.TH snmpa_mib_data 3erl "snmp 5.13.5" "Ericsson AB" "Erlang Module Definition"
.SH NAME
snmpa_mib_data \- Behaviour module for the SNMP agent mib-server 
  data module.
.SH DESCRIPTION
.LP
This module defines the behaviour of the SNMP agent mib-server data module\&. A \fIsnmpa_mib_data\fR\& compliant module must export the following functions:
.RS 2
.TP 2
*
new/1
.LP
.TP 2
*
close/1
.LP
.TP 2
*
sync/1
.LP
.TP 2
*
load_mib/4
.LP
.TP 2
*
unload_mib/4
.LP
.TP 2
*
lookup/2
.LP
.TP 2
*
next/3
.LP
.TP 2
*
register_subagent/3
.LP
.TP 2
*
unregister_subagent/2
.LP
.TP 2
*
which_mib/2
.LP
.TP 2
*
which_mibs/1
.LP
.TP 2
*
whereis_mib/2
.LP
.TP 2
*
dump/2
.LP
.TP 2
*
info/1
.LP
.TP 2
*
backup/2
.LP
.TP 2
*
code_change/4
.LP
.RE

.LP
The semantics of them and their exact signatures are explained below\&.
.LP
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, \fIsnmpa_mib_data_tttn\fR\& for details\&.
.SH "CALLBACK FUNCTIONS"

.LP
The following functions must be exported from a \fImib-server\fR\& data callback module:
.SH EXPORTS
.LP
.B
Module:new(Storage) -> State
.br
.RS
.LP
Types:

.RS 3
Storage = mib_storage()
.br
State = term()
.br
.RE
.RE
.RS
.LP
Create a new mib-server data instance\&.
.RE

.LP
.B
Module:close(State) -> void()
.br
.RS
.LP
Types:

.RS 3
State = term()
.br
.RE
.RE
.RS
.LP
Close the mib-storage\&.
.RE

.LP
.B
Module:sync(State) -> void()
.br
.RS
.LP
Types:

.RS 3
State = term()
.br
.RE
.RE
.RS
.LP
Synchronize (write to disc, if possible) the mib-server data\&. This depends on the \fImib_storage\fR\& 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)\&.
.RE

.LP
.B
Module:load_mib(State, Filename, MeOverride, TeOverride) -> {ok, NewState} | {error, Reason}
.br
.RS
.LP
Types:

.RS 3
State = NewState = term()
.br
Filename = filename()
.br
MeOverride = boolean()
.br
TeOverride = boolean()
.br
Reason = already_loaded | term()
.br
.RE
.RE
.RS
.LP
Load the mib specified by the \fIFilename\fR\& argument into the mib-server\&. The \fIMeOverride\fR\& and \fITeOverride\fR\& arguments specifies how the mib-server shall handle duplicate mib- and trap- entries\&.
.RE

.LP
.B
Module:unload_mib(State, Filename) -> {ok, NewState} | {error, Reason}
.br
.RS
.LP
Types:

.RS 3
State = NewState = term()
.br
Filename = filename()
.br
Reason = not_loaded | term()
.br
.RE
.RE
.RS
.LP
Unload the mib specified by the \fIFilename\fR\& argument from the mib-server\&.
.RE

.LP
.B
Module:lookup(State, Oid) -> Reply
.br
.RS
.LP
Types:

.RS 3
State = term()
.br
Reply = {variable, ME} | {table_column, ME, TEOid} | {subagent, SAPid, SAOid} | {false, Reason}
.br
Oid = TEOid = SAOid = oid()
.br
SAPid = pid()
.br
ME = me()
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Find the mib-entry corresponding to the \fIOid\fR\&\&. If it is a variable, the \fIOid\fR\& must be <Oid for var>\&.0 and if it is a table, \fIOid\fR\& must be <table>\&.<entry>\&.<col>\&.<any>\&.
.RE

.LP
.B
Module:next(State, Oid, MibView) -> Reply
.br
.RS
.LP
Types:

.RS 3
State = term()
.br
Reply = false | endOfTable | {subagent, SAPid, SAOid} | {variable, ME, VarOid} | {table, TableOid, TableRestOid, ME}
.br
Oid = SAOid = VarOid = TableOid = TableRestOid = oid()
.br
SAPid = pid()
.br
ME = me()
.br
.RE
.RE
.RS
.LP
Finds the lexicographically next oid\&.
.RE

.LP
.B
Module:register_subagent(State, Oid, Pid) -> Reply
.br
.RS
.LP
Types:

.RS 3
State = NewState = term()
.br
Reply = {ok, NewState} | {error, Reason}
.br
Oid = oid()
.br
Pid = pid()
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Register the subagent, process, handling part of the mib-tree\&.
.RE

.LP
.B
Module:unregister_subagent(State, PidOrOid) -> Reply
.br
.RS
.LP
Types:

.RS 3
State = NewState = term()
.br
Reply = {ok, NewState} | {ok, NewState, Pid} | {error, Reason}
.br
PidOrOid = pid() | oid()
.br
Pid = pid()
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Unregister the subagent, handling part of the mib-tree, as specified by the \fIoid()\fR\& or \fIpid()\fR\& (\fIPidOrOid\fR\&)\&.
.LP
When unregister the subagent using an \fIoid()\fR\&, the \fIpid()\fR\& of the process handling the sub-tree is also returned\&.
.RE

.LP
.B
Module:dump(State, Destination) -> Reply
.br
.RS
.LP
Types:

.RS 3
State = term()
.br
Reply = ok | {error, Reason}
.br
Destination = io | filename()
.br
Pid = pid()
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Dump the mib-server data to \fIstdio\fR\& (Destination = \fIio\fR\&) or the specified file\&.
.RE

.LP
.B
Module:which_mib(State, Oid) -> Reply
.br
.RS
.LP
Types:

.RS 3
State = term()
.br
Reply = {ok, MibFile} | {error, Reason}
.br
Oid = oid()
.br
MibFile = string()
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Retrieve the mib-file to which an given \fIoid()\fR\& belongs\&.
.RE

.LP
.B
Module:which_mibs(State) -> Reply
.br
.RS
.LP
Types:

.RS 3
State = term()
.br
Reply = [{MibName, Filename}]
.br
MibName = atom()
.br
Filename = string()
.br
.RE
.RE
.RS
.LP
Retrieve all loaded mib-files\&.
.RE

.LP
.B
Module:whereis_mib(State, MibName) -> Reply
.br
.RS
.LP
Types:

.RS 3
State = term()
.br
MibName = atom()
.br
Reply = {ok, Filename} | {error, Reason}
.br
Filename = string()
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Retrieve the mib file for the mib\&.
.RE

.LP
.B
Module:info(State) -> Reply
.br
.RS
.LP
Types:

.RS 3
State = term()
.br
Reply = {ok, Filename} | {error, Reason}
.br
Filename = string()
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Retrieve misc info for the mib data\&.
.LP
This is a utility function used to inspect, for instance, memory usage, in a simple way\&.
.RE

.LP
.B
Module:backup(State, BackupDir) -> Reply
.br
.RS
.LP
Types:

.RS 3
State = term()
.br
Reply = ok | {error, Reason}
.br
BackupDir = string()
.br
Reason = term()
.br
.RE
.RE
.RS
.LP
Perform a backup of the mib-server data\&.
.LP
Note that its implementation dependent (and also dependent on mib-storage is used) if a backup is possible\&.
.RE

.LP
.B
Module:code_change(Destination, Vsn, Extra, State) -> NewState
.br
.RS
.LP
Types:

.RS 3
Destination = up | down
.br
Vsn = term()
.br
Extra = term()
.br
State = NewState = term()
.br
.RE
.RE
.RS
.LP
Perform a code-change (upgrade or downgrade)\&.
.LP
See gen_server for more info regarding the \fIVsn\fR\& and \fIExtra\fR\& arguments\&.
.RE