-- File: PupErrors.mesa,  Last Edit:
  -- MAS  April 17, 1980  8:43 PM
  -- HGM  October 24, 1979  8:30 PM

-- Copyright  Xerox Corporation 1979, 1980

DIRECTORY
  StatsDefs: FROM "StatsDefs" USING [StatIncr],
  PupRouterDefs: FROM "PupRouterDefs" USING [SneakySendUnlocked],
  PupStream: FROM "PupStream" USING [CloseReason],
  PupDefs: FROM "PupDefs",
  DriverDefs: FROM "DriverDefs" USING [
    Glitch, doStats, doDebug, Network,
    PutOnGlobalDoneQueue],
  BufferDefs: FROM "BufferDefs",  -- SHARES
  PupTypes: FROM "PupTypes" USING [
    allHosts, PupErrorCode, badChecksumPupErrorCode,
    noProcessPupErrorCode, resourceLimitsPupErrorCode],
  DriverTypes: FROM "DriverTypes" USING [bufferSeal];

PupErrors: PROGRAM
  IMPORTS StatsDefs, PupRouterDefs, DriverDefs, PupDefs
  EXPORTS PupRouterDefs, PupStream, PupDefs
  SHARES BufferDefs =
BEGIN OPEN DriverDefs, PupDefs;

Network: TYPE = DriverDefs.Network;

-- PktStream/ByteStream SIGNALs live here so they are defined only once
StreamClosing: PUBLIC ERROR [why: PupStream.CloseReason, text: STRING] = CODE;
RejectThisRequest: PUBLIC ERROR [error: STRING] = CODE;


suppressErrors: BOOLEAN _ FALSE;
suppressBufferFull: BOOLEAN _ FALSE;

BufferSealBroken: PUBLIC ERROR = CODE;
BufferDidntArrive: PUBLIC ERROR = CODE;

SetErrorSuppression: PUBLIC PROCEDURE [dontSendErrors: BOOLEAN] =
  BEGIN
  suppressErrors _ dontSendErrors;
  END;

SetBufferFullSuppression: PUBLIC PROCEDURE [dontSend: BOOLEAN] =
  BEGIN
  suppressBufferFull _ dontSend;
  END;


RejectPupWithBadChecksum: PUBLIC PROCEDURE [b: PupBuffer] =
  BEGIN
  Reject[b,PupTypes.badChecksumPupErrorCode];
  END;

Reject: PUBLIC PROCEDURE [b: PupBuffer, code: PupTypes.PupErrorCode] =
  BEGIN
  IF BuildErrorPup[b,code,NIL] THEN PupRouterDefs.SneakySendUnlocked[b];
  END;

SendErrorPup: PUBLIC PROCEDURE [b: PupBuffer, code: PupTypes.PupErrorCode, text: STRING] =
  BEGIN
  IF BuildErrorPup[b,code,text] THEN  PupRouterSendThis[b];
  END;

BuildErrorPup: PUBLIC PROCEDURE [
    b: PupBuffer, code: PupTypes.PupErrorCode, text: STRING]
  RETURNS [ok: BOOLEAN] =
  BEGIN OPEN PupTypes;
  i: CARDINAL;
  p: POINTER TO ARRAY [0..9] OF WORD = LOOPHOLE[@b.pupLength];
  temp: PupSocketID;
  network: Network _ b.network;
  IF doDebug AND b.seal#DriverTypes.bufferSeal THEN Glitch[BufferSealBroken];
  IF suppressErrors OR (suppressBufferFull AND code=resourceLimitsPupErrorCode)
  OR b.pupType=error OR b.dest.host=PupTypes.allHosts THEN
    BEGIN DriverDefs.PutOnGlobalDoneQueue[b]; RETURN[FALSE]; END;
  IF doDebug AND b.network=NIL THEN Glitch[BufferDidntArrive];
  FOR i IN [0..9] DO b.errorHeader[i] _ p[i]; ENDLOOP;
  b.pupType _ error;
  b.errorCode _ code;
  b.errorOptions _ 0;
  temp _ b.dest.socket;
  b.dest _ b.source;
  b.source _ [[network.netNumber],[network.hostNumber],temp];
  IF text=NIL THEN SELECT code FROM
    badChecksumPupErrorCode => text _ "Bad Software Checksum"L;
    noProcessPupErrorCode => text _ "No such Port"L;
    resourceLimitsPupErrorCode => text _ "Buffers full"L;
    ENDCASE => NULL;
  IF text#NIL THEN 
    BEGIN
    FOR i_0,i+1 UNTIL i=text.length DO b.errorText[i] _ text[i]; ENDLOOP;
    END
  ELSE i _ 0;
  SetPupContentsBytes[b,2*(10+1+1)+i];  -- Yetch
  IF doStats THEN StatsDefs.StatIncr[statErrorPupsSent];
  RETURN[TRUE];
  END;

-- initialization
END.  -- PupErrors(2048)\871b85B9t10 5t0 52b17B192b19B98b24B91b25B97b7B153b12B155b13B