zebra: Add a configurable knob zebra nexthop-group keep (1-3600)

Allow end operator to set how long a nexthop-group is kept around in the system after it is no-longer being used. Signed-off-by: Donald Sharp <sharpd@nvidia.com>
FRRouting · Jun 16, 2022 · c9af62e · c9af62e
1 parent 35729f3
commit c9af62e
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Showing 5 changed files with 34 additions and 2 deletions.
diff --git a/doc/user/zebra.rst b/doc/user/zebra.rst
@@ -273,6 +273,12 @@ Nexthop tracking doesn't resolve nexthops via the default route by default.
 Allowing this might be useful when e.g. you want to allow BGP to peer across
 the default route.
 
+.. clicmd:: zebra nexthop-group keep (1-3600)
+
+   Set the time that zebra will keep a created and installed nexthop group
+   before removing it from the system if the nexthop group is no longer
+   being used.  The default time is 180 seconds.
+
 .. clicmd:: ip nht resolve-via-default
 
    Allow IPv4 nexthop tracking to resolve via the default route. This parameter

diff --git a/zebra/zebra_nhg.c b/zebra/zebra_nhg.c
@@ -1649,8 +1649,8 @@ void zebra_nhg_decrement_ref(struct nhg_hash_entry *nhe)
 	    !CHECK_FLAG(nhe->flags, NEXTHOP_GROUP_KEEP_AROUND)) {
 		nhe->refcnt = 1;
 		SET_FLAG(nhe->flags, NEXTHOP_GROUP_KEEP_AROUND);
-		thread_add_timer(zrouter.master, zebra_nhg_timer, nhe, 180,
-				 &nhe->timer);
+		thread_add_timer(zrouter.master, zebra_nhg_timer, nhe,
+				 zrouter.nhg_keep, &nhe->timer);
 	}
 
 	if (!zebra_nhg_depends_is_empty(nhe))

diff --git a/zebra/zebra_router.c b/zebra/zebra_router.c
@@ -278,6 +278,8 @@ void zebra_router_init(bool asic_offload, bool notify_on_ack)
 
 	zrouter.packets_to_process = ZEBRA_ZAPI_PACKETS_TO_PROCESS;
 
+	zrouter.nhg_keep = ZEBRA_DEFAULT_NHG_KEEP_TIMER;
+
 	zebra_vxlan_init();
 	zebra_mlag_init();
 

diff --git a/zebra/zebra_router.h b/zebra/zebra_router.h
@@ -219,6 +219,9 @@ struct zebra_router {
 	bool notify_on_ack;
 
 	bool supports_nhgs;
+
+#define ZEBRA_DEFAULT_NHG_KEEP_TIMER 180
+	uint32_t nhg_keep;
 };
 
 #define GRACEFUL_RESTART_TIME 60

diff --git a/zebra/zebra_vty.c b/zebra/zebra_vty.c
@@ -3850,11 +3850,31 @@ DEFUN (no_ip_zebra_import_table,
 	return (zebra_import_table(AFI_IP, VRF_DEFAULT, table_id, 0, NULL, 0));
 }
 
+DEFPY (zebra_nexthop_group_keep,
+       zebra_nexthop_group_keep_cmd,
+       "[no] zebra nexthop-group keep (1-3600)",
+       NO_STR
+       ZEBRA_STR
+       "Nexthop-Group\n"
+       "How long to keep\n"
+       "Time in seconds from 1-3600\n")
+{
+	if (no)
+		zrouter.nhg_keep = ZEBRA_DEFAULT_NHG_KEEP_TIMER;
+	else
+		zrouter.nhg_keep = keep;
+
+	return CMD_SUCCESS;
+}
+
 static int config_write_protocol(struct vty *vty)
 {
 	if (allow_delete)
 		vty_out(vty, "allow-external-route-update\n");
 
+	if (zrouter.nhg_keep != ZEBRA_DEFAULT_NHG_KEEP_TIMER)
+		vty_out(vty, "zebra nexthop-group keep %u\n", zrouter.nhg_keep);
+
 	if (zrouter.ribq->spec.hold != ZEBRA_RIB_PROCESS_HOLD_TIME)
 		vty_out(vty, "zebra work-queue %u\n", zrouter.ribq->spec.hold);
 
@@ -4433,6 +4453,7 @@ void zebra_vty_init(void)
 	install_element(CONFIG_NODE, &ip_multicast_mode_cmd);
 	install_element(CONFIG_NODE, &no_ip_multicast_mode_cmd);
 
+	install_element(CONFIG_NODE, &zebra_nexthop_group_keep_cmd);
 	install_element(CONFIG_NODE, &ip_zebra_import_table_distance_cmd);
 	install_element(CONFIG_NODE, &no_ip_zebra_import_table_cmd);
 	install_element(CONFIG_NODE, &zebra_workqueue_timer_cmd);