Implemented requests and responses of arbitrary sizes using resources.

Examples/Filetransfer.py

@@ -502,7 +502,6 @@ def download_concluded(resource):
 
     saved_filename = current_filename
 
-
     if resource.status == RNS.Resource.COMPLETE:
         counter = 0
         while os.path.isfile(saved_filename):

Examples/Request.py

@@ -23,7 +23,7 @@ APP_NAME = "example_utilities"
 # A reference to the latest client link that connected
 latest_client_link = None
 
-def random_text_generator(path, data, request_id, remote_identity_hash, requested_at):
+def random_text_generator(path, data, request_id, remote_identity, requested_at):
     RNS.log("Generating response to request "+RNS.prettyhexrep(request_id))
     texts = ["They looked up", "On each full moon", "Becky was upset", "I’ll stay away from it", "The pet shop stocks everything"]
     return texts[random.randint(0, len(texts)-1)]

RNS/Destination.py

@@ -220,7 +220,7 @@ class Destination:
         Registers a request handler.
 
         :param path: The path for the request handler to be registered.
-        :param response_generator: A function or method with the signature *response_generator(path, data, request_id, remote_identity_hash, requested_at)* to be called. Whatever this funcion returns will be sent as a response to the requester. If the function returns ``None``, no response will be sent.
+        :param response_generator: A function or method with the signature *response_generator(path, data, request_id, remote_identity, requested_at)* to be called. Whatever this funcion returns will be sent as a response to the requester. If the function returns ``None``, no response will be sent.
         :param allow: One of ``RNS.Destination.ALLOW_NONE``, ``RNS.Destination.ALLOW_ALL`` or ``RNS.Destination.ALLOW_LIST``. If ``RNS.Destination.ALLOW_LIST`` is set, the request handler will only respond to requests for identified peers in the supplied list.
         :param allowed_list: A list of *bytes-like* :ref:`RNS.Identity<api-identity>` hashes.
         :raises: ``ValueError`` if any of the supplied arguments are invalid.

RNS/Link.py

@@ -280,10 +280,25 @@ class Link:
 
         if len(packed_request) <= Link.MDU:
             request_packet   = RNS.Packet(self, packed_request, RNS.Packet.DATA, context = RNS.Packet.REQUEST)
-            return RequestReceipt(self, request_packet.send(), response_callback, failed_callback)
+
+            return RequestReceipt(
+                self,
+                packet_receipt = request_packet.send(),
+                response_callback = response_callback,
+                failed_callback = failed_callback
+            )
+
         else:
-            # TODO: Implement sending requests as Resources
-            raise IOError("Request size of "+str(len(packed_request))+" exceeds MDU of "+str(Link.MDU)+" bytes")
+            request_id = RNS.Identity.truncated_hash(packed_request)
+            RNS.log("Sending request "+RNS.prettyhexrep(request_id)+" as resource.", RNS.LOG_DEBUG)
+            request_resource = RNS.Resource(packed_request, self, request_id = request_id, is_response = False)
+
+            return RequestReceipt(
+                self,
+                resource = request_resource,
+                response_callback = response_callback,
+                failed_callback = failed_callback
+            )
 
 
     def rtt_packet(self, packet):
@@ -446,6 +461,77 @@ class Link:
         keepalive_packet.send()
         self.had_outbound()
 
