[mirror_frr.git] / bgpd / bgp_clist.c

/* BGP community-list and extcommunity-list.
 * Copyright (C) 1999 Kunihiro Ishiguro
 *
 * 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 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 "command.h"
#include "prefix.h"
#include "memory.h"
#include "queue.h"
#include "filter.h"
#include "stream.h"

#include "bgpd/bgpd.h"
#include "bgpd/bgp_community.h"
#include "bgpd/bgp_ecommunity.h"
#include "bgpd/bgp_lcommunity.h"
#include "bgpd/bgp_aspath.h"
#include "bgpd/bgp_regex.h"
#include "bgpd/bgp_clist.h"

/* Lookup master structure for community-list or
   extcommunity-list.  */
struct community_list_master *
community_list_master_lookup(struct community_list_handler *ch, int master)
{
	if (ch)
		switch (master) {
		case COMMUNITY_LIST_MASTER:
			return &ch->community_list;
		case EXTCOMMUNITY_LIST_MASTER:
			return &ch->extcommunity_list;
		case LARGE_COMMUNITY_LIST_MASTER:
			return &ch->lcommunity_list;
		}
	return NULL;
}

/* Allocate a new community list entry.  */
static struct community_entry *community_entry_new(void)
{
	return XCALLOC(MTYPE_COMMUNITY_LIST_ENTRY,
		       sizeof(struct community_entry));
}

/* Free community list entry.  */
static void community_entry_free(struct community_entry *entry)
{
	switch (entry->style) {
	case COMMUNITY_LIST_STANDARD:
		if (entry->u.com)
			community_free(entry->u.com);
		break;
	case LARGE_COMMUNITY_LIST_STANDARD:
		if (entry->u.lcom)
			lcommunity_free(&entry->u.lcom);
		break;
	case EXTCOMMUNITY_LIST_STANDARD:
		/* In case of standard extcommunity-list, configuration string
		   is made by ecommunity_ecom2str().  */
		if (entry->config)
			XFREE(MTYPE_ECOMMUNITY_STR, entry->config);
		if (entry->u.ecom)
			ecommunity_free(&entry->u.ecom);
		break;
	case COMMUNITY_LIST_EXPANDED:
	case EXTCOMMUNITY_LIST_EXPANDED:
	case LARGE_COMMUNITY_LIST_EXPANDED:
		if (entry->config)
			XFREE(MTYPE_COMMUNITY_LIST_CONFIG, entry->config);
		if (entry->reg)
			bgp_regex_free(entry->reg);
	default:
		break;
	}
	XFREE(MTYPE_COMMUNITY_LIST_ENTRY, entry);
}

/* Allocate a new community-list.  */
static struct community_list *community_list_new(void)
{
	return XCALLOC(MTYPE_COMMUNITY_LIST, sizeof(struct community_list));
}

/* Free community-list.  */
static void community_list_free(struct community_list *list)
{
	if (list->name)
		XFREE(MTYPE_COMMUNITY_LIST_NAME, list->name);
	XFREE(MTYPE_COMMUNITY_LIST, list);
}

static struct community_list *
community_list_insert(struct community_list_handler *ch, const char *name,
		      int master)
{
	size_t i;
	long number;
	struct community_list *new;
	struct community_list *point;
	struct community_list_list *list;
	struct community_list_master *cm;

	/* Lookup community-list master.  */
	cm = community_list_master_lookup(ch, master);
	if (!cm)
		return NULL;

	/* Allocate new community_list and copy given name. */
	new = community_list_new();
	new->name = XSTRDUP(MTYPE_COMMUNITY_LIST_NAME, name);

	/* If name is made by all digit character.  We treat it as
	   number. */
	for (number = 0, i = 0; i < strlen(name); i++) {
		if (isdigit((int)name[i]))
			number = (number * 10) + (name[i] - '0');
		else
			break;
	}

	/* In case of name is all digit character */
	if (i == strlen(name)) {
		new->sort = COMMUNITY_LIST_NUMBER;

		/* Set access_list to number list. */
		list = &cm->num;

		for (point = list->head; point; point = point->next)
			if (atol(point->name) >= number)
				break;
	} else {
		new->sort = COMMUNITY_LIST_STRING;

		/* Set access_list to string list. */
		list = &cm->str;

