ospf_transmit_utilities.c

vxworks下ospf协议栈

/* ospf_transmit_utilities.c */

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

/*modification history
___________________
 21,10April02,bt			Modified ospf_determine_packet_destination() for NBMA	  
 20,3may01,jkw				Added checks for NULL pointers and alarm messages
 19,26september00,reshma	Added WindRiver CopyRight
 18,25september00,reshma	RFC-1587 implementation for OSPF NSSA Option, also tested against ANVL.
 17,07july00,reshma			Unix compatibility related changes.
 16,04april00,reshma		Added some MIB support (Read only).Passed all important ANVL OSPF tests.
 15,23december99,reshma		Compatibility with VxWorks-IP and VxWorks RTM-interface
 14,07january99,jack		Change in function ospf_determine_destination to set destination for
							virtual links and point to point links
 13,06janauary99,jack		Change in function ospf_determine_destination
 12,28december98,jack		Compiled and added some comments
 11,23november98,jack		Changed %p in printing to %lx
 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_transmit_utilities.c is used for creating and deleting OSPF packets that need to be 
transmitted.  This file will find out the correct destination for each OSPF packet.
This file is used whenever a new OSPF packet needs to be transmitted.
*/

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

/*******************************************************************************************************************************/
/******************************************************************************************************************************/
OSPF_HEADER *ospf_get_an_ospf_send_packet (ULONG size_of_packet)
{
	OSPF_HEADER *sptr_return;

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

	sptr_return = (OSPF_HEADER *) buffer_malloc (size_of_packet);

	if (sptr_return == NULL)
		{
		OSPF_PRINTF_ALARM (OSPF_ALARM_PRINTF, "OSPF: buffer_malloc () failed\n");
		OSPF_PRINTF_ALARM (OSPF_ALARM_PRINTF, "OSPF: error allocating packet of size:%u \r\n", size_of_packet);
		ospf_print_memory_error_message_and_free_buffer_if_necessary ((void *) NULL, "OSPF_HEADER");
        }
	else
		{
		memset (sptr_return, 0x00, size_of_packet);

		OSPF_PRINTF_MEMORY (OSPF_MEMORY_PRINTF, "OSPF: pointer to send packet, %lx\r\n", sptr_return);
		}

	return (sptr_return);
}
/**************************************************************************************************************************************/
void ospf_free_an_ospf_send_packet (OSPF_HEADER *sptr_tx_packet)
{
/*	OSPF_PRINTF_MEMORY (OSPF_MEMORY_PRINTF,"OSPF: Free of %08lx\r\n",(ULONG) sptr_tx_packet);*/

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

	buffer_free ((void *) sptr_tx_packet);

	sptr_tx_packet = NULL;

	return;
}
/**********************************************************************************************************************************/
ULONG ospf_determine_packet_destination (OSPF_INTERFACE *sptr_interface,OSPF_NEIGHBOR *sptr_neighbor)
{
	ULONG destination;

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

	if (sptr_neighbor != NULL)
		{
		destination = ospf_determine_destination (sptr_interface, sptr_neighbor);
		}
	else
		{
		switch (sptr_interface->type)
			{
			case OSPF_BROADCAST:
				{
				if (ospf.ip_multicast == TRUE)
					{
					switch (sptr_interface->state)
						{
						case OSPF_INTERFACE_DESIGNATED_ROUTER:
						case OSPF_INTERFACE_BACKUP_DESIGNATED_ROUTER:
							{
							destination = OSPF_ADDR_ALLSPF;

							break;
							}

						default:
							{
							destination = OSPF_ADDR_ALLDR;

							break;
							}
						}
					}
				else
					{
					destination = 0x00000000L;

					break;
					}

				break;
				}

			case OSPF_NBMA:
				{
				/*destination = OSPF_ALL_EXCHANGE_NEIGHBORS;*/

				/*__NBMA_PTMP__*/
				destination = ospf_determine_destination (sptr_interface, sptr_interface->sptr_neighbor);
				break;
				}

#if defined (__RFC_2328__)
			/* RFC 2178 G.2 */
			case OSPF_POINT_TO_MULTIPOINT:
				{
				destination = OSPF_ALL_EXCHANGE_NEIGHBORS;

				break;
				}

#endif /*__RFC_2328__*/

			case OSPF_POINT_TO_POINT:
			case OSPF_VIRTUAL_LINK:
				{
				destination = ospf_determine_destination (sptr_interface, sptr_interface->sptr_neighbor);

				break;
				}

			default:
				{
				destination = 0x00000000L;

				break;
				}
			}
		}

	return (destination);
}
/******************************************************************************************************************************/
ULONG ospf_determine_destination (OSPF_INTERFACE *sptr_interface,OSPF_NEIGHBOR *sptr_neighbor)
{
	ULONG destination;
	PARAMETER_NOT_USED (sptr_interface);

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

#if defined (__UNNUMBERED_LINK__)	/* -bt- */
	if((sptr_interface->type == OSPF_POINT_TO_POINT) && (sptr_interface->address == 0))
	{
		/* set the unnumbered destination ip */
		destination = sptr_interface->unnumbered_dest_ip;
	}
	else
#endif	/* __UNNUMBERED_LINK__ -bt- */

	if ( (ospf.ip_multicast == TRUE)  && (sptr_interface->type == OSPF_POINT_TO_POINT) /* && (sptr_interface->flags._bit.multicast == TRUE) */)
		{
		destination = OSPF_ADDR_ALLSPF;
		}
	else if ( (sptr_interface->type == OSPF_VIRTUAL_LINK) && (sptr_neighbor != NULL) )
		{
		destination = sptr_neighbor->address;
		}
	else
		{
		if (sptr_neighbor != NULL)
			{
			destination = sptr_neighbor->address;
			}
		else
			{
			destination = 0x00000000L;      /*#$-NOTE:note18-$#*/
			}
		}

	return (destination);
}