/*
 * Copyright (c) 2009, Swedish Institute of 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.
 */

/**
 * \addtogroup rpl-lite
 * @{
 *
 * \file
 *         ContikiRPL, an implementation of RPL: IPv6 Routing Protocol
 *         for Low-Power and Lossy Networks (IETF RFC 6550)
 *
 * \author Joakim Eriksson <joakime@sics.se>, Nicolas Tsiftes <nvt@sics.se>
 *  Simon Duquennoy <simon.duquennoy@inria.fr>
 */

#include "net/routing/rpl-lite/rpl.h"
#include "net/routing/routing.h"

/* Log configuration */
#include "sys/log.h"
#define LOG_MODULE "RPL"
#define LOG_LEVEL LOG_LEVEL_RPL

uip_ipaddr_t rpl_multicast_addr;

/*---------------------------------------------------------------------------*/
int
rpl_lollipop_greater_than(int a, int b)
{
  /* Check if we are comparing an initial value with an old value */
  if(a > RPL_LOLLIPOP_CIRCULAR_REGION && b <= RPL_LOLLIPOP_CIRCULAR_REGION) {
    return (RPL_LOLLIPOP_MAX_VALUE + 1 + b - a) > RPL_LOLLIPOP_SEQUENCE_WINDOWS;
  }
  /* Otherwise check if a > b and comparable => ok, or
     if they have wrapped and are still comparable */
  return (a > b && (a - b) < RPL_LOLLIPOP_SEQUENCE_WINDOWS) ||
    (a < b && (b - a) > (RPL_LOLLIPOP_CIRCULAR_REGION + 1-
			 RPL_LOLLIPOP_SEQUENCE_WINDOWS));
}
/*---------------------------------------------------------------------------*/
const uip_ipaddr_t *
rpl_get_global_address(void)
{
  int i;
  uint8_t state;
  uip_ipaddr_t *ipaddr = NULL;
  uip_ipaddr_t *prefix = NULL;
  uint8_t prefix_length = 0;

  if(curr_instance.used && curr_instance.dag.prefix_info.length != 0) {
    prefix = &curr_instance.dag.prefix_info.prefix;
    prefix_length = curr_instance.dag.prefix_info.length;
  }

  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_PREFERRED &&
       !uip_is_addr_linklocal(&uip_ds6_if.addr_list[i].ipaddr) &&
       (prefix == NULL || uip_ipaddr_prefixcmp(prefix, &uip_ds6_if.addr_list[i].ipaddr, prefix_length))) {
      ipaddr = &uip_ds6_if.addr_list[i].ipaddr;
    }
  }
  return ipaddr;
}
/*---------------------------------------------------------------------------*/
void
rpl_link_callback(const linkaddr_t *addr, int status, int numtx)
{
  if(curr_instance.used == 1 ) {
    rpl_nbr_t *nbr = rpl_neighbor_get_from_lladdr((uip_lladdr_t *)addr);
    if(nbr != NULL) {
      /* Link stats were updated, and we need to update our internal state.
      Updating from here is unsafe; postpone */
      LOG_INFO("packet sent to ");
      LOG_INFO_LLADDR(addr);
      LOG_INFO_(", status %u, tx %u, new link metric %u\n", status, numtx, rpl_neighbor_get_link_metric(nbr));
      rpl_timers_schedule_state_update();
    }
  }
}
/*---------------------------------------------------------------------------*/
int
rpl_is_reachable(void)
{
  return curr_instance.used && curr_instance.dag.state == DAG_REACHABLE;
}
/*---------------------------------------------------------------------------*/
static void
set_ip_from_prefix(uip_ipaddr_t *ipaddr, rpl_prefix_t *prefix)
{
  memset(ipaddr, 0, sizeof(uip_ipaddr_t));
  memcpy(ipaddr, &prefix->prefix, (prefix->length + 7) / 8);
  uip_ds6_set_addr_iid(ipaddr, &uip_lladdr);
}
/*---------------------------------------------------------------------------*/
void
rpl_reset_prefix(rpl_prefix_t *last_prefix)
{
  uip_ipaddr_t ipaddr;
  uip_ds6_addr_t *rep;
  set_ip_from_prefix(&ipaddr, last_prefix);
  rep = uip_ds6_addr_lookup(&ipaddr);
  if(rep != NULL) {
    LOG_INFO("removing global IP address ");
    LOG_INFO_6ADDR(&ipaddr);
    LOG_INFO_("\n");
    uip_ds6_addr_rm(rep);
  }
  curr_instance.dag.prefix_info.length = 0;
}
/*---------------------------------------------------------------------------*/
int
rpl_set_prefix_from_addr(uip_ipaddr_t *addr, unsigned len, uint8_t flags)
{
  uip_ipaddr_t ipaddr;

  if(addr == NULL || len == 0 || len > 128 || !(flags & UIP_ND6_RA_FLAG_AUTONOMOUS)) {
    LOG_WARN("prefix not included, not-supported or invalid\n");
    return 0;
  }

  /* Try and initialize prefix */
  memset(&curr_instance.dag.prefix_info.prefix, 0, sizeof(rpl_prefix_t));
  memcpy(&curr_instance.dag.prefix_info.prefix, addr, (len + 7) / 8);
  curr_instance.dag.prefix_info.length = len;
  curr_instance.dag.prefix_info.lifetime = RPL_ROUTE_INFINITE_LIFETIME;
  curr_instance.dag.prefix_info.flags = flags;

  /* Add global address if not already there */
  set_ip_from_prefix(&ipaddr, &curr_instance.dag.prefix_info);
  if(uip_ds6_addr_lookup(&ipaddr) == NULL) {
    LOG_INFO("adding global IP address ");
    LOG_INFO_6ADDR(&ipaddr);
    LOG_INFO_("\n");
    uip_ds6_addr_add(&ipaddr, 0, ADDR_AUTOCONF);
  }
  return 1;
}
/*---------------------------------------------------------------------------*/
int
rpl_set_prefix(rpl_prefix_t *prefix)
{
  if(prefix != NULL && rpl_set_prefix_from_addr(&prefix->prefix, prefix->length, prefix->flags)) {
    curr_instance.dag.prefix_info.lifetime = prefix->lifetime;
    return 1;
  }
  return 0;
}
/*---------------------------------------------------------------------------*/
static void
init(void)
{
  LOG_INFO("initializing\n");

  /* Initialize multicast address and register it */
  uip_create_linklocal_rplnodes_mcast(&rpl_multicast_addr);
  uip_ds6_maddr_add(&rpl_multicast_addr);

  rpl_dag_init();
  rpl_neighbor_init();
  rpl_timers_init();
  rpl_icmp6_init();

  rpl_ns_init();
}
/*---------------------------------------------------------------------------*/
static void
drop_route(uip_ds6_route_t *route)
{
  /* Do nothing. RPL-lite only supports non-storing mode, i.e. no routes */
}
/*---------------------------------------------------------------------------*/
const struct routing_driver rpl_lite_driver = {
  "RPL Lite",
  init,
  rpl_dag_root_set_prefix,
  rpl_dag_root_start,
  rpl_global_repair,
  rpl_local_repair,
  rpl_ext_header_remove,
  rpl_ext_header_update,
  rpl_ext_header_hbh_update,
  rpl_ext_header_srh_update,
  rpl_ext_header_srh_get_next_hop,
  rpl_link_callback,
  drop_route,
};
/*---------------------------------------------------------------------------*/

/** @}*/