ldpd: implement RFC 5918 (Typed Wildcard FEC)

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

ldpd/init.c

@@ -25,6 +25,7 @@
 
 static int	gen_init_prms_tlv(struct ibuf *, struct nbr *);
 static int	gen_cap_dynamic_tlv(struct ibuf *);
+static int	gen_cap_twcard_tlv(struct ibuf *, int);
 
 void
 send_init(struct nbr *nbr)
@@ -36,7 +37,7 @@ send_init(struct nbr *nbr)
 	debug_msg_send("initialization: lsr-id %s", inet_ntoa(nbr->id));
 
 	size = LDP_HDR_SIZE + LDP_MSG_SIZE + SESS_PRMS_SIZE +
-	    CAP_TLV_DYNAMIC_SIZE;
+	    CAP_TLV_DYNAMIC_SIZE + CAP_TLV_TWCARD_SIZE;
 	if ((buf = ibuf_open(size)) == NULL)
 		fatal(__func__);
 
@@ -45,6 +46,7 @@ send_init(struct nbr *nbr)
 	err |= gen_msg_hdr(buf, MSG_TYPE_INIT, size);
 	err |= gen_init_prms_tlv(buf, nbr);
 	err |= gen_cap_dynamic_tlv(buf);
+	err |= gen_cap_twcard_tlv(buf, 1);
 	if (err) {
 		ibuf_free(buf);
 		return;
@@ -146,6 +148,25 @@ recv_init(struct nbr *nbr, char *buf, uint16_t len)
 			    "Capability Announcement capability", __func__,
 			    inet_ntoa(nbr->id));
 			break;
+		case TLV_TYPE_TWCARD_CAP:
+			if (tlv_len != CAP_TLV_TWCARD_LEN) {
+				session_shutdown(nbr, S_BAD_TLV_LEN, msg.id,
+				    msg.type);
+				return (-1);
+			}
+
+			if (caps_rcvd & F_CAP_TLV_RCVD_TWCARD) {
+				session_shutdown(nbr, S_BAD_TLV_VAL, msg.id,
+				    msg.type);
+				return (-1);
+			}
+			caps_rcvd |= F_CAP_TLV_RCVD_TWCARD;
+
+			nbr->flags |= F_NBR_CAP_TWCARD;
+
+			log_debug("%s: lsr-id %s announced the Typed Wildcard "
+			    "FEC capability", __func__, inet_ntoa(nbr->id));
+			break;
 		default:
 			if (!(ntohs(tlv.type) & UNKNOWN_FLAG))
 				send_notification_rtlvs(nbr, S_UNSSUPORTDCAP,
@@ -193,6 +214,9 @@ send_capability(struct nbr *nbr, uint16_t capability, int enable)
 	err |= gen_msg_hdr(buf, MSG_TYPE_CAPABILITY, size);
 
 	switch (capability) {
+	case TLV_TYPE_TWCARD_CAP:
+		err |= gen_cap_twcard_tlv(buf, enable);
+		break;
 	case TLV_TYPE_DYNAMIC_CAP:
 		/*
 		 * RFC 5561 - Section 9:
@@ -218,6 +242,8 @@ int
 recv_capability(struct nbr *nbr, char *buf, uint16_t len)
 {
 	struct ldp_msg	 msg;
+	int		 enable = 0;
+	int		 caps_rcvd = 0;
 
 	log_debug("%s: lsr-id %s", __func__, inet_ntoa(nbr->id));
 
@@ -230,6 +256,7 @@ recv_capability(struct nbr *nbr, char *buf, uint16_t len)
 		struct tlv 	 tlv;
 		uint16_t	 tlv_type;
 		uint16_t	 tlv_len;
+		uint8_t		 reserved;
 
 		if (len < sizeof(tlv)) {
 			session_shutdown(nbr, S_BAD_TLV_LEN, msg.id, msg.type);
@@ -247,6 +274,31 @@ recv_capability(struct nbr *nbr, char *buf, uint16_t len)
 		len -= TLV_HDR_SIZE;
 
