/*
 * Copyright (c) 2001-2003 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. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 lwIP TCP/IP stack.
 * 
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

#include "lwip/debug.h"

#include <stdlib.h> 

#include "lwip/def.h"
#include "netif/delif.h"

#ifdef linux
#include "netif/tapif.h"
#else /* linux */
#include "netif/tunif.h"
#endif /* linux */

#include "lwip/sys.h"


#define DELIF_INPUT_DROPRATE 0.1
#define DELIF_OUTPUT_DROPRATE 0.1

#define DELIF_INPUT_DELAY  500      /* Miliseconds. */
#define DELIF_OUTPUT_DELAY 500      /* Miliseconds. */

#define DELIF_TIMEOUT 10

struct delif {
  err_t (* input)(struct pbuf *p, struct netif *inp);
  struct netif *netif;
};

struct delif_pbuf {
  struct delif_pbuf *next;
  struct pbuf *p;
  ip_addr_t *ipaddr;
  unsigned int time;
};

static struct delif_pbuf *input_list = NULL;
static struct delif_pbuf *output_list = NULL;
/*-----------------------------------------------------------------------------------*/
static void
delif_input_timeout(void *arg)
{
  struct netif *netif;
  struct delif *delif;
  struct delif_pbuf *dp;
  unsigned int timeout, now;

  timeout = DELIF_TIMEOUT;
  
  netif = arg;
  delif = netif->state;

  
  /* Check if there is anything on the input list. */
  dp = input_list;
  while (dp != NULL) {
    now = sys_now();

    if (dp->time <= now) {
      delif->input(dp->p, netif);
      if (dp->next != NULL) {
        if (dp->next->time > now) {
          timeout = dp->next->time - now;
        } else {
          timeout = 0;
        }
        LWIP_DEBUGF(DELIF_DEBUG, ("delif_output_timeout: timeout %u.\n", timeout));

      }
      input_list = dp->next;
      free(dp);
      dp = input_list;
    } else {
      dp = dp->next;	
    }
  }
  
  sys_timeout(timeout, delif_input_timeout, arg);
}
/*-----------------------------------------------------------------------------------*/
static void
delif_output_timeout(void *arg)
{
  struct netif *netif;
  struct delif *delif;
  struct delif_pbuf *dp;
  unsigned int timeout, now;

  timeout = DELIF_TIMEOUT;

  netif = arg;
  delif = netif->state;

  /* Check if there is anything on the output list. */
  dp = output_list;
  while (dp != NULL) {
    now = sys_now();
    if (dp->time <= now) {
      LWIP_DEBUGF(DELIF_DEBUG, ("delif_output_timeout: now %u dp->time %u\n",
        now, dp->time));
      delif->netif->output(delif->netif, dp->p, dp->ipaddr);
      if (dp->next != NULL) {
        if (dp->next->time > now) {
          timeout = dp->next->time - now;
        } else {
          timeout = 0;
        }
        LWIP_DEBUGF(DELIF_DEBUG, ("delif_output_timeout: timeout %u.\n", timeout));

      }
      pbuf_free(dp->p);

      output_list = dp->next;
      free(dp);
      dp = output_list;
    } else {
      dp = dp->next;	
    }
  }

  
  sys_timeout(timeout, delif_output_timeout, arg);
}
/*-----------------------------------------------------------------------------------*/
static err_t
delif_output(struct netif *netif, struct pbuf *p, ip_addr_t *ipaddr)
{
  struct delif_pbuf *dp, *np;
  struct pbuf *q;
  int i, j;
  char *data;

  LWIP_DEBUGF(DELIF_DEBUG, ("delif_output\n"));
    
#ifdef DELIF_OUTPUT_DROPRATE
  if (((double)rand()/(double)RAND_MAX) < DELIF_OUTPUT_DROPRATE) {
    LWIP_DEBUGF(DELIF_DEBUG, ("delif_output: Packet dropped\n"));
    return 0;
  }
#endif /* DELIF_OUTPUT_DROPRATE */

