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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) 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 * import os, sys, io try: import errno except ImportError: errno = None EBADF = getattr(errno, 'EBADF', 9) EINTR = getattr(errno, 'EINTR', 4) EAGAIN = getattr(errno, 'EAGAIN', 11) EWOULDBLOCK = getattr(errno, 'EWOULDBLOCK', 11) __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") class socket(_socket.socket): """A subclass of _socket.socket adding the makefile() method.""" __slots__ = ["__weakref__", "_io_refs", "_closed"] def __init__(self, family=AF_INET, type=SOCK_STREAM, proto=0, fileno=None): _socket.socket.__init__(self, family, type, proto, fileno) self._io_refs = 0 self._closed = False def __enter__(self): return self def __exit__(self, *args): if not self._closed: self.close() def __repr__(self): """Wrap __repr__() to reveal the real class name.""" s = _socket.socket.__repr__(self) if s.startswith("<socket object"): s = "<%s.%s%s%s" % (self.__class__.__module__, self.__class__.__name__, getattr(self, '_closed', False) and " [closed] " or "", s[7:]) return s def dup(self): """dup() -> socket object Return a new socket object connected to the same system resource. """ fd = dup(self.fileno()) sock = self.__class__(self.family, self.type, self.proto, fileno=fd) sock.settimeout(self.gettimeout()) return sock def accept(self): """accept() -> (socket object, address info) Wait for an incoming connection. Return a new socket representing the connection, and the address of the client. For IP sockets, the address info is a pair (hostaddr, port). """ fd, addr = self._accept() sock = socket(self.family, self.type, self.proto, fileno=fd) # Issue #7995: if no default timeout is set and the listening # socket had a (non-zero) timeout, force the new socket in blocking # mode to override platform-specific socket flags inheritance. if getdefaulttimeout() is None and self.gettimeout(): sock.setblocking(True) return sock, addr def makefile(self, mode="r", buffering=None, *, encoding=None, errors=None, newline=None): """makefile(...) -> an I/O stream connected to the socket The arguments are as for io.open() after the filename, except the only mode characters supported are 'r', 'w' and 'b'. The semantics are similar too. (XXX refactor to share code?) """ for c in mode: if c not in {"r", "w", "b"}: raise ValueError("invalid mode %r (only r, w, b allowed)") writing = "w" in mode reading = "r" in mode or not writing assert reading or writing binary = "b" in mode rawmode = "" if reading: rawmode += "r" if writing: rawmode += "w" raw = SocketIO(self, rawmode) self._io_refs += 1 if buffering is None: buffering = -1 if buffering < 0: buffering = io.DEFAULT_BUFFER_SIZE if buffering == 0: if not binary: raise ValueError("unbuffered streams must be binary") return raw if reading and writing: buffer = io.BufferedRWPair(raw, raw, buffering) elif reading: buffer = io.BufferedReader(raw, buffering) else: assert writing buffer = io.BufferedWriter(raw, buffering) if binary: return buffer text = io.TextIOWrapper(buffer, encoding, errors, newline) text.mode = mode return text def _decref_socketios(self): if self._io_refs > 0: self._io_refs -= 1 if self._closed: self.close() def _real_close(self, _ss=_socket.socket): # This function should not reference any globals. See issue #808164. _ss.close(self) def close(self): # This function should not reference any globals. See issue #808164. self._closed = True if self._io_refs <= 0: self._real_close() def detach(self): """detach() -> file descriptor Close the socket object without closing the underlying file descriptor. The object cannot be used after this call, but the file descriptor can be reused for other purposes. The file descriptor is returned. """ self._closed = True return super().detach() def fromfd(fd, family, type, proto=0): """ fromfd(fd, family, type[, proto]) -> socket object Create a socket object from a duplicate of the given file descriptor. The remaining arguments are the same as for socket(). """ nfd = dup(fd) return socket(family, type, proto, nfd) if hasattr(_socket, "socketpair"): def socketpair(family=None, type=SOCK_STREAM, proto=0): """socketpair([family[, type[, proto]]]) -> (socket object, socket object) Create a pair of socket objects from the sockets returned by the platform socketpair() function. The arguments are the same as for socket() except the default family is AF_UNIX if defined on the platform; otherwise, the default is AF_INET. """ if family is None: try: family = AF_UNIX except NameError: family = AF_INET a, b = _socket.socketpair(family, type, proto) a = socket(family, type, proto, a.detach()) b = socket(family, type, proto, b.detach()) return a, b _blocking_errnos = { EAGAIN, EWOULDBLOCK } class SocketIO(io.RawIOBase): """Raw I/O implementation for stream sockets. This class supports the makefile() method on sockets. It provides the raw I/O interface on top of a socket object. """ # One might wonder why not let FileIO do the job instead. There are two # main reasons why FileIO is not adapted: # - it wouldn't work under Windows (where you can't used read() and # write() on a socket handle) # - it wouldn't work with socket timeouts (FileIO would ignore the # timeout and consider the socket non-blocking) # XXX More docs def __init__(self, sock, mode): if mode not in ("r", "w", "rw", "rb", "wb", "rwb"): raise ValueError("invalid mode: %r" % mode) io.RawIOBase.__init__(self) self._sock = sock if "b" not in mode: mode += "b" self._mode = mode self._reading = "r" in mode self._writing = "w" in mode self._timeout_occurred = False def readinto(self, b): """Read up to len(b) bytes into the writable buffer *b* and return the number of bytes read. If the socket is non-blocking and no bytes are available, None is returned. If *b* is non-empty, a 0 return value indicates that the connection was shutdown at the other end. """ self._checkClosed() self._checkReadable() if self._timeout_occurred: raise IOError("cannot read from timed out object") while True: try: return self._sock.recv_into(b) except timeout: self._timeout_occurred = True raise except error as e: n = e.args[0] if n == EINTR: continue if n in _blocking_errnos: return None raise def write(self, b): """Write the given bytes or bytearray object *b* to the socket and return the number of bytes written. This can be less than len(b) if not all data could be written. If the socket is non-blocking and no bytes could be written None is returned. """ self._checkClosed() self._checkWritable() try: return self._sock.send(b) except error as e: # XXX what about EINTR? if e.args[0] in _blocking_errnos: return None raise def readable(self): """True if the SocketIO is open for reading. """ return self._reading and not self.closed def writable(self): """True if the SocketIO is open for writing. """ return self._writing and not self.closed def fileno(self): """Return the file descriptor of the underlying socket. """ self._checkClosed() return self._sock.fileno() @property def name(self): if not self.closed: return self.fileno() else: return -1 @property def mode(self): return self._mode def close(self): """Close the SocketIO object. This doesn't close the underlying socket, except if all references to it have disappeared. """ if self.closed: return io.RawIOBase.close(self) self._sock._decref_socketios() self._sock = None 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 _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. An 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")