590 lines
22 KiB
Python
590 lines
22 KiB
Python
import random
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import socket
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import pickle
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import threading
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import io
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import hashlib
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import simplecrypto
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from struct import Struct
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import uuid
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import bisect
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DATA_DIVIDE_LENGTH = 8000
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PACKET_HEADER_SIZE = 512 # Pickle service info
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DATA_LENGTH = DATA_DIVIDE_LENGTH
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SENT_SIZE = PACKET_HEADER_SIZE + DATA_LENGTH + 272 # Encrypted data always 272 bytes bigger
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class Connection:
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SMALLEST_STARTING_SEQ = 0
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HIGHEST_STARTING_SEQ = 4294967295
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def __init__(self, remote, encrypted=False):
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self.fileno = 0
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self.peer_addr = remote
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self.seq = Connection.gen_starting_seq_num()
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self.recv_seq = -1
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self.my_key = None
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if encrypted:
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self.my_key = simplecrypto.RsaKeypair()
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self.pubkey = self.my_key.publickey.serialize()
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self.peer_pub = None
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self.recv_lock = threading.Lock()
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self.send_lock = threading.Lock()
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self.packet_buffer = {
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'ACK': [],
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'SYN-ACK': [],
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'DATA': [],
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'FIN-ACK': []
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}
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@staticmethod
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def gen_starting_seq_num():
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return random.randint(Connection.SMALLEST_STARTING_SEQ, Connection.HIGHEST_STARTING_SEQ)
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def seq_inc(self, inc=1):
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self.seq += inc
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return self.seq
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def set_ack(self, ack):
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self.ack = ack
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return ack
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class EUDPPacket:
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def __cmp__(self, other):
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return (self.seq > other.seq) - (self.seq < other.seq)
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def __lt__(self, other):
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return self.seq < other.seq
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def __gt__(self, other):
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return self.seq > other.seq
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def __eq__(self, other):
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return self.seq == other.seq
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class Ack(EUDPPacket):
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type = 'ACK'
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def __init__(self, id_):
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self.id = id_
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self.seq = 0
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class Fin(EUDPPacket):
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type = 'FIN'
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def __init__(self):
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self.id = uuid.uuid4().bytes
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self.seq = 0
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class FinAck(EUDPPacket):
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type = 'FIN-ACK'
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def __init__(self, id_):
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self.id = id_
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self.seq = 0
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class Syn(EUDPPacket):
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type = 'SYN'
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checksum = None
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def __init__(self):
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self.id = uuid.uuid4().bytes
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self.seq = 0
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def set_pub(self, pubkey):
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self.checksum = EUDP.checksum(pubkey)
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self.pubkey = pubkey
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class SynAck(EUDPPacket):
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type = 'SYN-ACK'
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checksum = None
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def __init__(self, id_):
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self.id = id_
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self.seq = 0
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def set_pub(self, pubkey):
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self.checksum = EUDP.checksum(pubkey)
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self.pubkey = pubkey
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class Packet(EUDPPacket):
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type = 'DATA'
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def __init__(self):
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self.id = uuid.uuid4().bytes
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self.checksum = 0
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self.data = b''
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self.seq = 0
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def __repr__(self):
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return f'Packet(seq={self.seq})'
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def __str__(self):
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return 'UUID: %d, DATA:%s' % (uuid.UUID(bytes=self.id), self.data)
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def set_data(self, data):
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self.checksum = EUDP.checksum(data)
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self.data = data
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allowed_unpickle_class = {
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'Packet': Packet,
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'Ack': Ack,
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'Fin': Fin,
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'FinAck': FinAck,
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'Syn': Syn,
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'SynAck': SynAck
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}
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class RestrictedUnpickler(pickle.Unpickler):
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def find_class(self, module, name):
