Open_Plugin add checksum on struct offsets

Adding a checksum over the struct offset will allow checking
for compatibility across machines rather than using packed structs
to ensure compability

For any file created by the user from the device  this isn't really a concern

But for files between machines, across installs (sim v device),
possibly even across compilers this at least will alert the user
rather than returning junk data

Change-Id: Id0531bbaa7013dce24dece270849f0a10ac99c20

1 files changed, 15 insertions, 3 deletions

diff --git a/apps/open_plugin.h b/apps/open_plugin.h
index e1d49bf329..adfb9a75bc 100644
--- a/apps/open_plugin.h
+++ b/apps/open_plugin.h
@@ -41,19 +41,31 @@ enum {
     OPEN_PLUGIN_LANG_IGNORE     = (-2),
     OPEN_PLUGIN_LANG_IGNOREALL  = (-3),
     OPEN_PLUGIN_NOT_FOUND     = (-1),
-    OPEN_PLUGIN_NEEDS_FLUSHED = (-2)
+    OPEN_PLUGIN_NEEDS_FLUSHED = (-2),
 };
 
 struct open_plugin_entry_t
 {
-/* hash and lang_id need to be the first items */
+/* hash lang_id checksum need to be the first items */
     uint32_t hash;
     int32_t  lang_id;
+    uint32_t  checksum;
     char name[OPEN_PLUGIN_NAMESZ+1];
     /*char key[OPEN_PLUGIN_BUFSZ+1];*/
     char path[OPEN_PLUGIN_BUFSZ+1];
     char param[OPEN_PLUGIN_BUFSZ+1];
-}__attribute__((packed));
+};
+
+#define OPEN_PLUGIN_CHECKSUM (uint32_t)              \
+(                                                    \
+    (sizeof(struct open_plugin_entry_t) << 16)     + \
+    offsetof(struct open_plugin_entry_t, hash)     + \
+    offsetof(struct open_plugin_entry_t, lang_id)  + \
+    offsetof(struct open_plugin_entry_t, checksum) + \
+    offsetof(struct open_plugin_entry_t, name)     + \
+    /*offsetof(struct open_plugin_entry_t, key)+*/   \
+    offsetof(struct open_plugin_entry_t, path)     + \
+    offsetof(struct open_plugin_entry_t, param))
 
 inline static void open_plugin_get_hash(const char *key, uint32_t *hash)
 {