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This library is stripped down version of NetServices library. HTTP server and client function is NOT supported.

lwip/core/pbuf.c@0:dcf3c92487ca, 2011-07-20 (annotated)

Committer:: idinor
Date:: Wed Jul 20 11:45:39 2011 +0000
Revision:: 0:dcf3c92487ca

Who changed what in which revision?

User	Revision	Line number	New contents of line
idinor	0:dcf3c92487ca	1	/**
idinor	0:dcf3c92487ca	2	* @file
idinor	0:dcf3c92487ca	3	* Packet buffer management
idinor	0:dcf3c92487ca	4	*
idinor	0:dcf3c92487ca	5	* Packets are built from the pbuf data structure. It supports dynamic
idinor	0:dcf3c92487ca	6	* memory allocation for packet contents or can reference externally
idinor	0:dcf3c92487ca	7	* managed packet contents both in RAM and ROM. Quick allocation for
idinor	0:dcf3c92487ca	8	* incoming packets is provided through pools with fixed sized pbufs.
idinor	0:dcf3c92487ca	9	*
idinor	0:dcf3c92487ca	10	* A packet may span over multiple pbufs, chained as a singly linked
idinor	0:dcf3c92487ca	11	* list. This is called a "pbuf chain".
idinor	0:dcf3c92487ca	12	*
idinor	0:dcf3c92487ca	13	* Multiple packets may be queued, also using this singly linked list.
idinor	0:dcf3c92487ca	14	* This is called a "packet queue".
idinor	0:dcf3c92487ca	15	*
idinor	0:dcf3c92487ca	16	* So, a packet queue consists of one or more pbuf chains, each of
idinor	0:dcf3c92487ca	17	* which consist of one or more pbufs. CURRENTLY, PACKET QUEUES ARE
idinor	0:dcf3c92487ca	18	* NOT SUPPORTED!!! Use helper structs to queue multiple packets.
idinor	0:dcf3c92487ca	19	*
idinor	0:dcf3c92487ca	20	* The differences between a pbuf chain and a packet queue are very
idinor	0:dcf3c92487ca	21	* precise but subtle.
idinor	0:dcf3c92487ca	22	*
idinor	0:dcf3c92487ca	23	* The last pbuf of a packet has a ->tot_len field that equals the
idinor	0:dcf3c92487ca	24	* ->len field. It can be found by traversing the list. If the last
idinor	0:dcf3c92487ca	25	* pbuf of a packet has a ->next field other than NULL, more packets
idinor	0:dcf3c92487ca	26	* are on the queue.
idinor	0:dcf3c92487ca	27	*
idinor	0:dcf3c92487ca	28	* Therefore, looping through a pbuf of a single packet, has an
idinor	0:dcf3c92487ca	29	* loop end condition (tot_len == p->len), NOT (next == NULL).
idinor	0:dcf3c92487ca	30	*/
idinor	0:dcf3c92487ca	31
idinor	0:dcf3c92487ca	32	/*
idinor	0:dcf3c92487ca	33	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
idinor	0:dcf3c92487ca	34	* All rights reserved.
idinor	0:dcf3c92487ca	35	*
idinor	0:dcf3c92487ca	36	* Redistribution and use in source and binary forms, with or without modification,
idinor	0:dcf3c92487ca	37	* are permitted provided that the following conditions are met:
idinor	0:dcf3c92487ca	38	*
idinor	0:dcf3c92487ca	39	* 1. Redistributions of source code must retain the above copyright notice,
idinor	0:dcf3c92487ca	40	* this list of conditions and the following disclaimer.
idinor	0:dcf3c92487ca	41	* 2. Redistributions in binary form must reproduce the above copyright notice,
idinor	0:dcf3c92487ca	42	* this list of conditions and the following disclaimer in the documentation
idinor	0:dcf3c92487ca	43	* and/or other materials provided with the distribution.
idinor	0:dcf3c92487ca	44	* 3. The name of the author may not be used to endorse or promote products
idinor	0:dcf3c92487ca	45	* derived from this software without specific prior written permission.
idinor	0:dcf3c92487ca	46	*
idinor	0:dcf3c92487ca	47	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
idinor	0:dcf3c92487ca	48	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
idinor	0:dcf3c92487ca	49	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
idinor	0:dcf3c92487ca	50	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
idinor	0:dcf3c92487ca	51	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
idinor	0:dcf3c92487ca	52	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
idinor	0:dcf3c92487ca	53	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
idinor	0:dcf3c92487ca	54	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
idinor	0:dcf3c92487ca	55	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
idinor	0:dcf3c92487ca	56	* OF SUCH DAMAGE.
idinor	0:dcf3c92487ca	57	*
idinor	0:dcf3c92487ca	58	* This file is part of the lwIP TCP/IP stack.
idinor	0:dcf3c92487ca	59	*
idinor	0:dcf3c92487ca	60	* Author: Adam Dunkels <adam@sics.se>
idinor	0:dcf3c92487ca	61	*
idinor	0:dcf3c92487ca	62	*/
idinor	0:dcf3c92487ca	63
idinor	0:dcf3c92487ca	64	#include "lwip/opt.h"
idinor	0:dcf3c92487ca	65
idinor	0:dcf3c92487ca	66	#include "lwip/stats.h"
idinor	0:dcf3c92487ca	67	#include "lwip/def.h"
idinor	0:dcf3c92487ca	68	#include "lwip/mem.h"
idinor	0:dcf3c92487ca	69	#include "lwip/memp.h"
idinor	0:dcf3c92487ca	70	#include "lwip/pbuf.h"
idinor	0:dcf3c92487ca	71	#include "lwip/sys.h"
idinor	0:dcf3c92487ca	72	#include "arch/perf.h"
idinor	0:dcf3c92487ca	73	#if TCP_QUEUE_OOSEQ
idinor	0:dcf3c92487ca	74	#include "lwip/tcp_impl.h"
idinor	0:dcf3c92487ca	75	#endif
idinor	0:dcf3c92487ca	76	#if LWIP_CHECKSUM_ON_COPY
idinor	0:dcf3c92487ca	77	#include "lwip/inet_chksum.h"
idinor	0:dcf3c92487ca	78	#endif
idinor	0:dcf3c92487ca	79
idinor	0:dcf3c92487ca	80	#include <string.h>
idinor	0:dcf3c92487ca	81
idinor	0:dcf3c92487ca	82	#define SIZEOF_STRUCT_PBUF LWIP_MEM_ALIGN_SIZE(sizeof(struct pbuf))
idinor	0:dcf3c92487ca	83	/* Since the pool is created in memp, PBUF_POOL_BUFSIZE will be automatically
idinor	0:dcf3c92487ca	84	aligned there. Therefore, PBUF_POOL_BUFSIZE_ALIGNED can be used here. */
idinor	0:dcf3c92487ca	85	#define PBUF_POOL_BUFSIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE)
idinor	0:dcf3c92487ca	86
idinor	0:dcf3c92487ca	87	#if !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS
idinor	0:dcf3c92487ca	88	#define PBUF_POOL_IS_EMPTY()
idinor	0:dcf3c92487ca	89	#else /* !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS */
idinor	0:dcf3c92487ca	90	/** Define this to 0 to prevent freeing ooseq pbufs when the PBUF_POOL is empty */
idinor	0:dcf3c92487ca	91	#ifndef PBUF_POOL_FREE_OOSEQ
idinor	0:dcf3c92487ca	92	#define PBUF_POOL_FREE_OOSEQ 1
idinor	0:dcf3c92487ca	93	#endif /* PBUF_POOL_FREE_OOSEQ */
idinor	0:dcf3c92487ca	94
idinor	0:dcf3c92487ca	95	#if PBUF_POOL_FREE_OOSEQ
idinor	0:dcf3c92487ca	96	#include "lwip/tcpip.h"
idinor	0:dcf3c92487ca	97	#define PBUF_POOL_IS_EMPTY() pbuf_pool_is_empty()
idinor	0:dcf3c92487ca	98	static u8_t pbuf_free_ooseq_queued;
idinor	0:dcf3c92487ca	99	/**
idinor	0:dcf3c92487ca	100	* Attempt to reclaim some memory from queued out-of-sequence TCP segments
idinor	0:dcf3c92487ca	101	* if we run out of pool pbufs. It's better to give priority to new packets
idinor	0:dcf3c92487ca	102	* if we're running out.
idinor	0:dcf3c92487ca	103	*
idinor	0:dcf3c92487ca	104	* This must be done in the correct thread context therefore this function
idinor	0:dcf3c92487ca	105	* can only be used with NO_SYS=0 and through tcpip_callback.
idinor	0:dcf3c92487ca	106	*/
idinor	0:dcf3c92487ca	107	static void
idinor	0:dcf3c92487ca	108	pbuf_free_ooseq(void* arg)
idinor	0:dcf3c92487ca	109	{
idinor	0:dcf3c92487ca	110	struct tcp_pcb* pcb;
idinor	0:dcf3c92487ca	111	SYS_ARCH_DECL_PROTECT(old_level);
idinor	0:dcf3c92487ca	112	LWIP_UNUSED_ARG(arg);
idinor	0:dcf3c92487ca	113
idinor	0:dcf3c92487ca	114	SYS_ARCH_PROTECT(old_level);
idinor	0:dcf3c92487ca	115	pbuf_free_ooseq_queued = 0;
idinor	0:dcf3c92487ca	116	SYS_ARCH_UNPROTECT(old_level);
idinor	0:dcf3c92487ca	117
idinor	0:dcf3c92487ca	118	for (pcb = tcp_active_pcbs; NULL != pcb; pcb = pcb->next) {
idinor	0:dcf3c92487ca	119	if (NULL != pcb->ooseq) {
idinor	0:dcf3c92487ca	120	/** Free the ooseq pbufs of one PCB only */
idinor	0:dcf3c92487ca	121	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free_ooseq: freeing out-of-sequence pbufs\n"));
idinor	0:dcf3c92487ca	122	tcp_segs_free(pcb->ooseq);
idinor	0:dcf3c92487ca	123	pcb->ooseq = NULL;
idinor	0:dcf3c92487ca	124	return;
idinor	0:dcf3c92487ca	125	}
idinor	0:dcf3c92487ca	126	}
idinor	0:dcf3c92487ca	127	}
idinor	0:dcf3c92487ca	128
idinor	0:dcf3c92487ca	129	/** Queue a call to pbuf_free_ooseq if not already queued. */
idinor	0:dcf3c92487ca	130	static void
idinor	0:dcf3c92487ca	131	pbuf_pool_is_empty(void)
idinor	0:dcf3c92487ca	132	{
idinor	0:dcf3c92487ca	133	u8_t queued;
idinor	0:dcf3c92487ca	134	SYS_ARCH_DECL_PROTECT(old_level);
idinor	0:dcf3c92487ca	135
idinor	0:dcf3c92487ca	136	SYS_ARCH_PROTECT(old_level);
idinor	0:dcf3c92487ca	137	queued = pbuf_free_ooseq_queued;
idinor	0:dcf3c92487ca	138	pbuf_free_ooseq_queued = 1;
idinor	0:dcf3c92487ca	139	SYS_ARCH_UNPROTECT(old_level);
idinor	0:dcf3c92487ca	140
idinor	0:dcf3c92487ca	141	if(!queued) {
idinor	0:dcf3c92487ca	142	/* queue a call to pbuf_free_ooseq if not already queued */
idinor	0:dcf3c92487ca	143	if(tcpip_callback_with_block(pbuf_free_ooseq, NULL, 0) != ERR_OK) {
idinor	0:dcf3c92487ca	144	SYS_ARCH_PROTECT(old_level);
idinor	0:dcf3c92487ca	145	pbuf_free_ooseq_queued = 0;
idinor	0:dcf3c92487ca	146	SYS_ARCH_UNPROTECT(old_level);
idinor	0:dcf3c92487ca	147	}
idinor	0:dcf3c92487ca	148	}
idinor	0:dcf3c92487ca	149	}
idinor	0:dcf3c92487ca	150	#endif /* PBUF_POOL_FREE_OOSEQ */
idinor	0:dcf3c92487ca	151	#endif /* !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS */
idinor	0:dcf3c92487ca	152
idinor	0:dcf3c92487ca	153	/**
idinor	0:dcf3c92487ca	154	* Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
idinor	0:dcf3c92487ca	155	*
idinor	0:dcf3c92487ca	156	* The actual memory allocated for the pbuf is determined by the
idinor	0:dcf3c92487ca	157	* layer at which the pbuf is allocated and the requested size
idinor	0:dcf3c92487ca	158	* (from the size parameter).
idinor	0:dcf3c92487ca	159	*
idinor	0:dcf3c92487ca	160	* @param layer flag to define header size
idinor	0:dcf3c92487ca	161	* @param length size of the pbuf's payload
idinor	0:dcf3c92487ca	162	* @param type this parameter decides how and where the pbuf
idinor	0:dcf3c92487ca	163	* should be allocated as follows:
idinor	0:dcf3c92487ca	164	*
idinor	0:dcf3c92487ca	165	* - PBUF_RAM: buffer memory for pbuf is allocated as one large
idinor	0:dcf3c92487ca	166	* chunk. This includes protocol headers as well.
idinor	0:dcf3c92487ca	167	* - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
idinor	0:dcf3c92487ca	168	* protocol headers. Additional headers must be prepended
idinor	0:dcf3c92487ca	169	* by allocating another pbuf and chain in to the front of
idinor	0:dcf3c92487ca	170	* the ROM pbuf. It is assumed that the memory used is really
idinor	0:dcf3c92487ca	171	* similar to ROM in that it is immutable and will not be
idinor	0:dcf3c92487ca	172	* changed. Memory which is dynamic should generally not
idinor	0:dcf3c92487ca	173	* be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
idinor	0:dcf3c92487ca	174	* - PBUF_REF: no buffer memory is allocated for the pbuf, even for
idinor	0:dcf3c92487ca	175	* protocol headers. It is assumed that the pbuf is only
idinor	0:dcf3c92487ca	176	* being used in a single thread. If the pbuf gets queued,
idinor	0:dcf3c92487ca	177	* then pbuf_take should be called to copy the buffer.
idinor	0:dcf3c92487ca	178	* - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
idinor	0:dcf3c92487ca	179	* the pbuf pool that is allocated during pbuf_init().
idinor	0:dcf3c92487ca	180	*
idinor	0:dcf3c92487ca	181	* @return the allocated pbuf. If multiple pbufs where allocated, this
idinor	0:dcf3c92487ca	182	* is the first pbuf of a pbuf chain.
idinor	0:dcf3c92487ca	183	*/
idinor	0:dcf3c92487ca	184	struct pbuf *
idinor	0:dcf3c92487ca	185	pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
idinor	0:dcf3c92487ca	186	{
idinor	0:dcf3c92487ca	187	struct pbuf p, q, *r;
idinor	0:dcf3c92487ca	188	u16_t offset;
idinor	0:dcf3c92487ca	189	s32_t rem_len; /* remaining length */
idinor	0:dcf3c92487ca	190	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
idinor	0:dcf3c92487ca	191
idinor	0:dcf3c92487ca	192	/* determine header offset */
idinor	0:dcf3c92487ca	193	offset = 0;
idinor	0:dcf3c92487ca	194	switch (layer) {
idinor	0:dcf3c92487ca	195	case PBUF_TRANSPORT:
idinor	0:dcf3c92487ca	196	/* add room for transport (often TCP) layer header */
idinor	0:dcf3c92487ca	197	offset += PBUF_TRANSPORT_HLEN;
idinor	0:dcf3c92487ca	198	/* FALLTHROUGH */
idinor	0:dcf3c92487ca	199	case PBUF_IP:
idinor	0:dcf3c92487ca	200	/* add room for IP layer header */
idinor	0:dcf3c92487ca	201	offset += PBUF_IP_HLEN;
idinor	0:dcf3c92487ca	202	/* FALLTHROUGH */
idinor	0:dcf3c92487ca	203	case PBUF_LINK:
idinor	0:dcf3c92487ca	204	/* add room for link layer header */
idinor	0:dcf3c92487ca	205	offset += PBUF_LINK_HLEN;
idinor	0:dcf3c92487ca	206	break;
idinor	0:dcf3c92487ca	207	case PBUF_RAW:
idinor	0:dcf3c92487ca	208	break;
idinor	0:dcf3c92487ca	209	default:
idinor	0:dcf3c92487ca	210	LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0);
idinor	0:dcf3c92487ca	211	return NULL;
idinor	0:dcf3c92487ca	212	}
idinor	0:dcf3c92487ca	213
idinor	0:dcf3c92487ca	214	switch (type) {
idinor	0:dcf3c92487ca	215	case PBUF_POOL:
idinor	0:dcf3c92487ca	216	/* allocate head of pbuf chain into p */
idinor	0:dcf3c92487ca	217	p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
idinor	0:dcf3c92487ca	218	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
idinor	0:dcf3c92487ca	219	if (p == NULL) {
idinor	0:dcf3c92487ca	220	PBUF_POOL_IS_EMPTY();
idinor	0:dcf3c92487ca	221	return NULL;
idinor	0:dcf3c92487ca	222	}
idinor	0:dcf3c92487ca	223	p->type = type;
idinor	0:dcf3c92487ca	224	p->next = NULL;
idinor	0:dcf3c92487ca	225
idinor	0:dcf3c92487ca	226	/* make the payload pointer point 'offset' bytes into pbuf data memory */
idinor	0:dcf3c92487ca	227	p->payload = LWIP_MEM_ALIGN((void )((u8_t )p + (SIZEOF_STRUCT_PBUF + offset)));
idinor	0:dcf3c92487ca	228	LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned",
idinor	0:dcf3c92487ca	229	((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
idinor	0:dcf3c92487ca	230	/* the total length of the pbuf chain is the requested size */
idinor	0:dcf3c92487ca	231	p->tot_len = length;
idinor	0:dcf3c92487ca	232	/* set the length of the first pbuf in the chain */
idinor	0:dcf3c92487ca	233	p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
idinor	0:dcf3c92487ca	234	LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
idinor	0:dcf3c92487ca	235	((u8_t*)p->payload + p->len <=
idinor	0:dcf3c92487ca	236	(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
idinor	0:dcf3c92487ca	237	LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT",
idinor	0:dcf3c92487ca	238	(PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 );
idinor	0:dcf3c92487ca	239	/* set reference count (needed here in case we fail) */
idinor	0:dcf3c92487ca	240	p->ref = 1;
idinor	0:dcf3c92487ca	241
idinor	0:dcf3c92487ca	242	/* now allocate the tail of the pbuf chain */
idinor	0:dcf3c92487ca	243
idinor	0:dcf3c92487ca	244	/* remember first pbuf for linkage in next iteration */
idinor	0:dcf3c92487ca	245	r = p;
idinor	0:dcf3c92487ca	246	/* remaining length to be allocated */
idinor	0:dcf3c92487ca	247	rem_len = length - p->len;
idinor	0:dcf3c92487ca	248	/* any remaining pbufs to be allocated? */
idinor	0:dcf3c92487ca	249	while (rem_len > 0) {
idinor	0:dcf3c92487ca	250	q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
idinor	0:dcf3c92487ca	251	if (q == NULL) {
idinor	0:dcf3c92487ca	252	PBUF_POOL_IS_EMPTY();
idinor	0:dcf3c92487ca	253	/* free chain so far allocated */
idinor	0:dcf3c92487ca	254	pbuf_free(p);
idinor	0:dcf3c92487ca	255	/* bail out unsuccesfully */
idinor	0:dcf3c92487ca	256	return NULL;
idinor	0:dcf3c92487ca	257	}
idinor	0:dcf3c92487ca	258	q->type = type;
idinor	0:dcf3c92487ca	259	q->flags = 0;
idinor	0:dcf3c92487ca	260	q->next = NULL;
idinor	0:dcf3c92487ca	261	/* make previous pbuf point to this pbuf */
idinor	0:dcf3c92487ca	262	r->next = q;
idinor	0:dcf3c92487ca	263	/* set total length of this pbuf and next in chain */
idinor	0:dcf3c92487ca	264	LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff);
idinor	0:dcf3c92487ca	265	q->tot_len = (u16_t)rem_len;
idinor	0:dcf3c92487ca	266	/* this pbuf length is pool size, unless smaller sized tail */
idinor	0:dcf3c92487ca	267	q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
idinor	0:dcf3c92487ca	268	q->payload = (void )((u8_t )q + SIZEOF_STRUCT_PBUF);
idinor	0:dcf3c92487ca	269	LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
idinor	0:dcf3c92487ca	270	((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
idinor	0:dcf3c92487ca	271	LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
idinor	0:dcf3c92487ca	272	((u8_t*)p->payload + p->len <=
idinor	0:dcf3c92487ca	273	(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
idinor	0:dcf3c92487ca	274	q->ref = 1;
idinor	0:dcf3c92487ca	275	/* calculate remaining length to be allocated */
idinor	0:dcf3c92487ca	276	rem_len -= q->len;
idinor	0:dcf3c92487ca	277	/* remember this pbuf for linkage in next iteration */
idinor	0:dcf3c92487ca	278	r = q;
idinor	0:dcf3c92487ca	279	}
idinor	0:dcf3c92487ca	280	/* end of chain */
idinor	0:dcf3c92487ca	281	/r->next = NULL;/
idinor	0:dcf3c92487ca	282
idinor	0:dcf3c92487ca	283	break;
idinor	0:dcf3c92487ca	284	case PBUF_RAM:
idinor	0:dcf3c92487ca	285	/* If pbuf is to be allocated in RAM, allocate memory for it. */
idinor	0:dcf3c92487ca	286	p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
idinor	0:dcf3c92487ca	287	if (p == NULL) {
idinor	0:dcf3c92487ca	288	return NULL;
idinor	0:dcf3c92487ca	289	}
idinor	0:dcf3c92487ca	290	/* Set up internal structure of the pbuf. */
idinor	0:dcf3c92487ca	291	p->payload = LWIP_MEM_ALIGN((void )((u8_t )p + SIZEOF_STRUCT_PBUF + offset));
idinor	0:dcf3c92487ca	292	p->len = p->tot_len = length;
idinor	0:dcf3c92487ca	293	p->next = NULL;
idinor	0:dcf3c92487ca	294	p->type = type;
idinor	0:dcf3c92487ca	295
idinor	0:dcf3c92487ca	296	LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
idinor	0:dcf3c92487ca	297	((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
idinor	0:dcf3c92487ca	298	break;
idinor	0:dcf3c92487ca	299	/* pbuf references existing (non-volatile static constant) ROM payload? */
idinor	0:dcf3c92487ca	300	case PBUF_ROM:
idinor	0:dcf3c92487ca	301	/* pbuf references existing (externally allocated) RAM payload? */
idinor	0:dcf3c92487ca	302	case PBUF_REF:
idinor	0:dcf3c92487ca	303	/* only allocate memory for the pbuf structure */
idinor	0:dcf3c92487ca	304	p = (struct pbuf *)memp_malloc(MEMP_PBUF);
idinor	0:dcf3c92487ca	305	if (p == NULL) {
idinor	0:dcf3c92487ca	306	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
idinor	0:dcf3c92487ca	307	("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n",
idinor	0:dcf3c92487ca	308	(type == PBUF_ROM) ? "ROM" : "REF"));
idinor	0:dcf3c92487ca	309	return NULL;
idinor	0:dcf3c92487ca	310	}
idinor	0:dcf3c92487ca	311	/* caller must set this field properly, afterwards */
idinor	0:dcf3c92487ca	312	p->payload = NULL;
idinor	0:dcf3c92487ca	313	p->len = p->tot_len = length;
idinor	0:dcf3c92487ca	314	p->next = NULL;
idinor	0:dcf3c92487ca	315	p->type = type;
idinor	0:dcf3c92487ca	316	break;
idinor	0:dcf3c92487ca	317	default:
idinor	0:dcf3c92487ca	318	LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
idinor	0:dcf3c92487ca	319	return NULL;
idinor	0:dcf3c92487ca	320	}
idinor	0:dcf3c92487ca	321	/* set reference count */
idinor	0:dcf3c92487ca	322	p->ref = 1;
idinor	0:dcf3c92487ca	323	/* set flags */
idinor	0:dcf3c92487ca	324	p->flags = 0;
idinor	0:dcf3c92487ca	325	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
idinor	0:dcf3c92487ca	326	return p;
idinor	0:dcf3c92487ca	327	}
idinor	0:dcf3c92487ca	328
idinor	0:dcf3c92487ca	329	#if LWIP_SUPPORT_CUSTOM_PBUF
idinor	0:dcf3c92487ca	330	/** Initialize a custom pbuf (already allocated).
