""" Please make sure you read the README COMPLETELY BEFORE reading anything below.
It is very critical that you read coding guidelines in Section E in README file.
"""
from cvalue import *
from lazytarget import *
from configuration import *
import caching
import lldb
def IterateTAILQ_HEAD(headval, element_name):
""" iterate over a TAILQ_HEAD in kernel. refer to bsd/sys/queue.h
params:
headval - value : value object representing the head of the list
element_name- str : string name of the field which holds the list links.
returns:
A generator does not return. It is used for iterating.
value : an object that is of type as headval->tqh_first. Always a pointer object
example usage:
list_head = kern.GetGlobalVariable('mountlist')
for entryobj in IterateTAILQ_HEAD(list_head, 'mnt_list'):
print GetEntrySummary(entryobj)
"""
iter_val = headval.tqh_first
while unsigned(iter_val) != 0 :
yield iter_val
iter_val = iter_val.__getattr__(element_name).tqe_next
def IterateLinkedList(element, field_name):
""" iterate over a linked list.
This is equivalent to elt = element; while(elt) { do_work(elt); elt = elt-><field_name>; }
params:
element - value : value object representing element in the list.
field_name - str : name of field that holds pointer to next element
returns: Nothing. This is used as iterable
example usage:
first_zone = kern.GetGlobalVariable('first_zone')
for zone in IterateLinkedList(first_zone, 'next_zone'):
print GetZoneSummary(zone)
"""
elt = element
while unsigned(elt) != 0:
yield elt
elt = elt.__getattr__(field_name)
def IterateListEntry(element, element_type, field_name):
""" iterate over a list as defined with LIST_HEAD in bsd/sys/queue.h
params:
element - value : Value object for lh_first
element_type - str : Type of the next element
field_name - str : Name of the field in next element's structure
returns:
A generator does not return. It is used for iterating
value : an object thats of type (element_type) head->le_next. Always a pointer object
example usage:
headp = kern.globals.initproc.p_children
for pp in IterateListEntry(headp, 'struct proc *', 'p_sibling'):
print GetProcInfo(pp)
"""
elt = element.lh_first
if type(element_type) == str:
element_type = gettype(element_type)
while unsigned(elt) != 0:
yield elt
next_el = elt.__getattr__(field_name).le_next
elt = cast(next_el, element_type)
def IterateQueue(queue_head, element_ptr_type, element_field_name):
""" iterate over a queue in kernel of type queue_head_t. refer to osfmk/kern/queue.h
params:
queue_head - value : Value object for queue_head.
element_ptr_type - lldb.SBType : a pointer type of the element 'next' points to. Typically its structs like thread, task etc..
- str : OR a string describing the type. ex. 'task *'
element_field_name - str : name of the field in target struct.
returns:
A generator does not return. It is used for iterating.
value : an object thats of type (element_type) queue_head->next. Always a pointer object
"""
if type(element_ptr_type) == str :
element_ptr_type = gettype(element_ptr_type)
queue_head = queue_head.GetSBValue()
queue_head_addr = 0x0
if queue_head.TypeIsPointerType():
queue_head_addr = queue_head.GetValueAsUnsigned()
else:
queue_head_addr = queue_head.GetAddress().GetLoadAddress(LazyTarget.GetTarget())
cur_elt = queue_head.GetChildMemberWithName('next')
while True:
if not cur_elt.IsValid() or cur_elt.GetValueAsUnsigned() == 0 or cur_elt.GetValueAsUnsigned() == queue_head_addr:
break
elt = cur_elt.Cast(element_ptr_type)
yield value(elt)
cur_elt = elt.GetChildMemberWithName(element_field_name).GetChildMemberWithName('next')
class KernelTarget(object):
""" A common kernel object that provides access to kernel objects and information.
The class holds global lists for task, terminated_tasks, procs, zones, zombroc etc.
It also provides a way to symbolicate an address or create a value from an address.
"""
def __init__(self, debugger):
""" Initialize the kernel debugging environment.
Target properties like architecture and connectedness are lazy-evaluted.
"""
self._debugger = debugger self._threads_list = []
self._tasks_list = []
self._allproc = []
self._terminated_tasks_list = []
self._zones_list = []
self._zombproc_list = []
self._kernel_types_cache = {} self._version = None
self._arch = None
self._ptrsize = None self.symbolicator = None
class _GlobalVariableFind(object):
def __init__(self, kern):
self._xnu_kernobj_12obscure12 = kern
def __getattr__(self, name):
v = self._xnu_kernobj_12obscure12.GetGlobalVariable(name)
if not v.GetSBValue().IsValid():
raise ValueError('no such global variable by name: %s '%str(name))
return v
self.globals = _GlobalVariableFind(self)
LazyTarget.Initialize(debugger)
def _GetSymbolicator(self):
""" Internal function: To initialize the symbolication from lldb.utils
"""
if not self.symbolicator is None:
return self.symbolicator
from lldb.utils import symbolication
symbolicator = symbolication.Symbolicator()
symbolicator.target = LazyTarget.GetTarget()
self.symbolicator = symbolicator
return self.symbolicator
def Symbolicate(self, addr):
""" simple method to get name of function/variable from an address. this is equivalent of gdb 'output /a 0xaddress'
params:
addr - int : typically hex value like 0xffffff80002c0df0
returns:
str - '' if no symbol found else the symbol name.
