X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fnetifd.git;a=blobdiff_plain;f=interface.c;h=23c70326131dc6a5e0d2e45700178d04d95fb6e9;hp=3a404326ebd19b4e707e26c6a061608bc9c51032;hb=381f47c5af62cec173528f5f539558d7a18b6d30;hpb=8a1a1dda9cfff45a7cd48f5d108d0174fadd84ee

diff --git a/interface.c b/interface.c
index 3a40432..23c7032 100644
--- a/interface.c
+++ b/interface.c
@@ -1,3 +1,16 @@
+/*
+ * netifd - network interface daemon
+ * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -12,13 +25,25 @@
 #include "system.h"
 
 struct vlist_tree interfaces;
+static LIST_HEAD(iface_all_users);
+static unsigned int interface_serial = 0;
 
 enum {
 	IFACE_ATTR_IFNAME,
 	IFACE_ATTR_PROTO,
 	IFACE_ATTR_AUTO,
 	IFACE_ATTR_DEFAULTROUTE,
+	IFACE_ATTR_PEERDNS,
+	IFACE_ATTR_DNS,
+	IFACE_ATTR_DNS_SEARCH,
 	IFACE_ATTR_METRIC,
+	IFACE_ATTR_INTERFACE,
+	IFACE_ATTR_IP6ASSIGN,
+	IFACE_ATTR_IP6HINT,
+	IFACE_ATTR_IP4TABLE,
+	IFACE_ATTR_IP6TABLE,
+	IFACE_ATTR_IP6CLASS,
+	IFACE_ATTR_DELEGATE,
 	IFACE_ATTR_MAX
 };
 
@@ -27,12 +52,28 @@ static const struct blobmsg_policy iface_attrs[IFACE_ATTR_MAX] = {
 	[IFACE_ATTR_IFNAME] = { .name = "ifname", .type = BLOBMSG_TYPE_STRING },
 	[IFACE_ATTR_AUTO] = { .name = "auto", .type = BLOBMSG_TYPE_BOOL },
 	[IFACE_ATTR_DEFAULTROUTE] = { .name = "defaultroute", .type = BLOBMSG_TYPE_BOOL },
+	[IFACE_ATTR_PEERDNS] = { .name = "peerdns", .type = BLOBMSG_TYPE_BOOL },
 	[IFACE_ATTR_METRIC] = { .name = "metric", .type = BLOBMSG_TYPE_INT32 },
+	[IFACE_ATTR_DNS] = { .name = "dns", .type = BLOBMSG_TYPE_ARRAY },
+	[IFACE_ATTR_DNS_SEARCH] = { .name = "dns_search", .type = BLOBMSG_TYPE_ARRAY },
+	[IFACE_ATTR_INTERFACE] = { .name = "interface", .type = BLOBMSG_TYPE_STRING },
+	[IFACE_ATTR_IP6ASSIGN] = { .name = "ip6assign", .type = BLOBMSG_TYPE_INT32 },
+	[IFACE_ATTR_IP6HINT] = { .name = "ip6hint", .type = BLOBMSG_TYPE_STRING },
+	[IFACE_ATTR_IP4TABLE] = { .name = "ip4table", .type = BLOBMSG_TYPE_STRING },
+	[IFACE_ATTR_IP6TABLE] = { .name = "ip6table", .type = BLOBMSG_TYPE_STRING },
+	[IFACE_ATTR_IP6CLASS] = { .name = "ip6class", .type = BLOBMSG_TYPE_ARRAY },
+	[IFACE_ATTR_DELEGATE] = { .name = "delegate", .type = BLOBMSG_TYPE_BOOL },
 };
 
-const struct config_param_list interface_attr_list = {
+static const struct uci_blob_param_info iface_attr_info[IFACE_ATTR_MAX] = {
+	[IFACE_ATTR_DNS] = { .type = BLOBMSG_TYPE_STRING },
+	[IFACE_ATTR_IP6CLASS] = { .type = BLOBMSG_TYPE_STRING },
+};
+
+const struct uci_blob_param_list interface_attr_list = {
 	.n_params = IFACE_ATTR_MAX,
 	.params = iface_attrs,
+	.info = iface_attr_info,
 };
 
 static void
@@ -52,7 +93,7 @@ void interface_add_error(struct interface *iface, const char *subsystem,
 	struct interface_error *error;
 	int i, len = 0;
 	int *datalen = NULL;
-	char *dest;
+	char *dest, *d_subsys, *d_code;
 
 	if (n_data) {
 		len = n_data * sizeof(char *);
@@ -63,13 +104,13 @@ void interface_add_error(struct interface *iface, const char *subsystem,
 		}
 	}
 
-	error = calloc(1, sizeof(*error) + sizeof(char *) + len);
+	error = calloc_a(sizeof(*error) + sizeof(char *) + len,
+		&d_subsys, subsystem ? strlen(subsystem) + 1 : 0,
+		&d_code, code ? strlen(code) + 1 : 0);
 	if (!error)
 		return;
 
 	list_add_tail(&error->list, &iface->errors);
-	error->subsystem = subsystem;
-	error->code = code;
 
 	dest = (char *) &error->data[n_data + 1];
 	for (i = 0; i < n_data; i++) {
@@ -77,7 +118,13 @@ void interface_add_error(struct interface *iface, const char *subsystem,
 		memcpy(dest, data[i], datalen[i]);
 		dest += datalen[i];
 	}
-	error->data[n_data] = NULL;
+	error->data[n_data++] = NULL;
+
+	if (subsystem)
+		error->subsystem = strcpy(d_subsys, subsystem);
+
+	if (code)
+		error->code = strcpy(d_code, code);
 }
 
 static void
@@ -104,9 +151,9 @@ interface_add_data(struct interface *iface, const struct blob_attr *data)
 	if (!blobmsg_check_attr(data, true))
 		return UBUS_STATUS_INVALID_ARGUMENT;
 
-	n = calloc(1, sizeof(*data) + blob_pad_len(data));
+	n = calloc(1, sizeof(*n) + blob_pad_len(data));
 	memcpy(n->data, data, blob_pad_len(data));
-	n->node.key = blobmsg_name(data);
+	n->node.key = blobmsg_name(n->data);
 
 	o = avl_find_element(&iface->data, n->node.key, o, node);
 	if (o)
@@ -120,18 +167,29 @@ static void
 interface_event(struct interface *iface, enum interface_event ev)
 {
 	struct interface_user *dep, *tmp;
+	struct device *adev = NULL;
 
 	list_for_each_entry_safe(dep, tmp, &iface->users, list)
-		dep->cb(dep, IFEV_UP);
+		dep->cb(dep, iface, ev);
+
+	list_for_each_entry_safe(dep, tmp, &iface_all_users, list)
+		dep->cb(dep, iface, ev);
 
-	interface_queue_event(iface, ev);
+	switch (ev) {
+	case IFEV_UP:
+		adev = iface->l3_dev.dev;
+		/* fall through */
+	case IFEV_DOWN:
+		alias_notify_device(iface->name, adev);
+		break;
+	default:
+		break;
+	}
 }
 
 static void
 interface_flush_state(struct interface *iface)
 {
-	if (iface->main_dev.dev)
-		device_release(&iface->main_dev);
 	if (iface->l3_dev.dev)
 		device_release(&iface->l3_dev);
 	interface_data_flush(iface);
@@ -140,19 +198,20 @@ interface_flush_state(struct interface *iface)
 static void
 mark_interface_down(struct interface *iface)
 {
-	if (iface->state == IFS_UP)
+	enum interface_state state = iface->state;
+
+	iface->state = IFS_DOWN;
+	if (state == IFS_UP)
 		interface_event(iface, IFEV_DOWN);
 	interface_ip_set_enabled(&iface->config_ip, false);
 	interface_ip_flush(&iface->proto_ip);
 	interface_flush_state(iface);
-	iface->state = IFS_DOWN;
+	system_flush_routes();
 }
 
 void
 __interface_set_down(struct interface *iface, bool force)
 {
-	interface_clear_errors(iface);
-
 	if (iface->state == IFS_DOWN ||
 		iface->state == IFS_TEARDOWN)
 		return;
@@ -163,6 +222,9 @@ __interface_set_down(struct interface *iface, bool force)
 	interface_proto_event(iface->proto, PROTO_CMD_TEARDOWN, force);
 	if (force)
 		interface_flush_state(iface);
+
+	if (iface->dynamic)
+		vlist_delete(&interfaces, &iface->node);
 }
 
 static void
@@ -184,6 +246,8 @@ interface_cb(struct device_user *dep, enum device_event ev)
 	}
 
 	interface_set_available(iface, new_state);
+	if (!new_state && dep->dev->external)
+		interface_set_main_dev(iface, NULL);
 }
 
 void
@@ -205,10 +269,15 @@ interface_set_available(struct interface *iface, bool new_state)
 void
 interface_add_user(struct interface_user *dep, struct interface *iface)
 {
+	if (!iface) {
+		list_add(&dep->list, &iface_all_users);
+		return;
+	}
+
 	dep->iface = iface;
 	list_add(&dep->list, &iface->users);
 	if (iface->state == IFS_UP)
-		dep->cb(dep, IFEV_UP);
+		dep->cb(dep, iface, IFEV_UP);
 }
 
 void
@@ -219,43 +288,162 @@ interface_remove_user(struct interface_user *dep)
 }
 
 static void
+interface_add_assignment_classes(struct interface *iface, struct blob_attr *list)
+{
+	struct blob_attr *cur;
+	int rem;
+
+	blobmsg_for_each_attr(cur, list, rem) {
+		if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
+			continue;
+
+		if (!blobmsg_check_attr(cur, NULL))
+			continue;
+
+		struct interface_assignment_class *c = malloc(sizeof(*c) + blobmsg_data_len(cur));
+		memcpy(c->name, blobmsg_data(cur), blobmsg_data_len(cur));
+		list_add(&c->head, &iface->assignment_classes);
+	}
+}
+
+static void
+interface_clear_assignment_classes(struct interface *iface)
+{
+	while (!list_empty(&iface->assignment_classes)) {
+		struct interface_assignment_class *c = list_first_entry(&iface->assignment_classes,
+				struct interface_assignment_class, head);
+		list_del(&c->head);
+		free(c);
+	}
+}
+
+static void
+interface_merge_assignment_data(struct interface *old, struct interface *new)
+{
+	bool changed = (old->assignment_hint != new->assignment_hint ||
+			old->assignment_length != new->assignment_length ||
+			list_empty(&old->assignment_classes) != list_empty(&new->assignment_classes));
+
+	struct interface_assignment_class *c;
+	list_for_each_entry(c, &new->assignment_classes, head) {
+		// Compare list entries one-by-one to see if there was a change
+		if (list_empty(&old->assignment_classes)) // The new list is longer
+			changed = true;
+
+		if (changed)
+			break;
+
+		struct interface_assignment_class *c_old = list_first_entry(&old->assignment_classes,
+				struct interface_assignment_class, head);
+
+		if (strcmp(c_old->name, c->name)) // An entry didn't match
+			break;
+
+		list_del(&c_old->head);
+		free(c_old);
+	}
+
+	// The old list was longer than the new one or the last entry didn't match
+	if (!list_empty(&old->assignment_classes)) {
+		interface_clear_assignment_classes(old);
+		changed = true;
+	}
+
+	list_splice_init(&new->assignment_classes, &old->assignment_classes);
+
+	if (changed) {
+		old->assignment_hint = new->assignment_hint;
+		old->assignment_length = new->assignment_length;
+		interface_refresh_assignments(true);
+	}
+}
+
+static void
+interface_alias_cb(struct interface_user *dep, struct interface *iface, enum interface_event ev)
+{
+	struct interface *alias = container_of(dep, struct interface, parent_iface);
+	struct device *dev = iface->l3_dev.dev;
+
+	switch (ev) {
+	case IFEV_UP:
+		if (!dev)
+			return;
+
+		interface_set_main_dev(alias, dev);
+		interface_set_available(alias, true);
+		break;
+	case IFEV_DOWN:
+		interface_set_available(alias, false);
+		interface_set_main_dev(alias, NULL);
+		break;
+	case IFEV_FREE:
+		interface_remove_user(dep);
+		break;
+	case IFEV_RELOAD:
+	case IFEV_UPDATE:
+		break;
+	}
+}
+
+static void
 interface_claim_device(struct interface *iface)
 {
-	struct device *dev;
+	struct interface *parent;
+	struct device *dev = NULL;
+
+	if (iface->parent_iface.iface)
+		interface_remove_user(&iface->parent_iface);
 
