db	323	return p;
donatien	0:b802fc31f1db	324	}
donatien	0:b802fc31f1db	325
donatien	0:b802fc31f1db	326
donatien	0:b802fc31f1db	327	/**
donatien	0:b802fc31f1db	328	* Shrink a pbuf chain to a desired length.
donatien	0:b802fc31f1db	329	*
donatien	0:b802fc31f1db	330	* @param p pbuf to shrink.
donatien	0:b802fc31f1db	331	* @param new_len desired new length of pbuf chain
donatien	0:b802fc31f1db	332	*
donatien	0:b802fc31f1db	333	* Depending on the desired length, the first few pbufs in a chain might
donatien	0:b802fc31f1db	334	* be skipped and left unchanged. The new last pbuf in the chain will be
donatien	0:b802fc31f1db	335	* resized, and any remaining pbufs will be freed.
donatien	0:b802fc31f1db	336	*
donatien	0:b802fc31f1db	337	* @note If the pbuf is ROM/REF, only the ->tot_len and ->len fields are adjusted.
donatien	0:b802fc31f1db	338	* @note May not be called on a packet queue.
donatien	0:b802fc31f1db	339	*
donatien	0:b802fc31f1db	340	* @note Despite its name, pbuf_realloc cannot grow the size of a pbuf (chain).
donatien	0:b802fc31f1db	341	*/
donatien	0:b802fc31f1db	342	void
donatien	0:b802fc31f1db	343	pbuf_realloc(struct pbuf *p, u16_t new_len)
donatien	0:b802fc31f1db	344	{
donatien	0:b802fc31f1db	345	struct pbuf *q;
donatien	0:b802fc31f1db	346	u16_t rem_len; /* remaining length */
donatien	0:b802fc31f1db	347	s32_t grow;
donatien	0:b802fc31f1db	348
donatien	0:b802fc31f1db	349	LWIP_ASSERT("pbuf_realloc: p != NULL", p != NULL);
donatien	0:b802fc31f1db	350	LWIP_ASSERT("pbuf_realloc: sane p->type", p->type == PBUF_POOL \|\|
donatien	0:b802fc31f1db	351	p->type == PBUF_ROM \|\|
donatien	0:b802fc31f1db	352	p->type == PBUF_RAM \|\|
donatien	0:b802fc31f1db	353	p->type == PBUF_REF);
donatien	0:b802fc31f1db	354
donatien	0:b802fc31f1db	355	/* desired length larger than current length? */
donatien	0:b802fc31f1db	356	if (new_len >= p->tot_len) {
donatien	0:b802fc31f1db	357	/* enlarging not yet supported */
donatien	0:b802fc31f1db	358	return;
donatien	0:b802fc31f1db	359	}
donatien	0:b802fc31f1db	360
donatien	0:b802fc31f1db	361	/* the pbuf chain grows by (new_len - p->tot_len) bytes
donatien	0:b802fc31f1db	362	* (which may be negative in case of shrinking) */
donatien	0:b802fc31f1db	363	grow = new_len - p->tot_len;
donatien	0:b802fc31f1db	364
donatien	0:b802fc31f1db	365	/* first, step over any pbufs that should remain in the chain */
donatien	0:b802fc31f1db	366	rem_len = new_len;
donatien	0:b802fc31f1db	367	q = p;
donatien	0:b802fc31f1db	368	/* should this pbuf be kept? */
donatien	0:b802fc31f1db	369	while (rem_len > q->len) {
donatien	0:b802fc31f1db	370	/* decrease remaining length by pbuf length */
donatien	0:b802fc31f1db	371	rem_len -= q->len;
donatien	0:b802fc31f1db	372	/* decrease total length indicator */
donatien	0:b802fc31f1db	373	LWIP_ASSERT("grow < max_u16_t", grow < 0xffff);
donatien	0:b802fc31f1db	374	q->tot_len += (u16_t)grow;
donatien	0:b802fc31f1db	375	/* proceed to next pbuf in chain */
donatien	0:b802fc31f1db	376	q = q->next;
donatien	0:b802fc31f1db	377	LWIP_ASSERT("pbuf_realloc: q != NULL", q != NULL);
donatien	0:b802fc31f1db	378	}
donatien	0:b802fc31f1db	379	/* we have now reached the new last pbuf (in q) */
donatien	0:b802fc31f1db	380	/* rem_len == desired length for pbuf q */
donatien	0:b802fc31f1db	381
donatien	0:b802fc31f1db	382	/* shrink allocated memory for PBUF_RAM */
donatien	0:b802fc31f1db	383	/* (other types merely adjust their length fields */
donatien	0:b802fc31f1db	384	if ((q->type == PBUF_RAM) && (rem_len != q->len)) {
donatien	0:b802fc31f1db	385	/* reallocate and adjust the length of the pbuf that will be split */
donatien	0:b802fc31f1db	386	q = (struct pbuf )mem_trim(q, (u16_t)((u8_t )q->payload - (u8_t *)q) + rem_len);
donatien	0:b802fc31f1db	387	LWIP_ASSERT("mem_trim returned q == NULL", q != NULL);
donatien	0:b802fc31f1db	388	}
donatien	0:b802fc31f1db	389	/* adjust length fields for new last pbuf */
donatien	0:b802fc31f1db	390	q->len = rem_len;
donatien	0:b802fc31f1db	391	q->tot_len = q->len;
donatien	0:b802fc31f1db	392
donatien	0:b802fc31f1db	393	/* any remaining pbufs in chain? */
donatien	0:b802fc31f1db	394	if (q->next != NULL) {
donatien	0:b802fc31f1db	395	/* free remaining pbufs in chain */
donatien	0:b802fc31f1db	396	pbuf_free(q->next);
donatien	0:b802fc31f1db	397	}
donatien	0:b802fc31f1db	398	/* q is last packet in chain */
donatien	0:b802fc31f1db	399	q->next = NULL;
donatien	0:b802fc31f1db	400
donatien	0:b802fc31f1db	401	}
donatien	0:b802fc31f1db	402
donatien	0:b802fc31f1db	403	/**
donatien	0:b802fc31f1db	404	* Adjusts the payload pointer to hide or reveal headers in the payload.
