Make it possible to store multiple LSP to a FEC. This is another step to

handle multipath routes in MPLS.
Looks good to michele@

3 files changed, 247 insertions, 185 deletions

diff --git a/usr.sbin/ldpd/lde.c b/usr.sbin/ldpd/lde.c
index 0a87fafa813..58935519ca8 100644
--- a/usr.sbin/ldpd/lde.c
+++ b/usr.sbin/ldpd/lde.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lde.c,v 1.19 2010/06/30 05:21:38 claudio Exp $ */
+/*	$OpenBSD: lde.c,v 1.20 2010/06/30 22:15:02 claudio Exp $ */
 
 /*
  * Copyright (c) 2004, 2005 Claudio Jeker <claudio@openbsd.org>
@@ -431,29 +431,34 @@ lde_assign_label(void)
 }
 
 void
-lde_send_change_klabel(struct rt_node *r)
+lde_send_change_klabel(struct rt_node *rr, struct rt_lsp *rl)
 {
 	struct kroute	kr;
 
 	bzero(&kr, sizeof(kr));
-	kr.prefix.s_addr = r->fec.prefix.s_addr;
-	kr.prefixlen = r->fec.prefixlen;
-	kr.nexthop.s_addr = r->nexthop.s_addr;
-	kr.local_label = r->local_label;
-	kr.remote_label = r->remote_label;
+	kr.prefix.s_addr = rr->fec.prefix.s_addr;
+	kr.prefixlen = rr->fec.prefixlen;
+	kr.local_label = rr->local_label;
+
+	kr.nexthop.s_addr = rl->nexthop.s_addr;
+	kr.remote_label = rl->remote_label;
 
 	imsg_compose_event(iev_main, IMSG_KLABEL_CHANGE, 0, 0, -1,
 	     &kr, sizeof(kr));
 }
 
 void
-lde_send_delete_klabel(struct rt_node *r)
+lde_send_delete_klabel(struct rt_node *rr, struct rt_lsp *rl)
 {
 	struct kroute	 kr;
 
 	bzero(&kr, sizeof(kr));
-	kr.prefix.s_addr = r->fec.prefix.s_addr;
-	kr.prefixlen = r->fec.prefixlen;
+	kr.prefix.s_addr = rr->fec.prefix.s_addr;
+	kr.prefixlen = rr->fec.prefixlen;
+	kr.local_label = rr->local_label;
+
+	kr.nexthop.s_addr = rl->nexthop.s_addr;
+	kr.remote_label = rl->remote_label;
 
 	imsg_compose_event(iev_main, IMSG_KLABEL_DELETE, 0, 0, -1,
 	     &kr, sizeof(kr));
@@ -585,10 +590,11 @@ lde_nbr_clear(void)
 void
 lde_nbr_do_mappings(struct rt_node *rn)
 {
+	struct map	 map;
 	struct lde_nbr	*ln;
 	struct lde_map	*lm;
 	struct lde_req	*lr;
-	struct map	 map;
+	struct rt_lsp	*rl;
 
 	map.label = rn->local_label;
 	map.prefix = rn->fec.prefix;
@@ -610,9 +616,12 @@ lde_nbr_do_mappings(struct rt_node *rn)
 		if (ldeconf->mode & MODE_DIST_ORDERED) {
 			/* ordered mode needs the downstream path to be
 			 * ready before we can send the mapping upstream */
-			if (rn->nexthop.s_addr != INADDR_ANY &&
-			    rn->remote_label == NO_LABEL)
-				/* not local FEC but no remote-label, skip */
+			LIST_FOREACH(rl, &rn->lsp, entry) {
+				/* no remote-label, skip */
+				if (rl->remote_label == NO_LABEL)
+					continue;
+			}
+			if (rl == NULL)
 				continue;
 		}
 
