[IPV6]: ROUTE: Add Router Reachability Probing (RFC4191). (27097255) · Commits · e / devices / android_kernel_teracube_emerald

net/ipv6/route.c

+39 −0

Original line number	Diff line number	Diff line
		@@ -218,6 +218,42 @@ static __inline__ struct rt6_info rt6_device_match(struct rt6_info rt,
		return rt;
		}

		#ifdef CONFIG_IPV6_ROUTER_PREF
		static void rt6_probe(struct rt6_info *rt)
		{
		struct neighbour *neigh = rt ? rt->rt6i_nexthop : NULL;
		/*
		* Okay, this does not seem to be appropriate
		* for now, however, we need to check if it
		* is really so; aka Router Reachability Probing.
		*
		* Router Reachability Probe MUST be rate-limited
		* to no more than one per minute.
		*/
		if (!neigh \|\| (neigh->nud_state & NUD_VALID))
		return;
		read_lock_bh(&neigh->lock);
		if (!(neigh->nud_state & NUD_VALID) &&
		time_after(jiffies, neigh->updated + 60 * HZ)) {
		struct in6_addr mcaddr;
		struct in6_addr *target;

		neigh->updated = jiffies;
		read_unlock_bh(&neigh->lock);

		target = (struct in6_addr *)&neigh->primary_key;
		addrconf_addr_solict_mult(target, &mcaddr);
		ndisc_send_ns(rt->rt6i_dev, NULL, target, &mcaddr, NULL);
		} else
		read_unlock_bh(&neigh->lock);
		}
		#else
		static inline void rt6_probe(struct rt6_info *rt)
		{
		return;
		}
		#endif

		/*
		* Default Router Selection (RFC 2461 6.3.6)
		*/
		@@ -287,8 +323,11 @@ static struct rt6_info rt6_select(struct rt6_info *head, int oif,
		continue;

		if (m > mpri) {
		rt6_probe(match);
		match = rt;
		mpri = m;
		} else {
		rt6_probe(rt);
		}
		}