Be more compliant with RFC 4447.

When sending a label withdraw during the pseudowire Control Word
negotiation, append a "Wrong C-bit" status TLV after the FEC TLV (in
conformance to RFC 4447 section 6.2). Apparently this has no use other
than aiding in troubleshooting.

Also, extend the recv_labelmessage() function to accept Status TLVs and
ignore them instead of shutting down the session.

7 files changed, 53 insertions, 24 deletions

diff --git a/usr.sbin/ldpd/l2vpn.c b/usr.sbin/ldpd/l2vpn.c
index 0c973887a74..cdd0985ef5c 100644
--- a/usr.sbin/ldpd/l2vpn.c
+++ b/usr.sbin/ldpd/l2vpn.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: l2vpn.c,v 1.19 2016/06/27 19:08:39 renato Exp $ */
+/*	$OpenBSD: l2vpn.c,v 1.20 2016/07/01 23:33:46 renato Exp $ */
 
 /*
  * Copyright (c) 2015 Renato Westphal <renato@openbsd.org>
@@ -258,6 +258,7 @@ int
 l2vpn_pw_negotiate(struct lde_nbr *ln, struct fec_node *fn, struct map *map)
 {
 	struct l2vpn_pw		*pw;
+	struct status_tlv	 status;
 
 	/* NOTE: thanks martini & friends for all this mess */
 
@@ -277,8 +278,11 @@ l2vpn_pw_negotiate(struct lde_nbr *ln, struct fec_node *fn, struct map *map)
 			return (1);
 		} else if (!(map->flags & F_MAP_PW_CWORD) &&
 		    (pw->flags & F_PW_CWORD_CONF)) {
-			/* TODO append a "Wrong C-bit" status code */
-			lde_send_labelwithdraw(ln, fn, NO_LABEL);
+			/* append a "Wrong C-bit" status code */
+			status.status_code = S_WRONG_CBIT;
+			status.msg_id = map->messageid;
+			status.msg_type = htons(MSG_TYPE_LABELMAPPING);
+			lde_send_labelwithdraw(ln, fn, NO_LABEL, &status);
 
 			pw->flags &= ~F_PW_CWORD;
 			lde_send_labelmapping(ln, fn, 1);
diff --git a/usr.sbin/ldpd/labelmapping.c b/usr.sbin/ldpd/labelmapping.c
index 43dc7a0c32b..501cec93075 100644
--- a/usr.sbin/ldpd/labelmapping.c
+++ b/usr.sbin/ldpd/labelmapping.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: labelmapping.c,v 1.53 2016/07/01 23:29:55 renato Exp $ */
+/*	$OpenBSD: labelmapping.c,v 1.54 2016/07/01 23:33:46 renato Exp $ */
 
 /*
  * Copyright (c) 2014, 2015 Renato Westphal <renato@openbsd.org>
@@ -75,7 +75,6 @@ send_labelmessage(struct nbr *nbr, uint16_t type, struct mapping_head *mh)
 
 		/* calculate size */
 		msg_size = LDP_MSG_SIZE + TLV_HDR_LEN;
-
 		switch (me->map.type) {
 		case MAP_TYPE_WILDCARD:
 			msg_size += FEC_ELM_WCARD_LEN;
@@ -95,11 +94,12 @@ send_labelmessage(struct nbr *nbr, uint16_t type, struct mapping_head *mh)
 				msg_size += PW_STATUS_TLV_LEN;
 			break;
 		}
-
 		if (me->map.label != NO_LABEL)
 			msg_size += LABEL_TLV_LEN;
 		if (me->map.flags & F_MAP_REQ_ID)
 			msg_size += REQID_TLV_LEN;
+		if (me->map.flags & F_MAP_STATUS)
+			msg_size += STATUS_SIZE;
 
