zebra:re-install dependent nhgs on interface up

Upon interface up associated singleton NHG's
dependent NHGs needs to be reinstalled as
kernel would have deleted if there is no route
referencing it.

Ticket:#3416477
Issue:3416477
Testing Done:
flap interfaces which are part of route NHG,
upon interfaces up event, NHGs are resynced
into dplane.

Signed-off-by: Chirag Shah <chirag@nvidia.com>
(cherry picked from commit 69cf016ee2c50e624172695b7ea84d52006ebd34)

diff --git a/zebra/zebra_nhg.c b/zebra/zebra_nhg.c
index 78fa22de71f77b99012d0a6b4e71545ab1f5af0a..b171675402890e224a9f2693edf095fedbf64de4 100644 (file)
--- a/zebra/zebra_nhg.c
+++ b/zebra/zebra_nhg.c
@@ -1140,13 +1140,23 @@ static void zebra_nhg_handle_uninstall(struct nhg_hash_entry *nhe)
        zebra_nhg_free(nhe);
 }
 
-static void zebra_nhg_handle_install(struct nhg_hash_entry *nhe)
+static void zebra_nhg_handle_install(struct nhg_hash_entry *nhe, bool install)
 {
        /* Update validity of groups depending on it */
        struct nhg_connected *rb_node_dep;
 
-       frr_each_safe(nhg_connected_tree, &nhe->nhg_dependents, rb_node_dep)
+       frr_each_safe (nhg_connected_tree, &nhe->nhg_dependents, rb_node_dep) {
                zebra_nhg_set_valid(rb_node_dep->nhe);
+               /* install dependent NHG into kernel */
+               if (install) {
+                       if (IS_ZEBRA_DEBUG_NHG_DETAIL)
+                               zlog_debug(
+                                       "%s nh id %u (flags 0x%x) associated dependent NHG %pNG install",
+                                       __func__, nhe->id, nhe->flags,
+                                       rb_node_dep->nhe);
+                       zebra_nhg_install_kernel(rb_node_dep->nhe);
+               }
+       }
 }
 
 /*
@@ -3035,7 +3045,7 @@ void zebra_nhg_install_kernel(struct nhg_hash_entry *nhe)
                        break;
                case ZEBRA_DPLANE_REQUEST_SUCCESS:
                        SET_FLAG(nhe->flags, NEXTHOP_GROUP_INSTALLED);
-                       zebra_nhg_handle_install(nhe);
+                       zebra_nhg_handle_install(nhe, false);
                        break;
                }
        }
@@ -3109,7 +3119,7 @@ void zebra_nhg_dplane_result(struct zebra_dplane_ctx *ctx)
                if (status == ZEBRA_DPLANE_REQUEST_SUCCESS) {
                        SET_FLAG(nhe->flags, NEXTHOP_GROUP_VALID);
                        SET_FLAG(nhe->flags, NEXTHOP_GROUP_INSTALLED);
-                       zebra_nhg_handle_install(nhe);
+                       zebra_nhg_handle_install(nhe, true);
 
                        /* If daemon nhg, send it an update */
                        if (PROTO_OWNED(nhe))
@@ -3627,7 +3637,30 @@ void zebra_interface_nhg_reinstall(struct interface *ifp)
                }
                /* Check for singleton NHG associated to interface */
                if (nexthop_is_ifindex_type(nh) &&
-                   zebra_nhg_depends_is_empty(rb_node_dep->nhe))
+                   zebra_nhg_depends_is_empty(rb_node_dep->nhe)) {
+                       struct nhg_connected *rb_node_dependent;
+
+                       if (IS_ZEBRA_DEBUG_NHG)
+                               zlog_debug(
+                                       "%s install nhe %pNG nh type %u flags 0x%x",
+                                       __func__, rb_node_dep->nhe, nh->type,
+                                       rb_node_dep->nhe->flags);
                        zebra_nhg_install_kernel(rb_node_dep->nhe);
+
+                       /* mark depedent uninstall, when interface associated
+                        * singleton is installed, install depedent
+                        */
+                       frr_each_safe (nhg_connected_tree,
+                                      &rb_node_dep->nhe->nhg_dependents,
+                                      rb_node_dependent) {
+                               if (IS_ZEBRA_DEBUG_NHG)
+                                       zlog_debug(
+                                               "%s dependent nhe %pNG unset installed flag",
+                                               __func__,
+                                               rb_node_dependent->nhe);
+                               UNSET_FLAG(rb_node_dependent->nhe->flags,
+                                          NEXTHOP_GROUP_INSTALLED);
+                       }
+               }
        }
 }