diff --git a/src/network/core/config.h b/src/network/core/config.h --- a/src/network/core/config.h +++ b/src/network/core/config.h @@ -31,7 +31,21 @@ static const uint16 NETWORK_ADMIN_PORT static const uint16 NETWORK_DEFAULT_DEBUGLOG_PORT = 3982; ///< The default port debug-log is sent to (TCP) static const uint16 UDP_MTU = 1460; ///< Number of bytes we can pack in a single UDP packet -static const uint16 TCP_MTU = 1460; ///< Number of bytes we can pack in a single TCP packet +/* + * Technically a TCP packet could become 64kiB, however the high bit is kept so it becomes possible in the future + * to go to (significantly) larger packets if needed. This would entail a strategy such as employed for UTF-8. + * + * Packets up to 32 KiB have the high bit not set: + * 00000000 00000000 0bbbbbbb aaaaaaaa -> aaaaaaaa 0bbbbbbb + * Send_uint16(GB(size, 0, 15) + * + * Packets up to 1 GiB, first uint16 has high bit set so it knows to read a + * next uint16 for the remaining bits of the size. + * 00dddddd cccccccc bbbbbbbb aaaaaaaa -> cccccccc 10dddddd aaaaaaaa bbbbbbbb + * Send_uint16(GB(size, 16, 14) | 0b10 << 14) + * Send_uint16(GB(size, 0, 16)) + */ +static const uint16 TCP_MTU = 32767; ///< Number of bytes we can pack in a single TCP packet static const uint16 COMPAT_MTU = 1460; ///< Number of bytes we can pack in a single packet for backward compatibility static const byte NETWORK_GAME_ADMIN_VERSION = 1; ///< What version of the admin network do we use?