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if module != 'builtins' and name in allowed_unpickle_class:
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return allowed_unpickle_class[name]
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raise pickle.UnpicklingError("global '%s.%s' is forbidden" %
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(module, name))
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def restricted_pickle_loads(s):
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return RestrictedUnpickler(io.BytesIO(s)).load()
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class EUDPChannel:
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HEADER = Struct('!I')
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POLL_TIMEOUT = 0.1
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def __init__(self, sock):
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self.sock = sock
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def poll(self):
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return self.sock.poll(self.POLL_TIMEOUT)
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def recv(self):
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header = self.sock.recv(self.HEADER.size)
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data_len = self.HEADER.unpack(header)[0]
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return self.sock.recv(data_len)
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def send(self, data):
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header = self.HEADER.pack(len(data))
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self.sock.send(header + data)
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class ConnectedSOCK(object):
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def __init__(self, low_sock, client_addr):
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self.client_addr = client_addr
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self.low_sock = low_sock
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self.channel = EUDPChannel(self)
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def __getattribute__(self, att):
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try:
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return object.__getattribute__(self, att)
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except AttributeError:
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return getattr(self.low_sock, att)
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def getpeername(self):
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return self.client_addr
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def send(self, data):
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if self.closed:
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raise EOFError
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return self.low_sock.send(data, self.client_addr)
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def sendall(self, data):
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if self.closed:
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raise EOFError
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self.low_sock.sendall(data, self.client_addr)
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def recv(self, size):
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if self.closed:
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raise EOFError
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return self.low_sock.recv(size, self.client_addr)
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@property
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def closed(self):
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return self.low_sock.own_socket._closed or self.client_addr not in self.low_sock.connections
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def close(self):
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if self.client_addr in self.low_sock.connections:
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self.low_sock.close(self.client_addr)
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def shutdown(self, *a, **kw):
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self.close()
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def poll(self, timeout):
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return self.low_sock.poll(timeout, self.client_addr)
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def packets_arrived(self, packet_type):
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return self.low_sock.packets_arrived(packet_type, self.client_addr)
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def fileno(self):
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if self.closed:
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raise EOFError
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return self.low_sock.fileno(self.client_addr)
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class EUDP(object):
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host = None
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port = None
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client = False
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def __init__(self,encrypted=False, **kw):
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self.encrypted = encrypted
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self.incoming_packet_event = threading.Event()
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self.new_conn_event = threading.Event()
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self.own_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
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self.own_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
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self.settimeout()
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self.connection_lock = threading.Lock()
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self.queue_lock = threading.Lock()
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self.channel = None
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self.connections = {}
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self.connection_queue = []
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self.syn_received = {}
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self.fileno_seq = 40000000
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def next_fileno(self):
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self.fileno_seq += 1
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return self.fileno_seq
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def packets_arrived(self, packet_type, connection=None):
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try:
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conn = self.connections[connection]
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except:
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raise EOFError
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with conn.recv_lock:
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return bool(len(conn.packet_buffer[packet_type]))
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def poll(self, timeout, connection=None):
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if connection not in list(self.connections.keys()):
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if connection is None:
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connection = list(self.connections.keys())[0]
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else:
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raise EOFError('Connection not in connected devices')
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if not self.closed:
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has_data = self.packets_arrived('DATA', connection)
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if has_data:
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return True
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else:
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if not timeout:
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timeout = 0.5
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while True and not self.closed:
