incubator-nuttx/net/udp/udp_devpoll.c

118 lines
3.9 KiB
C

/****************************************************************************
* net/udp/udp_devpoll.c
* Network device poll for the availability of UDP TX data
*
* Copyright (C) 2007-2009 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_UDP)
#include <debug.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/udp.h>
#include "devif/devif.h"
#include "udp/udp.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: udp_poll
*
* Description:
* Poll a UDP "connection" structure for availability of TX data
*
* Input Parameters:
* dev - The device driver structure to use in the send operation
* conn - The UDP "connection" to poll for TX data
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
void udp_poll(FAR struct net_driver_s *dev, FAR struct udp_conn_s *conn)
{
/* Verify that the UDP connection is valid */
if (conn->lport != 0)
{
/* 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)
udp_ipv4_select(dev);
#else /* if defined(CONFIG_NET_IPv6) */
udp_ipv6_select(dev);
#endif
dev->d_len = 0;
dev->d_sndlen = 0;
/* Perform the application callback */
(void)udp_callback(dev, conn, UDP_POLL);
/* If the application has data to send, setup the UDP/IP header */
if (dev->d_sndlen > 0)
{
udp_send(dev, conn);
return;
}
}
/* Make sure that d_len is zero meaning that there is nothing to be sent */
dev->d_len = 0;
}
#endif /* CONFIG_NET && CONFIG_NET_UDP */