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  • Pablo Neira Ayuso's avatar
    netfilter: xt_cluster: fix use of cluster match with 32 nodes · 280f37af
    Pablo Neira Ayuso authored
    
    
    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: default avatarPablo Neira Ayuso <pablo@netfilter.org>
    Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
    280f37af