idinor	0:dcf3c92487ca	331	*
idinor	0:dcf3c92487ca	332	* @param layer flag to define header size
idinor	0:dcf3c92487ca	333	* @param length size of the pbuf's payload
idinor	0:dcf3c92487ca	334	* @param type type of the pbuf (only used to treat the pbuf accordingly, as
idinor	0:dcf3c92487ca	335	* this function allocates no memory)
idinor	0:dcf3c92487ca	336	* @param p pointer to the custom pbuf to initialize (already allocated)
idinor	0:dcf3c92487ca	337	* @param payload_mem pointer to the buffer that is used for payload and headers,
idinor	0:dcf3c92487ca	338	* must be at least big enough to hold 'length' plus the header size,
idinor	0:dcf3c92487ca	339	* may be NULL if set later
idinor	0:dcf3c92487ca	340	* @param payload_mem_len the size of the 'payload_mem' buffer, must be at least
idinor	0:dcf3c92487ca	341	* big enough to hold 'length' plus the header size
idinor	0:dcf3c92487ca	342	*/
idinor	0:dcf3c92487ca	343	struct pbuf*
idinor	0:dcf3c92487ca	344	pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type, struct pbuf_custom *p,
idinor	0:dcf3c92487ca	345	void *payload_mem, u16_t payload_mem_len)
idinor	0:dcf3c92487ca	346	{
idinor	0:dcf3c92487ca	347	u16_t offset;
idinor	0:dcf3c92487ca	348	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloced_custom(length=%"U16_F")\n", length));
idinor	0:dcf3c92487ca	349
idinor	0:dcf3c92487ca	350	/* determine header offset */
idinor	0:dcf3c92487ca	351	offset = 0;
idinor	0:dcf3c92487ca	352	switch (l) {
idinor	0:dcf3c92487ca	353	case PBUF_TRANSPORT:
idinor	0:dcf3c92487ca	354	/* add room for transport (often TCP) layer header */
idinor	0:dcf3c92487ca	355	offset += PBUF_TRANSPORT_HLEN;
idinor	0:dcf3c92487ca	356	/* FALLTHROUGH */
idinor	0:dcf3c92487ca	357	case PBUF_IP:
idinor	0:dcf3c92487ca	358	/* add room for IP layer header */
idinor	0:dcf3c92487ca	359	offset += PBUF_IP_HLEN;
idinor	0:dcf3c92487ca	360	/* FALLTHROUGH */
idinor	0:dcf3c92487ca	361	case PBUF_LINK:
idinor	0:dcf3c92487ca	362	/* add room for link layer header */
idinor	0:dcf3c92487ca	363	offset += PBUF_LINK_HLEN;
idinor	0:dcf3c92487ca	364	break;
idinor	0:dcf3c92487ca	365	case PBUF_RAW:
idinor	0:dcf3c92487ca	366	break;
idinor	0:dcf3c92487ca	367	default:
idinor	0:dcf3c92487ca	368	LWIP_ASSERT("pbuf_alloced_custom: bad pbuf layer", 0);
idinor	0:dcf3c92487ca	369	return NULL;
idinor	0:dcf3c92487ca	370	}
idinor	0:dcf3c92487ca	371
idinor	0:dcf3c92487ca	372	if (LWIP_MEM_ALIGN_SIZE(offset) + length < payload_mem_len) {
idinor	0:dcf3c92487ca	373	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_WARNING, ("pbuf_alloced_custom(length=%"U16_F") buffer too short\n", length));
idinor	0:dcf3c92487ca	374	return NULL;
idinor	0:dcf3c92487ca	375	}
idinor	0:dcf3c92487ca	376
idinor	0:dcf3c92487ca	377	p->pbuf.next = NULL;
idinor	0:dcf3c92487ca	378	if (payload_mem != NULL) {
idinor	0:dcf3c92487ca	379	p->pbuf.payload = LWIP_MEM_ALIGN((void )((u8_t )payload_mem + offset));
idinor	0:dcf3c92487ca	380	} else {
idinor	0:dcf3c92487ca	381	p->pbuf.payload = NULL;
idinor	0:dcf3c92487ca	382	}
idinor	0:dcf3c92487ca	383	p->pbuf.flags = PBUF_FLAG_IS_CUSTOM;
idinor	0:dcf3c92487ca	384	p->pbuf.len = p->pbuf.tot_len = length;
idinor	0:dcf3c92487ca	385	p->pbuf.type = type;
idinor	0:dcf3c92487ca	386	p->pbuf.ref = 1;
idinor	0:dcf3c92487ca	387	return &p->pbuf;
idinor	0:dcf3c92487ca	388	}
idinor	0:dcf3c92487ca	389	#endif /* LWIP_SUPPORT_CUSTOM_PBUF */
idinor	0:dcf3c92487ca	390
idinor	0:dcf3c92487ca	391	/**
idinor	0:dcf3c92487ca	392	* Shrink a pbuf chain to a desired length.
idinor	0:dcf3c92487ca	393	*
idinor	0:dcf3c92487ca	394	* @param p pbuf to shrink.
idinor	0:dcf3c92487ca	395	* @param new_len desired new length of pbuf chain
idinor	0:dcf3c92487ca	396	*
idinor	0:dcf3c92487ca	397	* Depending on the desired length, the first few pbufs in a chain might
idinor	0:dcf3c92487ca	398	* be skipped and left unchanged. The new last pbuf in the chain will be
idinor	0:dcf3c92487ca	399	* resized, and any remaining pbufs will be freed.
idinor	0:dcf3c92487ca	400	*
idinor	0:dcf3c92487ca	401	* @note If the pbuf is ROM/REF, only the ->tot_len and ->len fields are adjusted.
idinor	0:dcf3c92487ca	402	* @note May not be called on a packet queue.
idinor	0:dcf3c92487ca	403	*
idinor	0:dcf3c92487ca	404	* @note Despite its name, pbuf_realloc cannot grow the size of a pbuf (chain).
