fix some ep3 command leaks

ReceiveCommands.cc

@@ -1596,11 +1596,17 @@ void process_create_game_dc_gc(shared_ptr<ServerState> s, shared_ptr<Client> c,
   check_size(size, sizeof(Cmd));
   const auto* cmd = reinterpret_cast<const Cmd*>(data);
 
+  // only allow EC from Ep3 clients
+  bool client_is_ep3 = c->flags & ClientFlag::Episode3Games;
+  if ((command == 0xEC) && !client_is_ep3) {
+    return;
+  }
+
   uint8_t episode = cmd->episode;
   if (c->version == GameVersion::DC) {
     episode = 1;
   }
-  if (c->flags & ClientFlag::Episode3Games) {
+  if (client_is_ep3) {
     episode = 0xFF;
   }
 

ReceiveSubcommands.cc

@@ -58,6 +58,12 @@ void forward_subcommand(shared_ptr<Lobby> l, shared_ptr<Client> c,
     uint8_t command, uint8_t flag, const PSOSubcommand* p,
     size_t count) {
 
+  // if the command is an Ep3-only command, make sure an Ep3 client sent it
+  bool command_is_ep3 = (command & 0xF0) == 0xC0;
+  if (command_is_ep3 && !(c->flags & ClientFlag::Episode3Games)) {
+    return;
+  }
+
   if (command_is_private(command)) {
     if (flag >= l->max_clients) {
       return;
@@ -66,11 +72,25 @@ void forward_subcommand(shared_ptr<Lobby> l, shared_ptr<Client> c,
     if (!target) {
       return;
     }
+    if (command_is_ep3 && !(target->flags & ClientFlag::Episode3Games)) {
+      return;
+    }
     send_command(target, command, flag, p, count * 4);
+
+  } else {
+    if (command_is_ep3) {
+      for (auto& target : l->clients) {
+        if (!target || (target == c) || !(target->flags & ClientFlag::Episode3Games)) {
+          continue;
+        }
+        send_command(target, command, flag, p, count * 4);
+      }
+
     } else {
       send_command_excluding_client(l, c, command, flag, p, count * 4);
     }
   }
+}