source: python/trunk/Lib/socket.py@ 381

Last change on this file since 381 was 2, checked in by Yuri Dario, 15 years ago

Initial import for vendor code.
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1# Wrapper module for _socket, providing some additional facilities
2# implemented in Python.
3
4"""\
5This module provides socket operations and some related functions.
6On Unix, it supports IP (Internet Protocol) and Unix domain sockets.
7On other systems, it only supports IP. Functions specific for a
8socket are available as methods of the socket object.
9
10Functions:
11
12socket() -- create a new socket object
13socketpair() -- create a pair of new socket objects [*]
14fromfd() -- create a socket object from an open file descriptor [*]
15gethostname() -- return the current hostname
16gethostbyname() -- map a hostname to its IP number
17gethostbyaddr() -- map an IP number or hostname to DNS info
18getservbyname() -- map a service name and a protocol name to a port number
19getprotobyname() -- map a protocol name (e.g. 'tcp') to a number
20ntohs(), ntohl() -- convert 16, 32 bit int from network to host byte order
21htons(), htonl() -- convert 16, 32 bit int from host to network byte order
22inet_aton() -- convert IP addr string (123.45.67.89) to 32-bit packed format
23inet_ntoa() -- convert 32-bit packed format IP to string (123.45.67.89)
24ssl() -- secure socket layer support (only available if configured)
25socket.getdefaulttimeout() -- get the default timeout value
26socket.setdefaulttimeout() -- set the default timeout value
27create_connection() -- connects to an address, with an optional timeout
28
29 [*] not available on all platforms!
30
31Special objects:
32
33SocketType -- type object for socket objects
34error -- exception raised for I/O errors
35has_ipv6 -- boolean value indicating if IPv6 is supported
36
37Integer constants:
38
39AF_INET, AF_UNIX -- socket domains (first argument to socket() call)
40SOCK_STREAM, SOCK_DGRAM, SOCK_RAW -- socket types (second argument)
41
42Many other constants may be defined; these may be used in calls to
43the setsockopt() and getsockopt() methods.
44"""
45
46import _socket
47from _socket import *
48
49try:
50 import _ssl
51except ImportError:
52 # no SSL support
53 pass
54else:
55 def ssl(sock, keyfile=None, certfile=None):
56 # we do an internal import here because the ssl
57 # module imports the socket module
58 import ssl as _realssl
59 warnings.warn("socket.ssl() is deprecated. Use ssl.wrap_socket() instead.",
60 DeprecationWarning, stacklevel=2)
61 return _realssl.sslwrap_simple(sock, keyfile, certfile)
62
63 # we need to import the same constants we used to...
64 from _ssl import SSLError as sslerror
65 from _ssl import \
66 RAND_add, \
67 RAND_egd, \
68 RAND_status, \
69 SSL_ERROR_ZERO_RETURN, \
70 SSL_ERROR_WANT_READ, \
71 SSL_ERROR_WANT_WRITE, \
72 SSL_ERROR_WANT_X509_LOOKUP, \
73 SSL_ERROR_SYSCALL, \
74 SSL_ERROR_SSL, \
75 SSL_ERROR_WANT_CONNECT, \
76 SSL_ERROR_EOF, \
77 SSL_ERROR_INVALID_ERROR_CODE
78
79import os, sys, warnings
80
81try:
82 from cStringIO import StringIO
83except ImportError:
84 from StringIO import StringIO
85
86try:
87 from errno import EBADF
88except ImportError:
89 EBADF = 9
90
91__all__ = ["getfqdn", "create_connection"]
92__all__.extend(os._get_exports_list(_socket))
93
94
95_realsocket = socket
96
97# WSA error codes
98if sys.platform.lower().startswith("win"):
99 errorTab = {}
100 errorTab[10004] = "The operation was interrupted."
101 errorTab[10009] = "A bad file handle was passed."
102 errorTab[10013] = "Permission denied."
103 errorTab[10014] = "A fault occurred on the network??" # WSAEFAULT
104 errorTab[10022] = "An invalid operation was attempted."
105 errorTab[10035] = "The socket operation would block"
106 errorTab[10036] = "A blocking operation is already in progress."
107 errorTab[10048] = "The network address is in use."
108 errorTab[10054] = "The connection has been reset."
109 errorTab[10058] = "The network has been shut down."
110 errorTab[10060] = "The operation timed out."
111 errorTab[10061] = "Connection refused."
