From 280f37afa2c270ff029cb420b34396aa002909c3 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 5 May 2009 17:46:07 +0200 Subject: [PATCH] netfilter: xt_cluster: fix use of cluster match with 32 nodes 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. 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 Signed-off-by: Patrick McHardy --- include/linux/netfilter/xt_cluster.h | 2 ++ net/netfilter/xt_cluster.c | 8 +++++++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/include/linux/netfilter/xt_cluster.h b/include/linux/netfilter/xt_cluster.h index 5e0a0d0..8866826 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..69a639f 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: you have exceeded the maximum " + "number of cluster nodes (%u > %u)\n", + info->total_nodes, XT_CLUSTER_NODES_MAX); + return false; + } + if (info->node_mask >= (1ULL << info->total_nodes)) { printk(KERN_ERR "xt_cluster: this node mask cannot be " "higher than the total number of nodes\n"); return false; -- 1.8.2.3