ldpd: Fix issue when starting up LDP with no configuration.

LDP would mark all routes as learned on a non-ldp interface.  Then
when LDP was configured the labels were not updated correctly.  This
commit fixes issues 6841 and 6842.

Signed-off-by: Lynne Morrison <lynne@voltanet.io>

7 files changed, 222 insertions, 15 deletions

diff --git a/ldpd/lde.c b/ldpd/lde.c
index 734c1ea230..df64f908ea 100644
--- a/ldpd/lde.c
+++ b/ldpd/lde.c
@@ -468,6 +468,10 @@ lde_dispatch_parent(struct thread *thread)
 			iface = if_lookup_name(ldeconf, kif->ifname);
 			if (iface) {
 				if_update_info(iface, kif);
+
+				/* if up see if any labels need to be updated */
+				if (kif->operative)
+					lde_route_update(iface, AF_UNSPEC);
 				break;
 			}
 
@@ -786,7 +790,6 @@ lde_send_change_klabel(struct fec_node *fn, struct fec_nh *fnh)
 		kr.remote_label = fnh->remote_label;
 		kr.route_type = fnh->route_type;
 		kr.route_instance = fnh->route_instance;
-
 		lde_imsg_compose_parent(IMSG_KLABEL_CHANGE, 0, &kr,
 		    sizeof(kr));
 		break;
@@ -2271,3 +2274,156 @@ lde_check_filter_af(int af, struct ldpd_af_conf *af_conf,
 	if (strcmp(af_conf->acl_label_expnull_for, filter_name) == 0)
 		lde_change_expnull_for_filter(af);
 }
+
+void lde_route_update(struct iface *iface, int af)
+{
+	struct fec	*f;
+	struct fec_node	*fn;
+	struct fec_nh	*fnh;
+	struct lde_nbr  *ln;
+
+	/* update label of non-connected routes */
+	log_debug("update labels for interface %s", iface->name);
+	RB_FOREACH(f, fec_tree, &ft) {
+		fn = (struct fec_node *)f;
+		if (IS_MPLS_UNRESERVED_LABEL(fn->local_label))
+			continue;
+
+		switch (af) {
+		case AF_INET:
+			if (fn->fec.type != FEC_TYPE_IPV4)
+				continue;
+			break;
+		case AF_INET6:
+			if (fn->fec.type != FEC_TYPE_IPV6)
+				continue;
+			break;
+		default:
+			/* unspecified so process both address families */
+			break;
+		}
+
+		LIST_FOREACH(fnh, &fn->nexthops, entry) {
+			/*
+			 * If connected leave existing label. If LDP
+			 * configured on interface or a static route
+			 * may need new label. If no LDP configured
+			 * treat fec as a connected route
+			 */
+			if (fnh->flags & F_FEC_NH_CONNECTED)
+				break;
+
+			if (fnh->ifindex != iface->ifindex)
+				continue;
+
+			fnh->flags &= ~F_FEC_NH_NO_LDP;
+			if (IS_MPLS_RESERVED_LABEL(fn->local_label)) {
+				fn->local_label = NO_LABEL;
+				fn->local_label = lde_update_label(fn);
+				if (fn->local_label != NO_LABEL)
+					RB_FOREACH(ln, nbr_tree, &lde_nbrs)
+						lde_send_labelmapping(
+						    ln, fn, 0);
+			}
+			break;
+		}
+	}
+	RB_FOREACH(ln, nbr_tree, &lde_nbrs)
+		lde_imsg_compose_ldpe(IMSG_MAPPING_ADD_END, ln->peerid,
+		    0, NULL, 0);
+}
+
+void lde_route_update_release(struct iface *iface, int af)
+{
+	struct lde_nbr	*ln;
+	struct fec	*f;
