1 files changed, 113 insertions, 0 deletions
diff --git a/rustables/src/expr/mod.rs b/rustables/src/expr/mod.rs
new file mode 100644
index 0000000..1364904
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+++ b/rustables/src/expr/mod.rs
@@ -0,0 +1,113 @@
+//! A module with all the nftables expressions that can be added to [`Rule`]s to build up how
+//! they match against packets.
+//!
+//! [`Rule`]: struct.Rule.html
+
+use super::rule::Rule;
+use rustables_sys::{self as sys, libc};
+
+/// Trait for every safe wrapper of an nftables expression.
+pub trait Expression {
+    /// Allocates and returns the low level `nftnl_expr` representation of this expression.
+    /// The caller to this method is responsible for freeing the 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::*;
+
+mod cmp;
+pub use self::cmp::*;
+
+mod counter;
+pub use self::counter::*;
+
+pub mod ct;
+pub use self::ct::*;
+
+mod immediate;
+pub use self::immediate::*;
+
+mod log;
+pub use self::log::*;
+
+mod lookup;
+pub use self::lookup::*;
+
+mod masquerade;
+pub use self::masquerade::*;
+
+mod meta;
+pub use self::meta::*;
+
+mod nat;
+pub use self::nat::*;
+
+mod payload;
+pub use self::payload::*;
+
+mod verdict;
+pub use self::verdict::*;
+
+#[macro_export(local_inner_macros)]
+macro_rules! nft_expr {
+    (bitwise mask $mask:expr,xor $xor:expr) => {
+        nft_expr_bitwise!(mask $mask, xor $xor)
+    };
+    (cmp $op:tt $data:expr) => {
+        nft_expr_cmp!($op $data)
+    };
+    (counter) => {
+        $crate::expr::Counter
+    };
+    (ct $key:ident set) => {
+        nft_expr_ct!($key set)
+    };
+    (ct $key:ident) => {
+        nft_expr_ct!($key)
+    };
+    (immediate $expr:ident $value:expr) => {
+        nft_expr_immediate!($expr $value)
+    };
+    (log) => {
+        nft_expr_log!()
+    };
+    (lookup $set:expr) => {
+        nft_expr_lookup!($set)
+    };
+    (masquerade) => {
+        $crate::expr::Masquerade
+    };
+    (meta $expr:ident set) => {
+        nft_expr_meta!($expr set)
+    };
+    (meta $expr:ident) => {
+        nft_expr_meta!($expr)
+    };
+    (payload $proto:ident $field:ident) => {
+        nft_expr_payload!($proto $field)
+    };
+    (verdict $verdict:ident) => {
+        nft_expr_verdict!($verdict)
+    };
+    (verdict $verdict:ident $chain:expr) => {
+        nft_expr_verdict!($verdict $chain)
+    };
+}