ip64-addr.c

/*
 * Copyright (c) 2012, Thingsquare, http://www.thingsquare.com/.
 * 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. Neither the name of the copyright holder nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``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
 * COPYRIGHT HOLDER OR CONTRIBUTORS 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.
 *
 */
#include "ipv6/ip64-addr.h"
 
#include <stdio.h>
#include <string.h>
 
/* Log configuration */
#include "sys/log.h"
#define LOG_MODULE "IPv6"
#define LOG_LEVEL LOG_LEVEL_NONE
 
/*
 * By defult we do use the well-known-prefix for the IP64 address prefix, see
 * RFC6052, https://tools.ietf.org/html/rfc6052#section-2.1 .
 * To make use of ::ffff:<IPv4> define IP64_NAT64_USE_WELL_KNOWN_PREFIX to zero.
 */
#ifndef IP64_NAT64_USE_WELL_KNOWN_PREFIX
#define IP64_NAT64_USE_WELL_KNOWN_PREFIX 1
#endif /* IP64_NAT64_USE_WELL_KNOWN_PREFIX */
 
#if IP64_NAT64_USE_WELL_KNOWN_PREFIX
static uip_ip6addr_t ip64_prefix = {{ 0, 0x64, 0xff, 0x9b, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}};
#else
static uip_ip6addr_t ip64_prefix = {{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 0, 0, 0, 0}};
#endif /*  IP64_NAT64_USE_WELL_KNOWN_PREFIX */
 
static uint8_t ip64_prefix_len = 96;
 
/*---------------------------------------------------------------------------*/
void
ip64_addr_copy4(uip_ip4addr_t *dest, const uip_ip4addr_t *src)
{
  memcpy(dest, src, sizeof(uip_ip4addr_t));
}
/*---------------------------------------------------------------------------*/
void
ip64_addr_copy6(uip_ip6addr_t *dest, const uip_ip6addr_t *src)
{
  memcpy(dest, src, sizeof(uip_ip6addr_t));
}
/*---------------------------------------------------------------------------*/
int
ip64_addr_4to6(const uip_ip4addr_t *ipv4addr,
               uip_ip6addr_t *ipv6addr)
{
  /* This function converts an IPv4 addresses into an IPv6
     addresses. It returns 0 if it failed to convert the address and
     non-zero if it could successfully convert the address. */
 
  uip_ipaddr_copy(ipv6addr, &ip64_prefix);
  ipv6addr->u8[12] = ipv4addr->u8[0];
  ipv6addr->u8[13] = ipv4addr->u8[1];
  ipv6addr->u8[14] = ipv4addr->u8[2];
  ipv6addr->u8[15] = ipv4addr->u8[3];
  LOG_DBG("ip64_addr_4to6: IPv6-encoded IPv4 address %d.%d.%d.%d => ",
          ipv4addr->u8[0], ipv4addr->u8[1],
          ipv4addr->u8[2], ipv4addr->u8[3]);
  LOG_DBG_6ADDR(ipv6addr);
  LOG_DBG("\n");
 
  /* Conversion succeeded, we return non-zero. */
  return 1;
}
/*---------------------------------------------------------------------------*/
int
ip64_addr_6to4(const uip_ip6addr_t *ipv6addr,
               uip_ip4addr_t *ipv4addr)
{
  /* This function converts IPv6 addresses to IPv4 addresses. It
     returns 0 if it failed to convert the address and non-zero if it
     could successfully convert the address. */
 
  if(ip64_addr_is_ip64(ipv6addr)) {
    ipv4addr->u8[0] = ipv6addr->u8[12];
    ipv4addr->u8[1] = ipv6addr->u8[13];
    ipv4addr->u8[2] = ipv6addr->u8[14];
    ipv4addr->u8[3] = ipv6addr->u8[15];
 
    LOG_DBG("ip64_addr_6to4: IPv6-encoded IPv4 address %d.%d.%d.%d <=",
            ipv4addr->u8[0], ipv4addr->u8[1],
            ipv4addr->u8[2], ipv4addr->u8[3]);
    LOG_DBG_6ADDR(ipv6addr);
    LOG_DBG("\n");
 
    /* Conversion succeeded, we return non-zero. */
    return 1;
  }
  /* We could not convert the IPv6 address, so we return 0. */
  return 0;
}
/*---------------------------------------------------------------------------*/
int
ip64_addr_is_ip64(const uip_ip6addr_t *ipv6addr)
{
  return uip_ipaddr_prefixcmp(ipv6addr, &ip64_prefix, ip64_prefix_len);
}
/*---------------------------------------------------------------------------*/
void
ip64_addr_set_prefix(const uip_ip6addr_t *prefix, uint8_t prefix_len)
{
  uip_ipaddr_copy(&ip64_prefix, prefix);
  ip64_prefix_len = prefix_len;
}
/*---------------------------------------------------------------------------*/