donatien	0:b802fc31f1db	405	*
donatien	0:b802fc31f1db	406	* Adjusts the ->payload pointer so that space for a header
donatien	0:b802fc31f1db	407	* (dis)appears in the pbuf payload.
donatien	0:b802fc31f1db	408	*
donatien	0:b802fc31f1db	409	* The ->payload, ->tot_len and ->len fields are adjusted.
donatien	0:b802fc31f1db	410	*
donatien	0:b802fc31f1db	411	* @param p pbuf to change the header size.
donatien	0:b802fc31f1db	412	* @param header_size_increment Number of bytes to increment header size which
donatien	0:b802fc31f1db	413	* increases the size of the pbuf. New space is on the front.
donatien	0:b802fc31f1db	414	* (Using a negative value decreases the header size.)
donatien	0:b802fc31f1db	415	* If hdr_size_inc is 0, this function does nothing and returns succesful.
donatien	0:b802fc31f1db	416	*
donatien	0:b802fc31f1db	417	* PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so
donatien	0:b802fc31f1db	418	* the call will fail. A check is made that the increase in header size does
donatien	0:b802fc31f1db	419	* not move the payload pointer in front of the start of the buffer.
donatien	0:b802fc31f1db	420	* @return non-zero on failure, zero on success.
donatien	0:b802fc31f1db	421	*
donatien	0:b802fc31f1db	422	*/
donatien	0:b802fc31f1db	423	u8_t
donatien	0:b802fc31f1db	424	pbuf_header(struct pbuf *p, s16_t header_size_increment)
donatien	0:b802fc31f1db	425	{
donatien	0:b802fc31f1db	426	u16_t type;
donatien	0:b802fc31f1db	427	void *payload;
donatien	0:b802fc31f1db	428	u16_t increment_magnitude;
donatien	0:b802fc31f1db	429
donatien	0:b802fc31f1db	430	LWIP_ASSERT("p != NULL", p != NULL);
donatien	0:b802fc31f1db	431	if ((header_size_increment == 0) \|\| (p == NULL))
donatien	0:b802fc31f1db	432	return 0;
donatien	0:b802fc31f1db	433
donatien	0:b802fc31f1db	434	if (header_size_increment < 0){
donatien	0:b802fc31f1db	435	increment_magnitude = -header_size_increment;
donatien	0:b802fc31f1db	436	/* Check that we aren't going to move off the end of the pbuf */
donatien	0:b802fc31f1db	437	LWIP_ERROR("increment_magnitude <= p->len", (increment_magnitude <= p->len), return 1;);
donatien	0:b802fc31f1db	438	} else {
donatien	0:b802fc31f1db	439	increment_magnitude = header_size_increment;
donatien	0:b802fc31f1db	440	#if 0
donatien	0:b802fc31f1db	441	/* Can't assert these as some callers speculatively call
donatien	0:b802fc31f1db	442	pbuf_header() to see if it's OK. Will return 1 below instead. */
donatien	0:b802fc31f1db	443	/* Check that we've got the correct type of pbuf to work with */
donatien	0:b802fc31f1db	444	LWIP_ASSERT("p->type == PBUF_RAM \|\| p->type == PBUF_POOL",
donatien	0:b802fc31f1db	445	p->type == PBUF_RAM \|\| p->type == PBUF_POOL);
donatien	0:b802fc31f1db	446	/* Check that we aren't going to move off the beginning of the pbuf */
donatien	0:b802fc31f1db	447	LWIP_ASSERT("p->payload - increment_magnitude >= p + SIZEOF_STRUCT_PBUF",
donatien	0:b802fc31f1db	448	(u8_t )p->payload - increment_magnitude >= (u8_t )p + SIZEOF_STRUCT_PBUF);
donatien	0:b802fc31f1db	449	#endif
donatien	0:b802fc31f1db	450	}
donatien	0:b802fc31f1db	451
donatien	0:b802fc31f1db	452	type = p->type;
donatien	0:b802fc31f1db	453	/* remember current payload pointer */
donatien	0:b802fc31f1db	454	payload = p->payload;
donatien	0:b802fc31f1db	455
donatien	0:b802fc31f1db	456	/* pbuf types containing payloads? */
donatien	0:b802fc31f1db	457	if (type == PBUF_RAM \|\| type == PBUF_POOL) {
donatien	0:b802fc31f1db	458	/* set new payload pointer */
donatien	0:b802fc31f1db	459	p->payload = (u8_t *)p->payload - header_size_increment;
donatien	0:b802fc31f1db	460	/* boundary check fails? */
donatien	0:b802fc31f1db	461	if ((u8_t )p->payload < (u8_t )p + SIZEOF_STRUCT_PBUF) {
donatien	0:b802fc31f1db	462	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
donatien	0:b802fc31f1db	463	("pbuf_header: failed as %p < %p (not enough space for new header size)\n",
donatien	0:b802fc31f1db	464	(void )p->payload, (void )(p + 1)));
donatien	0:b802fc31f1db	465	/* restore old payload pointer */
donatien	0:b802fc31f1db	466	p->payload = payload;
donatien	0:b802fc31f1db	467	/* bail out unsuccesfully */
donatien	0:b802fc31f1db	468	return 1;
donatien	0:b802fc31f1db	469	}
donatien	0:b802fc31f1db	470	/* pbuf types refering to external payloads? */
donatien	0:b802fc31f1db	471	} else if (type == PBUF_REF \|\| type == PBUF_ROM) {
donatien	0:b802fc31f1db	472	/* hide a header in the payload? */
donatien	0:b802fc31f1db	473	if ((header_size_increment < 0) && (increment_magnitude <= p->len)) {
donatien	0:b802fc31f1db	474	/* increase payload pointer */
donatien	0:b802fc31f1db	475	p->payload = (u8_t *)p->payload - header_size_increment;
donatien	0:b802fc31f1db	476	} else {
donatien	0:b802fc31f1db	477	/* cannot expand payload to front (yet!)
