ospf_hello.c

vxworks下ospf协议栈

/* ospf_hello.c - used for sending, receiving and processing Hello packets */

/* Copyright 1998 - 2003 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
modification history
--------------------
02i,26may03,agi Changed rwos_get_system_elapsed_time_second() to
                ospf_get_system_elapsed_time_second()
                Added code inspection changes
02h,20may03,agi    Removed dependency on RWOS
02g,22apr03,ram	   SPR#76812 Modifications for OSPF performance enhancements
02f,26feb03,kkz    SPR 86263 - Don't recalc DR unless necessary
02e,06jan03,ram	   SPR 85432 Changes to allow more OSPF external route processing
02d,11dec02,fli    SPR 81628 - Fixes for ANVL 13.6 to pass on MIPS board
02c,03dec02,ram    SPR 84312 - Change elapsed time to return seconds
02b,22nov02,dsk    SPR 76417, ANVL 13.17 DUT is not setting ANVL as a correct BDR router.
02a,19nov02,mwv    merge TMS code SPR 84284
01z,22oct02,hme    Fix SPR #294168  not able detect and handle on-way links using
                   HELLO packets
01y,09oct02,hme    Fix TSR #291468
01x,25apr02,jkw    Change displaying of interface from hex to decimal.
01w,13oct01,kc     Dynamic configuration changes.
01v,26sep01,kc     Don't determine destination neighbor id for ppp or vl if interface
                   is going down in ospf_set_destination_and_neighbor_information()
01u,26sep01,kc     Skip ospf_determine_number_of_neighbors_for_hello_packet() in
                   ospf_send_hello() if interface is going down
01t,11may01,aos    Added null pointer checks
01s,3may01,jkw     Added checks for NULL pointers and alarm messages
01r,26sep00,reshma Added WindRiver CopyRight
01q,25sep00,reshma RFC-1587 implementation for OSPF NSSA Option, also tested against ANVL.
01p,07jul00,reshma Unix compatibility related changes.
01o,04apr00,reshma Added some MIB support (Read only).Passed all important ANVL OSPF tests.
01n,23dec99,reshma Compatibility with VxWorks-IP and VxWorks RTM-interface
01m,06jan99,jack   Change in setting sest router on virtual links and point to point in
                   function ospf_set_destination_and_neighbor_information
01l,13aug98,jack   ifdefed lsl control calls
01k,28dec98,jack   Compiled and added some comments
01j,11nov98,jack   Config changes, linted and big endian changes
01i,30oct98,jack   Incorporate changes for compilation on Vxworks
01h,23aug98,jack   ANVL tested OSPF with PATRICIA tree route table and no recursion
01g,10aug98,jack   PATRICIA Route Table Based OSPF Code Base
01f,04jun98,jack   Integration with RTM and BGP
01e,24apr98,jack   RTM changes
01d,10jul97,cindy  Pre-release v1.52b
01c,02oct97,cindy  Release Version 1.52
01b,22oct96,cindy  Release Version 1.50
01a,05jun96,cindy  First Beta Release
*/

/*
DESCRIPTION
ospf_hello.c is used for sending and receiving hello packets.  This file will extract information
from the hello packet and validate whether the hello packet is valid or not.  This file will
send create hello packets to be sent to other OSPF routers.
This file is used from the timer task to send hello packets and on the receive task when receiving
hello packets.
*/


