StorageManager: more rust cleanups

- add From traits for mapping return status
- no more need for StorageError::Success w/ switch to Result's
- narrow unsafe blocks where possible

Change-Id: I92e0666e2651eb3647ac4e351d14bf55bc76bbb0
GitOrigin-RevId: 24416448d1c326632f556e224fcca7ac38397dc6

apps/system/components/StorageManager/kata-storage-component/src/run.rs

@@ -10,7 +10,6 @@ extern crate kata_panic;
 use kata_allocator;
 use kata_logger::KataLogger;
 use kata_storage_interface::KeyValueData;
-use kata_storage_interface::StorageError;
 use kata_storage_interface::StorageManagerError;
 use kata_storage_interface::StorageManagerInterface;
 use kata_storage_manager::KATA_STORAGE;
@@ -35,17 +34,6 @@ pub extern "C" fn pre_init() {
     }
 }
 
-fn map_storage_error(se: StorageError, def: StorageManagerError) -> StorageManagerError {
-    match se {
-        StorageError::Success => StorageManagerError::SmeSuccess,
-        StorageError::BundleNotFound => StorageManagerError::SmeBundleNotFound,
-        StorageError::KeyNotFound => StorageManagerError::SmeKeyNotFound,
-        StorageError::KeyInvalid => StorageManagerError::SmeKeyInvalid,
-        StorageError::ValueInvalid => StorageManagerError::SmeValueInvalid,
-        _ => def,
-    }
-}
-
 // StorageInterface glue stubs.
 #[no_mangle]
 pub extern "C" fn storage_read(
@@ -57,18 +45,15 @@ pub extern "C" fn storage_read(
             Ok(key) => {
                 // TODO(sleffler): de-badge reply cap to get bundle_id
                 match KATA_STORAGE.read("fubar", key) {
-                    // NB: no serialization, returns raw data
                     Ok(value) => {
+                        // NB: no serialization, returns raw data
                         (*c_raw_value).copy_from_slice(&value);
                         StorageManagerError::SmeSuccess
                     }
-                    Err(e) => map_storage_error(e, StorageManagerError::SmeReadFailed),
+                    Err(e) => StorageManagerError::from(e),
                 }
             }
-            Err(e) => {
-                trace!("read: keyinvalid {:?}", e);
-                StorageManagerError::SmeKeyInvalid
-            }
+            Err(_) => StorageManagerError::SmeKeyInvalid,
         }
     }
 }
@@ -79,42 +64,29 @@ pub extern "C" fn storage_write(
     c_raw_value_len: usize,
     c_raw_value: *const u8,
 ) -> StorageManagerError {
-    unsafe {
-        match CStr::from_ptr(c_key).to_str() {
-            Ok(key) => {
-                // TODO(sleffler): de-badge reply cap to get bundle_id
-                match KATA_STORAGE.write(
+    match unsafe { CStr::from_ptr(c_key).to_str() } {
+        Ok(key) => {
+            // TODO(sleffler): de-badge reply cap to get bundle_id
+            unsafe {
+                KATA_STORAGE.write(
                     "fubar",
                     key,
                     slice::from_raw_parts(c_raw_value, c_raw_value_len),
-                ) {
-                    Ok(_) => StorageManagerError::SmeSuccess,
-                    Err(e) => map_storage_error(e, StorageManagerError::SmeWriteFailed),
-                }
-            }
-            Err(e) => {
-                trace!("write: keyinvalid {:?}", e);
-                StorageManagerError::SmeKeyInvalid
+                )
             }
+            .into()
         }
+        Err(_) => StorageManagerError::SmeKeyInvalid,
     }
 }
 
