Commit 705ef89a authored by Petr Machata's avatar Petr Machata Committed by Jakub Kicinski
Browse files

net: core: neighbour: Extract ARP queue processing to a helper function 



In order to make manipulation with this bit of code clearer, extract it
to a helper function, neigh_update_process_arp_queue().

Signed-off-by: default avatarPetr Machata <petrm@nvidia.com>
Reviewed-by: default avatarIdo Schimmel <idosch@nvidia.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/8b0fa0abe2cf0e24484903f5436fe0ac64163057.1769012464.git.petrm@nvidia.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 0ecdccb8

net/core/neighbour.c

+43 −35
Original line number Diff line number Diff line
@@ -1302,6 +1302,47 @@ static void neigh_update_hhs(struct neighbour *neigh) 
	}

}



static void neigh_update_process_arp_queue(struct neighbour *neigh)

	__releases(neigh->lock)

	__acquires(neigh->lock)

{

	struct sk_buff *skb;



	/* Again: avoid deadlock if something went wrong. */

	while (neigh->nud_state & NUD_VALID &&

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

		struct dst_entry *dst = skb_dst(skb);

		struct neighbour *n2, *n1 = neigh;



		write_unlock_bh(&neigh->lock);



		rcu_read_lock();



		/* Why not just use 'neigh' as-is?  The problem is that

		 * things such as shaper, eql, and sch_teql can end up

		 * using alternative, different, neigh objects to output

		 * the packet in the output path.  So what we need to do

		 * here is re-lookup the top-level neigh in the path so

		 * we can reinject the packet there.

		 */

		n2 = NULL;

		if (dst &&

		    READ_ONCE(dst->obsolete) != DST_OBSOLETE_DEAD) {

			n2 = dst_neigh_lookup_skb(dst, skb);

			if (n2)

				n1 = n2;

		}

		READ_ONCE(n1->output)(n1, skb);

		if (n2)

			neigh_release(n2);

		rcu_read_unlock();



		write_lock_bh(&neigh->lock);

	}

	__skb_queue_purge(&neigh->arp_queue);

	neigh->arp_queue_len_bytes = 0;

}



/* Generic update routine.

   -- lladdr is new lladdr or NULL, if it is not supplied.

   -- new    is new state.
@@ -1461,43 +1502,10 @@ static int __neigh_update(struct neighbour *neigh, const u8 *lladdr, 
		neigh_connect(neigh);

	else

		neigh_suspect(neigh);

	if (!(old & NUD_VALID)) {

		struct sk_buff *skb;



		/* Again: avoid dead loop if something went wrong */



		while (neigh->nud_state & NUD_VALID &&

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

			struct dst_entry *dst = skb_dst(skb);

			struct neighbour *n2, *n1 = neigh;

			write_unlock_bh(&neigh->lock);



			rcu_read_lock();



			/* Why not just use 'neigh' as-is?  The problem is that

			 * things such as shaper, eql, and sch_teql can end up

			 * using alternative, different, neigh objects to output

			 * the packet in the output path.  So what we need to do

			 * here is re-lookup the top-level neigh in the path so

			 * we can reinject the packet there.

			 */

			n2 = NULL;

			if (dst &&

			    READ_ONCE(dst->obsolete) != DST_OBSOLETE_DEAD) {

				n2 = dst_neigh_lookup_skb(dst, skb);

				if (n2)

					n1 = n2;

			}

			READ_ONCE(n1->output)(n1, skb);

			if (n2)

				neigh_release(n2);

			rcu_read_unlock();

	if (!(old & NUD_VALID))

		neigh_update_process_arp_queue(neigh);



			write_lock_bh(&neigh->lock);

		}

		__skb_queue_purge(&neigh->arp_queue);

		neigh->arp_queue_len_bytes = 0;

	}

out:

	if (update_isrouter)

		neigh_update_is_router(neigh, flags, &notify);