Fix if_type exception handling (Linux)

src/interface/linux.rs

@@ -5,16 +5,20 @@ use crate::interface::InterfaceType;
 pub fn get_interface_type(if_name: String) -> InterfaceType {
     let if_type_path: String = format!("/sys/class/net/{}/type", if_name);
     let r = read_to_string(if_type_path);
-    let if_type_string = match r {
-        Ok(content) => content.trim().to_string(),
-        Err(_) => String::from("999"),
-    };
+    match r {
+        Ok(content) => {
+            let if_type_string = content.trim().to_string();
             match if_type_string.parse::<u32>() {
                 Ok(if_type) => {
-            InterfaceType::try_from(if_type).unwrap_or(InterfaceType::Unknown)
+                    return InterfaceType::try_from(if_type).unwrap_or(InterfaceType::Unknown);
                 },
                 Err(_) => {
-            InterfaceType::Unknown
+                    return InterfaceType::Unknown;
                 }
             }
+        },
+        Err(_) => {
+            return InterfaceType::Unknown;
+        }
+    };   
 }

src/interface/types.rs

@@ -80,7 +80,7 @@ impl InterfaceType {
             InterfaceType::Atm => 19,
             InterfaceType::Wireless80211 => 801,
             InterfaceType::Tunnel => 768,
-            _ => 999,
+            _ => u32::MAX,
         }
     }