[mirror_frr.git] / bgpd / bgp_label.c

/* BGP carrying label information
 * Copyright (C) 2013 Cumulus Networks, Inc.
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * GNU Zebra is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <zebra.h>

#include "command.h"
#include "thread.h"
#include "prefix.h"
#include "zclient.h"
#include "stream.h"
#include "network.h"
#include "log.h"
#include "memory.h"
#include "nexthop.h"
#include "mpls.h"

#include "bgpd/bgpd.h"
#include "bgpd/bgp_table.h"
#include "bgpd/bgp_route.h"
#include "bgpd/bgp_attr.h"
#include "bgpd/bgp_label.h"
#include "bgpd/bgp_packet.h"
#include "bgpd/bgp_debug.h"
#include "bgpd/bgp_errors.h"

extern struct zclient *zclient;

int bgp_parse_fec_update(void)
{
	struct stream *s;
	struct bgp_node *rn;
	struct bgp *bgp;
	struct bgp_table *table;
	struct prefix p;
	uint32_t label;
	afi_t afi;
	safi_t safi;

	s = zclient->ibuf;

	memset(&p, 0, sizeof(struct prefix));
	p.family = stream_getw(s);
	p.prefixlen = stream_getc(s);
	stream_get(p.u.val, s, PSIZE(p.prefixlen));
	label = stream_getl(s);

	/* hack for the bgp instance & SAFI = have to send/receive it */
	afi = family2afi(p.family);
	safi = SAFI_UNICAST;
	bgp = bgp_get_default();
	if (!bgp) {
		zlog_debug("no default bgp instance");
		return -1;
	}

	table = bgp->rib[afi][safi];
	if (!table) {
		zlog_debug("no %u unicast table", p.family);
		return -1;
	}
	rn = bgp_node_lookup(table, &p);
	if (!rn) {
		zlog_debug("no node for the prefix");
		return -1;
	}

	/* treat it as implicit withdraw - the label is invalid */
	if (label == MPLS_INVALID_LABEL)
		bgp_unset_valid_label(&rn->local_label);
	else {
		label_ntop(label, 1, &rn->local_label);
		bgp_set_valid_label(&rn->local_label);
	}
	SET_FLAG(rn->flags, BGP_NODE_LABEL_CHANGED);
	bgp_unlock_node(rn);
	bgp_process(bgp, rn, afi, safi);
	return 1;
}

mpls_label_t bgp_adv_label(struct bgp_node *rn, struct bgp_path_info *pi,
			   struct peer *to, afi_t afi, safi_t safi)
{
	struct peer *from;
	mpls_label_t remote_label;
	int reflect;

	if (!rn || !pi || !to)
		return MPLS_INVALID_LABEL;

	remote_label = pi->extra ? pi->extra->label[0] : MPLS_INVALID_LABEL;
	from = pi->peer;
	reflect =
		((from->sort == BGP_PEER_IBGP) && (to->sort == BGP_PEER_IBGP));

	if (reflect
	    && !CHECK_FLAG(to->af_flags[afi][safi],
			   PEER_FLAG_FORCE_NEXTHOP_SELF))
		return remote_label;

	if (CHECK_FLAG(to->af_flags[afi][safi], PEER_FLAG_NEXTHOP_UNCHANGED))
		return remote_label;

	return rn->local_label;
}

/**
 * This is passed as the callback function to bgp_labelpool.c:bgp_lp_get()
 * by bgp_reg_dereg_for_label() when a label needs to be obtained from
 * label pool.
 * Note that it will reject the allocated label if a label index is found,
 * because the label index supposes predictable labels
 */
int bgp_reg_for_label_callback(mpls_label_t new_label, void *labelid,
			       bool allocated)
{
	struct bgp_path_info *pi = (struct bgp_path_info *)labelid;
	struct bgp_node *rn = (struct bgp_node *)pi->net;
	char addr[PREFIX_STRLEN];

	prefix2str(&rn->p, addr, PREFIX_STRLEN);

	if (BGP_DEBUG(labelpool, LABELPOOL))
		zlog_debug("%s: FEC %s label=%u, allocated=%d", __func__, addr,
			   new_label, allocated);

	if (!allocated) {
		/*
		 * previously-allocated label is now invalid
		 */
		if (pi->attr->label_index == MPLS_INVALID_LABEL_INDEX
		    && pi->attr->label != MPLS_LABEL_NONE
		    && CHECK_FLAG(rn->flags, BGP_NODE_REGISTERED_FOR_LABEL)) {
			bgp_unregister_for_label(rn);
			label_ntop(MPLS_LABEL_IMPLICIT_NULL, 1,
				   &rn->local_label);
			bgp_set_valid_label(&rn->local_label);
		}
		return 0;
	}