 		/* maximum pdu length exceeded, we need a new ldp pdu */
 		if (size + msg_size > nbr->max_pdu_len) {
@@ -119,6 +119,9 @@ send_labelmessage(struct nbr *nbr, uint16_t type, struct mapping_head *mh)
 			err |= gen_reqid_tlv(buf, me->map.requestid);
 	    	if (me->map.flags & F_MAP_PW_STATUS)
 			err |= gen_pw_status_tlv(buf, me->map.pw_status);
+		if (me->map.flags & F_MAP_STATUS)
+			err |= gen_status_tlv(buf, me->map.status.code,
+			    me->map.status.msg_id, me->map.status.msg_type);
 		if (err) {
 			ibuf_free(buf);
 			return;
@@ -304,6 +307,14 @@ recv_labelmessage(struct nbr *nbr, char *buf, uint16_t len, uint16_t type)
 				break;
 			}
 			break;
+		case TLV_TYPE_STATUS:
+			if (tlv_len != STATUS_TLV_LEN) {
+				session_shutdown(nbr, S_BAD_TLV_LEN,
+				    lm.msgid, lm.type);
+				goto err;
+			}
+			/* ignore */
+			break;
 		case TLV_TYPE_PW_STATUS:
 			switch (type) {
 			case MSG_TYPE_LABELMAPPING:
diff --git a/usr.sbin/ldpd/lde.c b/usr.sbin/ldpd/lde.c
index cb0553d1eed..81fe48e256b 100644
--- a/usr.sbin/ldpd/lde.c
+++ b/usr.sbin/ldpd/lde.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lde.c,v 1.59 2016/06/18 01:25:53 renato Exp $ */
+/*	$OpenBSD: lde.c,v 1.60 2016/07/01 23:33:46 renato Exp $ */
 
 /*
  * Copyright (c) 2013, 2016 Renato Westphal <renato@openbsd.org>
@@ -816,7 +816,8 @@ lde_send_labelmapping(struct lde_nbr *ln, struct fec_node *fn, int single)
 }
 
 void
-lde_send_labelwithdraw(struct lde_nbr *ln, struct fec_node *fn, uint32_t label)
+lde_send_labelwithdraw(struct lde_nbr *ln, struct fec_node *fn, uint32_t label,
+    struct status_tlv *status)
 {
 	struct lde_wdraw	*lw;
 	struct map		 map;
@@ -851,6 +852,13 @@ lde_send_labelwithdraw(struct lde_nbr *ln, struct fec_node *fn, uint32_t label)
 		map.label = label;
 	}
 
+	if (status) {
+		map.status.code = status->status_code;
+		map.status.msg_id = status->msg_id;
+		map.status.msg_type = status->msg_type;
+		map.flags |= F_MAP_STATUS;
+	}
+
 	/* SWd.1: send label withdraw. */
 	lde_imsg_compose_ldpe(IMSG_WITHDRAW_ADD, ln->peerid, 0,
  	    &map, sizeof(map));
@@ -881,7 +889,7 @@ lde_send_labelwithdraw_all(struct fec_node *fn, uint32_t label)
 	struct lde_nbr		*ln;
 
 	RB_FOREACH(ln, nbr_tree, &lde_nbrs)
-		lde_send_labelwithdraw(ln, fn, label);
+		lde_send_labelwithdraw(ln, fn, label, NULL);
 }
 
 void
@@ -1182,14 +1190,15 @@ lde_change_egress_label(int af, int was_implicit)
 	RB_FOREACH(ln, nbr_tree, &lde_nbrs) {
 		/* explicit withdraw */
 		if (was_implicit)
-			lde_send_labelwithdraw(ln, NULL, MPLS_LABEL_IMPLNULL);
+			lde_send_labelwithdraw(ln, NULL, MPLS_LABEL_IMPLNULL,
+			    NULL);
 		else {
 			if (ln->v4_enabled)
 				lde_send_labelwithdraw(ln, NULL,
-				    MPLS_LABEL_IPV4NULL);
+				    MPLS_LABEL_IPV4NULL, NULL);
 			if (ln->v6_enabled)
 				lde_send_labelwithdraw(ln, NULL,
-				    MPLS_LABEL_IPV6NULL);
+				    MPLS_LABEL_IPV6NULL, NULL);
 		}
 
 		/* advertise new label of connected prefixes */
diff --git a/usr.sbin/ldpd/lde.h b/usr.sbin/ldpd/lde.h
index d882d77c0e8..3d2a06c48cb 100644
--- a/usr.sbin/ldpd/lde.h
+++ b/usr.sbin/ldpd/lde.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lde.h,v 1.41 2016/06/18 17:13:05 renato Exp $ */
+/*	$OpenBSD: lde.h,v 1.42 2016/07/01 23:33:46 renato Exp $ */
 
