def single_operand_parser(self, address, op, idx):
"""Parse a PPC operand."""
def constraint_value(value):
if value > 2**16:
return -(2**32 - value)
return value
# Operand parsing
#
if op.type == OPERAND_TYPE_NO_OPERAND:
return None
#print '>>>', hex(address), idx, op.type
segment = idaapi.getseg(address)
addressing_mode = segment.bitness
# Start creating the AST, the root entry is always the width of the
# operand
operand = [self.OPERAND_WIDTH[self.as_byte_value(op.dtyp)]]
# Compose the rest of the AST
#
if op.type == OPERAND_TYPE_DISPLACEMENT:
# A displacement operatior might refer to a variable...
#
var_name = None
# Try to get any name that might have been assigned to the
# variable. It's only done if the register is:
# sp/esp (4) os bp/ebp (5)
#
flags = idc.GetFlags(address)
if (idx == 0
and idc.isStkvar0(flags)) or (idx == 1
and idc.isStkvar1(flags)):
var_name = self.get_operand_stack_variable_name(
address, op, idx)
#if has_sib_byte(op) is True:
# when SIB byte set, process the SIB indexing
# phrase = parse_phrase(op)
#else:
phrase = [
self.NODE_TYPE_OPERATOR_PLUS,
[
self.NODE_TYPE_REGISTER,
self.REGISTERS[self.as_byte_value(op.reg)], 0
]
]
if var_name:
value = arch.ExpressionNamedValue(long(op.addr), var_name)
else:
value = constraint_value(op.addr)
operand.extend([[
self.NODE_TYPE_DEREFERENCE,
phrase + [[self.NODE_TYPE_VALUE, value, 1]]
]])
elif op.type == OPERAND_TYPE_REGISTER:
operand.extend([[
self.NODE_TYPE_REGISTER,
self.REGISTERS[self.as_byte_value(op.reg)], 1
]])
elif op.type == OPERAND_TYPE_MEMORY:
addr_name = self.get_address_name(op.addr)
if addr_name:
value = arch.ExpressionNamedValue(long(op.addr), addr_name)
else:
value = op.addr
operand.extend([[
self.NODE_TYPE_DEREFERENCE, [self.NODE_TYPE_VALUE, value, 0]
]])
elif op.type == OPERAND_TYPE_IMMEDIATE:
# Keep the value's size
#
if self.as_byte_value(op.dtyp) == 0:
mask = 0xff
elif self.as_byte_value(op.dtyp) == 1:
mask = 0xffff
else:
mask = 0xffffffff
operand.extend([[self.NODE_TYPE_VALUE, op.value & mask, 0]])
elif op.type in (OPERAND_TYPE_NEAR, OPERAND_TYPE_FAR):
addr_name = self.get_address_name(op.addr)
if addr_name:
value = arch.ExpressionNamedValue(long(op.addr), addr_name)
else:
value = op.addr
operand.extend([[self.NODE_TYPE_VALUE, value, 0]])
elif op.type == OPERAND_TYPE_PHRASE:
print '***Dunno how to parse PHRASE'
operand.extend([[
self.NODE_TYPE_SYMBOL,
'UNK_PHRASE(val:%d, reg:%d, type:%d)' %
(op.value, self.as_byte_value(op.reg), op.type), 0
]])
elif op.type == OPERAND_TYPE_IDPSPEC0:
# Handle Special Purpose Registers
#
register = self.SPR_REGISTERS.get(
op.value, 'UNKNOWN_REGISTER(val:%x)' % op.value)
operand.extend([[self.NODE_TYPE_REGISTER, register, 0]])
elif op.type == OPERAND_TYPE_IDPSPEC1:
#print '***Dunno how to parse OPERAND_TYPE_IDPSPEC1'
#operand.extend([[self.NODE_TYPE_SYMBOL,
# 'UNK_IDPSPEC1(val:%d, reg:%d, type:%d)' % (
# op.value, op.reg, op.type), 0]])
operand.extend([[
self.NODE_TYPE_REGISTER,
self.REGISTERS[self.as_byte_value(op.reg)], 1
]])
operand.extend([[
self.NODE_TYPE_REGISTER,
self.REGISTERS[self.as_byte_value(op.specflag1)], 2
]])
elif op.type == OPERAND_TYPE_IDPSPEC2:
# IDSPEC2 is operand type for all rlwinm and rlwnm
# instructions which are in general op reg, reg, byte, byte, byte
# or eqivalent. simplified mnemonics sometimes take less than
# five arguments.
#
# Keep the value's size
#
if self.as_byte_value(op.dtyp) == 0:
mask = 0xff
elif self.as_byte_value(op.dtyp) == 1:
mask = 0xffff
else:
mask = 0xffffffff
operand_1 = []
operand_2 = []
operand_3 = []
