netfilter: nft_meta_bridge: add NFT_META_BRI_IIFPVID support

This patch allows you to match on the bridge port pvid, eg.

nft add rule bridge firewall zones counter meta ibrpvid 10

Signed-off-by: wenxu <[email protected]>
Reviewed-by: Nikolay Aleksandrov <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>

Author: wenxu

include/uapi/linux/netfilter/nf_tables.h

@@ -795,6 +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_IIFPVID: packet input bridge port pvid
  */
 enum nft_meta_keys {
 	NFT_META_LEN,
@@ -825,6 +826,7 @@ enum nft_meta_keys {
 	NFT_META_SECPATH,
 	NFT_META_IIFKIND,
 	NFT_META_OIFKIND,
+	NFT_META_BRI_IIFPVID,
 };
 
 /**

net/bridge/netfilter/nft_meta_bridge.c

@@ -7,6 +7,7 @@
 #include <linux/netfilter/nf_tables.h>
 #include <net/netfilter/nf_tables.h>
 #include <net/netfilter/nft_meta.h>
+#include <linux/if_bridge.h>
 
 static const struct net_device *
 nft_meta_get_bridge(const struct net_device *dev)
@@ -37,6 +38,17 @@ static void nft_meta_bridge_get_eval(const struct nft_expr *expr,
 		if (!br_dev)
 			goto err;
 		break;
+	case NFT_META_BRI_IIFPVID: {
+		u16 p_pvid;
+
+		br_dev = nft_meta_get_bridge(in);
+		if (!br_dev || !br_vlan_enabled(br_dev))
+			goto err;
+
+		br_vlan_get_pvid_rcu(in, &p_pvid);
+		nft_reg_store16(dest, p_pvid);
+		return;
+	}
 	default:
 		goto out;
 	}
@@ -62,6 +74,9 @@ static int nft_meta_bridge_get_init(const struct nft_ctx *ctx,
 	case NFT_META_BRI_OIFNAME:
 		len = IFNAMSIZ;
 		break;
+	case NFT_META_BRI_IIFPVID:
+		len = sizeof(u16);
+		break;
 	default:
 		return nft_meta_get_init(ctx, expr, tb);
 	}