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lwip/core/pbuf.c@11:da4498f591ee, 2010-08-05 (annotated)

Committer:: donatien
Date:: Thu Aug 05 15:01:33 2010 +0000
Revision:: 11:da4498f591ee
Parent:: 5:dd63a1e02b1b

Who changed what in which revision?

User	Revision	Line number	New contents of line
donatien	0:632c9925f013	1	/**
donatien	0:632c9925f013	2	* @file
donatien	0:632c9925f013	3	* Packet buffer management
donatien	0:632c9925f013	4	*
donatien	0:632c9925f013	5	* Packets are built from the pbuf data structure. It supports dynamic
donatien	0:632c9925f013	6	* memory allocation for packet contents or can reference externally
donatien	0:632c9925f013	7	* managed packet contents both in RAM and ROM. Quick allocation for
donatien	0:632c9925f013	8	* incoming packets is provided through pools with fixed sized pbufs.
donatien	0:632c9925f013	9	*
donatien	0:632c9925f013	10	* A packet may span over multiple pbufs, chained as a singly linked
donatien	0:632c9925f013	11	* list. This is called a "pbuf chain".
donatien	0:632c9925f013	12	*
donatien	0:632c9925f013	13	* Multiple packets may be queued, also using this singly linked list.
donatien	0:632c9925f013	14	* This is called a "packet queue".
donatien	0:632c9925f013	15	*
donatien	0:632c9925f013	16	* So, a packet queue consists of one or more pbuf chains, each of
donatien	0:632c9925f013	17	* which consist of one or more pbufs. CURRENTLY, PACKET QUEUES ARE
donatien	0:632c9925f013	18	* NOT SUPPORTED!!! Use helper structs to queue multiple packets.
donatien	0:632c9925f013	19	*
donatien	0:632c9925f013	20	* The differences between a pbuf chain and a packet queue are very
donatien	0:632c9925f013	21	* precise but subtle.
donatien	0:632c9925f013	22	*
donatien	0:632c9925f013	23	* The last pbuf of a packet has a ->tot_len field that equals the
donatien	0:632c9925f013	24	* ->len field. It can be found by traversing the list. If the last
donatien	0:632c9925f013	25	* pbuf of a packet has a ->next field other than NULL, more packets
donatien	0:632c9925f013	26	* are on the queue.
donatien	0:632c9925f013	27	*
donatien	0:632c9925f013	28	* Therefore, looping through a pbuf of a single packet, has an
donatien	0:632c9925f013	29	* loop end condition (tot_len == p->len), NOT (next == NULL).
donatien	0:632c9925f013	30	*/
donatien	0:632c9925f013	31
donatien	0:632c9925f013	32	/*
donatien	0:632c9925f013	33	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
donatien	0:632c9925f013	34	* All rights reserved.
donatien	0:632c9925f013	35	*
donatien	0:632c9925f013	36	* Redistribution and use in source and binary forms, with or without modification,
donatien	0:632c9925f013	37	* are permitted provided that the following conditions are met:
donatien	0:632c9925f013	38	*
donatien	0:632c9925f013	39	* 1. Redistributions of source code must retain the above copyright notice,
donatien	0:632c9925f013	40	* this list of conditions and the following disclaimer.
donatien	0:632c9925f013	41	* 2. Redistributions in binary form must reproduce the above copyright notice,
donatien	0:632c9925f013	42	* this list of conditions and the following disclaimer in the documentation
donatien	0:632c9925f013	43	* and/or other materials provided with the distribution.
donatien	0:632c9925f013	44	* 3. The name of the author may not be used to endorse or promote products
donatien	0:632c9925f013	45	* derived from this software without specific prior written permission.
donatien	0:632c9925f013	46	*
donatien	0:632c9925f013	47	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
donatien	0:632c9925f013	48	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
donatien	0:632c9925f013	49	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
donatien	0:632c9925f013	50	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
donatien	0:632c9925f013	51	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
donatien	0:632c9925f013	52	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
donatien	0:632c9925f013	53	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
donatien	0:632c9925f013	54	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
donatien	0:632c9925f013	55	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
donatien	0:632c9925f013	56	* OF SUCH DAMAGE.
donatien	0:632c9925f013	57	*
donatien	0:632c9925f013	58	* This file is part of the lwIP TCP/IP stack.
donatien	0:632c9925f013	59	*
donatien	0:632c9925f013	60	* Author: Adam Dunkels <adam@sics.se>
donatien	0:632c9925f013	61	*
donatien	0:632c9925f013	62	*/
donatien	0:632c9925f013	63
donatien	0:632c9925f013	64	#include "lwip/opt.h"
donatien	0:632c9925f013	65
donatien	0:632c9925f013	66	#include "lwip/stats.h"
donatien	0:632c9925f013	67	#include "lwip/def.h"
donatien	0:632c9925f013	68	#include "lwip/mem.h"
donatien	0:632c9925f013	69	#include "lwip/memp.h"
donatien	0:632c9925f013	70	#include "lwip/pbuf.h"
donatien	0:632c9925f013	71	#include "lwip/sys.h"
donatien	0:632c9925f013	72	#include "arch/perf.h"
donatien	0:632c9925f013	73	#if TCP_QUEUE_OOSEQ
donatien	0:632c9925f013	74	#include "lwip/tcp_impl.h"
donatien	0:632c9925f013	75	#endif
donatien	5:dd63a1e02b1b	76	#if LWIP_CHECKSUM_ON_COPY
donatien	5:dd63a1e02b1b	77	#include "lwip/inet_chksum.h"
donatien	5:dd63a1e02b1b	78	#endif
donatien	0:632c9925f013	79
donatien	0:632c9925f013	80	#include <string.h>
donatien	0:632c9925f013	81
donatien	0:632c9925f013	82	#define SIZEOF_STRUCT_PBUF LWIP_MEM_ALIGN_SIZE(sizeof(struct pbuf))
donatien	0:632c9925f013	83	/* Since the pool is created in memp, PBUF_POOL_BUFSIZE will be automatically
donatien	0:632c9925f013	84	aligned there. Therefore, PBUF_POOL_BUFSIZE_ALIGNED can be used here. */
donatien	0:632c9925f013	85	#define PBUF_POOL_BUFSIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE)
donatien	0:632c9925f013	86
donatien	5:dd63a1e02b1b	87	#if !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS
donatien	0:632c9925f013	88	#define PBUF_POOL_IS_EMPTY()
donatien	5:dd63a1e02b1b	89	#else /* !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS */
donatien	0:632c9925f013	90	/** Define this to 0 to prevent freeing ooseq pbufs when the PBUF_POOL is empty */
donatien	0:632c9925f013	91	#ifndef PBUF_POOL_FREE_OOSEQ
donatien	0:632c9925f013	92	#define PBUF_POOL_FREE_OOSEQ 1
donatien	0:632c9925f013	93	#endif /* PBUF_POOL_FREE_OOSEQ */
donatien	0:632c9925f013	94
donatien	0:632c9925f013	95	#if PBUF_POOL_FREE_OOSEQ
donatien	0:632c9925f013	96	#include "lwip/tcpip.h"
donatien	0:632c9925f013	97	#define PBUF_POOL_IS_EMPTY() pbuf_pool_is_empty()
donatien	0:632c9925f013	98	static u8_t pbuf_free_ooseq_queued;
donatien	0:632c9925f013	99	/**
donatien	0:632c9925f013	100	* Attempt to reclaim some memory from queued out-of-sequence TCP segments
donatien	0:632c9925f013	101	* if we run out of pool pbufs. It's better to give priority to new packets
donatien	0:632c9925f013	102	* if we're running out.
donatien	0:632c9925f013	103	*
donatien	0:632c9925f013	104	* This must be done in the correct thread context therefore this function
donatien	0:632c9925f013	105	* can only be used with NO_SYS=0 and through tcpip_callback.
donatien	0:632c9925f013	106	*/
donatien	0:632c9925f013	107	static void
donatien	0:632c9925f013	108	pbuf_free_ooseq(void* arg)
donatien	0:632c9925f013	109	{
donatien	0:632c9925f013	110	struct tcp_pcb* pcb;
donatien	0:632c9925f013	111	SYS_ARCH_DECL_PROTECT(old_level);
donatien	0:632c9925f013	112	LWIP_UNUSED_ARG(arg);
donatien	0:632c9925f013	113
donatien	0:632c9925f013	114	SYS_ARCH_PROTECT(old_level);
donatien	0:632c9925f013	115	pbuf_free_ooseq_queued = 0;
donatien	0:632c9925f013	116	SYS_ARCH_UNPROTECT(old_level);
donatien	0:632c9925f013	117
donatien	0:632c9925f013	118	for (pcb = tcp_active_pcbs; NULL != pcb; pcb = pcb->next) {
donatien	0:632c9925f013	119	if (NULL != pcb->ooseq) {
donatien	0:632c9925f013	120	/** Free the ooseq pbufs of one PCB only */
donatien	0:632c9925f013	121	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free_ooseq: freeing out-of-sequence pbufs\n"));
donatien	0:632c9925f013	122	tcp_segs_free(pcb->ooseq);
donatien	0:632c9925f013	123	pcb->ooseq = NULL;
donatien	0:632c9925f013	124	return;
donatien	0:632c9925f013	125	}
donatien	0:632c9925f013	126	}
donatien	0:632c9925f013	127	}
donatien	0:632c9925f013	128
donatien	0:632c9925f013	129	/** Queue a call to pbuf_free_ooseq if not already queued. */
donatien	0:632c9925f013	130	static void
donatien	0:632c9925f013	131	pbuf_pool_is_empty(void)
donatien	0:632c9925f013	132	{
donatien	0:632c9925f013	133	u8_t queued;
donatien	0:632c9925f013	134	SYS_ARCH_DECL_PROTECT(old_level);
donatien	0:632c9925f013	135
donatien	0:632c9925f013	136	SYS_ARCH_PROTECT(old_level);
donatien	0:632c9925f013	137	queued = pbuf_free_ooseq_queued;
donatien	0:632c9925f013	138	pbuf_free_ooseq_queued = 1;
donatien	0:632c9925f013	139	SYS_ARCH_UNPROTECT(old_level);
donatien	0:632c9925f013	140
donatien	0:632c9925f013	141	if(!queued) {
donatien	0:632c9925f013	142	/* queue a call to pbuf_free_ooseq if not already queued */
donatien	0:632c9925f013	143	if(tcpip_callback_with_block(pbuf_free_ooseq, NULL, 0) != ERR_OK) {
donatien	0:632c9925f013	144	SYS_ARCH_PROTECT(old_level);
donatien	0:632c9925f013	145	pbuf_free_ooseq_queued = 0;
donatien	0:632c9925f013	146	SYS_ARCH_UNPROTECT(old_level);
donatien	0:632c9925f013	147	}
donatien	0:632c9925f013	148	}
donatien	0:632c9925f013	149	}
donatien	0:632c9925f013	150	#endif /* PBUF_POOL_FREE_OOSEQ */
donatien	5:dd63a1e02b1b	151	#endif /* !LWIP_TCP \|\| !TCP_QUEUE_OOSEQ \|\| NO_SYS */
donatien	0:632c9925f013	152
donatien	0:632c9925f013	153	/**
donatien	0:632c9925f013	154	* Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
donatien	0:632c9925f013	155	*
donatien	0:632c9925f013	156	* The actual memory allocated for the pbuf is determined by the
donatien	0:632c9925f013	157	* layer at which the pbuf is allocated and the requested size
donatien	0:632c9925f013	158	* (from the size parameter).
