metasploit-framework/lib/metasm/samples/struct_offset.rb

60 lines
1.9 KiB
Ruby

# This file is part of Metasm, the Ruby assembly manipulation suite
# Copyright (C) 2006-2009 Yoann GUILLOT
#
# Licence is LGPL, see LICENCE in the top-level directory
#
# This exemple illustrates the usage of the C parser to compute the offset of members of a given structure
# usage: struct_offset.rb <c file> <struct name>
#
require 'metasm'
include Metasm
require 'optparse'
opts = { :hdrs => [], :defs => {}, :path => [], :cpu => 'X86', :offbase => 16 }
OptionParser.new { |opt|
opt.on('-o outfile') { |f| opts[:outfile] = f }
opt.on('-H additional_header') { |f| opts[:hdrs] << f }
opt.on('-I path', '--includepath path') { |f| opts[:path] << f }
opt.on('-D var') { |f| k, v = f.split('=', 2) ; opts[:defs].update k => (v || '') }
opt.on('-d') { opts[:offbase] = 10 }
opt.on('--cpu CpuClass') { |c| opts[:cpu] = c }
opt.on('--gcc') { opts[:gcc] = true }
opt.on('--vs', '--visualstudio') { opts[:vs] = true }
}.parse!(ARGV)
cp = Metasm.const_get(opts[:cpu]).new.new_cparser
cp.prepare_gcc if opts[:gcc]
cp.prepare_visualstudio if opts[:vs]
pp = cp.lexer
pp.warn_redefinition = false
pp.include_search_path[0, 0] = opts[:path]
opts[:defs].each { |k, v| pp.define k, v }
cp.parse opts[:hdrs].map { |h| "#include <#{h}>" }.join("\n")
abort 'need source + struct name' unless ARGV.length >= 2
cp.parse_file(ARGV.shift)
$stdout.reopen File.open(opts[:outfile], 'w') if opts[:outfile]
ARGV.each { |structname|
st = cp.toplevel.struct[structname] || cp.toplevel.symbol[structname]
st = st.type while st.kind_of? Metasm::C::Pointer or st.kind_of? Metasm::C::TypeDef
if not st.kind_of? C::Struct
puts "// unknown #{structname}", ''
next
end
puts "// #{structname}" if not st.name
puts "struct #{st.name} { // size = #{cp.sizeof(st).to_s(opts[:offbase])}"
st.members.each { |m|
puts "\t#{m.type.to_s[1..-2]} #{m.name if m.name}; // +#{st.offsetof(cp, m.name).to_s(opts[:offbase])}"
}
puts '};', ''
}