# Get the object representing the instruction's data.
# It varies between IDA pre-5.7 and 5.7 onwards, the following check
# will take care of it (for more detail look into the similar
# construct in arch.py)
#
if hasattr(idaapi, 'cmd'):
idaapi.decode_insn(address)
ida_instruction = idaapi.cmd
else:
idaapi.ua_code(address)
ida_instruction = idaapi.cvar.cmd
if (ida_instruction.auxpref & 0x0020):
#print "SH"
operand_1 = [self.OPERAND_WIDTH[self.as_byte_value(op.dtyp)]]
operand_1.extend([[
self.NODE_TYPE_VALUE,
self.as_byte_value(op.reg) & mask, 0
]])
else:
operand_1 = [self.OPERAND_WIDTH[self.as_byte_value(op.dtyp)]]
operand_1.extend([[
self.NODE_TYPE_REGISTER,
self.REGISTERS[self.as_byte_value(op.reg)], 0
]])
#print operand_1
if (ida_instruction.auxpref & 0x0040):
#print "MB"
operand_2 = [self.OPERAND_WIDTH[self.as_byte_value(op.dtyp)]]
operand_2.extend([[
self.NODE_TYPE_VALUE,
self.as_byte_value(op.specflag1) & mask, 0
]])
#print operand_2
if (ida_instruction.auxpref & 0x0080):
#print "ME"
operand_3 = [self.OPERAND_WIDTH[self.as_byte_value(op.dtyp)]]
operand_3.extend([[
self.NODE_TYPE_VALUE,
self.as_byte_value(op.specflag2) & mask, 0
]])
#print operand_3
operand = [operand_1]
#operand = operand_1
if (ida_instruction.auxpref & 0x0040):
#print "MB2"
operand.append(operand_2)
if (ida_instruction.auxpref & 0x0080):
#print "ME2"
operand.append(operand_3)
#print operand
# operand = operand_1
#print operand
#print '>>>', hex(address), idx, op.type, op.reg
#operand.extend([[self.NODE_TYPE_OPERATOR_COMMA, [self.NODE_TYPE_VALUE, op.reg&mask, 0], [self.NODE_TYPE_VALUE, self.as_byte_value(op.specflag1)&mask, 1], [self.NODE_TYPE_VALUE, self.as_byte_value(op.specflag2)&mask, 2]]])
elif op.type == OPERAND_TYPE_IDPSPEC3:
# CR registers
#
operand.extend([[
self.NODE_TYPE_REGISTER,
self.CR_REGISTERS[self.as_byte_value(op.reg)], 0
]])
elif op.type == OPERAND_TYPE_IDPSPEC4:
# The bit in the CR to check for
#
operand.extend(
[[self.NODE_TYPE_REGISTER,
self.as_byte_value(op.reg), 0]])
elif op.type == OPERAND_TYPE_IDPSPEC5:
# Device Control Register, implementation specific
operand.extend([[self.NODE_TYPE_REGISTER,
'DCR(%x)' % op.value, 0]])
return operand
def single_operand_parser(self, address, op, idx):
"""Parse a metapc operand."""
# Convenience functions
#
def has_sib_byte(op):
# Does the instruction use the SIB byte?
return self.as_byte_value(op.specflag1) == 1
def get_sib_scale(op):
return (None, 2, 4, 8)[self.as_byte_value(op.specflag2) >> 6]
def get_sib_scaled_index_reg(op):
return self.SIB_INDEX_REGISTERS[
(self.as_byte_value(op.specflag2) >> 3) & 0x7]
def get_sib_base_reg(op):
#
# [ [7-6] [5-3] [2-0] ]
# MOD/RM = ( (mod_2 << 6) | (reg_opcode_3 << 3) | rm_3 )
# There's not MOD/RM made available by IDA!?
#
# [ [7-6] [5-3] [2-0] ]
# SIB = ( (scale_2 << 6) | (index_3 << 3) | base )
# op.specflag2
#
# instruction = op + modrm + sib + disp + imm
#
# If MOD is zero there's no base register, otherwise it's EBP
# But IDA exposes no MOD/RM.
# Following a discussion in IDA's forums:
# http://www.hex-rays.com/forum/viewtopic.php?f=8&t=1424&p=8479&hilit=mod+rm#p8479
# checking for it can be done in the following manner:
#
SIB_byte = self.as_byte_value(op.specflag2)
return self.SIB_BASE_REGISTERS[SIB_byte & 0x7]
def get_segment_prefix(op):
seg_idx = (op.specval >> 16)
if seg_idx == 0:
return None
if (op.specval >> 16) < len(self.REGISTERS[0]):
seg_prefix = self.REGISTERS[0][op.specval >> 16] + ':'
else:
seg_prefix = op.specval & 0xffff
# This must return a string in case a segment register selector is used
# or and int/long of a descriptor itself.
#
return seg_prefix
def parse_phrase(op, has_displacement=False):
"""Parse the expression used for indexed memory access.