donatien	0:b802fc31f1db	478	* bail out unsuccesfully */
donatien	0:b802fc31f1db	479	return 1;
donatien	0:b802fc31f1db	480	}
donatien	0:b802fc31f1db	481	}
donatien	0:b802fc31f1db	482	else {
donatien	0:b802fc31f1db	483	/* Unknown type */
donatien	0:b802fc31f1db	484	LWIP_ASSERT("bad pbuf type", 0);
donatien	0:b802fc31f1db	485	return 1;
donatien	0:b802fc31f1db	486	}
donatien	0:b802fc31f1db	487	/* modify pbuf length fields */
donatien	0:b802fc31f1db	488	p->len += header_size_increment;
donatien	0:b802fc31f1db	489	p->tot_len += header_size_increment;
donatien	0:b802fc31f1db	490
donatien	0:b802fc31f1db	491	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_header: old %p new %p (%"S16_F")\n",
donatien	0:b802fc31f1db	492	(void )payload, (void )p->payload, header_size_increment));
donatien	0:b802fc31f1db	493
donatien	0:b802fc31f1db	494	return 0;
donatien	0:b802fc31f1db	495	}
donatien	0:b802fc31f1db	496
donatien	0:b802fc31f1db	497	/**
donatien	0:b802fc31f1db	498	* Dereference a pbuf chain or queue and deallocate any no-longer-used
donatien	0:b802fc31f1db	499	* pbufs at the head of this chain or queue.
donatien	0:b802fc31f1db	500	*
donatien	0:b802fc31f1db	501	* Decrements the pbuf reference count. If it reaches zero, the pbuf is
donatien	0:b802fc31f1db	502	* deallocated.
donatien	0:b802fc31f1db	503	*
donatien	0:b802fc31f1db	504	* For a pbuf chain, this is repeated for each pbuf in the chain,
donatien	0:b802fc31f1db	505	* up to the first pbuf which has a non-zero reference count after
donatien	0:b802fc31f1db	506	* decrementing. So, when all reference counts are one, the whole
donatien	0:b802fc31f1db	507	* chain is free'd.
donatien	0:b802fc31f1db	508	*
donatien	0:b802fc31f1db	509	* @param p The pbuf (chain) to be dereferenced.
donatien	0:b802fc31f1db	510	*
donatien	0:b802fc31f1db	511	* @return the number of pbufs that were de-allocated
donatien	0:b802fc31f1db	512	* from the head of the chain.
donatien	0:b802fc31f1db	513	*
donatien	0:b802fc31f1db	514	* @note MUST NOT be called on a packet queue (Not verified to work yet).
donatien	0:b802fc31f1db	515	* @note the reference counter of a pbuf equals the number of pointers
donatien	0:b802fc31f1db	516	* that refer to the pbuf (or into the pbuf).
donatien	0:b802fc31f1db	517	*
donatien	0:b802fc31f1db	518	* @internal examples:
donatien	0:b802fc31f1db	519	*
donatien	0:b802fc31f1db	520	* Assuming existing chains a->b->c with the following reference
donatien	0:b802fc31f1db	521	* counts, calling pbuf_free(a) results in:
donatien	0:b802fc31f1db	522	*
donatien	0:b802fc31f1db	523	* 1->2->3 becomes ...1->3
donatien	0:b802fc31f1db	524	* 3->3->3 becomes 2->3->3
donatien	0:b802fc31f1db	525	* 1->1->2 becomes ......1
donatien	0:b802fc31f1db	526	* 2->1->1 becomes 1->1->1
donatien	0:b802fc31f1db	527	* 1->1->1 becomes .......
