Cleanup client init states by bumping protocol version

Don't use TOSERVER_RECEIVED_MEDIA but TOSERVER_CLIENT_READY as indicatio for client ready
Handle clients with protocol version < 23 (almost) same way as before
Make client tell server about it's version
Add client state to not send bogus player position updates prior init complete
Add access to statistics information (peer connction time,rtt,version)
Fix clients standing stalled in world while preloading item visuals (new clients only)
Add get_player_information to read client specific information from lua

doc/lua_api.txt

@@ -1200,6 +1200,29 @@ minetest.features
 minetest.has_feature(arg) -> bool, missing_features
 ^ arg: string or table in format {foo=true, bar=true}
 ^ missing_features: {foo=true, bar=true}
+minetest.get_player_information(playername)
+^ table containing information about player peer:
+{
+	address = "127.0.0.1",     -- ip address of client
+	ip_version = 4,            -- IPv4 / IPv6
+	min_rtt = 0.01,            -- minimum round trip time
+	max_rtt = 0.2,             -- maximum round trip time
+	avg_rtt = 0.02,            -- average round trip time
+	min_jitter = 0.01,         -- minimum packet time jitter
+	max_jitter = 0.5,          -- maximum packet time jitter
+	avg_jitter = 0.03,         -- average packet time jitter
+	connection_uptime = 200,   -- seconds since client connected
+
+	-- following information is available on debug build only!!!
+	-- DO NOT USE IN MODS
+	--ser_vers = 26,             -- serialization version used by client
+	--prot_vers = 23,            -- protocol version used by client
+	--major = 0,                 -- major version number
+	--minor = 4,                 -- minor version number
+	--patch = 10,                -- patch version number
+	--vers_string = "0.4.9-git", -- full version string
+	--state = "Active"           -- current client state
+}
 
 Logging:
 minetest.debug(line)

src/client.cpp

@@ -47,6 +47,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "serialization.h"
 #include "util/serialize.h"
 #include "config.h"
+#include "cmake_config_githash.h"
 #include "util/directiontables.h"
 #include "util/pointedthing.h"
 #include "version.h"
@@ -252,7 +253,8 @@ Client::Client(
 	m_last_time_of_day_f(-1),
 	m_time_of_day_update_timer(0),
 	m_recommended_send_interval(0.1),
-	m_removed_sounds_check_timer(0)
+	m_removed_sounds_check_timer(0),
+	m_state(LC_Created)
 {
 	m_packetcounter_timer = 0.0;
 	//m_delete_unused_sectors_timer = 0.0;
@@ -325,17 +327,6 @@ void Client::connect(Address address)
 	m_con.Connect(address);
 }
 
-bool Client::connectedAndInitialized()
-{
-	if(m_con.Connected() == false)
-		return false;
-
-	if(m_server_ser_ver == SER_FMT_VER_INVALID)
-		return false;
-
-	return true;
-}
-
 void Client::step(float dtime)
 {
 	DSTACK(__FUNCTION_NAME);
@@ -372,9 +363,6 @@ void Client::step(float dtime)
 			m_packetcounter.clear();
 		}
 	}
-
-	// Get connection status
-	bool connected = connectedAndInitialized();
 
 #if 0
 	{
@@ -467,7 +455,7 @@ void Client::step(float dtime)
 	}
 #endif
 
-	if(connected == false)
+	if(m_state == LC_Created)
 	{
 		float &counter = m_connection_reinit_timer;
 		counter -= dtime;
@@ -632,7 +620,7 @@ void Client::step(float dtime)
 		{
 			counter = 0.0;
 			// connectedAndInitialized() is true, peer exists.
-			float avg_rtt = m_con.GetPeerAvgRTT(PEER_ID_SERVER);
+			float avg_rtt = getRTT();
 			infostream<<"Client: avg_rtt="<<avg_rtt<<std::endl;
 		}
 	}
@@ -643,7 +631,7 @@ void Client::step(float dtime)
 	{
 		float &counter = m_playerpos_send_timer;
 		counter += dtime;
-		if(counter >= m_recommended_send_interval)
+		if((m_state == LC_Ready) && (counter >= m_recommended_send_interval))
 		{
 			counter = 0.0;
 			sendPlayerPos();
@@ -1051,6 +1039,8 @@ void Client::ProcessData(u8 *data, u32 datasize, u16 sender_peer_id)
 		// Send as reliable
 		m_con.Send(PEER_ID_SERVER, 1, reply, true);
 
