View Source snmpa_discovery_handler behaviour (snmp v5.18)
Behaviour module for the SNMP agent discovery handler.
This module defines the behaviour of the agent discovery handler. A
snmpa_discovery_handler
compliant module must export the following functions:
The semantics of them and their exact signatures are explained below.
Summary
Callbacks
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/1,3 for more info.
Callbacks
-callback stage1_finish(TargetName, ManagerEngineID, ExtraInfo) -> ignore | {ok, UsmEntry | [UsmEntry]} | {ok, UsmEntry | [UsmEntry], NewExtraInfo} when TargetName :: snmp_target_mib:name(), ManagerEngineID :: snmp_framework_mib:engine_id(), ExtraInfo :: term(), UsmEntry :: snmp_user_based_sm_mib:usm_entry(), 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/1,3 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 snmpa:discovery/6
for more info) and
possible continue with stage 2 of the discovery process.
The ExtraInfo
argument is passed on from the snmpa:discovery/6
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.