Added support for ThirdParty packet types

The kiss clients now detect if the incomming packet is a third party
packet and then sends up the subpacket instead of the encapsulated
packet up to the consumer.

aprsd/client.py

@@ -235,7 +235,11 @@ class KISSClient(Client):
         # LOG.debug(f"Decoding {msg}")
 
         raw = aprslib.parse(str(frame))
-        return core.Packet.factory(raw)
+        packet = core.Packet.factory(raw)
+        if isinstance(packet, core.ThirdParty):
+            return packet.subpacket
+        else:
+            return packet
 
     @trace.trace
     def setup_connection(self):

aprsd/packets/core.py

@@ -25,6 +25,7 @@ PACKET_TYPE_OBJECT = "object"
 PACKET_TYPE_UNKNOWN = "unknown"
 PACKET_TYPE_STATUS = "status"
 PACKET_TYPE_BEACON = "beacon"
+PACKET_TYPE_THIRDPARTY = "thirdparty"
 PACKET_TYPE_UNCOMPRESSED = "uncompressed"
 
 
@@ -115,6 +116,7 @@ class Packet(metaclass=abc.ABCMeta):
 
     @staticmethod
     def factory(raw_packet):
+        """Factory method to create a packet from a raw packet string."""
         raw = raw_packet
         raw["raw_dict"] = raw.copy()
         translate_fields = {
@@ -133,6 +135,19 @@ class Packet(metaclass=abc.ABCMeta):
         packet_type = get_packet_type(raw)
         raw["packet_type"] = packet_type
         class_name = TYPE_LOOKUP[packet_type]
+        if packet_type == PACKET_TYPE_THIRDPARTY:
+            # We have an encapsulated packet!
+            # So we need to decode it and return the inner packet
+            # as the packet we are going to process.
+            # This is a recursive call to the factory
+            subpacket_raw = raw["subpacket"]
+            subpacket = Packet.factory(subpacket_raw)
+            del raw["subpacket"]
+            # raw["subpacket"] = subpacket
+            packet = dacite.from_dict(data_class=class_name, data=raw)
+            packet.subpacket = subpacket
+            return packet
+
         if packet_type == PACKET_TYPE_UNKNOWN:
             # Try and figure it out here
             if "latitude" in raw:
@@ -552,6 +567,22 @@ class WeatherPacket(GPSPacket):
         )
 
 
+class ThirdParty(Packet):
+    # Holds the encapsulated packet
+    subpacket: Packet = None
+
+    def __repr__(self):
+        """Build the repr version of the packet."""
+        repr_str = (
+            f"{self.__class__.__name__}:"
+            f" From: {self.from_call}  "
+            f" To: {self.to_call}  "
+            f" Subpacket: {repr(self.subpacket)}"
+        )
+
+        return repr_str
+
+
 TYPE_LOOKUP = {
     PACKET_TYPE_WX: WeatherPacket,
     PACKET_TYPE_MESSAGE: MessagePacket,
@@ -562,6 +593,7 @@ TYPE_LOOKUP = {
     PACKET_TYPE_STATUS: StatusPacket,
     PACKET_TYPE_BEACON: GPSPacket,
     PACKET_TYPE_UNKNOWN: Packet,
+    PACKET_TYPE_THIRDPARTY: ThirdParty,
 }
 
 
@@ -588,6 +620,8 @@ def get_packet_type(packet: dict):
     elif pkt_format == PACKET_TYPE_UNCOMPRESSED:
         if packet.get("symbol", None) == "_":
             packet_type = PACKET_TYPE_WX
+    elif pkt_format == PACKET_TYPE_THIRDPARTY:
+        packet_type = PACKET_TYPE_THIRDPARTY
     return packet_type