text: /*
   * Copyright (c) 2010, Loughborough University - Computer Science
   * 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 Institute 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 INSTITUTE 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 INSTITUTE 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.
   *
   * This file is part of the Contiki operating system.
   */
  
  /**
   * \file
   *         This node is part of the RPL multicast example. It is an RPL root
   *         and sends a multicast message periodically. For the example to work,
   *         we need one of those nodes.
   *
   * \author
   *         George Oikonomou - <oikonomou@users.sourceforge.net>
   */
  
  #include "contiki.h"
  #include "contiki-lib.h"
  #include "contiki-net.h"
  #include "net/ipv6/multicast/uip-mcast6.h"
  
  #include <string.h>
  
  #define DEBUG DEBUG_PRINT
  #include "net/ip/uip-debug.h"
  #include "net/rpl/rpl.h"
  
  #define MAX_PAYLOAD_LEN 120
  #define MCAST_SINK_UDP_PORT 3001 /* Host byte order */
  #define SEND_INTERVAL CLOCK_SECOND /* clock ticks */
  #define ITERATIONS 100 /* messages */
  
  /* Start sending messages START_DELAY secs after we start so that routing can
   * converge */
  #define START_DELAY 60
  
  static struct uip_udp_conn * mcast_conn;
  static char buf[MAX_PAYLOAD_LEN];
  static uint32_t seq_id;
  
  #if !NETSTACK_CONF_WITH_IPV6 || !UIP_CONF_ROUTER || !UIP_CONF_IPV6_MULTICAST || !UIP_CONF_IPV6_RPL
  #error "This example can not work with the current contiki configuration"
  #error "Check the values of: NETSTACK_CONF_WITH_IPV6, UIP_CONF_ROUTER, UIP_CONF_IPV6_RPL"
  #endif
  /*---------------------------------------------------------------------------*/
  PROCESS(rpl_root_process, "RPL ROOT, Multicast Sender");
  AUTOSTART_PROCESSES(&rpl_root_process);
  /*---------------------------------------------------------------------------*/
  static void
  multicast_send(void)
  {
    uint32_t id;
  
    id = uip_htonl(seq_id);
    memset(buf, 0, MAX_PAYLOAD_LEN);
    memcpy(buf, &id, sizeof(seq_id));
  
    PRINTF("Send to: ");
    PRINT6ADDR(&mcast_conn->ripaddr);
    PRINTF(" Remote Port %u,", uip_ntohs(mcast_conn->rport));
    PRINTF(" (msg=0x%08lx)", (unsigned long)uip_ntohl(*((uint32_t *)buf)));
    PRINTF(" %lu bytes\n", (unsigned long)sizeof(id));
  
    seq_id++;
    uip_udp_packet_send(mcast_conn, buf, sizeof(id));
  }
  /*---------------------------------------------------------------------------*/
  static void
  prepare_mcast(void)
  {
    uip_ipaddr_t ipaddr;
  
    /*
     * IPHC will use stateless multicast compression for this destination
     * (M=1, DAC=0), with 32 inline bits (1E 89 AB CD)
     */
    uip_ip6addr(&ipaddr, 0xFF1E,0,0,0,0,0,0x89,0xABCD);
    mcast_conn = udp_new(&ipaddr, UIP_HTONS(MCAST_SINK_UDP_PORT), NULL);
  }
  /*---------------------------------------------------------------------------*/
  static void
  set_own_addresses(void)
  {
    int i;
    uint8_t state;
    rpl_dag_t *dag;
    uip_ipaddr_t ipaddr;
  
    uip_ip6addr(&ipaddr, 0xaaaa, 0, 0, 0, 0, 0, 0, 0);
    uip_ds6_set_addr_iid(&ipaddr, &uip_lladdr);
    uip_ds6_addr_add(&ipaddr, 0, ADDR_AUTOCONF);
  
    PRINTF("Our IPv6 addresses:\n");
    for(i = 0; i < UIP_DS6_ADDR_NB; i++) {
      state = uip_ds6_if.addr_list[i].state;
      if(uip_ds6_if.addr_list[i].isused && (state == ADDR_TENTATIVE || state
          == ADDR_PREFERRED)) {
        PRINTF("  ");
        PRINT6ADDR(&uip_ds6_if.addr_list[i].ipaddr);
        PRINTF("\n");
        if(state == ADDR_TENTATIVE) {
          uip_ds6_if.addr_list[i].state = ADDR_PREFERRED;
        }
      }
    }
  
    /* Become root of a new DODAG with ID our global v6 address */
    dag = rpl_set_root(RPL_DEFAULT_INSTANCE, &ipaddr);
    if(dag != NULL) {
      rpl_set_prefix(dag, &ipaddr, 64);
      PRINTF("Created a new RPL dag with ID: ");
      PRINT6ADDR(&dag->dag_id);
      PRINTF("\n");
    }
  }
  /*---------------------------------------------------------------------------*/
  PROCESS_THREAD(rpl_root_process, ev, data)
  {
    static struct etimer et;
  
    PROCESS_BEGIN();
  
    PRINTF("Multicast Engine: '%s'\n", UIP_MCAST6.name);
  
    NETSTACK_MAC.off(1);
  
    set_own_addresses();
  
    prepare_mcast();
  
    etimer_set(&et, START_DELAY * CLOCK_SECOND);
    while(1) {
      PROCESS_YIELD();
      if(etimer_expired(&et)) {
        if(seq_id == ITERATIONS) {
          etimer_stop(&et);
        } else {
          multicast_send();
          etimer_set(&et, SEND_INTERVAL);
        }
      }
    }
  
    PROCESS_END();
  }
  /*---------------------------------------------------------------------------*/
  