/* BGP Extended Communities Attribute
   Copyright (C) 2000 Kunihiro Ishiguro <kunihiro@zebra.org>

This file is part of GNU Zebra.

GNU Zebra 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, or (at your option) any
later version.

GNU Zebra 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 GNU Zebra; see the file COPYING.  If not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.  */

#include <zebra.h>

#include "hash.h"
#include "memory.h"
#include "prefix.h"
#include "command.h"

#include "bgpd/bgpd.h"
#include "bgpd/bgp_ecommunity.h"

/* Extended community value is eight octet.  */
struct ecommunity_val
{
  char val[8];
};

/* For parse Extended Community attribute tupple. */
struct ecommunity_as
{
  as_t as;
  u_int32_t val;
};

struct ecommunity_ip
{
  struct in_addr ip;
  u_int16_t val;
};

/* Hash of community attribute. */
struct hash *ecomhash;

/* Allocate a new ecommunities.  */
struct ecommunity *
ecommunity_new ()
{
  return (struct ecommunity *) XCALLOC (MTYPE_ECOMMUNITY,
					sizeof (struct ecommunity));
}

/* Allocate ecommunities.  */
void
ecommunity_free (struct ecommunity *ecom)
{
  if (ecom->val)
    XFREE (MTYPE_ECOMMUNITY_VAL, ecom->val);

  if (ecom->str)
    XFREE (MTYPE_ECOMMUNITY_STR, ecom->str);

  XFREE (MTYPE_ECOMMUNITY, ecom);
}

void *
ecommunity_hash_alloc (struct ecommunity *val)
{
  struct ecommunity *ecom;

  ecom = ecommunity_new ();

  ecom->size = val->size;
  ecom->val = XMALLOC (MTYPE_ECOMMUNITY_VAL, val->size * BGP_RD_SIZE);
  memcpy (ecom->val, val->val, val->size * BGP_RD_SIZE);

  return ecom;
}

struct ecommunity *
ecommunity_parse (char *pnt, u_short length)
{
  struct ecommunity tmp;
  struct ecommunity *find;

  if (length % BGP_RD_SIZE)
    return NULL;

  tmp.size = length / BGP_RD_SIZE;
  tmp.val = pnt;

  find = (struct ecommunity *) hash_get (ecomhash, &tmp,
					 ecommunity_hash_alloc);
  find->refcnt++;

  return find;
}

struct ecommunity *
ecommunity_dup (struct ecommunity *ecom)
{
  struct ecommunity *new;

  new = XMALLOC (MTYPE_ECOMMUNITY, sizeof (struct ecommunity));
  memset (new, 0, sizeof (struct ecommunity));
  new->size = ecom->size;
  if (new->size)
    {
      new->val = XMALLOC (MTYPE_ECOMMUNITY_VAL, ecom->size * BGP_RD_SIZE);
      memcpy (new->val, ecom->val, ecom->size * BGP_RD_SIZE);
    }
  else
    new->val = NULL;
  return new;
}

struct ecommunity *
ecommunity_merge (struct ecommunity *ecom1, struct ecommunity *ecom2)
{
  if (ecom1->val)
    ecom1->val = XREALLOC (MTYPE_ECOMMUNITY_VAL, ecom1->val, 
			   (ecom1->size + ecom2->size) * BGP_RD_SIZE);
  else
    ecom1->val = XMALLOC (MTYPE_ECOMMUNITY_VAL,
			  (ecom1->size + ecom2->size) * BGP_RD_SIZE);

  memcpy (ecom1->val + (ecom1->size * BGP_RD_SIZE),
	  ecom2->val, ecom2->size * BGP_RD_SIZE);
  ecom1->size += ecom2->size;

  return ecom1;
}

struct ecommunity *
ecommunity_intern (struct ecommunity *ecom)
{
  struct ecommunity *find;

  assert (ecom->refcnt == 0);

  find = (struct ecommunity *) hash_get (ecomhash, ecom, hash_alloc_intern);