+		m_state = LC_Init;
+
 		return;
 	}
 
@@ -1937,7 +1927,7 @@ void Client::Send(u16 channelnum, SharedBuffer<u8> data, bool reliable)
 
 void Client::interact(u8 action, const PointedThing& pointed)
 {
-	if(connectedAndInitialized() == false){
+	if(m_state != LC_Ready){
 		infostream<<"Client::interact() "
 				"cancelled (not connected)"
 				<<std::endl;
@@ -2152,6 +2142,27 @@ void Client::sendRespawn()
 	Send(0, data, true);
 }
 
+void Client::sendReady()
+{
+	DSTACK(__FUNCTION_NAME);
+	std::ostringstream os(std::ios_base::binary);
+
+	writeU16(os, TOSERVER_CLIENT_READY);
+	writeU8(os,VERSION_MAJOR);
+	writeU8(os,VERSION_MINOR);
+	writeU8(os,VERSION_PATCH_ORIG);
+	writeU8(os,0);
+
+	writeU16(os,strlen(CMAKE_VERSION_GITHASH));
+	os.write(CMAKE_VERSION_GITHASH,strlen(CMAKE_VERSION_GITHASH));
+
+	// Make data buffer
+	std::string s = os.str();
+	SharedBuffer<u8> data((u8*)s.c_str(), s.size());
+	// Send as reliable
+	Send(0, data, true);
+}
+
 void Client::sendPlayerPos()
 {
 	LocalPlayer *myplayer = m_env.getLocalPlayer();
@@ -2650,16 +2661,14 @@ void Client::afterContentReceived(IrrlichtDevice *device, gui::IGUIFont* font)
 	infostream<<"- Starting mesh update thread"<<std::endl;
 	m_mesh_update_thread.Start();
 
+	m_state = LC_Ready;
+	sendReady();
 	infostream<<"Client::afterContentReceived() done"<<std::endl;
 }
 
 float Client::getRTT(void)
 {
-	try{
-		return m_con.GetPeerAvgRTT(PEER_ID_SERVER);
-	} catch(con::PeerNotFoundException &e){
-		return 1337;
-	}
+	return m_con.getPeerStat(PEER_ID_SERVER,con::AVG_RTT);
 }
 
 // IGameDef interface

src/client.h

@@ -57,6 +57,12 @@ struct QueuedMeshUpdate
 	~QueuedMeshUpdate();
 };
 
+enum LocalClientState {
+	LC_Created,
+	LC_Init,
+	LC_Ready
+};
+
 /*
 	A thread-safe queue of mesh update tasks
 */
@@ -319,14 +325,7 @@ class Client : public con::PeerHandler, public InventoryManager, public IGameDef
 		calling this, as it is sent in the initialization.
 	*/
 	void connect(Address address);
-	/*
-		returns true when
-			m_con.Connected() == true
-			AND m_server_ser_ver != SER_FMT_VER_INVALID
-		throws con::PeerNotFoundException if connection has been deleted,
-		eg. timed out.
-	*/
-	bool connectedAndInitialized();
+
 	/*
 		Stuff that references the environment is valid only as
 		long as this is not called. (eg. Players)
@@ -354,6 +353,7 @@ class Client : public con::PeerHandler, public InventoryManager, public IGameDef
 	void sendDamage(u8 damage);
 	void sendBreath(u16 breath);
 	void sendRespawn();
+	void sendReady();
 
 	ClientEnvironment& getEnv()
 	{ return m_env; }
@@ -454,6 +454,8 @@ class Client : public con::PeerHandler, public InventoryManager, public IGameDef
 	// Send a notification that no conventional media transfer is needed
 	void received_media();
 
+	LocalClientState getState() { return m_state; }
+
 private:
 
 	// Virtual methods from con::PeerHandler
@@ -537,6 +539,9 @@ class Client : public con::PeerHandler, public InventoryManager, public IGameDef
 
 	// Storage for mesh data for creating multiple instances of the same mesh
 	std::map<std::string, std::string> m_mesh_data;
+
+	// own state
+	LocalClientState m_state;
 };
 
