mgmtd: Enroll Staticd as a backend client for MGMTD

This commmit introduces Staticd as a backend client for the MGMTd
framework. All the static commands will be diverted to the MGMT
daemon and will use the transactional model to make changes to the
internal state. Similar mechanism can be used by other daemons to use
the MGMT framework in the future.

This commit includes the following functionalities in the changeset:
1. Diverts all the staticd (config only) commands to MGMTd.
2. Enrolls staticd as a backend client to use the MGMT framework.
3. Modify the staticd NB config handlers so that they can be compiled
   into a library and loaded in the MGMTd process context.

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, 55 insertions, 0 deletions

diff --git a/staticd/static_main.c b/staticd/static_main.c
index 0d0de7e8d3..d429162196 100644
--- a/staticd/static_main.c
+++ b/staticd/static_main.c
@@ -27,6 +27,8 @@
 #include "static_debug.h"
 #include "static_nb.h"
 
+#include "mgmt_be_client.h"
+
 char backup_config_file[256];
 
 bool mpls_enabled;
@@ -51,6 +53,8 @@ struct option longopts[] = { { 0 } };
 /* Master of threads. */
 struct thread_master *master;
 
+uintptr_t mgmt_lib_hndl;
+
 static struct frr_daemon_info staticd_di;
 /* SIGHUP handler. */
 static void sighup(void)
@@ -67,6 +71,8 @@ static void sigint(void)
 	/* Disable BFD events to avoid wasting processing. */
 	bfd_protocol_integration_set_shutdown(true);
 
+	mgmt_be_client_lib_destroy(mgmt_lib_hndl);
+
 	static_vrf_terminate();
 
 	static_zebra_stop();
@@ -100,6 +106,51 @@ struct frr_signal_t static_signals[] = {
 	},
 };
 
+static void static_mgmt_be_client_connect(uintptr_t lib_hndl,
+					  uintptr_t usr_data, bool connected)
+{
+	(void)usr_data;
+
+	assert(lib_hndl == mgmt_lib_hndl);
+
+	zlog_debug("Got %s %s MGMTD Backend Client Server",
+		   connected ? "connected" : "disconnected",
+		   connected ? "to" : "from");
+
+	if (connected)
+		(void)mgmt_be_subscribe_yang_data(mgmt_lib_hndl, NULL, 0);
+}
+
+#if 0
+static void
+static_mgmt_txn_notify(uintptr_t lib_hndl, uintptr_t usr_data,
+			struct mgmt_be_client_txn_ctx *txn_ctx,
+			bool destroyed)
+{
+	zlog_debug("Got Txn %s Notify from MGMTD server",
+		   destroyed ? "DESTROY" : "CREATE");
+
+	if (!destroyed) {
+		/*
+		 * TODO: Allocate and install a private scratchpad for this
+		 * transaction if required
+		 */
+	} else {
+		/*
+		 * TODO: Uninstall and deallocate the private scratchpad for
+		 * this transaction if installed earlier.
+		 */
+	}
+}
+#endif
+
+static struct mgmt_be_client_params mgmt_params = {
+	.name = "staticd",
+	.conn_retry_intvl_sec = 3,
+	.client_connect_notify = static_mgmt_be_client_connect,
+	.txn_notify = NULL, /* static_mgmt_txn_notify */
+};
+
 static const struct frr_yang_module_info *const staticd_yang_modules[] = {
 	&frr_filter_info,
 	&frr_interface_info,
@@ -150,6 +201,10 @@ int main(int argc, char **argv, char **envp)
 	static_zebra_init();
 	static_vty_init();
 
+	/* Initialize MGMT backend functionalities */
+	mgmt_lib_hndl = mgmt_be_client_lib_init(&mgmt_params, master);
+	assert(mgmt_lib_hndl);
+
 	hook_register(routing_conf_event,
 		      routing_control_plane_protocols_name_validate);