 		switch (tlv_type) {
+		case TLV_TYPE_TWCARD_CAP:
+			if (tlv_len != CAP_TLV_TWCARD_LEN) {
+				session_shutdown(nbr, S_BAD_TLV_LEN, msg.id,
+				    msg.type);
+				return (-1);
+			}
+
+			if (caps_rcvd & F_CAP_TLV_RCVD_TWCARD) {
+				session_shutdown(nbr, S_BAD_TLV_VAL, msg.id,
+				    msg.type);
+				return (-1);
+			}
+			caps_rcvd |= F_CAP_TLV_RCVD_TWCARD;
+
+			memcpy(&reserved, buf, sizeof(reserved));
+			enable = reserved & STATE_BIT;
+			if (enable)
+				nbr->flags |= F_NBR_CAP_TWCARD;
+			else
+				nbr->flags &= ~F_NBR_CAP_TWCARD;
+
+			log_debug("%s: lsr-id %s %s the Typed Wildcard FEC "
+			    "capability", __func__, inet_ntoa(nbr->id),
+			    (enable) ? "announced" : "withdrew");
+			break;
 		case TLV_TYPE_DYNAMIC_CAP:
 			/*
 		 	 * RFC 5561 - Section 9:
@@ -305,3 +357,17 @@ gen_cap_dynamic_tlv(struct ibuf *buf)
 
 	return (ibuf_add(buf, &cap, CAP_TLV_DYNAMIC_SIZE));
 }
+
+static int
+gen_cap_twcard_tlv(struct ibuf *buf, int enable)
+{
+	struct capability_tlv	cap;
+
+	memset(&cap, 0, sizeof(cap));
+	cap.type = htons(TLV_TYPE_TWCARD_CAP);
+	cap.length = htons(CAP_TLV_TWCARD_LEN);
+	if (enable)
+		cap.reserved = STATE_BIT;
+
+	return (ibuf_add(buf, &cap, CAP_TLV_TWCARD_SIZE));
+}

ldpd/labelmapping.c

@@ -90,6 +90,16 @@ send_labelmessage(struct nbr *nbr, uint16_t type, struct mapping_head *mh)
 	    		if (me->map.flags & F_MAP_PW_STATUS)
 				msg_size += PW_STATUS_TLV_SIZE;
 			break;
+		case MAP_TYPE_TYPED_WCARD:
+			msg_size += FEC_ELM_TWCARD_MIN_LEN;
+			switch (me->map.fec.twcard.type) {
+			case MAP_TYPE_PREFIX:
+				msg_size += sizeof(uint16_t);
+				break;
+			default:
+				fatalx("send_labelmessage: unexpected fec type");
+			}
+			break;
 		}
 		if (me->map.label != NO_LABEL)
 			msg_size += LABEL_TLV_SIZE;
@@ -208,6 +218,24 @@ recv_labelmessage(struct nbr *nbr, char *buf, uint16_t len, uint16_t type)
 			}
 		}
 
+		/*
+		 * RFC 5561 - Section 4:
+		 * "An LDP implementation that supports the Typed Wildcard
+		 * FEC Element MUST support its use in Label Request, Label
+		 * Withdraw, and Label Release messages".
+		 */
+		if (map.type == MAP_TYPE_TYPED_WCARD) {
+			switch (type) {
+			case MSG_TYPE_LABELMAPPING:
+			case MSG_TYPE_LABELABORTREQ:
+				session_shutdown(nbr, S_UNKNOWN_FEC, msg.id,
+				    msg.type);
+				goto err;
+			default:
+				break;
+			}
+		}
+
 		/*
 		 * LDP supports the use of multiple FEC Elements per
 		 * FEC for the Label Mapping message only.
@@ -524,7 +552,7 @@ gen_fec_tlv(struct ibuf *buf, struct map *map)
 {
 	struct tlv	ft;
 	uint16_t	family, len, pw_type, ifmtu;
-	uint8_t		pw_len = 0;
+	uint8_t		pw_len = 0, twcard_len;
 	uint32_t	group_id, pwid;
 	int		err = 0;
 