@@ -642,6 +651,33 @@ lde_nbr_do_mappings(struct rt_node *rn)
 	}
 }
 
+struct lde_map *
+lde_map_add(struct lde_nbr *ln, struct rt_node *rn, int sent)
+{
+	struct lde_map  *me;
+
+	me = calloc(1, sizeof(*me));
+	if (me == NULL)
+		fatal("lde_map_add");
+
+	me->fec = rn->fec;
+	me->nexthop = ln;
+
+	if (sent) {
+		LIST_INSERT_HEAD(&rn->upstream, me, entry);
+		if (fec_insert(&ln->sent_map, &me->fec))
+			log_warnx("failed to add %s/%u to sent map",
+			    inet_ntoa(me->fec.prefix), me->fec.prefixlen);
+	} else {
+		LIST_INSERT_HEAD(&rn->downstream, me, entry);
+		if (fec_insert(&ln->recv_map, &me->fec))
+			log_warnx("failed to add %s/%u to recv map",
+			    inet_ntoa(me->fec.prefix), me->fec.prefixlen);
+	}
+
+	return (me);
+}
+
 void
 lde_map_free(void *ptr)
 {
diff --git a/usr.sbin/ldpd/lde.h b/usr.sbin/ldpd/lde.h
index 16a09be974c..8bc08c29895 100644
--- a/usr.sbin/ldpd/lde.h
+++ b/usr.sbin/ldpd/lde.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lde.h,v 1.14 2010/06/30 05:21:38 claudio Exp $ */
+/*	$OpenBSD: lde.h,v 1.15 2010/06/30 22:15:02 claudio Exp $ */
 
 /*
  * Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org>
@@ -77,26 +77,31 @@ struct lde_nbr {
 	u_int16_t			 lspace;
 };
 
+struct rt_lsp {
+	LIST_ENTRY(rt_lsp)	entry;
+
+	struct in_addr		nexthop;
+	u_int32_t		remote_label;
+};
+
 struct rt_node {
 	struct fec		fec;
-	struct in_addr		nexthop;
 
+	LIST_HEAD(, rt_lsp)	lsp;		/* label switching pathes */
 	LIST_HEAD(, lde_map)	downstream;	/* recv mappings */
 	LIST_HEAD(, lde_map)	upstream;	/* sent mappings */
 
 	u_int32_t		local_label;
-	u_int32_t		remote_label;
 	u_int16_t		lspace;
 	u_int8_t		flags;
-	u_int8_t		present;	/* Is it present in fib? */
 };
 
 /* lde.c */
 pid_t		lde(struct ldpd_conf *, int [2], int [2], int [2]);
 int		lde_imsg_compose_ldpe(int, u_int32_t, pid_t, void *, u_int16_t);
 u_int32_t	lde_assign_label(void);
-void		lde_send_change_klabel(struct rt_node *);
-void		lde_send_delete_klabel(struct rt_node *);
+void		lde_send_change_klabel(struct rt_node *, struct rt_lsp *);
+void		lde_send_delete_klabel(struct rt_node *, struct rt_lsp *);
 void		lde_send_labelmapping(u_int32_t, struct map *);
 void		lde_send_labelrequest(u_int32_t, struct map *);
 void		lde_send_labelrelease(u_int32_t, struct map *);
@@ -105,6 +110,7 @@ void		lde_send_notification(u_int32_t, u_int32_t, u_int32_t,
 
 void		lde_nbr_del(struct lde_nbr *);
 void		lde_nbr_do_mappings(struct rt_node *);
+struct lde_map *lde_map_add(struct lde_nbr *, struct rt_node *, int);
 struct lde_nbr *lde_find_address(struct in_addr);
 
 
diff --git a/usr.sbin/ldpd/lde_lib.c b/usr.sbin/ldpd/lde_lib.c
index 3b4051a39fe..cc4be767118 100644
--- a/usr.sbin/ldpd/lde_lib.c
+++ b/usr.sbin/ldpd/lde_lib.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lde_lib.c,v 1.23 2010/06/30 05:21:38 claudio Exp $ */
+/*	$OpenBSD: lde_lib.c,v 1.24 2010/06/30 22:15:02 claudio Exp $ */
 
 /*
  * Copyright (c) 2009 Michele Marchetto <michele@openbsd.org>
@@ -40,6 +40,12 @@
 
 static int fec_compare(struct fec *, struct fec *);
 
+void		 rt_free(void *);
+struct rt_node	*rt_add(struct in_addr, u_int8_t);
+struct rt_lsp	*rt_lsp_find(struct rt_node *, struct in_addr);
+struct rt_lsp	*rt_lsp_add(struct rt_node *, struct in_addr);
+void		 rt_lsp_del(struct rt_lsp *);
+
 RB_PROTOTYPE(fec_tree, fec, entry, fec_compare)
 RB_GENERATE(fec_tree, fec, entry, fec_compare)
 
@@ -118,34 +124,48 @@ fec_clear(struct fec_tree *fh, void (*free_cb)(void *))
 }
 
 
+/* routing table functions */
 void
 rt_dump(pid_t pid)
 {
 	struct fec		*f;
-	struct rt_node		*r;
+	struct rt_node		*rr;
+	struct rt_lsp		*rl;
+	struct lde_map		*me;
 	static struct ctl_rt	 rtctl;
 
 	RB_FOREACH(f, fec_tree, &rt) {
-		r = (struct rt_node *)f;
-		rtctl.prefix.s_addr = r->fec.prefix.s_addr;
-		rtctl.prefixlen = r->fec.prefixlen;
-		rtctl.nexthop.s_addr = r->nexthop.s_addr;
-		rtctl.flags = r->flags;
-		rtctl.local_label = r->local_label;
-		rtctl.remote_label = r->remote_label;
-
-		if (!r->present)
-			rtctl.in_use = 0;
-		else
+		rr = (struct rt_node *)f;
+		rtctl.prefix = rr->fec.prefix;
+		rtctl.prefixlen = rr->fec.prefixlen;
+		rtctl.flags = rr->flags;
+		rtctl.local_label = rr->local_label;
+
+		LIST_FOREACH(rl, &rr->lsp, entry) {
+			rtctl.nexthop = rl->nexthop;
+			rtctl.remote_label = rl->remote_label;
 			rtctl.in_use = 1;
 
-		if (rtctl.nexthop.s_addr == htonl(INADDR_LOOPBACK))
-			rtctl.connected = 1;
-		else
-			rtctl.connected = 0;
+			if (rtctl.nexthop.s_addr == htonl(INADDR_ANY))
+				rtctl.connected = 1;
+			else
+				rtctl.connected = 0;
 
-		lde_imsg_compose_ldpe(IMSG_CTL_SHOW_LIB, 0, pid, &rtctl,
-		    sizeof(rtctl));
+			lde_imsg_compose_ldpe(IMSG_CTL_SHOW_LIB, 0, pid,
+			    &rtctl, sizeof(rtctl));
+		}
+		if (LIST_EMPTY(&rr->lsp)) {
+			LIST_FOREACH(me, &rr->downstream, entry) {
+				rtctl.in_use = 0;
+				rtctl.connected = 0;
+				/* we don't know the nexthop use id instead */
+				rtctl.nexthop = me->nexthop->id;
+				rtctl.remote_label = me->label;
+
+				lde_imsg_compose_ldpe(IMSG_CTL_SHOW_LIB, 0, pid,
+				    &rtctl, sizeof(rtctl));
+			}
+		}
 	}
 }
 
@@ -169,15 +189,94 @@ rt_snap(u_int32_t peerid)
 }
 
 void
+rt_free(void *arg)
+{
+	struct rt_node	*rr = arg;
+	struct rt_lsp	*rl;
+
+	while ((rl = LIST_FIRST(&rr->lsp))) {
+		LIST_REMOVE(rl, entry);
+		free(rl);
+	}
+
+	if (!LIST_EMPTY(&rr->downstream))
+		log_warnx("rt_free: fec %s/%u downstream list not empty",
+		    inet_ntoa(rr->fec.prefix), rr->fec.prefixlen);
+	if (!LIST_EMPTY(&rr->upstream))
+		log_warnx("rt_free: fec %s/%u upstream list not empty",
+		    inet_ntoa(rr->fec.prefix), rr->fec.prefixlen);
+
+	free(rl);
+}
+
+void
 rt_clear(void)
 {
-	fec_clear(&rt, free);
+	fec_clear(&rt, rt_free);
+}
+
+struct rt_node *
+rt_add(struct in_addr prefix, u_int8_t prefixlen)
+{
+	struct rt_node	*rn;
+
+	rn = calloc(1, sizeof(*rn));
+	if (rn == NULL)
+		fatal("rt_add");
+
+	rn->fec.prefix.s_addr = prefix.s_addr;
+	rn->fec.prefixlen = prefixlen;
+	rn->local_label = NO_LABEL;
+	LIST_INIT(&rn->upstream);
+	LIST_INIT(&rn->downstream);
+	LIST_INIT(&rn->lsp);
+
+	if (fec_insert(&rt, &rn->fec))
+		log_warnx("failed to add %s/%u to rt tree",
+		    inet_ntoa(rn->fec.prefix), rn->fec.prefixlen);
+
+	return (rn);
+}
+
+struct rt_lsp *
+rt_lsp_find(struct rt_node *rn, struct in_addr nexthop)
+{
+	struct rt_lsp	*rl;
+
+	LIST_FOREACH(rl, &rn->lsp, entry)
+		if (rl->nexthop.s_addr == nexthop.s_addr)
+			return (rl);
+	return (NULL);
+}
+
+struct rt_lsp *
+rt_lsp_add(struct rt_node *rn, struct in_addr nexthop)
+{
+	struct rt_lsp	*rl;
+
+	rl = calloc(1, sizeof(*rl));
+	if (rl == NULL)
+		fatal("rt_lsp_add");
+
+	rl->nexthop.s_addr = nexthop.s_addr;
+	rl->remote_label = NO_LABEL;
+	LIST_INSERT_HEAD(&rn->lsp, rl, entry);
+
+	return (rl);
+}
+
+void
+rt_lsp_del(struct rt_lsp *rl)
+{
+	LIST_REMOVE(rl, entry);
+	free(rl);
 }
 
