/*
 * PIM for Quagga
 * Copyright (C) 2008  Everton da Silva Marques
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <zebra.h>

#include "log.h"
#include "memory.h"
#include "linklist.h"
#include "if.h"
#include "hash.h"
#include "jhash.h"

#include "pimd.h"
#include "pim_oil.h"
#include "pim_str.h"
#include "pim_iface.h"
#include "pim_time.h"

struct list *pim_channel_oil_list = NULL;
struct hash *pim_channel_oil_hash = NULL;

char *
pim_channel_oil_dump (struct channel_oil *c_oil, char *buf, size_t size)
{
  struct prefix_sg sg;
  int i;

  memset (buf, 0, size);
  sg.src = c_oil->oil.mfcc_origin;
  sg.grp = c_oil->oil.mfcc_mcastgrp;
  sprintf(buf, "%s IIF: %d, OIFS: ",
          pim_str_sg_dump (&sg), c_oil->oil.mfcc_parent);

  for (i = 0 ; i < MAXVIFS ; i++)
    {
      if (c_oil->oil.mfcc_ttls[i] != 0)
        {
          char buf1[10];
          sprintf(buf1, "%d ", i);
          strcat(buf, buf1);
        }
    }

  return buf;
}

static int
pim_channel_oil_compare (struct channel_oil *c1, struct channel_oil *c2)
{
  if (ntohl(c1->oil.mfcc_mcastgrp.s_addr) < ntohl(c2->oil.mfcc_mcastgrp.s_addr))
     return -1;

   if (ntohl(c1->oil.mfcc_mcastgrp.s_addr) > ntohl(c2->oil.mfcc_mcastgrp.s_addr))
     return 1;

   if (ntohl(c1->oil.mfcc_origin.s_addr) < ntohl(c2->oil.mfcc_origin.s_addr))
     return -1;

   if (ntohl(c1->oil.mfcc_origin.s_addr) > ntohl(c2->oil.mfcc_origin.s_addr))
     return 1;

   return 0;
}

static int
pim_oil_equal (const void *arg1, const void *arg2)
{
  const struct channel_oil *c1 = (const struct channel_oil *)arg1;
  const struct channel_oil *c2 = (const struct channel_oil *)arg2;

  if ((c1->oil.mfcc_mcastgrp.s_addr == c2->oil.mfcc_mcastgrp.s_addr) &&
      (c1->oil.mfcc_origin.s_addr == c2->oil.mfcc_origin.s_addr))
    return 1;

  return 0;
}

static unsigned int
pim_oil_hash_key (void *arg)
{
  struct channel_oil *oil = (struct channel_oil *)arg;

  return jhash_2words (oil->oil.mfcc_mcastgrp.s_addr, oil->oil.mfcc_origin.s_addr, 0);
}

void
pim_oil_init (void)
{
  pim_channel_oil_hash = hash_create_size (8192, pim_oil_hash_key,
					   pim_oil_equal, NULL);

  pim_channel_oil_list = list_new();
  if (!pim_channel_oil_list) {
    zlog_err("%s %s: failure: channel_oil_list=list_new()",
	     __FILE__, __PRETTY_FUNCTION__);
    return;
  }
  pim_channel_oil_list->del = (void (*)(void *)) pim_channel_oil_free;
  pim_channel_oil_list->cmp = (int (*)(void *, void *)) pim_channel_oil_compare;
}

void
pim_oil_terminate (void)
{
  if (pim_channel_oil_list)
    list_free(pim_channel_oil_list);
  pim_channel_oil_list = NULL;

  if (pim_channel_oil_hash)
    hash_free (pim_channel_oil_hash);
  pim_channel_oil_hash = NULL;
}

void pim_channel_oil_free(struct channel_oil *c_oil)
{
  XFREE(MTYPE_PIM_CHANNEL_OIL, c_oil);
}

static struct channel_oil *
pim_find_channel_oil(struct prefix_sg *sg)
{
  struct channel_oil *c_oil = NULL;
  struct channel_oil lookup;

  lookup.oil.mfcc_mcastgrp = sg->grp;
  lookup.oil.mfcc_origin   = sg->src;

  c_oil = hash_lookup (pim_channel_oil_hash, &lookup);

  return c_oil;
}

struct channel_oil *pim_channel_oil_add(struct prefix_sg *sg,
					int input_vif_index)
{
  struct channel_oil *c_oil;
  struct interface *ifp;

  c_oil = pim_find_channel_oil(sg);
  if (c_oil) {
    if (c_oil->oil.mfcc_parent != input_vif_index)
      {
        c_oil->oil_inherited_rescan = 1;
        if (PIM_DEBUG_MROUTE)
          zlog_debug ("%s: Existing channel oil %s points to %d, modifying to point at %d",
                      __PRETTY_FUNCTION__, pim_str_sg_dump(sg), c_oil->oil.mfcc_parent, input_vif_index);
      }
    c_oil->oil.mfcc_parent = input_vif_index;
    ++c_oil->oil_ref_count;
    c_oil->up = pim_upstream_find(sg); //channel might be present prior to upstream
    return c_oil;
  }

  ifp = pim_if_find_by_vif_index(input_vif_index);
  if (!ifp) {
    /* warning only */
    zlog_warn("%s: (S,G)=%s could not find input interface for input_vif_index=%d",
	      __PRETTY_FUNCTION__,
	      pim_str_sg_dump (sg), input_vif_index);
  }

  c_oil = XCALLOC(MTYPE_PIM_CHANNEL_OIL, sizeof(*c_oil));
  if (!c_oil) {
    zlog_err("PIM XCALLOC(%zu) failure", sizeof(*c_oil));
    return NULL;
  }

  c_oil->oil.mfcc_mcastgrp = sg->grp;
  c_oil->oil.mfcc_origin   = sg->src;
  c_oil = hash_get (pim_channel_oil_hash, c_oil, hash_alloc_intern);

  c_oil->oil.mfcc_parent   = input_vif_index;
  c_oil->oil_ref_count     = 1;
  c_oil->installed         = 0;
  c_oil->up = pim_upstream_find(sg);

  listnode_add_sort(pim_channel_oil_list, c_oil);

  return c_oil;
}

void pim_channel_oil_del(struct channel_oil *c_oil)
{
  --c_oil->oil_ref_count;

  if (c_oil->oil_ref_count < 1) {
    /*
     * notice that listnode_delete() can't be moved
     * into pim_channel_oil_free() because the later is
     * called by list_delete_all_node()
     */
    c_oil->up = NULL;
    listnode_delete(pim_channel_oil_list, c_oil);
    hash_release (pim_channel_oil_hash, c_oil);

    pim_channel_oil_free(c_oil);
  }
}

int
pim_channel_del_oif (struct channel_oil *channel_oil,
		     struct interface *oif,
		     uint32_t proto_mask)
{
  struct pim_interface *pim_ifp;

  zassert (channel_oil);
  zassert (oif);

  pim_ifp = oif->info;

  /*
   * Don't do anything if we've been asked to remove a source
   * that is not actually on it.
   */
  if (!(channel_oil->oif_flags[pim_ifp->mroute_vif_index] & proto_mask))
    {
      if (PIM_DEBUG_MROUTE)
	{
	  char group_str[INET_ADDRSTRLEN];
	  char source_str[INET_ADDRSTRLEN];
	  pim_inet4_dump("<group?>", channel_oil->oil.mfcc_mcastgrp, group_str, sizeof(group_str));
	  pim_inet4_dump("<source?>", channel_oil->oil.mfcc_origin, source_str, sizeof(source_str));
	  zlog_debug("%s %s: no existing protocol mask %u(%u) for requested OIF %s (vif_index=%d, min_ttl=%d) for channel (S,G)=(%s,%s)",
		     __FILE__, __PRETTY_FUNCTION__,
		     proto_mask, channel_oil->oif_flags[pim_ifp->mroute_vif_index],
		     oif->name, pim_ifp->mroute_vif_index,
		     channel_oil->oil.mfcc_ttls[pim_ifp->mroute_vif_index],
		     source_str, group_str);
	}
      return 0;
    }

  channel_oil->oif_flags[pim_ifp->mroute_vif_index] &= ~proto_mask;

  if (channel_oil->oif_flags[pim_ifp->mroute_vif_index])
    {
      if (PIM_DEBUG_MROUTE)
	{
	  char group_str[INET_ADDRSTRLEN];
	  char source_str[INET_ADDRSTRLEN];
	  pim_inet4_dump("<group?>", channel_oil->oil.mfcc_mcastgrp, group_str, sizeof(group_str));
	  pim_inet4_dump("<source?>", channel_oil->oil.mfcc_origin, source_str, sizeof(source_str));
	  zlog_debug("%s %s: other protocol masks remain for requested OIF %s (vif_index=%d, min_ttl=%d) for channel (S,G)=(%s,%s)",
		     __FILE__, __PRETTY_FUNCTION__,
		     oif->name, pim_ifp->mroute_vif_index,
		     channel_oil->oil.mfcc_ttls[pim_ifp->mroute_vif_index],
		     source_str, group_str);
	}
      return 0;
    }

  channel_oil->oil.mfcc_ttls[pim_ifp->mroute_vif_index] = 0;