		/* Set point to insertion point. */
		for (point = list->head; point; point = point->next)
			if (strcmp(point->name, name) >= 0)
				break;
	}

	/* Link to upper list.  */
	new->parent = list;

	/* In case of this is the first element of master. */
	if (list->head == NULL) {
		list->head = list->tail = new;
		return new;
	}

	/* In case of insertion is made at the tail of access_list. */
	if (point == NULL) {
		new->prev = list->tail;
		list->tail->next = new;
		list->tail = new;
		return new;
	}

	/* In case of insertion is made at the head of access_list. */
	if (point == list->head) {
		new->next = list->head;
		list->head->prev = new;
		list->head = new;
		return new;
	}

	/* Insertion is made at middle of the access_list. */
	new->next = point;
	new->prev = point->prev;

	if (point->prev)
		point->prev->next = new;
	point->prev = new;

	return new;
}

struct community_list *community_list_lookup(struct community_list_handler *ch,
					     const char *name, int master)
{
	struct community_list *list;
	struct community_list_master *cm;

	if (!name)
		return NULL;

	cm = community_list_master_lookup(ch, master);
	if (!cm)
		return NULL;

	for (list = cm->num.head; list; list = list->next)
		if (strcmp(list->name, name) == 0)
			return list;
	for (list = cm->str.head; list; list = list->next)
		if (strcmp(list->name, name) == 0)
			return list;

	return NULL;
}

static struct community_list *
community_list_get(struct community_list_handler *ch, const char *name,
		   int master)
{
	struct community_list *list;

	list = community_list_lookup(ch, name, master);
	if (!list)
		list = community_list_insert(ch, name, master);
	return list;
}

static void community_list_delete(struct community_list *list)
{
	struct community_list_list *clist;
	struct community_entry *entry, *next;

	for (entry = list->head; entry; entry = next) {
		next = entry->next;
		community_entry_free(entry);
	}

	clist = list->parent;

	if (list->next)
		list->next->prev = list->prev;
	else
		clist->tail = list->prev;

	if (list->prev)
		list->prev->next = list->next;
	else
		clist->head = list->next;

	community_list_free(list);
}

static int community_list_empty_p(struct community_list *list)
{
	return (list->head == NULL && list->tail == NULL) ? 1 : 0;
}

/* Add community-list entry to the list.  */
static void community_list_entry_add(struct community_list *list,
				     struct community_entry *entry)
{
	entry->next = NULL;
	entry->prev = list->tail;

	if (list->tail)
		list->tail->next = entry;
	else
		list->head = entry;
	list->tail = entry;
}

/* Delete community-list entry from the list.  */
static void community_list_entry_delete(struct community_list *list,
					struct community_entry *entry)
{
	if (entry->next)
		entry->next->prev = entry->prev;
	else
		list->tail = entry->prev;

	if (entry->prev)
		entry->prev->next = entry->next;
	else
		list->head = entry->next;

	community_entry_free(entry);

	if (community_list_empty_p(list))
		community_list_delete(list);
}

/* Lookup community-list entry from the list.  */
static struct community_entry *
community_list_entry_lookup(struct community_list *list, const void *arg,
			    int direct)
{
	struct community_entry *entry;

	for (entry = list->head; entry; entry = entry->next) {
		switch (entry->style) {
		case COMMUNITY_LIST_STANDARD:
			if (entry->direct == direct
			    && community_cmp(entry->u.com, arg))
				return entry;
			break;
		case EXTCOMMUNITY_LIST_STANDARD:
			if (entry->direct == direct
			    && ecommunity_cmp(entry->u.ecom, arg))
				return entry;
			break;
		case LARGE_COMMUNITY_LIST_STANDARD:
			if (entry->direct == direct
			    && lcommunity_cmp(entry->u.lcom, arg))
				return entry;
			break;
		case COMMUNITY_LIST_EXPANDED:
		case EXTCOMMUNITY_LIST_EXPANDED:
		case LARGE_COMMUNITY_LIST_EXPANDED:
			if (entry->direct == direct
			    && strcmp(entry->config, arg) == 0)
				return entry;
			break;
		default:
			break;
		}
	}
	return NULL;
}

static char *community_str_get(struct community *com, int i)
{
	int len;
	uint32_t comval;
	uint16_t as;
	uint16_t val;
	char *str;
	char *pnt;

	memcpy(&comval, com_nthval(com, i), sizeof(uint32_t));
	comval = ntohl(comval);

	switch (comval) {
	case COMMUNITY_INTERNET:
		len = strlen(" internet");
		break;
	case COMMUNITY_NO_EXPORT:
		len = strlen(" no-export");
		break;
	case COMMUNITY_NO_ADVERTISE:
		len = strlen(" no-advertise");
		break;
	case COMMUNITY_LOCAL_AS:
		len = strlen(" local-AS");
		break;
	case COMMUNITY_GSHUT:
		len = strlen(" graceful-shutdown");
		break;
	default:
		len = strlen(" 65536:65535");
		break;
	}

	/* Allocate memory.  */
	str = pnt = XMALLOC(MTYPE_COMMUNITY_STR, len);

	switch (comval) {
	case COMMUNITY_INTERNET:
		strcpy(pnt, "internet");
		pnt += strlen("internet");
		break;
	case COMMUNITY_NO_EXPORT:
		strcpy(pnt, "no-export");
		pnt += strlen("no-export");
		break;
	case COMMUNITY_NO_ADVERTISE:
		strcpy(pnt, "no-advertise");
		pnt += strlen("no-advertise");
		break;
	case COMMUNITY_LOCAL_AS:
		strcpy(pnt, "local-AS");
		pnt += strlen("local-AS");
		break;
	case COMMUNITY_GSHUT:
		strcpy(pnt, "graceful-shutdown");
		pnt += strlen("graceful-shutdown");
		break;
	default:
		as = (comval >> 16) & 0xFFFF;
		val = comval & 0xFFFF;
		sprintf(pnt, "%u:%d", as, val);
		pnt += strlen(pnt);
		break;
	}

	*pnt = '\0';

	return str;
}

/* Internal function to perform regular expression match for
 * a single community. */
static int community_regexp_include(regex_t *reg, struct community *com, int i)
{
	char *str;
	int rv;

	/* When there is no communities attribute it is treated as empty string.
	 */
	if (com == NULL || com->size == 0)
		str = XSTRDUP(MTYPE_COMMUNITY_STR, "");
	else
		str = community_str_get(com, i);

	/* Regular expression match.  */
	rv = regexec(reg, str, 0, NULL, 0);

	XFREE(MTYPE_COMMUNITY_STR, str);

	if (rv == 0)
		return 1;

	/* No match.  */
	return 0;
}

/* Internal function to perform regular expression match for community
   attribute.  */
static int community_regexp_match(struct community *com, regex_t *reg)
{
	const char *str;

	/* When there is no communities attribute it is treated as empty
	   string.  */
	if (com == NULL || com->size == 0)
		str = "";
	else
		str = community_str(com, false);

	/* Regular expression match.  */
	if (regexec(reg, str, 0, NULL, 0) == 0)
		return 1;

	/* No match.  */
	return 0;
}

static char *lcommunity_str_get(struct lcommunity *lcom, int i)
{
	struct lcommunity_val lcomval;
	uint32_t globaladmin;
	uint32_t localdata1;
	uint32_t localdata2;
	char *str;
	uint8_t *ptr;
	char *pnt;

	ptr = lcom->val + (i * LCOMMUNITY_SIZE);

	memcpy(&lcomval, ptr, LCOMMUNITY_SIZE);

	/* Allocate memory.  48 bytes taken off bgp_lcommunity.c */
	str = pnt = XMALLOC(MTYPE_LCOMMUNITY_STR, 48);

	ptr = (uint8_t *)lcomval.val;
	ptr = ptr_get_be32(ptr, &globaladmin);
	ptr = ptr_get_be32(ptr, &localdata1);
	ptr = ptr_get_be32(ptr, &localdata2);
	(void)ptr; /* consume value */

	sprintf(pnt, "%u:%u:%u", globaladmin, localdata1, localdata2);
	pnt += strlen(pnt);
	*pnt = '\0';

	return str;
}

/* Internal function to perform regular expression match for
 * a single community. */
static int lcommunity_regexp_include(regex_t *reg, struct lcommunity *lcom,
				     int i)
{
	char *str;

	/* When there is no communities attribute it is treated as empty string.
	 */
	if (lcom == NULL || lcom->size == 0)
		str = XSTRDUP(MTYPE_LCOMMUNITY_STR, "");
	else
		str = lcommunity_str_get(lcom, i);

	/* Regular expression match.  */
	if (regexec(reg, str, 0, NULL, 0) == 0) {
		XFREE(MTYPE_LCOMMUNITY_STR, str);
		return 1;
	}

	XFREE(MTYPE_LCOMMUNITY_STR, str);
	/* No match.  */
	return 0;
}

static int lcommunity_regexp_match(struct lcommunity *com, regex_t *reg)
{
	const char *str;

	/* When there is no communities attribute it is treated as empty
	   string.  */
	if (com == NULL || com->size == 0)
		str = "";
	else
		str = lcommunity_str(com, false);

	/* Regular expression match.  */
	if (regexec(reg, str, 0, NULL, 0) == 0)
		return 1;

	/* No match.  */
	return 0;
}


static int ecommunity_regexp_match(struct ecommunity *ecom, regex_t *reg)
{
	const char *str;

	/* When there is no communities attribute it is treated as empty
	   string.  */
	if (ecom == NULL || ecom->size == 0)
		str = "";
	else
		str = ecommunity_str(ecom);

	/* Regular expression match.  */
	if (regexec(reg, str, 0, NULL, 0) == 0)
		return 1;

	/* No match.  */
	return 0;
}

#if 0
/* Delete community attribute using regular expression match.  Return
   modified communites attribute.  */
static struct community *
community_regexp_delete (struct community *com, regex_t * reg)
{
  int i;
  uint32_t comval;
  /* Maximum is "65535:65535" + '\0'. */
  char c[12];
  const char *str;

  if (!com)
    return NULL;

  i = 0;
  while (i < com->size)
    {
      memcpy (&comval, com_nthval (com, i), sizeof (uint32_t));
      comval = ntohl (comval);

      switch (comval)
        {
        case COMMUNITY_INTERNET:
          str = "internet";
          break;
        case COMMUNITY_NO_EXPORT:
          str = "no-export";
          break;
        case COMMUNITY_NO_ADVERTISE:
          str = "no-advertise";
          break;
        case COMMUNITY_LOCAL_AS:
          str = "local-AS";
          break;
        default:
          sprintf (c, "%d:%d", (comval >> 16) & 0xFFFF, comval & 0xFFFF);
          str = c;
          break;
        }

      if (regexec (reg, str, 0, NULL, 0) == 0)
        community_del_val (com, com_nthval (com, i));
      else
        i++;
    }
  return com;
}
#endif

/* When given community attribute matches to the community-list return
   1 else return 0.  */
int community_list_match(struct community *com, struct community_list *list)
{
	struct community_entry *entry;

	for (entry = list->head; entry; entry = entry->next) {
		if (entry->any)
			return entry->direct == COMMUNITY_PERMIT ? 1 : 0;

		if (entry->style == COMMUNITY_LIST_STANDARD) {
			if (community_include(entry->u.com, COMMUNITY_INTERNET))
				return entry->direct == COMMUNITY_PERMIT ? 1
									 : 0;

			if (community_match(com, entry->u.com))
				return entry->direct == COMMUNITY_PERMIT ? 1
									 : 0;
		} else if (entry->style == COMMUNITY_LIST_EXPANDED) {
			if (community_regexp_match(com, entry->reg))
				return entry->direct == COMMUNITY_PERMIT ? 1
									 : 0;
		}
	}
	return 0;
}

int lcommunity_list_match(struct lcommunity *lcom, struct community_list *list)
{
	struct community_entry *entry;

	for (entry = list->head; entry; entry = entry->next) {
		if (entry->any)
			return entry->direct == COMMUNITY_PERMIT ? 1 : 0;

		if (entry->style == LARGE_COMMUNITY_LIST_STANDARD) {
			if (lcommunity_match(lcom, entry->u.lcom))
				return entry->direct == COMMUNITY_PERMIT ? 1
									 : 0;
		} else if (entry->style == LARGE_COMMUNITY_LIST_EXPANDED) {
			if (lcommunity_regexp_match(lcom, entry->reg))
				return entry->direct == COMMUNITY_PERMIT ? 1
									 : 0;
		}
	}
	return 0;
}

int ecommunity_list_match(struct ecommunity *ecom, struct community_list *list)
{
	struct community_entry *entry;

