
    <<Router.mesa - internal definitions module for the Pilot OISCP Router>>
        <<Copyright © 1985 by Xerox Corporation.  All rights reserved.>>
        <<BLyon on: January 28, 1981  6:41 PM>>

    DIRECTORY
        BufferDefs USING [OisBuffer],
        DriverDefs USING [DriverXmitStatus, Network],
        OISCPTypes USING [OISErrorCode],
        SocketInternal USING [SocketHandle],
        SpecialCommunication USING [RoutersFunction],
        NSAddress USING [HostNumber, NetworkAddress, NetworkNumber];

    Router: DEFINITIONS =
        BEGIN

        <<TYPEs and definitions>>

        SocketTable: TYPE = RECORD [
            length: CARDINAL, first: SocketInternal.SocketHandle];
        Nibble: TYPE = [0..17B];
        RoutingTableEntry: TYPE = REF RoutingTableObject;
        RoutingTableObject: TYPE = RECORD [
            next: RoutingTableEntry,
            destNetwork: NSAddress.NetworkNumber, -- ultimate destination network num.
            delay: Nibble,
            timeUnits: Nibble, -- if zero then this entry is discarded
            route: NSAddress.HostNumber,
            <<if =unknownHostID then the ultimate destination network is local.>>
            network: DriverDefs.Network]; -- use this network driver to reach route.
        XmitStatus: TYPE = DriverDefs.DriverXmitStatus;

        <<variables>>
        socketRouterLock: MONITORLOCK; -- lock shared by SocketImpl and RouterImpl.
        primaryMDS: BOOLEAN; -- whether the router is in the primary MDS or not.
        routersFunction: SpecialCommunication.RoutersFunction;
        <<whether the router is an internet router or not.>>
        checkIt: BOOLEAN; -- whether checksums are on or not.

        <<interface>>
        <<Procedures from RouterImpl>>
        OisRouterOn: PROCEDURE;
        OisRouterOff: PROCEDURE;
        AssignOisAddress: PROCEDURE RETURNS [NSAddress.NetworkAddress];
        AssignDestinationRelativeOisAddress: PROCEDURE [NSAddress.NetworkNumber] RETURNS [NSAddress.NetworkAddress];
        AddSocket: PROCEDURE [SocketInternal.SocketHandle];
        RemoveSocket: PROCEDURE [SocketInternal.SocketHandle];
        SendPacket: PROCEDURE [BufferDefs.OisBuffer];
        ReceivePacket: PROCEDURE [BufferDefs.OisBuffer];
        BroadcastThisPacket: PROCEDURE [BufferDefs.OisBuffer];  -- called from a user (like INR)
        SendBroadcastPacket: PROCEDURE [BufferDefs.OisBuffer];  -- called from dispatcher
        SendErrorPacket: PROCEDURE [offendingPkt: BufferDefs.OisBuffer,
            errCode: OISCPTypes.OISErrorCode, errParm: CARDINAL _ 0];  -- sends error pkt back to offender's source; do not call from inside 
            router's lock.
        FindMyHostID: PROCEDURE RETURNS [NSAddress.HostNumber];
        <<debugging>>
        SetOisCheckit: PROCEDURE [BOOLEAN];
        SetOisStormy: PROCEDURE [BOOLEAN];
        SetOisDriverLoopback: PROCEDURE [BOOLEAN];
        SetOisShowit: PROCEDURE [BOOLEAN];
        InspectOutgoingOiss: PROCEDURE [PROCEDURE [BufferDefs.OisBuffer]];
        InspectIncommingOiss: PROCEDURE [PROCEDURE [BufferDefs.OisBuffer]];
        CaptureErrors: PROCEDURE [PROCEDURE [UNSPECIFIED]];
        EnumerateRoutingTable: PROCEDURE [proc: PROCEDURE [RoutingTableEntry]];
        <<Procedures from RoutingTableImpl>>
        RoutingTableOn: PROCEDURE;
        RoutingTableOff: PROCEDURE;
        FindDestinationRelativeNetID: PROCEDURE [NSAddress.NetworkNumber] RETURNS [NSAddress.NetworkNumber];
        AddNetwork: PROCEDURE [DriverDefs.Network];
        RemoveNetwork: PROCEDURE [DriverDefs.Network];
        StateChanged: PROCEDURE [DriverDefs.Network];
        FindNetworkAndTransmit: PROCEDURE [BufferDefs.OisBuffer] RETURNS [XmitStatus];
        ForwardPacket: PROCEDURE [BufferDefs.OisBuffer];
        RoutingInformationPacket: PROCEDURE [BufferDefs.OisBuffer];

        END. -- Router

    LOG

    Time: January 19, 1980  4:01 PM By: Dalal  Action: Created interface.
    Time: August 1, 1980  6:51 PM By: BLyon  Action: replaced internetRouter by routersFunction and moved checksums stuff to Checksums 
    Interface.
    Time: August 4, 1980  6:51 PM By: BLyon  Action: added destNetwork to RoutingTableEntry and made the routingTable a linked list.
    Time: September 13, 1980  6:09 PM By: HGM  Action: added StateChanged.
    Time: September 18, 1980  3:31 PM By: BLyon  Action: deleted FindPrimaryNetID.
    Time: January 5, 1981  4:00 PM By: BLyon  Action: added EnumerateRoutingTable.