Returns its AST as a nested list of lists.
"""
# Check the addressing mode using in this segment
segment = idaapi.getseg(address)
if segment.bitness != 1:
raise Exception(
'Not yet handling addressing modes other than 32bit!')
base_reg = get_sib_base_reg(op)
scaled_index_reg = get_sib_scaled_index_reg(op)
scale = get_sib_scale(op)
if scale:
# return nested list for reg+reg*scale
if base_reg != '':
# The last values in each tuple indicate the
# preferred display position of each element.
# base_reg + (scale_reg * scale)
#
if scaled_index_reg == '':
return [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER, base_reg, 0]
]
return [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER, base_reg, 0],
[
self.NODE_TYPE_OPERATOR_TIMES,
[self.NODE_TYPE_REGISTER, scaled_index_reg, 0],
[self.NODE_TYPE_VALUE, scale, 1], 1
]
]
else:
# If there's no base register and
# mod == 01 or mod == 10 (=> operand has displacement)
# then we need to add EBP
if has_displacement:
return [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER, 'ebp', 0],
[
self.NODE_TYPE_OPERATOR_TIMES,
[self.NODE_TYPE_REGISTER, scaled_index_reg, 0],
[self.NODE_TYPE_VALUE, scale, 1], 1
]
]
return [
self.NODE_TYPE_OPERATOR_PLUS,
[
self.NODE_TYPE_OPERATOR_TIMES,
[self.NODE_TYPE_REGISTER, scaled_index_reg, 0],
[self.NODE_TYPE_VALUE, scale, 1], 0
]
]
else:
# return nested list for reg+reg
if base_reg == '':
if scaled_index_reg != '':
if has_displacement:
return [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER, 'ebp', 0],
[self.NODE_TYPE_REGISTER, scaled_index_reg, 1]
]
return [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER, scaled_index_reg, 0]
]
else:
if has_displacement:
return [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER, 'ebp', 0]
]
return []
else:
if scaled_index_reg != '':
return [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER, base_reg, 0],
[self.NODE_TYPE_REGISTER, scaled_index_reg, 1]
]
else:
return [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER, base_reg, 0]
]
# Operand parsing
#
if op.type == OPERAND_TYPE_NO_OPERAND:
return None
segment = idaapi.getseg(address)
addressing_mode = segment.bitness
# Start creating the AST, the root entry is always the width of the
# operand
operand = [self.OPERAND_WIDTH[self.as_byte_value(op.dtyp)]]
# If the operand indicates a displacement and it does
# the indexing through the SIB the it might be referring
# a variable on the stack and an attempt to retrieve it
# is made.
#
# Compose the rest of the AST
#
if op.type == OPERAND_TYPE_DISPLACEMENT:
# A displacement operatior might refer to a variable...
#
var_name = None
# Try to get any stack name that might have been assigned
# to the variable.
#
flags = idc.GetFlags(address)
if (idx == 0
and idc.isStkvar0(flags)) or (idx == 1
and idc.isStkvar1(flags)):
var_name = self.get_operand_stack_variable_name(
address, op, idx)
if has_sib_byte(op) is True:
# when SIB byte set, process the SIB indexing
phrase = parse_phrase(op, has_displacement=True)
else:
phrase = [
self.NODE_TYPE_OPERATOR_PLUS,
[
self.NODE_TYPE_REGISTER,
self.REGISTERS[addressing_mode + 1][op.reg], 0
]
]
if var_name:
value = arch.ExpressionNamedValue(long(op.addr), var_name)
else:
value = op.addr
# Calculate the index of the value depending on how many components
# we have in the phrase
#
idx_of_value = len(phrase) - 1
operand.extend([[
get_segment_prefix(op),
[
self.NODE_TYPE_DEREFERENCE,
phrase + [[self.NODE_TYPE_VALUE, value, idx_of_value]]
]
]])
elif op.type == OPERAND_TYPE_REGISTER:
operand.extend([[
self.NODE_TYPE_REGISTER,
self.REGISTERS[self.as_byte_value(op.dtyp)][op.reg], 0
]])
elif op.type == OPERAND_TYPE_MEMORY:
addr_name = self.get_address_name(op.addr)
if addr_name:
value = arch.ExpressionNamedValue(long(op.addr), addr_name)
else:
value = op.addr