	/*
	 * label index is assigned, this should be handled by SR-related code,
	 * so retry FEC registration and then reject label allocation for
	 * it to be released to label pool
	 */
	if (pi->attr->label_index != MPLS_INVALID_LABEL_INDEX) {
		flog_err(
			EC_BGP_LABEL,
			"%s: FEC %s Rejecting allocated label %u as Label Index is %u",
			__func__, addr, new_label, pi->attr->label_index);

		bgp_register_for_label(pi->net, pi);

		return -1;
	}

	if (pi->attr->label != MPLS_INVALID_LABEL) {
		if (new_label == pi->attr->label) {
			/* already have same label, accept but do nothing */
			return 0;
		}
		/* Shouldn't happen: different label allocation */
		flog_err(EC_BGP_LABEL,
			 "%s: %s had label %u but got new assignment %u",
			 __func__, addr, pi->attr->label, new_label);
		/* continue means use new one */
	}

	label_ntop(new_label, 1, &rn->local_label);
	bgp_set_valid_label(&rn->local_label);

	/*
	 * Get back to registering the FEC
	 */
	bgp_register_for_label(pi->net, pi);

	return 0;
}

void bgp_reg_dereg_for_label(struct bgp_node *rn, struct bgp_path_info *pi,
			     bool reg)
{
	bool with_label_index = false;
	struct stream *s;
	struct prefix *p;
	mpls_label_t *local_label;
	int command;
	uint16_t flags = 0;
	size_t flags_pos = 0;
	char addr[PREFIX_STRLEN];

	p = &(rn->p);
	local_label = &(rn->local_label);
	/* this prevents the loop when we're called by
	 * bgp_reg_for_label_callback()
	 */
	bool have_label_to_reg = bgp_is_valid_label(local_label)
			&& label_pton(local_label) != MPLS_LABEL_IMPLICIT_NULL;

	if (reg) {
		assert(pi);
		/*
		 * Determine if we will let zebra should derive label from
		 * label index instead of bgpd requesting from label pool
		 */
		if (CHECK_FLAG(pi->attr->flag,
			    ATTR_FLAG_BIT(BGP_ATTR_PREFIX_SID))
			&& pi->attr->label_index != BGP_INVALID_LABEL_INDEX) {
			with_label_index = true;
		} else {
			/*
			 * If no label index was provided -- assume any label
			 * from label pool will do. This means that label index
			 * always takes precedence over auto-assigned labels.
			 */
			if (!have_label_to_reg) {
				if (BGP_DEBUG(labelpool, LABELPOOL)) {
					prefix2str(p, addr, PREFIX_STRLEN);
					zlog_debug("%s: Requesting label from LP for %s",
						 __func__, addr);
				}
				/* bgp_reg_for_label_callback() will call back
				 * __func__ when it gets a label from the pool.
				 * This means we'll never register FECs without
				 * valid labels.
				 */
				bgp_lp_get(LP_TYPE_BGP_LU, pi,
				    bgp_reg_for_label_callback);
				return;
			}
		}
	}

	/* Check socket. */
	if (!zclient || zclient->sock < 0)
		return;

	/* If the route node has a local_label assigned or the
	 * path node has an MPLS SR label index allowing zebra to
	 * derive the label, proceed with registration. */
	s = zclient->obuf;
	stream_reset(s);
	command = (reg) ? ZEBRA_FEC_REGISTER : ZEBRA_FEC_UNREGISTER;
	zclient_create_header(s, command, VRF_DEFAULT);
	flags_pos = stream_get_endp(s); /* save position of 'flags' */
	stream_putw(s, flags);		/* initial flags */
	stream_putw(s, PREFIX_FAMILY(p));
	stream_put_prefix(s, p);
	if (reg) {
		if (have_label_to_reg) {
			flags |= ZEBRA_FEC_REGISTER_LABEL;
			stream_putl(s, label_pton(local_label));
		} else if (with_label_index) {
			flags |= ZEBRA_FEC_REGISTER_LABEL_INDEX;
			stream_putl(s, pi->attr->label_index);
		}
		SET_FLAG(rn->flags, BGP_NODE_REGISTERED_FOR_LABEL);
	} else
		UNSET_FLAG(rn->flags, BGP_NODE_REGISTERED_FOR_LABEL);

	/* Set length and flags */
	stream_putw_at(s, 0, stream_get_endp(s));

	/*
	 * We only need to write new flags if this is a register
	 */
	if (reg)
		stream_putw_at(s, flags_pos, flags);

	zclient_send_message(zclient);
}

static int bgp_nlri_get_labels(struct peer *peer, uint8_t *pnt, uint8_t plen,
			       mpls_label_t *label)
{
	uint8_t *data = pnt;
	uint8_t *lim = pnt + plen;
	uint8_t llen = 0;
	uint8_t label_depth = 0;

	for (; data < lim; data += BGP_LABEL_BYTES) {
		memcpy(label, data, BGP_LABEL_BYTES);
		llen += BGP_LABEL_BYTES;

		bgp_set_valid_label(label);
		label_depth += 1;

		if (bgp_is_withdraw_label(label) || label_bos(label))
			break;
	}

	/* If we RX multiple labels we will end up keeping only the last
	 * one. We do not yet support a label stack greater than 1. */
	if (label_depth > 1)
		zlog_info("%s rcvd UPDATE with label stack %d deep", peer->host,
			  label_depth);

	if (!(bgp_is_withdraw_label(label) || label_bos(label)))
		flog_warn(
			EC_BGP_INVALID_LABEL_STACK,
			"%s rcvd UPDATE with invalid label stack - no bottom of stack",
			peer->host);

	return llen;
}

int bgp_nlri_parse_label(struct peer *peer, struct attr *attr,
			 struct bgp_nlri *packet)
{
	uint8_t *pnt;
	uint8_t *lim;
	struct prefix p;
	int psize = 0;
	int prefixlen;
	afi_t afi;
	safi_t safi;
	int addpath_encoded;
	uint32_t addpath_id;
	mpls_label_t label = MPLS_INVALID_LABEL;
	uint8_t llen;

	pnt = packet->nlri;
	lim = pnt + packet->length;
	afi = packet->afi;
	safi = packet->safi;
	addpath_id = 0;

	addpath_encoded =
		(CHECK_FLAG(peer->af_cap[afi][safi], PEER_CAP_ADDPATH_AF_RX_ADV)
		 && CHECK_FLAG(peer->af_cap[afi][safi],
			       PEER_CAP_ADDPATH_AF_TX_RCV));

	for (; pnt < lim; pnt += psize) {
		/* Clear prefix structure. */
		memset(&p, 0, sizeof(struct prefix));

		if (addpath_encoded) {

			/* When packet overflow occurs return immediately. */
			if (pnt + BGP_ADDPATH_ID_LEN > lim)
				return -1;

			addpath_id = ntohl(*((uint32_t *)pnt));
			pnt += BGP_ADDPATH_ID_LEN;
		}

		/* Fetch prefix length. */
		prefixlen = *pnt++;
		p.family = afi2family(packet->afi);
		psize = PSIZE(prefixlen);

		/* sanity check against packet data */
		if ((pnt + psize) > lim) {
			flog_err(
				EC_BGP_UPDATE_RCV,
				"%s [Error] Update packet error / L-U (prefix length %d exceeds packet size %u)",
				peer->host, prefixlen, (uint)(lim - pnt));
			return -1;
		}

		/* Fill in the labels */
		llen = bgp_nlri_get_labels(peer, pnt, psize, &label);
		p.prefixlen = prefixlen - BSIZE(llen);

		/* There needs to be at least one label */
		if (prefixlen < 24) {
			flog_err(EC_BGP_UPDATE_RCV,
				 "%s [Error] Update packet error"
				 " (wrong label length %d)",
				 peer->host, prefixlen);
			bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
					BGP_NOTIFY_UPDATE_INVAL_NETWORK);
			return -1;
		}

		if ((afi == AFI_IP && p.prefixlen > 32)
		    || (afi == AFI_IP6 && p.prefixlen > 128))
			return -1;

		/* Fetch prefix from NLRI packet */
		memcpy(&p.u.prefix, pnt + llen, psize - llen);

