ospf_receive_database.c

vxworks下ospf协议栈

/* ospf_receive_database.c - OSPF receive database  */

/* Copyright 2000-2003 Wind River Systems, Inc. */

/*
modification history
--------------------
02d,26may03,agi     Changed rwos_get_system_elapsed_time_second() to 
                    ospf_get_system_elapsed_time_second()
02c,22apr03,ram	    SPR#76812 Modifications for OSPF performance enhancements
02b,07feb,03,agi    Fixed SPR#75769 - ANVL 23.10 and SPR#75772 - ANVL 23.11
02a,03dec02,ram     SPR 84312 - Change elapsed time to return seconds
23,16april02,jkw    One copy of external and type 11 lsa
22,09april02,jkw    Sequence number wrap.
21,08februay02,jkw  Ignore mtu size if virtual link.
20,23january02,jkw  Fix receiving of dd packets with opaque.
19,03september,jkw  Added Mistral updates for RFC 2178
18,23july01,jkw	    Added new configuration variables for ignoring tos and demand circuit
17,18july01,jkw	    Return received good on TWO-WAY receive as specified per the RFC
16,26september00,reshma	Added WindRiver CopyRight
15,25september00,reshma	RFC-1587 implementation for OSPF NSSA Option, also tested against ANVL.
14,07july00,reshma			Unix compatibility related changes.
13,04april00,reshma		Added some MIB support (Read only).Passed all important ANVL OSPF tests.
12,23december99,reshma		Compatibility with VxWorks-IP and VxWorks RTM-interface
11,28december98,jack		Compiled and added some comments
10,11november98,jack		Config changes, linted and big endian changes
09,30october98,jack		Incorporate changes for compilation on Vxworks
08,23august98,jack			ANVL tested OSPF with PATRICIA tree route table and no recursion
07,10august98,jack			PATRICIA Route Table Based OSPF Code Base
06,04june98,jack			Integration with RTM and BGP
05,24april98,jack			RTM changes
04,10july97,cindy			Pre-release v1.52b
03,02october97,cindy		Release Version 1.52
02,22october96,cindy		Release Version 1.50
01,05june96,cindy			First Beta Release
*/

/*
DESCRIPTION
ospf_receive_database.c is used for processing received database description packets.
This file is used whenever a new OSPF database description packet is received.
*/

#include "ospf.h"
#if defined (__OSPF_VIRTUAL_STACK__)
#include "ospf_vs_lib.h"
#endif /* __OSPF_VIRTUAL_STACK__ */

/**********************************************************************************************************************************/
static OSPF_RETURN_TYPE ospf_process_database_packet (OSPF_DATABASE_HEADER *sptr_database_packet_header,OSPF_NEIGHBOR *sptr_neighbor,
	OSPF_INTERFACE *sptr_interface,ULONG size_of_packet);
static OSPF_RETURN_TYPE ospf_neighbor_exchange_start_process_database_packet (OSPF_DATABASE_HEADER *sptr_database_packet_header,
	ULONG size_of_packet,OSPF_NEIGHBOR *sptr_neighbor,OSPF_INTERFACE *sptr_interface);
static void ospf_neighbor_exchange_process_database_packet (OSPF_DATABASE_HEADER *sptr_database_packet_header,ULONG size_of_packet,
	OSPF_NEIGHBOR *sptr_neighbor,OSPF_INTERFACE *sptr_interface);
static int check_database_packet_header_options(OSPF_DATABASE_HEADER *sptr_database_packet_header, OSPF_NEIGHBOR *sptr_neighbor,
	OSPF_INTERFACE *sptr_interface, seq_t database_description_sequence_number);
static void ospf_remove_last_sent_database_summary (OSPF_NEIGHBOR *sptr_neighbor);
static enum OSPF_PACKET_STATE ospf_accept_as_next_in_sequence (OSPF_DATABASE_HEADER *sptr_database_packet_header,ULONG size_of_packet,
	OSPF_NEIGHBOR *sptr_neighbor,OSPF_INTERFACE *sptr_interface);
static enum OSPF_PACKET_STATE ospf_parse_database_packet (OSPF_DATABASE_HEADER *sptr_database_header,OSPF_NEIGHBOR *sptr_neighbor,
	OSPF_INTERFACE *sptr_interface,ULONG size_of_packet);
static void ospf_neighbor_full_process_database_packet (OSPF_DATABASE_HEADER *sptr_database_packet_header,OSPF_NEIGHBOR *sptr_neighbor,
	OSPF_INTERFACE *sptr_interface);
/****************************************************************************//* section 10.6 of OSPF specification (page 90) */
enum OSPF_PACKET_STATE ospf_database_packet_received (OSPF_DATABASE_HEADER *sptr_database_packet_header,OSPF_NEIGHBOR *sptr_neighbor,
	OSPF_INTERFACE *sptr_interface,ULONG size_of_packet)
{
	ULONG ls_request_queue_count;
	OSPF_AREA_ENTRY *sptr_area;
	OSPF_RETURN_TYPE return_type;
#if defined (__RFC_2328__)
	/* RFC 2178 G.9 */
	USHORT interface_mtu;
	USHORT database_mtu;
#endif

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

	sptr_area = sptr_interface->sptr_area;

	ls_request_queue_count = sptr_neighbor->ls_request_queue_count;

#if defined (__RFC_2328__)
	if (sptr_interface->type != OSPF_VIRTUAL_LINK)
		{
		/* RFC 2178 G.9 */
		interface_mtu = (USHORT)ospf_get_interface_mtu(sptr_interface);
		database_mtu = sptr_database_packet_header->interface_mtu;
		/* Mistral Added Changes on  July 18th */
		database_mtu = net_to_host_short(database_mtu);

		if (database_mtu > interface_mtu)
			{
			return OSPF_ERROR_DATABASE_DESCRIPTION_MTU_MISMATCH;
			}
		}
#endif /*__RFC_2328__*/


	size_of_packet -= (OSPF_PACKET_SIZE + OSPF_DATABASE_HEADER_SIZE);

	return_type = ospf_process_database_packet (sptr_database_packet_header, sptr_neighbor, sptr_interface,	size_of_packet);

	if (return_type.exit_routine == FALSE)
		{
		if (sptr_interface->flags._bit.neighbor_change == TRUE)
			{
			ospf_execute_interface_state_machine (OSPF_NEIGHBOR_CHANGE, sptr_interface->state, sptr_interface);
			}

		ospf_generate_network_and_router_link_state_advertisements (sptr_interface);

		/*
		 * During the above packet processing, a node may have been added to the ls request queue.
		 * If a node was added and the list was previously empty, then send out an ls request packet right
		 * away.  Otherwise, there is already an ls request packet outstanding.  So let the retransmit
		 * process handle all sending of ls request packets (so we don't end up with more than one sent
		 * out at a time).
		 */

		if ((sptr_neighbor->state >= OSPF_NEIGHBOR_EXCHANGE) && (ls_request_queue_count == 0x00000000L /* list was previously empty */) &&
			(sptr_neighbor->ls_request_queue_count > 0x00000000L /* list is no longer empty */))
			{
			ospf_send_ls_request_packet (sptr_interface, sptr_neighbor);
			}
		}

	return (return_type.packet_state);
}
/******************************************************************************************************************************/
static OSPF_RETURN_TYPE ospf_process_database_packet (OSPF_DATABASE_HEADER *sptr_database_packet_header,OSPF_NEIGHBOR *sptr_neighbor,
	OSPF_INTERFACE *sptr_interface,ULONG size_of_packet)
{
	OSPF_RETURN_TYPE return_type;

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

	return_type.exit_routine = FALSE;
	return_type.packet_state = GOOD_RECEIVE;

	switch (sptr_neighbor->state)
		{
		case OSPF_NEIGHBOR_DOWN:
		case OSPF_NEIGHBOR_ATTEMPT:
			{
			return_type.exit_routine = TRUE;
			return_type.packet_state = OSPF_ERROR_DATABASE_DESCRIPTION_STATE;

			return (return_type);									/* ignore the packet */
			}

		case OSPF_NEIGHBOR_2_WAY:
			{
			return (return_type);  									/* ignore the packet */
			}

		case OSPF_NEIGHBOR_INITIALIZING:
		case OSPF_NEIGHBOR_EXCHANGE_START:
			{
			if (sptr_neighbor->state == OSPF_NEIGHBOR_INITIALIZING)		/* first transition state to NEIGHBOR_EXSTART */
				{
				ospf_execute_neighbor_state_machine (OSPF_TWO_WAY_RECEIVED, sptr_neighbor->state, sptr_interface, sptr_neighbor);

				if (sptr_neighbor->state != OSPF_NEIGHBOR_EXCHANGE_START)
					{
					break;
					}
				}

			return_type = ospf_neighbor_exchange_start_process_database_packet (sptr_database_packet_header, size_of_packet,
				sptr_neighbor, sptr_interface);

			break;
			}

		case OSPF_NEIGHBOR_EXCHANGE:
			{
			ospf_neighbor_exchange_process_database_packet (sptr_database_packet_header, size_of_packet, sptr_neighbor,
				sptr_interface);

			break;
			}

		case OSPF_NEIGHBOR_LOADING:
		case OSPF_NEIGHBOR_FULL:
			{
			ospf_neighbor_full_process_database_packet (sptr_database_packet_header, sptr_neighbor, sptr_interface);

			break;
			}

		default:
			{
			break;
			}
		}

	return (return_type);
}
/******************************************************************************************************************************/
static OSPF_RETURN_TYPE ospf_neighbor_exchange_start_process_database_packet (OSPF_DATABASE_HEADER *sptr_database_packet_header,
	ULONG size_of_packet,OSPF_NEIGHBOR *sptr_neighbor,OSPF_INTERFACE *sptr_interface)
{
	OSPF_RETURN_TYPE return_type;
	seq_t database_description_sequence_number;

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

	database_description_sequence_number = sptr_database_packet_header->sequence;
	database_description_sequence_number = net_to_host_long (database_description_sequence_number);

	/* first bullet item under ExStart in section 10.6 of OSPF specification (page 90) */

	if ((sptr_database_packet_header->flags._bit.initialize == TRUE) && (sptr_database_packet_header->flags._bit.more == TRUE) &&
		(sptr_database_packet_header->flags._bit.master == TRUE) &&	(size_of_packet == 0x00000000L) &&
		(sptr_neighbor->id > ospf.router_id))
		{
		sptr_neighbor->mode = OSPF_SLAVE;							/* router is now OSPF_SLAVE */
		sptr_neighbor->flags._byte = 0x0000;				/* set to slave */
		sptr_neighbor->database_description_sequence_number = database_description_sequence_number;
																		/* set the sequence number to that specified by the master */
		}

	/* second bullet item under ExStart in section 10.6 of OSPF specification (page 90) */

	else if ((sptr_database_packet_header->flags._bit.initialize == FALSE) && (sptr_database_packet_header->flags._bit.master == FALSE) &&
		(sptr_neighbor->database_description_sequence_number == database_description_sequence_number) &&
		(sptr_neighbor->id < ospf.router_id))
		{
		sptr_neighbor->mode = OSPF_MASTER;							/* router is now OSPF_MASTER */
		sptr_neighbor->flags._byte = 0x0000;
		sptr_neighbor->flags._bit.master = TRUE;			/* set to master */

	}
	else if (sptr_neighbor->id == ospf.router_id)
		{
		return_type.exit_routine = FALSE;
		return_type.packet_state = OSPF_ERROR_DATABASE_DESCRIPTION_ROUTER_ID;	/* ignore packet */

		return (return_type);
		}
	else
		{
		return_type.exit_routine = FALSE;
		return_type.packet_state = GOOD_RECEIVE;					/* ignore packet */

		return (return_type);
		}

#if defined (__OPAQUE_LSA__)
	/* Check for opaque capability */
	if ((sptr_database_packet_header->options._bit.opaque == TRUE)
		&& (ospf.opaque_capability == TRUE))
		{
		sptr_neighbor->opaque_capability = TRUE;