Core/Movement: Improve client control logic (#26348)

16 files changed, 502 insertions, 227 deletions

diff --git a/src/server/game/AI/CreatureAISelector.cpp b/src/server/game/AI/CreatureAISelector.cpp
index 06738fdc8ea..be45c7d5420 100644
--- a/src/server/game/AI/CreatureAISelector.cpp
+++ b/src/server/game/AI/CreatureAISelector.cpp
@@ -103,7 +103,7 @@ namespace FactorySelector
     {
         MovementGeneratorType type = unit->GetDefaultMovementType();
         if (Creature* creature = unit->ToCreature())
-            if (!creature->GetPlayerMovingMe())
+            if (!creature->GetCharmerOrSelfPlayer())
                 type = creature->GetDefaultMovementType();
 
         MovementGeneratorCreator const* mv_factory = sMovementGeneratorRegistry->GetRegistryItem(type);
diff --git a/src/server/game/Entities/Creature/Creature.cpp b/src/server/game/Entities/Creature/Creature.cpp
index d318a941784..4da1b249b64 100644
--- a/src/server/game/Entities/Creature/Creature.cpp
+++ b/src/server/game/Entities/Creature/Creature.cpp
@@ -2652,7 +2652,7 @@ void Creature::InitializeMovementFlags()
 void Creature::UpdateMovementFlags()
 {
     // Do not update movement flags if creature is controlled by a player (charm/vehicle)
-    if (m_playerMovingMe)
+    if (IsMovedByClient())
         return;
 
     // Creatures with CREATURE_FLAG_EXTRA_NO_MOVE_FLAGS_UPDATE should control MovementFlags in your own scripts
diff --git a/src/server/game/Entities/Player/Player.cpp b/src/server/game/Entities/Player/Player.cpp
index 21410f84f12..bbf68c2a1f9 100644
--- a/src/server/game/Entities/Player/Player.cpp
+++ b/src/server/game/Entities/Player/Player.cpp
@@ -41,6 +41,7 @@
 #include "DatabaseEnv.h"
 #include "DisableMgr.h"
 #include "Formulas.h"
+#include "GameClient.h"
 #include "GameEventMgr.h"
 #include "GameObjectAI.h"
 #include "GameTime.h"
@@ -307,9 +308,6 @@ Player::Player(WorldSession* session): Unit(true)
     m_resetTalentsTime = 0;
     m_itemUpdateQueueBlocked = false;
 
-    for (uint8 i = 0; i < MAX_MOVE_TYPE; ++i)
-        m_forced_speed_changes[i] = 0;
-
     /////////////////// Instance System /////////////////////
 
     m_HomebindTimer = 0;
@@ -354,8 +352,6 @@ Player::Player(WorldSession* session): Unit(true)
     // Player summoning
     m_summon_expire = 0;
 
-    m_unitMovedByMe = this;
-    m_playerMovingMe = this;
     m_seer = this;
 
     m_homebindMapId = 0;
@@ -1351,7 +1347,6 @@ void Player::Update(uint32 p_time)
     //because we don't want player's ghost teleported from graveyard
     if (IsHasDelayedTeleport() && IsAlive())
         TeleportTo(m_teleport_dest, m_teleport_options);
-
 }
 
 void Player::setDeathState(DeathState s)
@@ -22352,7 +22347,7 @@ bool Player::IsNeverVisible() const
 bool Player::CanAlwaysSee(WorldObject const* obj) const
 {
     // Always can see self
-    if (GetUnitBeingMoved() == obj)
+    if (GetCharmedOrSelf() == obj)
         return true;
 
     if (ObjectGuid guid = GetGuidValue(PLAYER_FARSIGHT))
@@ -22727,7 +22722,7 @@ void Player::SendInitialPacketsBeforeAddToMap()
     /// SMSG_RESYNC_RUNES
     ResyncRunes();
 
-    SetMovedUnit(this);
+    GetSession()->GetGameClient()->AddAllowedMover(this);
 }
 
 void Player::SendInitialPacketsAfterAddToMap()
@@ -24045,7 +24040,7 @@ void Player::SetClientControl(Unit* target, bool allowMove)
             SetViewpoint(target, true);
     }
 
-    SetMovedUnit(target);
+    GetGameClient()->SetMovedUnit(target, allowMove);
 }
 
 void Player::UpdateZoneDependentAuras(uint32 newZone)
@@ -26969,3 +26964,8 @@ std::string Player::GetDebugInfo() const
     sstr << Unit::GetDebugInfo();
     return sstr.str();
 }
+
+GameClient* Player::GetGameClient() const
+{
+    return GetSession()->GetGameClient();
+}
diff --git a/src/server/game/Entities/Player/Player.h b/src/server/game/Entities/Player/Player.h
index d8ae36a54d2..7a0aef3c5c5 100644
--- a/src/server/game/Entities/Player/Player.h
+++ b/src/server/game/Entities/Player/Player.h
@@ -61,6 +61,7 @@ class Channel;
 class CharacterCreateInfo;
 class Creature;
 class DynamicObject;
+class GameClient;
 class Group;
 class Guild;
 class Item;
@@ -1653,6 +1654,7 @@ class TC_GAME_API Player : public Unit, public GridObject<Player>
         void RemovedInsignia(Player* looterPlr);
 
         WorldSession* GetSession() const { return m_session; }
+        GameClient* GetGameClient() const;
 
         void BuildCreateUpdateBlockForPlayer(UpdateData* data, Player* target) const override;
         void DestroyForPlayer(Player* target, bool onDeath = false) const override;
@@ -2017,8 +2019,6 @@ class TC_GAME_API Player : public Unit, public GridObject<Player>
         template<class T>
         void UpdateVisibilityOf(T* target, UpdateData& data, std::set<Unit*>& visibleNow);
 
-        uint8 m_forced_speed_changes[MAX_MOVE_TYPE];
-
         bool HasAtLoginFlag(AtLoginFlags f) const { return (m_atLoginFlags & f) != 0; }
         void SetAtLoginFlag(AtLoginFlags f) { m_atLoginFlags |= f; }
         void RemoveAtLoginFlag(AtLoginFlags flags, bool persist = false);
diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index 0bb20566b21..888457c7cbc 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -33,6 +33,7 @@
 #include "CreatureAIImpl.h"
 #include "CreatureGroups.h"
 #include "Formulas.h"
+#include "GameClient.h"
 #include "GameObjectAI.h"
 #include "GameTime.h"
 #include "GridNotifiersImpl.h"
@@ -295,7 +296,7 @@ bool DispelableAura::RollDispel() const
 Unit::Unit(bool isWorldObject) :
     WorldObject(isWorldObject), m_lastSanctuaryTime(0), LastCharmerGUID(), movespline(new Movement::MoveSpline()),
     m_ControlledByPlayer(false), m_AutoRepeatFirstCast(false), m_procDeep(0), m_transformSpell(0),
-    m_removedAurasCount(0), m_unitMovedByMe(nullptr), m_playerMovingMe(nullptr), m_charmer(nullptr), m_charmed(nullptr),
+    m_removedAurasCount(0), m_charmer(nullptr), m_charmed(nullptr),
     i_motionMaster(new MotionMaster(this)), m_regenTimer(0), m_vehicle(nullptr), m_vehicleKit(nullptr),
     m_unitTypeMask(UNIT_MASK_NONE), m_Diminishing(), m_combatManager(this), m_threatManager(this),
     m_aiLocked(false), m_comboTarget(nullptr), m_comboPoints(0), m_spellHistory(new SpellHistory(this))
@@ -367,7 +368,11 @@ Unit::Unit(bool isWorldObject) :
     for (uint8 i = 0; i < MAX_MOVE_TYPE; ++i)
         m_speed_rate[i] = 1.0f;
 
+    for (uint8 i = 0; i < MAX_MOVE_TYPE; ++i)
+        m_forced_speed_changes[i] = 0;
+
     m_charmInfo = nullptr;
+    _gameClientMovingMe = nullptr;
 
     // remove aurastates allowing special moves
     for (uint8 i = 0; i < MAX_REACTIVE; ++i)
@@ -417,8 +422,6 @@ Unit::~Unit()
     ASSERT(m_removedAuras.empty());
     ASSERT(m_gameObj.empty());
     ASSERT(m_dynObj.empty());
-    ASSERT(!m_unitMovedByMe || (m_unitMovedByMe == this));
-    ASSERT(!m_playerMovingMe || (m_playerMovingMe == this));
 }
 
 void Unit::Update(uint32 p_time)
@@ -5496,7 +5499,7 @@ Unit* Unit::getAttackerForHelper() const                 // If someone wants to
         return nullptr;
 
     if (Unit* victim = GetVictim())
-        if ((!IsPet() && !GetPlayerMovingMe()) || IsInCombatWith(victim))
+        if ((!IsPet() && !IsCharmerOrSelfPlayer()) || IsInCombatWith(victim))
             return victim;
 
     CombatManager const& mgr = GetCombatManager();
@@ -6270,6 +6273,14 @@ bool Unit::isPossessing() const
         return false;
 }
 
+Unit* Unit::GetCharmerOrSelf() const
+{
+    if (IsCharmed())
+        return GetCharmer();
+    else
+        return const_cast<Unit*>(this);
+}
+
 Unit* Unit::GetNextRandomRaidMemberOrPet(float radius)
 {
     Player* player = nullptr;
@@ -8627,15 +8638,17 @@ void Unit::SetSpeedRate(UnitMoveType mtype, float rate)
     {
         // register forced speed changes for WorldSession::HandleForceSpeedChangeAck
         // and do it only for real sent packets and use run for run/mounted as client expected
-        ++ToPlayer()->m_forced_speed_changes[mtype];
+        ++m_forced_speed_changes[mtype];
 
         if (!IsInCombat())
             if (Pet* pet = ToPlayer()->GetPet())
                 pet->SetSpeedRate(mtype, m_speed_rate[mtype]);
     }
 
-    if (Player* playerMover = Unit::ToPlayer(GetUnitBeingMoved())) // unit controlled by a player.
+    if (IsMovedByClient()) // unit controlled by a player.
     {
+        Player* playerMover = GetGameClientMovingMe()->GetBasePlayer();
+
         // Send notification to self. this packet is only sent to one client (the client of the player concerned by the change).
         WorldPacket self;
         self.Initialize(moveTypeToOpcode[mtype][1], mtype != MOVE_RUN ? 8 + 4 + 4 : 8 + 4 + 1 + 4);
@@ -9933,13 +9946,6 @@ void CharmInfo::SetSpellAutocast(SpellInfo const* spellInfo, bool state)
     }
 }
 
-void Unit::SetMovedUnit(Unit* target)
-{
-    m_unitMovedByMe->m_playerMovingMe = nullptr;
-    m_unitMovedByMe = ASSERT_NOTNULL(target);
-    m_unitMovedByMe->m_playerMovingMe = ASSERT_NOTNULL(ToPlayer());
-}
-
 uint32 createProcHitMask(SpellNonMeleeDamage* damageInfo, SpellMissInfo missCondition)
 {
     uint32 hitMask = PROC_HIT_NONE;
@@ -10446,7 +10452,7 @@ void Unit::SendComboPoints()
         data << uint8(m_comboPoints);
         playerMe->SendDirectMessage(&data);
     }
-    Player* movingMe = GetPlayerMovingMe();
+    Player* movingMe = GetCharmerOrSelfPlayer();
     ObjectGuid ownerGuid = GetCharmerOrOwnerGUID();
     Player* owner = nullptr;
     if (ownerGuid.IsPlayer())
@@ -11435,11 +11441,8 @@ void Unit::SetFeared(bool apply)
     }
 
     // block / allow control to real player in control (eg charmer)
-    if (GetTypeId() == TYPEID_PLAYER)
-    {
-        if (m_playerMovingMe)
-            m_playerMovingMe->SetClientControl(this, !apply);
-    }
+    if (GetCharmerOrSelfPlayer())
+        GetCharmerOrSelfPlayer()->SetClientControl(this, !apply);
 }
 
 void Unit::SetConfused(bool apply)
@@ -11460,11 +11463,8 @@ void Unit::SetConfused(bool apply)
     }
 
     // block / allow control to real player in control (eg charmer)
-    if (GetTypeId() == TYPEID_PLAYER)
-    {
-        if (m_playerMovingMe)
-            m_playerMovingMe->SetClientControl(this, !apply);
-    }
+    if (GetCharmerOrSelfPlayer())
+        GetCharmerOrSelfPlayer()->SetClientControl(this, !apply);
 }
 
 bool Unit::SetCharmedBy(Unit* charmer, CharmType type, AuraApplication const* aurApp)
@@ -12163,18 +12163,7 @@ void Unit::UpdateObjectVisibility(bool forced)
 
 void Unit::KnockbackFrom(float x, float y, float speedXY, float speedZ)
 {
-    Player* player = ToPlayer();
-    if (!player)
-    {
-        if (Unit* charmer = GetCharmer())
-        {
-            player = charmer->ToPlayer();
-            if (player && player->GetUnitBeingMoved() != this)
-                player = nullptr;
-        }
-    }
-
-    if (!player)
+    if (IsMovedByServer())
     {
         GetMotionMaster()->MoveKnockbackFrom(x, y, speedXY, speedZ);
     }
@@ -12190,10 +12179,10 @@ void Unit::KnockbackFrom(float x, float y, float speedXY, float speedZ)
         data << float(speedXY);                                 // Horizontal speed
         data << float(-speedZ);                                 // Z Movement speed (vertical)
 
-        player->SendDirectMessage(&data);
+        GetGameClientMovingMe()->SendDirectMessage(&data);
 
-        if (player->HasAuraType(SPELL_AURA_MOD_INCREASE_MOUNTED_FLIGHT_SPEED) || player->HasAuraType(SPELL_AURA_FLY))
-            player->SetCanFly(true, true);
+        if (HasAuraType(SPELL_AURA_MOD_INCREASE_MOUNTED_FLIGHT_SPEED) || HasAuraType(SPELL_AURA_FLY))
+            SetCanFly(true, true);
     }
 }
 
@@ -12853,9 +12842,9 @@ void Unit::SendTeleportPacket(Position const& pos, bool teleportingTransport /*=
     moveUpdateTeleport << GetPackGUID();
     Unit* broadcastSource = this;
 
-    // should this really be the unit _being_ moved? not the unit doing the moving?
-    if (Player* playerMover = Unit::ToPlayer(GetUnitBeingMoved()))
+    if (IsMovedByClient())
     {
+        Player* playerMover = GetGameClientMovingMe()->GetBasePlayer();
         WorldPacket moveTeleport(MSG_MOVE_TELEPORT_ACK, 41);
         moveTeleport << GetPackGUID();
         moveTeleport << uint32(0);                                     // this value increments every time
diff --git a/src/server/game/Entities/Unit/Unit.h b/src/server/game/Entities/Unit/Unit.h
index a78c049d9f6..87c2e6d1e87 100644
--- a/src/server/game/Entities/Unit/Unit.h
+++ b/src/server/game/Entities/Unit/Unit.h
@@ -71,6 +71,7 @@ class AuraApplication;
 class AuraEffect;
 class Creature;
 class DynamicObject;
+class GameClient;
 class GameObject;
 class Guardian;
 class Item;
@@ -1184,6 +1185,7 @@ class TC_GAME_API Unit : public WorldObject
         void RemoveAllControlled();
 
         bool IsCharmed() const { return !GetCharmerGUID().IsEmpty(); }
+        bool IsCharming() const { return !GetCharmedGUID().IsEmpty(); }
         bool isPossessed() const { return HasUnitState(UNIT_STATE_POSSESSED); }
         bool isPossessedByPlayer() const;
         bool isPossessing() const;
@@ -1193,12 +1195,17 @@ class TC_GAME_API Unit : public WorldObject
         CharmInfo* InitCharmInfo();
         void DeleteCharmInfo();
 
-        // all of these are for DIRECT CLIENT CONTROL only
-        void SetMovedUnit(Unit* target);
-        // returns the unit that this player IS CONTROLLING
-        Unit* GetUnitBeingMoved() const { return m_unitMovedByMe; }
-        // returns the player that this unit is BEING CONTROLLED BY
-        Player* GetPlayerMovingMe() const { return m_playerMovingMe; }
+        // base client control of this unit (possess effects, vehicles and similar). Not affected by temporary CC.
+        bool IsCharmerOrSelfPlayer() const { return GetCharmerOrSelf()->IsPlayer(); }
+        Unit* GetCharmerOrSelf() const;
+        Player* GetCharmerOrSelfPlayer() const { return ToPlayer(GetCharmerOrSelf());}
+        Unit* GetCharmedOrSelf() const { return IsCharming() ? GetCharmed() : const_cast<Unit*>(this); }
+
+        // real time client control status of this unit (possess effects, vehicles and similar). For example, if this unit is a player temporarly under fear, it will return false.
+        bool IsMovedByClient() const { return _gameClientMovingMe != nullptr; }
+        bool IsMovedByServer() const { return !IsMovedByClient(); }
+        GameClient* GetGameClientMovingMe() const { return _gameClientMovingMe; }
+        void SetGameClientMovingMe(GameClient* gameClientMovingMe) { _gameClientMovingMe = gameClientMovingMe; }
 
         SharedVisionList const& GetSharedVisionList() { return m_sharedVision; }
         void AddPlayerToVision(Player* player);
@@ -1673,6 +1680,8 @@ class TC_GAME_API Unit : public WorldObject
         // Movement info
         Movement::MoveSpline * movespline;
 
+        uint8 m_forced_speed_changes[MAX_MOVE_TYPE];
+
         int32 GetHighestExclusiveSameEffectSpellGroupValue(AuraEffect const* aurEff, AuraType auraType, bool checkMiscValue = false, int32 miscValue = 0) const;
         bool IsHighestExclusiveAura(Aura const* aura, bool removeOtherAuraApplications = false);
         bool IsHighestExclusiveAuraEffect(SpellInfo const* spellInfo, AuraType auraType, int32 effectAmount, uint8 auraEffectMask, bool removeOtherAuraApplications = false);
@@ -1751,12 +1760,11 @@ class TC_GAME_API Unit : public WorldObject
 
         float m_speed_rate[MAX_MOVE_TYPE];
 
-        Unit* m_unitMovedByMe;    // only ever set for players, and only for direct client control
-        Player* m_playerMovingMe; // only set for direct client control (possess effects, vehicles and similar)
         Unit* m_charmer; // Unit that is charming ME
         Unit* m_charmed; // Unit that is being charmed BY ME
         CharmInfo* m_charmInfo;
         SharedVisionList m_sharedVision;
+        GameClient* _gameClientMovingMe;
 
         MotionMaster* i_motionMaster;
 
diff --git a/src/server/game/Handlers/MiscHandler.cpp b/src/server/game/Handlers/MiscHandler.cpp
index c9a4a483801..f549f75b49f 100644
--- a/src/server/game/Handlers/MiscHandler.cpp
+++ b/src/server/game/Handlers/MiscHandler.cpp
@@ -854,64 +854,6 @@ void WorldSession::HandleNextCinematicCamera(WorldPackets::Misc::NextCinematicCa
     GetPlayer()->GetCinematicMgr()->BeginCinematic();
 }
 
-void WorldSession::HandleFeatherFallAck(WorldPacket& recvData)
-{
-    TC_LOG_DEBUG("network", "WORLD: CMSG_MOVE_FEATHER_FALL_ACK");
-
-    // no used
-    recvData.rfinish();                       // prevent warnings spam
-}
-
-void WorldSession::HandleMoveUnRootAck(WorldPacket& recvData)
-{
-    // no used
-    recvData.rfinish();                       // prevent warnings spam
-/*
-    uint64 guid;
-    recvData >> guid;
-
-    // now can skip not our packet
-    if (_player->GetGUID() != guid)
-    {
-        recvData.rfinish();                   // prevent warnings spam
-        return;
-    }
-
-    TC_LOG_DEBUG("network", "WORLD: CMSG_FORCE_MOVE_UNROOT_ACK");
-
-    recvData.read_skip<uint32>();                          // unk
-
-    MovementInfo movementInfo;
-    movementInfo.guid = guid;
-    ReadMovementInfo(recvData, &movementInfo);
-    recvData.read_skip<float>();                           // unk2
-*/
-}
-
-void WorldSession::HandleMoveRootAck(WorldPacket& recvData)
-{
-    // no used
-    recvData.rfinish();                       // prevent warnings spam
-/*
-    uint64 guid;
-    recvData >> guid;
-
-    // now can skip not our packet
-    if (_player->GetGUID() != guid)
-    {
-        recvData.rfinish();                   // prevent warnings spam
-        return;
-    }
-
-    TC_LOG_DEBUG("network", "WORLD: CMSG_FORCE_MOVE_ROOT_ACK");
-
-    recvData.read_skip<uint32>();                          // unk
-
-    MovementInfo movementInfo;
-    ReadMovementInfo(recvData, &movementInfo);
-*/
-}
-
 void WorldSession::HandleCompleteMovie(WorldPackets::Misc::CompleteMovie& /*packet*/)
 {
     uint32 movie = _player->GetMovie();
@@ -1327,25 +1269,6 @@ void WorldSession::HandleSetRaidDifficultyOpcode(WorldPacket& recvData)
     }
 }
 
-void WorldSession::HandleMoveSetCanFlyAckOpcode(WorldPacket& recvData)
-{
-    // fly mode on/off
-    TC_LOG_DEBUG("network", "WORLD: CMSG_MOVE_SET_CAN_FLY_ACK");
-
-    ObjectGuid guid;                                            // guid - unused
-    recvData >> guid.ReadAsPacked();
-
-    recvData.read_skip<uint32>();                          // unk
-
-    MovementInfo movementInfo;
-    movementInfo.guid = guid;
-    ReadMovementInfo(recvData, &movementInfo);
-
-    recvData.read_skip<float>();                           // unk2
-
-    _player->GetUnitBeingMoved()->m_movementInfo.flags = movementInfo.GetMovementFlags();
-}
-
 void WorldSession::HandleSetTaxiBenchmarkOpcode(WorldPacket& recvData)
 {
     TC_LOG_DEBUG("network", "WORLD: CMSG_SET_TAXI_BENCHMARK_MODE");
diff --git a/src/server/game/Handlers/MovementHandler.cpp b/src/server/game/Handlers/MovementHandler.cpp
index 7b7ccf8771c..a292db59548 100644
--- a/src/server/game/Handlers/MovementHandler.cpp
+++ b/src/server/game/Handlers/MovementHandler.cpp
@@ -15,23 +15,25 @@
  * with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "Battleground.h"
 #include "Common.h"
-#include "WorldPacket.h"
-#include "WorldSession.h"
-#include "Opcodes.h"
-#include "Log.h"
 #include "Corpse.h"
-#include "Player.h"
+#include "GameTime.h"
+#include "GameClient.h"
+#include "InstanceSaveMgr.h"
+#include "Log.h"
 #include "MapManager.h"
 #include "MotionMaster.h"
 #include "MovementGenerator.h"
 #include "MoveSpline.h"
-#include "Transport.h"
-#include "Battleground.h"
-#include "InstanceSaveMgr.h"
+#include "ObjectAccessor.h"
 #include "ObjectMgr.h"
+#include "Opcodes.h"
+#include "Player.h"
+#include "Transport.h"
 #include "Vehicle.h"
-#include "GameTime.h"
+#include "WorldPacket.h"
+#include "WorldSession.h"
 #include <boost/accumulators/statistics/variance.hpp>
 #include <boost/accumulators/accumulators.hpp>
 #include <boost/accumulators/statistics.hpp>
@@ -212,17 +214,22 @@ void WorldSession::HandleMoveTeleportAck(WorldPacket& recvData)
 
     recvData >> guid.ReadAsPacked();
 
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
+        return;
+    }
+
     uint32 sequenceIndex, time;
     recvData >> sequenceIndex >> time;
 
-    Player* plMover = _player->GetUnitBeingMoved()->ToPlayer();
+    GameClient* client = GetGameClient();
+    Unit* mover = client->GetActivelyMovedUnit();
+    Player* plMover = mover->ToPlayer();
 
     if (!plMover || !plMover->IsBeingTeleportedNear())
         return;
 
