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

  "extcommunity",
  route_match_ecommunity,
  route_match_ecommunity_compile,
  route_match_ecommunity_free
};

/* `match nlri` and `set nlri` are replaced by `address-family ipv4`
   and `address-family vpnv4'.  */

/* `match origin' */
route_map_result_t
route_match_origin (void *rule, struct prefix *prefix, 
		    route_map_object_t type, void *object)
{
  u_char *origin;
  struct bgp_info *bgp_info;

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

  return RMAP_NOMATCH;
}

void *
route_match_origin_compile (char *arg)
{
  u_char *origin;

  origin = XMALLOC (MTYPE_ROUTE_MAP_COMPILED, sizeof (u_char));

  if (strcmp (arg, "igp") == 0)
    *origin = 0;
  else if (strcmp (arg, "egp") == 0)
    *origin = 1;
  else
    *origin = 2;

  return origin;
}

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

/* Route map commands for origin matching. */
struct route_map_rule_cmd route_match_origin_cmd =
{
  "origin",
  route_match_origin,
  route_match_origin_compile,
  route_match_origin_free
};
/* `set ip next-hop IP_ADDRESS' */

/* Set nexthop to object.  ojbect must be pointer to struct attr. */
struct rmap_ip_nexthop_set
{
  struct in_addr *address;
  int peer_address;
};

route_map_result_t
route_set_ip_nexthop (void *rule, struct prefix *prefix,
		      route_map_object_t type, void *object)
{
  struct rmap_ip_nexthop_set *rins = rule;
  struct in_addr peer_address;
  struct bgp_info *bgp_info;
  struct peer *peer;

  if (type == RMAP_BGP)
    {
      bgp_info = object;
      peer = bgp_info->peer;

      if (rins->peer_address)
	{
	  if (CHECK_FLAG (peer->rmap_type, PEER_RMAP_TYPE_IN) 
	      && peer->su_remote 
	      && sockunion_family (peer->su_remote) == AF_INET)
	    {
              inet_aton (sockunion_su2str (peer->su_remote), &peer_address);
              bgp_info->attr->nexthop = peer_address;
	      bgp_info->attr->flag |= ATTR_FLAG_BIT (BGP_ATTR_NEXT_HOP);
	    }
	  else if (CHECK_FLAG (peer->rmap_type, PEER_RMAP_TYPE_OUT)
		   && peer->su_local
		   && sockunion_family (peer->su_local) == AF_INET)
	    {
              inet_aton (sockunion_su2str (peer->su_local), &peer_address);
              bgp_info->attr->nexthop = peer_address;
	      bgp_info->attr->flag |= ATTR_FLAG_BIT (BGP_ATTR_NEXT_HOP);
	    }
	}
      else
	{
	  /* Set next hop value. */ 
	  bgp_info->attr->flag |= ATTR_FLAG_BIT (BGP_ATTR_NEXT_HOP);
	  bgp_info->attr->nexthop = *rins->address;
	}
    }

  return RMAP_OKAY;
}

/* Route map `ip nexthop' compile function.  Given string is converted
   to struct in_addr structure. */
void *
route_set_ip_nexthop_compile (char *arg)
{
  struct rmap_ip_nexthop_set *rins;
  struct in_addr *address = NULL;
  int peer_address = 0;
  int ret;

  if (strcmp (arg, "peer-address") == 0)
    peer_address = 1;
  else
    {
      address = XMALLOC (MTYPE_ROUTE_MAP_COMPILED, sizeof (struct in_addr));
      ret = inet_aton (arg, address);

      if (ret == 0)
	{
	  XFREE (MTYPE_ROUTE_MAP_COMPILED, address);
	  return NULL;
	}
    }

  rins = XMALLOC (MTYPE_ROUTE_MAP_COMPILED, sizeof (struct rmap_ip_nexthop_set));
  memset (rins, 0, sizeof (struct rmap_ip_nexthop_set));

  rins->address = address;
  rins->peer_address = peer_address;

  return rins;
}

/* Free route map's compiled `ip nexthop' value. */
void
route_set_ip_nexthop_free (void *rule)
{
  struct rmap_ip_nexthop_set *rins = rule;

  if (rins->address)
    XFREE (MTYPE_ROUTE_MAP_COMPILED, rins->address);
    
  XFREE (MTYPE_ROUTE_MAP_COMPILED, rins);
}

/* Route map commands for ip nexthop set. */
struct route_map_rule_cmd route_set_ip_nexthop_cmd =
{
  "ip next-hop",
  route_set_ip_nexthop,
  route_set_ip_nexthop_compile,
  route_set_ip_nexthop_free
};

/* `set local-preference LOCAL_PREF' */

/* Set local preference. */
route_map_result_t
route_set_local_pref (void *rule, struct prefix *prefix,
		      route_map_object_t type, void *object)
{
  u_int32_t *local_pref;
  struct bgp_info *bgp_info;

  if (type == RMAP_BGP)
    {
      /* Fetch routemap's rule information. */
      local_pref = rule;
      bgp_info = object;
    
      /* Set local preference value. */ 
      bgp_info->attr->flag |= ATTR_FLAG_BIT (BGP_ATTR_LOCAL_PREF);
      bgp_info->attr->local_pref = *local_pref;
    }

  return RMAP_OKAY;
}

/* set local preference compilation. */
void *
route_set_local_pref_compile (char *arg)
{
  u_int32_t *local_pref;
  char *endptr = NULL;

  /* Local preference value shoud be integer. */
  if (! all_digit (arg))
    return NULL;

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

/* Free route map's local preference value. */
void
route_set_local_pref_free (void *rule)
{
  XFREE (MTYPE_ROUTE_MAP_COMPILED, rule);
}

/* Set local preference rule structure. */
struct route_map_rule_cmd route_set_local_pref_cmd = 
{
  "local-preference",
  route_set_local_pref,
  route_set_local_pref_compile,
  route_set_local_pref_free,
};

/* `set weight WEIGHT' */

/* Set weight. */
route_map_result_t
route_set_weight (void *rule, struct prefix *prefix, route_map_object_t type,
		  void *object)
{
  u_int32_t *weight;
  struct bgp_info *bgp_info;

  if (type == RMAP_BGP)
    {
      /* Fetch routemap's rule information. */
      weight = rule;
      bgp_info = object;
    
      /* Set weight value. */ 
      bgp_info->attr->weight = *weight;
    }

  return RMAP_OKAY;
}

/* set local preference compilation. */
void *
route_set_weight_compile (char *arg)
{
  u_int32_t *weight;
  char *endptr = NULL;

  /* Local preference value shoud be integer. */
  if (! all_digit (arg))
    return NULL;

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

/* Free route map's local preference value. */
void
route_set_weight_free (void *rule)
{
  XFREE (MTYPE_ROUTE_MAP_COMPILED, rule);
}

/* Set local preference rule structure. */
struct route_map_rule_cmd route_set_weight_cmd = 
{
  "weight",
  route_set_weight,
  route_set_weight_compile,
  route_set_weight_free,
};

/* `set metric METRIC' */

/* Set metric to attribute. */
route_map_result_t
route_set_metric (void *rule, struct prefix *prefix, 
		  route_map_object_t type, void *object)
{
  char *metric;
  u_int32_t metric_val;
  struct bgp_info *bgp_info;

  if (type == RMAP_BGP)
    {
      /* Fetch routemap's rule information. */
      metric = rule;
      bgp_info = object;

      if (! (bgp_info->attr->flag & ATTR_FLAG_BIT (BGP_ATTR_MULTI_EXIT_DISC)))
	bgp_info->attr->med = 0;
      bgp_info->attr->flag |= ATTR_FLAG_BIT (BGP_ATTR_MULTI_EXIT_DISC);

      if (all_digit (metric))
	{
	  metric_val = strtoul (metric, (char **)NULL, 10);
	  bgp_info->attr->med = metric_val;
	}
      else
	{
	  metric_val = strtoul (metric+1, (char **)NULL, 10);

	  if (strncmp (metric, "+", 1) == 0)
	    {
	      if (bgp_info->attr->med/2 + metric_val/2 > ULONG_MAX/2)
		bgp_info->attr->med = ULONG_MAX-1;
	      else
		bgp_info->attr->med += metric_val;
	    }
	  else if (strncmp (metric, "-", 1) == 0)
	    {
	      if (bgp_info->attr->med <= metric_val) 
		bgp_info->attr->med = 0;
	      else
		bgp_info->attr->med -= metric_val;
	    }
	}
    }
  return RMAP_OKAY;
}

/* set metric compilation. */
void *
route_set_metric_compile (char *arg)
{
  u_int32_t metric;
  char *endptr = NULL;

  if (all_digit (arg))
    {
      /* set metric value check*/
      metric = strtoul (arg, &endptr, 10);
      if (*endptr != '\0' || metric == ULONG_MAX)
        return NULL;
    }
  else
    {
      /* set metric +/-value check */
      if ((strncmp (arg, "+", 1) != 0
	   && strncmp (arg, "-", 1) != 0)
	   || (! all_digit (arg+1)))
	return NULL;

      metric = strtoul (arg+1, &endptr, 10);
      if (*endptr != '\0' || metric == ULONG_MAX)
	return NULL;
    }

  return XSTRDUP (MTYPE_ROUTE_MAP_COMPILED, arg);
}

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

/* Set metric rule structure. */
struct route_map_rule_cmd route_set_metric_cmd = 
{
  "metric",
  route_set_metric,
  route_set_metric_compile,
  route_set_metric_free,
};

/* `set as-path prepend ASPATH' */

/* For AS path prepend mechanism. */
route_map_result_t
route_set_aspath_prepend (void *rule, struct prefix *prefix, route_map_object_t type, void *object)
{
  struct aspath *aspath;
  struct aspath *new;
  struct bgp_info *binfo;

  if (type == RMAP_BGP)
    {
      aspath = rule;
      binfo = object;
    
      if (binfo->attr->aspath->refcnt)
	new = aspath_dup (binfo->attr->aspath);
      else
	new = binfo->attr->aspath;

      aspath_prepend (aspath, new);
      binfo->attr->aspath = new;
    }

  return RMAP_OKAY;
}

/* Compile function for as-path prepend. */
void *
route_set_aspath_prepend_compile (char *arg)
{
  struct aspath *aspath;

  aspath = aspath_str2aspath (arg);
  if (! aspath)
    return NULL;
  return aspath;
}

/* Compile function for as-path prepend. */
void
route_set_aspath_prepend_free (void *rule)
{
  struct aspath *aspath = rule;
  aspath_free (aspath);
}

/* Set metric rule structure. */
struct route_map_rule_cmd route_set_aspath_prepend_cmd = 
{
  "as-path prepend",
  route_set_aspath_prepend,
  route_set_aspath_prepend_compile,
  route_set_aspath_prepend_free,
};

/* `set community COMMUNITY' */
struct rmap_com_set
{
  struct community *com;
  int additive;
  int none;
};

/* For community set mechanism. */
route_map_result_t
route_set_community (void *rule, struct prefix *prefix,
		     route_map_object_t type, void *object)
{
  struct rmap_com_set *rcs;
  struct bgp_info *binfo;
  struct attr *attr;
  struct community *new = NULL;
  struct community *old;
  struct community *merge;

  if (type == RMAP_BGP)
    {
      rcs = rule;
      binfo = object;
      attr = binfo->attr;
      old = attr->community;

      /* "none" case.  */
      if (rcs->none)
	{
	  attr->flag &= ~(ATTR_FLAG_BIT (BGP_ATTR_COMMUNITIES));
	  attr->community = NULL;
	  return RMAP_OKAY;
	}

      /* "additive" case.  */
      if (rcs->additive && old)
	{
	  merge = community_merge (community_dup (old), rcs->com);
	  new = community_uniq_sort (merge);
	  community_free (merge);
	}
      else
	new = community_dup (rcs->com);

      attr->community = new;
      attr->flag |= ATTR_FLAG_BIT (BGP_ATTR_COMMUNITIES);
    }

  return RMAP_OKAY;
}

/* Compile function for set community. */
void *
route_set_community_compile (char *arg)
{
  struct rmap_com_set *rcs;
  struct community *com = NULL;
  char *sp;
  int additive = 0;
  int none = 0;
  
  if (strcmp (arg, "none") == 0)
    none = 1;
  else
    {
      sp = strstr (arg, "additive");

      if (sp && sp > arg)
  	{
	  /* "additive" keyworkd is included.  */
	  additive = 1;
	  *(sp - 1) = '\0';
	}

      com = community_str2com (arg);

      if (additive)
	*(sp - 1) = ' ';

      if (! com)
	return NULL;
    }
  
  rcs = XMALLOC (MTYPE_ROUTE_MAP_COMPILED, sizeof (struct rmap_com_set));
  memset (rcs, 0, sizeof (struct rmap_com_set));
  
  rcs->com = com;
  rcs->additive = additive;
  rcs->none = none;
  
  return rcs;
}

/* Free function for set community. */
void
route_set_community_free (void *rule)
{
  struct rmap_com_set *rcs = rule;

  if (rcs->com)
    community_free (rcs->com);
  XFREE (MTYPE_ROUTE_MAP_COMPILED, rcs);
}

/* Set community rule structure. */
struct route_map_rule_cmd route_set_community_cmd = 
{
  "community",
  route_set_community,
  route_set_community_compile,
  route_set_community_free,
};

/* `set comm-list (<1-99>|<100-199>|WORD) delete' */

/* For community set mechanism. */
route_map_result_t
route_set_community_delete (void *rule, struct prefix *prefix,
			    route_map_object_t type, void *object)