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

//

//      net/ip.c

//

//      Stand-alone IP networking support for RedBoot

//

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

// ####ECOSGPLCOPYRIGHTBEGIN####                                            

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

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

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, 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.,    

// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 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 v2.                                               

//

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

// on this file might be covered by the GNU General Public 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>

#ifndef CYGDAT_REDBOOT_DEFAULT_IP_ADDR

# define CYGDAT_REDBOOT_DEFAULT_IP_ADDR 0, 0, 0, 0

#endif

#ifndef CYGDAT_REDBOOT_DEFAULT_IP_ADDR_MASK

# define CYGDAT_REDBOOT_DEFAULT_IP_ADDR_MASK 255, 255, 255, 0

#endif

#ifndef CYGDAT_REDBOOT_DEFAULT_GATEWAY_IP_ADDR

# define CYGDAT_REDBOOT_DEFAULT_GATEWAY_IP_ADDR 0, 0, 0, 0

#endif

ip_addr_t __local_ip_addr = { CYGDAT_REDBOOT_DEFAULT_IP_ADDR };

#ifdef CYGSEM_REDBOOT_NETWORKING_USE_GATEWAY

ip_addr_t __local_ip_mask = { CYGDAT_REDBOOT_DEFAULT_IP_ADDR_MASK };

ip_addr_t __local_ip_gate = { CYGDAT_REDBOOT_DEFAULT_GATEWAY_IP_ADDR };

#endif

static word ip_ident;

#ifdef CYGSEM_REDBOOT_NETWORKING_USE_GATEWAY

/*

 * See if an address is on the local network

 */

int

__ip_addr_local(ip_addr_t *addr)

{

  return !(

           ((__local_ip_addr[0] ^ (*addr)[0]) & __local_ip_mask[0]) |

           ((__local_ip_addr[1] ^ (*addr)[1]) & __local_ip_mask[1]) |

           ((__local_ip_addr[2] ^ (*addr)[2]) & __local_ip_mask[2]) |

           ((__local_ip_addr[3] ^ (*addr)[3]) & __local_ip_mask[3]));

}

#endif

/*

 * Match given IP address to our address.

 * Check for broadcast matches as well.

 */

static int

ip_addr_match(ip_addr_t addr)

{

    if (addr[0] == 255 && addr[1] == 255 && addr[2] == 255 && addr[3] == 255)

        return 1;

    if (!memcmp(addr, __local_ip_addr, sizeof(ip_addr_t)))

        return 1;

    /*

     * Consider it an address match if we haven't gotten our IP address yet.

     * Some DHCP servers will address IP packets to the assigned address

     * instead of a IP broadcast address.

     */

    if (__local_ip_addr[0] == 0 && __local_ip_addr[1] == 0 &&

        __local_ip_addr[2] == 0 && __local_ip_addr[3] == 0)

        return 1;

    return 0;

}

extern void __tcp_handler(pktbuf_t *, ip_route_t *);

/*

 * Handle IP packets coming from the polled ethernet interface.

 */

void

__ip_handler(pktbuf_t *pkt, enet_addr_t *src_enet_addr)

{

    ip_header_t *ip = pkt->ip_hdr;

    ip_route_t  r;

    int         hdr_bytes;

    /* first make sure its ours and has a good checksum. */

    if (!ip_addr_match(ip->destination) ||

        __sum((word *)ip, ip->hdr_len << 2, 0) != 0) {

        __pktbuf_free(pkt);

        return;

    }

    memcpy(r.ip_addr, ip->source, sizeof(ip_addr_t));

    memcpy(r.enet_addr, src_enet_addr, sizeof(enet_addr_t));

    hdr_bytes = ip->hdr_len << 2;

    pkt->pkt_bytes = ntohs(ip->length) - hdr_bytes;

    switch (ip->protocol) {

#if NET_SUPPORT_ICMP

      case IP_PROTO_ICMP:

        pkt->icmp_hdr = (icmp_header_t *)(((char *)ip) + hdr_bytes);

        __icmp_handler(pkt, &r);

        break;

#endif

#if NET_SUPPORT_TCP

      case IP_PROTO_TCP:

        pkt->tcp_hdr = (tcp_header_t *)(((char *)ip) + hdr_bytes);

        __tcp_handler(pkt, &r);

        break;

#endif

#if NET_SUPPORT_UDP

      case IP_PROTO_UDP:

        pkt->udp_hdr = (udp_header_t *)(((char *)ip) + hdr_bytes);

        __udp_handler(pkt, &r);

        break;

#endif

      default:

        __pktbuf_free(pkt);

        break;

    }

}

/*

 * Send an IP packet.

 *

 * The IP data field should contain pkt->pkt_bytes of data.

 * pkt->[udp|tcp|icmp]_hdr points to the IP data field. Any

 * IP options are assumed to be already in place in the IP

 * options field.

 */

int

__ip_send(pktbuf_t *pkt, int protocol, ip_route_t *dest)

{

    ip_header_t *ip = pkt->ip_hdr;

    int         hdr_bytes;

    unsigned short cksum;

    /*

     * Figure out header length. The use udp_hdr is

     * somewhat arbitrary, but works because it is

     * a union with other IP protocol headers.

     */

    hdr_bytes = (((char *)pkt->udp_hdr) - ((char *)ip));

    pkt->pkt_bytes += hdr_bytes;

    ip->version = 4;

    ip->hdr_len = hdr_bytes >> 2;

    ip->tos = 0;

    ip->length = htons(pkt->pkt_bytes);

    ip->ident = htons(ip_ident);

    ip_ident++;

    ip->fragment = 0;

    ip->ttl = 255;

    ip->ttl = 64;

    ip->protocol = protocol;

    ip->checksum = 0;

    memcpy(ip->source, __local_ip_addr, sizeof(ip_addr_t));

    memcpy(ip->destination, dest->ip_addr, sizeof(ip_addr_t));

    cksum = __sum((word *)ip, hdr_bytes, 0);

    ip->checksum = htons(cksum);

    __enet_send(pkt, &dest->enet_addr, ETH_TYPE_IP);

    return 0;

}