1 files changed, 69 insertions, 0 deletions
diff --git a/src/expr/bitwise.rs b/src/expr/bitwise.rs
new file mode 100644
index 0000000..59ef41b
--- /dev/null
+++ b/src/expr/bitwise.rs
@@ -0,0 +1,69 @@
+use super::{Expression, Rule, ToSlice};
+use crate::sys::{self, libc};
+use std::ffi::c_void;
+use std::os::raw::c_char;
+
+/// Expression for performing bitwise masking and XOR on the data in a register.
+pub struct Bitwise<M: ToSlice, X: ToSlice> {
+    mask: M,
+    xor: X,
+}
+
+impl<M: ToSlice, X: ToSlice> Bitwise<M, X> {
+    /// Returns a new `Bitwise` instance that first masks the value it's applied to with `mask`
+    /// and then performs xor with the value in `xor`.
+    pub fn new(mask: M, xor: X) -> Self {
+        Self { mask, xor }
+    }
+}
+
+impl<M: ToSlice, X: ToSlice> Expression for Bitwise<M, X> {
+    fn get_raw_name() -> *const c_char {
+        b"bitwise\0" as *const _ as *const c_char
+    }
+
+    fn to_expr(&self, _rule: &Rule) -> *mut sys::nftnl_expr {
+        unsafe {
+            let expr = try_alloc!(sys::nftnl_expr_alloc(Self::get_raw_name()));
+
+            let mask = self.mask.to_slice();
+            let xor = self.xor.to_slice();
+            assert!(mask.len() == xor.len());
+            let len = mask.len() as u32;
+
+            sys::nftnl_expr_set_u32(
+                expr,
+                sys::NFTNL_EXPR_BITWISE_SREG as u16,
+                libc::NFT_REG_1 as u32,
+            );
+            sys::nftnl_expr_set_u32(
+                expr,
+                sys::NFTNL_EXPR_BITWISE_DREG as u16,
+                libc::NFT_REG_1 as u32,
+            );
+            sys::nftnl_expr_set_u32(expr, sys::NFTNL_EXPR_BITWISE_LEN as u16, len);
+
+            sys::nftnl_expr_set(
+                expr,
+                sys::NFTNL_EXPR_BITWISE_MASK as u16,
+                mask.as_ref() as *const _ as *const c_void,
+                len,
+            );
+            sys::nftnl_expr_set(
+                expr,
+                sys::NFTNL_EXPR_BITWISE_XOR as u16,
+                xor.as_ref() as *const _ as *const c_void,
+                len,
+            );
+
+            expr
+        }
+    }
+}
+
+#[macro_export]
+macro_rules! nft_expr_bitwise {
+    (mask $mask:expr,xor $xor:expr) => {
+        $crate::expr::Bitwise::new($mask, $xor)
+    };
+}