Improved path response handling. Prepared destination path response handling for multi-path Transport.

This commit is contained in:
Mark Qvist 2022-12-22 11:28:56 +01:00
parent dd7931d421
commit b305eb8e0a
2 changed files with 51 additions and 23 deletions

View File

@ -69,6 +69,8 @@ class Destination:
OUT = 0x12;
directions = [IN, OUT]
PR_TAG_WINDOW = 30
@staticmethod
def expand_name(identity, app_name, *aspects):
"""
@ -132,6 +134,7 @@ class Destination:
self.proof_strategy = Destination.PROVE_NONE
self.mtu = 0
self.path_responses = {}
self.links = []
if identity == None and direction == Destination.IN and self.type != Destination.PLAIN:
@ -163,7 +166,7 @@ class Destination:
return "<"+self.name+"/"+self.hexhash+">"
def announce(self, app_data=None, path_response=False, send=True):
def announce(self, app_data=None, path_response=False, attached_interface=None, tag=None, send=True):
"""
Creates an announce packet for this destination and broadcasts it on all
relevant interfaces. Application specific data can be added to the announce.
@ -173,35 +176,60 @@ class Destination:
"""
if self.type != Destination.SINGLE:
raise TypeError("Only SINGLE destination types can be announced")
destination_hash = self.hash
random_hash = RNS.Identity.get_random_hash()[0:5]+int(time.time()).to_bytes(5, "big")
if app_data == None and self.default_app_data != None:
if isinstance(self.default_app_data, bytes):
app_data = self.default_app_data
elif callable(self.default_app_data):
returned_app_data = self.default_app_data()
if isinstance(returned_app_data, bytes):
app_data = returned_app_data
signed_data = self.hash+self.identity.get_public_key()+self.name_hash+random_hash
if app_data != None:
signed_data += app_data
now = time.time()
stale_responses = []
for entry_tag in self.path_responses:
entry = self.path_responses[entry_tag]
if now > entry[0]+Destination.PR_TAG_WINDOW:
stale_responses.append(entry_tag)
signature = self.identity.sign(signed_data)
for entry_tag in stale_responses:
self.path_responses.pop(entry_tag)
announce_data = self.identity.get_public_key()+self.name_hash+random_hash+signature
if (path_response == True and tag != None) and tag in self.path_responses:
# This code is currently not used, since Transport will block duplicate
# path requests based on tags. When multi-path support is implemented in
# Transport, this will allow Transport to detect redundant paths to the
# same destination, and select the best one based on chosen criteria,
# since it will be able to detect that a single emitted announce was
# received via multiple paths. The difference in reception time will
# potentially also be useful in determining characteristics of the
# multiple available paths, and to choose the best one.
RNS.log("Using cached announce data for answering path request with tag "+RNS.prettyhexrep(tag), RNS.LOG_EXTREME)
announce_data = self.path_responses[tag][1]
else:
destination_hash = self.hash
random_hash = RNS.Identity.get_random_hash()[0:5]+int(time.time()).to_bytes(5, "big")
if app_data != None:
announce_data += app_data
if app_data == None and self.default_app_data != None:
if isinstance(self.default_app_data, bytes):
app_data = self.default_app_data
elif callable(self.default_app_data):
returned_app_data = self.default_app_data()
if isinstance(returned_app_data, bytes):
app_data = returned_app_data
signed_data = self.hash+self.identity.get_public_key()+self.name_hash+random_hash
if app_data != None:
signed_data += app_data
signature = self.identity.sign(signed_data)
announce_data = self.identity.get_public_key()+self.name_hash+random_hash+signature
if app_data != None:
announce_data += app_data
self.path_responses[tag] = [time.time(), announce_data]
if path_response:
announce_context = RNS.Packet.PATH_RESPONSE
else:
announce_context = RNS.Packet.NONE
announce_packet = RNS.Packet(self, announce_data, RNS.Packet.ANNOUNCE, context = announce_context)
announce_packet = RNS.Packet(self, announce_data, RNS.Packet.ANNOUNCE, context = announce_context, attached_interface = attached_interface)
if send:
announce_packet.send()

View File

@ -1948,10 +1948,9 @@ class Transport:
local_destination = next((d for d in Transport.destinations if d.hash == destination_hash), None)
if local_destination != None:
local_destination.announce(path_response=True)
local_destination.announce(path_response=True, tag=tag, attached_interface=attached_interface)
RNS.log("Answering path request for "+RNS.prettyhexrep(destination_hash)+interface_str+", destination is local to this system", RNS.LOG_DEBUG)
elif (RNS.Reticulum.transport_enabled() or is_from_local_client) and (destination_hash in Transport.destination_table):
packet = Transport.destination_table[destination_hash][6]
next_hop = Transport.destination_table[destination_hash][1]
@ -1996,9 +1995,10 @@ class Transport:
# Forward path request on all interfaces
# except the local client
RNS.log("Forwarding path request from local client for "+RNS.prettyhexrep(destination_hash)+interface_str+" to all other interfaces", RNS.LOG_DEBUG)
request_tag = RNS.Identity.get_random_hash()
for interface in Transport.interfaces:
if not interface == attached_interface:
Transport.request_path(destination_hash, interface)
Transport.request_path(destination_hash, interface, tag = request_tag)
elif should_search_for_unknown:
if destination_hash in Transport.discovery_path_requests: