macbrdb.c

以太网交换机协议平台stp协议的设计与实现源代码。

/*
 * $Log:: /OEM Source Code/Spantree/macbrd $
 * 
 * 1     12/04/98 2:36p Release Engineer
 * code cleanup, bug fixes, code style
 * changes, linted, system level test
 * STP v4.3.0
 * 
 * 2     3/27/96 7:07p Ross
 * Initial check in with source safe
 * 
 * 1     2/06/96 11:06p Ross
 * Adding new version control
*/
/*	$Modname: macbrdb.c$  $version: 1.22$      $date: 03/31/95$   */
/*
* 	$lgb$
1.0 01/05/92 ross
1.1 01/25/92 ross
1.2 04/22/92 ross
1.3 07/30/92 ross
1.4 08/05/92 ross
1.5 08/15/92 ross added dynamic hashing, fixed bug which installed bridge addresses in table.
1.6 08/21/92 ross
1.7 08/21/92 ross
1.8 08/22/92 ross Added support for multiple instances of stp_class
1.9 08/22/92 ross delete find_matching_source_e...
1.10 08/22/92 ross made as many functions as possible static
1.11 11/23/92 ross changed ETHERNET_ADDRESS to MAC_ADDRESS to appear more generic (cosmetic)
1.12 01/10/93 ross adding support for dlci number if FD table.
1.13 01/15/93 ross
1.14 01/20/93 ross
1.15 01/29/93 ross changed constants in macbrrx.c and macbrdb.c to better match snmp, fixed frame relay bug.
1.16 01/30/93 ross delete references to stp dlci
1.17 07/16/93 ross added some mib statistics
1.18 10/28/93 ross added some parenthesis for readability.
1.19 01/13/94 ross changed a 1 in static add to spanning tree port number.
1.20 03/07/94 ross removed external references to mac_address, function used instead.
1.21 06/15/94 ross cosmetic changes and snmp access routines.
1.22 03/31/95 ross Changes for new rwutils library.
* 	$lge$
*/
/************************************************************************/
/*	Copyright (C) 1989-1998 RouterWare, Inc. 										*/
/*	Unpublished - rights reserved under the Copyright Laws of the			*/
/*	United States.  Use, duplication, or disclosure by the 					*/
/*	Government is subject to restrictions as set forth in 					*/
/*	subparagraph (c)(1)(ii) of the Rights in Technical Data and 			*/
/*	Computer Software clause at 252.227-7013.										*/
/*	RouterWare, Inc., 3961 MacArthur Blvd. Suite 212, Newport Beach Ca   */
/************************************************************************/
#include	<string.h>
#include	<stdlib.h>
#include "macbridg.h" 
/****************************************************************************/
void initialize_hashing_table (void)
{
	ULONG	entry_number;
	FILTERING_DATABASE_ENTRY *sptr_current_entry;

	stp_class.sptr_fd_table = (FILTERING_DATABASE_TABLE *) 
		table_malloc (stp_class.number_of_fd_entries,sizeof (FILTERING_DATABASE_ENTRY));

	stp_class.sptr_hash_table =
		(HASH_TABLE *) table_malloc (stp_class.number_of_hash_table_entries,
		sizeof (stp_class.sptr_first_entry_in_fd_table->links));

	stp_class.sptr_first_entry_in_fd_table = (FILTERING_DATABASE_ENTRY *) stp_class.sptr_fd_table;

	stp_class.free_fd_entries_queue.sptr_forward_link = NULL;
	stp_class.free_fd_entries_queue.sptr_backward_link = NULL;
	sptr_current_entry = stp_class.sptr_first_entry_in_fd_table;

	for (entry_number = 0x00000000L ; entry_number < stp_class.number_of_fd_entries; ++entry_number,++sptr_current_entry)
		{
		add_entry_to_queue (&stp_class.free_fd_entries_queue,&sptr_current_entry->links);
		}
}
/****************************************************************************/
enum FD_TABLE_ENTRY_TYPE add_entry_to_filtering_database (USHORT source_mac_address_ushort,
	ULONG source_mac_address_ulong,USHORT port_number,enum FD_TABLE_ENTRY_TYPE type)
{
	FILTERING_DATABASE_ENTRY	*sptr_matching_fd_entry;

	sptr_matching_fd_entry = (FILTERING_DATABASE_ENTRY *)
		stp_class.sptr_hash_table->entry[source_mac_address_ushort & stp_class.hash_mask].sptr_forward_link;

	while (sptr_matching_fd_entry != NULL)
		{
		if (sptr_matching_fd_entry->source_address._ushort == source_mac_address_ushort &&
			sptr_matching_fd_entry->source_address._ulong == source_mac_address_ulong)
			break;

		sptr_matching_fd_entry = (FILTERING_DATABASE_ENTRY *) sptr_matching_fd_entry->links.sptr_forward_link;
		}

	if (sptr_matching_fd_entry == NULL)
		{
 		sptr_matching_fd_entry =
			(FILTERING_DATABASE_ENTRY *) get_entry_from_queue (&stp_class.free_fd_entries_queue);

