Work on announce routing

RNS/Destination.py

@@ -208,7 +208,11 @@ class Destination:
 
 		signature = self.identity.sign(signed_data)
 
+		# TODO: Check if this could be optimised by only
+		# carrying the hash in the destination field, not
+		# also redundantly inside the signed blob as here
 		announce_data = self.hash+self.identity.getPublicKey()+random_hash+signature
+
 		if app_data != None:
 			announce_data += app_data
 

RNS/Packet.py

@@ -62,7 +62,6 @@ class Packet:
 			self.transport_id   = transport_id
 			self.data 		    = data
 			self.flags	 	    = self.getPackedFlags()
-			self.MTU     		= RNS.Reticulum.MTU
 
 			self.raw    		= None
 			self.packed 		= False
@@ -74,7 +73,8 @@ class Packet:
 			self.packed         = True
 			self.fromPacked     = True
 
-		self.sent_at = None
+		self.MTU         = RNS.Reticulum.MTU
+		self.sent_at     = None
 		self.packet_hash = None
 
 	def getPackedFlags(self):
@@ -120,8 +120,13 @@ class Packet:
 					self.ciphertext = self.destination.encrypt(self.data)
 
 			if self.header_type == Packet.HEADER_2:
-				if t_destination != None:
-					self.header += self.t_destination
+				if self.transport_id != None:
+					self.header += self.transport_id
+					self.header += self.destination.hash
+
+					if self.packet_type == Packet.ANNOUNCE:
+						# Announce packets are not encrypted
+						self.ciphertext = self.data
 				else:
 					raise IOError("Packet with header type 2 must have a transport ID")
 

RNS/Transport.py

@@ -1,6 +1,7 @@
 import os
 import RNS
 import time
+import math
 import threading
 import traceback
 from time import sleep
@@ -14,6 +15,15 @@ class Transport:
 	TUNNEL       = 0x03;
 	types        = [BROADCAST, TRANSPORT, RELAY, TUNNEL]
 
+	REACHABILITY_UNREACHABLE = 0x00
+	REACHABILITY_DIRECT      = 0x01
+	REACHABILITY_TRANSPORT	 = 0x02
+
+	PATHFINDER_M    = 18	# Max hops
+	PATHFINDER_C    = 2.0	# Decay constant
+	PATHFINDER_R	= 2		# Retransmit retries
+	PATHFINDER_T	= 10	# Retry grace period
+
 	interfaces	 	= []	# All active interfaces
 	destinations    = []	# All active destinations
 	pending_links   = []	# Links that are being established
@@ -21,12 +31,17 @@ class Transport:
 	packet_hashlist = []	# A list of packet hashes for duplicate detection
 	receipts		= []	# Receipts of all outgoing packets for proof processing
 
+	announce_table    = {}
+	destination_table = {}
+
 	jobs_locked = False
 	jobs_running = False
 	job_interval = 0.250
-	receipts_last_checked   = 0.0
-	receipts_check_interval = 1.0
-	hashlist_maxsize        = 1000000
+	receipts_last_checked    = 0.0
+	receipts_check_interval  = 1.0
+	announces_last_checked   = 0.0
+	announces_check_interval = 1.0
+	hashlist_maxsize         = 1000000
 
 	identity = None
 
@@ -68,11 +83,12 @@ class Transport:
 
 	@staticmethod
 	def jobs():
+		outgoing = []
 		Transport.jobs_running = True
 		try:
 			if not Transport.jobs_locked:
 				# Process receipts list for timed-out packets
-				if Transport.receipts_last_checked+Transport.receipts_check_interval < time.time():
+				if time.time() > Transport.receipts_last_checked+Transport.receipts_check_interval:
 					for receipt in Transport.receipts:
 						thread = threading.Thread(target=receipt.check_timeout)
 						thread.setDaemon(True)
@@ -82,6 +98,37 @@ class Transport:
 
 					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]
+						# 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("Removing due to exceeded retries", RNS.LOG_INFO)
+							Transport.announce_table.pop(destination_hash)
+							break
+						else:
+							if time.time() > announce_entry[1]:
+								# RNS.log("Rebroadcasting announce", RNS.LOG_INFO)
+								announce_entry[1] = time.time() + math.pow(Transport.PATHFINDER_C, announce_entry[4]) + Transport.PATHFINDER_T
+								announce_entry[2] += 1
+								packet = announce_entry[5]
+								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.encode("hex_codec")
+								new_packet = RNS.Packet(announce_destination, announce_data, RNS.Packet.ANNOUNCE, header_type = RNS.Packet.HEADER_2, transport_type = Transport.TRANSPORT, transport_id = Transport.identity.hash)
+								new_packet.hops = announce_entry[4]
+								RNS.log("Rebroadcasting announce for "+RNS.prettyhexrep(announce_destination.hash)+" with hop count "+str(new_packet.hops), RNS.LOG_INFO)
+								outgoing.append(new_packet)
+
+					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)
@@ -93,6 +140,9 @@ class Transport:
 
 		Transport.jobs_running = False
 
+		for packet in outgoing:
+			packet.send()
+
 	@staticmethod
 	def outbound(packet):
 		while (Transport.jobs_running):
@@ -165,7 +215,33 @@ class Transport:
 			
 			if packet.packet_type == RNS.Packet.ANNOUNCE:
 				if RNS.Identity.validateAnnounce(packet):
-					Transport.cache(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
+						# announcein question from our pending table
+						if packet.destination_hash in Transport.announce_table:
+							announce_entry = Transport.announce_table[packet.destination_hash]
+							if packet.hops == announce_entry[4]+1 and announce_entry[2] > 0:
+								now = time.time()
+								if now < announce_entry[2]:
+									# TODO: Remove
+									RNS.log("Another node retransmitted our transported announce for "+RNS.prettyhexrep(packet.destination_hash)+", removing it from pending table", RNS.LOG_DEBUG)
+									Transport.announce_table.pop(announce_entry)
+
+					else:
+						received_from = packet.destination_hash
+
+					# If the announce has not reached the retransmission
+					# limit, insert it into our pending table
+					packet.hops += 1
+					if (packet.hops < Transport.PATHFINDER_M+1):
+						now = time.time()
+						retransmit_timeout = now + math.pow(Transport.PATHFINDER_C, packet.hops)
+						retries = 0
+						Transport.announce_table[packet.destination_hash] = [now, retransmit_timeout, retries, received_from, packet.hops, packet]
+						Transport.destination_table[packet.destination_hash] = [now, received_from, packet.hops]
 			
 			elif packet.packet_type == RNS.Packet.LINKREQUEST:
 				for destination in Transport.destinations:
@@ -288,6 +364,8 @@ 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")