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Updated: Wednesday, July 27, 2022
 
 

NetSNMP::agent (3)

Name

NetSNMP::agent - snmp agent.

Synopsis

use NetSNMP::agent;

my $agent = new NetSNMP::agent('Name' => 'my_agent_name');

Description

User Contributed Perl Documentation                                   agent(3)



NAME
       NetSNMP::agent - Perl extension for the net-snmp agent.

SYNOPSIS
         use NetSNMP::agent;

         my $agent = new NetSNMP::agent('Name' => 'my_agent_name');

DESCRIPTION
       This module implements an API set to make a SNMP agent act as a snmp
       agent, a snmp subagent (using the AgentX subagent protocol) and/or
       embedded perl-APIs directly within the traditional net-snmp agent
       demon.

       Also see the tutorial about the genaral Net-SNMP C API, which this
       module implements in a perl-way, and a perl specific tutorial at:

         http://www.net-snmp.org/tutorial-5/toolkit/

EXAMPLES
   Sub-agent example
               use NetSNMP::agent (':all');
               use NetSNMP::ASN qw(ASN_OCTET_STR);

               my $value = "hello world";
               sub myhandler {
                   my ($handler, $registration_info, $request_info, $requests) = @_;
                   my $request;

                   for($request = $requests; $request; $request = $request->next()) {
                       my $oid = $request->getOID();
                       if ($request_info->getMode() == MODE_GET) {
                           # ... generally, you would calculate value from oid
                           if ($oid == new NetSNMP::OID(".1.3.6.1.4.1.8072.9999.9999.7375.1.0")) {
                               $request->setValue(ASN_OCTET_STR, $value);
                           }
                       } elsif ($request_info->getMode() == MODE_GETNEXT) {
                           # ... generally, you would calculate value from oid
                           if ($oid < new NetSNMP::OID(".1.3.6.1.4.1.8072.9999.9999.7375.1.0")) {
                               $request->setOID(".1.3.6.1.4.1.8072.9999.9999.7375.1.0");
                               $request->setValue(ASN_OCTET_STR, $value);
                           }
                       } elsif ($request_info->getMode() == MODE_SET_RESERVE1) {
                           if ($oid != new NetSNMP::OID(".1.3.6.1.4.1.8072.9999.9999.7375.1.0")) {  # do error checking here
                               $request->setError($request_info, SNMP_ERR_NOSUCHNAME);
                           }
                       } elsif ($request_info->getMode() == MODE_SET_ACTION) {
                           # ... (or use the value)
                           $value = $request->getValue();
                       }
                   }

               }

               my $agent = new NetSNMP::agent(
                                       # makes the agent read a my_agent_name.conf file
                                       'Name' => "my_agent_name",
                                       'AgentX' => 1
                                       );
               $agent->register("my_agent_name", ".1.3.6.1.4.1.8072.9999.9999.7375",
                                \&myhandler);

               my $running = 1;
               while($running) {
                       $agent->agent_check_and_process(1);
               }

               $agent->shutdown();

   Embedded agent example
               # place this in a .pl file, and then in your snmpd.conf file put:
               #    perl do '/path/to/file.pl';

               use NetSNMP::agent;
               my $agent;

               sub myhandler {
                   my ($handler, $registration_info, $request_info, $requests) = @_;
                   # ...
               }

               $agent = new NetSNMP::agent(
                                       'Name' => 'my_agent_name'
                                       );

               $agent->register("my_agent_name", ".1.3.6.1.4.1.8072.9999.9999.7375",
                                \&myhandler);

               $agent->main_loop();

CONSTRUCTOR
           new ( OPTIONS )
               This is the constructor for a new NetSNMP::agent object.

           Possible options are:

               Name    - Name of the agent (optional, defaults to "perl")
                         (The snmp library will read a NAME.conf snmp
                         configuration file based on this argument.)
               AgentX  - Make us a sub-agent (0 = false, 1 = true)
                         (The Net-SNMP master agent must be running first)
               Ports   - Ports this agent will listen on (EG: "udp:161,tcp:161")

           Example:

               $agent = new NetSNMP::agent(
                                        'Name' => 'my_agent_name',
                                        'AgentX' => 1
                                        );

METHODS
           register (NAME, OID, \&handler_routine )
               Registers the callback handler with given OID.

               $agent->register();

               A return code of 0 indicates no error.

           agent_check_and_process ( BLOCKING )
               Run one iteration of the main loop.

               BLOCKING - Blocking or non-blocking call. 1 = true, 0 = false.

               $agent->agent_check_and_process(1);

           main_loop ()
               Runs the agent in a loop. Does not return.

           shutdown ()
               Nicely shuts down the agent or sub-agent.

               $agent->shutdown();

HANDLER CALLBACKS
           handler ( HANDLER, REGISTRATION_INFO, REQUEST_INFO, REQUESTS )

               The handler is called with the following parameters:

               HANDLER                 - FIXME
               REGISTRATION_INFO       - what are the correct meanings of these?
               REQUEST_INFO            -
               REQUESTS                -

           Example handler:

               sub myhandler {
                   my ($handler, $reg_info, $request_info, $requests) = @_;
                   # ...
               }

       The handler subroutine will be called when a SNMP request received by
       the agent for anything below the registered OID.  The handler is passed
       4 arguments: $handler, $registration_info, $request_info, $requests.
       These match the arguments passed to the C version of the same API.
       Note that they are not entirely complete objects but are functional
       "enough" at this point in time.

   $request_info object functions
           getMode ()
               Returns the mode of the request. See the MODES section for
               list of valid modes.