-    if (guid != plMover->GetGUID())
-        return;
-
     plMover->SetSemaphoreTeleportNear(false);
 
     uint32 old_zone = plMover->GetZoneId();
@@ -259,10 +266,17 @@ void WorldSession::HandleMovementOpcodes(WorldPacket& recvData)
 {
     uint16 opcode = recvData.GetOpcode();
 
-    Unit* mover = _player->GetUnitBeingMoved();
+    ObjectGuid guid;
+    recvData >> guid.ReadAsPacked();
 
-    ASSERT(mover != nullptr);                      // there must always be a mover
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
+        return;
+    }
 
+    GameClient* client = GetGameClient();
+    Unit* mover = client->GetActivelyMovedUnit();
     Player* plrMover = mover->ToPlayer();
 
     // ignore, waiting processing in WorldSession::HandleMoveWorldportAckOpcode and WorldSession::HandleMoveTeleportAck
@@ -273,9 +287,6 @@ void WorldSession::HandleMovementOpcodes(WorldPacket& recvData)
     }
 
     /* extract packet */
-    ObjectGuid guid;
-
-    recvData >> guid.ReadAsPacked();
 
     MovementInfo movementInfo;
     movementInfo.guid = guid;
@@ -283,10 +294,6 @@ void WorldSession::HandleMovementOpcodes(WorldPacket& recvData)
 
     recvData.rfinish();                         // prevent warnings spam
 
-    // prevent tampered movement data
-    if (guid != mover->GetGUID())
-        return;
-
     if (!movementInfo.pos.IsPositionValid())
     {
         recvData.rfinish();                     // prevent warnings spam
@@ -416,7 +423,7 @@ void WorldSession::HandleMovementOpcodes(WorldPacket& recvData)
 
         if (movementInfo.pos.GetPositionZ() < plrMover->GetMap()->GetMinHeight(movementInfo.pos.GetPositionX(), movementInfo.pos.GetPositionY()))
         {
-            if (!(plrMover->GetBattleground() && plrMover->GetBattleground()->HandlePlayerUnderMap(_player)))
+            if (!(plrMover->GetBattleground() && plrMover->GetBattleground()->HandlePlayerUnderMap(plrMover)))
             {
                 // NOTE: this is actually called many times while falling
                 // even after the player has been teleported away
@@ -448,13 +455,15 @@ void WorldSession::HandleForceSpeedChangeAck(WorldPacket &recvData)
 
     recvData >> guid.ReadAsPacked();
 
-    // now can skip not our packet
-    if (_player->GetGUID() != guid)
+    if (!IsRightUnitBeingMoved(guid))
     {
-        recvData.rfinish();                   // prevent warnings spam
+        recvData.rfinish();                     // prevent warnings spam
         return;
     }
 
+    GameClient* client = GetGameClient();
+    Unit* mover = client->GetActivelyMovedUnit();
+
     // continue parse packet
 
     recvData >> unk1;                                      // counter or moveEvent
@@ -491,25 +500,25 @@ void WorldSession::HandleForceSpeedChangeAck(WorldPacket &recvData)
 
     // skip all forced speed changes except last and unexpected
     // in run/mounted case used one ACK and it must be skipped.m_forced_speed_changes[MOVE_RUN} store both.
-    if (_player->m_forced_speed_changes[force_move_type] > 0)
+    if (mover->m_forced_speed_changes[force_move_type] > 0)
     {
-        --_player->m_forced_speed_changes[force_move_type];
-        if (_player->m_forced_speed_changes[force_move_type] > 0)
+        --mover->m_forced_speed_changes[force_move_type];
+        if (mover->m_forced_speed_changes[force_move_type] > 0)
             return;
     }
 
-    if (!_player->GetTransport() && std::fabs(_player->GetSpeed(move_type) - newspeed) > 0.01f)
+    if (!mover->GetTransport() && std::fabs(mover->GetSpeed(move_type) - newspeed) > 0.01f)
     {
-        if (_player->GetSpeed(move_type) > newspeed)         // must be greater - just correct
+        if (mover->GetSpeed(move_type) > newspeed)         // must be greater - just correct
         {
             TC_LOG_ERROR("network", "%sSpeedChange player %s is NOT correct (must be %f instead %f), force set to correct value",
-                move_type_name[move_type], _player->GetName().c_str(), _player->GetSpeed(move_type), newspeed);
-            _player->SetSpeedRate(move_type, _player->GetSpeedRate(move_type));
+                move_type_name[move_type], _player->GetName().c_str(), mover->GetSpeed(move_type), newspeed);
+            mover->SetSpeedRate(move_type, mover->GetSpeedRate(move_type));
         }
         else                                                // must be lesser - cheating
         {
             TC_LOG_DEBUG("misc", "Player %s from account id %u kicked for incorrect speed (must be %f instead %f)",
-                _player->GetName().c_str(), _player->GetSession()->GetAccountId(), _player->GetSpeed(move_type), newspeed);
+                _player->GetName().c_str(), _player->GetSession()->GetAccountId(), mover->GetSpeed(move_type), newspeed);
             _player->GetSession()->KickPlayer("WorldSession::HandleForceSpeedChangeAck Incorrect speed");
         }
     }
@@ -522,9 +531,21 @@ void WorldSession::HandleSetActiveMoverOpcode(WorldPacket &recvData)
     ObjectGuid guid;
     recvData >> guid;
 
-    if (GetPlayer()->IsInWorld())
-        if (_player->GetUnitBeingMoved()->GetGUID() != guid)
-            TC_LOG_DEBUG("network", "HandleSetActiveMoverOpcode: incorrect mover guid: mover is %s and should be %s" , guid.ToString().c_str(), _player->GetUnitBeingMoved()->GetGUID().ToString().c_str());
+    GameClient* client = GetGameClient();
+
+    // step 1: look at the list of units that this client is allowed to move. check if the client is allowed to even move the
+    // unit that is mentioned in the packet. if not, either silently ignore, log this event or kick the client.
+    if (!client->IsAllowedToMove(guid))
+    {
+        // @todo log or kick or do nothing depending on configuration
+        TC_LOG_DEBUG("entities.unit", "set active mover FAILED for client of player %s. GUID %s.", _player->GetName().c_str(), guid.ToString().c_str());
+        return;
+    }
+
+    // step 2:
+    TC_LOG_DEBUG("entities.unit", "set active mover OK for client of player %s. GUID %s.", _player->GetName().c_str(), guid.ToString().c_str());
+    Unit* newActivelyMovedUnit = ObjectAccessor::GetUnit(*_player, guid);
+    client->SetActivelyMovedUnit(newActivelyMovedUnit);
 }
 
 void WorldSession::HandleMoveNotActiveMover(WorldPacket &recvData)
@@ -533,13 +554,20 @@ void WorldSession::HandleMoveNotActiveMover(WorldPacket &recvData)
 
     ObjectGuid old_mover_guid;
     recvData >> old_mover_guid.ReadAsPacked();
+    recvData.rfinish();                   // prevent warnings spam.
+    // the movement info in this kind of packet is ignored for now. It's unclear if it should be used.
 