 #[no_mangle]
 pub extern "C" fn storage_delete(c_key: *const cstr_core::c_char) -> StorageManagerError {
-    unsafe {
-        match CStr::from_ptr(c_key).to_str() {
-            Ok(key) => {
-                // TODO(sleffler): de-badge reply cap to get bundle_id
-                match KATA_STORAGE.delete("fubar", key) {
-                    Ok(_) => StorageManagerError::SmeSuccess,
-                    Err(e) => map_storage_error(e, StorageManagerError::SmeDeleteFailed),
-                }
-            }
-            Err(e) => {
-                trace!("delete: keyinvalid {:?}", e);
-                StorageManagerError::SmeKeyInvalid
-            }
+    match unsafe { CStr::from_ptr(c_key).to_str() } {
+        Ok(key) => {
+            // TODO(sleffler): de-badge reply cap to get bundle_id
+            unsafe { KATA_STORAGE.delete("fubar", key) }.into()
         }
+        Err(_) => StorageManagerError::SmeKeyInvalid,
     }
 }

apps/system/components/StorageManager/kata-storage-interface/src/lib.rs

@@ -16,8 +16,7 @@ pub type KeyValueData = [u8; KEY_VALUE_DATA_SIZE];
 
 #[derive(Debug, Eq, PartialEq)]
 pub enum StorageError {
-    Success = 0,
-    BundleNotFound,
+    BundleNotFound = 0,
     KeyNotFound,
     KeyInvalid,
     ValueInvalid,
@@ -29,27 +28,28 @@ pub enum StorageError {
     DeleteFailed,
 }
 
-impl From<postcard::Error> for StorageError {
-    fn from(_err: postcard::Error) -> StorageError {
-        StorageError::SerializeFailed
-    }
-}
 impl From<SecurityRequestError> for StorageError {
     fn from(err: SecurityRequestError) -> StorageError {
         match err {
-            SecurityRequestError::SreSuccess => StorageError::Success,
             SecurityRequestError::SreBundleNotFound => StorageError::BundleNotFound,
             SecurityRequestError::SreKeyNotFound => StorageError::KeyNotFound,
             SecurityRequestError::SreValueInvalid => StorageError::ValueInvalid,
             SecurityRequestError::SreKeyInvalid => StorageError::KeyInvalid,
+            SecurityRequestError::SreSerializeFailed => StorageError::SerializeFailed,
             SecurityRequestError::SreReadFailed => StorageError::ReadFailed,
             SecurityRequestError::SreWriteFailed => StorageError::WriteFailed,
             SecurityRequestError::SreDeleteFailed => StorageError::DeleteFailed,
-            _ => StorageError::UnknownSecurityError,  // NB: cannot happen
+            _ => StorageError::UnknownSecurityError, // NB: cannot happen
         }
     }
 }
 
+impl From<postcard::Error> for StorageError {
+    fn from(_err: postcard::Error) -> StorageError {
+        StorageError::SerializeFailed
+    }
+}
+
 pub trait StorageManagerInterface {
     fn read(&self, bundle_id: &str, key: &str) -> Result<KeyValueData, StorageError>;
     fn write(&self, bundle_id: &str, key: &str, value: &[u8]) -> Result<(), StorageError>;
@@ -73,6 +73,31 @@ pub enum StorageManagerError {
     SmeReadFailed,
     SmeWriteFailed,
     SmeDeleteFailed,
+    SmeUnknownError,
+}
+
+impl From<StorageError> for StorageManagerError {
+    fn from(err: StorageError) -> StorageManagerError {
+        match err {
+            StorageError::BundleNotFound => StorageManagerError::SmeBundleNotFound,
+            StorageError::KeyNotFound => StorageManagerError::SmeKeyNotFound,
+            StorageError::KeyInvalid => StorageManagerError::SmeKeyInvalid,
+            StorageError::ValueInvalid => StorageManagerError::SmeValueInvalid,
+            StorageError::ReadFailed => StorageManagerError::SmeReadFailed,
+            StorageError::WriteFailed => StorageManagerError::SmeWriteFailed,
+            StorageError::DeleteFailed => StorageManagerError::SmeDeleteFailed,
+            _ => StorageManagerError::SmeUnknownError,
+        }
+    }
+}
+
+impl From<Result<(), StorageError>> for StorageManagerError {
+    fn from(result: Result<(), StorageError>) -> StorageManagerError {
+        result.map_or_else(
+            |e| StorageManagerError::from(e),
+            |_v| StorageManagerError::SmeSuccess,
+        )
+    }
 }
 
 impl From<cstr_core::NulError> for StorageManagerError {