Implemented announce ingress control

RNS/Interfaces/Interface.py

@@ -1,6 +1,6 @@
 # MIT License
 #
-# Copyright (c) 2016-2022 Mark Qvist / unsigned.io
+# Copyright (c) 2016-2023 Mark Qvist / unsigned.io
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -40,26 +40,116 @@ class Interface:
     MODE_BOUNDARY       = 0x05
     MODE_GATEWAY        = 0x06
 
-    # Which interface modes a Transport Node
-    # should actively discover paths for.
+    # Which interface modes a Transport Node should
+    # actively discover paths for.
     DISCOVER_PATHS_FOR  = [MODE_ACCESS_POINT, MODE_GATEWAY]
 
-    # How many samples to use for incoming
-    # announce frequency calculation
+    # How many samples to use for announce
+    # frequency calculations
     IA_FREQ_SAMPLES     = 6
     OA_FREQ_SAMPLES     = 6
 
+    # Maximum amount of ingress limited announces
+    # to hold at any given time.
+    MAX_HELD_ANNOUNCES  = 256
+
+    # How long a spawned interface will be
+    # considered to be newly created. Two
+    # hours by default.
+    IC_NEW_TIME              = 2*60*60
+    IC_BURST_FREQ_NEW        = 3.5
+    IC_BURST_FREQ            = 12
+    IC_BURST_HOLD            = 1*60
+    IC_BURST_PENALTY         = 5*60
+    IC_HELD_RELEASE_INTERVAL = 30
+
     def __init__(self):
         self.rxb = 0
         self.txb = 0
+        self.created = time.time()
         self.online = False
+
         self.ingress_control = True
+        self.ic_max_held_announces = Interface.MAX_HELD_ANNOUNCES
+        self.ic_burst_hold = Interface.IC_BURST_HOLD
+        self.ic_burst_active = False
+        self.ic_burst_activated = 0
+        self.ic_held_release = 0
+        self.ic_burst_freq_new = Interface.IC_BURST_FREQ_NEW
+        self.ic_burst_freq = Interface.IC_BURST_FREQ
+        self.ic_new_time = Interface.IC_NEW_TIME
+        self.ic_burst_penalty = Interface.IC_BURST_PENALTY
+        self.ic_held_release_interval = Interface.IC_HELD_RELEASE_INTERVAL
+        self.held_announces = {}
+
         self.ia_freq_deque = deque(maxlen=Interface.IA_FREQ_SAMPLES)
         self.oa_freq_deque = deque(maxlen=Interface.OA_FREQ_SAMPLES)
 
     def get_hash(self):
         return RNS.Identity.full_hash(str(self).encode("utf-8"))
 
+    # This is a generic function for determining when an interface
+    # should activate ingress limiting. Since this can vary for
+    # different interface types, this function should be overwritten
+    # in case a particular interface requires a different approach.
+    def should_ingress_limit(self):
+        if self.ingress_control:
+            freq_threshold = self.ic_burst_freq_new if self.age() < self.ic_new_time else self.ic_burst_freq
+            ia_freq = self.incoming_announce_frequency()
+
+            if self.ic_burst_active:
+                if ia_freq < freq_threshold and time.time() > self.ic_burst_activated+self.ic_burst_hold:
+                    self.ic_burst_active = False
+                    self.ic_held_release = time.time() + self.ic_burst_penalty
+                return True
+
+            else:
+                if ia_freq > freq_threshold:
+                    self.ic_burst_active = True
+                    self.ic_burst_activated = time.time()
+                    return True
+
+                else:
+                    return False
+
+        else:
+            return False
+
+    def age(self):
+        return time.time()-self.created
+
+    def hold_announce(self, announce_packet):
+        if announce_packet.destination_hash in self.held_announces:
+            self.held_announces[announce_packet.destination_hash] = announce_packet
+        elif not len(self.held_announces) >= self.ic_max_held_announces:
+            self.held_announces[announce_packet.destination_hash] = announce_packet
+
+    def process_held_announces(self):
+        try:
+            if not self.should_ingress_limit() and len(self.held_announces) > 0 and time.time() > self.ic_held_release:
+                freq_threshold = self.ic_burst_freq_new if self.age() < self.ic_new_time else self.ic_burst_freq
+                ia_freq = self.incoming_announce_frequency()
+                if ia_freq < freq_threshold:
+                    selected_announce_packet = None
+                    min_hops = RNS.Transport.PATHFINDER_M
+                    for destination_hash in self.held_announces:
+                        announce_packet = self.held_announces[destination_hash]
+                        if announce_packet.hops < min_hops:
+                            min_hops = announce_packet.hops
+                            selected_announce_packet = announce_packet
+
+                    if selected_announce_packet != None:
+                        RNS.log("Releasing held announce packet "+str(selected_announce_packet)+" from "+str(self), RNS.LOG_EXTREME)
+                        self.ic_held_release = time.time() + self.ic_held_release_interval
+                        self.held_announces.pop(selected_announce_packet.destination_hash)
+                        def release():
+                            RNS.Transport.inbound(selected_announce_packet.raw, selected_announce_packet.receiving_interface)
+                        threading.Thread(target=release, daemon=True).start()
+        
+        except Exception as e:
+            RNS.log("An error occurred while processing held announces for "+str(self), RNS.LOG_ERROR)
+            RNS.log("The contained exception was: "+str(e), RNS.LOG_ERROR)
+
     def received_announce(self):
         self.ia_freq_deque.append(time.time())
         if hasattr(self, "parent_interface") and self.parent_interface != None: