shell bypass 403
# cython: language_level=3, auto_pickle=False
from cpython.ref cimport PyObject, Py_INCREF, Py_DECREF, Py_XDECREF, Py_XINCREF
from cpython.exc cimport PyErr_Fetch, PyErr_Restore
from cpython.pystate cimport PyThreadState_Get
cimport cython
loglevel = 0
reflog = []
cdef log(level, action, obj, lineno):
if loglevel >= level:
reflog.append((lineno, action, id(obj)))
LOG_NONE, LOG_ALL = range(2)
@cython.final
cdef class Context(object):
cdef readonly object name, filename
cdef readonly dict refs
cdef readonly list errors
cdef readonly Py_ssize_t start
def __cinit__(self, name, line=0, filename=None):
self.name = name
self.start = line
self.filename = filename
self.refs = {} # id -> (count, [lineno])
self.errors = []
cdef regref(self, obj, lineno, bint is_null):
log(LOG_ALL, u'regref', u"<NULL>" if is_null else obj, lineno)
if is_null:
self.errors.append(f"NULL argument on line {lineno}")
return
id_ = id(obj)
count, linenumbers = self.refs.get(id_, (0, []))
self.refs[id_] = (count + 1, linenumbers)
linenumbers.append(lineno)
cdef bint delref(self, obj, lineno, bint is_null) except -1:
# returns whether it is ok to do the decref operation
log(LOG_ALL, u'delref', u"<NULL>" if is_null else obj, lineno)
if is_null:
self.errors.append(f"NULL argument on line {lineno}")
return False
id_ = id(obj)
count, linenumbers = self.refs.get(id_, (0, []))
if count == 0:
self.errors.append(f"Too many decrefs on line {lineno}, reference acquired on lines {linenumbers!r}")
return False
elif count == 1:
del self.refs[id_]
return True
else:
self.refs[id_] = (count - 1, linenumbers)
return True
cdef end(self):
if self.refs:
msg = u"References leaked:"
for count, linenos in self.refs.itervalues():
msg += f"\n ({count}) acquired on lines: {u', '.join([f'{x}' for x in linenos])}"
self.errors.append(msg)
if self.errors:
return u"\n".join([u'REFNANNY: '+error for error in self.errors])
else:
return None
cdef void report_unraisable(object e=None):
try:
if e is None:
import sys
e = sys.exc_info()[1]
print(f"refnanny raised an exception: {e}")
except:
pass # We absolutely cannot exit with an exception
# All Python operations must happen after any existing
# exception has been fetched, in case we are called from
# exception-handling code.
cdef PyObject* SetupContext(char* funcname, int lineno, char* filename) except NULL:
if Context is None:
# Context may be None during finalize phase.
# In that case, we don't want to be doing anything fancy
# like caching and resetting exceptions.
return NULL
cdef (PyObject*) type = NULL, value = NULL, tb = NULL, result = NULL
PyThreadState_Get()
PyErr_Fetch(&type, &value, &tb)
try:
ctx = Context(funcname, lineno, filename)
Py_INCREF(ctx)
result = <PyObject*>ctx
except Exception, e:
report_unraisable(e)
PyErr_Restore(type, value, tb)
return result
cdef void GOTREF(PyObject* ctx, PyObject* p_obj, int lineno):
if ctx == NULL: return
cdef (PyObject*) type = NULL, value = NULL, tb = NULL
PyErr_Fetch(&type, &value, &tb)
try:
try:
if p_obj is NULL:
(<Context>ctx).regref(None, lineno, True)
else:
(<Context>ctx).regref(<object>p_obj, lineno, False)
except:
report_unraisable()
except:
# __Pyx_GetException may itself raise errors
pass
PyErr_Restore(type, value, tb)
cdef int GIVEREF_and_report(PyObject* ctx, PyObject* p_obj, int lineno):
if ctx == NULL: return 1
cdef (PyObject*) type = NULL, value = NULL, tb = NULL
cdef bint decref_ok = False
PyErr_Fetch(&type, &value, &tb)
try:
try:
if p_obj is NULL:
decref_ok = (<Context>ctx).delref(None, lineno, True)
else:
decref_ok = (<Context>ctx).delref(<object>p_obj, lineno, False)
except:
report_unraisable()
except:
# __Pyx_GetException may itself raise errors
pass
PyErr_Restore(type, value, tb)
return decref_ok
cdef void GIVEREF(PyObject* ctx, PyObject* p_obj, int lineno):
GIVEREF_and_report(ctx, p_obj, lineno)
cdef void INCREF(PyObject* ctx, PyObject* obj, int lineno):
Py_XINCREF(obj)
PyThreadState_Get()
GOTREF(ctx, obj, lineno)
cdef void DECREF(PyObject* ctx, PyObject* obj, int lineno):
if GIVEREF_and_report(ctx, obj, lineno):
Py_XDECREF(obj)
PyThreadState_Get()
cdef void FinishContext(PyObject** ctx):
if ctx == NULL or ctx[0] == NULL: return
cdef (PyObject*) type = NULL, value = NULL, tb = NULL
cdef object errors = None
cdef Context context
PyThreadState_Get()
PyErr_Fetch(&type, &value, &tb)
try:
try:
context = <Context>ctx[0]
errors = context.end()
if errors:
print(f"{context.filename.decode('latin1')}: {context.name.decode('latin1')}()")
print(errors)
context = None
except:
report_unraisable()
except:
# __Pyx_GetException may itself raise errors
pass
Py_XDECREF(ctx[0])
ctx[0] = NULL
PyErr_Restore(type, value, tb)
ctypedef struct RefNannyAPIStruct:
void (*INCREF)(PyObject*, PyObject*, int)
void (*DECREF)(PyObject*, PyObject*, int)
void (*GOTREF)(PyObject*, PyObject*, int)
void (*GIVEREF)(PyObject*, PyObject*, int)
PyObject* (*SetupContext)(char*, int, char*) except NULL
void (*FinishContext)(PyObject**)
cdef RefNannyAPIStruct api
api.INCREF = INCREF
api.DECREF = DECREF
api.GOTREF = GOTREF
api.GIVEREF = GIVEREF
api.SetupContext = SetupContext
api.FinishContext = FinishContext
cdef extern from "Python.h":
object PyLong_FromVoidPtr(void*)
RefNannyAPI = PyLong_FromVoidPtr(<void*>&api)