donatien	0:632c9925f013	159	*
donatien	0:632c9925f013	160	* @param layer flag to define header size
donatien	0:632c9925f013	161	* @param length size of the pbuf's payload
donatien	0:632c9925f013	162	* @param type this parameter decides how and where the pbuf
donatien	0:632c9925f013	163	* should be allocated as follows:
donatien	0:632c9925f013	164	*
donatien	0:632c9925f013	165	* - PBUF_RAM: buffer memory for pbuf is allocated as one large
donatien	0:632c9925f013	166	* chunk. This includes protocol headers as well.
donatien	0:632c9925f013	167	* - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
donatien	0:632c9925f013	168	* protocol headers. Additional headers must be prepended
donatien	0:632c9925f013	169	* by allocating another pbuf and chain in to the front of
donatien	0:632c9925f013	170	* the ROM pbuf. It is assumed that the memory used is really
donatien	0:632c9925f013	171	* similar to ROM in that it is immutable and will not be
donatien	0:632c9925f013	172	* changed. Memory which is dynamic should generally not
donatien	0:632c9925f013	173	* be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
donatien	0:632c9925f013	174	* - PBUF_REF: no buffer memory is allocated for the pbuf, even for
donatien	0:632c9925f013	175	* protocol headers. It is assumed that the pbuf is only
donatien	0:632c9925f013	176	* being used in a single thread. If the pbuf gets queued,
donatien	0:632c9925f013	177	* then pbuf_take should be called to copy the buffer.
donatien	0:632c9925f013	178	* - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
donatien	0:632c9925f013	179	* the pbuf pool that is allocated during pbuf_init().
donatien	0:632c9925f013	180	*
donatien	0:632c9925f013	181	* @return the allocated pbuf. If multiple pbufs where allocated, this
donatien	0:632c9925f013	182	* is the first pbuf of a pbuf chain.
donatien	0:632c9925f013	183	*/
donatien	0:632c9925f013	184	struct pbuf *
donatien	0:632c9925f013	185	pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
donatien	0:632c9925f013	186	{
donatien	0:632c9925f013	187	struct pbuf p, q, *r;
donatien	0:632c9925f013	188	u16_t offset;
donatien	0:632c9925f013	189	s32_t rem_len; /* remaining length */
donatien	0:632c9925f013	190	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
donatien	0:632c9925f013	191
donatien	0:632c9925f013	192	/* determine header offset */
donatien	0:632c9925f013	193	offset = 0;
donatien	0:632c9925f013	194	switch (layer) {
donatien	0:632c9925f013	195	case PBUF_TRANSPORT:
donatien	0:632c9925f013	196	/* add room for transport (often TCP) layer header */
donatien	0:632c9925f013	197	offset += PBUF_TRANSPORT_HLEN;
donatien	0:632c9925f013	198	/* FALLTHROUGH */
donatien	0:632c9925f013	199	case PBUF_IP:
donatien	0:632c9925f013	200	/* add room for IP layer header */
donatien	0:632c9925f013	201	offset += PBUF_IP_HLEN;
donatien	0:632c9925f013	202	/* FALLTHROUGH */
donatien	0:632c9925f013	203	case PBUF_LINK:
donatien	0:632c9925f013	204	/* add room for link layer header */
donatien	0:632c9925f013	205	offset += PBUF_LINK_HLEN;
donatien	0:632c9925f013	206	break;
donatien	0:632c9925f013	207	case PBUF_RAW:
donatien	0:632c9925f013	208	break;
donatien	0:632c9925f013	209	default:
donatien	0:632c9925f013	210	LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0);
donatien	0:632c9925f013	211	return NULL;
donatien	0:632c9925f013	212	}
donatien	0:632c9925f013	213
donatien	0:632c9925f013	214	switch (type) {
donatien	0:632c9925f013	215	case PBUF_POOL:
donatien	0:632c9925f013	216	/* allocate head of pbuf chain into p */
donatien	0:632c9925f013	217	p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
donatien	0:632c9925f013	218	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
donatien	0:632c9925f013	219	if (p == NULL) {
donatien	0:632c9925f013	220	PBUF_POOL_IS_EMPTY();
donatien	0:632c9925f013	221	return NULL;
donatien	0:632c9925f013	222	}
donatien	0:632c9925f013	223	p->type = type;
donatien	0:632c9925f013	224	p->next = NULL;
donatien	0:632c9925f013	225
donatien	0:632c9925f013	226	/* make the payload pointer point 'offset' bytes into pbuf data memory */
donatien	0:632c9925f013	227	p->payload = LWIP_MEM_ALIGN((void )((u8_t )p + (SIZEOF_STRUCT_PBUF + offset)));
donatien	0:632c9925f013	228	LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned",
donatien	0:632c9925f013	229	((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
donatien	0:632c9925f013	230	/* the total length of the pbuf chain is the requested size */
donatien	0:632c9925f013	231	p->tot_len = length;
donatien	0:632c9925f013	232	/* set the length of the first pbuf in the chain */
donatien	0:632c9925f013	233	p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
donatien	0:632c9925f013	234	LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
donatien	0:632c9925f013	235	((u8_t*)p->payload + p->len <=
donatien	0:632c9925f013	236	(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
donatien	0:632c9925f013	237	LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT",
donatien	0:632c9925f013	238	(PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 );
donatien	0:632c9925f013	239	/* set reference count (needed here in case we fail) */
donatien	0:632c9925f013	240	p->ref = 1;
donatien	0:632c9925f013	241
donatien	0:632c9925f013	242	/* now allocate the tail of the pbuf chain */
donatien	0:632c9925f013	243
donatien	0:632c9925f013	244	/* remember first pbuf for linkage in next iteration */
donatien	0:632c9925f013	245	r = p;
donatien	0:632c9925f013	246	/* remaining length to be allocated */
donatien	0:632c9925f013	247	rem_len = length - p->len;
donatien	0:632c9925f013	248	/* any remaining pbufs to be allocated? */
donatien	0:632c9925f013	249	while (rem_len > 0) {
donatien	0:632c9925f013	250	q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
donatien	0:632c9925f013	251	if (q == NULL) {
donatien	0:632c9925f013	252	PBUF_POOL_IS_EMPTY();
donatien	0:632c9925f013	253	/* free chain so far allocated */
donatien	0:632c9925f013	254	pbuf_free(p);
donatien	0:632c9925f013	255	/* bail out unsuccesfully */
donatien	0:632c9925f013	256	return NULL;
donatien	0:632c9925f013	257	}
donatien	0:632c9925f013	258	q->type = type;
donatien	0:632c9925f013	259	q->flags = 0;
donatien	0:632c9925f013	260	q->next = NULL;
donatien	0:632c9925f013	261	/* make previous pbuf point to this pbuf */
donatien	0:632c9925f013	262	r->next = q;
donatien	0:632c9925f013	263	/* set total length of this pbuf and next in chain */
donatien	0:632c9925f013	264	LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff);
donatien	0:632c9925f013	265	q->tot_len = (u16_t)rem_len;
donatien	0:632c9925f013	266	/* this pbuf length is pool size, unless smaller sized tail */
donatien	0:632c9925f013	267	q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
donatien	0:632c9925f013	268	q->payload = (void )((u8_t )q + SIZEOF_STRUCT_PBUF);
donatien	0:632c9925f013	269	LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
donatien	0:632c9925f013	270	((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
donatien	0:632c9925f013	271	LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
donatien	0:632c9925f013	272	((u8_t*)p->payload + p->len <=
donatien	0:632c9925f013	273	(u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
donatien	0:632c9925f013	274	q->ref = 1;
donatien	0:632c9925f013	275	/* calculate remaining length to be allocated */
donatien	0:632c9925f013	276	rem_len -= q->len;
donatien	0:632c9925f013	277	/* remember this pbuf for linkage in next iteration */
donatien	0:632c9925f013	278	r = q;
donatien	0:632c9925f013	279	}
donatien	0:632c9925f013	280	/* end of chain */
donatien	0:632c9925f013	281	/r->next = NULL;/
donatien	0:632c9925f013	282
donatien	0:632c9925f013	283	break;
donatien	0:632c9925f013	284	case PBUF_RAM:
donatien	0:632c9925f013	285	/* If pbuf is to be allocated in RAM, allocate memory for it. */
donatien	0:632c9925f013	286	p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
donatien	0:632c9925f013	287	if (p == NULL) {
donatien	0:632c9925f013	288	return NULL;
donatien	0:632c9925f013	289	}
donatien	0:632c9925f013	290	/* Set up internal structure of the pbuf. */
donatien	0:632c9925f013	291	p->payload = LWIP_MEM_ALIGN((void )((u8_t )p + SIZEOF_STRUCT_PBUF + offset));
donatien	0:632c9925f013	292	p->len = p->tot_len = length;
donatien	0:632c9925f013	293	p->next = NULL;
donatien	0:632c9925f013	294	p->type = type;
donatien	0:632c9925f013	295
donatien	0:632c9925f013	296	LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
donatien	0:632c9925f013	297	((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
donatien	0:632c9925f013	298	break;
donatien	0:632c9925f013	299	/* pbuf references existing (non-volatile static constant) ROM payload? */
donatien	0:632c9925f013	300	case PBUF_ROM:
donatien	0:632c9925f013	301	/* pbuf references existing (externally allocated) RAM payload? */
donatien	0:632c9925f013	302	case PBUF_REF:
donatien	0:632c9925f013	303	/* only allocate memory for the pbuf structure */
donatien	0:632c9925f013	304	p = (struct pbuf *)memp_malloc(MEMP_PBUF);
donatien	0:632c9925f013	305	if (p == NULL) {
donatien	0:632c9925f013	306	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
donatien	0:632c9925f013	307	("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n",
donatien	0:632c9925f013	308	(type == PBUF_ROM) ? "ROM" : "REF"));
donatien	0:632c9925f013	309	return NULL;
donatien	0:632c9925f013	310	}
donatien	0:632c9925f013	311	/* caller must set this field properly, afterwards */
donatien	0:632c9925f013	312	p->payload = NULL;
donatien	0:632c9925f013	313	p->len = p->tot_len = length;
donatien	0:632c9925f013	314	p->next = NULL;
donatien	0:632c9925f013	315	p->type = type;
donatien	0:632c9925f013	316	break;
donatien	0:632c9925f013	317	default:
donatien	0:632c9925f013	318	LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
donatien	0:632c9925f013	319	return NULL;
donatien	0:632c9925f013	320	}
donatien	0:632c9925f013	321	/* set reference count */
donatien	0:632c9925f013	322	p->ref = 1;
donatien	0:632c9925f013	323	/* set flags */
donatien	0:632c9925f013	324	p->flags = 0;
donatien	0:632c9925f013	325	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
donatien	0:632c9925f013	326	return p;
donatien	0:632c9925f013	327	}
donatien	0:632c9925f013	328
donatien	5:dd63a1e02b1b	329	#if LWIP_SUPPORT_CUSTOM_PBUF
donatien	5:dd63a1e02b1b	330	/** Initialize a custom pbuf (already allocated).
