snmpa_mib_data - Behaviour module for the SNMP agent mib-server

       The following functions must be exported from a mib-server data callback module:

       This  module  defines  the behaviour of the SNMP agent mib-server data module. A snmpa_mib_data compliant
       module must export the following functions:

         * new/1

         * close/1

         * sync/1

         * load_mib/4

         * unload_mib/4

         * lookup/2

         * next/3

         * register_subagent/3

         * unregister_subagent/2

         * which_mib/2

         * which_mibs/1

         * whereis_mib/2

         * dump/2

         * info/1

         * backup/2

         * code_change/4

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

       Note that the data extracted from the imported (loaded) mibs are stored  partly  by  the  mib-server  and
       partly  by  the  symbolic-store  server.  See the default mib-server data module, snmpa_mib_data_tttn for
       details.

Module:new(Storage)->State

              Types:

                 Storage = mib_storage()
                 State = term()

              Create a new mib-server data instance.

       Module:close(State)->void()

              Types:

                 State = term()

              Close the mib-storage.

       Module:sync(State)->void()

              Types:

                 State = term()

              Synchronize (write to disc, if possible) the mib-server data.  This  depends  on  the  mib_storage
              option,  and will only have an effect if the mib-storage option has an actual disc component (such
              as dets, or ets with a file).

       Module:load_mib(State,Filename,MeOverride,TeOverride)->{ok,NewState}|{error,Reason}

              Types:

                 State = NewState = term()
                 Filename = filename()
                 MeOverride = boolean()
                 TeOverride = boolean()
                 Reason = already_loaded | term()

              Load the mib specified by the Filename argument into the mib-server. The MeOverride and TeOverride
              arguments specifies how the mib-server shall handle duplicate mib- and trap- entries.

       Module:unload_mib(State,Filename)->{ok,NewState}|{error,Reason}

              Types:

                 State = NewState = term()
                 Filename = filename()
                 Reason = not_loaded | term()

              Unload the mib specified by the Filename argument from the mib-server.

       Module:lookup(State,Oid)->Reply

              Types:

                 State = term()
                 Reply = {variable, ME} | {table_column, ME, TEOid} | {subagent, SAPid, SAOid} | {false, Reason}
                 Oid = TEOid = SAOid = oid()
                 SAPid = pid()
                 ME = me()
                 Reason = term()

              Find the mib-entry corresponding to the Oid. If it is a variable, the Oid must be <Oid for  var>.0
              and if it is a table, Oid must be <table>.<entry>.<col>.<any>.

       Module:next(State,Oid,MibView)->Reply

              Types:

                 State = term()
                 Reply  =  false  |  endOfTable  |  {subagent,  SAPid, SAOid} | {variable, ME, VarOid} | {table,
                 TableOid, TableRestOid, ME}
                 Oid = SAOid = VarOid = TableOid = TableRestOid = oid()
                 SAPid = pid()
                 ME = me()

              Finds the lexicographically next oid.

       Module:register_subagent(State,Oid,Pid)->Reply

              Types:

                 State = NewState = term()
                 Reply = {ok, NewState} | {error, Reason}
                 Oid = oid()
                 Pid = pid()
                 Reason = term()

              Register the subagent, process, handling part of the mib-tree.

       Module:unregister_subagent(State,PidOrOid)->Reply

              Types:

                 State = NewState = term()
                 Reply = {ok, NewState} | {ok, NewState, Pid} | {error, Reason}
                 PidOrOid = pid() | oid()
                 Pid = pid()
                 Reason = term()

              Unregister the subagent, handling part of the  mib-tree,  as  specified  by  the  oid()  or  pid()
              (PidOrOid).

              When  unregister  the  subagent  using an oid(), the pid() of the process handling the sub-tree is
              also returned.

       Module:dump(State,Destination)->Reply

              Types:

                 State = term()
                 Reply = ok | {error, Reason}
                 Destination = io | filename()
                 Pid = pid()
                 Reason = term()

              Dump the mib-server data to stdio (Destination = io) or the specified file.

       Module:which_mib(State,Oid)->Reply

              Types:

                 State = term()
                 Reply = {ok, MibFile} | {error, Reason}
                 Oid = oid()
                 MibFile = string()
                 Reason = term()

              Retrieve the mib-file to which an given oid() belongs.

       Module:which_mibs(State)->Reply

              Types:

                 State = term()
                 Reply = [{MibName, Filename}]
                 MibName = atom()
                 Filename = string()

              Retrieve all loaded mib-files.

       Module:whereis_mib(State,MibName)->Reply

              Types:

                 State = term()
                 MibName = atom()
                 Reply = {ok, Filename} | {error, Reason}
                 Filename = string()
                 Reason = term()

              Retrieve the mib file for the mib.

       Module:info(State)->Reply

              Types:

                 State = term()
                 Reply = {ok, Filename} | {error, Reason}
                 Filename = string()
                 Reason = term()

              Retrieve misc info for the mib data.

              This is a utility function used to inspect, for instance, memory usage, in a simple way.

       Module:backup(State,BackupDir)->Reply

              Types:

                 State = term()
                 Reply = ok | {error, Reason}
                 BackupDir = string()
                 Reason = term()

              Perform a backup of the mib-server data.

              Note that its implementation dependant (and also dependent on mib-storage is used) if a backup  is
              possible.

       Module:code_change(Destination,Vsn,Extra,State)->NewState

              Types:

                 Destination = up | down
                 Vsn = term()
                 Extra = term()
                 State = NewState = term()

              Perform a code-change (upgrade or downgrade).

              See gen_server for more info regarding the Vsn and Extra arguments.

Ericsson AB                                         snmp 5.11                               snmpa_mib_data(3erl)

       snmpa_mib_data - Behaviour module for the SNMP agent mib-server
         data module.