-	if (iface->ifname &&
+	if (iface->parent_ifname) {
+		parent = vlist_find(&interfaces, iface->parent_ifname, parent, node);
+		iface->parent_iface.cb = interface_alias_cb;
+		interface_add_user(&iface->parent_iface, parent);
+	} else if (iface->ifname &&
 		!(iface->proto_handler->flags & PROTO_FLAG_NODEV)) {
 		dev = device_get(iface->ifname, true);
-		if (dev)
-			interface_set_main_dev(iface, dev);
 	}
+
+	if (dev)
+		interface_set_main_dev(iface, dev);
+
 	if (iface->proto_handler->flags & PROTO_FLAG_INIT_AVAILABLE)
 		interface_set_available(iface, true);
 }
 
+static void
+interface_cleanup_state(struct interface *iface)
+{
+	interface_set_available(iface, false);
+
+	interface_flush_state(iface);
+	interface_clear_errors(iface);
+	interface_set_proto_state(iface, NULL);
+
+	if (iface->main_dev.dev)
+		interface_set_main_dev(iface, NULL);
+}
 
 static void
-interface_cleanup(struct interface *iface, bool reload)
+interface_cleanup(struct interface *iface)
 {
 	struct interface_user *dep, *tmp;
 
+	if (iface->parent_iface.iface)
+		interface_remove_user(&iface->parent_iface);
+
 	list_for_each_entry_safe(dep, tmp, &iface->users, list)
 		interface_remove_user(dep);
 
-	interface_dequeue_event(iface);
+	interface_clear_assignment_classes(iface);
 	interface_ip_flush(&iface->config_ip);
-	interface_flush_state(iface);
-	interface_clear_errors(iface);
-	if (iface->main_dev.dev &&
-	    (!reload || !iface->main_dev.hotplug))
-		interface_set_main_dev(iface, NULL);
-	interface_set_proto_state(iface, NULL);
+	interface_cleanup_state(iface);
 }
 
 static void
 interface_do_free(struct interface *iface)
 {
-	interface_cleanup(iface, false);
+	interface_event(iface, IFEV_FREE);
+	interface_cleanup(iface);
 	free(iface->config);
 	netifd_ubus_remove_interface(iface);
 	avl_delete(&interfaces.avl, &iface->node.avl);
@@ -265,7 +453,8 @@ interface_do_free(struct interface *iface)
 static void
 interface_do_reload(struct interface *iface)
 {
-	interface_cleanup(iface, true);
+	interface_event(iface, IFEV_RELOAD);
+	interface_cleanup_state(iface);
 	proto_init_interface(iface, iface->config);
 	interface_claim_device(iface);
 }
@@ -273,7 +462,10 @@ interface_do_reload(struct interface *iface)
 static void
 interface_handle_config_change(struct interface *iface)
 {
-	switch(iface->config_state) {
+	enum interface_config_state state = iface->config_state;
+
+	iface->config_state = IFC_NORMAL;
+	switch(state) {
 	case IFC_NORMAL:
 		break;
 	case IFC_RELOAD:
@@ -294,15 +486,16 @@ interface_proto_cb(struct interface_proto_state *state, enum interface_proto_eve
 
 	switch (ev) {
 	case IFPEV_UP:
-		if (iface->state != IFS_SETUP)
+		if (iface->state != IFS_SETUP) {
+			interface_event(iface, IFEV_UPDATE);
 			return;
+		}
 
 		interface_ip_set_enabled(&iface->config_ip, true);
 		system_flush_routes();
 		iface->state = IFS_UP;
 		iface->start_time = system_get_rtime();
 		interface_event(iface, IFEV_UP);
-		interface_write_resolv_conf();
 		netifd_log_message(L_NOTICE, "Interface '%s' is now up\n", iface->name);
 		break;
 	case IFPEV_DOWN:
@@ -311,7 +504,8 @@ interface_proto_cb(struct interface_proto_state *state, enum interface_proto_eve
 
 		netifd_log_message(L_NOTICE, "Interface '%s' is now down\n", iface->name);
 		mark_interface_down(iface);
-		system_flush_routes();
+		if (iface->main_dev.dev)
+			device_release(&iface->main_dev);
 		interface_handle_config_change(iface);
 		break;
 	case IFPEV_LINK_LOST:
@@ -319,13 +513,12 @@ interface_proto_cb(struct interface_proto_state *state, enum interface_proto_eve
 			return;
 
 		netifd_log_message(L_NOTICE, "Interface '%s' has lost the connection\n", iface->name);
-		if (iface->state == IFS_UP)
-			interface_event(iface, IFEV_DOWN);
 		mark_interface_down(iface);
-		system_flush_routes();
 		iface->state = IFS_SETUP;
 		break;
 	}
+
+	interface_write_resolv_conf();
 }
 
 void interface_set_proto_state(struct interface *iface, struct interface_proto_state *state)
@@ -343,20 +536,22 @@ void interface_set_proto_state(struct interface *iface, struct interface_proto_s
 	state->iface = iface;
 }
 
-void
-interface_init(struct interface *iface, const char *name,
-	       struct blob_attr *config)
+struct interface *
+interface_alloc(const char *name, struct blob_attr *config)
 {
+	struct interface *iface;
 	struct blob_attr *tb[IFACE_ATTR_MAX];
 	struct blob_attr *cur;
 	const char *proto_name = NULL;
+	char *iface_name;
 
-	strncpy(iface->name, name, sizeof(iface->name) - 1);
+	iface = calloc_a(sizeof(*iface), &iface_name, strlen(name) + 1);
+	iface->name = strcpy(iface_name, name);
 	INIT_LIST_HEAD(&iface->errors);
 	INIT_LIST_HEAD(&iface->users);
 	INIT_LIST_HEAD(&iface->hotplug_list);
-	interface_ip_init(&iface->proto_ip, iface);
-	interface_ip_init(&iface->config_ip, iface);
+	INIT_LIST_HEAD(&iface->assignment_classes);
+	interface_ip_init(iface);
 	avl_init(&iface->data, avl_strcmp, false, NULL);
 	iface->config_ip.enabled = false;
 
@@ -373,12 +568,60 @@ interface_init(struct interface *iface, const char *name,
 	iface->autostart = blobmsg_get_bool_default(tb[IFACE_ATTR_AUTO], true);
 	iface->proto_ip.no_defaultroute =
 		!blobmsg_get_bool_default(tb[IFACE_ATTR_DEFAULTROUTE], true);
+	iface->proto_ip.no_dns =
+		!blobmsg_get_bool_default(tb[IFACE_ATTR_PEERDNS], true);
+
+	if ((cur = tb[IFACE_ATTR_DNS]))
+		interface_add_dns_server_list(&iface->config_ip, cur);
+
+	if ((cur = tb[IFACE_ATTR_DNS_SEARCH]))
+		interface_add_dns_search_list(&iface->config_ip, cur);
+
+	if ((cur = tb[IFACE_ATTR_METRIC]))
+		iface->metric = blobmsg_get_u32(cur);
+
+	if ((cur = tb[IFACE_ATTR_IP6ASSIGN]))
+		iface->assignment_length = blobmsg_get_u32(cur);
+
+	iface->assignment_hint = -1;
+	if ((cur = tb[IFACE_ATTR_IP6HINT]))
+		iface->assignment_hint = strtol(blobmsg_get_string(cur), NULL, 16) &
+				~((1 << (64 - iface->assignment_length)) - 1);
+
+	if ((cur = tb[IFACE_ATTR_IP6CLASS]))
+		interface_add_assignment_classes(iface, cur);
+
+
+	if ((cur = tb[IFACE_ATTR_IP4TABLE])) {
+		if (!system_resolve_rt_table(blobmsg_data(cur), &iface->ip4table))
+			DPRINTF("Failed to resolve routing table: %s\n", (char *) blobmsg_data(cur));
+	}
+
+	// Set a default exteranl routing table for IPv6 to do source-based-filtering
+	struct interface *iface_old = vlist_find(&interfaces, name, iface_old, node);
+	if (iface_old && iface_old->ip6table > 1000 && iface_old->ip6table < 2000)
+		iface->ip6table = iface_old->ip6table;
+	else
+		iface->ip6table = 1000 + ++interface_serial;
+
+	if ((cur = tb[IFACE_ATTR_IP6TABLE])) {
+		if (!system_resolve_rt_table(blobmsg_data(cur), &iface->ip6table))
+			DPRINTF("Failed to resolve routing table: %s\n", (char *) blobmsg_data(cur));
+	}
+
+	iface->proto_ip.no_delegation = !blobmsg_get_bool_default(tb[IFACE_ATTR_DELEGATE], true);
 