112 errorTab[10063] = "The name is too long."
113 errorTab[10064] = "The host is down."
114 errorTab[10065] = "The host is unreachable."
115 __all__.append("errorTab")
116
117
118
119def getfqdn(name=''):
120 """Get fully qualified domain name from name.
121
122 An empty argument is interpreted as meaning the local host.
123
124 First the hostname returned by gethostbyaddr() is checked, then
125 possibly existing aliases. In case no FQDN is available, hostname
126 from gethostname() is returned.
127 """
128 name = name.strip()
129 if not name or name == '0.0.0.0':
130 name = gethostname()
131 try:
132 hostname, aliases, ipaddrs = gethostbyaddr(name)
133 except error:
134 pass
135 else:
136 aliases.insert(0, hostname)
137 for name in aliases:
138 if '.' in name:
139 break
140 else:
141 name = hostname
142 return name
143
144
145_socketmethods = (
146 'bind', 'connect', 'connect_ex', 'fileno', 'listen',
147 'getpeername', 'getsockname', 'getsockopt', 'setsockopt',
148 'sendall', 'setblocking',
149 'settimeout', 'gettimeout', 'shutdown')
150
151if os.name == "nt":
152 _socketmethods = _socketmethods + ('ioctl',)
153
154if sys.platform == "riscos":
155 _socketmethods = _socketmethods + ('sleeptaskw',)
156
157# All the method names that must be delegated to either the real socket
158# object or the _closedsocket object.
159_delegate_methods = ("recv", "recvfrom", "recv_into", "recvfrom_into",
160 "send", "sendto")
161
162class _closedsocket(object):
163 __slots__ = []
164 def _dummy(*args):
165 raise error(EBADF, 'Bad file descriptor')
166 # All _delegate_methods must also be initialized here.
167 send = recv = recv_into = sendto = recvfrom = recvfrom_into = _dummy
168 __getattr__ = _dummy
169
170# Wrapper around platform socket objects. This implements
171# a platform-independent dup() functionality. The
172# implementation currently relies on reference counting
173# to close the underlying socket object.
174class _socketobject(object):
175
176 __doc__ = _realsocket.__doc__
177
178 __slots__ = ["_sock", "__weakref__"] + list(_delegate_methods)
179
180 def __init__(self, family=AF_INET, type=SOCK_STREAM, proto=0, _sock=None):
181 if _sock is None:
182 _sock = _realsocket(family, type, proto)
183 self._sock = _sock
184 for method in _delegate_methods:
185 setattr(self, method, getattr(_sock, method))
186
187 def close(self):
188 self._sock = _closedsocket()
189 dummy = self._sock._dummy
190 for method in _delegate_methods:
191 setattr(self, method, dummy)
192 close.__doc__ = _realsocket.close.__doc__
193
194 def accept(self):
195 sock, addr = self._sock.accept()
196 return _socketobject(_sock=sock), addr
197 accept.__doc__ = _realsocket.accept.__doc__
198
199 def dup(self):
200 """dup() -> socket object
201
202 Return a new socket object connected to the same system resource."""
203 return _socketobject(_sock=self._sock)
204
205 def makefile(self, mode='r', bufsize=-1):
206 """makefile([mode[, bufsize]]) -> file object
207
208 Return a regular file object corresponding to the socket. The mode
209 and bufsize arguments are as for the built-in open() function."""
210 return _fileobject(self._sock, mode, bufsize)
211
212 family = property(lambda self: self._sock.family, doc="the socket family")
213 type = property(lambda self: self._sock.type, doc="the socket type")
214 proto = property(lambda self: self._sock.proto, doc="the socket protocol")
215
216 _s = ("def %s(self, *args): return self._sock.%s(*args)\n\n"
217 "%s.__doc__ = _realsocket.%s.__doc__\n")
218 for _m in _socketmethods:
219 exec _s % (_m, _m, _m, _m)
220 del _m, _s
221
222socket = SocketType = _socketobject
223
224class _fileobject(object):
225 """Faux file object attached to a socket object."""
226
227 default_bufsize = 8192
228 name = "<socket>"
229
230 __slots__ = ["mode", "bufsize", "softspace",
231 # "closed" is a property, see below
232 "_sock", "_rbufsize", "_wbufsize", "_rbuf", "_wbuf", "_wbuf_len",
233 "_close"]
234
235 def __init__(self, sock, mode='rb', bufsize=-1, close=False):
236 self._sock = sock
237 self.mode = mode # Not actually used in this version
238 if bufsize < 0:
239 bufsize = self.default_bufsize
240 self.bufsize = bufsize
241 self.softspace = False
242 # _rbufsize is the suggested recv buffer size. It is *strictly*
243 # obeyed within readline() for recv calls. If it is larger than
244 # default_bufsize it will be used for recv calls within read().
