tweak(network): Increase message buffer and max packet sizes to reduce connection issues

Author: Mauller

Core/GameEngine/Include/Common/GameDefines.h

@@ -45,6 +45,11 @@
 #define RETAIL_COMPATIBLE_PATHFINDING_ALLOCATION (1)
 #endif
 
+// Disable non retail fixes in the networking, such as putting more data per UDP packet
+#ifndef RETAIL_COMPATIBLE_NETWORKING
+#define RETAIL_COMPATIBLE_NETWORKING (1)
+#endif
+
 // This is essentially synonymous for RETAIL_COMPATIBLE_CRC. There is a lot wrong with AIGroup, such as use-after-free, double-free, leaks,
 // but we cannot touch it much without breaking retail compatibility. Do not shy away from using massive hacks when fixing issues with AIGroup,
 // but put them behind this macro.

Core/GameEngine/Include/GameNetwork/LANAPI.h

@@ -44,7 +44,7 @@ static const Int g_lanHostNameLength = 1;
 static const Int g_lanGameNameLength = 16; // reduced length because of game option length
 static const Int g_lanGameNameReservedLength = 16; // save N wchars for ID info
 static const Int g_lanMaxChatLength = 100;
-static const Int m_lanMaxOptionsLength = MAX_PACKET_SIZE - ( 8 + (g_lanGameNameLength+1)*2 + 4 + (g_lanPlayerNameLength+1)*2
+static const Int m_lanMaxOptionsLength = MAX_LANAPI_PACKET_SIZE - ( 8 + (g_lanGameNameLength+1)*2 + 4 + (g_lanPlayerNameLength+1)*2
 																														+ (g_lanLoginNameLength+1) + (g_lanHostNameLength+1) );
 static const Int g_maxSerialLength = 23; // including the trailing '\0'
 
@@ -271,7 +271,7 @@ struct LANMessage
 };
 #pragma pack(pop)
 
-static_assert(sizeof(LANMessage) <= MAX_PACKET_SIZE, "LANMessage struct cannot be larger than the max packet size");
+static_assert(sizeof(LANMessage) <= MAX_LANAPI_PACKET_SIZE, "LANMessage struct cannot be larger than the max packet size");
 
 
 /**

Core/GameEngine/Include/GameNetwork/NetworkDefs.h

@@ -48,17 +48,34 @@ enum ConnectionNumbers CPP_11(: Int)
 	NUM_CONNECTIONS
 };
 
-static const Int MAX_SLOTS = MAX_PLAYER+1;
+static constexpr const Int MAX_SLOTS = MAX_PLAYER+1;
 
+// TheSuperHackers @info As we are not detecting for network fragmentation and adjusting max payload, we set 1200 bytes UDP payload as a safe upper limit for various networks
+// We chose 1200 bytes as when taking mobile networks into account, maximum transmission unit sizes can vary from 1340 - 1500 bytes
+// and when the packet headers for PPPOE, IPV6 and virtual network encapsulation are considered, we need a lower safe UDP payload to prevent fragmentation.
+static constexpr const Int MAX_UDP_PAYLOAD = 1200;
 // UDP (8 bytes) + IP header (28 bytes) = 36 bytes total.  We want a total packet size of 512, so 512 - 36 = 476
-static const Int MAX_PACKET_SIZE = 476;
+static constexpr const Int RESTRICTED_UDP_PAYLOAD = 476;
+
+// TheSuperHackers @info The legacy lanapi cannot use a larger packet size without breaking the gameinfo command
+static constexpr const Int MAX_LANAPI_PACKET_SIZE = RESTRICTED_UDP_PAYLOAD;
+
+// TheSuperHackers @bugfix Mauller 08/02/2026 Allow larger ethernet UDP payload to be used for game messages, this fixes connection issues and eliminates disconnection bugs
+#if RETAIL_COMPATIBLE_NETWORKING
+static constexpr const Int MAX_PACKET_SIZE = RESTRICTED_UDP_PAYLOAD;
+static constexpr const Int MAX_MESSAGE_LEN = 1024;
+#else
+static constexpr const Int MAX_PACKET_SIZE = MAX_UDP_PAYLOAD;
+static constexpr const Int MAX_MESSAGE_LEN = MAX_UDP_PAYLOAD;
+#endif
+
+// TheSuperHackers @bugfix Mauller 08/02/2026 Double send and receive buffer sizes to alleviate the occurance of disconnection issues in retail and non retail code.
+static constexpr const Int MAX_MESSAGES = 256;
 
 /**
  * Command packet - contains frame #, total # of commands, and each command.  This is what gets sent
  * to each player every frame
  */
-#define MAX_MESSAGE_LEN 1024
-#define MAX_MESSAGES 128
 static const Int numCommandsPerCommandPacket = (MAX_MESSAGE_LEN - sizeof(UnsignedInt) - sizeof(UnsignedShort))/sizeof(GameMessage);
 #pragma pack(push, 1)
 struct CommandPacket

Core/GameEngine/Source/GameNetwork/LANAPI.cpp

@@ -68,7 +68,7 @@ LANGame::LANGame( void )
 LANAPI::LANAPI( void ) : m_transport(nullptr)
 {
 	DEBUG_LOG(("LANAPI::LANAPI() - max game option size is %d, sizeof(LANMessage)=%d, MAX_PACKET_SIZE=%d",
-		m_lanMaxOptionsLength, sizeof(LANMessage), MAX_PACKET_SIZE));
+		m_lanMaxOptionsLength, sizeof(LANMessage), MAX_LANAPI_PACKET_SIZE));
 
 	m_lastResendTime = 0;
 	//