Proper client timeout detection (#19906)

- Properly detect client timeout when logged into a character after a configurable time (default 60s) has passed without the client sending any packets.
- Fixes issues with crashed clients leaving characters in the world for a very long time (default 15 minutes), as well as edge case exploits involving intentionally pausing client execution for some amount of time.

6 files changed, 27 insertions, 10 deletions

diff --git a/src/server/game/Server/WorldSession.cpp b/src/server/game/Server/WorldSession.cpp
index a7a959bd0ea..05f69568507 100644
--- a/src/server/game/Server/WorldSession.cpp
+++ b/src/server/game/Server/WorldSession.cpp
@@ -137,7 +137,7 @@ WorldSession::WorldSession(uint32 id, std::string&& name, std::shared_ptr<WorldS
     if (sock)
     {
         m_Address = sock->GetRemoteIpAddress().to_string();
-        ResetTimeOutTime();
+        ResetTimeOutTime(false);
         LoginDatabase.PExecute("UPDATE account SET online = 1 WHERE id = %u;", GetAccountId());     // One-time query
     }
 
@@ -271,7 +271,8 @@ bool WorldSession::Update(uint32 diff, PacketFilter& updater)
     UpdateTimeOutTime(diff);
 
     ///- Before we process anything:
-    /// If necessary, kick the player from the character select screen
+    /// If necessary, kick the player because the client didn't send anything for too long
+    /// (or they've been idling in character select)
     if (IsConnectionIdle())
         m_Socket->CloseSocket();
 
@@ -633,9 +634,12 @@ char const* WorldSession::GetTrinityString(uint32 entry) const
     return sObjectMgr->GetTrinityString(entry, GetSessionDbLocaleIndex());
 }
 
-void WorldSession::ResetTimeOutTime()
+void WorldSession::ResetTimeOutTime(bool onlyActive)
 {
-    m_timeOutTime = int32(sWorld->getIntConfig(CONFIG_SOCKET_TIMEOUTTIME));
+    if (GetPlayer())
+        m_timeOutTime = int32(sWorld->getIntConfig(CONFIG_SOCKET_TIMEOUTTIME_ACTIVE));
+    else if (!onlyActive)
+        m_timeOutTime = int32(sWorld->getIntConfig(CONFIG_SOCKET_TIMEOUTTIME));
 }
 
 void WorldSession::Handle_NULL(WorldPacket& null)
@@ -1198,7 +1202,7 @@ void WorldSession::InitializeSessionCallback(SQLQueryHolder* realmHolder)
         SendAuthWaitQue(0);
 
     SetInQueue(false);
-    ResetTimeOutTime();
+    ResetTimeOutTime(false);
 
     SendAddonsInfo();
     SendClientCacheVersion(sWorld->getIntConfig(CONFIG_CLIENTCACHE_VERSION));
diff --git a/src/server/game/Server/WorldSession.h b/src/server/game/Server/WorldSession.h
index 9271fb06e06..237fa991456 100644
--- a/src/server/game/Server/WorldSession.h
+++ b/src/server/game/Server/WorldSession.h
@@ -439,7 +439,7 @@ class TC_GAME_API WorldSession
             m_timeOutTime -= int32(diff);
         }
 
-        void ResetTimeOutTime();
+        void ResetTimeOutTime(bool onlyActive);
 
         bool IsConnectionIdle() const
         {
diff --git a/src/server/game/Server/WorldSocket.cpp b/src/server/game/Server/WorldSocket.cpp
index 699c5a38a92..f759e2d27dd 100644
--- a/src/server/game/Server/WorldSocket.cpp
+++ b/src/server/game/Server/WorldSocket.cpp
@@ -357,7 +357,10 @@ WorldSocket::ReadDataHandlerResult WorldSocket::ReadDataHandler()
             return ReadDataHandlerResult::Error;
         }
         case CMSG_KEEP_ALIVE:
+            sessionGuard.lock();
             LogOpcodeText(opcode, sessionGuard);
+            if (_worldSession)
+                _worldSession->ResetTimeOutTime(true);
             break;
         default:
         {
@@ -378,9 +381,8 @@ WorldSocket::ReadDataHandlerResult WorldSocket::ReadDataHandler()
                 break;
             }
 
