app: Write a new design for NDNApp (v2).

Add support for PIT Token.
Add SignedInterest support for NFD mgmt command Interests.

Ref: named-data#48

examples/appv2/consumer.py

@@ -0,0 +1,58 @@
+# -----------------------------------------------------------------------------
+# Copyright (C) 2019-2022 The python-ndn authors
+#
+# This file is part of python-ndn.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# -----------------------------------------------------------------------------
+import logging
+from ndn import utils, appv2, types
+from ndn import encoding as enc
+
+
+logging.basicConfig(format='[{asctime}]{levelname}:{message}',
+                    datefmt='%Y-%m-%d %H:%M:%S',
+                    level=logging.INFO,
+                    style='{')
+
+
+app = appv2.NDNApp()
+
+
+async def main():
+    try:
+        timestamp = utils.timestamp()
+        name = enc.Name.from_str('/example/testApp/randomData') + [enc.Component.from_timestamp(timestamp)]
+        print(f'Sending Interest {enc.Name.to_str(name)}, {enc.InterestParam(must_be_fresh=True, lifetime=6000)}')
+        # TODO: Write a better validator
+        data_name, content, pkt_context = await app.express(
+            name, validator=appv2.pass_all,
+            must_be_fresh=True, can_be_prefix=False, lifetime=6000)
+
+        print(f'Received Data Name: {enc.Name.to_str(data_name)}')
+        print(pkt_context['meta_info'])
+        print(bytes(content) if content else None)
+    except types.InterestNack as e:
+        print(f'Nacked with reason={e.reason}')
+    except types.InterestTimeout:
+        print(f'Timeout')
+    except types.InterestCanceled:
+        print(f'Canceled')
+    except types.ValidationFailure:
+        print(f'Data failed to validate')
+    finally:
+        app.shutdown()
+
+
+if __name__ == '__main__':
+    app.run_forever(after_start=main())

examples/appv2/producer.py

@@ -0,0 +1,48 @@
+# -----------------------------------------------------------------------------
+# Copyright (C) 2019-2022 The python-ndn authors
+#
+# This file is part of python-ndn.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# -----------------------------------------------------------------------------
+import typing
+import logging
+from ndn import appv2
+from ndn import encoding as enc
+
+
+logging.basicConfig(format='[{asctime}]{levelname}:{message}',
+                    datefmt='%Y-%m-%d %H:%M:%S',
+                    level=logging.INFO,
+                    style='{')
+
+
+app = appv2.NDNApp()
+keychain = app.default_keychain()
+
+
+@app.route('/example/testApp')
+def on_interest(name: enc.FormalName, _app_param: typing.Optional[enc.BinaryStr],
+                reply: appv2.ReplyFunc, context: appv2.PktContext):
+    print(f'>> I: {enc.Name.to_str(name)}, {context["int_param"]}')
+    content = "Hello, world!".encode()
+    reply(app.make_data(name, content=content, signer=keychain.get_signer({}),
+                        freshness_period=10000))
+    print(f'<< D: {enc.Name.to_str(name)}')
+    print(enc.MetaInfo(freshness_period=10000))
+    print(f'Content: (size: {len(content)})')
+    print('')
+
+
+if __name__ == '__main__':
+    app.run_forever()

src/ndn/app.py

@@ -259,7 +259,7 @@ async def _wait_for_data(self, future: aio.Future, lifetime: int, node_name: For
             else:
                 return data_name, meta_info, content
         else:
-            raise ValidationFailure(data_name, meta_info, content)
+            raise ValidationFailure(data_name, meta_info, content, sig)
 
     async def main_loop(self, after_start: Awaitable = None) -> bool:
         """

src/ndn/app_support/nfd_mgmt.py

@@ -128,6 +128,10 @@ class GeneralStatus(TlvModel):
     n_out_nacks = UintField(0x98)
     n_satisfied_interests = UintField(0x99)
     n_unsatisfied_interests = UintField(0x9a)
+    # The following comes from DNMP's extension to NFD mgmt protocol:
+    # https://github.com/pollere/DNMP-v2/blob/c4359ae1af03824ec1ee8cd27a7d52c9151fa813/formats/forwarder-status.proto
+    # It does not show up in the standard protocol:
+    # https://redmine.named-data.net/projects/nfd/wiki/ForwarderStatus
     n_fragmentation_errors = UintField(0xc8)
     n_out_over_mtu = UintField(0xc9)
     n_in_lp_invalid = UintField(0xca)
@@ -228,25 +232,8 @@ class CsInfo(TlvModel):
 
 
 def make_command(module, command, face: Optional[Face] = None, **kwargs):
-    local = face.isLocalFace() if face else True
-
-    if local:
-        ret = Name.from_str(f"/localhost/nfd/{module}/{command}")
-    else:
-        ret = Name.from_str(f"/localhop/nfd/{module}/{command}")
-    # Command parameters
-    cp = ControlParameters()
-    cp.cp = ControlParametersValue()
-    for k, v in kwargs.items():
-        if k == 'strategy':
-            cp.cp.strategy = Strategy()
-            cp.cp.strategy.name = v
-        else:
-            setattr(cp.cp, k, v)
-    ret.append(Component.from_bytes(cp.encode()))
+    ret = make_command_v2(module, command, face, **kwargs)
 
-    # Note: when shifting from command Interest to signed Interest, remove all following lines
-    # and add ``app_param=b'', digest_sha256=True`` to app.express_interest
     # Timestamp and nonce
     ret.append(Component.from_bytes(struct.pack('!Q', timestamp())))
     ret.append(Component.from_bytes(struct.pack('!Q', gen_nonce_64())))
@@ -270,6 +257,30 @@ def make_command(module, command, face: Optional[Face] = None, **kwargs):
     return ret
 
 
+def make_command_v2(module, command, face: Optional[Face] = None, **kwargs):
+    # V2 returns the Command Interest name for the NDNv3 signed Interest
+    # Note: this behavior is supported by NFD and YaNFD but has not been documented yet (on 06/26/2022):
+    # https://redmine.named-data.net/projects/nfd/wiki/ControlCommand
+    # Add ``app_param=b'', signer=sec.DigestSha256Signer(for_interest=True)`` to app.express when using this.
+    local = face.isLocalFace() if face else True
+
+    if local:
+        ret = Name.from_str(f"/localhost/nfd/{module}/{command}")
+    else:
+        ret = Name.from_str(f"/localhop/nfd/{module}/{command}")
+    # Command parameters
+    cp = ControlParameters()
+    cp.cp = ControlParametersValue()
+    for k, v in kwargs.items():
+        if k == 'strategy':
+            cp.cp.strategy = Strategy()
+            cp.cp.strategy.name = v
+        else:
+            setattr(cp.cp, k, v)
+    ret.append(Component.from_bytes(cp.encode()))
+    return ret
+
+
 def parse_response(buf):
     buf = parse_and_check_tl(memoryview(buf), 0x65)
     cr = ControlResponse.parse(buf)