Class: Xlat::Protocols::Tcp

Inherits:
Tcpudp
  • Object
show all
Defined in:
lib/xlat/protocols/tcp.rb

Constant Summary collapse

PROTOCOL_ID = 
6
DATA_OFFSET_OFFSET = 
12
CHECKSUM_OFFSET = 
16
OPTION_KIND_END = 
0
OPTION_KIND_NOOP = 
1
OPTION_KIND_MSS = 
2
FLAG_FIN = 
0x01
FLAG_SYN = 
0x02
FLAG_RST = 
0x04
FLAG_PST = 
0x08
FLAG_ACK = 
0x10
FLAG_URG = 
0x20
FLAG_ECE = 
0x40
FLAG_CWR = 
0x80

Instance Method Summary collapse

Methods inherited from Tcpudp

#_adjust_checksum, #initialize, #tuple

Methods included from Common

sum16be

Constructor Details

This class inherits a constructor from Xlat::Protocols::Tcpudp

Instance Method Details

#apply(cs_delta) ⇒ Object 



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# File 'lib/xlat/protocols/tcp.rb', line 56

def apply(cs_delta)
  return if cs_delta.zero?

  packet = @packet
  return if packet.l4_bytes_length < 18

  bytes = packet.l4_bytes
  offset = packet.l4_bytes_offset

  checksum = bytes.get_value(:U16, offset + 16)
  checksum = _adjust_checksum(checksum, cs_delta)
  bytes.set_value(:U16, offset + 16, checksum)
end

#parse ⇒ Object 



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# File 'lib/xlat/protocols/tcp.rb', line 46

def parse
  packet = @packet
  return nil if packet.l4_bytes_length < (@icmp_payload ? 4 : 20)

  # bytes = packet.l4_bytes
  # offset = packet.l4_bytes_offset

  super
end