/*
 * Copyright (c) 2007, 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.
 *
 */

/**
 * \file
 *         Code for tunnelling uIP packets over the Rime mesh routing module
 * \author
 *         Adam Dunkels <adam@sics.se>
 */

#include <stdio.h>

#include "net/rime/rime.h"
#include "net/ipv4/uip-fw.h"
#include "net/ipv4/uip-over-mesh.h"

#define ROUTE_TRICKLE_INTERVAL CLOCK_SECOND * 32
#define ROUTE_DISCOVERY_INTERVAL CLOCK_SECOND * 4
#define ROUTE_TIMEOUT CLOCK_SECOND * 4

static struct queuebuf *queued_packet;
static linkaddr_t queued_receiver;

 /* Connection for route discovery: */
static struct route_discovery_conn route_discovery;

/* Connection for sending data packets to the next hop node: */
static struct unicast_conn dataconn;

/* Connection for sending gateway announcement message to the entire
   network: */
static struct trickle_conn gateway_announce_conn;

#define DEBUG 0
#if DEBUG
#include <stdio.h>
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...)
#endif

#define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])

static struct uip_fw_netif *gw_netif;
static linkaddr_t gateway;
static uip_ipaddr_t netaddr, netmask;

/*---------------------------------------------------------------------------*/
static void
recv_data(struct unicast_conn *c, const linkaddr_t *from)
{
  struct route_entry *e;
  linkaddr_t source;

  uip_len = packetbuf_copyto(&uip_buf[UIP_LLH_LEN]);

  source.u8[0] = BUF->srcipaddr.u8[2];
  source.u8[1] = BUF->srcipaddr.u8[3];

  e = route_lookup(&source);
  if(e == NULL) {
    route_add(&source, from, 10, 0);
  } else {
    route_refresh(e);
  }

  /* If we received data via a gateway, we refresh the gateway route.
   * Note: we refresh OUR gateway route, although we are not sure it forwarded the data. */
  if(!uip_ipaddr_maskcmp(&BUF->srcipaddr, &netaddr, &netmask)) {
    e = route_lookup(&gateway);
    if(e != NULL) {
      route_refresh(e);
    }
  }


  PRINTF("uip-over-mesh: %d.%d: recv_data with len %d\n",
	 linkaddr_node_addr.u8[0], linkaddr_node_addr.u8[1], uip_len);
  tcpip_input();
}
/*---------------------------------------------------------------------------*/
static void
send_data(linkaddr_t *next)
{
  PRINTF("uip-over-mesh: %d.%d: send_data with len %d\n",
	 linkaddr_node_addr.u8[0], linkaddr_node_addr.u8[1],
	 packetbuf_totlen());
  unicast_send(&dataconn, next);
}
/*---------------------------------------------------------------------------*/
static void
new_route(struct route_discovery_conn *c, const linkaddr_t *to)
{
  struct route_entry *rt;

  if(queued_packet) {
    PRINTF("uip-over-mesh: new route, sending queued packet\n");

    queuebuf_to_packetbuf(queued_packet);
    queuebuf_free(queued_packet);
    queued_packet = NULL;

    rt = route_lookup(&queued_receiver);
    if(rt) {
      route_decay(rt);
      send_data(&queued_receiver);
    }
  }
}
/*---------------------------------------------------------------------------*/
static void
timedout(struct route_discovery_conn *c)
{
  PRINTF("uip-over-mesh: packet timed out\n");
  if(queued_packet) {
    PRINTF("uip-over-mesh: freeing queued packet\n");
    queuebuf_free(queued_packet);
    queued_packet = NULL;
  }
}
/*---------------------------------------------------------------------------*/
static const struct unicast_callbacks data_callbacks = { recv_data };
static const struct route_discovery_callbacks rdc = { new_route, timedout };
/*---------------------------------------------------------------------------*/
struct gateway_msg {
  linkaddr_t gateway;
};

static uint8_t is_gateway;

static void
gateway_announce_recv(struct trickle_conn *c)
{
  struct gateway_msg *msg;
  msg = packetbuf_dataptr();
  PRINTF("%d.%d: gateway message: %d.%d\n",
	 linkaddr_node_addr.u8[0], linkaddr_node_addr.u8[1],
	 msg->gateway.u8[0], msg->gateway.u8[1]);

  if(!is_gateway) {
    uip_over_mesh_set_gateway(&msg->gateway);
  }

}
/*---------------------------------------------------------------------------*/
void
uip_over_mesh_make_announced_gateway(void)
{
  struct gateway_msg msg;
  /* Make this node the gateway node, unless it already is the
     gateway. */
  if(!is_gateway) {
    PRINTF("%d.%d: making myself the gateway\n",
	   linkaddr_node_addr.u8[0], linkaddr_node_addr.u8[1]);
    uip_over_mesh_set_gateway(&linkaddr_node_addr);
    linkaddr_copy(&(msg.gateway), &linkaddr_node_addr);
    packetbuf_copyfrom(&msg, sizeof(struct gateway_msg));
    trickle_send(&gateway_announce_conn);
    is_gateway = 1;
  }
}
const static struct trickle_callbacks trickle_call = {gateway_announce_recv};
/*---------------------------------------------------------------------------*/
void
uip_over_mesh_init(uint16_t channels)
{

