forked from Archive/PX4-Autopilot
251 lines
8.4 KiB
C
251 lines
8.4 KiB
C
/****************************************************************************
|
|
* net/uip/uip_tcptimer.c
|
|
* Poll for the availability of TCP TX data
|
|
*
|
|
* Copyright (C) 2007-2010 Gregory Nutt. All rights reserved.
|
|
* Author: Gregory Nutt <gnutt@nuttx.org>
|
|
*
|
|
* Adapted for NuttX from logic in uIP which also has a BSD-like license:
|
|
*
|
|
* Original author Adam Dunkels <adam@dunkels.com>
|
|
* Copyright () 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.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
#if defined(CONFIG_NET) && defined(CONFIG_NET_TCP)
|
|
|
|
#include <stdint.h>
|
|
#include <debug.h>
|
|
|
|
#include <nuttx/net/uip/uipopt.h>
|
|
#include <nuttx/net/uip/uip.h>
|
|
#include <nuttx/net/uip/uip-arch.h>
|
|
|
|
#include "uip_internal.h"
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Variables
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Variables
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: uip_tcptimer
|
|
*
|
|
* Description:
|
|
* Handle a TCP timer expiration for the provided TCP connection
|
|
*
|
|
* Parameters:
|
|
* dev - The device driver structure to use in the send operation
|
|
* conn - The TCP "connection" to poll for TX data
|
|
* hsed - The polling interval in halves of a second
|
|
*
|
|
* Return:
|
|
* None
|
|
*
|
|
* Assumptions:
|
|
* Called from the interrupt level or with interrupts disabled.
|
|
*
|
|
****************************************************************************/
|
|
|
|
void uip_tcptimer(struct uip_driver_s *dev, struct uip_conn *conn, int hsec)
|
|
{
|
|
uint8_t result;
|
|
|
|
dev->d_snddata = &dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
|
|
dev->d_appdata = &dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
|
|
|
|
/* Increase the TCP sequence number */
|
|
|
|
uip_tcpnextsequence();
|
|
|
|
/* Reset the length variables. */
|
|
|
|
dev->d_len = 0;
|
|
dev->d_sndlen = 0;
|
|
|
|
/* Check if the connection is in a state in which we simply wait
|
|
* for the connection to time out. If so, we increase the
|
|
* connection's timer and remove the connection if it times
|
|
* out.
|
|
*/
|
|
|
|
if (conn->tcpstateflags == UIP_TIME_WAIT || conn->tcpstateflags == UIP_FIN_WAIT_2)
|
|
{
|
|
/* Increment the connection timer */
|
|
|
|
(conn->timer) += hsec;
|
|
if (conn->timer >= UIP_TIME_WAIT_TIMEOUT)
|
|
{
|
|
conn->tcpstateflags = UIP_CLOSED;
|
|
nllvdbg("TCP state: UIP_CLOSED\n");
|
|
}
|
|
}
|
|
else if (conn->tcpstateflags != UIP_CLOSED)
|
|
{
|
|
/* If the connection has outstanding data, we increase the connection's
|
|
* timer and see if it has reached the RTO value in which case we
|
|
* retransmit.
|
|
*/
|
|
|
|
if (conn->unacked > 0)
|
|
{
|
|
/* The connection has outstanding data */
|
|
|
|
if (conn->timer > hsec)
|
|
{
|
|
/* Will not yet decrement to zero */
|
|
|
|
conn->timer -= hsec;
|
|
}
|
|
else
|
|
{
|
|
/* Will decrement to zero */
|
|
|
|
conn->timer = 0;
|
|
|
|
/* Should we close the connection? */
|
|
|
|
if (conn->nrtx == UIP_MAXRTX ||
|
|
((conn->tcpstateflags == UIP_SYN_SENT ||
|
|
conn->tcpstateflags == UIP_SYN_RCVD) &&
|
|
conn->nrtx == UIP_MAXSYNRTX))
|
|
{
|
|
conn->tcpstateflags = UIP_CLOSED;
|
|
nllvdbg("TCP state: UIP_CLOSED\n");
|
|
|
|
/* We call uip_tcpcallback() with UIP_TIMEDOUT to
|
|
* inform the application that the connection has
|
|
* timed out.
|
|
*/
|
|
|
|
result = uip_tcpcallback(dev, conn, UIP_TIMEDOUT);
|
|
|
|
/* We also send a reset packet to the remote host. */
|
|
|
|
uip_tcpsend(dev, conn, TCP_RST | TCP_ACK, UIP_IPTCPH_LEN);
|
|
goto done;
|
|
}
|
|
|
|
/* Exponential backoff. */
|
|
|
|
conn->timer = UIP_RTO << (conn->nrtx > 4 ? 4: conn->nrtx);
|
|
(conn->nrtx)++;
|
|
|
|
/* Ok, so we need to retransmit. We do this differently
|
|
* depending on which state we are in. In ESTABLISHED, we
|
|
* call upon the application so that it may prepare the
|
|
* data for the retransmit. In SYN_RCVD, we resend the
|
|
* SYNACK that we sent earlier and in LAST_ACK we have to
|
|
* retransmit our FINACK.
|
|
*/
|
|
|
|
#ifdef CONFIG_NET_STATISTICS
|
|
uip_stat.tcp.rexmit++;
|
|
#endif
|
|
switch(conn->tcpstateflags & UIP_TS_MASK)
|
|
{
|
|
case UIP_SYN_RCVD:
|
|
/* In the SYN_RCVD state, we should retransmit our
|
|
* SYNACK.
|
|
*/
|
|
|
|
uip_tcpack(dev, conn, TCP_ACK | TCP_SYN);
|
|
goto done;
|
|
|
|
case UIP_SYN_SENT:
|
|
/* In the SYN_SENT state, we retransmit out SYN. */
|
|
|
|
uip_tcpack(dev, conn, TCP_SYN);
|
|
goto done;
|
|
|
|
case UIP_ESTABLISHED:
|
|
/* In the ESTABLISHED state, we call upon the application
|
|
* to do the actual retransmit after which we jump into
|
|
* the code for sending out the packet.
|
|
*/
|
|
|
|
result = uip_tcpcallback(dev, conn, UIP_REXMIT);
|
|
uip_tcprexmit(dev, conn, result);
|
|
goto done;
|
|
|
|
case UIP_FIN_WAIT_1:
|
|
case UIP_CLOSING:
|
|
case UIP_LAST_ACK:
|
|
/* In all these states we should retransmit a FINACK. */
|
|
|
|
uip_tcpsend(dev, conn, TCP_FIN | TCP_ACK, UIP_IPTCPH_LEN);
|
|
goto done;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* The connection does not have outstanding data */
|
|
|
|
else if ((conn->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED)
|
|
{
|
|
/* If there was no need for a retransmission, we poll the
|
|
* application for new data.
|
|
*/
|
|
|
|
result = uip_tcpcallback(dev, conn, UIP_POLL);
|
|
uip_tcpappsend(dev, conn, result);
|
|
goto done;
|
|
}
|
|
}
|
|
|
|
/* Nothing to be done */
|
|
|
|
dev->d_len = 0;
|
|
|
|
done:
|
|
return;
|
|
}
|
|
|
|
#endif /* CONFIG_NET && CONFIG_NET_TCP */
|