move l3 device tracking to interface core to enforce proper order of address/route removal on device or interface state changes

7 files changed, 61 insertions, 30 deletions

diff --git a/device.c b/device.c
index 47b5875..0560a70 100644
--- a/device.c
+++ b/device.c
@@ -466,6 +466,9 @@ void device_add_user(struct device_user *dep, struct device *dev)
 	if (dep->dev)
 		device_remove_user(dep);
 
+	if (!dev)
+		return;
+
 	dep->dev = dev;
 	list_add_tail(&dep->list, &dev->users);
 	if (dep->cb && dev->present) {
diff --git a/interface-event.c b/interface-event.c
index 4e0773d..5ab6240 100644
--- a/interface-event.c
+++ b/interface-event.c
@@ -57,8 +57,8 @@ call_hotplug(void)
 	current_ev = current->hotplug_ev;
 	list_del_init(&current->hotplug_list);
 
-	if (current_ev == IFEV_UP && current->l3_dev->dev)
-		device = current->l3_dev->dev->ifname;
+	if (current_ev == IFEV_UP && current->l3_dev.dev)
+		device = current->l3_dev.dev->ifname;
 
 	D(SYSTEM, "Call hotplug handler for interface '%s' (%s)\n", current->name, device ? device : "none");
 	run_cmd(current->name, device, current_ev == IFEV_UP);
diff --git a/interface-ip.c b/interface-ip.c
index 8c46168..bbf2ccf 100644
--- a/interface-ip.c
+++ b/interface-ip.c
@@ -128,7 +128,7 @@ interface_update_proto_addr(struct vlist_tree *tree,
 
 	ip = container_of(tree, struct interface_ip_settings, addr);
 	iface = ip->iface;
-	dev = iface->l3_dev->dev;
+	dev = iface->l3_dev.dev;
 
 	if (node_new) {
 		a_new = container_of(node_new, struct device_addr, node);
@@ -193,7 +193,7 @@ interface_update_proto_route(struct vlist_tree *tree,
 
 	ip = container_of(tree, struct interface_ip_settings, route);
 	iface = ip->iface;
-	dev = iface->l3_dev->dev;
+	dev = iface->l3_dev.dev;
 
 	route_old = container_of(node_old, struct device_route, node);
 	route_new = container_of(node_new, struct device_route, node);
@@ -353,7 +353,7 @@ void interface_ip_set_enabled(struct interface_ip_settings *ip, bool enabled)
 	struct device *dev;
 
 	ip->enabled = enabled;
-	dev = ip->iface->l3_dev->dev;
+	dev = ip->iface->l3_dev.dev;
 	if (!dev)
 		return;
 
diff --git a/interface.c b/interface.c
index f281a9b..902f55b 100644
--- a/interface.c
+++ b/interface.c
@@ -94,11 +94,10 @@ interface_event(struct interface *iface, enum interface_event ev)
 static void
 interface_flush_state(struct interface *iface)
 {
-	interface_ip_flush(&iface->proto_ip);
 	if (iface->main_dev.dev)
 		device_release(&iface->main_dev);
-	if (iface->l3_dev != &iface->main_dev && iface->l3_dev->dev)
-		device_release(iface->l3_dev);
+	if (iface->l3_dev.dev)
+		device_release(&iface->l3_dev);
 }
 
 static void
@@ -191,7 +190,7 @@ interface_claim_device(struct interface *iface)
 		!(iface->proto_handler->flags & PROTO_FLAG_NODEV)) {
 		dev = device_get(iface->ifname, true);
 		if (dev)
-			device_add_user(&iface->main_dev, dev);
+			interface_set_main_dev(iface, dev);
 	}
 	if (iface->proto_handler->flags & PROTO_FLAG_INIT_AVAILABLE)
 		interface_set_available(iface, true);
@@ -211,8 +210,7 @@ interface_cleanup(struct interface *iface, bool reload)
 	interface_clear_errors(iface);
 	if (iface->main_dev.dev &&
 	    (!reload || !iface->main_dev.hotplug))
-		device_remove_user(&iface->main_dev);
-	iface->l3_dev = &iface->main_dev;
+		interface_set_main_dev(iface, NULL);
 	interface_set_proto_state(iface, NULL);
 }
 
@@ -323,7 +321,6 @@ interface_init(struct interface *iface, const char *name,
 	iface->config_ip.enabled = false;
 
 	iface->main_dev.cb = interface_cb;
-	iface->l3_dev = &iface->main_dev;
 
 	blobmsg_parse(iface_attrs, IFACE_ATTR_MAX, tb,
 		      blob_data(config), blob_len(config));
@@ -356,6 +353,46 @@ interface_add(struct interface *iface, struct blob_attr *config)
 	vlist_add(&interfaces, &iface->node, iface->name);
 }
 
