fuzz update/node/lib/metasm/samples/dbg-plugins/heapscan.rb
#    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


# metasm debugger plugin
# adds some heap_* functions to interract with the target heap chunks
# functions:
#  heap_scan, scan for malloc chunks in the heaps and xrefs between them
#  heap_scanstruct, scan for arrays/linkedlists in the chunk graph
#  heap_chunk [addr], display a chunk
#  heap_array [addr], display an array of chunks from their root
#  heap_list [addr], display a linkedlist
#  heap_strscan [str], scan the memory for a raw string, display chunks xrefs
#  heap_snap, make a snapshot of the currently displayed structure, hilight fields change


# use precompiled native version when available
$heapscan_dir = File.join(File.dirname(plugin_filename).gsub('\\', '/'), 'heapscan')
require File.join($heapscan_dir, 'heapscan')

fname = case OS.current.shortname
when 'linos'
	'compiled_heapscan_lin'
when 'winos'
	case OS.current.version[0]
	when 5; 'compiled_heapscan_win'
	when 6; 'compiled_heapscan_win7'
	end
end
fname = File.join($heapscan_dir, fname)
if not File.exist?(fname + '.so') and File.exist?(fname + '.c')
	puts "compiling native scanner..."
	exe = DynLdr.host_exe.compile_c_file(DynLdr.host_cpu, fname + '.c')
	DynLdr.compile_binary_module_hack(exe)
	exe.encode_file(fname + '.so', :lib)
end
require fname if File.exist?(fname + '.so')

def heapscan_time(s='')
	@heapscan_time ||= nil
	t = Time.now
	log s + ' %.2fs' % (t-@heapscan_time) if @heapscan_time and s != ''
	@heapscan_time = t
	Gui.main_iter if gui
end

def heap; @heap ; end
def heap=(h) ; @heap = h ; end

def heapscan_scan(xr=true)
	heaps = []
	mmaps = []
	libc = nil
	pr = os_process
	pr.mappings.each { |a, l, p, f|
		case f.to_s
		when /heap/
			heaps << [a, l]
		when /libc[^a-zA-Z]/
			libc ||= a if p == 'r-xp'
		when ''
			mmaps << [a, l]
		end
	}

	heapscan_time ''
	@disassembler.parse_c ''
	if pr and OS.current.name =~ /winos/i
		if OS.current.version[0] == 5
			@heap = WindowsHeap.new(self)
			@heap.cp = @disassembler.c_parser
			@heap.cp.parse_file File.join($heapscan_dir, 'winheap.h') unless @heap.cp.toplevel.struct['_HEAP']
		else
			@heap = Windows7Heap.new(self)
			@heap.cp = @disassembler.c_parser
			@heap.cp.parse_file File.join($heapscan_dir, 'winheap7.h') unless @heap.cp.toplevel.struct['_HEAP']
		end
		@heap.heaps = heaps
	else
		@heap = LinuxHeap.new(self)
		@heap.cp = @disassembler.c_parser
		@heap.mmaps = mmaps
		@heap.scan_libc(libc)
		heapscan_time "libc!main_arena #{'%x' % @heap.main_arena_ptr}"
	end

	hsz = 0
	(heaps + mmaps).each { |a, l|
		hsz += l
		@heap.range.update a => l
	}

	log "#{hsz/1024/1024}M heap"

	@heap.scan_chunks
	heapscan_time "#{@heap.chunks.length} chunks"
	return if not xr

	@heap.scan_chunks_xr
	heapscan_time "#{@heap.xrchunksto.length} src, #{@heap.xrchunksfrom.length} dst"
end

def heapscan_structs
	heapscan_time
	@heap.bucketize
	heapscan_time "#{@heap.buckets.length} buckets"

	@heap.find_arrays
	heapscan_time "#{@heap.allarrays.length} arrays (#{@heap.allarrays.flatten.length} elems)"

	@heap.find_linkedlists
	heapscan_time "#{@heap.alllists.length} lists (#{@heap.alllists.flatten.length} elems)"
end

def heapscan_kernels
	heapscan_time
	@heap.find_kernels
	heapscan_time "#{@heap.kernels.length} kernels"
end

def heapscan_roots
	heapscan_time
	@heap.find_roots
	heapscan_time "#{@heap.roots.length} roots"
end

def heapscan_graph
	heapscan_time
	@heap.dump_graph
	heapscan_time 'graph.gv'
end

def gui_show_list(addr)
	a = resolve(addr)
	#@heap.cp.parse("struct ptr { void *ptr; };") if not @heap.cp.toplevel.struct['ptr']
	h = @heap.linkedlists[a]
	off = h.keys.first
	lst = h[off]

	if not st = lst.map { |l| @heap.chunk_struct[l] }.compact.first
		st = Metasm::C::Struct.new
		st.name = "list_#{'%x' % lst.first}"
		st.members = []
		(@heap.chunks[lst.first] / 4).times { |i|
			n = "u#{i}"
			t = Metasm::C::BaseType.new(:int)
			if i == off/4
				n = "next"
				t = Metasm::C::Pointer.new(st)
			end
			st.members << Metasm::C::Variable.new(n, t)
		}
		@heap.cp.toplevel.struct[st.name] = st
	end
	lst.each { |l| @heap.chunk_struct[l] = st }

	$ghw.addr_struct = {}
	lst.each { |aa|
		$ghw.addr_struct[aa] = @heap.cp.decode_c_struct(st.name, @memory, aa)
	}
	gui.parent_widget.mem.focus_addr(lst.first, :graphheap)
end

def gui_show_array(addr)
	head = resolve(addr)
	e = @heap.xrchunksto[head].to_a.find { |ee| @heap.arrays[ee] and @heap.arrays[ee][head] }
	return if not e
	lst = @heap.arrays[e][head]

	if not st = @heap.chunk_struct[head]
		st = Metasm::C::Struct.new
		st.name = "array_#{'%x' % head}"
		st.members = []
		(@heap.chunks[head] / 4).times { |i|
			n = "u#{i}"
			v = @memory[head+4*i, 4].unpack('L').first
			if @heap.chunks[v]
				t = Metasm::C::Pointer.new(Metasm::C::BaseType.new(:void))
			else
				t = Metasm::C::BaseType.new(:int)
			end
			st.members << Metasm::C::Variable.new(n, t)
		}
		@heap.cp.toplevel.struct[st.name] ||= st
	end
	@heap.chunk_struct[head] = st

	$ghw.addr_struct = { head => @heap.cp.decode_c_struct(st.name, @memory, head) }

	if not st = lst.map { |l| @heap.chunk_struct[l] }.compact.first
		e = lst.first
		st = Metasm::C::Struct.new
		st.name = "elem_#{'%x' % head}"
		st.members = []
		(@heap.chunks[e] / 4).times { |i|
			n = "u#{i}"
			v = @memory[e+4*i, 4].unpack('L').first
			if @heap.chunks[v]
				t = Metasm::C::Pointer.new(Metasm::C::BaseType.new(:void))
			else
				t = Metasm::C::BaseType.new(:int)
			end
			st.members << Metasm::C::Variable.new(n, t)
		}
		@heap.cp.toplevel.struct[st.name] ||= st
	end
	lst.each { |l| @heap.chunk_struct[l] = st }

	lst.each { |aa|
		$ghw.addr_struct[aa] = @heap.cp.decode_c_struct(st.name, @memory, aa)
	}
	gui.parent_widget.mem.focus_addr(head, :graphheap)
end


if gui
	require File.join($heapscan_dir, 'graphheap')
	$ghw = Metasm::Gui::GraphHeapWidget.new(@disassembler, gui.parent_widget.mem)
	gui.parent_widget.mem.addview :graphheap, $ghw
	$ghw.show if $ghw.respond_to?(:show)

	gui.new_command('heap_scan', 'scan the heap(s)') { |*a| heapscan_scan ; $ghw.heap = @heap }
	gui.new_command('heap_scan_noxr', 'scan the heap(s), no xrefs') { |*a| heapscan_scan(false) ; $ghw.heap = @heap }
	gui.new_command('heap_scan_xronly', 'scan the heap(s) for xrefs') { |*a| $ghw.heap.scan_chunks_xr }
	gui.new_command('heap_scanstructs', 'scan the heap for arrays/lists') { |*a| heapscan_structs }
	gui.new_command('heap_list', 'show a linked list') { |a|
		if a.to_s != ''
			gui_show_list(a)
		else
			l = [['addr', 'len']]
			@heap.alllists.each { |al|
				l << [Expression[al.first], al.length]
			}
			gui.listwindow('lists', l) { |*aa| gui_show_list(aa[0][0]) }
		end
	}
	gui.new_command('heap_array', 'show an array') { |a|
		if a.to_s != ''
			gui_show_array(a)
		else
			l = [['addr', 'len']]
			@heap.allarrays.each { |al|
				l << [Expression[al.first], al.length]
			}
			gui.listwindow('arrays', l) { |*aa| gui_show_array(aa[0][0]) }
		end
	}
	gui.new_command('heap_chunk', 'show a chunk') { |a|
		a = resolve(a)
		gui.parent_widget.mem.focus_addr(a, :graphheap)
		$ghw.do_focus_addr(a)
	}
	gui.new_command('heap_strscan', 'scan a string') { |a|
		sa = pattern_scan(a)
		log "found #{sa.length} strings : #{sa.map { |aa| Expression[aa] }.join(' ')}"
		sa.each { |aa|
			next if not ck = @heap.find_chunk(aa)
			log "ptr #{Expression[aa]} in chunk #{Expression[ck]} (#{Expression[@heap.chunks[ck]]}) in list #{@heap.linkedlists && @heap.linkedlists[ck] && true} in array #{@heap.arrays[ck].map { |k, v| "#{Expression[k]} (#{v.length})" }.join(', ') if @heap.arrays and @heap.arrays[ck]}"
		}
	}
	gui.new_command('heap_ptrscan', 'scan a pointer') { |a|
		a = resolve(a)
		if @heap.chunks[a]
			pa = @heap.xrchunksfrom[a].to_a
		else
			pa = pattern_scan(Expression.encode_imm(a, @cpu.size/8, @cpu.endianness))
		end
		log "found #{pa.length} pointers : #{pa.map { |aa| Expression[aa] }.join(' ')}"
		pa.each { |aa|
			next if not ck = @heap.find_chunk(aa)
			log "ptr @#{Expression[aa]} in chunk #{Expression[ck]} (#{Expression[@heap.chunks[ck]]}) in list #{@heap.linkedlists && @heap.linkedlists[ck] && true} in array #{@heap.arrays[ck].map { |k, v| "#{Expression[k]} (#{v.length})" }.join(', ') if @heap.arrays and @heap.arrays[ck]}"
		}
	}

	gui.new_command('heap_snap', 'snapshot the current heap struct') { |a|
		$ghw.snap
	}
	gui.new_command('heap_snap_add', 'snapshot, ignore fields changed between now and last snap') { |a|
		$ghw.snap_add
	}
end