+	struct fec_node	*fn;
+	struct fec_nh	*fnh;
+
+	/* update label of interfaces no longer running LDP */
+	log_debug("release all labels for interface %s af %s", iface->name,
+	    af == AF_INET ? "ipv4" : "ipv6");
+	RB_FOREACH(f, fec_tree, &ft) {
+		fn = (struct fec_node *)f;
+
+		switch (af) {
+		case AF_INET:
+			if (fn->fec.type != FEC_TYPE_IPV4)
+				continue;
+			break;
+		case AF_INET6:
+			if (fn->fec.type != FEC_TYPE_IPV6)
+				continue;
+			break;
+		default:
+			fatalx("lde_route_update_release: unknown af");
+		}
+
+		if (fn->local_label == NO_LABEL)
+			continue;
+
+		LIST_FOREACH(fnh, &fn->nexthops, entry) {
+			/*
+			 * If connected leave existing label. If LDP
+			 * removed from interface may need new label
+			 * and would be treated as a connected route
+			 */
+			if (fnh->flags & F_FEC_NH_CONNECTED)
+				break;
+
+			if (fnh->ifindex != iface->ifindex)
+				continue;
+
+			fnh->flags |= F_FEC_NH_NO_LDP;
+			RB_FOREACH(ln, nbr_tree, &lde_nbrs)
+				lde_send_labelwithdraw(ln, fn, NULL, NULL);
+			lde_free_label(fn->local_label);
+			fn->local_label = NO_LABEL;
+			fn->local_label = lde_update_label(fn);
+			if (fn->local_label != NO_LABEL)
+				RB_FOREACH(ln, nbr_tree, &lde_nbrs)
+					lde_send_labelmapping(ln, fn, 0);
+			break;
+		}
+	}
+	RB_FOREACH(ln, nbr_tree, &lde_nbrs)
+		lde_imsg_compose_ldpe(IMSG_MAPPING_ADD_END, ln->peerid,
+		    0, NULL, 0);
+}
+
+void lde_route_update_release_all(int af)
+{
+	struct lde_nbr	*ln;
+	struct fec	*f;
+	struct fec_node	*fn;
+	struct fec_nh	*fnh;
+
+	/* remove labels from all interfaces as LDP is no longer running for
+	 * this address family
+	 */
+	log_debug("release all labels for address family %s",
+	    af == AF_INET ? "ipv4" : "ipv6");
+	RB_FOREACH(f, fec_tree, &ft) {
+		fn = (struct fec_node *)f;
+		switch (af) {
+		case AF_INET:
+			if (fn->fec.type != FEC_TYPE_IPV4)
+				continue;
+			break;
+		case AF_INET6:
+			if (fn->fec.type != FEC_TYPE_IPV6)
+				continue;
+			break;
+		default:
+			fatalx("lde_route_update_release: unknown af");
+		}
+
+		RB_FOREACH(ln, nbr_tree, &lde_nbrs)
+			lde_send_labelwithdraw(ln, fn, NULL, NULL);
+
+		LIST_FOREACH(fnh, &fn->nexthops, entry) {
+			fnh->flags |= F_FEC_NH_NO_LDP;
+			lde_send_delete_klabel(fn, fnh);
+		}
+	}
+}
diff --git a/ldpd/lde.h b/ldpd/lde.h
index 9e6db3a90b..660aeafb34 100644
--- a/ldpd/lde.h
+++ b/ldpd/lde.h
@@ -193,6 +193,9 @@ void		 lde_change_allocate_filter(int);
 void		 lde_change_advertise_filter(int);
 void		 lde_change_accept_filter(int);
 void		 lde_change_expnull_for_filter(int);
+void		 lde_route_update(struct iface *, int);
+void		 lde_route_update_release(struct iface *, int);
+void		 lde_route_update_release_all(int);
 struct lde_addr	*lde_address_find(struct lde_nbr *, int,
 		    union ldpd_addr *);
 