+    def handle_request(self, request_id, unpacked_request):
+        requested_at = unpacked_request[0]
+        path_hash    = unpacked_request[1]
+        request_data = unpacked_request[2]
+
+        if path_hash in self.destination.request_handlers:
+            request_handler = self.destination.request_handlers[path_hash]
+            path               = request_handler[0]
+            response_generator = request_handler[1]
+            allow              = request_handler[2]
+            allowed_list       = request_handler[3]
+
+            allowed = False
+            if not allow == RNS.Destination.ALLOW_NONE:
+                if allow == RNS.Destination.ALLOW_LIST:
+                    if self.__remote_identity.hash in allowed_list:
+                        allowed = True
+                elif allow == RNS.Destination.ALLOW_ALL:
+                    allowed = True
+
+            if allowed:
+                RNS.log("Handling request "+RNS.prettyhexrep(request_id)+" for: "+str(path), RNS.LOG_DEBUG)
+                response = response_generator(path, request_data, request_id, self.__remote_identity, requested_at)
+                if response != None:
+                    packed_response = umsgpack.packb([request_id, response])
+
+                    if len(packed_response) <= Link.MDU:
+                        RNS.Packet(self, packed_response, RNS.Packet.DATA, context = RNS.Packet.RESPONSE).send()
+                    else:
+                        response_resource = RNS.Resource(packed_response, self, request_id = request_id, is_response = True)
+            else:
+                identity_string = RNS.prettyhexrep(self.get_remote_identity()) if self.get_remote_identity() != None else "<Unknown>"
+                RNS.log("Request "+RNS.prettyhexrep(request_id)+" from "+identity_string+" not allowed for: "+str(path), RNS.LOG_DEBUG)
+
+    def handle_response(self, request_id, response_data):
+        remove = None
+        for pending_request in self.pending_requests:
+            if pending_request.request_id == request_id:
+                remove = pending_request
+                try:
+                    pending_request.response_received(response_data)
+                except Exception as e:
+                    RNS.log("Error occurred while handling response. The contained exception was: "+str(e), RNS.LOG_ERROR)
+
+                break
+
+        if remove != None:
+            self.pending_requests.remove(remove)
+
+    def request_resource_concluded(self, resource):
+        if resource.status == RNS.Resource.COMPLETE:
+            packed_request    = resource.data.read()
+            unpacked_request  = umsgpack.unpackb(packed_request)
+            request_id        = RNS.Identity.truncated_hash(packed_request)
+            request_data      = unpacked_request
+
+            self.handle_request(request_id, request_data)
+        else:
+            RNS.log("Incoming request resource failed with status: "+RNS.hexrep([resource.status]), RNS.LOG_DEBUG)
+
+    def response_resource_concluded(self, resource):
+        if resource.status == RNS.Resource.COMPLETE:
+            packed_response   = resource.data.read()
+            unpacked_response = umsgpack.unpackb(packed_response)
+            request_id        = unpacked_response[0]
+            response_data     = unpacked_response[1]
+
+            self.handle_response(request_id, response_data)
+        else:
+            RNS.log("Incoming response resource failed with status: "+RNS.hexrep([resource.status]), RNS.LOG_DEBUG)
+
     def receive(self, packet):
         self.watchdog_lock = True
         if not self.status == Link.CLOSED and not (self.initiator and packet.context == RNS.Packet.KEEPALIVE and packet.data == bytes([0xFF])):
@@ -493,65 +579,20 @@ class Link:
                             request_id = packet.getTruncatedHash()
                             packed_request = self.decrypt(packet.data)
                             unpacked_request = umsgpack.unpackb(packed_request)
-                            requested_at = unpacked_request[0]
-                            path_hash    = unpacked_request[1]
-                            request_data = unpacked_request[2]
-
-                            if path_hash in self.destination.request_handlers:
-                                request_handler = self.destination.request_handlers[path_hash]
-                                path               = request_handler[0]
-                                response_generator = request_handler[1]
-                                allow              = request_handler[2]
-                                allowed_list       = request_handler[3]
-
-                                allowed = False
-                                if not allow == RNS.Destination.ALLOW_NONE:
-                                    if allow == RNS.Destination.ALLOW_LIST:
-                                        if self.__remote_identity in allowed_list:
-                                            allowed = True
-                                    elif allow == RNS.Destination.ALLOW_ALL:
-                                        allowed = True
-
-                                if allowed:
-                                    response = response_generator(path, request_data, request_id, self.__remote_identity, requested_at)
-                                    if response != None:
-                                        packed_response = umsgpack.packb([request_id, True, response])
-
-                                        if len(packed_response) <= Link.MDU:
-                                            RNS.Packet(self, packed_response, RNS.Packet.DATA, context = RNS.Packet.RESPONSE).send()
-                                        else:
-                                            # TODO: Implement transfer as resource
-                                            packed_response = umsgpack.packb([request_id, False, None])
-                                            raise Exception("Response transfer as resource not implemented")
-
+                            self.handle_request(request_id, unpacked_request)
                         except Exception as e:
                             RNS.log("Error occurred while handling request. The contained exception was: "+str(e), RNS.LOG_ERROR)
 
                     elif packet.context == RNS.Packet.RESPONSE:
+                        try:
                             packed_response = self.decrypt(packet.data)
                             unpacked_response = umsgpack.unpackb(packed_response)
                             request_id = unpacked_response[0]
-
-                        if unpacked_response[1] == True:
-                            remove = None
-                            for pending_request in self.pending_requests:
-                                if pending_request.request_id == request_id:
-                                    response_data = unpacked_response[2]
-                                    remove = pending_request
-                                    try:
-                                        pending_request.response_received(response_data)
+                            response_data = unpacked_response[1]
+                            self.handle_response(request_id, response_data)
                         except Exception as e:
                             RNS.log("Error occurred while handling response. The contained exception was: "+str(e), RNS.LOG_ERROR)
 
-                                    break
-
-                            if remove != None:
-                                self.pending_requests.remove(remove)
-
-                        else:
-                            # TODO: Implement receiving responses as Resources
-                            raise Exception("Response transfer as resource not implemented")
-
                     elif packet.context == RNS.Packet.LRRTT:
                         if not self.initiator:
                             self.rtt_packet(packet)
@@ -561,7 +602,12 @@ class Link:
 
                     elif packet.context == RNS.Packet.RESOURCE_ADV:
                         packet.plaintext = self.decrypt(packet.data)
-                        if self.resource_strategy == Link.ACCEPT_NONE:
+
+                        if RNS.ResourceAdvertisement.is_request(packet):
+                            RNS.Resource.accept(packet, callback=self.request_resource_concluded)
+                        elif RNS.ResourceAdvertisement.is_response(packet):
+                            RNS.Resource.accept(packet, callback=self.response_resource_concluded)
+                        elif self.resource_strategy == Link.ACCEPT_NONE:
                             pass
                         elif self.resource_strategy == Link.ACCEPT_APP:
                             if self.callbacks.resource != None:
@@ -785,8 +831,18 @@ class RequestReceipt():
     DELIVERED = 0x02
     READY     = 0x03
 
-    def __init__(self, link, packet_receipt, response_callback = None, failed_callback = None):
+    def __init__(self, link, packet_receipt = None, resource = None, response_callback = None, failed_callback = None):
+        self.packet_receipt = packet_receipt
+        self.resource = resource
+
+        if self.packet_receipt != None:
             self.hash = packet_receipt.truncated_hash
+            self.packet_receipt.set_timeout_callback(self.request_timed_out)
+
+        elif self.resource != None:
+            self.hash = resource.request_id
+            resource.set_callback(self.request_resource_concluded)
+        
         self.link               = link
         self.request_id         = self.hash
 
@@ -800,11 +856,19 @@ class RequestReceipt():
         self.callbacks.response = response_callback
         self.callbacks.failed   = failed_callback
 
-        self.packet_receipt = packet_receipt
-        self.packet_receipt.set_timeout_callback(self.request_timed_out)
-
         self.link.pending_requests.append(self)
 
+    def request_resource_concluded(self, resource):
+        if resource.status == RNS.Resource.COMPLETE:
+            RNS.log("Request "+RNS.prettyhexrep(self.request_id)+" successfully sent as resource.", RNS.LOG_DEBUG)
+        else:
+            RNS.log("Sending request "+RNS.prettyhexrep(self.request_id)+" as resource failed with status: "+RNS.hexrep([resource.status]), RNS.LOG_DEBUG)
+            self.status = RequestReceipt.FAILED
+            self.concluded_at = time.time()
+            self.link.pending_requests.remove(self)
+
+            if self.callbacks.failed != None:
+                self.callbacks.failed(self)
 
     def request_timed_out(self, packet_receipt):
         self.status = RequestReceipt.FAILED
@@ -817,6 +881,7 @@ class RequestReceipt():
     def response_received(self, response):
         self.response = response
 
+        if self.packet_receipt != None:
             self.packet_receipt.status = RNS.PacketReceipt.DELIVERED
             self.packet_receipt.proved = True
             self.packet_receipt.concluded_at = time.time()

RNS/Resource.py

@@ -21,6 +21,8 @@ class Resource:
     :param progress_callback: A *callable* with the signature *callback(resource)*. Will be called whenever the resource transfer progress is updated.
     :param segment_index: Internal use, ignore.
     :param original_hash: Internal use, ignore.
+    :param is_request: Internal use, ignore.
+    :param is_response: Internal use, ignore.
     """
     WINDOW_FLEXIBILITY   = 4
     WINDOW_MIN           = 1
@@ -119,6 +121,7 @@ class Resource:
             resource.link.register_incoming_resource(resource)
 
             RNS.log("Accepting resource advertisement for "+RNS.prettyhexrep(resource.hash), RNS.LOG_DEBUG)
+            if resource.link.callbacks.resource_started != None:
                 resource.link.callbacks.resource_started(resource)
 
             resource.hashmap_update(0, resource.hashmap_raw)
@@ -133,7 +136,7 @@ class Resource:
     # Create a resource for transmission to a remote destination
     # The data passed can be either a bytes-array or a file opened
     # in binary read mode.
-    def __init__(self, data, link, advertise=True, auto_compress=True, callback=None, progress_callback=None, segment_index = 1, original_hash = None):
+    def __init__(self, data, link, advertise=True, auto_compress=True, callback=None, progress_callback=None, segment_index = 1, original_hash = None, request_id = None, is_response = False):
         data_size = None
         resource_data = None
         if hasattr(data, "read"):
@@ -188,6 +191,8 @@ class Resource:
         self.__watchdog_job_id = 0
         self.__progress_callback = progress_callback
         self.rtt = None
+        self.request_id = request_id
+        self.is_response = is_response
 