donatien	5:dd63a1e02b1b	331	*
donatien	5:dd63a1e02b1b	332	* @param layer flag to define header size
donatien	5:dd63a1e02b1b	333	* @param length size of the pbuf's payload
donatien	5:dd63a1e02b1b	334	* @param type type of the pbuf (only used to treat the pbuf accordingly, as
donatien	5:dd63a1e02b1b	335	* this function allocates no memory)
donatien	5:dd63a1e02b1b	336	* @param p pointer to the custom pbuf to initialize (already allocated)
donatien	5:dd63a1e02b1b	337	* @param payload_mem pointer to the buffer that is used for payload and headers,
donatien	5:dd63a1e02b1b	338	* must be at least big enough to hold 'length' plus the header size,
donatien	5:dd63a1e02b1b	339	* may be NULL if set later
donatien	5:dd63a1e02b1b	340	* @param payload_mem_len the size of the 'payload_mem' buffer, must be at least
donatien	5:dd63a1e02b1b	341	* big enough to hold 'length' plus the header size
donatien	5:dd63a1e02b1b	342	*/
donatien	5:dd63a1e02b1b	343	struct pbuf*
donatien	5:dd63a1e02b1b	344	pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type, struct pbuf_custom *p,
donatien	5:dd63a1e02b1b	345	void *payload_mem, u16_t payload_mem_len)
donatien	5:dd63a1e02b1b	346	{
donatien	5:dd63a1e02b1b	347	u16_t offset;
donatien	5:dd63a1e02b1b	348	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_alloced_custom(length=%"U16_F")\n", length));
donatien	5:dd63a1e02b1b	349
donatien	5:dd63a1e02b1b	350	/* determine header offset */
donatien	5:dd63a1e02b1b	351	offset = 0;
donatien	5:dd63a1e02b1b	352	switch (l) {
donatien	5:dd63a1e02b1b	353	case PBUF_TRANSPORT:
donatien	5:dd63a1e02b1b	354	/* add room for transport (often TCP) layer header */
donatien	5:dd63a1e02b1b	355	offset += PBUF_TRANSPORT_HLEN;
donatien	5:dd63a1e02b1b	356	/* FALLTHROUGH */
donatien	5:dd63a1e02b1b	357	case PBUF_IP:
donatien	5:dd63a1e02b1b	358	/* add room for IP layer header */
donatien	5:dd63a1e02b1b	359	offset += PBUF_IP_HLEN;
donatien	5:dd63a1e02b1b	360	/* FALLTHROUGH */
donatien	5:dd63a1e02b1b	361	case PBUF_LINK:
donatien	5:dd63a1e02b1b	362	/* add room for link layer header */
donatien	5:dd63a1e02b1b	363	offset += PBUF_LINK_HLEN;
donatien	5:dd63a1e02b1b	364	break;
donatien	5:dd63a1e02b1b	365	case PBUF_RAW:
donatien	5:dd63a1e02b1b	366	break;
donatien	5:dd63a1e02b1b	367	default:
donatien	5:dd63a1e02b1b	368	LWIP_ASSERT("pbuf_alloced_custom: bad pbuf layer", 0);
donatien	5:dd63a1e02b1b	369	return NULL;
donatien	5:dd63a1e02b1b	370	}
donatien	5:dd63a1e02b1b	371
donatien	5:dd63a1e02b1b	372	if (LWIP_MEM_ALIGN_SIZE(offset) + length < payload_mem_len) {
donatien	5:dd63a1e02b1b	373	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_WARNING, ("pbuf_alloced_custom(length=%"U16_F") buffer too short\n", length));
donatien	5:dd63a1e02b1b	374	return NULL;
donatien	5:dd63a1e02b1b	375	}
donatien	5:dd63a1e02b1b	376
donatien	5:dd63a1e02b1b	377	p->pbuf.next = NULL;
donatien	5:dd63a1e02b1b	378	if (payload_mem != NULL) {
donatien	5:dd63a1e02b1b	379	p->pbuf.payload = LWIP_MEM_ALIGN((void )((u8_t )payload_mem + offset));
donatien	5:dd63a1e02b1b	380	} else {
donatien	5:dd63a1e02b1b	381	p->pbuf.payload = NULL;
donatien	5:dd63a1e02b1b	382	}
donatien	5:dd63a1e02b1b	383	p->pbuf.flags = PBUF_FLAG_IS_CUSTOM;
donatien	5:dd63a1e02b1b	384	p->pbuf.len = p->pbuf.tot_len = length;
donatien	5:dd63a1e02b1b	385	p->pbuf.type = type;
donatien	5:dd63a1e02b1b	386	p->pbuf.ref = 1;
donatien	5:dd63a1e02b1b	387	return &p->pbuf;
donatien	5:dd63a1e02b1b	388	}
donatien	5:dd63a1e02b1b	389	#endif /* LWIP_SUPPORT_CUSTOM_PBUF */
donatien	0:632c9925f013	390
donatien	0:632c9925f013	391	/**
donatien	0:632c9925f013	392	* Shrink a pbuf chain to a desired length.
donatien	0:632c9925f013	393	*
donatien	0:632c9925f013	394	* @param p pbuf to shrink.
donatien	0:632c9925f013	395	* @param new_len desired new length of pbuf chain
donatien	0:632c9925f013	396	*
donatien	0:632c9925f013	397	* Depending on the desired length, the first few pbufs in a chain might
donatien	0:632c9925f013	398	* be skipped and left unchanged. The new last pbuf in the chain will be
donatien	0:632c9925f013	399	* resized, and any remaining pbufs will be freed.
donatien	0:632c9925f013	400	*
donatien	0:632c9925f013	401	* @note If the pbuf is ROM/REF, only the ->tot_len and ->len fields are adjusted.
donatien	0:632c9925f013	402	* @note May not be called on a packet queue.
donatien	0:632c9925f013	403	*
donatien	0:632c9925f013	404	* @note Despite its name, pbuf_realloc cannot grow the size of a pbuf (chain).
donatien	0:632c9925f013	405	*/
donatien	0:632c9925f013	406	void
donatien	0:632c9925f013	407	pbuf_realloc(struct pbuf *p, u16_t new_len)
donatien	0:632c9925f013	408	{
donatien	0:632c9925f013	409	struct pbuf *q;
donatien	0:632c9925f013	410	u16_t rem_len; /* remaining length */
donatien	0:632c9925f013	411	s32_t grow;
donatien	0:632c9925f013	412
donatien	0:632c9925f013	413	LWIP_ASSERT("pbuf_realloc: p != NULL", p != NULL);
donatien	0:632c9925f013	414	LWIP_ASSERT("pbuf_realloc: sane p->type", p->type == PBUF_POOL \|\|
donatien	0:632c9925f013	415	p->type == PBUF_ROM \|\|
donatien	0:632c9925f013	416	p->type == PBUF_RAM \|\|
donatien	0:632c9925f013	417	p->type == PBUF_REF);
donatien	0:632c9925f013	418
donatien	0:632c9925f013	419	/* desired length larger than current length? */
donatien	0:632c9925f013	420	if (new_len >= p->tot_len) {
donatien	0:632c9925f013	421	/* enlarging not yet supported */
donatien	0:632c9925f013	422	return;
donatien	0:632c9925f013	423	}
donatien	0:632c9925f013	424
donatien	0:632c9925f013	425	/* the pbuf chain grows by (new_len - p->tot_len) bytes
donatien	0:632c9925f013	426	* (which may be negative in case of shrinking) */
donatien	0:632c9925f013	427	grow = new_len - p->tot_len;
donatien	0:632c9925f013	428
donatien	0:632c9925f013	429	/* first, step over any pbufs that should remain in the chain */
donatien	0:632c9925f013	430	rem_len = new_len;
donatien	0:632c9925f013	431	q = p;
donatien	0:632c9925f013	432	/* should this pbuf be kept? */
donatien	0:632c9925f013	433	while (rem_len > q->len) {
donatien	0:632c9925f013	434	/* decrease remaining length by pbuf length */
donatien	0:632c9925f013	435	rem_len -= q->len;
donatien	0:632c9925f013	436	/* decrease total length indicator */
donatien	0:632c9925f013	437	LWIP_ASSERT("grow < max_u16_t", grow < 0xffff);
donatien	0:632c9925f013	438	q->tot_len += (u16_t)grow;
donatien	0:632c9925f013	439	/* proceed to next pbuf in chain */
donatien	0:632c9925f013	440	q = q->next;
donatien	0:632c9925f013	441	LWIP_ASSERT("pbuf_realloc: q != NULL", q != NULL);
donatien	0:632c9925f013	442	}
donatien	0:632c9925f013	443	/* we have now reached the new last pbuf (in q) */
donatien	0:632c9925f013	444	/* rem_len == desired length for pbuf q */
donatien	0:632c9925f013	445
donatien	0:632c9925f013	446	/* shrink allocated memory for PBUF_RAM */
donatien	0:632c9925f013	447	/* (other types merely adjust their length fields */
donatien	0:632c9925f013	448	if ((q->type == PBUF_RAM) && (rem_len != q->len)) {
donatien	0:632c9925f013	449	/* reallocate and adjust the length of the pbuf that will be split */
donatien	0:632c9925f013	450	q = (struct pbuf )mem_trim(q, (u16_t)((u8_t )q->payload - (u8_t *)q) + rem_len);
donatien	0:632c9925f013	451	LWIP_ASSERT("mem_trim returned q == NULL", q != NULL);
donatien	0:632c9925f013	452	}
donatien	0:632c9925f013	453	/* adjust length fields for new last pbuf */
donatien	0:632c9925f013	454	q->len = rem_len;
donatien	0:632c9925f013	455	q->tot_len = q->len;
donatien	0:632c9925f013	456
donatien	0:632c9925f013	457	/* any remaining pbufs in chain? */
donatien	0:632c9925f013	458	if (q->next != NULL) {
donatien	0:632c9925f013	459	/* free remaining pbufs in chain */
donatien	0:632c9925f013	460	pbuf_free(q->next);
donatien	0:632c9925f013	461	}
donatien	0:632c9925f013	462	/* q is last packet in chain */
donatien	0:632c9925f013	463	q->next = NULL;
donatien	0:632c9925f013	464
donatien	0:632c9925f013	465	}
donatien	0:632c9925f013	466
donatien	0:632c9925f013	467	/**
donatien	0:632c9925f013	468	* Adjusts the payload pointer to hide or reveal headers in the payload.
