Merge pull request #7686 from volta-networks/fix_ldpsync_igps_detect_client_close

isisd, ospfd: IGPs detect LDP down via zapi client close message

isisd/isis_ldp_sync.c

@@ -293,7 +293,7 @@ void isis_ldp_sync_ldp_fail(struct isis_circuit *circuit)
 
 	ldp_sync_info = circuit->ldp_sync_info;
 
-	/* LDP failed to send hello:
+	/* LDP client close detected:
 	 *  stop holddown timer
 	 *  set cost of interface to LSInfinity so traffic will use different
 	 *  interface until LDP restarts and has learned all labels from peer
@@ -521,6 +521,44 @@ void isis_ldp_sync_holddown_timer_add(struct isis_circuit *circuit)
 			 &ldp_sync_info->t_holddown);
 }
 
+/*
+ * LDP-SYNC handle client close routine
+ */
+void isis_ldp_sync_handle_client_close(struct zapi_client_close_info *info)
+{
+	struct isis_area *area;
+	struct listnode *node;
+	struct isis_circuit *circuit;
+	struct interface *ifp;
+	struct vrf *vrf = vrf_lookup_by_id(VRF_DEFAULT);
+	struct isis *isis = isis_lookup_by_vrfid(VRF_DEFAULT);
+
+	/* if isis is not enabled or LDP-SYNC is not configured ignore */
+	if (!isis
+	    || !CHECK_FLAG(isis->ldp_sync_cmd.flags, LDP_SYNC_FLAG_ENABLE))
+		return;
+
+	/* Check if the LDP main client session closed */
+	if (info->proto != ZEBRA_ROUTE_LDP || info->session_id == 0)
+		return;
+
+	/* Handle the zebra notification that the LDP client session closed.
+	 *  set cost to LSInfinity
+	 *  send request to LDP for LDP-SYNC state for each interface
+	 */
+	zlog_err("ldp_sync: LDP down");
+
+	FOR_ALL_INTERFACES (vrf, ifp) {
+		for (ALL_LIST_ELEMENTS_RO(isis->area_list, node, area)) {
+			circuit =
+				circuit_lookup_by_ifp(ifp, area->circuit_list);
+			if (circuit == NULL)
+				continue;
+			isis_ldp_sync_if_start(circuit, true);
+		}
+	}
+}
+
 /*
  * LDP-SYNC hello timer routines
  */

isisd/isis_ldp_sync.h

@@ -20,6 +20,8 @@
 #ifndef _ZEBRA_ISIS_LDP_SYNC_H
 #define _ZEBRA_ISIS_LDP_SYNC_H
 
+#include "zclient.h"
+
 /* Macro to log debug message */
 #define ils_debug(...)                                                         \
 	do {                                                                   \
@@ -36,6 +38,8 @@ extern void isis_ldp_sync_if_start(struct isis_circuit *circuit,
 extern void isis_ldp_sync_if_remove(struct isis_circuit *circuit, bool remove);
 extern void isis_ldp_sync_if_complete(struct isis_circuit *circuit);
 extern void isis_ldp_sync_holddown_timer_add(struct isis_circuit *circuit);
+extern void
+isis_ldp_sync_handle_client_close(struct zapi_client_close_info *info);
 extern void isis_ldp_sync_hello_timer_add(void);
 extern void isis_ldp_sync_ldp_fail(struct isis_circuit *circuit);
 extern int isis_ldp_sync_state_update(struct ldp_igp_sync_if_state state);

isisd/isis_zebra.c

@@ -699,6 +699,20 @@ stream_failure:
 	return ret;
 }
 
+static int isis_zebra_client_close_notify(ZAPI_CALLBACK_ARGS)
+{
+	int ret = 0;
+
+	struct zapi_client_close_info info;
+
+	if (zapi_client_close_notify_decode(zclient->ibuf, &info) < 0)
+		return -1;
+
+	isis_ldp_sync_handle_client_close(&info);
+
+	return ret;
+}
+
 void isis_zebra_init(struct thread_master *master, int instance)
 {
 	/* Initialize asynchronous zclient. */
@@ -727,6 +741,8 @@ void isis_zebra_init(struct thread_master *master, int instance)
 	zclient_sync->privs = &isisd_privs;
 
 	zclient->opaque_msg_handler = isis_opaque_msg_handler;
+
+	zclient->zebra_client_close_notify = isis_zebra_client_close_notify;
 }
 
 void isis_zebra_stop(void)

ospfd/ospf_ldp_sync.c

@@ -253,6 +253,33 @@ void ospf_ldp_sync_if_complete(struct interface *ifp)
 	}
 }
 
+void ospf_ldp_sync_handle_client_close(struct zapi_client_close_info *info)
+{
+	struct ospf *ospf;
+	struct vrf *vrf;
+	struct interface *ifp;
+
+	/* if ospf is not enabled or LDP-SYNC is not configured ignore */
+	ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);
+	if (ospf == NULL
+	    || !CHECK_FLAG(ospf->ldp_sync_cmd.flags, LDP_SYNC_FLAG_ENABLE))
+		return;
+
+	/* Check if the LDP main client session closed */
+	if (info->proto != ZEBRA_ROUTE_LDP || info->session_id == 0)
+		return;
+
+	/* Handle the zebra notification that the LDP client session closed.
+	 *  set cost to LSInfinity
+	 *  send request to LDP for LDP-SYNC state for each interface
+	 */
+	zlog_err("ldp_sync: LDP down");
+
+	vrf = vrf_lookup_by_id(ospf->vrf_id);
+	FOR_ALL_INTERFACES (vrf, ifp)
+		ospf_ldp_sync_if_start(ifp, true);
+}
+
 void ospf_ldp_sync_ldp_fail(struct interface *ifp)
 {
 	struct ospf_if_params *params;
@@ -264,7 +291,7 @@ void ospf_ldp_sync_ldp_fail(struct interface *ifp)
 	params = IF_DEF_PARAMS(ifp);
 	ldp_sync_info = params->ldp_sync_info;
 
-	/* LDP failed to send hello:
+	/* LDP client close detected:
 	 *  stop holddown timer
 	 *  set cost of interface to LSInfinity so traffic will use different
 	 *  interface until LDP has learned all labels from peer

ospfd/ospf_ldp_sync.h

@@ -50,6 +50,8 @@ extern void ospf_ldp_sync_if_write_config(struct vty *vty,
 extern int ospf_ldp_sync_state_update(struct ldp_igp_sync_if_state state);
 extern int ospf_ldp_sync_announce_update(struct ldp_igp_sync_announce announce);
 extern int ospf_ldp_sync_hello_update(struct ldp_igp_sync_hello hello);
+extern void
+ospf_ldp_sync_handle_client_close(struct zapi_client_close_info *info);
 extern void ospf_ldp_sync_state_req_msg(struct interface *ifp);
 extern void ospf_ldp_sync_init(void);
 extern void ospf_ldp_sync_gbl_exit(struct ospf *ospf, bool remove);

ospfd/ospf_zebra.c

@@ -1986,6 +1986,20 @@ stream_failure:
 	return ret;
 }
 
+static int ospf_zebra_client_close_notify(ZAPI_CALLBACK_ARGS)
+{
+	int ret = 0;
+
+	struct zapi_client_close_info info;
+
+	if (zapi_client_close_notify_decode(zclient->ibuf, &info) < 0)
+		return -1;
+
+	ospf_ldp_sync_handle_client_close(&info);
+
+	return ret;
+}
+
 void ospf_zebra_init(struct thread_master *master, unsigned short instance)
 {
 	/* Allocate zebra structure. */
@@ -2021,6 +2035,8 @@ void ospf_zebra_init(struct thread_master *master, unsigned short instance)
 	prefix_list_delete_hook(ospf_prefix_list_update);
 
 	zclient->opaque_msg_handler = ospf_opaque_msg_handler;
+
+	zclient->zebra_client_close_notify = ospf_zebra_client_close_notify;
 }
 
 void ospf_zebra_send_arp(const struct interface *ifp, const struct prefix *p)