dns: derive Error for dns::Error

crates/dns/Cargo.toml

@@ -11,6 +11,7 @@ license.workspace = true
 [dependencies]
 sl-std = { workspace = true }
 log = { workspace = true }
+error-derive = { workspace = true }
 
 [lints]
 workspace = true

crates/dns/src/domain.rs

@@ -187,7 +187,7 @@ impl Domain {
                 nameserver = DNS_CACHE.get(&ns_domain)?;
             } else {
                 // We did not make any progress
-                return Err(DNSError::CouldNotResolve(self.clone()));
+                return Err(DNSError::CouldNotResolve);
             }
         }
         Err(DNSError::MaxResolutionStepsExceeded)

crates/dns/src/lib.rs

@@ -9,6 +9,7 @@ mod resource_type;
 use crate::resource_type::{ResourceRecord, ResourceRecordClass};
 pub use dns_cache::DNS_CACHE;
 pub use domain::Domain;
+use error_derive::Error;
 
 use std::{
     io,
@@ -23,18 +24,23 @@ const MAX_RESOLUTION_STEPS: usize = 5;
 /// See [this list of root servers](https://www.iana.org/domains/root/servers).
 const ROOT_SERVER: IpAddr = IpAddr::V4(Ipv4Addr::new(199, 7, 83, 42));
 
-#[derive(Debug)]
+#[derive(Debug, Error)]
 pub enum DNSError {
+    #[msg = "invalid response"]
     InvalidResponse,
-    CouldNotResolve(Domain),
+
+    #[msg = "could not resolve"]
+    CouldNotResolve,
+
+    #[msg = "maximum number of resolution steps exceeded"]
     MaxResolutionStepsExceeded,
+
+    #[msg = "unexpected id"]
     UnexpectedID,
+
+    #[msg = "io error"]
     IO(io::Error),
-    DomainTooLong,
-}
 
-impl From<io::Error> for DNSError {
-    fn from(value: io::Error) -> Self {
-        Self::IO(value)
-    }
+    #[msg = "domain too long"]
+    DomainTooLong,
 }