Implemented link establishment on ultra low bandwidth links

RNS/Link.py

@@ -112,9 +112,10 @@ class Link:
                 link = Link(owner = owner, peer_pub_bytes=data[:Link.ECPUBSIZE//2], peer_sig_pub_bytes=data[Link.ECPUBSIZE//2:Link.ECPUBSIZE])
                 link.set_link_id(packet)
                 link.destination = packet.destination
-                link.establishment_timeout = Link.ESTABLISHMENT_TIMEOUT_PER_HOP * max(1, packet.hops)
+                link.establishment_timeout = Link.ESTABLISHMENT_TIMEOUT_PER_HOP * max(1, packet.hops) + Link.KEEPALIVE
                 link.establishment_cost += len(packet.raw)
                 RNS.log("Validating link request "+RNS.prettyhexrep(link.link_id), RNS.LOG_VERBOSE)
+                RNS.log(f"Establishment timeout is {RNS.prettytime(link.establishment_timeout)} for incoming link request "+RNS.prettyhexrep(link.link_id), RNS.LOG_EXTREME)
                 link.handshake()
                 link.attached_interface = packet.receiving_interface
                 link.prove()
@@ -175,7 +176,8 @@ class Link:
             self.sig_prv = self.owner.identity.sig_prv
         else:
             self.initiator = True
-            self.establishment_timeout = Link.ESTABLISHMENT_TIMEOUT_PER_HOP * max(1, RNS.Transport.hops_to(destination.hash))
+            self.establishment_timeout  = RNS.Reticulum.get_instance().get_first_hop_timeout(destination.hash)
+            self.establishment_timeout += Link.ESTABLISHMENT_TIMEOUT_PER_HOP * max(1, RNS.Transport.hops_to(destination.hash))
             self.prv     = X25519PrivateKey.generate()
             self.sig_prv = Ed25519PrivateKey.generate()
 
@@ -211,6 +213,7 @@ class Link:
             self.packet.send()
             self.had_outbound()
             RNS.log("Link request "+RNS.prettyhexrep(self.link_id)+" sent to "+str(self.destination), RNS.LOG_DEBUG)
+            RNS.log(f"Establishment timeout is {RNS.prettytime(self.establishment_timeout)} for link request "+RNS.prettyhexrep(self.link_id), RNS.LOG_EXTREME)
 
 
     def load_peer(self, peer_pub_bytes, peer_sig_pub_bytes):

RNS/Packet.py

@@ -371,8 +371,8 @@ class PacketReceipt:
         if packet.destination.type == RNS.Destination.LINK:
             self.timeout    = packet.destination.rtt * packet.destination.traffic_timeout_factor
         else:
-            self.timeout    = Packet.TIMEOUT_PER_HOP * RNS.Transport.hops_to(self.destination.hash)
-
+            self.timeout    = RNS.Reticulum.get_instance().get_first_hop_timeout(destination.hash)
+            self.timeout   += Packet.TIMEOUT_PER_HOP * RNS.Transport.hops_to(self.destination.hash)
 
     def get_status(self):
         """

RNS/Reticulum.py

@@ -117,7 +117,7 @@ class Reticulum:
     # from interface speed, but a better general approach would most
     # probably be to let Reticulum somehow continously build a map of
     # per-hop latencies and use this map for the timeout calculation. 
-    DEFAULT_PER_HOP_TIMEOUT = 6
+    DEFAULT_PER_HOP_TIMEOUT = 4
 
     # Length of truncated hashes in bits.
     TRUNCATED_HASHLENGTH = 128
@@ -146,6 +146,8 @@ class Reticulum:
     storagepath      = ""
     cachepath        = ""
 
+    __instance       = None
+    
     @staticmethod
     def exit_handler():
         # This exit handler is called whenever Reticulum is asked to
@@ -168,6 +170,13 @@ class Reticulum:
         RNS.exit()
 
 
+    @staticmethod
+    def get_instance():
+        """
+        Return the currently running Reticulum instance
+        """
+        return Reticulum.__instance
+
     def __init__(self,configdir=None, loglevel=None, logdest=None, verbosity=None):
         """
         Initialises and starts a Reticulum instance. This must be
@@ -177,6 +186,11 @@ class Reticulum:
         :param configdir: Full path to a Reticulum configuration directory.
         """
 
+        if Reticulum.__instance != None:
+            raise OSError("Attempt to reinitialise Reticulum, when it was already running")
+        else:
+            Reticulum.__instance = self
+
         RNS.vendor.platformutils.platform_checks()
 
         if configdir != None:
@@ -303,6 +317,11 @@ class Reticulum:
                     self.local_interface_port
                 )
                 interface.OUT = True
+                if hasattr(Reticulum, "_force_shared_instance_bitrate"):
+                    interface.bitrate = Reticulum._force_shared_instance_bitrate
+                    interface._force_bitrate = True
+                    RNS.log(f"Forcing shared instance bitrate of {RNS.prettyspeed(interface.bitrate)}ps", RNS.LOG_WARNING)
+                    interface._force_bitrate = Reticulum._force_shared_instance_bitrate
                 RNS.Transport.interfaces.append(interface)
                 