+void
+interface_set_l3_dev(struct interface *iface, struct device *dev)
+{
+	bool enabled = iface->config_ip.enabled;
+	bool claimed = iface->l3_dev.claimed;
+
+	if (iface->l3_dev.dev == dev)
+		return;
+
+	interface_ip_set_enabled(&iface->config_ip, false);
+	interface_ip_flush(&iface->proto_ip);
+	device_add_user(&iface->l3_dev, dev);
+
+	if (dev) {
+		if (claimed)
+			device_claim(&iface->l3_dev);
+		interface_ip_set_enabled(&iface->config_ip, enabled);
+	}
+}
+
+void
+interface_set_main_dev(struct interface *iface, struct device *dev)
+{
+	bool set_l3 = (iface->main_dev.dev == iface->l3_dev.dev);
+	bool claimed = iface->l3_dev.claimed;
+
+	if (iface->main_dev.dev == dev)
+		return;
+
+	device_add_user(&iface->main_dev, dev);
+	if (set_l3)
+		interface_set_l3_dev(iface, dev);
+
+	if (claimed)
+		device_claim(&iface->l3_dev);
+
+	if (!iface->l3_dev.dev)
+		interface_set_l3_dev(iface, dev);
+}
+
 int
 interface_remove_link(struct interface *iface, struct device *dev)
 {
@@ -392,7 +429,7 @@ interface_add_link(struct interface *iface, struct device *dev)
 			return UBUS_STATUS_NOT_SUPPORTED;
 	}
 
-	device_add_user(&iface->main_dev, dev);
+	interface_set_main_dev(iface, dev);
 	iface->main_dev.hotplug = true;
 	return 0;
 }
@@ -477,8 +514,8 @@ interface_update_complete(struct interface *iface)
 
 	interface_ip_update_complete(&iface->proto_ip);
 	vlist_for_each_element(&iface->config_ip.route, route, node) {
-		if (iface->l3_dev->dev) {
-			system_add_route(iface->l3_dev->dev, route);
+		if (iface->l3_dev.dev) {
+			system_add_route(iface->l3_dev.dev, route);
 			route->enabled = true;
 		}
 	}
diff --git a/interface.h b/interface.h
index f0b26f5..b2ecd23 100644
--- a/interface.h
+++ b/interface.h
@@ -76,7 +76,7 @@ struct interface {
 	struct device_user main_dev;
 
 	/* interface that layer 3 communication will go through */
-	struct device_user *l3_dev;
+	struct device_user l3_dev;
 
 	struct blob_attr *config;
 
@@ -111,6 +111,8 @@ int interface_set_up(struct interface *iface);
 int interface_set_down(struct interface *iface);
 void __interface_set_down(struct interface *iface, bool force);
 
+void interface_set_main_dev(struct interface *iface, struct device *dev);
+void interface_set_l3_dev(struct interface *iface, struct device *dev);
 
 void interface_add_user(struct interface_user *dep, struct interface *iface);
 void interface_remove_user(struct interface_user *dep);
diff --git a/proto-shell.c b/proto-shell.c
index 8238c0d..b5d436a 100644
--- a/proto-shell.c
+++ b/proto-shell.c
@@ -41,8 +41,6 @@ struct proto_shell_state {
 	struct proto_shell_handler *handler;
 	struct blob_attr *config;
 
-	struct device_user l3_dev;
-
 	struct uloop_timeout teardown_timeout;
 
 	struct netifd_process script_task;
@@ -79,9 +77,6 @@ proto_shell_handler(struct interface_proto_state *proto,
 		if (state->sm == S_TEARDOWN)
 			return 0;
 
-		if (state->l3_dev.dev)
-			device_remove_user(&state->l3_dev);
-
 		if (state->script_task.uloop.pending) {
 			if (state->sm != S_SETUP_ABORT) {
 				uloop_timeout_set(&state->teardown_timeout, 1000);
@@ -204,8 +199,6 @@ proto_shell_free(struct interface_proto_state *proto)
 	struct proto_shell_state *state;
 
 	state = container_of(proto, struct proto_shell_state, proto);
-	if (state->l3_dev.dev)
-		device_remove_user(&state->l3_dev);
 	netifd_kill_process(&state->script_task);
 	netifd_kill_process(&state->proto_task);
 	free(state->config);
@@ -305,9 +298,6 @@ proto_shell_update_link(struct proto_shell_state *state, struct blob_attr *data,
 		if (!iface->main_dev.dev)
 			return UBUS_STATUS_INVALID_ARGUMENT;
 	} else {
-		if (state->l3_dev.dev)
-			device_remove_user(&state->l3_dev);
-
 		devname = blobmsg_data(tb[NOTIFY_IFNAME]);
 		if (tb[NOTIFY_TUNNEL]) {
 			dev = proto_shell_create_tunnel(devname,
@@ -320,9 +310,8 @@ proto_shell_update_link(struct proto_shell_state *state, struct blob_attr *data,
 				return UBUS_STATUS_NOT_FOUND;
 		}
 
-		device_add_user(&state->l3_dev, dev);
-		iface->l3_dev = &state->l3_dev;
-		device_claim(&state->l3_dev);
+		interface_set_l3_dev(iface, dev);
+		device_claim(&iface->l3_dev);
 	}
 
 	interface_update_start(iface);
diff --git a/ubus.c b/ubus.c
index 6d79a0a..40c6374 100644
--- a/ubus.c
+++ b/ubus.c
@@ -303,7 +303,7 @@ netifd_handle_status(struct ubus_context *ctx, struct ubus_object *obj,
 	if (iface->state == IFS_UP) {
 		time_t cur = system_get_rtime();
 		blobmsg_add_u32(&b, "uptime", cur - iface->start_time);
-		blobmsg_add_string(&b, "l3_device", iface->l3_dev->dev->ifname);
+		blobmsg_add_string(&b, "l3_device", iface->l3_dev.dev->ifname);
 	}
 
 	dev = iface->main_dev.dev;