feat/606-enable-nat-traversal-via-hole-punching (#668)

* feat: base implementation of dcutr for hole-punching

* chore: removed circuit-relay imports from __init__

* feat: implemented dcutr protocol

* added test suite with mock setup

* Fix pre-commit hook issues in DCUtR implementation

* usages of CONNECT_TYPE and SYNC_TYPE have been replaced with HolePunch.Type.CONNECT and HolePunch.Type.SYNC

* added unit tests for dcutr and nat module and

* added multiaddr.get_peer_id() with proper DNS address handling and fixed method signature inconsistencies

* added assertions to verify DCUtR hole punch result in integration test

---------

Co-authored-by: Manu Sheel Gupta <manusheel.edu@gmail.com>

libp2p/relay/circuit_v2/pb/__init__.py

@@ -5,6 +5,11 @@ Contains generated protobuf code for circuit_v2 relay protocol.
 """
 
 # Import the classes to be accessible directly from the package
+
+from .dcutr_pb2 import (
+    HolePunch,
+)
+
 from .circuit_pb2 import (
     HopMessage,
     Limit,
@@ -13,4 +18,4 @@ from .circuit_pb2 import (
     StopMessage,
 )
 
-__all__ = ["HopMessage", "Limit", "Reservation", "Status", "StopMessage"]
+__all__ = ["HopMessage", "Limit", "Reservation", "Status", "StopMessage", "HolePunch"]

libp2p/relay/circuit_v2/pb/dcutr.proto

@@ -0,0 +1,14 @@
+syntax = "proto2";
+
+package holepunch.pb;
+
+message HolePunch {
+  enum Type {
+    CONNECT = 100;
+    SYNC = 300;
+  }
+
+  required Type type = 1;
+
+  repeated bytes ObsAddrs = 2;
+}

libp2p/relay/circuit_v2/pb/dcutr_pb2.py

@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: libp2p/relay/circuit_v2/pb/dcutr.proto
+"""Generated protocol buffer code."""
+from google.protobuf.internal import builder as _builder
+from google.protobuf import descriptor as _descriptor
+from google.protobuf import descriptor_pool as _descriptor_pool
+from google.protobuf import symbol_database as _symbol_database
+# @@protoc_insertion_point(imports)
+
+_sym_db = _symbol_database.Default()
+
+
+
+
+DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(b'\n&libp2p/relay/circuit_v2/pb/dcutr.proto\x12\x0cholepunch.pb\"\x69\n\tHolePunch\x12*\n\x04type\x18\x01 \x02(\x0e\x32\x1c.holepunch.pb.HolePunch.Type\x12\x10\n\x08ObsAddrs\x18\x02 \x03(\x0c\"\x1e\n\x04Type\x12\x0b\n\x07CONNECT\x10\x64\x12\t\n\x04SYNC\x10\xac\x02')
+
+_builder.BuildMessageAndEnumDescriptors(DESCRIPTOR, globals())
+_builder.BuildTopDescriptorsAndMessages(DESCRIPTOR, 'libp2p.relay.circuit_v2.pb.dcutr_pb2', globals())
+if _descriptor._USE_C_DESCRIPTORS == False:
+  DESCRIPTOR._options = None
+  _HOLEPUNCH._serialized_start=56
+  _HOLEPUNCH._serialized_end=161
+  _HOLEPUNCH_TYPE._serialized_start=131
+  _HOLEPUNCH_TYPE._serialized_end=161
+# @@protoc_insertion_point(module_scope)

libp2p/relay/circuit_v2/pb/dcutr_pb2.pyi

@@ -0,0 +1,54 @@
+"""
+@generated by mypy-protobuf.  Do not edit manually!
+isort:skip_file
+"""
+
+import builtins
+import collections.abc
+import google.protobuf.descriptor
+import google.protobuf.internal.containers
+import google.protobuf.message
+import typing
+
+DESCRIPTOR: google.protobuf.descriptor.FileDescriptor
+
+@typing.final
+class HolePunch(google.protobuf.message.Message):
+    """HolePunch message for the DCUtR protocol."""
+    
+    DESCRIPTOR: google.protobuf.descriptor.Descriptor
+    
+    class Type(builtins.int):
+        """Message types for HolePunch"""
+        @builtins.classmethod
+        def Name(cls, number: builtins.int) -> builtins.str: ...
+        @builtins.classmethod
+        def Value(cls, name: builtins.str) -> 'HolePunch.Type': ...
+        @builtins.classmethod
+        def keys(cls) -> typing.List[builtins.str]: ...
+        @builtins.classmethod
+        def values(cls) -> typing.List['HolePunch.Type']: ...
+        @builtins.classmethod
+        def items(cls) -> typing.List[typing.Tuple[builtins.str, 'HolePunch.Type']]: ...
+    
+    CONNECT: HolePunch.Type  # 100
+    SYNC: HolePunch.Type  # 300
+    
+    TYPE_FIELD_NUMBER: builtins.int
+    OBSADDRS_FIELD_NUMBER: builtins.int
+    type: HolePunch.Type
+    
+    @property
+    def ObsAddrs(self) -> google.protobuf.internal.containers.RepeatedScalarFieldContainer[builtins.bytes]: ...
+    
+    def __init__(
+        self,
+        *,
+        type: HolePunch.Type = ...,
+        ObsAddrs: collections.abc.Iterable[builtins.bytes] = ...,
+    ) -> None: ...
+    
+    def HasField(self, field_name: typing.Literal["type", b"type"]) -> builtins.bool: ...
+    def ClearField(self, field_name: typing.Literal["ObsAddrs", b"ObsAddrs", "type", b"type"]) -> None: ...
+
+global___HolePunch = HolePunch