NAME

       snmpm_user - Behaviour module for the SNMP manager user.

DESCRIPTION

       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

         * handle_invalid_result/2

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

       Some of the function has no defined return value (void()), they can ofcourse  return  anythyng.  But  the
       functions  that do have specified return value(s) must adhere to this. None of the functions can use exit
       of throw to return.

DATA TYPES

       snmp_gen_info() = {ErrorStatus :: atom(),
                          ErrorIndex  :: pos_integer(),
                          Varbinds    :: [snmp:varbind()]}
       snmp_v1_trap_info() :: {Enteprise :: snmp:oid(),
                               Generic   :: integer(),
                               Spec      :: integer(),
                               Timestamp :: integer(),
                               Varbinds  :: [snmp:varbind()]}

EXPORTS

       handle_error(ReqId, Reason, UserData) -> void()

              Types:

                 ReqId = integer()
                 Reason = {unexpected_pdu, SnmpInfo} | {invalid_sec_info, SecInfo, SnmpInfo}  |  {empty_message,
                 Addr, Port} | term()
                 SnmpInfo = snmp_gen_info()
                 SecInfo = term()
                 Addr = ip_address()
                 Port = integer()
                 UserData = term()

              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

              Types:

                 Addr = ip_address()
                 Port = integer()
                 Type = pdu | trap | report | inform
                 SnmpInfo = SnmpPduInfo | SnmpTrapInfo | SnmpReportInfo | SnmpInformInfo
                 SnmpPduInfo = snmp_gen_info()
                 SnmpTrapInfo = snmp_v1_trap_info()
                 SnmpReportInfo = snmp_gen_info()
                 SnmpInformInfo = snmp_gen_info()
                 UserData = term()
                 Reply = ignore | {register, UserId, TargetName, AgentConfig}
                 UserId = term()
                 TargetName = target_name()
                 AgentConfig = [agent_config()]

              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_config(), 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, AgentConfig} is the default user.

       handle_pdu(TargetName, ReqId, SnmpPduInfo, UserData) -> void()

              Types:

                 TargetName = target_name()
                 ReqId = term()
                 SnmpPduInfo = snmp_gen_info()
                 UserData = term()

              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

              Types:

                 TargetName = TargetName2 = target_name()
                 SnmpTrapInfo = snmp_v1_trap_info() | snmp_gen_info()
                 UserData = term()
                 Reply = ignore | unregister | {register, UserId, TargetName2, AgentConfig}
                 UserId = term()
                 AgentConfig = [agent_config()]

              Handle a trap/notification message from an agent.

              For more info about the agent_config(), see register_agent

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

       handle_inform(TargetName, SnmpInformInfo, UserData) -> Reply

              Types:

                 TargetName = TargetName2 = target_name()
                 SnmpInformInfo = snmp_gen_info()
                 UserData = term()
                 Reply = ignore | no_reply | unregister | {register, UserId, TargetName2, AgentConfig}
                 UserId = term()
                 AgentConfig = [agent_config()]

              Handle a inform message.

              For more info about the agent_config(), see register_agent

              The only user which would return {register, UserId, TargetName2, AgentConfig} 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

              Types:

                 TargetName = TargetName2 = target_name()
                 Addr = ip_address()
                 Port = integer()
                 SnmpReportInfo = snmp_gen_info()
                 UserData = term()
                 Reply = ignore | unregister | {register, UserId, TargetName2, AgentConfig}
                 UserId = term()
                 AgentConfig = [agent_config()]

              Handle a report message.

              For more info about the agent_config(), see register_agent

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

       handle_invalid_result(IN, OUT) -> void()

              Types:

                 IN = {Func, Args}
                 Func = atom()
                 Args = list()
                 OUT = {crash, CrashInfo} | {result, InvalidResult}
                 CrashInfo = {ErrorType, Error, Stacktrace}
                 ErrorType = atom()
                 Error = term()
                 Stacktrace = list()
                 InvalidResult = term()

              If any of the other callback functions crashes (exit, throw or a plain crash) or return an invalid
              result  (if  a  valid return has been specified), this function is called. The purpose is to allow
              the user handle this error (for instance to issue an error report).

              IN reprecents the function called (and  its  arguments).  OUT  represents  the  unexpected/invalid
              result.

Ericsson AB                                         snmp 4.25                                   snmpm_user(3erl)