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/****************************************************************************
* net/icmp/icmp_input.c
* Handling incoming ICMP/ICMP6 input
*
* Copyright (C) 2007-2009, 2012, 2014 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>
#ifdef CONFIG_NET
#include <stdint.h>
#include <debug.h>
#include <net/if.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/netstats.h>
#include "devif/devif.h"
#include "icmp/icmp.h"
#include "utils/utils.h"
#ifdef CONFIG_NET_ICMP
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define ICMPBUF ((struct icmp_iphdr_s *)&dev->d_buf[NET_LLH_LEN])
/****************************************************************************
* Public Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
#ifdef CONFIG_NET_ICMP_PING
FAR struct devif_callback_s *g_echocallback = NULL;
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: icmp_input
*
* Description:
* Handle incoming ICMP/ICMP6 input
*
* Parameters:
* dev - The device driver structure containing the received ICMP/ICMP6
* packet
*
* Return:
* None
*
* Assumptions:
* Called from the interrupt level or with interrupts disabled.
*
****************************************************************************/
void icmp_input(FAR struct net_driver_s *dev)
{
FAR struct icmp_iphdr_s *picmp = ICMPBUF;
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmp.recv++;
#endif
#ifndef CONFIG_NET_IPv6
/* ICMPv4 processing code follows. */
/* ICMP echo (i.e., ping) processing. This is simple, we only change the
* ICMP type from ECHO to ECHO_REPLY and adjust the ICMP checksum before
* we return the packet.
*/
if (picmp->type == ICMP_ECHO_REQUEST)
{
/* If we are configured to use ping IP address assignment, we use
* the destination IP address of this ping packet and assign it to
* ourself.
*/
#ifdef CONFIG_NET_PINGADDRCONF
if (dev->d_ipaddr == 0)
{
dev->d_ipaddr = picmp->destipaddr;
}
#endif
/* Change the ICMP type */
picmp->type = ICMP_ECHO_REPLY;
/* Swap IP addresses. */
net_ipaddr_hdrcopy(picmp->destipaddr, picmp->srcipaddr);
net_ipaddr_hdrcopy(picmp->srcipaddr, &dev->d_ipaddr);
/* Recalculate the ICMP checksum */
#if 0
/* The slow way... sum over the ICMP message */
picmp->icmpchksum = 0;
picmp->icmpchksum = ~icmp_chksum(dev, (((uint16_t)picmp->len[0] << 8) | (uint16_t)picmp->len[1]) - IPHDR_LEN);
if (picmp->icmpchksum == 0)
{
picmp->icmpchksum = 0xffff;
}
#else
/* The quick way -- Since only the type has changed, just adjust the
* checksum for the change of type
*/
if (picmp->icmpchksum >= HTONS(0xffff - (ICMP_ECHO_REQUEST << 8)))
{
picmp->icmpchksum += HTONS(ICMP_ECHO_REQUEST << 8) + 1;
}
else
{
picmp->icmpchksum += HTONS(ICMP_ECHO_REQUEST << 8);
}
#endif
nllvdbg("Outgoing ICMP packet length: %d (%d)\n",
dev->d_len, (picmp->len[0] << 8) | picmp->len[1]);
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmp.sent++;
g_netstats.ip.sent++;
#endif
}
/* If an ICMP echo reply is received then there should also be
* a thread waiting to received the echo response.
*/
#ifdef CONFIG_NET_ICMP_PING
else if (picmp->type == ICMP_ECHO_REPLY && g_echocallback)
{
(void)devif_callback_execute(dev, picmp, UIP_ECHOREPLY, g_echocallback);
}
#endif
/* Otherwise the ICMP input was not processed */
else
{
nlldbg("Unknown ICMP cmd: %d\n", picmp->type);
goto typeerr;
}
return;
typeerr:
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmp.typeerr++;
g_netstats.icmp.drop++;
#endif
dev->d_len = 0;
#else /* !CONFIG_NET_IPv6 */
/* If we get a neighbor solicitation for our address we should send
* a neighbor advertisement message back.
*/
if (picmp->type == ICMP6_NEIGHBOR_SOLICITATION)
{
if (net_ipaddr_cmp(picmp->icmp6data, dev->d_ipaddr))
{
if (picmp->options[0] == ICMP6_OPTION_SOURCE_LINK_ADDRESS)
{
/* Save the sender's address in our neighbor list. */
net_neighbor_add(picmp->srcipaddr, &(picmp->options[2]));
}
/* We should now send a neighbor advertisement back to where the
* neighbor solicitation came from.
*/
picmp->type = ICMP6_NEIGHBOR_ADVERTISEMENT;
picmp->flags = ICMP6_FLAG_S; /* Solicited flag. */
picmp->reserved1 = picmp->reserved2 = picmp->reserved3 = 0;
net_ipaddr_hdrcopy(picmp->destipaddr, picmp->srcipaddr);
net_ipaddr_hdrcopy(picmp->srcipaddr, &dev->d_ipaddr);
picmp->options[0] = ICMP6_OPTION_TARGET_LINK_ADDRESS;
picmp->options[1] = 1; /* Options length, 1 = 8 bytes. */
memcpy(&(picmp->options[2]), &dev->d_mac, IFHWADDRLEN);
picmp->icmpchksum = 0;
picmp->icmpchksum = ~icmp_6chksum(dev);
}
else
{
goto drop;
}
}
else if (picmp->type == ICMP6_ECHO_REQUEST)
{
/* ICMP echo (i.e., ping) processing. This is simple, we only
* change the ICMP type from ECHO to ECHO_REPLY and update the
* ICMP checksum before we return the packet.
*/
picmp->type = ICMP6_ECHO_REPLY;
net_ipaddr_hdrcopy(picmp->destipaddr, picmp->srcipaddr);
net_ipaddr_hdrcopy(picmp->srcipaddr, &dev->d_ipaddr);
picmp->icmpchksum = 0;
picmp->icmpchksum = ~icmp_6chksum(dev);
}
/* If an ICMP echo reply is received then there should also be
* a thread waiting to received the echo response.
*/
#ifdef CONFIG_NET_ICMP_PING
else if (picmp->type == ICMP6_ECHO_REPLY && g_echocallback)
{
uint16_t flags = UIP_ECHOREPLY;
if (g_echocallback)
{
/* Dispatch the ECHO reply to the waiting thread */
flags = devif_callback_execute(dev, picmp, flags, g_echocallback);
}
/* If the ECHO reply was not handled, then drop the packet */
if (flags == UIP_ECHOREPLY)
{
/* The ECHO reply was not handled */
goto drop;
}
}
#endif
else
{
nlldbg("Unknown ICMP6 cmd: %d\n", picmp->type);
goto typeerr;
}
nllvdbg("Outgoing ICMP6 packet length: %d (%d)\n",
dev->d_len, (picmp->len[0] << 8) | picmp->len[1]);
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmp.sent++;
g_netstats.ip.sent++;
#endif
return;
typeerr:
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmp.typeerr++;
#endif
drop:
#ifdef CONFIG_NET_STATISTICS
g_netstats.icmp.drop++;
#endif
dev->d_len = 0;
#endif /* !CONFIG_NET_IPv6 */
}
#endif /* CONFIG_NET_ICMP */
#endif /* CONFIG_NET */
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