idinor	0:dcf3c92487ca	405	*/
idinor	0:dcf3c92487ca	406	void
idinor	0:dcf3c92487ca	407	pbuf_realloc(struct pbuf *p, u16_t new_len)
idinor	0:dcf3c92487ca	408	{
idinor	0:dcf3c92487ca	409	struct pbuf *q;
idinor	0:dcf3c92487ca	410	u16_t rem_len; /* remaining length */
idinor	0:dcf3c92487ca	411	s32_t grow;
idinor	0:dcf3c92487ca	412
idinor	0:dcf3c92487ca	413	LWIP_ASSERT("pbuf_realloc: p != NULL", p != NULL);
idinor	0:dcf3c92487ca	414	LWIP_ASSERT("pbuf_realloc: sane p->type", p->type == PBUF_POOL \|\|
idinor	0:dcf3c92487ca	415	p->type == PBUF_ROM \|\|
idinor	0:dcf3c92487ca	416	p->type == PBUF_RAM \|\|
idinor	0:dcf3c92487ca	417	p->type == PBUF_REF);
idinor	0:dcf3c92487ca	418
idinor	0:dcf3c92487ca	419	/* desired length larger than current length? */
idinor	0:dcf3c92487ca	420	if (new_len >= p->tot_len) {
idinor	0:dcf3c92487ca	421	/* enlarging not yet supported */
idinor	0:dcf3c92487ca	422	return;
idinor	0:dcf3c92487ca	423	}
idinor	0:dcf3c92487ca	424
idinor	0:dcf3c92487ca	425	/* the pbuf chain grows by (new_len - p->tot_len) bytes
idinor	0:dcf3c92487ca	426	* (which may be negative in case of shrinking) */
idinor	0:dcf3c92487ca	427	grow = new_len - p->tot_len;
idinor	0:dcf3c92487ca	428
idinor	0:dcf3c92487ca	429	/* first, step over any pbufs that should remain in the chain */
idinor	0:dcf3c92487ca	430	rem_len = new_len;
idinor	0:dcf3c92487ca	431	q = p;
idinor	0:dcf3c92487ca	432	/* should this pbuf be kept? */
idinor	0:dcf3c92487ca	433	while (rem_len > q->len) {
idinor	0:dcf3c92487ca	434	/* decrease remaining length by pbuf length */
idinor	0:dcf3c92487ca	435	rem_len -= q->len;
idinor	0:dcf3c92487ca	436	/* decrease total length indicator */
idinor	0:dcf3c92487ca	437	LWIP_ASSERT("grow < max_u16_t", grow < 0xffff);
idinor	0:dcf3c92487ca	438	q->tot_len += (u16_t)grow;
idinor	0:dcf3c92487ca	439	/* proceed to next pbuf in chain */
idinor	0:dcf3c92487ca	440	q = q->next;
idinor	0:dcf3c92487ca	441	LWIP_ASSERT("pbuf_realloc: q != NULL", q != NULL);
idinor	0:dcf3c92487ca	442	}
idinor	0:dcf3c92487ca	443	/* we have now reached the new last pbuf (in q) */
idinor	0:dcf3c92487ca	444	/* rem_len == desired length for pbuf q */
idinor	0:dcf3c92487ca	445
idinor	0:dcf3c92487ca	446	/* shrink allocated memory for PBUF_RAM */
idinor	0:dcf3c92487ca	447	/* (other types merely adjust their length fields */
idinor	0:dcf3c92487ca	448	if ((q->type == PBUF_RAM) && (rem_len != q->len)) {
idinor	0:dcf3c92487ca	449	/* reallocate and adjust the length of the pbuf that will be split */
idinor	0:dcf3c92487ca	450	q = (struct pbuf )mem_trim(q, (u16_t)((u8_t )q->payload - (u8_t *)q) + rem_len);
idinor	0:dcf3c92487ca	451	LWIP_ASSERT("mem_trim returned q == NULL", q != NULL);
idinor	0:dcf3c92487ca	452	}
idinor	0:dcf3c92487ca	453	/* adjust length fields for new last pbuf */
idinor	0:dcf3c92487ca	454	q->len = rem_len;
idinor	0:dcf3c92487ca	455	q->tot_len = q->len;
idinor	0:dcf3c92487ca	456
idinor	0:dcf3c92487ca	457	/* any remaining pbufs in chain? */
idinor	0:dcf3c92487ca	458	if (q->next != NULL) {
idinor	0:dcf3c92487ca	459	/* free remaining pbufs in chain */
idinor	0:dcf3c92487ca	460	pbuf_free(q->next);
idinor	0:dcf3c92487ca	461	}
idinor	0:dcf3c92487ca	462	/* q is last packet in chain */
idinor	0:dcf3c92487ca	463	q->next = NULL;
idinor	0:dcf3c92487ca	464
idinor	0:dcf3c92487ca	465	}
idinor	0:dcf3c92487ca	466
idinor	0:dcf3c92487ca	467	/**
idinor	0:dcf3c92487ca	468	* Adjusts the payload pointer to hide or reveal headers in the payload.
idinor	0:dcf3c92487ca	469	*
idinor	0:dcf3c92487ca	470	* Adjusts the ->payload pointer so that space for a header
idinor	0:dcf3c92487ca	471	* (dis)appears in the pbuf payload.
idinor	0:dcf3c92487ca	472	*
idinor	0:dcf3c92487ca	473	* The ->payload, ->tot_len and ->len fields are adjusted.
idinor	0:dcf3c92487ca	474	*
idinor	0:dcf3c92487ca	475	* @param p pbuf to change the header size.
idinor	0:dcf3c92487ca	476	* @param header_size_increment Number of bytes to increment header size which
idinor	0:dcf3c92487ca	477	* increases the size of the pbuf. New space is on the front.
idinor	0:dcf3c92487ca	478	* (Using a negative value decreases the header size.)
idinor	0:dcf3c92487ca	479	* If hdr_size_inc is 0, this function does nothing and returns succesful.
idinor	0:dcf3c92487ca	480	*
idinor	0:dcf3c92487ca	481	* PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so
idinor	0:dcf3c92487ca	482	* the call will fail. A check is made that the increase in header size does
idinor	0:dcf3c92487ca	483	* not move the payload pointer in front of the start of the buffer.
idinor	0:dcf3c92487ca	484	* @return non-zero on failure, zero on success.
idinor	0:dcf3c92487ca	485	*
idinor	0:dcf3c92487ca	486	*/
idinor	0:dcf3c92487ca	487	u8_t
idinor	0:dcf3c92487ca	488	pbuf_header(struct pbuf *p, s16_t header_size_increment)
idinor	0:dcf3c92487ca	489	{
idinor	0:dcf3c92487ca	490	u16_t type;
idinor	0:dcf3c92487ca	491	void *payload;
idinor	0:dcf3c92487ca	492	u16_t increment_magnitude;
idinor	0:dcf3c92487ca	493
idinor	0:dcf3c92487ca	494	LWIP_ASSERT("p != NULL", p != NULL);
idinor	0:dcf3c92487ca	495	if ((header_size_increment == 0) \|\| (p == NULL)) {
idinor	0:dcf3c92487ca	496	return 0;
idinor	0:dcf3c92487ca	497	}
idinor	0:dcf3c92487ca	498
idinor	0:dcf3c92487ca	499	if (header_size_increment < 0){
idinor	0:dcf3c92487ca	500	increment_magnitude = -header_size_increment;
idinor	0:dcf3c92487ca	501	/* Check that we aren't going to move off the end of the pbuf */
idinor	0:dcf3c92487ca	502	LWIP_ERROR("increment_magnitude <= p->len", (increment_magnitude <= p->len), return 1;);
idinor	0:dcf3c92487ca	503	} else {
idinor	0:dcf3c92487ca	504	increment_magnitude = header_size_increment;
idinor	0:dcf3c92487ca	505	#if 0
idinor	0:dcf3c92487ca	506	/* Can't assert these as some callers speculatively call
idinor	0:dcf3c92487ca	507	pbuf_header() to see if it's OK. Will return 1 below instead. */
idinor	0:dcf3c92487ca	508	/* Check that we've got the correct type of pbuf to work with */
idinor	0:dcf3c92487ca	509	LWIP_ASSERT("p->type == PBUF_RAM \|\| p->type == PBUF_POOL",
idinor	0:dcf3c92487ca	510	p->type == PBUF_RAM \|\| p->type == PBUF_POOL);
idinor	0:dcf3c92487ca	511	/* Check that we aren't going to move off the beginning of the pbuf */
idinor	0:dcf3c92487ca	512	LWIP_ASSERT("p->payload - increment_magnitude >= p + SIZEOF_STRUCT_PBUF",
idinor	0:dcf3c92487ca	513	(u8_t )p->payload - increment_magnitude >= (u8_t )p + SIZEOF_STRUCT_PBUF);
idinor	0:dcf3c92487ca	514	#endif
idinor	0:dcf3c92487ca	515	}
idinor	0:dcf3c92487ca	516
idinor	0:dcf3c92487ca	517	type = p->type;
idinor	0:dcf3c92487ca	518	/* remember current payload pointer */
idinor	0:dcf3c92487ca	519	payload = p->payload;
idinor	0:dcf3c92487ca	520
idinor	0:dcf3c92487ca	521	/* pbuf types containing payloads? */
idinor	0:dcf3c92487ca	522	if (type == PBUF_RAM \|\| type == PBUF_POOL) {
idinor	0:dcf3c92487ca	523	/* set new payload pointer */
idinor	0:dcf3c92487ca	524	p->payload = (u8_t *)p->payload - header_size_increment;
idinor	0:dcf3c92487ca	525	/* boundary check fails? */
idinor	0:dcf3c92487ca	526	if ((u8_t )p->payload < (u8_t )p + SIZEOF_STRUCT_PBUF) {
idinor	0:dcf3c92487ca	527	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
idinor	0:dcf3c92487ca	528	("pbuf_header: failed as %p < %p (not enough space for new header size)\n",
idinor	0:dcf3c92487ca	529	(void )p->payload, (void )(p + 1)));
idinor	0:dcf3c92487ca	530	/* restore old payload pointer */
idinor	0:dcf3c92487ca	531	p->payload = payload;
idinor	0:dcf3c92487ca	532	/* bail out unsuccesfully */
idinor	0:dcf3c92487ca	533	return 1;
idinor	0:dcf3c92487ca	534	}
idinor	0:dcf3c92487ca	535	/* pbuf types refering to external payloads? */
idinor	0:dcf3c92487ca	536	} else if (type == PBUF_REF \|\| type == PBUF_ROM) {
idinor	0:dcf3c92487ca	537	/* hide a header in the payload? */
idinor	0:dcf3c92487ca	538	if ((header_size_increment < 0) && (increment_magnitude <= p->len)) {
idinor	0:dcf3c92487ca	539	/* increase payload pointer */
idinor	0:dcf3c92487ca	540	p->payload = (u8_t *)p->payload - header_size_increment;
idinor	0:dcf3c92487ca	541	} else {
idinor	0:dcf3c92487ca	542	/* cannot expand payload to front (yet!)
idinor	0:dcf3c92487ca	543	* bail out unsuccesfully */
idinor	0:dcf3c92487ca	544	return 1;
idinor	0:dcf3c92487ca	545	}
idinor	0:dcf3c92487ca	546	} else {
idinor	0:dcf3c92487ca	547	/* Unknown type */
idinor	0:dcf3c92487ca	548	LWIP_ASSERT("bad pbuf type", 0);
idinor	0:dcf3c92487ca	549	return 1;
idinor	0:dcf3c92487ca	550	}
idinor	0:dcf3c92487ca	551	/* modify pbuf length fields */
idinor	0:dcf3c92487ca	552	p->len += header_size_increment;
idinor	0:dcf3c92487ca	553	p->tot_len += header_size_increment;
idinor	0:dcf3c92487ca	554
idinor	0:dcf3c92487ca	555	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_header: old %p new %p (%"S16_F")\n",
idinor	0:dcf3c92487ca	556	(void )payload, (void )p->payload, header_size_increment));
idinor	0:dcf3c92487ca	557
idinor	0:dcf3c92487ca	558	return 0;
idinor	0:dcf3c92487ca	559	}
idinor	0:dcf3c92487ca	560
idinor	0:dcf3c92487ca	561	/**
idinor	0:dcf3c92487ca	562	* Dereference a pbuf chain or queue and deallocate any no-longer-used
idinor	0:dcf3c92487ca	563	* pbufs at the head of this chain or queue.
idinor	0:dcf3c92487ca	564	*
idinor	0:dcf3c92487ca	565	* Decrements the pbuf reference count. If it reaches zero, the pbuf is
idinor	0:dcf3c92487ca	566	* deallocated.
idinor	0:dcf3c92487ca	567	*
idinor	0:dcf3c92487ca	568	* For a pbuf chain, this is repeated for each pbuf in the chain,
idinor	0:dcf3c92487ca	569	* up to the first pbuf which has a non-zero reference count after
idinor	0:dcf3c92487ca	570	* decrementing. So, when all reference counts are one, the whole
idinor	0:dcf3c92487ca	571	* chain is free'd.
idinor	0:dcf3c92487ca	572	*
idinor	0:dcf3c92487ca	573	* @param p The pbuf (chain) to be dereferenced.
idinor	0:dcf3c92487ca	574	*
idinor	0:dcf3c92487ca	575	* @return the number of pbufs that were de-allocated
idinor	0:dcf3c92487ca	576	* from the head of the chain.
