Benjamin Peterson | e711caf | 2008-06-11 16:44:04 +0000 | [diff] [blame^] | 1 | # |
| 2 | # A higher level module for using sockets (or Windows named pipes) |
| 3 | # |
| 4 | # multiprocessing/connection.py |
| 5 | # |
| 6 | # Copyright (c) 2006-2008, R Oudkerk --- see COPYING.txt |
| 7 | # |
| 8 | |
| 9 | __all__ = [ 'Client', 'Listener', 'Pipe' ] |
| 10 | |
| 11 | import os |
| 12 | import sys |
| 13 | import socket |
| 14 | import time |
| 15 | import tempfile |
| 16 | import itertools |
| 17 | |
| 18 | import _multiprocessing |
| 19 | from multiprocessing import current_process |
| 20 | from multiprocessing.util import get_temp_dir, Finalize, sub_debug, debug |
| 21 | from multiprocessing.forking import duplicate, close |
| 22 | |
| 23 | |
| 24 | # |
| 25 | # |
| 26 | # |
| 27 | |
| 28 | BUFSIZE = 8192 |
| 29 | |
| 30 | _mmap_counter = itertools.count() |
| 31 | |
| 32 | default_family = 'AF_INET' |
| 33 | families = ['AF_INET'] |
| 34 | |
| 35 | if hasattr(socket, 'AF_UNIX'): |
| 36 | default_family = 'AF_UNIX' |
| 37 | families += ['AF_UNIX'] |
| 38 | |
| 39 | if sys.platform == 'win32': |
| 40 | default_family = 'AF_PIPE' |
| 41 | families += ['AF_PIPE'] |
| 42 | |
| 43 | # |
| 44 | # |
| 45 | # |
| 46 | |
| 47 | def arbitrary_address(family): |
| 48 | ''' |
| 49 | Return an arbitrary free address for the given family |
| 50 | ''' |
| 51 | if family == 'AF_INET': |
| 52 | return ('localhost', 0) |
| 53 | elif family == 'AF_UNIX': |
| 54 | return tempfile.mktemp(prefix='listener-', dir=get_temp_dir()) |
| 55 | elif family == 'AF_PIPE': |
| 56 | return tempfile.mktemp(prefix=r'\\.\pipe\pyc-%d-%d-' % |
| 57 | (os.getpid(), next(_mmap_counter))) |
| 58 | else: |
| 59 | raise ValueError('unrecognized family') |
| 60 | |
| 61 | |
| 62 | def address_type(address): |
| 63 | ''' |
| 64 | Return the types of the address |
| 65 | |
| 66 | This can be 'AF_INET', 'AF_UNIX', or 'AF_PIPE' |
| 67 | ''' |
| 68 | if type(address) == tuple: |
| 69 | return 'AF_INET' |
| 70 | elif type(address) is str and address.startswith('\\\\'): |
| 71 | return 'AF_PIPE' |
| 72 | elif type(address) is str: |
| 73 | return 'AF_UNIX' |
| 74 | else: |
| 75 | raise ValueError('address type of %r unrecognized' % address) |
| 76 | |
| 77 | # |
| 78 | # Public functions |
| 79 | # |
| 80 | |
| 81 | class Listener(object): |
| 82 | ''' |
| 83 | Returns a listener object. |
| 84 | |
| 85 | This is a wrapper for a bound socket which is 'listening' for |
| 86 | connections, or for a Windows named pipe. |
| 87 | ''' |
| 88 | def __init__(self, address=None, family=None, backlog=1, authkey=None): |
| 89 | family = family or (address and address_type(address)) \ |
| 90 | or default_family |
| 91 | address = address or arbitrary_address(family) |
| 92 | |
| 93 | if family == 'AF_PIPE': |
| 94 | self._listener = PipeListener(address, backlog) |
| 95 | else: |
| 96 | self._listener = SocketListener(address, family, backlog) |
| 97 | |
| 98 | if authkey is not None and not isinstance(authkey, bytes): |
| 99 | raise TypeError('authkey should be a byte string') |
| 100 | |
| 101 | self._authkey = authkey |
| 102 | |
| 103 | def accept(self): |
| 104 | ''' |
| 105 | Accept a connection on the bound socket or named pipe of `self`. |
| 106 | |
| 107 | Returns a `Connection` object. |
| 108 | ''' |
| 109 | c = self._listener.accept() |
| 110 | if self._authkey: |
| 111 | deliver_challenge(c, self._authkey) |
| 112 | answer_challenge(c, self._authkey) |
| 113 | return c |
| 114 | |
| 115 | def close(self): |