@@ -594,6 +622,43 @@ gen_fec_tlv(struct ibuf *buf, struct map *map)
 			err |= ibuf_add(buf, &ifmtu, sizeof(uint16_t));
 		}
 		break;
+	case MAP_TYPE_TYPED_WCARD:
+		len = FEC_ELM_TWCARD_MIN_LEN;
+		switch (map->fec.twcard.type) {
+		case MAP_TYPE_PREFIX:
+			len += sizeof(uint16_t);
+			break;
+		default:
+			fatalx("gen_fec_tlv: unexpected fec type");
+		}
+		ft.length = htons(len);
+		err |= ibuf_add(buf, &ft, sizeof(ft));
+		err |= ibuf_add(buf, &map->type, sizeof(uint8_t));
+		err |= ibuf_add(buf, &map->fec.twcard.type, sizeof(uint8_t));
+
+		switch (map->fec.twcard.type) {
+		case MAP_TYPE_PREFIX:
+			twcard_len = sizeof(uint16_t);
+			err |= ibuf_add(buf, &twcard_len, sizeof(uint8_t));
+
+			switch (map->fec.twcard.u.prefix_af) {
+			case AF_INET:
+				family = htons(AF_IPV4);
+				break;
+			case AF_INET6:
+				family = htons(AF_IPV6);
+				break;
+			default:
+				fatalx("gen_fec_tlv: unknown af");
+				break;
+			}
+
+			err |= ibuf_add(buf, &family, sizeof(uint16_t));
+			break;
+		default:
+			fatalx("gen_fec_tlv: unexpected fec type");
+		}
+		break;
 	default:
 		break;
 	}
@@ -606,7 +671,7 @@ tlv_decode_fec_elm(struct nbr *nbr, struct ldp_msg *msg, char *buf,
     uint16_t len, struct map *map)
 {
 	uint16_t	off = 0;
-	uint8_t		pw_len;
+	uint8_t		pw_len, twcard_len;
 
 	map->type = *buf;
 	off += sizeof(uint8_t);
@@ -750,6 +815,57 @@ tlv_decode_fec_elm(struct nbr *nbr, struct ldp_msg *msg, char *buf,
 			pw_len -= stlv.length;
 		}
 
+		return (off);
+	case MAP_TYPE_TYPED_WCARD:
+		if (len < FEC_ELM_TWCARD_MIN_LEN) {
+			session_shutdown(nbr, S_BAD_TLV_LEN, msg->id,
+			    msg->type);
+			return (-1);
+		}
+
+		memcpy(&map->fec.twcard.type, buf + off, sizeof(uint8_t));
+		off += sizeof(uint8_t);
+		memcpy(&twcard_len, buf + off, sizeof(uint8_t));
+		off += sizeof(uint8_t);
+		if (len != FEC_ELM_TWCARD_MIN_LEN + twcard_len) {
+			session_shutdown(nbr, S_BAD_TLV_LEN, msg->id,
+			    msg->type);
+			return (-1);
+		}
+
+		switch (map->fec.twcard.type) {
+		case MAP_TYPE_PREFIX:
+			if (twcard_len != sizeof(uint16_t)) {
+				session_shutdown(nbr, S_BAD_TLV_LEN, msg->id,
+				    msg->type);
+				return (-1);
+			}
+
+			memcpy(&map->fec.twcard.u.prefix_af, buf + off,
+			    sizeof(uint16_t));
+			map->fec.twcard.u.prefix_af =
+			    ntohs(map->fec.twcard.u.prefix_af);
+			off += sizeof(uint16_t);
+
+			switch (map->fec.twcard.u.prefix_af) {
+			case AF_IPV4:
+				map->fec.twcard.u.prefix_af = AF_INET;
+				break;
+			case AF_IPV6:
+				map->fec.twcard.u.prefix_af = AF_INET6;
+				break;
+			default:
+				session_shutdown(nbr, S_BAD_TLV_VAL, msg->id,
+				    msg->type);
+				return (-1);
+			}
+			break;
+		default:
+			send_notification(nbr->tcp, S_UNKNOWN_FEC, msg->id,
+			    msg->type);
+			return (-1);
+		}
+
 		return (off);
 	default:
 		send_notification(nbr->tcp, S_UNKNOWN_FEC, msg->id, msg->type);

ldpd/lde.c

@@ -1003,6 +1003,20 @@ lde_send_labelwithdraw_wcard(struct lde_nbr *ln, uint32_t label)
 	lde_send_labelwithdraw(ln, NULL, &wcard, NULL);
 }
 
+void
+lde_send_labelwithdraw_twcard_prefix(struct lde_nbr *ln, uint16_t af,
+    uint32_t label)
+{
+	struct map	 wcard;
+
+	memset(&wcard, 0, sizeof(wcard));
+	wcard.type = MAP_TYPE_TYPED_WCARD;
+	wcard.fec.twcard.type = MAP_TYPE_PREFIX;
+	wcard.fec.twcard.u.prefix_af = af;
+	wcard.label = label;
+	lde_send_labelwithdraw(ln, NULL, &wcard, NULL);
+}
+
 void
 lde_send_labelwithdraw_pwid_wcard(struct lde_nbr *ln, uint16_t pw_type,
     uint32_t group_id)

ldpd/lde.h

@@ -145,6 +145,8 @@ void		 lde_send_labelmapping(struct lde_nbr *, struct fec_node *,
 void		 lde_send_labelwithdraw(struct lde_nbr *, struct fec_node *,
 		    struct map *, struct status_tlv *);
 void		 lde_send_labelwithdraw_wcard(struct lde_nbr *, uint32_t);
+void		 lde_send_labelwithdraw_twcard_prefix(struct lde_nbr *,
+		    uint16_t, uint32_t);
 void		 lde_send_labelwithdraw_pwid_wcard(struct lde_nbr *, uint16_t,
 		    uint32_t);
 void		 lde_send_labelrelease(struct lde_nbr *, struct fec_node *,
@@ -181,6 +183,7 @@ void		 lde_kernel_remove(struct fec *, int, union ldpd_addr *,
 void		 lde_kernel_update(struct fec *);
 void		 lde_check_mapping(struct map *, struct lde_nbr *);
 void		 lde_check_request(struct map *, struct lde_nbr *);
+void		 lde_check_request_wcard(struct map *, struct lde_nbr *);
 void		 lde_check_release(struct map *, struct lde_nbr *);
 void		 lde_check_release_wcard(struct map *, struct lde_nbr *);
 void		 lde_check_withdraw(struct map *, struct lde_nbr *);

ldpd/lde_lib.c

@@ -555,6 +555,12 @@ lde_check_request(struct map *map, struct lde_nbr *ln)
 	struct fec_node	*fn;
 	struct fec_nh	*fnh;
 
+	/* wildcard label request */
+	if (map->type == MAP_TYPE_TYPED_WCARD) {
+		lde_check_request_wcard(map, ln);
+		return;
+	}
+
 	/* LRq.1: skip loop detection (not necessary) */
 
 	/* LRq.2: is there a next hop for fec? */
@@ -605,6 +611,40 @@ lde_check_request(struct map *map, struct lde_nbr *ln)
 	 */
 }
 
+void
+lde_check_request_wcard(struct map *map, struct lde_nbr *ln)
+{
+	struct fec	*f;
+	struct fec_node	*fn;
+	struct lde_req	*lre;
+
+	RB_FOREACH(f, fec_tree, &ft) {
+		fn = (struct fec_node *)f;
+
+		/* only a typed wildcard is possible here */
+		if (lde_wildcard_apply(map, &fn->fec, NULL) == 0)
+			continue;
+
+		/* LRq.2: is there a next hop for fec? */
+		if (LIST_EMPTY(&fn->nexthops))
+			continue;
+
+		/* LRq.6: first check if we have a pending request running */
+		lre = (struct lde_req *)fec_find(&ln->recv_req, &fn->fec);
+		if (lre != NULL)
+			/* LRq.7: duplicate request */
+			continue;
+
+		/* LRq.8: record label request */
+		lre = lde_req_add(ln, &fn->fec, 0);
+		if (lre != NULL)
+			lre->msg_id = ntohl(map->msg_id);
+
+		/* LRq.9: perform LSR label distribution */
+		lde_send_labelmapping(ln, fn, 1);
+	}
+}
+
 void
 lde_check_release(struct map *map, struct lde_nbr *ln)
 {
@@ -615,6 +655,7 @@ lde_check_release(struct map *map, struct lde_nbr *ln)
 
 	/* wildcard label release */
 	if (map->type == MAP_TYPE_WILDCARD ||
+	    map->type == MAP_TYPE_TYPED_WCARD ||
 	    (map->type == MAP_TYPE_PWID && !(map->flags & F_MAP_PW_ID))) {
 		lde_check_release_wcard(map, ln);
 		return;
@@ -690,6 +731,7 @@ lde_check_withdraw(struct map *map, struct lde_nbr *ln)
 
