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Reticulum/RNS/Transport.py
Mark Qvist dfb5af5dd1 Added docstrings, refactored method names.
2021-05-16 23:14:49 +02:00

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import os
import RNS
import time
import math
import struct
import threading
import traceback
from time import sleep
from .vendor import umsgpack as umsgpack
class Transport:
# Constants
BROADCAST = 0x00;
TRANSPORT = 0x01;
RELAY = 0x02;
TUNNEL = 0x03;
types = [BROADCAST, TRANSPORT, RELAY, TUNNEL]
REACHABILITY_UNREACHABLE = 0x00
REACHABILITY_DIRECT = 0x01
REACHABILITY_TRANSPORT = 0x02
APP_NAME = "rnstransport"
# TODO: Document the addition of random windows
# and max local rebroadcasts.
PATHFINDER_M = 18 # Max hops
PATHFINDER_C = 2.0 # Decay constant
PATHFINDER_R = 1 # Retransmit retries
PATHFINDER_T = 10 # Retry grace period
PATHFINDER_RW = 10 # Random window for announce rebroadcast
PATHFINDER_E = 60*15 # Path expiration in seconds
# TODO: Calculate an optimal number for this in
# various situations
LOCAL_REBROADCASTS_MAX = 2 # How many local rebroadcasts of an announce is allowed
PATH_REQUEST_GRACE = 0.35 # Grace time before a path announcement is made, allows directly reachable peers to respond first
PATH_REQUEST_RW = 2 # Path request random window
LINK_TIMEOUT = RNS.Link.KEEPALIVE * 2
REVERSE_TIMEOUT = 30*60 # Reverse table entries are removed after max 30 minutes
DESTINATION_TIMEOUT = 60*60*24*7 # Destination table entries are removed if unused for one week
MAX_RECEIPTS = 1024 # Maximum number of receipts to keep track of
interfaces = [] # All active interfaces
destinations = [] # All active destinations
pending_links = [] # Links that are being established
active_links = [] # Links that are active
packet_hashlist = [] # A list of packet hashes for duplicate detection
receipts = [] # Receipts of all outgoing packets for proof processing
# TODO: "destination_table" should really be renamed to "path_table"
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
link_table = {} # A lookup table containing hops for links
held_announces = {} # A table containing temporarily held announce-table entries
announce_handlers = [] # A table storing externally registered announce handlers
# Transport control destinations are used
# for control purposes like path requests
control_destinations = []
control_hashes = []
# Interfaces for communicating with
# local clients connected to a shared
# Reticulum instance
local_client_interfaces = []
jobs_locked = False
jobs_running = False
job_interval = 0.250
receipts_last_checked = 0.0
receipts_check_interval = 1.0
announces_last_checked = 0.0
announces_check_interval = 1.0
hashlist_maxsize = 1000000
tables_last_culled = 0.0
tables_cull_interval = 5.0
identity = None
@staticmethod
def start(reticulum_instance):
Transport.owner = reticulum_instance
if Transport.identity == None:
transport_identity_path = RNS.Reticulum.storagepath+"/transport_identity"
if os.path.isfile(transport_identity_path):
Transport.identity = RNS.Identity.from_file(transport_identity_path)
if Transport.identity == None:
RNS.log("No valid Transport Identity in storage, creating...", RNS.LOG_VERBOSE)
Transport.identity = RNS.Identity()
Transport.identity.to_file(transport_identity_path)
else:
RNS.log("Loaded Transport Identity from storage", RNS.LOG_VERBOSE)
packet_hashlist_path = RNS.Reticulum.storagepath+"/packet_hashlist"
if os.path.isfile(packet_hashlist_path):
try:
file = open(packet_hashlist_path, "rb")
Transport.packet_hashlist = umsgpack.unpackb(file.read())
file.close()
except Exception as e:
RNS.log("Could not load packet hashlist from storage, the contained exception was: "+str(e), RNS.LOG_ERROR)
# Create transport-specific destinations
Transport.path_request_destination = RNS.Destination(None, RNS.Destination.IN, RNS.Destination.PLAIN, Transport.APP_NAME, "path", "request")
Transport.path_request_destination.packet_callback(Transport.path_request_handler)
Transport.control_destinations.append(Transport.path_request_destination)
Transport.control_hashes.append(Transport.path_request_destination.hash)
thread = threading.Thread(target=Transport.jobloop)
thread.setDaemon(True)
thread.start()
if RNS.Reticulum.transport_enabled():
destination_table_path = RNS.Reticulum.storagepath+"/destination_table"
if os.path.isfile(destination_table_path) and not Transport.owner.is_connected_to_shared_instance:
serialised_destinations = []
try:
file = open(destination_table_path, "rb")
serialised_destinations = umsgpack.unpackb(file.read())
file.close()
for serialised_entry in serialised_destinations:
destination_hash = serialised_entry[0]
timestamp = serialised_entry[1]
received_from = serialised_entry[2]
hops = serialised_entry[3]
expires = serialised_entry[4]
random_blobs = serialised_entry[5]
receiving_interface = Transport.find_interface_from_hash(serialised_entry[6])
announce_packet = Transport.get_cached_packet(serialised_entry[7])
if announce_packet != None and receiving_interface != None:
announce_packet.unpack()
# We increase the hops, since reading a packet
# from cache is equivalent to receiving it again
# over an interface. It is cached with it's non-
# increased hop-count.
announce_packet.hops += 1
Transport.destination_table[destination_hash] = [timestamp, received_from, hops, expires, random_blobs, receiving_interface, announce_packet]
RNS.log("Loaded path table entry for "+RNS.prettyhexrep(destination_hash)+" from storage", RNS.LOG_DEBUG)
else:
RNS.log("Could not reconstruct path table entry from storage for "+RNS.prettyhexrep(destination_hash), RNS.LOG_DEBUG)
if announce_packet == None:
RNS.log("The announce packet could not be loaded from cache", RNS.LOG_DEBUG)
if receiving_interface == None:
RNS.log("The interface is no longer available", RNS.LOG_DEBUG)
if len(Transport.destination_table) == 1:
specifier = "entry"
else:
specifier = "entries"
RNS.log("Loaded "+str(len(Transport.destination_table))+" path table "+specifier+" from storage", RNS.LOG_VERBOSE)
except Exception as e:
RNS.log("Could not load destination table from storage, the contained exception was: "+str(e), RNS.LOG_ERROR)
RNS.log("Transport instance "+str(Transport.identity)+" started")
@staticmethod
def jobloop():
while (True):
Transport.jobs()
sleep(Transport.job_interval)
@staticmethod
def jobs():
outgoing = []
Transport.jobs_running = True
try:
if not Transport.jobs_locked:
# Process receipts list for timed-out packets
if time.time() > Transport.receipts_last_checked+Transport.receipts_check_interval:
while len(Transport.receipts) > Transport.MAX_RECEIPTS:
culled_receipt = Transport.receipts.pop(0)
culled_receipt.timeout = -1
receipt.check_timeout()
for receipt in Transport.receipts:
receipt.check_timeout()
if receipt.status != RNS.PacketReceipt.SENT:
Transport.receipts.remove(receipt)
Transport.receipts_last_checked = time.time()
# Process announces needing retransmission
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]
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)
break
else:
if time.time() > announce_entry[1]:
announce_entry[1] = time.time() + math.pow(Transport.PATHFINDER_C, announce_entry[4]) + Transport.PATHFINDER_T + Transport.PATHFINDER_RW
announce_entry[2] += 1
packet = announce_entry[5]
block_rebroadcasts = announce_entry[7]
attached_interface = announce_entry[8]
announce_context = RNS.Packet.NONE
if block_rebroadcasts:
announce_context = RNS.Packet.PATH_RESPONSE
announce_data = packet.data
announce_identity = RNS.Identity.recall(packet.destination_hash)
announce_destination = RNS.Destination(announce_identity, RNS.Destination.OUT, RNS.Destination.SINGLE, "unknown", "unknown");
announce_destination.hash = packet.destination_hash
announce_destination.hexhash = announce_destination.hash.hex()
new_packet = RNS.Packet(
announce_destination,
announce_data,
RNS.Packet.ANNOUNCE,
context = announce_context,
header_type = RNS.Packet.HEADER_2,
transport_type = Transport.TRANSPORT,
transport_id = Transport.identity.hash,
attached_interface = attached_interface
)
new_packet.hops = announce_entry[4]
if block_rebroadcasts:
RNS.log("Rebroadcasting announce as path response for "+RNS.prettyhexrep(announce_destination.hash)+" with hop count "+str(new_packet.hops), RNS.LOG_DEBUG)
else:
RNS.log("Rebroadcasting announce for "+RNS.prettyhexrep(announce_destination.hash)+" with hop count "+str(new_packet.hops), RNS.LOG_DEBUG)
outgoing.append(new_packet)
# This handles an edge case where a peer sends a past
# request for a destination just after an announce for
# said destination has arrived, but before it has been
# rebroadcast locally. In such a case the actual announce
# is temporarily held, and then reinserted when the path
# request has been served to the peer.
if destination_hash in Transport.held_announces:
held_entry = Transport.held_announces.pop(destination_hash)
Transport.announce_table[destination_hash] = held_entry
RNS.log("Reinserting held announce into table", RNS.LOG_DEBUG)
Transport.announces_last_checked = time.time()
# Cull the packet hashlist if it has reached max size
while (len(Transport.packet_hashlist) > Transport.hashlist_maxsize):
Transport.packet_hashlist.pop(0)
if time.time() > Transport.tables_last_culled + Transport.tables_cull_interval:
# Cull the reverse table according to timeout
for truncated_packet_hash in Transport.reverse_table:
reverse_entry = Transport.reverse_table[truncated_packet_hash]
if time.time() > reverse_entry[2] + Transport.REVERSE_TIMEOUT:
Transport.reverse_table.pop(truncated_packet_hash)
# Cull the link table according to timeout
stale_links = []
for link_id in Transport.link_table:
link_entry = Transport.link_table[link_id]
if time.time() > link_entry[0] + Transport.LINK_TIMEOUT:
stale_links.append(link_id)
# Cull the path table
stale_paths = []
for destination_hash in Transport.destination_table:
destination_entry = Transport.destination_table[destination_hash]
attached_interface = destination_entry[5]
if time.time() > destination_entry[0] + Transport.DESTINATION_TIMEOUT:
stale_paths.append(destination_hash)
RNS.log("Path to "+RNS.prettyhexrep(destination_hash)+" timed out and was removed", RNS.LOG_DEBUG)
if not attached_interface in Transport.interfaces:
stale_paths.append(destination_hash)
RNS.log("Path to "+RNS.prettyhexrep(destination_hash)+" was removed since the attached interface no longer exists", RNS.LOG_DEBUG)
i = 0
for link_id in stale_links:
Transport.link_table.pop(link_id)
i += 1
if i > 0:
if i == 1:
RNS.log("Dropped "+str(i)+" link", RNS.LOG_DEBUG)
else:
RNS.log("Dropped "+str(i)+" links", RNS.LOG_DEBUG)
i = 0
for destination_hash in stale_paths:
Transport.destination_table.pop(destination_hash)
i += 1
if i > 0:
if i == 1:
RNS.log("Removed "+str(i)+" path", RNS.LOG_DEBUG)
else:
RNS.log("Removed "+str(i)+" paths", RNS.LOG_DEBUG)
Transport.tables_last_culled = time.time()
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)
traceback.print_exc()
Transport.jobs_running = False
for packet in outgoing:
packet.send()
@staticmethod
def outbound(packet):
while (Transport.jobs_running):
sleep(0.01)
Transport.jobs_locked = True
# TODO: This updateHash call might be redundant
packet.update_hash()
sent = False
# Check if we have a known path for the destination in the path 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 there's more than one hop to the destination, and we know
# a path, we insert the packet into transport by adding the next
# transport nodes address to the header, and modifying the flags.
# This rule applies both for "normal" transport, and when connected
# to a local shared Reticulum instance.
if Transport.destination_table[packet.destination_hash][2] > 1:
if packet.header_type == RNS.Packet.HEADER_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:]
# TODO: Remove at some point
# RNS.log("Packet was inserted into transport via "+RNS.prettyhexrep(Transport.destination_table[packet.destination_hash][1])+" on: "+str(outbound_interface), RNS.LOG_EXTREME)
outbound_interface.processOutgoing(new_raw)
Transport.destination_table[packet.destination_hash][0] = time.time()
sent = True
# In the special case where we are connected to a local shared
# Reticulum instance, and the destination is one hop away, we
# also add transport headers to inject the packet into transport
# via the shared instance. Normally a packet for a destination
# one hop away would just be broadcast directly, but since we
# are "behind" a shared instance, we need to get that instance
# to transport it onto the network.
elif Transport.destination_table[packet.destination_hash][2] == 1 and Transport.owner.is_connected_to_shared_instance:
if packet.header_type == RNS.Packet.HEADER_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:]
# TODO: Remove at some point
# RNS.log("Packet was inserted into transport via "+RNS.prettyhexrep(Transport.destination_table[packet.destination_hash][1])+" on: "+str(outbound_interface), RNS.LOG_EXTREME)
outbound_interface.processOutgoing(new_raw)
Transport.destination_table[packet.destination_hash][0] = time.time()
sent = True
# If none of the above applies, we know the destination is
# directly reachable, and also on which interface, so we
# simply transmit the packet directly on that one.
else:
outbound_interface.processOutgoing(packet.raw)
sent = True
# If we don't have a known path for the destination, we'll
# broadcast the packet on all outgoing interfaces, or the
# just the relevant interface if the packet has an attached
# interface, or belongs to a link.
else:
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 packet.attached_interface != None and interface != packet.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
packet.sent_at = time.time()
# Don't generate receipt if it has been explicitly disabled
if (packet.create_receipt == True and
# Only generate receipts for DATA packets
packet.packet_type == RNS.Packet.DATA and
# Don't generate receipts for PLAIN destinations
packet.destination.type != RNS.Destination.PLAIN and
# Don't generate receipts for link-related packets
not (packet.context >= RNS.Packet.KEEPALIVE and packet.context <= RNS.Packet.LRPROOF) and
# Don't generate receipts for resource packets
not (packet.context >= RNS.Packet.RESOURCE and packet.context <= RNS.Packet.RESOURCE_RCL)):
packet.receipt = RNS.PacketReceipt(packet)
Transport.receipts.append(packet.receipt)
Transport.cache(packet)
Transport.jobs_locked = False
return sent
@staticmethod
def packet_filter(packet):
# TODO: Think long and hard about this.
# Is it even strictly necessary with the current
# transport rules?
if packet.context == RNS.Packet.KEEPALIVE:
return True
if packet.context == RNS.Packet.RESOURCE_REQ:
return True
if packet.context == RNS.Packet.RESOURCE_PRF:
return True
if packet.context == RNS.Packet.RESOURCE:
return True
if packet.context == RNS.Packet.CACHE_REQUEST:
return True
if packet.destination_type == RNS.Destination.PLAIN:
return True
if not packet.packet_hash in Transport.packet_hashlist:
return True
else:
if packet.packet_type == RNS.Packet.ANNOUNCE:
return True
RNS.log("Filtered packet with hash "+RNS.prettyhexrep(packet.packet_hash), RNS.LOG_DEBUG)
return False
@staticmethod
def inbound(raw, interface=None):
while (Transport.jobs_running):
# TODO: Decrease this for performance
sleep(0.1)
Transport.jobs_locked = True
packet = RNS.Packet(None, raw)
packet.unpack()
packet.receiving_interface = interface
packet.hops += 1
RNS.log(str(interface)+" received packet with hash "+RNS.prettyhexrep(packet.packet_hash), RNS.LOG_EXTREME)
if len(Transport.local_client_interfaces) > 0:
if Transport.is_local_client_interface(interface):
packet.hops -= 1
elif Transport.interface_to_shared_instance(interface):
packet.hops -= 1
if Transport.packet_filter(packet):
Transport.packet_hashlist.append(packet.packet_hash)
Transport.cache(packet)
# Check special conditions for local clients connected
# through a shared Reticulum instance
from_local_client = (packet.receiving_interface in Transport.local_client_interfaces)
for_local_client = (packet.packet_type != RNS.Packet.ANNOUNCE) and (packet.destination_hash in Transport.destination_table and Transport.destination_table[packet.destination_hash][2] == 0)
for_local_client_link = (packet.packet_type != RNS.Packet.ANNOUNCE) and (packet.destination_hash in Transport.link_table and Transport.link_table[packet.destination_hash][4] in Transport.local_client_interfaces)
for_local_client_link |= (packet.packet_type != RNS.Packet.ANNOUNCE) and (packet.destination_hash in Transport.link_table and Transport.link_table[packet.destination_hash][2] in Transport.local_client_interfaces)
proof_for_local_client = (packet.destination_hash in Transport.reverse_table) and (Transport.reverse_table[packet.destination_hash][0] in Transport.local_client_interfaces)
# Plain broadcast packets from local clients are sent
# directly on all attached interfaces, since they are
# never injected into transport.
if not packet.destination_hash in Transport.control_hashes:
if packet.destination_type == RNS.Destination.PLAIN and packet.transport_type == Transport.BROADCAST:
# Send to all interfaces except the originator
if from_local_client:
for interface in Transport.interfaces:
if interface != packet.receiving_interface:
interface.processOutgoing(packet.raw)
# If the packet was not from a local client, send
# it directly to all local clients
else:
for interface in Transport.local_client_interfaces:
interface.processOutgoing(packet.raw)
# General transport handling. Takes care of directing
# packets according to transport tables and recording
# entries in reverse and link tables.
if RNS.Reticulum.transport_enabled() or from_local_client or for_local_client or for_local_client_link:
# If there is no transport id, but the packet is
# for a local client, we generate the transport
# id (it was stripped on the previous hop, since
# we "spoof" the hop count for clients behind a
# shared instance, so they look directly reach-
# able), and reinsert, so the normal transport
# implementation can handle the packet.
if packet.transport_id == None and for_local_client:
packet.transport_id = Transport.identity.hash
# If this is a cache request, and we can fullfill
# it, do so and stop processing. Otherwise resume
# normal processing.
if packet.context == RNS.Packet.CACHE_REQUEST:
if Transport.cache_request_packet(packet):
return
# If the packet is in transport, check whether we
# are the designated next hop, and process it
# accordingly if we are.
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]
remaining_hops = Transport.destination_table[packet.destination_hash][2]
RNS.log("Next hop to destination is "+RNS.prettyhexrep(next_hop)+" with "+str(remaining_hops)+" hops remaining, transporting it.", RNS.LOG_DEBUG)
if remaining_hops > 1:
# Just increase hop count and transmit
new_raw = packet.raw[0:1]
new_raw += struct.pack("!B", packet.hops)
new_raw += next_hop
new_raw += packet.raw[12:]
elif remaining_hops == 1:
# Strip transport headers and transmit
new_flags = (RNS.Packet.HEADER_1) << 6 | (Transport.BROADCAST) << 4 | (packet.flags & 0b00001111)
new_raw = struct.pack("!B", new_flags)
new_raw += struct.pack("!B", packet.hops)
new_raw += packet.raw[12:]
elif remaining_hops == 0:
# Just increase hop count and transmit
new_raw = packet.raw[0:1]
new_raw += struct.pack("!B", packet.hops)
new_raw += packet.raw[2:]
outbound_interface = Transport.destination_table[packet.destination_hash][5]
outbound_interface.processOutgoing(new_raw)
Transport.destination_table[packet.destination_hash][0] = time.time()
if packet.packet_type == RNS.Packet.LINKREQUEST:
# Entry format is
link_entry = [ time.time(), # 0: Timestamp,
next_hop, # 1: Next-hop transport ID
outbound_interface, # 2: Next-hop interface
remaining_hops, # 3: Remaining hops
packet.receiving_interface, # 4: Received on interface
packet.hops, # 5: Taken hops
packet.destination_hash, # 6: Original destination hash
False] # 7: Validated
Transport.link_table[packet.getTruncatedHash()] = link_entry
else:
# Entry format is
reverse_entry = [ packet.receiving_interface, # 0: Received on interface
outbound_interface, # 1: Outbound interface
time.time()] # 2: Timestamp
Transport.reverse_table[packet.getTruncatedHash()] = reverse_entry
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)
# Link transport handling. Directs packets according
# to entries in the link tables
if packet.packet_type != RNS.Packet.ANNOUNCE and packet.packet_type != RNS.Packet.LINKREQUEST and packet.context != RNS.Packet.LRPROOF:
if packet.destination_hash in Transport.link_table:
link_entry = Transport.link_table[packet.destination_hash]
