netfilter: nft_numgen: add number generation offset

Add support of an offset value for incremental counter and random. With
this option the sysadmin is able to start the counter to a certain value
and then apply the generated number.

Example:

	meta mark set numgen inc mod 2 offset 100

This will generate marks with the serie 100, 101, 100, 101, ...

Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Laura Garcia Liebana <nevola@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 bc0eb6a1066d..bcfb892ff148 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -1136,12 +1136,14 @@ enum nft_trace_types {
  * @NFTA_NG_DREG: destination register (NLA_U32)
  * @NFTA_NG_MODULUS: maximum counter value (NLA_U32)
  * @NFTA_NG_TYPE: operation type (NLA_U32)
+ * @NFTA_NG_OFFSET: offset to be added to the counter (NLA_U32)
  */
 enum nft_ng_attributes {
         NFTA_NG_UNSPEC,
         NFTA_NG_DREG,
         NFTA_NG_MODULUS,
         NFTA_NG_TYPE,
+        NFTA_NG_OFFSET,
         __NFTA_NG_MAX
 };
 #define NFTA_NG_MAX     (__NFTA_NG_MAX - 1)