nic_router: reset uplink IP on link state change

repos/os/src/server/nic_router/domain.cc

@@ -53,6 +53,9 @@ Domain_base::Domain_base(Xml_node const node)
 
 void Domain::ip_config(Ipv4_config const &new_ip_config)
 {
+	if (!_ip_config_dynamic) {
+		throw Ip_config_static(); }
+
 	/* discard old IP config if any */
 	if (ip_config().valid) {
 
@@ -86,6 +89,10 @@ void Domain::ip_config(Ipv4_config const &new_ip_config)
 				interface.attach_to_remote_ip_config();
 			});
 		});
+	} else {
+		_interfaces.for_each([&] (Interface &interface) {
+			interface.attach_to_domain_finish();
+		});
 	}
 }
 
@@ -93,7 +100,8 @@ void Domain::ip_config(Ipv4_config const &new_ip_config)
 void Domain::discard_ip_config()
 {
 	/* install invalid IP config */
-	ip_config(Ipv4_address(), Ipv4_address(), Ipv4_address(), Ipv4_address());
+	Ipv4_config const new_ip_config;
+	ip_config(new_ip_config);
 }
 
 

repos/os/src/server/nic_router/domain.h

@@ -129,8 +129,9 @@ class Net::Domain : public Domain_base,
 
 	public:
 
-		struct Invalid     : Genode::Exception { };
-		struct No_next_hop : Genode::Exception { };
+		struct Invalid          : Genode::Exception { };
+		struct Ip_config_static : Genode::Exception { };
+		struct No_next_hop      : Genode::Exception { };
 
 		Domain(Configuration          &config,
 		       Genode::Xml_node const  node,

repos/os/src/server/nic_router/interface.cc

@@ -256,11 +256,11 @@ void Interface::_detach_from_domain_raw()
 void Interface::_attach_to_domain(Domain_name const &domain_name)
 {
 	_attach_to_domain_raw(domain_name);
-	_attach_to_domain_finish();
+	attach_to_domain_finish();
 }
 
 
-void Interface::_attach_to_domain_finish()
+void Interface::attach_to_domain_finish()
 {
 	/* if domain has yet no IP config, participate in requesting one */
 	Domain &domain = _domain();
@@ -1631,7 +1631,7 @@ void Interface::handle_config_3()
 	catch (Pointer<Update_domain>::Invalid) {
 
 		/* if the interface moved to another domain, finish the operation */
-		try { _attach_to_domain_finish(); }
+		try { attach_to_domain_finish(); }
 		catch (Pointer<Domain>::Invalid) { }
 	}
 }

repos/os/src/server/nic_router/interface.h

@@ -271,8 +271,6 @@ class Net::Interface : private Interface_list::Element
 
 		void _attach_to_domain_raw(Domain_name const &domain_name);
 
-		void _attach_to_domain_finish();
-
 		void _apply_foreign_arp();
 
 		void _send_icmp_dst_unreachable(Ipv4_address_prefix const &local_intf,
@@ -382,6 +380,8 @@ class Net::Interface : private Interface_list::Element
 
 		void init();
 
+		void attach_to_domain_finish();
+
 
 		/***************
 		 ** Accessors **

repos/os/src/server/nic_router/uplink.cc

@@ -34,10 +34,19 @@ Net::Uplink::Uplink(Env                 &env,
 	Nic::Connection(env, this, BUF_SIZE, BUF_SIZE, label.string()),
 	Net::Interface(env.ep(), timer, mac_address(), alloc, Mac_address(),
 	               config, interfaces, _intf_policy),
-	_label(label)
+	_label(label),
+	_link_state_handler(env.ep(), *this, &Uplink::_handle_link_state)
 {
 	rx_channel()->sigh_ready_to_ack(_sink_ack);
 	rx_channel()->sigh_packet_avail(_sink_submit);
 	tx_channel()->sigh_ack_avail(_source_ack);
 	tx_channel()->sigh_ready_to_submit(_source_submit);
+	Nic::Connection::link_state_sigh(_link_state_handler);
+}
+
+
+void Net::Uplink::_handle_link_state()
+{
+	try { domain().discard_ip_config(); }
+	catch (Domain::Ip_config_static) { }
 }

repos/os/src/server/nic_router/uplink.h

@@ -62,10 +62,13 @@ class Net::Uplink : public Uplink_base,
 			BUF_SIZE = Nic::Session::QUEUE_SIZE * PKT_SIZE,
 		};
 
-		Genode::Session_label const &_label;
+		Genode::Session_label    const &_label;
+		Genode::Signal_handler<Uplink>  _link_state_handler;
 
 		Ipv4_address_prefix _read_interface();
 
+		void _handle_link_state();
+
 
 		/********************
 		 ** Net::Interface **