		/* Check address. */
		if (afi == AFI_IP && safi == SAFI_LABELED_UNICAST) {
			if (IN_CLASSD(ntohl(p.u.prefix4.s_addr))) {
				/* From RFC4271 Section 6.3:
				 *
				 * If a prefix in the NLRI field is semantically
				 * incorrect
				 * (e.g., an unexpected multicast IP address),
				 * an error SHOULD
				 * be logged locally, and the prefix SHOULD be
				 * ignored.
				  */
				flog_err(
					EC_BGP_UPDATE_RCV,
					"%s: IPv4 labeled-unicast NLRI is multicast address %s, ignoring",
					peer->host, inet_ntoa(p.u.prefix4));
				continue;
			}
		}

		/* Check address. */
		if (afi == AFI_IP6 && safi == SAFI_LABELED_UNICAST) {
			if (IN6_IS_ADDR_LINKLOCAL(&p.u.prefix6)) {
				char buf[BUFSIZ];

				flog_err(
					EC_BGP_UPDATE_RCV,
					"%s: IPv6 labeled-unicast NLRI is link-local address %s, ignoring",
					peer->host,
					inet_ntop(AF_INET6, &p.u.prefix6, buf,
						  BUFSIZ));

				continue;
			}

			if (IN6_IS_ADDR_MULTICAST(&p.u.prefix6)) {
				char buf[BUFSIZ];

				flog_err(
					EC_BGP_UPDATE_RCV,
					"%s: IPv6 unicast NLRI is multicast address %s, ignoring",
					peer->host,
					inet_ntop(AF_INET6, &p.u.prefix6, buf,
						  BUFSIZ));

				continue;
			}
		}

		if (attr) {
			bgp_update(peer, &p, addpath_id, attr, packet->afi,
				   SAFI_UNICAST, ZEBRA_ROUTE_BGP,
				   BGP_ROUTE_NORMAL, NULL, &label, 1, 0, NULL);
		} else {
			bgp_withdraw(peer, &p, addpath_id, attr, packet->afi,
				     SAFI_UNICAST, ZEBRA_ROUTE_BGP,
				     BGP_ROUTE_NORMAL, NULL, &label, 1, NULL);
		}
	}

	/* Packet length consistency check. */
	if (pnt != lim) {
		flog_err(
			EC_BGP_UPDATE_RCV,
			"%s [Error] Update packet error / L-U (%zu data remaining after parsing)",
			peer->host, lim - pnt);
		return -1;
	}

