Adds support for pull-based advert requests and responses.

src/meshcore/commands/control_data.py

@@ -7,6 +7,9 @@ from ..packets import ControlType, PacketType
 
 logger = logging.getLogger("meshcore")
 
+# Command codes
+CMD_REQUEST_ADVERT = 57  # 0x39
+
 class ControlDataCommandHandler(CommandHandlerBase):
     """Helper functions to handle binary requests through binary commands"""
 
@@ -48,3 +51,46 @@ class ControlDataCommandHandler(CommandHandlerBase):
         else:
             res.payload["tag"] = tag
             return res
+
+    async def request_advert(self, prefix: bytes, path: bytes) -> Event:
+        """
+        Request advertisement from a node via pull-based system.
+
+        Args:
+            prefix: First byte of target node's public key (PATH_HASH_SIZE = 1)
+            path: Path to reach the node (1-64 bytes)
+
+        Returns:
+            Event with type OK on success, ERROR on failure.
+            The actual response arrives asynchronously as ADVERT_RESPONSE event.
+
+        Raises:
+            ValueError: If prefix is not 1 byte or path is empty/too long
+
+        Example:
+            # Get repeater from contacts
+            contacts = (await mc.commands.get_contacts()).payload
+            repeater = next(c for c in contacts.values() if c['adv_type'] == 2)
+
+            # Extract prefix and path
+            prefix = bytes.fromhex(repeater['public_key'])[:1]
+            path = bytes(repeater.get('out_path', [])) or prefix
+
+            # Send request
+            result = await mc.commands.request_advert(prefix, path)
+            if result.type == EventType.ERROR:
+                print(f"Failed: {result.payload}")
+                return
+
+            # Wait for response
+            response = await mc.wait_for_event(EventType.ADVERT_RESPONSE, timeout=30)
+            if response:
+                print(f"Node: {response.payload['node_name']}")
+        """
+        if len(prefix) != 1:
+            raise ValueError("Prefix must be exactly 1 byte (PATH_HASH_SIZE)")
+        if not path or len(path) > 64:
+            raise ValueError("Path must be 1-64 bytes")
+
+        cmd = bytes([CMD_REQUEST_ADVERT]) + prefix + bytes([len(path)]) + path
+        return await self.send(cmd, [EventType.OK, EventType.ERROR])