From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Westphal Subject: [PATCH v5 nf-next 2/4] netfilter: labels: don't emit ct event if labels were not changed Date: Tue, 12 Apr 2016 18:14:24 +0200 Message-ID: <1460477666-17823-3-git-send-email-fw@strlen.de> References: <1460477666-17823-1-git-send-email-fw@strlen.de> Cc: Florian Westphal To: Return-path: Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:37353 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751120AbcDLQOP (ORCPT ); Tue, 12 Apr 2016 12:14:15 -0400 In-Reply-To: <1460477666-17823-1-git-send-email-fw@strlen.de> Sender: netfilter-devel-owner@vger.kernel.org List-ID: make the replace function only send a ctnetlink event if the contents of the new set is different. Otherwise 'ct label set ct label | bar' will cause netlink event storm since we "replace" labels for each packet. Signed-off-by: Florian Westphal --- No changes since last version. net/netfilter/nf_conntrack_labels.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/net/netfilter/nf_conntrack_labels.c b/net/netfilter/nf_conntrack_labels.c index 3a30900..bd7f26b 100644 --- a/net/netfilter/nf_conntrack_labels.c +++ b/net/netfilter/nf_conntrack_labels.c @@ -33,14 +33,18 @@ int nf_connlabel_set(struct nf_conn *ct, u16 bit) } EXPORT_SYMBOL_GPL(nf_connlabel_set); -static void replace_u32(u32 *address, u32 mask, u32 new) +static int replace_u32(u32 *address, u32 mask, u32 new) { u32 old, tmp; do { old = *address; tmp = (old & mask) ^ new; + if (old == tmp) + return 0; } while (cmpxchg(address, old, tmp) != old); + + return 1; } int nf_connlabels_replace(struct nf_conn *ct, @@ -49,6 +53,7 @@ int nf_connlabels_replace(struct nf_conn *ct, { struct nf_conn_labels *labels; unsigned int size, i; + int changed = 0; u32 *dst; labels = nf_ct_labels_find(ct); @@ -60,16 +65,15 @@ int nf_connlabels_replace(struct nf_conn *ct, words32 = size / sizeof(u32); dst = (u32 *) labels->bits; - if (words32) { - for (i = 0; i < words32; i++) - replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]); - } + for (i = 0; i < words32; i++) + changed |= replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]); size /= sizeof(u32); for (i = words32; i < size; i++) /* pad */ replace_u32(&dst[i], 0, 0); - nf_conntrack_event_cache(IPCT_LABEL, ct); + if (changed) + nf_conntrack_event_cache(IPCT_LABEL, ct); return 0; } EXPORT_SYMBOL_GPL(nf_connlabels_replace); -- 2.7.3