  if (pim_mroute_add (channel_oil, __PRETTY_FUNCTION__)) {
    if (PIM_DEBUG_MROUTE)
      {
        char group_str[INET_ADDRSTRLEN];
        char source_str[INET_ADDRSTRLEN];
        pim_inet4_dump("<group?>", channel_oil->oil.mfcc_mcastgrp, group_str, sizeof(group_str));
        pim_inet4_dump("<source?>", channel_oil->oil.mfcc_origin, source_str, sizeof(source_str));
        zlog_debug("%s %s: could not remove output interface %s (vif_index=%d) for channel (S,G)=(%s,%s)",
                   __FILE__, __PRETTY_FUNCTION__,
                   oif->name, pim_ifp->mroute_vif_index,
                   source_str, group_str);
      }
    return -1;
  }

  --channel_oil->oil_size;

  if (PIM_DEBUG_MROUTE)
    {
      char group_str[INET_ADDRSTRLEN];
      char source_str[INET_ADDRSTRLEN];
      pim_inet4_dump("<group?>", channel_oil->oil.mfcc_mcastgrp, group_str, sizeof(group_str));
      pim_inet4_dump("<source?>", channel_oil->oil.mfcc_origin, source_str, sizeof(source_str));
      zlog_debug("%s %s: (S,G)=(%s,%s): proto_mask=%u IIF:%d OIF=%s vif_index=%d",
		 __FILE__, __PRETTY_FUNCTION__,
		 source_str, group_str,
	         proto_mask, channel_oil->oil.mfcc_parent ,oif->name, pim_ifp->mroute_vif_index);
    }

  return 0;
}


int pim_channel_add_oif(struct channel_oil *channel_oil,
		   struct interface *oif,
		   uint32_t proto_mask)
{
  struct pim_interface *pim_ifp;
  int old_ttl;

  /*
   * If we've gotten here we've gone bad, but let's
   * not take down pim
   */
  if (!channel_oil)
    {
      zlog_warn ("Attempt to Add OIF for non-existent channel oil");
      return -1;
    }

  pim_ifp = oif->info;

#ifdef PIM_ENFORCE_LOOPFREE_MFC
  /*
    Prevent creating MFC entry with OIF=IIF.

    This is a protection against implementation mistakes.

    PIM protocol implicitely ensures loopfree multicast topology.

    IGMP must be protected against adding looped MFC entries created
    by both source and receiver attached to the same interface. See
    TODO T22.
  */
  if (pim_ifp->mroute_vif_index == channel_oil->oil.mfcc_parent) {
    channel_oil->oil_inherited_rescan = 1;
    if (PIM_DEBUG_MROUTE)
      {
	char group_str[INET_ADDRSTRLEN];
	char source_str[INET_ADDRSTRLEN];
	pim_inet4_dump("<group?>", channel_oil->oil.mfcc_mcastgrp, group_str, sizeof(group_str));
	pim_inet4_dump("<source?>", channel_oil->oil.mfcc_origin, source_str, sizeof(source_str));
	zlog_debug("%s %s: refusing protocol mask %u request for IIF=OIF=%s (vif_index=%d) for channel (S,G)=(%s,%s)",
		   __FILE__, __PRETTY_FUNCTION__,
		   proto_mask, oif->name, pim_ifp->mroute_vif_index,
		   source_str, group_str);
      }
    return -2;
  }
#endif

  /* Prevent single protocol from subscribing same interface to
     channel (S,G) multiple times */
  if (channel_oil->oif_flags[pim_ifp->mroute_vif_index] & proto_mask) {
    if (PIM_DEBUG_MROUTE)
      {
	char group_str[INET_ADDRSTRLEN];
	char source_str[INET_ADDRSTRLEN];
	pim_inet4_dump("<group?>", channel_oil->oil.mfcc_mcastgrp, group_str, sizeof(group_str));
	pim_inet4_dump("<source?>", channel_oil->oil.mfcc_origin, source_str, sizeof(source_str));
	zlog_debug("%s %s: existing protocol mask %u requested OIF %s (vif_index=%d, min_ttl=%d) for channel (S,G)=(%s,%s)",
		   __FILE__, __PRETTY_FUNCTION__,
		   proto_mask, oif->name, pim_ifp->mroute_vif_index,
		   channel_oil->oil.mfcc_ttls[pim_ifp->mroute_vif_index],
		   source_str, group_str);
      }
    return -3;
  }