if has_sib_byte(op) is True:
# when SIB byte set, process the SIB indexing
phrase = parse_phrase(op)
idx_of_value = len(phrase) - 1
operand.extend([[
get_segment_prefix(op),
[
self.NODE_TYPE_DEREFERENCE,
phrase + [[self.NODE_TYPE_VALUE, value, idx_of_value]]
]
]])
else:
operand.extend([[
get_segment_prefix(op),
[
self.NODE_TYPE_DEREFERENCE,
[self.NODE_TYPE_VALUE, value, 0]
]
]])
elif op.type == OPERAND_TYPE_IMMEDIATE:
width = self.OPERAND_WIDTH[self.as_byte_value(op.dtyp)]
if width == arch.Arch.NODE_TYPE_OPERATOR_WIDTH_BYTE_1:
value = op.value & 0xff
elif width == arch.Arch.NODE_TYPE_OPERATOR_WIDTH_BYTE_2:
value = op.value & 0xffff
elif width == arch.Arch.NODE_TYPE_OPERATOR_WIDTH_BYTE_4:
value = op.value & 0xffffffff
else:
value = op.value
operand.extend([[self.NODE_TYPE_VALUE, value, 0]])
elif op.type in (OPERAND_TYPE_NEAR, OPERAND_TYPE_FAR):
addr_name = self.get_address_name(op.addr)
if addr_name:
value = arch.ExpressionNamedValue(long(op.addr), addr_name)
else:
value = op.addr
seg_prefix = get_segment_prefix(op)
if isinstance(seg_prefix, str):
operand.extend([[seg_prefix, [self.NODE_TYPE_VALUE, value,
0]]])
elif isinstance(seg_prefix, (int, long)):
operand.extend([[
self.NODE_TYPE_OPERATOR_SEGMENT_GEN,
[self.NODE_TYPE_VALUE, seg_prefix, 0],
[self.NODE_TYPE_VALUE, value, 1]
]])
elif op.type == OPERAND_TYPE_PHRASE:
if has_sib_byte(op) is True:
phrase = parse_phrase(op)
# Detect observed cases (in GCC compiled sshd) where GCC's instruction
# encoding would be parsed into a phrase with an addition of a single
# register, without any other summands.
# In those cases, if there's a name associated to the zero such as
# a stack variable, we will add a zero to the sum. We do that to have
# an expression to which alias an expression substitution (in the past
# we were removing the addition altogether)
# If there's no name we will remove the redundant 0
#
#
# This case has been observed for the encoding of [esp] where the tree
# would be "[" -> "+" -> "esp".
#
#
if phrase[0] == self.NODE_TYPE_OPERATOR_PLUS and len(
phrase) == 2:
var_name = self.get_operand_stack_variable_name(
address, op, idx)
if var_name:
value = arch.ExpressionNamedValue(0, var_name)
phrase.append([self.NODE_TYPE_VALUE, value, 1])
else:
phrase = phrase[1]
operand.extend([[
get_segment_prefix(op),
[self.NODE_TYPE_DEREFERENCE, phrase]
]])
else:
operand.extend([[
get_segment_prefix(op),
[
self.NODE_TYPE_DEREFERENCE,
[
self.NODE_TYPE_REGISTER,
self.REGISTERS[addressing_mode + 1][op.phrase], 0
]
]
]])
elif op.type == OPERAND_TYPE_IDPSPEC0:
# The operand refers to the TR* registers
operand.extend([[self.NODE_TYPE_REGISTER, 'tr%d' % op.reg, 0]])
elif op.type == OPERAND_TYPE_IDPSPEC1:
# The operand refers to the DR* registers
operand.extend([[self.NODE_TYPE_REGISTER, 'dr%d' % op.reg, 0]])
elif op.type == OPERAND_TYPE_IDPSPEC2:
# The operand refers to the CR* registers
operand.extend([[self.NODE_TYPE_REGISTER, 'cr%d' % op.reg, 0]])
elif op.type == OPERAND_TYPE_IDPSPEC3:
# The operand refers to the FPU register stack
operand.extend([[self.NODE_TYPE_REGISTER, 'st(%d)' % op.reg, 0]])
elif op.type == OPERAND_TYPE_IDPSPEC4:
# The operand is a MMX register
operand.extend([[self.NODE_TYPE_REGISTER, 'mm%d' % op.reg, 0]])
elif op.type == OPERAND_TYPE_IDPSPEC5:
# The operand is a MMX register
operand.extend([[self.NODE_TYPE_REGISTER, 'xmm%d' % op.reg, 0]])
# If no other thing that a width, i.e. ['b2'] is retrieved
# we assume there was no operand... this is a hack but I've seen
# IDA pretend there's a first operand like this:
#
# fld ['b2'], ['b4', ['ds', ['[', ['+', ['$', 'edx'], [...]]]]]
#
# So, in these cases I want no first operand...
#if len(operand)==1:
# return None
return operand
def single_operand_parser(self, address, op, idx):
"""Parse a PPC operand."""
