/****************************************************************************
* net/udp/udp_input.c
* Handling incoming UDP input
*
* Copyright (C) 2007-2009, 2011 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/uip.h>
#include <nuttx/net/netdev.h>
#include "uip/uip.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define UDPBUF ((struct uip_udpip_hdr *)&dev->d_buf[UIP_LLH_LEN])
/****************************************************************************
* Public Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: uip_udpinput
*
* Description:
* Handle incoming UDP input
*
* Parameters:
* dev - The device driver structure containing the received UDP packet
*
* Return:
* OK The packet has been processed and can be deleted
* ERROR Hold the packet and try again later. There is a listening socket
* but no receive in place to catch the packet yet.
*
* Assumptions:
* Called from the interrupt level or with interrupts disabled.
*
****************************************************************************/
int uip_udpinput(FAR struct uip_driver_s *dev)
{
struct uip_udp_conn *conn;
struct uip_udpip_hdr *pbuf = UDPBUF;
int ret = OK;
#ifdef CONFIG_NET_STATISTICS
uip_stat.udp.recv++;
#endif
/* UDP processing is really just a hack. We don't do anything to the UDP/IP
* headers, but let the UDP application do all the hard work. If the
* application sets d_sndlen, it has a packet to send.
*/
dev->d_len -= UIP_IPUDPH_LEN;
#ifdef CONFIG_NET_UDP_CHECKSUMS
dev->d_appdata = &dev->d_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
if (pbuf->udpchksum != 0 && uip_udpchksum(dev) != 0xffff)
{
#ifdef CONFIG_NET_STATISTICS
uip_stat.udp.drop++;
uip_stat.udp.chkerr++;
#endif
nlldbg("Bad UDP checksum\n");
dev->d_len = 0;
}
else
#endif
{
/* Demultiplex this UDP packet between the UDP "connections". */
conn = uip_udpactive(pbuf);
if (conn)
{
uint16_t flags;
/* Set-up for the application callback */
dev->d_appdata = &dev->d_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
dev->d_snddata = &dev->d_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
dev->d_sndlen = 0;
/* Perform the application callback */
flags = uip_udpcallback(dev, conn, UIP_NEWDATA);
/* If the operation was successful, the UIP_NEWDATA flag is removed
* and thus the packet can be deleted (OK will be returned).
*/
if ((flags & UIP_NEWDATA) != 0)
{
/* No.. the packet was not processed now. Return ERROR so
* that the driver may retry again later.
*/
ret = ERROR;
}
/* If the application has data to send, setup the UDP/IP header */
if (dev->d_sndlen > 0)
{
uip_udpsend(dev, conn);
}
}
else
{
nlldbg("No listener on UDP port\n");
dev->d_len = 0;
}
}
return ret;
}
#endif /* CONFIG_NET && CONFIG_NET_UDP */
