20042009 Ericsson AB. All Rights Reserved. The contents of this file are subject to the Erlang Public License, Version 1.1, (the "License"); you may not use this file except in compliance with the License. You should have received a copy of the Erlang Public License along with this software. If not, it can be retrieved online at http://www.erlang.org/. Software distributed under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the specific language governing rights and limitations under the License. snmpm_user snmpm_user.xml
snmpm_user Behaviour module for the SNMP manager user.

This module defines the behaviour of the manager user. A snmpm_user compliant module must export the following functions:

handle_error/3

handle_agent/4

handle_pdu/4

handle_trap/3

handle_inform/3

handle_report/3

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

Note that if an agent is registered using the old, no longer documented, functions (using Addr and Port), the old variant of the callback functions, handle_pdu, handle_trap, handle_inform and handle_report, will be called.

handle_error(ReqId, Reason, UserData) -> Reply Handle error ReqId = integer() Reason = {unexpected_pdu, SnmpInfo} | {invalid_sec_info, SecInfo, SnmpInfo} | {empty_message, Addr, Port} | term() Addr = ip_address() Port = integer() UserData = term() Reply = ignore

This function is called when the manager needs to communicate an "asynchronous" error, to the user: e.g. failure to send an asynchronous message (i.e. encoding error), a received message was discarded due to security error, the manager failed to generate a response message to a received inform-request, or when receiving an unexpected PDU from an agent (could be an expired async request).

If ReqId is less then 0, it means that this information was not available to the manager (that info was never retrieved before the message was discarded).

For SnmpInfo see handle_agent below.

 handle_agent(Addr, Port, Type, SnmpInfo, UserData) -> Reply Handle agent Addr = ip_address() Port = integer() Type = pdu | trap | report | inform SnmpInfo = SnmpPduInfo | SnmpTrapInfo | SnmpReportInfo | SnmpInformInfo ErrorStatus = atom() ErrorIndex = integer() Varbinds = [varbind()] varbind() = #varbind UserData = term() Reply = ignore | {register, UserId, TargetName, agent_info()} UserId = term() TargetName = target_name() agent_info() = [{agent_info_item(), agent_info_value()}]

This function is called when a message is received from an unknown agent.

Note that this will always be the default user that is called.

For more info about the agent_info(), see register_agent.

The arguments Type and SnmpInfo relates in the following way:

pdu - SnmpPduInfo (see handle_pdu for more info).

trap - SnmpTrapInfo (see handle_trap for more info).

report - SnmpReportInfo (see handle_report for more info).

inform - SnmpInformInfo (see handle_inform for more info).

The only user which would return {register, UserId, TargetName, agent_info()} is the default user.

 handle_pdu(TargetName, ReqId, SnmpPduInfo, UserData) -> Reply Handle the reply to an asynchronous request TargetName = target_name() ReqId = term() SnmpPduInfo = {ErrorStatus, ErrorIndex, Varbinds} ErrorStatus = atom() ErrorIndex = integer() Varbinds = [varbind()] varbind() = #varbind UserData = term() Reply = ignore

Handle the reply to an asynchronous request, such as async_get, async_get_next or async_set.

It could also be a late reply to a synchronous request.

ReqId is returned by the asynchronous request function.

 handle_trap(TargetName, SnmpTrapInfo, UserData) -> Reply Handle a trap/notification message TargetName = TargetName2 = target_name() SnmpTrapInfo = {Enteprise, Generic, Spec, Timestamp, Varbinds} | {ErrorStatus, ErrorIndex, Varbinds} Enterprise = oid() Generic = integer() Spec = integer() Timestamp = integer() ErrorStatus = atom() ErrorIndex = integer() Varbinds = [varbind()] varbind() = #varbind UserData = term() Reply = ignore | unregister | {register, UserId, TargetName2, agent_info()} UserId = term() agent_info() = [{agent_info_item(), agent_info_value()}]

Handle a trap/notification message from an agent.

For more info about the agent_info(), see register_agent

The only user which would return {register, UserId, TargetName2, agent_info()} is the default user.

 handle_inform(TargetName, SnmpInformInfo, UserData) -> Reply Handle a inform message TargetName = TargetName2 = target_name() SnmpInformInfo = {ErrorStatus, ErrorIndex, Varbinds} ErrorStatus = atom() ErrorIndex = integer() Varbinds = [varbind()] varbind() = #varbind UserData = term() Reply = ignore | unregister | {register, UserId, TargetName2, agent_info()} UserId = term() agent_info() = [{agent_info_item(), agent_info_value()}]

Handle a inform message.

For more info about the agent_info(), see register_agent

The only user which would return {register, UserId, TargetName2, agent_info()} is the default user.

If the inform request behaviour configuration option is set to user or {user, integer()}, the response (acknowledgment) to this inform-request will be sent when this function returns.

 handle_report(TargetName, SnmpReportInfo, UserData) -> Reply Handle a report message TargetName = TargetName2 = target_name() Addr = ip_address() Port = integer() SnmpReportInfo = {ErrorStatus, ErrorIndex, Varbinds} ErrorStatus = atom() ErrorIndex = integer() Varbinds = [varbind()] varbind() = #varbind UserData = term() Reply = ignore | unregister | {register, UserId, TargetName2, agent_info()} UserId = term() agent_info() = [{agent_info_item(), agent_info_value()}]

Handle a report message.

For more info about the agent_info(), see register_agent

The only user which would return {register, UserId, TargetName2, agent_info()} is the default user.