donatien	0:632c9925f013	469	*
donatien	0:632c9925f013	470	* Adjusts the ->payload pointer so that space for a header
donatien	0:632c9925f013	471	* (dis)appears in the pbuf payload.
donatien	0:632c9925f013	472	*
donatien	0:632c9925f013	473	* The ->payload, ->tot_len and ->len fields are adjusted.
donatien	0:632c9925f013	474	*
donatien	0:632c9925f013	475	* @param p pbuf to change the header size.
donatien	0:632c9925f013	476	* @param header_size_increment Number of bytes to increment header size which
donatien	0:632c9925f013	477	* increases the size of the pbuf. New space is on the front.
donatien	0:632c9925f013	478	* (Using a negative value decreases the header size.)
donatien	0:632c9925f013	479	* If hdr_size_inc is 0, this function does nothing and returns succesful.
donatien	0:632c9925f013	480	*
donatien	0:632c9925f013	481	* PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so
donatien	0:632c9925f013	482	* the call will fail. A check is made that the increase in header size does
donatien	0:632c9925f013	483	* not move the payload pointer in front of the start of the buffer.
donatien	0:632c9925f013	484	* @return non-zero on failure, zero on success.
donatien	0:632c9925f013	485	*
donatien	0:632c9925f013	486	*/
donatien	0:632c9925f013	487	u8_t
donatien	0:632c9925f013	488	pbuf_header(struct pbuf *p, s16_t header_size_increment)
donatien	0:632c9925f013	489	{
donatien	0:632c9925f013	490	u16_t type;
donatien	0:632c9925f013	491	void *payload;
donatien	0:632c9925f013	492	u16_t increment_magnitude;
donatien	0:632c9925f013	493
donatien	0:632c9925f013	494	LWIP_ASSERT("p != NULL", p != NULL);
donatien	5:dd63a1e02b1b	495	if ((header_size_increment == 0) \|\| (p == NULL)) {
donatien	0:632c9925f013	496	return 0;
donatien	5:dd63a1e02b1b	497	}
donatien	0:632c9925f013	498
donatien	0:632c9925f013	499	if (header_size_increment < 0){
donatien	0:632c9925f013	500	increment_magnitude = -header_size_increment;
donatien	0:632c9925f013	501	/* Check that we aren't going to move off the end of the pbuf */
donatien	0:632c9925f013	502	LWIP_ERROR("increment_magnitude <= p->len", (increment_magnitude <= p->len), return 1;);
donatien	0:632c9925f013	503	} else {
donatien	0:632c9925f013	504	increment_magnitude = header_size_increment;
donatien	0:632c9925f013	505	#if 0
donatien	0:632c9925f013	506	/* Can't assert these as some callers speculatively call
donatien	0:632c9925f013	507	pbuf_header() to see if it's OK. Will return 1 below instead. */
donatien	0:632c9925f013	508	/* Check that we've got the correct type of pbuf to work with */
donatien	0:632c9925f013	509	LWIP_ASSERT("p->type == PBUF_RAM \|\| p->type == PBUF_POOL",
donatien	0:632c9925f013	510	p->type == PBUF_RAM \|\| p->type == PBUF_POOL);
donatien	0:632c9925f013	511	/* Check that we aren't going to move off the beginning of the pbuf */
donatien	0:632c9925f013	512	LWIP_ASSERT("p->payload - increment_magnitude >= p + SIZEOF_STRUCT_PBUF",
donatien	0:632c9925f013	513	(u8_t )p->payload - increment_magnitude >= (u8_t )p + SIZEOF_STRUCT_PBUF);
donatien	0:632c9925f013	514	#endif
donatien	0:632c9925f013	515	}
donatien	0:632c9925f013	516
donatien	0:632c9925f013	517	type = p->type;
donatien	0:632c9925f013	518	/* remember current payload pointer */
donatien	0:632c9925f013	519	payload = p->payload;
donatien	0:632c9925f013	520
donatien	0:632c9925f013	521	/* pbuf types containing payloads? */
donatien	0:632c9925f013	522	if (type == PBUF_RAM \|\| type == PBUF_POOL) {
donatien	0:632c9925f013	523	/* set new payload pointer */
donatien	0:632c9925f013	524	p->payload = (u8_t *)p->payload - header_size_increment;
donatien	0:632c9925f013	525	/* boundary check fails? */
donatien	0:632c9925f013	526	if ((u8_t )p->payload < (u8_t )p + SIZEOF_STRUCT_PBUF) {
donatien	0:632c9925f013	527	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
donatien	0:632c9925f013	528	("pbuf_header: failed as %p < %p (not enough space for new header size)\n",
donatien	0:632c9925f013	529	(void )p->payload, (void )(p + 1)));
donatien	0:632c9925f013	530	/* restore old payload pointer */
donatien	0:632c9925f013	531	p->payload = payload;
donatien	0:632c9925f013	532	/* bail out unsuccesfully */
donatien	0:632c9925f013	533	return 1;
donatien	0:632c9925f013	534	}
donatien	0:632c9925f013	535	/* pbuf types refering to external payloads? */
donatien	0:632c9925f013	536	} else if (type == PBUF_REF \|\| type == PBUF_ROM) {
donatien	0:632c9925f013	537	/* hide a header in the payload? */
donatien	0:632c9925f013	538	if ((header_size_increment < 0) && (increment_magnitude <= p->len)) {
donatien	0:632c9925f013	539	/* increase payload pointer */
donatien	0:632c9925f013	540	p->payload = (u8_t *)p->payload - header_size_increment;
donatien	0:632c9925f013	541	} else {
donatien	0:632c9925f013	542	/* cannot expand payload to front (yet!)
donatien	0:632c9925f013	543	* bail out unsuccesfully */
donatien	0:632c9925f013	544	return 1;
donatien	0:632c9925f013	545	}
donatien	5:dd63a1e02b1b	546	} else {
donatien	0:632c9925f013	547	/* Unknown type */
donatien	0:632c9925f013	548	LWIP_ASSERT("bad pbuf type", 0);
donatien	0:632c9925f013	549	return 1;
donatien	0:632c9925f013	550	}
donatien	0:632c9925f013	551	/* modify pbuf length fields */
donatien	0:632c9925f013	552	p->len += header_size_increment;
donatien	0:632c9925f013	553	p->tot_len += header_size_increment;
donatien	0:632c9925f013	554
donatien	0:632c9925f013	555	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_header: old %p new %p (%"S16_F")\n",
donatien	0:632c9925f013	556	(void )payload, (void )p->payload, header_size_increment));
donatien	0:632c9925f013	557
donatien	0:632c9925f013	558	return 0;
donatien	0:632c9925f013	559	}
donatien	0:632c9925f013	560
donatien	0:632c9925f013	561	/**
donatien	0:632c9925f013	562	* Dereference a pbuf chain or queue and deallocate any no-longer-used
donatien	0:632c9925f013	563	* pbufs at the head of this chain or queue.
donatien	0:632c9925f013	564	*
donatien	0:632c9925f013	565	* Decrements the pbuf reference count. If it reaches zero, the pbuf is
donatien	0:632c9925f013	566	* deallocated.
donatien	0:632c9925f013	567	*
donatien	0:632c9925f013	568	* For a pbuf chain, this is repeated for each pbuf in the chain,
donatien	0:632c9925f013	569	* up to the first pbuf which has a non-zero reference count after
donatien	0:632c9925f013	570	* decrementing. So, when all reference counts are one, the whole
donatien	0:632c9925f013	571	* chain is free'd.
donatien	0:632c9925f013	572	*
donatien	0:632c9925f013	573	* @param p The pbuf (chain) to be dereferenced.
donatien	0:632c9925f013	574	*
donatien	0:632c9925f013	575	* @return the number of pbufs that were de-allocated
donatien	0:632c9925f013	576	* from the head of the chain.
donatien	0:632c9925f013	577	*
donatien	0:632c9925f013	578	* @note MUST NOT be called on a packet queue (Not verified to work yet).
donatien	0:632c9925f013	579	* @note the reference counter of a pbuf equals the number of pointers
donatien	0:632c9925f013	580	* that refer to the pbuf (or into the pbuf).