 void
 lde_kernel_insert(struct kroute *kr)
 {
 	struct rt_node		*rn;
+	struct rt_lsp		*rl;
 	struct lde_nbr_address	*addr;
 	struct lde_map		*map;
 
@@ -186,56 +285,12 @@ lde_kernel_insert(struct kroute *kr)
 
 	rn = (struct rt_node *)fec_find_prefix(&rt, kr->prefix.s_addr,
 	    kr->prefixlen);
-	if (rn == NULL) {
-		rn = calloc(1, sizeof(*rn));
-		if (rn == NULL)
-			fatal("lde_insert");
-
-		rn->fec.prefix.s_addr = kr->prefix.s_addr;
-		rn->fec.prefixlen = kr->prefixlen;
-		rn->remote_label = NO_LABEL;
-		rn->local_label = NO_LABEL;
-		LIST_INIT(&rn->upstream);
-		LIST_INIT(&rn->downstream);
-
-		if (fec_insert(&rt, &rn->fec))
-			log_warnx("failed to add %s/%u to rt tree",
-			    inet_ntoa(rn->fec.prefix), rn->fec.prefixlen);
-	}
-
-	if (rn->present) {
-		if (kr->nexthop.s_addr == rn->nexthop.s_addr)
-			return;
-
-		/* The nexthop has changed, change also the label associated
-		   with prefix */
-		rn->remote_label = NO_LABEL;
-		rn->nexthop.s_addr = kr->nexthop.s_addr;
-
-		if ((ldeconf->mode & MODE_RET_LIBERAL) == 0) {
-			/* XXX: we support just liberal retention for now */
-			log_warnx("lde_kernel_insert: missing mode");
-			return;
-		}
-
-		LIST_FOREACH(map, &rn->downstream, entry) {
-			addr = lde_address_find(map->nexthop, &rn->nexthop);
-			if (addr != NULL) {
-				rn->remote_label = map->label;
-				break;
-			}
-		}
-
-		log_debug("lde_kernel_insert: prefix %s%u, "
-		    "changing label to %u", inet_ntoa(rn->fec.prefix),
-		    rn->fec.prefixlen, map ? map->label : 0);
-
-		lde_send_change_klabel(rn);
-		return;
-	}
+	if (rn == NULL)
+		rn = rt_add(kr->prefix, kr->prefixlen);
 
-	rn->present = 1;
-	rn->nexthop.s_addr = kr->nexthop.s_addr;
+	rl = rt_lsp_find(rn, kr->nexthop);
+	if (rl == NULL)
+		rl = rt_lsp_add(rn, kr->nexthop);
 
 	/* There is static assigned label for this route, record it in lib */
 	if (kr->local_label != NO_LABEL) {
@@ -243,24 +298,23 @@ lde_kernel_insert(struct kroute *kr)
 		return;
 	}
 
+	if (rn->local_label == NO_LABEL) {
+		if (kr->nexthop.s_addr == INADDR_ANY)
+			/* Directly connected route */
+			rn->local_label = MPLS_LABEL_IMPLNULL;
+		else
+			rn->local_label = lde_assign_label();
+	}
+
 	LIST_FOREACH(map, &rn->downstream, entry) {
-		addr = lde_address_find(map->nexthop, &rn->nexthop);
+		addr = lde_address_find(map->nexthop, &rl->nexthop);
 		if (addr != NULL) {
-			rn->remote_label = map->label;
+			rl->remote_label = map->label;
 			break;
 		}
 	}
 
