Implemented basic multi-hop transport

This commit is contained in:
Mark Qvist 2020-03-01 16:56:49 +01:00
parent 03705372f8
commit 7867d7ded9
4 changed files with 124 additions and 39 deletions

View File

@ -20,10 +20,14 @@ class UdpInterface(Interface):
self.bind_ip = bindip
self.bind_port = bindport
UdpInterfaceHandler.interface = self
def handlerFactory(callback):
def createHandler(*args, **keys):
return UdpInterfaceHandler(callback, *args, **keys)
return createHandler
self.owner = owner
address = (self.bind_ip, self.bind_port)
self.server = SocketServer.UDPServer(address, UdpInterfaceHandler)
self.server = SocketServer.UDPServer(address, handlerFactory(self.processIncoming))
thread = threading.Thread(target=self.server.serve_forever)
thread.setDaemon(True)
@ -49,9 +53,10 @@ class UdpInterface(Interface):
return "UdpInterface["+self.name+"/"+self.bind_ip+":"+str(self.bind_port)+"]"
class UdpInterfaceHandler(SocketServer.BaseRequestHandler):
interface = None
def __init__(self, callback, *args, **keys):
self.callback = callback
SocketServer.BaseRequestHandler.__init__(self, *args, **keys)
def handle(self):
if (UdpInterfaceHandler.interface != None):
data = self.request[0]
UdpInterfaceHandler.interface.processIncoming(data)
data = self.request[0]
self.callback(data)

View File

@ -12,7 +12,7 @@ class Packet:
# Header types
HEADER_1 = 0x00 # Normal header format
HEADER_2 = 0x01 # Header format used for link packets in transport
HEADER_2 = 0x01 # Header format used for packets in transport
HEADER_3 = 0x02 # Reserved
HEADER_4 = 0x03 # Reserved
header_types = [HEADER_1, HEADER_2, HEADER_3, HEADER_4]
@ -85,6 +85,7 @@ class Packet:
return packed_flags
def pack(self):
self.destination_hash = self.destination.hash
self.header = ""
self.header += struct.pack("!B", self.flags)
self.header += struct.pack("!B", self.hops)
@ -141,6 +142,7 @@ class Packet:
raise IOError("Packet size of "+str(len(self.raw))+" exceeds MTU of "+str(self.MTU)+" bytes")
self.packed = True
self.updateHash()
def unpack(self):
self.flags = ord(self.raw[0])
@ -163,6 +165,7 @@ class Packet:
self.data = self.raw[13:]
self.packed = False
self.updateHash()
def send(self):
if not self.sent:
@ -222,9 +225,13 @@ class Packet:
return RNS.Identity.fullHash(self.getHashablePart())
def getHashablePart(self):
# TODO: This assumes transport headers are stripped
# by Transport before going anywhere else
return self.raw[0:1]+self.raw[2:]
hashable_part = struct.pack("!B", struct.unpack("!B", self.raw[0])[0] & 0b00001111)
if self.header_type == Packet.HEADER_2:
hashable_part += self.raw[12:]
else:
hashable_part += self.raw[2:]
return hashable_part
class ProofDestination:
def __init__(self, packet):

View File

@ -265,7 +265,6 @@ class Resource:
expected_data = self.hash + self.expected_proof
expected_proof_packet = RNS.Packet(self.link, expected_data, packet_type=RNS.Packet.PROOF, context=RNS.Packet.RESOURCE_PRF)
expected_proof_packet.pack()
expected_proof_packet.updateHash()
RNS.Transport.cache_request(expected_proof_packet.packet_hash)
self.last_part_sent = time.time()
sleep_time = 0.001

