def get_data(segs, cpp_in):
'''[str] -> str -> [c_ast]'''
def gen(((ti, ea, declstr), node)):
'''(tinfo_t, ea_t) -> c_ast'''
# NOTE mutates node
has_data = ida.seg_name(ea) != '.bss'
ptr = ida.can_be_off32(ea)
if ptr not in [ida.BADADDR, 0]:
ptr_ti = ida.get_or_guess_tinfo(ptr)
ti_node = cdecl.get_decls(declstr).decls[utils.cpp_decomp_tag][0]
return gen(((ptr_ti, ptr, ''), ti_node))
# XXX our data segment has no strings, but that's probably specific to
# the one binary we're dealing with
elif ti.is_array():
ai = ida.array_type_data_t()
ti.get_array_details(ai)
item_size = ai.elem_type.get_size()
typename = get_type_for_c_ast_constant(ai.elem_type)
length = (ida.item_end(ea) - ida.item_head(ea)) / item_size
if has_data is True:
if ai.elem_type.is_char():
node.init = ep_ct.constant(typename, c_stringify(
ida.get_string(ea)))
else:
items = list(get_item(ea + j * item_size, ti)
for j in xrange(0, length))
node.init = ep_ct.initlist(
[ep_ct.constant(typename, str(x)) for x in items])
else:
if has_data is True:
typename = get_type_for_c_ast_constant(ti)
node.init = ep_ct.constant(typename,
str(get_item(ea, ti)))
return node
def get_item(ea, ti):
'''ea_t -> tinfo_t -> c.types obj | int | str'''
if ti.is_array():
ai = ida.array_details(ti)
if ai.elem_type.is_char():
return ida.get_string(ea)
else:
sz = ai.elem_type.get_size()
ret = get_one_item(ea, ai.elem_type, sz)
return ret
else:
sz = ida.size_of(ti)
return get_one_item(ea, ti, sz)
def get_arg_for_va_function(callee, start_ea):
'''str -> ea_t -> str'''
# XXX hacky; not a very general function
# XXX imperative
# get a relevant item needed for processing a variadic function
sw = {
'printf' : regs.gpr(abi.arg_regs[0]),
'scanf' : regs.gpr(abi.arg_regs[0]),
'sscanf' : regs.gpr(abi.arg_regs[1])
}
try:
wanted_reg = sw[callee]
except KeyError:
raise utils.BugError('unrecognized callee %s' % callee)
distance = 0
fn = ida.get_func(start_ea)
# first, look at the delay slot
ea = ida.next_head(start_ea, fn.endEA)
while True:
if distance > 10:
raise VarargsError(
'gave up looking for needed varargs argument for %s between ' +
'%s..%s' % (ida.atoa(ea), ida.atoa(start_ea)))
if ea == start_ea:
ea = ida.prev_head(ea)
continue # skip the call insn
elif list(ida.code_refs_from(ea, 0)) != []:
raise VarargsError(
'encountered branch/jump while looking for varargs argument ' +
'between %s..%s' % (ida.atoa(ea), ida.atoa(start_ea)))
rd = ida.get_op(ea, 0)
if rd.val == wanted_reg:
opvals = ida.get_opvals(ea) # XXX should try to track stkvar values
s = ida.get_string(opvals[-1].target)
if s is not None:
return s
ea = ida.prev_head(ea)
distance += 1
def get_arg_for_va_function(callee, start_ea):
"""str -> ea_t -> str"""
# XXX hacky; not a very general function
# XXX imperative
# get a relevant item needed for processing a variadic function
sw = {"printf": regs.gpr(abi.arg_regs[0]), "scanf": regs.gpr(abi.arg_regs[0]), "sscanf": regs.gpr(abi.arg_regs[1])}
try:
wanted_reg = sw[callee]
except KeyError:
raise utils.BugError("unrecognized callee %s" % callee)
distance = 0
fn = ida.get_func(start_ea)
# first, look at the delay slot
ea = ida.next_head(start_ea, fn.endEA)
while True:
if distance > 10:
raise VarargsError(
"gave up looking for needed varargs argument for %s between "
+ "%s..%s" % (ida.atoa(ea), ida.atoa(start_ea))
)
if ea == start_ea:
ea = ida.prev_head(ea)
continue # skip the call insn
elif list(ida.code_refs_from(ea, 0)) != []:
raise VarargsError(
"encountered branch/jump while looking for varargs argument "
+ "between %s..%s" % (ida.atoa(ea), ida.atoa(start_ea))
)
rd = ida.get_op(ea, 0)
if rd.val == wanted_reg:
opvals = ida.get_opvals(ea) # XXX should try to track stkvar values
s = ida.get_string(opvals[-1].target)
if s is not None:
return s
ea = ida.prev_head(ea)
distance += 1
