bgp_routemap.c

大名鼎鼎的路由器源码。程序分ZEBRA、OSPFRIP等3个包。程序框架采用一个路由协议一个进程的方式

/* Route map function of bgpd.
   Copyright (C) 1998, 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 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 "prefix.h"
#include "filter.h"
#include "routemap.h"
#include "command.h"
#include "linklist.h"
#include "plist.h"
#include "memory.h"
#include "log.h"
#ifdef HAVE_GNU_REGEX
#include <regex.h>
#else
#include "regex-gnu.h"
#endif /* HAVE_GNU_REGEX */
#include "buffer.h"
#include "sockunion.h"

#include "bgpd/bgpd.h"
#include "bgpd/bgp_table.h"
#include "bgpd/bgp_attr.h"
#include "bgpd/bgp_aspath.h"
#include "bgpd/bgp_route.h"
#include "bgpd/bgp_regex.h"
#include "bgpd/bgp_community.h"
#include "bgpd/bgp_clist.h"
#include "bgpd/bgp_filter.h"
#include "bgpd/bgp_mplsvpn.h"
#include "bgpd/bgp_ecommunity.h"

/* Memo of route-map commands.

o Cisco route-map

 match as-path          :  Done
       community        :  Done
       interface        :  Not yet
       ip address       :  Done
       ip next-hop      :  Done
       ip route-source  :  (This will not be implemented by bgpd)
       ip prefix-list   :  Done
       ipv6 address     :  Done
       ipv6 next-hop    :  Done
       ipv6 route-source:  (This will not be implemented by bgpd)
       ipv6 prefix-list :  Done
       length           :  (This will not be implemented by bgpd)
       metric           :  Done
       route-type       :  (This will not be implemented by bgpd)
       tag              :  (This will not be implemented by bgpd)

 set  as-path prepend   :  Done
      as-path tag       :  Not yet
      automatic-tag     :  (This will not be implemented by bgpd)
      community         :  Done
      comm-list         :  Not yet
      dampning          :  Not yet
      default           :  (This will not be implemented by bgpd)
      interface         :  (This will not be implemented by bgpd)
      ip default        :  (This will not be implemented by bgpd)
      ip next-hop       :  Done
      ip precedence     :  (This will not be implemented by bgpd)
      ip tos            :  (This will not be implemented by bgpd)
      level             :  (This will not be implemented by bgpd)
      local-preference  :  Done
      metric            :  Done
      metric-type       :  Not yet
      origin            :  Done
      tag               :  (This will not be implemented by bgpd)
      weight            :  Done

o Local extention

  set ipv6 next-hop global: Done
  set ipv6 next-hop local : Done

*/ 

/* `match ip address IP_ACCESS_LIST' */

/* Match function should return 1 if match is success else return
   zero. */
route_map_result_t
route_match_ip_address (void *rule, struct prefix *prefix, 
			route_map_object_t type, void *object)
{
  struct access_list *alist;
  /* struct prefix_ipv4 match; */

  if (type == RMAP_BGP)
    {
      alist = access_list_lookup (AFI_IP, (char *) rule);
      if (alist == NULL)
	return RMAP_NOMATCH;
    
      return (access_list_apply (alist, prefix) == FILTER_DENY ?
	      RMAP_NOMATCH : RMAP_MATCH);
    }
  return RMAP_NOMATCH;
}

/* Route map `ip address' match statement.  `arg' should be
   access-list name. */
void *
route_match_ip_address_compile (char *arg)
{
  return XSTRDUP (MTYPE_ROUTE_MAP_COMPILED, arg);
}

/* Free route map's compiled `ip address' value. */
void
route_match_ip_address_free (void *rule)
{
  XFREE (MTYPE_ROUTE_MAP_COMPILED, rule);
}

/* Route map commands for ip address matching. */
struct route_map_rule_cmd route_match_ip_address_cmd =
{
  "ip address",
  route_match_ip_address,
  route_match_ip_address_compile,
  route_match_ip_address_free
};

/* `match ip next-hop IP_ADDRESS' */

/* Match function return 1 if match is success else return zero. */
route_map_result_t
route_match_ip_next_hop (void *rule, struct prefix *prefix, 
			 route_map_object_t type, void *object)
{
  struct access_list *alist;
  struct bgp_info *bgp_info;
  struct prefix_ipv4 p;

  if (type == RMAP_BGP)
    {
      bgp_info = object;
      p.family = AF_INET;
      p.prefix = bgp_info->attr->nexthop;
      p.prefixlen = IPV4_MAX_BITLEN;

      alist = access_list_lookup (AFI_IP, (char *) rule);
      if (alist == NULL)
	return RMAP_NOMATCH;

      return (access_list_apply (alist, &p) == FILTER_DENY ?
              RMAP_NOMATCH : RMAP_MATCH);
    }
  return RMAP_NOMATCH;
}

/* Route map `ip next-hop' match statement. `arg' is
   access-list name. */
void *
route_match_ip_next_hop_compile (char *arg)
{
  return XSTRDUP (MTYPE_ROUTE_MAP_COMPILED, arg);
}