idinor	0:dcf3c92487ca	577	*
idinor	0:dcf3c92487ca	578	* @note MUST NOT be called on a packet queue (Not verified to work yet).
idinor	0:dcf3c92487ca	579	* @note the reference counter of a pbuf equals the number of pointers
idinor	0:dcf3c92487ca	580	* that refer to the pbuf (or into the pbuf).
idinor	0:dcf3c92487ca	581	*
idinor	0:dcf3c92487ca	582	* @internal examples:
idinor	0:dcf3c92487ca	583	*
idinor	0:dcf3c92487ca	584	* Assuming existing chains a->b->c with the following reference
idinor	0:dcf3c92487ca	585	* counts, calling pbuf_free(a) results in:
idinor	0:dcf3c92487ca	586	*
idinor	0:dcf3c92487ca	587	* 1->2->3 becomes ...1->3
idinor	0:dcf3c92487ca	588	* 3->3->3 becomes 2->3->3
idinor	0:dcf3c92487ca	589	* 1->1->2 becomes ......1
idinor	0:dcf3c92487ca	590	* 2->1->1 becomes 1->1->1
idinor	0:dcf3c92487ca	591	* 1->1->1 becomes .......
idinor	0:dcf3c92487ca	592	*
idinor	0:dcf3c92487ca	593	*/
idinor	0:dcf3c92487ca	594	u8_t
idinor	0:dcf3c92487ca	595	pbuf_free(struct pbuf *p)
idinor	0:dcf3c92487ca	596	{
idinor	0:dcf3c92487ca	597	u16_t type;
idinor	0:dcf3c92487ca	598	struct pbuf *q;
idinor	0:dcf3c92487ca	599	u8_t count;
idinor	0:dcf3c92487ca	600
idinor	0:dcf3c92487ca	601	if (p == NULL) {
idinor	0:dcf3c92487ca	602	LWIP_ASSERT("p != NULL", p != NULL);
idinor	0:dcf3c92487ca	603	/* if assertions are disabled, proceed with debug output */
idinor	0:dcf3c92487ca	604	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
idinor	0:dcf3c92487ca	605	("pbuf_free(p == NULL) was called.\n"));
idinor	0:dcf3c92487ca	606	return 0;
idinor	0:dcf3c92487ca	607	}
idinor	0:dcf3c92487ca	608	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free(%p)\n", (void *)p));
idinor	0:dcf3c92487ca	609
idinor	0:dcf3c92487ca	610	PERF_START;
idinor	0:dcf3c92487ca	611
idinor	0:dcf3c92487ca	612	LWIP_ASSERT("pbuf_free: sane type",
idinor	0:dcf3c92487ca	613	p->type == PBUF_RAM \|\| p->type == PBUF_ROM \|\|
idinor	0:dcf3c92487ca	614	p->type == PBUF_REF \|\| p->type == PBUF_POOL);
idinor	0:dcf3c92487ca	615
idinor	0:dcf3c92487ca	616	count = 0;
idinor	0:dcf3c92487ca	617	/* de-allocate all consecutive pbufs from the head of the chain that
idinor	0:dcf3c92487ca	618	* obtain a zero reference count after decrementing*/
idinor	0:dcf3c92487ca	619	while (p != NULL) {
idinor	0:dcf3c92487ca	620	u16_t ref;
idinor	0:dcf3c92487ca	621	SYS_ARCH_DECL_PROTECT(old_level);
idinor	0:dcf3c92487ca	622	/* Since decrementing ref cannot be guaranteed to be a single machine operation
idinor	0:dcf3c92487ca	623	* we must protect it. We put the new ref into a local variable to prevent
idinor	0:dcf3c92487ca	624	* further protection. */
idinor	0:dcf3c92487ca	625	SYS_ARCH_PROTECT(old_level);
idinor	0:dcf3c92487ca	626	/* all pbufs in a chain are referenced at least once */
idinor	0:dcf3c92487ca	627	LWIP_ASSERT("pbuf_free: p->ref > 0", p->ref > 0);
idinor	0:dcf3c92487ca	628	/* decrease reference count (number of pointers to pbuf) */
idinor	0:dcf3c92487ca	629	ref = --(p->ref);
idinor	0:dcf3c92487ca	630	SYS_ARCH_UNPROTECT(old_level);
idinor	0:dcf3c92487ca	631	/* this pbuf is no longer referenced to? */
idinor	0:dcf3c92487ca	632	if (ref == 0) {
idinor	0:dcf3c92487ca	633	/* remember next pbuf in chain for next iteration */
idinor	0:dcf3c92487ca	634	q = p->next;
idinor	0:dcf3c92487ca	635	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free: deallocating %p\n", (void *)p));
idinor	0:dcf3c92487ca	636	type = p->type;
idinor	0:dcf3c92487ca	637	#if LWIP_SUPPORT_CUSTOM_PBUF
idinor	0:dcf3c92487ca	638	/* is this a custom pbuf? */
idinor	0:dcf3c92487ca	639	if ((p->flags & PBUF_FLAG_IS_CUSTOM) != 0) {
idinor	0:dcf3c92487ca	640	struct pbuf_custom pc = (struct pbuf_custom)p;
idinor	0:dcf3c92487ca	641	LWIP_ASSERT("pc->custom_free_function != NULL", pc->custom_free_function != NULL);
idinor	0:dcf3c92487ca	642	pc->custom_free_function(p);
idinor	0:dcf3c92487ca	643	} else
idinor	0:dcf3c92487ca	644	#endif /* LWIP_SUPPORT_CUSTOM_PBUF */
idinor	0:dcf3c92487ca	645	{
idinor	0:dcf3c92487ca	646	/* is this a pbuf from the pool? */
idinor	0:dcf3c92487ca	647	if (type == PBUF_POOL) {
idinor	0:dcf3c92487ca	648	memp_free(MEMP_PBUF_POOL, p);
idinor	0:dcf3c92487ca	649	/* is this a ROM or RAM referencing pbuf? */
idinor	0:dcf3c92487ca	650	} else if (type == PBUF_ROM \|\| type == PBUF_REF) {
idinor	0:dcf3c92487ca	651	memp_free(MEMP_PBUF, p);
idinor	0:dcf3c92487ca	652	/* type == PBUF_RAM */
idinor	0:dcf3c92487ca	653	} else {
idinor	0:dcf3c92487ca	654	mem_free(p);
idinor	0:dcf3c92487ca	655	}
idinor	0:dcf3c92487ca	656	}
idinor	0:dcf3c92487ca	657	count++;
idinor	0:dcf3c92487ca	658	/* proceed to next pbuf */
idinor	0:dcf3c92487ca	659	p = q;
idinor	0:dcf3c92487ca	660	/* p->ref > 0, this pbuf is still referenced to */
idinor	0:dcf3c92487ca	661	/* (and so the remaining pbufs in chain as well) */
idinor	0:dcf3c92487ca	662	} else {
idinor	0:dcf3c92487ca	663	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref));
idinor	0:dcf3c92487ca	664	/* stop walking through the chain */
idinor	0:dcf3c92487ca	665	p = NULL;
idinor	0:dcf3c92487ca	666	}
idinor	0:dcf3c92487ca	667	}
idinor	0:dcf3c92487ca	668	PERF_STOP("pbuf_free");
idinor	0:dcf3c92487ca	669	/* return number of de-allocated pbufs */
idinor	0:dcf3c92487ca	670	return count;
idinor	0:dcf3c92487ca	671	}
idinor	0:dcf3c92487ca	672
idinor	0:dcf3c92487ca	673	/**
idinor	0:dcf3c92487ca	674	* Count number of pbufs in a chain
idinor	0:dcf3c92487ca	675	*
idinor	0:dcf3c92487ca	676	* @param p first pbuf of chain
idinor	0:dcf3c92487ca	677	* @return the number of pbufs in a chain
idinor	0:dcf3c92487ca	678	*/
idinor	0:dcf3c92487ca	679
idinor	0:dcf3c92487ca	680	u8_t
idinor	0:dcf3c92487ca	681	pbuf_clen(struct pbuf *p)
idinor	0:dcf3c92487ca	682	{
idinor	0:dcf3c92487ca	683	u8_t len;
idinor	0:dcf3c92487ca	684
idinor	0:dcf3c92487ca	685	len = 0;
idinor	0:dcf3c92487ca	686	while (p != NULL) {
idinor	0:dcf3c92487ca	687	++len;
idinor	0:dcf3c92487ca	688	p = p->next;
idinor	0:dcf3c92487ca	689	}
idinor	0:dcf3c92487ca	690	return len;
idinor	0:dcf3c92487ca	691	}
idinor	0:dcf3c92487ca	692
idinor	0:dcf3c92487ca	693	/**
idinor	0:dcf3c92487ca	694	* Increment the reference count of the pbuf.
idinor	0:dcf3c92487ca	695	*
idinor	0:dcf3c92487ca	696	* @param p pbuf to increase reference counter of
idinor	0:dcf3c92487ca	697	*
idinor	0:dcf3c92487ca	698	*/
idinor	0:dcf3c92487ca	699	void
idinor	0:dcf3c92487ca	700	pbuf_ref(struct pbuf *p)
idinor	0:dcf3c92487ca	701	{
idinor	0:dcf3c92487ca	702	SYS_ARCH_DECL_PROTECT(old_level);
idinor	0:dcf3c92487ca	703	/* pbuf given? */
idinor	0:dcf3c92487ca	704	if (p != NULL) {
idinor	0:dcf3c92487ca	705	SYS_ARCH_PROTECT(old_level);
idinor	0:dcf3c92487ca	706	++(p->ref);
idinor	0:dcf3c92487ca	707	SYS_ARCH_UNPROTECT(old_level);
idinor	0:dcf3c92487ca	708	}
idinor	0:dcf3c92487ca	709	}
idinor	0:dcf3c92487ca	710
idinor	0:dcf3c92487ca	711	/**
idinor	0:dcf3c92487ca	712	* Concatenate two pbufs (each may be a pbuf chain) and take over
idinor	0:dcf3c92487ca	713	* the caller's reference of the tail pbuf.
idinor	0:dcf3c92487ca	714	*
idinor	0:dcf3c92487ca	715	* @note The caller MAY NOT reference the tail pbuf afterwards.
idinor	0:dcf3c92487ca	716	* Use pbuf_chain() for that purpose.