diff --git a/ldpd/lde_lib.c b/ldpd/lde_lib.c
index 11d85b7449..bed276c7b1 100644
--- a/ldpd/lde_lib.c
+++ b/ldpd/lde_lib.c
@@ -404,10 +404,15 @@ lde_kernel_update(struct fec *fec)
 			 * if LDP configured on interface or a static route
 			 * clear flag else treat fec as a connected route
 			 */
-			iface = if_lookup(ldeconf,fnh->ifindex);
-			if (iface || fnh->route_type == ZEBRA_ROUTE_STATIC)
-				fnh->flags &=~F_FEC_NH_NO_LDP;
-			else
+			if (ldeconf->flags & F_LDPD_ENABLED) {
+				iface = if_lookup(ldeconf,fnh->ifindex);
+				if (fnh->flags & F_FEC_NH_CONNECTED ||
+				    iface ||
+				    fnh->route_type == ZEBRA_ROUTE_STATIC)
+					fnh->flags &=~F_FEC_NH_NO_LDP;
+				else
+					fnh->flags |= F_FEC_NH_NO_LDP;
+			} else
 				fnh->flags |= F_FEC_NH_NO_LDP;
 		} else {
 			lde_send_delete_klabel(fn, fnh);
@@ -437,6 +442,10 @@ lde_kernel_update(struct fec *fec)
 				lde_send_labelmapping(ln, fn, 1);
 	}
 
+	/* if no label created yet then don't try to program labeled route */
+	if (fn->local_label == NO_LABEL)
+		return;
+
 	LIST_FOREACH(fnh, &fn->nexthops, entry) {
 		lde_send_change_klabel(fn, fnh);
 
@@ -567,7 +576,8 @@ lde_check_mapping(struct map *map, struct lde_nbr *ln, int rcvd_label_mapping)
 				fnh->flags &= ~F_FEC_NH_DEFER;
 			}
 			fnh->remote_label = map->label;
-			lde_send_change_klabel(fn, fnh);
+			if (fn->local_label != NO_LABEL)
+				lde_send_change_klabel(fn, fnh);
 			break;
 		case FEC_TYPE_PWID:
 			pw = (struct l2vpn_pw *) fn->data;
diff --git a/ldpd/ldp_vty_cmds.c b/ldpd/ldp_vty_cmds.c
index fc84c7f76b..53a384fe55 100644
--- a/ldpd/ldp_vty_cmds.c
+++ b/ldpd/ldp_vty_cmds.c
@@ -616,6 +616,8 @@ DEFPY  (ldp_show_mpls_ldp_binding,
 	"Show detailed information\n"
 	JSON_STR)
 {
+	if (!(ldpd_conf->flags & F_LDPD_ENABLED))
+		return CMD_SUCCESS;
 	if (!local_label_str)
 		local_label = NO_LABEL;
 	if (!remote_label_str)
diff --git a/ldpd/ldpd.c b/ldpd/ldpd.c
index 927c3a3c03..dca379e4eb 100644
--- a/ldpd/ldpd.c
+++ b/ldpd/ldpd.c
@@ -1329,6 +1329,7 @@ merge_af(int af, struct ldpd_af_conf *af_conf, struct ldpd_af_conf *xa)
 	int		 reset_nbrs_ipv4 = 0;
 	int		 reset_nbrs = 0;
 	int		 update_sockets = 0;
+	int		 change_ldp_disabled = 0;
 
 	/* update timers */
 	if (af_conf->keepalive != xa->keepalive) {
@@ -1362,6 +1363,11 @@ merge_af(int af, struct ldpd_af_conf *af_conf, struct ldpd_af_conf *xa)
 	    != (xa->flags & F_LDPD_AF_ALLOCHOSTONLY))
 		change_host_label = 1;
 
+	/* disabling LDP for address family */
+	if ((af_conf->flags & F_LDPD_AF_ENABLED) &&
+	    !(xa->flags & F_LDPD_AF_ENABLED))
+		change_ldp_disabled = 1;
+
 	af_conf->flags = xa->flags;
 
 	/* update the transport address */
@@ -1409,6 +1415,9 @@ merge_af(int af, struct ldpd_af_conf *af_conf, struct ldpd_af_conf *xa)
 			lde_change_egress_label(af);
 		if (change_host_label)
 			lde_change_allocate_filter(af);
+		if (change_ldp_disabled)
+			lde_route_update_release_all(af);
+
 		break;
 	case PROC_LDP_ENGINE:
 		if (stop_init_backoff)
@@ -1434,13 +1443,22 @@ merge_ifaces(struct ldpd_conf *conf, struct ldpd_conf *xconf)
 	struct iface		*iface, *itmp, *xi;
 
