Implemet connless packing

tests/packets7/lis2_test.py

@@ -113,14 +113,24 @@ def test_lis2_connless7():
 
     server = msg.servers[0]
     assert server.port == 8298
+    assert server.ipaddr == "5.78.73.17" # hetzner
     server = msg.servers[1]
     assert server.port == 8300
+    assert server.ipaddr == "5.78.73.17"
     server = msg.servers[2]
     assert server.port == 8303
+    assert server.ipaddr == "5.78.73.17"
     server = msg.servers[3]
     assert server.port == 8304
+    assert server.ipaddr == "5.78.73.17"
     server = msg.servers[4]
     assert server.port == 8305
+    assert server.ipaddr == "5.78.73.17"
     # ..
     server = msg.servers[74]
     assert server.port == 8346
+    assert server.ipaddr == "37.230.210.231" # rus4.ddnet.org
+
+    repack: bytes = packet.pack()
+
+    assert repack == data

twnet_parser/master_server.py

@@ -1,11 +1,13 @@
-from typing import Annotated
+from typing import Literal
 
 class MastersrvAddr():
     def __init__(
             self,
-            ipaddr: Annotated[bytes, 16] = bytes(16),
-            port: int = 0
+            family: Literal[4, 6] = 4,
+            ipaddr: str = '127.0.0.1',
+            port: int = 8303
         ) -> None:
-        self.ipaddr: Annotated[bytes, 16] = ipaddr
+        self.family: Literal[4, 6] = family
+        self.ipaddr: str = ipaddr
         self.port: int = port
 

twnet_parser/packer.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 
-from typing import Final
+from typing import Final, Literal
 
 from twnet_parser.master_server import MastersrvAddr
 
@@ -46,8 +46,17 @@ class Unpacker():
         servers: list[MastersrvAddr] = []
         while len(self.data()) >= 18:
             ipaddr = self.get_raw(16)
+            ipv4_mapping = b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xFF\xFF'
+            family: Literal[4, 6] = 4
+            addr_str: str = ''
+            if ipaddr[0:12] == ipv4_mapping:
+                addr_str = f"{ipaddr[12]}.{ipaddr[13]}.{ipaddr[14]}.{ipaddr[15]}"
+            else:
+                # TODO: make ipv6 nicer
+                addr_str = str(ipaddr)
+                family = 6
             port = self.get_be_uint16() # TODO: i randomly assumed this would work
-            servers.append(MastersrvAddr(ipaddr, int(port)))
+            servers.append(MastersrvAddr(family, addr_str, int(port)))
         return servers
 
     def get_uint8(self) -> int:
@@ -154,7 +163,13 @@ def pack_uint8(num: int) -> bytes:
 def pack_packed_addresses(servers: list[MastersrvAddr]) -> bytes:
     res: bytes = b''
     for server in servers:
-        res += server.ipaddr
+        if server.family == 4:
+            ipv4_mapping = b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xFF\xFF'
+            res += ipv4_mapping
+            res += bytes([int(x) for x in server.ipaddr.split('.')])
+        else:
+            # TODO: ipv6 is wrong
+            res += server.ipaddr.encode('utf-8')
         res += pack_be_uint16(server.port)
     return res
 

twnet_parser/packet.py

@@ -98,6 +98,10 @@ class PacketHeader(PrettyPrint):
             flags |= PACKETFLAG7_CONNLESS
         if self.num_chunks is None:
             self.num_chunks = 0
+        if self.flags.connless:
+            return bytes([ \
+                ((PACKETFLAG7_CONNLESS<<2)&0xfc) | (self.connless_version&0x03)
+            ]) + self.token + self.response_token
         return bytes([ \
             ((flags << 2)&0xfc) | ((self.ack>>8)&0x03), \
             self.ack&0xff, \
@@ -116,18 +120,19 @@ class TwPacket(PrettyPrint):
         payload: bytes = b''
         msg: Union[CtrlMessage, NetMessage, ConnlessMessage]
         is_control: bool = False
+        is_connless: bool = False
         for msg in self.messages:
-            # TODO: this is super ugly
-            # revist https://gitlab.com/teeworlds-network/twnet_parser/-/issues/1
-            # we can not check isinstance() not sure why
-            # maybe because CtrlMessage and NetMessage are no actual classes
-            # but just ducktyping helpers
-            if not hasattr(msg, 'system_message'):
+            if msg.message_type == 'connless':
+                is_connless = True
+                msg = cast(ConnlessMessage, msg)
+                payload += bytes(msg.message_id)
+                payload += msg.pack()
+            elif msg.message_type == 'control':
                 is_control = True
                 msg = cast(CtrlMessage, msg)
                 payload += pack_int(msg.message_id)
                 payload += msg.pack(we_are_a_client)
-            else:
+            else: # game or system message
                 msg = cast(NetMessage, msg)
                 msg_payload: bytes = pack_int(
                     (msg.message_id<<1) |
@@ -146,6 +151,9 @@ class TwPacket(PrettyPrint):
         if is_control:
             if self.header.flags.control is None:
                 self.header.flags.control = True
+        if is_connless:
+            if self.header.flags.connless is None:
+                self.header.flags.connless = True
         return self.header.pack() + payload
 
 class PacketHeaderParser7():