	for (entry = list->head; entry; entry = entry->next) {
		if (entry->any)
			return entry->direct == COMMUNITY_PERMIT ? 1 : 0;

		if (entry->style == EXTCOMMUNITY_LIST_STANDARD) {
			if (ecommunity_match(ecom, entry->u.ecom))
				return entry->direct == COMMUNITY_PERMIT ? 1
									 : 0;
		} else if (entry->style == EXTCOMMUNITY_LIST_EXPANDED) {
			if (ecommunity_regexp_match(ecom, entry->reg))
				return entry->direct == COMMUNITY_PERMIT ? 1
									 : 0;
		}
	}
	return 0;
}

/* Perform exact matching.  In case of expanded community-list, do
   same thing as community_list_match().  */
int community_list_exact_match(struct community *com,
			       struct community_list *list)
{
	struct community_entry *entry;

	for (entry = list->head; entry; entry = entry->next) {
		if (entry->any)
			return entry->direct == COMMUNITY_PERMIT ? 1 : 0;

		if (entry->style == COMMUNITY_LIST_STANDARD) {
			if (community_include(entry->u.com, COMMUNITY_INTERNET))
				return entry->direct == COMMUNITY_PERMIT ? 1
									 : 0;

			if (community_cmp(com, entry->u.com))
				return entry->direct == COMMUNITY_PERMIT ? 1
									 : 0;
		} else if (entry->style == COMMUNITY_LIST_EXPANDED) {
			if (community_regexp_match(com, entry->reg))
				return entry->direct == COMMUNITY_PERMIT ? 1
									 : 0;
		}
	}
	return 0;
}

/* Delete all permitted communities in the list from com.  */
struct community *community_list_match_delete(struct community *com,
					      struct community_list *list)
{
	struct community_entry *entry;
	uint32_t val;
	uint32_t com_index_to_delete[com->size];
	int delete_index = 0;
	int i;

	/* Loop over each community value and evaluate each against the
	 * community-list.  If we need to delete a community value add its index
	 * to com_index_to_delete.
	 */
	for (i = 0; i < com->size; i++) {
		val = community_val_get(com, i);

		for (entry = list->head; entry; entry = entry->next) {
			if (entry->any) {
				if (entry->direct == COMMUNITY_PERMIT) {
					com_index_to_delete[delete_index] = i;
					delete_index++;
				}
				break;
			}

			else if ((entry->style == COMMUNITY_LIST_STANDARD)
				 && (community_include(entry->u.com,
						       COMMUNITY_INTERNET)
				     || community_include(entry->u.com, val))) {
				if (entry->direct == COMMUNITY_PERMIT) {
					com_index_to_delete[delete_index] = i;
					delete_index++;
				}
				break;
			}

			else if ((entry->style == COMMUNITY_LIST_EXPANDED)
				 && community_regexp_include(entry->reg, com,
							     i)) {
				if (entry->direct == COMMUNITY_PERMIT) {
					com_index_to_delete[delete_index] = i;
					delete_index++;
				}
				break;
			}
		}
	}

	/* Delete all of the communities we flagged for deletion */
	for (i = delete_index - 1; i >= 0; i--) {
		val = community_val_get(com, com_index_to_delete[i]);
		community_del_val(com, &val);
	}

	return com;
}

/* To avoid duplicated entry in the community-list, this function
   compares specified entry to existing entry.  */
static int community_list_dup_check(struct community_list *list,
				    struct community_entry *new)
{
	struct community_entry *entry;

	for (entry = list->head; entry; entry = entry->next) {
		if (entry->style != new->style)
			continue;

		if (entry->direct != new->direct)
			continue;

		if (entry->any != new->any)
			continue;

		if (entry->any)
			return 1;

		switch (entry->style) {
		case COMMUNITY_LIST_STANDARD:
			if (community_cmp(entry->u.com, new->u.com))
				return 1;
			break;
		case LARGE_COMMUNITY_LIST_STANDARD:
			if (lcommunity_cmp(entry->u.lcom, new->u.lcom))
				return 1;
			break;
		case EXTCOMMUNITY_LIST_STANDARD:
			if (ecommunity_cmp(entry->u.ecom, new->u.ecom))
				return 1;
			break;
		case COMMUNITY_LIST_EXPANDED:
		case EXTCOMMUNITY_LIST_EXPANDED:
		case LARGE_COMMUNITY_LIST_EXPANDED:
			if (strcmp(entry->config, new->config) == 0)
				return 1;
			break;
		default:
			break;
		}
	}
	return 0;
}

