1 files changed, 18 insertions, 1 deletions
diff --git a/nftnl/src/expr/mod.rs b/nftnl/src/expr/mod.rs
index e4c4adb..19a9d3f 100644
--- a/nftnl/src/expr/mod.rs
+++ b/nftnl/src/expr/mod.rs
@@ -4,7 +4,7 @@
 //! [`Rule`]: struct.Rule.html
 
 use super::rule::Rule;
-use nftnl_sys as sys;
+use nftnl_sys::{self as sys, libc};
 
 /// Trait for every safe wrapper of an nftables expression.
 pub trait Expression {
@@ -13,6 +13,23 @@ pub trait Expression {
     fn to_expr(&self, rule: &Rule) -> *mut sys::nftnl_expr;
 }
 
+/// A netfilter data register. The expressions store and read data to and from these
+/// when evaluating rule statements.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+#[repr(i32)]
+pub enum Register {
+    Reg1 = libc::NFT_REG_1,
+    Reg2 = libc::NFT_REG_2,
+    Reg3 = libc::NFT_REG_3,
+    Reg4 = libc::NFT_REG_4,
+}
+
+impl Register {
+    pub fn to_raw(self) -> u32 {
+        self as u32
+    }
+}
+
 mod bitwise;
 pub use self::bitwise::*;