From patchwork Mon Jul 11 08:48:45 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Miller X-Patchwork-Id: 104187 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id C3CE5B6F64 for ; Mon, 11 Jul 2011 18:49:02 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757460Ab1GKIs5 (ORCPT ); Mon, 11 Jul 2011 04:48:57 -0400 Received: from shards.monkeyblade.net ([198.137.202.13]:55704 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757440Ab1GKIs4 (ORCPT ); Mon, 11 Jul 2011 04:48:56 -0400 Received: from localhost (74-93-104-98-Washington.hfc.comcastbusiness.net [74.93.104.98]) (authenticated bits=0) by shards.monkeyblade.net (8.14.4/8.14.4) with ESMTP id p6B8mjJg018889 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 11 Jul 2011 01:48:47 -0700 Date: Mon, 11 Jul 2011 01:48:45 -0700 (PDT) Message-Id: <20110711.014845.1009062692530385177.davem@davemloft.net> To: roland@purestorage.com Cc: johnwheffner@gmail.com, mj@ucw.cz, netdev@vger.kernel.org Subject: [PATCH 2/2] ipv4: Use universal hash for ARP. From: David Miller X-Mailer: Mew version 6.3 on Emacs 23.2 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (shards.monkeyblade.net [198.137.202.13]); Mon, 11 Jul 2011 01:48:47 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org We need to make sure the multiplier is odd. Signed-off-by: David S. Miller --- include/net/arp.h | 7 +++++++ net/core/neighbour.c | 1 + net/ipv4/arp.c | 3 +-- 3 files changed, 9 insertions(+), 2 deletions(-) diff --git a/include/net/arp.h b/include/net/arp.h index 91f0568..723bde5 100644 --- a/include/net/arp.h +++ b/include/net/arp.h @@ -8,6 +8,13 @@ extern struct neigh_table arp_tbl; +static inline u32 arp_hashfn(u32 key, const struct net_device *dev, u32 hash_rnd) +{ + u32 val = key ^ dev->ifindex; + + return val * hash_rnd; +} + extern void arp_init(void); extern int arp_find(unsigned char *haddr, struct sk_buff *skb); extern int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg); diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 4d5fc94..50bd960 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -334,6 +334,7 @@ static struct neigh_hash_table *neigh_hash_alloc(unsigned int shift) ret->hash_buckets = buckets; ret->hash_shift = shift; get_random_bytes(&ret->hash_rnd, sizeof(ret->hash_rnd)); + ret->hash_rnd |= 1; return ret; } diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index 1b74d3b..4412b57 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -97,7 +97,6 @@ #include #include #include -#include #include #ifdef CONFIG_SYSCTL #include @@ -232,7 +231,7 @@ static u32 arp_hash(const void *pkey, const struct net_device *dev, __u32 hash_rnd) { - return jhash_2words(*(u32 *)pkey, dev->ifindex, hash_rnd); + return arp_hashfn(*(u32 *)pkey, dev, hash_rnd); } static int arp_constructor(struct neighbour *neigh)