X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=blobdiff_plain;f=tools%2Ffastbgp%2Fplay.py;h=e6e8fd98b45f107ceac8868c28a3f52cb9477e75;hb=ee32d14d7f71c4622ba1f42babcbeafd47403e94;hp=5551bc8df1480839bdd63afdc4ccb388041dd913;hpb=b288e180bf8fd557b92ef4e8dbb34eb1a175bbbd;p=integration%2Ftest.git diff --git a/tools/fastbgp/play.py b/tools/fastbgp/play.py index 5551bc8df1..e6e8fd98b4 100755 --- a/tools/fastbgp/play.py +++ b/tools/fastbgp/play.py @@ -11,17 +11,19 @@ EXABGP in this type of scenario.""" # terms of the Eclipse Public License v1.0 which accompanies this distribution, # and is available at http://www.eclipse.org/legal/epl-v10.html +from copy import deepcopy +from SimpleXMLRPCServer import SimpleXMLRPCServer import argparse import binascii import ipaddr +import logging +import Queue import select import socket -import time -import logging import struct - import thread -from copy import deepcopy +import threading +import time __author__ = "Vratko Polak" @@ -30,6 +32,25 @@ __license__ = "Eclipse Public License v1.0" __email__ = "vrpolak@cisco.com" +class SafeDict(dict): + '''Thread safe dictionary + + The object will serve as thread safe data storage. + It should be used with "with" statement. + ''' + + def __init__(self, * p_arg, ** n_arg): + super(SafeDict, self).__init__() + self._lock = threading.Lock() + + def __enter__(self): + self._lock.acquire() + return self + + def __exit__(self, type, value, traceback): + self._lock.release() + + def parse_arguments(): """Use argparse to get arguments, @@ -104,9 +125,40 @@ def parse_arguments(): str_help = "Minimum number of updates to reach to include result into csv." parser.add_argument("--threshold", default="1000", type=int, help=str_help) str_help = "RFC 4760 Multiprotocol Extensions for BGP-4 supported" - parser.add_argument("--rfc4760", default="yes", type=str, help=str_help) + parser.add_argument("--rfc4760", default=True, type=bool, help=str_help) + str_help = "Link-State NLRI supported" + parser.add_argument("--bgpls", default=False, type=bool, help=str_help) + str_help = "Link-State NLRI: Identifier" + parser.add_argument("-lsid", default="1", type=int, help=str_help) + str_help = "Link-State NLRI: Tunnel ID" + parser.add_argument("-lstid", default="1", type=int, help=str_help) + str_help = "Link-State NLRI: LSP ID" + parser.add_argument("-lspid", default="1", type=int, help=str_help) + str_help = "Link-State NLRI: IPv4 Tunnel Sender Address" + parser.add_argument("--lstsaddr", default="1.2.3.4", + type=ipaddr.IPv4Address, help=str_help) + str_help = "Link-State NLRI: IPv4 Tunnel End Point Address" + parser.add_argument("--lsteaddr", default="5.6.7.8", + type=ipaddr.IPv4Address, help=str_help) + str_help = "Link-State NLRI: Identifier Step" + parser.add_argument("-lsidstep", default="1", type=int, help=str_help) + str_help = "Link-State NLRI: Tunnel ID Step" + parser.add_argument("-lstidstep", default="2", type=int, help=str_help) + str_help = "Link-State NLRI: LSP ID Step" + parser.add_argument("-lspidstep", default="4", type=int, help=str_help) + str_help = "Link-State NLRI: IPv4 Tunnel Sender Address Step" + parser.add_argument("-lstsaddrstep", default="16", type=int, help=str_help) + str_help = "Link-State NLRI: IPv4 Tunnel End Point Address Step" + parser.add_argument("-lsteaddrstep", default="1", type=int, help=str_help) str_help = "How many play utilities are to be started." parser.add_argument("--multiplicity", default="1", type=int, help=str_help) + str_help = "Open message includes multiprotocol extension capability l2vpn-evpn.