-    MovementInfo mi;
-    ReadMovementInfo(recvData, &mi);
+    GameClient* client = GetGameClient();
 
-    mi.guid = old_mover_guid;
+    if (client->GetActivelyMovedUnit() == nullptr || client->GetActivelyMovedUnit()->GetGUID() != old_mover_guid)
+    {
+        // this shouldn't never happen in theory
+        TC_LOG_WARN("entities.unit", "unset active mover FAILED for client of player %s. GUID %s.", _player->GetName().c_str(), old_mover_guid.ToString().c_str());
+        return;
+    }
 
-    _player->m_movementInfo = mi;
+    TC_LOG_DEBUG("entities.unit", "unset active mover OK for client of player %s. GUID %s.", _player->GetName().c_str(), old_mover_guid.ToString().c_str());
+    client->SetActivelyMovedUnit(nullptr);
 }
 
 void WorldSession::HandleMountSpecialAnimOpcode(WorldPacket& /*recvData*/)
@@ -557,19 +585,25 @@ void WorldSession::HandleMoveKnockBackAck(WorldPacket& recvData)
     ObjectGuid guid;
     recvData >> guid.ReadAsPacked();
 
-    if (_player->GetUnitBeingMoved()->GetGUID() != guid)
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
         return;
+    }
 
     recvData.read_skip<uint32>();                          // unk
 
     MovementInfo movementInfo;
     ReadMovementInfo(recvData, &movementInfo);
 
-    _player->m_movementInfo = movementInfo;
+    GameClient* client = GetGameClient();
+    Unit* mover = client->GetActivelyMovedUnit();
+
+    mover->m_movementInfo = movementInfo;
 
     WorldPacket data(MSG_MOVE_KNOCK_BACK, 66);
     data << guid.WriteAsPacked();
-    _player->BuildMovementPacket(&data);
+    mover->BuildMovementPacket(&data);
 
     // knockback specific info
     data << movementInfo.jump.sinAngle;
@@ -577,7 +611,7 @@ void WorldSession::HandleMoveKnockBackAck(WorldPacket& recvData)
     data << movementInfo.jump.xyspeed;
     data << movementInfo.jump.zspeed;
 
-    _player->SendMessageToSet(&data, false);
+    client->GetBasePlayer()->SendMessageToSet(&data, false);
 }
 
 void WorldSession::HandleMoveHoverAck(WorldPacket& recvData)
@@ -587,6 +621,12 @@ void WorldSession::HandleMoveHoverAck(WorldPacket& recvData)
     ObjectGuid guid;                                        // guid - unused
     recvData >> guid.ReadAsPacked();
 
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
+        return;
+    }
+
     recvData.read_skip<uint32>();                           // unk
 
     MovementInfo movementInfo;
@@ -602,6 +642,113 @@ void WorldSession::HandleMoveWaterWalkAck(WorldPacket& recvData)
     ObjectGuid guid;                                        // guid - unused
     recvData >> guid.ReadAsPacked();
 
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
+        return;
+    }
+
+    recvData.read_skip<uint32>();                           // unk
+
+    MovementInfo movementInfo;
+    ReadMovementInfo(recvData, &movementInfo);
+
+    recvData.read_skip<uint32>();                           // unk2
+}
+
+void WorldSession::HandleMoveRootAck(WorldPacket& recvData)
+{
+    TC_LOG_DEBUG("network", "CMSG_FORCE_MOVE_ROOT_ACK");
+
+    ObjectGuid guid;                                        // guid - unused
+    recvData >> guid.ReadAsPacked();
+
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
+        return;
+    }
+
+    recvData.read_skip<uint32>();                           // unk
+
+    MovementInfo movementInfo;
+    ReadMovementInfo(recvData, &movementInfo);
+}
+
+void WorldSession::HandleFeatherFallAck(WorldPacket& recvData)
+{
+    TC_LOG_DEBUG("network", "WORLD: CMSG_MOVE_FEATHER_FALL_ACK");
+
+    ObjectGuid guid;                                        // guid - unused
+    recvData >> guid.ReadAsPacked();
+
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
+        return;
+    }
+
+    recvData.read_skip<uint32>();                           // unk
+
+    MovementInfo movementInfo;
+    ReadMovementInfo(recvData, &movementInfo);
+
+    recvData.read_skip<uint32>();                           // unk2
+}
+
+void WorldSession::HandleMoveUnRootAck(WorldPacket& recvData)
+{
+    TC_LOG_DEBUG("network", "WORLD: CMSG_FORCE_MOVE_UNROOT_ACK");
+
+    ObjectGuid guid;                                        // guid - unused
+    recvData >> guid.ReadAsPacked();
+
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
+        return;
+    }
+
+    recvData.read_skip<uint32>();                           // unk
+
+    MovementInfo movementInfo;
+    ReadMovementInfo(recvData, &movementInfo);
+}
+
+void WorldSession::HandleMoveSetCanFlyAckOpcode(WorldPacket& recvData)
+{
+    TC_LOG_DEBUG("network", "WORLD: CMSG_MOVE_SET_CAN_FLY_ACK");
+
+    ObjectGuid guid;                                        // guid - unused
+    recvData >> guid.ReadAsPacked();
+
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
+        return;
+    }
+
+    recvData.read_skip<uint32>();                           // unk
+
+    MovementInfo movementInfo;
+    ReadMovementInfo(recvData, &movementInfo);
+
+    recvData.read_skip<uint32>();                           // unk2
+}
+
+void WorldSession::HandleMoveSetCanTransitionBetweenSwinAndFlyAck(WorldPacket& recvData)
+{
+    TC_LOG_DEBUG("network", "WORLD: CMSG_MOVE_SET_CAN_TRANSITION_BETWEEN_SWIM_AND_FLY_ACK");
+
+    ObjectGuid guid;
+    recvData >> guid.ReadAsPacked();
+
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
+        return;
+    }
+
     recvData.read_skip<uint32>();                           // unk
 
     MovementInfo movementInfo;
@@ -610,6 +757,65 @@ void WorldSession::HandleMoveWaterWalkAck(WorldPacket& recvData)
     recvData.read_skip<uint32>();                           // unk2
 }
 
+void WorldSession::HandleMoveGravityDisableAck(WorldPacket& recvData)
+{
+    TC_LOG_DEBUG("network", "WORLD: CMSG_MOVE_GRAVITY_DISABLE_ACK");
+
+    ObjectGuid guid;
+    recvData >> guid.ReadAsPacked();
+
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
+        return;
+    }
+
+    recvData.read_skip<uint32>();                           // unk
+
+    MovementInfo movementInfo;
+    ReadMovementInfo(recvData, &movementInfo);
+}
+
+void WorldSession::HandleMoveGravityEnableAck(WorldPacket& recvData)
+{
+    TC_LOG_DEBUG("network", "WORLD: CMSG_MOVE_GRAVITY_ENABLE_ACK");
+
+    ObjectGuid guid;
+    recvData >> guid.ReadAsPacked();
+
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
+        return;
+    }
+
+    recvData.read_skip<uint32>();                           // unk
+
+    MovementInfo movementInfo;
+    ReadMovementInfo(recvData, &movementInfo);
+}
+
+void WorldSession::HandleMoveSetCollisionHgtAck(WorldPacket& recvData)
+{
+    TC_LOG_DEBUG("network", "WORLD: CMSG_MOVE_SET_COLLISION_HGT_ACK");
+
+    ObjectGuid guid;
+    float  newValue;
+    recvData >> guid.ReadAsPacked();
+
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
+        return;
+    }
+
+    recvData.read_skip<uint32>();                           // movement counter
+    recvData >> newValue;
+
+    MovementInfo movementInfo;
+    ReadMovementInfo(recvData, &movementInfo);
+}
+
 void WorldSession::HandleSummonResponseOpcode(WorldPacket& recvData)
 {
     if (!_player->IsAlive() || _player->IsInCombat())
@@ -632,21 +838,14 @@ void WorldSession::HandleMoveTimeSkippedOpcode(WorldPacket& recvData)
     recvData >> guid.ReadAsPacked();
     recvData >> timeSkipped;
 
-    Unit* mover = GetPlayer()->m_unitMovedByMe;
-
-    if (!mover)
-    {
-        TC_LOG_WARN("entities.player", "WorldSession::HandleMoveTimeSkippedOpcode wrong mover state from the unit moved by the player %s", GetPlayer()->GetGUID().ToString().c_str());
-        return;
-    }
-
-    // prevent tampered movement data
-    if (guid != mover->GetGUID())
+    if (!IsRightUnitBeingMoved(guid))
     {
-        TC_LOG_WARN("entities.player", "WorldSession::HandleMoveTimeSkippedOpcode wrong guid from the unit moved by the player %s", GetPlayer()->GetGUID().ToString().c_str());
+        recvData.rfinish();                     // prevent warnings spam
         return;
     }
 
+    GameClient* client = GetGameClient();
+    Unit* mover = client->GetActivelyMovedUnit();
     mover->m_movementInfo.time += timeSkipped;
 
