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

From: Pablo Neira Ayuso <pablo@netfilter.org>
To: wenxu <wenxu@ucloud.cn>
Cc: fw@strlen.de, netfilter-devel@vger.kernel.org
Subject: Re: [PATCH nf-next v3 5/9] netfilter: nft_tunnel: support NFT_TUNNEL_SRC/DST_IP match
Date: Wed, 14 Aug 2019 10:00:37 +0200	[thread overview]
Message-ID: <20190814080037.w7xi2htgshg2adsd@salvia> (raw)
In-Reply-To: <ba98af8c-fcd3-50dd-770d-ddb85a887031@ucloud.cn>

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.

Thanks.