r5sdk/r5dev/game/server/player.cpp
Kawe Mazidjatari 42e02b4569 UserCmd: limit command backlog to prevent exploitation
Implement UserCmd command backlog limiting (the new convar 'sv_maxUserCmdProcessTicks' dictates how many ticks can be processed per second). Defaulted to 10, which is (default tick interval (0.05) * default cvar val (10) = 0.5ms window), which is equal to the default of cvar 'sv_maxunlag'.

Before this patch, you could stuff several seconds worth of usercmd's in one second and achieve speed hacking.
2024-06-01 11:29:29 +02:00

316 lines
11 KiB
C++

//======== Copyright (c) Valve Corporation, All rights reserved. ============//
//
// Purpose:
//
//===========================================================================//
#include "core/stdafx.h"
#include "common/protocol.h"
#include "game/shared/shareddefs.h"
#include "game/shared/usercmd.h"
#include "game/server/movehelper_server.h"
#include "gameinterface.h"
#include "player.h"
#include "engine/server/server.h"
// NOTE[ AMOS ]: default tick interval (0.05) * default cvar value (10) = total time buffer of 0.5, which is the default of cvar 'sv_maxunlag'.
static ConVar sv_maxUserCmdProcessTicks("sv_maxUserCmdProcessTicks", "10", FCVAR_NONE, "Maximum number of client-issued UserCmd ticks that can be replayed in packet loss conditions, 0 to allow no restrictions.");
//------------------------------------------------------------------------------
// Purpose: executes a null command for this player
//------------------------------------------------------------------------------
void CPlayer::RunNullCommand(void)
{
CUserCmd cmd;
float flOldFrameTime = (*g_pGlobals)->m_flFrameTime;
float flOldCurTime = (*g_pGlobals)->m_flCurTime;
cmd.frametime = flOldFrameTime;
cmd.command_time = flOldCurTime;
pl.fixangle = FIXANGLE_NONE;
EyeAngles(&cmd.viewangles);
SetTimeBase((*g_pGlobals)->m_flCurTime);
MoveHelperServer()->SetHost(this);
PlayerRunCommand(&cmd, MoveHelperServer());
SetLastUserCommand(&cmd);
(*g_pGlobals)->m_flFrameTime = flOldFrameTime;
(*g_pGlobals)->m_flCurTime = flOldCurTime;
MoveHelperServer()->SetHost(NULL);
}
//------------------------------------------------------------------------------
// Purpose: gets the eye angles of this player
// Input : *pAngles -
// Output : QAngle*
//------------------------------------------------------------------------------
QAngle* CPlayer::EyeAngles(QAngle* pAngles)
{
return CPlayer__EyeAngles(this, pAngles);
}
//------------------------------------------------------------------------------
// Purpose: sets the time base for this player
// Input : flTimeBase -
//------------------------------------------------------------------------------
inline void CPlayer::SetTimeBase(float flTimeBase)
{
float flTime = float(TIME_TO_TICKS(flTimeBase));
if (flTime < 0.0f)
flTime = 0.0f;
SetLastUCmdSimulationRemainderTime(flTime);
float flSimulationTime = flTimeBase - m_lastUCmdSimulationRemainderTime * TICK_INTERVAL;
if (flSimulationTime >= 0.0f)
{
flTime = flSimulationTime;
}
SetTotalExtraClientCmdTimeAttempted(flTime);
}
//------------------------------------------------------------------------------
// Purpose: sets the last user cmd simulation remainder time
// Input : flRemainderTime -
//------------------------------------------------------------------------------
void CPlayer::SetLastUCmdSimulationRemainderTime(float flRemainderTime)
{
if (m_lastUCmdSimulationRemainderTime != flRemainderTime)
{
edict_t nEdict = NetworkProp()->GetEdict();
if (nEdict != FL_EDICT_INVALID)
{
_InterlockedOr16((SHORT*)(*g_pGlobals)->m_pEdicts + nEdict + 32, 0x200u);
}
m_lastUCmdSimulationRemainderTime = flRemainderTime;
}
}
//------------------------------------------------------------------------------
// Purpose: sets the total extra client cmd time attempted
// Input : flAttemptedTime -
//------------------------------------------------------------------------------
void CPlayer::SetTotalExtraClientCmdTimeAttempted(float flAttemptedTime)
{
if (m_totalExtraClientCmdTimeAttempted != flAttemptedTime)
{
edict_t nEdict = NetworkProp()->GetEdict();
if (nEdict != FL_EDICT_INVALID)
{
_InterlockedOr16((SHORT*)(*g_pGlobals)->m_pEdicts + nEdict + 32, 0x200u);
}
m_totalExtraClientCmdTimeAttempted = flAttemptedTime;
}
}
//------------------------------------------------------------------------------
// Purpose: clamps the unlag amount to sv_unlag + clockdrift
// Input : *cmd -
//------------------------------------------------------------------------------
void CPlayer::ClampUnlag(CUserCmd* cmd)
{
const CClient* client = g_pServer->GetClient(GetEdict() - 1);
const CNetChan* chan = client->GetNetChan();
const float clockDriftMsecs = sv_clockcorrection_msecs->GetFloat() / 1000.0f;
const float maxUnlag = sv_maxunlag->GetFloat();
const float latencyAmount = Clamp(chan->GetLatency(FLOW_OUTGOING), 0.0f, maxUnlag);
const float serverTime = (*g_pGlobals)->m_flCurTime;
// Command issue time from client, note that this value can be altered
// from the client, and therefore be used to exploit lag compensation.
const float commandTime = cmd->command_time;
const float lastCommandTime = m_LastCmd.command_time;
const float commandDelta = fabs(commandTime - serverTime);
bool recomputeUnlag = false;
// Check delta first, otherwise player could set commandTime to a fixed
// time and circumvent the system, as commandTime < lastCommandTime or
// commandTime > localCurTime will always fail.
if (commandDelta > maxUnlag)
{
// Too much to unlag, clamp to max !!!
recomputeUnlag = true;
DevWarning(eDLL_T::SERVER, "%s: commandDelta( %f ) > maxUnlag( %f ) !!!\n",
__FUNCTION__, commandDelta, maxUnlag);
}
else if (commandTime < (lastCommandTime - clockDriftMsecs))
{
// Can never be lower than last !!!
recomputeUnlag = true;
DevWarning(eDLL_T::SERVER, "%s: cmd->command_time( %f ) < (m_LastCmd.command_time( %f ) - clockDriftMsecs( %f )) !!!\n",
__FUNCTION__, commandTime, lastCommandTime, clockDriftMsecs);
}
else if (commandTime > (serverTime + clockDriftMsecs))
{
// Too far in the future, clamp to max !!!
recomputeUnlag = true;
DevWarning(eDLL_T::SERVER, "%s: cmd->command_time( %f ) > (g_pGlobals->m_flCurTime( %f ) + clockDriftMsecs( %f )) !!!\n",
__FUNCTION__, commandTime, serverTime, clockDriftMsecs);
}
if (recomputeUnlag)
{
// Clamp it to server time minus latency. Note that it could still
// be lower than previous, hence the clamp on the recomputation.
float newCommandTime = Clamp(serverTime - latencyAmount, lastCommandTime, serverTime);
cmd->command_time = newCommandTime;
DevWarning(eDLL_T::SERVER, "%s: Clamped cmd->command_time( %f ) to %f !!!\n",
__FUNCTION__, commandTime, newCommandTime);
}
}
//------------------------------------------------------------------------------
// Purpose: processes user cmd's for this player
// Input : *cmds -
// numCmds -
// totalCmds -
// droppedPackets -
// paused -
//------------------------------------------------------------------------------
// TODO: this code is experimental and has reported problems from players with
// high latency, needs to be debugged or a different approach needs to be taken!
