ip64-slip-interface.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 "net/ipv6/uip.h"
#include "net/ipv6/uip-ds6.h"
#include "dev/slip.h"

#include "ip64/ip64.h"

#include <string.h>
#include <stdio.h>

#define UIP_IP_BUF        ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN])

#define DEBUG DEBUG_NONE
#include "net/ipv6/uip-debug.h"

static uip_ipaddr_t last_sender;

/*---------------------------------------------------------------------------*/
void
ip64_slip_interface_input(uint8_t *packet, uint16_t len)
{
  /* Dummy definition: this function is not actually called, but must
     be here to conform to the ip65-interface.h structure. */
}
/*---------------------------------------------------------------------------*/
static void
input_callback(void)
{
  /*PRINTF("SIN: %u\n", uip_len);*/
  if(uip_buf[UIP_LLH_LEN] == '!') {
    PRINTF("Got configuration message of type %c\n", uip_buf[UIP_LLH_LEN + 1]);
    uip_clear_buf();
#if 0
    if(uip_buf[UIP_LLH_LEN + 1] == 'P') {
      uip_ipaddr_t prefix;
      /* Here we set a prefix !!! */
      memset(&prefix, 0, 16);
      memcpy(&prefix, &uip_buf[UIP_LLH_LEN + 2], 8);
      PRINTF("Setting prefix ");
      PRINT6ADDR(&prefix);
      PRINTF("\n");
      set_prefix_64(&prefix);
    }
#endif
  } else if(uip_buf[UIP_LLH_LEN] == '?') {
    PRINTF("Got request message of type %c\n", uip_buf[UIP_LLH_LEN + 1]);
    if(uip_buf[UIP_LLH_LEN + 1] == 'M') {
      const char *hexchar = "0123456789abcdef";
      int j;
      /* this is just a test so far... just to see if it works */
      uip_buf[0] = '!';
      for(j = 0; j < 8; j++) {
        uip_buf[2 + j * 2] = hexchar[uip_lladdr.addr[j] >> 4];
        uip_buf[3 + j * 2] = hexchar[uip_lladdr.addr[j] & 15];
      }
      uip_len = 18;
      slip_write(uip_buf, uip_len);
    }
    uip_clear_buf();
  } else {
    
    /* Save the last sender received over SLIP to avoid bouncing the
       packet back if no route is found */
    uip_ipaddr_copy(&last_sender, &UIP_IP_BUF->srcipaddr);
    
    uint16_t len = ip64_4to6(&uip_buf[UIP_LLH_LEN], uip_len, 
                             ip64_packet_buffer);
    if(len > 0) {
      memcpy(&uip_buf[UIP_LLH_LEN], ip64_packet_buffer, len);
      uip_len = len;
      /*      PRINTF("send len %d\n", len); */
    } else {
      uip_clear_buf();
    }
  }
}
/*---------------------------------------------------------------------------*/
static void
init(void)
{
  PRINTF("ip64-slip-interface: init\n");
  process_start(&slip_process, NULL);
  slip_set_input_callback(input_callback);
}
/*---------------------------------------------------------------------------*/
static int
output(void)
{
  int len;

  PRINTF("ip64-slip-interface: output source ");

  /*
  PRINT6ADDR(&UIP_IP_BUF->srcipaddr);
  PRINTF(" destination ");
  PRINT6ADDR(&UIP_IP_BUF->destipaddr);
  PRINTF("\n");
  */
  if(uip_ipaddr_cmp(&last_sender, &UIP_IP_BUF->srcipaddr)) {
    PRINTF("ip64-interface: output, not sending bounced message\n");
  } else {
    len = ip64_6to4(&uip_buf[UIP_LLH_LEN], uip_len,
                    ip64_packet_buffer);
    PRINTF("ip64-interface: output len %d\n", len);
    if(len > 0) {
      memcpy(&uip_buf[UIP_LLH_LEN], ip64_packet_buffer, len);
      uip_len = len;
      slip_send();
      return len;
    }
  }
  return 0;
}
/*---------------------------------------------------------------------------*/
const struct uip_fallback_interface ip64_slip_interface = {
  init, output
};
/*---------------------------------------------------------------------------*/