idinor	0:dcf3c92487ca	717	*
idinor	0:dcf3c92487ca	718	* @see pbuf_chain()
idinor	0:dcf3c92487ca	719	*/
idinor	0:dcf3c92487ca	720
idinor	0:dcf3c92487ca	721	void
idinor	0:dcf3c92487ca	722	pbuf_cat(struct pbuf h, struct pbuf t)
idinor	0:dcf3c92487ca	723	{
idinor	0:dcf3c92487ca	724	struct pbuf *p;
idinor	0:dcf3c92487ca	725
idinor	0:dcf3c92487ca	726	LWIP_ERROR("(h != NULL) && (t != NULL) (programmer violates API)",
idinor	0:dcf3c92487ca	727	((h != NULL) && (t != NULL)), return;);
idinor	0:dcf3c92487ca	728
idinor	0:dcf3c92487ca	729	/* proceed to last pbuf of chain */
idinor	0:dcf3c92487ca	730	for (p = h; p->next != NULL; p = p->next) {
idinor	0:dcf3c92487ca	731	/* add total length of second chain to all totals of first chain */
idinor	0:dcf3c92487ca	732	p->tot_len += t->tot_len;
idinor	0:dcf3c92487ca	733	}
idinor	0:dcf3c92487ca	734	/* { p is last pbuf of first h chain, p->next == NULL } */
idinor	0:dcf3c92487ca	735	LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len);
idinor	0:dcf3c92487ca	736	LWIP_ASSERT("p->next == NULL", p->next == NULL);
idinor	0:dcf3c92487ca	737	/* add total length of second chain to last pbuf total of first chain */
idinor	0:dcf3c92487ca	738	p->tot_len += t->tot_len;
idinor	0:dcf3c92487ca	739	/* chain last pbuf of head (p) with first of tail (t) */
idinor	0:dcf3c92487ca	740	p->next = t;
idinor	0:dcf3c92487ca	741	/* p->next now references t, but the caller will drop its reference to t,
idinor	0:dcf3c92487ca	742	* so netto there is no change to the reference count of t.
idinor	0:dcf3c92487ca	743	*/
idinor	0:dcf3c92487ca	744	}
idinor	0:dcf3c92487ca	745
idinor	0:dcf3c92487ca	746	/**
idinor	0:dcf3c92487ca	747	* Chain two pbufs (or pbuf chains) together.
idinor	0:dcf3c92487ca	748	*
idinor	0:dcf3c92487ca	749	* The caller MUST call pbuf_free(t) once it has stopped
idinor	0:dcf3c92487ca	750	* using it. Use pbuf_cat() instead if you no longer use t.
idinor	0:dcf3c92487ca	751	*
idinor	0:dcf3c92487ca	752	* @param h head pbuf (chain)
idinor	0:dcf3c92487ca	753	* @param t tail pbuf (chain)
idinor	0:dcf3c92487ca	754	* @note The pbufs MUST belong to the same packet.
idinor	0:dcf3c92487ca	755	* @note MAY NOT be called on a packet queue.
idinor	0:dcf3c92487ca	756	*
idinor	0:dcf3c92487ca	757	* The ->tot_len fields of all pbufs of the head chain are adjusted.
idinor	0:dcf3c92487ca	758	* The ->next field of the last pbuf of the head chain is adjusted.
idinor	0:dcf3c92487ca	759	* The ->ref field of the first pbuf of the tail chain is adjusted.
idinor	0:dcf3c92487ca	760	*
idinor	0:dcf3c92487ca	761	*/
idinor	0:dcf3c92487ca	762	void
idinor	0:dcf3c92487ca	763	pbuf_chain(struct pbuf h, struct pbuf t)
idinor	0:dcf3c92487ca	764	{
idinor	0:dcf3c92487ca	765	pbuf_cat(h, t);
idinor	0:dcf3c92487ca	766	/* t is now referenced by h */
idinor	0:dcf3c92487ca	767	pbuf_ref(t);
idinor	0:dcf3c92487ca	768	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_chain: %p references %p\n", (void )h, (void )t));
idinor	0:dcf3c92487ca	769	}
idinor	0:dcf3c92487ca	770
idinor	0:dcf3c92487ca	771	/**
idinor	0:dcf3c92487ca	772	* Dechains the first pbuf from its succeeding pbufs in the chain.
idinor	0:dcf3c92487ca	773	*
idinor	0:dcf3c92487ca	774	* Makes p->tot_len field equal to p->len.
idinor	0:dcf3c92487ca	775	* @param p pbuf to dechain
idinor	0:dcf3c92487ca	776	* @return remainder of the pbuf chain, or NULL if it was de-allocated.
idinor	0:dcf3c92487ca	777	* @note May not be called on a packet queue.
idinor	0:dcf3c92487ca	778	*/
idinor	0:dcf3c92487ca	779	struct pbuf *
idinor	0:dcf3c92487ca	780	pbuf_dechain(struct pbuf *p)
idinor	0:dcf3c92487ca	781	{
idinor	0:dcf3c92487ca	782	struct pbuf *q;
idinor	0:dcf3c92487ca	783	u8_t tail_gone = 1;
idinor	0:dcf3c92487ca	784	/* tail */
idinor	0:dcf3c92487ca	785	q = p->next;
idinor	0:dcf3c92487ca	786	/* pbuf has successor in chain? */
idinor	0:dcf3c92487ca	787	if (q != NULL) {
idinor	0:dcf3c92487ca	788	/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
idinor	0:dcf3c92487ca	789	LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len);
idinor	0:dcf3c92487ca	790	/* enforce invariant if assertion is disabled */
idinor	0:dcf3c92487ca	791	q->tot_len = p->tot_len - p->len;
idinor	0:dcf3c92487ca	792	/* decouple pbuf from remainder */
idinor	0:dcf3c92487ca	793	p->next = NULL;
idinor	0:dcf3c92487ca	794	/* total length of pbuf p is its own length only */
idinor	0:dcf3c92487ca	795	p->tot_len = p->len;
idinor	0:dcf3c92487ca	796	/* q is no longer referenced by p, free it */
idinor	0:dcf3c92487ca	797	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_dechain: unreferencing %p\n", (void *)q));
idinor	0:dcf3c92487ca	798	tail_gone = pbuf_free(q);
idinor	0:dcf3c92487ca	799	if (tail_gone > 0) {
idinor	0:dcf3c92487ca	800	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE,
idinor	0:dcf3c92487ca	801	("pbuf_dechain: deallocated %p (as it is no longer referenced)\n", (void *)q));
idinor	0:dcf3c92487ca	802	}
idinor	0:dcf3c92487ca	803	/* return remaining tail or NULL if deallocated */
idinor	0:dcf3c92487ca	804	}
idinor	0:dcf3c92487ca	805	/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
idinor	0:dcf3c92487ca	806	LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len);
idinor	0:dcf3c92487ca	807	return ((tail_gone > 0) ? NULL : q);
idinor	0:dcf3c92487ca	808	}
idinor	0:dcf3c92487ca	809
idinor	0:dcf3c92487ca	810	/**
idinor	0:dcf3c92487ca	811	*
idinor	0:dcf3c92487ca	812	* Create PBUF_RAM copies of pbufs.
idinor	0:dcf3c92487ca	813	*
idinor	0:dcf3c92487ca	814	* Used to queue packets on behalf of the lwIP stack, such as
idinor	0:dcf3c92487ca	815	* ARP based queueing.
idinor	0:dcf3c92487ca	816	*
idinor	0:dcf3c92487ca	817	* @note You MUST explicitly use p = pbuf_take(p);
idinor	0:dcf3c92487ca	818	*
idinor	0:dcf3c92487ca	819	* @note Only one packet is copied, no packet queue!
idinor	0:dcf3c92487ca	820	*
idinor	0:dcf3c92487ca	821	* @param p_to pbuf destination of the copy
idinor	0:dcf3c92487ca	822	* @param p_from pbuf source of the copy
idinor	0:dcf3c92487ca	823	*
idinor	0:dcf3c92487ca	824	* @return ERR_OK if pbuf was copied
idinor	0:dcf3c92487ca	825	* ERR_ARG if one of the pbufs is NULL or p_to is not big
idinor	0:dcf3c92487ca	826	* enough to hold p_from
idinor	0:dcf3c92487ca	827	*/
idinor	0:dcf3c92487ca	828	err_t
idinor	0:dcf3c92487ca	829	pbuf_copy(struct pbuf p_to, struct pbuf p_from)
idinor	0:dcf3c92487ca	830	{
idinor	0:dcf3c92487ca	831	u16_t offset_to=0, offset_from=0, len;
idinor	0:dcf3c92487ca	832
idinor	0:dcf3c92487ca	833	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_copy(%p, %p)\n",
idinor	0:dcf3c92487ca	834	(void)p_to, (void)p_from));
idinor	0:dcf3c92487ca	835
idinor	0:dcf3c92487ca	836	/* is the target big enough to hold the source? */
idinor	0:dcf3c92487ca	837	LWIP_ERROR("pbuf_copy: target not big enough to hold source", ((p_to != NULL) &&
idinor	0:dcf3c92487ca	838	(p_from != NULL) && (p_to->tot_len >= p_from->tot_len)), return ERR_ARG;);
idinor	0:dcf3c92487ca	839
idinor	0:dcf3c92487ca	840	/* iterate through pbuf chain */
idinor	0:dcf3c92487ca	841	do
idinor	0:dcf3c92487ca	842	{
idinor	0:dcf3c92487ca	843	LWIP_ASSERT("p_to != NULL", p_to != NULL);
idinor	0:dcf3c92487ca	844	/* copy one part of the original chain */
idinor	0:dcf3c92487ca	845	if ((p_to->len - offset_to) >= (p_from->len - offset_from)) {
idinor	0:dcf3c92487ca	846	/* complete current p_from fits into current p_to */
idinor	0:dcf3c92487ca	847	len = p_from->len - offset_from;
idinor	0:dcf3c92487ca	848	} else {
idinor	0:dcf3c92487ca	849	/* current p_from does not fit into current p_to */
idinor	0:dcf3c92487ca	850	len = p_to->len - offset_to;
idinor	0:dcf3c92487ca	851	}
idinor	0:dcf3c92487ca	852	MEMCPY((u8_t)p_to->payload + offset_to, (u8_t)p_from->payload + offset_from, len);
idinor	0:dcf3c92487ca	853	offset_to += len;
idinor	0:dcf3c92487ca	854	offset_from += len;
idinor	0:dcf3c92487ca	855	LWIP_ASSERT("offset_to <= p_to->len", offset_to <= p_to->len);
idinor	0:dcf3c92487ca	856	if (offset_to == p_to->len) {
idinor	0:dcf3c92487ca	857	/* on to next p_to (if any) */
idinor	0:dcf3c92487ca	858	offset_to = 0;
idinor	0:dcf3c92487ca	859	p_to = p_to->next;
idinor	0:dcf3c92487ca	860	}
idinor	0:dcf3c92487ca	861	LWIP_ASSERT("offset_from <= p_from->len", offset_from <= p_from->len);
idinor	0:dcf3c92487ca	862	if (offset_from >= p_from->len) {
idinor	0:dcf3c92487ca	863	/* on to next p_from (if any) */
idinor	0:dcf3c92487ca	864	offset_from = 0;
idinor	0:dcf3c92487ca	865	p_from = p_from->next;
idinor	0:dcf3c92487ca	866	}
idinor	0:dcf3c92487ca	867
idinor	0:dcf3c92487ca	868	if((p_from != NULL) && (p_from->len == p_from->tot_len)) {
idinor	0:dcf3c92487ca	869	/* don't copy more than one packet! */
idinor	0:dcf3c92487ca	870	LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
idinor	0:dcf3c92487ca	871	(p_from->next == NULL), return ERR_VAL;);
idinor	0:dcf3c92487ca	872	}
idinor	0:dcf3c92487ca	873	if((p_to != NULL) && (p_to->len == p_to->tot_len)) {
idinor	0:dcf3c92487ca	874	/* don't copy more than one packet! */
idinor	0:dcf3c92487ca	875	LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
idinor	0:dcf3c92487ca	876	(p_to->next == NULL), return ERR_VAL;);
idinor	0:dcf3c92487ca	877	}
idinor	0:dcf3c92487ca	878	} while (p_from);
idinor	0:dcf3c92487ca	879	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_copy: end of chain reached.\n"));
idinor	0:dcf3c92487ca	880	return ERR_OK;
idinor	0:dcf3c92487ca	881	}
idinor	0:dcf3c92487ca	882
idinor	0:dcf3c92487ca	883	/**
idinor	0:dcf3c92487ca	884	* Copy (part of) the contents of a packet buffer
idinor	0:dcf3c92487ca	885	* to an application supplied buffer.
idinor	0:dcf3c92487ca	886	*
idinor	0:dcf3c92487ca	887	* @param buf the pbuf from which to copy data
idinor	0:dcf3c92487ca	888	* @param dataptr the application supplied buffer
idinor	0:dcf3c92487ca	889	* @param len length of data to copy (dataptr must be big enough). No more
idinor	0:dcf3c92487ca	890	* than buf->tot_len will be copied, irrespective of len
idinor	0:dcf3c92487ca	891	* @param offset offset into the packet buffer from where to begin copying len bytes
idinor	0:dcf3c92487ca	892	* @return the number of bytes copied, or 0 on failure
idinor	0:dcf3c92487ca	893	*/
idinor	0:dcf3c92487ca	894	u16_t
idinor	0:dcf3c92487ca	895	pbuf_copy_partial(struct pbuf buf, void dataptr, u16_t len, u16_t offset)
idinor	0:dcf3c92487ca	896	{
idinor	0:dcf3c92487ca	897	struct pbuf *p;
idinor	0:dcf3c92487ca	898	u16_t left;
idinor	0:dcf3c92487ca	899	u16_t buf_copy_len;
idinor	0:dcf3c92487ca	900	u16_t copied_total = 0;
idinor	0:dcf3c92487ca	901
idinor	0:dcf3c92487ca	902	LWIP_ERROR("pbuf_copy_partial: invalid buf", (buf != NULL), return 0;);
idinor	0:dcf3c92487ca	903	LWIP_ERROR("pbuf_copy_partial: invalid dataptr", (dataptr != NULL), return 0;);
idinor	0:dcf3c92487ca	904
idinor	0:dcf3c92487ca	905	left = 0;
idinor	0:dcf3c92487ca	906
idinor	0:dcf3c92487ca	907	if((buf == NULL) \|\| (dataptr == NULL)) {
idinor	0:dcf3c92487ca	908	return 0;
idinor	0:dcf3c92487ca	909	}
idinor	0:dcf3c92487ca	910
idinor	0:dcf3c92487ca	911	/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
idinor	0:dcf3c92487ca	912	for(p = buf; len != 0 && p != NULL; p = p->next) {
idinor	0:dcf3c92487ca	913	if ((offset != 0) && (offset >= p->len)) {
idinor	0:dcf3c92487ca	914	/* don't copy from this buffer -> on to the next */
idinor	0:dcf3c92487ca	915	offset -= p->len;
idinor	0:dcf3c92487ca	916	} else {
idinor	0:dcf3c92487ca	917	/* copy from this buffer. maybe only partially. */
idinor	0:dcf3c92487ca	918	buf_copy_len = p->len - offset;
idinor	0:dcf3c92487ca	919	if (buf_copy_len > len)
idinor	0:dcf3c92487ca	920	buf_copy_len = len;
idinor	0:dcf3c92487ca	921	/* copy the necessary parts of the buffer */
idinor	0:dcf3c92487ca	922	MEMCPY(&((char)dataptr)[left], &((char)p->payload)[offset], buf_copy_len);
idinor	0:dcf3c92487ca	923	copied_total += buf_copy_len;
idinor	0:dcf3c92487ca	924	left += buf_copy_len;
idinor	0:dcf3c92487ca	925	len -= buf_copy_len;
idinor	0:dcf3c92487ca	926	offset = 0;
idinor	0:dcf3c92487ca	927	}
idinor	0:dcf3c92487ca	928	}
idinor	0:dcf3c92487ca	929	return copied_total;
idinor	0:dcf3c92487ca	930	}
idinor	0:dcf3c92487ca	931
idinor	0:dcf3c92487ca	932	/**
idinor	0:dcf3c92487ca	933	* Copy application supplied data into a pbuf.
idinor	0:dcf3c92487ca	934	* This function can only be used to copy the equivalent of buf->tot_len data.
idinor	0:dcf3c92487ca	935	*
idinor	0:dcf3c92487ca	936	* @param buf pbuf to fill with data
idinor	0:dcf3c92487ca	937	* @param dataptr application supplied data buffer
idinor	0:dcf3c92487ca	938	* @param len length of the application supplied data buffer
idinor	0:dcf3c92487ca	939	*
idinor	0:dcf3c92487ca	940	* @return ERR_OK if successful, ERR_MEM if the pbuf is not big enough
idinor	0:dcf3c92487ca	941	*/
idinor	0:dcf3c92487ca	942	err_t
idinor	0:dcf3c92487ca	943	pbuf_take(struct pbuf buf, const void dataptr, u16_t len)
idinor	0:dcf3c92487ca	944	{
idinor	0:dcf3c92487ca	945	struct pbuf *p;
idinor	0:dcf3c92487ca	946	u16_t buf_copy_len;
idinor	0:dcf3c92487ca	947	u16_t total_copy_len = len;
idinor	0:dcf3c92487ca	948	u16_t copied_total = 0;
idinor	0:dcf3c92487ca	949
idinor	0:dcf3c92487ca	950	LWIP_ERROR("pbuf_take: invalid buf", (buf != NULL), return 0;);
idinor	0:dcf3c92487ca	951	LWIP_ERROR("pbuf_take: invalid dataptr", (dataptr != NULL), return 0;);
idinor	0:dcf3c92487ca	952
idinor	0:dcf3c92487ca	953	if ((buf == NULL) \|\| (dataptr == NULL) \|\| (buf->tot_len < len)) {
idinor	0:dcf3c92487ca	954	return ERR_ARG;
idinor	0:dcf3c92487ca	955	}
idinor	0:dcf3c92487ca	956
idinor	0:dcf3c92487ca	957	/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
idinor	0:dcf3c92487ca	958	for(p = buf; total_copy_len != 0; p = p->next) {
idinor	0:dcf3c92487ca	959	LWIP_ASSERT("pbuf_take: invalid pbuf", p != NULL);
idinor	0:dcf3c92487ca	960	buf_copy_len = total_copy_len;
idinor	0:dcf3c92487ca	961	if (buf_copy_len > p->len) {
idinor	0:dcf3c92487ca	962	/* this pbuf cannot hold all remaining data */
idinor	0:dcf3c92487ca	963	buf_copy_len = p->len;
idinor	0:dcf3c92487ca	964	}
idinor	0:dcf3c92487ca	965	/* copy the necessary parts of the buffer */
idinor	0:dcf3c92487ca	966	MEMCPY(p->payload, &((char*)dataptr)[copied_total], buf_copy_len);
idinor	0:dcf3c92487ca	967	total_copy_len -= buf_copy_len;
idinor	0:dcf3c92487ca	968	copied_total += buf_copy_len;
idinor	0:dcf3c92487ca	969	}
idinor	0:dcf3c92487ca	970	LWIP_ASSERT("did not copy all data", total_copy_len == 0 && copied_total == len);
idinor	0:dcf3c92487ca	971	return ERR_OK;
idinor	0:dcf3c92487ca	972	}
idinor	0:dcf3c92487ca	973
idinor	0:dcf3c92487ca	974	/**
idinor	0:dcf3c92487ca	975	* Creates a single pbuf out of a queue of pbufs.
idinor	0:dcf3c92487ca	976	*
idinor	0:dcf3c92487ca	977	* @remark: Either the source pbuf 'p' is freed by this function or the original
idinor	0:dcf3c92487ca	978	* pbuf 'p' is returned, therefore the caller has to check the result!
idinor	0:dcf3c92487ca	979	*
idinor	0:dcf3c92487ca	980	* @param p the source pbuf
idinor	0:dcf3c92487ca	981	* @param layer pbuf_layer of the new pbuf
idinor	0:dcf3c92487ca	982	*
idinor	0:dcf3c92487ca	983	* @return a new, single pbuf (p->next is NULL)
idinor	0:dcf3c92487ca	984	* or the old pbuf if allocation fails
idinor	0:dcf3c92487ca	985	*/
idinor	0:dcf3c92487ca	986	struct pbuf*
idinor	0:dcf3c92487ca	987	pbuf_coalesce(struct pbuf *p, pbuf_layer layer)
idinor	0:dcf3c92487ca	988	{
idinor	0:dcf3c92487ca	989	struct pbuf *q;
idinor	0:dcf3c92487ca	990	err_t err;
idinor	0:dcf3c92487ca	991	if (p->next == NULL) {
idinor	0:dcf3c92487ca	992	return p;
idinor	0:dcf3c92487ca	993	}
idinor	0:dcf3c92487ca	994	q = pbuf_alloc(layer, p->tot_len, PBUF_RAM);
idinor	0:dcf3c92487ca	995	if (q == NULL) {
idinor	0:dcf3c92487ca	996	/* @todo: what do we do now? */
idinor	0:dcf3c92487ca	997	return p;
idinor	0:dcf3c92487ca	998	}
idinor	0:dcf3c92487ca	999	err = pbuf_copy(q, p);
idinor	0:dcf3c92487ca	1000	LWIP_ASSERT("pbuf_copy failed", err == ERR_OK);
idinor	0:dcf3c92487ca	1001	pbuf_free(p);
idinor	0:dcf3c92487ca	1002	return q;
idinor	0:dcf3c92487ca	1003	}
idinor	0:dcf3c92487ca	1004
idinor	0:dcf3c92487ca	1005	#if LWIP_CHECKSUM_ON_COPY
idinor	0:dcf3c92487ca	1006	/**
idinor	0:dcf3c92487ca	1007	* Copies data into a single pbuf (not into a pbuf queue!) and updates
idinor	0:dcf3c92487ca	1008	* the checksum while copying
idinor	0:dcf3c92487ca	1009	*
idinor	0:dcf3c92487ca	1010	* @param p the pbuf to copy data into
idinor	0:dcf3c92487ca	1011	* @param start_offset offset of p->payload where to copy the data to
idinor	0:dcf3c92487ca	1012	* @param dataptr data to copy into the pbuf
idinor	0:dcf3c92487ca	1013	* @param len length of data to copy into the pbuf
idinor	0:dcf3c92487ca	1014	* @param chksum pointer to the checksum which is updated
idinor	0:dcf3c92487ca	1015	* @return ERR_OK if successful, another error if the data does not fit
idinor	0:dcf3c92487ca	1016	* within the (first) pbuf (no pbuf queues!)
