Edit File: socket.py
# Wrapper module for _socket, providing some additional facilities # implemented in Python. """\ This module provides socket operations and some related functions. On Unix, it supports IP (Internet Protocol) and Unix domain sockets. On other systems, it only supports IP. Functions specific for a socket are available as methods of the socket object. Functions: socket() -- create a new socket object socketpair() -- create a pair of new socket objects [*] fromfd() -- create a socket object from an open file descriptor [*] gethostname() -- return the current hostname gethostbyname() -- map a hostname to its IP number gethostbyaddr() -- map an IP number or hostname to DNS info getservbyname() -- map a service name and a protocol name to a port number getprotobyname() -- map a protocol name (e.g. 'tcp') to a number ntohs(), ntohl() -- convert 16, 32 bit int from network to host byte order htons(), htonl() -- convert 16, 32 bit int from host to network byte order inet_aton() -- convert IP addr string (123.45.67.89) to 32-bit packed format inet_ntoa() -- convert 32-bit packed format IP to string (123.45.67.89) ssl() -- secure socket layer support (only available if configured) socket.getdefaulttimeout() -- get the default timeout value socket.setdefaulttimeout() -- set the default timeout value create_connection() -- connects to an address, with an optional timeout and optional source address. [*] not available on all platforms! Special objects: SocketType -- type object for socket objects error -- exception raised for I/O errors has_ipv6 -- boolean value indicating if IPv6 is supported Integer constants: AF_INET, AF_UNIX -- socket domains (first argument to socket() call) SOCK_STREAM, SOCK_DGRAM, SOCK_RAW -- socket types (second argument) Many other constants may be defined; these may be used in calls to the setsockopt() and getsockopt() methods. """ import _socket from _socket import * from functools import partial from types import MethodType try: import _ssl except ImportError: # no SSL support pass else: def ssl(sock, keyfile=None, certfile=None): # we do an internal import here because the ssl # module imports the socket module import ssl as _realssl warnings.warn("socket.ssl() is deprecated. Use ssl.wrap_socket() instead.", DeprecationWarning, stacklevel=2) return _realssl.sslwrap_simple(sock, keyfile, certfile) # we need to import the same constants we used to... from _ssl import SSLError as sslerror from _ssl import \ RAND_add, \ RAND_status, \ SSL_ERROR_ZERO_RETURN, \ SSL_ERROR_WANT_READ, \ SSL_ERROR_WANT_WRITE, \ SSL_ERROR_WANT_X509_LOOKUP, \ SSL_ERROR_SYSCALL, \ SSL_ERROR_SSL, \ SSL_ERROR_WANT_CONNECT, \ SSL_ERROR_EOF, \ SSL_ERROR_INVALID_ERROR_CODE try: from _ssl import RAND_egd except ImportError: # LibreSSL does not provide RAND_egd pass import os, sys, warnings try: from cStringIO import StringIO except ImportError: from StringIO import StringIO try: import errno except ImportError: errno = None EBADF = getattr(errno, 'EBADF', 9) EINTR = getattr(errno, 'EINTR', 4) __all__ = ["getfqdn", "create_connection"] __all__.extend(os._get_exports_list(_socket)) _realsocket = socket # WSA error codes if sys.platform.lower().startswith("win"): errorTab = {} errorTab[10004] = "The operation was interrupted." errorTab[10009] = "A bad file handle was passed." errorTab[10013] = "Permission denied." errorTab[10014] = "A fault occurred on the network??" # WSAEFAULT errorTab[10022] = "An invalid operation was attempted." errorTab[10035] = "The socket operation would block" errorTab[10036] = "A blocking operation is already in progress." errorTab[10048] = "The network address is in use." errorTab[10054] = "The connection has been reset." errorTab[10058] = "The network has been shut down." errorTab[10060] = "The operation timed out." errorTab[10061] = "Connection refused." errorTab[10063] = "The name is too long." errorTab[10064] = "The