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self.incoming_packet_event.wait(timeout)
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has_data = self.packets_arrived('DATA', connection)
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if not has_data:
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continue
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else:
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return has_data
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else:
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self.incoming_packet_event.wait(timeout)
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return self.packets_arrived('DATA', connection)
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return False
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def get_free_port(self):
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s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
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s.bind(('', 0))
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port = s.getsockname()[1]
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s.close()
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return port
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def setsockopt(self, *a, **kw):
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pass
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def settimeout(self, timeout=5):
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self.own_socket.settimeout(timeout)
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def setblocking(self, mode):
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self.own_socket.setblocking(mode)
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def __repr__(self):
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return 'EUDP()'
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def __str__(self):
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return 'Connections: %s' \
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% str(self.connections)
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def getsockname(self):
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return self.own_socket.getsockname()
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def getpeername(self):
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if len(self.connections):
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return list(self.connections.keys())[0]
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else:
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raise EOFError('Not connected')
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def bind(self, addr):
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self.host = addr[0]
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self.port = addr[1]
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self.own_socket.bind(addr)
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def send(self, data, connection=None):
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if self.closed:
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raise EOFError
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try:
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if connection not in list(self.connections.keys()):
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if connection is None:
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connection = list(self.connections.keys())[0]
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else:
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raise EOFError('Connection not in connected devices')
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conn = self.connections[connection]
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data_parts = EUDP.data_divider(data)
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for data_part in data_parts:
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data_chunk = data_part if not self.encrypted else conn.peer_pub.encrypt_raw(data_part)
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packet = Packet()
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packet.set_data(data_chunk)
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self.__send_packet(connection, packet, retransmit=True)
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return len(data)
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except socket.error as error:
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raise EOFError('Socket was closed before executing command. Error is: %s.' % error)
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def sendall(self, data, connection=None):
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_ = self.send(data, connection)
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def recv(self, size, connection=None):
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if self.closed:
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raise EOFError
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try:
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if connection not in list(self.connections.keys()):
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if connection is None:
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connection = list(self.connections.keys())[0]
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else:
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raise EOFError('Connection not in connected devices')
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data = self.find_correct_packet('DATA', connection, size)
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if not self.status:
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raise EOFError('Disconnecting')
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return data
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except socket.error as error:
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raise EOFError('Socket was closed before executing command. Error is: %s.' % error)
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def __send_packet(self, peer_addr, packet, retransmit=False, wait_cond='ACK'):
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conn = self.connections[peer_addr]
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packet.seq = conn.seq_inc()
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packet_to_send = pickle.dumps(packet)
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if not retransmit:
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self.own_socket.sendto(packet_to_send, peer_addr)
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else:
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data_not_received = True
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retransmit_count = 0
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while data_not_received and retransmit_count < 3:
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data_not_received = False
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try:
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self.own_socket.sendto(packet_to_send, peer_addr)
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answer = self.find_correct_packet(wait_cond, peer_addr, want_id=packet.id)
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if not answer:
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data_not_received = True
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retransmit_count += 1
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except socket.timeout:
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data_not_received = True
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if not answer:
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self.drop_connection(peer_addr)
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raise EOFError('Connection lost')
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return answer
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def listen_handler(self, max_connections):
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try:
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while True and self.status:
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try:
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answer, address = self.find_correct_packet('SYN')
