class MultiProcessingDocumentParser(object):
"""
A document parser that performs all it's tasks in different processes and
returns results to the main process.
Also implements a parsing timeout just in case the parser enters an infinite
loop.
:author: Andres Riancho ([email protected])
"""
DEBUG = core_profiling_is_enabled()
MAX_WORKERS = 2 if is_running_on_ci() else (multiprocessing.cpu_count() /
2) or 1
# Increasing the timeout when profiling is enabled seems to fix issue #9713
#
# https://github.com/andresriancho/w3af/issues/9713
PROFILING_ENABLED = (user_wants_memory_profiling()
or user_wants_pytracemalloc()
or user_wants_cpu_profiling())
# in seconds
PARSER_TIMEOUT = 60 * 3 if PROFILING_ENABLED else 10
# Document parsers can go crazy on memory usage when parsing some very
# specific HTML / PDF documents. Sometimes when this happens the operating
# system does an out of memory (OOM) kill of a "randomly chosen" process.
#
# We limit the memory which can be used by parsing processes to this constant
#
# The feature was tested in test_pebble_limit_memory_usage.py
MEMORY_LIMIT = get_memory_limit()
def __init__(self):
self._pool = None
self._start_lock = threading.RLock()
def start_workers(self):
"""
Start the pool and workers
:return: The pool instance
"""
with self._start_lock:
if self._pool is None:
# Start the process pool
log_queue = om.manager.get_in_queue()
self._pool = ProcessPool(self.MAX_WORKERS,
max_tasks=20,
initializer=init_worker,
initargs=(log_queue,
self.MEMORY_LIMIT))
return self._pool
def stop_workers(self):
"""
Stop the pool workers
:return: None
"""
if self._pool is not None:
self._pool.stop()
self._pool.join()
self._pool = None
def get_document_parser_for(self, http_response):
"""
Get a document parser for http_response
This parses the http_response in a pool worker. This method has two
features:
* We can kill the worker if the parser is taking too long
* We can have different parsers
:param http_response: The http response instance
:return: An instance of DocumentParser
"""
# Start the worker processes if needed
self.start_workers()
apply_args = (process_document_parser, http_response, self.DEBUG)
# Push the task to the workers
try:
future = self._pool.schedule(apply_with_return_error,
args=(apply_args, ),
timeout=self.PARSER_TIMEOUT)
except RuntimeError, rte:
# We get here when the pebble pool management thread dies and
# suddenly starts answering all calls with:
#
# RuntimeError('Unexpected error within the Pool')
#
# The scan needs to stop because we can't parse any more
# HTTP responses, which is a very critical part of the process
msg = str(rte)
raise ScanMustStopException(msg)
try:
parser_output = future.result()
except TimeoutError:
msg = ('[timeout] The parser took more than %s seconds'
' to complete parsing of "%s", killed it!')
args = (self.PARSER_TIMEOUT, http_response.get_url())
raise TimeoutError(msg % args)
# We still need to perform some error handling here...
if isinstance(parser_output, Error):
if isinstance(parser_output.exc_value, MemoryError):
msg = ('The parser exceeded the memory usage limit of %s bytes'
' while trying to parse "%s". The parser was stopped in'
' order to prevent OOM issues.')
args = (self.MEMORY_LIMIT, http_response.get_url())
om.out.debug(msg % args)
raise MemoryError(msg % args)
parser_output.reraise()
# Success!
return parser_output
class MultiProcessingDocumentParser(object):
"""
A document parser that performs all it's tasks in different processes and
returns results to the main process.
Also implements a parsing timeout just in case the parser enters an infinite
loop.
