Add route lifetime from Router Advertisement

Sends route lifetime to NETLINK RTA_EXPIRES

Partially addresses NetworkConfiguration#428

src/if-linux.c

@@ -1735,6 +1735,10 @@ if_route(unsigned char cmd, const struct rt *rt)
 	if (!sa_is_loopback(&rt->rt_gateway))
 		add_attr_32(&nlm.hdr, sizeof(nlm), RTA_OIF, rt->rt_ifp->index);
 
+	/* add route lifetime */
+    logdebugx("Sending RTA_EXPIRES %d", rt->rt_expires);
+    add_attr_32(&nlm.hdr, sizeof(nlm), RTA_EXPIRES, rt->rt_expires);
+
 	if (rt->rt_metric != 0)
 		add_attr_32(&nlm.hdr, sizeof(nlm), RTA_PRIORITY,
 		    rt->rt_metric);

src/ipv6.c

@@ -2370,6 +2370,8 @@ inet6_raroutes(rb_tree_t *routes, struct dhcpcd_ctx *ctx)
 #ifdef HAVE_ROUTE_PREF
 		rt->rt_pref = ipv6nd_rtpref(rap->flags);
 #endif
+		rt->rt_expires = rap->lifetime;
+
 		rt_proto_add(routes, rt);
 	}
 	return 0;

src/route.h

@@ -120,6 +120,7 @@ struct rt {
 #define	RTDF_GATELINK		0x40		/* Gateway is on link */
 	size_t			rt_order;
 	rb_node_t		rt_tree;
+	int				rt_expires;		/* current lifetime of route */
 };
 
 extern const rb_tree_ops_t rt_compare_list_ops;