From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH] netfilter: unfold two loops in physdev_mt() Date: Thu, 19 Feb 2009 09:00:11 +0100 Message-ID: <499D118B.1040309@cosmosbay.com> References: <497F4C2F.9000804@hp.com> <497F5BCD.9060807@hp.com> <497F5F86.9010101@hp.com> <498063E7.5030106@cosmosbay.com> <49808708.3050502@trash.net> <498090C1.5020400@cosmosbay.com> <49809716.3020204@cosmosbay.com> <4981CBE2.5020306@cosmosbay.com> <87ocxox0bu.fsf@basil.nowhere.org> <498330B2.4060004@cosmosbay.com> <20090130172705.GB18453@one.firstfloor.org> <499032A4.9090301@trash.net> <499C24FF.90302@cosmosbay.com> <499C2766.5090904@trash.net> <499C3871.4030600@cosmosbay.com> <499C4739.3000800@cosmosbay.com> <499C4FEB.7040706@trash.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , Netfilter Developers , Linux Network Development list To: Patrick McHardy Return-path: Received: from gw1.cosmosbay.com ([212.99.114.194]:44836 "EHLO gw1.cosmosbay.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751556AbZBSIAY (ORCPT ); Thu, 19 Feb 2009 03:00:24 -0500 In-Reply-To: <499C4FEB.7040706@trash.net> Sender: netdev-owner@vger.kernel.org List-ID: xt_physdev netfilter module can use an ifname_compare() helper so that two loops are unfolded. Signed-off-by: Eric Dumazet --- net/netfilter/xt_physdev.c | 32 +++++++++++++++++++++----------- 1 files changed, 21 insertions(+), 11 deletions(-) diff --git a/net/netfilter/xt_physdev.c b/net/netfilter/xt_physdev.c index 4b13ef7..44a234e 100644 --- a/net/netfilter/xt_physdev.c +++ b/net/netfilter/xt_physdev.c @@ -20,10 +20,27 @@ MODULE_DESCRIPTION("Xtables: Bridge physical device match"); MODULE_ALIAS("ipt_physdev"); MODULE_ALIAS("ip6t_physdev"); +static unsigned long ifname_compare(const char *_a, const char *_b, const char *_mask) +{ + const unsigned long *a = (const unsigned long *)_a; + const unsigned long *b = (const unsigned long *)_b; + const unsigned long *mask = (const unsigned long *)_mask; + unsigned long ret; + + ret = (a[0] ^ b[0]) & mask[0]; + if (IFNAMSIZ > sizeof(unsigned long)) + ret |= (a[1] ^ b[1]) & mask[1]; + if (IFNAMSIZ > 2 * sizeof(unsigned long)) + ret |= (a[2] ^ b[2]) & mask[2]; + if (IFNAMSIZ > 3 * sizeof(unsigned long)) + ret |= (a[3] ^ b[3]) & mask[3]; + BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long)); + return ret; +} + static bool physdev_mt(const struct sk_buff *skb, const struct xt_match_param *par) { - int i; static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); const struct xt_physdev_info *info = par->matchinfo; unsigned long ret; @@ -68,11 +85,7 @@ physdev_mt(const struct sk_buff *skb, const struct xt_match_param *par) if (!(info->bitmask & XT_PHYSDEV_OP_IN)) goto match_outdev; indev = nf_bridge->physindev ? nf_bridge->physindev->name : nulldevname; - for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { - ret |= (((const unsigned long *)indev)[i] - ^ ((const unsigned long *)info->physindev)[i]) - & ((const unsigned long *)info->in_mask)[i]; - } + ret = ifname_compare(indev, info->physindev, info->in_mask); if (!ret ^ !(info->invert & XT_PHYSDEV_OP_IN)) return false; @@ -82,11 +95,8 @@ match_outdev: return true; outdev = nf_bridge->physoutdev ? nf_bridge->physoutdev->name : nulldevname; - for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { - ret |= (((const unsigned long *)outdev)[i] - ^ ((const unsigned long *)info->physoutdev)[i]) - & ((const unsigned long *)info->out_mask)[i]; - } + ret = ifname_compare(outdev, info->physoutdev, info->out_mask); + return (!!ret ^ !(info->invert & XT_PHYSDEV_OP_OUT)); }