/* Free route map's compiled `ip address' value. */
void
route_match_ip_next_hop_free (void *rule)
{
  XFREE (MTYPE_ROUTE_MAP_COMPILED, rule);
}

/* Route map commands for ip next-hop matching. */
struct route_map_rule_cmd route_match_ip_next_hop_cmd =
{
  "ip next-hop",
  route_match_ip_next_hop,
  route_match_ip_next_hop_compile,
  route_match_ip_next_hop_free
};

/* `match ip address prefix-list PREFIX_LIST' */

route_map_result_t
route_match_ip_address_prefix_list (void *rule, struct prefix *prefix, 
				    route_map_object_t type, void *object)
{
  struct prefix_list *plist;

  if (type == RMAP_BGP)
    {
      plist = prefix_list_lookup (AFI_IP, (char *) rule);
      if (plist == NULL)
	return RMAP_NOMATCH;
    
      return (prefix_list_apply (plist, prefix) == PREFIX_DENY ?
	      RMAP_NOMATCH : RMAP_MATCH);
    }
  return RMAP_NOMATCH;
}

void *
route_match_ip_address_prefix_list_compile (char *arg)
{
  return XSTRDUP (MTYPE_ROUTE_MAP_COMPILED, arg);
}

void
route_match_ip_address_prefix_list_free (void *rule)
{
  XFREE (MTYPE_ROUTE_MAP_COMPILED, rule);
}

struct route_map_rule_cmd route_match_ip_address_prefix_list_cmd =
{
  "ip address prefix-list",
  route_match_ip_address_prefix_list,
  route_match_ip_address_prefix_list_compile,
  route_match_ip_address_prefix_list_free
};

/* `match ip next-hop prefix-list PREFIX_LIST' */

route_map_result_t
route_match_ip_next_hop_prefix_list (void *rule, struct prefix *prefix,
                                    route_map_object_t type, void *object)
{
  struct prefix_list *plist;
  struct bgp_info *bgp_info;
  struct prefix_ipv4 p;

  if (type == RMAP_BGP)
    {
      bgp_info = object;
      p.family = AF_INET;
      p.prefix = bgp_info->attr->nexthop;
      p.prefixlen = IPV4_MAX_BITLEN;

      plist = prefix_list_lookup (AFI_IP, (char *) rule);
      if (plist == NULL)
        return RMAP_NOMATCH;

      return (prefix_list_apply (plist, &p) == PREFIX_DENY ?
              RMAP_NOMATCH : RMAP_MATCH);
    }
  return RMAP_NOMATCH;
}

void *
route_match_ip_next_hop_prefix_list_compile (char *arg)
{
  return XSTRDUP (MTYPE_ROUTE_MAP_COMPILED, arg);
}

void
route_match_ip_next_hop_prefix_list_free (void *rule)
{
  XFREE (MTYPE_ROUTE_MAP_COMPILED, rule);
}

struct route_map_rule_cmd route_match_ip_next_hop_prefix_list_cmd =
{
  "ip next-hop prefix-list",
  route_match_ip_next_hop_prefix_list,
  route_match_ip_next_hop_prefix_list_compile,
  route_match_ip_next_hop_prefix_list_free
};

/* `match metric METRIC' */

/* Match function return 1 if match is success else return zero. */
route_map_result_t
route_match_metric (void *rule, struct prefix *prefix, 
		    route_map_object_t type, void *object)
{
  u_int32_t *med;
  struct bgp_info *bgp_info;

  if (type == RMAP_BGP)
    {
      med = rule;
      bgp_info = object;
    
      if (bgp_info->attr->med == *med)
	return RMAP_MATCH;
      else
	return RMAP_NOMATCH;
    }
  return RMAP_NOMATCH;
}

/* Route map `match metric' match statement. `arg' is MED value */
void *
route_match_metric_compile (char *arg)
{
  u_int32_t *med;
  char *endptr = NULL;

  med = XMALLOC (MTYPE_ROUTE_MAP_COMPILED, sizeof (u_int32_t));
  *med = strtoul (arg, &endptr, 10);
  if (*endptr != '\0' || *med == ULONG_MAX)
    {
      XFREE (MTYPE_ROUTE_MAP_COMPILED, med);
      return NULL;
    }
  return med;
}

/* Free route map's compiled `match metric' value. */
void
route_match_metric_free (void *rule)
{
  XFREE (MTYPE_ROUTE_MAP_COMPILED, rule);
}

/* Route map commands for metric matching. */
struct route_map_rule_cmd route_match_metric_cmd =
{
  "metric",
  route_match_metric,
  route_match_metric_compile,
  route_match_metric_free
};

/* `match as-path ASPATH' */

/* Match function for as-path match.  I assume given object is */
route_map_result_t
route_match_aspath (void *rule, struct prefix *prefix, 
		    route_map_object_t type, void *object)
{
  
  struct as_list *as_list;
  struct bgp_info *bgp_info;

  if (type == RMAP_BGP)
    {
      as_list = as_list_lookup ((char *) rule);
      if (as_list == NULL)
	return RMAP_NOMATCH;
    
      bgp_info = object;
    