/* Set community-list.  */
int community_list_set(struct community_list_handler *ch, const char *name,
		       const char *str, int direct, int style)
{
	struct community_entry *entry = NULL;
	struct community_list *list;
	struct community *com = NULL;
	regex_t *regex = NULL;

	/* Get community list. */
	list = community_list_get(ch, name, COMMUNITY_LIST_MASTER);

	/* When community-list already has entry, new entry should have same
	   style.  If you want to have mixed style community-list, you can
	   comment out this check.  */
	if (!community_list_empty_p(list)) {
		struct community_entry *first;

		first = list->head;

		if (style != first->style) {
			return (first->style == COMMUNITY_LIST_STANDARD
					? COMMUNITY_LIST_ERR_STANDARD_CONFLICT
					: COMMUNITY_LIST_ERR_EXPANDED_CONFLICT);
		}
	}

	if (str) {
		if (style == COMMUNITY_LIST_STANDARD)
			com = community_str2com(str);
		else
			regex = bgp_regcomp(str);

		if (!com && !regex)
			return COMMUNITY_LIST_ERR_MALFORMED_VAL;
	}

	entry = community_entry_new();
	entry->direct = direct;
	entry->style = style;
	entry->any = (str ? 0 : 1);
	entry->u.com = com;
	entry->reg = regex;
	entry->config =
		(regex ? XSTRDUP(MTYPE_COMMUNITY_LIST_CONFIG, str) : NULL);

	/* Do not put duplicated community entry.  */
	if (community_list_dup_check(list, entry))
		community_entry_free(entry);
	else {
		community_list_entry_add(list, entry);
		route_map_notify_dependencies(name, RMAP_EVENT_CLIST_ADDED);
	}

	return 0;
}

/* Unset community-list */
int community_list_unset(struct community_list_handler *ch, const char *name,
			 const char *str, int direct, int style)
{
	struct community_entry *entry = NULL;
	struct community_list *list;
	struct community *com = NULL;

	/* Lookup community list.  */
	list = community_list_lookup(ch, name, COMMUNITY_LIST_MASTER);
	if (list == NULL)
		return COMMUNITY_LIST_ERR_CANT_FIND_LIST;

	/* Delete all of entry belongs to this community-list.  */
	if (!str) {
		community_list_delete(list);
		route_map_notify_dependencies(name, RMAP_EVENT_CLIST_DELETED);
		return 0;
	}

	if (style == COMMUNITY_LIST_STANDARD)
		com = community_str2com(str);

	if (com) {
		entry = community_list_entry_lookup(list, com, direct);
		community_free(com);
	} else
		entry = community_list_entry_lookup(list, str, direct);

	if (!entry)
		return COMMUNITY_LIST_ERR_CANT_FIND_LIST;

	community_list_entry_delete(list, entry);
	route_map_notify_dependencies(name, RMAP_EVENT_CLIST_DELETED);

	return 0;
}

/* Delete all permitted large communities in the list from com.  */
struct lcommunity *lcommunity_list_match_delete(struct lcommunity *lcom,
						struct community_list *list)
{
	struct community_entry *entry;
	uint32_t com_index_to_delete[lcom->size];
	uint8_t *ptr;
	int delete_index = 0;
	int i;

	/* Loop over each lcommunity value and evaluate each against the
	 * community-list.  If we need to delete a community value add its index
	 * to com_index_to_delete.
	 */
	for (i = 0; i < lcom->size; i++) {
		ptr = lcom->val + (i * LCOMMUNITY_SIZE);
		for (entry = list->head; entry; entry = entry->next) {
			if (entry->any) {
				if (entry->direct == COMMUNITY_PERMIT) {
					com_index_to_delete[delete_index] = i;
					delete_index++;
				}
				break;
			}

			else if ((entry->style == LARGE_COMMUNITY_LIST_STANDARD)
				 && lcommunity_include(entry->u.lcom, ptr)) {
				if (entry->direct == COMMUNITY_PERMIT) {
					com_index_to_delete[delete_index] = i;
					delete_index++;
				}
				break;
			}

			else if ((entry->style == LARGE_COMMUNITY_LIST_EXPANDED)
				 && lcommunity_regexp_include(entry->reg, lcom,
							      i)) {
				if (entry->direct == COMMUNITY_PERMIT) {
					com_index_to_delete[delete_index] = i;
					delete_index++;
				}
				break;
			}
		}
	}

