netfilter: nf_tables: nft_meta module get/set ops

This patch adds kernel support for the meta expression in get/set
flavour. The set operation indicates that a given packet has to be
set with a property, currently one of mark, priority, nftrace.
The get op is what was currently working: evaluate the given
packet property.

In the nftrace case, the value is always 1. Such behaviour is copied
from net/netfilter/xt_TRACE.c

The NFTA_META_DREG and NFTA_META_SREG attributes are mutually
exclusives.

Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index b25481e16f0a..aa86a15293e1 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -555,11 +555,13 @@ enum nft_meta_keys {
  *
  * @NFTA_META_DREG: destination register (NLA_U32)
  * @NFTA_META_KEY: meta data item to load (NLA_U32: nft_meta_keys)
+ * @NFTA_META_SREG: source register (NLA_U32)
  */
 enum nft_meta_attributes {
         NFTA_META_UNSPEC,
         NFTA_META_DREG,
         NFTA_META_KEY,
+        NFTA_META_SREG,
         __NFTA_META_MAX
 };
 #define NFTA_META_MAX           (__NFTA_META_MAX - 1)