# If receiving and outbound interface is
# the same for this link, direction doesn't
# matter, and we simply send the packet on.
outbound_interface = None
if link_entry[2] == link_entry[4]:
# But check that taken hops matches one
# of the expectede values.
if packet.hops == link_entry[3] or packet.hops == link_entry[5]:
outbound_interface = link_entry[2]
else:
# If interfaces differ, we transmit on
# the opposite interface of what the
# packet was received on.
if packet.receiving_interface == link_entry[2]:
# Also check that expected hop count matches
if packet.hops == link_entry[3]:
outbound_interface = link_entry[4]
elif packet.receiving_interface == link_entry[4]:
# Also check that expected hop count matches
if packet.hops == link_entry[5]:
outbound_interface = link_entry[2]
if outbound_interface != None:
new_raw = packet.raw[0:1]
new_raw += struct.pack("!B", packet.hops)
new_raw += packet.raw[2:]
outbound_interface.processOutgoing(new_raw)
Transport.link_table[packet.destination_hash][0] = time.time()
else:
pass
# 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:
local_destination = next((d for d in Transport.destinations if d.hash == packet.destination_hash), None)
if local_destination == None and RNS.Identity.validate_announce(packet):
if packet.transport_id != None:
received_from = packet.transport_id
# Check if this is a next retransmission from
# another node. If it is, we're removing the
# announce in question from our pending table
if RNS.Reticulum.transport_enabled() and packet.destination_hash in Transport.announce_table:
announce_entry = Transport.announce_table[packet.destination_hash]
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-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)
Transport.announce_table.pop(packet.destination_hash)
else:
received_from = packet.destination_hash
# Check if this announce should be inserted into
# announce and destination tables
should_add = False
# 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):
random_blob = packet.data[RNS.Identity.DERKEYSIZE//8+10:RNS.Identity.DERKEYSIZE//8+20]
random_blobs = []
if packet.destination_hash in Transport.destination_table:
random_blobs = Transport.destination_table[packet.destination_hash][4]
# If we already have a path to the announced
# destination, but the hop count is equal or
# less, we'll update our tables.
if packet.hops <= Transport.destination_table[packet.destination_hash][2]:
# Make sure we haven't heard the random
# blob before, so announces can't be
# replayed to forge paths.
# TODO: Check whether this approach works
# under all circumstances
if not random_blob in random_blobs:
should_add = True
else:
should_add = False
else:
# If an announce arrives with a larger hop
# count than we already have in the table,
# ignore it, unless the path is expired
if (time.time() > Transport.destination_table[packet.destination_hash][3]):
# We also check that the announce hash is
# different from ones we've already heard,
# to avoid loops in the network
if not random_blob in random_blobs:
# TODO: Check that this ^ approach actually
# works under all circumstances
RNS.log("Replacing destination table entry for "+str(RNS.prettyhexrep(packet.destination_hash))+" with new announce due to expired path", RNS.LOG_DEBUG)
should_add = True
else:
should_add = False
else:
should_add = False
else:
# If this destination is unknown in our table
# we should add it
should_add = True
if should_add:
now = time.time()
retries = 0
expires = now + Transport.PATHFINDER_E
announce_hops = packet.hops
local_rebroadcasts = 0
block_rebroadcasts = False
attached_interface = None
retransmit_timeout = now + math.pow(Transport.PATHFINDER_C, packet.hops) + (RNS.rand() * Transport.PATHFINDER_RW)
random_blobs.append(random_blob)
if (RNS.Reticulum.transport_enabled() or Transport.from_local_client(packet)) and packet.context != RNS.Packet.PATH_RESPONSE:
