Class: PacketGen::Header::SNMP

Inherits:

ASN1Base

• Object
• RASN1::Model
• ASN1Base
• PacketGen::Header::SNMP

Defined in:

lib/packetgen/header/snmp.rb

Overview

Simple Network Management Protocol (SNMP)

See github.com/sdaubert/packetgen/wiki/SNMP

Author:

• Sylvain Daubert

Since:

• 2.0.0

Defined Under Namespace

Classes: Bulk, GetNextRequest, GetRequest, GetResponse, InformRequest, PDUs, Report, SetRequest, Trapv1, Trapv2, VarBind, VariableBindings

Constant Summary

UDP_PORT1 =

Agents listen to this port

Since:

• 2.0.0

161

UDP_PORT2 =

Configuration sinks listen to this port

Since:

• 2.0.0

162

PDU_GET =

rubocop:disable Naming/ConstantName

Since:

• 2.0.0

0

PDU_NEXT =

Since:

• 2.0.0

1

PDU_RESPONSE =

Since:

• 2.0.0

2

PDU_SET =

Since:

• 2.0.0

3

PDU_TRAPv1 =

Since:

• 2.0.0

4

PDU_BULK =

Since:

• 2.0.0

5

PDU_INFORM =

Since:

• 2.0.0

6

PDU_TRAPv2 =

Since:

• 2.0.0

7

PDU_REPORT =

Since:

• 2.0.0

8

ERRORS =

rubocop:enable Naming/ConstantName

Since:

• 2.0.0

{
  'no_error' => 0,
  'too_big' => 1,
  'no_such_name' => 2,
  'bad_value' => 3,
  'read_only' => 4,
  'generic_error' => 5,
  'no_access' => 6,
  'wrong_type' => 7,
  'wrong_length' => 8,
  'wrong_encoding' => 9,
  'wrong_value' => 10,
  'no_creation' => 11,
  'inconsistent_value' => 12,
  'ressource_unavailable' => 13,
  'commit_failed' => 14,
  'undo_failed' => 15,
  'authorization_error' => 16,
  'not_writable' => 17,
  'inconsistent_name' => 18
}.freeze

Instance Method Summary

• #added_to_packet(packet) ⇒ void private
• #data ⇒ GetRequest

  accessor to data payload.

• #initialize(options = {}) ⇒ SNMP constructor

  A new instance of SNMP.

• #inspect ⇒ Object
• #pdu ⇒ GetRequest, ...

  shortcut to PDU.

Methods inherited from ASN1Base

define_attributes, known_headers, #read

Methods included from PacketGen::Headerable

included, #method_name, #packet, #packet=, #parse?, #protocol_name, #read

Constructor Details

#initialize(options = {}) ⇒ SNMP

Returns a new instance of SNMP.

Parameters:

• options (Hash) (defaults to: {})

Options Hash (options):

• :version (Integer, String)
• :community (String)
• :chosen_pdu (Integer) —

  Set PDU type

• :pdu (Hash) —

  Set PDU content

Since:

• 2.0.0

# File 'lib/packetgen/header/snmp.rb', line 262

def initialize(options={})
  super
  data.chosen = options[:chosen_pdu] if options[:chosen_pdu]
  return unless options[:pdu]

  data.root.value[data.chosen] = data.root.chosen_value.class.new(options[:pdu])
end

Instance Method Details

#added_to_packet(packet) ⇒ void

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Note:

This method is used internally by PacketGen and should not be directly called

This method returns an undefined value.

Parameters:

• packet (Packet)

Since:

• 2.7.0 Set UDP sport according to bindings, only if sport is 0. Needed by new bind API.

# File 'lib/packetgen/header/snmp.rb', line 303

def added_to_packet(packet)
  return unless packet.is? 'UDP'
  return unless packet.udp.sport.zero?

  packet.udp.sport = packet.udp.dport
end

#data ⇒ GetRequest

accessor to data payload

Returns:

• (GetRequest)

Since:

• 2.0.0

# File 'lib/packetgen/header/snmp.rb', line 272

def data
  @elements[:data]
end

#inspect ⇒ Object

Since:

• 2.0.0

# File 'lib/packetgen/header/snmp.rb', line 286

def inspect
  str = super
  str << Inspect.shift_level
  str << if self[:data].chosen.nil?
           Inspect::FMT_ATTR % [self[:data].type, :data, '']
         else
           inspect_data
         end
end

#pdu ⇒ GetRequest, ...

shortcut to PDU

Returns:

• (GetRequest, Bulk, Trapv1, nil) —

  return `nil` if no CHOICE was done

Since:

• 2.0.0

# File 'lib/packetgen/header/snmp.rb', line 278

def pdu
  if data.chosen.nil?
    nil
  else
    data.root.chosen_value
  end
end