144 lines
4.7 KiB
C
144 lines
4.7 KiB
C
/****************************************************************************
|
|
* net/iob/iob_copyout.c
|
|
*
|
|
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
|
|
* Author: Gregory Nutt <gnutt@nuttx.org>
|
|
*
|
|
* 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 NuttX 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 OWNER 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.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#if defined(CONFIG_DEBUG) && defined(CONFIG_IOB_DEBUG)
|
|
/* Force debug output (from this file only) */
|
|
|
|
# undef CONFIG_DEBUG_NET
|
|
# define CONFIG_DEBUG_NET 1
|
|
#endif
|
|
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
#include <assert.h>
|
|
|
|
#include <nuttx/net/iob.h>
|
|
|
|
#include "iob.h"
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
#ifndef MIN
|
|
# define MIN(a,b) ((a) < (b) ? (a) : (b))
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Private Types
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Data
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Data
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: iob_copyout
|
|
*
|
|
* Description:
|
|
* Copy data 'len' bytes of data into the user buffer starting at 'offset'
|
|
* in the I/O buffer, returning that actual number of bytes copied out.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int iob_copyout(FAR uint8_t *dest, FAR const struct iob_s *iob,
|
|
unsigned int len, unsigned int offset)
|
|
{
|
|
FAR const uint8_t *src;
|
|
unsigned int ncopy;
|
|
unsigned int avail;
|
|
unsigned int remaining;
|
|
|
|
/* Skip to the I/O buffer containing the offset */
|
|
|
|
while (offset >= iob->io_len)
|
|
{
|
|
offset -= iob->io_len;
|
|
iob = iob->io_flink;
|
|
if (iob == NULL)
|
|
{
|
|
/* We have no requested data in iob chain */
|
|
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* Then loop until all of the I/O data is copied to the user buffer */
|
|
|
|
remaining = len;
|
|
while (iob && remaining > 0)
|
|
{
|
|
/* Get the source I/O buffer offset address and the amount of data
|
|
* available from that address.
|
|
*/
|
|
|
|
src = &iob->io_data[iob->io_offset + offset];
|
|
avail = iob->io_len - offset;
|
|
|
|
/* Copy the from the I/O buffer in to the user buffer */
|
|
|
|
ncopy = MIN(avail, remaining);
|
|
memcpy(dest, src, ncopy);
|
|
|
|
/* Adjust the total length of the copy and the destination address in
|
|
* the user buffer.
|
|
*/
|
|
|
|
remaining -= ncopy;
|
|
dest += ncopy;
|
|
|
|
/* Skip to the next I/O buffer in the chain */
|
|
|
|
iob = iob->io_flink;
|
|
offset = 0;
|
|
}
|
|
|
|
return len - remaining;
|
|
}
|