View Source snmpa_mib_data behaviour (snmp v5.16)

Behaviour module for the SNMP agent mib-server data 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.

Summary

Types

filename()

mib_view()

mib_view_elem()

mib_view_inclusion()

mib_view_mask()

Callbacks

backup(State, BackupDir)

Perform a backup of the mib-server data.

close(State)

Close the mib-storage.

code_change(Direction, Vsn, Extra, State)

Perform a code-change (upgrade or downgrade).

dump(State, Destination)

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

info(State)

Retrieve misc info for the mib data.

load_mib(State, FileName, MeOverride, TeOverride)

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.

lookup(State, Oid)

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

new(MibStorage)

Create a new mib-server data instance.

next(State, Oid, MibView)

Finds the lexicographically next oid.

register_subagent(State, Oid, Pid)

sync(State)

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).

unload_mib(State, Filename)

unload_mib(State, FileName, MeOverride, TeOverride)

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

unregister_subagent(State, PidOrOid)

Unregister the subagent, handling part of the mib-tree, as specified by the oid() or pid/0 (PidOrOid).

whereis_mib(State, MibName)

Retrieve the mib file for the mib.

which_mib(State, Oid)

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

which_mibs(State)

Retrieve all loaded mib-files.

Types

filename()

(not exported) (since OTP R16B01)

-type filename() :: file:filename().

mib_view()

(since OTP R16B01)

-type mib_view() :: [mib_view_elem()].

mib_view_elem()

(since OTP R16B01)

-type mib_view_elem() ::
    {SubTree :: snmp:oid(), Mask :: [non_neg_integer()], Inclusion :: mib_view_inclusion()}.

mib_view_inclusion()

(since OTP R16B01)

-type mib_view_inclusion() :: 1 | 2.

mib_view_mask()

(since OTP R16B01)

-type mib_view_mask() :: [non_neg_integer()].

Callbacks

backup(State, BackupDir)

(since OTP R16B01)

-callback backup(State :: term(), BackupDir :: string()) -> ok | {error, Reason :: term()}.

Perform a backup of the mib-server data.

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

close(State)

(since OTP R16B01)

-callback close(State :: term()) -> ok.

Close the mib-storage.

code_change(Direction, Vsn, Extra, State)

(since OTP R16B01)

-callback code_change(Direction :: up | down, Vsn :: term(), Extra :: term(), State :: term()) ->
               NewState :: term().

Perform a code-change (upgrade or downgrade).

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

dump(State, Destination)

(since OTP R16B01)

-callback dump(State :: term(), Destination :: io | filename()) -> ok | {error, Reason :: term()}.

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

info(State)

(since OTP R16B01)

-callback info(State :: term()) -> list().

Retrieve misc info for the mib data.

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

load_mib(State, FileName, MeOverride, TeOverride)

(since OTP R16B01)

-callback load_mib(State :: term(),
         FileName :: filename(),
         MeOverride :: boolean(),
         TeOverride :: boolean()) ->
            {ok, NewState :: term()} | {error, 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.

lookup(State, Oid)

(since OTP R16B01)

-callback lookup(State :: term(), Oid :: snmp:oid()) ->
          {false, Reason :: term()} |
          {variable, MibEntry :: snmpa:me()} |
          {table_column, MibEntry :: snmpa:me(), TableEntryOid :: snmp:oid()} |
          {subagent, SubAgentPid :: pid(), SAOid :: snmp:oid()}.

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

new(MibStorage)

(since OTP R16B01)

-callback new(MibStorage :: snmpa:mib_storage()) -> State :: term().

Create a new mib-server data instance.

next(State, Oid, MibView)

(since OTP R16B01)

-callback next(State :: term(), Oid :: snmp:oid(), MibView :: mib_view()) ->
        endOfView | false |
        {subagent, SubAgentPid :: pid(), SAOid :: snmp:oid()} |
        {variable, MibEntry :: snmpa:me(), VarOid :: snmp:oid()} |
        {table, TableOid :: snmp:oid(), TableRestOid :: snmp:oid(), MibEntry :: snmpa:me()}.

Finds the lexicographically next oid.

register_subagent(State, Oid, Pid)

(since OTP R16B01)

-callback register_subagent(State :: term(), Oid :: snmp:oid(), Pid :: pid()) ->
                     {ok, NewState :: term()} | {error, Reason :: term()}.

sync(State)

(since OTP R16B01)

-callback sync(State :: term()) -> ok.

unload_mib(State, Filename)

(optional) (since OTP R16B01)

-callback unload_mib(State, Filename) -> {ok, NewState} | {error, Reason}
              when
                  State :: term(),
                  Filename :: filename(),
                  NewState :: term(),
                  Reason :: not_loaded | term().

unload_mib(State, FileName, MeOverride, TeOverride)

(since OTP R16B01)

-callback unload_mib(State :: term(),
           FileName :: filename(),
           MeOverride :: boolean(),
           TeOverride :: boolean()) ->
              {ok, NewState :: term()} | {error, Reason :: not_loaded | term()}.

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

unregister_subagent(State, PidOrOid)

(since OTP R16B01)

-callback unregister_subagent(State :: term(), PidOrOid :: pid() | snmp:oid()) ->
                       {ok, NewState :: term()} |
                       {ok, NewState :: term(), Pid :: pid()} |
                       {error, Reason :: term()}.

Unregister the subagent, handling part of the mib-tree, as specified by the oid() or pid/0 (PidOrOid).

When unregister the subagent using an oid(), the pid/0 of the process handling the sub-tree is also returned.

whereis_mib(State, MibName)

(since OTP R16B01)

-callback whereis_mib(State :: term(), MibName :: atom()) ->
               {ok, Filename :: filename()} | {error, Reason :: term()}.

Retrieve the mib file for the mib.

which_mib(State, Oid)

(since OTP R16B01)

-callback which_mib(State :: term(), Oid :: snmp:oid()) -> {ok, Mib :: string()} | {error, Reason :: term()}.

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

which_mibs(State)

(since OTP R16B01)

-callback which_mibs(State :: term()) -> [{MibName :: atom(), Filename :: filename()}].

Retrieve all loaded mib-files.