import time import errno import random import socket import struct import logging import collections import ConfigParser import selectors2 as selectors import threading from contextlib import closing import os,sys,inspect # Add parent dir to PATH to import messaging_lib current_dir = os.path.dirname(os.path.abspath(inspect.getfile(inspect.currentframe()))) parent_dir = os.path.dirname(current_dir) sys.path.insert(0, parent_dir) logging.basicConfig(level=logging.DEBUG) logger = logging.getLogger(__name__) import messaging_lib as messaging ConfigOption = collections.namedtuple("ConfigOption", ["section", "option", "value"]) active_client = None # maybe needs to be refactored class Client(object): def __init__(self, config_path="client_config.ini"): self.selector = selectors.DefaultSelector() self.client_socket = None self.server_connection = messaging.ConnectionManager() self.server_host = None self.server_port = None self.broadcast_port = None self.connected = False self.client_id = None # Init configs self.config_path = config_path self.config = ConfigParser.ConfigParser() self.load_config() global active_client active_client = self def load_config(self): self.config.read(self.config_path) self.broadcast_port = self.config.getint('SERVER', 'broadcast_port') self.server_port = self.config.getint('SERVER', 'port') self.server_host = self.config.get('SERVER', 'host') self.BUFFER_SIZE = self.config.getint('SERVER', 'buffer_size') self.USE_NTP = self.config.getboolean('NTP', 'use_ntp') self.NTP_HOST = self.config.get('NTP', 'host') self.NTP_PORT = self.config.getint('NTP', 'port') self.files_directory = self.config.get('FILETRANSFER', 'files_directory') self.client_id = self.config.get('PRIVATE', 'id') if self.client_id == 'default': self.client_id = 'copter' + str(random.randrange(9999)).zfill(4) self.write_config(False, 'PRIVATE', 'id', self.client_id) elif self.client_id == '/hostname': self.client_id = socket.gethostname() def rewrite_config(self): with open(self.config_path, 'w') as file: self.config.write(file) def write_config(self, reload_config=True, *config_options): for config_option in config_options: self.config.set(config_option.section, config_option.option, config_option.value) self.rewrite_config() if reload_config: self.load_config() @staticmethod def get_ntp_time(ntp_host, ntp_port): NTP_PACKET_FORMAT = "!12I" NTP_DELTA = 2208988800L # 1970-01-01 00:00:00 NTP_QUERY = '\x1b' + 47 * '\0' with closing(socket.socket(socket.AF_INET, socket.SOCK_DGRAM)) as s: s.sendto(bytes(NTP_QUERY), (ntp_host, ntp_port)) msg, address = s.recvfrom(1024) unpacked = struct.unpack(NTP_PACKET_FORMAT, msg[0:struct.calcsize(NTP_PACKET_FORMAT)]) return unpacked[10] + float(unpacked[11]) / 2 ** 32 - NTP_DELTA def time_now(self): if self.USE_NTP: timenow = self.get_ntp_time(self.NTP_HOST, self.NTP_PORT) else: timenow = time.time() return timenow def start(self): logger.info("Starting client") try: while True: self._reconnect() #self._process_connections() except (KeyboardInterrupt, ): logger.critical("Caught interrupt, exiting!") self.selector.close() def _reconnect(self, timeout=3.0, attempt_limit=5): logger.info("Trying to connect to {}:{} ...".format(self.server_host, self.server_port)) attempt_count = 0 while not self.connected: logger.info("Waiting for connection, attempt {}".format(attempt_count)) try: self.client_socket = socket.socket() self.client_socket.settimeout(timeout) self.client_socket.connect((self.server_host, self.server_port)) except socket.error as error: if isinstance(error, OSError): if error.errno == errno.EINTR: logger.critical("Shutting down on keyboard interrupt") raise KeyboardInterrupt logger.warning("Can not connect due error: {}".format(error)) attempt_count += 1 time.sleep(timeout) else: logger.info("Connection to server successful!") self._connect() break if attempt_count >= attempt_limit: logger.info("Too many attempts. Trying to get new server IP") self.broadcast_bind(timeout*2, attempt_limit) attempt_count = 0 def _connect(self): self.connected = True self.client_socket.setblocking(False) events = selectors.EVENT_READ # | selectors.EVENT_WRITE self.selector.register(self.client_socket, events, data=self.server_connection) self.server_connection.connect(self.selector, self.client_socket, (self.server_host, self.server_port)) self._process_connections() def broadcast_bind(self, timeout=3.0, attempt_limit=5): broadcast_client = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) broadcast_client.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1) broadcast_client.bind(("", self.broadcast_port)) broadcast_client.settimeout(timeout) attempt_count = 0 try: while attempt_count <= attempt_limit: try: data, addr = broadcast_client.recvfrom(self.BUFFER_SIZE) except socket.error as error: logger.warning("Could not receive broadcast due error: {}".format(error)) attempt_count += 1 else: message = messaging.MessageManager() message.income_raw = data message.process_message() if message.content: logger.info("Received broadcast message {} from {}".format(message.content, addr)) if message.content["command"] == "server_ip": args = message.content["args"] self.server_port = int(args["port"]) self.server_host = args["host"] self.write_config(False, ConfigOption("SERVER", "port", self.server_port), ConfigOption("SERVER", "host", self.server_host)) logger.info("Binding to new IP: {}:{}".format(self.server_host, self.server_port)) self.on_broadcast_bind() break finally: broadcast_client.close() def on_broadcast_bind(self): pass def _process_connections(self): while True: events = self.selector.select(timeout=1) # logging.debug("tick") for key, mask in events: # TODO add notifier to client! connection = key.data if connection is None: pass else: try: connection.process_events(mask) except Exception as error: logger.error( "Exception {} occurred for {}! Resetting connection!".format(error, connection.addr) ) self.server_connection.close() self.connected = False if isinstance(error, OSError): if error.errno == errno.EINTR: raise KeyboardInterrupt if not self.selector.get_map(): logger.warning("No active connections left!") return @messaging.request_callback("id") def _response_id(): return active_client.client_id @messaging.request_callback("time") def _response_time(): return active_client.time_now() @messaging.message_callback("config_write") def _command_config_write(*args, **kwargs): options = [ConfigOption(**raw_option) for raw_option in kwargs["options"]] logger.info("Writing config options: {}".format(options)) active_client.write_config(kwargs["reload"], *options) if __name__ == "__main__": client = Client() client.start()