ospf_transmit_update.c

vxworks下ospf协议栈

/* ospf_transmit_update.c - OSPF transmit update */

/* Copyright 2000-2003 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
modification history
--------------------
02a,14aug03,kkz     Fixed compiler warning (removed unused variable)
01z,26jun03,agi     Re-added early LSA retransmission fix made compatible with
                    new routing table
01y,23jun03,agi     Backed out SPR#88619 early LSA retransmission changes, not
                    compatible with new routing table
01x,26may03,agi     Changed rwos_get_system_elapsed_time_second() to
                    ospf_get_system_elapsed_time_second()
01w,22may03,dsk     SPR 88619 Fix early LSA retransmission, more parts of same fix
01v,22may03,dsk     SPR 88619 Fix early LSA retransmission
01u,17feb03,mwv     SPR 85906 - use ip header size in calculation for packet fragmentation
01t,29nov02,htm     Added fix for SPRs 81633, 81674 (ANVL 12.4, 12.5, 26.7).
01s,11oct01,jkw     Set pointer to NULL after table_free.
01r,22aug01,jkw     Added opaque lsa updates.
01q,11may01,aos     Added null pointer checks and fixed to iteration of the database node.
01p,26sep00,reshma  Added WindRiver CopyRight
01o,25sep00,reshma  RFC-1587 implementation for OSPF NSSA Option, also tested against ANVL.
01n,07jul00,reshma  Unix compatibility related changes.
01m,04apr00,reshma  Added some MIB support (Read only).Passed all important ANVL OSPF tests.
01l,23dec99,reshma  Compatibility with VxWorks-IP and VxWorks RTM-interface
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_transmit_update.c is used for transmitting link state update packets. This
file finds all the appropriate link state advertisements in the link state
database and adds them to the link state update.

This file is used whenever a new OSPF link state update packets need to be
transmitted.
*/

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

/*******************************************************************************************************************************/
/* SPR 88619 start */
static void ospf_build_and_send_ls_update_packets (OSPF_LS_DATABASE_NODE *sptr_ls_database_list,ULONG destination_router,
    OSPF_INTERFACE *sptr_interface,enum BOOLEAN retransmit_flag, enum BOOLEAN advertisement_installed,
    OSPF_NEIGHBOR *sptr_neighbor);
static enum BOOLEAN ospf_check_if_advertisement_should_be_sent (OSPF_LS_DATABASE_NODE *sptr_database_node,OSPF_INTERFACE *sptr_interface,
    ULONG destination_router,
    enum BOOLEAN retransmit_flag,
    OSPF_NEIGHBOR *sptr_neighbor);
/* SPR 88619 end */
static enum BOOLEAN ospf_check_if_packet_is_full (OSPF_LS_DATABASE_NODE *sptr_database_node,OSPF_INTERFACE *sptr_interface,
    ULONG packet_length);
static UNION_OSPF_ADVERTISEMENT_HEADER *ospf_add_advertisement_to_ls_update_packet (
    OSPF_LS_DATABASE_NODE *sptr_database_node,
    UNION_OSPF_ADVERTISEMENT_HEADER *sptr_advertisement_header,
    OSPF_HEADER *sptr_packet,
    ULONG *sptr_packet_length, enum BOOLEAN advertisement_installed);
/* SPR 88619 start */
static OSPF_LSA_TIMESTAMP_PER_INTERFACE_LIST * ospf_find_timestamp_for_lsdb_entry(OSPF_LS_DATABASE_ENTRY *sptr_ls_database_entry,
                                   ULONG destination_router_id,
                                   OSPF_INTERFACE *sptr_interface,
                                   ULONG *last_tx_time,
                                   OSPF_NEIGHBOR *sptr_neighbor);

static void ospf_update_lsa_transmit_timestamp(OSPF_LS_DATABASE_ENTRY *sptr_database_entry,
                                        OSPF_LSA_TIMESTAMP_PER_INTERFACE_LIST *sptr_retx_timestamp_list,
                                        ULONG timestamp,
                                        ULONG destination_router,
                                        OSPF_NEIGHBOR *sptr_neighbor,
                                        ULONG if_index);

/* SPR 88619 end */
/*******************************************************************************//* section 13.3 of OSPF specification (page 138) */
void ospf_send_ls_update (OSPF_LS_DATABASE_NODE *sptr_database_list,OSPF_NEIGHBOR *sptr_neighbor,OSPF_INTERFACE *sptr_interface,
    enum BOOLEAN retransmit_flag, enum BOOLEAN advertisement_installed)
{
    char print_buffer[PRINT_BUFFER_SIZE];
    ULONG destination_router;

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

    if (sptr_interface->state == OSPF_INTERFACE_IS_DOWN)
        {
        OSPF_CONVERT_IP_ADDRESS_TO_DOT_FORMAT_FOR_DEBUG (print_buffer, sptr_interface->address);

        OSPF_PRINTF_DEBUG (OSPF_DEBUG_PRINTF, "OSPF:  Interface %s is down.  Cannot send LS Update packet.\r\n", print_buffer);

        return;
        }

    if ( (sptr_neighbor != NULL) && (retransmit_flag == TRUE) )       /* retransmissions are sent unicast */
        {
        destination_router = sptr_neighbor->address;
        }
    else
        {
        destination_router = ospf_determine_packet_destination (sptr_interface, sptr_neighbor);
        }

    ospf_build_and_send_ls_update_packets (sptr_database_list, destination_router, sptr_interface, retransmit_flag, advertisement_installed,
                                           sptr_neighbor);

    return;
}
/**********************************************************************************************************************************/
static void ospf_build_and_send_ls_update_packets (OSPF_LS_DATABASE_NODE *sptr_ls_database_list,ULONG destination_router,
    OSPF_INTERFACE *sptr_interface,enum BOOLEAN retransmit_flag, enum BOOLEAN advertisement_installed,
    OSPF_NEIGHBOR *sptr_neighbor)
{
    OSPF_HEADER *sptr_packet;
    OSPF_LS_DATABASE_NODE *sptr_database_node;
    UNION_OSPF_ADVERTISEMENT_HEADER *sptr_advertisement_header;
    enum BOOLEAN include_node_in_packet;
    enum BOOLEAN packet_is_full;
    ULONG packet_length;

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

    sptr_packet = ospf_new_link_state_update (&sptr_advertisement_header, sptr_interface);

    if (sptr_packet == NULL)
        {

        OSPF_PRINTF_DEBUG (OSPF_ALARM_PRINTF, "OSPF: ospf_build_and_send_ls_update_packets::ospf_new_link_state_update() failed!\r\n");

        return;
        }

    packet_length = OSPF_PACKET_SIZE + OSPF_LS_UPDATE_HEADER_SIZE;

    for (sptr_database_node = sptr_ls_database_list; sptr_database_node != NULL;
        sptr_database_node = sptr_database_node->sptr_forward_link)
        {
        /* SPR 88619 start */
        include_node_in_packet = ospf_check_if_advertisement_should_be_sent (sptr_database_node,
                                                                             sptr_interface,
                                                                             destination_router,
                                                                             retransmit_flag,
                                                                             sptr_neighbor);
        /* SPR 88619 end */

        if (include_node_in_packet == FALSE)
            {
            continue;                                                                   /* skip to next node */
            }

        packet_is_full = ospf_check_if_packet_is_full (sptr_database_node, sptr_interface, packet_length);

        if (packet_is_full == TRUE) /* the packet can't hold any more advertisements, so send it out and start building a new packet */
            {
            if (sptr_packet->rest_of_packet.ls_update.number_of_advertisements == 0x00000000L)
                {
                /* the first advertisement we want to put in the packet is huge and won't fit. So skip it and go on the the next one.*/

                memset (sptr_packet, 0x0, packet_length);

                packet_length = OSPF_PACKET_SIZE + OSPF_LS_UPDATE_HEADER_SIZE;

                continue; /* gon on to the next one */
                }
            else
                {
                sptr_packet->rest_of_packet.ls_update.number_of_advertisements = host_to_net_long  (
                    sptr_packet->rest_of_packet.ls_update.number_of_advertisements);

                ospf_tx_packet (sptr_packet, sptr_interface, OSPF_LINK_STATE_UPDATE_PACKET, packet_length, destination_router, FALSE);