donatien	0:b802fc31f1db	528	*
donatien	0:b802fc31f1db	529	*/
donatien	0:b802fc31f1db	530	u8_t
donatien	0:b802fc31f1db	531	pbuf_free(struct pbuf *p)
donatien	0:b802fc31f1db	532	{
donatien	0:b802fc31f1db	533	u16_t type;
donatien	0:b802fc31f1db	534	struct pbuf *q;
donatien	0:b802fc31f1db	535	u8_t count;
donatien	0:b802fc31f1db	536
donatien	0:b802fc31f1db	537	if (p == NULL) {
donatien	0:b802fc31f1db	538	LWIP_ASSERT("p != NULL", p != NULL);
donatien	0:b802fc31f1db	539	/* if assertions are disabled, proceed with debug output */
donatien	0:b802fc31f1db	540	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
donatien	0:b802fc31f1db	541	("pbuf_free(p == NULL) was called.\n"));
donatien	0:b802fc31f1db	542	return 0;
donatien	0:b802fc31f1db	543	}
donatien	0:b802fc31f1db	544	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free(%p)\n", (void *)p));
donatien	0:b802fc31f1db	545
donatien	0:b802fc31f1db	546	PERF_START;
donatien	0:b802fc31f1db	547
donatien	0:b802fc31f1db	548	LWIP_ASSERT("pbuf_free: sane type",
donatien	0:b802fc31f1db	549	p->type == PBUF_RAM \|\| p->type == PBUF_ROM \|\|
donatien	0:b802fc31f1db	550	p->type == PBUF_REF \|\| p->type == PBUF_POOL);
donatien	0:b802fc31f1db	551
donatien	0:b802fc31f1db	552	count = 0;
donatien	0:b802fc31f1db	553	/* de-allocate all consecutive pbufs from the head of the chain that
donatien	0:b802fc31f1db	554	* obtain a zero reference count after decrementing*/
donatien	0:b802fc31f1db	555	while (p != NULL) {
donatien	0:b802fc31f1db	556	u16_t ref;
donatien	0:b802fc31f1db	557	SYS_ARCH_DECL_PROTECT(old_level);
donatien	0:b802fc31f1db	558	/* Since decrementing ref cannot be guaranteed to be a single machine operation
donatien	0:b802fc31f1db	559	* we must protect it. We put the new ref into a local variable to prevent
donatien	0:b802fc31f1db	560	* further protection. */
donatien	0:b802fc31f1db	561	SYS_ARCH_PROTECT(old_level);
donatien	0:b802fc31f1db	562	/* all pbufs in a chain are referenced at least once */
donatien	0:b802fc31f1db	563	LWIP_ASSERT("pbuf_free: p->ref > 0", p->ref > 0);
donatien	0:b802fc31f1db	564	/* decrease reference count (number of pointers to pbuf) */
donatien	0:b802fc31f1db	565	ref = --(p->ref);
donatien	0:b802fc31f1db	566	SYS_ARCH_UNPROTECT(old_level);
donatien	0:b802fc31f1db	567	/* this pbuf is no longer referenced to? */
donatien	0:b802fc31f1db	568	if (ref == 0) {
donatien	0:b802fc31f1db	569	/* remember next pbuf in chain for next iteration */
donatien	0:b802fc31f1db	570	q = p->next;
donatien	0:b802fc31f1db	571	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free: deallocating %p\n", (void *)p));
donatien	0:b802fc31f1db	572	type = p->type;
donatien	0:b802fc31f1db	573	/* is this a pbuf from the pool? */
donatien	0:b802fc31f1db	574	if (type == PBUF_POOL) {
donatien	0:b802fc31f1db	575	memp_free(MEMP_PBUF_POOL, p);
donatien	0:b802fc31f1db	576	/* is this a ROM or RAM referencing pbuf? */
donatien	0:b802fc31f1db	577	} else if (type == PBUF_ROM \|\| type == PBUF_REF) {
donatien	0:b802fc31f1db	578	memp_free(MEMP_PBUF, p);
donatien	0:b802fc31f1db	579	/* type == PBUF_RAM */
donatien	0:b802fc31f1db	580	} else {
donatien	0:b802fc31f1db	581	mem_free(p);
donatien	0:b802fc31f1db	582	}
donatien	0:b802fc31f1db	583	count++;
donatien	0:b802fc31f1db	584	/* proceed to next pbuf */
donatien	0:b802fc31f1db	585	p = q;
donatien	0:b802fc31f1db	586	/* p->ref > 0, this pbuf is still referenced to */
donatien	0:b802fc31f1db	587	/* (and so the remaining pbufs in chain as well) */
donatien	0:b802fc31f1db	588	} else {
donatien	0:b802fc31f1db	589	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref));
donatien	0:b802fc31f1db	590	/* stop walking through the chain */
donatien	0:b802fc31f1db	591	p = NULL;
donatien	0:b802fc31f1db	592	}
donatien	0:b802fc31f1db	593	}
donatien	0:b802fc31f1db	594	PERF_STOP("pbuf_free");
donatien	0:b802fc31f1db	595	/* return number of de-allocated pbufs */
donatien	0:b802fc31f1db	596	return count;
donatien	0:b802fc31f1db	597	}
donatien	0:b802fc31f1db	598
donatien	0:b802fc31f1db	599	/**
donatien	0:b802fc31f1db	600	* Count number of pbufs in a chain
donatien	0:b802fc31f1db	601	*
donatien	0:b802fc31f1db	602	* @param p first pbuf of chain
donatien	0:b802fc31f1db	603	* @return the number of pbufs in a chain
donatien	0:b802fc31f1db	604	*/
donatien	0:b802fc31f1db	605
donatien	0:b802fc31f1db	606	u8_t
donatien	0:b802fc31f1db	607	pbuf_clen(struct pbuf *p)
donatien	0:b802fc31f1db	608	{
donatien	0:b802fc31f1db	609	u8_t len;
donatien	0:b802fc31f1db	610
donatien	0:b802fc31f1db	611	len = 0;
donatien	0:b802fc31f1db	612	while (p != NULL) {
donatien	0:b802fc31f1db	613	++len;
donatien	0:b802fc31f1db	614	p = p->next;
donatien	0:b802fc31f1db	615	}
donatien	0:b802fc31f1db	616	return len;
donatien	0:b802fc31f1db	617	}
donatien	0:b802fc31f1db	618
donatien	0:b802fc31f1db	619	/**
donatien	0:b802fc31f1db	620	* Increment the reference count of the pbuf.
