netfilter: nft_meta_bridge: Add NFT_META_BRI_IIFVPROTO support

This patch allows you to match on bridge vlan protocol, eg.

nft add rule bridge firewall zones counter meta ibrvproto 0x8100
Signed-off-by: wenxu <wenxu@ucloud.cn>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/uapi/linux/netfilter/nf_tables.h

@@ -796,6 +796,7 @@ enum nft_exthdr_attributes {
  * @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_IIFPVID: packet input bridge port pvid
+ * @NFT_META_BRI_IIFVPROTO: packet input bridge vlan proto
  */
 enum nft_meta_keys {
 	NFT_META_LEN,
@@ -827,6 +828,7 @@ enum nft_meta_keys {
 	NFT_META_IIFKIND,
 	NFT_META_OIFKIND,
 	NFT_META_BRI_IIFPVID,
+	NFT_META_BRI_IIFVPROTO,
 };
 
 /**

net/bridge/netfilter/nft_meta_bridge.c

@@ -49,6 +49,17 @@ static void nft_meta_bridge_get_eval(const struct nft_expr *expr,
 		nft_reg_store16(dest, p_pvid);
 		return;
 	}
+	case NFT_META_BRI_IIFVPROTO: {
+		u16 p_proto;
+
+		br_dev = nft_meta_get_bridge(in);
+		if (!br_dev || !br_vlan_enabled(br_dev))
+			goto err;
+
+		br_vlan_get_proto(br_dev, &p_proto);
+		nft_reg_store16(dest, p_proto);
+		return;
+	}
 	default:
 		goto out;
 	}
@@ -75,6 +86,7 @@ static int nft_meta_bridge_get_init(const struct nft_ctx *ctx,
 		len = IFNAMSIZ;
 		break;
 	case NFT_META_BRI_IIFPVID:
+	case NFT_META_BRI_IIFVPROTO:
 		len = sizeof(u16);
 		break;
 	default: