Re: [PATCH 1/2 nf-next] netfilter: nft_meta: add NFT_META_BRI_PVID support

[wenxu <wenxu@ucloud.cn>]

I will post the nftable patches latter. Thanks!

在 2019/6/20 1:02, Pablo Neira Ayuso 写道:
> On Wed, Jun 19, 2019 at 03:16:24PM +0800, wenxu@ucloud.cn wrote:
>> From: wenxu <wenxu@ucloud.cn>
>>
>> nft add table bridge firewall
>> nft add chain bridge firewall zones { type filter hook prerouting priority - 300 \; }
>> nft add rule bridge firewall zones counter ct zone set vlan id map { 100 : 1, 200 : 2 }
>> As above set the bridge port with pvid, the received packet don't contain
>> the vlan tag which means the packet should belong to vlan 200 through pvid.
>> With this pacth user can get the pvid of bridge ports: "meta brpvid"
> Would you also post the patches for nftables for review?
>
> Would you post an example on how you use "meta brpvid" in your
> ruleset? I don't see this is used in the example above,
>
> More comments below.
>
>> Signed-off-by: wenxu <wenxu@ucloud.cn>
>> ---
>>  include/uapi/linux/netfilter/nf_tables.h |  2 ++
>>  net/netfilter/nft_meta.c                 | 17 +++++++++++++++++
>>  2 files changed, 19 insertions(+)
>>
>> diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
>> index 31a6b8f..4a16124 100644
>> --- a/include/uapi/linux/netfilter/nf_tables.h
>> +++ b/include/uapi/linux/netfilter/nf_tables.h
>> @@ -793,6 +793,7 @@ enum nft_exthdr_attributes {
>>   * @NFT_META_SECPATH: boolean, secpath_exists (!!skb->sp)
>>   * @NFT_META_IIFKIND: packet input interface kind name (dev->rtnl_link_ops->kind)
>>   * @NFT_META_OIFKIND: packet output interface kind name (dev->rtnl_link_ops->kind)
>> + * @NFT_META_BRI_PVID: packet input bridge port pvid
>>   */
>>  enum nft_meta_keys {
>>  	NFT_META_LEN,
>> @@ -823,6 +824,7 @@ enum nft_meta_keys {
>>  	NFT_META_SECPATH,
>>  	NFT_META_IIFKIND,
>>  	NFT_META_OIFKIND,
>> +	NFT_META_BRI_PVID,
>>  };
>>  
>>  /**
>> diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
>> index 987d2d6..1fdb565 100644
>> --- a/net/netfilter/nft_meta.c
>> +++ b/net/netfilter/nft_meta.c
>> @@ -243,6 +243,18 @@ void nft_meta_get_eval(const struct nft_expr *expr,
>>  			goto err;
>>  		strncpy((char *)dest, p->br->dev->name, IFNAMSIZ);
>>  		return;
>> +	case NFT_META_BRI_PVID:
>> +		if (in == NULL || (p = br_port_get_rtnl_rcu(in)) == NULL)
>> +			goto err;
>> +		if (br_opt_get(p->br, BROPT_VLAN_ENABLED)) {
>> +			u16 pvid = br_get_pvid(nbp_vlan_group_rcu(p));
>> +
>> +			if (pvid) {
>> +				nft_reg_store16(dest, pvid);
> I think you should store pvid into dest if pvid is zero too, right?
> You cannot assume destination register is set to zero.
>
>> +				return;
>> +			}
>> +		}
>> +		goto err;
>>  #endif
>>  	case NFT_META_IIFKIND:
>>  		if (in == NULL || in->rtnl_link_ops == NULL)
>> @@ -370,6 +382,11 @@ static int nft_meta_get_init(const struct nft_ctx *ctx,
>>  			return -EOPNOTSUPP;
>>  		len = IFNAMSIZ;
>>  		break;
>> +	case NFT_META_BRI_PVID:
>> +		if (ctx->family != NFPROTO_BRIDGE)
>> +			return -EOPNOTSUPP;
>> +		len = sizeof(u16);
>> +		break;
>>  #endif
>>  	default:
>>  		return -EOPNOTSUPP;
>> -- 
>> 1.8.3.1
>>