     WorldPacket data(MSG_MOVE_TIME_SKIPPED, recvData.size());
diff --git a/src/server/game/Handlers/SpellHandler.cpp b/src/server/game/Handlers/SpellHandler.cpp
index c3ac4582ad4..775a57c448e 100644
--- a/src/server/game/Handlers/SpellHandler.cpp
+++ b/src/server/game/Handlers/SpellHandler.cpp
@@ -67,7 +67,7 @@ void WorldSession::HandleUseItemOpcode(WorldPacket& recvPacket)
     Player* pUser = _player;
 
     // ignore for remote control state
-    if (pUser->GetUnitBeingMoved() != pUser)
+    if (pUser->IsCharming())
         return;
 
     uint8 bagIndex, slot, castFlags;
@@ -178,7 +178,7 @@ void WorldSession::HandleOpenItemOpcode(WorldPacket& recvPacket)
     Player* player = GetPlayer();
 
     // ignore for remote control state
-    if (player->GetUnitBeingMoved() != player)
+    if (player->IsCharming())
         return;
 
     // additional check, client outputs message on its own
@@ -298,8 +298,8 @@ void WorldSession::HandleGameObjectUseOpcode(WorldPacket& recvData)
     if (GameObject* obj = GetPlayer()->GetGameObjectIfCanInteractWith(guid))
     {
         // ignore for remote control state
-        if (GetPlayer()->GetUnitBeingMoved() != GetPlayer())
-            if (!(GetPlayer()->IsOnVehicle(GetPlayer()->GetUnitBeingMoved()) || GetPlayer()->IsMounted()) && !obj->GetGOInfo()->IsUsableMounted())
+        if (GetPlayer()->IsCharming())
+            if (!(GetPlayer()->IsOnVehicle(GetPlayer()->GetCharmed()) || GetPlayer()->IsMounted()) && !obj->GetGOInfo()->IsUsableMounted())
                 return;
 
         obj->Use(GetPlayer());
@@ -314,7 +314,7 @@ void WorldSession::HandleGameobjectReportUse(WorldPacket& recvPacket)
     TC_LOG_DEBUG("network", "WORLD: Recvd CMSG_GAMEOBJ_REPORT_USE Message [%s]", guid.ToString().c_str());
 
     // ignore for remote control state
-    if (_player->GetUnitBeingMoved() != _player)
+    if (_player->IsCharming())
         return;
 
     if (GameObject* go = GetPlayer()->GetGameObjectIfCanInteractWith(guid))
@@ -336,7 +336,7 @@ void WorldSession::HandleCastSpellOpcode(WorldPacket& recvPacket)
     TC_LOG_DEBUG("network", "WORLD: got cast spell packet, castCount: %u, spellId: %u, castFlags: %u, data length = %u", castCount, spellId, castFlags, (uint32)recvPacket.size());
 
     // ignore for remote control state (for player case)
-    Unit* mover = _player->GetUnitBeingMoved();
+    Unit* mover = _player->GetCharmedOrSelf();
     if (mover != _player && mover->GetTypeId() == TYPEID_PLAYER)
     {
         recvPacket.rfinish(); // prevent spam at ignore packet
@@ -546,9 +546,10 @@ void WorldSession::HandleCancelAutoRepeatSpellOpcode(WorldPackets::Spells::Cance
 
 void WorldSession::HandleCancelChanneling(WorldPackets::Spells::CancelChannelling& cancelChanneling)
 {
+    Unit* mover = _player->GetCharmedOrSelf();
+
     // ignore for remote control state (for player case)
-    Unit* mover = _player->GetUnitBeingMoved();
-    if (mover != _player && mover->GetTypeId() == TYPEID_PLAYER)
+    if (_player->GetCharmed() && _player->GetCharmed()->GetTypeId() == TYPEID_PLAYER)
         return;
 
     SpellInfo const* spellInfo = sSpellMgr->GetSpellInfo(cancelChanneling.ChannelSpell);
@@ -569,7 +570,7 @@ void WorldSession::HandleCancelChanneling(WorldPackets::Spells::CancelChannellin
 void WorldSession::HandleTotemDestroyed(WorldPackets::Totem::TotemDestroyed& totemDestroyed)
 {
     // ignore for remote control state
-    if (_player->GetUnitBeingMoved() != _player)
+    if (_player->IsCharming())
         return;
 
     uint8 slotId = totemDestroyed.Slot;
diff --git a/src/server/game/Handlers/TaxiHandler.cpp b/src/server/game/Handlers/TaxiHandler.cpp
index 2d077ed1527..0b8754dd978 100644
--- a/src/server/game/Handlers/TaxiHandler.cpp
+++ b/src/server/game/Handlers/TaxiHandler.cpp
@@ -202,8 +202,14 @@ void WorldSession::HandleMoveSplineDoneOpcode(WorldPacket& recvData)
 {
     TC_LOG_DEBUG("network", "WORLD: Received CMSG_MOVE_SPLINE_DONE");
 
-    uint64 guid; // used only for proper packet read
-    recvData.readPackGUID(guid);
+    ObjectGuid guid;
+    recvData >> guid.ReadAsPacked();
+
+    if (!IsRightUnitBeingMoved(guid))
+    {
+        recvData.rfinish();                     // prevent warnings spam
+        return;
+    }
 
     MovementInfo movementInfo;                              // used only for proper packet read
     ReadMovementInfo(recvData, &movementInfo);
diff --git a/src/server/game/Server/GameClient.cpp b/src/server/game/Server/GameClient.cpp
new file mode 100644
index 00000000000..f2a662d63dd
--- /dev/null
+++ b/src/server/game/Server/GameClient.cpp
@@ -0,0 +1,63 @@
+/*
+ * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "GameClient.h"
+#include "WorldSession.h"
+#include "Unit.h"
+#include "Player.h"
+
+GameClient::GameClient(WorldSession* sessionToServer)
+{
+    _sessionToServer = sessionToServer;
+    _activelyMovedUnit = nullptr;
+}
+
+void GameClient::AddAllowedMover(Unit* unit)
+{
+    _allowedMovers.insert(unit->GetGUID());
+    unit->SetGameClientMovingMe(this);
+}
+
+void GameClient::RemoveAllowedMover(Unit* unit)
+{
+    _allowedMovers.erase(unit->GetGUID());
+    if (unit->GetGameClientMovingMe() == this)
+        unit->SetGameClientMovingMe(nullptr);
+}
+
+bool GameClient::IsAllowedToMove(Unit* unit) const
+{
+    return _allowedMovers.count(unit->GetGUID());
+}
+
+bool GameClient::IsAllowedToMove(ObjectGuid guid) const
+{
+    return _allowedMovers.count(guid);
+}
+
+void GameClient::SetMovedUnit(Unit* target, bool allowMove)
+{
+    if (allowMove)
+        AddAllowedMover(target);
+    else
+        RemoveAllowedMover(target);
+}
+
+void GameClient::SendDirectMessage(WorldPacket const* data) const
+{
+    GetBasePlayer()->SendDirectMessage(data);
+}
diff --git a/src/server/game/Server/GameClient.h b/src/server/game/Server/GameClient.h
new file mode 100644
index 00000000000..4baf5015ddb
--- /dev/null
+++ b/src/server/game/Server/GameClient.h
@@ -0,0 +1,54 @@
+/*
+ * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GAMECLIENT_H
+#define __GAMECLIENT_H
+
+#include "WorldSession.h"
+
+class Player;
+class Unit;
+
+class TC_GAME_API GameClient
+{
+    public:
+        GameClient(WorldSession* sessionToServer);
+
+        void AddAllowedMover(Unit* unit);
+        void RemoveAllowedMover(Unit* unit);
+        bool IsAllowedToMove(Unit* unit) const;
+        bool IsAllowedToMove(ObjectGuid guid) const;
+        void SetMovedUnit(Unit* target, bool allowMove);
+
+        Unit* GetActivelyMovedUnit() const { return _activelyMovedUnit; }
+        void SetActivelyMovedUnit(Unit* activelyMovedUnit) { _activelyMovedUnit = activelyMovedUnit; }
+
+        Player* GetBasePlayer() const { return _sessionToServer->GetPlayer(); }
+
+        void SendDirectMessage(WorldPacket const* data) const;
+    private:
+        // describe all units that this client has direct control over. Example, a player on a vehicle has client control over himself and the vehicle at the same time.
+        GuidUnorderedSet _allowedMovers;
+
+        // set/unset upon receiving CMSG_SET_ACTIVE_MOVER and CMSG_MOVE_NOT_ACTIVE_MOVER by the client
+        // in other words, this field is set by the client (as long as the change is allowed by the server)
+        Unit* _activelyMovedUnit;
+
+        WorldSession* _sessionToServer;
+};
+
+#endif // __GAMECLIENT_H
diff --git a/src/server/game/Server/Protocol/Opcodes.cpp b/src/server/game/Server/Protocol/Opcodes.cpp
index a8d84a8d0ea..0dff9c1ea93 100644
--- a/src/server/game/Server/Protocol/Opcodes.cpp
+++ b/src/server/game/Server/Protocol/Opcodes.cpp
@@ -960,7 +960,7 @@ void OpcodeTable::Initialize()
     /*0x33D*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_MOTD,                      STATUS_NEVER);
     /*0x33E*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_MOVE_SET_CAN_TRANSITION_BETWEEN_SWIM_AND_FLY, STATUS_NEVER);
     /*0x33F*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_MOVE_UNSET_CAN_TRANSITION_BETWEEN_SWIM_AND_FLY, STATUS_NEVER);
-    /*0x340*/ DEFINE_HANDLER(CMSG_MOVE_SET_CAN_TRANSITION_BETWEEN_SWIM_AND_FLY_ACK, STATUS_NEVER, PROCESS_INPLACE,  &WorldSession::Handle_NULL                     );
+    /*0x340*/ DEFINE_HANDLER(CMSG_MOVE_SET_CAN_TRANSITION_BETWEEN_SWIM_AND_FLY_ACK, STATUS_LOGGEDIN, PROCESS_THREADSAFE, &WorldSession::HandleMoveSetCanTransitionBetweenSwinAndFlyAck);
     /*0x341*/ DEFINE_HANDLER(MSG_MOVE_START_SWIM_CHEAT,                    STATUS_NEVER,    PROCESS_INPLACE,      &WorldSession::Handle_NULL                     );
     /*0x342*/ DEFINE_HANDLER(MSG_MOVE_STOP_SWIM_CHEAT,                     STATUS_NEVER,    PROCESS_INPLACE,      &WorldSession::Handle_NULL                     );
     /*0x343*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_MOVE_SET_CAN_FLY,          STATUS_NEVER);
@@ -1245,7 +1245,7 @@ void OpcodeTable::Initialize()
     /*0x45A*/ DEFINE_HANDLER(MSG_MOVE_SET_PITCH_RATE_CHEAT,                STATUS_NEVER,    PROCESS_INPLACE,      &WorldSession::Handle_NULL                     );
     /*0x45B*/ DEFINE_HANDLER(MSG_MOVE_SET_PITCH_RATE,                      STATUS_NEVER,    PROCESS_INPLACE,      &WorldSession::Handle_NULL                     );
     /*0x45C*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_FORCE_PITCH_RATE_CHANGE,   STATUS_NEVER);
-    /*0x45D*/ DEFINE_HANDLER(CMSG_FORCE_PITCH_RATE_CHANGE_ACK,             STATUS_NEVER,    PROCESS_INPLACE,      &WorldSession::Handle_NULL                     );
+    /*0x45D*/ DEFINE_HANDLER(CMSG_FORCE_PITCH_RATE_CHANGE_ACK,             STATUS_LOGGEDIN, PROCESS_THREADSAFE,   &WorldSession::HandleForceSpeedChangeAck);
     /*0x45E*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_SPLINE_SET_PITCH_RATE,     STATUS_NEVER);
     /*0x45F*/ DEFINE_HANDLER(CMSG_CALENDAR_EVENT_INVITE_NOTES,             STATUS_NEVER,    PROCESS_INPLACE,      &WorldSession::Handle_NULL                     );
     /*0x460*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_CALENDAR_EVENT_INVITE_NOTES, STATUS_NEVER);
@@ -1359,9 +1359,9 @@ void OpcodeTable::Initialize()
     /*0x4CC*/ DEFINE_HANDLER(CMSG_END_BATTLEFIELD_CHEAT,                   STATUS_NEVER,    PROCESS_INPLACE,      &WorldSession::Handle_NULL                     );
     /*0x4CD*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_MULTIPLE_PACKETS,          STATUS_NEVER);
     /*0x4CE*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_MOVE_GRAVITY_DISABLE,      STATUS_NEVER);
-    /*0x4CF*/ DEFINE_HANDLER(CMSG_MOVE_GRAVITY_DISABLE_ACK,                STATUS_NEVER,    PROCESS_INPLACE,      &WorldSession::Handle_NULL                     );
+    /*0x4CF*/ DEFINE_HANDLER(CMSG_MOVE_GRAVITY_DISABLE_ACK,                STATUS_LOGGEDIN, PROCESS_THREADSAFE,   &WorldSession::HandleMoveGravityDisableAck      );
     /*0x4D0*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_MOVE_GRAVITY_ENABLE,       STATUS_NEVER);
-    /*0x4D1*/ DEFINE_HANDLER(CMSG_MOVE_GRAVITY_ENABLE_ACK,                 STATUS_NEVER,    PROCESS_INPLACE,      &WorldSession::Handle_NULL                     );
+    /*0x4D1*/ DEFINE_HANDLER(CMSG_MOVE_GRAVITY_ENABLE_ACK,                 STATUS_LOGGEDIN, PROCESS_THREADSAFE,   &WorldSession::HandleMoveGravityEnableAck);
     /*0x4D2*/ DEFINE_SERVER_OPCODE_HANDLER(MSG_MOVE_GRAVITY_CHNG,          STATUS_NEVER);
     /*0x4D3*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_SPLINE_MOVE_GRAVITY_DISABLE, STATUS_NEVER);
     /*0x4D4*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_SPLINE_MOVE_GRAVITY_ENABLE, STATUS_NEVER);
@@ -1431,7 +1431,7 @@ void OpcodeTable::Initialize()
     /*0x514*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_SEND_ALL_COMBAT_LOG,       STATUS_NEVER);
     /*0x515*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_OPEN_LFG_DUNGEON_FINDER,   STATUS_NEVER);
     /*0x516*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_MOVE_SET_COLLISION_HGT,    STATUS_NEVER);
-    /*0x517*/ DEFINE_HANDLER(CMSG_MOVE_SET_COLLISION_HGT_ACK,              STATUS_UNHANDLED, PROCESS_INPLACE,     &WorldSession::Handle_NULL                     );
+    /*0x517*/ DEFINE_HANDLER(CMSG_MOVE_SET_COLLISION_HGT_ACK,              STATUS_LOGGEDIN, PROCESS_THREADSAFE,   &WorldSession::HandleMoveSetCollisionHgtAck    );
     /*0x518*/ DEFINE_HANDLER(MSG_MOVE_SET_COLLISION_HGT,                   STATUS_NEVER,    PROCESS_INPLACE,      &WorldSession::Handle_NULL                     );
     /*0x519*/ DEFINE_HANDLER(CMSG_CLEAR_RANDOM_BG_WIN_TIME,                STATUS_NEVER,    PROCESS_INPLACE,      &WorldSession::Handle_NULL                     );
     /*0x51A*/ DEFINE_HANDLER(CMSG_CLEAR_HOLIDAY_BG_WIN_TIME,               STATUS_NEVER,    PROCESS_INPLACE,      &WorldSession::Handle_NULL                     );
diff --git a/src/server/game/Server/WorldSession.cpp b/src/server/game/Server/WorldSession.cpp
index 18b46ffd73e..2405631cd75 100644
--- a/src/server/game/Server/WorldSession.cpp
+++ b/src/server/game/Server/WorldSession.cpp
@@ -28,6 +28,7 @@
 #include "Common.h"
 #include "DatabaseEnv.h"
 #include "DBCStructure.h"
+#include "GameClient.h"
 #include "GameTime.h"
 #include "Group.h"
 #include "Guild.h"
@@ -136,7 +137,8 @@ WorldSession::WorldSession(uint32 id, std::string&& name, std::shared_ptr<WorldS
     _pendingTimeSyncRequests(),
     _timeSyncNextCounter(0),
     _timeSyncTimer(0),
-    _calendarEventCreationCooldown(0)
+    _calendarEventCreationCooldown(0),
+    _gameClient(new GameClient(this))
 {
     memset(m_Tutorials, 0, sizeof(m_Tutorials));
 
@@ -165,6 +167,8 @@ WorldSession::~WorldSession()
 
     delete _RBACData;
 
+    delete _gameClient;
+
     ///- empty incoming packet queue
     WorldPacket* packet = nullptr;
     while (_recvQueue.next(packet))
@@ -973,8 +977,8 @@ void WorldSession::ReadMovementInfo(WorldPacket &data, MovementInfo* mi)
     */
 
     REMOVE_VIOLATING_FLAGS(mi->HasMovementFlag(MOVEMENTFLAG_FLYING | MOVEMENTFLAG_CAN_FLY) && GetSecurity() == SEC_PLAYER &&
-        !GetPlayer()->GetUnitBeingMoved()->HasAuraType(SPELL_AURA_FLY) &&
-        !GetPlayer()->GetUnitBeingMoved()->HasAuraType(SPELL_AURA_MOD_INCREASE_MOUNTED_FLIGHT_SPEED),
+        !GetPlayer()->GetCharmedOrSelf()->HasAuraType(SPELL_AURA_FLY) &&
+        !GetPlayer()->GetCharmedOrSelf()->HasAuraType(SPELL_AURA_MOD_INCREASE_MOUNTED_FLIGHT_SPEED),
         MOVEMENTFLAG_FLYING | MOVEMENTFLAG_CAN_FLY);
 
     //! Cannot fly and fall at the same time
@@ -1655,3 +1659,26 @@ void WorldSession::SendTimeSync()
     _timeSyncTimer = _timeSyncNextCounter == 0 ? 5000 : 10000;
     _timeSyncNextCounter++;
 }
+
+bool WorldSession::IsRightUnitBeingMoved(ObjectGuid guid)
+{
+    GameClient* client = GetGameClient();
+
+    // the client is attempting to tamper movement data
+    if (!client->GetActivelyMovedUnit() || client->GetActivelyMovedUnit()->GetGUID() != guid)
+    {
+        TC_LOG_INFO("entities.unit", "Attempt at tampering movement data by Player %s", _player->GetName().c_str());
+        return false;
+    }
+
+    // This can happen if a legitimate client has lost control of a unit but hasn't received SMSG_CONTROL_UPDATE before
+    // sending this packet yet. The server should silently ignore all MOVE messages coming from the client as soon
+    // as control over that unit is revoked (through a 'SMSG_CONTROL_UPDATE allowMove=false' message).
+    if (!client->IsAllowedToMove(guid))
+    {
+        TC_LOG_DEBUG("entities.unit", "Bad or outdated movement data by Player %s", _player->GetName().c_str());
+        return false;
+    }
+
+    return true;
+}
diff --git a/src/server/game/Server/WorldSession.h b/src/server/game/Server/WorldSession.h
index d2d31892004..582b083f2ff 100644
--- a/src/server/game/Server/WorldSession.h
+++ b/src/server/game/Server/WorldSession.h
@@ -37,6 +37,7 @@
 #include <boost/circular_buffer.hpp>
 
 class Creature;
+class GameClient;
 class GameObject;
 class InstanceSave;
 class Item;
@@ -427,6 +428,8 @@ class TC_GAME_API WorldSession
         void InitializeSession();
         void InitializeSessionCallback(CharacterDatabaseQueryHolder const& realmHolder);
 
+        GameClient* GetGameClient() const { return _gameClient; };
+
         rbac::RBACData* GetRBACData();
         bool HasPermission(uint32 permissionId);
         void LoadPermissions();
@@ -622,20 +625,25 @@ class TC_GAME_API WorldSession
         // played time
         void HandlePlayedTime(WorldPackets::Character::PlayedTimeClient& packet);
 
-        // new
-        void HandleMoveUnRootAck(WorldPacket& recvPacket);
-        void HandleMoveRootAck(WorldPacket& recvPacket);
-
         // new inspect
         void HandleInspectOpcode(WorldPacket& recvPacket);
 
         // new party stats
         void HandleInspectHonorStatsOpcode(WorldPacket& recvPacket);
 
+        void HandleForceSpeedChangeAck(WorldPacket& recvData);
+        void HandleMoveKnockBackAck(WorldPacket& recvPacket);
+        void HandleMoveTeleportAck(WorldPacket& recvPacket);
         void HandleMoveWaterWalkAck(WorldPacket& recvPacket);
         void HandleFeatherFallAck(WorldPacket& recvData);
-
         void HandleMoveHoverAck(WorldPacket& recvData);
+        void HandleMoveUnRootAck(WorldPacket& recvPacket);
+        void HandleMoveRootAck(WorldPacket& recvPacket);
+        void HandleMoveSetCanFlyAckOpcode(WorldPacket& recvData);
+        void HandleMoveSetCanTransitionBetweenSwinAndFlyAck(WorldPacket& recvData);
+        void HandleMoveGravityDisableAck(WorldPacket& recvData);
+        void HandleMoveGravityEnableAck(WorldPacket& recvData);
+        void HandleMoveSetCollisionHgtAck(WorldPacket& recvData);
 
         void HandleMountSpecialAnimOpcode(WorldPacket& recvdata);
 
@@ -646,12 +654,6 @@ class TC_GAME_API WorldSession
         // repair
         void HandleRepairItemOpcode(WorldPacket& recvPacket);
 
-        // Knockback
-        void HandleMoveKnockBackAck(WorldPacket& recvPacket);
-
-        void HandleMoveTeleportAck(WorldPacket& recvPacket);
-        void HandleForceSpeedChangeAck(WorldPacket& recvData);
-
         void HandleRepopRequest(WorldPackets::Misc::RepopRequest& packet);
         void HandleAutostoreLootItemOpcode(WorldPacket& recvPacket);
         void HandleLootMoneyOpcode(WorldPacket& recvPacket);
@@ -987,7 +989,6 @@ class TC_GAME_API WorldSession
         void HandleFarSightOpcode(WorldPacket& recvData);
         void HandleSetDungeonDifficultyOpcode(WorldPacket& recvData);
         void HandleSetRaidDifficultyOpcode(WorldPacket& recvData);
-        void HandleMoveSetCanFlyAckOpcode(WorldPacket& recvData);
         void HandleSetTitleOpcode(WorldPacket& recvData);
         void HandleRealmSplitOpcode(WorldPacket& recvData);
         void HandleTimeSyncResponse(WorldPacket& recvData);
@@ -1170,6 +1171,9 @@ class TC_GAME_API WorldSession
             return _legitCharacters.find(lowGUID) != _legitCharacters.end();
         }
 
+        // Movement helpers
+        bool IsRightUnitBeingMoved(ObjectGuid guid);
+
         // this stores the GUIDs of the characters who can login
         // characters who failed on Player::BuildEnumData shouldn't login
         GuidSet _legitCharacters;
@@ -1239,6 +1243,7 @@ class TC_GAME_API WorldSession
 
         // Packets cooldown
         time_t _calendarEventCreationCooldown;
+        GameClient* _gameClient;
 
         WorldSession(WorldSession const& right) = delete;
         WorldSession& operator=(WorldSession const& right) = delete;
diff --git a/src/server/game/Spells/Spell.cpp b/src/server/game/Spells/Spell.cpp
index cd78f49cd84..b95ce469b08 100644
--- a/src/server/game/Spells/Spell.cpp
+++ b/src/server/game/Spells/Spell.cpp
@@ -6186,7 +6186,7 @@ SpellCastResult Spell::CheckCasterAuras(uint32* param1) const
     if (unitCaster->GetCharmerGUID())
     {
         if (Unit* charmer = unitCaster->GetCharmer())
-            if (charmer->GetUnitBeingMoved() != unitCaster && !CheckSpellCancelsCharm(param1))
+            if (charmer->GetCharmed() != unitCaster && !CheckSpellCancelsCharm(param1))
                 result = SPELL_FAILED_CHARMED;
     }
     */