	/* Delete all of the communities we flagged for deletion */
	for (i = delete_index - 1; i >= 0; i--) {
		ptr = lcom->val + (com_index_to_delete[i] * LCOMMUNITY_SIZE);
		lcommunity_del_val(lcom, ptr);
	}

	return lcom;
}

/* Set lcommunity-list.  */
int lcommunity_list_set(struct community_list_handler *ch, const char *name,
			const char *str, int direct, int style)
{
	struct community_entry *entry = NULL;
	struct community_list *list;
	struct lcommunity *lcom = NULL;
	regex_t *regex = NULL;

	/* Get community list. */
	list = community_list_get(ch, name, LARGE_COMMUNITY_LIST_MASTER);

	/* When community-list already has entry, new entry should have same
	   style.  If you want to have mixed style community-list, you can
	   comment out this check.  */
	if (!community_list_empty_p(list)) {
		struct community_entry *first;

		first = list->head;

		if (style != first->style) {
			return (first->style == COMMUNITY_LIST_STANDARD
					? COMMUNITY_LIST_ERR_STANDARD_CONFLICT
					: COMMUNITY_LIST_ERR_EXPANDED_CONFLICT);
		}
	}

	if (str) {
		if (style == LARGE_COMMUNITY_LIST_STANDARD)
			lcom = lcommunity_str2com(str);
		else
			regex = bgp_regcomp(str);

		if (!lcom && !regex)
			return COMMUNITY_LIST_ERR_MALFORMED_VAL;
	}

	entry = community_entry_new();
	entry->direct = direct;
	entry->style = style;
	entry->any = (str ? 0 : 1);
	entry->u.lcom = lcom;
	entry->reg = regex;
	entry->config =
		(regex ? XSTRDUP(MTYPE_COMMUNITY_LIST_CONFIG, str) : NULL);

	/* Do not put duplicated community entry.  */
	if (community_list_dup_check(list, entry))
		community_entry_free(entry);
	else
		community_list_entry_add(list, entry);

	return 0;
}

/* Unset community-list.  When str is NULL, delete all of
   community-list entry belongs to the specified name.  */
int lcommunity_list_unset(struct community_list_handler *ch, const char *name,
			  const char *str, int direct, int style)
{
	struct community_entry *entry = NULL;
	struct community_list *list;
	struct lcommunity *lcom = NULL;
	regex_t *regex = NULL;

	/* Lookup community list.  */
	list = community_list_lookup(ch, name, LARGE_COMMUNITY_LIST_MASTER);
	if (list == NULL)
		return COMMUNITY_LIST_ERR_CANT_FIND_LIST;

	/* Delete all of entry belongs to this community-list.  */
	if (!str) {
		community_list_delete(list);
		return 0;
	}

	if (style == LARGE_COMMUNITY_LIST_STANDARD)
		lcom = lcommunity_str2com(str);
	else
		regex = bgp_regcomp(str);

	if (!lcom && !regex)
		return COMMUNITY_LIST_ERR_MALFORMED_VAL;

	if (lcom)
		entry = community_list_entry_lookup(list, lcom, direct);
	else
		entry = community_list_entry_lookup(list, str, direct);

	if (lcom)
		lcommunity_free(&lcom);
	if (regex)
		bgp_regex_free(regex);

	if (!entry)
		return COMMUNITY_LIST_ERR_CANT_FIND_LIST;

	community_list_entry_delete(list, entry);

	return 0;
}

/* Set extcommunity-list.  */
int extcommunity_list_set(struct community_list_handler *ch, const char *name,
			  const char *str, int direct, int style)
{
	struct community_entry *entry = NULL;
	struct community_list *list;
	struct ecommunity *ecom = NULL;
	regex_t *regex = NULL;

	if (str == NULL)
		return COMMUNITY_LIST_ERR_MALFORMED_VAL;