donatien	0:b802fc31f1db	621	*
donatien	0:b802fc31f1db	622	* @param p pbuf to increase reference counter of
donatien	0:b802fc31f1db	623	*
donatien	0:b802fc31f1db	624	*/
donatien	0:b802fc31f1db	625	void
donatien	0:b802fc31f1db	626	pbuf_ref(struct pbuf *p)
donatien	0:b802fc31f1db	627	{
donatien	0:b802fc31f1db	628	SYS_ARCH_DECL_PROTECT(old_level);
donatien	0:b802fc31f1db	629	/* pbuf given? */
donatien	0:b802fc31f1db	630	if (p != NULL) {
donatien	0:b802fc31f1db	631	SYS_ARCH_PROTECT(old_level);
donatien	0:b802fc31f1db	632	++(p->ref);
donatien	0:b802fc31f1db	633	SYS_ARCH_UNPROTECT(old_level);
donatien	0:b802fc31f1db	634	}
donatien	0:b802fc31f1db	635	}
donatien	0:b802fc31f1db	636
donatien	0:b802fc31f1db	637	/**
donatien	0:b802fc31f1db	638	* Concatenate two pbufs (each may be a pbuf chain) and take over
donatien	0:b802fc31f1db	639	* the caller's reference of the tail pbuf.
donatien	0:b802fc31f1db	640	*
donatien	0:b802fc31f1db	641	* @note The caller MAY NOT reference the tail pbuf afterwards.
donatien	0:b802fc31f1db	642	* Use pbuf_chain() for that purpose.
donatien	0:b802fc31f1db	643	*
donatien	0:b802fc31f1db	644	* @see pbuf_chain()
donatien	0:b802fc31f1db	645	*/
donatien	0:b802fc31f1db	646
donatien	0:b802fc31f1db	647	void
donatien	0:b802fc31f1db	648	pbuf_cat(struct pbuf h, struct pbuf t)
donatien	0:b802fc31f1db	649	{
donatien	0:b802fc31f1db	650	struct pbuf *p;
donatien	0:b802fc31f1db	651
donatien	0:b802fc31f1db	652	LWIP_ERROR("(h != NULL) && (t != NULL) (programmer violates API)",
donatien	0:b802fc31f1db	653	((h != NULL) && (t != NULL)), return;);
donatien	0:b802fc31f1db	654
donatien	0:b802fc31f1db	655	/* proceed to last pbuf of chain */
donatien	0:b802fc31f1db	656	for (p = h; p->next != NULL; p = p->next) {
donatien	0:b802fc31f1db	657	/* add total length of second chain to all totals of first chain */
donatien	0:b802fc31f1db	658	p->tot_len += t->tot_len;
donatien	0:b802fc31f1db	659	}
donatien	0:b802fc31f1db	660	/* { p is last pbuf of first h chain, p->next == NULL } */
donatien	0:b802fc31f1db	661	LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len);
donatien	0:b802fc31f1db	662	LWIP_ASSERT("p->next == NULL", p->next == NULL);
donatien	0:b802fc31f1db	663	/* add total length of second chain to last pbuf total of first chain */
donatien	0:b802fc31f1db	664	p->tot_len += t->tot_len;
donatien	0:b802fc31f1db	665	/* chain last pbuf of head (p) with first of tail (t) */
donatien	0:b802fc31f1db	666	p->next = t;
donatien	0:b802fc31f1db	667	/* p->next now references t, but the caller will drop its reference to t,
donatien	0:b802fc31f1db	668	* so netto there is no change to the reference count of t.
donatien	0:b802fc31f1db	669	*/
donatien	0:b802fc31f1db	670	}
donatien	0:b802fc31f1db	671
donatien	0:b802fc31f1db	672	/**
donatien	0:b802fc31f1db	673	* Chain two pbufs (or pbuf chains) together.
donatien	0:b802fc31f1db	674	*
donatien	0:b802fc31f1db	675	* The caller MUST call pbuf_free(t) once it has stopped
donatien	0:b802fc31f1db	676	* using it. Use pbuf_cat() instead if you no longer use t.
donatien	0:b802fc31f1db	677	*
donatien	0:b802fc31f1db	678	* @param h head pbuf (chain)
donatien	0:b802fc31f1db	679	* @param t tail pbuf (chain)
donatien	0:b802fc31f1db	680	* @note The pbufs MUST belong to the same packet.
donatien	0:b802fc31f1db	681	* @note MAY NOT be called on a packet queue.
donatien	0:b802fc31f1db	682	*
donatien	0:b802fc31f1db	683	* The ->tot_len fields of all pbufs of the head chain are adjusted.
donatien	0:b802fc31f1db	684	* The ->next field of the last pbuf of the head chain is adjusted.
donatien	0:b802fc31f1db	685	* The ->ref field of the first pbuf of the tail chain is adjusted.
donatien	0:b802fc31f1db	686	*
donatien	0:b802fc31f1db	687	*/
donatien	0:b802fc31f1db	688	void
donatien	0:b802fc31f1db	689	pbuf_chain(struct pbuf h, struct pbuf t)
donatien	0:b802fc31f1db	690	{
donatien	0:b802fc31f1db	691	pbuf_cat(h, t);
donatien	0:b802fc31f1db	692	/* t is now referenced by h */
donatien	0:b802fc31f1db	693	pbuf_ref(t);
donatien	0:b802fc31f1db	694	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_chain: %p references %p\n", (void )h, (void )t));
donatien	0:b802fc31f1db	695	}
donatien	0:b802fc31f1db	696
donatien	0:b802fc31f1db	697	/**
donatien	0:b802fc31f1db	698	* Dechains the first pbuf from its succeeding pbufs in the chain.
donatien	0:b802fc31f1db	699	*
donatien	0:b802fc31f1db	700	* Makes p->tot_len field equal to p->len.
donatien	0:b802fc31f1db	701	* @param p pbuf to dechain
donatien	0:b802fc31f1db	702	* @return remainder of the pbuf chain, or NULL if it was de-allocated.
donatien	0:b802fc31f1db	703	* @note May not be called on a packet queue.
