partly working implementation

src/error.rs

@@ -0,0 +1,37 @@
+use std::error::Error;
+use std::fmt;
+use std::fmt::Display;
+
+#[derive(Default, Debug)]
+pub struct NoQdiscFoundError;
+
+impl Error for NoQdiscFoundError {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        // The compiler transparently casts `&sqlx::Error` into a `&dyn Error`
+        None
+    }
+}
+
+// Implement std::fmt::Display for AppError
+impl Display for NoQdiscFoundError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Couldn't find a CAKE qdisc for interface") // user-facing output
+    }
+}
+
+#[derive(Default, Debug)]
+pub struct PingParseError;
+
+impl Error for PingParseError {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        // The compiler transparently casts `&sqlx::Error` into a `&dyn Error`
+        None
+    }
+}
+
+// Implement std::fmt::Display for AppError
+impl Display for PingParseError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Couldn't parse received ping packet") // user-facing output
+    }
+}