# If the announce is from a local client,
# we announce it immediately, but only one
# time.
if Transport.from_local_client(packet):
retransmit_timeout = now
retries = Transport.PATHFINDER_R
Transport.announce_table[packet.destination_hash] = [
now,
retransmit_timeout,
retries,
received_from,
announce_hops,
packet,
local_rebroadcasts,
block_rebroadcasts,
attached_interface
]
# If we have any local clients connected, we re-
# transmit the announce to them immediately
if (len(Transport.local_client_interfaces)):
announce_identity = RNS.Identity.recall(packet.destination_hash)
announce_destination = RNS.Destination(announce_identity, RNS.Destination.OUT, RNS.Destination.SINGLE, "unknown", "unknown");
announce_destination.hash = packet.destination_hash
announce_destination.hexhash = announce_destination.hash.hex()
announce_context = RNS.Packet.NONE
announce_data = packet.data
new_announce = RNS.Packet(
announce_destination,
announce_data,
RNS.Packet.ANNOUNCE,
context = announce_context,
header_type = RNS.Packet.HEADER_2,
transport_type = Transport.TRANSPORT,
transport_id = Transport.identity.hash,
attached_interface = attached_interface
)
new_announce.hops = packet.hops
new_announce.send()
Transport.destination_table[packet.destination_hash] = [now, received_from, announce_hops, expires, random_blobs, packet.receiving_interface, packet]
RNS.log("Path to "+RNS.prettyhexrep(packet.destination_hash)+" is now "+str(announce_hops)+" hops away via "+RNS.prettyhexrep(received_from)+" on "+str(packet.receiving_interface), RNS.LOG_VERBOSE)
# Call externally registered callbacks from apps
# wanting to know when an announce arrives
for handler in Transport.announce_handlers:
try:
# Check that the announced destination matches
# the handlers aspect filter
execute_callback = False
if handler.aspect_filter == None:
# If the handlers aspect filter is set to
# None, we execute the callback in all cases
execute_callback = True
else:
announce_identity = RNS.Identity.recall(packet.destination_hash)
handler_expected_hash = RNS.Destination.hash_from_name_and_identity(handler.aspect_filter, announce_identity)
if packet.destination_hash == handler_expected_hash:
execute_callback = True
if execute_callback:
handler.received_announce(
destination_hash=packet.destination_hash,
announced_identity=announce_identity,
app_data=RNS.Identity.recall_app_data(packet.destination_hash)
)
except Exception as e:
RNS.log("Error while processing external announce callback.", RNS.LOG_ERROR)
RNS.log("The contained exception was: "+str(e), RNS.LOG_ERROR)
# Handling for linkrequests to local destinations
elif packet.packet_type == RNS.Packet.LINKREQUEST:
for destination in Transport.destinations:
if destination.hash == packet.destination_hash and destination.type == packet.destination_type:
packet.destination = destination
destination.receive(packet)
# Handling for local data packets
elif packet.packet_type == RNS.Packet.DATA:
if packet.destination_type == RNS.Destination.LINK:
for link in Transport.active_links:
if link.link_id == packet.destination_hash:
packet.link = link
link.receive(packet)
else:
for destination in Transport.destinations:
if destination.hash == packet.destination_hash and destination.type == packet.destination_type:
packet.destination = destination
destination.receive(packet)
if destination.proof_strategy == RNS.Destination.PROVE_ALL:
packet.prove()
elif destination.proof_strategy == RNS.Destination.PROVE_APP:
if destination.callbacks.proof_requested:
if destination.callbacks.proof_requested(packet):
packet.prove()
# Handling for proofs and link-request proofs
elif packet.packet_type == RNS.Packet.PROOF:
if packet.context == RNS.Packet.LRPROOF:
# This is a link request proof, check if it
# needs to be transported
if (RNS.Reticulum.transport_enabled() or for_local_client_link or from_local_client) and packet.destination_hash in Transport.link_table:
link_entry = Transport.link_table[packet.destination_hash]
if packet.receiving_interface == link_entry[2]:
# TODO: Should we validate the LR proof at each transport
# step before transporting it?
RNS.log("Link request proof received on correct interface, transporting it via "+str(link_entry[4]), RNS.LOG_DEBUG)
new_raw = packet.raw[0:1]
new_raw += struct.pack("!B", packet.hops)
new_raw += packet.raw[2:]
Transport.link_table[packet.destination_hash][7] = True
link_entry[4].processOutgoing(new_raw)
else:
RNS.log("Link request proof received on wrong interface, not transporting it.", RNS.LOG_DEBUG)
else:
# Check if we can deliver it to a local
# pending link
for link in Transport.pending_links:
if link.link_id == packet.destination_hash:
link.validate_proof(packet)
elif packet.context == RNS.Packet.RESOURCE_PRF:
for link in Transport.active_links:
if link.link_id == packet.destination_hash:
link.receive(packet)
else:
if packet.destination_type == RNS.Destination.LINK:
for link in Transport.active_links:
if link.link_id == packet.destination_hash:
packet.link = link
if len(packet.data) == RNS.PacketReceipt.EXPL_LENGTH:
proof_hash = packet.data[:RNS.Identity.HASHLENGTH//8]
else:
proof_hash = None
# Check if this proof neds to be transported
if (RNS.Reticulum.transport_enabled() or from_local_client or proof_for_local_client) and packet.destination_hash in Transport.reverse_table:
reverse_entry = Transport.reverse_table.pop(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:
# Only test validation if hash matches
if receipt.hash == proof_hash:
receipt_validated = receipt.validate_proof_packet(packet)
else:
# In case of an implicit proof, we have
# to check every single outstanding receipt
receipt_validated = receipt.validate_proof_packet(packet)
if receipt_validated:
Transport.receipts.remove(receipt)
Transport.jobs_locked = False
@staticmethod
def register_destination(destination):
destination.MTU = RNS.Reticulum.MTU
if destination.direction == RNS.Destination.IN:
for registered_destination in Transport.destinations:
if destination.hash == registered_destination.hash:
raise KeyError("Attempt to register an already registered destination.")
