Added originator check to path rediscovery on failed links

RNS/Link.py

@@ -900,6 +900,13 @@ class Link:
     def register_incoming_resource(self, resource):
         self.incoming_resources.append(resource)
 
+    def has_incoming_resource(self, resource):
+        for incoming_resource in self.incoming_resources:
+            if incoming_resource.hash == resource.hash:
+                return True
+
+        return False
+
     def cancel_outgoing_resource(self, resource):
         if resource in self.outgoing_resources:
             self.outgoing_resources.remove(resource)

RNS/Resource.py

@@ -172,6 +172,7 @@ class Resource:
 
             resource.consecutive_completed_height = 0
             
+            if not resource.link.has_incoming_resource(resource):
                 resource.link.register_incoming_resource(resource)
 
                 RNS.log("Accepting resource advertisement for "+RNS.prettyhexrep(resource.hash), RNS.LOG_DEBUG)
@@ -179,13 +180,18 @@ class Resource:
                     try:
                         resource.link.callbacks.resource_started(resource)
                     except Exception as e:
-                    RNS.log("Error while executing resource started callback from "+str(self)+". The contained exception was: "+str(e), RNS.LOG_ERROR)
+                        RNS.log("Error while executing resource started callback from "+str(resource)+". The contained exception was: "+str(e), RNS.LOG_ERROR)
 
                 resource.hashmap_update(0, resource.hashmap_raw)
 
                 resource.watchdog_job()
 
                 return resource
+
+            else:
+                RNS.log("Ignoring resource advertisement for "+RNS.prettyhexrep(resource.hash)+", resource already transferring", RNS.LOG_DEBUG)
+                return None
+
         except Exception as e:
             RNS.log("Could not decode resource advertisement, dropping resource", RNS.LOG_DEBUG)
             return None
@@ -397,8 +403,7 @@ class Resource:
         thread.start()
 
     def __advertise_job(self):
-        data = ResourceAdvertisement(self).pack()
-        self.advertisement_packet = RNS.Packet(self.link, data, context=RNS.Packet.RESOURCE_ADV)
+        self.advertisement_packet = RNS.Packet(self.link, ResourceAdvertisement(self).pack(), context=RNS.Packet.RESOURCE_ADV)
         while not self.link.ready_for_new_resource():
             self.status = Resource.QUEUED
             sleep(0.25)
@@ -445,7 +450,8 @@ class Resource:
                         try:
                             RNS.log("No part requests received, retrying resource advertisement...", RNS.LOG_DEBUG)
                             self.retries_left -= 1
-                            self.advertisement_packet.resend()
+                            self.advertisement_packet = RNS.Packet(self.link, ResourceAdvertisement(self).pack(), context=RNS.Packet.RESOURCE_ADV)
+                            self.advertisement_packet.send()
                             self.last_activity = time.time()
                             self.adv_sent = self.last_activity
                             sleep_time = 0.001

RNS/Transport.py

@@ -66,6 +66,7 @@ class Transport:
     PATH_REQUEST_TIMEOUT = 15           # Default timuout for client path requests in seconds
     PATH_REQUEST_GRACE   = 0.35         # Grace time before a path announcement is made, allows directly reachable peers to respond first
     PATH_REQUEST_RW      = 2            # Path request random window
+    PATH_REQUEST_MI      = 5            # Minimum interval in seconds for automated path requests
 
     LINK_TIMEOUT         = RNS.Link.STALE_TIME * 1.25
     REVERSE_TIMEOUT      = 30*60        # Reverse table entries are removed after 30 minutes
@@ -92,6 +93,7 @@ class Transport:
     announce_handlers    = []           # A table storing externally registered announce handlers
     tunnels              = {}           # A table storing tunnels to other transport instances
     announce_rate_table  = {}           # A table for keeping track of announce rates
+    path_requests        = {}           # A table for storing path request timestamps
     
     discovery_path_requests  = {}       # A table for keeping track of path requests on behalf of other nodes
     discovery_pr_tags        = []       # A table for keeping track of tagged path requests
@@ -285,6 +287,7 @@ class Transport:
     @staticmethod
     def jobs():
         outgoing = []
+        path_requests = []
         Transport.jobs_running = True
 
         try:
@@ -380,8 +383,24 @@ class Transport:
                     stale_links = []
                     for link_id in Transport.link_table:
                         link_entry = Transport.link_table[link_id]
+                        if link_entry[7] == True:
                             if time.time() > link_entry[0] + Transport.LINK_TIMEOUT:
                                 stale_links.append(link_id)
+                        else:
+                            if time.time() > link_entry[8]:
+                                stale_links.append(link_id)
+
+                                last_path_request = 0
+                                if link_entry[6] in Transport.path_requests:
+                                    last_path_request = Transport.path_requests[link_entry[6]]
+
+                                # If this link request was originated from this instance
+                                # or a local client, attempt to rediscover a path to the
+                                # destination, if it has not already happened recently.
+                                lr_taken_hops = link_entry[5]
+                                if lr_taken_hops == 0 and time.time() - last_path_request > Transport.PATH_REQUEST_MI:
+                                    RNS.log("Trying to rediscover path for "+RNS.prettyhexrep(link_entry[6])+" since an attempted link was never established", RNS.LOG_DEBUG)
+                                    path_requests.append(link_entry[6])
 
