ospf_routing_table_lookups.c

vxworks下ospf协议栈

						{
							if (sptr_routing_table_node->sptr_routing_table_entry->path_cost < best_sptr_routing_table_node->sptr_routing_table_entry->path_cost)
							{
								best_sptr_routing_table_node = sptr_routing_table_node;
							}
							else if (sptr_routing_table_node->sptr_routing_table_entry->path_cost == best_sptr_routing_table_node->sptr_routing_table_entry->path_cost)
							{
								if (sptr_routing_table_node->sptr_routing_table_entry->sptr_area->area_id > best_sptr_routing_table_node->sptr_routing_table_entry->sptr_area->area_id)
								{
									best_sptr_routing_table_node = sptr_routing_table_node;
								}
							}
						}
						else if(((sptr_routing_table_node->sptr_routing_table_entry->path_type == OSPF_ROUTE_PATH_TYPE_INTRA) &&
						   		(sptr_routing_table_node->sptr_routing_table_entry->sptr_area->area_id != OSPF_BACKBONE)) &&
						   		((best_sptr_routing_table_node->sptr_routing_table_entry->path_type != OSPF_ROUTE_PATH_TYPE_INTRA) ||
						   		(best_sptr_routing_table_node->sptr_routing_table_entry->sptr_area->area_id == OSPF_BACKBONE)))
						{
							best_sptr_routing_table_node = sptr_routing_table_node;
						}
						else if (((sptr_routing_table_node->sptr_routing_table_entry->path_type != OSPF_ROUTE_PATH_TYPE_INTRA) ||
								(sptr_routing_table_node->sptr_routing_table_entry->sptr_area->area_id == OSPF_BACKBONE)) &&
								((best_sptr_routing_table_node->sptr_routing_table_entry->path_type != OSPF_ROUTE_PATH_TYPE_INTRA) ||
								(best_sptr_routing_table_node->sptr_routing_table_entry->sptr_area->area_id == OSPF_BACKBONE)))
						{
							if (sptr_routing_table_node->sptr_routing_table_entry->path_cost < best_sptr_routing_table_node->sptr_routing_table_entry->path_cost)
							{
								best_sptr_routing_table_node = sptr_routing_table_node;
							}
							else if (sptr_routing_table_node->sptr_routing_table_entry->path_cost == best_sptr_routing_table_node->sptr_routing_table_entry->path_cost)
							{
								if (sptr_routing_table_node->sptr_routing_table_entry->sptr_area->area_id > best_sptr_routing_table_node->sptr_routing_table_entry->sptr_area->area_id)
								{
									best_sptr_routing_table_node = sptr_routing_table_node;
								}
							}
						}
					}
					else
					{
						/* rfc 1583 compliant search */
						if (sptr_routing_table_node->sptr_routing_table_entry->path_cost < best_sptr_routing_table_node->sptr_routing_table_entry->path_cost)
						{
							best_sptr_routing_table_node = sptr_routing_table_node;
						}
						else if (sptr_routing_table_node->sptr_routing_table_entry->path_cost == best_sptr_routing_table_node->sptr_routing_table_entry->path_cost)
						{
							if (sptr_routing_table_node->sptr_routing_table_entry->sptr_area->area_id > best_sptr_routing_table_node->sptr_routing_table_entry->sptr_area->area_id)
							{
								best_sptr_routing_table_node = sptr_routing_table_node;
							}
						}
					}
				}
			}
		}
	}

	if (best_sptr_routing_table_node != NULL)
	{
		return (best_sptr_routing_table_node->sptr_routing_table_entry);
	}

	return (NULL);
}

/*******************************************************************************//* section 16.3 of OSPF specification (page 158) */
/* UNH 4.2 start */
/******************************************************************************
*
* ospf_find_routing_table_entry_for_ABR
*
* DESCRIPTION:
* This function searches the routing table to find an entry for
* the given area border router and for the given area (first fit)
* NOTE: For an ABR, there are several ABR routing table entries, one ABR routing table
*    entry for each area the router is attached to.
* PARAMETERS:
*   destination_id_to_look = the router ID of the area border router
*   area_id = area id for which to locate a routing table entry.
*
* RETURNS: pointer to the routing table entry
*/

OSPF_ROUTING_TABLE_ENTRY* ospf_find_routing_table_entry_for_ABR(ULONG destination_id_to_look, ULONG area_id)
{
    OSPF_ROUTING_TABLE_NODE *sptr_routing_table_node = NULL;
    OSPF_ROUTING_TABLE_ENTRY *sptr_routing_table_entry = NULL;
	ULONG hash_id;