// Defaulted to OFF for now
static ConVar sv_unlag_clamp("sv_unlag_clamp", "0", FCVAR_RELEASE, "Clamp the difference between the current time and received command time to sv_maxunlag + sv_clockcorrection_msecs.");
void CPlayer::ProcessUserCmds(CUserCmd* cmds, int numCmds, int totalCmds,
int droppedPackets, bool paused)
{
if (totalCmds <= 0)
return;
CUserCmd* lastCmd = &m_Commands[MAX_QUEUED_COMMANDS_PROCESS];
for (int i = totalCmds - 1; i >= 0; i--)
{
CUserCmd* cmd = &cmds[i];
const int commandNumber = cmd->command_number;
if (commandNumber <= m_latestCommandQueued)
continue;
m_latestCommandQueued = commandNumber;
const int lastCommandNumber = lastCmd->command_number;
if (lastCommandNumber == MAX_QUEUED_COMMANDS_PROCESS)
return;
if (sv_unlag_clamp.GetBool())
ClampUnlag(cmd);
CUserCmd* queuedCmd = &m_Commands[lastCommandNumber];
queuedCmd->Copy(cmd);
if (++lastCmd->command_number > player_userCmdsQueueWarning->GetInt())
{
const float curTime = float(Plat_FloatTime());
if ((curTime - m_lastCommandCountWarnTime) > 0.5f)
m_lastCommandCountWarnTime = curTime;
}
}
lastCmd->tick_count += droppedPackets;
m_bGamePaused = paused;
}
//------------------------------------------------------------------------------
// Purpose: runs user command for this player
// Input : *pUserCmd -
// *pMover -
//------------------------------------------------------------------------------
void CPlayer::PlayerRunCommand(CUserCmd* pUserCmd, IMoveHelper* pMover)
{
CPlayer__PlayerRunCommand(this, pUserCmd, pMover);
}
//------------------------------------------------------------------------------
// Purpose: stores off a user command
// Input : *pUserCmd -
//------------------------------------------------------------------------------
void CPlayer::SetLastUserCommand(CUserCmd* pUserCmd)
{
m_LastCmd.Copy(pUserCmd);
}
//------------------------------------------------------------------------------
// Purpose: run physics simulation for player
// Input : *player (this) -
// numPerIteration -
// adjustTimeBase -
//------------------------------------------------------------------------------
bool Player_PhysicsSimulate(CPlayer* player, int numPerIteration, bool adjustTimeBase)
{
CClientExtended* const cle = g_pServer->GetClientExtended(player->GetEdict() - 1);
const int numUserCmdProcessTicksMax = sv_maxUserCmdProcessTicks.GetInt();
if (numUserCmdProcessTicksMax && (*g_pGlobals)->m_nGameMode != GameMode_t::SP_MODE) // don't apply this filter in SP games
cle->InitializeMovementTimeForUserCmdProcessing(numUserCmdProcessTicksMax, TICK_INTERVAL);
else // Otherwise we don't care to track time
cle->SetRemainingMovementTimeForUserCmdProcessing(FLT_MAX);
return CPlayer__PhysicsSimulate(player, numPerIteration, adjustTimeBase);
}
/*
=====================
CC_CreateFakePlayer_f
Creates a fake player
on the server
=====================
*/
static void CC_CreateFakePlayer_f(const CCommand& args)
{
if (!g_pServer->IsActive())
return;
if (args.ArgC() < 3)
{
Msg(eDLL_T::SERVER, "usage 'sv_addbot': name(string) teamid(int)\n");
return;
}
const int numPlayers = g_pServer->GetNumClients();
// Already at max, don't create.
if (numPlayers >= g_ServerGlobalVariables->m_nMaxClients)
return;
const char* playerName = args.Arg(1);
int teamNum = atoi(args.Arg(2));
const int maxTeams = int(g_pServer->GetMaxTeams()) + 1;
// Clamp team count, going above the limit will
// cause a crash. Going below 0 means that the
// engine will assign the bot to the last team.
if (teamNum > maxTeams)
teamNum = maxTeams;
g_pEngineServer->LockNetworkStringTables(true);
const edict_t nHandle = g_pEngineServer->CreateFakeClient(playerName, teamNum);
g_pServerGameClients->ClientFullyConnect(nHandle, false);
g_pEngineServer->LockNetworkStringTables(false);
}
static ConCommand sv_addbot("sv_addbot", CC_CreateFakePlayer_f, "Creates a bot on the server", FCVAR_RELEASE);
void VPlayer::Detour(const bool bAttach) const
{
DetourSetup(&CPlayer__PhysicsSimulate, &Player_PhysicsSimulate, bAttach);
}