donatien	0:b802fc31f1db	704	*/
donatien	0:b802fc31f1db	705	struct pbuf *
donatien	0:b802fc31f1db	706	pbuf_dechain(struct pbuf *p)
donatien	0:b802fc31f1db	707	{
donatien	0:b802fc31f1db	708	struct pbuf *q;
donatien	0:b802fc31f1db	709	u8_t tail_gone = 1;
donatien	0:b802fc31f1db	710	/* tail */
donatien	0:b802fc31f1db	711	q = p->next;
donatien	0:b802fc31f1db	712	/* pbuf has successor in chain? */
donatien	0:b802fc31f1db	713	if (q != NULL) {
donatien	0:b802fc31f1db	714	/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
donatien	0:b802fc31f1db	715	LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len);
donatien	0:b802fc31f1db	716	/* enforce invariant if assertion is disabled */
donatien	0:b802fc31f1db	717	q->tot_len = p->tot_len - p->len;
donatien	0:b802fc31f1db	718	/* decouple pbuf from remainder */
donatien	0:b802fc31f1db	719	p->next = NULL;
donatien	0:b802fc31f1db	720	/* total length of pbuf p is its own length only */
donatien	0:b802fc31f1db	721	p->tot_len = p->len;
donatien	0:b802fc31f1db	722	/* q is no longer referenced by p, free it */
donatien	0:b802fc31f1db	723	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_dechain: unreferencing %p\n", (void *)q));
donatien	0:b802fc31f1db	724	tail_gone = pbuf_free(q);
donatien	0:b802fc31f1db	725	if (tail_gone > 0) {
donatien	0:b802fc31f1db	726	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE,
donatien	0:b802fc31f1db	727	("pbuf_dechain: deallocated %p (as it is no longer referenced)\n", (void *)q));
donatien	0:b802fc31f1db	728	}
donatien	0:b802fc31f1db	729	/* return remaining tail or NULL if deallocated */
donatien	0:b802fc31f1db	730	}
donatien	0:b802fc31f1db	731	/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
donatien	0:b802fc31f1db	732	LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len);
donatien	0:b802fc31f1db	733	return ((tail_gone > 0) ? NULL : q);
donatien	0:b802fc31f1db	734	}
donatien	0:b802fc31f1db	735
donatien	0:b802fc31f1db	736	/**
donatien	0:b802fc31f1db	737	*
donatien	0:b802fc31f1db	738	* Create PBUF_RAM copies of pbufs.
donatien	0:b802fc31f1db	739	*
donatien	0:b802fc31f1db	740	* Used to queue packets on behalf of the lwIP stack, such as
donatien	0:b802fc31f1db	741	* ARP based queueing.
donatien	0:b802fc31f1db	742	*
donatien	0:b802fc31f1db	743	* @note You MUST explicitly use p = pbuf_take(p);
donatien	0:b802fc31f1db	744	*
donatien	0:b802fc31f1db	745	* @note Only one packet is copied, no packet queue!
donatien	0:b802fc31f1db	746	*
donatien	0:b802fc31f1db	747	* @param p_to pbuf destination of the copy
donatien	0:b802fc31f1db	748	* @param p_from pbuf source of the copy
donatien	0:b802fc31f1db	749	*
donatien	0:b802fc31f1db	750	* @return ERR_OK if pbuf was copied
donatien	0:b802fc31f1db	751	* ERR_ARG if one of the pbufs is NULL or p_to is not big
donatien	0:b802fc31f1db	752	* enough to hold p_from
donatien	0:b802fc31f1db	753	*/
donatien	0:b802fc31f1db	754	err_t
donatien	0:b802fc31f1db	755	pbuf_copy(struct pbuf p_to, struct pbuf p_from)
donatien	0:b802fc31f1db	756	{
donatien	0:b802fc31f1db	757	u16_t offset_to=0, offset_from=0, len;
donatien	0:b802fc31f1db	758
donatien	0:b802fc31f1db	759	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_copy(%p, %p)\n",
donatien	0:b802fc31f1db	760	(void)p_to, (void)p_from));
donatien	0:b802fc31f1db	761
donatien	0:b802fc31f1db	762	/* is the target big enough to hold the source? */
donatien	0:b802fc31f1db	763	LWIP_ERROR("pbuf_copy: target not big enough to hold source", ((p_to != NULL) &&
donatien	0:b802fc31f1db	764	(p_from != NULL) && (p_to->tot_len >= p_from->tot_len)), return ERR_ARG;);
donatien	0:b802fc31f1db	765
donatien	0:b802fc31f1db	766	/* iterate through pbuf chain */
donatien	0:b802fc31f1db	767	do
donatien	0:b802fc31f1db	768	{
donatien	0:b802fc31f1db	769	LWIP_ASSERT("p_to != NULL", p_to != NULL);
donatien	0:b802fc31f1db	770	/* copy one part of the original chain */
donatien	0:b802fc31f1db	771	if ((p_to->len - offset_to) >= (p_from->len - offset_from)) {
donatien	0:b802fc31f1db	772	/* complete current p_from fits into current p_to */
donatien	0:b802fc31f1db	773	len = p_from->len - offset_from;
donatien	0:b802fc31f1db	774	} else {
donatien	0:b802fc31f1db	775	/* current p_from does not fit into current p_to */
donatien	0:b802fc31f1db	776	len = p_to->len - offset_to;
donatien	0:b802fc31f1db	777	}
donatien	0:b802fc31f1db	778	MEMCPY((u8_t)p_to->payload + offset_to, (u8_t)p_from->payload + offset_from, len);
donatien	0:b802fc31f1db	779	offset_to += len;
donatien	0:b802fc31f1db	780	offset_from += len;
donatien	0:b802fc31f1db	781	LWIP_ASSERT("offset_to <= p_to->len", offset_to <= p_to->len);