def constraint_value(value):
if value>2**16:
return -(2**32-value)
return value
# Operand parsing
#
if op.type == OPERAND_TYPE_NO_OPERAND:
return None
#print '>>>', hex(address), idx, op.type
segment = idaapi.getseg(address)
addressing_mode = segment.bitness
# Start creating the AST, the root entry is always the width of the
# operand
operand = [self.OPERAND_WIDTH[self.as_byte_value(op.dtyp)]]
# Compose the rest of the AST
#
if op.type == OPERAND_TYPE_DISPLACEMENT:
# A displacement operatior might refer to a variable...
#
var_name = None
# Try to get any name that might have been assigned to the
# variable. It's only done if the register is:
# sp/esp (4) os bp/ebp (5)
#
flags = idc.GetFlags(address)
if (idx==0 and idc.isStkvar0(flags)) or (
idx==1 and idc.isStkvar1(flags)):
var_name = self.get_operand_stack_variable_name(address, op, idx)
#if has_sib_byte(op) is True:
# when SIB byte set, process the SIB indexing
# phrase = parse_phrase(op)
#else:
phrase = [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER,
self.REGISTERS[self.as_byte_value(op.reg)], 0]]
if var_name:
value = arch.ExpressionNamedValue(long(op.addr), var_name)
else:
value = constraint_value(op.addr)
operand.extend([
[self.NODE_TYPE_DEREFERENCE,
phrase+[ [self.NODE_TYPE_VALUE, value, 1]] ] ])
elif op.type == OPERAND_TYPE_REGISTER:
operand.extend([
[self.NODE_TYPE_REGISTER, self.REGISTERS[self.as_byte_value(op.reg)], 1]])
elif op.type == OPERAND_TYPE_MEMORY:
addr_name = self.get_address_name(op.addr)
if addr_name:
value = arch.ExpressionNamedValue(long(op.addr), addr_name)
else:
value = op.addr
operand.extend([
[self.NODE_TYPE_DEREFERENCE,
[self.NODE_TYPE_VALUE, value, 0]] ])
elif op.type == OPERAND_TYPE_IMMEDIATE:
# Keep the value's size
#
if self.as_byte_value(op.dtyp) == 0:
mask = 0xff
elif self.as_byte_value(op.dtyp) == 1:
mask = 0xffff
else:
mask = 0xffffffff
operand.extend([[self.NODE_TYPE_VALUE, op.value&mask, 0]])
elif op.type in (OPERAND_TYPE_NEAR, OPERAND_TYPE_FAR):
addr_name = self.get_address_name(op.addr)
if addr_name:
value = arch.ExpressionNamedValue(long(op.addr), addr_name)
else:
value = op.addr
operand.extend([[self.NODE_TYPE_VALUE, value, 0]])
elif op.type == OPERAND_TYPE_PHRASE:
print '***Dunno how to parse PHRASE'
operand.extend([[self.NODE_TYPE_SYMBOL,
'UNK_PHRASE(val:%d, reg:%d, type:%d)' % (
op.value, self.as_byte_value(op.reg), op.type), 0]])
elif op.type == OPERAND_TYPE_IDPSPEC0:
# Handle Special Purpose Registers
#
register = self.SPR_REGISTERS.get(
op.value, 'UNKNOWN_REGISTER(val:%x)' % op.value)
operand.extend([
[self.NODE_TYPE_REGISTER, register, 0]])
elif op.type == OPERAND_TYPE_IDPSPEC1:
#print '***Dunno how to parse OPERAND_TYPE_IDPSPEC1'
#operand.extend([[self.NODE_TYPE_SYMBOL,
# 'UNK_IDPSPEC1(val:%d, reg:%d, type:%d)' % (
# op.value, op.reg, op.type), 0]])
operand.extend([
[self.NODE_TYPE_REGISTER, self.REGISTERS[self.as_byte_value(op.reg)], 1]])
operand.extend([
[self.NODE_TYPE_REGISTER, self.REGISTERS[self.as_byte_value(op.specflag1)], 2]])
elif op.type == OPERAND_TYPE_IDPSPEC2:
# IDSPEC2 is operand type for all rlwinm and rlwnm
# instructions which are in general op reg, reg, byte, byte, byte
# or eqivalent. simplified mnemonics sometimes take less than
# five arguments.
#
# Keep the value's size
#
if self.as_byte_value(op.dtyp) == 0:
mask = 0xff
elif self.as_byte_value(op.dtyp) == 1:
mask = 0xffff
else:
mask = 0xffffffff
operand_1 = []
operand_2 = []
operand_3 = []