      /* Perform match. */
      return ((as_list_apply (as_list, bgp_info->attr->aspath) == AS_FILTER_DENY) ? RMAP_NOMATCH : RMAP_MATCH);
    }
  return RMAP_NOMATCH;
}

/* Compile function for as-path match. */
void *
route_match_aspath_compile (char *arg)
{
  return XSTRDUP (MTYPE_ROUTE_MAP_COMPILED, arg);
}

/* Compile function for as-path match. */
void
route_match_aspath_free (void *rule)
{
  XFREE (MTYPE_ROUTE_MAP_COMPILED, rule);
}

/* Route map commands for aspath matching. */
struct route_map_rule_cmd route_match_aspath_cmd = 
{
  "as-path",
  route_match_aspath,
  route_match_aspath_compile,
  route_match_aspath_free
};

#if ROUTE_MATCH_ASPATH_OLD
/* `match as-path ASPATH' */

/* Match function for as-path match.  I assume given object is */
int
route_match_aspath (void *rule, struct prefix *prefix, void *object)
{
  regex_t *regex;
  struct bgp_info *bgp_info;

  regex = rule;
  bgp_info = object;
  
  /* Perform match. */
  return bgp_regexec (regex, bgp_info->attr->aspath);
}

/* Compile function for as-path match. */
void *
route_match_aspath_compile (char *arg)
{
  regex_t *regex;

  regex = bgp_regcomp (arg);
  if (! regex)
    return NULL;

  return regex;
}

/* Compile function for as-path match. */
void
route_match_aspath_free (void *rule)
{
  regex_t *regex = rule;

  bgp_regex_free (regex);
}

/* Route map commands for aspath matching. */
struct route_map_rule_cmd route_match_aspath_cmd = 
{
  "as-path",
  route_match_aspath,
  route_match_aspath_compile,
  route_match_aspath_free
};
#endif /* ROUTE_MATCH_ASPATH_OLD */

/* `match community COMMUNIY' */
struct rmap_community
{
  char *name;
  int exact;
};

/* Match function for community match. */
route_map_result_t
route_match_community (void *rule, struct prefix *prefix, 
		       route_map_object_t type, void *object)
{
  struct community_list *list;
  struct bgp_info *bgp_info;
  struct rmap_community *rcom;

  if (type == RMAP_BGP) 
    {
      bgp_info = object;
      rcom = rule;

      list = community_list_lookup (bgp_clist, rcom->name, COMMUNITY_LIST_AUTO);
      if (! list)
	return RMAP_NOMATCH;

      if (rcom->exact)
	{
	  if (community_list_exact_match (bgp_info->attr->community, list))
	    return RMAP_MATCH;
	}
      else
	{
	  if (community_list_match (bgp_info->attr->community, list))
	    return RMAP_MATCH;
	}
    }
  return RMAP_NOMATCH;
}

/* Compile function for community match. */
void *
route_match_community_compile (char *arg)
{
  struct rmap_community *rcom;
  int len;
  char *p;

  rcom = XCALLOC (MTYPE_ROUTE_MAP_COMPILED, sizeof (struct rmap_community));

  p = strchr (arg, ' ');
  if (p)
    {
      len = p - arg;
      rcom->name = XCALLOC (MTYPE_ROUTE_MAP_COMPILED, len + 1);
      memcpy (rcom->name, arg, len);
      rcom->exact = 1;
    }
  else
    {
      rcom->name = XSTRDUP (MTYPE_ROUTE_MAP_COMPILED, arg);
      rcom->exact = 0;
    }
  return rcom;
}

/* Compile function for community match. */
void
route_match_community_free (void *rule)
{
  struct rmap_community *rcom = rule;

  XFREE (MTYPE_ROUTE_MAP_COMPILED, rcom->name); 
  XFREE (MTYPE_ROUTE_MAP_COMPILED, rcom);
}

/* Route map commands for community matching. */
struct route_map_rule_cmd route_match_community_cmd = 
{
  "community",
  route_match_community,
  route_match_community_compile,
  route_match_community_free
};

/* Match function for extcommunity match. */
route_map_result_t
route_match_ecommunity (void *rule, struct prefix *prefix, 
			route_map_object_t type, void *object)
{
  struct community_list *list;
  struct bgp_info *bgp_info;

  if (type == RMAP_BGP) 
    {
      bgp_info = object;

      list = community_list_lookup (bgp_clist, (char *) rule,
				    EXTCOMMUNITY_LIST_AUTO);
      if (! list)
	return RMAP_NOMATCH;

      if (ecommunity_list_match (bgp_info->attr->ecommunity, list))
	return RMAP_MATCH;
    }
  return RMAP_NOMATCH;
}

/* Compile function for extcommunity match. */
void *
route_match_ecommunity_compile (char *arg)
{
  return XSTRDUP (MTYPE_ROUTE_MAP_COMPILED, arg);
}

/* Compile function for extcommunity match. */
void
route_match_ecommunity_free (void *rule)
{
  XFREE (MTYPE_ROUTE_MAP_COMPILED, rule);
}

/* Route map commands for community matching. */
struct route_map_rule_cmd route_match_ecommunity_cmd = 
{