-- File: PupRouterOut.mesa,  Last Edit: HGM  October 16, 1979  11:08 PM

-- Copyright  Xerox Corporation 1979, 1980

DIRECTORY
  StatsDefs: FROM "StatsDefs" USING [StatIncr],
  CommUtilDefs: FROM "CommUtilDefs" USING [GetTicks],
  PupRouterDefs: FROM "PupRouterDefs" USING [
    routerLock, maxHop, OutThings,
    PupRoutingTableEntry, BeSurePupIsOn, SetPupChecksum],
  DriverDefs: FROM "DriverDefs" USING [
    firstNetwork, doDebug, doShow, doStats, doStorms,
    Glitch, Network, PutOnGlobalDoneQueue],
  PupDefs: FROM "PupDefs" USING [
    outgoingPup, zappedOutgoingPup, PupBuffer],
  BufferDefs: FROM "BufferDefs",
  PupTypes: FROM "PupTypes" USING [
    allNets, allHosts, PupType,
    PupAddress, PupHostID, PupNetID],
  DriverTypes: FROM "DriverTypes" USING [bufferSeal];

PupRouterOut: MONITOR LOCKS PupRouterDefs.routerLock
  IMPORTS StatsDefs, CommUtilDefs, PupRouterDefs, DriverDefs
  EXPORTS PupRouterDefs, PupDefs
  SHARES BufferDefs, DriverTypes =
BEGIN OPEN StatsDefs, PupRouterDefs, DriverDefs, PupDefs, PupTypes;

pupRoutingTableOut: PUBLIC DESCRIPTOR FOR ARRAY OF PupRoutingTableEntry;
dataWordsPerPup: PUBLIC CARDINAL;

outThings: PUBLIC OutThings _ [
  outStormy: FALSE,
  showOut: FALSE,
  outShower: ];

-- parameters for killing packets
lightning: INTEGER _ 30;
bolt: INTEGER _ 10;

BufferSealBroken: PUBLIC ERROR = CODE;
IllegalPupLength: PUBLIC ERROR = CODE;

PupRouterSendThis: PUBLIC ENTRY PROCEDURE [b: PupBuffer] =
  BEGIN
  IF b.dest.net=allNets AND b.dest.host=allHosts THEN
    BEGIN
    PupRouterBroadcastThis[b];
    RETURN;
    END;
  SendUnlocked[b];
  END;

SneakySendUnlocked: PUBLIC PROCEDURE [b: PupBuffer] = JustSendUnlocked;
JustSendUnlocked: INTERNAL PROCEDURE [b: PupBuffer] =
  BEGIN
  SendUnlocked[b];
  END;

SendUnlocked: INTERNAL PROCEDURE [b: PupBuffer] =
  BEGIN
  d: PupAddress _ b.dest;
  n: PupNetID _ d.net;
  routing: POINTER TO PupRoutingTableEntry;
  network: Network;
  h: PupHostID;
  IF doStats THEN StatIncr[statPupSent];

  IF doDebug THEN BeSurePupIsOn[];
  IF doDebug AND b.seal#DriverTypes.bufferSeal THEN Glitch[BufferSealBroken];

  IF doStorms AND outThings.outStormy  -- for debugging only
  AND (lightning_lightning+1)>bolt OR lightning<0 THEN
    BEGIN
    IF lightning>bolt THEN
      BEGIN
      IF bolt>100 THEN
        BEGIN
        lightning_-INTEGER[CommUtilDefs.GetTicks[] MOD 20B];
        bolt_10;
        END
      ELSE BEGIN lightning_0; bolt_bolt+1; END;
      END;
    IF doShow AND outThings.showOut THEN outThings.outShower[zappedOutgoingPup,b];
    PutOnGlobalDoneQueue[b];
    IF doStats THEN StatIncr[statZappedP];
    RETURN;
    END;

  -- Maybe we should do something for the local case?

  b.pupTransportControl _ 0;
  routing _ @pupRoutingTableOut[n];
  network _ routing.network;
  IF n ~IN [0..LENGTH[pupRoutingTableOut]) OR routing.hop>maxHop OR network=NIL THEN
    BEGIN  -- don't know where to send it
    IF doStats THEN StatIncr[statPupsSentNowhere];
    IF n ~IN [0..LENGTH[pupRoutingTableOut]) OR network=NIL THEN
      BEGIN -- Send him an error Pup, but beware of RequeueProc-- END;
    PutOnGlobalDoneQueue[b];
    RETURN;  -- wait to see if there is an alternate path
    END;
  b.source.host _ [network.hostNumber];  -- tell the truth
  b.source.net _ [network.netNumber];
  IF doShow AND outThings.showOut THEN outThings.outShower[outgoingPup,b];
  h _ routing.route;
  IF h=0 THEN h _ b.dest.host;  -- we are on the same net
  IF doDebug AND ((b.pupLength+1)/2)>dataWordsPerPup+wordsPerPupHeader THEN
    DriverDefs.Glitch[IllegalPupLength];
  SetPupChecksum[b];
  network.encapsulatePup[b,h];
  network.sendBuffer[b];
  END;

PupRouterBroadcastThis: PUBLIC PROCEDURE [b: PupBuffer] =
  BEGIN
  IF doStats THEN StatIncr[statPupBroadcast];
  IF doDebug THEN BeSurePupIsOn[];
  IF doDebug AND b.seal#DriverTypes.bufferSeal THEN Glitch[BufferSealBroken];
  IF DriverDefs.firstNetwork=NIL THEN BEGIN PutOnGlobalDoneQueue[b]; RETURN; END;
  b.allNets _ TRUE;  -- this is where it gets turned on
  b.network _ DriverDefs.firstNetwork;
  b.dest.host _ allHosts;
  PupBroadcaster[b];
  END;

-- b.network is already set up to the desired network
PupBroadcaster: PUBLIC PROCEDURE [b: PupBuffer] =
  BEGIN
  network: Network _ b.network;
  IF b.bypassZeroNet AND network.netNumber=0 THEN
    BEGIN PutOnGlobalDoneQueue[b]; RETURN; END;  -- goes (slowly) around in circles
  b.pupTransportControl _ 0;
  b.dest.net _ b.source.net _ [network.netNumber];
  b.source.host _ [network.hostNumber];
  network.encapsulatePup[b,PupTypes.allHosts];
  SetPupChecksum[b];
  network.sendBuffer[b];
  END;

-- Pup is assumed to have arrived from somewhere else.  We fixup defaults here.
SwapPupSourceAndDest: PUBLIC PROCEDURE [b: PupBuffer] =
  BEGIN
  network: DriverDefs.Network _ b.network;
  temp: PupAddress;
  IF doDebug AND b.seal#DriverTypes.bufferSeal THEN Glitch[BufferSealBroken];
  temp _ b.source;
  b.source _ b.dest;
  b.dest _ temp;
  -- in case we are returning a broadcast packet
  IF b.dest.net=0 THEN b.dest.net _ [network.netNumber];
  IF b.source.net=0 THEN b.source.net _ [network.netNumber];
  IF b.source.host=PupTypes.allHosts THEN b.source.host _ [network.hostNumber];
  END;

ReturnPup: PUBLIC PROCEDURE [b: PupBuffer, type: PupTypes.PupType, bytes: CARDINAL] =
  BEGIN
  SwapPupSourceAndDest[b];
  SendPup[b,type,bytes];
  END;


wordsPerPupHeader: CARDINAL = 11;
bytesPerPupHeader: CARDINAL = wordsPerPupHeader*2;

GetPupContentsBytes: PUBLIC PROCEDURE [b: PupBuffer] RETURNS [bytes: CARDINAL] =
  BEGIN
  RETURN[b.pupLength-bytesPerPupHeader];
  END;

SetPupContentsBytes: PUBLIC PROCEDURE [b: PupBuffer, bytes: CARDINAL] =
  BEGIN
  IF bytes>dataWordsPerPup*2 THEN Glitch[IllegalPupLength];
  b.pupLength _ bytes+bytesPerPupHeader;
  END;

SetPupContentsWords: PUBLIC PROCEDURE [b: PupBuffer, words: CARDINAL] =
  BEGIN
  IF words>dataWordsPerPup THEN Glitch[IllegalPupLength];
  b.pupLength _ words*2+bytesPerPupHeader;
  END;

SendPup: PUBLIC PROCEDURE [b: PupBuffer, type: PupType, bytes: CARDINAL] =
  BEGIN
  b.pupType _ type;
  SetPupContentsBytes[b,bytes];
  PupRouterSendThis[b];
  END;


END.  -- PupRouterOut(2048)\738b12B593b17B193b18B54b16B73b12B235t10 13t0 1015b54B554b22B108t10 13t0 368b14B511b21B242i49I36t10 19t0 42t10 19t0 60t10 9t0 4t10 7t0 10b9B232b19B119b19B170b19B170b7B