From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Timo=20Ter=C3=A4s?= Subject: [PATCH net-next] neigh: probe application via netlink in NUD_PROBE Date: Wed, 26 Feb 2014 11:43:04 +0200 Message-ID: <1393407784-8906-1-git-send-email-timo.teras@iki.fi> References: <20140225.181844.1715731388552960836.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: =?UTF-8?q?Timo=20Ter=C3=A4s?= To: David Miller , netdev@vger.kernel.org Return-path: Received: from mail-la0-f47.google.com ([209.85.215.47]:38538 "EHLO mail-la0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751106AbaBZJm3 (ORCPT ); Wed, 26 Feb 2014 04:42:29 -0500 Received: by mail-la0-f47.google.com with SMTP id y1so435336lam.20 for ; Wed, 26 Feb 2014 01:42:27 -0800 (PST) In-Reply-To: <20140225.181844.1715731388552960836.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: iproute2 arpd seems to expect this as there's code and comments to handle netlink probes with NUD_PROBE set. It is used to flush the arpd cached mappings. opennhrp instead turns off unicast probes (so it can handle all neighbour discovery). Without this change it will not see NUD_PROBE probes and cannot reconfirm the mapping. Thus currently neigh entry will just fail and can cause few packets dropped until broadcast discovery is restarted. Earlier discussion on the subject: http://marc.info/?t=3D139305877100001&r=3D1&w=3D2 Signed-off-by: Timo Ter=C3=A4s --- net/core/neighbour.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index b9e9e0d..36d3f8c 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -836,10 +836,10 @@ out: static __inline__ int neigh_max_probes(struct neighbour *n) { struct neigh_parms *p =3D n->parms; - return (n->nud_state & NUD_PROBE) ? - NEIGH_VAR(p, UCAST_PROBES) : - NEIGH_VAR(p, UCAST_PROBES) + NEIGH_VAR(p, APP_PROBES) + - NEIGH_VAR(p, MCAST_PROBES); + int max_probes =3D NEIGH_VAR(p, UCAST_PROBES) + NEIGH_VAR(p, APP_PROB= ES); + if (!(n->nud_state & NUD_PROBE)) + max_probes +=3D NEIGH_VAR(p, MCAST_PROBES); + return max_probes; } =20 static void neigh_invalidate(struct neighbour *neigh) --=20 1.9.0