Do not evaluate timers if the server is shutting down

This should fix issues with segfaults when the server is being
terminated that sometimes occur because things like NPC path traversal
keep running while the process is executing the signal handler.

README.md

@@ -25,6 +25,8 @@ OpenFusion is a reverse-engineered server for FusionFall. It primarily targets v
 4. To create an account, simply enter the details you wish to use at the login screen then click Log In. Do *not* click register, as this will just lead to a blank screen.
 5. Make a new character, and enjoy the game! Your progress will be saved automatically, and you can resume playing by entering the login details you used in step 4.
 
+Instructions for getting the client to run on Linux through Wine can be found [here](https://github.com/OpenFusionProject/OpenFusion/wiki/Running-the-game-client-on-Linux).
+
 ### Hosting a server
 
 1. Grab `OpenFusionServer-1.4-original.zip` or `OpenFusionServer-1.4-academy.zip` from [here](https://github.com/OpenFusionProject/OpenFusion/releases/tag/1.4).
@@ -35,7 +37,7 @@ OpenFusion is a reverse-engineered server for FusionFall. It primarily targets v
     3. Lastly Game Version - select `beta-20100104` if you downloaded the original zip, or `beta-20111013` if you downloaded the academy zip.
 5. Once you've added the server to the list, connect to it and log in. If you're having trouble with this, refer to steps 4 and 5 from the previous section.
 
-If you want, [compiled binaries (artifacts) for each functional commit can be found here.](http://cdn.dexlabs.systems/of-builds/)
+If you want to run the latest development builds of the server, [compiled binaries (artifacts) for each functional commit can be found here.](http://cdn.dexlabs.systems/of-builds/)
 
 For a more detailed overview of the game's architecture and how to configure it, read the following sections.
 

src/Combat.cpp

@@ -56,14 +56,10 @@ static std::pair<int,int> getDamage(int attackPower, int defensePower, bool shou
     return ret;
 }
 
-static void pcAttackNpcs(CNSocket *sock, CNPacketData *data) {
-    auto pkt = (sP_CL2FE_REQ_PC_ATTACK_NPCs*)data->buf;
+static bool checkRapidFire(CNSocket *sock, int targetCount) {
     Player *plr = PlayerManager::getPlayer(sock);
-    auto targets = (int32_t*)data->trailers;
-
-    // rapid fire anti-cheat
-    // TODO: move this out of here, when generalizing packet frequency validation
     time_t currTime = getTime();
+
     if (currTime - plr->lastShot < plr->fireRate * 80)
         plr->suspicionRating += plr->fireRate * 100 + plr->lastShot - currTime; // gain suspicion for rapid firing
     else if (currTime - plr->lastShot < plr->fireRate * 180 && plr->suspicionRating > 0)
@@ -71,15 +67,28 @@ static void pcAttackNpcs(CNSocket *sock, CNPacketData *data) {
 
     plr->lastShot = currTime;
 
-    if (pkt->iNPCCnt > 3) // 3+ targets should never be possible
+    // 3+ targets should never be possible
+    if (targetCount > 3)
         plr->suspicionRating += 10000;
 
-    if (plr->suspicionRating > 10000) { // kill the socket when the player is too suspicious
+    // kill the socket when the player is too suspicious
+    if (plr->suspicionRating > 10000) {
         sock->kill();
         CNShardServer::_killConnection(sock);
-        return;
+        return true;
     }
-        
+
+    return false;
+}
+
+static void pcAttackNpcs(CNSocket *sock, CNPacketData *data) {
+    auto pkt = (sP_CL2FE_REQ_PC_ATTACK_NPCs*)data->buf;
+    Player *plr = PlayerManager::getPlayer(sock);
+    auto targets = (int32_t*)data->trailers;
+
+    // kick the player if firing too rapidly
+    if (settings::ANTICHEAT && checkRapidFire(sock, pkt->iNPCCnt))
+        return;
 
     /*
      * IMPORTANT: This validates memory safety in addition to preventing

src/servers/CNShardServer.cpp

@@ -115,6 +115,10 @@ void CNShardServer::kill() {
 void CNShardServer::onStep() {
     time_t currTime = getTime();
 
+    // do not evaluate timers if the server is shutting down
+    if (!active)
+        return;
+
     for (TimerEvent& event : Timers) {
         if (event.scheduledEvent == 0) {
             // event hasn't been queued yet, go ahead and do that

src/settings.cpp

@@ -20,6 +20,7 @@ bool settings::LOCALHOSTWORKAROUND = true;
 time_t settings::TIMEOUT = 60000;
 int settings::VIEWDISTANCE = 25600;
 bool settings::SIMULATEMOBS = true;
+bool settings::ANTICHEAT = true;
 
 // default spawn point
 #ifndef ACADEMY
@@ -108,6 +109,7 @@ void settings::init() {
     ACCLEVEL = reader.GetInteger("shard", "accountlevel", ACCLEVEL);
     EVENTMODE = reader.GetInteger("shard", "eventmode", EVENTMODE);
     DISABLEFIRSTUSEFLAG = reader.GetBoolean("shard", "disablefirstuseflag", DISABLEFIRSTUSEFLAG);
+    ANTICHEAT = reader.GetBoolean("shard", "anticheat", ANTICHEAT);
     MONITORENABLED = reader.GetBoolean("monitor", "enabled", MONITORENABLED);
     MONITORPORT = reader.GetInteger("monitor", "port", MONITORPORT);
     MONITORINTERVAL = reader.GetInteger("monitor", "interval", MONITORINTERVAL);

src/settings.hpp

@@ -10,6 +10,7 @@ namespace settings {
     extern int SHARDPORT;
     extern std::string SHARDSERVERIP;
     extern bool LOCALHOSTWORKAROUND;
+    extern bool ANTICHEAT;
     extern time_t TIMEOUT;
     extern int VIEWDISTANCE;
     extern bool SIMULATEMOBS;

tdata

@@ -1 +1 @@
-Subproject commit 8230fb8649d6da8de71e918c24efbb55d1c08a88
+Subproject commit cc65dbb402b5baa2b604ed66132edd88cc82a52a