  if (find != ecom)
    ecommunity_free (ecom);

  find->refcnt++;

  if (! find->str)
    find->str = ecommunity_ecom2str (find, ECOMMUNITY_FORMAT_DISPLAY);

  return find;
}

void
ecommunity_unintern (struct ecommunity *ecom)
{
  if (ecom->refcnt)
    ecom->refcnt--;

  if (ecom->refcnt == 0)
    {
      struct ecommunity *ret;
  
      ret = (struct ecommunity *) hash_release (ecomhash, ecom);
      assert (ret != NULL);

      ecommunity_free (ecom);
    }
}

unsigned int
ecommunity_hash_make (struct ecommunity *ecom)
{
  int c;
  unsigned int key;
  unsigned char *pnt;

  key = 0;
  pnt = (unsigned char *)ecom->val;
  
  for (c = 0; c < ecom->size * BGP_RD_SIZE; c++)
    key += pnt[c];

  return key;
}

int
ecommunity_cmp (struct ecommunity *ecom1, struct ecommunity *ecom2)
{
  if (ecom1->size == ecom2->size
      && memcmp (ecom1->val, ecom2->val, ecom1->size * BGP_RD_SIZE) == 0)
    return 1;
  return 0;
}

int
ecommunity_add_val (struct ecommunity *ecom, struct bgp_rd *rd)
{
  u_char *p;
  int ret;
  int c;

  if (ecom->val == NULL)
    {
      ecom->size++;
      ecom->val = XMALLOC (MTYPE_ECOMMUNITY_VAL, ecom_length (ecom));
      memcpy (ecom->val, rd->val, BGP_RD_SIZE);
      return 1;
    }

  c = 0;
  for (p = ecom->val; c < ecom->size; p += 8, c++)
    {
      ret = memcmp (p, rd->val, BGP_RD_SIZE);
      if (ret == 0)
        return 0;

      if (ret > 0)
        break;
    }

  ecom->size++;
  ecom->val = XREALLOC (MTYPE_ECOMMUNITY_VAL, ecom->val, ecom_length (ecom));

  memmove (ecom->val + (c + 1) * BGP_RD_SIZE,
	   ecom->val + c * BGP_RD_SIZE, (ecom->size - 1 - c) * BGP_RD_SIZE);
  memcpy (ecom->val + c * BGP_RD_SIZE, rd->val, BGP_RD_SIZE);

  return 1;
}

/* Extended Communities token enum. */
enum ecommunity_token
{
  ecommunity_token_rt,
  ecommunity_token_soo,
  ecommunity_token_val,
  ecommunity_token_unknown
};

/* Get next Extended Communities token from the string. */
char *
ecommunity_gettoken (char *str, struct ecommunity_val *eval,
		     enum ecommunity_token *token)
{
  int ret;
  int dot = 0;
  int digit = 0;
  int separator = 0;
  u_int32_t val_low = 0;
  u_int32_t val_high = 0;
  char *p = str;
  struct in_addr ip;
  char ipstr[INET_ADDRSTRLEN + 1];

  /* Skip white space. */
  while (isspace ((int) *p))
    {
      p++;
      str++;
    }

  /* Check the end of the line. */
  if (*p == '\0')
    return NULL;

  /* "rt" and "soo" keyword parse. */
  if (! isdigit ((int) *p)) 
    {
      /* "rt" match check.  */
      if (tolower ((int) *p) == 'r')
	{
	  p++;
 	  if (tolower ((int) *p) == 't')
	    {
	      p++;
	      *token = ecommunity_token_rt;
	      return p;
	    }
	  if (isspace ((int) *p) || *p == '\0')
	    {
	      *token = ecommunity_token_rt;
	      return p;
	    }
	  goto error;
	}
      /* "soo" match check.  */
      else if (tolower ((int) *p) == 's')
	{
	  p++;
 	  if (tolower ((int) *p) == 'o')
	    {
	      p++;
	      if (tolower ((int) *p) == 'o')
		{
		  p++;
		  *token = ecommunity_token_soo;
		  return p;
		}
	      if (isspace ((int) *p) || *p == '\0')
		{
		  *token = ecommunity_token_soo;
		  return p;
		}
	      goto error;
	    }
	  if (isspace ((int) *p) || *p == '\0')
	    {
	      *token = ecommunity_token_soo;
	      return p;
	    }
	  goto error;
	}
      goto error;
    }
  
  while (isdigit ((int) *p) || *p == ':' || *p == '.') 
    {
      if (*p == ':') 
	{
	  if (separator)
	    goto error;

	  separator = 1;
	  digit = 0;

	  if (dot)
	    {
	      if ((p - str) > INET_ADDRSTRLEN)
		goto error;

	      memset (ipstr, 0, INET_ADDRSTRLEN + 1);
	      memcpy (ipstr, str, p - str);

	      ret = inet_aton (ipstr, &ip);
	      if (ret == 0)
		goto error;
	    }
	  else
	    val_high = val_low;

	  val_low = 0;
	}
      else if (*p == '.')
	{
	  if (separator)
	    goto error;
	  dot++;
	  if (dot > 4)
	    goto error;
	}
      else
	{
	  digit = 1;
	  val_low *= 10;
	  val_low += (*p - '0');
	}
      p++;
    }

  /* Low digit part must be there. */
  if (! digit || ! separator)
    goto error;

  /* Encode result into routing distinguisher.  */
  if (dot)
    {
      eval->val[0] = ECOMMUNITY_ENCODE_IP;
      eval->val[1] = 0;
      memcpy (&eval->val[2], &ip, sizeof (struct in_addr));
      eval->val[6] = (val_low >> 8) & 0xff;
      eval->val[7] = val_low & 0xff;
    }
  else
    {
      eval->val[0] = ECOMMUNITY_ENCODE_AS;
      eval->val[1] = 0;
      eval->val[2] = (val_high >>8) & 0xff;
      eval->val[3] = val_high & 0xff;
      eval->val[4] = (val_low >>24) & 0xff;
      eval->val[5] = (val_low >>16) & 0xff;
      eval->val[6] = (val_low >>8) & 0xff;
      eval->val[7] = val_low & 0xff;
    }
  *token = ecommunity_token_val;
  return p;

 error:
  *token = ecommunity_token_unknown;
  return p;
}

/* Convert string to extended community attribute. 

   When type is already known, please specify both str and type.  str
   should not include keyword such as "rt" and "soo".  Type is
   ECOMMUNITY_ROUTE_TARGET or ECOMMUNITY_SITE_ORIGIN.
   keyword_included should be zero.

   For example route-map's "set extcommunity" command case:

   "rt 100:1 100:2 100:3"        -> str = "100:1 100:2 100:3"
                                    type = ECOMMUNITY_ROUTE_TARGET
                                    keyword_included = 0

   "soo 100:1"                   -> str = "100:1"
                                    type = ECOMMUNITY_SITE_ORIGIN
                                    keyword_included = 0

   When string includes keyword for each extended community value.
   Please specify keyword_included as non-zero value.

   For example standard extcommunity-list case:

   "rt 100:1 rt 100:2 soo 100:1" -> str = "rt 100:1 rt 100:2 soo 100:1"
                                    type = 0
                                    keyword_include = 1
*/
struct ecommunity *
ecommunity_str2com (char *str, int type, int keyword_included)
{
  struct ecommunity *ecom = NULL;
  enum ecommunity_token token;
  struct ecommunity_val eval;
  int keyword = 0;

  while ((str = ecommunity_gettoken (str, &eval, &token)))
    {
      switch (token)
	{
	case ecommunity_token_rt:
	case ecommunity_token_soo:
	  if (! keyword_included || keyword)
	    {
	      if (ecom)
		ecommunity_free (ecom);
	      return NULL;
	    }
	  keyword = 1;

	  if (token == ecommunity_token_rt)
	    {
	      type = ECOMMUNITY_ROUTE_TARGET;
	    }
	  if (token == ecommunity_token_soo)
	    {
	      type = ECOMMUNITY_SITE_ORIGIN;
	    }
	  break;
	case ecommunity_token_val:
	  if (keyword_included)
	    {
	      if (! keyword)
		{
		  if (ecom)
		    ecommunity_free (ecom);
		  return NULL;
		}
	      keyword = 0;
	    }
	  if (ecom == NULL)
	    ecom = ecommunity_new ();
	  eval.val[1] = type;
	  ecommunity_add_val (ecom, (struct bgp_rd *) &eval);
	  break;
	case ecommunity_token_unknown:
	default:
	  if (ecom)
	    ecommunity_free (ecom);
	  return NULL;
	  break;
	}
    }
  return ecom;
}

/* Convert extended community attribute to string.  

   Due to historical reason of industry standard implementation, there
   are three types of format.

   route-map set extcommunity format
        "rt 100:1 100:2"
        "soo 100:3"

   extcommunity-list
        "rt 100:1 rt 100:2 soo 100:3"

   "show ip bgp" and extcommunity-list regular expression matching
        "RT:100:1 RT:100:2 SoO:100:3"

   For each formath please use below definition for format:

   ECOMMUNITY_FORMAT_ROUTE_MAP
   ECOMMUNITY_FORMAT_COMMUNITY_LIST
   ECOMMUNITY_FORMAT_DISPLAY
*/
char *
ecommunity_ecom2str (struct ecommunity *ecom, int format)
{
  int i;
  u_char *pnt;
  struct ecommunity_as eas;
  struct ecommunity_ip eip;
  int encode = 0;
  int type = 0;
#define ECOMMUNITY_STR_DEFAULT_LEN  26
  int str_size;
  int str_pnt;
  u_char *str_buf;
  char *prefix;
  int len = 0;
  int first = 1;

  if (ecom->size == 0)
    {
      str_buf = XMALLOC (MTYPE_ECOMMUNITY_STR, 1);
      str_buf[0] = '\0';
      return str_buf;
    }

  /* Prepare buffer.  */
  str_buf = XMALLOC (MTYPE_ECOMMUNITY_STR, ECOMMUNITY_STR_DEFAULT_LEN + 1);
  str_size = ECOMMUNITY_STR_DEFAULT_LEN + 1;
  str_pnt = 0;

  for (i = 0; i < ecom->size; i++)
    {
      pnt = ecom->val + (i * 8);

      /* High-order octet of type. */
      encode = *pnt++;
      if (encode != ECOMMUNITY_ENCODE_AS && encode != ECOMMUNITY_ENCODE_IP)
	{
	  if (str_buf)
	    XFREE (MTYPE_ECOMMUNITY_STR, str_buf);
	  return "Unknown";
	}
      
      /* Low-order octet of type. */
      type = *pnt++;
      if (type !=  ECOMMUNITY_ROUTE_TARGET && type != ECOMMUNITY_SITE_ORIGIN)
	{
	  if (str_buf)
	    XFREE (MTYPE_ECOMMUNITY_STR, str_buf);
	  return "Unknown";
	}

      switch (format)
	{
	case ECOMMUNITY_FORMAT_COMMUNITY_LIST:
	  prefix = (type == ECOMMUNITY_ROUTE_TARGET ? "rt " : "soo ");
	  break;
	case ECOMMUNITY_FORMAT_DISPLAY:
	  prefix = (type == ECOMMUNITY_ROUTE_TARGET ? "RT:" : "SoO:");
	  break;
	case ECOMMUNITY_FORMAT_ROUTE_MAP:
	  prefix = "";
	  break;
	default:
	  if (str_buf)
	    XFREE (MTYPE_ECOMMUNITY_STR, str_buf);
	  return "Unknown";
	  break;
	}

