https://github.com/neo-project/neo/pull/2101

neo3/network/message.py

@@ -26,6 +26,7 @@ class MessageType(IntEnum):
     TRANSACTION = 0x2b
     BLOCK = 0x2c
     CONSENSUS = 0x2d
+    EXTENSIBLE = 0x2e
     REJECT = 0x2f
 
     FILTERLOAD = 0x30

neo3/network/payloads/__init__.py

@@ -15,9 +15,11 @@
                     GetBlockByIndexPayload)
 from .filter import FilterAddPayload, FilterLoadPayload
 from .oracle import OracleReponseCode, OracleResponse
+from .extensible import ExtensiblePayload
 
 __all__ = ['EmptyPayload', 'InventoryPayload', 'InventoryType', 'VersionPayload', 'NetworkAddress',
            'AddrPayload', 'PingPayload', 'Witness', 'WitnessScope', 'Header', 'Block', 'MerkleBlockPayload',
            'HeadersPayload', 'ConsensusData', 'ConsensusPayload', 'Transaction', 'TransactionAttribute',
            'TransactionAttributeType', 'Signer', 'GetBlocksPayload', 'GetBlockByIndexPayload', 'FilterAddPayload',
-           'FilterLoadPayload', 'TrimmedBlock', 'IVerifiable', 'OracleReponseCode', 'OracleReponseCode']
+           'FilterLoadPayload', 'TrimmedBlock', 'IVerifiable', 'OracleReponseCode', 'OracleReponseCode',
+           'ExtensiblePayload']

neo3/network/payloads/extensible.py

@@ -0,0 +1,71 @@
+from __future__ import annotations
+import hashlib
+from typing import List
+from neo3 import storage, settings
+from neo3.core import types, serialization, Size as s, utils
+from neo3.network import payloads
+from neo3.network.payloads import InventoryType
+
+
+class ExtensiblePayload(payloads.IInventory):
+    def __init__(self,
+                 category: str,
+                 valid_block_start: int,
+                 valid_block_end: int,
+                 sender: types.UInt160,
+                 data: bytes,
+                 witness: payloads.Witness):
+        self.category = category
+        self.valid_block_start = valid_block_start
+        self.valid_block_end = valid_block_end
+        self.sender = sender
+        self.data = data
+        self.witness = witness
+
+    def __len__(self):
+        return (utils.get_var_size(self.category)
+                + s.uint32
+                + s.uint32
+                + s.uint160
+                + utils.get_var_size(self.data)
+                + 1
+                + len(self.witness))
+
+    def serialize(self, writer: serialization.BinaryWriter) -> None:
+        self.serialize_unsigned(writer)
+        writer.write_uint8(1)
+        writer.write_serializable(self.witness)
+
+    def serialize_unsigned(self, writer: serialization.BinaryWriter) -> None:
+        writer.write_var_string(self.category)
+        writer.write_uint32(self.valid_block_start)
+        writer.write_uint32(self.valid_block_end)
+        writer.write_serializable(self.sender)
+        writer.write_var_bytes(self.data)
+
+    def deserialize(self, reader: serialization.BinaryReader) -> None:
+        self.deserialize_unsigned(reader)
+        if reader.read_uint8() != 1:
+            raise ValueError("Deserialization error - check byte incorrect")
+        self.witness = reader.read_serializable(payloads.Witness)
+
+    def deserialize_unsigned(self, reader: serialization.BinaryReader) -> None:
+        self.category = reader.read_var_string(32)
+        self.valid_block_start = reader.read_uint32()
+        self.valid_block_end = reader.read_uint32()
+        if self.valid_block_start > self.valid_block_end:
+            raise ValueError("Deserialization error - valid_block_starts is bigger than valid_block_end")
+        self.sender = reader.read_serializable(types.UInt160)
+        self.data = reader.read_var_bytes(0xFFFF)
+
+    def hash(self) -> types.UInt256:
+        intermediate_data = hashlib.sha256(self.get_hash_data(settings.network.magic)).digest()
+        data = hashlib.sha256(intermediate_data).digest()
+        return types.UInt256(data)
+
+    @property
+    def inventory_type(self) -> InventoryType:
+        return InventoryType.EXTENSIBLE
+
+    def get_script_hashes_for_verifying(self, snapshot: storage.Snapshot) -> List[types.UInt160]:
+        return [self.sender]

neo3/network/payloads/inventory.py

@@ -12,6 +12,7 @@ class InventoryType(IntEnum):
     TX = 0x2b
     BLOCK = 0x2c
     CONSENSUS = 0x2d
+    EXTENSIBLE = 0x2e
 
 
 class InventoryPayload(serialization.ISerializable):