               $mode = $request->getMode();

   $registration_info object functions
           getRootOID ()
               Returns a NetSNMP::OID object that describes the registration
               point that the handler is getting called for (in case you
               register one handler function with multiple OIDs, which should
               be rare anyway)

               $root_oid = $request->getRootOID();

   $request object functions
           next ()
               Returns the next request in the list or undef if there is no
               next request.

               $request = $request->next();

           getOID ()
               Returns the oid of the request (a NetSNMP::OID class).

               $oid = $request->getOID();

           setOID (new NetSNMP::OID("someoid"))
               Sets the OID of the request to a passed oid value.  This
               should generally only be done during handling of GETNEXT
               requests.

               $request->setOID(new NetSNMP::OID("someoid"));

           getValue ()
               Returns the value of the request. Used for example when
               setting values.

               $value = $request->getValue();

               FIXME: how to get the type of the value? Is it even available?
                      [Wes: no, not yet.]

           setValue ( TYPE, DATA )
               Sets the data to be returned to the daemon.

               Returns 1 on success, 0 on error.

               TYPE - Type of the data. See NetSNMP::ASN for valid types.
               DATA - The data to return.

               $ret = $request->setValue(ASN_OCTET_STR, "test");

           setError ( REQUEST_INFO, ERROR_CODE )
               Sets the given error code for the request. See the ERROR CODES
               section for list of valid codes.

               $request->setError($request_info, SNMP_ERR_NOTWRITABLE);

           getProcessed ()
               The processed flag indicates that a request does not need to
               be dealt with because someone else (a higher handler) has
               dealt with it already.

               $processed = $request->getProcessed();

           setProcessed ( PROCESSED )
               Sets the processed flag flag in the request.  You generally
               should not have to set this yourself.

               PROCESSED - 0 = false, 1 = true

               $request->setProcessed(1);

           getDelegated ()
               If you can handle a request in the background or at a future
               time (EG, you're waiting on a file handle, or network traffic,
               or ...), the delegated flag can be set in the request.  When
               the request is processed in the future the flag should be set
               back to 0 so the agent will know that it can wrap up the
               original request and send it back to the manager.  This has
               not been tested within perl, but it hopefully should work.

               $delegated = $request->getDelegated();

           setDelegated ( DELEGATED )
               Sets the delegated flag.

               DELEGATED - 0 = false, 1 = true

               $request->setDelegated(1);

           getRepeat ()
               The repeat flag indicates that a getbulk operation is being
               handled and this indicates how many answers need to be
               returned.  Generally, if you didn't register to directly
               handle getbulk support yourself, you won't need to deal with
               this value.

               $repeat = $request->getRepeat();

           setRepeat ( REPEAT )
               Sets the repeat count (decrement after answering requests if
               you handle getbulk requests yourself)

               REPEAT -  repeat count FIXME

               $request->setRepeat(5);

           getSourceIp ()

               Gets the IPv4 address of the device making the request to the handler.

               use Socket;
               print "Source: ", inet_ntoa($request->getSourceIp()), "\n";

           getDestIp ()

               Gets the IPv4 address of the destination that the request was sent to.

               use Socket;
               print "Destination: ", inet_ntoa($request->getDestIp()), "\n";

MODES
               MODE_GET
               MODE_GETBULK
               MODE_GETNEXT
               MODE_SET_ACTION
               MODE_SET_BEGIN
               MODE_SET_COMMIT
               MODE_SET_FREE
               MODE_SET_RESERVE1
               MODE_SET_RESERVE2
               MODE_SET_UNDO

ERROR CODES
               SNMP_ERR_NOERROR
               SNMP_ERR_TOOBIG
               SNMP_ERR_NOSUCHNAME
               SNMP_ERR_BADVALUE
               SNMP_ERR_READONLY
               SNMP_ERR_GENERR
               SNMP_ERR_NOACCESS
               SNMP_ERR_WRONGTYPE
               SNMP_ERR_WRONGLENGTH
               SNMP_ERR_WRONGENCODING
               SNMP_ERR_WRONGVALUE
               SNMP_ERR_NOCREATION
               SNMP_ERR_INCONSISTENTVALUE
               SNMP_ERR_RESOURCEUNAVAILABLE
               SNMP_ERR_COMMITFAILED
               SNMP_ERR_UNDOFAILED
               SNMP_ERR_AUTHORIZATIONERROR
               SNMP_ERR_NOTWRITABLE

AUTHOR
       Please mail the net-snmp-users@lists.sourceforge.net mailing list for
       help, questions or comments about this module.

       Module written by:
          Wes Hardaker  <hardaker@users.sourceforge.net>

       Documentation written by:
          Toni Willberg <toniw@iki.fi>
          Wes Hardaker  <hardaker@users.sourceforge.net>


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+---------------------------------+
       |ATTRIBUTE TYPE |        ATTRIBUTE VALUE          |
       +---------------+---------------------------------+
       |Availability   | system/management/snmp/net-snmp |
       +---------------+---------------------------------+
       |Stability      | Volatile                        |
       +---------------+---------------------------------+

SEE ALSO
       NetSNMP::OID(3), NetSNMP::ASN(3), perl(1).



NOTES
       Source code for open source software components in Oracle Solaris can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-
       code-downloads.html.

       This software was built from source available at
       https://github.com/oracle/solaris-userland.  The original community
       source was downloaded from  https://sourceforge.net/projects/net-
       snmp/files/net-snmp/5.8/net-snmp-5.8.tar.gz.

       Further information about this software can be found on the open source
       community website at http://www.net-snmp.org/.



perl v5.32.0                      2018-07-16                          agent(3)