Class: SNMP::TrapListener

Inherits:
Object
  • Object
show all
Defined in:
lib/snmp/manager.rb

Overview

SNMP Trap Listener

Listens to a socket and processes received traps and informs in a separate thread.

Example

require 'snmp'

m = SNMP::TrapListener.new(:Port => 1062, :Community => 'public') do |manager|
  manager.on_trap_default { |trap| p trap }
end
m.join

Defined Under Namespace

Classes: Config

Constant Summary collapse

NULL_HANDLER =
Proc.new {}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}, &block) ⇒ TrapListener

Start a trap handler thread. If a block is provided then the block is executed before trap handling begins. This block is typically used to define the trap handler blocks.

The trap handler blocks execute in the context of the trap handler thread.

The most specific trap handler is executed when a trap arrives. Only one handler is executed. The handlers are checked in the following order:

  1. handler for a specific OID

  2. handler for a specific SNMP version

  3. default handler

The default for the :community option is 'nil' allows traps with any community to be accepted. To only accept traps from a specific community, the community may also be set to a string (e.g. 'public') or a list of strings (e.g. ['public', 'my_private_community'] ).



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# File 'lib/snmp/manager.rb', line 616

def initialize(options={}, &block)
  config = Config.new(options)
  @transport = config.create_transport
  @community = config.community
  @max_bytes = config.max_recv_bytes
  @mib = MIB.new
  load_modules(config.mib_modules, config.mib_dir)
  @config = config.applied_config

  @handler_init = block
  @oid_handler = {}
  @v1_handler = nil
  @v2c_handler = nil
  @default_handler = nil
  @lock = Mutex.new
  @handler_thread = Thread.new(self) { |m| process_traps(m) }
end

Instance Attribute Details

#configObject (readonly)

Retrieves the current configuration of this TrapListener.



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# File 'lib/snmp/manager.rb', line 595

def config
  @config
end

Instance Method Details

#exitObject Also known as: kill, terminate

Stops the trap handler thread and releases the socket.

See also Thread#exit.



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# File 'lib/snmp/manager.rb', line 688

def exit
  @handler_thread.exit
  @transport.close
end

#joinObject

Joins the current thread to the trap handler thread.

See also Thread#join.



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# File 'lib/snmp/manager.rb', line 679

def join
  @handler_thread.join
end

#on_trap(object_id, &block) ⇒ Object

Define a trap handler block for a specific trap ObjectId. This handler only applies to SNMPv2 traps. Note that symbolic OIDs are not supported by this method (like in the SNMP.Manager class).

Raises:

  • (ArgumentError)


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# File 'lib/snmp/manager.rb', line 649

def on_trap(object_id, &block)
  raise ArgumentError, "a block must be provided" unless block
  @lock.synchronize { @oid_handler[ObjectId.new(object_id)] = block }
end

#on_trap_default(&block) ⇒ Object

Define the default trap handler. The default trap handler block is executed only if no other block is applicable. This handler should expect to receive both SNMPv1_Trap and SNMPv2_Trap objects.

Raises:

  • (ArgumentError)


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# File 'lib/snmp/manager.rb', line 639

def on_trap_default(&block)
  raise ArgumentError, "a block must be provided" unless block
  @lock.synchronize { @default_handler = block }
end

#on_trap_v1(&block) ⇒ Object

Define a trap handler block for all SNMPv1 traps. The trap yielded to the block will always be an SNMPv1_Trap.

Raises:

  • (ArgumentError)


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# File 'lib/snmp/manager.rb', line 658

def on_trap_v1(&block)
  raise ArgumentError, "a block must be provided" unless block
  @lock.synchronize { @v1_handler = block }
end

#on_trap_v2c(&block) ⇒ Object

Define a trap handler block for all SNMPv2c traps. The trap yielded to the block will always be an SNMPv2_Trap. Note that InformRequest is a subclass of SNMPv2_Trap, so inform PDUs are also received by this handler.

Raises:

  • (ArgumentError)


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# File 'lib/snmp/manager.rb', line 669

def on_trap_v2c(&block)
  raise ArgumentError, "a block must be provided" unless block
  @lock.synchronize { @v2c_handler = block }
end