s3-tests/s3tests/fuzz_headers.py
Kyle Marsh 14288ad2f6 S3 Fuzzer: Incorporate Tv's suggestions
Tv looked over the fuzzer and had some idiomatic and design suggestions.

Adds several tests and reworks how expansion happens in addition to idiom
changes.
2011-09-12 12:57:43 -07:00

281 lines
8.6 KiB
Python

from boto.s3.connection import S3Connection
from optparse import OptionParser
from boto import UserAgent
from . import common
import traceback
import itertools
import random
import string
import struct
import yaml
import sys
import re
class DecisionGraphError(Exception):
""" Raised when a node in a graph tries to set a header or
key that was previously set by another node
"""
def __init__(self, value):
self.value = value
def __str__(self):
return repr(self.value)
class RecursionError(Exception):
"""Runaway recursion in string formatting"""
def __init__(self, msg):
self.msg = msg
def __str__(self):
return '{0.__doc__}: {0.msg!r}'.format(self)
def assemble_decision(decision_graph, prng):
""" Take in a graph describing the possible decision space and a random
number generator and traverse the graph to build a decision
"""
return descend_graph(decision_graph, 'start', prng)
def descend_graph(decision_graph, node_name, prng):
""" Given a graph and a particular node in that graph, set the values in
the node's "set" list, pick a choice from the "choice" list, and
recurse. Finally, return dictionary of values
"""
node = decision_graph[node_name]
try:
choice = make_choice(node['choices'], prng)
if choice == '':
decision = {}
else:
decision = descend_graph(decision_graph, choice, prng)
except IndexError:
decision = {}
for key, choices in node['set'].iteritems():
if key in decision:
raise DecisionGraphError("Node %s tried to set '%s', but that key was already set by a lower node!" %(node_name, key))
decision[key] = make_choice(choices, prng)
if 'headers' in node:
decision.setdefault('headers', [])
for desc in node['headers']:
try:
(repetition_range, header, value) = desc
except ValueError:
(header, value) = desc
repetition_range = '1'
try:
size_min, size_max = repetition_range.split('-', 1)
except ValueError:
size_min = size_max = repetition_range
size_min = int(size_min)
size_max = int(size_max)
num_reps = prng.randint(size_min, size_max)
if header in [h for h, v in decision['headers']]:
raise DecisionGraphError("Node %s tried to add header '%s', but that header already exists!" %(node_name, header))
for _ in xrange(num_reps):
decision['headers'].append([header, value])
return decision
def make_choice(choices, prng):
""" Given a list of (possibly weighted) options or just a single option!,
choose one of the options taking weights into account and return the
choice
"""
if isinstance(choices, str):
return choices
weighted_choices = []
for option in choices:
if option is None:
weighted_choices.append('')
continue
try:
(weight, value) = option.split(None, 1)
except ValueError:
weight = '1'
value = option
weight = int(weight)
if value == 'null' or value == 'None':
value = ''
for _ in xrange(weight):
weighted_choices.append(value)
return prng.choice(weighted_choices)
def expand_headers(decision):
expanded_headers = []
for header in decision['headers']:
h = expand(decision, header[0])
v = expand(decision, header[1])
expanded_headers.append([h, v])
return expanded_headers
def expand(decision, value):
c = itertools.count()
fmt = RepeatExpandingFormatter()
new = fmt.vformat(value, [], decision)
return new
class RepeatExpandingFormatter(string.Formatter):
def __init__(self, _recursion=0):
super(RepeatExpandingFormatter, self).__init__()
# this class assumes it is always instantiated once per
# formatting; use that to detect runaway recursion
self._recursion = _recursion
def get_value(self, key, args, kwargs):
