Python select.error() Examples

def _internal_poll(self, _deadstate=None, _waitpid=os.waitpid,
                _WNOHANG=os.WNOHANG, _os_error=os.error, _ECHILD=errno.ECHILD):
            """Check if child process has terminated.  Returns returncode
            attribute.

            This method is called by __del__, so it cannot reference anything
            outside of the local scope (nor can any methods it calls).

            """
            if self.returncode is None:
                try:
                    pid, sts = _waitpid(self.pid, _WNOHANG)
                    if pid == self.pid:
                        self._handle_exitstatus(sts)
                except _os_error as e:
                    if _deadstate is not None:
                        self.returncode = _deadstate
                    elif e.errno == _ECHILD:
                        # This happens if SIGCLD is set to be ignored or
                        # waiting for child processes has otherwise been
                        # disabled for our process.  This child is dead, we
                        # can't get the status.
                        # http://bugs.python.org/issue15756
                        self.returncode = 0
            return self.returncode 

def set_reuse_addr(self):
        # try to re-use a server port if possible
        try:
            self.socket.setsockopt(
                socket.SOL_SOCKET, socket.SO_REUSEADDR,
                self.socket.getsockopt(socket.SOL_SOCKET,
                                       socket.SO_REUSEADDR) | 1
                )
        except socket.error:
            pass

    # ==================================================
    # predicates for select()
    # these are used as filters for the lists of sockets
    # to pass to select().
    # ================================================== 

def _retry_on_intr(fn, timeout):
        if timeout is None:
            deadline = float("inf")
        else:
            deadline = monotonic() + timeout

        while True:
            try:
                return fn(timeout)
            # OSError for 3 <= pyver < 3.5, select.error for pyver <= 2.7
            except (OSError, select.error) as e:
                # 'e.args[0]' incantation works for both OSError and select.error
                if e.args[0] != errno.EINTR:
                    raise
                else:
                    timeout = deadline - monotonic()
                    if timeout < 0:
                        timeout = 0
                    if timeout == float("inf"):
                        timeout = None
                    continue 

def proxy(src, dst, callback=None):
    timeout = 10
    try:
        read_ready, _, _ = select.select([src], [], [], timeout)
        while len(read_ready):
            if callback:
                callback(src, dst)
            else:
                dst.send(src.recv(8192))
            read_ready, _, _ = select.select([src], [], [], timeout)
    except (socket.error, select.error, OSError, ValueError):
        pass
    try:
        src.shutdown(socket.SHUT_RDWR)
    except (socket.error, OSError, ValueError):
        pass
    src.close()
    try:
        dst.shutdown(socket.SHUT_RDWR)
    except (socket.error, OSError, ValueError):
        pass
    dst.close() 

def check(self):
		try:
			common.internal_print("Checking module on server: {0}".format(self.get_module_name()))

			server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
			server_socket.settimeout(3)
			server_socket.connect((self.config.get("Global", "remoteserverip"), int(self.config.get(self.get_module_configname(), "serverport"))))
			client_fake_thread = TCP_generic_thread(0, 0, None, None, server_socket, None, self.authentication, self.encryption_module, self.verbosity, self.config, self.get_module_name())
			client_fake_thread.do_check()
			client_fake_thread.communication(True)

			self.cleanup(server_socket)

		except socket.timeout:
			common.internal_print("Checking failed: {0}".format(self.get_module_name()), -1)
			self.cleanup(server_socket)
		except socket.error as exception:
			if exception.args[0] == 111:
				common.internal_print("Checking failed: {0}".format(self.get_module_name()), -1)
			else:
				common.internal_print("Connection error: {0}".format(self.get_module_name()), -1)
			self.cleanup(server_socket)

		return 

def check(self):
		try:
			common.internal_print("Checking module on server: {0}".format(self.get_module_name()))

			server_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
			self.server_tuple = (self.config.get("Global", "remoteserverip"), int(self.config.get(self.get_module_configname(), "serverport")))
			self.comms_socket = server_socket
			self.serverorclient = 0
			self.authenticated = False

			self.do_check()
			self.communication(True)

