/** | |
* @file | |
* Network buffer management | |
* | |
*/ | |
/* | |
* Copyright (c) 2001-2004 Swedish Institute of Computer Science. | |
* All rights reserved. | |
* | |
* Redistribution and use in source and binary forms, with or without modification, | |
* are permitted provided that the following conditions are met: | |
* | |
* 1. Redistributions of source code must retain the above copyright notice, | |
* this list of conditions and the following disclaimer. | |
* 2. Redistributions in binary form must reproduce the above copyright notice, | |
* this list of conditions and the following disclaimer in the documentation | |
* and/or other materials provided with the distribution. | |
* 3. The name of the author may not be used to endorse or promote products | |
* derived from this software without specific prior written permission. | |
* | |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED | |
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT | |
* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | |
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT | |
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING | |
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY | |
* OF SUCH DAMAGE. | |
* | |
* This file is part of the lwIP TCP/IP stack. | |
* | |
* Author: Adam Dunkels <adam@sics.se> | |
* | |
*/ | |
#include "lwip/opt.h" | |
#if LWIP_NETCONN /* don't build if not configured for use in lwipopts.h */ | |
#include "lwip/netbuf.h" | |
#include "lwip/memp.h" | |
#include <string.h> | |
/** | |
* Create (allocate) and initialize a new netbuf. | |
* The netbuf doesn't yet contain a packet buffer! | |
* | |
* @return a pointer to a new netbuf | |
* NULL on lack of memory | |
*/ | |
struct | |
netbuf *netbuf_new(void) | |
{ | |
struct netbuf *buf; | |
buf = memp_malloc(MEMP_NETBUF); | |
if (buf != NULL) { | |
buf->p = NULL; | |
buf->ptr = NULL; | |
buf->addr = NULL; | |
return buf; | |
} else { | |
return NULL; | |
} | |
} | |
/** | |
* Deallocate a netbuf allocated by netbuf_new(). | |
* | |
* @param buf pointer to a netbuf allocated by netbuf_new() | |
*/ | |
void | |
netbuf_delete(struct netbuf *buf) | |
{ | |
if (buf != NULL) { | |
if (buf->p != NULL) { | |
pbuf_free(buf->p); | |
buf->p = buf->ptr = NULL; | |
} | |
memp_free(MEMP_NETBUF, buf); | |
} | |
} | |
/** | |
* Allocate memory for a packet buffer for a given netbuf. | |
* | |
* @param buf the netbuf for which to allocate a packet buffer | |
* @param size the size of the packet buffer to allocate | |
* @return pointer to the allocated memory | |
* NULL if no memory could be allocated | |
*/ | |
void * | |
netbuf_alloc(struct netbuf *buf, u16_t size) | |
{ | |
LWIP_ERROR("netbuf_alloc: invalid buf", (buf != NULL), return NULL;); | |
/* Deallocate any previously allocated memory. */ | |
if (buf->p != NULL) { | |
pbuf_free(buf->p); | |
} | |
buf->p = pbuf_alloc(PBUF_TRANSPORT, size, PBUF_RAM); | |
if (buf->p == NULL) { | |
return NULL; | |
} | |
LWIP_ASSERT("check that first pbuf can hold size", | |
(buf->p->len >= size)); | |
buf->ptr = buf->p; | |
return buf->p->payload; | |
} | |
/** | |
* Free the packet buffer included in a netbuf | |
* | |
* @param buf pointer to the netbuf which contains the packet buffer to free | |
*/ | |
void | |
netbuf_free(struct netbuf *buf) | |
{ | |
LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return;); | |
if (buf->p != NULL) { | |
pbuf_free(buf->p); | |
} | |
buf->p = buf->ptr = NULL; | |
} | |
/** | |
* Let a netbuf reference existing (non-volatile) data. | |
* | |
* @param buf netbuf which should reference the data | |
* @param dataptr pointer to the data to reference | |
* @param size size of the data | |
* @return ERR_OK if data is referenced | |
* ERR_MEM if data couldn't be referenced due to lack of memory | |
*/ | |
err_t | |
netbuf_ref(struct netbuf *buf, const void *dataptr, u16_t size) | |
{ | |
LWIP_ERROR("netbuf_ref: invalid buf", (buf != NULL), return ERR_ARG;); | |
if (buf->p != NULL) { | |
pbuf_free(buf->p); | |
} | |
buf->p = pbuf_alloc(PBUF_TRANSPORT, 0, PBUF_REF); | |
if (buf->p == NULL) { | |
buf->ptr = NULL; | |
return ERR_MEM; | |
} | |
buf->p->payload = (void*)dataptr; | |
buf->p->len = buf->p->tot_len = size; | |
buf->ptr = buf->p; | |
return ERR_OK; | |
} | |
/** | |
* Chain one netbuf to another (@see pbuf_chain) | |
* | |
* @param head the first netbuf | |
* @param tail netbuf to chain after head | |
*/ | |
void | |
netbuf_chain(struct netbuf *head, struct netbuf *tail) | |
{ | |
LWIP_ERROR("netbuf_ref: invalid head", (head != NULL), return;); | |
LWIP_ERROR("netbuf_chain: invalid tail", (tail != NULL), return;); | |
pbuf_chain(head->p, tail->p); | |
head->ptr = head->p; | |
memp_free(MEMP_NETBUF, tail); | |
} | |
/** | |
* Get the data pointer and length of the data inside a netbuf. | |
* | |
* @param buf netbuf to get the data from | |
* @param dataptr pointer to a void pointer where to store the data pointer | |
* @param len pointer to an u16_t where the length of the data is stored | |
* @return ERR_OK if the information was retreived, | |
* ERR_BUF on error. | |
*/ | |
err_t | |
netbuf_data(struct netbuf *buf, void **dataptr, u16_t *len) | |
{ | |
LWIP_ERROR("netbuf_data: invalid buf", (buf != NULL), return ERR_ARG;); | |
LWIP_ERROR("netbuf_data: invalid dataptr", (dataptr != NULL), return ERR_ARG;); | |
LWIP_ERROR("netbuf_data: invalid len", (len != NULL), return ERR_ARG;); | |
if (buf->ptr == NULL) { | |
return ERR_BUF; | |
} | |
*dataptr = buf->ptr->payload; | |
*len = buf->ptr->len; | |
return ERR_OK; | |
} | |
/** | |
* Move the current data pointer of a packet buffer contained in a netbuf | |
* to the next part. | |
* The packet buffer itself is not modified. | |
* | |
* @param buf the netbuf to modify | |
* @return -1 if there is no next part | |
* 1 if moved to the next part but now there is no next part | |
* 0 if moved to the next part and there are still more parts | |
*/ | |
s8_t | |
netbuf_next(struct netbuf *buf) | |
{ | |
LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return -1;); | |
if (buf->ptr->next == NULL) { | |
return -1; | |
} | |
buf->ptr = buf->ptr->next; | |
if (buf->ptr->next == NULL) { | |
return 1; | |
} | |
return 0; | |
} | |
/** | |
* Move the current data pointer of a packet buffer contained in a netbuf | |
* to the beginning of the packet. | |
* The packet buffer itself is not modified. | |
* | |
* @param buf the netbuf to modify | |
*/ | |
void | |
netbuf_first(struct netbuf *buf) | |
{ | |
LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return;); | |
buf->ptr = buf->p; | |
} | |
#endif /* LWIP_NETCONN */ |