                     # Cull the path table
                     stale_paths = []
@@ -513,6 +532,9 @@ class Transport:
         for packet in outgoing:
             packet.send()
 
+        for destination_hash in path_requests:
+            Transport.request_path(destination_hash)
+
     @staticmethod
     def transmit(interface, raw):
         try:
@@ -998,15 +1020,19 @@ class Transport:
                             outbound_interface = Transport.destination_table[packet.destination_hash][5]
 
                             if packet.packet_type == RNS.Packet.LINKREQUEST:
+                                now = time.time()
+                                proof_timeout = now + RNS.Link.ESTABLISHMENT_TIMEOUT_PER_HOP * max(1, remaining_hops)
+
                                 # Entry format is
-                                link_entry = [  time.time(),                    # 0: Timestamp,
+                                link_entry = [  now,                            # 0: Timestamp,
                                                 next_hop,                       # 1: Next-hop transport ID
                                                 outbound_interface,             # 2: Next-hop interface
                                                 remaining_hops,                 # 3: Remaining hops
                                                 packet.receiving_interface,     # 4: Received on interface
                                                 packet.hops,                    # 5: Taken hops
                                                 packet.destination_hash,        # 6: Original destination hash
-                                                False]                          # 7: Validated
+                                                False,                          # 7: Validated
+                                                proof_timeout]                  # 8: Proof timeout timestamp
 
                                 Transport.link_table[packet.getTruncatedHash()] = link_entry
 
@@ -1206,9 +1232,9 @@ class Transport:
                             
                             retransmit_timeout = now + (RNS.rand() * Transport.PATHFINDER_RW)
 
-                            if packet.receiving_interface.mode == RNS.Interfaces.Interface.Interface.MODE_ACCESS_POINT:
+                            if hasattr(packet.receiving_interface, "mode") and packet.receiving_interface.mode == RNS.Interfaces.Interface.Interface.MODE_ACCESS_POINT:
                                 expires            = now + Transport.AP_PATH_TIME
-                            elif packet.receiving_interface.mode == RNS.Interfaces.Interface.Interface.MODE_ROAMING:
+                            elif hasattr(packet.receiving_interface, "mode") and packet.receiving_interface.mode == RNS.Interfaces.Interface.Interface.MODE_ROAMING:
                                 expires            = now + Transport.ROAMING_PATH_TIME
                             else:
                                 expires            = now + Transport.PATHFINDER_E
@@ -1381,6 +1407,7 @@ class Transport:
 
             # Handling for linkrequests to local destinations
             elif packet.packet_type == RNS.Packet.LINKREQUEST:
+                if packet.transport_id == None or packet.transport_id == Transport.identity.hash:
                     for destination in Transport.destinations:
                         if destination.hash == packet.destination_hash and destination.type == packet.destination_type:
                             packet.destination = destination
@@ -1418,14 +1445,29 @@ class Transport:
                     if (RNS.Reticulum.transport_enabled() or for_local_client_link or from_local_client) and packet.destination_hash in Transport.link_table:
                         link_entry = Transport.link_table[packet.destination_hash]
                         if packet.receiving_interface == link_entry[2]:
-                            # TODO: Should we validate the LR proof at each transport
-                            # step before transporting it?
-                            # RNS.log("Link request proof received on correct interface, transporting it via "+str(link_entry[4]), RNS.LOG_EXTREME)
+                            try:
+                                if len(packet.data) == RNS.Identity.SIGLENGTH//8+RNS.Link.ECPUBSIZE//2:
+                                    peer_pub_bytes = packet.data[RNS.Identity.SIGLENGTH//8:RNS.Identity.SIGLENGTH//8+RNS.Link.ECPUBSIZE//2]
+                                    peer_identity = RNS.Identity.recall(link_entry[6])
+                                    peer_sig_pub_bytes = peer_identity.get_public_key()[RNS.Link.ECPUBSIZE//2:RNS.Link.ECPUBSIZE]
+
+                                    signed_data = packet.destination_hash+peer_pub_bytes+peer_sig_pub_bytes
+                                    signature = packet.data[:RNS.Identity.SIGLENGTH//8]
+
+                                    if peer_identity.validate(signature, signed_data):
+                                        RNS.log("Link request proof validated for transport via "+str(link_entry[4]), RNS.LOG_EXTREME)
                                         new_raw = packet.raw[0:1]
                                         new_raw += struct.pack("!B", packet.hops)
                                         new_raw += packet.raw[2:]
                                         Transport.link_table[packet.destination_hash][7] = True
                                         Transport.transmit(link_entry[4], new_raw)
+
+                                    else:
+                                        RNS.log("Invalid link request proof in transport for link "+RNS.prettyhexrep(packet.destination_hash)+", dropping proof.", RNS.LOG_DEBUG)
+
+                            except Exception as e:
+                                RNS.log("Error while transporting link request proof. The contained exception was: "+str(e), RNS.LOG_ERROR)
+
                         else:
                             RNS.log("Link request proof received on wrong interface, not transporting it.", RNS.LOG_DEBUG)
                     else:
@@ -1829,6 +1871,7 @@ class Transport:
                     on_interface.announce_allowed_at = now + wait_time
 
         packet.send()
+        Transport.path_requests[destination_hash] = time.time()
 
     @staticmethod
     def path_request_handler(data, packet):