(svn r21363) -Add: support for limiting the amount of (accepted) incoming data

src/network/core/tcp.h

@@ -39,7 +39,7 @@ public:
 	bool SendPackets(bool closing_down = false);
 	bool IsPacketQueueEmpty();
 
-	Packet *ReceivePacket();
+	virtual Packet *ReceivePacket();
 
 	bool CanSendReceive();
 

src/network/network_server.cpp

@@ -62,6 +62,7 @@ ServerNetworkGameSocketHandler::ServerNetworkGameSocketHandler(SOCKET s) : Netwo
 {
 	this->status = STATUS_INACTIVE;
 	this->client_id = _network_client_id++;
+	this->receive_limit = _settings_client.network.bytes_per_frame_burst;
 	NetworkClientInfo *ci = new NetworkClientInfo(this->client_id);
 	this->SetInfo(ci);
 	ci->client_playas = COMPANY_INACTIVE_CLIENT;
@@ -77,6 +78,19 @@ ServerNetworkGameSocketHandler::~ServerNetworkGameSocketHandler()
 	OrderBackup::ResetUser(this->client_id);
 }
 
+Packet *ServerNetworkGameSocketHandler::ReceivePacket()
+{
+	/* Only allow receiving when we have some buffer free; this value
+	 * can go negative, but eventually it will become positive again. */
+	if (this->receive_limit <= 0) return NULL;
+
+	/* We can receive a packet, so try that and if needed account for
+	 * the amount of received data. */
+	Packet *p = this->NetworkTCPSocketHandler::ReceivePacket();
+	if (p != NULL) this->receive_limit -= p->size;
+	return p;
+}
+
 NetworkRecvStatus ServerNetworkGameSocketHandler::CloseConnection(NetworkRecvStatus status)
 {
 	assert(status != NETWORK_RECV_STATUS_OKAY);
@@ -1540,6 +1554,11 @@ void NetworkServer_Tick(bool send_frame)
 	/* Now we are done with the frame, inform the clients that they can
 	 *  do their frame! */
 	FOR_ALL_CLIENT_SOCKETS(cs) {
+		/* We allow a number of bytes per frame, but only to the burst amount
+		 * to be available for packet receiving at any particular time. */
+		cs->receive_limit = min(cs->receive_limit + _settings_client.network.bytes_per_frame,
+				_settings_client.network.bytes_per_frame_burst);
+
 		/* Check if the speed of the client is what we can expect from a client */
 		if (cs->status == NetworkClientSocket::STATUS_ACTIVE) {
 			/* 1 lag-point per day */

src/network/network_server.h

@@ -70,10 +70,12 @@ public:
 	uint32 last_token_frame;     ///< The last frame we received the right token
 	ClientStatus status;         ///< Status of this client
 	CommandQueue outgoing_queue; ///< The command-queue awaiting delivery
+	int receive_limit;           ///< Amount of bytes that we can receive at this moment
 
 	ServerNetworkGameSocketHandler(SOCKET s);
 	~ServerNetworkGameSocketHandler();
 
+	virtual Packet *ReceivePacket();
 	NetworkRecvStatus CloseConnection(NetworkRecvStatus status);
 	void GetClientName(char *client_name, size_t size) const;
 

src/settings_type.h

@@ -141,6 +141,8 @@ struct NetworkSettings {
 	uint8  frame_freq;                                    ///< how often do we send commands to the clients
 	uint16 commands_per_frame;                            ///< how many commands may be sent each frame_freq frames?
 	uint16 max_commands_in_queue;                         ///< how many commands may there be in the incoming queue before dropping the connection?
+	uint16 bytes_per_frame;                               ///< how many bytes may, over a long period, be received per frame?
+	uint16 bytes_per_frame_burst;                         ///< how many bytes may, over a short period, be received?
 	uint16 max_join_time;                                 ///< maximum amount of time, in game ticks, a client may take to join
 	bool   pause_on_join;                                 ///< pause the game when people join
 	uint16 server_port;                                   ///< port the server listens on

src/table/settings.h

@@ -633,6 +633,8 @@ const SettingDesc _settings[] = {
 	  SDTC_VAR(network.frame_freq,            SLE_UINT8,C|S,NO,     0,        0,      100, 0, STR_NULL,                                       NULL),
 	  SDTC_VAR(network.commands_per_frame,   SLE_UINT16, S, NO,     4,        1,    65535, 0, STR_NULL,                                       NULL),
 	  SDTC_VAR(network.max_commands_in_queue,SLE_UINT16, S, NO,    32,        1,    65535, 0, STR_NULL,                                       NULL),
+	  SDTC_VAR(network.bytes_per_frame,      SLE_UINT16, S, NO,     8,        1,    65535, 0, STR_NULL,                                       NULL),
+	  SDTC_VAR(network.bytes_per_frame_burst,SLE_UINT16, S, NO,   256,        1,    65535, 0, STR_NULL,                                       NULL),
 	  SDTC_VAR(network.max_join_time,        SLE_UINT16, S, NO,   500,        0,    32000, 0, STR_NULL,                                       NULL),
 	 SDTC_BOOL(network.pause_on_join,                    S, NO,  true,                        STR_NULL,                                       NULL),
 	  SDTC_VAR(network.server_port,          SLE_UINT16, S, NO,NETWORK_DEFAULT_PORT,0,65535,0,STR_NULL,                                       NULL),