Note: this function only finds the first symbol. If you expect multiple symbol conflict please use SymbolicateFromAddress()
"""
ret_str = ''
syms = self.SymbolicateFromAddress(addr)
if len(syms) > 0:
ret_str +=syms[0].GetName()
return ret_str
def SymbolicateFromAddress(self, addr):
""" symbolicates any given address based on modules loaded in the target.
params:
addr - int : typically hex value like 0xffffff80002c0df0
returns:
[] of SBSymbol: In case we don't find anything than empty array is returned.
Note: a type of symbol can be figured out by gettype() function of SBSymbol.
example usage:
syms = kern.Symbolicate(0xffffff80002c0df0)
for s in syms:
if s.GetType() == lldb.eSymbolTypeCode:
print "Function", s.GetName()
if s.GetType() == lldb.eSymbolTypeData:
print "Variable", s.GetName()
"""
if type(int(1)) != type(addr):
if str(addr).strip().find("0x") == 0 :
addr = int(addr, 16)
else:
addr = int(addr)
ret_array = []
symbolicator = self._GetSymbolicator()
syms = symbolicator.symbolicate(addr)
if not syms:
return ret_array
for s in syms:
ret_array.append(s.get_symbol_context().symbol)
return ret_array
def IsDebuggerConnected(self):
proc_state = LazyTarget.GetProcess().state
if proc_state == lldb.eStateInvalid : return False
if proc_state in [lldb.eStateStopped, lldb.eStateSuspended] : return True
def GetGlobalVariable(self, name):
""" Get the value object representation for a kernel global variable
params:
name : str - name of the variable. ex. version
returns: value - python object representing global variable.
raises : Exception in case the variable is not found.
"""
return value(LazyTarget.GetTarget().FindGlobalVariables(name, 0).GetValueAtIndex(0))
def GetLoadAddressForSymbol(self, name):
""" Get the load address of a symbol in the kernel.
params:
name : str - name of the symbol to lookup
returns: int - the load address as an integer. Use GetValueFromAddress to cast to a value.
raises : LookupError - if the symbol is not found.
"""
name = str(name)
target = LazyTarget.GetTarget()
syms_arr = target.FindSymbols(name)
if syms_arr.IsValid() and len(syms_arr) > 0:
symbol = syms_arr[0].GetSymbol()
if symbol.IsValid():
return int(symbol.GetStartAddress().GetLoadAddress(target))
raise LookupError("Symbol not found: " + name)
def GetValueFromAddress(self, addr, type_str = 'void *'):
""" convert a address to value
params:
addr - int : typically hex value like 0xffffff80008dc390
type_str - str: type to cast to. Default type will be void *
returns:
value : a value object which has address as addr and type is type_str
"""
obj = value(self.globals.version.GetSBValue().CreateValueFromExpression(None,'(void *)'+str(addr)))
obj = cast(obj, type_str)
return obj
def GetValueAsType(self, v, t):
""" Retrieves a global variable 'v' of type 't' wrapped in a vue object.
If 'v' is an address, creates a vue object of the appropriate type.
If 'v' is a name, looks for the global variable and asserts its type.
Throws:
NameError - If 'v' cannot be found
TypeError - If 'v' is of the wrong type
"""
if islong(v):
return self.GetValueFromAddress(v, t)
else:
var = LazyTarget.GetTarget().FindGlobalVariables(v, 1)[0]
if not var:
raise NameError("Failed to find global variable '{0}'".format(v))
if var.GetTypeName() != t:
raise TypeError("{0} must be of type '{1}', not '{2}'".format(v, t, var.GetTypeName()))
return value(var)
def _GetIterator(self, iter_head_name, next_element_name='next', iter_head_type=None):
""" returns an iterator for a collection in kernel memory.
params:
iter_head_name - str : name of queue_head or list head variable.
next_element_name - str : name of the element that leads to next element.
for ex. in struct zone list 'next_zone' is the linking element.
