ffi-udis86

Description

FFI::UDis86 provides Ruby FFI bindings for the udis86, a x86 and x86-64 disassembler.

Features

Examples

Create a new disassembler:

include FFI::UDis86

ud = UD.create(:syntax => :att, :mode => 64)

Set the input buffer:

ud.input_buffer = "\x90\x90\xc3"

Add an input callback:

ud.input_callback { |ud| ops.shift || -1 }

Read a file:

UD.open(path) do |ud|
  ...
end

Disassemble and print instructions:

ud.disas do |insn|
  puts insn
end

Disassemble and print information about the instruction and operands:

asm = "\x75\x62\x48\x83\xc4\x20\x5b\xc3\x48\x8d\x0d\x23\x0c\x01\x00\x49\x89\xf0"

ud = FFI::UDis86::UD.create(
  :buffer => asm,
  :mode => 64,
  :vendor => :amd,
  :syntax => :att
)

ud.disas do |insn|
  puts insn
  puts "  * Offset: #{insn.insn_offset}"
  puts "  * Length: #{insn.insn_length}"
  puts "  * Mnemonic: #{insn.mnemonic}"

  operands = insn.operands.reverse.map do |operand|
    if operand.is_mem?
      ptr = [operand.base]
      ptr << operand.index if operand.index
      ptr << operand.scale if operand.scale

      "Memory Access (#{ptr.join(',')})"
    elsif operand.is_imm?
      'Immediate Data'
    elsif operand.is_jmp_imm?
      'Relative Offset'
    elsif operand.is_const?
      'Constant'
    elsif operand.is_reg?
      "Register (#{operand.reg})"
    end
  end

  puts '  * Operands: ' + operands.join(' -> ')
end

Requirements

Install

$ sudo gem install ffi-udis86

License

See LICENSE for license information.