idinor	0:dcf3c92487ca	1017	*/
idinor	0:dcf3c92487ca	1018	err_t
idinor	0:dcf3c92487ca	1019	pbuf_fill_chksum(struct pbuf p, u16_t start_offset, const void dataptr,
idinor	0:dcf3c92487ca	1020	u16_t len, u16_t *chksum)
idinor	0:dcf3c92487ca	1021	{
idinor	0:dcf3c92487ca	1022	u32_t acc;
idinor	0:dcf3c92487ca	1023	u16_t copy_chksum;
idinor	0:dcf3c92487ca	1024	char *dst_ptr;
idinor	0:dcf3c92487ca	1025	LWIP_ASSERT("p != NULL", p != NULL);
idinor	0:dcf3c92487ca	1026	LWIP_ASSERT("dataptr != NULL", dataptr != NULL);
idinor	0:dcf3c92487ca	1027	LWIP_ASSERT("chksum != NULL", chksum != NULL);
idinor	0:dcf3c92487ca	1028	LWIP_ASSERT("len != 0", len != 0);
idinor	0:dcf3c92487ca	1029
idinor	0:dcf3c92487ca	1030	if ((start_offset >= p->len) \|\| (start_offset + len > p->len)) {
idinor	0:dcf3c92487ca	1031	return ERR_ARG;
idinor	0:dcf3c92487ca	1032	}
idinor	0:dcf3c92487ca	1033
idinor	0:dcf3c92487ca	1034	dst_ptr = ((char*)p->payload) + start_offset;
idinor	0:dcf3c92487ca	1035	copy_chksum = LWIP_CHKSUM_COPY(dst_ptr, dataptr, len);
idinor	0:dcf3c92487ca	1036	if ((start_offset & 1) != 0) {
idinor	0:dcf3c92487ca	1037	copy_chksum = SWAP_BYTES_IN_WORD(copy_chksum);
idinor	0:dcf3c92487ca	1038	}
idinor	0:dcf3c92487ca	1039	acc = *chksum;
idinor	0:dcf3c92487ca	1040	acc += copy_chksum;
idinor	0:dcf3c92487ca	1041	*chksum = FOLD_U32T(acc);
idinor	0:dcf3c92487ca	1042	return ERR_OK;
idinor	0:dcf3c92487ca	1043	}
idinor	0:dcf3c92487ca	1044	#endif /* LWIP_CHECKSUM_ON_COPY */
idinor	0:dcf3c92487ca	1045
idinor	0:dcf3c92487ca	1046	/** Get one byte from the specified position in a pbuf
idinor	0:dcf3c92487ca	1047	* WARNING: returns zero for offset >= p->tot_len
idinor	0:dcf3c92487ca	1048	*
idinor	0:dcf3c92487ca	1049	* @param p pbuf to parse
idinor	0:dcf3c92487ca	1050	* @param offset offset into p of the byte to return
idinor	0:dcf3c92487ca	1051	* @return byte at an offset into p OR ZERO IF 'offset' >= p->tot_len
idinor	0:dcf3c92487ca	1052	*/
idinor	0:dcf3c92487ca	1053	u8_t
idinor	0:dcf3c92487ca	1054	pbuf_get_at(struct pbuf* p, u16_t offset)
idinor	0:dcf3c92487ca	1055	{
idinor	0:dcf3c92487ca	1056	u16_t copy_from = offset;
idinor	0:dcf3c92487ca	1057	struct pbuf* q = p;
idinor	0:dcf3c92487ca	1058
idinor	0:dcf3c92487ca	1059	/* get the correct pbuf */
idinor	0:dcf3c92487ca	1060	while ((q != NULL) && (q->len <= copy_from)) {
idinor	0:dcf3c92487ca	1061	copy_from -= q->len;
idinor	0:dcf3c92487ca	1062	q = q->next;
idinor	0:dcf3c92487ca	1063	}
idinor	0:dcf3c92487ca	1064	/* return requested data if pbuf is OK */
idinor	0:dcf3c92487ca	1065	if ((q != NULL) && (q->len > copy_from)) {
idinor	0:dcf3c92487ca	1066	return ((u8_t*)q->payload)[copy_from];
idinor	0:dcf3c92487ca	1067	}
idinor	0:dcf3c92487ca	1068	return 0;
idinor	0:dcf3c92487ca	1069	}
idinor	0:dcf3c92487ca	1070
idinor	0:dcf3c92487ca	1071	/** Compare pbuf contents at specified offset with memory s2, both of length n
idinor	0:dcf3c92487ca	1072	*
idinor	0:dcf3c92487ca	1073	* @param p pbuf to compare
idinor	0:dcf3c92487ca	1074	* @param offset offset into p at wich to start comparing
idinor	0:dcf3c92487ca	1075	* @param s2 buffer to compare
idinor	0:dcf3c92487ca	1076	* @param n length of buffer to compare
idinor	0:dcf3c92487ca	1077	* @return zero if equal, nonzero otherwise
idinor	0:dcf3c92487ca	1078	* (0xffff if p is too short, diffoffset+1 otherwise)
idinor	0:dcf3c92487ca	1079	*/
idinor	0:dcf3c92487ca	1080	u16_t
idinor	0:dcf3c92487ca	1081	pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n)
idinor	0:dcf3c92487ca	1082	{
idinor	0:dcf3c92487ca	1083	u16_t start = offset;
idinor	0:dcf3c92487ca	1084	struct pbuf* q = p;
idinor	0:dcf3c92487ca	1085
idinor	0:dcf3c92487ca	1086	/* get the correct pbuf */
idinor	0:dcf3c92487ca	1087	while ((q != NULL) && (q->len <= start)) {
idinor	0:dcf3c92487ca	1088	start -= q->len;
idinor	0:dcf3c92487ca	1089	q = q->next;
idinor	0:dcf3c92487ca	1090	}
idinor	0:dcf3c92487ca	1091	/* return requested data if pbuf is OK */
idinor	0:dcf3c92487ca	1092	if ((q != NULL) && (q->len > start)) {
idinor	0:dcf3c92487ca	1093	u16_t i;
idinor	0:dcf3c92487ca	1094	for(i = 0; i < n; i++) {
idinor	0:dcf3c92487ca	1095	u8_t a = pbuf_get_at(q, start + i);
idinor	0:dcf3c92487ca	1096	u8_t b = ((u8_t*)s2)[i];
idinor	0:dcf3c92487ca	1097	if (a != b) {
idinor	0:dcf3c92487ca	1098	return i+1;
idinor	0:dcf3c92487ca	1099	}
idinor	0:dcf3c92487ca	1100	}
idinor	0:dcf3c92487ca	1101	return 0;
idinor	0:dcf3c92487ca	1102	}
idinor	0:dcf3c92487ca	1103	return 0xffff;
idinor	0:dcf3c92487ca	1104	}
idinor	0:dcf3c92487ca	1105
idinor	0:dcf3c92487ca	1106	/** Find occurrence of mem (with length mem_len) in pbuf p, starting at offset
idinor	0:dcf3c92487ca	1107	* start_offset.
idinor	0:dcf3c92487ca	1108	*
idinor	0:dcf3c92487ca	1109	* @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
idinor	0:dcf3c92487ca	1110	* return value 'not found'
idinor	0:dcf3c92487ca	1111	* @param mem search for the contents of this buffer
idinor	0:dcf3c92487ca	1112	* @param mem_len length of 'mem'
idinor	0:dcf3c92487ca	1113	* @param start_offset offset into p at which to start searching
idinor	0:dcf3c92487ca	1114	* @return 0xFFFF if substr was not found in p or the index where it was found
idinor	0:dcf3c92487ca	1115	*/
idinor	0:dcf3c92487ca	1116	u16_t
idinor	0:dcf3c92487ca	1117	pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset)
idinor	0:dcf3c92487ca	1118	{
idinor	0:dcf3c92487ca	1119	u16_t i;
idinor	0:dcf3c92487ca	1120	u16_t max = p->tot_len - mem_len;
idinor	0:dcf3c92487ca	1121	if (p->tot_len >= mem_len + start_offset) {
idinor	0:dcf3c92487ca	1122	for(i = start_offset; i <= max; ) {
idinor	0:dcf3c92487ca	1123	u16_t plus = pbuf_memcmp(p, i, mem, mem_len);
idinor	0:dcf3c92487ca	1124	if (plus == 0) {
idinor	0:dcf3c92487ca	1125	return i;
idinor	0:dcf3c92487ca	1126	} else {
idinor	0:dcf3c92487ca	1127	i += plus;
idinor	0:dcf3c92487ca	1128	}
idinor	0:dcf3c92487ca	1129	}
idinor	0:dcf3c92487ca	1130	}
idinor	0:dcf3c92487ca	1131	return 0xFFFF;
idinor	0:dcf3c92487ca	1132	}
idinor	0:dcf3c92487ca	1133
idinor	0:dcf3c92487ca	1134	/** Find occurrence of substr with length substr_len in pbuf p, start at offset
idinor	0:dcf3c92487ca	1135	* start_offset
idinor	0:dcf3c92487ca	1136	* WARNING: in contrast to strstr(), this one does not stop at the first \0 in
idinor	0:dcf3c92487ca	1137	* the pbuf/source string!
idinor	0:dcf3c92487ca	1138	*
idinor	0:dcf3c92487ca	1139	* @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
idinor	0:dcf3c92487ca	1140	* return value 'not found'
idinor	0:dcf3c92487ca	1141	* @param substr string to search for in p, maximum length is 0xFFFE
idinor	0:dcf3c92487ca	1142	* @return 0xFFFF if substr was not found in p or the index where it was found
idinor	0:dcf3c92487ca	1143	*/
idinor	0:dcf3c92487ca	1144	u16_t
idinor	0:dcf3c92487ca	1145	pbuf_strstr(struct pbuf* p, const char* substr)
idinor	0:dcf3c92487ca	1146	{
idinor	0:dcf3c92487ca	1147	size_t substr_len;
idinor	0:dcf3c92487ca	1148	if ((substr == NULL) \|\| (substr[0] == 0) \|\| (p->tot_len == 0xFFFF)) {
idinor	0:dcf3c92487ca	1149	return 0xFFFF;
idinor	0:dcf3c92487ca	1150	}
idinor	0:dcf3c92487ca	1151	substr_len = strlen(substr);
idinor	0:dcf3c92487ca	1152	if (substr_len >= 0xFFFF) {
idinor	0:dcf3c92487ca	1153	return 0xFFFF;
idinor	0:dcf3c92487ca	1154	}
idinor	0:dcf3c92487ca	1155	return pbuf_memfind(p, substr, (u16_t)substr_len, 0);
idinor	0:dcf3c92487ca	1156	}

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Type:	Library
Created:	20 Jul 2011
Imports:	35
Forks:	0
Commits:	1
Dependents:	1
Dependencies:	0
Followers:	1

lwip/core/pbuf.c@0:dcf3c92487ca, 2011-07-20 (annotated)

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