:author: Andres Riancho ([email protected])
"""
# in seconds
PARSER_TIMEOUT = 10
DEBUG = core_profiling_is_enabled()
MAX_WORKERS = 2 if is_running_on_ci() else (multiprocessing.cpu_count() /
2) or 1
def __init__(self):
self._pool = None
self._processes = None
self._start_lock = threading.RLock()
def start_workers(self):
"""
Start the pool and workers
:return: The pool instance
"""
with self._start_lock:
if self._pool is None:
# pylint: disable=E1101
# Keep track of which pid is processing which http response
self._processes = manager.dict()
# pylint: enable=E1101
# The pool
log_queue = om.manager.get_in_queue()
self._pool = ProcessPool(self.MAX_WORKERS,
maxtasksperchild=20,
initializer=init_worker,
initargs=(log_queue, ))
return self._pool
def stop_workers(self):
"""
Stop the pool workers
:return: None
"""
if self._pool is not None:
self._pool.terminate()
self._pool = None
self._processes.clear()
self._processes = None
def _kill_parser_process(self, hash_string, http_response):
"""
Kill the process that's handling the parsing of http_response which
can be identified by hash_string
:param hash_string: The hash for the http_response
:param http_response: The HTTP response which is being parsed
:return: None
"""
# Near the timeout error, so we make sure that the pid is still
# running our "buggy" input
pid = self._processes.pop(hash_string, None)
if pid is not None:
try:
os.kill(pid, signal.SIGTERM)
except OSError, ose:
msg = ('An error occurred while killing the parser'
' process: "%s"')
om.out.debug(msg % ose)
msg = ('[timeout] The parser took more than %s seconds to complete'
' parsing of "%s", killed it!')
if user_wants_memory_profiling() or user_wants_pytracemalloc():
msg += (' Keep in mind that you\'re profiling memory usage and'
' there is a known bug where memory profilers break the'
' parser cache. See issue #9713 for more information'
' https://github.com/andresriancho/w3af/issues/9713')
om.out.debug(msg % (self.PARSER_TIMEOUT, http_response.get_url()))
class MultiProcessingDocumentParser(object):
"""
A document parser that performs all it's tasks in different processes and
returns results to the main process.
Also implements a parsing timeout just in case the parser enters an infinite
loop.
:author: Andres Riancho ([email protected])
"""
DEBUG = core_profiling_is_enabled()
MAX_WORKERS = 2 if is_running_on_ci() else (multiprocessing.cpu_count() / 2) or 1
# Increasing the timeout when profiling is enabled seems to fix issue #9713
#
# https://github.com/andresriancho/w3af/issues/9713
PROFILING_ENABLED = (user_wants_memory_profiling() or
user_wants_pytracemalloc() or
user_wants_cpu_profiling())
# in seconds
PARSER_TIMEOUT = 60 * 3 if PROFILING_ENABLED else 10
def __init__(self):
self._pool = None
self._processes = None
self._start_lock = threading.RLock()
def start_workers(self):
"""
Start the pool and workers
:return: The pool instance
"""
with self._start_lock:
if self._pool is None:
# pylint: disable=E1101
# Keep track of which pid is processing which http response
self._processes = manager.dict()
# pylint: enable=E1101
# The pool
log_queue = om.manager.get_in_queue()
self._pool = ProcessPool(self.MAX_WORKERS,
maxtasksperchild=20,
initializer=init_worker,
initargs=(log_queue,))
return self._pool
def stop_workers(self):
"""
Stop the pool workers
:return: None
"""
if self._pool is not None:
self._pool.terminate()
self._pool = None
if self._processes is not None:
self._processes.clear()
self._processes = None
def _kill_parser_process(self, hash_string, http_response):
"""
Kill the process that's handling the parsing of http_response which
can be identified by hash_string
:param hash_string: The hash for the http_response
:param http_response: The HTTP response which is being parsed
:return: None
"""
# Near the timeout error, so we make sure that the pid is still
# running our "buggy" input
pid = self._processes.pop(hash_string, None)
if pid is not None:
try:
os.kill(pid, signal.SIGTERM)
except OSError, ose:
msg = ('An error occurred while killing the parser'
' process: "%s"')
om.out.debug(msg % ose)
msg = ('[timeout] The parser took more than %s seconds to complete'
' parsing of "%s", killed it!')
if self.PROFILING_ENABLED:
msg += (' You are running a profiling session which requires more'
' CPU and resources to be run; the'
' MultiProcessingDocumentParser failed to parse the HTML'
' document. Try to increase the PARSER_TIMEOUT and try'
' again.\n\n'
'This issue invalidates the profiling session!\n\n'
'See issue #9713 for more information'
' https://github.com/andresriancho/w3af/issues/9713')
log_function = om.out.error if self.PROFILING_ENABLED else om.out.debug
log_function(msg % (self.PARSER_TIMEOUT, http_response.get_url()))
class MultiProcessingDocumentParser(object):
"""
A document parser that performs all it's tasks in different processes and
returns results to the main process.
