MPLS constants and NLAs

netlink-packet-route/src/rtnl/constants.rs

@@ -1201,3 +1201,17 @@ pub const IFLA_XDP_PROG_ID: u32 = 4;
 // pub const PREFIX_UNSPEC: int = 0;
 // pub const PREFIX_ADDRESS: int = 1;
 // pub const PREFIX_CACHEINFO: int = 2;
+
+pub const LWTUNNEL_ENCAP_NONE: u16 = 0;
+pub const LWTUNNEL_ENCAP_MPLS: u16 = 1;
+pub const LWTUNNEL_ENCAP_IP: u16 = 2;
+pub const LWTUNNEL_ENCAP_ILA: u16 = 3;
+pub const LWTUNNEL_ENCAP_IP6: u16 = 4;
+pub const LWTUNNEL_ENCAP_SEG6: u16 = 5;
+pub const LWTUNNEL_ENCAP_BPF: u16 = 6;
+pub const LWTUNNEL_ENCAP_SEG6_LOCAL: u16 = 7;
+pub const LWTUNNEL_ENCAP_RPL: u16 = 8;
+
+pub const MPLS_IPTUNNEL_UNSPEC: u16 = 0;
+pub const MPLS_IPTUNNEL_DST: u16 = 1;
+pub const MPLS_IPTUNNEL_TTL: u16 = 2;

netlink-packet-route/src/rtnl/route/nlas/mod.rs

@@ -9,6 +9,9 @@ pub use self::metrics::*;
 mod mfc_stats;
 pub use self::mfc_stats::*;
 
+mod mpls_ip_tunnel;
+pub use self::mpls_ip_tunnel::*;
+
 mod next_hops;
 pub use self::next_hops::*;
 

netlink-packet-route/src/rtnl/route/nlas/mpls_ip_tunnel.rs

@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: MIT
+
+use anyhow::Context;
+
+use crate::{
+    constants::*,
+    nlas::{DefaultNla, Nla, NlaBuffer},
+    parsers::parse_u8,
+    traits::Parseable,
+    DecodeError,
+};
+
+/// Netlink attributes for `RTA_ENCAP` with `RTA_ENCAP_TYPE` set to `LWTUNNEL_ENCAP_MPLS`.
+pub enum MplsIpTunnel {
+    Destination(Vec<u8>),
+    Ttl(u8),
+    Other(DefaultNla),
+}
+
+impl Nla for MplsIpTunnel {
+    fn value_len(&self) -> usize {
+        use self::MplsIpTunnel::*;
+        match self {
+            Destination(bytes) => bytes.len(),
+            Ttl(_) => 1,
+            Other(attr) => attr.value_len(),
+        }
+    }
+
+    fn kind(&self) -> u16 {
+        use self::MplsIpTunnel::*;
+        match self {
+            Destination(_) => MPLS_IPTUNNEL_DST,
+            Ttl(_) => MPLS_IPTUNNEL_TTL,
+            Other(attr) => attr.kind(),
+        }
+    }
+
+    fn emit_value(&self, buffer: &mut [u8]) {
+        use self::MplsIpTunnel::*;
+        match self {
+            Destination(bytes) => buffer.copy_from_slice(bytes.as_slice()),
+            Ttl(ttl) => buffer[0] = *ttl,
+            Other(attr) => attr.emit_value(buffer),
+        }
+    }
+}
+
+impl<'a, T: AsRef<[u8]> + ?Sized> Parseable<NlaBuffer<&'a T>> for MplsIpTunnel {
+    fn parse(buf: &NlaBuffer<&'a T>) -> Result<Self, DecodeError> {
+        use self::MplsIpTunnel::*;
+        let payload = buf.value();
+        Ok(match buf.kind() {
+            MPLS_IPTUNNEL_DST => Destination(payload.to_vec()),
+            MPLS_IPTUNNEL_TTL => Ttl(parse_u8(payload).context("invalid MPLS_IPTUNNEL_TTL value")?),
+            _ => Other(DefaultNla::parse(buf).context("invalid NLA value (unknown type) value")?),
+        })
+    }
+}