From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: [PATCH 2/3] netfilter: iptables: fix use of cluster match with 32 nodes Date: Fri, 24 Apr 2009 12:30:31 +0200 Message-ID: <20090424103031.30250.30352.stgit@Decadence> References: <20090424102534.30250.37215.stgit@Decadence> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: kaber@trash.net To: netfilter-devel@vger.kernel.org Return-path: Received: from mail.us.es ([193.147.175.20]:40433 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752674AbZDXKak (ORCPT ); Fri, 24 Apr 2009 06:30:40 -0400 In-Reply-To: <20090424102534.30250.37215.stgit@Decadence> Sender: netfilter-devel-owner@vger.kernel.org List-ID: This patch fixes a problem when you use 32 nodes in the cluster match: % iptables -I PREROUTING -t mangle -i eth0 -m cluster \ --cluster-total-nodes 32 --cluster-local-node 32 \ --cluster-hash-seed 0xdeadbeef -j MARK --set-mark 0xffff iptables: Invalid argument. Run `dmesg' for more information. % dmesg | tail -1 xt_cluster: this node mask cannot be higher than the total number of nodes The problem is related to this checking: if (info->node_mask >= (1 << info->total_nodes)) { printk(KERN_ERR "xt_cluster: this node mask cannot be " "higher than the total number of nodes\n"); return false; } (1 << 32) is 1. Thus, the checking fails. This patch skips the case in which total_nodes is 32 and it adds an extra validation to ensure that we don't go over 32 nodes. BTW, I said this before but I insist: I have only tested the cluster match with 2 nodes getting ~45% extra performance in an active-active setup. The maximum limit of 32 nodes is still completely arbitrary. I'd really appreciate if people that have more nodes in their setups let me know. Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/xt_cluster.h | 2 ++ net/netfilter/xt_cluster.c | 8 +++++++- 2 files changed, 9 insertions(+), 1 deletions(-) diff --git a/include/linux/netfilter/xt_cluster.h b/include/linux/netfilter/xt_cluster.h index 5e0a0d0..12c7b13 100644 --- a/include/linux/netfilter/xt_cluster.h +++ b/include/linux/netfilter/xt_cluster.h @@ -12,4 +12,6 @@ struct xt_cluster_match_info { u_int32_t flags; }; +#define XT_CLUSTER_NODES_MAX 32 + #endif /* _XT_CLUSTER_MATCH_H */ diff --git a/net/netfilter/xt_cluster.c b/net/netfilter/xt_cluster.c index 6c48476..04af29e 100644 --- a/net/netfilter/xt_cluster.c +++ b/net/netfilter/xt_cluster.c @@ -135,7 +135,13 @@ static bool xt_cluster_mt_checkentry(const struct xt_mtchk_param *par) { struct xt_cluster_match_info *info = par->matchinfo; - if (info->node_mask >= (1 << info->total_nodes)) { + if (info->total_nodes > XT_CLUSTER_NODES_MAX) { + printk(KERN_ERR "xt_cluster: too many total nodes (%u > %u)\n", + info->total_nodes, XT_CLUSTER_NODES_MAX); + return false; + } + if (info->total_nodes < XT_CLUSTER_NODES_MAX && + info->node_mask >= (1 << info->total_nodes)) { printk(KERN_ERR "xt_cluster: this node mask cannot be " "higher than the total number of nodes\n"); return false;