		if (sptr_matching_fd_entry == NULL)
			{
			++stp_class.port[port_number].number_of_frames_received_while_database_is_full;
			++stp_class.this_bridge.number_of_frames_received_while_database_is_full;
			return (OUT_OF_DATABASE_ENTRIES);
			}

		sptr_matching_fd_entry->source_address._ushort = source_mac_address_ushort;
		sptr_matching_fd_entry->source_address._ulong = source_mac_address_ulong;
		sptr_matching_fd_entry->timer_value = bridge_timer;
		sptr_matching_fd_entry->type = (BYTE_ENUM (FD_TABLE_ENTRY_TYPE)) type;
		sptr_matching_fd_entry->port_number = (BYTE) port_number;

  		add_entry_to_queue ((LINK *) &stp_class.sptr_hash_table->entry[source_mac_address_ushort &
			stp_class.hash_mask],&sptr_matching_fd_entry->links);

		return (NOT_IN_DATABASE);
		}
	else
		{
		if (sptr_matching_fd_entry->type == DELETE_ENTRY_ON_TIMEOUT)
			{
			if (sptr_matching_fd_entry->port_number != port_number)
				{
				sptr_matching_fd_entry->source_address._ushort = source_mac_address_ushort;
				sptr_matching_fd_entry->source_address._ulong = source_mac_address_ulong;
				sptr_matching_fd_entry->timer_value = bridge_timer;
				sptr_matching_fd_entry->port_number = (BYTE) port_number;
													   
				return (IN_DATABASE_DIFFERENT_PORT);
				}
			else
				{
				sptr_matching_fd_entry->timer_value = bridge_timer;
				return (IN_DATABASE_SAME_PORT);
				}
			}
		else /* add custom filtering here */
			return (PERMANENT_TABLE_ENTRY);
		}
}
/****************************************************************************/
FILTERING_DATABASE_ENTRY *get_destination_address_database_entry (USHORT destination_mac_address_ushort,
	ULONG destination_mac_address_ulong)
{
	FILTERING_DATABASE_ENTRY	*sptr_database_entry;

	sptr_database_entry = (FILTERING_DATABASE_ENTRY	*)
		stp_class.sptr_hash_table->entry[destination_mac_address_ushort &
			stp_class.hash_mask].sptr_forward_link;

	while (sptr_database_entry != NULL)
		{
		if (destination_mac_address_ushort == sptr_database_entry->source_address._ushort &&
			destination_mac_address_ulong == sptr_database_entry->source_address._ulong)
			{
			break; /* found entry in database */
			}

		sptr_database_entry = (FILTERING_DATABASE_ENTRY	*) sptr_database_entry->links.sptr_forward_link;
		}

	return (sptr_database_entry);
}
/****************************************************************************/
void database_entry_timer_check (void)
{
	FILTERING_DATABASE_ENTRY	*sptr_fd_entry;
	ULONG	entry_number;
	ULONG number_of_entries_per_timer_check;

	sptr_fd_entry = stp_class.sptr_first_entry_in_fd_table + stp_class.current_entry_to_check_age;

	number_of_entries_per_timer_check = stp_class.number_of_fd_entries / stp_class.clock_ticks_per_second;

	for (entry_number = 0x00000000L; entry_number < stp_class.number_of_fd_entries;
		++sptr_fd_entry,++entry_number,++stp_class.current_entry_to_check_age)
		{
	  	if (entry_number > number_of_entries_per_timer_check)
			{
	  		break;
			}

		if (stp_class.current_entry_to_check_age >= stp_class.number_of_fd_entries)
			{
			stp_class.current_entry_to_check_age = 0x00000000L;
			}

		if (sptr_fd_entry->port_number != 0 &&	sptr_fd_entry->type == DELETE_ENTRY_ON_TIMEOUT)
			{
			if ((sptr_fd_entry->timer_value + stp_class.this_bridge.aging_time_for_fd) < bridge_timer)
				{
				++stp_class.number_of_entries_timed_out;

 				delete_entry_from_queue ((LINK *)
					&stp_class.sptr_hash_table->entry[sptr_fd_entry->source_address._ushort &
						stp_class.hash_mask].sptr_forward_link,&sptr_fd_entry->links);
 
				memset (sptr_fd_entry, (int) NULL, sizeof (FILTERING_DATABASE_ENTRY));

 				add_entry_to_queue (&stp_class.free_fd_entries_queue,&sptr_fd_entry->links);
 				}
			}
		}
}
/****************************************************************************/
void add_bridge_addresses_to_static_forwarding_table (void)
{
	USHORT spanning_tree_port_number;
	MAC_ADDRESS mac_address;

   	add_entry_to_filtering_database (swap (0x0001),bridge_group_address._ulong,0x0000,PERMANENT_TABLE_ENTRY);
	add_entry_to_filtering_database (swap (0x0002),bridge_group_address._ulong,0x0000,PERMANENT_TABLE_ENTRY);