Commit 5ef12d98 authored by Timo Teras's avatar Timo Teras Committed by David S. Miller
Browse files

neigh: fix state transition INCOMPLETE->FAILED via Netlink request 



The current code errors out the INCOMPLETE neigh entry skb queue only from
the timer if maximum probes have been attempted and there has been no reply.
This also causes the transtion to FAILED state.

However, the neigh entry can be also updated via Netlink to inform that the
address is unavailable.  Currently, neigh_update() just stops the timers and
leaves the pending skb's unreleased. This results that the clean up code in
the timer callback is never called, preventing also proper garbage collection.

This fixes neigh_update() to process the pending skb queue immediately if
INCOMPLETE -> FAILED state transtion occurs due to a Netlink request.

Signed-off-by: default avatarTimo Teras <timo.teras@iki.fi>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2b85a34e

net/core/neighbour.c

+28 −18
Original line number Diff line number Diff line
@@ -771,6 +771,28 @@ static __inline__ int neigh_max_probes(struct neighbour *n) 
		p->ucast_probes + p->app_probes + p->mcast_probes);

}



static void neigh_invalidate(struct neighbour *neigh)

{

	struct sk_buff *skb;



	NEIGH_CACHE_STAT_INC(neigh->tbl, res_failed);

	NEIGH_PRINTK2("neigh %p is failed.\n", neigh);

	neigh->updated = jiffies;



	/* It is very thin place. report_unreachable is very complicated

	   routine. Particularly, it can hit the same neighbour entry!



	   So that, we try to be accurate and avoid dead loop. --ANK

	 */

	while (neigh->nud_state == NUD_FAILED &&

	       (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {

		write_unlock(&neigh->lock);

		neigh->ops->error_report(neigh, skb);

		write_lock(&neigh->lock);

	}

	skb_queue_purge(&neigh->arp_queue);

}



/* Called when a timer expires for a neighbour entry. */



static void neigh_timer_handler(unsigned long arg)
@@ -835,26 +857,9 @@ static void neigh_timer_handler(unsigned long arg) 


	if ((neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) &&

	    atomic_read(&neigh->probes) >= neigh_max_probes(neigh)) {

		struct sk_buff *skb;



		neigh->nud_state = NUD_FAILED;

		neigh->updated = jiffies;

		notify = 1;

		NEIGH_CACHE_STAT_INC(neigh->tbl, res_failed);

		NEIGH_PRINTK2("neigh %p is failed.\n", neigh);



		/* It is very thin place. report_unreachable is very complicated

		   routine. Particularly, it can hit the same neighbour entry!



		   So that, we try to be accurate and avoid dead loop. --ANK

		 */

		while (neigh->nud_state == NUD_FAILED &&

		       (skb = __skb_dequeue(&neigh->arp_queue)) != NULL) {

			write_unlock(&neigh->lock);

			neigh->ops->error_report(neigh, skb);

			write_lock(&neigh->lock);

		}

		skb_queue_purge(&neigh->arp_queue);

		neigh_invalidate(neigh);

	}



	if (neigh->nud_state & NUD_IN_TIMER) {
@@ -1001,6 +1006,11 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, 
		neigh->nud_state = new;

		err = 0;

		notify = old & NUD_VALID;

		if ((old & (NUD_INCOMPLETE | NUD_PROBE)) &&

		    (new & NUD_FAILED)) {

			neigh_invalidate(neigh);

			notify = 1;

		}

		goto out;

	}

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