	return 0;
}
Commit	Line	Data
cd1964ff DS	1	/* BGP carrying label information
	2	* Copyright (C) 2013 Cumulus Networks, Inc.
	3	*
	4	* This file is part of GNU Zebra.
	5	*
	6	* GNU Zebra is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License as published by the
	8	* Free Software Foundation; either version 2, or (at your option) any
	9	* later version.
	10	*
	11	* GNU Zebra is distributed in the hope that it will be useful, but
	12	* WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	* General Public License for more details.
	15	*
896014f4 DL	16	* You should have received a copy of the GNU General Public License along
	17	* with this program; see the file COPYING; if not, write to the Free Software
	18	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
cd1964ff DS	19	*/
	20
	21	#include <zebra.h>
	22
	23	#include "command.h"
	24	#include "thread.h"
	25	#include "prefix.h"
	26	#include "zclient.h"
	27	#include "stream.h"
	28	#include "network.h"
	29	#include "log.h"
	30	#include "memory.h"
	31	#include "nexthop.h"
	32	#include "mpls.h"
	33
	34	#include "bgpd/bgpd.h"
	35	#include "bgpd/bgp_table.h"
	36	#include "bgpd/bgp_route.h"
	37	#include "bgpd/bgp_attr.h"
	38	#include "bgpd/bgp_label.h"
	39	#include "bgpd/bgp_packet.h"
	40	#include "bgpd/bgp_debug.h"
14454c9f	41	#include "bgpd/bgp_errors.h"
cd1964ff DS	42
	43	extern struct zclient *zclient;
	44
d62a17ae	45	int bgp_parse_fec_update(void)
cd1964ff	46	{
d62a17ae	47	struct stream *s;
	48	struct bgp_node *rn;
	49	struct bgp *bgp;
	50	struct bgp_table *table;
	51	struct prefix p;
d7c0a89a	52	uint32_t label;
d62a17ae	53	afi_t afi;
	54	safi_t safi;
	55
	56	s = zclient->ibuf;
	57
	58	memset(&p, 0, sizeof(struct prefix));
	59	p.family = stream_getw(s);
	60	p.prefixlen = stream_getc(s);
a85297a7	61	stream_get(p.u.val, s, PSIZE(p.prefixlen));
d62a17ae	62	label = stream_getl(s);
	63
	64	/* hack for the bgp instance & SAFI = have to send/receive it */
	65	afi = family2afi(p.family);
	66	safi = SAFI_UNICAST;
	67	bgp = bgp_get_default();
	68	if (!bgp) {
	69	zlog_debug("no default bgp instance");
	70	return -1;
	71	}
	72
	73	table = bgp->rib[afi][safi];
	74	if (!table) {
	75	zlog_debug("no %u unicast table", p.family);
	76	return -1;
	77	}
	78	rn = bgp_node_lookup(table, &p);
	79	if (!rn) {
	80	zlog_debug("no node for the prefix");
	81	return -1;
	82	}
	83
	84	/* treat it as implicit withdraw - the label is invalid */
	85	if (label == MPLS_INVALID_LABEL)
	86	bgp_unset_valid_label(&rn->local_label);
	87	else {
	88	label_ntop(label, 1, &rn->local_label);
	89	bgp_set_valid_label(&rn->local_label);
	90	}
	91	SET_FLAG(rn->flags, BGP_NODE_LABEL_CHANGED);
	92	bgp_unlock_node(rn);
	93	bgp_process(bgp, rn, afi, safi);
	94	return 1;
cd1964ff DS	95	}
cd1964ff DS	96
40381db7	97	mpls_label_t bgp_adv_label(struct bgp_node rn, struct bgp_path_info pi,
d62a17ae	98	struct peer *to, afi_t afi, safi_t safi)
cd1964ff	99	{
d62a17ae	100	struct peer *from;
	101	mpls_label_t remote_label;
	102	int reflect;
cd1964ff	103
40381db7	104	if (!rn \|\| !pi \|\| !to)
d62a17ae	105	return MPLS_INVALID_LABEL;
cd1964ff	106
40381db7 DS	107	remote_label = pi->extra ? pi->extra->label[0] : MPLS_INVALID_LABEL;
40381db7 DS	108	from = pi->peer;
d62a17ae	109	reflect =
d62a17ae	110	((from->sort == BGP_PEER_IBGP) && (to->sort == BGP_PEER_IBGP));
cd1964ff	111
d62a17ae	112	if (reflect
	113	&& !CHECK_FLAG(to->af_flags[afi][safi],
	114	PEER_FLAG_FORCE_NEXTHOP_SELF))
	115	return remote_label;
cd1964ff	116
d62a17ae	117	if (CHECK_FLAG(to->af_flags[afi][safi], PEER_FLAG_NEXTHOP_UNCHANGED))
d62a17ae	118	return remote_label;
cd1964ff	119
d62a17ae	120	return rn->local_label;
