zephyr/net/ip/net_buf.c

117 lines
3.0 KiB
C

/*! @file
@brief Network buffers
Network data is passed between application and IP stack via
a net_buf struct.
*/
/*
* Copyright (c) 2015 Intel Corporation
*
* 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) Neither the name of Intel Corporation nor the names of its contributors
* may be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT HOLDER OR CONTRIBUTORS 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.
*/
#include <nanokernel.h>
#include <toolchain.h>
#include <string.h>
#include <stdint.h>
#include <net/net_core.h>
#include <net/net_buf.h>
/* Available (free) buffers queue */
#define NUM_BUFS 2
static struct net_buf buffers[NUM_BUFS];
static struct nano_fifo free_bufs;
struct net_buf *net_buf_get_reserve(uint16_t reserve_head)
{
struct net_buf *buf;
buf = nano_fifo_get(&free_bufs);
if (!buf) {
NET_ERR("Failed to get free buffer\n");
return NULL;
}
buf->data = buf->buf + reserve_head;
buf->len = 0;
NET_DBG("buf %p reserve %u\n", buf, reserve_head);
return buf;
}
struct net_buf *net_buf_get(struct net_context *context)
{
struct net_buf *buf = net_buf_get_reserve(0);
if (!buf) {
return buf;
}
buf->context = context;
return buf;
}
void net_buf_put(struct net_buf *buf)
{
NET_DBG("buf %p\n", buf);
nano_fifo_put(&free_bufs, buf);
}
uint8_t *net_buf_add(struct net_buf *buf, uint16_t len)
{
uint8_t *tail = buf->data + buf->len;
buf->len += len;
return tail;
}
uint8_t *net_buf_push(struct net_buf *buf, uint16_t len)
{
buf->data -= len;
buf->len += len;
return buf->data;
}
uint8_t *net_buf_pull(struct net_buf *buf, uint16_t len)
{
buf->len -= len;
return buf->data += len;
}
void net_buf_init(void)
{
nano_fifo_init(&free_bufs);
for (int i = 0; i < NUM_BUFS; i++) {
nano_fifo_put(&free_bufs, &buffers[i]);
}
}