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/****************************************************************************
* net/tcp/tcp_seqno.c
*
* Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Large parts of this file were leveraged from uIP logic:
*
* Copyright (c) 2001-2003, Adam Dunkels.
* 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.
*
****************************************************************************/
/****************************************************************************
* Compilation Switches
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#if defined(CONFIG_NET) && defined(CONFIG_NET_TCP)
#include <stdint.h>
#include <debug.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/netdev.h>
#include "devif/devif.h"
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/* g_tcpsequence is used to generate initial TCP sequence numbers */
static uint32_t g_tcpsequence;
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: tcp_setsequence
*
* Description:
* Set the TCP/IP sequence number
*
* Assumptions:
* This function may called from the interrupt level
*
****************************************************************************/
void tcp_setsequence(FAR uint8_t *seqno, uint32_t value)
{
/* Copy the sequence number in network (big-endian) order */
*seqno++ = value >> 24;
*seqno++ = (value >> 16) & 0xff;
*seqno++ = (value >> 8) & 0xff;
*seqno = value & 0xff;
}
/****************************************************************************
* Name: tcp_getsequence
*
* Description:
* Get the TCP/IP sequence number
*
* Assumptions:
* This function may called from the interrupt level
*
****************************************************************************/
uint32_t tcp_getsequence(FAR uint8_t *seqno)
{
uint32_t value;
/* Combine the sequence number from network (big-endian) order */
value = (uint32_t)seqno[0] << 24 |
(uint32_t)seqno[1] << 16 |
(uint32_t)seqno[2] << 8 |
(uint32_t)seqno[3];
return value;
}
/****************************************************************************
* Name: tcp_addsequence
*
* Description:
* Add the length to get the next TCP sequence number.
*
* Assumptions:
* This function may called from the interrupt level
*
****************************************************************************/
uint32_t tcp_addsequence(FAR uint8_t *seqno, uint16_t len)
{
return tcp_getsequence(seqno) + (uint32_t)len;
}
/****************************************************************************
* Name: tcp_initsequence
*
* Description:
* Set the (initial) the TCP/IP sequence number when a TCP connection is
* established.
*
* Assumptions:
* This function may called from the interrupt level
*
****************************************************************************/
void tcp_initsequence(FAR uint8_t *seqno)
{
tcp_setsequence(seqno, g_tcpsequence);
}
/****************************************************************************
* Name: tcp_nextsequence
*
* Description:
* Increment the TCP/IP sequence number
*
* Assumptions:
* This function is called from the interrupt level
*
****************************************************************************/
void tcp_nextsequence(void)
{
g_tcpsequence++;
}
#endif /* CONFIG_NET && CONFIG_NET_TCP */
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