Re: [PATCH nf-next v3 5/9] netfilter: nft_tunnel: support NFT_TUNNEL_SRC/DST_IP match

[wenxu <wenxu@ucloud.cn>]

On 8/14/2019 2:19 AM, Pablo Neira Ayuso wrote:
> On Thu, Aug 01, 2019 at 10:01:22PM +0800, wenxu@ucloud.cn wrote:
>> From: wenxu <wenxu@ucloud.cn>
>>
>> Add new two NFT_TUNNEL_SRC/DST_IP match in nft_tunnel
>>
>> Signed-off-by: wenxu <wenxu@ucloud.cn>
>> ---
>> v3: no change
>>
>>  include/uapi/linux/netfilter/nf_tables.h |  2 ++
>>  net/netfilter/nft_tunnel.c               | 46 +++++++++++++++++++++++++-------
>>  2 files changed, 38 insertions(+), 10 deletions(-)
>>
>> diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
>> index 82abaa1..173690a 100644
>> --- a/include/uapi/linux/netfilter/nf_tables.h
>> +++ b/include/uapi/linux/netfilter/nf_tables.h
>> @@ -1765,6 +1765,8 @@ enum nft_tunnel_key_attributes {
>>  enum nft_tunnel_keys {
>>  	NFT_TUNNEL_PATH,
>>  	NFT_TUNNEL_ID,
>> +	NFT_TUNNEL_SRC_IP,
>> +	NFT_TUNNEL_DST_IP,
>>  	__NFT_TUNNEL_MAX
>>  };
>>  #define NFT_TUNNEL_MAX	(__NFT_TUNNEL_MAX - 1)
>> diff --git a/net/netfilter/nft_tunnel.c b/net/netfilter/nft_tunnel.c
>> index 3d4c2ae..e218163 100644
>> --- a/net/netfilter/nft_tunnel.c
>> +++ b/net/netfilter/nft_tunnel.c
>> @@ -18,6 +18,18 @@ struct nft_tunnel {
>>  	enum nft_tunnel_mode	mode:8;
>>  };
>>  
>> +bool nft_tunnel_mode_validate(enum nft_tunnel_mode priv_mode, u8 tun_mode)
>> +{
>> +	if (priv_mode == NFT_TUNNEL_MODE_NONE ||
>> +	    (priv_mode == NFT_TUNNEL_MODE_RX &&
>> +	     !(tun_mode & IP_TUNNEL_INFO_TX)) ||
>> +	    (priv_mode == NFT_TUNNEL_MODE_TX &&
>> +	     (tun_mode & IP_TUNNEL_INFO_TX)))
>> +		return true;
>> +
>> +	return false;
>> +}
> Make an initial patch to add nft_tunnel_mode_validate().
>
>>  static void nft_tunnel_get_eval(const struct nft_expr *expr,
>>  				struct nft_regs *regs,
>>  				const struct nft_pktinfo *pkt)
>> @@ -34,11 +46,7 @@ static void nft_tunnel_get_eval(const struct nft_expr *expr,
>>  			nft_reg_store8(dest, false);
>>  			return;
>>  		}
>> -		if (priv->mode == NFT_TUNNEL_MODE_NONE ||
>> -		    (priv->mode == NFT_TUNNEL_MODE_RX &&
>> -		     !(tun_info->mode & IP_TUNNEL_INFO_TX)) ||
>> -		    (priv->mode == NFT_TUNNEL_MODE_TX &&
>> -		     (tun_info->mode & IP_TUNNEL_INFO_TX)))
>> +		if (nft_tunnel_mode_validate(priv->mode, tun_info->mode))
>>  			nft_reg_store8(dest, true);
>>  		else
>>  			nft_reg_store8(dest, false);
> [...]
>> +	case NFT_TUNNEL_DST_IP:
>> +		if (!tun_info) {
>> +			regs->verdict.code = NFT_BREAK;
>> +			return;
>> +		}
>> +		if (nft_tunnel_mode_validate(priv->mode, tun_info->mode))
>> +			*dest = ntohl(tun_info->key.u.ipv4.dst);
> No need to convert this from network to host endianess.
>
>> +		else
>> +			regs->verdict.code = NFT_BREAK;
>> +		break;
>>  	default:
>>  		WARN_ON(1);
>>  		regs->verdict.code = NFT_BREAK;
>> @@ -86,6 +110,8 @@ static int nft_tunnel_get_init(const struct nft_ctx *ctx,
>>  		len = sizeof(u8);
>>  		break;
>>  	case NFT_TUNNEL_ID:
>> +	case NFT_TUNNEL_SRC_IP:
>> +	case NFT_TUNNEL_DST_IP:
> Missing policy updates, ie. nft_tunnel_key_policy.

I don't understand why it need update nft_tunnel_key_policy
which is used for tunnel_obj action. This NFT_TUNNEL_SRC/DST_IP is used
for tunnel_expr

>