CREATE OR ALTER EXCEPTION db__xGetOut 'Отвали!';
-- CREATE OR ALTER EXCEPTION db__xIamSS 'Я супер сервер!!!';
-- CREATE OR ALTER EXCEPTION db__xIamCS 'Классик';

SET TERM ^;
CREATE OR ALTER TRIGGER db__TR_CONN
  ON CONNECT
AS
  DECLARE VARIABLE remoteProcess VARCHAR(255) CHARACTER SET UTF8;
  DECLARE VARIABLE isSuperServer SMALLINT DEFAULT 0;
BEGIN
  IF (CURRENT_USER = 'SERVER_MON_USER') THEN
    BEGIN
      SELECT MON$REMOTE_PROCESS,
          Iif(MON$SERVER_PID = MON$REMOTE_PID, 1, 0)
        FROM MON$ATTACHMENTS
        WHERE MON$ATTACHMENT_ID = CURRENT_CONNECTION
          AND MON$REMOTE_PROTOCOL = 'TCPv4'
          AND MON$REMOTE_ADDRESS = '127.0.0.1'
          -- AND MON$REMOTE_PROCESS = MON$LOCAL_PROCESS
        INTO: remoteProcess, isSuperServer;
      IF (:remoteProcess IS NULL) THEN EXCEPTION db__xGetOut;
      -- IF (:isSuperServer = 1) THEN
      --   EXCEPTION db__xIamSS;
      -- ELSE
      --   EXCEPTION db__xIamCS;
    END
END^
SET TERM ;^

WHEN ANY DO
  BEGIN
    nestLevel = 0;
    xn = EXCEPTION_NUMBER(nestLevel);  -- номер исключения уровня нашего подключения
    WHILE (:xn IS NOT NULL) DO
      BEGIN
        exception_number = xn;
        nestLevel = nestLevel + 1;
        xn = EXCEPTION_NUMBER(nestLevel); -- номер исключения уровня внешнего провайдера n+1
      END
    SUSPEND;
  END