MrtParser/main.rb

require_relative 'parser'

def parse_for_aspath(stream)
  contributors = []
  relations = {}
  origins = {}
  meta = {}

  until stream.eof?
    record = Mrt::MrtRecord.read stream
    raise 'Unsupported type.' unless record.header.get_type == :TABLE_DUMP_V2

    case record.header.get_subtype
    when :PEER_INDEX_TABLE
      meta[:table] = record.data.view_name
      meta[:collector_router_id] = IPAddr.new(record.data.get_collector_router_id)
      record.data.peer_entries.each do |peer|
        if peer.peer_as != 0 && !contributors.include?(peer.peer_as)
          contributors << peer.peer_as
        end
      end
    when :RIB_IPV6_UNICAST, :RIB_IPV6_UNICAST_ADDPATH, :RIB_IPV4_UNICAST, :RIB_IPV4_UNICAST_ADDPATH
      prefix = "#{IPAddr.new(record.data.get_prefix)}/#{record.data.prefix_length}"

      # Begin loop rib entries
      record.data.rib_entries.each do |rib|
        rib.attributes.each do |attr|

          if attr.is_valid?
            case attr.get_type
            when :AS_PATH
              if attr.attribute.get_type == :AS_SEQUENCE

                # Add prefix to ASN
                aspath = attr.attribute.path_segment_value.to_a
                origins[prefix] = [] unless origins[prefix]
                unless origins[prefix].include? aspath.last
                  puts "#{aspath.last} is announcing #{prefix}."
                  origins[prefix] << aspath.last
                end

                # Add ASN relationsships
                for i in 0...(aspath.length - 1)
                  relations[aspath[i]] = [] unless relations[aspath[i]]
                  relations[aspath[i + 1]] = [] unless relations[aspath[i + 1]]

                  unless relations[aspath[i]].include? aspath[i + 1]
                    puts "AS#{aspath[i]} is a neighbor of AS#{aspath[i + 1]}."
                    relations[aspath[i]] << aspath[i + 1]
                  end
                  relations[aspath[i + 1]] << aspath[i] unless relations[aspath[i + 1]].include? aspath[i]
                end

              end
            end
          end

        end
      end
      # End loop rib entries
    end
  end

  return [meta, contributors, relations, origins]
end

if ARGV[0]
  filename = ARGV[0]
else
  puts 'No MRT file given. Assuming first mrt file.'
  filename = Dir['*.mrt'].first
  if filename
    puts "Using #{filename} as MRT file."
  else
    puts 'No MRT file found'
    exit 1
  end
end

unless File.readable? filename
  puts "File #{filename} is not readable."
  exit 1
end

file = File.new(filename, 'rb')
result = parse_for_aspath file
file.close

puts "BGP Collector: #{result[0][:collector_router_id]}"
puts "Table: #{result[0][:table]}"
puts "Detected #{result[1].length} contributors."
puts "Detected #{result[2].length} ASNs."
puts "Detected #{result[3].length} prefixes."