sorry for this.

nftables should be set the token byetorder as BYTEORDER_HOST_ENDIAN


BR

wenxu

On 7/25/2019 4:31 PM, Pablo Neira Ayuso wrote:
> On Thu, Jul 25, 2019 at 03:43:53PM +0800, we...@ucloud.cn wrote:
>> From: wenxu <we...@ucloud.cn>
>>
>> In the action store tun_id to reg in a host endian.
> This is correct.
>
>> But the nft_cmp action get the user data in a net endian which lead
>> match failed.
>>
>> nft --debug=netlink add rule netdev firewall aclin ip daddr 10.0.0.7
>> tunnel tun_id 1000 fwd to eth0
>>
>> the expr tunnel tun_id 1000 --> [ cmp eq reg 1 0xe8030000 ]:
>> the cmp expr set the tun_id 1000 in network endian.
>>
>> So the tun_id should be store as network endian. Which is the
>> same as nft_payload match. 
>>
>> [ meta load protocol => reg 1 ]
>> [ cmp eq reg 1 0x00000008 ]
>> [ payload load 4b @ network header + 16 => reg 1 ]
>> [ cmp eq reg 1 0x0700000a ]
>> [ tunnel load id => reg 1 ]
>> [ cmp eq reg 1 0xe8030000 ]
>> [ immediate reg 1 0x0000000f ]
>> [ fwd sreg_dev 1 ]
>>
>> Fixes: aaecfdb5c5dd ("netfilter: nf_tables: match on tunnel metadata")
>> Signed-off-by: wenxu <we...@ucloud.cn>
>> ---
>>  net/netfilter/nft_tunnel.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/net/netfilter/nft_tunnel.c b/net/netfilter/nft_tunnel.c
>> index 3d4c2ae..c9f4585 100644
>> --- a/net/netfilter/nft_tunnel.c
>> +++ b/net/netfilter/nft_tunnel.c
>> @@ -53,7 +53,7 @@ static void nft_tunnel_get_eval(const struct nft_expr 
>> *expr,
>>                   !(tun_info->mode & IP_TUNNEL_INFO_TX)) ||
>>                  (priv->mode == NFT_TUNNEL_MODE_TX &&
>>                   (tun_info->mode & IP_TUNNEL_INFO_TX)))
>> -                    *dest = ntohl(tunnel_id_to_key32(tun_info->key.tun_id));
>> +                    *dest = tunnel_id_to_key32(tun_info->key.tun_id);
> Data is _never_ stored in network byteorder in registers.
>

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