Also implements a parsing timeout just in case the parser enters an infinite
loop.
:author: Andres Riancho ([email protected])
"""
DEBUG = core_profiling_is_enabled()
MAX_WORKERS = 2 if is_running_on_ci() else (multiprocessing.cpu_count() /
2) or 1
# Increasing the timeout when profiling is enabled seems to fix issue #9713
#
# https://github.com/andresriancho/w3af/issues/9713
PROFILING_ENABLED = (user_wants_memory_profiling()
or user_wants_pytracemalloc()
or user_wants_cpu_profiling())
# in seconds
PARSER_TIMEOUT = 60 * 3 if PROFILING_ENABLED else 10
def __init__(self):
self._pool = None
self._start_lock = threading.RLock()
def start_workers(self):
"""
Start the pool and workers
:return: The pool instance
"""
with self._start_lock:
if self._pool is None:
# Start the process pool
log_queue = om.manager.get_in_queue()
self._pool = ProcessPool(self.MAX_WORKERS,
max_tasks=20,
initializer=init_worker,
initargs=(log_queue, ))
return self._pool
def stop_workers(self):
"""
Stop the pool workers
:return: None
"""
if self._pool is not None:
self._pool.stop()
self._pool.join()
self._pool = None
def get_document_parser_for(self, http_response):
"""
Get a document parser for http_response
This parses the http_response in a pool worker. This method has two
features:
* We can kill the worker if the parser is taking too long
* We can have different parsers
:param http_response: The http response instance
:return: An instance of DocumentParser
"""
# Start the worker processes if needed
self.start_workers()
apply_args = (process_document_parser, http_response, self.DEBUG)
# Push the task to the workers
future = self._pool.schedule(apply_with_return_error,
args=(apply_args, ),
timeout=self.PARSER_TIMEOUT)
try:
parser_output = future.result()
except TimeoutError:
# Act just like when there is no parser
msg = ('[timeout] The parser took more than %s seconds'
' to complete parsing of "%s", killed it!')
args = (self.PARSER_TIMEOUT, http_response.get_url())
raise BaseFrameworkException(msg % args)
else:
if isinstance(parser_output, Error):
parser_output.reraise()
return parser_output
def get_tags_by_filter(self, http_response, tags, yield_text=False):
"""
Return Tag instances for the tags which match the `tags` filter,
parsing and all lxml stuff is done in another process and the Tag
instances are sent to the main process (the one calling this method)
through a pipe
Some things to note:
* Not all responses can be parsed, so I need to call DocumentParser
and handle exceptions
* The parser selected by DocumentParser might not have tags, and
it might not have get_tags_by_filter. In this case just return an
empty list
* Just like get_document_parser_for we have a timeout in place,
when we hit the timeout just return an empty list, this is not
the best thing to do, but makes the plugin code easier to write
(plugins would ignore this anyways)
:param tags: The filter
:param yield_text: Should we yield the tag text?
:return: A list of Tag instances as defined in sgml.py
:see: SGMLParser.get_tags_by_filter
"""
# Start the worker processes if needed
self.start_workers()
apply_args = (process_get_tags_by_filter, http_response, tags,
yield_text, self.DEBUG)
# Push the task to the workers
future = self._pool.schedule(apply_with_return_error,
args=(apply_args, ),
timeout=self.PARSER_TIMEOUT)
try:
filtered_tags = future.result()
except TimeoutError:
# We hit a timeout, return an empty list
return []
else:
# There was an exception in the parser, maybe the HTML was really
# broken, or it wasn't an HTML at all.
if isinstance(filtered_tags, Error):
return []
return filtered_tags