\ +Enabling this flag makes the script not decoding the update mesage, because of not\ +supported decoding for these elements." + parser.add_argument("--evpn", default=False, action="store_true", help=str_help) + parser.add_argument("--wfr", default=10, type=int, help="Wait for read timeout") + str_help = "Skipping well known attributes for update message" + parser.add_argument("--skipattr", default=False, action="store_true", help=str_help) arguments = parser.parse_args() if arguments.multiplicity < 1: print "Multiplicity", arguments.multiplicity, "is not positive." @@ -236,17 +288,22 @@ def read_open_message(bgp_socket): # Some validation. if len(msg_in) < 37: # 37 is minimal length of open message with 4-byte AS number. - logger.error("Got something else than open with 4-byte AS number: " + - binascii.hexlify(msg_in)) - raise MessageError("Got something else than open with 4-byte AS number", msg_in) + error_msg = ( + "Message length (" + str(len(msg_in)) + ") is smaller than " + "minimal length of OPEN message with 4-byte AS number (37)" + ) + logger.error(error_msg + ": " + binascii.hexlify(msg_in)) + raise MessageError(error_msg, msg_in) # TODO: We could check BGP marker, but it is defined only later; # decide what to do. reported_length = get_short_int_from_message(msg_in) if len(msg_in) != reported_length: - logger.error("Message length is not " + str(reported_length) + - " as stated in " + binascii.hexlify(msg_in)) - raise MessageError("Message length is not " + reported_length + - " as stated in ", msg_in) + error_msg = ( + "Expected message length (" + reported_length + + ") does not match actual length (" + str(len(msg_in)) + ")" + ) + logger.error(error_msg + binascii.hexlify(msg_in)) + raise MessageError(error_msg, msg_in) logger.info("Open message received.") return msg_in @@ -295,7 +352,24 @@ class MessageGenerator(object): self.remaining_prefixes_threshold = self.total_prefix_amount - args.prefill self.results_file_name_default = args.results self.performance_threshold_default = args.threshold - self.rfc4760 = args.rfc4760 == "yes" + self.rfc4760 = args.rfc4760 + self.bgpls = args.bgpls + self.evpn = args.evpn + self.skipattr = args.skipattr + # Default values when BGP-LS Attributes are used + if self.bgpls: + self.prefix_count_to_add_default = 1 + self.prefix_count_to_del_default = 0 + self.ls_nlri_default = {"Identifier": args.lsid, + "TunnelID": args.lstid, + "LSPID": args.lspid, + "IPv4TunnelSenderAddress": args.lstsaddr, + "IPv4TunnelEndPointAddress": args.lsteaddr} + self.lsid_step = args.lsidstep + self.lstid_step = args.lstidstep + self.lspid_step = args.lspidstep + self.lstsaddr_step = args.lstsaddrstep + self.lsteaddr_step = args.lsteaddrstep # Default values used for randomized part s1_slots = ((self.total_prefix_amount - self.remaining_prefixes_threshold - 1) / @@ -314,7 +388,6 @@ class MessageGenerator(object): self.prefix_count_to_add_default + 1) self.randomize_lowest_default = s2_first_index self.randomize_highest_default = s2_last_index - # Initialising counters self.phase1_start_time = 0 self.phase1_stop_time = 0 @@ -496,7 +569,27 @@ class MessageGenerator(object): new_index = index return new_index - # Get list of prefixes + def get_ls_nlri_values(self, index): + """Generates LS-NLRI parameters. + http://tools.ietf.org/html/draft-ietf-idr-te-lsp-distribution-03 + + Arguments: + :param index: index (iteration) + Returns: + :return: dictionary of LS NLRI parameters and values + """ + # generating list of LS NLRI parameters + identifier = self.ls_nlri_default["Identifier"] + index / self.lsid_step + ipv4_tunnel_sender_address = self.ls_nlri_default["IPv4TunnelSenderAddress"] + index / self.lstsaddr_step + tunnel_id = self.ls_nlri_default["TunnelID"] + index / self.lstid_step + lsp_id = self.ls_nlri_default["LSPID"] + index / self.lspid_step + ipv4_tunnel_endpoint_address = self.ls_nlri_default["IPv4TunnelEndPointAddress"] + index / self.lsteaddr_step + ls_nlri_values = {"Identifier": identifier, + "IPv4TunnelSenderAddress": ipv4_tunnel_sender_address, + "TunnelID": tunnel_id, "LSPID": lsp_id, + "IPv4TunnelEndPointAddress": ipv4_tunnel_endpoint_address} + return ls_nlri_values + def get_prefix_list(self, slot_index, slot_size=None, prefix_base=None, prefix_len=None, prefix_count=None, randomize=None): """Generates list of IP address prefixes. @@ -605,20 +698,26 @@ class MessageGenerator(object): logger.debug("Prefixes to be withdrawn in this iteration:") prefix_list_to_del = self.get_prefix_list(slot_index_to_del, prefix_count=prefix_count_to_del) - # generating the mesage - if self.single_update_default: - # Send prefixes to be introduced and withdrawn - # in one UPDATE message - msg_out = self.update_message(wr_prefixes=prefix_list_to_del, - nlri_prefixes=prefix_list_to_add) + # generating the UPDATE mesage with LS-NLRI only + if self.bgpls: + ls_nlri = self.get_ls_nlri_values(self.iteration) + msg_out = self.update_message(wr_prefixes=[], nlri_prefixes=[], + **ls_nlri) else: - # Send prefixes to be introduced and withdrawn - # in separate UPDATE messages (if needed) - msg_out = self.update_message(wr_prefixes=[], - nlri_prefixes=prefix_list_to_add) - if prefix_count_to_del: - msg_out += self.update_message(wr_prefixes=prefix_list_to_del, - nlri_prefixes=[]) + # generating the UPDATE message with prefix lists + if self.single_update_default: + # Send prefixes to be introduced and withdrawn + # in one UPDATE message + msg_out = self.update_message(wr_prefixes=prefix_list_to_del, + nlri_prefixes=prefix_list_to_add) + else: + # Send prefixes to be introduced and withdrawn + # in separate UPDATE messages (if needed) + msg_out = self.update_message(wr_prefixes=[], + nlri_prefixes=prefix_list_to_add) + if prefix_count_to_del: + msg_out += self.update_message(wr_prefixes=prefix_list_to_del, + nlri_prefixes=[]) # updating counters - who knows ... maybe I am last time here ;) if straightforward_scenario: self.phase1_stop_time = time.time() @@ -699,6 +798,31 @@ class MessageGenerator(object): ) optional_parameters_hex += optional_parameter_hex + if self.bgpls: + optional_parameter_hex = ( + "\x02" # Param type ("Capability Ad") + "\x06" # Length (6 bytes) + "\x01" # Capability type (NLRI Unicast), + # see RFC 4760, secton 8 + "\x04" # Capability value length + "\x40\x04" # AFI (BGP-LS) + "\x00" # (reserved) + "\x47" # SAFI (BGP-LS) + ) + optional_parameters_hex += optional_parameter_hex + + if self.evpn: + optional_parameter_hex = ( + "\x02" # Param type ("Capability Ad") + "\x06" # Length (6 bytes) + "\x01" # Multiprotocol extetension capability, + "\x04" # Capability value length + "\x00\x19" # AFI (L2-VPN) + "\x00" # (reserved) + "\x46" # SAFI (EVPN) + ) + optional_parameters_hex += optional_parameter_hex + optional_parameter_hex = ( "\x02" # Param type ("Capability Ad") "\x06" # Length (6 bytes) @@ -770,7 +894,8 @@ class MessageGenerator(object): def update_message(self, wr_prefixes=None, nlri_prefixes=None, wr_prefix_length=None, nlri_prefix_length=None, my_autonomous_system=None, next_hop=None, - originator_id=None, cluster_list_item=None): + originator_id=None, cluster_list_item=None, + end_of_rib=False, **ls_nlri_params): """Generates an UPDATE Message (rfc4271#section-4.3) Arguments: @@ -802,6 +927,8 @@ class MessageGenerator(object): originator_id = self.originator_id_default if cluster_list_item is None: cluster_list_item = self.cluster_list_item_default + ls_nlri = self.ls_nlri_default.copy() + ls_nlri.update(ls_nlri_params) # Marker marker_hex = "\xFF" * 16 @@ -811,12 +938,13 @@ class MessageGenerator(object): type_hex = struct.pack("B", type) # Withdrawn Routes - bytes = ((wr_prefix_length - 1) / 8) + 1 withdrawn_routes_hex = "" - for prefix in wr_prefixes: - withdrawn_route_hex = (struct.pack("B", wr_prefix_length) + - struct.pack(">I", int(prefix))[:bytes]) - withdrawn_routes_hex += withdrawn_route_hex + if not self.bgpls: + bytes = ((wr_prefix_length - 1) / 8) + 1 + for prefix in wr_prefixes: + withdrawn_route_hex = (struct.pack("B", wr_prefix_length) + + struct.pack(">I", int(prefix))[:bytes]) + withdrawn_routes_hex += withdrawn_route_hex # Withdrawn Routes Length withdrawn_routes_length = len(withdrawn_routes_hex) @@ -825,7 +953,7 @@ class MessageGenerator(object): # TODO: to replace hardcoded string by encoding? # Path Attributes path_attributes_hex = "" - if nlri_prefixes != []: + if not self.skipattr: path_attributes_hex += ( "\x40" # Flags ("Well-Known") "\x01" # Type (ORIGIN) @@ -841,6 +969,13 @@ class MessageGenerator(object): ) my_as_hex = struct.pack(">I", my_autonomous_system) path_attributes_hex += my_as_hex # AS segment (4 bytes) + path_attributes_hex += ( + "\x40" # Flags ("Well-Known") + "\x05" # Type (LOCAL_PREF) + "\x04" # Length (4) + "\x00\x00\x00\x64" # (100) + ) + if nlri_prefixes != []: path_attributes_hex += ( "\x40" # Flags ("Well-Known") "\x03" # Type (NEXT_HOP) @@ -865,17 +1000,40 @@ class MessageGenerator(object): ) # one CLUSTER_LIST item (4 bytes) path_attributes_hex += struct.pack(">I", int(cluster_list_item)) + if self.bgpls and not end_of_rib: + path_attributes_hex += ( + "\x80" # Flags ("Optional, non-transitive") + "\x0e" # Type (MP_REACH_NLRI) + "\x22" # Length (34) + "\x40\x04" # AFI (BGP-LS) + "\x47" # SAFI (BGP-LS) + "\x04" # Next Hop Length (4) + ) + path_attributes_hex += struct.pack(">I", int(next_hop)) + path_attributes_hex += "\x00" # Reserved + path_attributes_hex += ( + "\x00\x05" # LS-NLRI.NLRIType (IPv4 TE LSP NLRI) + "\x00\x15" # LS-NLRI.TotalNLRILength (21) + "\x07" # LS-NLRI.Variable.ProtocolID (RSVP-TE) + ) + path_attributes_hex += struct.pack(">Q", int(ls_nlri["Identifier"])) + path_attributes_hex += struct.pack(">I", int(ls_nlri["IPv4TunnelSenderAddress"])) + path_attributes_hex += struct.pack(">H", int(ls_nlri["TunnelID"])) + path_attributes_hex += struct.pack(">H", int(ls_nlri["LSPID"])) + path_attributes_hex += struct.pack(">I", int(ls_nlri["IPv4TunnelEndPointAddress"])) + # Total Path Attributes Length total_path_attributes_length = len(path_attributes_hex) total_path_attributes_length_hex = struct.pack(">H", total_path_attributes_length) # Network Layer Reachability Information - bytes = ((nlri_prefix_length - 1) / 8) + 1 nlri_hex = "" - for prefix in nlri_prefixes: - nlri_prefix_hex = (struct.pack("B", nlri_prefix_length) + - struct.pack(">I", int(prefix))[:bytes]) - nlri_hex += nlri_prefix_hex + if not self.bgpls: + bytes = ((nlri_prefix_length - 1) / 8) + 1 + for prefix in nlri_prefixes: + nlri_prefix_hex = (struct.pack("B", nlri_prefix_length) + + struct.pack(">I", int(prefix))[:bytes]) + nlri_hex += nlri_prefix_hex # Length (big-endian) length = ( @@ -923,6 +1081,8 @@ class MessageGenerator(object): logger.debug(" Originator id=" + str(originator_id)) if cluster_list_item is not None: logger.debug(" Cluster list=" + str(cluster_list_item)) + if self.bgpls: + logger.debug(" MP_REACH_NLRI: %s", ls_nlri) logger.debug(" Network Layer Reachability Information=" + str(nlri_prefixes) + "/" + str(nlri_prefix_length) + " (0x" + binascii.hexlify(nlri_hex) + ")") @@ -1118,12 +1278,14 @@ class ReadTracker(object): for idle waiting. """ - def __init__(self, bgp_socket, timer): + def __init__(self, bgp_socket, timer, storage, evpn=False, wait_for_read=10): """The reader initialisation. Arguments: bgp_socket: socket to be used for sending timer: timer to be used for scheduling + storage: thread safe dict + evpn: flag that evpn functionality is tested """ # References to outside objects. self.socket = bgp_socket @@ -1144,6 +1306,9 @@ class ReadTracker(object): self.prefixes_withdrawn = 0 self.rx_idle_time = 0 self.rx_activity_detected = True + self.storage = storage + self.evpn = evpn + self.wfr = wait_for_read def read_message_chunk(self): """Read up to one message @@ -1341,6 +1506,16 @@ class ReadTracker(object): # message header - message type msg_type_hex = msg[18:19] msg_type = int(binascii.b2a_hex(msg_type_hex), 16) + + with self.storage as stor: + # this will replace the previously stored message + stor['update'] = binascii.hexlify(msg) + + logger.debug("Evpn {}".format(self.evpn)) + if self.evpn: + logger.debug("Skipping update decoding due to evpn data expected") + return + if msg_type == 2: logger.debug("Message type: 0x%s (update)", binascii.b2a_hex(msg_type_hex)) @@ -1360,13 +1535,13 @@ class ReadTracker(object): logger.debug("withdrawn_prefix_received: %s", prefix) # total path attribute length total_pa_length_offset = 21 + wdr_length - total_pa_length_hex = msg[total_pa_length_offset:total_pa_length_offset+2] + total_pa_length_hex = msg[total_pa_length_offset:total_pa_length_offset + 2] total_pa_length = int(binascii.b2a_hex(total_pa_length_hex), 16) logger.debug("Total path attribute lenght: 0x%s (%s)", binascii.b2a_hex(total_pa_length_hex), total_pa_length) # path attributes pa_offset = total_pa_length_offset + 2 - pa_hex = msg[pa_offset:pa_offset+total_pa_length] + pa_hex = msg[pa_offset:pa_offset + total_pa_length] logger.debug("Path attributes: 0x%s", binascii.b2a_hex(pa_hex)) self.decode_path_attributes(pa_hex) # network layer reachability information length @@ -1374,7 +1549,7 @@ class ReadTracker(object): logger.debug("Calculated NLRI length: %s", nlri_length) # network layer reachability information nlri_offset = pa_offset + total_pa_length - nlri_hex = msg[nlri_offset:nlri_offset+nlri_length] + nlri_hex = msg[nlri_offset:nlri_offset + nlri_length] logger.debug("NLRI: 0x%s", binascii.b2a_hex(nlri_hex)) nlri_prefix_list = get_prefix_list_from_hex(nlri_hex) logger.debug("NLRI prefix list: %s", nlri_prefix_list) @@ -1398,7 +1573,7 @@ class ReadTracker(object): # Compute time to the first predictable state change event_time = self.timer.get_next_event_time() # snapshot_time would be imprecise - wait_timedelta = min(event_time - time.time(), 10) + wait_timedelta = min(event_time - time.time(), self.wfr) if wait_timedelta < 0: # The program got around to waiting to an event in "very near # future" so late that it became a "past" event, thus tell @@ -1489,20 +1664,23 @@ class WriteTracker(object): class StateTracker(object): """Main loop has state so complex it warrants this separate class.""" - def __init__(self, bgp_socket, generator, timer): + def __init__(self, bgp_socket, generator, timer, inqueue, storage, cliargs): """The state tracker initialisation. Arguments: bgp_socket: socket to be used for sending / receiving generator: generator to be used for message generation timer: timer to be used for scheduling + inqueue: user initiated messages queue + storage: thread safe dict to store data for the rpc server + cliargs: cli args from the user """ # References to outside objects. self.socket = bgp_socket self.generator = generator self.timer = timer # Sub-trackers. - self.reader = ReadTracker(bgp_socket, timer) + self.reader = ReadTracker(bgp_socket, timer, storage, evpn=cliargs.evpn, wait_for_read=cliargs.wfr) self.writer = WriteTracker(bgp_socket, generator, timer) # Prioritization state. self.prioritize_writing = False @@ -1515,6 +1693,7 @@ class StateTracker(object): # TODO: Alternative is to switch fairly between reading and # writing (called round robin from now on). # Message counting is done in generator. + self.inqueue = inqueue def perform_one_loop_iteration(self): """ The main loop iteration @@ -1532,6 +1711,14 @@ class StateTracker(object): logger.info("KEEP ALIVE is sent.") # We are sending a message now, so let's prioritize it. self.prioritize_writing = True + + try: + msg = self.inqueue.get_nowait() + logger.info("Received message: {}".format(msg)) + msgbin = binascii.unhexlify(msg) + self.writer.enqueue_message_for_sending(msgbin) + except Queue.Empty: + pass # Now we know what our priorities are, we have to check # which actions are available. # socket.socket() returns three lists, @@ -1581,7 +1768,8 @@ class StateTracker(object): self.generator.store_results() logger.info("Finally an END-OF-RIB is sent.") msg_out += self.generator.update_message(wr_prefixes=[], - nlri_prefixes=[]) + nlri_prefixes=[], + end_of_rib=True) self.writer.enqueue_message_for_sending(msg_out) # Attempt for real sending to be done in next iteration. return @@ -1618,13 +1806,15 @@ def create_logger(loglevel, logfile): return logger -def job(arguments): +def job(arguments, inqueue, storage): """One time initialisation and iterations looping. Notes: Establish BGP connection and run iterations. Arguments: :arguments: Command line arguments + :inqueue: Data to be sent from play.py + :storage: Shared dict for rpc server Returns: :return: None """ @@ -1645,10 +1835,9 @@ def job(arguments): # Using exact keepalive length to not to see possible updates. msg_in = bgp_socket.recv(19) if msg_in != generator.keepalive_message(): - logger.error("Open not confirmed by keepalive, instead got " + - binascii.hexlify(msg_in)) - raise MessageError("Open not confirmed by keepalive, instead got", - msg_in) + error_msg = "Open not confirmed by keepalive, instead got" + logger.error(error_msg + ": " + binascii.hexlify(msg_in)) + raise MessageError(error_msg, msg_in) timer.reset_peer_hold_time() # Send the keepalive to indicate the connection is accepted. timer.snapshot() # Remember this time. @@ -1658,11 +1847,56 @@ def job(arguments): # Use the remembered time. timer.reset_my_keepalive_time(timer.snapshot_time) # End of initial handshake phase. - state = StateTracker(bgp_socket, generator, timer) + state = StateTracker(bgp_socket, generator, timer, inqueue, storage, arguments) while True: # main reactor loop state.perform_one_loop_iteration() +class Rpcs: + '''Handler for SimpleXMLRPCServer''' + def __init__(self, sendqueue, storage): + '''Init method + + Arguments: + :sendqueue: queue for data to be sent towards odl + :storage: thread safe dict + ''' + self.queue = sendqueue + self.storage = storage + + def send(self, text): + '''Data to be sent + + Arguments: + :text: hes string of the data to be sent + ''' + self.queue.put(text) + + def get(self, text=''): + '''Reads data form the storage + + - returns stored data or an empty string, at the moment only + 'update' is stored + + Arguments: + :text: a key to the storage to get the data + Returns: + :data: stored data + ''' + with self.storage as stor: + return stor.get(text, '') + + def clean(self, text=''): + '''Cleans data form the storage + + Arguments: + :text: a key to the storage to clean the data + ''' + with self.storage as stor: + if text in stor: + del stor[text] + + def threaded_job(arguments): """Run the job threaded @@ -1676,6 +1910,8 @@ def threaded_job(arguments): prefix_current = arguments.firstprefix myip_current = arguments.myip thread_args = [] + rpcqueue = Queue.Queue() + storage = SafeDict() while 1: amount_per_util = (amount_left - 1) / utils_left + 1 # round up @@ -1696,14 +1932,14 @@ def threaded_job(arguments): try: # Create threads for t in thread_args: - thread.start_new_thread(job, (t,)) + thread.start_new_thread(job, (t, rpcqueue, storage)) except Exception: print "Error: unable to start thread." raise SystemExit(2) - # Work remains forever - while 1: - time.sleep(5) + rpcserver = SimpleXMLRPCServer((arguments.myip.compressed, 8000), allow_none=True) + rpcserver.register_instance(Rpcs(rpcqueue, storage)) + rpcserver.serve_forever() if __name__ == "__main__":