Introduce a garbage collector for dead entries in the LIB.

If we lose a route and all of its associated labels, then there's no
point on keeping an entry for it in the LIB.

3 files changed, 63 insertions, 3 deletions

diff --git a/usr.sbin/ldpd/lde.c b/usr.sbin/ldpd/lde.c
index 6190f28a737..75762dba938 100644
--- a/usr.sbin/ldpd/lde.c
+++ b/usr.sbin/ldpd/lde.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lde.c,v 1.51 2016/05/23 18:31:12 renato Exp $ */
+/*	$OpenBSD: lde.c,v 1.52 2016/05/23 18:46:13 renato Exp $ */
 
 /*
  * Copyright (c) 2004, 2005 Claudio Jeker <claudio@openbsd.org>
@@ -159,6 +159,10 @@ lde(struct ldpd_conf *xconf, int pipe_parent2lde[2], int pipe_ldpe2lde[2],
 	    iev_main->handler, iev_main);
 	event_add(&iev_main->ev, NULL);
 
+	/* setup and start the LIB garbage collector */
+	evtimer_set(&gc_timer, lde_gc_timer, NULL);
+	lde_gc_start_timer();
+
 	gettimeofday(&now, NULL);
 	global.uptime = now.tv_sec;
 
@@ -177,6 +181,7 @@ lde(struct ldpd_conf *xconf, int pipe_parent2lde[2], int pipe_ldpe2lde[2],
 void
 lde_shutdown(void)
 {
+	lde_gc_stop_timer();
 	lde_nbr_clear();
 	fec_tree_clear();
 
diff --git a/usr.sbin/ldpd/lde.h b/usr.sbin/ldpd/lde.h
index 02dd3faef38..9097715ebf7 100644
--- a/usr.sbin/ldpd/lde.h
+++ b/usr.sbin/ldpd/lde.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lde.h,v 1.33 2016/05/23 18:36:55 renato Exp $ */
+/*	$OpenBSD: lde.h,v 1.34 2016/05/23 18:46:13 renato Exp $ */
 
 /*
  * Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org>
@@ -160,6 +160,12 @@ void		 lde_check_release_wcard(struct map *, struct lde_nbr *);
 void		 lde_check_withdraw(struct map *, struct lde_nbr *);
 void		 lde_check_withdraw_wcard(struct map *, struct lde_nbr *);
 void		 lde_label_list_free(struct lde_nbr *);
+void		 lde_gc_timer(int, short, void *);
+void		 lde_gc_start_timer(void);
+void		 lde_gc_stop_timer(void);
+
+#define LDE_GC_INTERVAL 300
+extern struct event gc_timer;
 
 /* l2vpn.c */
 struct l2vpn	*l2vpn_new(const char *);
diff --git a/usr.sbin/ldpd/lde_lib.c b/usr.sbin/ldpd/lde_lib.c
index 1f63fa48608..c7582c2eebb 100644
--- a/usr.sbin/ldpd/lde_lib.c
+++ b/usr.sbin/ldpd/lde_lib.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lde_lib.c,v 1.52 2016/05/23 18:44:47 renato Exp $ */
+/*	$OpenBSD: lde_lib.c,v 1.53 2016/05/23 18:46:13 renato Exp $ */
 
 /*
  * Copyright (c) 2009 Michele Marchetto <michele@openbsd.org>
@@ -54,6 +54,7 @@ RB_PROTOTYPE(nbr_tree, lde_nbr, entry, lde_nbr_compare)
 extern struct ldpd_conf		*ldeconf;
 
 struct fec_tree	ft = RB_INITIALIZER(&ft);
+struct event gc_timer;
 
 /* FEC tree functions */
 void
@@ -709,3 +710,51 @@ lde_check_withdraw_wcard(struct map *map, struct lde_nbr *ln)
 			lde_map_del(ln, me, 0);
 	}
 }
+
+/* gabage collector timer: timer to remove dead entries from the LIB */
+
+/* ARGSUSED */
+void
+lde_gc_timer(int fd, short event, void *arg)
+{
+	struct fec	*fec, *safe;
+	struct fec_node	*fn;
+	int		 count = 0;
+
+	RB_FOREACH_SAFE(fec, fec_tree, &ft, safe) {
+		fn = (struct fec_node *) fec;
+
+		if (!LIST_EMPTY(&fn->nexthops) ||
+		    !LIST_EMPTY(&fn->downstream) ||
+		    !LIST_EMPTY(&fn->upstream))
+			continue;
+
+		fec_remove(&ft, &fn->fec);
+		free(fn);
+		count++;
+	}
+
+	if (count > 0)
+		log_debug("%s: %u entries removed", __func__, count);
+
+	lde_gc_start_timer();
+}
+
+void
+lde_gc_start_timer(void)
+{
+	struct timeval	 tv;
+
+	timerclear(&tv);
+	tv.tv_sec = LDE_GC_INTERVAL;
+	if (evtimer_add(&gc_timer, &tv) == -1)
+		fatal(__func__);
+}
+
+void
+lde_gc_stop_timer(void)
+{
+	if (evtimer_pending(&gc_timer, NULL) &&
+	    evtimer_del(&gc_timer) == -1)
+		fatal(__func__);
+}