Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help 
agent(3)	       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 daemon.

     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 argu-
     ments: $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>

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

perl v5.42.3			   2025-12-23				agent(3)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=NetSNMP::agent&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>

home | help