added client custom callback query capability

src/wh_client.c

@@ -240,4 +240,19 @@ int wh_Client_CustomResponse(whClientContext*          c,
     memcpy(outResp, &resp, sizeof(resp));
 
     return WH_ERROR_OK;
+}
+
+int wh_Client_CustomRequestCheckRegistered(whClientContext* c, uint32_t id)
+{
+    whMessageCustom_Request req = {0};
+
+    if (c == NULL || id >= WH_MESSAGE_ACTION_MAX) {
+        return WH_ERROR_BADARGS;
+    }
+
+    req.id = id;
+    req.type = WH_MESSAGE_CUSTOM_TYPE_QUERY;
+
+    return wh_Client_SendRequest(c, WH_MESSAGE_GROUP_CUSTOM, req.id,
+                                 sizeof(req), &req);
 }

src/wh_message_custom.c

@@ -12,6 +12,9 @@ static void _translateCustomData(uint16_t magic, uint32_t translatedType,
 {
     if (translatedType < WH_MESSAGE_CUSTOM_TYPE_USER_DEFINED_START) {
         switch (translatedType) {
+            case WH_MESSAGE_CUSTOM_TYPE_QUERY: {
+                /* right now, no further translations required */
+            } break;
             case WH_MESSAGE_CUSTOM_TYPE_DMA32: {
                 dst->dma32.client_addr =
                     wh_Translate32(magic, src->dma32.client_addr);
@@ -51,9 +54,14 @@ int wh_MessageCustom_TranslateRequest(uint16_t                       magic,
     if ((src == NULL) || (dst == NULL)) {
         return WH_ERROR_BADARGS;
     }
+
     dst->id   = wh_Translate16(magic, src->id);
     dst->type = wh_Translate32(magic, src->type);
-    _translateCustomData(magic, dst->type, &src->data, &dst->data);
+
+    /* Translate data if this isn't just a callback query */
+    if (dst->type != WH_MESSAGE_CUSTOM_TYPE_QUERY) {
+        _translateCustomData(magic, dst->type, &src->data, &dst->data);
+    }
 
     return WH_ERROR_OK;
 }
@@ -74,7 +82,11 @@ int wh_MessageCustom_TranslateResponse(uint16_t                        magic,
      * Probably still should...*/
     dst->id   = wh_Translate16(magic, src->id);
     dst->type = wh_Translate32(magic, src->type);
-    _translateCustomData(magic, dst->type, &src->data, &dst->data);
+
+    /* Translate data if this isn't just a callback query */
+    if (src->type != WH_MESSAGE_CUSTOM_TYPE_QUERY) {
+        _translateCustomData(magic, dst->type, &src->data, &dst->data);
+    }
 
     return WH_ERROR_OK;
 }

src/wh_server_custom.c

@@ -52,17 +52,18 @@ int wh_Server_HandleCustomRequest(whServerContext* server, uint16_t magic,
     }
 
     if (customHandlerTable[action] != NULL) {
-        /* Invoke the registered callback, storing the return value in the
-         * reponse  */
-        resp.rc = customHandlerTable[action](server, &req, &resp);
-        /* TODO: propagate wolfHSM error codes (requires modifiying caller
-         * function)*/
+        /* If this isn't a query to check if the callback exists, invoke the
+         * registered callback, storing the return value in the reponse  */
+        if (req.type != WH_MESSAGE_CUSTOM_TYPE_QUERY) {
+            resp.rc = customHandlerTable[action](server, &req, &resp);
+        }
+        /* TODO: propagate other wolfHSM error codes (requires modifiying caller
+         * function) once generic server code supports it */
         resp.err = WH_ERROR_OK;
     }
     else {
-        /* No callback was registered, populate response errors, but we must
+        /* No callback was registered, populate response error. We must
          * return success to ensure the "error" response is sent  */
-        /* TODO: what should we set resp.rc to? */
         resp.err = WH_ERROR_NO_HANDLER;
     }
 

test/wh_test_clientserver.c

@@ -74,8 +74,15 @@ static int _testCallbacks(whServerContext* server, whClientContext* client)
     char       output[sizeof(input)] = {0};
 
     for (counter = 0; counter < WH_MESSAGE_ACTION_MAX; counter++) {
-        /* First, test that an unregistered callback returns error */
         req.id = counter;
+
+        /* Check that the callback shows as unregistered */
+        WH_TEST_RETURN_ON_FAIL(wh_Client_CustomRequestCheckRegistered(client, req.id));
+        WH_TEST_RETURN_ON_FAIL(wh_Server_HandleRequestMessage(server));
+        WH_TEST_RETURN_ON_FAIL(wh_Client_CustomResponse(client, &resp));
+        WH_TEST_ASSERT_RETURN(resp.err == WH_ERROR_NO_HANDLER);
+
+        /* Test that calling an unregistered callback returns error */
         WH_TEST_RETURN_ON_FAIL(wh_Client_CustomRequest(client, &req));
         WH_TEST_RETURN_ON_FAIL(wh_Server_HandleRequestMessage(server));
         WH_TEST_RETURN_ON_FAIL(wh_Client_CustomResponse(client, &resp));
@@ -85,6 +92,12 @@ static int _testCallbacks(whServerContext* server, whClientContext* client)
         WH_TEST_RETURN_ON_FAIL(
             wh_Server_RegisterCustomCb(counter, _customServerCb));
 
+        /* Check that the callback now shows as registered */
+        WH_TEST_RETURN_ON_FAIL(wh_Client_CustomRequestCheckRegistered(client, req.id));
+        WH_TEST_RETURN_ON_FAIL(wh_Server_HandleRequestMessage(server));
+        WH_TEST_RETURN_ON_FAIL(wh_Client_CustomResponse(client, &resp));
+        WH_TEST_ASSERT_RETURN(resp.err == WH_ERROR_OK);
+
         /* prepare the rest of the request */
         if (sizeof(uintptr_t) == sizeof(uint64_t)) {
             /* 64-bit host system */
@@ -115,8 +128,6 @@ static int _testCallbacks(whServerContext* server, whClientContext* client)
         memset(&resp, 0, sizeof(resp));
     }
 
-    /* TODO: query registered callback list and ensure it is populated correctly */
-
     return WH_ERROR_OK;
 }
 

wolfhsm/wh_client.h

@@ -180,6 +180,7 @@ int wh_Client_NvmReadDma(whClientContext* c,
 
 
 /* Client custom-callback support */
+int wh_Client_CustomRequestCheckRegistered(whClientContext* c, uint32_t id);
 int wh_Client_CustomRequest(whClientContext* c, const whMessageCustom_Request* req);
 int wh_Client_CustomResponse(whClientContext* c, whMessageCustom_Response *resp);
 

wolfhsm/wh_message_custom.h

@@ -9,9 +9,9 @@
  * to interpret whMessageCustomData */
 typedef enum {
     /* message types reserved for internal usage*/
-    WH_MESSAGE_CUSTOM_TYPE_DMA32      = 0,
-    WH_MESSAGE_CUSTOM_TYPE_DMA64      = 1,
-    WH_MESSAGE_CUSTOM_TYPE_RESERVED_2 = 2,
+    WH_MESSAGE_CUSTOM_TYPE_QUERY      = 0,
+    WH_MESSAGE_CUSTOM_TYPE_DMA32      = 1,
+    WH_MESSAGE_CUSTOM_TYPE_DMA64      = 2,
     WH_MESSAGE_CUSTOM_TYPE_RESERVED_3 = 3,
     WH_MESSAGE_CUSTOM_TYPE_RESERVED_4 = 4,
     WH_MESSAGE_CUSTOM_TYPE_RESERVED_5 = 5,