Add C++ API

Change-Id: Iff634f22d43470e2dc028387b3816257fd7b4156
Signed-off-by: Klement Sekera <ksekera@cisco.com>
diff --git a/src/vpp-api/vapi/vapi_common.h b/src/vpp-api/vapi/vapi_common.h
new file mode 100644
index 0000000..ce64469
--- /dev/null
+++ b/src/vpp-api/vapi/vapi_common.h
@@ -0,0 +1,61 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+#ifndef vapi_common_h_included
+#define vapi_common_h_included
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef enum
+{
+  VAPI_OK = 0,	      /**< success */
+  VAPI_EINVAL,	      /**< invalid value encountered */
+  VAPI_EAGAIN,	      /**< operation would block */
+  VAPI_ENOTSUP,	      /**< operation not supported */
+  VAPI_ENOMEM,	      /**< out of memory */
+  VAPI_ENORESP,	      /**< no response to request */
+  VAPI_EMAP_FAIL,     /**< failure while mapping api */
+  VAPI_ECON_FAIL,     /**< failure while connecting to vpp */
+  VAPI_EINCOMPATIBLE, /**< fundamental incompatibility while connecting to vpp
+                           (control ping/control ping reply mismatch) */
+  VAPI_MUTEX_FAILURE, /**< failure manipulating internal mutex(es) */
+  VAPI_EUSER,	      /**< user error used for breaking dispatch,
+                           never used by VAPI */
+} vapi_error_e;
+
+typedef enum
+{
+  VAPI_MODE_BLOCKING = 1,    /**< operations block until response received */
+  VAPI_MODE_NONBLOCKING = 2, /**< operations never block */
+} vapi_mode_e;
+
+typedef enum
+{
+  VAPI_WAIT_FOR_READ,	     /**< wait until some message is readable */
+  VAPI_WAIT_FOR_WRITE,	     /**< wait until a message can be written */
+  VAPI_WAIT_FOR_READ_WRITE,  /**< wait until a read or write can be done */
+} vapi_wait_mode_e;
+
+typedef int vapi_msg_id_t;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif