On Tue, May 30, 2017 at 3:50 PM, Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> wrote:
> On Tue, May 30, 2017 at 12:08:55PM +0200, Pablo Neira Ayuso wrote:
>> On Tue, May 30, 2017 at 01:55:34PM +0530, Shyam Saini wrote:
>> > Add translation for cluster match to nftables
>> >
>> > $ sudo iptables-translate -A PREROUTING -t mangle -i eth1 -m cluster --cluster-total-nodes 2 --cluster-local-node 1 --cluster-hash-seed
>> > 0xdeadbeef -j MARK --set-mark 0xffff
>> > nft add rule ip mangle PREROUTING iifname eth1 jhash ct original saddr mod 2 seed 0xdeadbeef eq 0 meta pkttype set host counter meta mark set
>> > 0xffff
>> >
>> > $ sudo iptables-translate -A PREROUTING -t mangle -i eth1 -m cluster --cluster-total-nodes 2 --cluster-local-nodemask 1 --cluster-hash-seed
>> > 0xdeadbeef -j MARK --set-mark 0xffff
>> > nft add rule ip mangle PREROUTING iifname eth1 jhash ct original saddr mod 2 seed 0xdeadbeef eq 0 meta pkttype set host counter meta mark set
>> > 0xffff
>> >
>> > --debug=netlink Result
>> > ip mangle PREROUTING
>> > [ meta load iifname => reg 1 ]
>> > [ cmp eq reg 1 0x31687465 0x00000000 0x00000000 0x00000000 ]
>> > [ ct load src => reg 2 , dir original ]
>> > [ hash reg 1 = jhash(reg 2, 4, 0xdeadbeef) % mod 2 ]
>> > [ cmp eq reg 1 0x00000000 ]
>> > [ immediate reg 1 0x00000000 ]
>> > [ meta set pkttype with reg 1 ]
>> > [ counter pkts 0 bytes 0 ]
>> > [ immediate reg 1 0x0000ffff ]
>> > [ meta set mark with reg 1 ]
>> >
>> > For Example:
>> >
>> > If we have total 2 nodes (i.e, --cluster-total-nodes is 2) in the cluster then
>> > modulus 2 = {0, 1}
>> >
>> > For node 1 (--cluster-local-node 1)
>> > jhash ct original saddr mod 2 seed 0xdeadbeef eq 0
>> >
>> > For node 2 (--cluster-local-node 2)
>> > jhash ct original saddr mod 2 seed 0xdeadbeef eq 1
>> >
>> > Signed-off-by: Shyam Saini <mayhs11saini@xxxxxxxxx>
>> > ---
>> > extensions/libxt_cluster.c | 11 +++++++++++
>> > 1 file changed, 11 insertions(+)
>> >
>> > diff --git a/extensions/libxt_cluster.c b/extensions/libxt_cluster.c
>> > index 3adff12..f2abd18 100644
>> > --- a/extensions/libxt_cluster.c
>> > +++ b/extensions/libxt_cluster.c
>> > @@ -126,6 +126,16 @@ cluster_save(const void *ip, const struct xt_entry_match *match)
>> > info->total_nodes, info->hash_seed);
>> > }
>> >
>> > +static int cluster_xlate(struct xt_xlate *xl,
>> > + const struct xt_xlate_mt_params *params)
>> > +{
>> > + const struct xt_cluster_match_info *info = (const struct xt_cluster_match_info *)params->match->data;
>> > +
>> > + xt_xlate_add(xl, "jhash ct original saddr mod %u seed 0x%08x eq 0 meta pkttype set host",
>>
>> This should use "eq %u" because:
>>
>> xt_xlate_add(xl, "jhash ct original saddr mod %u seed 0x%08x eq %u meta pkttype set host",
>
> Forget this I mentioned below, got mixed with another email to you.
>
> What I'm telling here is, the "eq %u" should be used to translate
> info->node_mask.
>
> Note that info->node_mask is a bitmask, so you have to interpret this
> accordingly from the translation.
by this you mean, we have to take bitwise AND with generated jhash?
http://elixir.free-electrons.com/linux/latest/source/net/netfilter/xt_cluster.c#L132
> Note that we have to support --cluster-local-nodemask too, you can
> translate this using a set, ie.
>
> jhash ct original saddr mod 4 seed 0x1234 { 0, 1 } meta pkttype set host
>
Translation should print set of node id depending on the number of nodes.
For example for total_nodes = 4, it should print
jhash ct original saddr mod 4 seed 0x1234 { 0, 1, 2, 3 } meta pkttype set host
Right?
> OK?
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