XR NPU counter to pcap

xr2pcap.rb

#!/usr/bin/env ruby

##  1) capture data => monitor np counter MDF_PUNT_POLICE_DROP np0 count 25 location 0/2/CPU0
##
##  2) You'll need 'text2pcap' => sudo apt-get install wireshark-common
##
##  3) Run with file as argument:
##  [ytti@lintukoto ~/tmp/ios-xr-npu-monitor-pcap]% ./xr2pcap.rb r04.miamfl02.us.bb.MDF_PUNT_POLICE_DROP.ioscap
##  Input from: r04.miamfl02.us.bb.MDF_PUNT_POLICE_DROP.txt
##  Output to: r04.miamfl02.us.bb.MDF_PUNT_POLICE_DROP.pcap
##  Output format: PCAP
##  ...
##  Read 20 potential packets, wrote 20 packets (2791 bytes).
##
##  4) Run with data from stdin:
##  [ytti@lintukoto ~/tmp/ios-xr-npu-monitor-pcap]% cat r04.miamfl02.us.bb.MDF_PUNT_POLICE_DROP.ioscap|./xr2pcap.rb
##  Input from: packets.txt
##  Output to: packets.pcap
##  Output format: PCAP
##  ...
##  Read 20 potential packets, wrote 20 packets (2791 bytes).

class XRNPUCounter
  PACKET_START = /byte packet/
  LINE_RE      = /^....: (.{48}).*/

  def self.parse lines
    c = new
    packets = c.parse_lines lines
    c.parse_packets packets
  end

  def parse_lines lines
    packet   = false
    count    = -1
    packets  = []
    lines.each do |line|
      next if not packet and not line.match PACKET_START
      if line.match PACKET_START
        packet = true
        count += 1
        packets[count] = ""
        next
      end
      packets[count] += line
      packet = false if not line.match(/^\d/)
    end
    packets
  end

  def parse_packets packets
    parsed = []
    packets.each do |packet|
      hex = []
      packet.lines.each do |line|
        line = line.sub LINE_RE, '\1'
        hex << line.split
      end
      parsed.push "0000000 " + hex.flatten.join(" ")
    end
    parsed
  end
end


if $0 == __FILE__
  begin
    packets = XRNPUCounter.parse ARGF
    file = ARGF.filename.split "."
    file = if file.size > 1
             file[0..-2].join "."
           else
             "packets"
           end
    File.write "#{file}.txt", packets.join("\n")
    # we could write the packets to STDIN via popen, but meh, nice to have interim
    %x(text2pcap #{file}.txt #{file}.pcap)
  rescue => error
    warn error.class.to_s + ": " + error.message
    raise if $DEBUG
  end
end