fix: NotImplemented for GetObject/HeadObject PartNumber

Fixes #1520

Removes the incorrect logic for HeadObject returning successful response, when querying an incomplete multipart upload.

Implements the logic to return `NotImplemented` error if `GetObject`/`HeadObject` is attempted with `partNumber` in azure and posix backends. The front-end part is preserved to be used in s3 proxy backend.

s3api/controllers/object-get.go

@@ -380,6 +380,7 @@ func (c S3ApiController) GetObject(ctx *fiber.Ctx) (*Response, error) {
 	versionId := ctx.Query("versionId")
 	acceptRange := ctx.Get("Range")
 	checksumMode := types.ChecksumMode(ctx.Get("x-amz-checksum-mode"))
+	partNumberQuery := int32(ctx.QueryInt("partNumber", -1))
 
 	// Extract response override query parameters
 	responseOverrides := map[string]*string{
@@ -440,6 +441,20 @@ func (c S3ApiController) GetObject(ctx *fiber.Ctx) (*Response, error) {
 		}, err
 	}
 
+	var partNumber *int32
+	if ctx.Request().URI().QueryArgs().Has("partNumber") {
+		if partNumberQuery < minPartNumber || partNumberQuery > maxPartNumber {
+			debuglogger.Logf("invalid part number: %d", partNumberQuery)
+			return &Response{
+				MetaOpts: &MetaOptions{
+					BucketOwner: parsedAcl.Owner,
+				},
+			}, s3err.GetAPIError(s3err.ErrInvalidPartNumber)
+		}
+
+		partNumber = &partNumberQuery
+	}
+
 	// validate the checksum mode
 	if checksumMode != "" && checksumMode != types.ChecksumModeEnabled {
 		debuglogger.Logf("invalid x-amz-checksum-mode header value: %v", checksumMode)
@@ -462,6 +477,7 @@ func (c S3ApiController) GetObject(ctx *fiber.Ctx) (*Response, error) {
 		IfUnmodifiedSince: conditionalHeaders.IfUnmodeSince,
 		VersionId:         &versionId,
 		ChecksumMode:      checksumMode,
+		PartNumber:        partNumber,
 	})
 	if err != nil {
 		var headers map[string]*string

s3api/controllers/object-get_test.go

@@ -710,6 +710,23 @@ func TestS3ApiController_GetObject(t *testing.T) {
 				err: s3err.GetInvalidChecksumHeaderErr("x-amz-checksum-mode"),
 			},
 		},
+		{
+			name: "invalid part number",
+			input: testInput{
+				locals: defaultLocals,
+				queries: map[string]string{
+					"partNumber": "-2",
+				},
+			},
+			output: testOutput{
+				response: &Response{
+					MetaOpts: &MetaOptions{
+						BucketOwner: "root",
+					},
+				},
+				err: s3err.GetAPIError(s3err.ErrInvalidPartNumber),
+			},
+		},
 		{
 			name: "backend returns error",
 			input: testInput{
@@ -733,8 +750,6 @@ func TestS3ApiController_GetObject(t *testing.T) {
 				err: s3err.GetAPIError(s3err.ErrInvalidAccessKeyID),
 			},
 		},
-		// TODO: add a test case for overflowing content-length
-		// simulate a 32 bit arch to test the case
 		{
 			name: "successful response",
 			input: testInput{