cd1964ff DS	121	}
cd1964ff DS	122
57592a53 AD	123	/**
	124	* This is passed as the callback function to bgp_labelpool.c:bgp_lp_get()
	125	* by bgp_reg_dereg_for_label() when a label needs to be obtained from
	126	* label pool.
	127	* Note that it will reject the allocated label if a label index is found,
	128	* because the label index supposes predictable labels
	129	*/
	130	int bgp_reg_for_label_callback(mpls_label_t new_label, void *labelid,
	131	bool allocated)
	132	{
	133	struct bgp_path_info pi = (struct bgp_path_info )labelid;
	134	struct bgp_node rn = (struct bgp_node )pi->net;
	135	char addr[PREFIX_STRLEN];
	136
	137	prefix2str(&rn->p, addr, PREFIX_STRLEN);
	138
	139	if (BGP_DEBUG(labelpool, LABELPOOL))
	140	zlog_debug("%s: FEC %s label=%u, allocated=%d", __func__, addr,
	141	new_label, allocated);
	142
	143	if (!allocated) {
	144	/*
	145	* previously-allocated label is now invalid
	146	*/
	147	if (pi->attr->label_index == MPLS_INVALID_LABEL_INDEX
	148	&& pi->attr->label != MPLS_LABEL_NONE
	149	&& CHECK_FLAG(rn->flags, BGP_NODE_REGISTERED_FOR_LABEL)) {
	150	bgp_unregister_for_label(rn);
	151	label_ntop(MPLS_LABEL_IMPLICIT_NULL, 1,
	152	&rn->local_label);
	153	bgp_set_valid_label(&rn->local_label);
	154	}
	155	return 0;
	156	}
	157
	158	/*
	159	* label index is assigned, this should be handled by SR-related code,
	160	* so retry FEC registration and then reject label allocation for
	161	* it to be released to label pool
	162	*/
	163	if (pi->attr->label_index != MPLS_INVALID_LABEL_INDEX) {
	164	flog_err(
	165	EC_BGP_LABEL,
	166	"%s: FEC %s Rejecting allocated label %u as Label Index is %u",
	167	__func__, addr, new_label, pi->attr->label_index);
	168
	169	bgp_register_for_label(pi->net, pi);
	170
	171	return -1;
	172	}
	173
	174	if (pi->attr->label != MPLS_INVALID_LABEL) {
	175	if (new_label == pi->attr->label) {
	176	/* already have same label, accept but do nothing */
	177	return 0;
	178	}
	179	/* Shouldn't happen: different label allocation */
	180	flog_err(EC_BGP_LABEL,
	181	"%s: %s had label %u but got new assignment %u",
	182	__func__, addr, pi->attr->label, new_label);
	183	/* continue means use new one */
	184	}
	185
	186	label_ntop(new_label, 1, &rn->local_label);
187	bgp_set_valid_label(&rn->local_label);
188
189	/*
190	* Get back to registering the FEC
191	*/
192	bgp_register_for_label(pi->net, pi);
193
194	return 0;
195	}
196
40381db7	197	void bgp_reg_dereg_for_label(struct bgp_node rn, struct bgp_path_info pi,
57592a53	198	bool reg)
cd1964ff	199	{
57592a53	200	bool with_label_index = false;
d62a17ae	201	struct stream *s;
d62a17ae	202	struct prefix *p;
57592a53	203	mpls_label_t *local_label;
d62a17ae	204	int command;
d7c0a89a	205	uint16_t flags = 0;
d62a17ae	206	size_t flags_pos = 0;
57592a53 AD	207	char addr[PREFIX_STRLEN];
	208
	209	p = &(rn->p);
	210	local_label = &(rn->local_label);
	211	/* this prevents the loop when we're called by
	212	* bgp_reg_for_label_callback()
	213	*/
	214	bool have_label_to_reg = bgp_is_valid_label(local_label)
	215	&& label_pton(local_label) != MPLS_LABEL_IMPLICIT_NULL;
	216
	217	if (reg) {
	218	assert(pi);
	219	/*
	220	* Determine if we will let zebra should derive label from
	221	* label index instead of bgpd requesting from label pool
	222	*/
	223	if (CHECK_FLAG(pi->attr->flag,
	224	ATTR_FLAG_BIT(BGP_ATTR_PREFIX_SID))
	225	&& pi->attr->label_index != BGP_INVALID_LABEL_INDEX) {
	226	with_label_index = true;
	227	} else {
	228	/*
	229	* If no label index was provided -- assume any label
	230	* from label pool will do. This means that label index
	231	* always takes precedence over auto-assigned labels.
