zebra: convert interface ipv6 nd mtu command to NB

Signed-off-by: Igor Ryzhov <iryzhov@nfware.com>

yang/frr-zebra.yang

@@ -2342,6 +2342,17 @@ module frr-zebra {
             "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
                        - AdvOtherConfigFlag";
         }
+        leaf link-mtu {
+          type uint32;
+          default "0";
+          description
+            "The value to be placed in MTU options sent by the
+            router.  A value of zero indicates that no MTU options
+            are sent.";
+          reference
+            "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)
+                       - AdvLinkMTU";
+        }
         leaf reachable-time {
           type uint32 {
             range "0..3600000";

zebra/rtadv.c

@@ -2090,34 +2090,24 @@ DEFUN (no_ipv6_nd_router_preference,
 	return CMD_SUCCESS;
 }
 
-DEFUN (ipv6_nd_mtu,
+DEFPY_YANG (ipv6_nd_mtu,
        ipv6_nd_mtu_cmd,
-       "ipv6 nd mtu (1-65535)",
+       "[no] ipv6 nd mtu ![(1-65535)]",
-       "Interface IPv6 config commands\n"
-       "Neighbor discovery\n"
-       "Advertised MTU\n"
-       "MTU in bytes\n")
-{
-	int idx_number = 3;
-	VTY_DECLVAR_CONTEXT(interface, ifp);
-	struct zebra_if *zif = ifp->info;
-	zif->rtadv.AdvLinkMTU = strtoul(argv[idx_number]->arg, NULL, 10);
-	return CMD_SUCCESS;
-}
-
-DEFUN (no_ipv6_nd_mtu,
-       no_ipv6_nd_mtu_cmd,
-       "no ipv6 nd mtu [(1-65535)]",
        NO_STR
        "Interface IPv6 config commands\n"
        "Neighbor discovery\n"
        "Advertised MTU\n"
        "MTU in bytes\n")
 {
-	VTY_DECLVAR_CONTEXT(interface, ifp);
+	if (!no)
-	struct zebra_if *zif = ifp->info;
+		nb_cli_enqueue_change(vty,
-	zif->rtadv.AdvLinkMTU = 0;
+				      "./frr-zebra:zebra/ipv6-router-advertisements/link-mtu",
-	return CMD_SUCCESS;
+				      NB_OP_MODIFY, mtu_str);
+	else
+		nb_cli_enqueue_change(vty,
+				      "./frr-zebra:zebra/ipv6-router-advertisements/link-mtu",
+				      NB_OP_DESTROY, NULL);
+	return nb_cli_apply_changes(vty, NULL);
 }
 
 static struct rtadv_rdnss *rtadv_rdnss_new(void)
@@ -2798,7 +2788,6 @@ void rtadv_cmd_init(void)
 	install_element(INTERFACE_NODE, &ipv6_nd_router_preference_cmd);
 	install_element(INTERFACE_NODE, &no_ipv6_nd_router_preference_cmd);
 	install_element(INTERFACE_NODE, &ipv6_nd_mtu_cmd);
-	install_element(INTERFACE_NODE, &no_ipv6_nd_mtu_cmd);
 	install_element(INTERFACE_NODE, &ipv6_nd_rdnss_cmd);
 	install_element(INTERFACE_NODE, &no_ipv6_nd_rdnss_cmd);
 	install_element(INTERFACE_NODE, &ipv6_nd_dnssl_cmd);

zebra/zebra_nb.c

@@ -570,6 +570,12 @@ const struct frr_yang_module_info frr_zebra_info = {
 				.modify = lib_interface_zebra_ipv6_router_advertisements_other_config_flag_modify,
 			}
 		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-zebra:zebra/ipv6-router-advertisements/link-mtu",
+			.cbs = {
+				.modify = lib_interface_zebra_ipv6_router_advertisements_link_mtu_modify,
+			}
+		},
 		{
 			.xpath = "/frr-interface:lib/interface/frr-zebra:zebra/ipv6-router-advertisements/reachable-time",
 			.cbs = {

zebra/zebra_nb.h

@@ -189,6 +189,8 @@ int lib_interface_zebra_ipv6_router_advertisements_managed_flag_modify(
 	struct nb_cb_modify_args *args);
 int lib_interface_zebra_ipv6_router_advertisements_other_config_flag_modify(
 	struct nb_cb_modify_args *args);
+int lib_interface_zebra_ipv6_router_advertisements_link_mtu_modify(
+	struct nb_cb_modify_args *args);
 int lib_interface_zebra_ipv6_router_advertisements_reachable_time_modify(
 	struct nb_cb_modify_args *args);
 int lib_interface_zebra_ipv6_router_advertisements_default_lifetime_modify(

zebra/zebra_nb_config.c

@@ -2551,6 +2551,29 @@ int lib_interface_zebra_ipv6_router_advertisements_other_config_flag_modify(
 	return NB_OK;
 }
 
+/*
+ * XPath: /frr-interface:lib/interface/frr-zebra:zebra/ipv6-router-advertisements/link-mtu
+ */
+int lib_interface_zebra_ipv6_router_advertisements_link_mtu_modify(
+	struct nb_cb_modify_args *args)
+{
+	struct interface *ifp;
+	struct zebra_if *zif;
+	uint32_t mtu;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	ifp = nb_running_get_entry(args->dnode, NULL, true);
+	zif = ifp->info;
+
+	mtu = yang_dnode_get_uint32(args->dnode, NULL);
+
+	zif->rtadv.AdvLinkMTU = mtu;
+
+	return NB_OK;
+}
+
 /*
  * XPath: /frr-interface:lib/interface/frr-zebra:zebra/ipv6-router-advertisements/reachable-time
  */