donatien	0:632c9925f013	581	*
donatien	0:632c9925f013	582	* @internal examples:
donatien	0:632c9925f013	583	*
donatien	0:632c9925f013	584	* Assuming existing chains a->b->c with the following reference
donatien	0:632c9925f013	585	* counts, calling pbuf_free(a) results in:
donatien	0:632c9925f013	586	*
donatien	0:632c9925f013	587	* 1->2->3 becomes ...1->3
donatien	0:632c9925f013	588	* 3->3->3 becomes 2->3->3
donatien	0:632c9925f013	589	* 1->1->2 becomes ......1
donatien	0:632c9925f013	590	* 2->1->1 becomes 1->1->1
donatien	0:632c9925f013	591	* 1->1->1 becomes .......
donatien	0:632c9925f013	592	*
donatien	0:632c9925f013	593	*/
donatien	0:632c9925f013	594	u8_t
donatien	0:632c9925f013	595	pbuf_free(struct pbuf *p)
donatien	0:632c9925f013	596	{
donatien	0:632c9925f013	597	u16_t type;
donatien	0:632c9925f013	598	struct pbuf *q;
donatien	0:632c9925f013	599	u8_t count;
donatien	0:632c9925f013	600
donatien	0:632c9925f013	601	if (p == NULL) {
donatien	0:632c9925f013	602	LWIP_ASSERT("p != NULL", p != NULL);
donatien	0:632c9925f013	603	/* if assertions are disabled, proceed with debug output */
donatien	0:632c9925f013	604	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
donatien	0:632c9925f013	605	("pbuf_free(p == NULL) was called.\n"));
donatien	0:632c9925f013	606	return 0;
donatien	0:632c9925f013	607	}
donatien	0:632c9925f013	608	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free(%p)\n", (void *)p));
donatien	0:632c9925f013	609
donatien	0:632c9925f013	610	PERF_START;
donatien	0:632c9925f013	611
donatien	0:632c9925f013	612	LWIP_ASSERT("pbuf_free: sane type",
donatien	0:632c9925f013	613	p->type == PBUF_RAM \|\| p->type == PBUF_ROM \|\|
donatien	0:632c9925f013	614	p->type == PBUF_REF \|\| p->type == PBUF_POOL);
donatien	0:632c9925f013	615
donatien	0:632c9925f013	616	count = 0;
donatien	0:632c9925f013	617	/* de-allocate all consecutive pbufs from the head of the chain that
donatien	0:632c9925f013	618	* obtain a zero reference count after decrementing*/
donatien	0:632c9925f013	619	while (p != NULL) {
donatien	0:632c9925f013	620	u16_t ref;
donatien	0:632c9925f013	621	SYS_ARCH_DECL_PROTECT(old_level);
donatien	0:632c9925f013	622	/* Since decrementing ref cannot be guaranteed to be a single machine operation
donatien	0:632c9925f013	623	* we must protect it. We put the new ref into a local variable to prevent
donatien	0:632c9925f013	624	* further protection. */
donatien	0:632c9925f013	625	SYS_ARCH_PROTECT(old_level);
donatien	0:632c9925f013	626	/* all pbufs in a chain are referenced at least once */
donatien	0:632c9925f013	627	LWIP_ASSERT("pbuf_free: p->ref > 0", p->ref > 0);
donatien	0:632c9925f013	628	/* decrease reference count (number of pointers to pbuf) */
donatien	0:632c9925f013	629	ref = --(p->ref);
donatien	0:632c9925f013	630	SYS_ARCH_UNPROTECT(old_level);
donatien	0:632c9925f013	631	/* this pbuf is no longer referenced to? */
donatien	0:632c9925f013	632	if (ref == 0) {
donatien	0:632c9925f013	633	/* remember next pbuf in chain for next iteration */
donatien	0:632c9925f013	634	q = p->next;
donatien	0:632c9925f013	635	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free: deallocating %p\n", (void *)p));
donatien	0:632c9925f013	636	type = p->type;
donatien	5:dd63a1e02b1b	637	#if LWIP_SUPPORT_CUSTOM_PBUF
donatien	5:dd63a1e02b1b	638	/* is this a custom pbuf? */
donatien	5:dd63a1e02b1b	639	if ((p->flags & PBUF_FLAG_IS_CUSTOM) != 0) {
donatien	5:dd63a1e02b1b	640	struct pbuf_custom pc = (struct pbuf_custom)p;
donatien	5:dd63a1e02b1b	641	LWIP_ASSERT("pc->custom_free_function != NULL", pc->custom_free_function != NULL);
donatien	5:dd63a1e02b1b	642	pc->custom_free_function(p);
donatien	5:dd63a1e02b1b	643	} else
donatien	5:dd63a1e02b1b	644	#endif /* LWIP_SUPPORT_CUSTOM_PBUF */
donatien	5:dd63a1e02b1b	645	{
donatien	5:dd63a1e02b1b	646	/* is this a pbuf from the pool? */
donatien	5:dd63a1e02b1b	647	if (type == PBUF_POOL) {
donatien	5:dd63a1e02b1b	648	memp_free(MEMP_PBUF_POOL, p);
donatien	5:dd63a1e02b1b	649	/* is this a ROM or RAM referencing pbuf? */
donatien	5:dd63a1e02b1b	650	} else if (type == PBUF_ROM \|\| type == PBUF_REF) {
donatien	5:dd63a1e02b1b	651	memp_free(MEMP_PBUF, p);
donatien	5:dd63a1e02b1b	652	/* type == PBUF_RAM */
donatien	5:dd63a1e02b1b	653	} else {
donatien	5:dd63a1e02b1b	654	mem_free(p);
donatien	5:dd63a1e02b1b	655	}
donatien	0:632c9925f013	656	}
donatien	0:632c9925f013	657	count++;
donatien	0:632c9925f013	658	/* proceed to next pbuf */
donatien	0:632c9925f013	659	p = q;
donatien	0:632c9925f013	660	/* p->ref > 0, this pbuf is still referenced to */
donatien	0:632c9925f013	661	/* (and so the remaining pbufs in chain as well) */
donatien	0:632c9925f013	662	} else {
donatien	0:632c9925f013	663	LWIP_DEBUGF( PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref));
donatien	0:632c9925f013	664	/* stop walking through the chain */
donatien	0:632c9925f013	665	p = NULL;
donatien	0:632c9925f013	666	}
donatien	0:632c9925f013	667	}
donatien	0:632c9925f013	668	PERF_STOP("pbuf_free");
donatien	0:632c9925f013	669	/* return number of de-allocated pbufs */
donatien	0:632c9925f013	670	return count;
donatien	0:632c9925f013	671	}
donatien	0:632c9925f013	672
donatien	0:632c9925f013	673	/**
donatien	0:632c9925f013	674	* Count number of pbufs in a chain
donatien	0:632c9925f013	675	*
donatien	0:632c9925f013	676	* @param p first pbuf of chain
donatien	0:632c9925f013	677	* @return the number of pbufs in a chain
donatien	0:632c9925f013	678	*/
donatien	0:632c9925f013	679
donatien	0:632c9925f013	680	u8_t
donatien	0:632c9925f013	681	pbuf_clen(struct pbuf *p)
donatien	0:632c9925f013	682	{
donatien	0:632c9925f013	683	u8_t len;
donatien	0:632c9925f013	684
donatien	0:632c9925f013	685	len = 0;
donatien	0:632c9925f013	686	while (p != NULL) {
donatien	0:632c9925f013	687	++len;
donatien	0:632c9925f013	688	p = p->next;
donatien	0:632c9925f013	689	}
donatien	0:632c9925f013	690	return len;
donatien	0:632c9925f013	691	}
donatien	0:632c9925f013	692
donatien	0:632c9925f013	693	/**
donatien	0:632c9925f013	694	* Increment the reference count of the pbuf.
donatien	0:632c9925f013	695	*
donatien	0:632c9925f013	696	* @param p pbuf to increase reference counter of
donatien	0:632c9925f013	697	*
donatien	0:632c9925f013	698	*/
donatien	0:632c9925f013	699	void
donatien	0:632c9925f013	700	pbuf_ref(struct pbuf *p)
donatien	0:632c9925f013	701	{
donatien	0:632c9925f013	702	SYS_ARCH_DECL_PROTECT(old_level);
donatien	0:632c9925f013	703	/* pbuf given? */
donatien	0:632c9925f013	704	if (p != NULL) {
donatien	0:632c9925f013	705	SYS_ARCH_PROTECT(old_level);
donatien	0:632c9925f013	706	++(p->ref);
donatien	0:632c9925f013	707	SYS_ARCH_UNPROTECT(old_level);
donatien	0:632c9925f013	708	}
donatien	0:632c9925f013	709	}
donatien	0:632c9925f013	710
donatien	0:632c9925f013	711	/**
donatien	0:632c9925f013	712	* Concatenate two pbufs (each may be a pbuf chain) and take over
donatien	0:632c9925f013	713	* the caller's reference of the tail pbuf.
donatien	0:632c9925f013	714	*
donatien	0:632c9925f013	715	* @note The caller MAY NOT reference the tail pbuf afterwards.
donatien	0:632c9925f013	716	* Use pbuf_chain() for that purpose.
donatien	0:632c9925f013	717	*
donatien	0:632c9925f013	718	* @see pbuf_chain()
donatien	0:632c9925f013	719	*/
donatien	0:632c9925f013	720
donatien	0:632c9925f013	721	void
donatien	0:632c9925f013	722	pbuf_cat(struct pbuf h, struct pbuf t)
donatien	0:632c9925f013	723	{
donatien	0:632c9925f013	724	struct pbuf *p;
donatien	0:632c9925f013	725
donatien	0:632c9925f013	726	LWIP_ERROR("(h != NULL) && (t != NULL) (programmer violates API)",
donatien	0:632c9925f013	727	((h != NULL) && (t != NULL)), return;);
donatien	0:632c9925f013	728
donatien	0:632c9925f013	729	/* proceed to last pbuf of chain */
donatien	0:632c9925f013	730	for (p = h; p->next != NULL; p = p->next) {
donatien	0:632c9925f013	731	/* add total length of second chain to all totals of first chain */
donatien	0:632c9925f013	732	p->tot_len += t->tot_len;
donatien	0:632c9925f013	733	}
donatien	0:632c9925f013	734	/* { p is last pbuf of first h chain, p->next == NULL } */
donatien	0:632c9925f013	735	LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len);
donatien	0:632c9925f013	736	LWIP_ASSERT("p->next == NULL", p->next == NULL);
donatien	0:632c9925f013	737	/* add total length of second chain to last pbuf total of first chain */
donatien	0:632c9925f013	738	p->tot_len += t->tot_len;
donatien	0:632c9925f013	739	/* chain last pbuf of head (p) with first of tail (t) */
donatien	0:632c9925f013	740	p->next = t;
donatien	0:632c9925f013	741	/* p->next now references t, but the caller will drop its reference to t,
donatien	0:632c9925f013	742	* so netto there is no change to the reference count of t.