host is down." errorTab[10065] = "The host is unreachable." __all__.append("errorTab") def getfqdn(name=''): """Get fully qualified domain name from name. An empty argument is interpreted as meaning the local host. First the hostname returned by gethostbyaddr() is checked, then possibly existing aliases. In case no FQDN is available, hostname from gethostname() is returned. """ name = name.strip() if not name or name == '0.0.0.0': name = gethostname() try: hostname, aliases, ipaddrs = gethostbyaddr(name) except error: pass else: aliases.insert(0, hostname) for name in aliases: if '.' in name: break else: name = hostname return name _socketmethods = ( 'bind', 'connect', 'connect_ex', 'fileno', 'listen', 'getpeername', 'getsockname', 'getsockopt', 'setsockopt', 'sendall', 'setblocking', 'settimeout', 'gettimeout', 'shutdown') if os.name == "nt": _socketmethods = _socketmethods + ('ioctl',) if sys.platform == "riscos": _socketmethods = _socketmethods + ('sleeptaskw',) # All the method names that must be delegated to either the real socket # object or the _closedsocket object. _delegate_methods = ("recv", "recvfrom", "recv_into", "recvfrom_into", "send", "sendto") class _closedsocket(object): __slots__ = [] def _dummy(*args): raise error(EBADF, 'Bad file descriptor') # All _delegate_methods must also be initialized here. send = recv = recv_into = sendto = recvfrom = recvfrom_into = _dummy __getattr__ = _dummy # Wrapper around platform socket objects. This implements # a platform-independent dup() functionality. The # implementation currently relies on reference counting # to close the underlying socket object. class _socketobject(object): __doc__ = _realsocket.__doc__ __slots__ = ["_sock", "__weakref__"] + list(_delegate_methods) def __init__(self, family=AF_INET, type=SOCK_STREAM, proto=0, _sock=None): if _sock is None: _sock = _realsocket(family, type, proto) self._sock = _sock for method in _delegate_methods: setattr(self, method, getattr(_sock, method)) def close(self, _closedsocket=_closedsocket, _delegate_methods=_delegate_methods, setattr=setattr): # This function should not reference any globals. See issue #808164. self._sock = _closedsocket() dummy = self._sock._dummy for method in _delegate_methods: setattr(self, method, dummy) close.__doc__ = _realsocket.close.__doc__ def accept(self): sock, addr = self._sock.accept() return _socketobject(_sock=sock), addr accept.__doc__ = _realsocket.accept.__doc__ def dup(self): """dup() -> socket object Return a new socket object connected to the same system resource.""" return _socketobject(_sock=self._sock) def makefile(self, mode='r', bufsize=-1): """makefile([mode[, bufsize]]) -> file object Return a regular file object corresponding to the socket. The mode and bufsize arguments are as for the built-in open() function.""" return _fileobject(self._sock, mode, bufsize) family = property(lambda self: self._sock.family, doc="the socket family") type = property(lambda self: self._sock.type, doc="the socket type") proto = property(lambda self: self._sock.proto, doc="the socket protocol") def meth(name,self,*args): return getattr(self._sock,name)(*args) for _m in _socketmethods: p = partial(meth,_m) p.__name__ = _m p.__doc__ = getattr(_realsocket,_m).__doc__ m = MethodType(p,None,_socketobject) setattr(_socketobject,_m,m) socket = SocketType = _socketobject class _fileobject(object): """Faux file object attached to a socket object.""" default_bufsize = 8192 name = "<socket>" __slots__ = ["mode", "bufsize", "softspace", # "closed" is a property, see below "_sock", "_rbufsize", "_wbufsize", "_rbuf", "_wbuf", "_wbuf_len", "_close"] def __init__(self, sock, mode='rb', bufsize=-1, close=False): self._sock = sock self.mode = mode # Not actually used in this version if bufsize < 0: bufsize = self.default_bufsize self.bufsize = bufsize self.softspace = False # _rbufsize is the suggested recv buffer