 	/* wildcard label withdraw */
 	if (map->type == MAP_TYPE_WILDCARD ||
+	    map->type == MAP_TYPE_TYPED_WCARD ||
 	    (map->type == MAP_TYPE_PWID && !(map->flags & F_MAP_PW_ID))) {
 		lde_check_withdraw_wcard(map, ln);
 		return;
@@ -793,6 +835,20 @@ lde_wildcard_apply(struct map *wcard, struct fec *fec, struct lde_map *me)
 	case MAP_TYPE_WILDCARD:
 		/* full wildcard */
 		return (1);
+	case MAP_TYPE_TYPED_WCARD:
+		switch (wcard->fec.twcard.type) {
+		case MAP_TYPE_PREFIX:
+			if (wcard->fec.twcard.u.prefix_af == AF_INET &&
+			    fec->type != FEC_TYPE_IPV4)
+				return (0);
+			if (wcard->fec.twcard.u.prefix_af == AF_INET6 &&
+			    fec->type != FEC_TYPE_IPV6)
+				return (0);
+			return (1);
+		default:
+			fatalx("lde_wildcard_apply: unexpected fec type");
+		}
+		break;
 	case MAP_TYPE_PWID:
 		/* RFC4447 pw-id group wildcard */
 		if (fec->type != FEC_TYPE_PWID)

ldpd/ldp.h

@@ -99,6 +99,8 @@
 /* RFC 5561 */
 #define TLV_TYPE_RETURNED_TLVS	0x8304
 #define TLV_TYPE_DYNAMIC_CAP	0x8506
+/* RFC 5918 */
+#define TLV_TYPE_TWCARD_CAP	0x850B
 /* RFC 7552 */
 #define TLV_TYPE_DUALSTACK	0x8701
 
@@ -241,10 +243,14 @@ struct capability_tlv {
 #define STATE_BIT		0x80
 
 #define F_CAP_TLV_RCVD_DYNAMIC	0x01
+#define F_CAP_TLV_RCVD_TWCARD	0x02
 
 #define CAP_TLV_DYNAMIC_SIZE	5
 #define CAP_TLV_DYNAMIC_LEN	1
 
+#define CAP_TLV_TWCARD_SIZE	5
+#define CAP_TLV_TWCARD_LEN	1
+
 #define	AF_IPV4			0x1
 #define	AF_IPV6			0x2
 
@@ -261,9 +267,11 @@ struct address_list_tlv {
 #define FEC_ELM_PREFIX_MIN_LEN	4
 #define FEC_PWID_ELM_MIN_LEN	8
 #define FEC_PWID_SIZE		4
+#define FEC_ELM_TWCARD_MIN_LEN	3
 
 #define	MAP_TYPE_WILDCARD	0x01
 #define	MAP_TYPE_PREFIX		0x02
+#define	MAP_TYPE_TYPED_WCARD	0x05
 #define	MAP_TYPE_PWID		0x80
 #define	MAP_TYPE_GENPWID	0x81
 

ldpd/ldpd.h

@@ -220,6 +220,12 @@ struct map {
 			uint32_t	group_id;
 			uint16_t	ifmtu;
 		} pwid;
+		struct {
+			uint8_t		type;
+			union {
+				uint16_t	prefix_af;
+			} u;
+		} twcard;
 	} fec;
 	struct {
 		uint32_t	status_code;

ldpd/ldpe.h

@@ -112,6 +112,7 @@ struct nbr {
 };
 #define F_NBR_GTSM_NEGOTIATED	 0x01
 #define F_NBR_CAP_DYNAMIC	 0x02
+#define F_NBR_CAP_TWCARD	 0x04
 
 RB_HEAD(nbr_id_head, nbr);
 RB_PROTOTYPE(nbr_id_head, nbr, id_tree, nbr_id_compare)

ldpd/log.c

@@ -332,6 +332,23 @@ log_map(const struct map *map)
 		    pw_type_name(map->fec.pwid.type)) == -1)
 			return ("???");
 		break;
+	case MAP_TYPE_TYPED_WCARD:
+		if (snprintf(buf, sizeof(buf), "typed wildcard") < 0)
+			return ("???");
+		switch (map->fec.twcard.type) {
+		case MAP_TYPE_PREFIX:
+			if (snprintf(buf + strlen(buf), sizeof(buf) -
+			    strlen(buf), " (prefix, address-family %s)",
+			    af_name(map->fec.twcard.u.prefix_af)) < 0)
+				return ("???");
+			break;
+		default:
+			if (snprintf(buf + strlen(buf), sizeof(buf) -
+			    strlen(buf), " (unknown type)") < 0)
+				return ("???");
+			break;
+		}
+		break;
 	default:
 		return ("???");
 	}