 /*
  * Copyright (c) 2013, 2016 Renato Westphal <renato@openbsd.org>
@@ -134,7 +134,7 @@ void		 lde_map2fec(struct map *, struct in_addr, struct fec *);
 void		 lde_send_labelmapping(struct lde_nbr *, struct fec_node *,
 		    int);
 void		 lde_send_labelwithdraw(struct lde_nbr *, struct fec_node *,
-		    uint32_t);
+		    uint32_t, struct status_tlv *);
 void		 lde_send_labelwithdraw_all(struct fec_node *, uint32_t);
 void		 lde_send_labelrelease(struct lde_nbr *, struct fec_node *,
 		    uint32_t);
diff --git a/usr.sbin/ldpd/ldpd.h b/usr.sbin/ldpd/ldpd.h
index 03a90a46a12..de7902f381b 100644
--- a/usr.sbin/ldpd/ldpd.h
+++ b/usr.sbin/ldpd/ldpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ldpd.h,v 1.78 2016/07/01 23:14:31 renato Exp $ */
+/*	$OpenBSD: ldpd.h,v 1.79 2016/07/01 23:33:46 renato Exp $ */
 
 /*
  * Copyright (c) 2013, 2016 Renato Westphal <renato@openbsd.org>
@@ -205,16 +205,22 @@ struct map {
 			uint16_t	ifmtu;
 		} pwid;
 	} fec;
+	struct {
+		uint32_t	code;
+		uint32_t	msg_id;
+		uint16_t	msg_type;
+	} status;
 	uint32_t	label;
 	uint32_t	requestid;
 	uint32_t	pw_status;
 	uint8_t		flags;
 };
 #define F_MAP_REQ_ID	0x01	/* optional request message id present */
-#define F_MAP_PW_CWORD	0x02	/* pseudowire control word */
-#define F_MAP_PW_ID	0x04	/* pseudowire connection id */
-#define F_MAP_PW_IFMTU	0x08	/* pseudowire interface parameter */
-#define F_MAP_PW_STATUS	0x10	/* pseudowire status */
+#define F_MAP_STATUS	0x02	/* status */
+#define F_MAP_PW_CWORD	0x04	/* pseudowire control word */
+#define F_MAP_PW_ID	0x08	/* pseudowire connection id */
+#define F_MAP_PW_IFMTU	0x10	/* pseudowire interface parameter */
+#define F_MAP_PW_STATUS	0x20	/* pseudowire status */
 
 struct notify_msg {
 	uint32_t	status;
diff --git a/usr.sbin/ldpd/ldpe.h b/usr.sbin/ldpd/ldpe.h
index 4d9d77dfc57..84f4c2a74ef 100644
--- a/usr.sbin/ldpd/ldpe.h
+++ b/usr.sbin/ldpd/ldpe.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ldpe.h,v 1.65 2016/07/01 23:29:55 renato Exp $ */
+/*	$OpenBSD: ldpe.h,v 1.66 2016/07/01 23:33:46 renato Exp $ */
 
 /*
  * Copyright (c) 2013, 2016 Renato Westphal <renato@openbsd.org>
@@ -163,6 +163,7 @@ void	 send_notification(uint32_t, struct tcp_conn *, uint32_t,
 	    uint16_t);
 void	 send_notification_nbr(struct nbr *, uint32_t, uint32_t, uint16_t);
 int	 recv_notification(struct nbr *, char *, uint16_t);
+int	 gen_status_tlv(struct ibuf *, uint32_t, uint32_t, uint16_t);
 
 /* address.c */
 void	 send_address(struct nbr *, int, struct if_addr *, int);
diff --git a/usr.sbin/ldpd/notification.c b/usr.sbin/ldpd/notification.c
index 6c290ceaa82..b482c099068 100644
--- a/usr.sbin/ldpd/notification.c
+++ b/usr.sbin/ldpd/notification.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: notification.c,v 1.37 2016/07/01 23:29:55 renato Exp $ */
+/*	$OpenBSD: notification.c,v 1.38 2016/07/01 23:33:46 renato Exp $ */
 
 /*
  * Copyright (c) 2009 Michele Marchetto <michele@openbsd.org>
@@ -25,8 +25,6 @@
 #include "log.h"
 #include "ldpe.h"
 
-static int	 gen_status_tlv(struct ibuf *, uint32_t, uint32_t, uint16_t);
-
 void
 send_notification_full(struct tcp_conn *tcp, struct notify_msg *nm)
 {
@@ -221,7 +219,7 @@ recv_notification(struct nbr *nbr, char *buf, uint16_t len)
 	return (0);
 }
 
-static int
+int
 gen_status_tlv(struct ibuf *buf, uint32_t status, uint32_t msgid, uint16_t type)
 {
 	struct status_tlv	st;