         self.receiver_min_consecutive_height = 0
 
@@ -250,6 +255,7 @@ class Resource:
 
                 self.random_hash       = RNS.Identity.get_random_hash()[:Resource.RANDOM_HASH_SIZE]
                 self.hash = RNS.Identity.full_hash(data+self.random_hash)
+                self.truncated_hash = RNS.Identity.truncated_hash(data+self.random_hash)
                 self.expected_proof = RNS.Identity.full_hash(data+self.hash)
 
                 if original_hash == None:
@@ -739,6 +745,9 @@ class Resource:
                 self.link.resource_concluded(self)
                 self.callback(self)
 
+    def set_callback(self, callback):
+        self.callback = callback
+
     def progress_callback(self, callback):
         self.__progress_callback = callback
 
@@ -767,10 +776,35 @@ class Resource:
 
 
 class ResourceAdvertisement:
-    HASHMAP_MAX_LEN      = 73
+    HASHMAP_MAX_LEN      = 70
     COLLISION_GUARD_SIZE = 2*Resource.WINDOW_MAX+HASHMAP_MAX_LEN
 
-    def __init__(self, resource=None):
+    @staticmethod
+    def is_request(advertisement_packet):
+        adv = ResourceAdvertisement.unpack(advertisement_packet.plaintext)
+        if adv.q != None and adv.u:
+            return True
+        else:
+            return False
+
+
+    @staticmethod
+    def is_response(advertisement_packet):
+        adv = ResourceAdvertisement.unpack(advertisement_packet.plaintext)
+
+        if adv.q != None and adv.p:
+            return True
+        else:
+            return False
+
+
+    @staticmethod
+    def get_request_id(advertisement_packet):
+        adv = ResourceAdvertisement.unpack(advertisement_packet.plaintext)
+        return adv.q
+
+
+    def __init__(self, resource=None, request_id=None, is_response=False):
         if resource != None:
             self.t = resource.size              # Transfer size
             self.d = resource.total_size        # Total uncompressed data size
@@ -784,7 +818,21 @@ class ResourceAdvertisement:
             self.s = resource.split             # Split flag
             self.i = resource.segment_index     # Segment index
             self.l = resource.total_segments    # Total segments
-            self.f = 0x00 | self.s << 2 | self.c << 1 | self.e # Flags
+            self.q = resource.request_id        # ID of associated request
+            self.u = False                      # Is request flag
+            self.p = False                      # Is response flag
+
+            if self.q != None:
+                if not resource.is_response:
+                    self.u = True
+                    self.p = False
+                else:
+                    self.u = False
+                    self.p = True
+
+            # Flags
+            self.f = 0x00 | self.p << 4 | self.u << 3 | self.s << 2 | self.c << 1 | self.e
+
 
     def pack(self, segment=0):
         hashmap_start = segment*ResourceAdvertisement.HASHMAP_MAX_LEN
@@ -803,12 +851,14 @@ class ResourceAdvertisement:
             "o": self.o,    # Original hash
             "i": self.i,    # Segment index
             "l": self.l,    # Total segments
+            "q": self.q,    # Request ID
             "f": self.f,    # Resource flags
             "m": hashmap
         }
 
         return umsgpack.packb(dictionary)
 
+
     @staticmethod
     def unpack(data):
         dictionary = umsgpack.unpackb(data)
@@ -824,8 +874,11 @@ class ResourceAdvertisement:
         adv.f = dictionary["f"]
         adv.i = dictionary["i"]
         adv.l = dictionary["l"]
+        adv.q = dictionary["q"]
         adv.e = True if (adv.f & 0x01) == 0x01 else False
         adv.c = True if ((adv.f >> 1) & 0x01) == 0x01 else False
         adv.s = True if ((adv.f >> 2) & 0x01) == 0x01 else False
+        adv.u = True if ((adv.f >> 3) & 0x01) == 0x01 else False
+        adv.p = True if ((adv.f >> 4) & 0x01) == 0x01 else False
 
         return adv

RNS/__init__.py

@@ -14,7 +14,7 @@ from .Transport import Transport
 from .Destination import Destination
 from .Packet import Packet
 from .Packet import PacketReceipt
-from .Resource import Resource
+from .Resource import Resource, ResourceAdvertisement
 
 modules = glob.glob(os.path.dirname(__file__)+"/*.py")
 __all__ = [ os.path.basename(f)[:-3] for f in modules if not f.endswith('__init__.py')]