donatien	0:b802fc31f1db	782	if (offset_to == p_to->len) {
donatien	0:b802fc31f1db	783	/* on to next p_to (if any) */
donatien	0:b802fc31f1db	784	offset_to = 0;
donatien	0:b802fc31f1db	785	p_to = p_to->next;
donatien	0:b802fc31f1db	786	}
donatien	0:b802fc31f1db	787	LWIP_ASSERT("offset_from <= p_from->len", offset_from <= p_from->len);
donatien	0:b802fc31f1db	788	if (offset_from >= p_from->len) {
donatien	0:b802fc31f1db	789	/* on to next p_from (if any) */
donatien	0:b802fc31f1db	790	offset_from = 0;
donatien	0:b802fc31f1db	791	p_from = p_from->next;
donatien	0:b802fc31f1db	792	}
donatien	0:b802fc31f1db	793
donatien	0:b802fc31f1db	794	if((p_from != NULL) && (p_from->len == p_from->tot_len)) {
donatien	0:b802fc31f1db	795	/* don't copy more than one packet! */
donatien	0:b802fc31f1db	796	LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
donatien	0:b802fc31f1db	797	(p_from->next == NULL), return ERR_VAL;);
donatien	0:b802fc31f1db	798	}
donatien	0:b802fc31f1db	799	if((p_to != NULL) && (p_to->len == p_to->tot_len)) {
donatien	0:b802fc31f1db	800	/* don't copy more than one packet! */
donatien	0:b802fc31f1db	801	LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
donatien	0:b802fc31f1db	802	(p_to->next == NULL), return ERR_VAL;);
donatien	0:b802fc31f1db	803	}
donatien	0:b802fc31f1db	804	} while (p_from);
donatien	0:b802fc31f1db	805	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_copy: end of chain reached.\n"));
donatien	0:b802fc31f1db	806	return ERR_OK;
donatien	0:b802fc31f1db	807	}
donatien	0:b802fc31f1db	808
donatien	0:b802fc31f1db	809	/**
donatien	0:b802fc31f1db	810	* Copy (part of) the contents of a packet buffer
donatien	0:b802fc31f1db	811	* to an application supplied buffer.
donatien	0:b802fc31f1db	812	*
donatien	0:b802fc31f1db	813	* @param buf the pbuf from which to copy data
donatien	0:b802fc31f1db	814	* @param dataptr the application supplied buffer
donatien	0:b802fc31f1db	815	* @param len length of data to copy (dataptr must be big enough). No more
donatien	0:b802fc31f1db	816	* than buf->tot_len will be copied, irrespective of len
donatien	0:b802fc31f1db	817	* @param offset offset into the packet buffer from where to begin copying len bytes
donatien	0:b802fc31f1db	818	* @return the number of bytes copied, or 0 on failure
donatien	0:b802fc31f1db	819	*/
donatien	0:b802fc31f1db	820	u16_t
donatien	0:b802fc31f1db	821	pbuf_copy_partial(struct pbuf buf, void dataptr, u16_t len, u16_t offset)
donatien	0:b802fc31f1db	822	{
donatien	0:b802fc31f1db	823	struct pbuf *p;
donatien	0:b802fc31f1db	824	u16_t left;
donatien	0:b802fc31f1db	825	u16_t buf_copy_len;
donatien	0:b802fc31f1db	826	u16_t copied_total = 0;
donatien	0:b802fc31f1db	827
donatien	0:b802fc31f1db	828	LWIP_ERROR("pbuf_copy_partial: invalid buf", (buf != NULL), return 0;);
donatien	0:b802fc31f1db	829	LWIP_ERROR("pbuf_copy_partial: invalid dataptr", (dataptr != NULL), return 0;);
donatien	0:b802fc31f1db	830
donatien	0:b802fc31f1db	831	left = 0;
donatien	0:b802fc31f1db	832
donatien	0:b802fc31f1db	833	if((buf == NULL) \|\| (dataptr == NULL)) {
donatien	0:b802fc31f1db	834	return 0;
donatien	0:b802fc31f1db	835	}
donatien	0:b802fc31f1db	836
donatien	0:b802fc31f1db	837	/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
donatien	0:b802fc31f1db	838	for(p = buf; len != 0 && p != NULL; p = p->next) {
donatien	0:b802fc31f1db	839	if ((offset != 0) && (offset >= p->len)) {
donatien	0:b802fc31f1db	840	/* don't copy from this buffer -> on to the next */
donatien	0:b802fc31f1db	841	offset -= p->len;
donatien	0:b802fc31f1db	842	} else {
donatien	0:b802fc31f1db	843	/* copy from this buffer. maybe only partially. */
donatien	0:b802fc31f1db	844	buf_copy_len = p->len - offset;
donatien	0:b802fc31f1db	845	if (buf_copy_len > len)
donatien	0:b802fc31f1db	846	buf_copy_len = len;
donatien	0:b802fc31f1db	847	/* copy the necessary parts of the buffer */
donatien	0:b802fc31f1db	848	MEMCPY(&((char)dataptr)[left], &((char)p->payload)[offset], buf_copy_len);
donatien	0:b802fc31f1db	849	copied_total += buf_copy_len;
donatien	0:b802fc31f1db	850	left += buf_copy_len;
donatien	0:b802fc31f1db	851	len -= buf_copy_len;
donatien	0:b802fc31f1db	852	offset = 0;
donatien	0:b802fc31f1db	853	}
donatien	0:b802fc31f1db	854	}
donatien	0:b802fc31f1db	855	return copied_total;
donatien	0:b802fc31f1db	856	}
donatien	0:b802fc31f1db	857
donatien	0:b802fc31f1db	858	/**
donatien	0:b802fc31f1db	859	* Copy application supplied data into a pbuf.
donatien	0:b802fc31f1db	860	* This function can only be used to copy the equivalent of buf->tot_len data.
