ospf_hello.c

vxworks下ospf协议栈

				/* On a point to point or virtual link, always send directly to connected neighbor, this need to be configured */

				*sptr_destination_router = ospf_determine_destination (sptr_interface, sptr_interface->sptr_neighbor);

				if (goingdown == FALSE)
					{
                    /* DC1: end modification */
					if (sptr_neighbor != NULL)
						{
						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;
			}
#if defined ( __RFC_2328__)
		/* RFC 2178 Section G.2 */
		case OSPF_POINT_TO_MULTIPOINT:
			{
			ospf_setup_to_send_on_a_point_to_multipoint_network (sptr_interface, sptr_neighbor, goingdown, sptr_destination_router, ulptr_recently_seen_neighbor,
				sptr_packet, ulptr_length_of_packet);
			break;
			}
#endif /* __RFC_2328__ */

		default:
			{
			*sptr_destination_router = 0x00000000L;							/* something's not right, so don't send to anyone */

			break;
			}
		}

	return;
}

/*************************************************************************
*
* ospf_setup_to_send_on_an_NBMA_network - set up the hello packet to send on an NBMA network
*
* This routine will set up the hello packet to be sent over
* an NBMA network.  It will find the appropriate neighbors to
* send the hello packet to.
*
* <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_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
    )
    {
	OSPF_PRINTF_PROLOGUE (OSPF_PROLOGUE_PRINTF, "OSPF: Entering ospf_setup_to_send_on_an_NBMA_network\r\n");

	if (sptr_neighbor != NULL)
		{
		*sptr_destination_router = sptr_neighbor->address;	/* If provided with a neighbor pointer, just send to that neighbor */

		if (goingdown == FALSE)
			{
			ulptr_recently_seen_neighbor = ospf_add_neighbor_to_end_of_hello_packet (ulptr_recently_seen_neighbor, sptr_neighbor->id, ulptr_length_of_packet);
			}
		}
	else
		{
		/*
		 * Figure out which group to send to and include the smallest subset of neighbors possible.  Ideally we would only
		 * include the neighbor we are sending the packet to, but the overhead of sending the packet is potentially too great
		 */

		switch (sptr_interface->state)
			{
			case OSPF_INTERFACE_DESIGNATED_ROUTER_OTHER:
				{
				ospf_setup_to_send_to_designated_router_and_backup_designated_router (sptr_interface, sptr_destination_router,
					ulptr_recently_seen_neighbor, goingdown, ulptr_length_of_packet);

				break;
				}

			case OSPF_INTERFACE_WAITING:
				{
				ospf_setup_to_send_to_all_eligible_neighbors (sptr_interface, sptr_destination_router, ulptr_recently_seen_neighbor, goingdown,
					sptr_neighbor, ulptr_length_of_packet);

				break;
				}

			case OSPF_INTERFACE_DESIGNATED_ROUTER:
			case OSPF_INTERFACE_BACKUP_DESIGNATED_ROUTER:
				{
				ospf_setup_to_send_to_all_neighbors_in_up_state (sptr_interface, sptr_destination_router, ulptr_recently_seen_neighbor, goingdown,
					sptr_neighbor, sptr_packet, ulptr_length_of_packet);

				break;
				}

			default:
				{
                /* something's not right, so don't send to anyone */
				*sptr_destination_router = 0x00000000L;				

				break;
				}
			}
		}
    }

#if defined (__RFC_2328__)
/*RFC 2178 G.2 */

/*************************************************************************
*
* ospf_setup_to_send_on_a_point_to_multipoint_network - set up the hello packet to send on point to multipoint network
*
* This routine will set up the hello packet to be sent over
* a point to multipoint network.  It will find the appropriate neighbors to
* send the hello packet to.
*
* <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_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)
{
	OSPF_PRINTF_PROLOGUE (OSPF_PROLOGUE_PRINTF, "OSPF: Entering ospf_setup_to_send_on_a_point_to_multipoint_network\r\n");

	if (sptr_neighbor != NULL)
		{
		*sptr_destination_router = sptr_neighbor->address;	/* If provided with a neighbor pointer, just send to that neighbor */

		if (goingdown == FALSE)
			{
			ulptr_recently_seen_neighbor = ospf_add_neighbor_to_end_of_hello_packet (ulptr_recently_seen_neighbor, sptr_neighbor->id, ulptr_length_of_packet);
			}
		}
	else
		{
		ospf_setup_to_send_to_all_neighbors_in_exchange_state (sptr_interface, sptr_destination_router, ulptr_recently_seen_neighbor, goingdown,
			sptr_neighbor, sptr_packet, ulptr_length_of_packet);
		}

	return;
}
#endif /* __RFC_2328__ */


/*************************************************************************
*
* ospf_setup_to_send_to_designated_router_and_backup_designated_router - set up the designated router and backup designated router
*
* This routine will set the hello packet to be sent to the
* designated router and backup designated router.
*
* <sptr_interface> OSPF interface
*
* <sptr_destination_router> Destination router
*
* <ulptr_recently_seen_neighbor> Recently seen neighbor identifier
*
* <going_down> Whether or not the router is going down
*
* <ulptr_length_of_packet> Length of hello packet
*
* RETURNS: N/A
*
* ERRNO: N/A
*
* NOMANUAL
*/
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)
{
	OSPF_PRINTF_PROLOGUE (OSPF_PROLOGUE_PRINTF, "OSPF: Entering ospf_setup_to_send_to_designated_router_and_backup_designated_router\r\n");

