add errors for redundant and missing image preference settings

Author: lzrd

gateway-messages/src/sp_to_mgs.rs

@@ -1298,6 +1298,8 @@ pub enum UpdateError {
     SignatureNotValidated,
     VersionNotSupported,
     InvalidPreferredSlotId,
+    AlreadyPending,
+    NonePending,
 }
 
 impl fmt::Display for UpdateError {
@@ -1358,10 +1360,13 @@ impl fmt::Display for UpdateError {
                 write!(f, "invalid component for operation")
             }
             Self::InvalidPreferredSlotId => {
-                write!(
-                    f,
-                    "updating a bootloader preferred slot is not permitted"
-                )
+                write!(f, "specified slot ID is not valid for this operation")
+            }
+            Self::AlreadyPending => {
+                write!(f, "pending preference must be canceled first")
+            }
+            Self::NonePending => {
+                write!(f, "no pending preference to cancel")
             }
         }
     }

gateway-messages/tests/versioning/v21.rs

@@ -16,20 +16,21 @@
 use gateway_messages::MgsRequest;
 use gateway_messages::SpComponent;
 use gateway_messages::SpResponse;
+use gateway_messages::UpdateError;
 
 use super::assert_serialized;
 
 #[test]
 fn mgs_request() {
     let request = MgsRequest::ComponentCancelPendingActiveSlot {
-        component: SpComponent::SP_ITSELF,
+        component: SpComponent::ROT,
         slot: 0x0102,
         persist: true,
     };
     #[rustfmt::skip]
     let expected = &[
         50, // ComponentCancelPendingActiveSlot
-        b's', b'p', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // SP_ITSELF
+        b'r', b'o', b't', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ROT
         2, 1, // slot
         1, // persist = true
     ];
@@ -42,3 +43,11 @@ fn sp_response() {
     let expected = &[52];
     assert_serialized(expected, &response);
 }
+
+#[test]
+fn error_enums() {
+    let response: [UpdateError; 2] =
+        [UpdateError::AlreadyPending, UpdateError::NonePending];
+    let expected = vec![35, 36];
+    assert_serialized(&expected, &response);
+}

gateway-sp-comms/src/error.rs

@@ -116,6 +116,12 @@ pub enum UpdateError {
     InvalidComponent,
     #[error("an image was not found")]
     ImageNotFound,
+    #[error("cannot update preferred boot image")]
+    InvalidPreferredSlotId,
+    #[error("pending preference must be canceled first")]
+    AlreadyPending,
+    #[error("no pending preference to cancel")]
+    NonePending,
 }
 
 #[derive(Debug, thiserror::Error, SlogInlineError)]