-	if (rn->local_label == NO_LABEL) {
-		/* Directly connected route */
-		if (kr->nexthop.s_addr == INADDR_ANY) {
-			rn->local_label = MPLS_LABEL_IMPLNULL;
-			rn->nexthop.s_addr = htonl(INADDR_LOOPBACK);
-		} else
-			rn->local_label = lde_assign_label();
-	}
-
-	lde_send_change_klabel(rn);
+	lde_send_change_klabel(rn, rl);
 
 	/* Redistribute the current mapping to every nbr */
 	lde_nbr_do_mappings(rn);
@@ -270,8 +324,7 @@ void
 lde_kernel_remove(struct kroute *kr)
 {
 	struct rt_node		*rn;
-	struct lde_map		*map;
-	struct lde_nbr		*ln;
+	struct rt_lsp		*rl;
 
 	log_debug("kernel remove route %s/%u", inet_ntoa(kr->prefix),
 	    kr->prefixlen);
@@ -279,36 +332,27 @@ lde_kernel_remove(struct kroute *kr)
 	rn = (struct rt_node *)fec_find_prefix(&rt, kr->prefix.s_addr,
 	    kr->prefixlen);
 	if (rn == NULL)
+		/* route lost */
 		return;
 
-	if (ldeconf->mode & MODE_RET_LIBERAL) {
-		ln = lde_find_address(rn->nexthop);
-		if (ln) {
-			map = calloc(1, sizeof(*map));
-			if (map == NULL)
-				fatal("lde_kernel_remove");
-
-			map->label = rn->remote_label;
-			map->fec = rn->fec;
-			map->nexthop = ln;
-			LIST_INSERT_HEAD(&rn->downstream, map, entry);
-			if (fec_insert(&ln->recv_map, &map->fec))
-				log_warnx("failed to add %s/%u to recv map (1)",
-				    inet_ntoa(map->fec.prefix),
-				    map->fec.prefixlen);
-		}
-	}
+	rl = rt_lsp_find(rn, kr->nexthop);
+	if (rl == NULL)
+		/* nexthop lost */
 
-	rn->remote_label = NO_LABEL;
-	rn->nexthop.s_addr = INADDR_ANY;
-	rn->present = 0;
+	rt_lsp_del(rl);
+
+	/* XXX handling of total loss of route, withdraw mappings, etc */
+
+	/* Redistribute the current mapping to every nbr */
+	lde_nbr_do_mappings(rn);
 }
 
 void
 lde_check_mapping(struct map *map, struct lde_nbr *ln)
 {
 	struct rt_node		*rn;
-	struct lde_nbr_address	*addr;
+	struct rt_lsp		*rl;
+	struct lde_nbr_address	*addr = NULL;
 	struct lde_map		*me;
 
 	log_debug("label mapping from nbr %s, FEC %s/%u, label %u",
@@ -322,22 +366,8 @@ lde_check_mapping(struct map *map, struct lde_nbr *ln)
 		if (ldeconf->mode & MODE_RET_CONSERVATIVE)
 			return;
 
-		rn = calloc(1, sizeof(*rn));
-		if (rn == NULL)
-			fatal("lde_check_mapping");
-
-		rn->fec.prefix = map->prefix;
-		rn->fec.prefixlen = map->prefixlen;
+		rn = rt_add(map->prefix, map->prefixlen);
 		rn->local_label = lde_assign_label();
-		rn->remote_label = NO_LABEL;
-		rn->present = 0;
-
-		LIST_INIT(&rn->upstream);
-		LIST_INIT(&rn->downstream);
-
-		if (fec_insert(&rt, &rn->fec))
-			log_warnx("failed to add %s/%u to rt tree",
-			    inet_ntoa(rn->fec.prefix), rn->fec.prefixlen);
 	}
 
 	LIST_FOREACH(me, &rn->downstream, entry) {
@@ -355,54 +385,34 @@ lde_check_mapping(struct map *map, struct lde_nbr *ln)
 		}
 	}
 
