zebra: restart start-up delay timer when the first uplink comes up

When all the uplinks go down the VTEP is disconnected from the
VxLAN overlay and this was handled by proto-downing the ES bonds. When
the uplinks come up again we need to re-enable the ES bonds but that
needs to be done after a delay to allow the EVPN network to converge.

And that is done by firing off the startup-delay timer on first
uplink-up.

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

diff --git a/zebra/zebra_evpn_mh.c b/zebra/zebra_evpn_mh.c
index a9cb9ce9295f0365f696c8cc2cdb6ab80248e62d..bda2708f9f95936217d31358c6cb42a78f544936 100644 (file)
--- a/zebra/zebra_evpn_mh.c
+++ b/zebra/zebra_evpn_mh.c
@@ -71,6 +71,7 @@ static void zebra_evpn_mh_uplink_cfg_update(struct zebra_if *zif, bool set);
 static void zebra_evpn_mh_update_protodown_es(struct zebra_evpn_es *es,
                                              bool resync_dplane);
 static void zebra_evpn_mh_clear_protodown_es(struct zebra_evpn_es *es);
+static void zebra_evpn_mh_startup_delay_timer_start(const char *rc);
 
 esi_t zero_esi_buf, *zero_esi = &zero_esi_buf;
 
@@ -3383,6 +3384,13 @@ void zebra_evpn_mh_uplink_oper_update(struct zebra_if *zif)
        if (old_protodown == new_protodown)
                return;
 
+       /* if protodown_rc XXX_UPLINK_DOWN is about to be cleared
+        * fire up the start-up delay timer to allow the EVPN network
+        * to converge (Type-2 routes need to be advertised and processed)
+        */
+       if (!new_protodown && (zmh_info->uplink_oper_up_cnt == 1))
+               zebra_evpn_mh_startup_delay_timer_start("uplink-up");
+
        zebra_evpn_mh_update_protodown(ZEBRA_PROTODOWN_EVPN_UPLINK_DOWN,
                                       new_protodown);
 }
@@ -3398,15 +3406,8 @@ static int zebra_evpn_mh_startup_delay_exp_cb(struct thread *t)
        return 0;
 }
 
-static void zebra_evpn_mh_startup_delay_timer_start(bool init)
+static void zebra_evpn_mh_startup_delay_timer_start(const char *rc)
 {
-       /* 1. This timer can be started during init.
-        * 2. It can also be restarted if it is alreay running and the
-        * admin wants to increase or decrease its value
-        */
-       if (!init && !zmh_info->startup_delay_timer)
-               return;
-
        if (zmh_info->startup_delay_timer) {
                if (IS_ZEBRA_DEBUG_EVPN_MH_ES)
                        zlog_debug("startup-delay timer cancelled");
@@ -3416,8 +3417,9 @@ static void zebra_evpn_mh_startup_delay_timer_start(bool init)
 
        if (zmh_info->startup_delay_time) {
                if (IS_ZEBRA_DEBUG_EVPN_MH_ES)
-                       zlog_debug("startup-delay timer started for %d sec",
-                                  zmh_info->startup_delay_time);
+                       zlog_debug(
+                               "startup-delay timer started for %d sec on %s",
+                               zmh_info->startup_delay_time, rc);
                thread_add_timer(zrouter.master,
                                 zebra_evpn_mh_startup_delay_exp_cb, NULL,
                                 zmh_info->startup_delay_time,
@@ -3478,7 +3480,12 @@ int zebra_evpn_mh_startup_delay_update(struct vty *vty, uint32_t duration,
                duration = ZEBRA_EVPN_MH_STARTUP_DELAY_DEF;
 
        zmh_info->startup_delay_time = duration;
-       zebra_evpn_mh_startup_delay_timer_start(false /* init */);
+
+       /* if startup_delay_timer is running allow it to be adjusted
+        * up or down
+        */
+       if (zmh_info->startup_delay_timer)
+               zebra_evpn_mh_startup_delay_timer_start("config");
 
        return 0;
 }
@@ -3528,7 +3535,7 @@ void zebra_evpn_mh_init(void)
                        zebra_evpn_acc_vl_cmp, "access VLAN hash table");
 
        zmh_info->startup_delay_time = ZEBRA_EVPN_MH_STARTUP_DELAY_DEF;
-       zebra_evpn_mh_startup_delay_timer_start(true /*init*/);
+       zebra_evpn_mh_startup_delay_timer_start("init");
 }
 
 void zebra_evpn_mh_terminate(void)