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BSc-Thesis/proj/server/src/intercept.py

449 lines
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Python
Executable File

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
from typing import Optional, TypedDict
from socketserver import UnixStreamServer, StreamRequestHandler, ThreadingMixIn
import argparse
import os
import re
type Pointer[T] = tuple[int, T]
type Flags = tuple[int, list[str]]
StructTimeSpec = TypedDict('StructTimeSpec', {'tv_sec': int, 'tv_nsec': int})
class ThreadedUnixStreamServer(ThreadingMixIn, UnixStreamServer):
pass
class Handler(StreamRequestHandler):
pid: int
stack: list[tuple[int, str, tuple]]
ret_addr: int
def before(self) -> None: pass
def after(self) -> None: pass
def before_fallback(self, func_name: str, *args) -> str: pass
def after_fallback(self, func_name: str, *args, **kwargs) -> None: pass
def handle(self):
first = self.rfile.readline()
self.pid = int(first.split(b':')[1])
self.stack = []
print(f'Process with PID {self.pid} connected')
self.before()
try:
while True:
msg = self.rfile.readline()
if not msg:
return
self.handle_msg(msg)
finally:
self.after()
@staticmethod
def parse_str(argument: str) -> tuple[str or bytes, int]:
if not ((len(argument) >= 2 and argument[0] == '"') or (len(argument) >= 3 and argument[0] == 'b' and argument[1] == '"')):
raise ValueError()
idx = 1
esc, fin = False, False
data = b'' if argument[0] == 'b' else ''
tmp = None
for ch in argument[1:]:
idx += 1
if fin:
if ch in (' ', '\t'):
continue
elif ch in (',', ']'):
idx -= 1
break
elif tmp:
tmp += ch
if len(tmp) == 2:
data += bytes([int(tmp, 16)]) if argument[0] == 'b' else chr(int(tmp, 16))
tmp = None
elif esc:
if ch in ('\\', '"'):
data += ch.encode('ascii') if argument[0] == 'b' else ch
elif ch == 'x':
tmp = ''
esc = False
else:
raise ValueError()
elif ch == '"':
fin = True
elif ch == '\\':
esc = True
else:
data += ch.encode('utf-8') if argument[0] == 'b' else ch
if not fin:
raise ValueError()
return data, idx
@staticmethod
def parse_arg(argument: str) -> tuple[any, int]:
if argument == '':
return None, 0
m = re.match(r'\s*\(nil\)', argument)
if m:
return 0, len(m.group(0))
m = re.match(r'^\s*(.*?)([,:]|$)', argument)
a, e = m.group(1), m.group(2)
idx = len(m.group(0))
if a.startswith('0x'):
val = int(a[2:], 16)
elif a.startswith('0') and len(a) > 1:
val = int(a[1:], 8)
else:
val = int(a, 10)
if e in (',', ''):
return val, idx
if argument[idx] == '[':
idx += 1
l, i = Handler.parse_args(argument[idx:])
idx += i
if idx < len(argument) and argument[idx] == ',':
idx += 1
return (val, list(l)), idx
elif argument[idx] == '|':
m = re.match(r'^[| A-Za-z0-9_]*', argument[idx:])
flags = m.group(0)
if not flags.startswith('|') or not flags.endswith('|'):
raise ValueError()
idx += len(flags)
if idx < len(argument) and argument[idx] == ',':
idx += 1
flags = [f.strip() for f in flags[1:-1].split('|') if len(f.strip()) > 0]
return (val, flags), idx
elif argument[idx] == '"':
s, i = Handler.parse_str(argument[idx:])
idx += i
if idx < len(argument) and argument[idx] == ',':
idx += 1
return (val, s), idx
elif argument[idx] == '{':
m = re.match(r'^[^}]*', argument[idx:])
value = m.group(0)
if not value.startswith('{') or not value.endswith('}'):
raise ValueError()
idx += len(value)
if idx < len(argument) and argument[idx] == ',':
idx += 1
entries = {}
for e in [v.strip() for v in value[1:-1].split(',') if len(e.strip()) > 0]:
k, v = e.split(':', 1)
entries[k.strip()] = int(v.strip(), 0)
return (val, entries), idx
else:
raise ValueError()
@staticmethod
def parse_args(arguments: str) -> tuple[tuple, int]:
args = []
idx = 0
while idx < len(arguments):
if arguments[idx] == ']':
idx += 1
break
val, i = Handler.parse_arg(arguments[idx:])
args.append(val)
idx += i
return tuple(args), idx
def handle_msg(self, msg: bytes):
timestamp, data = msg.rstrip(b'\n').split(b' ', 1)
if not data.startswith(b'return ') and not data == b'return':
call = data.decode('utf-8')
print(f'[{self.pid}] {call}')
func_name = call[:call.find('(')]
self.ret_addr = int(call[call.rfind(':') + 1:], 0)
args, _ = Handler.parse_args(call[call.find('(') + 1:call.rfind(':') - 1])
self.stack.append((self.ret_addr, func_name, args))
try:
func = getattr(self, f'before_{func_name}')
if not callable(func):
func = None
except AttributeError:
func = None
try:
if func is None:
raise NotImplementedError()
command = func(*args) or self.before_fallback(func_name, *args) or 'ok'