View File

@ -2,6 +2,7 @@ import os
import RNS
import time
import math
import struct
import threading
import traceback
from time import sleep
@ -41,6 +42,7 @@ class Transport:
announce_table = {} # A table for storing announces currently waiting to be retransmitted
destination_table = {} # A lookup table containing the next hop to a given destination
reverse_table = {} # A lookup table for storing packet hashes used to return proofs and replies
jobs_locked = False
jobs_running = False
@ -110,10 +112,6 @@ class Transport:
if time.time() > Transport.announces_last_checked+Transport.announces_check_interval:
for destination_hash in Transport.announce_table:
announce_entry = Transport.announce_table[destination_hash]
# TODO: remove comment and log output
# [time_heard, retransmit_timeout, retries, received_from, packet.hops, packet]
# RNS.log("Announce entry retries: "+str(announce_entry[2]), RNS.LOG_INFO)
# RNS.log("Max retries: "+str(Transport.PATHFINDER_R), RNS.LOG_INFO)
if announce_entry[2] > Transport.PATHFINDER_R:
RNS.log("Dropping announce for "+RNS.prettyhexrep(destination_hash)+", retries exceeded", RNS.LOG_DEBUG)
Transport.announce_table.pop(destination_hash)
@ -140,6 +138,12 @@ class Transport:
while (len(Transport.packet_hashlist) > Transport.hashlist_maxsize):
Transport.packet_hashlist.pop(0)
# Cull the reverse table according to max size and/or age of entries
# TODO: Implement this
# Cull the destination table in some way
# TODO: Implement this
except Exception as e:
RNS.log("An exception occurred while running Transport jobs.", RNS.LOG_ERROR)
RNS.log("The contained exception was: "+str(e), RNS.LOG_ERROR)
@ -156,24 +160,53 @@ class Transport:
sleep(0.01)
Transport.jobs_locked = True
# TODO: This updateHash call might be redundant
packet.updateHash()
sent = False
for interface in Transport.interfaces:
if interface.OUT:
should_transmit = True
if packet.destination.type == RNS.Destination.LINK:
if packet.destination.status == RNS.Link.CLOSED:
should_transmit = False
if interface != packet.destination.attached_interface:
should_transmit = False
if should_transmit:
# TODO: Remove
RNS.log("Transmitting "+str(len(packet.raw))+" bytes via: "+str(interface), RNS.LOG_EXTREME)
RNS.log("Hash is "+RNS.prettyhexrep(packet.packet_hash), RNS.LOG_EXTREME)
interface.processOutgoing(packet.raw)
sent = True
# Check if we have a known path for the destination
# in the destination table
if packet.packet_type != RNS.Packet.ANNOUNCE and packet.destination_hash in Transport.destination_table:
outbound_interface = Transport.destination_table[packet.destination_hash][5]
if Transport.destination_table[packet.destination_hash][2] > 1:
# Insert packet into transport
new_flags = (RNS.Packet.HEADER_2) << 6 | (Transport.TRANSPORT) << 4 | (packet.flags & 0b00001111)
new_raw = struct.pack("!B", new_flags)
new_raw += packet.raw[1:2]
new_raw += Transport.destination_table[packet.destination_hash][1]
new_raw += packet.raw[2:]
# RNS.log("Transporting "+str(len(packet.raw))+" bytes via "+RNS.prettyhexrep(Transport.destination_table[packet.destination_hash][1])+" on: "+str(outbound_interface), RNS.LOG_EXTREME)
# RNS.log("Hash is "+RNS.prettyhexrep(packet.packet_hash), RNS.LOG_EXTREME)
RNS.log("Packet was inserted into transport via "+RNS.prettyhexrep(Transport.destination_table[packet.destination_hash][1])+" on: "+str(outbound_interface), RNS.LOG_DEBUG)
outbound_interface.processOutgoing(new_raw)
sent = True
else:
# Destination is directly reachable, and we know on
# what interface, so transmit only on that one
# TODO: Strip transport headers here
RNS.log("Transmitting "+str(len(packet.raw))+" bytes on: "+str(outbound_interface), RNS.LOG_EXTREME)
RNS.log("Hash is "+RNS.prettyhexrep(packet.packet_hash), RNS.LOG_EXTREME)
outbound_interface.processOutgoing(packet.raw)
sent = True
else:
# Broadcast packet on all outgoing interfaces
for interface in Transport.interfaces:
if interface.OUT:
should_transmit = True
if packet.destination.type == RNS.Destination.LINK:
if packet.destination.status == RNS.Link.CLOSED:
should_transmit = False
if interface != packet.destination.attached_interface:
should_transmit = False
if should_transmit:
RNS.log("Transmitting "+str(len(packet.raw))+" bytes on: "+str(interface), RNS.LOG_EXTREME)
RNS.log("Hash is "+RNS.prettyhexrep(packet.packet_hash), RNS.LOG_EXTREME)
interface.processOutgoing(packet.raw)
sent = True
if sent:
packet.sent = True
@ -199,11 +232,15 @@ class Transport:
return True
if not packet.packet_hash in Transport.packet_hashlist:
return True
else:
if packet.packet_type == RNS.Packet.ANNOUNCE:
return True
return False
@staticmethod
def inbound(raw, interface=None):
# TODO: Rewrite the redundant cache calls in this method
while (Transport.jobs_running):
sleep(0.1)
@ -211,18 +248,44 @@ class Transport:
packet = RNS.Packet(None, raw)
packet.unpack()
packet.updateHash()
packet.receiving_interface = interface
packet.hops += 1
RNS.log(str(interface)+" received packet with hash "+RNS.prettyhexrep(packet.packet_hash), RNS.LOG_EXTREME)
# TODO: Rewrite these redundant cache calls
if Transport.packet_filter(packet):
Transport.packet_hashlist.append(packet.packet_hash)
if packet.transport_id != None and packet.packet_type != RNS.Packet.ANNOUNCE:
if packet.transport_id == Transport.identity.hash:
RNS.log("Received packet in transport for "+RNS.prettyhexrep(packet.destination_hash)+" with matching transport ID, transporting it...", RNS.LOG_DEBUG)
if packet.destination_hash in Transport.destination_table:
next_hop = Transport.destination_table[packet.destination_hash][1]
RNS.log("Packet hops: "+str(packet.hops), RNS.LOG_DEBUG)
RNS.log("Next hop to destination is "+RNS.prettyhexrep(next_hop)+", transporting it.", RNS.LOG_DEBUG)
new_raw = packet.raw[0:1]
new_raw += struct.pack("!B", packet.hops)
new_raw += next_hop
new_raw += packet.raw[12:]
outbound_interface = Transport.destination_table[packet.destination_hash][5]
outbound_interface.processOutgoing(new_raw)
Transport.reverse_table[packet.packet_hash[:10]] = [packet.receiving_interface, outbound_interface, time.time()]
else:
# TODO: There should probably be some kind of REJECT
# mechanism here, to signal to the source that their
# expected path failed
RNS.log("Got packet in transport, but no known path to final destination. Dropping packet.", RNS.LOG_DEBUG)
else:
# TODO: Remove this log statement
RNS.log("Received packet in transport, but transport ID doesn't match, not transporting it further.", RNS.LOG_DEBUG)
# Announce handling. Handles logic related to incoming
# announces, queueing rebroadcasts of these, and removal
# of queued announce rebroadcasts once handed to the next node
if packet.packet_type == RNS.Packet.ANNOUNCE:
if RNS.Identity.validateAnnounce(packet):
if (packet.transport_id != None):
if packet.transport_id != None:
received_from = packet.transport_id
# Check if this is a next retransmission from
@ -231,14 +294,14 @@ class Transport:
if packet.destination_hash in Transport.announce_table:
announce_entry = Transport.announce_table[packet.destination_hash]
if packet.hops == announce_entry[4]:
if packet.hops-1 == announce_entry[4]:
RNS.log("Heard a local rebroadcast of announce for "+RNS.prettyhexrep(packet.destination_hash), RNS.LOG_DEBUG)
announce_entry[6] += 1
if announce_entry[6] >= Transport.LOCAL_REBROADCASTS_MAX:
RNS.log("Max local rebroadcasts of announce for "+RNS.prettyhexrep(packet.destination_hash)+" reached, dropping announce from our table", RNS.LOG_DEBUG)
Transport.announce_table.pop(packet.destination_hash)
if packet.hops == announce_entry[4]+1 and announce_entry[2] > 0:
if packet.hops-1 == announce_entry[4]+1 and announce_entry[2] > 0:
now = time.time()
if now < announce_entry[1]:
RNS.log("Rebroadcasted announce for "+RNS.prettyhexrep(packet.destination_hash)+" has been passed on to next node, no further tries needed", RNS.LOG_DEBUG)
@ -250,7 +313,7 @@ class Transport:
# Check if this announce should be inserted into
# announce and destination tables
should_add = False
packet.hops += 1
# First, check that the announce is not for a destination
# local to this system, and that hops are less than the max
if (not any(packet.destination_hash == d.hash for d in Transport.destinations) and packet.hops < Transport.PATHFINDER_M+1):
@ -302,7 +365,8 @@ class Transport:
random_blobs.append(random_blob)
retransmit_timeout = now + math.pow(Transport.PATHFINDER_C, packet.hops) + (RNS.rand() * Transport.PATHFINDER_RW)
Transport.announce_table[packet.destination_hash] = [now, retransmit_timeout, retries, received_from, packet.hops, packet, local_rebroadcasts]
Transport.destination_table[packet.destination_hash] = [now, received_from, packet.hops, expires, random_blobs]
Transport.destination_table[packet.destination_hash] = [now, received_from, packet.hops, expires, random_blobs, packet.receiving_interface]
RNS.log("Path to "+RNS.prettyhexrep(packet.destination_hash)+" is now via "+RNS.prettyhexrep(received_from)+" on "+str(packet.receiving_interface), RNS.LOG_DEBUG)
elif packet.packet_type == RNS.Packet.LINKREQUEST:
for destination in Transport.destinations:
@ -358,6 +422,18 @@ class Transport:
else:
proof_hash = None
# Check if this proof neds to be transported
if packet.destination_hash in Transport.reverse_table:
reverse_entry = Transport.reverse_table[packet.destination_hash]
if packet.receiving_interface == reverse_entry[1]:
RNS.log("Proof received on correct interface, transporting it via "+str(reverse_entry[0]), RNS.LOG_DEBUG)
new_raw = packet.raw[0:1]
new_raw += struct.pack("!B", packet.hops)
new_raw += packet.raw[2:]
reverse_entry[0].processOutgoing(new_raw)
else:
RNS.log("Proof received on wrong interface, not transporting it.", RNS.LOG_DEBUG)
for receipt in Transport.receipts:
receipt_validated = False
if proof_hash != None:
@ -425,8 +501,6 @@ class Transport:
def cache_request_packet(packet):
if len(packet.data) == RNS.Identity.HASHLENGTH/8:
packet_hash = RNS.hexrep(packet.data, delimit=False)
# TODO: There's some pretty obvious file access
# issues here. Make sure this can't happen
path = RNS.Reticulum.cachepath+"/"+packet_hash
if os.path.isfile(path):
file = open(path, "r")