| 116 | ''' |
| 117 | Close the bound socket or named pipe of `self`. |
| 118 | ''' |
| 119 | return self._listener.close() |
| 120 | |
| 121 | address = property(lambda self: self._listener._address) |
| 122 | last_accepted = property(lambda self: self._listener._last_accepted) |
| 123 | |
| 124 | |
| 125 | def Client(address, family=None, authkey=None): |
| 126 | ''' |
| 127 | Returns a connection to the address of a `Listener` |
| 128 | ''' |
| 129 | family = family or address_type(address) |
| 130 | if family == 'AF_PIPE': |
| 131 | c = PipeClient(address) |
| 132 | else: |
| 133 | c = SocketClient(address) |
| 134 | |
| 135 | if authkey is not None and not isinstance(authkey, bytes): |
| 136 | raise TypeError('authkey should be a byte string') |
| 137 | |
| 138 | if authkey is not None: |
| 139 | answer_challenge(c, authkey) |
| 140 | deliver_challenge(c, authkey) |
| 141 | |
| 142 | return c |
| 143 | |
| 144 | |
| 145 | if sys.platform != 'win32': |
| 146 | |
| 147 | def Pipe(duplex=True): |
| 148 | ''' |
| 149 | Returns pair of connection objects at either end of a pipe |
| 150 | ''' |
| 151 | if duplex: |
| 152 | s1, s2 = socket.socketpair() |
| 153 | c1 = _multiprocessing.Connection(os.dup(s1.fileno())) |
| 154 | c2 = _multiprocessing.Connection(os.dup(s2.fileno())) |
| 155 | s1.close() |
| 156 | s2.close() |
| 157 | else: |
| 158 | fd1, fd2 = os.pipe() |
| 159 | c1 = _multiprocessing.Connection(fd1, writable=False) |
| 160 | c2 = _multiprocessing.Connection(fd2, readable=False) |
| 161 | |
| 162 | return c1, c2 |
| 163 | |
| 164 | else: |
| 165 | |
| 166 | from ._multiprocessing import win32 |
| 167 | |
| 168 | def Pipe(duplex=True): |
| 169 | ''' |
| 170 | Returns pair of connection objects at either end of a pipe |
| 171 | ''' |
| 172 | address = arbitrary_address('AF_PIPE') |
| 173 | if duplex: |
| 174 | openmode = win32.PIPE_ACCESS_DUPLEX |
| 175 | access = win32.GENERIC_READ | win32.GENERIC_WRITE |
| 176 | obsize, ibsize = BUFSIZE, BUFSIZE |
| 177 | else: |
| 178 | openmode = win32.PIPE_ACCESS_INBOUND |
| 179 | access = win32.GENERIC_WRITE |
| 180 | obsize, ibsize = 0, BUFSIZE |
| 181 | |
| 182 | h1 = win32.CreateNamedPipe( |
| 183 | address, openmode, |
| 184 | win32.PIPE_TYPE_MESSAGE | win32.PIPE_READMODE_MESSAGE | |
| 185 | win32.PIPE_WAIT, |
| 186 | 1, obsize, ibsize, win32.NMPWAIT_WAIT_FOREVER, win32.NULL |
| 187 | ) |
| 188 | h2 = win32.CreateFile( |
| 189 | address, access, 0, win32.NULL, win32.OPEN_EXISTING, 0, win32.NULL |
| 190 | ) |
| 191 | win32.SetNamedPipeHandleState( |
| 192 | h2, win32.PIPE_READMODE_MESSAGE, None, None |
| 193 | ) |
| 194 | |
| 195 | try: |
| 196 | win32.ConnectNamedPipe(h1, win32.NULL) |
| 197 | except WindowsError as e: |
| 198 | if e.args[0] != win32.ERROR_PIPE_CONNECTED: |
| 199 | raise |
| 200 | |
| 201 | c1 = _multiprocessing.PipeConnection(h1, writable=duplex) |
| 202 | c2 = _multiprocessing.PipeConnection(h2, readable=duplex) |
| 203 | |
| 204 | return c1, c2 |
| 205 | |
| 206 | # |
| 207 | # Definitions for connections based on sockets |
| 208 | # |
| 209 | |
| 210 | class SocketListener(object): |
| 211 | ''' |
| 212 | Represtation of a socket which is bound to an address and listening |
| 213 | ''' |
| 214 | def __init__(self, address, family, backlog=1): |
| 215 | self._socket = socket.socket(getattr(socket, family)) |
| 216 | self._socket.bind(address) |
| 217 | self._socket.listen(backlog) |
| 218 | address = self._socket.getsockname() |
| 219 | if type(address) is tuple: |
| 220 | address = (socket.getfqdn(address[0]),) + address[1:] |
| 221 | self._address = address |
| 222 | self._family = family |
| 223 | self._last_accepted = None |
| 224 | |
| 225 | sub_debug('listener bound to address %r', self._address) |
| 226 | |
| 227 | if family == 'AF_UNIX': |
| 228 | self._unlink = Finalize( |
| 229 | self, os.unlink, args=(self._address,), exitpriority=0 |
| 230 | ) |
| 231 | else: |
| 232 | self._unlink = None |
| 233 | |
| 234 | def accept(self): |
| 235 | s, self._last_accepted = self._socket.accept() |
| 236 | fd = duplicate(s.fileno()) |
| 237 | conn = _multiprocessing.Connection(fd) |
| 238 | s.close() |
| 239 | return conn |
| 240 | |
| 241 | def close(self): |
| 242 | self._socket.close() |
| 243 | if self._unlink is not None: |
| 244 | self._unlink() |
| 245 | |
| 246 | |
| 247 | def SocketClient(address): |
| 248 | ''' |
| 249 | Return a connection object connected to the socket given by `address` |
| 250 | ''' |
| 251 | family = address_type(address) |
| 252 | s = socket.socket( getattr(socket, family) ) |
| 253 | |
| 254 | while 1: |
| 255 | try: |
| 256 | s.connect(address) |
| 257 | except socket.error as e: |
| 258 | if e.args[0] != 10061: # 10061 => connection refused |
| 259 | debug('failed to connect to address %s', address) |
| 260 | raise |
| 261 | time.sleep(0.01) |
| 262 | else: |
| 263 | break |
| 264 | else: |
| 265 | raise |
| 266 | |
| 267 | fd = duplicate(s.fileno()) |
| 268 | conn = _multiprocessing.Connection(fd) |
| 269 | s.close() |
| 270 | return conn |
| 271 | |
| 272 | # |
| 273 | # Definitions for connections based on named pipes |
| 274 | # |
| 275 | |
| 276 | if sys.platform == 'win32': |
| 277 | |
| 278 | class PipeListener(object): |
| 279 | ''' |
| 280 | Representation of a named pipe |
| 281 | ''' |
| 282 | def __init__(self, address, backlog=None): |
| 283 | self._address = address |
| 284 | handle = win32.CreateNamedPipe( |
| 285 | address, win32.PIPE_ACCESS_DUPLEX, |
| 286 | win32.PIPE_TYPE_MESSAGE | win32.PIPE_READMODE_MESSAGE | |
| 287 | win32.PIPE_WAIT, |
| 288 | win32.PIPE_UNLIMITED_INSTANCES, BUFSIZE, BUFSIZE, |
| 289 | win32.NMPWAIT_WAIT_FOREVER, win32.NULL |
| 290 | ) |
| 291 | self._handle_queue = [handle] |
| 292 | self._last_accepted = None |
| 293 | |
| 294 | sub_debug('listener created with address=%r', self._address) |
| 295 | |
| 296 | self.close = Finalize( |
| 297 | self, PipeListener._finalize_pipe_listener, |
| 298 | args=(self._handle_queue, self._address), exitpriority=0 |
| 299 | ) |
| 300 | |
| 301 | def accept(self): |
| 302 | newhandle = win32.CreateNamedPipe( |
| 303 | self._address, win32.PIPE_ACCESS_DUPLEX, |
| 304 | win32.PIPE_TYPE_MESSAGE | win32.PIPE_READMODE_MESSAGE | |
| 305 | win32.PIPE_WAIT, |
| 306 | win32.PIPE_UNLIMITED_INSTANCES, BUFSIZE, BUFSIZE, |
| 307 | win32.NMPWAIT_WAIT_FOREVER, win32.NULL |
| 308 | ) |
| 309 | self._handle_queue.append(newhandle) |
| 310 | handle = self._handle_queue.pop(0) |
| 311 | try: |
| 312 | win32.ConnectNamedPipe(handle, win32.NULL) |
| 313 | except WindowsError as e: |
| 314 | if e.args[0] != win32.ERROR_PIPE_CONNECTED: |
| 315 | raise |
| 316 | return _multiprocessing.PipeConnection(handle) |
| 317 | |
| 318 | @staticmethod |
| 319 | def _finalize_pipe_listener(queue, address): |
| 320 | sub_debug('closing listener with address=%r', address) |
| 321 | for handle in queue: |
| 322 | close(handle) |
| 323 | |
| 324 | def PipeClient(address): |
| 325 | ''' |
| 326 | Return a connection object connected to the pipe given by `address` |
| 327 | ''' |
