Class: Packet

Inherits:
Object
  • Object
show all
Defined in:
lib/packet.rb

Overview

Class holding the parsed packet data

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(data, prefix = '') ⇒ Packet

Returns a new instance of Packet.



13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
 
# File 'lib/packet.rb', line 13

def initialize(data, prefix = '')
  # @data and @payload
  # are strings representing the raw bytes
  #
  # @prefix is a String that will be displayed
  #         when printing the packet
  #         use '>' and '<' for example to indicate
  #         network direction (client/server)
  @prefix = prefix
  @addr = NetAddr.new(nil, nil)
  @huffman = Huffman.new
  @client_id = nil
  @client = nil
  @data = data
  flags_byte = @data[0].unpack('B*')
  @flags = PacketFlags.new(flags_byte.first[2..5]).hash
  @payload = @data[PACKET_HEADER_SIZE..]
  return unless  flags_compressed

  @payload = @huffman.decompress(@payload.unpack('C*'))
  @payload = @payload.pack('C*')
end

Instance Attribute Details

#addr ⇒ Object (readonly)

Returns the value of attribute addr.



10
11
12
 
# File 'lib/packet.rb', line 10

def addr
  @addr
end

#client ⇒ Object

Returns the value of attribute client.



11
12
13
 
# File 'lib/packet.rb', line 11

def client
  @client
end

#client_id ⇒ Object

Returns the value of attribute client_id.



11
12
13
 
# File 'lib/packet.rb', line 11

def client_id
  @client_id
end

#flags ⇒ Object (readonly)

Returns the value of attribute flags.



10
11
12
 
# File 'lib/packet.rb', line 10

def flags
  @flags
end

#payload ⇒ Object (readonly)

Returns the value of attribute payload.



10
11
12
 
# File 'lib/packet.rb', line 10

def payload
  @payload
end

Instance Method Details

#annotate_first_row(bytes) ⇒ Object 



36
37
38
39
40
41
42
43
44
45
 
# File 'lib/packet.rb', line 36

def annotate_first_row(bytes)
  header = bytes[0..2].join(' ').yellow
  token = bytes[3..6].join(' ').green
  payload = bytes[7..].join(' ')
  puts @prefix + "  data: #{[header, token, payload].join(' ')}"
  print "#{@prefix}        "
  print 'header'.ljust(3 * 3, ' ').yellow
  print 'token'.ljust(4 * 3, ' ').green
  puts 'data'
end

#flags_compressed ⇒ Object 



62
63
64
 
# File 'lib/packet.rb', line 62

def flags_compressed
  @flags[:compressed]
end

#flags_connless ⇒ Object 



66
67
68
 
# File 'lib/packet.rb', line 66

def flags_connless
  @flags[:connection] == false
end

#flags_control ⇒ Object 



70
71
72
 
# File 'lib/packet.rb', line 70

def flags_control
  @flags[:control]
end

#to_s ⇒ Object 



47
48
49
50
51
52
53
54
55
56
57
58
59
60
 
# File 'lib/packet.rb', line 47

def to_s
  puts "#{@prefix}Packet"
  puts @prefix + "  flags: #{@flags}"
  bytes = str_hex(@data).split
  # TODO: check terminal size?
  max_width = 14
  rows = bytes.groups_of(max_width)
  annotate_first_row(rows.first)
  rows[1..].each do |row|
    print "#{@prefix}        "
    puts row.join(' ')
  end
  puts ''
end