	232	*/
	233	if (!have_label_to_reg) {
	234	if (BGP_DEBUG(labelpool, LABELPOOL)) {
	235	prefix2str(p, addr, PREFIX_STRLEN);
	236	zlog_debug("%s: Requesting label from LP for %s",
	237	__func__, addr);
	238	}
	239	/* bgp_reg_for_label_callback() will call back
	240	* __func__ when it gets a label from the pool.
	241	* This means we'll never register FECs without
	242	* valid labels.
	243	*/
	244	bgp_lp_get(LP_TYPE_BGP_LU, pi,
	245	bgp_reg_for_label_callback);
	246	return;
	247	}
	248	}
	249	}
d62a17ae	250
	251	/* Check socket. */
	252	if (!zclient \|\| zclient->sock < 0)
	253	return;
	254
57592a53 AD	255	/* If the route node has a local_label assigned or the
	256	* path node has an MPLS SR label index allowing zebra to
	257	* derive the label, proceed with registration. */
d62a17ae	258	s = zclient->obuf;
	259	stream_reset(s);
	260	command = (reg) ? ZEBRA_FEC_REGISTER : ZEBRA_FEC_UNREGISTER;
	261	zclient_create_header(s, command, VRF_DEFAULT);
	262	flags_pos = stream_get_endp(s); /* save position of 'flags' */
	263	stream_putw(s, flags); /* initial flags */
	264	stream_putw(s, PREFIX_FAMILY(p));
	265	stream_put_prefix(s, p);
	266	if (reg) {
57592a53 AD	267	if (have_label_to_reg) {
	268	flags \|= ZEBRA_FEC_REGISTER_LABEL;
	269	stream_putl(s, label_pton(local_label));
	270	} else if (with_label_index) {
	271	flags \|= ZEBRA_FEC_REGISTER_LABEL_INDEX;
	272	stream_putl(s, pi->attr->label_index);
d62a17ae	273	}
	274	SET_FLAG(rn->flags, BGP_NODE_REGISTERED_FOR_LABEL);
	275	} else
	276	UNSET_FLAG(rn->flags, BGP_NODE_REGISTERED_FOR_LABEL);
	277
	278	/* Set length and flags */
	279	stream_putw_at(s, 0, stream_get_endp(s));
e0b84ba1 DS	280
	281	/*
	282	* We only need to write new flags if this is a register
	283	*/
	284	if (reg)
	285	stream_putw_at(s, flags_pos, flags);
d62a17ae	286
d62a17ae	287	zclient_send_message(zclient);
cd1964ff DS	288	}
cd1964ff DS	289
d7c0a89a	290	static int bgp_nlri_get_labels(struct peer peer, uint8_t pnt, uint8_t plen,
d62a17ae	291	mpls_label_t *label)
cd1964ff	292	{
d7c0a89a QY	293	uint8_t *data = pnt;
	294	uint8_t *lim = pnt + plen;
	295	uint8_t llen = 0;
	296	uint8_t label_depth = 0;
d62a17ae	297
	298	for (; data < lim; data += BGP_LABEL_BYTES) {
	299	memcpy(label, data, BGP_LABEL_BYTES);
	300	llen += BGP_LABEL_BYTES;
	301
	302	bgp_set_valid_label(label);
	303	label_depth += 1;
	304
	305	if (bgp_is_withdraw_label(label) \|\| label_bos(label))
	306	break;
	307	}
	308
	309	/* If we RX multiple labels we will end up keeping only the last
	310	* one. We do not yet support a label stack greater than 1. */
	311	if (label_depth > 1)
01c4f23c	312	zlog_info("%s rcvd UPDATE with label stack %d deep", peer->host,
d62a17ae	313	label_depth);
	314
	315	if (!(bgp_is_withdraw_label(label) \|\| label_bos(label)))
01c4f23c	316	flog_warn(
e50f7cfd	317	EC_BGP_INVALID_LABEL_STACK,
d62a17ae	318	"%s rcvd UPDATE with invalid label stack - no bottom of stack",
	319	peer->host);
	320
	321	return llen;
cd1964ff DS	322	}
cd1964ff DS	323
d62a17ae	324	int bgp_nlri_parse_label(struct peer peer, struct attr attr,
d62a17ae	325	struct bgp_nlri *packet)
cd1964ff	326	{
d7c0a89a QY	327	uint8_t *pnt;
d7c0a89a QY	328	uint8_t *lim;
d62a17ae	329	struct prefix p;
	330	int psize = 0;
	331	int prefixlen;
	332	afi_t afi;
	333	safi_t safi;
	334	int addpath_encoded;
d7c0a89a	335	uint32_t addpath_id;
d62a17ae	336	mpls_label_t label = MPLS_INVALID_LABEL;
d7c0a89a	337	uint8_t llen;
d62a17ae	338
d62a17ae	339	pnt = packet->nlri;
	340	lim = pnt + packet->length;
	341	afi = packet->afi;
	342	safi = packet->safi;
	343	addpath_id = 0;
	344
	345	addpath_encoded =
	346	(CHECK_FLAG(peer->af_cap[afi][safi], PEER_CAP_ADDPATH_AF_RX_ADV)