		except KeyboardInterrupt:
			self.cleanup()
			raise
		except socket.timeout:
			common.internal_print("Checking failed: {0}".format(self.get_module_name()), -1)
		except socket.error:
			self.cleanup()
			raise

		self.cleanup()

		return 

def connect(self):
		try:
			common.internal_print("Starting client: {0}".format(self.get_module_name()))
			server_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
			self.server_tuple = (self.config.get("Global", "remoteserverip"), int(self.config.get(self.get_module_configname(), "serverport")))
			self.comms_socket = server_socket
			self.serverorclient = 0
			self.authenticated = False

			self.do_hello()
			self.communication(False)

		except KeyboardInterrupt:
			self.do_logoff()
			self.cleanup()
			raise
		except socket.error:
			self.cleanup()
			raise

		self.cleanup()

		return 

def _send_buffer(self, buff, target, send_all=False):
        size = len(buff)
        tosend = size
        already_sent = 0

        while tosend > 0:
            try:
                # i should be able to send a bytearray
                sent = target.send(buff[already_sent:])
                if sent == 0:
                    raise RuntimeError('socket connection broken')

                already_sent += sent
                tosend -= sent

            except socket.error as e:
                # if full buffers then wait for them to drain and try again
                if e.errno in [errno.EAGAIN, errno.EWOULDBLOCK]:
                    if send_all:
                        continue
                    return buff[already_sent:]
                else:
                    raise exception.SocketException(str(e))
        return None 

def send(self, channel_type, message, additional_data):
		if channel_type == common.CONTROL_CHANNEL_BYTE:
			transformed_message = self.transform(self.encryption, common.CONTROL_CHANNEL_BYTE+message, 1)
		else:
			transformed_message = self.transform(self.encryption, common.DATA_CHANNEL_BYTE+message, 1)

		common.internal_print("{0} sent: {1}".format(self.module_short, len(transformed_message)), 0, self.verbosity, common.DEBUG)

		# WORKAROUND?!
		# Windows: It looks like when the buffer fills up the OS does not do
		# congestion control, instead throws and exception/returns with
		# WSAEWOULDBLOCK which means that we need to try it again later.
		# So we sleep 100ms and hope that the buffer has more space for us.
		# If it does then it sends the data, otherwise tries it in an infinite
		# loop...
		while True:
			try:
				return self.comms_socket.send(struct.pack(">H", len(transformed_message))+transformed_message)
			except socket.error as se:
				if se.args[0] == 10035: # WSAEWOULDBLOCK
					time.sleep(0.1)
					pass
				else:
					raise 

def _retry_on_intr(fn, timeout):
        if timeout is None:
            deadline = float("inf")
        else:
            deadline = monotonic() + timeout

        while True:
            try:
                return fn(timeout)
            # OSError for 3 <= pyver < 3.5, select.error for pyver <= 2.7
            except (OSError, select.error) as e:
                # 'e.args[0]' incantation works for both OSError and select.error
                if e.args[0] != errno.EINTR:
                    raise
                else:
                    timeout = deadline - monotonic()
                    if timeout < 0:
                        timeout = 0
                    if timeout == float("inf"):
                        timeout = None
                    continue 

def _retry_on_intr(fn, timeout):
        if timeout is None:
            deadline = float("inf")
        else:
            deadline = monotonic() + timeout

        while True:
            try:
                return fn(timeout)
            # OSError for 3 <= pyver < 3.5, select.error for pyver <= 2.7
            except (OSError, select.error) as e:
                # 'e.args[0]' incantation works for both OSError and select.error
                if e.args[0] != errno.EINTR:
                    raise
                else:
                    timeout = deadline - monotonic()
                    if timeout < 0:
                        timeout = 0
                    if timeout == float("inf"):
                        timeout = None
                    continue 

def _read_messages(self):
        while self.connected:
            try:
                r, w, e = select.select([self.sock], [], [])
            except select.error:
                break

            if r and self.connected:
                with self.cLock:
                    data = self.recv()
                    message = json.loads(data)

                    # If id is present -> notifies main thread to return this message as a reply
                    # Otherwise puts message into events queue so it will be dispatched as event
                    if 'id' in message:
                        self.replies[message['id']] = message
                        self.cLock.notify()
                    else:
                        self.events.put(message) 

def unregister(self, fileobj):
        """Unregisters a file object from being monitored."""
        try:
            key = self._fd_to_key.pop(self._fileobj_lookup(fileobj))
        except KeyError:
            raise KeyError("{!r} is not registered".format(fileobj))

        # Getting the fileno of a closed socket on Windows errors with EBADF.
        except socket.error as e:  # Platform-specific: Windows.
            if e.errno != errno.EBADF:
                raise
            else:
                for key in self._fd_to_key.values():
                    if key.fileobj is fileobj:
                        self._fd_to_key.pop(key.fd)
                        break
                else:
                    raise KeyError("{!r} is not registered".format(fileobj))
        return key 

def unregister(self, fileobj):
        """ Unregister a file object from being monitored. """
        try:
            key = self._fd_to_key.pop(self._fileobj_lookup(fileobj))
        except KeyError:
            raise KeyError("{0!r} is not registered".format(fileobj))

        # Getting the fileno of a closed socket on Windows errors with EBADF.
        except socket.error as e:  # Platform-specific: Windows.
            if e.errno != errno.EBADF:
                raise
            else:
                for key in self._fd_to_key.values():
                    if key.fileobj is fileobj:
                        self._fd_to_key.pop(key.fd)
                        break
                else:
                    raise KeyError("{0!r} is not registered".format(fileobj))
        return key 

def wrap_error(func, *args, **kw):
        """
        Wrap socket.error, IOError, OSError, select.error to raise new specialized
        exceptions of Python 3.3 like InterruptedError (PEP 3151).
        """
        try:
            return func(*args, **kw)
        except (socket.error, IOError, OSError) as exc:
            if hasattr(exc, 'winerror'):
                _wrap_error(exc, _MAP_ERRNO, exc.winerror)
                # _MAP_ERRNO does not contain all Windows errors.
                # For some errors like "file not found", exc.errno should
                # be used (ex: ENOENT).
            _wrap_error(exc, _MAP_ERRNO, exc.errno)
            raise
        except select.error as exc:
            if exc.args:
                _wrap_error(exc, _MAP_ERRNO, exc.args[0])
            raise 

def _internal_poll(self, _deadstate=None, _waitpid=os.waitpid,
                _WNOHANG=os.WNOHANG, _os_error=os.error):
            """Check if child process has terminated.  Returns returncode
            attribute.

            This method is called by __del__, so it cannot reference anything
            outside of the local scope (nor can any methods it calls).

            """
            if self.returncode is None:
                try:
                    pid, sts = _waitpid(self.pid, _WNOHANG)
                    if pid == self.pid:
                        self._handle_exitstatus(sts)
                except _os_error:
                    if _deadstate is not None:
                        self.returncode = _deadstate
            return self.returncode 

def non_polling_read(self, read_length, timeout):
        data = ''
        bytes_left = read_length

        while bytes_left > 0:
            try:
                ready, _, _ = select.select([self._sock.fileno()], [], [], timeout)

                if not ready:
                    raise NetBIOSTimeout

                received = self._sock.recv(bytes_left)
                if len(received) == 0:
                    raise NetBIOSError, ('Error while reading from remote', ERRCLASS_OS, None)

                data = data + received
                bytes_left = read_length - len(data)
            except select.error, ex:
                if ex[0] != errno.EINTR and ex[0] != errno.EAGAIN:
                    raise NetBIOSError, ('Error occurs while reading from remote', ERRCLASS_OS, ex[0]) 

def _setup_connection(self, dstaddr, timeout=None):
        port = randint(10000, 60000)
        af, socktype, proto, _canonname, _sa = socket.getaddrinfo(dstaddr, port, socket.AF_INET, socket.SOCK_DGRAM)[0]
        s = socket.socket(af, socktype, proto)
        has_bind = 1
        for _i in range(0, 10):
            # We try to bind to a port for 10 tries
            try:
                s.bind((INADDR_ANY, randint(10000, 60000)))
                s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
                has_bind = 1
            except socket.error:
                pass
        if not has_bind:
            raise NetBIOSError, ('Cannot bind to a good UDP port', ERRCLASS_OS, errno.EAGAIN)
        self.__sock = s 

