Implemented transport table cleanup

RNS/Transport.py

@@ -38,6 +38,10 @@ class Transport:
 	PATH_REQUEST_GRACE  = 0.25       # 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
+
 	interfaces	 	    = []		 # All active interfaces
 	destinations        = []		 # All active destinations
 	pending_links       = []		 # Links that are being established
@@ -58,6 +62,8 @@ class Transport:
 	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
 
@@ -151,11 +157,26 @@ 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
+				if time.time() > Transport.tables_last_culled + Transport.tables_cull_interval:
-				# TODO: Implement this
+					# 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
+					for link_id in Transport.link_table:
+						link_entry = Transport.link_table[link_id]
+						if time.time() > link_entry[0] + Transport.LINK_TIMEOUT:
+							Transport.link_table.pop(link_id)
 
 					# Cull the destination table in some way
-				# TODO: Implement this
+					for destination_hash in Transport.destination_table:
+						destination_entry = Transport.destination_table[destination_hash]
+						if time.time() > destination_entry[0] + Transport.DESTINATION_TIMEOUT:
+							Transport.destination_table.pop(destination_hash)
+
+					Transport.tables_last_culled = time.time()
 
 		except Exception as e:
 			RNS.log("An exception occurred while running Transport jobs.", RNS.LOG_ERROR)
@@ -191,6 +212,7 @@ class Transport:
 				new_raw += packet.raw[2:]
 				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)
+				Transport.destination_table[packet.destination_hash][0] = time.time()
 				sent = True
 			else:
 				# Destination is directly reachable, and we know on
@@ -254,7 +276,6 @@ class Transport:
 
 	@staticmethod
 	def inbound(raw, interface=None):
-		# TODO: Rewrite the redundant cache calls in this method
 		while (Transport.jobs_running):
 			sleep(0.1)
 			
@@ -269,6 +290,7 @@ class Transport:
 
 		if Transport.packet_filter(packet):
 			Transport.packet_hashlist.append(packet.packet_hash)
+			Transport.cache(packet)
 			
 			# General transport handling. Takes care of directing
 			# packets according to transport tables and recording
@@ -295,6 +317,7 @@ class Transport:
 
 						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
@@ -357,6 +380,7 @@ class Transport:
 						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
 
@@ -459,7 +483,6 @@ class Transport:
 					if destination.hash == packet.destination_hash and destination.type == packet.destination_type:
 						packet.destination = destination
 						destination.receive(packet)
-						Transport.cache(packet)
 			
 			elif packet.packet_type == RNS.Packet.DATA:
 				if packet.destination_type == RNS.Destination.LINK:
@@ -467,13 +490,11 @@ class Transport:
 						if link.link_id == packet.destination_hash:
 							packet.link = link
 							link.receive(packet)
-							Transport.cache(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)
-							Transport.cache(packet)
 
 							if destination.proof_strategy == RNS.Destination.PROVE_ALL:
 								packet.prove()
@@ -526,7 +547,7 @@ class Transport:
 
 					# Check if this proof neds to be transported
 					if packet.destination_hash in Transport.reverse_table:
-						reverse_entry = Transport.reverse_table[packet.destination_hash]
+						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]
@@ -581,8 +602,8 @@ class Transport:
 	def shouldCache(packet):
 		# TODO: Implement sensible rules for which
 		# packets to cache
-		if packet.context == RNS.Packet.RESOURCE_PRF:
+		#if packet.context == RNS.Packet.RESOURCE_PRF:
-			return True
+		#	return True
 
 		return False
 
@@ -599,6 +620,8 @@ class Transport:
 				RNS.log("Error writing packet to cache", RNS.LOG_ERROR)
 				RNS.log("The contained exception was: "+str(e))
 
+	# TODO: Implement cache requests. Needs methodology
+	# rethinking. This is skeleton code.
 	@staticmethod
 	def cache_request_packet(packet):
 		if len(packet.data) == RNS.Identity.HASHLENGTH/8:
@@ -612,6 +635,8 @@ class Transport:
 				# TODO: Implement outbound for this
 
 
+	# TODO: Implement cache requests. Needs methodology
+	# rethinking. This is skeleton code.
 	@staticmethod
 	def cache_request(packet_hash):
 		RNS.log("Cache request for "+RNS.prettyhexrep(packet_hash), RNS.LOG_EXTREME)
@@ -668,6 +693,8 @@ class Transport:
 		else:
 			RNS.log("No known path to requested destination, ignoring request", RNS.LOG_DEBUG)
 
+	# TODO: Currently only used for cache requests.
+	# Needs rethink.
 	@staticmethod
 	def transport_destination():
 		# TODO: implement this