	OSPF_PRINTF_DEBUG (OSPF_DEBUG_PRINTF, "OSPF: Entering ospf_find_routing_table_entry_for_ABR\r\n");

	hash_id = destination_id_to_look;
	hash_id = hash_id & OSPF_RT_HASH_MASK;

    for (sptr_routing_table_node = ospf.sptr_routing_table_head[OSPF_ROUTE_TABLE_ROUTER][hash_id];
         sptr_routing_table_node != NULL;
		 sptr_routing_table_node = sptr_routing_table_node->sptr_forward_link)
		{
		if ((sptr_routing_table_node->sptr_routing_table_entry->destination_type == OSPF_DESTINATION_TYPE_ABR) &&
			(sptr_routing_table_node->sptr_routing_table_entry->destination_id == destination_id_to_look) &&
			(sptr_routing_table_node->sptr_routing_table_entry->sptr_area->area_id == area_id))
	    {
            sptr_routing_table_entry = sptr_routing_table_node->sptr_routing_table_entry;
        }
    }
    return sptr_routing_table_entry;
}
/* UNH 4.2 end */

/*******************************************************************************************************************************/
OSPF_ROUTING_TABLE_NODE *ospf_find_routing_table_node (ULONG destination_id_to_look, enum OSPF_LS_TYPE lsa_header_type,
                                                       enum OSPF_ROUTE_PATH_TYPE path_type,OSPF_AREA_ENTRY *sptr_area)          /* NEWRT LOOKUP */
{
    OSPF_ROUTING_TABLE_NODE *sptr_routing_table_node;
    enum OSPF_ROUTE_DESTINATION_TYPE destination_type;
    OSPF_ROUTING_TABLE_NODE *best_sptr_routing_table_node = NULL;
    enum BOOLEAN first_pass = TRUE;
    ULONG hash_id;
	enum OSPF_ROUTE_TABLE_TYPE table_type = OSPF_ROUTE_TABLE_NETWORK;

    OSPF_PRINTF_DEBUG (OSPF_DEBUG_PRINTF, "OSPF: Entering ospf_find_routing_table_node\r\n");

    switch(lsa_header_type)
    {
		case OSPF_LS_SUMMARY_NETWORK:
		case OSPF_LS_NETWORK:

			destination_type = OSPF_DESTINATION_TYPE_NETWORK;
			table_type = OSPF_ROUTE_TABLE_NETWORK;
			break;

		case OSPF_LS_AS_EXTERNAL:
#if defined (__NSSA__)
		case OSPF_LS_TYPE_7:
#endif /* __NSSA__	*/

			destination_type = OSPF_DESTINATION_TYPE_ASE;
			break;

		case OSPF_LS_SUMMARY_AS_BOUNDARY_ROUTER:
		case OSPF_DESTINATION_TYPE_ASBR:

			destination_type = OSPF_DESTINATION_TYPE_ASBR;
			table_type = OSPF_ROUTE_TABLE_ROUTER;
			break;

		case OSPF_LS_ROUTER_ABR:

			destination_type = OSPF_DESTINATION_TYPE_ABR;
			table_type = OSPF_ROUTE_TABLE_ROUTER;
			break;

		default:
			destination_type = OSPF_DESTINATION_TYPE_WILDCARD;
			break;
	}

	hash_id = destination_id_to_look;
	hash_id = hash_id & OSPF_RT_HASH_MASK;

	/* Look in both router and network tables for destination type wild*/
	if(destination_type == OSPF_DESTINATION_TYPE_WILDCARD)
	{
		for(table_type = OSPF_ROUTE_TABLE_NETWORK; table_type < OSPF_ROUTE_TABLE_MAX; table_type++)
		{
			for(sptr_routing_table_node = ospf.sptr_routing_table_head[table_type][hash_id];
				sptr_routing_table_node != NULL;
				sptr_routing_table_node = sptr_routing_table_node->sptr_forward_link)
			{
        		if ((sptr_routing_table_node->sptr_routing_table_entry->destination_id == destination_id_to_look) &&
            	   ((sptr_routing_table_node->sptr_routing_table_entry->path_type == path_type) || (path_type == OSPF_ROUTE_PATH_TYPE_WILDCARD)) &&
            	   ((sptr_routing_table_node->sptr_routing_table_entry->sptr_area == sptr_area) || (sptr_area == NULL)))
            	{
            		if (first_pass)
            		{
            	    	best_sptr_routing_table_node = sptr_routing_table_node;
            	    	first_pass = FALSE;
            	    }
            		else
            	    {
#if defined (__RFC_2328__)
            		    if (sptr_routing_table_node->sptr_routing_table_entry->path_cost > best_sptr_routing_table_node->sptr_routing_table_entry->path_cost)
#else
            		    if (sptr_routing_table_node->sptr_routing_table_entry->path_cost < best_sptr_routing_table_node->sptr_routing_table_entry->path_cost)
#endif
            	        {
            		        best_sptr_routing_table_node = sptr_routing_table_node;
            	        }
            	    }
            	}
        	}
		}
	}
	else
	{
		/* Destination type is not wild*/
		for(sptr_routing_table_node = ospf.sptr_routing_table_head[table_type][hash_id];
			sptr_routing_table_node != NULL;
			sptr_routing_table_node = sptr_routing_table_node->sptr_forward_link)
		{
        	if ((sptr_routing_table_node->sptr_routing_table_entry->destination_type == destination_type) &&
               (sptr_routing_table_node->sptr_routing_table_entry->destination_id == destination_id_to_look) &&
               ((sptr_routing_table_node->sptr_routing_table_entry->path_type == path_type) || (path_type == OSPF_ROUTE_PATH_TYPE_WILDCARD)) &&
               ((sptr_routing_table_node->sptr_routing_table_entry->sptr_area == sptr_area) || (sptr_area == NULL)))
            {

            	if (first_pass)
            	{
            	   	best_sptr_routing_table_node = sptr_routing_table_node;
            	   	first_pass = FALSE;
            	}
            	else
            	{
#if defined (__RFC_2328__)
            	    if (sptr_routing_table_node->sptr_routing_table_entry->path_cost > best_sptr_routing_table_node->sptr_routing_table_entry->path_cost)
#else
            	    if (sptr_routing_table_node->sptr_routing_table_entry->path_cost < best_sptr_routing_table_node->sptr_routing_table_entry->path_cost)
#endif
                    {
            	        best_sptr_routing_table_node = sptr_routing_table_node;
                    }
                }
            }
        }
	}

	return(best_sptr_routing_table_node);

}

/* Fix for SPR# 297651 (SPR#83274) */
/*******************************************************************************************************************************/
OSPF_ROUTING_TABLE_NODE *ospf_find_router_or_network_routing_table_node (ULONG destination_id_to_look, enum OSPF_LS_TYPE lsa_header_type,
                                                                         enum OSPF_ROUTE_PATH_TYPE path_type,OSPF_AREA_ENTRY *sptr_area)
{
    OSPF_ROUTING_TABLE_NODE *sptr_routing_table_node;
    OSPF_ROUTING_TABLE_NODE *best_sptr_routing_table_node = NULL;
    enum BOOLEAN first_pass = TRUE;
    ULONG hash_id;
	enum OSPF_ROUTE_TABLE_TYPE table_type;

    OSPF_PRINTF_DEBUG (OSPF_DEBUG_PRINTF, "OSPF: Entering ospf_find_router_or_network_routing_table_node\r\n");

    switch(lsa_header_type)
    {
        case OSPF_LS_SUMMARY_AS_BOUNDARY_ROUTER:
        case OSPF_LS_ROUTER:
        case OSPF_LS_ROUTER_ABR:
        case OSPF_LS_ROUTER_ASBR:

  			table_type = OSPF_ROUTE_TABLE_ROUTER;
			break;

		default:

			table_type = OSPF_ROUTE_TABLE_NETWORK;
			break;
	}

	hash_id = destination_id_to_look;
	hash_id = hash_id & OSPF_RT_HASH_MASK;

	for(sptr_routing_table_node = ospf.sptr_routing_table_head[table_type][hash_id];
		sptr_routing_table_node != NULL;
		sptr_routing_table_node = sptr_routing_table_node->sptr_forward_link)
	{
       	if ((sptr_routing_table_node->sptr_routing_table_entry->destination_id == destination_id_to_look) &&
            ((sptr_routing_table_node->sptr_routing_table_entry->path_type == path_type) || (path_type == OSPF_ROUTE_PATH_TYPE_WILDCARD)) &&
            ((sptr_routing_table_node->sptr_routing_table_entry->sptr_area == sptr_area) || (sptr_area == NULL)))
        {
           	if (first_pass)
           	{
           	   	best_sptr_routing_table_node = sptr_routing_table_node;
           	   	first_pass = FALSE;
           	}
           	else
           	{
#if defined (__RFC_2328__)
           	    if (sptr_routing_table_node->sptr_routing_table_entry->path_cost > best_sptr_routing_table_node->sptr_routing_table_entry->path_cost)
#else
           	    if (sptr_routing_table_node->sptr_routing_table_entry->path_cost < best_sptr_routing_table_node->sptr_routing_table_entry->path_cost)
#endif
                {
           	        best_sptr_routing_table_node = sptr_routing_table_node;
                }
            }
        }
    }

    return(best_sptr_routing_table_node);
}

/* SPR#76812 -- End */