def fsfreeze(self, vm, port=QEMU_GUEST_AGENT_PORT, timeout=0):
        s_ctl = self._get_agent_ctl_safe(vm, port, timeout)
        s_ctl.stdin.write('{"execute":"guest-fsfreeze-freeze"}')
        data = os.read(s_ctl.stdout.fileno(), QMP_READ_SIZE)
        try:
            ret = json.loads(data)
        except:
            raise AgentError("Failed to parse agent output")

        if "error" in ret:
            raise AgentError("Error while freezing VM: " + ret["error"]["desc"])

        ret = json.loads(data)["return"]
        if  ret <= 0:
            raise AgentError("No filesystem frozen")

        s_ctl.terminate() 

def _read_a_command(self):
        """
        Read data from the VM until a complete command is read
        """
        while not '\n' in self.databuff:
            rdr, _, _ = select.select([self.sp_r, self.sock], [], [])
            if self.sp_r in rdr:
                # The host agent is shutting down
                # so we interrupt our read
                return None
            elif rdr:
                try:
                    tdata = self.sock.recv(32768)
                except socket.error:
                    tdata = None

                if not tdata:
                    return None
                else:
                    self.databuff = self.databuff + tdata

        sret = self.databuff.split("\n")
        self.databuff = "\n".join(sret[1:])
        ret = sret[0]
        return ret 

def _print_at(self, text, x, y, width):
            """
            Print string at the required location.

            :param text: The text string to print.
            :param x: The x coordinate
            :param y: The Y coordinate
            :param width: The width of the character (for dual-width glyphs in CJK languages).
            """
            # We can throw temporary errors on resizing, so catch and ignore
            # them on the assumption that we'll resize shortly.
            try:
                # Move the cursor if necessary
                if x != self._cur_x or y != self._cur_y:
                    self._stdout.SetConsoleCursorPosition(
                        win32console.PyCOORDType(x, y))

                # Print the text at the required location and update the current
                # position.
                self._stdout.WriteConsole(text)
                self._cur_x = x + width
                self._cur_y = y
            except pywintypes.error:
                pass 

def sleep(self):
        """\
        Sleep until PIPE is readable or we timeout.
        A readable PIPE means a signal occurred.
        """
        try:
            ready = select.select([self.PIPE[0]], [], [], 1.0)
            if not ready[0]:
                return
            while os.read(self.PIPE[0], 1):
                pass
        except select.error as e:
            if e.args[0] not in [errno.EAGAIN, errno.EINTR]:
                raise
        except OSError as e:
            if e.errno not in [errno.EAGAIN, errno.EINTR]:
                raise
        except KeyboardInterrupt:
            sys.exit() 

def wait(self, timeout):
        try:
            self.notify()
            ret = select.select(self.wait_fds, [], [], timeout)
            if ret[0]:
                if self.PIPE[0] in ret[0]:
                    os.read(self.PIPE[0], 1)
                return ret[0]

        except select.error as e:
            if e.args[0] == errno.EINTR:
                return self.sockets
            if e.args[0] == errno.EBADF:
                if self.nr < 0:
                    return self.sockets
                else:
                    raise StopWaiting
            raise 

def unregister(self, fileobj):
        """ Unregister a file object from being monitored. """
        try:
            key = self._fd_to_key.pop(self._fileobj_lookup(fileobj))
        except KeyError:
            raise KeyError("{0!r} is not registered".format(fileobj))

        # Getting the fileno of a closed socket on Windows errors with EBADF.
        except socket.error as e:  # Platform-specific: Windows.
            if e.errno != errno.EBADF:
                raise
            else:
                for key in self._fd_to_key.values():
                    if key.fileobj is fileobj:
                        self._fd_to_key.pop(key.fd)
                        break
                else:
                    raise KeyError("{0!r} is not registered".format(fileobj))
        return key 

def unregister(self, fileobj):
        """ Unregister a file object from being monitored. """
        try:
            key = self._fd_to_key.pop(self._fileobj_lookup(fileobj))
        except KeyError:
            raise KeyError("{0!r} is not registered".format(fileobj))

        # Getting the fileno of a closed socket on Windows errors with EBADF.
        except socket.error as e:  # Platform-specific: Windows.
            if e.errno != errno.EBADF:
                raise
            else:
                for key in self._fd_to_key.values():
                    if key.fileobj is fileobj:
                        self._fd_to_key.pop(key.fd)
                        break
                else:
                    raise KeyError("{0!r} is not registered".format(fileobj))
        return key 

def send(self, channel_type, message, additional_data):
		addr = additional_data[0]
		identifier = additional_data[1]
		sequence = additional_data[2]
		queue_length = additional_data[3]

		if queue_length < 256:
			ql = chr(queue_length)
		else:
			ql = chr(255)

		if channel_type == common.CONTROL_CHANNEL_BYTE:
			transformed_message = self.transform(self.get_client_encryption(additional_data), ql+common.CONTROL_CHANNEL_BYTE+message, 1)
		else:
			transformed_message = self.transform(self.get_client_encryption(additional_data), ql+common.DATA_CHANNEL_BYTE+message, 1)

		common.internal_print("ICMP sent: {0} seq: {1} id: {2}".format(len(transformed_message), sequence, identifier), 0, self.verbosity, common.DEBUG)

		packet = self.icmp.create_packet(self.ICMP_send, identifier, sequence,
			self.ICMP_prefix+struct.pack(">H", len(transformed_message))+transformed_message)

		# WORKAROUND?!
		# Windows: It looks like when the buffer fills up the OS does not do
		# congestion control, instead throws and exception/returns with
		# WSAEWOULDBLOCK which means that we need to try it again later.
		# So we sleep 100ms and hope that the buffer has more space for us.
		# If it does then it sends the data, otherwise tries it in an infinite
		# loop...
		while True:
			try:
				return self.comms_socket.sendto(packet, addr)
			except socket.error as se:
				if se.args[0] == 10035: # WSAEWOULDBLOCK
					time.sleep(0.1)
					pass
				else:
					raise 

def __init__(self, error):
        super(AgentError, self).__init__('Guest agent failure: '
                                              + error) 

def poll2(timeout=0.0, map=None):
    # Use the poll() support added to the select module in Python 2.0
    if map is None:
        map = socket_map
    if timeout is not None:
        # timeout is in milliseconds
        timeout = int(timeout*1000)
    pollster = select.poll()
    if map:
        for fd, obj in map.items():
            flags = 0
            if obj.readable():
                flags |= select.POLLIN | select.POLLPRI
            if obj.writable():
                flags |= select.POLLOUT
            if flags:
                # Only check for exceptions if object was either readable
                # or writable.
                flags |= select.POLLERR | select.POLLHUP | select.POLLNVAL
                pollster.register(fd, flags)
        try:
            r = pollster.poll(timeout)
        except select.error, err:
            if err.args[0] != EINTR:
                raise
            r = []
        for fd, flags in r:
            obj = map.get(fd)
            if obj is None:
                continue
            readwrite(obj, flags) 

def _handle_monitor(self, monitor_data):
        """
        Run the callback for a given Qemu Monitor answer or async notification
        """
        logging.debug("Qemu monitor: received %s",
                      str(monitor_data))

        try:
            json_msg = json.loads(monitor_data)
        except Exception as e:
            # TODO: We should implement a better recovery strategy
            # from leftover garbage in the serial port
            logging.error("Host agent: cannot decode data from Qemu monitor: %s",
                          str(e))
            return

        if 'event' in json_msg:
            kept_cbs = []
            for cb in self.async_cb:
                keep = cb(json_msg)
                if keep:
                    kept_cbs.append(cb)
            self.async_cb = kept_cbs
        else:
            try:
                cb = self.sync_cb.get(False)
            except Queue.Empty:
                logging.error("Qemu monitor sent unexpected reply: %s", json_msg)
                return
            cb(json_msg) 

def validate_reply(self, data):
        if data is None:
            raise PcoccError('Qemu monitor disconnected')

        if 'error' in data:
            if 'desc' in data['error']:
                raise PcoccError('Qemu monitor command failed: {}'.format(
                                 str(data['error']['desc'])))
            else:
                raise PcoccError('Qemu monitor command failed')

        return data