size. It is *strictly* # obeyed within readline() for recv calls. If it is larger than # default_bufsize it will be used for recv calls within read(). if bufsize == 0: self._rbufsize = 1 elif bufsize == 1: self._rbufsize = self.default_bufsize else: self._rbufsize = bufsize self._wbufsize = bufsize # We use StringIO for the read buffer to avoid holding a list # of variously sized string objects which have been known to # fragment the heap due to how they are malloc()ed and often # realloc()ed down much smaller than their original allocation. self._rbuf = StringIO() self._wbuf = [] # A list of strings self._wbuf_len = 0 self._close = close def _getclosed(self): return self._sock is None closed = property(_getclosed, doc="True if the file is closed") def close(self): try: if self._sock: self.flush() finally: if self._close: self._sock.close() self._sock = None def __del__(self): try: self.close() except: # close() may fail if __init__ didn't complete pass def flush(self): if self._wbuf: data = "".join(self._wbuf) self._wbuf = [] self._wbuf_len = 0 buffer_size = max(self._rbufsize, self.default_bufsize) data_size = len(data) write_offset = 0 view = memoryview(data) try: while write_offset < data_size: self._sock.sendall(view[write_offset:write_offset+buffer_size]) write_offset += buffer_size finally: if write_offset < data_size: remainder = data[write_offset:] del view, data # explicit free self._wbuf.append(remainder) self._wbuf_len = len(remainder) def fileno(self): return self._sock.fileno() def write(self, data): data = str(data) # XXX Should really reject non-string non-buffers if not data: return self._wbuf.append(data) self._wbuf_len += len(data) if (self._wbufsize == 0 or (self._wbufsize == 1 and '\n' in data) or (self._wbufsize > 1 and self._wbuf_len >= self._wbufsize)): self.flush() def writelines(self, list): # XXX We could do better here for very long lists # XXX Should really reject non-string non-buffers lines = filter(None, map(str, list)) self._wbuf_len += sum(map(len, lines)) self._wbuf.extend(lines) if (self._wbufsize <= 1 or self._wbuf_len >= self._wbufsize): self.flush() def read(self, size=-1): # Use max, disallow tiny reads in a loop as they are very inefficient. # We never leave read() with any leftover data from a new recv() call # in our internal buffer. rbufsize = max(self._rbufsize, self.default_bufsize) # Our use of StringIO rather than lists of string objects returned by # recv() minimizes memory usage and fragmentation that occurs when # rbufsize is large compared to the typical return value of recv(). buf = self._rbuf buf.seek(0, 2) # seek end if size < 0: # Read until EOF self._rbuf = StringIO() # reset _rbuf. we consume it via buf. while True: try: data = self._sock.recv(rbufsize) except error, e: if e.args[0] == EINTR: continue raise if not data: break buf.write(data) return buf.getvalue() else: # Read until size bytes or EOF seen, whichever comes first buf_len = buf.tell() if buf_len >= size: # Already have size bytes in our buffer? Extract and return. buf.seek(0) rv = buf.read(size) self._rbuf = StringIO() self._rbuf.write(buf.read()) return rv self._rbuf = StringIO() # reset _rbuf. we consume it via buf. while True: left = size - buf_len # recv() will malloc the amount of memory given as its # parameter even though it often returns much less data # than that. The returned data string is short lived # as we copy it into a StringIO and free it. This avoids # fragmentation issues on many platforms. try: data = self._sock.recv(left) except error, e: if e.args[0] == EINTR: continue raise if not data: break n = len(data) if n == size and not buf_len: # Shortcut. Avoid buffer data copies when: # - We have no data in our buffer. # AND # - Our call to recv returned exactly the # number of bytes we were asked to read. return data if n == left: buf.write(data) del data # explicit free break assert n <= left, "recv(%d) returned %d bytes" % (left, n) buf.write(data) buf_len += n del data # explicit free #assert buf_len == buf.tell() return buf.getvalue() def readline(self, size=-1): buf = self._rbuf buf.seek(0, 2) # seek end if buf.tell() > 0: # check if we already have it in our buffer buf.seek(0) bline = buf.readline(size) if bline.endswith('\n') or len(bline) == size: self._rbuf = StringIO() self._rbuf.write(buf.read()) return bline del bline if size < 0: # Read until \n or EOF, whichever comes first if self._rbufsize <= 1: # Speed up unbuffered case buf.seek(0) buffers = [buf.read()] self._rbuf = StringIO() # reset _rbuf. we consume it via buf. data = None recv = self._sock.recv while True: try: while data != "\n": data = recv(1) if not data: break buffers.append(data) except error, e: # The try..except to catch EINTR was moved outside the # recv loop to avoid the per byte overhead. if e.args[0] == EINTR: continue raise break return "".join(buffers) buf.seek(0, 2) # seek end self._rbuf = StringIO() # reset _rbuf. we consume it via buf. while True: try: data = self._sock.recv(self._rbufsize) except error, e: if e.args[0] == EINTR: continue raise if not data: break nl = data.find('\n') if nl >= 0: nl += 1 buf.write(data[:nl]) self._rbuf.write(data[nl:]) del data break buf.write(data) return buf.getvalue() else: # Read until size bytes or \n or EOF seen, whichever comes first buf.seek(0, 2) # seek end buf_len = buf.tell() if buf_len >= size: buf.seek(0) rv = buf.read(size) self._rbuf = StringIO() self._rbuf.write(buf.read()) return rv self._rbuf = StringIO() # reset _rbuf. we consume it via buf. while True: try: data = self._sock.recv(self._rbufsize) except error, e: if e.args[0] == EINTR: continue raise if not data: break left = size - buf_len # did we just receive a newline? nl = data.find('\n', 0, left) if nl >= 0: nl += 1 # save the excess data to _rbuf self._rbuf.write(data[nl:]) if buf_len: buf.write(data[:nl]) break else: # Shortcut. Avoid data copy through buf when returning # a substring of our first recv(). return data[:nl] n = len(data) if n == size and not buf_len: # Shortcut. Avoid data copy through buf when # returning exactly all of our first recv(). return data if n >= left: buf.write(data[:left]) self._rbuf.write(data[left:]) break buf.write(data) buf_len += n #assert buf_len == buf.tell() return buf.getvalue() def readlines(self, sizehint=0): total = 0 list = [] while True: line = self.readline() if not line: break list.append(line) total += len(line) if sizehint and total >= sizehint: break return list # Iterator protocols def __iter__(self): return self def next(self): line = self.readline() if not line: raise StopIteration return line _GLOBAL_DEFAULT_TIMEOUT = object() def create_connection(address, timeout=_GLOBAL_DEFAULT_TIMEOUT, source_address=None): """Connect to *address* and return the socket object. Convenience function. Connect to *address* (a 2-tuple ``(host, port)``) and return the socket object. Passing the optional *timeout* parameter will set the timeout on the socket instance before attempting to connect. If no *timeout* is supplied, the global default timeout setting returned by :func:`getdefaulttimeout` is used. If *source_address* is set it must be a tuple of (host, port) for the socket to bind as a source address before making the connection. A host of '' or port 0 tells the OS to use the default. """ host, port = address err = None for res in getaddrinfo(host, port, 0, SOCK_STREAM): af, socktype, proto, canonname, sa = res sock = None try: sock = socket(af, socktype, proto) if timeout is not _GLOBAL_DEFAULT_TIMEOUT: sock.settimeout(timeout) if source_address: sock.bind(source_address) sock.connect(sa) return sock except error as _: err = _ if sock is not None: sock.close() if err is not None: raise err else: raise error("getaddrinfo returns an empty list")
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