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//==========================================================================

//

//      net/icmp.c

//

//      Stand-alone ICMP networking support for RedBoot

//

//==========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

//

// eCos is free software; you can redistribute it and/or modify it under

// the terms of the GNU General Public License as published by the Free

// Software Foundation; either version 2 or (at your option) any later version.

//

// eCos is distributed in the hope that it will be useful, but WITHOUT ANY

// WARRANTY; without even the implied warranty of MERCHANTABILITY or

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

// for more details.

//

// You should have received a copy of the GNU General Public License along

// with eCos; if not, write to the Free Software Foundation, Inc.,

// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

//

// As a special exception, if other files instantiate templates or use macros

// or inline functions from this file, or you compile this file and link it

// with other works to produce a work based on this file, this file does not

// by itself cause the resulting work to be covered by the GNU General Public

// License. However the source code for this file must still be made available

// in accordance with section (3) of the GNU General Public License.

//

// This exception does not invalidate any other reasons why a work based on

// this file might be covered by the GNU General Public License.

//

// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.

// at http://sources.redhat.com/ecos/ecos-license/

// -------------------------------------------

//####ECOSGPLCOPYRIGHTEND####

//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):    gthomas

// Contributors: gthomas

// Date:         2000-07-14

// Purpose:      

// Description:  

//              

// This code is part of RedBoot (tm).

//

//####DESCRIPTIONEND####

//

//==========================================================================

#include <net/net.h>

/*

 * Handle ICMP packets.

 */

static void default_icmp_handler(pktbuf_t *pkt, ip_route_t *dest);

static icmp_handler_t icmp_handler = default_icmp_handler;

/*

 * Install a user defined user_handler for incoming icmp packets.

 * Returns zero if successful, -1 if the user_handler is already used.

 */

int

__icmp_install_listener(icmp_handler_t user_handler)

{

    if (icmp_handler == user_handler) {

        return -1;

    }

    icmp_handler = user_handler;

    return 0;

}

/*

 * Replace a user defined handler by the default handler.

 */

void

__icmp_remove_listener(void)

{

  if (icmp_handler != default_icmp_handler) {

      icmp_handler = default_icmp_handler;

  }

}

/*

 * ICMP entry point with an IP packet pkt and the destination dest a reply

 * should be sent to.

 */

void

__icmp_handler(pktbuf_t *pkt, ip_route_t *dest)

{

    (*icmp_handler)(pkt, dest);

    BSPLOG(bsp_log("icmp: dest[%s] type[%d] seq[%d]\n",

                   inet_ntoa(pkt->ip_hdr->destination),

                   pkt->icmp_hdr->type,

                   pkt->icmp_hdr->seqnum));

    __pktbuf_free(pkt);

}

/*

 * The default ICMP handler only handles ICMP incoming echo request and

 * outgoing echo reply.

 */

static void

default_icmp_handler(pktbuf_t *pkt, ip_route_t *dest)

{

    word cksum;

    if (pkt->icmp_hdr->type == ICMP_TYPE_ECHOREQUEST

        && pkt->icmp_hdr->code == 0

        && __sum((word *)pkt->icmp_hdr, pkt->pkt_bytes, 0) == 0) {

        pkt->icmp_hdr->type = ICMP_TYPE_ECHOREPLY;

        pkt->icmp_hdr->checksum = 0;

        cksum = __sum((word *)pkt->icmp_hdr, pkt->pkt_bytes, 0);

        pkt->icmp_hdr->checksum = htons(cksum);

        __ip_send(pkt, IP_PROTO_ICMP, dest);

    }

}