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

/***********************************************************************************************************************************/
static ULONG ospf_determine_number_of_neighbors_for_hello_packet (OSPF_INTERFACE *sptr_interface);
static OSPF_HEADER *ospf_new_hello (ULONG number_of_neighbors,ULONG authentication_size);
static void ospf_initialize_hello_packet_header (OSPF_HELLO_HEADER *sptr_hello,OSPF_INTERFACE *sptr_interface,enum BOOLEAN goingdown);
static void ospf_set_destination_and_neighbor_information (OSPF_INTERFACE *sptr_interface,OSPF_NEIGHBOR *sptr_neighbor,enum BOOLEAN goingdown,
	ULONG *sptr_destination_router,ULONG *ulptr_recently_seen_neighbor,OSPF_HEADER *sptr_packet,ULONG *ulptr_length_of_packet);
static void ospf_setup_to_send_on_an_NBMA_network (OSPF_INTERFACE *sptr_interface,OSPF_NEIGHBOR *sptr_neighbor,enum BOOLEAN goingdown,
	ULONG *sptr_destination_router,ULONG *ulptr_recently_seen_neighbor,OSPF_HEADER *sptr_packet,ULONG *ulptr_length_of_packet);
#if defined (__RFC_2328__)
static void ospf_setup_to_send_on_a_point_to_multipoint_network (OSPF_INTERFACE *sptr_interface,OSPF_NEIGHBOR *sptr_neighbor,enum BOOLEAN goingdown,
	ULONG *sptr_destination_router,ULONG *ulptr_recently_seen_neighbor,OSPF_HEADER *sptr_packet,ULONG *ulptr_length_of_packet);
#endif /* __RFC_2328__ */
static void	ospf_setup_to_send_to_designated_router_and_backup_designated_router (OSPF_INTERFACE *sptr_interface,ULONG *sptr_destination_router,
	ULONG *ulptr_recently_seen_neighbor,enum BOOLEAN goingdown,ULONG *ulptr_length_of_packet);
static void	ospf_setup_to_send_to_all_eligible_neighbors (OSPF_INTERFACE *sptr_interface,ULONG *sptr_destination_router,
	ULONG *ulptr_recently_seen_neighbor,enum BOOLEAN goingdown,OSPF_NEIGHBOR *sptr_neighbor,ULONG *ulptr_length_of_packet);
static void	ospf_setup_to_send_to_all_neighbors_in_up_state (OSPF_INTERFACE *sptr_interface,ULONG *sptr_destination_router,
	ULONG *ulptr_recently_seen_neighbor,enum BOOLEAN goingdown,OSPF_NEIGHBOR *sptr_neighbor,OSPF_HEADER *sptr_packet,
	ULONG *ulptr_length_of_packet);
#if defined (__RFC_2328__)
static void	ospf_setup_to_send_to_all_neighbors_in_exchange_state (OSPF_INTERFACE *sptr_interface,ULONG *sptr_destination_router,
	ULONG *ulptr_recently_seen_neighbor,enum BOOLEAN goingdown,OSPF_NEIGHBOR *sptr_neighbor,OSPF_HEADER *sptr_packet,
	ULONG *ulptr_length_of_packet);
#endif /* __RFC_2328__ */
static ULONG* ospf_add_neighbor_to_end_of_hello_packet (ULONG *ulptr_end_of_hello_packet,ULONG neighbor_id,ULONG *ulptr_length_of_packet);
static enum OSPF_PACKET_STATE ospf_check_hello_packet_validity (OSPF_HELLO_HEADER *sptr_hello,OSPF_INTERFACE *sptr_interface,
	ULONG router_id);
static OSPF_NEIGHBOR *ospf_extract_neighbor_information_from_hello_packet  (OSPF_HELLO_HEADER *sptr_hello,OSPF_NEIGHBOR *sptr_new_neighbor,
	OSPF_INTERFACE *sptr_interface,ULONG source_address,ULONG router_id,ULONG cryptographic_sequence_number);
static void ospf_examine_rest_of_hello_packet_and_generate_events_as_necessary (OSPF_HELLO_HEADER *sptr_hello,OSPF_NEIGHBOR *sptr_new_neighbor,
	OSPF_INTERFACE *sptr_interface,ULONG size_of_packet);
static enum BOOLEAN ospf_examine_neighbors_in_hello_packet (OSPF_HELLO_HEADER *sptr_hello,OSPF_NEIGHBOR *sptr_new_neighbor,
	OSPF_INTERFACE *sptr_interface,ULONG size_of_packet);
static void ospf_update_router_priority_for_neighbor (OSPF_NEIGHBOR *sptr_new_neighbor,USHORT router_priority,
	OSPF_INTERFACE *sptr_interface);
static ULONG ospf_check_if_only_dr_is_present_and_no_bdr (OSPF_INTERFACE *sptr_interface,
		OSPF_HELLO_HEADER *sptr_hello, ULONG size_of_packet );


