Add mtu network setting

rust/agama-lib/share/profile.schema.json

@@ -58,6 +58,11 @@
                 "description": "Custom mac-address (can also be 'preserve', 'permanent', 'random' or 'stable')",
                 "type": "string"
               },
+              "mtu": {
+                "description": "Connection MTU",
+                "type": "integer",
+                "minimum": 0
+              },
               "method4": {
                 "description": "IPv4 configuration method (e.g., 'auto')",
                 "type": "string",

rust/agama-lib/src/network/proxies.rs

@@ -112,6 +112,10 @@ trait Connection {
     fn mac_address(&self) -> zbus::Result<String>;
     #[dbus_proxy(property)]
     fn set_mac_address(&self, mac_address: &str) -> zbus::Result<()>;
+    #[dbus_proxy(property)]
+    fn mtu(&self) -> zbus::Result<u32>;
+    #[dbus_proxy(property)]
+    fn set_mtu(&self, mtu: u32) -> zbus::Result<()>;
 }
 
 #[dbus_proxy(

rust/agama-lib/src/network/settings.rs

@@ -103,6 +103,12 @@ pub struct NetworkConnection {
     pub mac_address: Option<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub status: Option<Status>,
+    #[serde(skip_serializing_if = "is_zero", default)]
+    pub mtu: u32,
+}
+
+fn is_zero(u: &u32) -> bool {
+    *u == 0
 }
 
 impl NetworkConnection {

rust/agama-server/src/network/model.rs

@@ -600,6 +600,7 @@ impl TryFrom<NetworkConnection> for Connection {
         connection.ip_config.gateway4 = conn.gateway4;
         connection.ip_config.gateway6 = conn.gateway6;
         connection.interface = conn.interface;
+        connection.mtu = conn.mtu;
 
         Ok(connection)
     }
@@ -620,6 +621,7 @@ impl TryFrom<Connection> for NetworkConnection {
         let gateway6 = conn.ip_config.gateway6;
         let interface = conn.interface;
         let status = Some(conn.status);
+        let mtu = conn.mtu;
 
         let mut connection = NetworkConnection {
             id,
@@ -632,6 +634,7 @@ impl TryFrom<Connection> for NetworkConnection {
             mac_address,
             interface,
             addresses,
+            mtu,
             ..Default::default()
         };