Transport.destinations.append(destination)
@staticmethod
def deregister_destination(destination):
if destination in Transport.destinations:
Transport.destinations.remove(destination)
@staticmethod
def register_link(link):
RNS.log("Registering link "+str(link), RNS.LOG_DEBUG)
if link.initiator:
Transport.pending_links.append(link)
else:
Transport.active_links.append(link)
@staticmethod
def activate_link(link):
RNS.log("Activating link "+str(link), RNS.LOG_DEBUG)
if link in Transport.pending_links:
Transport.pending_links.remove(link)
Transport.active_links.append(link)
link.status = RNS.Link.ACTIVE
else:
RNS.log("Attempted to activate a link that was not in the pending table", RNS.LOG_ERROR)
@staticmethod
def register_announce_handler(handler):
"""
Registers an announce handler.
:param handler: Must be an object with an *aspect_filter* attribute and a *received_announce(destination_hash, announced_identity, app_data)* callable. See the :ref:`Announce Example<example-announce>` for more info.
"""
if hasattr(handler, "received_announce") and callable(handler.received_announce):
if hasattr(handler, "aspect_filter"):
Transport.announce_handlers.append(handler)
@staticmethod
def deregister_announce_handler(handler):
"""
Deregisters an announce handler.
:param handler: The announce handler to be deregistered.
"""
while handler in Transport.announce_handlers:
Transport.announce_handlers.remove(handler)
@staticmethod
def find_interface_from_hash(interface_hash):
for interface in Transport.interfaces:
if interface.get_hash() == interface_hash:
return interface
return None
@staticmethod
def should_cache(packet):
if packet.context == RNS.Packet.RESOURCE_PRF:
return True
return False
# When caching packets to storage, they are written
# exactly as they arrived over their interface. This
# means that they have not had their hop count
# increased yet! Take note of this when reading from
# the packet cache.
@staticmethod
def cache(packet, force_cache=False):
if RNS.Transport.should_cache(packet) or force_cache:
try:
packet_hash = RNS.hexrep(packet.get_hash(), delimit=False)
interface_reference = None
if packet.receiving_interface != None:
interface_reference = str(packet.receiving_interface)
file = open(RNS.Reticulum.cachepath+"/"+packet_hash, "wb")
file.write(umsgpack.packb([packet.raw, interface_reference]))
file.close()
except Exception as e:
RNS.log("Error writing packet to cache", RNS.LOG_ERROR)
RNS.log("The contained exception was: "+str(e))
@staticmethod
def get_cached_packet(packet_hash):
try:
packet_hash = RNS.hexrep(packet_hash, delimit=False)
path = RNS.Reticulum.cachepath+"/"+packet_hash
if os.path.isfile(path):
file = open(path, "rb")
cached_data = umsgpack.unpackb(file.read())
file.close()
packet = RNS.Packet(None, cached_data[0])
interface_reference = cached_data[1]
for interface in Transport.interfaces:
if str(interface) == interface_reference:
packet.receiving_interface = interface
return packet
else:
return None
except Exception as e:
RNS.log("Exception occurred while getting cached packet.", RNS.LOG_ERROR)
RNS.log("The contained exception was: "+str(e), RNS.LOG_ERROR)
@staticmethod
def cache_request_packet(packet):
if len(packet.data) == RNS.Identity.HASHLENGTH/8:
packet = Transport.get_cached_packet(packet.data)
if packet != None:
# If the packet was retrieved from the local
# cache, replay it to the Transport instance,
# so that it can be directed towards it original
# destination.
Transport.inbound(packet.raw, packet.receiving_interface)
return True
else:
return False
else:
return False
@staticmethod
def cache_request(packet_hash, destination):
cached_packet = Transport.get_cached_packet(packet_hash)
if cached_packet:
# The packet was found in the local cache,
# replay it to the Transport instance.
Transport.inbound(packet.raw, packet.receiving_interface)
else:
# The packet is not in the local cache,
# query the network.
RNS.Packet(destination, packet_hash, context = RNS.Packet.CACHE_REQUEST).send()
@staticmethod
def has_path(destination_hash):
"""
:param destination_hash: A destination hash as *bytes*.
:returns: *True* if a path to the destination is known, otherwise *False*.
"""
if destination_hash in Transport.destination_table:
return True
else:
return False
@staticmethod
def request_path(destination_hash):
"""
Requests a path to the destination from the network. If
another reachable peer on the network knows a path, it
will announce it.
:param destination_hash: A destination hash as *bytes*.