# Get the object representing the instruction's data.
# It varies between IDA pre-5.7 and 5.7 onwards, the following check
# will take care of it (for more detail look into the similar
# construct in arch.py)
#
if hasattr(idaapi, 'cmd' ):
idaapi.decode_insn(address)
ida_instruction = idaapi.cmd
else:
idaapi.ua_code(address)
ida_instruction = idaapi.cvar.cmd
if (ida_instruction.auxpref & 0x0020):
#print "SH"
operand_1 = [self.OPERAND_WIDTH[self.as_byte_value(op.dtyp)]]
operand_1.extend([[self.NODE_TYPE_VALUE, self.as_byte_value(op.reg)&mask, 0]])
else:
operand_1 = [self.OPERAND_WIDTH[self.as_byte_value(op.dtyp)]]
operand_1.extend([[self.NODE_TYPE_REGISTER, self.REGISTERS[self.as_byte_value(op.reg)], 0]])
#print operand_1
if (ida_instruction.auxpref & 0x0040):
#print "MB"
operand_2 = [self.OPERAND_WIDTH[self.as_byte_value(op.dtyp)]]
operand_2.extend([[self.NODE_TYPE_VALUE, self.as_byte_value(op.specflag1)&mask, 0]])
#print operand_2
if (ida_instruction.auxpref & 0x0080):
#print "ME"
operand_3 = [self.OPERAND_WIDTH[self.as_byte_value(op.dtyp)]]
operand_3.extend([[self.NODE_TYPE_VALUE, self.as_byte_value(op.specflag2)&mask, 0]])
#print operand_3
operand = [operand_1]
#operand = operand_1
if (ida_instruction.auxpref & 0x0040):
#print "MB2"
operand.append(operand_2)
if (ida_instruction.auxpref & 0x0080):
#print "ME2"
operand.append(operand_3)
#print operand
# operand = operand_1
#print operand
#print '>>>', hex(address), idx, op.type, op.reg
#operand.extend([[self.NODE_TYPE_OPERATOR_COMMA, [self.NODE_TYPE_VALUE, op.reg&mask, 0], [self.NODE_TYPE_VALUE, self.as_byte_value(op.specflag1)&mask, 1], [self.NODE_TYPE_VALUE, self.as_byte_value(op.specflag2)&mask, 2]]])
elif op.type == OPERAND_TYPE_IDPSPEC3:
# CR registers
#
operand.extend([
[self.NODE_TYPE_REGISTER, self.CR_REGISTERS[self.as_byte_value(op.reg)], 0]])
elif op.type == OPERAND_TYPE_IDPSPEC4:
# The bit in the CR to check for
#
operand.extend([[self.NODE_TYPE_REGISTER, self.as_byte_value(op.reg), 0]])
elif op.type == OPERAND_TYPE_IDPSPEC5:
# Device Control Register, implementation specific
operand.extend([[self.NODE_TYPE_REGISTER, 'DCR(%x)' % op.value, 0]])
return operand
def single_operand_parser(self, address, op, idx):
"""Parse a metapc operand."""
# Convenience functions
#
def has_sib_byte(op):
# Does the instruction use the SIB byte?
return self.as_byte_value(op.specflag1)==1
def get_sib_scale(op):
return (None, 2, 4, 8)[self.as_byte_value(op.specflag2)>>6]
def get_sib_scaled_index_reg(op):
return self.SIB_INDEX_REGISTERS[(self.as_byte_value(op.specflag2)>>3)&0x7]
def get_sib_base_reg(op):
#
# [ [7-6] [5-3] [2-0] ]
# MOD/RM = ( (mod_2 << 6) | (reg_opcode_3 << 3) | rm_3 )
# There's not MOD/RM made available by IDA!?
#
# [ [7-6] [5-3] [2-0] ]
# SIB = ( (scale_2 << 6) | (index_3 << 3) | base )
# op.specflag2
#
# instruction = op + modrm + sib + disp + imm
#
# If MOD is zero there's no base register, otherwise it's EBP
# But IDA exposes no MOD/RM.
# Following a discussion in IDA's forums:
# http://www.hex-rays.com/forum/viewtopic.php?f=8&t=1424&p=8479&hilit=mod+rm#p8479
# checking for it can be done in the following manner:
#
SIB_byte = self.as_byte_value(op.specflag2)
return self.SIB_BASE_REGISTERS[ SIB_byte & 0x7]
def get_segment_prefix(op):
seg_idx = (op.specval>>16)
if seg_idx == 0:
return None
if (op.specval>>16) < len(self.REGISTERS[0]) :
seg_prefix = self.REGISTERS[0][op.specval>>16] + ':'
else:
seg_prefix = op.specval&0xffff
# This must return a string in case a segment register selector is used
# or and int/long of a descriptor itself.
#
return seg_prefix
def parse_phrase(op, has_displacement=False):
"""Parse the expression used for indexed memory access.
Returns its AST as a nested list of lists.
