Re: [PATCH] netfilter: nft_meta: fix bridge port vlan ID selector

[wenxu <wenxu@ucloud.cn>]

在 2019/7/3 20:40, Pablo Neira Ayuso 写道:
> Use br_vlan_enabled() and br_vlan_get_pvid() helpers as Nikolay
> suggests.
>
> Rename NFT_META_BRI_PVID to NFT_META_BRI_IIFPVID before this patch hits
> the 5.3 release cycle, to leave room for matching for the output bridge
> port in the future.
>
> Reported-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
> Fixes: da4f10a4265b ("netfilter: nft_meta: add NFT_META_BRI_PVID support")
> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
> ---
>  include/uapi/linux/netfilter/nf_tables.h |  4 ++--
>  net/netfilter/nft_meta.c                 | 17 ++++++++++-------
>  2 files changed, 12 insertions(+), 9 deletions(-)
>
> diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
> index 8859535031e2..8a1bd0b1ec8c 100644
> --- a/include/uapi/linux/netfilter/nf_tables.h
> +++ b/include/uapi/linux/netfilter/nf_tables.h
> @@ -795,7 +795,7 @@ 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
> + * @NFT_META_BRI_IIFPVID: packet input bridge port pvid
>   */
>  enum nft_meta_keys {
>  	NFT_META_LEN,
> @@ -826,7 +826,7 @@ enum nft_meta_keys {
>  	NFT_META_SECPATH,
>  	NFT_META_IIFKIND,
>  	NFT_META_OIFKIND,
> -	NFT_META_BRI_PVID,
> +	NFT_META_BRI_IIFPVID,
>  };
>  
>  /**
> diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
> index 4f8116de70f8..b8d8adc0852e 100644
> --- a/net/netfilter/nft_meta.c
> +++ b/net/netfilter/nft_meta.c
> @@ -240,14 +240,17 @@ 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:
> +	case NFT_META_BRI_IIFPVID: {
> +		u16 p_pvid;
> +
>  		if (in == NULL || (p = br_port_get_rtnl_rcu(in)) == NULL)
>  			goto err;
> -		if (br_opt_get(p->br, BROPT_VLAN_ENABLED)) {
> -			nft_reg_store16(dest, br_get_pvid(nbp_vlan_group_rcu(p)));
> -			return;
> -		}
> -		goto err;
> +		if (!br_vlan_enabled(in))
> +			goto err;
> +		br_vlan_get_pvid(in, &p_pvid);
I find the function br_vlan_get_pvid is ASSERT_RTNL();. But in this senario is under packet path.
> +		nft_reg_store16(dest, p_pvid);
> +		return;
> +	}
>  #endif
>  	case NFT_META_IIFKIND:
>  		if (in == NULL || in->rtnl_link_ops == NULL)
> @@ -375,7 +378,7 @@ static int nft_meta_get_init(const struct nft_ctx *ctx,
>  			return -EOPNOTSUPP;
>  		len = IFNAMSIZ;
>  		break;
> -	case NFT_META_BRI_PVID:
> +	case NFT_META_BRI_IIFPVID:
>  		if (ctx->family != NFPROTO_BRIDGE)
>  			return -EOPNOTSUPP;
>  		len = sizeof(u16);