1snmpm_network_interface_filtEerrl(a3n)g Module Definsintmipomn_network_interface_filter(3)
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NAME

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

10       This module defines the behaviour of the manager network interface fil‐
11       ter.  A snmpm_network_interface_filter compliant module must export the
12       following functions:
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14         * accept_recv/2
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16         * accept_send/2
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18         * accept_recv_pdu/3
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20         * accept_send_pdu/2
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22       The semantics of them and their exact signatures are explained below.
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24       The purpose of the network interface filter is to allow  for  filtering
25       of  messages  (accept  or reject) receive and send. This is done on two
26       levels:
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28         * The first level is at the UDP entry / exit point, i.e.  immediately
29           after  the receipt of the message, before any message processing is
30           done (accept_recv) and immediately before sending the message,  af‐
31           ter all message processing is done (accept_send).
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33         * The second level is at the MPD entry / exit point, i.e. immediately
34           after the basic message processing (accept_recv_pdu) /  immediately
35           before the basic message processing (accept_send_pdu).
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37       Note  that  the  network interface filter is something which is used by
38       the network interface implementation provided by the  application  (sn‐
39       mpm_net_if  and  snmpm_net_if_mt).  The default filter accepts all mes‐
40       sages.
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42       A network interface filter can e.g. be used during testing or for  load
43       regulation.
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45       Legacy  network  interface  filter  modules  used arguments on the form
46       (IpAddr, PortNumber,...) instead of (Domain, Addr,  ...),  and  if  the
47       SNMP manager is run without changing the configuration to use transport
48       domains the network interface filter will still get the  old  arguments
49       and work as before.
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DATA TYPES

52       port() = integer() > 0
53       pdu_type() = 'get-request' | 'get-next-request' | 'get-response' |
54                    'set-request' | trap | 'get-bulk-request' | 'inform-request' |
55                    report | trappdu
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57
58       See also the  data types in snmpa_conf.
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EXPORTS

61       accept_recv(Domain, Addr) -> boolean()
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63              Types:
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65                 Domain = transportDomain()
66                 Addr = transportAddressWithPort()
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68              Called  at the reception of a message (before any processing has
69              been done).
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71              For the message to be rejected, the function must return false.
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73       accept_send(Domain, Addr) -> boolean()
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75              Types:
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77                 Domain = transportDomain()
78                 Addr = transportAddressWithPort()
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80              Called before the sending of a message (after all processing has
81              been done).
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83              For the message to be rejected, the function must return false.
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85       accept_recv_pdu(Domain, Addr, PduType) -> boolean()
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87              Types:
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89                 Domain = transportDomain()
90                 Addr = transportAddressWithPort()
91                 PduType = pdu_type()
92
93              Called  after  the basic message processing (MPD) has been done,
94              but before the pdu is handed over to the server for primary pro‐
95              cessing.
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97              For the pdu to be rejected, the function must return false.
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99       accept_send_pdu(Domain, Addr, PduType) -> boolean()
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101              Types:
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103                 Domain = transportDomain()
104                 Addr = transportAddressWithPort()
105                 PduType = pdu_type() > 0
106
107              Called before the basic message processing (MPD) is done, when a
108              pdu has been received from the master-agent.
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110              For the message to be rejected, the function must return false.
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114Ericsson AB                       snmp 5.13.3snmpm_network_interface_filter(3)