 	iface->config_autostart = iface->autostart;
+	return iface;
 }
 
-void
-interface_add(struct interface *iface, struct blob_attr *config)
+void interface_set_dynamic(struct interface *iface)
+{
+	iface->dynamic = true;
+	iface->node.version = -1; // Don't delete on reload
+}
+
+static bool __interface_add(struct interface *iface, struct blob_attr *config, bool alias)
 {
 	struct blob_attr *tb[IFACE_ATTR_MAX];
 	struct blob_attr *cur;
@@ -386,11 +629,36 @@ interface_add(struct interface *iface, struct blob_attr *config)
 	blobmsg_parse(iface_attrs, IFACE_ATTR_MAX, tb,
 		      blob_data(config), blob_len(config));
 
-	if ((cur = tb[IFACE_ATTR_IFNAME]))
-		iface->ifname = blobmsg_data(cur);
+	if (alias) {
+		if ((cur = tb[IFACE_ATTR_INTERFACE]))
+			iface->parent_ifname = blobmsg_data(cur);
+
+		if (!iface->parent_ifname)
+			return false;
+	} else {
+		if ((cur = tb[IFACE_ATTR_IFNAME]))
+			iface->ifname = blobmsg_data(cur);
+	}
+
 
 	iface->config = config;
 	vlist_add(&interfaces, &iface->node, iface->name);
+	return true;
+}
+
+void
+interface_add(struct interface *iface, struct blob_attr *config)
+{
+	__interface_add(iface, config, false);
+}
+
+bool
+interface_add_alias(struct interface *iface, struct blob_attr *config)
+{
+	if (iface->proto_handler->flags & PROTO_FLAG_NODEV)
+		return false;
+
+	return __interface_add(iface, config, true);
 }
 
 void
@@ -426,6 +694,9 @@ interface_set_main_dev(struct interface *iface, struct device *dev)
 		interface_set_l3_dev(iface, dev);
 
 	device_add_user(&iface->main_dev, dev);
+	if (!dev)
+		return;
+
 	if (claimed)
 		device_claim(&iface->l3_dev);
 
@@ -475,6 +746,37 @@ interface_add_link(struct interface *iface, struct device *dev)
 }
 
 int
+interface_handle_link(struct interface *iface, const char *name, bool add)
+{
+	struct device *dev;
+	int ret;
+
+	device_lock();
+
+	dev = device_get(name, add ? 2 : 0);
+	if (!dev) {
+		ret = UBUS_STATUS_NOT_FOUND;
+		goto out;
+	}
+
+	if (add) {
+		device_set_present(dev, true);
+		if (iface->device_config)
+			device_set_config(dev, &simple_device_type, iface->config);
+
+		system_if_apply_settings(dev, &dev->settings);
+		ret = interface_add_link(iface, dev);
+	} else {
+		ret = interface_remove_link(iface, dev);
+	}
+
+out:
+	device_unlock();
+
+	return ret;
+}
+
+int
 interface_set_up(struct interface *iface)
 {
 	int ret;
@@ -554,59 +856,87 @@ interface_update_complete(struct interface *iface)
 }
 