                 self.is_shared_instance = True
@@ -317,6 +336,10 @@ class Reticulum:
                         self.local_interface_port)
                     interface.target_port = self.local_interface_port
                     interface.OUT = True
+                    if hasattr(Reticulum, "_force_shared_instance_bitrate"):
+                        interface.bitrate = Reticulum._force_shared_instance_bitrate
+                        interface._force_bitrate = True
+                        RNS.log(f"Forcing shared instance bitrate of {RNS.prettyspeed(interface.bitrate)}ps", RNS.LOG_WARNING)
                     RNS.Transport.interfaces.append(interface)
                     self.is_shared_instance = False
                     self.is_standalone_instance = False
@@ -376,6 +399,9 @@ class Reticulum:
                     v = self.config["reticulum"].as_bool(option)
                     if v == True:
                         Reticulum.__allow_probes = True
+                if option == "force_shared_instance_bitrate":
+                    v = self.config["reticulum"].as_int(option)
+                    Reticulum._force_shared_instance_bitrate = v
                 if option == "panic_on_interface_error":
                     v = self.config["reticulum"].as_bool(option)
                     if v == True:
@@ -1074,6 +1100,9 @@ class Reticulum:
                     if path == "next_hop":
                         rpc_connection.send(self.get_next_hop(call["destination_hash"]))
 
+                    if path == "first_hop_timeout":
+                        rpc_connection.send(self.get_first_hop_timeout(call["destination_hash"]))
+
                     if path == "packet_rssi":
                         rpc_connection.send(self.get_packet_rssi(call["packet_hash"]))
 
@@ -1289,6 +1318,20 @@ class Reticulum:
         else:
             return str(RNS.Transport.next_hop_interface(destination))
 
+    def get_first_hop_timeout(self, destination):
+        if self.is_connected_to_shared_instance:
+            try:
+                rpc_connection = multiprocessing.connection.Client(self.rpc_addr, authkey=self.rpc_key)
+                rpc_connection.send({"get": "first_hop_timeout", "destination_hash": destination})
+                response = rpc_connection.recv()
+                return response
+            except Exception as e:
+                RNS.log("An error occurred while getting first hop timeout from shared instance: "+str(e), RNS.LOG_ERROR)
+                return RNS.Reticulum.DEFAULT_PER_HOP_TIMEOUT
+
+        else:
+            return RNS.Transport.first_hop_timeout(destination)
+
     def get_next_hop(self, destination):
         if self.is_connected_to_shared_instance:
             rpc_connection = multiprocessing.connection.Client(self.rpc_addr, authkey=self.rpc_key)

RNS/Transport.py

@@ -1197,7 +1197,8 @@ class Transport:
 
                             if packet.packet_type == RNS.Packet.LINKREQUEST:
                                 now = time.time()
-                                proof_timeout = now + RNS.Link.ESTABLISHMENT_TIMEOUT_PER_HOP * max(1, remaining_hops)
+                                proof_timeout  = Transport.extra_link_proof_timeout(packet.receiving_interface)
+                                proof_timeout += now + RNS.Link.ESTABLISHMENT_TIMEOUT_PER_HOP * max(1, remaining_hops)
 
                                 # Entry format is
                                 link_entry = [  now,                            # 0: Timestamp,
@@ -2026,6 +2027,45 @@ class Transport:
         else:
             return None
 
+    @staticmethod
+    def next_hop_interface_bitrate(destination_hash):
+        next_hop_interface = Transport.next_hop_interface(destination_hash)
+        if next_hop_interface != None:
+            return next_hop_interface.bitrate
+        else:
+            return None
+
+    @staticmethod
+    def next_hop_per_bit_latency(destination_hash):
+        next_hop_interface_bitrate = Transport.next_hop_interface_bitrate(destination_hash)
+        if next_hop_interface_bitrate != None:
+            return (1/next_hop_interface_bitrate)
+        else:
+            return None
+
+    @staticmethod
+    def next_hop_per_byte_latency(destination_hash):
+        per_byte_latency = Transport.next_hop_per_bit_latency(destination_hash)
+        if per_byte_latency != None:
+            return per_byte_latency*8
+        else:
+            return None
+
+    @staticmethod
+    def first_hop_timeout(destination_hash):
+        latency = Transport.next_hop_per_byte_latency(destination_hash)
+        if latency != None:
+            return RNS.Reticulum.MTU * latency
+        else:
+            return RNS.Reticulum.DEFAULT_PER_HOP_TIMEOUT
+
+    @staticmethod
+    def extra_link_proof_timeout(interface):
+        if interface != None:
+            return ((1/interface.bitrate)*8)*RNS.Reticulum.MTU
+        else:
+            return 0
+
     @staticmethod
     def expire_path(destination_hash):
         if destination_hash in Transport.destination_table:

RNS/__init__.py

@@ -161,6 +161,9 @@ def prettyhexrep(data):
     hexrep = "<"+delimiter.join("{:02x}".format(c) for c in data)+">"
     return hexrep
 
+def prettyspeed(num, suffix="b"):
+    return prettysize(num/8, suffix=suffix)+"ps"
+
 def prettysize(num, suffix='B'):
     units = ['','K','M','G','T','P','E','Z']
     last_unit = 'Y'