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.
   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 "linklist.h"
#include "memory.h"
#include "vector.h"
#include "prefix.h"
#include "routemap.h"
#include "command.h"

/* Vector for route match rules. */
static vector route_match_vec;

/* Vector for route set rules. */
static vector route_set_vec;

/* Route map rule. This rule has both `match' rule and `set' rule. */
struct route_map_rule
{
  /* Rule type. */
  struct route_map_rule_cmd *cmd;

  /* For pretty printing. */
  char *rule_str;

  /* Pre-compiled match rule. */
  void *value;

  /* Linked list. */
  struct route_map_rule *next;
  struct route_map_rule *prev;
};

/* Making route map list. */
struct route_map_list
{
  struct route_map *head;
  struct route_map *tail;

  void (*add_hook) (char *);
  void (*delete_hook) (char *);
  void (*event_hook) (route_map_event_t, char *); 
};

/* Master list of route map. */
static struct route_map_list route_map_master = { NULL, NULL, NULL, NULL };

static void
route_map_rule_delete (struct route_map_rule_list *,
		       struct route_map_rule *);

static void
route_map_index_delete (struct route_map_index *, int);

/* New route map allocation. Please note route map's name must be
   specified. */
static struct route_map *
route_map_new (char *name)
{
  struct route_map *new;

  new =  XCALLOC (MTYPE_ROUTE_MAP, sizeof (struct route_map));
  new->name = XSTRDUP (MTYPE_ROUTE_MAP_NAME, name);
  return new;
}

/* Add new name to route_map. */
static struct route_map *
route_map_add (char *name)
{
  struct route_map *map;
  struct route_map_list *list;

  map = route_map_new (name);
  list = &route_map_master;
    
  map->next = NULL;
  map->prev = list->tail;
  if (list->tail)
    list->tail->next = map;
  else
    list->head = map;
  list->tail = map;

  /* Execute hook. */
  if (route_map_master.add_hook)
    (*route_map_master.add_hook) (name);

  return map;
}

/* Route map delete from list. */
static void
route_map_delete (struct route_map *map)
{
  struct route_map_list *list;
  struct route_map_index *index;
  char *name;
  
  while ((index = map->head) != NULL)
    route_map_index_delete (index, 0);

  name = map->name;

  list = &route_map_master;

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

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

  XFREE (MTYPE_ROUTE_MAP, map);

  /* Execute deletion hook. */
  if (route_map_master.delete_hook)
    (*route_map_master.delete_hook) (name);

  if (name)
    XFREE (MTYPE_ROUTE_MAP_NAME, name);

}

/* Lookup route map by route map name string. */
struct route_map *
route_map_lookup_by_name (char *name)
{
  struct route_map *map;

  for (map = route_map_master.head; map; map = map->next)
    if (strcmp (map->name, name) == 0)
      return map;
  return NULL;
}

/* Lookup route map.  If there isn't route map create one and return
   it. */
struct route_map *
route_map_get (char *name)
{
  struct route_map *map;

  map = route_map_lookup_by_name (name);
  if (map == NULL)
    map = route_map_add (name);
  return map;
}

/* Return route map's type string. */
static char *
route_map_type_str (enum route_map_type type)
{
  switch (type)
    {
    case RMAP_PERMIT:
      return "permit";
      break;
    case RMAP_DENY:
      return "deny";
      break;
    default:
      return "";
      break;
    }
}

int
route_map_empty (struct route_map *map)
{
  if (map->head == NULL && map->tail == NULL)
    return 1;
  else
    return 0;
}

/* For debug. */
void
route_map_print ()
{
  struct route_map *map;
  struct route_map_index *index;
  struct route_map_rule *rule;

  for (map = route_map_master.head; map; map = map->next)
    for (index = map->head; index; index = index->next)
      {
	printf ("route-map %s %s %d\n", 
		map->name,
		route_map_type_str (index->type),
		index->pref);
	for (rule = index->match_list.head; rule; rule = rule->next)
	  printf (" match %s %s\n", rule->cmd->str, rule->rule_str);
	for (rule = index->set_list.head; rule; rule = rule->next)
	  printf (" set %s %s\n", rule->cmd->str, rule->rule_str);
	if (index->exitpolicy == RMAP_GOTO)
	  printf (" on-match goto %d\n", index->nextpref);
	if (index->exitpolicy == RMAP_NEXT)
	  printf (" on-match next\n");
      }
}

