mgmtd: Add MGMT Frontend Interface Framework

This commit introduces the Frontend Interface which can be used
by front-end management clients like Netconf server, Restconf
Server and CLI to interact with new FRR Management daemon (MGMTd)
to access and sometimes modify FRR management data.

This commit includes the following functionalities in the changeset:
1. Add new Frontend server for clients connect to.
2. Add a C-based Frontend client library which can be used by Frontend
   clients to communicate with MGMTd via the Frontend interface.
3. Maintain a frontend adapter for each connection from an appropriate
   Frontend client to facilitate client requests and track one or more
   client sessions across it.
4. Define the protobuf message format for messages to be exchanged
   between MGMTd Frontend module and the Frontend client.
5. This changeset also introduces an instance of MGMT Frontend client
   embedded within the lib/vty module that can be leveraged by any FRR
   daemon to connect to MGMTd's Frontend interface. The same has been
   integrated with and initialized within the MGMTd daemon's process
   context to implement a bunch of 'set-config', 'commit-apply',
   'get-config' and 'get-data' commands via VTYSH

Co-authored-by: Pushpasis Sarkar <pushpasis@gmail.com>
Co-authored-by: Abhinay Ramesh <rabhinay@vmware.com>
Co-authored-by: Ujwal P <ujwalp@vmware.com>
Signed-off-by: Yash Ranjan <ranjany@vmware.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/lib/mgmt_pb.h b/lib/mgmt_pb.h
new file mode 100644
index 0000000000..08bb748233
--- /dev/null
+++ b/lib/mgmt_pb.h
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * MGMTD protobuf main header file
+ * Copyright (C) 2021  Vmware, Inc.
+ *		       Pushpasis Sarkar <spushpasis@vmware.com>
+ */
+
+#ifndef _FRR_MGMTD_PB_H_
+#define _FRR_MGMTD_PB_H_
+
+#include "lib/mgmt.pb-c.h"
+
+#define mgmt_yang_data_xpath_init(ptr) mgmtd__yang_data_xpath__init(ptr)
+
+#define mgmt_yang_data_value_init(ptr) mgmtd__yang_data_value__init(ptr)
+
+#define mgmt_yang_data_init(ptr) mgmtd__yang_data__init(ptr)
+
+#define mgmt_yang_data_reply_init(ptr) mgmtd__yang_data_reply__init(ptr)
+
+#define mgmt_yang_cfg_data_req_init(ptr) mgmtd__yang_cfg_data_req__init(ptr)
+
+#define mgmt_yang_get_data_req_init(ptr) mgmtd__yang_get_data_req__init(ptr)
+
+#endif /* _FRR_MGMTD_PB_H_ */