      /* Make it sure size is enough.  */
      while (str_pnt + ECOMMUNITY_STR_DEFAULT_LEN >= str_size)
	{
	  str_size *= 2;
	  str_buf = XREALLOC (MTYPE_ECOMMUNITY_STR, str_buf, str_size);
	}

      /* Space between each value.  */
      if (! first)
	str_buf[str_pnt++] = ' ';

      /* Put string into buffer.  */
      if (encode == ECOMMUNITY_ENCODE_AS)
	{
	  eas.as = (*pnt++ << 8);
	  eas.as |= (*pnt++);

	  eas.val = (*pnt++ << 24);
	  eas.val |= (*pnt++ << 16);
	  eas.val |= (*pnt++ << 8);
	  eas.val |= (*pnt++);

	  len = sprintf (str_buf + str_pnt, "%s%d:%d", prefix,
			 eas.as, eas.val);
	  str_pnt += len;
	  first = 0;
	}
      else if (encode == ECOMMUNITY_ENCODE_IP)
	{
	  memcpy (&eip.ip, pnt, 4);
	  pnt += 4;
	  eip.val = (*pnt++ << 8);
	  eip.val |= (*pnt++);

	  len = sprintf (str_buf + str_pnt, "%s%s:%d", prefix,
			 inet_ntoa (eip.ip), eip.val);
	  str_pnt += len;
	  first = 0;
	}
    }
  return str_buf;
}

/* Transform RFC2547 routing distinguisher to extended communities
   type.  */
void
ecommunity_rd2com (struct bgp_rd *rd, u_char type)
{
  rd->val[0] = rd->val[1];
  rd->val[1] = type;
}

void
ecommunity_vty_out (struct vty *vty, struct ecommunity *ecom)
{
  int i;
  u_char *pnt;
  struct ecommunity_as eas;
  struct ecommunity_ip eip;
  int encode = 0;
  int type = 0;

  for (i = 0; i < ecom->size; i++)
    {
      pnt = ecom->val + (i * 8);

      /* High-order octet of type. */
      if (*pnt == ECOMMUNITY_ENCODE_AS)
	encode = ECOMMUNITY_ENCODE_AS;
      else if (*pnt == ECOMMUNITY_ENCODE_IP)
	encode = ECOMMUNITY_ENCODE_IP;
      pnt++;
      
      /* Low-order octet of type. */
      if (*pnt == ECOMMUNITY_ROUTE_TARGET)
	{
	  if (type != ECOMMUNITY_ROUTE_TARGET)
	    vty_out (vty, " RT:");
	  type = ECOMMUNITY_ROUTE_TARGET;
	}
      else if (*pnt == ECOMMUNITY_SITE_ORIGIN)
	{
	  if (type != ECOMMUNITY_SITE_ORIGIN)
	    vty_out (vty, " SoO:");
	  type = ECOMMUNITY_SITE_ORIGIN;
	}
      pnt++;

      if (encode == ECOMMUNITY_ENCODE_AS)
	{
	  eas.as = (*pnt++ << 8);
	  eas.as |= (*pnt++);

	  eas.val = (*pnt++ << 24);
	  eas.val |= (*pnt++ << 16);
	  eas.val |= (*pnt++ << 8);
	  eas.val |= (*pnt++);

	  vty_out (vty, "%d:%d", eas.as, eas.val);
	}
      else if (encode == ECOMMUNITY_ENCODE_IP)
	{
	  memcpy (&eip.ip, pnt, 4);
	  pnt += 4;
	  eip.val = (*pnt++ << 8);
	  eip.val |= (*pnt++);

	  vty_out (vty, "%s:%d", inet_ntoa (eip.ip), eip.val);
	}
    }
}

/* Initialize Extended Comminities related hash. */
void
ecommunity_init ()
{
  ecomhash = hash_create (ecommunity_hash_make, ecommunity_cmp);
}