returns:
iterable : typically used in conjunction with "for varname in iterable:"
"""
head_element = self.GetGlobalVariable(iter_head_name)
return head_element.GetSBValue().linked_list_iter(next_element_name)
def TruncPage(self, addr):
return (addr & ~(unsigned(self.GetGlobalVariable("page_size")) - 1))
def RoundPage(self, addr):
return trunc_page(addr + unsigned(self.GetGlobalVariable("page_size")) - 1)
def StraddlesPage(self, addr, size):
if size > unsigned(self.GetGlobalVariable("page_size")):
return True
return (((addr + size) & (unsigned(self.GetGlobalVariable("page_size"))-1)) < size)
def PhysToKernelVirt(self, addr):
if self.arch == 'x86_64':
return (addr + unsigned(self.GetGlobalVariable('physmap_base')))
elif self.arch == 'arm':
return (addr - unsigned(self.GetGlobalVariable("gPhysBase")) + unsigned(self.GetGlobalVariable("gVirtBase")))
else:
raise ValueError("PhysToVirt does not support {0}".format(arch))
def __getattribute__(self, name):
if name == 'zones' :
self._zones_list = caching.GetDynamicCacheData("kern._zones_list", [])
if len(self._zones_list) > 0: return self._zones_list
first_zone = self.GetGlobalVariable('first_zone')
for z in IterateLinkedList(first_zone, 'next_zone'):
self._zones_list.append(z)
caching.SaveDynamicCacheData("kern._zones_list", self._zones_list)
return self._zones_list
if name == 'threads' :
self._threads_list = caching.GetDynamicCacheData("kern._threads_list", [])
if len(self._threads_list) > 0 : return self._threads_list
thread_queue_head = self.GetGlobalVariable('threads')
thread_type = LazyTarget.GetTarget().FindFirstType('thread')
thread_ptr_type = thread_type.GetPointerType()
for th in IterateQueue(thread_queue_head, thread_ptr_type, 'threads'):
self._threads_list.append(th)
caching.SaveDynamicCacheData("kern._threads_list", self._threads_list)
return self._threads_list
if name == 'tasks' :
self._tasks_list = caching.GetDynamicCacheData("kern._tasks_list", [])
if len(self._tasks_list) > 0 : return self._tasks_list
task_queue_head = self.GetGlobalVariable('tasks')
task_type = LazyTarget.GetTarget().FindFirstType('task')
task_ptr_type = task_type.GetPointerType()
for tsk in IterateQueue(task_queue_head, task_ptr_type, 'tasks'):
self._tasks_list.append(tsk)
caching.SaveDynamicCacheData("kern._tasks_list", self._tasks_list)
return self._tasks_list
if name == 'terminated_tasks' :
self._terminated_tasks_list = caching.GetDynamicCacheData("kern._terminated_tasks_list", [])
if len(self._terminated_tasks_list) > 0 : return self._terminated_tasks_list
task_queue_head = self.GetGlobalVariable('terminated_tasks')
task_type = LazyTarget.GetTarget().FindFirstType('task')
task_ptr_type = task_type.GetPointerType()
for tsk in IterateQueue(task_queue_head, task_ptr_type, 'tasks'):
self._terminated_tasks_list.append(tsk)
caching.SaveDynamicCacheData("kern._terminated_tasks_list", self._terminated_tasks_list)
return self._terminated_tasks_list
if name == 'procs' :
self._allproc = caching.GetDynamicCacheData("kern._allproc", [])
if len(self._allproc) > 0 : return self._allproc
all_proc_head = self.GetGlobalVariable('allproc')
proc_val = cast(all_proc_head.lh_first, 'proc *')
while proc_val != 0:
self._allproc.append(proc_val)
proc_val = cast(proc_val.p_list.le_next, 'proc *')
caching.SaveDynamicCacheData("kern._allproc", self._allproc)
return self._allproc
if name == 'zombprocs' :
self._zombproc_list = caching.GetDynamicCacheData("kern._zombproc_list", [])
if len(self._zombproc_list) > 0 : return self._zombproc_list
zproc_head = self.GetGlobalVariable('zombproc')
proc_val = cast(zproc_head.lh_first, 'proc *')
while proc_val != 0:
self._zombproc_list.append(proc_val)
proc_val = cast(proc_val.p_list.le_next, 'proc *')
caching.SaveDynamicCacheData("kern._zombproc_list", self._zombproc_list)
return self._zombproc_list
if name == 'version' :
self._version = caching.GetStaticCacheData("kern.version", None)
if self._version != None : return self._version
self._version = str(self.GetGlobalVariable('version'))
caching.SaveStaticCacheData("kern.version", self._version)
return self._version
if name == 'arch' :
self._arch = caching.GetStaticCacheData("kern.arch", None)
if self._arch != None : return self._arch
arch = LazyTarget.GetTarget().triple.split('-')[0]
if arch in ('armv7', 'armv7s'):
self._arch = 'arm'
else:
self._arch = arch
caching.SaveStaticCacheData("kern.arch", self._arch)
return self._arch
if name == 'ptrsize' :
self._ptrsize = caching.GetStaticCacheData("kern.ptrsize", None)
if self._ptrsize != None : return self._ptrsize
arch = LazyTarget.GetTarget().triple.split('-')[0]
if arch in ('x86_64'):
self._ptrsize = 8
else:
self._ptrsize = 4
caching.SaveStaticCacheData("kern.ptrsize", self._ptrsize)
return self._ptrsize
return object.__getattribute__(self, name)