  /* Allow other protocol to request subscription of same interface to
   * channel (S,G), we need to note this information
   */
  if (channel_oil->oif_flags[pim_ifp->mroute_vif_index] & PIM_OIF_FLAG_PROTO_ANY) {

    channel_oil->oif_creation[pim_ifp->mroute_vif_index] = pim_time_monotonic_sec();
    channel_oil->oif_flags[pim_ifp->mroute_vif_index] |= proto_mask;
    /* Check the OIF really exists before returning, and only log
       warning otherwise */
    if (channel_oil->oil.mfcc_ttls[pim_ifp->mroute_vif_index] < 1) {
      {
        char group_str[INET_ADDRSTRLEN];
        char source_str[INET_ADDRSTRLEN];
        pim_inet4_dump("<group?>", channel_oil->oil.mfcc_mcastgrp, group_str, sizeof(group_str));
        pim_inet4_dump("<source?>", channel_oil->oil.mfcc_origin, source_str, sizeof(source_str));
        zlog_warn("%s %s: new protocol mask %u requested nonexistent OIF %s (vif_index=%d, min_ttl=%d) for channel (S,G)=(%s,%s)",
                  __FILE__, __PRETTY_FUNCTION__,
                  proto_mask, oif->name, pim_ifp->mroute_vif_index,
                  channel_oil->oil.mfcc_ttls[pim_ifp->mroute_vif_index],
                  source_str, group_str);
      }
    }

    return 0;
  }

  old_ttl = channel_oil->oil.mfcc_ttls[pim_ifp->mroute_vif_index];

  if (old_ttl > 0) {
    if (PIM_DEBUG_MROUTE)
      {
	char group_str[INET_ADDRSTRLEN];
	char source_str[INET_ADDRSTRLEN];
	pim_inet4_dump("<group?>", channel_oil->oil.mfcc_mcastgrp, group_str, sizeof(group_str));
	pim_inet4_dump("<source?>", channel_oil->oil.mfcc_origin, source_str, sizeof(source_str));
	zlog_debug("%s %s: interface %s (vif_index=%d) is existing output for channel (S,G)=(%s,%s)",
		   __FILE__, __PRETTY_FUNCTION__,
		   oif->name, pim_ifp->mroute_vif_index,
		   source_str, group_str);
      }
    return -4;
  }

  channel_oil->oil.mfcc_ttls[pim_ifp->mroute_vif_index] = PIM_MROUTE_MIN_TTL;

  if (pim_mroute_add(channel_oil, __PRETTY_FUNCTION__)) {
    if (PIM_DEBUG_MROUTE)
      {
	char group_str[INET_ADDRSTRLEN];
	char source_str[INET_ADDRSTRLEN];
	pim_inet4_dump("<group?>", channel_oil->oil.mfcc_mcastgrp, group_str, sizeof(group_str));
	pim_inet4_dump("<source?>", channel_oil->oil.mfcc_origin, source_str, sizeof(source_str));
	zlog_debug("%s %s: could not add output interface %s (vif_index=%d) for channel (S,G)=(%s,%s)",
		   __FILE__, __PRETTY_FUNCTION__,
		   oif->name, pim_ifp->mroute_vif_index,
		   source_str, group_str);
      }

    channel_oil->oil.mfcc_ttls[pim_ifp->mroute_vif_index] = old_ttl;
    return -5;
  }

  channel_oil->oif_creation[pim_ifp->mroute_vif_index] = pim_time_monotonic_sec();
  ++channel_oil->oil_size;
  channel_oil->oif_flags[pim_ifp->mroute_vif_index] |= proto_mask;

  if (PIM_DEBUG_MROUTE) {
    char group_str[INET_ADDRSTRLEN];
    char source_str[INET_ADDRSTRLEN];
    pim_inet4_dump("<group?>", channel_oil->oil.mfcc_mcastgrp, group_str, sizeof(group_str));
    pim_inet4_dump("<source?>", channel_oil->oil.mfcc_origin, source_str, sizeof(source_str));
    zlog_debug("%s %s: (S,G)=(%s,%s): proto_mask=%u OIF=%s vif_index=%d: DONE",
	       __FILE__, __PRETTY_FUNCTION__,
	       source_str, group_str,
	       proto_mask, oif->name, pim_ifp->mroute_vif_index);
  }

  return 0;
}

int
pim_channel_oil_empty (struct channel_oil *c_oil)
{
  static uint32_t zero[MAXVIFS];
  static int inited = 0;

  if (!c_oil)
    return 1;
  /*
   * Not sure that this is necessary, but I would rather ensure
   * that this works.
   */
  if (!inited)
    {
      memset(&zero, 0, sizeof(uint32_t) * MAXVIFS);
      inited = 1;
    }

  return !memcmp(c_oil->oif_flags, zero, MAXVIFS * sizeof(uint32_t));
}