pldm-platform: Fix oem_file_classification_name

The length field is now omitted entirely when oem_classification is set
to 0. Previously in that case length was included and set to zero, which
is not the correct message format.

The name field is renamed from oem_file_name to
oem_file_classification_name, and is now an Option.

Signed-off-by: Matt Johnston <[email protected]>

Author: mkj

pldm-file/examples/host.rs

@@ -192,7 +192,7 @@ fn handle_get_pdr(
             // TODO
             file_max_desc_count: 1,
             file_name: FILENAME.try_into().expect("Filename too long"),
-            oem_file_name: Default::default(),
+            oem_file_classification_name: Default::default(),
         }),
     )?;
     let enc = pdr_resp.to_bytes().context("Encoding failed")?;

pldm-platform/src/proto.rs

@@ -739,6 +739,10 @@ pub struct FileDescriptorPdr {
     pub container_id: u16,
     pub superior_directory: u16,
     pub file_classification: FileClassification,
+    /// OEM File Classification
+    ///
+    /// `oem_file_classification_name` must be `Some` if this is
+    /// non-zero (may be an empty string).
     pub oem_file_classification: u8,
     pub capabilities: u16,
     pub file_version: u32,
@@ -754,11 +758,20 @@ pub struct FileDescriptorPdr {
     #[deku(count = "file_name_len")]
     pub file_name: AsciiString<MAX_PDR_TRANSFER>,
 
-    #[deku(temp, temp_value = "self.oem_file_name.len() as u8")]
+    #[deku(skip, cond = "*oem_file_classification == 0")]
+    #[deku(
+        temp,
+        temp_value = "self.oem_file_classification_name.as_ref().map(|f| f.len()).unwrap_or(0) as u8"
+    )]
     pub oem_file_name_len: u8,
-    /// OEM file name.
+
+    /// OEM file classification name.
     ///
-    /// A null terminated string. Must be empty if `oem_file_classification == 0`.
+    /// A null terminated string. Must be `None` if `oem_file_classification == 0`.
+    #[deku(skip, cond = "*oem_file_classification == 0")]
+    #[deku(
+        assert = "(*oem_file_classification > 0) == oem_file_classification_name.is_some()"
+    )]
     #[deku(count = "oem_file_name_len")]
-    pub oem_file_name: AsciiString<MAX_PDR_TRANSFER>,
+    pub oem_file_classification_name: Option<AsciiString<MAX_PDR_TRANSFER>>,
 }