	*sptr_destination_router = OSPF_DESIGNATED_ROUTER_AND_BACKUP_DESIGNATED_ROUTER;

	if (goingdown == FALSE)
		{
		ulptr_recently_seen_neighbor = ospf_add_neighbor_to_end_of_hello_packet (ulptr_recently_seen_neighbor, sptr_interface->designated_router.id, ulptr_length_of_packet);
		ulptr_recently_seen_neighbor = ospf_add_neighbor_to_end_of_hello_packet (ulptr_recently_seen_neighbor, sptr_interface->backup_designated_router.id, ulptr_length_of_packet);
		}

	return;
}


/*************************************************************************
*
* ospf_setup_to_send_to_all_eligible_neighbors - set up the hello packet to send to all eligible neighbors
*
* This routine will set the hello packet to be sent to all
* eligible neighbors.
*
* <sptr_interface> OSPF interface
*
* <sptr_destination_router> Destination router
*
* <ulptr_recently_seen_neighbor> Recently seen neighbor identifier
*
* <going_down> Whether or not the router is going down
*
* <sptr_neighbor> Neighbor associated with the interface
*
* <ulptr_length_of_packet> Length of hello packet
*
* RETURNS: N/A
*
* ERRNO: N/A
*
* NOMANUAL
*/
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)
{
	OSPF_NEIGHBOR *sptr_next_neighbor = NULL;

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

	*sptr_destination_router = OSPF_ALL_ELIGIBLE_NEIGHBORS;

	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->priority)
				{
				ulptr_recently_seen_neighbor = ospf_add_neighbor_to_end_of_hello_packet (ulptr_recently_seen_neighbor, sptr_neighbor->id, ulptr_length_of_packet);
				}
			}
		}

	return;
}

/*************************************************************************
*
* ospf_setup_to_send_to_all_neighbors_in_up_state - set up the hello packet to send to all neighbors in up state
*
* This routine will set the hello packet to be sent to all
* neighbors in up state.
*
* <sptr_interface> OSPF interface
*
* <sptr_destination_router> Destination router
*
* <ulptr_recently_seen_neighbor> Recently seen neighbor identifier
*
* <going_down> Whether or not the router is going down
*
* <sptr_neighbor> Neighbor associated with the interface
*
* <sptr_packet> Hello packet header
*
* <ulptr_length_of_packet> Length of hello packet
*
* RETURNS: N/A
*
* ERRNO: N/A
*
* NOMANUAL
*/
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)
{
	ULONG interface_mtu;
	ULONG number_of_neighbors;
	ULONG authentication_size;
	OSPF_NEIGHBOR *sptr_next_neighbor = NULL;

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

	*sptr_destination_router = OSPF_ALL_UP_NEIGHBORS;

	if (goingdown == FALSE)
		{
		/*
		 * There is less processing overhead in sending one packet with all neighbors listed.  A large number of neighbors could require
		 * more buffer space than is allowed on a socket.  First build a packet with all neighbors listed.  If this packet replicated by
		 * the number of neighbors is greater than the available buffer space, or the packet is greater than the interface MTU, make a
		 * packet for each neighbor with only it's ID listed.
		 */

		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;
			if (sptr_neighbor->state != OSPF_NEIGHBOR_DOWN)
				{
				++number_of_neighbors;
				}
			}

		interface_mtu = ospf_get_interface_mtu (sptr_interface);

		authentication_size = ospf_get_authentication_size (sptr_interface);

		if ((*ulptr_length_of_packet + (number_of_neighbors * sizeof (ULONG)) + authentication_size) > interface_mtu)
			{
			/* Better to absorb the overhead of sending an individual packet to each neighbor */

			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_DOWN)
					{
					ulptr_recently_seen_neighbor = &(sptr_packet->rest_of_packet.hello.neighbor);

					*ulptr_length_of_packet = OSPF_PACKET_SIZE + OSPF_HELLO_HEADER_SIZE;

					ulptr_recently_seen_neighbor = ospf_add_neighbor_to_end_of_hello_packet (ulptr_recently_seen_neighbor, sptr_neighbor->id, ulptr_length_of_packet);

					ospf_tx_packet (sptr_packet, sptr_interface, OSPF_HELLO_PACKET, *ulptr_length_of_packet, *sptr_destination_router, FALSE);
					}
				}
			ospf_free_an_ospf_send_packet (sptr_packet);

			*sptr_destination_router = 0x00000000L;			/* done sending all hello packets, so clear the destination variable */
			}
		else
			{
			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_DOWN)
					{
					ulptr_recently_seen_neighbor = ospf_add_neighbor_to_end_of_hello_packet (ulptr_recently_seen_neighbor, sptr_neighbor->id, ulptr_length_of_packet);
					}
				}
			}
		}

	return;
}
#if defined (__RFC_2328__)
/* RFC 2178 G.2 */

/*************************************************************************
*
* ospf_setup_to_send_to_all_neighbors_in_exchange_state - set up the hello packet to send to all neighbors in exchange state
*
* This routine will set the hello packet to be sent to all
* neighbors in exchange state.
*
* <sptr_interface> OSPF interface
*
* <sptr_destination_router> Destination router
*
* <ulptr_recently_seen_neighbor> Recently seen neighbor identifier
*
* <going_down> Whether or not the router is going down
*
* <sptr_neighbor> Neighbor associated with the interface
*
* <sptr_packet> Hello packet header
*
* <ulptr_length_of_packet> Length of hello packet
*
* RETURNS: N/A
*
* ERRNO: N/A
*
* NOMANUAL
*/
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)