 	RB_FOREACH_SAFE(iface, iface_head, &conf->iface_tree, itmp) {
-		/* find deleted interfaces */
+		/* find deleted interfaces, which occurs when LDP is removed
+		 * for all address families
+		 */
 		if (if_lookup_name(xconf, iface->name) == NULL) {
 			switch (ldpd_process) {
 			case PROC_LDP_ENGINE:
 				ldpe_if_exit(iface);
 				break;
 			case PROC_LDE_ENGINE:
+				if (iface->ipv4.enabled)
+					lde_route_update_release(iface,
+					    AF_INET);
+				if (iface->ipv6.enabled)
+					lde_route_update_release(iface,
+					    AF_INET6);
+				break;
 			case PROC_MAIN:
 				break;
 			}
@@ -1468,6 +1486,29 @@ merge_ifaces(struct ldpd_conf *conf, struct ldpd_conf *xconf)
 			continue;
 		}
 
+		/* update labels when adding or removing ldp on an
+		 * interface
+		 */
+		if (ldpd_process == PROC_LDE_ENGINE) {
+			/* if we are removing lpd config for an address
+			 * family on an interface then advertise routes
+			 * learned over this interface as if they were
+			 * connected routes
+			 */
+			if (iface->ipv4.enabled && !xi->ipv4.enabled)
+				lde_route_update_release(iface, AF_INET);
+			if (iface->ipv6.enabled && !xi->ipv6.enabled)
+				lde_route_update_release(iface, AF_INET6);
+
+			/* if we are adding lpd config for an address
+			 * family on an interface then add proper labels
+			 */
+			if (!iface->ipv4.enabled && xi->ipv4.enabled)
+				lde_route_update(iface, AF_INET);
+			if (!iface->ipv6.enabled && xi->ipv6.enabled)
+				lde_route_update(iface, AF_INET6);
+		}
+
 		/* update existing interfaces */
 		merge_iface_af(&iface->ipv4, &xi->ipv4);
 		merge_iface_af(&iface->ipv6, &xi->ipv6);
diff --git a/ldpd/ldpe.c b/ldpd/ldpe.c
index 655313bf16..9078e711fb 100644
--- a/ldpd/ldpe.c
+++ b/ldpd/ldpe.c
@@ -614,10 +614,8 @@ ldpe_dispatch_lde(struct thread *thread)
 			map = imsg.data;
 
 			nbr = nbr_find_peerid(imsg.hdr.peerid);
-			if (nbr == NULL) {
-				log_debug("ldpe_dispatch_lde: cannot find neighbor");
+			if (nbr == NULL)
 				break;
-			}
 			if (nbr->state != NBR_STA_OPER)
 				break;
 
@@ -641,10 +639,8 @@ ldpe_dispatch_lde(struct thread *thread)
 		case IMSG_REQUEST_ADD_END:
 		case IMSG_WITHDRAW_ADD_END:
 			nbr = nbr_find_peerid(imsg.hdr.peerid);
-			if (nbr == NULL) {
-				log_debug("ldpe_dispatch_lde: cannot find neighbor");
+			if (nbr == NULL)
 				break;
-			}
 			if (nbr->state != NBR_STA_OPER)
 				break;
 
diff --git a/lib/mpls.h b/lib/mpls.h
index 8922a36664..74bd7aae3e 100644
--- a/lib/mpls.h
+++ b/lib/mpls.h
@@ -72,8 +72,7 @@ extern "C" {
 /* Maximum # labels that can be pushed. */
 #define MPLS_MAX_LABELS                    16
 
-#define IS_MPLS_RESERVED_LABEL(label)                                          \
-	(label >= MPLS_LABEL_RESERVED_MIN && label <= MPLS_LABEL_RESERVED_MAX)
+#define IS_MPLS_RESERVED_LABEL(label) (label <= MPLS_LABEL_RESERVED_MAX)
 
 #define IS_MPLS_UNRESERVED_LABEL(label)                                        \
 	(label >= MPLS_LABEL_UNRESERVED_MIN                                    \