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 4:00 PM, Pablo Neira Ayuso wrote:
> On Wed, Aug 14, 2019 at 03:54:03PM +0800, wenxu wrote:
>> 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
> It seems there is no policy object for _get_eval(), add it.

you means like the NFTA_TUNNEL_KEY_IP have policy NFTA_TUNNEL_KEY_IP_DST

and NFTA_TUNNEL_KEY_IP_SRC


But I think it doesn't need to nested the policy for NFT_TUNNEL_IP which contains

NFT_TUNNEL_IP_SRC and NFT_TUNNE_IP_DST.

A match rule only can match one field (NFT_TUNNEL_ID, NFT_TUNNEL_IP_SRC,

NFT_TUNNEL_IP_DST, ieg)

>
> Thanks.
>