"""
path_request_data = destination_hash + RNS.Identity.get_random_hash()
path_request_dst = RNS.Destination(None, RNS.Destination.OUT, RNS.Destination.PLAIN, Transport.APP_NAME, "path", "request")
packet = RNS.Packet(path_request_dst, path_request_data, packet_type = RNS.Packet.DATA, transport_type = RNS.Transport.BROADCAST, header_type = RNS.Packet.HEADER_1)
packet.send()
@staticmethod
def request_path_on_interface(destination_hash, interface):
path_request_data = destination_hash + RNS.Identity.get_random_hash()
path_request_dst = RNS.Destination(None, RNS.Destination.OUT, RNS.Destination.PLAIN, Transport.APP_NAME, "path", "request")
packet = RNS.Packet(path_request_dst, path_request_data, packet_type = RNS.Packet.DATA, transport_type = RNS.Transport.BROADCAST, header_type = RNS.Packet.HEADER_1, attached_interface = interface)
packet.send()
@staticmethod
def path_request_handler(data, packet):
if len(data) >= RNS.Identity.TRUNCATED_HASHLENGTH//8:
Transport.path_request(
data[:RNS.Identity.TRUNCATED_HASHLENGTH//8],
Transport.from_local_client(packet),
packet.receiving_interface
)
@staticmethod
def path_request(destination_hash, is_from_local_client, attached_interface):
RNS.log("Path request for "+RNS.prettyhexrep(destination_hash), RNS.LOG_DEBUG)
local_destination = next((d for d in Transport.destinations if d.hash == destination_hash), None)
if local_destination != None:
RNS.log("Destination is local to this system, announcing", RNS.LOG_DEBUG)
local_destination.announce(path_response=True)
elif (RNS.Reticulum.transport_enabled() or is_from_local_client) and destination_hash in Transport.destination_table:
RNS.log("Path found, inserting announce for transmission", RNS.LOG_DEBUG)
packet = Transport.destination_table[destination_hash][6]
received_from = Transport.destination_table[destination_hash][5]
now = time.time()
retries = Transport.PATHFINDER_R
local_rebroadcasts = 0
block_rebroadcasts = True
announce_hops = packet.hops
if is_from_local_client:
retransmit_timeout = now
else:
# TODO: Look at this timing
retransmit_timeout = now + Transport.PATH_REQUEST_GRACE # + (RNS.rand() * Transport.PATHFINDER_RW)
# This handles an edge case where a peer sends a past
# request for a destination just after an announce for
# said destination has arrived, but before it has been
# rebroadcast locally. In such a case the actual announce
# is temporarily held, and then reinserted when the path
# request has been served to the peer.
if packet.destination_hash in Transport.announce_table:
held_entry = Transport.announce_table[packet.destination_hash]
Transport.held_announces[packet.destination_hash] = held_entry
Transport.announce_table[packet.destination_hash] = [now, retransmit_timeout, retries, received_from, announce_hops, packet, local_rebroadcasts, block_rebroadcasts, attached_interface]
elif is_from_local_client:
# Forward path request on all interfaces
# except the local client
for interface in Transport.interfaces:
if not interface == attached_interface:
Transport.request_path_on_interface(destination_hash, interface)
elif not is_from_local_client and len(Transport.local_client_interfaces) > 0:
# Forward the path request on all local
# client interfaces
for interface in Transport.local_client_interfaces:
Transport.request_path_on_interface(destination_hash, interface)
else:
RNS.log("No known path to requested destination, ignoring request", RNS.LOG_DEBUG)
@staticmethod
def from_local_client(packet):
if hasattr(packet.receiving_interface, "parent_interface"):
return Transport.is_local_client_interface(packet.receiving_interface)
else:
return False
@staticmethod
def is_local_client_interface(interface):
if hasattr(interface, "parent_interface"):
if hasattr(interface.parent_interface, "is_local_shared_instance"):
return True
else:
return False
else:
return False
@staticmethod
def interface_to_shared_instance(interface):
if hasattr(interface, "is_connected_to_shared_instance"):
return True
else:
return False
@staticmethod
def exit_handler():
RNS.log("Saving packet hashlist to storage...", RNS.LOG_VERBOSE)
try:
packet_hashlist_path = RNS.Reticulum.storagepath+"/packet_hashlist"
file = open(packet_hashlist_path, "wb")
file.write(umsgpack.packb(Transport.packet_hashlist))
file.close()
RNS.log("Done packet hashlist to storage", RNS.LOG_VERBOSE)
except Exception as e:
RNS.log("Could not save packet hashlist to storage, the contained exception was: "+str(e), RNS.LOG_ERROR)
if not Transport.owner.is_connected_to_shared_instance:
RNS.log("Saving path table to storage...", RNS.LOG_VERBOSE)
try:
serialised_destinations = []
for destination_hash in Transport.destination_table:
# Get the destination entry from the destination table
de = Transport.destination_table[destination_hash]
interface_hash = de[5].get_hash()
# Only store destination table entry if the associated
# interface is still active
interface = Transport.find_interface_from_hash(interface_hash)
if interface != None:
# Get the destination entry from the destination table
de = Transport.destination_table[destination_hash]
timestamp = de[0]
received_from = de[1]
hops = de[2]
expires = de[3]
random_blobs = de[4]
packet_hash = de[6].get_hash()
serialised_entry = [
destination_hash,
timestamp,
received_from,
hops,
expires,
random_blobs,
interface_hash,
packet_hash
]
serialised_destinations.append(serialised_entry)
Transport.cache(de[6], force_cache=True)
destination_table_path = RNS.Reticulum.storagepath+"/destination_table"
file = open(destination_table_path, "wb")
file.write(umsgpack.packb(serialised_destinations))
file.close()
RNS.log("Done saving "+str(len(serialised_destinations))+" path table entries to storage", RNS.LOG_VERBOSE)
except Exception as e:
RNS.log("Could not save path table to storage, the contained exception was: "+str(e), RNS.LOG_ERROR)
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