Merge pull request #10838 from ton31337/feature/bgpd_callbacks_for_start_end_configurations

bgpd: Add BGP configuration start/end markers

bgpd/bgp_vty.c

@@ -17599,11 +17599,67 @@ static const struct cmd_variable_handler bgp_var_peergroup[] = {
 	{.tokenname = "PGNAME", .completions = bgp_ac_peergroup},
 	{.completions = NULL} };
 
+DEFINE_HOOK(bgp_config_end, (struct bgp *bgp), (bgp));
+
+static struct thread *t_bgp_cfg;
+
+bool bgp_config_inprocess(void)
+{
+	return thread_is_scheduled(t_bgp_cfg);
+}
+
+static void bgp_config_finish(struct thread *t)
+{
+	struct listnode *node;
+	struct bgp *bgp;
+
+	for (ALL_LIST_ELEMENTS_RO(bm->bgp, node, bgp))
+		hook_call(bgp_config_end, bgp);
+}
+
+static void bgp_config_start(void)
+{
+#define BGP_PRE_CONFIG_MAX_WAIT_SECONDS 600
+	THREAD_OFF(t_bgp_cfg);
+	thread_add_timer(bm->master, bgp_config_finish, NULL,
+			 BGP_PRE_CONFIG_MAX_WAIT_SECONDS, &t_bgp_cfg);
+}
+
+/* When we receive a hook the configuration is read,
+ * we start a timer to make sure we postpone sending
+ * EoR before route-maps are processed.
+ * This is especially valid if using `bgp route-map delay-timer`.
+ */
+static void bgp_config_end(void)
+{
+#define BGP_POST_CONFIG_DELAY_SECONDS 1
+	uint32_t bgp_post_config_delay =
+		thread_is_scheduled(bm->t_rmap_update)
+			? thread_timer_remain_second(bm->t_rmap_update)
+			: BGP_POST_CONFIG_DELAY_SECONDS;
+
+	/* If BGP config processing thread isn't running, then
+	 * we can return and rely it's properly handled.
+	 */
+	if (!bgp_config_inprocess())
+		return;
+
+	THREAD_OFF(t_bgp_cfg);
+
+	/* Start a new timer to make sure we don't send EoR
+	 * before route-maps are processed.
+	 */
+	thread_add_timer(bm->master, bgp_config_finish, NULL,
+			 bgp_post_config_delay, &t_bgp_cfg);
+}
+
 void bgp_vty_init(void)
 {
 	cmd_variable_handler_register(bgp_var_neighbor);
 	cmd_variable_handler_register(bgp_var_peergroup);
 
+	cmd_init_config_callbacks(bgp_config_start, bgp_config_end);
+
 	/* Install bgp top node. */
 	install_node(&bgp_node);
 	install_node(&bgp_ipv4_unicast_node);

bgpd/bgp_vty.h

@@ -164,6 +164,7 @@ extern void bgp_config_write_rpkt_quanta(struct vty *vty, struct bgp *bgp);
 extern void bgp_config_write_listen(struct vty *vty, struct bgp *bgp);
 extern void bgp_config_write_coalesce_time(struct vty *vty, struct bgp *bgp);
 extern int bgp_vty_return(struct vty *vty, int ret);
+extern bool bgp_config_inprocess(void);
 extern struct peer *peer_and_group_lookup_vty(struct vty *vty,
 					      const char *peer_str);
 

bgpd/bgpd.c

@@ -1731,6 +1731,8 @@ struct peer *peer_create(union sockunion *su, const char *conf_if,
 	peer->v_routeadv = (peer_sort(peer) == BGP_PEER_IBGP)
 				   ? BGP_DEFAULT_IBGP_ROUTEADV
 				   : BGP_DEFAULT_EBGP_ROUTEADV;
+	if (bgp_config_inprocess())
+		peer->shut_during_cfg = true;
 
 	peer = peer_lock(peer); /* bgp peer list reference */
 	peer->group = group;
@@ -7940,8 +7942,33 @@ void bgp_pthreads_finish(void)
 	frr_pthread_stop_all();
 }
 
+static int peer_unshut_after_cfg(struct bgp *bgp)
+{
+	struct listnode *node;
+	struct peer *peer;
+
+	for (ALL_LIST_ELEMENTS_RO(bgp->peer, node, peer)) {
+		if (!peer->shut_during_cfg)
+			continue;
+
+		if (bgp_debug_neighbor_events(peer))
+			zlog_debug("%s: released from config-pending hold",
+				   peer->host);
+
+		peer->shut_during_cfg = false;
+		if (peer_active(peer) && peer->status != Established) {
+			if (peer->status != Idle)
+				BGP_EVENT_ADD(peer, BGP_Stop);
+			BGP_EVENT_ADD(peer, BGP_Start);
+		}
+	}
+
+	return 0;
+}
+
 void bgp_init(unsigned short instance)
 {
+	hook_register(bgp_config_end, peer_unshut_after_cfg);
 
 	/* allocates some vital data structures used by peer commands in
 	 * vty_init */

bgpd/bgpd.h

@@ -771,6 +771,7 @@ DECLARE_HOOK(bgp_inst_delete, (struct bgp *bgp), (bgp));
 DECLARE_HOOK(bgp_inst_config_write,
 		(struct bgp *bgp, struct vty *vty),
 		(bgp, vty));
+DECLARE_HOOK(bgp_config_end, (struct bgp *bgp), (bgp));
 
 /* Thread callback information */
 struct afi_safi_info {
@@ -1676,6 +1677,8 @@ struct peer {
 	/* Long-lived Graceful Restart */
 	struct llgr_info llgr[AFI_MAX][SAFI_MAX];
 
+	bool shut_during_cfg;
+
 	QOBJ_FIELDS;
 };
 DECLARE_QOBJ_TYPE(peer);
@@ -1703,9 +1706,10 @@ DECLARE_QOBJ_TYPE(peer);
 
 /* Check if suppress start/restart of sessions to peer. */
 #define BGP_PEER_START_SUPPRESSED(P)                                           \
-	(CHECK_FLAG((P)->flags, PEER_FLAG_SHUTDOWN)                            \
+	(CHECK_FLAG((P)->flags, PEER_FLAG_SHUTDOWN) ||                         \
-	 || CHECK_FLAG((P)->sflags, PEER_STATUS_PREFIX_OVERFLOW)               \
+	 CHECK_FLAG((P)->sflags, PEER_STATUS_PREFIX_OVERFLOW) ||               \
-	 || CHECK_FLAG((P)->bgp->flags, BGP_FLAG_SHUTDOWN))
+	 CHECK_FLAG((P)->bgp->flags, BGP_FLAG_SHUTDOWN) ||                     \
+	 (P)->shut_during_cfg)
 
 #define PEER_ROUTE_ADV_DELAY(peer)					       \
 	(CHECK_FLAG(peer->thread_flags, PEER_THREAD_SUBGRP_ADV_DELAY))