val = super(RepeatExpandingFormatter, self).get_value(key, args, kwargs)
if self._recursion > 5:
raise RecursionError(key)
fmt = self.__class__(_recursion=self._recursion+1)
# must use vformat not **kwargs so our SpecialVariables is not
# downgraded to just a dict
n = fmt.vformat(val, args, kwargs)
return n
class SpecialVariables(dict):
charsets = {
'printable': string.printable,
'punctuation': string.punctuation,
'whitespace': string.whitespace,
'digits': string.digits
}
def __init__(self, orig_dict, prng):
super(SpecialVariables, self).__init__(orig_dict)
self.prng = prng
def __getitem__(self, key):
fields = key.split(None, 1)
fn = getattr(self, 'special_{name}'.format(name=fields[0]), None)
if fn is None:
return super(SpecialVariables, self).__getitem__(key)
if len(fields) == 1:
fields.append('')
return fn(fields[1])
def special_random(self, args):
arg_list = args.split()
try:
size_min, size_max = arg_list[0].split('-', 1)
except ValueError:
size_min = size_max = arg_list[0]
except IndexError:
size_min = '0'
size_max = '1000'
size_min = int(size_min)
size_max = int(size_max)
length = self.prng.randint(size_min, size_max)
try:
charset_arg = arg_list[1]
except IndexError:
charset_arg = 'printable'
if charset_arg == 'binary':
num_bytes = length + 8
tmplist = [self.prng.getrandbits(64) for _ in xrange(num_bytes / 8)]
tmpstring = struct.pack((num_bytes / 8) * 'Q', *tmplist)
tmpstring = tmpstring[0:length]
else:
charset = self.charsets[charset_arg]
tmpstring = ''.join([self.prng.choice(charset) for _ in xrange(length)]) # Won't scale nicely
return tmpstring.replace('{', '{{').replace('}', '}}')
def parse_options():
parser = OptionParser()
parser.add_option('-O', '--outfile', help='write output to FILE. Defaults to STDOUT', metavar='FILE')
parser.add_option('--seed', dest='seed', type='int', help='initial seed for the random number generator', metavar='SEED')
parser.add_option('--seed-file', dest='seedfile', help='read seeds for specific requests from FILE', metavar='FILE')
parser.add_option('-n', dest='num_requests', type='int', help='issue NUM requests before stopping', metavar='NUM')
parser.add_option('--decision-graph', dest='graph_filename', help='file in which to find the request decision graph', metavar='NUM')
parser.set_defaults(num_requests=5)
parser.set_defaults(graph_filename='request_decision_graph.yml')
return parser.parse_args()
def randomlist(seed=None):
""" Returns an infinite generator of random numbers
"""
rng = random.Random(seed)
while True:
yield rng.random()
def _main():
""" The main script
"""
(options, args) = parse_options()
random.seed(options.seed if options.seed else None)
s3_connection = common.s3.main
request_seeds = None
if options.seedfile:
FH = open(options.seedfile, 'r')
request_seeds = FH.readlines()
else:
random_list = randomlist(options.seed)
request_seeds = itertools.islice(random_list, options.num_requests)
graph_file = open(options.graph_filename, 'r')
decision_graph = yaml.safe_load(graph_file)
constants = {
'bucket_readable': 'TODO',
'bucket_not_readable': 'TODO',
'bucket_writable' : 'TODO',
'bucket_not_writable' : 'TODO',
'object_readable' : 'TODO',
'object_not_readable' : 'TODO',
'object_writable' : 'TODO',
'object_not_writable' : 'TODO',
}
for request_seed in request_seeds:
prng = random.Random(request_seed)
decision = assemble_decision(decision_graph, prng)
decision.update(constants)
request = expand_decision(decision, prng)
response = s3_connection.make_request(request['method'], request['path'], data=request['body'], headers=request['headers'], override_num_retries=0)
if response.status == 500 or response.status == 503:
print 'Request generated with seed %d failed:\n%s' % (request_seed, request)
pass
def main():
common.setup()
try:
_main()
except Exception as e:
traceback.print_exc()
common.teardown()