From be14bee66bd5f52838928b1907e5107d0e3ef1b0 Mon Sep 17 00:00:00 2001
From: Markus Pettersson <markus.pettersson@mullvad.net>
Date: Fri, 12 Sep 2025 20:36:17 +0200
Subject: [PATCH] Add function on RouteMessageBuilder for setting route MTU

---
 src/route/builder.rs | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/route/builder.rs b/src/route/builder.rs
index 233a5b2..dea7d1c 100644
--- a/src/route/builder.rs
+++ b/src/route/builder.rs
@@ -12,8 +12,8 @@ use netlink_packet_route::route::{
 use netlink_packet_route::{
     route::{
         RouteAddress, RouteAttribute, RouteFlags, RouteHeader, RouteMessage,
-        RouteNextHop, RouteNextHopFlags, RouteProtocol, RouteScope, RouteType,
-        RouteVia,
+        RouteMetric, RouteNextHop, RouteNextHopFlags, RouteProtocol,
+        RouteScope, RouteType, RouteVia,
     },
     AddressFamily,
 };
@@ -103,6 +103,14 @@ impl<T> RouteMessageBuilder<T> {
         self
     }
 
+    /// Sets the route mtu (metric)
+    pub fn mtu(mut self, mtu: u32) -> Self {
+        self.message
+            .attributes
+            .push(RouteAttribute::Metrics(vec![RouteMetric::Mtu(mtu)]));
+        self
+    }
+
     /// Sets the route table ID.
     ///
     /// Default is main route table.