donatien	0:b802fc31f1db	861	*
donatien	0:b802fc31f1db	862	* @param buf pbuf to fill with data
donatien	0:b802fc31f1db	863	* @param dataptr application supplied data buffer
donatien	0:b802fc31f1db	864	* @param len length of the application supplied data buffer
donatien	0:b802fc31f1db	865	*
donatien	0:b802fc31f1db	866	* @return ERR_OK if successful, ERR_MEM if the pbuf is not big enough
donatien	0:b802fc31f1db	867	*/
donatien	0:b802fc31f1db	868	err_t
donatien	0:b802fc31f1db	869	pbuf_take(struct pbuf buf, const void dataptr, u16_t len)
donatien	0:b802fc31f1db	870	{
donatien	0:b802fc31f1db	871	struct pbuf *p;
donatien	0:b802fc31f1db	872	u16_t buf_copy_len;
donatien	0:b802fc31f1db	873	u16_t total_copy_len = len;
donatien	0:b802fc31f1db	874	u16_t copied_total = 0;
donatien	0:b802fc31f1db	875
donatien	0:b802fc31f1db	876	LWIP_ERROR("pbuf_take: invalid buf", (buf != NULL), return 0;);
donatien	0:b802fc31f1db	877	LWIP_ERROR("pbuf_take: invalid dataptr", (dataptr != NULL), return 0;);
donatien	0:b802fc31f1db	878
donatien	0:b802fc31f1db	879	if ((buf == NULL) \|\| (dataptr == NULL) \|\| (buf->tot_len < len)) {
donatien	0:b802fc31f1db	880	return ERR_ARG;
donatien	0:b802fc31f1db	881	}
donatien	0:b802fc31f1db	882
donatien	0:b802fc31f1db	883	/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
donatien	0:b802fc31f1db	884	for(p = buf; total_copy_len != 0; p = p->next) {
donatien	0:b802fc31f1db	885	LWIP_ASSERT("pbuf_take: invalid pbuf", p != NULL);
donatien	0:b802fc31f1db	886	buf_copy_len = total_copy_len;
donatien	0:b802fc31f1db	887	if (buf_copy_len > p->len) {
donatien	0:b802fc31f1db	888	/* this pbuf cannot hold all remaining data */
donatien	0:b802fc31f1db	889	buf_copy_len = p->len;
donatien	0:b802fc31f1db	890	}
donatien	0:b802fc31f1db	891	/* copy the necessary parts of the buffer */
donatien	0:b802fc31f1db	892	MEMCPY(p->payload, &((char*)dataptr)[copied_total], buf_copy_len);
donatien	0:b802fc31f1db	893	total_copy_len -= buf_copy_len;
donatien	0:b802fc31f1db	894	copied_total += buf_copy_len;
donatien	0:b802fc31f1db	895	}
donatien	0:b802fc31f1db	896	LWIP_ASSERT("did not copy all data", total_copy_len == 0 && copied_total == len);
donatien	0:b802fc31f1db	897	return ERR_OK;
donatien	0:b802fc31f1db	898	}
donatien	0:b802fc31f1db	899
donatien	0:b802fc31f1db	900	/**
donatien	0:b802fc31f1db	901	* Creates a single pbuf out of a queue of pbufs.
donatien	0:b802fc31f1db	902	*
donatien	0:b802fc31f1db	903	* @remark: The source pbuf 'p' is not freed by this function because that can
donatien	0:b802fc31f1db	904	* be illegal in some places!
donatien	0:b802fc31f1db	905	*
donatien	0:b802fc31f1db	906	* @param p the source pbuf
donatien	0:b802fc31f1db	907	* @param layer pbuf_layer of the new pbuf
donatien	0:b802fc31f1db	908	*
donatien	0:b802fc31f1db	909	* @return a new, single pbuf (p->next is NULL)
donatien	0:b802fc31f1db	910	* or the old pbuf if allocation fails
donatien	0:b802fc31f1db	911	*/
donatien	0:b802fc31f1db	912	struct pbuf*
donatien	0:b802fc31f1db	913	pbuf_coalesce(struct pbuf *p, pbuf_layer layer)
donatien	0:b802fc31f1db	914	{
donatien	0:b802fc31f1db	915	struct pbuf *q;
donatien	0:b802fc31f1db	916	err_t err;
donatien	0:b802fc31f1db	917	if (p->next == NULL) {
donatien	0:b802fc31f1db	918	return p;
donatien	0:b802fc31f1db	919	}
donatien	0:b802fc31f1db	920	q = pbuf_alloc(layer, p->tot_len, PBUF_RAM);
donatien	0:b802fc31f1db	921	if (q == NULL) {
donatien	0:b802fc31f1db	922	/* @todo: what do we do now? */
donatien	0:b802fc31f1db	923	return p;
donatien	0:b802fc31f1db	924	}
donatien	0:b802fc31f1db	925	err = pbuf_copy(q, p);
donatien	0:b802fc31f1db	926	LWIP_ASSERT("pbuf_copy failed", err == ERR_OK);
donatien	0:b802fc31f1db	927	pbuf_free(p);
donatien	0:b802fc31f1db	928	return q;
donatien	0:b802fc31f1db	929	}

Repository toolbox

Export to desktop IDE

Build repository

Repository details

Type:	Program
Created:	09 Jul 2010
Imports:	20
Forks:	0
Commits:	5
Dependents:	0
Dependencies:	0
Followers:	3

This repository is Public (Unlisted).

lwip/core/pbuf.c@0:b802fc31f1db, 2010-07-09 (annotated)

Who changed what in which revision?

Repository toolbox

Repository details

Important Information for this Arm website

Access Warning