/* New route map allocation. Please note route map's name must be
   specified. */
struct route_map_index *
route_map_index_new ()
{
  struct route_map_index *new;

  new =  XCALLOC (MTYPE_ROUTE_MAP_INDEX, sizeof (struct route_map_index));
  new->exitpolicy = RMAP_EXIT; /* Default to Cisco-style */
  return new;
}

/* Free route map index. */
static void
route_map_index_delete (struct route_map_index *index, int notify)
{
  struct route_map_rule *rule;

  /* Free route match. */
  while ((rule = index->match_list.head) != NULL)
    route_map_rule_delete (&index->match_list, rule);

  /* Free route set. */
  while ((rule = index->set_list.head) != NULL)
    route_map_rule_delete (&index->set_list, rule);

  /* Remove index from route map list. */
  if (index->next)
    index->next->prev = index->prev;
  else
    index->map->tail = index->prev;

  if (index->prev)
    index->prev->next = index->next;
  else
    index->map->head = index->next;

    /* Execute event hook. */
  if (route_map_master.event_hook && notify)
    (*route_map_master.event_hook) (RMAP_EVENT_INDEX_DELETED,
				    index->map->name);

  XFREE (MTYPE_ROUTE_MAP_INDEX, index);
}

/* Lookup index from route map. */
struct route_map_index *
route_map_index_lookup (struct route_map *map, enum route_map_type type,
			int pref)
{
  struct route_map_index *index;

  for (index = map->head; index; index = index->next)
    if ((index->type == type || type == RMAP_ANY)
	&& index->pref == pref)
      return index;
  return NULL;
}

/* Add new index to route map. */
struct route_map_index *
route_map_index_add (struct route_map *map, enum route_map_type type,
		     int pref)
{
  struct route_map_index *index;
  struct route_map_index *point;

  /* Allocate new route map inex. */
  index = route_map_index_new ();
  index->map = map;
  index->type = type;
  index->pref = pref;
  
  /* Compare preference. */
  for (point = map->head; point; point = point->next)
    if (point->pref >= pref)
      break;

  if (map->head == NULL)
    {
      map->head = map->tail = index;
    }
  else if (point == NULL)
    {
      index->prev = map->tail;
      map->tail->next = index;
      map->tail = index;
    }
  else if (point == map->head)
    {
      index->next = map->head;
      map->head->prev = index;
      map->head = index;
    }
  else
    {
      index->next = point;
      index->prev = point->prev;
      if (point->prev)
	point->prev->next = index;
      point->prev = index;
    }

  /* Execute event hook. */
  if (route_map_master.event_hook)
    (*route_map_master.event_hook) (RMAP_EVENT_INDEX_ADDED,
				    map->name);

  return index;
}

/* Get route map index. */
struct route_map_index *
route_map_index_get (struct route_map *map, enum route_map_type type, 
		     int pref)
{
  struct route_map_index *index;

  index = route_map_index_lookup (map, RMAP_ANY, pref);
  if (index && index->type != type)
    {
      /* Delete index from route map. */
      route_map_index_delete (index, 1);
      index = NULL;
    }
  if (index == NULL)
    index = route_map_index_add (map, type, pref);
  return index;
}

/* New route map rule */
struct route_map_rule *
route_map_rule_new ()
{
  struct route_map_rule *new;

  new = XCALLOC (MTYPE_ROUTE_MAP_RULE, sizeof (struct route_map_rule));
  return new;
}

/* Install rule command to the match list. */
void
route_map_install_match (struct route_map_rule_cmd *cmd)
{
  vector_set (route_match_vec, cmd);
}

/* Install rule command to the set list. */
void
route_map_install_set (struct route_map_rule_cmd *cmd)
{
  vector_set (route_set_vec, cmd);
}

/* Lookup rule command from match list. */
struct route_map_rule_cmd *
route_map_lookup_match (char *name)
{
  int i;
  struct route_map_rule_cmd *rule;

  for (i = 0; i < vector_max (route_match_vec); i++)
    if ((rule = vector_slot (route_match_vec, i)) != NULL)
      if (strcmp (rule->str, name) == 0)
	return rule;
  return NULL;
}

/* Lookup rule command from set list. */
struct route_map_rule_cmd *
route_map_lookup_set (char *name)
{
  int i;
  struct route_map_rule_cmd *rule;

  for (i = 0; i < vector_max (route_set_vec); i++)
    if ((rule = vector_slot (route_set_vec, i)) != NULL)
      if (strcmp (rule->str, name) == 0)
	return rule;
  return NULL;
}

/* Add match and set rule to rule list. */
static void
route_map_rule_add (struct route_map_rule_list *list,
		    struct route_map_rule *rule)
{
  rule->next = NULL;
  rule->prev = list->tail;
  if (list->tail)
    list->tail->next = rule;
  else
    list->head = rule;
  list->tail = rule;
}

/* Delete rule from rule list. */
static void
route_map_rule_delete (struct route_map_rule_list *list,
		       struct route_map_rule *rule)
{
  if (rule->cmd->func_free)
    (*rule->cmd->func_free) (rule->value);

  if (rule->rule_str)
    XFREE (MTYPE_ROUTE_MAP_RULE_STR, rule->rule_str);

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

  XFREE (MTYPE_ROUTE_MAP_RULE, rule);
}

/* strcmp wrapper function which don't crush even argument is NULL. */
int
rulecmp (char *dst, char *src)
{
  if (dst == NULL)
    {
      if (src ==  NULL)
	return 0;
      else
	return 1;
    }
  else
    {
      if (src == NULL)
	return 1;
      else
	return strcmp (dst, src);
    }
  return 1;
}

/* Add match statement to route map. */
int
route_map_add_match (struct route_map_index *index, char *match_name,
		     char *match_arg)
{
  struct route_map_rule *rule;
  struct route_map_rule *next;
  struct route_map_rule_cmd *cmd;
  void *compile;
  int replaced = 0;

  /* First lookup rule for add match statement. */
  cmd = route_map_lookup_match (match_name);
  if (cmd == NULL)
    return RMAP_RULE_MISSING;

  /* Next call compile function for this match statement. */
  if (cmd->func_compile)
    {
      compile= (*cmd->func_compile)(match_arg);
      if (compile == NULL)
	return RMAP_COMPILE_ERROR;
    }
  else
    compile = NULL;

  /* If argument is completely same ignore it. */
  for (rule = index->match_list.head; rule; rule = next)
    {
      next = rule->next;
      if (rule->cmd == cmd)
	{	
	  route_map_rule_delete (&index->match_list, rule);
	  replaced = 1;
	}
    }

  /* Add new route map match rule. */
  rule = route_map_rule_new ();
  rule->cmd = cmd;
  rule->value = compile;
  if (match_arg)
    rule->rule_str = XSTRDUP (MTYPE_ROUTE_MAP_RULE_STR, match_arg);
  else
    rule->rule_str = NULL;

  /* Add new route match rule to linked list. */
  route_map_rule_add (&index->match_list, rule);

  /* Execute event hook. */
  if (route_map_master.event_hook)
    (*route_map_master.event_hook) (replaced ?
				    RMAP_EVENT_MATCH_REPLACED:
				    RMAP_EVENT_MATCH_ADDED,
				    index->map->name);

  return 0;
}

/* Delete specified route match rule. */
int
route_map_delete_match (struct route_map_index *index, char *match_name,
			char *match_arg)
{
  struct route_map_rule *rule;
  struct route_map_rule_cmd *cmd;

  cmd = route_map_lookup_match (match_name);
  if (cmd == NULL)
    return 1;
  
  for (rule = index->match_list.head; rule; rule = rule->next)
    if (rule->cmd == cmd && 
	(rulecmp (rule->rule_str, match_arg) == 0 || match_arg == NULL))
      {
	route_map_rule_delete (&index->match_list, rule);
	/* Execute event hook. */
	if (route_map_master.event_hook)
	  (*route_map_master.event_hook) (RMAP_EVENT_MATCH_DELETED,
					  index->map->name);
	return 0;
      }
  /* Can't find matched rule. */
  return 1;