 #endif // !CLIENT_HEADER

src/clientiface.cpp

@@ -17,6 +17,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
+#include <sstream>
+
 #include "clientiface.h"
 #include "player.h"
 #include "settings.h"
@@ -397,10 +399,11 @@ void RemoteClient::SetBlocksNotSent(std::map<v3s16, MapBlock*> &blocks)
 
 void RemoteClient::notifyEvent(ClientStateEvent event)
 {
+	std::ostringstream myerror;
 	switch (m_state)
 	{
 	case Invalid:
-		assert("State update for client in invalid state" != 0);
+		//intentionally do nothing
 		break;
 
 	case Created:
@@ -420,7 +423,8 @@ void RemoteClient::notifyEvent(ClientStateEvent event)
 
 		/* GotInit2 SetDefinitionsSent SetMediaSent */
 		default:
-			assert("Invalid client state transition!" == 0);
+			myerror << "Created: Invalid client state transition! " << event;
+			throw ClientStateError(myerror.str());
 		}
 		break;
 
@@ -446,7 +450,8 @@ void RemoteClient::notifyEvent(ClientStateEvent event)
 
 		/* Init SetDefinitionsSent SetMediaSent */
 		default:
-			assert("Invalid client state transition!" == 0);
+			myerror << "InitSent: Invalid client state transition! " << event;
+			throw ClientStateError(myerror.str());
 		}
 		break;
 
@@ -467,14 +472,15 @@ void RemoteClient::notifyEvent(ClientStateEvent event)
 
 		/* Init GotInit2 SetMediaSent */
 		default:
-			assert("Invalid client state transition!" == 0);
+			myerror << "InitDone: Invalid client state transition! " << event;
+			throw ClientStateError(myerror.str());
 		}
 		break;
 
 	case DefinitionsSent:
 		switch(event)
 		{
-		case SetMediaSent:
+		case SetClientReady:
 			m_state = Active;
 			break;
 
@@ -488,7 +494,8 @@ void RemoteClient::notifyEvent(ClientStateEvent event)
 
 		/* Init GotInit2 SetDefinitionsSent */
 		default:
-			assert("Invalid client state transition!" == 0);
+			myerror << "DefinitionsSent: Invalid client state transition! " << event;
+			throw ClientStateError(myerror.str());
 		}
 		break;
 
@@ -505,7 +512,8 @@ void RemoteClient::notifyEvent(ClientStateEvent event)
 
 		/* Init GotInit2 SetDefinitionsSent SetMediaSent SetDenied */
 		default:
-			assert("Invalid client state transition!" == 0);
+			myerror << "Active: Invalid client state transition! " << event;
+			throw ClientStateError(myerror.str());
 			break;
 		}
 		break;
@@ -516,6 +524,11 @@ void RemoteClient::notifyEvent(ClientStateEvent event)
 	}
 }
 
+u32 RemoteClient::uptime()
+{
+	return getTime(PRECISION_SECONDS) - m_connection_time;
+}
+
 ClientInterface::ClientInterface(con::Connection* con)
 :
 	m_con(con),
@@ -749,7 +762,7 @@ void ClientInterface::event(u16 peer_id, ClientStateEvent event)
 		n->second->notifyEvent(event);
 	}
 
-	if ((event == SetMediaSent) || (event == Disconnect) || (event == SetDenied))
+	if ((event == SetClientReady) || (event == Disconnect) || (event == SetDenied))
 	{
 		UpdatePlayerList();
 	}
@@ -763,9 +776,24 @@ u16 ClientInterface::getProtocolVersion(u16 peer_id)
 	std::map<u16, RemoteClient*>::iterator n;
 	n = m_clients.find(peer_id);
 
-	// No client to deliver event
+	// No client to get version
 	if (n == m_clients.end())
 		return 0;
 
 	return n->second->net_proto_version;
 }
+
+void ClientInterface::setClientVersion(u16 peer_id, u8 major, u8 minor, u8 patch, std::string full)
+{
+	JMutexAutoLock conlock(m_clients_mutex);
+
+	// Error check
+	std::map<u16, RemoteClient*>::iterator n;
+	n = m_clients.find(peer_id);
+
+	// No client to set versions
+	if (n == m_clients.end())
+		return;
+
+	n->second->setVersionInfo(major,minor,patch,full);
+}