From d873545ac70331a224967493f9296a854d292dd8 Mon Sep 17 00:00:00 2001 From: Ekdohibs Date: Mon, 30 Jan 2017 07:58:43 +0100 Subject: Fix anticheat resetting client position after the client is teleported Previously, m_move_pool could accomodate the client moving from the new position to the old one, and the server accepted the client to go back to its old position. However, it couldn't then accomodate the client moving from its old to its new position, and therefore would reset position to the old position. Thus, by emptying m_move_pool after a teleport, the server no longer accepts the client to go back to its old position. A drawback is however that a laggy client *will* trigger a few "moved_too_fast" anticheats before being told about its new position. Don't report player cheated if caused by lag. Fixes #5118 --- src/content_sao.cpp | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'src/content_sao.cpp') diff --git a/src/content_sao.cpp b/src/content_sao.cpp index 7a1171eb7..f87977f80 100644 --- a/src/content_sao.cpp +++ b/src/content_sao.cpp @@ -785,6 +785,7 @@ PlayerSAO::PlayerSAO(ServerEnvironment *env_, u16 peer_id_, bool is_singleplayer m_inventory(NULL), m_damage(0), m_last_good_position(0,0,0), + m_time_from_last_teleport(0), m_time_from_last_punch(0), m_nocheat_dig_pos(32767, 32767, 32767), m_nocheat_dig_time(0), @@ -1000,6 +1001,7 @@ void PlayerSAO::step(float dtime, bool send_recommended) // Increment cheat prevention timers m_dig_pool.add(dtime); m_move_pool.add(dtime); + m_time_from_last_teleport += dtime; m_time_from_last_punch += dtime; m_nocheat_dig_time += dtime; @@ -1106,6 +1108,8 @@ void PlayerSAO::setPos(const v3f &pos) setBasePosition(pos); // Movement caused by this command is always valid m_last_good_position = pos; + m_move_pool.empty(); + m_time_from_last_teleport = 0.0; m_env->getGameDef()->SendMovePlayer(m_peer_id); } @@ -1117,6 +1121,8 @@ void PlayerSAO::moveTo(v3f pos, bool continuous) setBasePosition(pos); // Movement caused by this command is always valid m_last_good_position = pos; + m_move_pool.empty(); + m_time_from_last_teleport = 0.0; m_env->getGameDef()->SendMovePlayer(m_peer_id); } @@ -1405,11 +1411,16 @@ bool PlayerSAO::checkMovementCheat() if (m_move_pool.grab(required_time)) { m_last_good_position = m_base_position; } else { - actionstream << "Player " << m_player->getName() - << " moved too fast; resetting position" - << std::endl; + const float LAG_POOL_MIN = 5.0; + float lag_pool_max = m_env->getMaxLagEstimate() * 2.0; + lag_pool_max = MYMAX(lag_pool_max, LAG_POOL_MIN); + if (m_time_from_last_teleport > lag_pool_max) { + actionstream << "Player " << m_player->getName() + << " moved too fast; resetting position" + << std::endl; + cheated = true; + } setBasePosition(m_last_good_position); - cheated = true; } return cheated; } -- cgit v1.2.3