From c6b739e28f2b15789c95dd28af3f193ec8f67531 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Tue, 24 Jan 2012 00:52:32 +0100
Subject: [PATCH] add a generic option for disabling the automatic default
 route on interfaces

---
 interface-ip.c | 27 ++++++++++++++++++++++-----
 interface.c    | 15 +++++++++++----
 interface.h    |  1 +
 utils.h        |  9 +++++++++
 4 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/interface-ip.c b/interface-ip.c
index d22e369..9bdad4f 100644
--- a/interface-ip.c
+++ b/interface-ip.c
@@ -155,6 +155,15 @@ interface_update_proto_addr(struct vlist_tree *tree,
 	}
 }
 
+static bool
+enable_route(struct interface_ip_settings *ip, struct device_route *route)
+{
+	if (ip->no_defaultroute && !route->mask)
+		return false;
+
+	return true;
+}
+
 static void
 interface_update_proto_route(struct vlist_tree *tree,
 			     struct vlist_node *node_new,
@@ -183,9 +192,12 @@ interface_update_proto_route(struct vlist_tree *tree,
 	}
 
 	if (node_new) {
-		if (!(route_new->flags & DEVADDR_EXTERNAL) && !keep)
+		bool _enabled = enable_route(ip, route_new);
+
+		if (!(route_new->flags & DEVADDR_EXTERNAL) && !keep && _enabled)
 			system_add_route(dev, route_new);
-		route_new->enabled = true;
+
+		route_new->enabled = _enabled;
 	}
 }
 
@@ -341,14 +353,19 @@ void interface_ip_set_enabled(struct interface_ip_settings *ip, bool enabled)
 	}
 
 	vlist_for_each_element(&ip->route, route, node) {
-		if (route->enabled == enabled)
+		bool _enabled = enabled;
+
+		if (!enable_route(ip, route))
+			_enabled = false;
+
+		if (route->enabled == _enabled)
 			continue;
 
-		if (enabled)
+		if (_enabled)
 			system_add_route(dev, route);
 		else
 			system_del_route(dev, route);
-		route->enabled = enabled;
+		route->enabled = _enabled;
 	}
 }
 
diff --git a/interface.c b/interface.c
index 257eaca..1db2efe 100644
--- a/interface.c
+++ b/interface.c
@@ -17,6 +17,7 @@ enum {
 	IFACE_ATTR_IFNAME,
 	IFACE_ATTR_PROTO,
 	IFACE_ATTR_AUTO,
+	IFACE_ATTR_DEFAULTROUTE,
 	IFACE_ATTR_MAX
 };
 
@@ -24,6 +25,7 @@ static const struct blobmsg_policy iface_attrs[IFACE_ATTR_MAX] = {
 	[IFACE_ATTR_PROTO] = { .name = "proto", .type = BLOBMSG_TYPE_STRING },
 	[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 },
 };
 
 const struct config_param_list interface_attr_list = {
@@ -326,10 +328,10 @@ interface_init(struct interface *iface, const char *name,
 
 	proto_attach_interface(iface, proto_name);
 
-	if ((cur = tb[IFACE_ATTR_AUTO]))
-		iface->autostart = blobmsg_get_bool(cur);
-	else
-		iface->autostart = true;
+	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->config_autostart = iface->autostart;
 }
 
@@ -499,6 +501,11 @@ interface_change_config(struct interface *if_old, struct interface *if_new)
 		goto reload;
 	}
 
+	if (if_old->proto_ip.no_defaultroute != if_new->proto_ip.no_defaultroute) {
+		if_old->proto_ip.no_defaultroute = if_new->proto_ip.no_defaultroute;
+		interface_ip_set_enabled(&if_old->proto_ip, if_old->proto_ip.enabled);
+	}
+
 	goto out;
 
 reload:
diff --git a/interface.h b/interface.h
index e50ccf6..4580c5b 100644
--- a/interface.h
+++ b/interface.h
@@ -42,6 +42,7 @@ struct interface_user {
 struct interface_ip_settings {
 	struct interface *iface;
 	bool enabled;
+	bool no_defaultroute;
 
 	struct vlist_tree addr;
 	struct vlist_tree route;
diff --git a/utils.h b/utils.h
index b5ae7e0..2866280 100644
--- a/utils.h
+++ b/utils.h
@@ -3,6 +3,15 @@
 
 #include <libubox/list.h>
 #include <libubox/avl.h>
+#include <libubox/blobmsg.h>
+
+static inline bool blobmsg_get_bool_default(struct blob_attr *attr, bool val)
+{
+	if (!attr)
+		return val;
+
+	return blobmsg_get_bool(attr);
+}
 
 #define __init __attribute__((constructor))
 
-- 
2.25.1