From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasily Khoruzhick Subject: [PATCH v3] neighbour: confirm neigh entries when ARP packet is received Date: Thu, 13 Sep 2018 11:12:03 -0700 Message-ID: <20180913181203.4207-1-vasilykh@arista.com> Cc: Vasily Khoruzhick To: "David S. Miller" , Roopa Prabhu , Alexey Dobriyan , Eric Dumazet , Stephen Hemminger , Jim Westfall , Wolfgang Bumiller , Vasily Khoruzhick , Kees Cook , Ihar Hrachyshka , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Sergei Shtylyov Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Update 'confirmed' timestamp when ARP packet is received. It shouldn't affect locktime logic and anyway entry can be confirmed by any higher-layer protocol. Thus it makes sense to confirm it when ARP packet is received. Fixes: 77d7123342 ("neighbour: update neigh timestamps iff update is effective") Signed-off-by: Vasily Khoruzhick --- v2: - update comment to match new code. v3: - fix wording in commit message, make 'Fixes' tag one line, remove extra new line between 'Fixes' and 'Signed-off-by'. net/core/neighbour.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index aa19d86937af..91592fceeaad 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1180,6 +1180,12 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, lladdr = neigh->ha; } + /* Update confirmed timestamp for neighbour entry after we + * received ARP packet even if it doesn't change IP to MAC binding. + */ + if (new & NUD_CONNECTED) + neigh->confirmed = jiffies; + /* If entry was valid and address is not changed, do not change entry state, if new one is STALE. */ @@ -1201,15 +1207,12 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, } } - /* Update timestamps only once we know we will make a change to the + /* Update timestamp only once we know we will make a change to the * neighbour entry. Otherwise we risk to move the locktime window with * noop updates and ignore relevant ARP updates. */ - if (new != old || lladdr != neigh->ha) { - if (new & NUD_CONNECTED) - neigh->confirmed = jiffies; + if (new != old || lladdr != neigh->ha) neigh->updated = jiffies; - } if (new != old) { neigh_del_timer(neigh); -- 2.18.0