add exthdr expressions

3 files changed, 50 insertions, 0 deletions

diff --git a/src/error.rs b/src/error.rs
index 80f06d7..fa0e26f 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -70,6 +70,9 @@ pub enum DecodeError {
     #[error("Invalid type for a conntrack key")]
     UnknownConntrackKey(u32),
 
+    #[error("Invalid type for an extension header expression")]
+    UnknownExtHdrOp(u32),
+
     #[error("Unsupported value for a link layer header field")]
     UnknownLinkLayerHeaderField(u32, u32),
 
diff --git a/src/expr/exthdr.rs b/src/expr/exthdr.rs
new file mode 100644
index 0000000..954b394
--- /dev/null
+++ b/src/expr/exthdr.rs
@@ -0,0 +1,44 @@
+use rustables_macros::{nfnetlink_enum, nfnetlink_struct};
+
+use crate::sys::{
+    NFTA_EXTHDR_DREG, NFTA_EXTHDR_FLAGS, NFTA_EXTHDR_LEN, NFTA_EXTHDR_OFFSET, NFTA_EXTHDR_OP,
+    NFTA_EXTHDR_SREG, NFTA_EXTHDR_TYPE, NFT_EXTHDR_OP_IPV6, NFT_EXTHDR_OP_TCPOPT,
+};
+
+use super::{Expression, Register};
+
+/// Header operation.
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[nfnetlink_enum(u32, nested = true)]
+pub enum ExtHdrOp {
+    /// IPv6.
+    Ipv6 = NFT_EXTHDR_OP_IPV6,
+    /// TCP options.
+    TcpOpt = NFT_EXTHDR_OP_TCPOPT,
+}
+
+/// Interacts with layer 4 header options.
+#[derive(Default, Debug, Clone, PartialEq, Eq)]
+#[nfnetlink_struct(nested = true)]
+pub struct ExtHdr {
+    #[field(NFTA_EXTHDR_DREG)]
+    dreg: Register,
+    #[field(NFTA_EXTHDR_TYPE)]
+    typ: u8,
+    #[field(NFTA_EXTHDR_OFFSET)]
+    offset: u32,
+    #[field(NFTA_EXTHDR_LEN)]
+    len: u32,
+    #[field(NFTA_EXTHDR_FLAGS)]
+    flags: u32,
+    #[field(NFTA_EXTHDR_OP)]
+    op: ExtHdrOp,
+    #[field(NFTA_EXTHDR_SREG)]
+    sreg: Register,
+}
+
+impl Expression for ExtHdr {
+    fn get_name() -> &'static str {
+        "exthdr"
+    }
+}
diff --git a/src/expr/mod.rs b/src/expr/mod.rs
index af29460..b0d9d51 100644
--- a/src/expr/mod.rs
+++ b/src/expr/mod.rs
@@ -24,6 +24,9 @@ pub use self::counter::*;
 pub mod ct;
 pub use self::ct::*;
 
+pub mod exthdr;
+pub use self::exthdr::*;
+
 mod immediate;
 pub use self::immediate::*;