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>

4 files changed, 89 insertions, 29 deletions

diff --git a/staticd/static_main.c b/staticd/static_main.c
index 0d0de7e8d..d42916219 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);
 
diff --git a/staticd/static_routes.c b/staticd/static_routes.c
index 3399686a9..1fbbf7e99 100644
--- a/staticd/static_routes.c
+++ b/staticd/static_routes.c
@@ -757,30 +757,6 @@ void static_ifindex_update(struct interface *ifp, bool up)
 	static_ifindex_update_af(ifp, up, AFI_IP6, SAFI_MULTICAST);
 }
 
-void static_get_nh_type(enum static_nh_type stype, char *type, size_t size)
-{
-	switch (stype) {
-	case STATIC_IFNAME:
-		strlcpy(type, "ifindex", size);
-		break;
-	case STATIC_IPV4_GATEWAY:
-		strlcpy(type, "ip4", size);
-		break;
-	case STATIC_IPV4_GATEWAY_IFNAME:
-		strlcpy(type, "ip4-ifindex", size);
-		break;
-	case STATIC_BLACKHOLE:
-		strlcpy(type, "blackhole", size);
-		break;
-	case STATIC_IPV6_GATEWAY:
-		strlcpy(type, "ip6", size);
-		break;
-	case STATIC_IPV6_GATEWAY_IFNAME:
-		strlcpy(type, "ip6-ifindex", size);
-		break;
-	};
-}
-
 struct stable_info *static_get_stable_info(struct route_node *rn)
 {
 	struct route_table *table;
diff --git a/staticd/static_routes.h b/staticd/static_routes.h
index eb7953db2..4fd7a1342 100644
--- a/staticd/static_routes.h
+++ b/staticd/static_routes.h
@@ -159,6 +159,31 @@ static_route_info_from_rnode(struct route_node *rn)
 	return (struct static_route_info *)(rn->info);
 }
 
+static inline void static_get_nh_type(enum static_nh_type stype, char *type,
+				      size_t size)
+{
+	switch (stype) {
+	case STATIC_IFNAME:
+		strlcpy(type, "ifindex", size);
+		break;
+	case STATIC_IPV4_GATEWAY:
+		strlcpy(type, "ip4", size);
+		break;
+	case STATIC_IPV4_GATEWAY_IFNAME:
+		strlcpy(type, "ip4-ifindex", size);
+		break;
+	case STATIC_BLACKHOLE:
+		strlcpy(type, "blackhole", size);
+		break;
+	case STATIC_IPV6_GATEWAY:
+		strlcpy(type, "ip6", size);
+		break;
+	case STATIC_IPV6_GATEWAY_IFNAME:
+		strlcpy(type, "ip6-ifindex", size);
+		break;
+	};
+}
+
 extern bool mpls_enabled;
 extern uint32_t zebra_ecmp_count;
 
@@ -192,8 +217,6 @@ extern struct static_path *static_add_path(struct route_node *rn,
 					   uint32_t table_id, uint8_t distance);
 extern void static_del_path(struct static_path *pn);
 
-extern void static_get_nh_type(enum static_nh_type stype, char *type,
-			       size_t size);
 extern bool static_add_nexthop_validate(const char *nh_vrf_name,
 					enum static_nh_type type,
 					struct ipaddr *ipaddr);
diff --git a/staticd/static_vty.c b/staticd/static_vty.c
index d87ca16c6..bfffbe6a6 100644
--- a/staticd/static_vty.c
+++ b/staticd/static_vty.c
@@ -1452,15 +1452,18 @@ DEFPY_YANG(debug_staticd, debug_staticd_cmd,
 	   "Debug route\n"
 	   "Debug bfd\n")
 {
+#ifndef INCLUDE_MGMTD_CMDDEFS_ONLY
 	/* If no specific category, change all */
 	if (strmatch(argv[argc - 1]->text, "static"))
 		static_debug_set(vty->node, !no, true, true, true);
 	else
 		static_debug_set(vty->node, !no, !!events, !!route, !!bfd);
+#endif /* ifndef INCLUDE_MGMTD_CMDDEFS_ONLY */
 
 	return CMD_SUCCESS;
 }
 
+#ifndef INCLUDE_MGMTD_CMDDEFS_ONLY
 DEFPY(staticd_show_bfd_routes, staticd_show_bfd_routes_cmd,
       "show bfd static route [json]$isjson",
       SHOW_STR
@@ -1496,9 +1499,15 @@ static struct cmd_node debug_node = {
 	.config_write = static_config_write_debug,
 };
 
+#endif /* ifndef INCLUDE_MGMTD_CMDDEFS_ONLY */
+
 void static_vty_init(void)
 {
+#ifndef INCLUDE_MGMTD_CMDDEFS_ONLY
 	install_node(&debug_node);
+	install_element(ENABLE_NODE, &show_debugging_static_cmd);
+	install_element(ENABLE_NODE, &staticd_show_bfd_routes_cmd);
+#endif /* ifndef INCLUDE_MGMTD_CMDDEFS_ONLY */
 
 	install_element(CONFIG_NODE, &ip_mroute_dist_cmd);
 
@@ -1516,9 +1525,6 @@ void static_vty_init(void)
 	install_element(CONFIG_NODE, &ipv6_route_cmd);
 	install_element(VRF_NODE, &ipv6_route_vrf_cmd);
 
-	install_element(ENABLE_NODE, &show_debugging_static_cmd);
 	install_element(ENABLE_NODE, &debug_staticd_cmd);
 	install_element(CONFIG_NODE, &debug_staticd_cmd);
-
-	install_element(ENABLE_NODE, &staticd_show_bfd_routes_cmd);
 }