 static void
+interface_replace_dns(struct interface_ip_settings *new, struct interface_ip_settings *old)
+{
+	vlist_simple_replace(&new->dns_servers, &old->dns_servers);
+	vlist_simple_replace(&new->dns_search, &old->dns_search);
+}
+
+static void
 interface_change_config(struct interface *if_old, struct interface *if_new)
 {
 	struct blob_attr *old_config = if_old->config;
-	const char *old_ifname = if_old->ifname;
-	const struct proto_handler *proto = if_old->proto_handler;
+	bool reload = false, reload_ip = false;
+
+#define FIELD_CHANGED_STR(field)					\
+		((!!if_old->field != !!if_new->field) ||		\
+		 (if_old->field &&					\
+		  strcmp(if_old->field, if_new->field) != 0))
+
+	if (FIELD_CHANGED_STR(parent_ifname)) {
+		if (if_old->parent_iface.iface)
+			interface_remove_user(&if_old->parent_iface);
+		reload = true;
+	}
+
+	if (FIELD_CHANGED_STR(ifname) ||
+	    if_old->proto_handler != if_new->proto_handler)
+		reload = true;
+
+	if (!if_old->proto_handler->config_params)
+		D(INTERFACE, "No config parameters for interface '%s'\n",
+		  if_old->name);
+	else if (!uci_blob_check_equal(if_old->config, if_new->config,
+				       if_old->proto_handler->config_params))
+		reload = true;
+
+#define UPDATE(field, __var) ({						\
+		bool __changed = (if_old->field != if_new->field);	\
+		if_old->field = if_new->field;				\
+		__var |= __changed;					\
+	})
 
-	interface_clear_errors(if_old);
 	if_old->config = if_new->config;
 	if (!if_old->config_autostart && if_new->config_autostart)
 		if_old->autostart = true;
 
+	if_old->device_config = if_new->device_config;
 	if_old->config_autostart = if_new->config_autostart;
 	if_old->ifname = if_new->ifname;
+	if_old->parent_ifname = if_new->parent_ifname;
 	if_old->proto_handler = if_new->proto_handler;
 
-	if ((!!old_ifname != !!if_new->ifname) ||
-	    (old_ifname && strcmp(old_ifname, if_new->ifname) != 0) ||
-	    proto != if_new->proto_handler) {
-		D(INTERFACE, "Reload interface '%s' because of ifname/proto change\n",
-		  if_old->name);
-		goto reload;
-	}
+	if_old->proto_ip.no_dns = if_new->proto_ip.no_dns;
+	interface_replace_dns(&if_old->config_ip, &if_new->config_ip);
 
-	if (!proto->config_params)
-		D(INTERFACE, "No config parameters for interface '%s'\n",
-		  if_old->name);
-	else if (!config_check_equal(old_config, if_new->config,
-				proto->config_params)) {
+	UPDATE(metric, reload_ip);
+	UPDATE(proto_ip.no_defaultroute, reload_ip);
+	UPDATE(ip4table, reload_ip);
+	UPDATE(ip6table, reload_ip);
+	interface_merge_assignment_data(if_old, if_new);
+
+#undef UPDATE
+
+	if (reload) {
 		D(INTERFACE, "Reload interface '%s because of config changes\n",
 		  if_old->name);
-		goto reload;
+		interface_clear_errors(if_old);
+		set_config_state(if_old, IFC_RELOAD);
+		goto out;
 	}
 
-#define UPDATE(field) ({						\
-		bool __changed = (if_old->field != if_new->field);	\
-		if_old->field = if_new->field;				\
-		__changed;						\
-	})
-
-	if (UPDATE(metric) || UPDATE(proto_ip.no_defaultroute)) {
+	if (reload_ip) {
 		interface_ip_set_enabled(&if_old->config_ip, false);
-		interface_ip_set_enabled(&if_old->config_ip, if_new->config_ip.enabled);
 		interface_ip_set_enabled(&if_old->proto_ip, false);
 		interface_ip_set_enabled(&if_old->proto_ip, if_new->proto_ip.enabled);
+		interface_ip_set_enabled(&if_old->config_ip, if_new->config_ip.enabled);
 	}
 
-#undef UPDATE
-
-	goto out;
+	interface_write_resolv_conf();
 
-reload:
-	set_config_state(if_old, IFC_RELOAD);
 out:
+	if_new->config = NULL;
+	interface_cleanup(if_new);
 	free(old_config);
 	free(if_new);
 }