nuttx/net/tcp/tcp_devpoll.c

125 lines
4.2 KiB
C

/****************************************************************************
* net/tcp/tcp_devpoll.c
* Driver poll for the availability of TCP TX data
*
* Copyright (C) 2007-2009, 2016 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/netconfig.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/tcp.h>
#include "devif/devif.h"
#include "tcp/tcp.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: tcp_poll
*
* Description:
* Poll a TCP connection structure for availability of TX data
*
* Parameters:
* dev - The device driver structure to use in the send operation
* conn - The TCP "connection" to poll for TX data
*
* Return:
* None
*
* Assumptions:
* Called with the network locked.
*
****************************************************************************/
void tcp_poll(FAR struct net_driver_s *dev, FAR struct tcp_conn_s *conn)
{
uint16_t result;
/* Discard any currently buffered data */
dev->d_len = 0;
dev->d_sndlen = 0;
/* Verify that the connection is established. */
if ((conn->tcpstateflags & TCP_STATE_MASK) == TCP_ESTABLISHED)
{
#ifdef CONFIG_NETDEV_MULTINIC
/* The TCP connection is established and, hence, should be bound
* to a device. Make sure that the polling device is the one that
* we are bound to.
*/
DEBUGASSERT(conn->dev != NULL);
if (dev == conn->dev)
#endif
{
/* Set up for the callback. We can't know in advance if the
* application is going to send a IPv4 or an IPv6 packet, so this
* setup may not actually be used.
*/
#if defined(CONFIG_NET_IPv4)
tcp_ipv4_select(dev);
#else /* if defined(CONFIG_NET_IPv6) */
tcp_ipv6_select(dev);
#endif
/* Perform the callback */
result = tcp_callback(dev, conn, TCP_POLL);
/* Handle the callback response */
tcp_appsend(dev, conn, result);
}
}
}
#endif /* CONFIG_NET && CONFIG_NET_TCP */