snmpm_network_interface_filter(3erl)			     Erlang Module Definition			      snmpm_network_interface_filter(3erl)

NAME

       snmpm_network_interface_filter - Behaviour module for the SNMP manager network-interface filter.

DESCRIPTION

       This  module  defines  the behaviour of the manager network interface filter. A snmpm_network_interface_filter compliant module must export
       the following functions:

	 * accept_recv/2

	 * accept_send/2

	 * accept_recv_pdu/3

	 * accept_send_pdu/2

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

       The purpose of the network interface filter is to allow for filtering of messages (accept or reject) receive and send. This is done on  two
       levels:

	 * The	first  level is at the UDP entry / exit point, i.e. immediately after the receipt of the message, before any message processing is
	   done (accept_recv) and immediately before sending the message, after all message processing is done (accept_send).

	 * The second level is at the MPD entry / exit point, i.e. immediately after the basic message processing (accept_recv_pdu) /  immediately
	   before the basic message processing (accept_send_pdu).

       Note  that  the	network  interface filter is something which is used by the network interface implementation provided by the application (
       snmpm_net_if ). The default filter accepts all messages.

       A network interface filter can e.g. be used during testing or for load regulation.

DATA TYPES

       port() = integer() > 0
       pdu_type() = 'get-request' | 'get-next-request' | 'get-response' | 'set-request' | trap | 'get-bulk-request' | 'inform-request' | report | trappdu

EXPORTS

       accept_recv(Addr, Port) -> boolean()

	      Types  Addr = ip_address()
		     Port = port()

	      Called at the reception of a message (before any processing has been done).

	      For the message to be rejected, the function must return false .

       accept_send(Addr, Port) -> boolean()

	      Types  Addr = ip_address()
		     Port = port()

	      Called before the sending of a message (after all processing has been done).

	      For the message to be rejected, the function must return false .

       accept_recv_pdu(Addr, Port, PduType) -> boolean()

	      Types  Addr = ip_address()
		     Port = port()
		     PduType = pdu_type()

	      Called after the basic message processing (MPD) has been done, but before the pdu is handed over to the server for primary  process-
	      ing.

	      For the pdu to be rejected, the function must return false .

       accept_send_pdu(Addr, Port, PduType) -> boolean()

	      Types  Addr = ip_address()
		     Port = port()
		     PduType = pdu_type() > 0

	      Called before the basic message processing (MPD) is done, when a pdu has been received from the master-agent.

	      For the message to be rejected, the function must return false .

Ericsson AB							     snmp 4.19				      snmpm_network_interface_filter(3erl)