Return attributes in GetVariable() on buffer error

UEFI 2.8 and newer specifies that GetVariable() returns variable
attributes even if the EFI_BUFFER_TOO_SMALL error is encountered.
Return this value in v2 protocol.

Note that in v2, in the EFI_BUFFER_TOO_SMALL case, `attributes` comes
after `data_len` to be compatible with v1.

Signed-off-by: Tu Dinh <[email protected]>

Author: dinhngtu

handler.c

@@ -277,14 +277,15 @@ internal_get_variable(const uint8_t *name, UINTN name_len, const EFI_GUID *guid,
 static void
 do_get_variable(uint8_t *comm_buf)
 {
+    UINT32 version;
     uint8_t *ptr, *name;
     EFI_GUID guid;
     UINTN name_len, data_len;
     BOOLEAN at_runtime;
     struct efi_variable *l;
 
     ptr = comm_buf;
-    if (snoop_command(&ptr, NULL, NULL, NULL) != EFI_SUCCESS) {
+    if (snoop_command(&ptr, &version, NULL, NULL) != EFI_SUCCESS) {
         assert(0);
         return;
     }
@@ -310,6 +311,8 @@ do_get_variable(uint8_t *comm_buf)
             if (data_len < l->data_len) {
                 serialize_result(&ptr, EFI_BUFFER_TOO_SMALL);
                 serialize_uintn(&ptr, l->data_len);
+                if (version >= 2)
+                    serialize_uint32(&ptr, l->attributes);
             } else {
                 serialize_result(&ptr, EFI_SUCCESS);
                 serialize_uint32(&ptr, l->attributes);

test.c

@@ -903,6 +903,7 @@ MULTI_TEST(test_get_variable_too_small)
 {
     uint8_t *ptr;
     UINTN data_len;
+    UINT32 attr;
     EFI_STATUS status;
 
     reset_test(version);
@@ -918,6 +919,11 @@ MULTI_TEST(test_get_variable_too_small)
     g_assert_cmpuint(status, ==, EFI_BUFFER_TOO_SMALL);
     data_len = unserialize_uintn(&ptr);
     g_assert_cmpuint(data_len, ==, sizeof(tdata1));
+
+    if (version >= 2) {
+        attr = unserialize_uint32(&ptr);
+        g_assert_cmpuint(attr, ==, ATTR_B);
+    }
 }
 
 MULTI_TEST(test_query_variable_info)