except NotImplementedError:
command = self.before_fallback(func_name, *args) or 'ok'
print(f'[{self.pid}] -> {command}')
self.wfile.write(command.encode('utf-8') + b'\n')
else:
ret = data.decode('utf-8')
ret_value, _ = Handler.parse_arg(ret[7:].split(';')[0])
self.ret_addr, func_name, args = self.stack.pop()
try:
func = getattr(self, f'after_{func_name}')
if not callable(func):
func = None
except AttributeError:
func = None
try:
if func is None:
raise NotImplementedError()
if ret_value is None:
func(*args)
else:
func(*args, ret_value)
except NotImplementedError:
if ret_value is None:
self.after_fallback(func_name, *args)
else:
self.after_fallback(func_name, *args, ret_value)
print(f'[{self.pid}] -> {ret}')
def before_malloc(self, size: int) -> str:
raise NotImplementedError()
def after_malloc(self, size: int,
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
def before_calloc(self, nmemb: int, size: int) -> str:
raise NotImplementedError()
def after_calloc(self, nmemb: int, size: int,
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
def before_realloc(self, ptr: int, size: int) -> str:
raise NotImplementedError()
def after_realloc(self, ptr: int, size: int,
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
def before_reallocarray(self, ptr: int, nmemb: int, size: int) -> str:
raise NotImplementedError()
def after_reallocarray(self, ptr: int, nmemb: int, size: int,
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
def before_free(self, ptr: int) -> str:
raise NotImplementedError()
def after_free(self, ptr: int) -> None:
raise NotImplementedError()
def before_getopt(self, argc: int, argv: Pointer[list[Pointer[bytes]]], optstring: Pointer[bytes]) -> str:
raise NotImplementedError()
def after_getopt(self, argc: int, argv: Pointer[list[Pointer[bytes]]], optstring: Pointer[bytes],
ret_value: int) -> None:
raise NotImplementedError()
def before_close(self, fildes: int) -> str:
raise NotImplementedError()
def after_close(self, fildes: int,
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
def before_sem_init(self, sem: int, pshared: int, value: int) -> str:
raise NotImplementedError()
def after_sem_init(self, sem: int, pshared: int, value: int,
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
def before_sem_open(self, name: str, oflag: Flags, mode: Optional[int], value: Optional[int]) -> str:
raise NotImplementedError()
def after_sem_open(self, name: str, oflag: Flags, mode: Optional[int], value: Optional[int],
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
def before_sem_post(self, sem: int) -> str:
raise NotImplementedError()
def after_sem_post(self, sem: int,
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
def before_sem_wait(self, sem: int) -> str:
raise NotImplementedError()
def after_sem_wait(self, sem: int,
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
def before_sem_trywait(self, sem: int) -> str:
raise NotImplementedError()
def after_sem_trywait(self, sem: int,
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
def before_sem_timedwait(self, sem: int, abs_timeout: Pointer[StructTimeSpec]) -> str:
raise NotImplementedError()
def after_sem_timedwait(self, sem: int, abs_timeout: Pointer[StructTimeSpec],
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
def before_sem_getvalue(self, sem: int, value_ptr: int) -> str:
raise NotImplementedError()
def after_sem_getvalue(self, sem:int, value_ptr: int,
ret_value: int, errno: str = None, value: int = None) -> None:
raise NotImplementedError()
def before_sem_close(self, sem: int) -> str:
raise NotImplementedError()
def after_sem_close(self, sem: int,
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
def before_sem_unlink(self, name: Pointer[bytes]) -> str:
raise NotImplementedError()
def after_sem_unlink(self, name: Pointer[bytes],
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
def before_sem_destroy(self, sem: int) -> str:
raise NotImplementedError()
def after_sem_destroy(self, sem: int,
ret_value: int, errno: str = None) -> None:
raise NotImplementedError()
class MemoryAllocationTester(Handler):
allocated: dict[int, int]
max_allocated: int
num_malloc: int
num_realloc: int
num_free: int
def before(self):
self.allocated = {}
self.max_allocated = 0
self.num_malloc = 0
self.num_realloc = 0
self.num_free = 0
def after(self):
if len(self.allocated) > 0:
print("Not free'd:")
for ptr, size in self.allocated.items():
print(f' 0x{ptr:x}: {size} bytes')
else:
print("All blocks free'd!")