  
  LWIP_DEBUGF(DELIF_DEBUG, ("delif_output\n"));


  dp = malloc(sizeof(struct delif_pbuf));
  data = malloc(p->tot_len);
    
  i = 0;
  for(q = p; q != NULL; q = q->next) {
    for(j = 0; j < q->len; j++) {
      data[i] = ((char *)q->payload)[j];
      i++;
    }
  }

  
  dp->p = pbuf_alloc(PBUF_LINK, 0, PBUF_ROM);
  dp->p->payload = data;
  dp->p->len = p->tot_len;
  dp->p->tot_len = p->tot_len;
  dp->ipaddr = ipaddr;
  dp->time = sys_now() + DELIF_OUTPUT_DELAY;
  dp->next = NULL;
  if (output_list == NULL) {
    output_list = dp;
  } else {
    for(np = output_list; np->next != NULL; np = np->next);
    np->next = dp;
  }
    

  return ERR_OK;
    

}
/*-----------------------------------------------------------------------------------*/
static err_t
delif_input(struct pbuf *p, struct netif *inp)
{
  struct delif_pbuf *dp, *np;

  LWIP_DEBUGF(DELIF_DEBUG, ("delif_input\n"));
#ifdef DELIF_INPUT_DROPRATE
  if (((double)rand()/(double)RAND_MAX) < DELIF_INPUT_DROPRATE) {
    LWIP_DEBUGF(DELIF_DEBUG, ("delif_input: Packet dropped\n"));
    pbuf_free(p);
    return ERR_OK;
  }
#endif /* DELIF_INPUT_DROPRATE */

  
  dp = malloc(sizeof(struct delif_pbuf));
  dp->p = p;
  dp->time = sys_now() + DELIF_INPUT_DELAY;
  dp->next = NULL;
  if (input_list == NULL) {
    input_list = dp;
  } else {
    for(np = input_list; np->next != NULL; np = np->next);
    np->next = dp;
  }
  return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
err_t
delif_init(struct netif *netif)
{
  struct delif *del;
  
  del = malloc(sizeof(struct delif));
  if (!del)
      return ERR_MEM;
  netif->state = del;
  netif->name[0] = 'd';
  netif->name[1] = 'e';
  netif->output = delif_output;

  del->netif = malloc(sizeof(struct netif));  
  if (!del->netif) {
      free(del);
      return ERR_MEM;
  }
#ifdef linux
  /*  tapif_init(del->netif);*/
  tunif_init(del->netif);
#else /* linux */
  tunif_init(del->netif);
#endif /* linux */
  del->input = netif->input;
  del->netif->input = delif_input;
  sys_timeout(DELIF_TIMEOUT, delif_input_timeout, netif);
  sys_timeout(DELIF_TIMEOUT, delif_output_timeout, netif);
  return ERR_OK;
}

/*-----------------------------------------------------------------------------------*/
static void 
delif_thread(void *arg)
{
  struct netif *netif = arg;
  struct delif *del;
  sys_sem_t sem;
  
  del = netif->state;
#ifdef linux
  tapif_init(del->netif);
#else /* linux */
  tunif_init(del->netif);
#endif /* linux */

  sys_timeout(DELIF_TIMEOUT, delif_input_timeout, netif);
  sys_timeout(DELIF_TIMEOUT, delif_output_timeout, netif);

  if(sys_sem_new(&sem, 0) != ERR_OK) {
    LWIP_ASSERT("Failed to create semaphore", 0);
  }
  sys_sem_wait(&sem);

}
/*-----------------------------------------------------------------------------------*/
err_t
delif_init_thread(struct netif *netif)
{
  struct delif *del;

  LWIP_DEBUGF(DELIF_DEBUG, ("delif_init_thread\n"));
  
  del = malloc(sizeof(struct delif));
  if (!del)
      return ERR_MEM;
  netif->state = del;
  netif->name[0] = 'd';
  netif->name[1] = 'e';
  netif->output = delif_output;

  del->netif = malloc(sizeof(struct netif));
  if (!del->netif) {
      free(del);
      return ERR_MEM;
  }
  del->netif->ip_addr = netif->ip_addr;
  del->netif->gw = netif->gw;
  del->netif->netmask = netif->netmask;
  del->input = netif->input;
  del->netif->input = delif_input;
  sys_thread_new("delif_thread", delif_thread, netif, DEFAULT_THREAD_STACKSIZE, DEFAULT_THREAD_PRIO);
  return ERR_OK;
}

/*-----------------------------------------------------------------------------------*/