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Транспорт сделан

utcp_objects
Роман Бородин 2019-04-04 22:25:49 +03:00
parent 4eebb0cb84
commit 90d83aede9
1 changed files with 82 additions and 21 deletions
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103
mods/stream.py
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@ -2,16 +2,15 @@ import socketserver
import pickle
import simplecrypto
from uuid import uuid4
from datetime import datetime, timedelta
import datetime, io
import threading
import time
from rpyc.lib import safe_import, Timeout
peers = {}
RETRANSMIT_RETRIES = 3
DATAGRAM_MAX_SIZE = 9000
RAW_DATA_MAX_SIZE = 8000
PACKET_NUM_SEQ_TTL = 300
SOCK_SEND_TIMEOUT = 60
@ -28,6 +27,20 @@ class InvalidPacket(Exception): pass
def pickle_data(data):
return pickle.dumps(data, protocol=4)
################
class RestrictedUnpickler(pickle.Unpickler):
def find_class(self, module, name):
# Only allow datetime
if module == "datetime" and name == 'datetime':
return getattr(datetime, name)
# Forbid everything else.
raise pickle.UnpicklingError("global '%s.%s' is forbidden" %
(module, name))
def restricted_pickle_loads(s):
"""Helper function analogous to pickle.loads()."""
return RestrictedUnpickler(io.BytesIO(s)).load()
################
# From rpyc.lib
class Timeout:
@ -48,7 +61,7 @@ class Timeout:
class Packet:
def __init__(self, packet_payload):
try:
d = pickle.loads(packet_payload)
d = restricted_pickle_loads(packet_payload)
self.sid = d['sid']
self.type = d['type']
self.reset_timestamp = d['reset_timestamp']
@ -68,14 +81,14 @@ class Peer:
self.confirm_wait_packet = None
self.last_packet = None
self.request_lock = threading.Lock()
self.num_seq_ttl = timedelta(seconds=PACKET_NUM_SEQ_TTL)
self.num_seq_ttl = datetime.timedelta(seconds=PACKET_NUM_SEQ_TTL)
self.last_sent_packet_num = -1
self.last_sent_packet_num_reset_time = datetime.utcnow()
self.last_sent_packet_num_reset_time = datetime.datetime.utcnow()
self.last_received_packet_num = -1
self.last_received_packet_num_reset_time = None
self.retransmit_count = 0
def next_packet_num(self):
new_time = datetime.utcnow()
new_time = datetime.datetime.utcnow()
if (new_time - self.last_sent_packet_num_reset_time) >= self.num_seq_ttl:
self.last_sent_packet_num = -1
self.last_sent_packet_num += 1
@ -98,18 +111,21 @@ class Peer:
if confirm:
self.last_packet = data
self.confirm_wait_packet = (d['reset_timestamp'], d['num'])
self.sock.sendto(pickle_data(d), self.endpoint)
self.sock.sendto(data, self.endpoint)
def mark_packet(self, d):
d['num'] = self.next_packet_num()
d['reset_timestamp'] = self.last_sent_packet_num_reset_time
return d
def retransmit(self):
pass
self.retransmit_count += 1
if self.retransmit_count > RETRANSMIT_RETRIES:
raise EOFError('retransmit limit reached')
self.sock.sendto(self.last_packet, self.endpoint)
def reply_my_pub_key(self, packet):
try:
self.peer_pub_key = simplecrypto.RsaPublicKey(packet.data)
except:
raise EOFError
raise EOFError('invalid pubkey data')
self.my_key = simplecrypto.RsaKeypair()
d = {
'type': PACKET_TYPE_PEER_PUB_KEY_REPLY,
@ -133,12 +149,23 @@ class Peer:
'reset_timestamp': packet.reset_timestamp
}
self.send(d)
def check_received_packet(self, packet):
if self.last_received_packet_num_reset_time:
if self.last_received_packet_num_reset_time > packet.reset_timestamp:
raise EOFError('packet from past')
elif self.last_received_packet_num_reset_time < packet.reset_timestamp:
self.last_received_packet_num_reset_time = packet.reset_timestamp
if (self.last_received_packet_num + 1) != packet.num:
raise EOFError('packet sequence corrupt')
else:
self.last_received_packet_num_reset_time = packet.reset_timestamp
self.last_received_packet_num = packet.num
def send_recv_confirmation(self, packet):
pass
def hello(self):
self.sid = uuid4().hex
d = {
'type': PACKET_TYPE_HELLO,
'reset_timestamp': None,
'num': None
}
self.sock.sendto(pickle_data(d))
def recv_packet(self, packet_payload):
@ -146,9 +173,9 @@ class Peer:
try:
packet = Packet(packet_payload)
if packet.type == PACKET_TYPE_GOODBUY:
raise EOFError
raise EOFError('connection closed')
except:
raise EOFError
raise EOFError('invalid packet')
if packet.type != PACKET_TYPE_HELLO and (not self.sid or self.sid != packet.sid):
self.hello()
return
@ -159,7 +186,7 @@ class Peer:
self.peer_pub_key = simplecrypto.RsaPublicKey(self.my_key.decrypt_raw(packet.data))
return
except:
raise EOFError
raise EOFError('create pubkey failed')
elif packet.type == PACKET_TYPE_PEER_PUB_KEY_REQUEST:
self.reply_my_pub_key(packet)
return
@ -168,14 +195,48 @@ class Peer:
return
############################################
if self.confirm_wait_packet:
if (packet.reset_timestamp, packet.num) == self.confirm_wait_packet:
if (packet.reset_timestamp, packet.num) == self.confirm_wait_packet and packet.type == PACKET_TYPE_CONFIRM_RECV:
self.confirm_packet_recv(packet)
return
else:
pass
self.retransmit()
return
############################################
else:
if packet.type == PACKET_TYPE_PACKET:
try:
raw = self.my_key.decrypt_raw(packet.data)
except:
raise EOFError('decrypt packet error')
self.check_received_packet(packet)
self.put_block(raw)
else:
raise EOFError('connection lost')
def send_packet(self, raw):
if self.confirm_wait_packet:
timeout = Timeout(SOCK_SEND_TIMEOUT)
while timeout.timeleft():
if not self.confirm_wait_packet: break
if self.confirm_wait_packet:
raise EOFError('connection lost')
d = {
'type': PACKET_TYPE_PACKET,
'data': raw
}
self.send(self.mark_packet(d), encrypted=True, confirm=True)
class UDPRequestHandler(socketserver.DatagramRequestHandler):
def finish(self):
'''Don't send anything'''
pass
def handle(self):
datagram = self.rfile.read(BUFSIZE)
if self.client_address not in peers:
datagram = self.rfile.read(DATAGRAM_MAX_SIZE)
peer_addr = self.client_address
if peer_addr not in peers: peers[peer_addr] = Peer(self.socket, peer_addr)
try:
peers[peer_addr].recv_packet(datagram)
except EOFError:
del peers[peer_addr]
class EncryptedUDPStream: