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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [Common/] [ethernet/] [lwIP_130/] [src/] [api/] [netbuf.c] - Rev 609
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/** * @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 */
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