Turn IOS-XR SPP/NETIO capture into an PCAP

sppcapture.rb

#!/usr/bin/env ruby

## 1) ssh asr9k | tee spp.capture
## 2) do spp/netio capture in asr9k
## 3) ./sppcapture.rb spp.capture
## 4) text2pcap spp.capture.packet spp.capture.pcap
## 5) open spp.capture.pcap

class SPPCapture
  FILE_EXTENSION = 'packet'
  PACKET_START   = /length \d+ phys_int_index \d+ next_ctx/
  PACKET_END     = /^------/
  POP_BYTES      = 72

  def self.to_ascii_file file
    file_base   = File.basename(file)
    file_ext    = File.extname(file)
    ext         = FILE_EXTENSION
    ext        += '2' if file_ext == FILE_EXTENSION
    file_output = [file_base, ext].join '.'

    trace   = new File.read(file)
    File.write file_output, trace.to_packets
    puts "packet written in '#{file_output}'"
    puts "run 'text2pcap #{file_output} #{file_base}.pcap' to generate pcap file"
  end

  def initialize data
    @packets = parse_data data
  end

  def to_packets
    str = ""
    @packets.each do |packet|
      str << "000000 " + packet[POP_BYTES..-1].join(" ") + "\n"
    end
    str
  end

  def parse_data data
    packets   = []
    packet    = []
    in_packet = false
    data.each_line do |line|
      next if not in_packet and not line.match PACKET_START

      if line.match PACKET_START
        in_packet = true
        next
      end

      if line.match PACKET_END
        in_packet = false
        packets << packet
        packet = []
        next
      end

      _offset, packet_data = line.strip.split ":"
      packet += packet_data.split
    end
    packets
  end


end

begin
  if $0 == __FILE__
    SPPCapture.to_ascii_file(ARGV.first)
  end
rescue => error
  warn error.message
end