.TH snmpa_discovery_handler 3erl "snmp 5.15" "Ericsson AB" "Erlang Module Definition"
.SH NAME
snmpa_discovery_handler \- Behaviour module for the SNMP agent discovery handler.
.SH DESCRIPTION
.LP
This module defines the behaviour of the agent discovery handler\&. A \fIsnmpa_discovery_handler\fR\& compliant module must export the following functions:
.RS 2
.TP 2
*
stage1_finish/2
.LP
.RE

.LP
The semantics of them and their exact signatures are explained below\&.
.SH EXPORTS
.LP
.B
stage1_finish(TargetName, ManagerEngineID, ExtraInfo) -> ignore | {ok, usm_entry() | [usm_entry()]} | {ok, usm_entry() | [usm_entry()], NewExtraInfo}
.br
.RS
.LP
Types:

.RS 3
TargetName = string()
.br
ManagerEngineID = string()
.br
ExtraInfo = term()
.br
usm_entry() = tuple() compatible with usm\&.conf
.br
NewExtraInfo = term()
.br
.RE
.RE
.RS
.LP
This function is called at the end of stage 1 of the discovery process\&. It should return either the atom \fIignore\fR\& or \fI{ok, usm_entry() | [usm_entry()]}\fR\&\&. See usm_entry() and usm_entry/13 for more info\&.
.LP
If the function returns \fIignore\fR\&, then it is assumed that either:
.RS 2
.TP 2
*
The caller (of the discovery function) will make the needed updates later\&. 
.LP
.TP 2
*
The callback function itself did the updates\&. 
.LP
.RE

.LP
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\&.
.LP
The \fIExtraInfo\fR\& argument is passed on from the discovery function\&.
.LP
This function may return an updated \fINewExtraInfo\fR\& that will be used in subsequent calls to the callback functions\&. Intended for future use\&.
.LP
The purpose of this function is to generate the usm- related security data needed for usm processing in the agent\&. Specifically, updating the usmUserTable\&.
.LP
When an \fIusm_entry()\fR\& tuple (or a list of such tuples) is returned, this data is then added to the \fIusmUserTable\fR\& by the (master-) agent\&.
.LP
When an \fIusm_entry()\fR\& tuple (or a list of such tuples) is returned, this data is then added to the \fIusmUserTable\fR\& by the (master-) agent\&.
.LP

.RS -4
.B
Note:
.RE
Note that the function does not check if this entry already exists\&.

.LP

.RS -4
.B
Note:
.RE
Note that this function is executed in the context of the master-agent process\&.

.RE