  PRINTF("Our address is %d.%d (%d.%d.%d.%d)\n",
	 linkaddr_node_addr.u8[0], linkaddr_node_addr.u8[1],
	 uip_hostaddr.u8[0], uip_hostaddr.u8[1],
	 uip_hostaddr.u8[2], uip_hostaddr.u8[3]);

  unicast_open(&dataconn, channels, &data_callbacks);
  route_discovery_open(&route_discovery, ROUTE_DISCOVERY_INTERVAL,
		       channels + 1, &rdc);
  trickle_open(&gateway_announce_conn, ROUTE_TRICKLE_INTERVAL, channels + 3,
	       &trickle_call);

  route_init();
  /* Set lifetime to 30 seconds for non-refreshed routes. */
  route_set_lifetime(30);
}
/*---------------------------------------------------------------------------*/
uint8_t
uip_over_mesh_send(void)
{
  linkaddr_t receiver;
  struct route_entry *rt;

  /* This function is called by the uip-fw module to send out an IP
     packet. We try to send the IP packet to the next hop route, or we
     queue the packet and send out a route request for the final
     receiver of the packet. */

  /* Packets destined to this network is sent using mesh, whereas
     packets destined to a network outside this network is sent towards
     the gateway node. */

  if(uip_ipaddr_maskcmp(&BUF->destipaddr, &netaddr, &netmask)) {
    receiver.u8[0] = BUF->destipaddr.u8[2];
    receiver.u8[1] = BUF->destipaddr.u8[3];
  } else {
    if(linkaddr_cmp(&gateway, &linkaddr_node_addr)) {
      PRINTF("uip_over_mesh_send: I am gateway, packet to %d.%d.%d.%d to local interface\n",
	     uip_ipaddr_to_quad(&BUF->destipaddr));
      if(gw_netif != NULL) {
	return gw_netif->output();
      }
      return UIP_FW_DROPPED;
    } else if(linkaddr_cmp(&gateway, &linkaddr_null)) {
      PRINTF("uip_over_mesh_send: No gateway setup, dropping packet\n");
      return UIP_FW_OK;
    } else {
      PRINTF("uip_over_mesh_send: forwarding packet to %d.%d.%d.%d towards gateway %d.%d\n",
	     uip_ipaddr_to_quad(&BUF->destipaddr),
	     gateway.u8[0], gateway.u8[1]);
      linkaddr_copy(&receiver, &gateway);
    }
  }

  PRINTF("uIP over mesh send to %d.%d with len %d\n",
	 receiver.u8[0], receiver.u8[1],
	 uip_len);


  packetbuf_copyfrom(&uip_buf[UIP_LLH_LEN], uip_len);

  rt = route_lookup(&receiver);
  if(rt == NULL) {
    PRINTF("uIP over mesh no route to %d.%d\n", receiver.u8[0], receiver.u8[1]);
    if(queued_packet == NULL) {
      queued_packet = queuebuf_new_from_packetbuf();
      linkaddr_copy(&queued_receiver, &receiver);
      route_discovery_discover(&route_discovery, &receiver, ROUTE_TIMEOUT);
    } else if(!linkaddr_cmp(&queued_receiver, &receiver)) {
      route_discovery_discover(&route_discovery, &receiver, ROUTE_TIMEOUT);
    }
  } else {
    route_decay(rt);
    send_data(&rt->nexthop);
  }
  return UIP_FW_OK;
}
/*---------------------------------------------------------------------------*/
void
uip_over_mesh_set_gateway_netif(struct uip_fw_netif *n)
{
  gw_netif = n;
}
/*---------------------------------------------------------------------------*/
void
uip_over_mesh_set_gateway(linkaddr_t *gw)
{
  linkaddr_copy(&gateway, gw);
}
/*---------------------------------------------------------------------------*/
void
uip_over_mesh_set_net(uip_ipaddr_t *addr, uip_ipaddr_t *mask)
{
  uip_ipaddr_copy(&netaddr, addr);
  uip_ipaddr_copy(&netmask, mask);
}
/*---------------------------------------------------------------------------*/