245 if bufsize == 0:
246 self._rbufsize = 1
247 elif bufsize == 1:
248 self._rbufsize = self.default_bufsize
249 else:
250 self._rbufsize = bufsize
251 self._wbufsize = bufsize
252 # We use StringIO for the read buffer to avoid holding a list
253 # of variously sized string objects which have been known to
254 # fragment the heap due to how they are malloc()ed and often
255 # realloc()ed down much smaller than their original allocation.
256 self._rbuf = StringIO()
257 self._wbuf = [] # A list of strings
258 self._wbuf_len = 0
259 self._close = close
260
261 def _getclosed(self):
262 return self._sock is None
263 closed = property(_getclosed, doc="True if the file is closed")
264
265 def close(self):
266 try:
267 if self._sock:
268 self.flush()
269 finally:
270 if self._close:
271 self._sock.close()
272 self._sock = None
273
274 def __del__(self):
275 try:
276 self.close()
277 except:
278 # close() may fail if __init__ didn't complete
279 pass
280
281 def flush(self):
282 if self._wbuf:
283 buffer = "".join(self._wbuf)
284 self._wbuf = []
285 self._wbuf_len = 0
286 self._sock.sendall(buffer)
287
288 def fileno(self):
289 return self._sock.fileno()
290
291 def write(self, data):
292 data = str(data) # XXX Should really reject non-string non-buffers
293 if not data:
294 return
295 self._wbuf.append(data)
296 self._wbuf_len += len(data)
297 if (self._wbufsize == 0 or
298 self._wbufsize == 1 and '\n' in data or
299 self._wbuf_len >= self._wbufsize):
300 self.flush()
301
302 def writelines(self, list):
303 # XXX We could do better here for very long lists
304 # XXX Should really reject non-string non-buffers
305 lines = filter(None, map(str, list))
306 self._wbuf_len += sum(map(len, lines))
307 self._wbuf.extend(lines)
308 if (self._wbufsize <= 1 or
309 self._wbuf_len >= self._wbufsize):
310 self.flush()
311
312 def _get_wbuf_len(self):
313 return self._wbuf_len
314
315 def read(self, size=-1):
316 # Use max, disallow tiny reads in a loop as they are very inefficient.
317 # We never leave read() with any leftover data from a new recv() call
318 # in our internal buffer.
319 rbufsize = max(self._rbufsize, self.default_bufsize)
320 # Our use of StringIO rather than lists of string objects returned by
321 # recv() minimizes memory usage and fragmentation that occurs when
322 # rbufsize is large compared to the typical return value of recv().
323 buf = self._rbuf
324 buf.seek(0, 2) # seek end
325 if size < 0:
326 # Read until EOF
327 self._rbuf = StringIO() # reset _rbuf. we consume it via buf.
328 while True:
329 data = self._sock.recv(rbufsize)
330 if not data:
331 break
332 buf.write(data)
333 return buf.getvalue()
334 else:
335 # Read until size bytes or EOF seen, whichever comes first
336 buf_len = buf.tell()
337 if buf_len >= size:
338 # Already have size bytes in our buffer? Extract and return.
339 buf.seek(0)
340 rv = buf.read(size)
341 self._rbuf = StringIO()
342 self._rbuf.write(buf.read())
343 return rv
344
345 self._rbuf = StringIO() # reset _rbuf. we consume it via buf.
346 while True:
347 left = size - buf_len
348 # recv() will malloc the amount of memory given as its
349 # parameter even though it often returns much less data
350 # than that. The returned data string is short lived
351 # as we copy it into a StringIO and free it. This avoids
352 # fragmentation issues on many platforms.
353 data = self._sock.recv(left)
354 if not data:
355 break
356 n = len(data)
357 if n == size and not buf_len:
358 # Shortcut. Avoid buffer data copies when:
359 # - We have no data in our buffer.
360 # AND
361 # - Our call to recv returned exactly the
362 # number of bytes we were asked to read.