/*************************************************************************
*
* ospf_send_hello - set up hello packet to be sent
*
* This routine will create and send a Hello packet to its neighbor.
*
* <sptr_interface> OSPF interface
*
* <sptr_neighbor> Neighbor associated with interface
*
* <goingdown> Whether or not the router is going down
*
* RETURNS: N/A
*
* ERRNO: N/A
*
* NOMANUAL
*/
/*********************************************************************************//* section 9.5 of OSPF specification (page 71) */
void ospf_send_hello (OSPF_INTERFACE *sptr_interface,OSPF_NEIGHBOR *sptr_neighbor,enum BOOLEAN goingdown)
{
	OSPF_HEADER *sptr_packet = NULL ;
	OSPF_HELLO_HEADER *sptr_hello =NULL;
	ULONG destination_router ;
	ULONG *ulptr_recently_seen_neighbor = NULL;
	ULONG length_of_packet  ;
	ULONG number_of_neighbors  ;
	ULONG authentication_size ;

	OSPF_PRINTF_PROLOGUE (OSPF_PROLOGUE_PRINTF, "OSPF: Entering ospf_send_hello\r\n");

#if defined (__OSPF_PASSIVE_INTERFACE__)
	if (sptr_interface->passive == TRUE)
		{
		OSPF_PRINTF_DEBUG (OSPF_DEBUG_PRINTF, "OSPF: ospf_send_hello:: interface %lx is passive!\r\n", sptr_interface->address);
		return;
		}
#endif /* __OSPF_PASSIVE_INTERFACE__ */

	sptr_packet = NULL;
	sptr_hello = NULL;
	destination_router = 0x00000000L;
	ulptr_recently_seen_neighbor = NULL;
	length_of_packet = 0x00000000;
	number_of_neighbors = 0x00000000;
	authentication_size = 0x00000000;

	number_of_neighbors = ospf_determine_number_of_neighbors_for_hello_packet (sptr_interface);

	authentication_size = ospf_get_authentication_size (sptr_interface);

	sptr_packet = ospf_new_hello (number_of_neighbors, authentication_size);
	/* Added changes as per TMS PR # 1583
	   To make sure sptr_packet if ospf_new_hello() failed*/
	if (sptr_packet == NULL)
		{
		OSPF_PRINTF_DEBUG (OSPF_ALARM_PRINTF, "OSPF: ospf_send_hello::ospf_new_hello() failed!\r\n");

		return;
		}

	sptr_hello = (OSPF_HELLO_HEADER *) &(sptr_packet->rest_of_packet.hello);

	ospf_initialize_hello_packet_header (sptr_hello, sptr_interface, goingdown);

	ulptr_recently_seen_neighbor = &(sptr_hello->neighbor);

	length_of_packet = OSPF_PACKET_SIZE + OSPF_HELLO_HEADER_SIZE;

	ospf_set_destination_and_neighbor_information (sptr_interface, sptr_neighbor, goingdown, &destination_router,
		ulptr_recently_seen_neighbor, sptr_packet, &length_of_packet);

	if (destination_router != 0x00000000L)							/* there's no one to send to */
		{
		ospf_tx_packet (sptr_packet, sptr_interface, OSPF_HELLO_PACKET, length_of_packet, destination_router, TRUE);
		}
	else
		{
		ospf_free_an_ospf_send_packet (sptr_packet);
		}

	return;
}

/*************************************************************************
*
* ospf_determine_number_of_neighbors_for_hello_packet - determine the number of neighbors for the hello packet
*
* This routine will find out all the neighbors on an interface.
*
* <sptr_interface> OSPF interface
*
* RETURNS: ULONG
*
* ERRNO: N/A
*
* NOMANUAL
*/

static ULONG ospf_determine_number_of_neighbors_for_hello_packet (OSPF_INTERFACE *sptr_interface)
{
	ULONG number_of_neighbors;
	OSPF_NEIGHBOR *sptr_neighbor = NULL;
	OSPF_NEIGHBOR *sptr_next_neighbor = NULL;
	char print_buffer[PRINT_BUFFER_SIZE];


	OSPF_PRINTF_PROLOGUE (OSPF_PROLOGUE_PRINTF, "OSPF: Entering ospf_determine_number_of_neighbors_for_hello_packet\r\n");

	number_of_neighbors = 0x00000000L;

	for (sptr_neighbor = sptr_interface->sptr_neighbor; sptr_neighbor != NULL; sptr_neighbor = sptr_next_neighbor)
		{
		sptr_next_neighbor = sptr_neighbor->sptr_forward_link;
		++number_of_neighbors;
		}

#if defined (__UNNUMBERED_LINK__)	/* -bt- */
	OSPF_PRINTF_ALARM (OSPF_ALARM_PRINTF, "Number of neighbors %d at Port %d with address ",
						number_of_neighbors,
						sptr_interface->port_number);
	OSPF_CONVERT_IP_ADDRESS_TO_DOT_FORMAT_FOR_DEBUG (print_buffer, sptr_interface->address);
	OSPF_PRINTF_ALARM (OSPF_ALARM_PRINTF, "%s \r\n", print_buffer);

#else	/* __UNNUMBERED_LINK__ -bt- */
	OSPF_PRINTF_ALARM (OSPF_ALARM_PRINTF, "Number of neighbors %d on interface with address ", number_of_neighbors);
	OSPF_CONVERT_IP_ADDRESS_TO_DOT_FORMAT_FOR_DEBUG (print_buffer, sptr_interface->address);
	OSPF_PRINTF_ALARM (OSPF_ALARM_PRINTF, "%s \r\n", print_buffer);
#endif	/* __UNNUMBERED_LINK__ -bt- */

	return (number_of_neighbors);
}

/*************************************************************************
*
* ospf_new_hello - create a new hello packet
*
* This routine will create a new hello packet
*
* <number_of_neighbors> Number of neighbors to allocate memory for
*
* <authentication_size> Size needed for authentication of interface
*
* RETURNS: OSPF_HEADER * or NULL
*
* ERRNO: N/A
*
* NOMANUAL
*/
static OSPF_HEADER *ospf_new_hello (ULONG number_of_neighbors,ULONG authentication_size)
{
	OSPF_HEADER *sptr_packet =NULL;

	OSPF_PRINTF_PROLOGUE (OSPF_PROLOGUE_PRINTF, "OSPF: Entering ospf_new_hello\r\n");

	sptr_packet = ospf_get_an_ospf_send_packet (OSPF_PACKET_SIZE + OSPF_HELLO_HEADER_SIZE + (number_of_neighbors * sizeof (ULONG)) + authentication_size);

	return (sptr_packet);
}

/*************************************************************************
*
* ospf_initialize_hello_packet_header - set values for hello packet header
*
* This routine will initialize all the variables inside the hello packet
* header along with the configured variables from configuration.
*
* <sptr_hello> Hello packet header
*
* <sptr_interface> OSPF interface
*
* <going_down> Whether or not the router is going down
*
* RETURNS: N/A
*
* ERRNO: N/A
*
* NOMANUAL
*/
static void ospf_initialize_hello_packet_header (OSPF_HELLO_HEADER *sptr_hello,OSPF_INTERFACE *sptr_interface,enum BOOLEAN goingdown)
{
	OSPF_PRINTF_PROLOGUE (OSPF_PROLOGUE_PRINTF, "OSPF: Entering ospf_initialize_hello_packet_header\r\n");

	if (sptr_interface->type == OSPF_VIRTUAL_LINK)
		{
		sptr_hello->network_mask = 0x00000000L;
		}
#if defined (__UNNUMBERED_LINK__) /* -bt- */
	else if ((sptr_interface->type == OSPF_POINT_TO_POINT) && (sptr_interface->address == 0))
		{
			/* unnumbered link rfc2328 */
			sptr_hello->network_mask = 0x00000000L;
		}
#endif	/* __UNNUMBERED_LINK__ -bt- */
	else
		{
		sptr_hello->network_mask = host_to_net_long (sptr_interface->netmask);
		}

