Babel: Set onlink flag for IPv4 routes with unreachable next hop (4e8f8afc) · Commits · 戴 / Bird

If the next hop of a route is not a reachable address, the route should be installed as onlink. This enables a configuration common in mesh networks where the mesh interface is assigned a /32 and babel handles the routing by installing onlink routes. Thanks to Toke Hoiland-Jorgensen for the patch.

proto/babel/babel.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -640,6 +640,14 @@ babel_announce_rte(struct babel_proto p, struct babel_entry e)
		.nh.iface = r->neigh->ifa->iface,
		};

		/*
		* If we cannot find a reachable neighbour, set the entry to be onlink. This
		* makes it possible to, e.g., assign /32 addresses on a mesh interface and
		* have routing work.
		*/
		if (!neigh_find(&p->p, r->next_hop, r->neigh->ifa->iface, 0))
		a0.nh.flags = RNF_ONLINK;

		rta *a = rta_lookup(&a0);
		rte *rte = rte_get_temp(a);
		rte->u.babel.seqno = r->seqno;

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