363 return data
364 if n == left:
365 buf.write(data)
366 del data # explicit free
367 break
368 assert n <= left, "recv(%d) returned %d bytes" % (left, n)
369 buf.write(data)
370 buf_len += n
371 del data # explicit free
372 #assert buf_len == buf.tell()
373 return buf.getvalue()
374
375 def readline(self, size=-1):
376 buf = self._rbuf
377 buf.seek(0, 2) # seek end
378 if buf.tell() > 0:
379 # check if we already have it in our buffer
380 buf.seek(0)
381 bline = buf.readline(size)
382 if bline.endswith('\n') or len(bline) == size:
383 self._rbuf = StringIO()
384 self._rbuf.write(buf.read())
385 return bline
386 del bline
387 if size < 0:
388 # Read until \n or EOF, whichever comes first
389 if self._rbufsize <= 1:
390 # Speed up unbuffered case
391 buf.seek(0)
392 buffers = [buf.read()]
393 self._rbuf = StringIO() # reset _rbuf. we consume it via buf.
394 data = None
395 recv = self._sock.recv
396 while data != "\n":
397 data = recv(1)
398 if not data:
399 break
400 buffers.append(data)
401 return "".join(buffers)
402
403 buf.seek(0, 2) # seek end
404 self._rbuf = StringIO() # reset _rbuf. we consume it via buf.
405 while True:
406 data = self._sock.recv(self._rbufsize)
407 if not data:
408 break
409 nl = data.find('\n')
410 if nl >= 0:
411 nl += 1
412 buf.write(data[:nl])
413 self._rbuf.write(data[nl:])
414 del data
415 break
416 buf.write(data)
417 return buf.getvalue()
418 else:
419 # Read until size bytes or \n or EOF seen, whichever comes first
420 buf.seek(0, 2) # seek end
421 buf_len = buf.tell()
422 if buf_len >= size:
423 buf.seek(0)
424 rv = buf.read(size)
425 self._rbuf = StringIO()
426 self._rbuf.write(buf.read())
427 return rv
428 self._rbuf = StringIO() # reset _rbuf. we consume it via buf.
429 while True:
430 data = self._sock.recv(self._rbufsize)
431 if not data:
432 break
433 left = size - buf_len
434 # did we just receive a newline?
435 nl = data.find('\n', 0, left)
436 if nl >= 0:
437 nl += 1
438 # save the excess data to _rbuf
439 self._rbuf.write(data[nl:])
440 if buf_len:
441 buf.write(data[:nl])
442 break
443 else:
444 # Shortcut. Avoid data copy through buf when returning
445 # a substring of our first recv().
446 return data[:nl]
447 n = len(data)
448 if n == size and not buf_len:
449 # Shortcut. Avoid data copy through buf when
450 # returning exactly all of our first recv().
451 return data
452 if n >= left:
453 buf.write(data[:left])
454 self._rbuf.write(data[left:])
455 break
456 buf.write(data)
457 buf_len += n
458 #assert buf_len == buf.tell()
459 return buf.getvalue()
460
461 def readlines(self, sizehint=0):
462 total = 0
463 list = []
464 while True:
465 line = self.readline()
466 if not line:
467 break
468 list.append(line)
469 total += len(line)
470 if sizehint and total >= sizehint:
471 break
472 return list
473
474 # Iterator protocols
475
476 def __iter__(self):
477 return self
478
479 def next(self):
480 line = self.readline()
481 if not line:
482 raise StopIteration
483 return line
484
485_GLOBAL_DEFAULT_TIMEOUT = object()
486
487def create_connection(address, timeout=_GLOBAL_DEFAULT_TIMEOUT):
488 """Connect to *address* and return the socket object.
489
490 Convenience function. Connect to *address* (a 2-tuple ``(host,
491 port)``) and return the socket object. Passing the optional
492 *timeout* parameter will set the timeout on the socket instance
493 before attempting to connect. If no *timeout* is supplied, the
494 global default timeout setting returned by :func:`getdefaulttimeout`
495 is used.
496 """
497
498 msg = "getaddrinfo returns an empty list"
499 host, port = address
500 for res in getaddrinfo(host, port, 0, SOCK_STREAM):
501 af, socktype, proto, canonname, sa = res
502 sock = None
503 try:
504 sock = socket(af, socktype, proto)
505 if timeout is not _GLOBAL_DEFAULT_TIMEOUT:
506 sock.settimeout(timeout)
507 sock.connect(sa)
508 return sock
509
510 except error, msg:
511 if sock is not None:
512 sock.close()
513
514 raise error, msg
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