"""
# Check the addressing mode using in this segment
segment = idaapi.getseg(address)
if segment.bitness != 1:
raise Exception(
'Not yet handling addressing modes other than 32bit!')
base_reg = get_sib_base_reg(op)
scaled_index_reg = get_sib_scaled_index_reg(op)
scale = get_sib_scale(op)
if scale:
# return nested list for reg+reg*scale
if base_reg != '':
# The last values in each tuple indicate the
# preferred display position of each element.
# base_reg + (scale_reg * scale)
#
if scaled_index_reg == '':
return [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER, base_reg, 0] ]
return [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER, base_reg, 0],
[self.NODE_TYPE_OPERATOR_TIMES,
[self.NODE_TYPE_REGISTER, scaled_index_reg, 0],
[self.NODE_TYPE_VALUE, scale, 1], 1 ] ]
else:
# If there's no base register and
# mod == 01 or mod == 10 (=> operand has displacement)
# then we need to add EBP
if has_displacement:
return [
self.NODE_TYPE_OPERATOR_PLUS,
[ self.NODE_TYPE_REGISTER, 'ebp', 0],
[ self.NODE_TYPE_OPERATOR_TIMES,
[self.NODE_TYPE_REGISTER, scaled_index_reg, 0],
[self.NODE_TYPE_VALUE, scale, 1], 1 ] ]
return [
self.NODE_TYPE_OPERATOR_PLUS,
[ self.NODE_TYPE_OPERATOR_TIMES,
[self.NODE_TYPE_REGISTER, scaled_index_reg, 0],
[self.NODE_TYPE_VALUE, scale, 1], 0 ] ]
else:
# return nested list for reg+reg
if base_reg == '':
if scaled_index_reg != '':
if has_displacement:
return [
self.NODE_TYPE_OPERATOR_PLUS,
[ self.NODE_TYPE_REGISTER, 'ebp', 0],
[ self.NODE_TYPE_REGISTER, scaled_index_reg, 1 ] ]
return [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER, scaled_index_reg, 0 ] ]
else:
if has_displacement:
return [self.NODE_TYPE_OPERATOR_PLUS, [self.NODE_TYPE_REGISTER, 'ebp', 0] ]
return [ ]
else:
if scaled_index_reg != '':
return [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER, base_reg, 0],
[self.NODE_TYPE_REGISTER, scaled_index_reg, 1 ] ]
else:
return [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER, base_reg, 0] ]
# Operand parsing
#
if op.type == OPERAND_TYPE_NO_OPERAND:
return None
segment = idaapi.getseg(address)
addressing_mode = segment.bitness
# Start creating the AST, the root entry is always the width of the
# operand
operand = [self.OPERAND_WIDTH[ self.as_byte_value( op.dtyp ) ]]
# If the operand indicates a displacement and it does
# the indexing through the SIB the it might be referring
# a variable on the stack and an attempt to retrieve it
# is made.
#
# Compose the rest of the AST
#
if op.type == OPERAND_TYPE_DISPLACEMENT:
# A displacement operatior might refer to a variable...
#
var_name = None
# Try to get any stack name that might have been assigned
# to the variable.
#
flags = idc.GetFlags(address)
if (idx==0 and idc.isStkvar0(flags)) or (
idx==1 and idc.isStkvar1(flags)):
var_name = self.get_operand_stack_variable_name(address, op, idx)
if has_sib_byte(op) is True:
# when SIB byte set, process the SIB indexing
phrase = parse_phrase(op, has_displacement=True)
else:
phrase = [
self.NODE_TYPE_OPERATOR_PLUS,
[self.NODE_TYPE_REGISTER,
self.REGISTERS[addressing_mode+1][op.reg], 0] ]
if var_name:
value = arch.ExpressionNamedValue(long(op.addr), var_name)
else:
value = op.addr
# Calculate the index of the value depending on how many components
# we have in the phrase
#
idx_of_value = len( phrase ) - 1
operand.extend([
[ get_segment_prefix(op),
[self.NODE_TYPE_DEREFERENCE,
phrase+[ [self.NODE_TYPE_VALUE, value, idx_of_value] ] ] ] ])
elif op.type == OPERAND_TYPE_REGISTER:
operand.extend([
[self.NODE_TYPE_REGISTER, self.REGISTERS[self.as_byte_value(op.dtyp)][op.reg], 0]])
elif op.type == OPERAND_TYPE_MEMORY:
addr_name = self.get_address_name(op.addr)
if addr_name:
value = arch.ExpressionNamedValue(long(op.addr), addr_name)
