zebra: remove FDB entries before de-activating a L2-NHG

NHG is activated i.e. programmed in the dataplane only if there
are active-VTEPs associated with it. When a NHG is de-activated
all the remote-mac entries associated with it need to be removed
before the NHG is removed.

Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>

zebra/zebra_evpn_mac.c

@@ -155,7 +155,8 @@ int zebra_evpn_rem_mac_install(zebra_evpn_t *zevpn, zebra_mac_t *mac,
 /*
  * Uninstall remote MAC from the forwarding plane.
  */
-int zebra_evpn_rem_mac_uninstall(zebra_evpn_t *zevpn, zebra_mac_t *mac)
+int zebra_evpn_rem_mac_uninstall(zebra_evpn_t *zevpn, zebra_mac_t *mac,
+				 bool force)
 {
 	const struct zebra_if *zif, *br_zif;
 	const struct zebra_l2info_vxlan *vxl;
@@ -167,6 +168,10 @@ int zebra_evpn_rem_mac_uninstall(zebra_evpn_t *zevpn, zebra_mac_t *mac)
 	if (!(mac->flags & ZEBRA_MAC_REMOTE))
 		return 0;
 
+	/* If the MAC was not installed there is no need to uninstall it */
+	if (!force && mac->es && !(mac->es->flags & ZEBRA_EVPNES_NHG_ACTIVE))
+		return -1;
+
 	if (!zevpn->vxlan_if) {
 		if (IS_ZEBRA_DEBUG_VXLAN)
 			zlog_debug(
@@ -216,7 +221,7 @@ void zebra_evpn_deref_ip2mac(zebra_evpn_t *zevpn, zebra_mac_t *mac)
 	 */
 	if (CHECK_FLAG(mac->flags, ZEBRA_MAC_REMOTE)
 	    && remote_neigh_count(mac) == 0) {
-		zebra_evpn_rem_mac_uninstall(zevpn, mac);
+		zebra_evpn_rem_mac_uninstall(zevpn, mac, false /*force*/);
 		zebra_evpn_es_mac_deref_entry(mac);
 		UNSET_FLAG(mac->flags, ZEBRA_MAC_REMOTE);
 	}
@@ -1076,7 +1081,8 @@ static void zebra_evpn_mac_del_hash_entry(struct hash_bucket *bucket, void *arg)
 					__func__);
 
 			if (mac->flags & ZEBRA_MAC_REMOTE)
-				zebra_evpn_rem_mac_uninstall(wctx->zevpn, mac);
+				zebra_evpn_rem_mac_uninstall(wctx->zevpn, mac,
+							     false /*force*/);
 		}
 
 		zebra_evpn_mac_del(wctx->zevpn, mac);
@@ -1694,7 +1700,7 @@ void zebra_evpn_rem_mac_del(zebra_evpn_t *zevpn, zebra_mac_t *mac)
 	 * go away, we need to uninstall the MAC.
 	 */
 	if (remote_neigh_count(mac) == 0) {
-		zebra_evpn_rem_mac_uninstall(zevpn, mac);
+		zebra_evpn_rem_mac_uninstall(zevpn, mac, false /*force*/);
 		zebra_evpn_es_mac_deref_entry(mac);
 		UNSET_FLAG(mac->flags, ZEBRA_MAC_REMOTE);
 	}

zebra/zebra_evpn_mac.h

@@ -204,7 +204,8 @@ static inline void zebra_evpn_mac_clear_sync_info(zebra_mac_t *mac)
 struct hash *zebra_mac_db_create(const char *desc);
 uint32_t num_valid_macs(zebra_evpn_t *zevi);
 uint32_t num_dup_detected_macs(zebra_evpn_t *zevi);
-int zebra_evpn_rem_mac_uninstall(zebra_evpn_t *zevi, zebra_mac_t *mac);
+int zebra_evpn_rem_mac_uninstall(zebra_evpn_t *zevi, zebra_mac_t *mac,
+				 bool force);
 int zebra_evpn_rem_mac_install(zebra_evpn_t *zevi, zebra_mac_t *mac,
 			       bool was_static);
 void zebra_evpn_deref_ip2mac(zebra_evpn_t *zevi, zebra_mac_t *mac);

zebra/zebra_evpn_mh.c

@@ -989,6 +989,25 @@ static void zebra_evpn_nhid_free(uint32_t nh_id)
 	bf_release_index(zmh_info->nh_id_bitmap, id);
 }
 
+/* update remote macs associated with the ES */
+static void zebra_evpn_nhg_mac_update(struct zebra_evpn_es *es)
+{
+	zebra_mac_t *mac;
+	struct listnode *node;
+
+	for (ALL_LIST_ELEMENTS_RO(es->mac_list, node, mac)) {
+		if (!CHECK_FLAG(mac->flags, ZEBRA_MAC_REMOTE))
+			continue;
+
+		if (es->flags & ZEBRA_EVPNES_NHG_ACTIVE)
+			zebra_evpn_rem_mac_install(mac->zevpn, mac,
+						   false /*was_static*/);
+		else
+			zebra_evpn_rem_mac_uninstall(mac->zevpn, mac,
+						     true /*force*/);
+	}
+}
+
 /* The MAC ECMP group is activated on the first VTEP */
 static void zebra_evpn_nhg_update(struct zebra_evpn_es *es)
 {
@@ -1028,7 +1047,6 @@ static void zebra_evpn_nhg_update(struct zebra_evpn_es *es)
 				   es->nhg_id, nh_str);
 		}
 
-		es->flags |= ZEBRA_EVPNES_NHG_ACTIVE;
 		kernel_upd_mac_nhg(es->nhg_id, nh_cnt, nh_ids);
 		if (!(es->flags & ZEBRA_EVPNES_NHG_ACTIVE)) {
 			es->flags |= ZEBRA_EVPNES_NHG_ACTIVE;
@@ -1036,6 +1054,7 @@ static void zebra_evpn_nhg_update(struct zebra_evpn_es *es)
 			if ((es->flags & ZEBRA_EVPNES_LOCAL))
 				zebra_evpn_es_br_port_dplane_update(es,
 								    __func__);
+			zebra_evpn_nhg_mac_update(es);
 		}
 	} else {
 		if (es->flags & ZEBRA_EVPNES_NHG_ACTIVE) {
@@ -1047,11 +1066,11 @@ static void zebra_evpn_nhg_update(struct zebra_evpn_es *es)
 			if ((es->flags & ZEBRA_EVPNES_LOCAL))
 				zebra_evpn_es_br_port_dplane_update(es,
 								    __func__);
+			zebra_evpn_nhg_mac_update(es);
 			kernel_del_mac_nhg(es->nhg_id);
 		}
 	}
 
-	/* XXX - update remote macs associated with the ES */
 }
 
 static void zebra_evpn_nh_add(struct zebra_evpn_es_vtep *es_vtep)