bgpd: Restoring GR functionality for unplanned BGP restart

Pdoijode · Pdoijode · commit d8b898fa94a4 · 2024-06-28T10:20:44.000-07:00
Previous changes were breaking GR kicking in on bgpd crash (i.e, on unplanned restart).
So restored the behavior.

Signed-off-by: Pooja Jagadeesh Doijode &lt;pdoijode@nvidia.com&gt;
diff --git a/bgpd/bgp_open.c b/bgpd/bgp_open.c
@@ -1598,7 +1598,7 @@ static void bgp_peer_send_gr_capability(struct stream *s, struct peer *peer,
 	rcapp = stream_get_endp(s);
 	stream_putc(s, 0);
 	restart_time = bgp->restart_time;
-	if (bgp_in_graceful_restart()) {
+	if (peer->bgp->t_startup || bgp_in_graceful_restart()) {
 		SET_FLAG(restart_time, GRACEFUL_RESTART_R_BIT);
 		SET_FLAG(peer->cap, PEER_CAP_GRACEFUL_RESTART_R_BIT_ADV);
 	}
diff --git a/bgpd/bgp_packet.c b/bgpd/bgp_packet.c
@@ -1295,7 +1295,7 @@ void bgp_capability_send(struct peer *peer, afi_t afi, safi_t safi,
 		stream_putc(s, 0);
 		gr_restart_time = peer->bgp->restart_time;
 
-		if (bgp_in_graceful_restart()) {
+		if (peer->bgp->t_startup || bgp_in_graceful_restart()) {
 			SET_FLAG(gr_restart_time, GRACEFUL_RESTART_R_BIT);
 			SET_FLAG(peer->cap, PEER_CAP_GRACEFUL_RESTART_R_BIT_ADV);
 		}
diff --git a/bgpd/bgp_vty.c b/bgpd/bgp_vty.c
@@ -3652,7 +3652,7 @@ DEFUN (bgp_neighbor_graceful_restart_disable_set,
 
 	ret = bgp_neighbor_graceful_restart(peer, PEER_DISABLE_CMD);
 	if (ret == BGP_GR_SUCCESS) {
-		if (bgp_in_graceful_restart())
+		if (peer->bgp->t_startup || bgp_in_graceful_restart())
 			bgp_peer_gr_flags_update(peer);
 
 		VTY_BGP_GR_ROUTER_DETECT(bgp, peer, peer->bgp->peer);
diff --git a/bgpd/bgp_vty.h b/bgpd/bgp_vty.h
@@ -60,6 +60,8 @@ struct bgp;
 
 #define VTY_BGP_GR_ROUTER_DETECT(_bgp, _peer, _peer_list)                      \
 	do {                                                                   \
+		if (_peer->bgp->t_startup)                                     \
+			bgp_peer_gr_flags_update(_peer);                       \
 		for (ALL_LIST_ELEMENTS(_peer_list, node, nnode, peer_loop)) {  \
 			if (CHECK_FLAG(peer_loop->flags,                       \
 				       PEER_FLAG_GRACEFUL_RESTART))            \
@@ -90,6 +92,8 @@ struct bgp;
 		struct listnode *node = { 0 };                                  \
 		struct listnode *nnode = { 0 };                                 \
 		for (ALL_LIST_ELEMENTS(_peer_list, node, nnode, peer_loop)) {   \
+			if (peer_loop->bgp->t_startup)                          \
+				bgp_peer_gr_flags_update(peer_loop);            \
 			if (CHECK_FLAG(peer_loop->flags,                        \
 				       PEER_FLAG_GRACEFUL_RESTART))             \
 				gr_router_detected = true;                      \
diff --git a/bgpd/bgpd.c b/bgpd/bgpd.c
@@ -3389,6 +3389,14 @@ int peer_group_bind(struct bgp *bgp, union sockunion *su, struct peer *peer,
 	return 0;
 }
 
+static void bgp_startup_timer_expire(struct event *thread)
+{
+	struct bgp *bgp;
+
+	bgp = EVENT_ARG(thread);
+	bgp->t_startup = NULL;
+}
+
 /*
  * On shutdown we call the cleanup function which
  * does a free of the link list nodes,  free up
@@ -3547,6 +3555,9 @@ static struct bgp *bgp_create(as_t *as, const char *name,
 	if (name)
 		bgp->name = XSTRDUP(MTYPE_BGP_NAME, name);
 
+	event_add_timer(bm->master, bgp_startup_timer_expire, bgp,
+			bgp->restart_time, &bgp->t_startup);
+
 	/* printable name we can use in debug messages */
 	if (inst_type == BGP_INSTANCE_TYPE_DEFAULT) {
 		bgp->name_pretty = XSTRDUP(MTYPE_BGP_NAME, "VRF default");
@@ -3953,6 +3964,7 @@ int bgp_delete(struct bgp *bgp)
 		EVENT_OFF(bgp->t_revalidate[afi][safi]);
 
 	EVENT_OFF(bgp->t_condition_check);
+	EVENT_OFF(bgp->t_startup);
 	EVENT_OFF(bgp->t_maxmed_onstartup);
 	EVENT_OFF(bgp->t_update_delay);
 	EVENT_OFF(bgp->t_establish_wait);
diff --git a/bgpd/bgpd.h b/bgpd/bgpd.h
@@ -447,6 +447,9 @@ struct bgp {
 	struct as_confed *confed_peers;
 	int confed_peers_cnt;
 
+	/* start-up timer on only once at the beginning */
+	struct event *t_startup;
+
 	uint32_t v_maxmed_onstartup; /* Duration of max-med on start-up */
 #define BGP_MAXMED_ONSTARTUP_UNCONFIGURED  0 /* 0 means off, its the default */
 	uint32_t maxmed_onstartup_value;     /* Max-med value when active on

Original file line number	Diff line number	Diff line change
`@@ -1598,7 +1598,7 @@ static void bgp_peer_send_gr_capability(struct stream s, struct peer peer,`
`1598`	`1598`	`rcapp = stream_get_endp(s);`
`1599`	`1599`	`stream_putc(s, 0);`
`1600`	`1600`	`restart_time = bgp->restart_time;`
`1601`		`- if (bgp_in_graceful_restart()) {`
	`1601`	`+ if (peer->bgp->t_startup \|\| bgp_in_graceful_restart()) {`
`1602`	`1602`	`SET_FLAG(restart_time, GRACEFUL_RESTART_R_BIT);`
`1603`	`1603`	`SET_FLAG(peer->cap, PEER_CAP_GRACEFUL_RESTART_R_BIT_ADV);`
`1604`	`1604`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1295,7 +1295,7 @@ void bgp_capability_send(struct peer *peer, afi_t afi, safi_t safi,`
`1295`	`1295`	`stream_putc(s, 0);`
`1296`	`1296`	`gr_restart_time = peer->bgp->restart_time;`
`1297`	`1297`
`1298`		`- if (bgp_in_graceful_restart()) {`
	`1298`	`+ if (peer->bgp->t_startup \|\| bgp_in_graceful_restart()) {`
`1299`	`1299`	`SET_FLAG(gr_restart_time, GRACEFUL_RESTART_R_BIT);`
`1300`	`1300`	`SET_FLAG(peer->cap, PEER_CAP_GRACEFUL_RESTART_R_BIT_ADV);`
`1301`	`1301`	`}`