1snmpa_mpd(3)               Erlang Module Definition               snmpa_mpd(3)
2
3
4

NAME

6       snmpa_mpd - Message Processing and Dispatch module for the SNMP agent
7

DESCRIPTION

9       The  module  snmpa_mpd  implements the version independent Message Pro‐
10       cessing and Dispatch functionality in SNMP for the agent.  It  is  sup‐
11       posed  to be used from a Network Interface process (Definition of Agent
12       Net if).
13

DATA TYPES

15       See the  data types in snmpa_conf.
16

EXPORTS

18       init(Vsns) -> mpd_state()
19
20              Types:
21
22                 Vsns = [Vsn]
23                 Vsn = v1 | v2 | v3
24
25              This function can be called from the net_if process at start-up.
26              The options list defines which versions to use.
27
28              It also initializes some SNMP counters.
29
30       process_packet(Packet,  From,  State, NoteStore, Log) -> {ok, Vsn, Pdu,
31       PduMS, ACMData} | {discarded, Reason} | {discovery, DiscoPacket}
32       process_packet(Packet, From, LocalEngineID, State, NoteStore,  Log)  ->
33       {ok, Vsn, Pdu, PduMS, ACMData} | {discarded, Reason} | {discovery, Dis‐
34       coPacket}
35
36              Types:
37
38                 Packet = binary()
39                 From = {TDomain, TAddr}
40                 TDomain = transportDomainUdpIpv4 | transportDomainUdpIpv6
41                 TAddr = {IpAddr, IpPort}
42                 LocalEngineID = string()
43                 IpAddr = inet:ip_address()
44                 IpPort = inet:port_number()
45                 State = mpd_state()
46                 NoteStore = pid()
47                 Log = snmp_log()
48                 Vsn = 'version-1' | 'version-2' | 'version-3'
49                 Pdu = #pdu
50                 PduMs = integer()
51                 ACMData = acm_data()
52                 Reason = term()
53                 DiscoPacket = binary()
54
55              Processes  an  incoming  packet.  Performs  authentication   and
56              decryption  as  necessary. The return values should be passed to
57              the agent.
58
59          Note:
60              Note that the use of the LocalEngineID argument is only intended
61              for  special  cases,  if  the  agent  is  to  "emulate" multiple
62              EngineIDs! By default, the agent uses the value of  SnmpEngineID
63              (see SNMP-FRAMEWORK-MIB).
64
65
66       generate_response_msg(Vsn, RePdu, Type, ACMData, Log) -> {ok, Packet} |
67       {discarded, Reason}
68       generate_response_msg(Vsn, RePdu, Type, ACMData, LocalEngineID, Log) ->
69       {ok, Packet} | {discarded, Reason}
70
71              Types:
72
73                 Vsn = 'version-1' | 'version-2' | 'version-3'
74                 RePdu = #pdu
75                 Type = atom()
76                 ACMData = acm_data()
77                 LocalEngineID = string()
78                 Packet = binary()
79
80              Generates a possibly encrypted response packet to be sent to the
81              network. Type is the #pdu.type of the original request.
82
83          Note:
84              Note that the use of the LocalEngineID argument is only intended
85              for  special  cases,  if  the  agent  is  to  "emulate" multiple
86              EngineIDs! By default, the agent uses the value of  SnmpEngineID
87              (see SNMP-FRAMEWORK-MIB).
88
89
90       generate_msg(Vsn,  NoteStore,  Pdu,  MsgData, To) -> {ok, PacketsAndAd‐
91       dresses} | {discarded, Reason}
92       generate_msg(Vsn, NoteStore, Pdu, MsgData, LocalEngineID, To)  ->  {ok,
93       PacketsAndAddresses} | {discarded, Reason}
94
95              Types:
96
97                 Vsn = 'version-1' | 'version-2' | 'version-3'
98                 NoteStore = pid()
99                 Pdu = #pdu
100                 MsgData = msg_data()
101                 LocalEngineID = string()
102                 To = [dest_addrs()]
103                 PacketsAndAddresses = [{TDomain, TAddress, Packet}]
104                 TDomain = snmpUDPDomain
105                 TAddress = {Ip, Udp}
106                 Ip = {integer(), integer(), integer(), integer()}
107                 Udp = integer()
108                 Packet = binary()
109
110              Generates  a possibly encrypted request packet to be sent to the
111              network.
112
113              MsgData is the message specific data used in the  SNMP  message.
114              This  value  is  received  in a send_pdu or send_pdu_req message
115              from the agent. In SNMPv1 and SNMPv2c, this message data is  the
116              community string. In SNMPv3, it is the context information.
117
118              To  is  a  list of destination addresses and their corresponding
119              security parameters. This value is received in the same  message
120              from the agent and then transformed trough process_taddrs before
121              passed to this function.
122
123          Note:
124              Note that the use of the LocalEngineID argument is only intended
125              for  special  cases,  if  the  agent  is  to  "emulate" multiple
126              EngineIDs! By default, the agent uses the value of  SnmpEngineID
127              (see SNMP-FRAMEWORK-MIB).
128
129
130       process_taddrs(TDests) -> Dests
131
132              Types:
133
134                 TDests = [TDest]
135                 TDest = {{TDomain, TAddr}, SecData} | {TDomain, TAddr}
136                 TDomain = term() % Not at tuple
137                 TAddr = term()
138                 SecData = term()
139                 Dests = [Dest]
140                 Dest = {{Domain, Addr}, SecData} | {Domain, Addr}
141                 Domain = transportDomain()
142                 Addr = transportAddress() % Depends on Domain
143
144              Transforms addresses from internal MIB format to one more useful
145              to Agent Net if.
146
147              See also generate_msg.
148
149       discarded_pdu(Variable) -> void()
150
151              Types:
152
153                 Variable = atom()
154
155              Increments the variable associated with a  discarded  pdu.  This
156              function  can  be  used  when the net_if process receives a dis‐
157              carded_pdu message from the agent.
158
159
160
161Ericsson AB                       snmp 5.2.12                     snmpa_mpd(3)