From mboxrd@z Thu Jan 1 00:00:00 1970 From: Duan Jiong Subject: [PATCH v2] neigh: set nud_state to NUD_INCOMPLETE when probing router reachability Date: Fri, 9 May 2014 13:16:48 +0800 Message-ID: <536C64C0.5050204@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="GB2312" Content-Transfer-Encoding: 7bit Cc: netdev , Jiri Benc , To: David Miller Return-path: Received: from cn.fujitsu.com ([59.151.112.132]:10110 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751520AbaEIFTP (ORCPT ); Fri, 9 May 2014 01:19:15 -0400 Sender: netdev-owner@vger.kernel.org List-ID: Since commit 7e98056964("ipv6: router reachability probing"), a router falls into NUD_FAILED will be probed. Now if function rt6_select() selects a router which neighbour state is NUD_FAILED, and at the same time function rt6_probe() changes the neighbour state to NUD_PROBE, then function dst_neigh_output() can directly send packets, but actually the neighbour still is unreachable. If we set nud_state to NUD_INCOMPLETE instead NUD_PROBE, packets will not be sent out until the neihbour is reachable. In addition, because the route should be probes with a single NS, so we must set neigh->probes to neigh_max_probes(), then the neigh timer timeout and function neigh_timer_handler() will not send other NS Messages. Signed-off-by: Duan Jiong --- Changes from v1: *modify changelog to explain in detail why use neigh_max_probes(). net/core/neighbour.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 8f8a96e..32d872e 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1248,8 +1248,8 @@ void __neigh_set_probe_once(struct neighbour *neigh) neigh->updated = jiffies; if (!(neigh->nud_state & NUD_FAILED)) return; - neigh->nud_state = NUD_PROBE; - atomic_set(&neigh->probes, NEIGH_VAR(neigh->parms, UCAST_PROBES)); + neigh->nud_state = NUD_INCOMPLETE; + atomic_set(&neigh->probes, neigh_max_probes(neigh)); neigh_add_timer(neigh, jiffies + NEIGH_VAR(neigh->parms, RETRANS_TIME)); } -- 1.8.3.1