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with self.queue_lock:
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if len(self.connection_queue) < max_connections:
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conn = Connection(address, self.encrypted)
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conn.fileno = self.next_fileno()
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if self.encrypted:
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try:
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conn.peer_pub = simplecrypto.RsaPublicKey(answer.pubkey)
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except:
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raise socket.error('Init peer public key error')
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self.connection_queue.append((answer, conn))
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self.blink_new_conn_event()
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else:
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if answer.id in map(lambda x: x[0].id, self.connection_queue):
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continue
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self.own_socket.sendto(b'Connections full', address)
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except KeyError:
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continue
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except TypeError:
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continue
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except socket.error as error:
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raise EOFError('Something went wrong in listen_handler func! Error is: %s.' + str(error))
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def listen(self, max_connections=1):
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self.status = 1
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self.central_receive()
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try:
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t = threading.Thread(target=self.listen_handler, args=(max_connections,))
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t.daemon = True
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t.start()
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except Exception as error:
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raise EOFError('Something went wrong in listen func! Error is: %s.' % str(error))
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def stop(self):
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self.own_socket.close()
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self.status = 0
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def shutdown(self, *a, **kw):
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self.close()
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self.status = 0
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self.connections = {}
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self.stop()
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def accept(self):
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while self.status:
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try:
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self.new_conn_event.wait(0.1)
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if self.connection_queue:
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with self.queue_lock:
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answer, conn = self.connection_queue.pop()
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conn.recv_seq = answer.seq
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self.connections[conn.peer_addr] = conn
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syn_ack = SynAck(answer.id)
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if self.encrypted:
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syn_ack.set_pub(conn.peer_pub.encrypt_raw(conn.pubkey))
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answer = self.__send_packet(conn.peer_addr, syn_ack, retransmit=True)
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return ConnectedSOCK(self, conn.peer_addr), conn.peer_addr
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except EOFError:
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if conn.peer_addr in self.connections:
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self.close(conn.peer_addr)
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continue
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except Exception as error:
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if conn.peer_addr in self.connections:
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self.close(conn.peer_addr)
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raise EOFError('Something went wrong in accept func: ' + str(error))
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def connect(self, server_address=('127.0.0.1', 10000)):
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if server_address in self.connections:
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raise EOFError('Already connected to peer')
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try:
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self.bind(('', self.get_free_port()))
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self.status = 1
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self.client = True
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self.central_receive()
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conn = Connection(server_address, self.encrypted)
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self.connections[server_address] = conn
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syn = Syn()
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if self.encrypted:
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syn.set_pub(conn.pubkey)
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try:
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answer = self.__send_packet(server_address, syn, retransmit=True, wait_cond='SYN-ACK')
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except EOFError:
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raise EOFError('Remote peer unreachable')
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if type(answer) == str: # == 'Connections full':
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raise socket.error('Server cant receive any connections right now.')
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if self.encrypted:
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try:
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peer_pub = conn.my_key.decrypt_raw(answer.pubkey)
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conn.peer_pub = simplecrypto.RsaPublicKey(peer_pub)
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except:
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raise socket.error('Decrypt peer public key error')
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ack = Ack(answer.id)
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self.__send_packet(server_address, ack)
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self.channel = EUDPChannel(self)
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conn.fileno = self.next_fileno()
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except socket.error as error:
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self.own_socket.close()
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self.connections = {}
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self.status = 0
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raise EOFError('The socket was closed. Error:' + str(error))
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def fileno(self, connection=None):
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if connection not in list(self.connections.keys()):
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if connection is None:
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connection = list(self.connections.keys())[0]
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else:
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raise EOFError('Connection not in connected devices')
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return self.connections[connection].fileno
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@property
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def closed(self):
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return not bool(len(self.connections))
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def drop_connection(self, connection):
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with self.connection_lock:
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if len(self.connections):
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self.connections.pop(connection)
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def close(self, connection=None):
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try:
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if connection not in list(self.connections.keys()):
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if connection is None:
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if len(self.connections):
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connection = list(self.connections.keys())[0]
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else:
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return
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else:
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raise EOFError('Connection not in connected devices')
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fin = Fin()
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answer = self.__send_packet(connection, fin, retransmit=True)
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answer = self.find_correct_packet('FIN-ACK', connection, want_id=fin.id)
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if not answer:
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raise Exception('The receiver didn\'t send the fin packet')
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else:
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self.drop_connection(connection)
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if not len(self.connections) and self.client:
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self.stop()
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except Exception as error:
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raise EOFError('Something went wrong in the close func! Error is: %s.' % error)
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def disconnect(self, connection, fin_id):
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try:
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ack = Ack(fin_id)
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self.__send_packet(connection, ack)
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fin_ack = FinAck(fin_id)
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try:
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self.__send_packet(connection, fin_ack)
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except:
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pass
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self.drop_connection(connection)
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except Exception as error:
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raise EOFError('Something went wrong in disconnect func:%s ' % error)
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@staticmethod
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def data_divider(data):
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'''Divides the data into a list where each element's length is 1024'''
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data = [data[i:i + DATA_DIVIDE_LENGTH] for i in range(0, len(data), DATA_DIVIDE_LENGTH)]
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return data
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@staticmethod
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def checksum(source_bytes):
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return hashlib.sha1(source_bytes).digest()
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def find_correct_packet(self, condition, address=('Any',), size=DATA_LENGTH, want_id=None):
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not_found = True
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tries = 0
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while not_found and tries < 2 and self.status:
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try:
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not_found = False
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if address[0] == 'Any':
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order = self.syn_received.popitem() # to reverse the tuple received
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return order[1], order[0]
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try:
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conn = self.connections[address]
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except:
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break
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if condition in ['ACK', 'SYN-ACK', 'FIN-ACK']:
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tries += 1
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if condition == 'DATA':
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if self.poll(0.1, address):
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data = b''
|
|
while size:
|
|
if not self.poll(0.1, address):
|
|
continue
|
|
with conn.recv_lock:
|
|
packet = conn.packet_buffer[condition][0]
|
|
chunk = packet.data[:size]
|
|
chunk_len = len(chunk)
|
|
data += chunk
|
|
packet.data = packet.data[size:]
|
|
size -= chunk_len
|
|
if not len(packet.data):
|
|
try:
|
|
conn.packet_buffer[condition].pop(0)
|
|
except IndexError:
|
|
size = 0
|
|
return data
|
|
else:
|
|
raise KeyError
|
|
else:
|
|
if self.packets_arrived(condition, address):
|
|
packet = conn.packet_buffer[condition].pop()
|
|
else:
|
|
raise KeyError
|
|
if want_id and packet.id != want_id:
|
|
raise KeyError
|
|
return packet
|
|
except KeyError:
|
|
not_found = True
|
|
self.incoming_packet_event.wait(0.5)
|
|
def blink_incoming_packet_event(self):
|
|
self.incoming_packet_event.set()
|
|
self.incoming_packet_event.clear()
|
|
def blink_new_conn_event(self):
|
|
self.new_conn_event.set()
|
|
self.new_conn_event.clear()
|
|
def multiplex(self, packet, address):
|
|
if address not in self.connections and not isinstance(packet, Syn):
|
|
return
|
|
if not isinstance(packet, Syn):
|
|
conn = self.connections[address]
|
|
if isinstance(packet, SynAck):
|
|
conn.recv_seq = packet.seq
|
|
elif conn.recv_seq == packet.seq: # Repeat ACK
|
|
ack = Ack(packet.id)
|
|
self.__send_packet(address, ack)
|
|
return
|
|
elif packet.seq < conn.recv_seq: # Possibly DUP
|
|
return
|
|
elif packet.seq > (conn.recv_seq + 1): # Intermediate packet lost
|
|
return
|
|
else:
|
|
conn.recv_seq = packet.seq
|
|
if isinstance(packet, Packet):
|
|
if packet.checksum == EUDP.checksum(packet.data):
|
|
if self.encrypted:
|
|
packet.data = conn.my_key.decrypt_raw(packet.data)
|
|
else:
|
|
return
|
|
if isinstance(packet, Fin):
|
|
self.disconnect(address, packet.id)
|
|
elif isinstance(packet, Syn):
|
|
if address in self.connections:
|
|
return
|
|
if packet.id not in map(lambda x: x.id, self.syn_received.values()):
|
|
self.syn_received[address] = packet
|
|
else:
|
|
with conn.recv_lock:
|
|
if packet.id not in map(lambda x: x.id, conn.packet_buffer[packet.type]):
|
|
bisect.insort(conn.packet_buffer[packet.type], packet)
|
|
if isinstance(packet, Packet):
|
|
ack = Ack(packet.id)
|
|
self.__send_packet(address, ack)
|
|
self.blink_incoming_packet_event()
|
|
|
|
def central_receive_handler(self):
|
|
while True and self.status:
|
|
try:
|
|
packet, address = self.own_socket.recvfrom(SENT_SIZE)
|
|
packet = restricted_pickle_loads(packet)
|
|
self.multiplex(packet, address)
|
|
except pickle.UnpicklingError:
|
|
continue
|
|
except socket.timeout:
|
|
continue
|
|
except socket.error:
|
|
self.own_socket.close()
|
|
self.status = 0
|
|
|
|
def central_receive(self):
|
|
t = threading.Thread(target=self.central_receive_handler)
|
|
t.daemon = True
|
|
t.start()
|