Class: LogStash::Codecs::Sflow

Inherits:
Base
  • Object
show all
Defined in:
lib/logstash/codecs/sflow.rb

Overview

The “sflow” codec is for decoding sflow v5 flows.

Instance Method Summary collapse

Constructor Details

#initialize(params = {}) ⇒ Sflow

Returns a new instance of Sflow.



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# File 'lib/logstash/codecs/sflow.rb', line 31

def initialize(params = {})
  super(params)
  @threadsafe = false
end

Instance Method Details

#assign_key_value(event, bindata_kv) ⇒ Object

def initialize



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# File 'lib/logstash/codecs/sflow.rb', line 38

def assign_key_value(event, bindata_kv)
  inspection_queue = [bindata_kv]

  while !inspection_queue.empty?
    kv = inspection_queue.shift()
    if kv.nil? || kv.to_s.eql?('')
      next
    end

    kv.each_pair do |k, v|
      if v.is_a?(BinData::Choice)
        inspection_queue.push(v)
      elsif !@removed_field.include?(k.to_s) && !v.is_a?(BinData::Array)
        event.set("#{k.to_s}", v.to_s)
      end
    end
  end
end

#common_sflow(event, decoded, sample) ⇒ Object

Parameters:

  • event (Object)
  • decoded (Object)
  • sample (Object)
  • record (Object) 


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# File 'lib/logstash/codecs/sflow.rb', line 61

def common_sflow(event, decoded, sample)
  event.set('agent_ip', decoded['agent_ip'].to_s)
  assign_key_value(event, decoded)
  assign_key_value(event, sample)
end

#decode(payload) ⇒ Object 



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# File 'lib/logstash/codecs/sflow.rb', line 103

def decode(payload)
  header = SFlowHeader.read(payload)
  unless @versions.include?(header.sflow_version)
    @logger.warn("Ignoring Sflow version v#{header.sflow_version}")
    return
  end

  decoded = SFlow.read(payload)

  events = []

  decoded['samples'].each do |sample|
    @logger.debug("sample: #{sample}")
    #Treat case with no flow decoded (Unknown flow)
    if sample['sample_data'].to_s.eql? ''
      @logger.warn("Unknown sample entreprise #{sample['sample_entreprise'].to_s} - format #{sample['sample_format'].to_s}")
      next
    end

    #treat sample flow and expanded sample flow
    if sample['sample_entreprise'] == 0 && (sample['sample_format'] == 1 || sample['sample_format'] == 3)
      # Create the logstash event
      event = LogStash::Event.new({})

      common_sflow(event, decoded, sample)

      sample['sample_data']['records'].each do |record|
        # Ensure that some data exist for the record
        if record['record_data'].to_s.eql? ''
          @logger.warn("Unknown sample_flow record: entreprise #{record['record_entreprise'].to_s}, format #{record['record_format'].to_s}")
          next
        end

        assign_key_value(event, record)

      end
      #compute frame_length_times_sampling_rate
      if event.include?('frame_length') and event.include?('sampling_rate')
        event.set('frame_length_times_sampling_rate', event.get('frame_length').to_i * event.get('sampling_rate').to_i)
      end

      if sample['sample_format'] == 1
        event.set('sflow_type', 'flow_sample')
      else
        event.set('sflow_type', 'expanded_flow_sample')
      end

      #Get interface dfescr if snmp_interface true
      snmp_call(event)

      events.push(event)

    #treat counter flow and expanded counter flow
    elsif sample['sample_entreprise'] == 0 && (sample['sample_format'] == 2 || sample['sample_format'] == 4)
      sample['sample_data']['records'].each do |record|
        # Ensure that some data exist for the record
        if record['record_data'].to_s.eql? ''
          @logger.warn("Unknown counter_flow record: entreprise #{record['record_entreprise'].to_s}, format #{record['record_format'].to_s}")
          next
        end

        # Create the logstash event
        event = LogStash::Event.new({})
        common_sflow(event, decoded, sample)

        assign_key_value(event, record)

        if sample['sample_format'] == 2
          event.set('sflow_type', 'counter_sample')
        else
          event.set('sflow_type', 'expanded_counter_sample')
        end


        #Get interface dfescr if snmp_interface true
        snmp_call(event)

        events.push(event)
      end
    end
  end

  events.each do |event|
    yield event
  end
rescue BinData::ValidityError, EOFError, IOError, RangeError => e
  @logger.warn("Invalid sflow packet received (#{e})")
#    Sflow.instance_variables.each { |ivar| puts "#{ivar}: #{Sflow.instance_variable_get(ivar)}" }
end

#register ⇒ Object 



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# File 'lib/logstash/codecs/sflow.rb', line 87

def register
  require 'logstash/codecs/sflow/datagram'
  require 'logstash/codecs/snmp/interface_resolver'

  # noinspection RubyResolve
  @removed_field = %w(record_length record_count record_entreprise record_format sample_entreprise sample_format
 sample_length sample_count sample_header data storage) | @optional_removed_field

  if @snmp_interface
    @snmp = SNMPInterfaceResolver.new(@snmp_community, @interface_cache_size, @interface_cache_ttl, @logger)
  end
end

#snmp_call(event) ⇒ Object 



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# File 'lib/logstash/codecs/sflow.rb', line 67

def snmp_call(event)
  if @snmp_interface
    if event.include?('source_id_type') and event.get('source_id_type').to_s == '0'
      if event.include?('source_id_index')
        event.set('source_id_index_descr', @snmp.get_interface(event.get('agent_ip'), event.get('source_id_index')))
      end
      if event.include?('input_interface')
        event.set('input_interface_descr', @snmp.get_interface(event.get('agent_ip'), event.get('input_interface')))
      end
      if event.include?('output_interface')
        event.set('output_interface_descr', @snmp.get_interface(event.get('agent_ip'), event.get('output_interface')))
      end
      if event.include?('interface_index')
        event.set('interface_index_descr', @snmp.get_interface(event.get('agent_ip'), event.get('interface_index')))
      end
    end
  end
end