| 328 | while 1: |
| 329 | try: |
| 330 | win32.WaitNamedPipe(address, 1000) |
| 331 | h = win32.CreateFile( |
| 332 | address, win32.GENERIC_READ | win32.GENERIC_WRITE, |
| 333 | 0, win32.NULL, win32.OPEN_EXISTING, 0, win32.NULL |
| 334 | ) |
| 335 | except WindowsError as e: |
| 336 | if e.args[0] not in (win32.ERROR_SEM_TIMEOUT, |
| 337 | win32.ERROR_PIPE_BUSY): |
| 338 | raise |
| 339 | else: |
| 340 | break |
| 341 | else: |
| 342 | raise |
| 343 | |
| 344 | win32.SetNamedPipeHandleState( |
| 345 | h, win32.PIPE_READMODE_MESSAGE, None, None |
| 346 | ) |
| 347 | return _multiprocessing.PipeConnection(h) |
| 348 | |
| 349 | # |
| 350 | # Authentication stuff |
| 351 | # |
| 352 | |
| 353 | MESSAGE_LENGTH = 20 |
| 354 | |
| 355 | CHALLENGE = '#CHALLENGE#' |
| 356 | WELCOME = '#WELCOME#' |
| 357 | FAILURE = '#FAILURE#' |
| 358 | |
| 359 | if sys.version_info >= (3, 0): # XXX can use bytes literals in 2.6/3.0 |
| 360 | CHALLENGE = CHALLENGE.encode('ascii') |
| 361 | WELCOME = WELCOME.encode('ascii') |
| 362 | FAILURE = FAILURE.encode('ascii') |
| 363 | |
| 364 | def deliver_challenge(connection, authkey): |
| 365 | import hmac |
| 366 | assert isinstance(authkey, bytes) |
| 367 | message = os.urandom(MESSAGE_LENGTH) |
| 368 | connection.send_bytes(CHALLENGE + message) |
| 369 | digest = hmac.new(authkey, message).digest() |
| 370 | response = connection.recv_bytes(256) # reject large message |
| 371 | if response == digest: |
| 372 | connection.send_bytes(WELCOME) |
| 373 | else: |
| 374 | connection.send_bytes(FAILURE) |
| 375 | raise AuthenticationError('digest received was wrong') |
| 376 | |
| 377 | def answer_challenge(connection, authkey): |
| 378 | import hmac |
| 379 | assert isinstance(authkey, bytes) |
| 380 | message = connection.recv_bytes(256) # reject large message |
| 381 | assert message[:len(CHALLENGE)] == CHALLENGE, 'message = %r' % message |
| 382 | message = message[len(CHALLENGE):] |
| 383 | digest = hmac.new(authkey, message).digest() |
| 384 | connection.send_bytes(digest) |
| 385 | response = connection.recv_bytes(256) # reject large message |
| 386 | if response != WELCOME: |
| 387 | raise AuthenticationError('digest sent was rejected') |
| 388 | |
| 389 | # |
| 390 | # Support for using xmlrpclib for serialization |
| 391 | # |
| 392 | |
| 393 | class ConnectionWrapper(object): |
| 394 | def __init__(self, conn, dumps, loads): |
| 395 | self._conn = conn |
| 396 | self._dumps = dumps |
| 397 | self._loads = loads |
| 398 | for attr in ('fileno', 'close', 'poll', 'recv_bytes', 'send_bytes'): |
| 399 | obj = getattr(conn, attr) |
| 400 | setattr(self, attr, obj) |
| 401 | def send(self, obj): |
| 402 | s = self._dumps(obj) |
| 403 | self._conn.send_bytes(s) |
| 404 | def recv(self): |
| 405 | s = self._conn.recv_bytes() |
| 406 | return self._loads(s) |
| 407 | |
| 408 | def _xml_dumps(obj): |
| 409 | return xmlrpclib.dumps((obj,), None, None, None, 1).encode('utf8') |
| 410 | |
| 411 | def _xml_loads(s): |
| 412 | (obj,), method = xmlrpclib.loads(s.decode('utf8')) |
| 413 | return obj |
| 414 | |
| 415 | class XmlListener(Listener): |
| 416 | def accept(self): |
| 417 | global xmlrpclib |
| 418 | import xmlrpc.client as xmlrpclib |
| 419 | obj = Listener.accept(self) |
| 420 | return ConnectionWrapper(obj, _xml_dumps, _xml_loads) |
| 421 | |
| 422 | def XmlClient(*args, **kwds): |
| 423 | global xmlrpclib |
| 424 | import xmlrpc.client as xmlrpclib |
| 425 | return ConnectionWrapper(Client(*args, **kwds), _xml_dumps, _xml_loads) |