                if (retransmit_flag == TRUE)        /* section 13.6 (page 144) - "When advertisements are to be retransmitted, only the number */
                    {                                       /* fitting in a single Link State Update packet should be sent." */
                    ospf_free_an_ospf_send_packet (sptr_packet);

                    return;
                    }

                memset (sptr_packet, 0x0, packet_length);

                sptr_advertisement_header = (UNION_OSPF_ADVERTISEMENT_HEADER *) &(sptr_packet->rest_of_packet.ls_update.advertisement_header);

                packet_length = OSPF_PACKET_SIZE + OSPF_LS_UPDATE_HEADER_SIZE;
                }
            }

        sptr_advertisement_header = ospf_add_advertisement_to_ls_update_packet (sptr_database_node, sptr_advertisement_header,
            sptr_packet, &packet_length, advertisement_installed);

        sptr_database_node->periodic_retransmit_time_counter = 0x00000000L;     /* reset timer */
        }

    if (sptr_packet->rest_of_packet.ls_update.number_of_advertisements > 0x00000000L)
        {
        /* the packet is not as full as it could be, but we ran out of advertisements to fill it up, so send it out anyway */

        sptr_packet->rest_of_packet.ls_update.number_of_advertisements = host_to_net_long  (
            sptr_packet->rest_of_packet.ls_update.number_of_advertisements);

        ospf_tx_packet (sptr_packet, sptr_interface, OSPF_LINK_STATE_UPDATE_PACKET, packet_length, destination_router, TRUE );
        }
    else
        {
        ospf_free_an_ospf_send_packet (sptr_packet);
        }

    return;
}

/* SPR 88619 start */

/**********************************************************************************************************************************/

/* Function ospf_find_timestamp_for_lsdb_entry
    finds the timestamp of last LSA transmission to a given destination
    for an LSDB entry

   Pseudocode:
    if transmit timestamp node of database node is given,
        just update timestamp
    else
        create transmit timestamp node
        update its timestamp
        enqueue in database node's list of transmit timestamps

*/

static OSPF_LSA_TIMESTAMP_PER_INTERFACE_LIST * ospf_find_timestamp_for_lsdb_entry
    (
    OSPF_LS_DATABASE_ENTRY *sptr_ls_database_entry,
    ULONG destination_router_id,
    OSPF_INTERFACE *sptr_interface,
    ULONG *last_tx_time,
    OSPF_NEIGHBOR *sptr_neighbor
    )
    {
    OSPF_LSA_TIMESTAMP_PER_INTERFACE_LIST *sptr_retx_timestamp_node = NULL;

    *last_tx_time = 0;

    for (sptr_retx_timestamp_node = sptr_ls_database_entry->sptr_lsa_retransmit_timestamps_per_neighbor;
         sptr_retx_timestamp_node != NULL;
         sptr_retx_timestamp_node = sptr_retx_timestamp_node->sptr_forward_link)
    {
        /* unicast case */
        if ((sptr_retx_timestamp_node->if_index == sptr_interface->ifnet_index) &&
            (sptr_retx_timestamp_node->neighbor_id == destination_router_id))
        {
            /* found timestamp of last transmission of this LSA to this neighbor.
            Record timestamp */
            *last_tx_time = sptr_retx_timestamp_node->timestamp;
            break;
        }
        /* multicast case */
        if ((sptr_neighbor != NULL) &&
            (sptr_neighbor->state == OSPF_NEIGHBOR_FULL))
        {
            if (/* if sending to DR or BDR, timestamp of last multicast transmission
                    to either all SPF routers or to all designated routers (DR and BDR) would do */
                 (destination_router_id == sptr_interface->designated_router.id) ||
                 (destination_router_id == sptr_interface->backup_designated_router.id))
            {

                if ((sptr_retx_timestamp_node->neighbor_id == OSPF_ADDR_ALLSPF) ||
                    (sptr_retx_timestamp_node->neighbor_id == OSPF_ADDR_ALLDR))
                {
                    /* found timestamp of last transmission of this LSA as multicast (all SPF routers,
                    or all designated routers and this is unicast transmission to DR or BDR. Accept
                    timestamp of last multicast transmission.
                    Record timestamp */
                    *last_tx_time = sptr_retx_timestamp_node->timestamp;
                    break;