NAME

       snmpa_discovery_handler - Behaviour module for the SNMP agent discovery handler.

DESCRIPTION

       This    module    defines    the   behaviour   of   the   agent   discovery   handler.   A
       snmpa_discovery_handler compliant module must export the following functions:

         * stage1_finish/2

       The semantics of them and their exact signatures are explained below.

EXPORTS

       stage1_finish(TargetName, ManagerEngineID, ExtraInfo)  ->  ignore  |  {ok,  usm_entry()  |
       [usm_entry()]} | {ok, usm_entry() | [usm_entry()], NewExtraInfo}

              Types:

                 TargetName = string()
                 ManagerEngineID = string()
                 ExtraInfo = term()
                 usm_entry() = tuple() compatible with usm.conf
                 NewExtraInfo = term()

              This  function  is called at the end of stage 1 of the discovery process. It should
              return either the atom ignore or {ok, usm_entry() | [usm_entry()]}. See usm_entry()
              and usm_entry/13 for more info.

              If the function returns ignore, then it is assumed that either:

                * The caller (of the discovery function) will make the needed updates later.

                * The callback function itself did the updates.

              In either case, the agent will do nothing, but return the retrieved ManagerEngineID
              (see discovery for more info) and possible continue with stage 2 of  the  discovery
              process.

              The ExtraInfo argument is passed on from the discovery function.

              This  function  may  return an updated NewExtraInfo that will be used in subsequent
              calls to the callback functions. Intended for future use.

              The purpose of this function is to generate the usm- related security  data  needed
              for usm processing in the agent. Specifically, updating the usmUserTable.

              When an usm_entry() tuple (or a list of such tuples) is returned, this data is then
              added to the usmUserTable by the (master-) agent.

              When an usm_entry() tuple (or a list of such tuples) is returned, this data is then
              added to the usmUserTable by the (master-) agent.

          Note:
              Note that the function does not check if this entry already exists.

          Note:
              Note that this function is executed in the context of the master-agent process.