vrrpd: tweak interface tracking on ifdown

Change the interface tracking code to react to an interface down by
automatically transitioning to Backup, instead of shutting down the
session. This is because we get ZEBRA_INTERFACE_DOWN messages when we
set an interface to protodown as part of transitioning to Backup; if we
shut down the session in response to these messages, we end up shutting
ourselves down every time we try to transition to Backup.

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

1 files changed, 16 insertions, 11 deletions

diff --git a/vrrpd/vrrp.c b/vrrpd/vrrp.c
index 113e42490d..3c8f3fbfb3 100644
--- a/vrrpd/vrrp.c
+++ b/vrrpd/vrrp.c
@@ -1203,6 +1203,9 @@ static void vrrp_change_state_backup(struct vrrp_router *r)
 	if (r->family == AF_INET6)
 		vrrp_zebra_radv_set(r, false);
 
+	/* Disable Adver_Timer */
+	THREAD_OFF(r->t_adver_timer);
+
 	vrrp_zclient_send_interface_protodown(r->mvl_ifp, true);
 }
 
@@ -1402,19 +1405,17 @@ static int vrrp_startup(struct vrrp_router *r)
  */
 static int vrrp_shutdown(struct vrrp_router *r)
 {
+	uint8_t saved_prio;
+
 	switch (r->fsm.state) {
 	case VRRP_STATE_MASTER:
-		/* Cancel the Adver_Timer */
-		THREAD_OFF(r->t_adver_timer);
 		/* Send an ADVERTISEMENT with Priority = 0 */
-		uint8_t saved_prio = r->priority;
+		saved_prio = r->priority;
 		r->priority = 0;
 		vrrp_send_advertisement(r);
 		r->priority = saved_prio;
 		break;
 	case VRRP_STATE_BACKUP:
-		/* Cancel the Master_Down_Timer */
-		THREAD_OFF(r->t_master_down_timer);
 		break;
 	case VRRP_STATE_INITIALIZE:
 		DEBUGD(&vrrp_dbg_proto,
@@ -1425,6 +1426,10 @@ static int vrrp_shutdown(struct vrrp_router *r)
 		break;
 	}
 
+	/* Cancel all timers */
+	THREAD_OFF(r->t_adver_timer);
+	THREAD_OFF(r->t_master_down_timer);
+
 	if (r->sock_rx > 0) {
 		close(r->sock_rx);
 		r->sock_rx = -1;
@@ -1858,22 +1863,22 @@ void vrrp_if_down(struct interface *ifp)
 
 	for (ALL_LIST_ELEMENTS_RO(vrs, ln, vr)) {
 		if (vr->v4->mvl_ifp == ifp || vr->ifp == ifp) {
-			if (vr->v4->fsm.state != VRRP_STATE_INITIALIZE) {
+			if (vr->v4->fsm.state == VRRP_STATE_MASTER) {
 				DEBUGD(&vrrp_dbg_auto,
 				       VRRP_LOGPFX VRRP_LOGPFX_VRID
-				       "Interface %s down; shutting down IPv4 VRRP router",
+				       "Interface %s down; transitioning IPv4 VRRP router to Backup",
 				       vr->vrid, ifp->name);
-				vrrp_event(vr->v4, VRRP_EVENT_SHUTDOWN);
+				vrrp_change_state(vr->v4, VRRP_STATE_BACKUP);
 			}
 		}
 
 		if (vr->v6->mvl_ifp == ifp || vr->ifp == ifp) {
-			if (vr->v6->fsm.state != VRRP_STATE_INITIALIZE) {
+			if (vr->v6->fsm.state == VRRP_STATE_MASTER) {
 				DEBUGD(&vrrp_dbg_auto,
 				       VRRP_LOGPFX VRRP_LOGPFX_VRID
-				       "Interface %s down; shutting down IPv6 VRRP router",
+				       "Interface %s down; transitioning IPv6 VRRP router to Backup",
 				       vr->vrid, ifp->name);
-				vrrp_event(vr->v6, VRRP_EVENT_SHUTDOWN);
+				vrrp_change_state(vr->v6, VRRP_STATE_BACKUP);
 			}
 		}
 	}