	sptr_hello->hello_interval = host_to_net_short ((USHORT) sptr_interface->hello_interval);

	if (sptr_interface->sptr_area->flags._bit.stub == TRUE)
		{
		sptr_hello->options._byte = 0x0000;
		}
#if defined (__NSSA__)
	else
		{
		if (sptr_interface->sptr_area->flags._bit.nssa == TRUE)
			{
			sptr_hello->options._byte = 0x0000;
			sptr_hello->options._bit.nssa = TRUE;
			}
#endif /*__NSSA__*/
		else
			{
			sptr_hello->options._byte = 0x0000;
			sptr_hello->options._bit.externals = TRUE;
			}
#if defined (__NSSA__)
		}
#endif /*__NSSA__*/

	sptr_hello->router_priority = (BYTE) sptr_interface->priority;

	sptr_hello->router_dead_interval = host_to_net_long (sptr_interface->router_dead_interval);

	if (goingdown == FALSE)
		{
		sptr_hello->designated_router = host_to_net_long (sptr_interface->designated_router.address);
		sptr_hello->backup_designated_router = host_to_net_long (sptr_interface->backup_designated_router.address);
		}

	return;
}

/*************************************************************************
*
* ospf_set_destination_and_neighbor_information - set destination and neighbor information
*
* This routine will set the destination and neighbor information
* for the hello packet.
*
* <sptr_interface> OSPF interface
*
* <sptr_neighbor> Neighbor associated with the interface
*
* <going_down> Whether or not the router is going down
*
* <sptr_destination_router> Destination router
*
* <ulptr_recently_seen_neighbor> Recently seen neighbor identifier
*
* <sptr_packet> Hello packet header
*
* <ulptr_length_of_packet> Length of hello packet
*
* RETURNS: N/A
*
* ERRNO: N/A
*
* NOMANUAL
*/
static void ospf_set_destination_and_neighbor_information (OSPF_INTERFACE *sptr_interface,OSPF_NEIGHBOR *sptr_neighbor,enum BOOLEAN goingdown,
	ULONG *sptr_destination_router,ULONG *ulptr_recently_seen_neighbor,OSPF_HEADER *sptr_packet,ULONG *ulptr_length_of_packet)
{
	OSPF_NEIGHBOR *sptr_next_neighbor = NULL;

	OSPF_PRINTF_PROLOGUE (OSPF_PROLOGUE_PRINTF, "OSPF: Entering ospf_set_destination_and_neighbor_information\r\n");

	switch (sptr_interface->type)
		{
		case OSPF_NBMA:
			{
			ospf_setup_to_send_on_an_NBMA_network (sptr_interface, sptr_neighbor, goingdown, sptr_destination_router, ulptr_recently_seen_neighbor,
				sptr_packet, ulptr_length_of_packet);

			break;
			}

		case OSPF_BROADCAST:
			{
			if (ospf.ip_multicast == TRUE)
				{
				/* On a multicast interface, include all neighbors since they can all see this packet */

				*sptr_destination_router = OSPF_ADDR_ALLSPF;

				if (goingdown == FALSE)
					{
					for (sptr_neighbor = sptr_interface->sptr_neighbor; sptr_neighbor != NULL;
						sptr_neighbor = sptr_next_neighbor)
						{
						sptr_next_neighbor = sptr_neighbor->sptr_forward_link;
						if (sptr_neighbor->state > OSPF_NEIGHBOR_ATTEMPT)
							{
							ulptr_recently_seen_neighbor = ospf_add_neighbor_to_end_of_hello_packet (ulptr_recently_seen_neighbor, sptr_neighbor->id, ulptr_length_of_packet);
							}
						}
					}
				}
			else
				{
				*sptr_destination_router = 0x00000000L;						/* something's not right, so don't send to anyone */
				}

			break;
			}

		case OSPF_POINT_TO_POINT:
		case OSPF_VIRTUAL_LINK:
			{
			if (ospf.ip_multicast == TRUE)
				{