	/* Get community list. */
	list = community_list_get(ch, name, EXTCOMMUNITY_LIST_MASTER);

	/* When community-list already has entry, new entry should have same
	   style.  If you want to have mixed style community-list, you can
	   comment out this check.  */
	if (!community_list_empty_p(list)) {
		struct community_entry *first;

		first = list->head;

		if (style != first->style) {
			return (first->style == EXTCOMMUNITY_LIST_STANDARD
					? COMMUNITY_LIST_ERR_STANDARD_CONFLICT
					: COMMUNITY_LIST_ERR_EXPANDED_CONFLICT);
		}
	}

	if (style == EXTCOMMUNITY_LIST_STANDARD)
		ecom = ecommunity_str2com(str, 0, 1);
	else
		regex = bgp_regcomp(str);

	if (!ecom && !regex)
		return COMMUNITY_LIST_ERR_MALFORMED_VAL;

	if (ecom)
		ecom->str =
			ecommunity_ecom2str(ecom, ECOMMUNITY_FORMAT_DISPLAY, 0);

	entry = community_entry_new();
	entry->direct = direct;
	entry->style = style;
	entry->any = 0;
	if (ecom)
		entry->config = ecommunity_ecom2str(
			ecom, ECOMMUNITY_FORMAT_COMMUNITY_LIST, 0);
	else if (regex)
		entry->config = XSTRDUP(MTYPE_COMMUNITY_LIST_CONFIG, str);

	entry->u.ecom = ecom;
	entry->reg = regex;

	/* Do not put duplicated community entry.  */
	if (community_list_dup_check(list, entry))
		community_entry_free(entry);
	else {
		community_list_entry_add(list, entry);
		route_map_notify_dependencies(name, RMAP_EVENT_ECLIST_ADDED);
	}

	return 0;
}

/* Unset extcommunity-list.
 *
 * When str is NULL, delete all extcommunity-list entries belonging to the
 * specified name.
 */
int extcommunity_list_unset(struct community_list_handler *ch, const char *name,
			    const char *str, int direct, int style)
{
	struct community_entry *entry = NULL;
	struct community_list *list;
	struct ecommunity *ecom = NULL;

	/* Lookup extcommunity list.  */
	list = community_list_lookup(ch, name, EXTCOMMUNITY_LIST_MASTER);
	if (list == NULL)
		return COMMUNITY_LIST_ERR_CANT_FIND_LIST;

	/* Delete all of entry belongs to this extcommunity-list.  */
	if (!str) {
		community_list_delete(list);
		route_map_notify_dependencies(name, RMAP_EVENT_ECLIST_DELETED);
		return 0;
	}

	if (style == EXTCOMMUNITY_LIST_STANDARD)
		ecom = ecommunity_str2com(str, 0, 1);

	if (ecom) {
		entry = community_list_entry_lookup(list, ecom, direct);
		ecommunity_free(&ecom);
	} else
		entry = community_list_entry_lookup(list, str, direct);

	if (!entry)
		return COMMUNITY_LIST_ERR_CANT_FIND_LIST;

	community_list_entry_delete(list, entry);
	route_map_notify_dependencies(name, RMAP_EVENT_ECLIST_DELETED);

	return 0;
}

/* Initializa community-list.  Return community-list handler.  */
struct community_list_handler *community_list_init(void)
{
	struct community_list_handler *ch;
	ch = XCALLOC(MTYPE_COMMUNITY_LIST_HANDLER,
		     sizeof(struct community_list_handler));
	return ch;
}

/* Terminate community-list.  */
void community_list_terminate(struct community_list_handler *ch)
{
	struct community_list_master *cm;
	struct community_list *list;

	cm = &ch->community_list;
	while ((list = cm->num.head) != NULL)
		community_list_delete(list);
	while ((list = cm->str.head) != NULL)
		community_list_delete(list);

	cm = &ch->lcommunity_list;
	while ((list = cm->num.head) != NULL)
		community_list_delete(list);
	while ((list = cm->str.head) != NULL)
		community_list_delete(list);

	cm = &ch->extcommunity_list;
	while ((list = cm->num.head) != NULL)
		community_list_delete(list);
	while ((list = cm->str.head) != NULL)
		community_list_delete(list);

	XFREE(MTYPE_COMMUNITY_LIST_HANDLER, ch);
}