	347	&& CHECK_FLAG(peer->af_cap[afi][safi],
	348	PEER_CAP_ADDPATH_AF_TX_RCV));
	349
	350	for (; pnt < lim; pnt += psize) {
	351	/* Clear prefix structure. */
	352	memset(&p, 0, sizeof(struct prefix));
d62a17ae	353
	354	if (addpath_encoded) {
	355
	356	/* When packet overflow occurs return immediately. */
	357	if (pnt + BGP_ADDPATH_ID_LEN > lim)
	358	return -1;
	359
	360	addpath_id = ntohl(((uint32_t )pnt));
	361	pnt += BGP_ADDPATH_ID_LEN;
	362	}
	363
	364	/* Fetch prefix length. */
	365	prefixlen = *pnt++;
	366	p.family = afi2family(packet->afi);
	367	psize = PSIZE(prefixlen);
	368
	369	/* sanity check against packet data */
	370	if ((pnt + psize) > lim) {
af4c2728	371	flog_err(
e50f7cfd	372	EC_BGP_UPDATE_RCV,
d62a17ae	373	"%s [Error] Update packet error / L-U (prefix length %d exceeds packet size %u)",
	374	peer->host, prefixlen, (uint)(lim - pnt));
	375	return -1;
	376	}
	377
	378	/* Fill in the labels */
	379	llen = bgp_nlri_get_labels(peer, pnt, psize, &label);
	380	p.prefixlen = prefixlen - BSIZE(llen);
	381
	382	/* There needs to be at least one label */
	383	if (prefixlen < 24) {
e50f7cfd	384	flog_err(EC_BGP_UPDATE_RCV,
1c50c1c0 QY	385	"%s [Error] Update packet error"
	386	" (wrong label length %d)",
	387	peer->host, prefixlen);
d62a17ae	388	bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
	389	BGP_NOTIFY_UPDATE_INVAL_NETWORK);
	390	return -1;
	391	}
	392
	393	if ((afi == AFI_IP && p.prefixlen > 32)
	394	\|\| (afi == AFI_IP6 && p.prefixlen > 128))
	395	return -1;
	396
	397	/* Fetch prefix from NLRI packet */
	398	memcpy(&p.u.prefix, pnt + llen, psize - llen);
	399
	400	/* Check address. */
	401	if (afi == AFI_IP && safi == SAFI_LABELED_UNICAST) {
	402	if (IN_CLASSD(ntohl(p.u.prefix4.s_addr))) {
	403	/* From RFC4271 Section 6.3:
	404	*
	405	* If a prefix in the NLRI field is semantically
	406	* incorrect
	407	* (e.g., an unexpected multicast IP address),
	408	* an error SHOULD
	409	* be logged locally, and the prefix SHOULD be
	410	* ignored.
9d303b37	411	*/
af4c2728	412	flog_err(
e50f7cfd	413	EC_BGP_UPDATE_RCV,
d62a17ae	414	"%s: IPv4 labeled-unicast NLRI is multicast address %s, ignoring",
	415	peer->host, inet_ntoa(p.u.prefix4));
	416	continue;
	417	}
	418	}
	419
	420	/* Check address. */
	421	if (afi == AFI_IP6 && safi == SAFI_LABELED_UNICAST) {
	422	if (IN6_IS_ADDR_LINKLOCAL(&p.u.prefix6)) {
	423	char buf[BUFSIZ];
	424
af4c2728	425	flog_err(
e50f7cfd	426	EC_BGP_UPDATE_RCV,
d62a17ae	427	"%s: IPv6 labeled-unicast NLRI is link-local address %s, ignoring",
	428	peer->host,
	429	inet_ntop(AF_INET6, &p.u.prefix6, buf,
	430	BUFSIZ));
	431
	432	continue;
	433	}
	434
	435	if (IN6_IS_ADDR_MULTICAST(&p.u.prefix6)) {
	436	char buf[BUFSIZ];
	437
af4c2728	438	flog_err(
e50f7cfd	439	EC_BGP_UPDATE_RCV,
d62a17ae	440	"%s: IPv6 unicast NLRI is multicast address %s, ignoring",
	441	peer->host,
	442	inet_ntop(AF_INET6, &p.u.prefix6, buf,
	443	BUFSIZ));
	444
	445	continue;
	446	}
	447	}
	448
	449	if (attr) {
	450	bgp_update(peer, &p, addpath_id, attr, packet->afi,
	451	SAFI_UNICAST, ZEBRA_ROUTE_BGP,
b57ba6d2	452	BGP_ROUTE_NORMAL, NULL, &label, 1, 0, NULL);
d62a17ae	453	} else {
	454	bgp_withdraw(peer, &p, addpath_id, attr, packet->afi,
	455	SAFI_UNICAST, ZEBRA_ROUTE_BGP,
b57ba6d2	456	BGP_ROUTE_NORMAL, NULL, &label, 1, NULL);
d62a17ae	457	}
	458	}
	459
	460	/* Packet length consistency check. */
	461	if (pnt != lim) {
af4c2728	462	flog_err(
e50f7cfd	463	EC_BGP_UPDATE_RCV,
d62a17ae	464	"%s [Error] Update packet error / L-U (%zu data remaining after parsing)",
	465	peer->host, lim - pnt);
	466	return -1;
	467	}
	468
	469	return 0;
cd1964ff	470	}