print(f'Max allocated: {self.max_allocated} bytes')
def update_max_allocated(self):
total = sum(self.allocated.values())
if total > self.max_allocated:
self.max_allocated = total
def after_malloc(self, size, ret_value, errno=None) -> None:
self.num_malloc += 1
if ret_value != 0:
print(ret_value)
self.allocated[ret_value] = size
self.update_max_allocated()
def after_calloc(self, nmemb, size, ret_value, errno=None) -> None:
self.num_malloc += 1
if ret_value != 0:
self.allocated[ret_value] = nmemb * size
self.update_max_allocated()
def after_realloc(self, ptr, size, ret_value, errno=None) -> None:
self.num_realloc += 1
if ptr != 0:
if ret_value != 0:
del self.allocated[ptr]
self.allocated[ret_value] = size
self.update_max_allocated()
def after_reallocarray(self, ptr, nmemb, size, ret_value, errno=None) -> None:
self.num_realloc += 1
if ptr != 0:
if ret_value != 0:
del self.allocated[ptr]
self.allocated[ret_value] = nmemb * size
self.update_max_allocated()
def after_free(self, ptr) -> None:
self.num_free += 1
if ptr != 0:
del self.allocated[ptr]
class ReturnValueCheckTester(Handler):
pass
class InterruptedCheckTester(Handler):
cycles: int = 50
counter: int = 0
last_func_name: Optional[str] = None
last_ret_addr: Optional[int] = None
tested_functions: dict[tuple[str, int], str]
@property
def while_testing(self) -> bool:
return self.counter % self.cycles != 0
def before(self) -> None:
self.tested_functions = {}
def after(self) -> None:
if self.while_testing:
self.error()
for (name, ret_addr), status in self.tested_functions.items():
print(f'{name} (0x{ret_addr:x}) -> {status}')
def error(self):
print(f'Error: Return value and errno EINTR not handled correctly in {self.last_func_name} (return address 0x{self.last_ret_addr:x})')
self.tested_functions[(self.last_func_name, self.last_ret_addr)] = 'failed'
self.counter = 0
self.last_func_name = None
self.last_ret_addr = None
def after_fallback(self, func_name: str, *args, **kwargs) -> None:
if self.while_testing and self.last_func_name != func_name:
self.error()
def before_sem_wait(self, sem: int) -> str:
if self.last_ret_addr and self.last_ret_addr != self.ret_addr:
self.error()
self.counter += 1
if self.while_testing:
self.last_ret_addr = self.ret_addr
self.last_func_name = 'sem_wait'
self.tested_functions[(self.last_func_name, self.last_ret_addr)] = 'running'
return 'fail EINTR'
else:
self.tested_functions[(self.last_func_name, self.last_ret_addr)] = 'passed'
self.last_ret_addr = None
self.last_func_name = None
return 'return 0'
def before_sem_trywait(self, sem: int) -> str:
self.counter += 1
if self.while_testing:
self.last_ret_addr = self.ret_addr
self.last_func_name = 'sem_trywait'
return 'fail EINTR'
else:
self.last_ret_addr = None
self.last_func_name = None
return 'return 0'
def before_sem_timedwait(self, sem: int, abs_timeout: Pointer[StructTimeSpec]) -> str:
self.counter += 1
if self.while_testing:
self.last_ret_addr = self.ret_addr
self.last_func_name = 'sem_timedwait'
return 'fail EINTR'
else:
self.last_ret_addr = None
self.last_func_name = None
return 'return 0'
def before_sem_post(self, sem: int) -> str:
return 'return 0'
def intercept(socket: str, handler: type[Handler]) -> None:
try:
with ThreadedUnixStreamServer(socket, handler) as server:
server.serve_forever()
except KeyboardInterrupt:
print('\nBye')
server.shutdown()
finally:
try:
os.unlink(socket)
except FileNotFoundError:
pass
def main() -> None:
parser = argparse.ArgumentParser()
parser.add_argument('socket', metavar='FILE')
args = parser.parse_args()
intercept(args.socket, Handler)
if __name__ == '__main__':
main()