-	addr = lde_address_find(ln, &rn->nexthop);
-	if (addr == NULL || !rn->present) {
+	LIST_FOREACH(rl, &rn->lsp, entry) {
+		addr = lde_address_find(ln, &rl->nexthop);
+		if (addr)
+			break;
+	}
+
+	if (addr == NULL) {
 		/* route not yet available */
 		if (ldeconf->mode & MODE_RET_CONSERVATIVE) {
 			lde_send_labelrelease(ln->peerid, map);
 			return;
 		}
 		/* in liberal mode just note the mapping */
-		if (me == NULL) {
-			me = calloc(1, sizeof(*me));
-			if (me == NULL)
-				fatal("lde_check_mapping");
-			me->fec = rn->fec;
-			me->nexthop = ln;
-
-			LIST_INSERT_HEAD(&rn->downstream, me, entry);
-			if (fec_insert(&ln->recv_map, &me->fec))
-				log_warnx("failed to add %s/%u to recv map (2)",
-				    inet_ntoa(me->fec.prefix),
-				    me->fec.prefixlen);
-		}
+		if (me == NULL)
+			me = lde_map_add(ln, rn, 0);
 		me->label = map->label;
 
 		return;
 	}
 
-	rn->remote_label = map->label;
-
-	/* If we are ingress for this LSP install the label */
-	if (rn->nexthop.s_addr == INADDR_ANY)
-		lde_send_change_klabel(rn);
+	rl->remote_label = map->label;
 
 	/* Record the mapping from this peer */	
-	if (me == NULL) {
-		me = calloc(1, sizeof(*me));
-		if (me == NULL)
-			fatal("lde_check_mapping");
-
-		me->fec = rn->fec;
-		me->nexthop = ln;
-		LIST_INSERT_HEAD(&rn->downstream, me, entry);
-		if (fec_insert(&ln->recv_map, &me->fec))
-			log_warnx("failed to add %s/%u to recv map (3)",
-			    inet_ntoa(me->fec.prefix), me->fec.prefixlen);
-	}
+	if (me == NULL)
+		me = lde_map_add(ln, rn, 0);
 	me->label = map->label;
 
-	lde_send_change_klabel(rn);
+	lde_send_change_klabel(rn, rl);
 
 	/* Redistribute the current mapping to every nbr */
 	lde_nbr_do_mappings(rn);
@@ -413,6 +423,7 @@ lde_check_request(struct map *map, struct lde_nbr *ln)
 {
 	struct lde_req	*lre;
 	struct rt_node	*rn;
+	struct rt_lsp	*rl;
 	struct lde_nbr	*lnn;
 	struct map	 localmap;
 
@@ -421,35 +432,44 @@ lde_check_request(struct map *map, struct lde_nbr *ln)
 
 	rn = (struct rt_node *)fec_find_prefix(&rt, map->prefix.s_addr,
 	    map->prefixlen);
-	if (rn == NULL || rn->remote_label == NO_LABEL) {
+	if (rn == NULL) {
 		lde_send_notification(ln->peerid, S_NO_ROUTE, map->messageid,
 		    MSG_TYPE_LABELREQUEST);
 		return;
 	}
 
-	if (lde_address_find(ln, &rn->nexthop)) {
-		lde_send_notification(ln->peerid, S_LOOP_DETECTED,
-		    map->messageid, MSG_TYPE_LABELREQUEST);
-		return;
-	}
-
+	/* first check if we have a pending request running */
 	lre = (struct lde_req *)fec_find(&ln->recv_req, &rn->fec);
 	if (lre != NULL)
 		return;
 
-	if (rn->nexthop.s_addr == INADDR_ANY ||
-	    rn->remote_label != NO_LABEL) {
+	LIST_FOREACH(rl, &rn->lsp, entry) {
+		if (lde_address_find(ln, &rl->nexthop)) {
+			lde_send_notification(ln->peerid, S_LOOP_DETECTED,
+			    map->messageid, MSG_TYPE_LABELREQUEST);
+			return;
+		}
+
+		if (rl->remote_label != NO_LABEL)
+			break;
+	}
+
+	/* there is a valid mapping available */
+	if (rl != NULL) {
 		bzero(&localmap, sizeof(localmap));
 		localmap.prefix = map->prefix;
 		localmap.prefixlen = map->prefixlen;
 		localmap.label = rn->local_label;
 
 		lde_send_labelmapping(ln->peerid, &localmap);
-	} else {
-		lnn = lde_find_address(rn->nexthop);
+		return;
+	}
+
+	/* no mapping available, try to request */
+	LIST_FOREACH(rl, &rn->lsp, entry) {
+		lnn = lde_find_address(rl->nexthop);
 		if (lnn == NULL)
-			/* XXX this feels wrong.... */
-			return;
+			continue;
 
 		lde_send_labelrequest(lnn->peerid, map);