donatien	0:632c9925f013	743	*/
donatien	0:632c9925f013	744	}
donatien	0:632c9925f013	745
donatien	0:632c9925f013	746	/**
donatien	0:632c9925f013	747	* Chain two pbufs (or pbuf chains) together.
donatien	0:632c9925f013	748	*
donatien	0:632c9925f013	749	* The caller MUST call pbuf_free(t) once it has stopped
donatien	0:632c9925f013	750	* using it. Use pbuf_cat() instead if you no longer use t.
donatien	0:632c9925f013	751	*
donatien	0:632c9925f013	752	* @param h head pbuf (chain)
donatien	0:632c9925f013	753	* @param t tail pbuf (chain)
donatien	0:632c9925f013	754	* @note The pbufs MUST belong to the same packet.
donatien	0:632c9925f013	755	* @note MAY NOT be called on a packet queue.
donatien	0:632c9925f013	756	*
donatien	0:632c9925f013	757	* The ->tot_len fields of all pbufs of the head chain are adjusted.
donatien	0:632c9925f013	758	* The ->next field of the last pbuf of the head chain is adjusted.
donatien	0:632c9925f013	759	* The ->ref field of the first pbuf of the tail chain is adjusted.
donatien	0:632c9925f013	760	*
donatien	0:632c9925f013	761	*/
donatien	0:632c9925f013	762	void
donatien	0:632c9925f013	763	pbuf_chain(struct pbuf h, struct pbuf t)
donatien	0:632c9925f013	764	{
donatien	0:632c9925f013	765	pbuf_cat(h, t);
donatien	0:632c9925f013	766	/* t is now referenced by h */
donatien	0:632c9925f013	767	pbuf_ref(t);
donatien	0:632c9925f013	768	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_chain: %p references %p\n", (void )h, (void )t));
donatien	0:632c9925f013	769	}
donatien	0:632c9925f013	770
donatien	0:632c9925f013	771	/**
donatien	0:632c9925f013	772	* Dechains the first pbuf from its succeeding pbufs in the chain.
donatien	0:632c9925f013	773	*
donatien	0:632c9925f013	774	* Makes p->tot_len field equal to p->len.
donatien	0:632c9925f013	775	* @param p pbuf to dechain
donatien	0:632c9925f013	776	* @return remainder of the pbuf chain, or NULL if it was de-allocated.
donatien	0:632c9925f013	777	* @note May not be called on a packet queue.
donatien	0:632c9925f013	778	*/
donatien	0:632c9925f013	779	struct pbuf *
donatien	0:632c9925f013	780	pbuf_dechain(struct pbuf *p)
donatien	0:632c9925f013	781	{
donatien	0:632c9925f013	782	struct pbuf *q;
donatien	0:632c9925f013	783	u8_t tail_gone = 1;
donatien	0:632c9925f013	784	/* tail */
donatien	0:632c9925f013	785	q = p->next;
donatien	0:632c9925f013	786	/* pbuf has successor in chain? */
donatien	0:632c9925f013	787	if (q != NULL) {
donatien	0:632c9925f013	788	/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
donatien	0:632c9925f013	789	LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len);
donatien	0:632c9925f013	790	/* enforce invariant if assertion is disabled */
donatien	0:632c9925f013	791	q->tot_len = p->tot_len - p->len;
donatien	0:632c9925f013	792	/* decouple pbuf from remainder */
donatien	0:632c9925f013	793	p->next = NULL;
donatien	0:632c9925f013	794	/* total length of pbuf p is its own length only */
donatien	0:632c9925f013	795	p->tot_len = p->len;
donatien	0:632c9925f013	796	/* q is no longer referenced by p, free it */
donatien	0:632c9925f013	797	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_dechain: unreferencing %p\n", (void *)q));
donatien	0:632c9925f013	798	tail_gone = pbuf_free(q);
donatien	0:632c9925f013	799	if (tail_gone > 0) {
donatien	0:632c9925f013	800	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE,
donatien	0:632c9925f013	801	("pbuf_dechain: deallocated %p (as it is no longer referenced)\n", (void *)q));
donatien	0:632c9925f013	802	}
donatien	0:632c9925f013	803	/* return remaining tail or NULL if deallocated */
donatien	0:632c9925f013	804	}
donatien	0:632c9925f013	805	/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
donatien	0:632c9925f013	806	LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len);
donatien	0:632c9925f013	807	return ((tail_gone > 0) ? NULL : q);
donatien	0:632c9925f013	808	}
donatien	0:632c9925f013	809
donatien	0:632c9925f013	810	/**
donatien	0:632c9925f013	811	*
donatien	0:632c9925f013	812	* Create PBUF_RAM copies of pbufs.
donatien	0:632c9925f013	813	*
donatien	0:632c9925f013	814	* Used to queue packets on behalf of the lwIP stack, such as
donatien	0:632c9925f013	815	* ARP based queueing.
donatien	0:632c9925f013	816	*
donatien	0:632c9925f013	817	* @note You MUST explicitly use p = pbuf_take(p);
donatien	0:632c9925f013	818	*
donatien	0:632c9925f013	819	* @note Only one packet is copied, no packet queue!
donatien	0:632c9925f013	820	*
donatien	0:632c9925f013	821	* @param p_to pbuf destination of the copy
donatien	0:632c9925f013	822	* @param p_from pbuf source of the copy
donatien	0:632c9925f013	823	*
donatien	0:632c9925f013	824	* @return ERR_OK if pbuf was copied
donatien	0:632c9925f013	825	* ERR_ARG if one of the pbufs is NULL or p_to is not big
donatien	0:632c9925f013	826	* enough to hold p_from
donatien	0:632c9925f013	827	*/
donatien	0:632c9925f013	828	err_t
donatien	0:632c9925f013	829	pbuf_copy(struct pbuf p_to, struct pbuf p_from)
donatien	0:632c9925f013	830	{
donatien	0:632c9925f013	831	u16_t offset_to=0, offset_from=0, len;
donatien	0:632c9925f013	832
donatien	0:632c9925f013	833	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_copy(%p, %p)\n",
donatien	0:632c9925f013	834	(void)p_to, (void)p_from));
donatien	0:632c9925f013	835
donatien	0:632c9925f013	836	/* is the target big enough to hold the source? */
donatien	0:632c9925f013	837	LWIP_ERROR("pbuf_copy: target not big enough to hold source", ((p_to != NULL) &&
donatien	0:632c9925f013	838	(p_from != NULL) && (p_to->tot_len >= p_from->tot_len)), return ERR_ARG;);
donatien	0:632c9925f013	839
donatien	0:632c9925f013	840	/* iterate through pbuf chain */
donatien	0:632c9925f013	841	do
donatien	0:632c9925f013	842	{
donatien	0:632c9925f013	843	LWIP_ASSERT("p_to != NULL", p_to != NULL);
donatien	0:632c9925f013	844	/* copy one part of the original chain */
donatien	0:632c9925f013	845	if ((p_to->len - offset_to) >= (p_from->len - offset_from)) {
donatien	0:632c9925f013	846	/* complete current p_from fits into current p_to */
donatien	0:632c9925f013	847	len = p_from->len - offset_from;
donatien	0:632c9925f013	848	} else {
donatien	0:632c9925f013	849	/* current p_from does not fit into current p_to */
donatien	0:632c9925f013	850	len = p_to->len - offset_to;
donatien	0:632c9925f013	851	}
donatien	0:632c9925f013	852	MEMCPY((u8_t)p_to->payload + offset_to, (u8_t)p_from->payload + offset_from, len);
donatien	0:632c9925f013	853	offset_to += len;
donatien	0:632c9925f013	854	offset_from += len;
donatien	0:632c9925f013	855	LWIP_ASSERT("offset_to <= p_to->len", offset_to <= p_to->len);
donatien	0:632c9925f013	856	if (offset_to == p_to->len) {
donatien	0:632c9925f013	857	/* on to next p_to (if any) */
donatien	0:632c9925f013	858	offset_to = 0;
donatien	0:632c9925f013	859	p_to = p_to->next;
donatien	0:632c9925f013	860	}
donatien	0:632c9925f013	861	LWIP_ASSERT("offset_from <= p_from->len", offset_from <= p_from->len);
donatien	0:632c9925f013	862	if (offset_from >= p_from->len) {
donatien	0:632c9925f013	863	/* on to next p_from (if any) */
donatien	0:632c9925f013	864	offset_from = 0;
donatien	0:632c9925f013	865	p_from = p_from->next;
donatien	0:632c9925f013	866	}
donatien	0:632c9925f013	867
donatien	0:632c9925f013	868	if((p_from != NULL) && (p_from->len == p_from->tot_len)) {
donatien	0:632c9925f013	869	/* don't copy more than one packet! */
donatien	0:632c9925f013	870	LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
donatien	0:632c9925f013	871	(p_from->next == NULL), return ERR_VAL;);
donatien	0:632c9925f013	872	}
donatien	0:632c9925f013	873	if((p_to != NULL) && (p_to->len == p_to->tot_len)) {
donatien	0:632c9925f013	874	/* don't copy more than one packet! */
donatien	0:632c9925f013	875	LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
donatien	0:632c9925f013	876	(p_to->next == NULL), return ERR_VAL;);
donatien	0:632c9925f013	877	}
donatien	0:632c9925f013	878	} while (p_from);
donatien	0:632c9925f013	879	LWIP_DEBUGF(PBUF_DEBUG \| LWIP_DBG_TRACE, ("pbuf_copy: end of chain reached.\n"));
donatien	0:632c9925f013	880	return ERR_OK;
donatien	0:632c9925f013	881	}
donatien	0:632c9925f013	882
donatien	0:632c9925f013	883	/**
donatien	0:632c9925f013	884	* Copy (part of) the contents of a packet buffer
donatien	0:632c9925f013	885	* to an application supplied buffer.
donatien	0:632c9925f013	886	*
donatien	0:632c9925f013	887	* @param buf the pbuf from which to copy data
donatien	0:632c9925f013	888	* @param dataptr the application supplied buffer
donatien	0:632c9925f013	889	* @param len length of data to copy (dataptr must be big enough). No more
donatien	0:632c9925f013	890	* than buf->tot_len will be copied, irrespective of len
donatien	0:632c9925f013	891	* @param offset offset into the packet buffer from where to begin copying len bytes
donatien	0:632c9925f013	892	* @return the number of bytes copied, or 0 on failure
donatien	0:632c9925f013	893	*/
donatien	0:632c9925f013	894	u16_t
donatien	0:632c9925f013	895	pbuf_copy_partial(struct pbuf buf, void dataptr, u16_t len, u16_t offset)
donatien	0:632c9925f013	896	{
donatien	0:632c9925f013	897	struct pbuf *p;
donatien	0:632c9925f013	898	u16_t left;
donatien	0:632c9925f013	899	u16_t buf_copy_len;
donatien	0:632c9925f013	900	u16_t copied_total = 0;
donatien	0:632c9925f013	901
donatien	0:632c9925f013	902	LWIP_ERROR("pbuf_copy_partial: invalid buf", (buf != NULL), return 0;);
donatien	0:632c9925f013	903	LWIP_ERROR("pbuf_copy_partial: invalid dataptr", (dataptr != NULL), return 0;);
donatien	0:632c9925f013	904
donatien	0:632c9925f013	905	left = 0;
donatien	0:632c9925f013	906
donatien	0:632c9925f013	907	if((buf == NULL) \|\| (dataptr == NULL)) {
donatien	0:632c9925f013	908	return 0;
donatien	0:632c9925f013	909	}
donatien	0:632c9925f013	910
donatien	0:632c9925f013	911	/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
donatien	0:632c9925f013	912	for(p = buf; len != 0 && p != NULL; p = p->next) {
donatien	0:632c9925f013	913	if ((offset != 0) && (offset >= p->len)) {
donatien	0:632c9925f013	914	/* don't copy from this buffer -> on to the next */
donatien	0:632c9925f013	915	offset -= p->len;
donatien	0:632c9925f013	916	} else {
donatien	0:632c9925f013	917	/* copy from this buffer. maybe only partially. */
donatien	0:632c9925f013	918	buf_copy_len = p->len - offset;
donatien	0:632c9925f013	919	if (buf_copy_len > len)
donatien	0:632c9925f013	920	buf_copy_len = len;
donatien	0:632c9925f013	921	/* copy the necessary parts of the buffer */
donatien	0:632c9925f013	922	MEMCPY(&((char)dataptr)[left], &((char)p->payload)[offset], buf_copy_len);
donatien	0:632c9925f013	923	copied_total += buf_copy_len;
donatien	0:632c9925f013	924	left += buf_copy_len;
donatien	0:632c9925f013	925	len -= buf_copy_len;
donatien	0:632c9925f013	926	offset = 0;
donatien	0:632c9925f013	927	}
donatien	0:632c9925f013	928	}
donatien	0:632c9925f013	929	return copied_total;
donatien	0:632c9925f013	930	}
donatien	0:632c9925f013	931
donatien	0:632c9925f013	932	/**
donatien	0:632c9925f013	933	* Copy application supplied data into a pbuf.
donatien	0:632c9925f013	934	* This function can only be used to copy the equivalent of buf->tot_len data.
donatien	0:632c9925f013	935	*
donatien	0:632c9925f013	936	* @param buf pbuf to fill with data
donatien	0:632c9925f013	937	* @param dataptr application supplied data buffer
donatien	0:632c9925f013	938	* @param len length of the application supplied data buffer
donatien	0:632c9925f013	939	*
donatien	0:632c9925f013	940	* @return ERR_OK if successful, ERR_MEM if the pbuf is not big enough
donatien	0:632c9925f013	941	*/
donatien	0:632c9925f013	942	err_t
donatien	0:632c9925f013	943	pbuf_take(struct pbuf buf, const void dataptr, u16_t len)
donatien	0:632c9925f013	944	{
donatien	0:632c9925f013	945	struct pbuf *p;
donatien	0:632c9925f013	946	u16_t buf_copy_len;
donatien	0:632c9925f013	947	u16_t total_copy_len = len;
donatien	0:632c9925f013	948	u16_t copied_total = 0;
donatien	0:632c9925f013	949
donatien	0:632c9925f013	950	LWIP_ERROR("pbuf_take: invalid buf", (buf != NULL), return 0;);
donatien	0:632c9925f013	951	LWIP_ERROR("pbuf_take: invalid dataptr", (dataptr != NULL), return 0;);
donatien	0:632c9925f013	952
donatien	0:632c9925f013	953	if ((buf == NULL) \|\| (dataptr == NULL) \|\| (buf->tot_len < len)) {
donatien	0:632c9925f013	954	return ERR_ARG;
donatien	0:632c9925f013	955	}
donatien	0:632c9925f013	956
donatien	0:632c9925f013	957	/* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
donatien	0:632c9925f013	958	for(p = buf; total_copy_len != 0; p = p->next) {
donatien	0:632c9925f013	959	LWIP_ASSERT("pbuf_take: invalid pbuf", p != NULL);
donatien	0:632c9925f013	960	buf_copy_len = total_copy_len;
donatien	0:632c9925f013	961	if (buf_copy_len > p->len) {
donatien	0:632c9925f013	962	/* this pbuf cannot hold all remaining data */
donatien	0:632c9925f013	963	buf_copy_len = p->len;
donatien	0:632c9925f013	964	}
donatien	0:632c9925f013	965	/* copy the necessary parts of the buffer */
donatien	0:632c9925f013	966	MEMCPY(p->payload, &((char*)dataptr)[copied_total], buf_copy_len);
donatien	0:632c9925f013	967	total_copy_len -= buf_copy_len;
donatien	0:632c9925f013	968	copied_total += buf_copy_len;
donatien	0:632c9925f013	969	}
donatien	0:632c9925f013	970	LWIP_ASSERT("did not copy all data", total_copy_len == 0 && copied_total == len);
donatien	0:632c9925f013	971	return ERR_OK;
donatien	0:632c9925f013	972	}
donatien	0:632c9925f013	973
donatien	0:632c9925f013	974	/**
donatien	0:632c9925f013	975	* Creates a single pbuf out of a queue of pbufs.
donatien	0:632c9925f013	976	*
donatien	5:dd63a1e02b1b	977	* @remark: Either the source pbuf 'p' is freed by this function or the original
donatien	5:dd63a1e02b1b	978	* pbuf 'p' is returned, therefore the caller has to check the result!
donatien	0:632c9925f013	979	*
donatien	0:632c9925f013	980	* @param p the source pbuf
donatien	0:632c9925f013	981	* @param layer pbuf_layer of the new pbuf
donatien	0:632c9925f013	982	*
donatien	0:632c9925f013	983	* @return a new, single pbuf (p->next is NULL)
donatien	0:632c9925f013	984	* or the old pbuf if allocation fails
donatien	0:632c9925f013	985	*/
donatien	0:632c9925f013	986	struct pbuf*
donatien	0:632c9925f013	987	pbuf_coalesce(struct pbuf *p, pbuf_layer layer)
donatien	0:632c9925f013	988	{
donatien	0:632c9925f013	989	struct pbuf *q;
donatien	0:632c9925f013	990	err_t err;
donatien	0:632c9925f013	991	if (p->next == NULL) {
donatien	0:632c9925f013	992	return p;
donatien	0:632c9925f013	993	}
donatien	0:632c9925f013	994	q = pbuf_alloc(layer, p->tot_len, PBUF_RAM);
donatien	0:632c9925f013	995	if (q == NULL) {
donatien	0:632c9925f013	996	/* @todo: what do we do now? */
donatien	0:632c9925f013	997	return p;
donatien	0:632c9925f013	998	}
donatien	0:632c9925f013	999	err = pbuf_copy(q, p);
donatien	0:632c9925f013	1000	LWIP_ASSERT("pbuf_copy failed", err == ERR_OK);
donatien	0:632c9925f013	1001	pbuf_free(p);
donatien	0:632c9925f013	1002	return q;
donatien	0:632c9925f013	1003	}
donatien	5:dd63a1e02b1b	1004
donatien	5:dd63a1e02b1b	1005	#if LWIP_CHECKSUM_ON_COPY
donatien	5:dd63a1e02b1b	1006	/**
donatien	5:dd63a1e02b1b	1007	* Copies data into a single pbuf (not into a pbuf queue!) and updates
donatien	5:dd63a1e02b1b	1008	* the checksum while copying
donatien	5:dd63a1e02b1b	1009	*
donatien	5:dd63a1e02b1b	1010	* @param p the pbuf to copy data into
donatien	5:dd63a1e02b1b	1011	* @param start_offset offset of p->payload where to copy the data to
donatien	5:dd63a1e02b1b	1012	* @param dataptr data to copy into the pbuf
donatien	5:dd63a1e02b1b	1013	* @param len length of data to copy into the pbuf
donatien	5:dd63a1e02b1b	1014	* @param chksum pointer to the checksum which is updated
donatien	5:dd63a1e02b1b	1015	* @return ERR_OK if successful, another error if the data does not fit
donatien	5:dd63a1e02b1b	1016	* within the (first) pbuf (no pbuf queues!)
donatien	5:dd63a1e02b1b	1017	*/
donatien	5:dd63a1e02b1b	1018	err_t
donatien	5:dd63a1e02b1b	1019	pbuf_fill_chksum(struct pbuf p, u16_t start_offset, const void dataptr,
donatien	5:dd63a1e02b1b	1020	u16_t len, u16_t *chksum)
donatien	5:dd63a1e02b1b	1021	{
donatien	5:dd63a1e02b1b	1022	u32_t acc;
donatien	5:dd63a1e02b1b	1023	u16_t copy_chksum;
donatien	5:dd63a1e02b1b	1024	char *dst_ptr;
donatien	5:dd63a1e02b1b	1025	LWIP_ASSERT("p != NULL", p != NULL);
donatien	5:dd63a1e02b1b	1026	LWIP_ASSERT("dataptr != NULL", dataptr != NULL);
donatien	5:dd63a1e02b1b	1027	LWIP_ASSERT("chksum != NULL", chksum != NULL);
donatien	5:dd63a1e02b1b	1028	LWIP_ASSERT("len != 0", len != 0);
donatien	5:dd63a1e02b1b	1029
donatien	5:dd63a1e02b1b	1030	if ((start_offset >= p->len) \|\| (start_offset + len > p->len)) {
donatien	5:dd63a1e02b1b	1031	return ERR_ARG;
donatien	5:dd63a1e02b1b	1032	}
donatien	5:dd63a1e02b1b	1033
donatien	5:dd63a1e02b1b	1034	dst_ptr = ((char*)p->payload) + start_offset;
donatien	5:dd63a1e02b1b	1035	copy_chksum = LWIP_CHKSUM_COPY(dst_ptr, dataptr, len);
donatien	5:dd63a1e02b1b	1036	if ((start_offset & 1) != 0) {
donatien	5:dd63a1e02b1b	1037	copy_chksum = SWAP_BYTES_IN_WORD(copy_chksum);
donatien	5:dd63a1e02b1b	1038	}
donatien	5:dd63a1e02b1b	1039	acc = *chksum;
donatien	5:dd63a1e02b1b	1040	acc += copy_chksum;
donatien	5:dd63a1e02b1b	1041	*chksum = FOLD_U32T(acc);
donatien	5:dd63a1e02b1b	1042	return ERR_OK;
donatien	5:dd63a1e02b1b	1043	}
donatien	5:dd63a1e02b1b	1044	#endif /* LWIP_CHECKSUM_ON_COPY */
donatien	5:dd63a1e02b1b	1045
donatien	5:dd63a1e02b1b	1046	/** Get one byte from the specified position in a pbuf
donatien	5:dd63a1e02b1b	1047	* WARNING: returns zero for offset >= p->tot_len
donatien	5:dd63a1e02b1b	1048	*
donatien	5:dd63a1e02b1b	1049	* @param p pbuf to parse
donatien	5:dd63a1e02b1b	1050	* @param offset offset into p of the byte to return
donatien	5:dd63a1e02b1b	1051	* @return byte at an offset into p OR ZERO IF 'offset' >= p->tot_len
donatien	5:dd63a1e02b1b	1052	*/
donatien	5:dd63a1e02b1b	1053	u8_t
donatien	5:dd63a1e02b1b	1054	pbuf_get_at(struct pbuf* p, u16_t offset)
donatien	5:dd63a1e02b1b	1055	{
donatien	5:dd63a1e02b1b	1056	u16_t copy_from = offset;
donatien	5:dd63a1e02b1b	1057	struct pbuf* q = p;
donatien	5:dd63a1e02b1b	1058
donatien	5:dd63a1e02b1b	1059	/* get the correct pbuf */
donatien	5:dd63a1e02b1b	1060	while ((q != NULL) && (q->len <= copy_from)) {
donatien	5:dd63a1e02b1b	1061	copy_from -= q->len;
donatien	5:dd63a1e02b1b	1062	q = q->next;
donatien	5:dd63a1e02b1b	1063	}
donatien	5:dd63a1e02b1b	1064	/* return requested data if pbuf is OK */
donatien	5:dd63a1e02b1b	1065	if ((q != NULL) && (q->len > copy_from)) {
donatien	5:dd63a1e02b1b	1066	return ((u8_t*)q->payload)[copy_from];
donatien	5:dd63a1e02b1b	1067	}
donatien	5:dd63a1e02b1b	1068	return 0;
donatien	5:dd63a1e02b1b	1069	}
donatien	5:dd63a1e02b1b	1070
donatien	5:dd63a1e02b1b	1071	/** Compare pbuf contents at specified offset with memory s2, both of length n
donatien	5:dd63a1e02b1b	1072	*
donatien	5:dd63a1e02b1b	1073	* @param p pbuf to compare
donatien	5:dd63a1e02b1b	1074	* @param offset offset into p at wich to start comparing
donatien	5:dd63a1e02b1b	1075	* @param s2 buffer to compare
donatien	5:dd63a1e02b1b	1076	* @param n length of buffer to compare
donatien	5:dd63a1e02b1b	1077	* @return zero if equal, nonzero otherwise
donatien	5:dd63a1e02b1b	1078	* (0xffff if p is too short, diffoffset+1 otherwise)
donatien	5:dd63a1e02b1b	1079	*/
donatien	5:dd63a1e02b1b	1080	u16_t
donatien	5:dd63a1e02b1b	1081	pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n)
donatien	5:dd63a1e02b1b	1082	{
donatien	5:dd63a1e02b1b	1083	u16_t start = offset;
donatien	5:dd63a1e02b1b	1084	struct pbuf* q = p;
donatien	5:dd63a1e02b1b	1085
donatien	5:dd63a1e02b1b	1086	/* get the correct pbuf */
donatien	5:dd63a1e02b1b	1087	while ((q != NULL) && (q->len <= start)) {
donatien	5:dd63a1e02b1b	1088	start -= q->len;
donatien	5:dd63a1e02b1b	1089	q = q->next;
donatien	5:dd63a1e02b1b	1090	}
donatien	5:dd63a1e02b1b	1091	/* return requested data if pbuf is OK */
donatien	5:dd63a1e02b1b	1092	if ((q != NULL) && (q->len > start)) {
donatien	5:dd63a1e02b1b	1093	u16_t i;
donatien	5:dd63a1e02b1b	1094	for(i = 0; i < n; i++) {
donatien	5:dd63a1e02b1b	1095	u8_t a = pbuf_get_at(q, start + i);
donatien	5:dd63a1e02b1b	1096	u8_t b = ((u8_t*)s2)[i];
donatien	5:dd63a1e02b1b	1097	if (a != b) {
donatien	5:dd63a1e02b1b	1098	return i+1;
donatien	5:dd63a1e02b1b	1099	}
donatien	5:dd63a1e02b1b	1100	}
donatien	5:dd63a1e02b1b	1101	return 0;
donatien	5:dd63a1e02b1b	1102	}
donatien	5:dd63a1e02b1b	1103	return 0xffff;
donatien	5:dd63a1e02b1b	1104	}
donatien	5:dd63a1e02b1b	1105
donatien	5:dd63a1e02b1b	1106	/** Find occurrence of mem (with length mem_len) in pbuf p, starting at offset
donatien	5:dd63a1e02b1b	1107	* start_offset.
donatien	5:dd63a1e02b1b	1108	*
donatien	5:dd63a1e02b1b	1109	* @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
donatien	5:dd63a1e02b1b	1110	* return value 'not found'
donatien	5:dd63a1e02b1b	1111	* @param mem search for the contents of this buffer
donatien	5:dd63a1e02b1b	1112	* @param mem_len length of 'mem'
donatien	5:dd63a1e02b1b	1113	* @param start_offset offset into p at which to start searching
donatien	5:dd63a1e02b1b	1114	* @return 0xFFFF if substr was not found in p or the index where it was found
donatien	5:dd63a1e02b1b	1115	*/
donatien	5:dd63a1e02b1b	1116	u16_t
donatien	5:dd63a1e02b1b	1117	pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset)
donatien	5:dd63a1e02b1b	1118	{
donatien	5:dd63a1e02b1b	1119	u16_t i;
donatien	5:dd63a1e02b1b	1120	u16_t max = p->tot_len - mem_len;
donatien	5:dd63a1e02b1b	1121	if (p->tot_len >= mem_len + start_offset) {
donatien	5:dd63a1e02b1b	1122	for(i = start_offset; i <= max; ) {
donatien	5:dd63a1e02b1b	1123	u16_t plus = pbuf_memcmp(p, i, mem, mem_len);
donatien	5:dd63a1e02b1b	1124	if (plus == 0) {
donatien	5:dd63a1e02b1b	1125	return i;
donatien	5:dd63a1e02b1b	1126	} else {
donatien	5:dd63a1e02b1b	1127	i += plus;
donatien	5:dd63a1e02b1b	1128	}
donatien	5:dd63a1e02b1b	1129	}
donatien	5:dd63a1e02b1b	1130	}
donatien	5:dd63a1e02b1b	1131	return 0xFFFF;
donatien	5:dd63a1e02b1b	1132	}
donatien	5:dd63a1e02b1b	1133
donatien	5:dd63a1e02b1b	1134	/** Find occurrence of substr with length substr_len in pbuf p, start at offset
donatien	5:dd63a1e02b1b	1135	* start_offset
donatien	5:dd63a1e02b1b	1136	* WARNING: in contrast to strstr(), this one does not stop at the first \0 in
donatien	5:dd63a1e02b1b	1137	* the pbuf/source string!
donatien	5:dd63a1e02b1b	1138	*
donatien	5:dd63a1e02b1b	1139	* @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
donatien	5:dd63a1e02b1b	1140	* return value 'not found'
donatien	5:dd63a1e02b1b	1141	* @param substr string to search for in p, maximum length is 0xFFFE
donatien	5:dd63a1e02b1b	1142	* @return 0xFFFF if substr was not found in p or the index where it was found
donatien	5:dd63a1e02b1b	1143	*/
donatien	5:dd63a1e02b1b	1144	u16_t
donatien	5:dd63a1e02b1b	1145	pbuf_strstr(struct pbuf* p, const char* substr)
donatien	5:dd63a1e02b1b	1146	{
donatien	5:dd63a1e02b1b	1147	size_t substr_len;
donatien	5:dd63a1e02b1b	1148	if ((substr == NULL) \|\| (substr[0] == 0) \|\| (p->tot_len == 0xFFFF)) {
donatien	5:dd63a1e02b1b	1149	return 0xFFFF;
donatien	5:dd63a1e02b1b	1150	}
donatien	5:dd63a1e02b1b	1151	substr_len = strlen(substr);
donatien	5:dd63a1e02b1b	1152	if (substr_len >= 0xFFFF) {
donatien	5:dd63a1e02b1b	1153	return 0xFFFF;
donatien	5:dd63a1e02b1b	1154	}
donatien	5:dd63a1e02b1b	1155	return pbuf_memfind(p, substr, (u16_t)substr_len, 0);
donatien	5:dd63a1e02b1b	1156	}

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Type:	Program
Created:	11 Jun 2010
Imports:	2654
Forks:	0
Commits:	12
Dependents:	3
Dependencies:	0
Followers:	13

This repository is Public (Unlisted).

lwip/core/pbuf.c@11:da4498f591ee, 2010-08-05 (annotated)

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