Message Processing and Dispatch module for the SNMP agent
The module snmpa_mpd
implements the version independent
Message Processing and Dispatch functionality in SNMP for the agent.
It is supposed to be used from a Network Interface process
(Definition of Agent Net if).
DATA TYPES
See the
data types in snmpa_conf
.
Functions
Vsns = [Vsn]
Vsn = v1 | v2 | v3
This function can be called from the net_if process at start-up. The options list defines which versions to use.
It also initializes some SNMP counters.
Packet = binary()
From = {TDomain, TAddr}
TDomain = transportDomainUdpIpv4 | transportDomainUdpIpv6
TAddr = {IpAddr, IpPort}
LocalEngineID = string()
IpAddr = inet:ip_address()
IpPort = inet:port_number()
State = mpd_state()
NoteStore = pid()
Log = snmp_log()
Vsn = 'version-1' | 'version-2' | 'version-3'
Pdu = #pdu
PduMs = integer()
ACMData = acm_data()
Reason = term()
DiscoPacket = binary()
Processes an incoming packet. Performs authentication and decryption as necessary. The return values should be passed to the agent.
Note!
Note that the use of the LocalEngineID argument is only intended
for special cases, if the agent is to "emulate" multiple EngineIDs!
By default, the agent uses the value of SnmpEngineID
(see SNMP-FRAMEWORK-MIB).
Vsn = 'version-1' | 'version-2' | 'version-3'
RePdu = #pdu
Type = atom()
ACMData = acm_data()
LocalEngineID = string()
Packet = binary()
Generates a possibly encrypted response packet to be sent to the
network. Type
is the #pdu.type
of the original
request.
Note!
Note that the use of the LocalEngineID argument is only intended
for special cases, if the agent is to "emulate" multiple EngineIDs!
By default, the agent uses the value of SnmpEngineID
(see SNMP-FRAMEWORK-MIB).
Vsn = 'version-1' | 'version-2' | 'version-3'
NoteStore = pid()
Pdu = #pdu
MsgData = msg_data()
LocalEngineID = string()
To = [dest_addrs()]
PacketsAndAddresses = [{TDomain, TAddress, Packet}]
TDomain = snmpUDPDomain
TAddress = {Ip, Udp}
Ip = {integer(), integer(), integer(), integer()}
Udp = integer()
Packet = binary()
Generates a possibly encrypted request packet to be sent to the network.
MsgData
is the message specific data used in
the SNMP message. This value is received in a
send_pdu
or
send_pdu_req
message from the agent. In SNMPv1 and
SNMPv2c, this message data is the community string. In
SNMPv3, it is the context information.
To
is a list of destination addresses and
their corresponding security parameters. This value is
received in the same message from the agent and then transformed
trough process_taddrs
before passed to this function.
Note!
Note that the use of the LocalEngineID argument is only intended
for special cases, if the agent is to "emulate" multiple EngineIDs!
By default, the agent uses the value of SnmpEngineID
(see SNMP-FRAMEWORK-MIB).
TDests = [TDest]
TDest = {{TDomain, TAddr}, SecData} | {TDomain, TAddr}
TDomain = term() % Not at tuple
TAddr = term()
SecData = term()
Dests = [Dest]
Dest = {{Domain, Addr}, SecData} | {Domain, Addr}
Domain = transportDomain()
Addr = transportAddress() % Depends on Domain
Transforms addresses from internal MIB format to one more useful to Agent Net if.
See also generate_msg
.
Variable = atom()
Increments the variable associated with a discarded pdu.
This function can be used when the net_if process receives a
discarded_pdu
message from the agent.