-            // Our Idle timer will reset on any non PING opcodes.
-            // Catches people idling on the login screen and any lingering ingame connections.
-            _worldSession->ResetTimeOutTime();
+            // Our Idle timer will reset on any non PING opcodes on login screen, allowing us to catch people idling.
+            _worldSession->ResetTimeOutTime(false);
 
             // Copy the packet to the heap before enqueuing
             _worldSession->QueuePacket(new WorldPacket(std::move(packet)));
diff --git a/src/server/game/World/World.cpp b/src/server/game/World/World.cpp
index 6f5f987e9aa..ae5cc87d097 100644
--- a/src/server/game/World/World.cpp
+++ b/src/server/game/World/World.cpp
@@ -353,7 +353,7 @@ bool World::RemoveQueuedPlayer(WorldSession* sess)
         if (*iter == sess)
         {
             sess->SetInQueue(false);
-            sess->ResetTimeOutTime();
+            sess->ResetTimeOutTime(false);
             iter = m_QueuedPlayer.erase(iter);
             found = true;                                   // removing queued session
             break;
@@ -664,6 +664,7 @@ void World::LoadConfigSettings(bool reload)
         m_int_configs[CONFIG_PORT_WORLD] = sConfigMgr->GetIntDefault("WorldServerPort", 8085);
 
     m_int_configs[CONFIG_SOCKET_TIMEOUTTIME] = sConfigMgr->GetIntDefault("SocketTimeOutTime", 900000);
+    m_int_configs[CONFIG_SOCKET_TIMEOUTTIME_ACTIVE] = sConfigMgr->GetIntDefault("SocketTimeOutTimeActive", 60000);
     m_int_configs[CONFIG_SESSION_ADD_DELAY] = sConfigMgr->GetIntDefault("SessionAddDelay", 10000);
 
     m_float_configs[CONFIG_GROUP_XP_DISTANCE] = sConfigMgr->GetFloatDefault("MaxGroupXPDistance", 74.0f);
diff --git a/src/server/game/World/World.h b/src/server/game/World/World.h
index 6b9e21dcf69..5254b32bbdf 100644
--- a/src/server/game/World/World.h
+++ b/src/server/game/World/World.h
@@ -389,6 +389,7 @@ enum WorldIntConfigs
     CONFIG_RESPAWN_DYNAMICMINIMUM_CREATURE,
     CONFIG_RESPAWN_DYNAMICMINIMUM_GAMEOBJECT,
     CONFIG_RESPAWN_GUIDWARNING_FREQUENCY,
+    CONFIG_SOCKET_TIMEOUTTIME_ACTIVE,
     INT_CONFIG_VALUE_COUNT
 };
 
diff --git a/src/server/worldserver/worldserver.conf.dist b/src/server/worldserver/worldserver.conf.dist
index 83dd87a487e..ba8a10c759d 100644
--- a/src/server/worldserver/worldserver.conf.dist
+++ b/src/server/worldserver/worldserver.conf.dist
@@ -305,6 +305,15 @@ InstanceMapLoadAllGrids = 0
 SocketTimeOutTime = 900000
 
 #
+#    SocketTimeOutTimeActive
+#        Description: Time (in milliseconds) after which an idle connection is dropped while
+#                     logged into the world.
+#                     The client sends keepalive packets every 30 seconds. Values <= 30s are not recommended.
+#        Default:     60000 - (1 minute)
+
+SocketTimeOutTimeActive = 60000
+
+#
 #    SessionAddDelay
 #        Description: Time (in microseconds) that a network thread will sleep after authentication
 #                     protocol handling before adding a connection to the world session map.