else:
value = op.addr
if has_sib_byte(op) is True:
# when SIB byte set, process the SIB indexing
phrase = parse_phrase(op)
idx_of_value = len( phrase ) - 1
operand.extend([
[ get_segment_prefix(op),
[self.NODE_TYPE_DEREFERENCE,
phrase+[[self.NODE_TYPE_VALUE, value, idx_of_value]] ] ] ])
else:
operand.extend([
[ get_segment_prefix(op),
[self.NODE_TYPE_DEREFERENCE,
[self.NODE_TYPE_VALUE, value, 0] ] ] ])
elif op.type == OPERAND_TYPE_IMMEDIATE:
width = self.OPERAND_WIDTH[self.as_byte_value(op.dtyp)]
if width == arch.Arch.NODE_TYPE_OPERATOR_WIDTH_BYTE_1:
value = op.value&0xff
elif width == arch.Arch.NODE_TYPE_OPERATOR_WIDTH_BYTE_2:
value = op.value&0xffff
elif width == arch.Arch.NODE_TYPE_OPERATOR_WIDTH_BYTE_4:
value = op.value&0xffffffff
else:
value = op.value
operand.extend([[self.NODE_TYPE_VALUE, value, 0]])
elif op.type in (OPERAND_TYPE_NEAR, OPERAND_TYPE_FAR):
addr_name = self.get_address_name(op.addr)
if addr_name:
value = arch.ExpressionNamedValue(long(op.addr), addr_name)
else:
value = op.addr
seg_prefix = get_segment_prefix(op)
if isinstance(seg_prefix, str):
operand.extend([
[ seg_prefix, [self.NODE_TYPE_VALUE, value, 0] ]])
elif isinstance(seg_prefix, (int, long)):
operand.extend([
[ self.NODE_TYPE_OPERATOR_SEGMENT_GEN,
[self.NODE_TYPE_VALUE, seg_prefix, 0],
[self.NODE_TYPE_VALUE, value, 1] ]] )
elif op.type == OPERAND_TYPE_PHRASE:
if has_sib_byte(op) is True:
phrase = parse_phrase(op)
# Detect observed cases (in GCC compiled sshd) where GCC's instruction
# encoding would be parsed into a phrase with an addition of a single
# register, without any other summands.
# In those cases, if there's a name associated to the zero such as
# a stack variable, we will add a zero to the sum. We do that to have
# an expression to which alias an expression substitution (in the past
# we were removing the addition altogether)
# If there's no name we will remove the redundant 0
#
#
# This case has been observed for the encoding of [esp] where the tree
# would be "[" -> "+" -> "esp".
#
#
if phrase[0] == self.NODE_TYPE_OPERATOR_PLUS and len(phrase) == 2:
var_name = self.get_operand_stack_variable_name(address, op, idx)
if var_name:
value = arch.ExpressionNamedValue(0, var_name)
phrase.append( [self.NODE_TYPE_VALUE, value, 1] )
else:
phrase = phrase[1]
operand.extend([
[get_segment_prefix(op),
[self.NODE_TYPE_DEREFERENCE, phrase] ]] )
else:
operand.extend([
[get_segment_prefix(op),
[self.NODE_TYPE_DEREFERENCE,
[self.NODE_TYPE_REGISTER,
self.REGISTERS[addressing_mode+1][op.phrase], 0] ] ]])
elif op.type == OPERAND_TYPE_IDPSPEC0:
# The operand refers to the TR* registers
operand.extend([
[self.NODE_TYPE_REGISTER, 'tr%d' % op.reg, 0]])
elif op.type == OPERAND_TYPE_IDPSPEC1:
# The operand refers to the DR* registers
operand.extend([
[self.NODE_TYPE_REGISTER, 'dr%d' % op.reg, 0]])
elif op.type == OPERAND_TYPE_IDPSPEC2:
# The operand refers to the CR* registers
operand.extend([
[self.NODE_TYPE_REGISTER, 'cr%d' % op.reg, 0]])
elif op.type == OPERAND_TYPE_IDPSPEC3:
# The operand refers to the FPU register stack
operand.extend([
[self.NODE_TYPE_REGISTER, 'st(%d)' % op.reg, 0]])
elif op.type == OPERAND_TYPE_IDPSPEC4:
# The operand is a MMX register
operand.extend([
[self.NODE_TYPE_REGISTER, 'mm%d' % op.reg, 0]])
elif op.type == OPERAND_TYPE_IDPSPEC5:
# The operand is a MMX register
operand.extend([
[self.NODE_TYPE_REGISTER, 'xmm%d' % op.reg, 0]])
# If no other thing that a width, i.e. ['b2'] is retrieved
# we assume there was no operand... this is a hack but I've seen
# IDA pretend there's a first operand like this:
#
# fld ['b2'], ['b4', ['ds', ['[', ['+', ['$', 'edx'], [...]]]]]
#
# So, in these cases I want no first operand...
#if len(operand)==1:
# return None
return operand
