From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE246C28EBD for ; Sun, 9 Jun 2019 17:06:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B0626206C3 for ; Sun, 9 Jun 2019 17:06:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560100003; bh=XgetBVUHZB7IorlSzlXg19e6QMGcHjs8QXLzyfF8Hg4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hjbQxsGZ99uQeIB2xcfn8kqyDMsjE4VPVFTa8XXPXAxl6hgGkwqjWt4yGTcEZ69FD y25mFzzCHA4PCTwpssar5s0a/T8qmO6ycW2YZOKdey7w+UUBwf9X338r+Lc+gXaCHZ gbiW44Oo9qx4iAHrYMoIW9RzoE0CEhd9JFm1Mrwg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389063AbfFIRGm (ORCPT ); Sun, 9 Jun 2019 13:06:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:46568 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389048AbfFIRGl (ORCPT ); Sun, 9 Jun 2019 13:06:41 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D90A3204EC; Sun, 9 Jun 2019 17:06:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560100000; bh=XgetBVUHZB7IorlSzlXg19e6QMGcHjs8QXLzyfF8Hg4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mCoTG0RsqdY46YWe4X/jbchv52UH0aNeXdSnJ7zyWJ8Cq3b1JCx4Qp8Uy0eGB+1gl XqJurXKWNTSQxe0kgMzeH0G8FWqpzKR0nt3Lmt4xiFr7m0yU7FnzdjGp8ZCZODlyhY tBnCYIlLrrZSBP8S6hwb/tjVhOHE7WHMqYpLOFoM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alan Maguire , David Ahern , "David S. Miller" Subject: [PATCH 4.4 230/241] neighbor: Call __ipv4_neigh_lookup_noref in neigh_xmit Date: Sun, 9 Jun 2019 18:42:52 +0200 Message-Id: <20190609164155.367695468@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190609164147.729157653@linuxfoundation.org> References: <20190609164147.729157653@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Ahern [ Upstream commit 4b2a2bfeb3f056461a90bd621e8bd7d03fa47f60 ] Commit cd9ff4de0107 changed the key for IFF_POINTOPOINT devices to INADDR_ANY but neigh_xmit which is used for MPLS encapsulations was not updated to use the altered key. The result is that every packet Tx does a lookup on the gateway address which does not find an entry, a new one is created only to find the existing one in the table right before the insert since arp_constructor was updated to reset the primary key. This is seen in the allocs and destroys counters: ip -s -4 ntable show | head -10 | grep alloc which increase for each packet showing the unnecessary overhread. Fix by having neigh_xmit use __ipv4_neigh_lookup_noref for NEIGH_ARP_TABLE. Fixes: cd9ff4de0107 ("ipv4: Make neigh lookup keys for loopback/point-to-point devices be INADDR_ANY") Reported-by: Alan Maguire Signed-off-by: David Ahern Tested-by: Alan Maguire Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/neighbour.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include #include @@ -2490,7 +2491,13 @@ int neigh_xmit(int index, struct net_dev if (!tbl) goto out; rcu_read_lock_bh(); - neigh = __neigh_lookup_noref(tbl, addr, dev); + if (index == NEIGH_ARP_TABLE) { + u32 key = *((u32 *)addr); + + neigh = __ipv4_neigh_lookup_noref(dev, key); + } else { + neigh = __neigh_lookup_noref(tbl, addr, dev); + } if (!neigh) neigh = __neigh_create(tbl, addr, dev, false); err = PTR_ERR(neigh);