restrict /e4mc stop and touchup mixin

src/main/java/vg/skye/e4mc_minecraft/mixins/ServerNetworkIoMixin.java

@@ -11,6 +11,7 @@ import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.ModifyArg;
 import org.spongepowered.asm.mixin.injection.Redirect;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 import vg.skye.e4mc_minecraft.E4mcClient;
@@ -45,9 +46,9 @@ public abstract class ServerNetworkIoMixin {
 		}
 	}
 
-	@Redirect(method = "bind", at = @At(value = "INVOKE", target = "Lio/netty/bootstrap/ServerBootstrap;channel(Ljava/lang/Class;)Lio/netty/bootstrap/AbstractBootstrap;", remap = false))
-	private AbstractBootstrap<ServerBootstrap, ServerChannel> redirectChannel(ServerBootstrap instance, Class<? extends ServerSocketChannel> aClass) {
-		return initializingE4mc.get() ? instance.channel(LocalServerChannel.class) : instance.channel(aClass);
+	@ModifyArg(method = "bind", at = @At(value = "INVOKE", target = "Lio/netty/bootstrap/ServerBootstrap;channel(Ljava/lang/Class;)Lio/netty/bootstrap/AbstractBootstrap;", remap = false))
+	private Class<? extends ServerChannel> redirectChannel(Class<? extends ServerChannel> aClass) {
+		return initializingE4mc.get() ? LocalServerChannel.class : aClass;
 	}
 
 	@Redirect(method = "bind", at = @At(value = "INVOKE", target = "Lio/netty/bootstrap/ServerBootstrap;localAddress(Ljava/net/InetAddress;I)Lio/netty/bootstrap/AbstractBootstrap;", remap = false))

src/main/kotlin/vg/skye/e4mc_minecraft/E4mcClient.kt

@@ -49,6 +49,13 @@ object E4mcClient : ModInitializer {
             dispatcher.register(literal("e4mc")
                 .then(
                     literal("stop")
+                        .requires { src ->
+                            if (src.server.isDedicated) {
+                                src.hasPermissionLevel(4)
+                            } else {
+                                src.server.isHost((src.player ?: return@requires false).gameProfile)
+                            }
+                        }
                         .executes { context ->
                             if (HANDLER != null) {
                                 HANDLER!!.close()