class Pcapz::Capture::BSD

Public Class Methods

new(interface = Interfacez.default) click to toggle source
# File lib/pcapz/capture_types/bsd.rb, line 4
def initialize(interface = Interfacez.default)
  @interface       = interface
  @buffer_size     = 0
  @file            = nil
  @internal_buffer = nil
  configure_bpf_dev
end

Public Instance Methods

file() click to toggle source
# File lib/pcapz/capture_types/bsd.rb, line 39
def file
  @file
end
next_packet() click to toggle source
# File lib/pcapz/capture_types/bsd.rb, line 18
def next_packet
  @internal_buffer.resume
rescue Interrupt
  exit
rescue
  @internal_buffer = Fiber.new do
    loop do
      begin
        buffer = @file.read_nonblock(@buffer_size)
        while buffer.size > 0
          Fiber.yield buffer.slice!(0,(((buffer.slice(12,4).unpack('L')[0])+18) + 3 & ~3))[18..-1] 
        end
      rescue IO::WaitReadable
        IO.select([@file])
        retry
      end
    end
  end
  retry
end
packets() { |next_packet| ... } click to toggle source
# File lib/pcapz/capture_types/bsd.rb, line 12
def packets
  until @file.closed?
    yield next_packet
  end
end
stop!() click to toggle source
# File lib/pcapz/capture_types/bsd.rb, line 43
def stop!
  return nil if stopped?
  @file.close
  stopped?
end
stopped?() click to toggle source
# File lib/pcapz/capture_types/bsd.rb, line 49
def stopped?
  @file.closed?
end

Private Instance Methods

configure_bpf_dev(interface: @interface) click to toggle source
# File lib/pcapz/capture_types/bsd.rb, line 55
def configure_bpf_dev(interface: @interface)
  Dir.glob('/dev/bpf*') do |item|
    begin
      @file = File.open(item)   
    rescue Errno::EBUSY
      next
    end
  end
  raise "Unable to start a packet capture on any device" if @file.nil?
  @file.ioctl(0x8020426c, [interface].pack("a#{interface.size+1}"))
  @file.ioctl(0x80044270, [1].pack('I'))
  @file.ioctl(0x40044274, [0].pack('N'))
  buf = [0].pack('i')
  @file.ioctl(0x40044266, buf)
  @buffer_size = buf.unpack('i')[0]
  timeout = [5,0].pack('LL')
  @file.ioctl(0x8008426d, timeout)
  return @file 
rescue
  @file.close unless @file.nil? or @file.closed?
  raise "Unable to create network listener on #{@interface}!"
end